Relevant bibliographies by topics / Sm3+ IONS

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Sm3+ IONS'

Author: Grafiati
Published: 11 September 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Sm3+ IONS.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Sm3+ IONS"

1

Nogami, Masayuki, Toyonori Eto, Kazuhiro Suzuki, and Tomokatsu Hayakawa. "Redox equilibrium and spectral hole burning in Sm2+-doped Al2O3–SiO2 glasses." Journal of Materials Research 17, no. 8 (August 2002): 2053–58. http://dx.doi.org/10.1557/jmr.2002.0304.

Full text
Abstract:
Sm2+ ion-doped Al2O3–SiO2 glasses were prepared using sol-gel and melt-quenching methods; the redox equilibrium and spectral hole burning were investigated. The Sm3+ ions were reduced into Sm2+ by heating in H2 gas or x-ray irradiation. The redox between the Sm3+ and Sm2+ obeyed first-order kinetics, the rate of which was larger for the sol-gel glasses. The Sm3+ ions were also reduced by x-ray irradiation and the activation energy for redox equilibrium was half of that for the glasses treated in H2 gas. Two different mechanisms were proposed for the redox reaction of the samarium ions. In the x-ray irradiated glasses, the Sm3+ ions were reduced into Sm2+ by electron transfer from the oxygen defect center, whereas the H2-gas reaction removed the oxygen ions to reduce the Sm3+ ions. The spectral hole burning of the x-ray-irradiated glasses could be burned by the reverse reaction of the reduction of the Sm3+ ions; that is, the electron transfer from the excited Sm2+ into the surrounding oxygen. A short distance between the Sm2+ and oxygen defect centers allowed fast hole burning. On the other hand, the hole burning in the H2-treated glasses was performed by electron transfer between Sm2+ and another trapping center such as Sm3+.
APA, Harvard, Vancouver, ISO, and other styles
2

Gou, Jing, Dongyang Zhang, Binxun Yu, Jing Wang, and Shengzhong Liu. "The Photoluminescence Behaviors of a Novel Reddish Orange Emitting Phosphor CaIn2O4:Sm3+Codoped with Zn2+or Al3+Ions." Journal of Nanomaterials 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/969724.

Full text
Abstract:
A novel reddish orange phosphor CaIn2O4:Sm3+codoped with Zn2+or Al3+ions was prepared by solid state reaction and their luminescence properties were investigated under near ultraviolet excitation. The strategy of Zn2+or Al3+ions codoping was used with the aim to improve the luminescence properties of CaIn2O4:Sm3+, but the concrete effects of the two ions is different. The introduction of Zn2+ions can produceZnIn'defects that favor charge balance in CaIn2O4:Sm3+to facilitate its photoluminescence. The effect of Al3+ions codoping can effectively transfer energy from charge-transfer absorption band to characteristic transition of Sm3+ions, utilizing more energy from host absorption for the photoluminescence of Sm3+ions. Based on these mechanisms, the luminescence intensity of CaIn2O4:0.6%Sm3+was enhanced to 1.59 times and 1.51 times when codoping amount of Zn2+and Al3+ions reached 0.6%. However, the chromaticity coordinates of CaIn2O4:0.6%Sm3+almost did not have any changes after Zn2+ions or Al3+ions codoping; those are still located at reddish orange region. The excellent luminescence properties of CaIn2O4:0.6%Sm3+,0.6%Zn2+and CaIn2O4:0.6%Sm3+,0.6%Al3+demonstrate that they both have potential application value as new-style reddish orange phosphors on light-emitting diode.
APA, Harvard, Vancouver, ISO, and other styles
3

Eremin, Evgeniy V., Nikita V. Volkov, Irina A. Gudim, and Vladislav L. Temerov. "Magnetic and Magnetoelectric Properties of Sm1-xLaxFe3(BO3)4 Single Crystals." Solid State Phenomena 233-234 (July 2015): 368–70. http://dx.doi.org/10.4028/www.scientific.net/ssp.233-234.368.

Full text
Abstract:
Sm1-xLaxFe3(BO3)4(х = 0, 0.5, and 0.75) single crystals are grown by the flux method and their characteristics are investigated in the temperature range 5−300 K and magnetic fields of up to 9 T. It is established that substitution of nonmagnetic La3+ions for magnetic Sm3+ions increases the magnetic moment and weakens the magnetoelectric effect in Sm1-xLaxFe3(BO3)4.
APA, Harvard, Vancouver, ISO, and other styles
4

Zhang, J.-G., P. C. Eklund, Z. L. Hua, L. G. Salamanca-Riba, M. Wuttig, P. K. Soltani, and G. M. Storti. "Photoluminescence and optical absorption in CaS : Eu2+ : Sm3+ thin films." Journal of Materials Research 7, no. 2 (February 1992): 411–17. http://dx.doi.org/10.1557/jmr.1992.0411.

Full text
Abstract:
The optical absorption and photoluminescence of Eu2+ : Sm3+-doped CaS films have been investigated in this paper. The energy dependence of the refractive index and absorption coefficient of the film were obtained by analyzing transmission and reflection spectra of the thin film. The refractive index at low energies is very close to the bulk value for CaS (n = 2.03) and decreases with increasing energy in the range of 1.2 to 2.5 eV. The energy gap of CaS: Eu2+ : Sm3+ thin films is found to be a direct gap with value Eg = 4.48 eV. Photoluminescence studies on annealed CaS: Eu2+ : Sm3+ thin films showed a broad band at ∼1.92 eV identified with emission from Eu2+ ions, and a set of sharp lines corresponding to emission from Sm3+ ions. Most of the strong features presented in the room temperature spectra are found in good agreement with previous bulk studies of CaS: Eu2+ and CaS: Sm3+. The abnormal increase of the Sm3+ photoluminescence with increasing temperature is explained by the phonon-assisted energy transfer from Eu2+ ions to Sm3+ ions.
APA, Harvard, Vancouver, ISO, and other styles
5

Xiao, Jun, Cong Wang, Xin Min, Xiaowen Wu, Yangai Liu, Zhaohui Huang, and Minghao Fang. "Multiple Energy Transfer in Luminescence-Tunable Single-Phased Phosphor NaGdTiO4: Tm3+, Dy3+, Sm3+." Nanomaterials 10, no. 7 (June 27, 2020): 1249. http://dx.doi.org/10.3390/nano10071249.

Full text
Abstract:
Advances in solid-state white-light-emitting diodes (WLEDs) necessitate the urgent development of highly efficient single-phase phosphors with tunable photoluminescence properties. Herein, the Tm3+, Dy3+, and Sm3+ ions are incorporated into the orthorhombic NaGdTiO4 (NGT) phosphors, resulting in phosphors that fulfill the aforementioned requirement. The emission spectrum of Tm3+ ions overlaps well with the adsorption spectra of both Dy3+ and Sm3+ ions. Under the excitation at 358 nm, the single-phase NaGdTiO4: Tm3+, Dy3+, Sm3+ phosphor exhibits tunable emission peaks in the blue, yellow, and red regions simultaneously, resulting in an intense white-light emission. The coexisting energy transfer behaviors from Tm3+ to Dy3+ and Sm3+ ions and the energy transfer from Dy3+ to Sm3+ ions are demonstrated to be responsible for this phenomenon. The phosphors with multiple energy transfers enable the development of single-phase white-light-emitting phosphors for phosphor-converted WLEDs.
APA, Harvard, Vancouver, ISO, and other styles
6

Zhang, Zhong Ju, Xu Dong Zheng, Zhi Cheng Shi, and Xin Wang. "Effect of Sm3+ Concentration on the Vibrational and Luminescent Properties of LaPO4." Materials Science Forum 848 (March 2016): 482–88. http://dx.doi.org/10.4028/www.scientific.net/msf.848.482.

Full text
Abstract:
Lanthanum orthophosphate (LaPO4) is a useful host for doping rare earth ions with high quantum efficiencies. In the present investigation the monoclinic LaPO4 and LaPO4:Sm3+ were synthesized via hydrothermal route. SEM, XRD, FTIR and Raman spectroscopy as well as the luminescence spectroscopy were utilized to character the samples of the Sm3+-doped LaPO4. The results indicated that the lattice parameters decreased linearly with Sm3+ concentration, and general linear hypsochromic shifts regarding Sm3+ concentration were observed in infrared spectroscopic wavenumbers and Raman band positions. The emission spectra showed that Sm3+ ions were in more non-centrosymmetric environment when Sm3+ concentration increased.
APA, Harvard, Vancouver, ISO, and other styles
7

Martel, J. F., S. Jandl, B. Viana, and D. Vivien. "Crystal-field study of Sm3+ ions in Sm2O3, Sm3+:Gd2O3 and Sm3+:Y2O3." Journal of Physics and Chemistry of Solids 61, no. 9 (September 2000): 1455–63. http://dx.doi.org/10.1016/s0022-3697(00)00009-3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Bishnoi, Swati, G. Swati, Paramjeet Singh, V. V. Jaiswal, Mukesh K. Sahu, Vinay Gupta, N. Vijayan, and D. Haranath. "Appearance of efficient luminescence energy transfer in doped orthovanadate nanocrystals." Journal of Applied Crystallography 50, no. 3 (April 27, 2017): 787–94. http://dx.doi.org/10.1107/s1600576717004277.

Full text
Abstract:
This paper reports the detailed synthesis mechanism and the structural, morphological and optical characterization of ultraviolet (∼311 nm) excitable samarium doped gadolinium yttrium orthovanadate, (Gd,Y)VO4:Sm3+, nanocrystals. X-ray diffraction and Rietveld refinement studies confirmed that the synthesized samples crystallize in a tetragonal structure withI41/amdspace group. The enhanced photoluminescence intensity of (Gd,Y)VO4:Sm3+compared with the existing YVO4:Sm3+phosphor clearly indicates the significant role of Gd3+ions. This has been attributed to the sensitization of the6PJenergy level of Gd3+ions by energy transfer from orthovanadate (VO43−) ions and subsequent energy trapping by Sm3+ions. The energy transfer from VO43−to Sm3+viaGd3+ions as intermediates and concentration quenching of Gd3+luminescence are discussed in detail. The optical band gap of the as-prepared nanocrystals has been estimated using UV–vis–NIR absorption spectroscopy, which reveals a slightly higher band gap (3.75 eV) for YVO4as compared to GdYVO4(3.50 eV). Furthermore, confocal microcopy, decay parameters and Commission Internationale de l'Eclairage chromatic coordinates have supplemented these studies, which established the suitability of these nanophosphors for achieving spectral conversion in silicon solar cells.
APA, Harvard, Vancouver, ISO, and other styles
9

Van Do, Phan, Nguyen Xuan Ca, Luong Duy Thanh, Nguyen Van Nghia, and Tran Thi Chung Thuy. "Optical properties and energy transfer in KYF4:Sm3+ and KYF4:Tb3+,Sm3+ polycrystalline materials." Physical Chemistry Chemical Physics 22, no. 47 (2020): 27590–99. http://dx.doi.org/10.1039/d0cp05257d.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Sun, K. W., Z. Liu, R. X. Wang, X. C. Ling, and J. W. Sun. "Photoluminescence properties of Ba0.7Sr0.3TiO3:Sm3+ modified K0.5Na0.5NbO3 perovskite oxide ceramics." Chalcogenide Letters 20, no. 8 (August 2023): 563–71. http://dx.doi.org/10.15251/cl.2023.208.563.

Full text
Abstract:
Ba0.7Sr0.3TiO3:Sm3+ modified KxNa(1-x)NbO3 ceramics with perovskite-type structure were synthesized via solid state sintering method. Sm3+ ions doping was designed for substituting both A and B sites in the ABO3 structure, Sm3+ doped Ba0.7Sr0.3TiO3 (Ba0.7Sr0.3TiO3:Sm3+) oxide precursor powders with the chemical formula of Ba0.7Sr0.3-xSmx(Ti1-xSmx)O3 (x=0.005 ， 0.015 ， 0.025) were synthesized. Combined Ba0.7Sr0.3TiO3:Sm3+ with K0.5Na0.5NbO3, the perovskite-type solid solution composite ceramics were fabricated via solid phase sintering method. X-Ray diffraction was used for investigating the phase structure of the precursor powders and luminescent composite ceramics. The photoluminescence properties of the Sm3+ ions in the Ba0.7Sr0.3TiO3-K0.5Na0.5NbO3 composite ceramic materials were systematically investigated by exploring the effects of composition of the composites, excitation wavelength and temperature on photoluminescence.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Sm3+ IONS"

1

MAKHLOGA, ASHISH, and VIDESH KUMAR. "Sm3+ IONS DOPED BOROSILICATE GLASS FOR VISIBLE PHOTONIC DEVICE APPLICATIONS." Thesis, DELHI TECHNOLOGICAL UNIVERSITY, 2021. http://dspace.dtu.ac.in:8080/jspui/handle/repository/18625.

Full text
Abstract:
An intense reddish-orange colour radiating Samarium doped Aluminium Calcium borosilicate (BSACS) glasses were synthesized with the help of the melt-quench method to analyze the photoluminescence properties using characterization methods like XRD, FT-IR, photoluminescence (PL) excitation, PL emission, and PL decay. XRD and FT-IR reveal the non-crystalline behavior along with the presence of numerous functional groups in BSACS host glass correspondingly. Under 402 nm excitation, three major peaks were found in the emission spectra which perfectly resembles to 4G5/2 → 6H5/2 (562 nm), 4G5/2 → 6H7/2 (599 nm), and 4G5/2 → 6H9/2 (646 nm) transitions of Samarium ions. 4G5/2 → 6H9/2 transition at 599 nm is comparatively more intense and noticeable. PL decay observed for 4G5/2 state reveals the exponential nature in which curves are fitted by using bi-exponential and tri- exponential fitting to assess the practically measured lifetimes (τexp). It is observed that the τexp values are decreasing with increasing Samarium ion concentration due to the cross-relaxation energy transference. All of the findings indicate that Sm3+ doped borosilicate glass is suitable for its usage in visible reddish orange photonic devices.
APA, Harvard, Vancouver, ISO, and other styles
2

Sharples, Joseph William. "Cooling rapidly and relaxing slowly with 4f ions." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/cooling-rapidly-and-relaxing-slowly-with-4f-ions(fab0aa0f-1ab7-4016-9d97-5edf6a629fa8).html.

Full text
Abstract:
Anisotropic magnetic materials have been proposed over the past twenty years or so as candidates for high density storage, so-called Single-Molecule Magnets (SMMs). These may in future be used to store data at the level of an individual molecule. Separately, isotropic materials may be harnessed for their large magnetocaloric effect which enables them to be used as refrigerants. This can potentially replace the increasingly rare and therefore expensive 3He and 4He currently employed either separately or in 3He-4He dilution refrigerators. This thesis examines the use of lanthanide(III) ions for these applications, by detailing the synthesis, characterisation and performance of three new classes of zero-dimensional compounds, {LnIII2}, {LnIII2ZnII4} and {LnIII7}. These are assessed by several techniques including SQUID magnetometry, heat capacity measurements luminescence spectroscopy, Electron Paramagnetic Resonance and ab initio calculations. In doing so we extended the use of a tripodal ligand widely employed in 3d chemistry to 4f ions, and found only the second 3d-4f phosphonate SMM. Investigating several members of a known three-dimensional lanthanide(III) polymer, {LnIII}n, showed the isotropic gadolinium(III) analogue is one of the very best of all known magnetic refrigerants in the low-temperature regime.
APA, Harvard, Vancouver, ISO, and other styles
3

Schick, Joachim. "Traitement d'effluents aqueux pollués par des ions nitrate ou phosphate ou des hydrocarbures de type BTEX : utilisation d'une zéolithe naturelle modifiée (SMZ) ou de zéolithes synthétiques." Thesis, Mulhouse, 2010. http://www.theses.fr/2010MULH3991.

Full text
Abstract:
Ce travail s'inscrit dans le cadre de la protection de l'environnement et s'intéresse spécifiquement à la dépollution d'effluents aqueux en vue de piéger d'une part les anions nitrate et/ou phosphate, responsables du phénomène d'eutrophisation, mais également le toluène, hydrocarbure couramment rencontré dans les effluents aqueux urbains et industriels ou les eaux naturelles. Le piégeage de ces polluants a été effectué sur des matériaux zéolithiques. Une grande partie des expérimentations utilise un matériau potentiellement efficace pour le piégeage des trois polluants cités plus haut, à savoir la SMZ ("Surfactant-Modified Zeolite"), classiquement préparée à partir d'une zéolithe naturelle, la clinoptilolite, et d'un tensioactif, le bromure d'hexadecyltriméthylammonium (HDTMA+). En piégeage d'ions nitrate, d'autres SMZ, réalisées à partir de zéolithes synthétiques (LTA, FAU) et diverses espèces organiques tensioactives ou non se montrent moins performantes que la SMZ classique, à l'exception d'un nouveau matériau préparé à partir de nanofeuillets de zéolithe MFI et modifié avec l'ion HDTMA+ (SMZN). Pour le piégeage des ions phosphate, les performances de la SMZ classique ont été comparées à celles de plusieurs zéolithes calciques. Enfin, le piégeage de toluène a été expérimenté sur quatre matériaux, la SMZ classique, un charbon actif et deux zéolithes hydrophobes, la silicalite-1 et la zéolithe bêta. Les expérimentations de piégeage ont été réalisées en système fermé ou en système ouvert. L'influence de la concentration initiale en polluants, du rapport liquide/solide, du débit de filtration, de la présence de compétiteurs et du temps de contact a été examinée
This work concerns the environmental protection, specifically the treatment of aqueous effluents. Effluents containing nitrate and/or phosphate anions, responsible for the eutrophication phenomenon, and also toluene, which is commonly found in urban and industrial flows and natural waters, were specifically studied. The removal of these pollutants was performed on zeolitic materials. A large part of the experiments use a material potentially efficient to remove the three pollutants mentioned above, namely the SMZ ("Surfactant-Modified Zeolite"), conventionally prepared from a natural zeolite, clinoptilolite, and a surfactant, hexadecyltrimethylammonium bromide (HDTMA+). For nitrate removal, other SMZ, prepared from synthetic zeolites (LTA, FAU) and various organic species (surfactant or not) were less efficient than conventional SMZ except a new material prepared from zeolite MFI nanosheets and modified with HDTMA+ ion. The efficiency of the conventional SMZ for the phosphate ions uptake was compared with those of several calcic zeolites. Finally, removal of toluene was performed on four materials, conventional SMZ, an activated carbon and two hydrophobic zeolites, namely silicalite-1 and beta zeolite. Uptake experiments were conducted in batch-wise and fixed-bed column systems, the second representing a more realistic simulation of dynamic field condition The influence of the initial pollutant concentration, the liquid/solid ratio, the filtration rate, the presence of competitive species and the contact time was examined
APA, Harvard, Vancouver, ISO, and other styles
4

Rabli, Djamal. "Extension de la méthode du potentiel modèle pour traiter la dynamique des systèmes moléculaires à couches ouvertes : applications : au transfert de charge dans les collisions entre Si3+ et He et entre He2+ et He métastable, à la détermination des potentiels adiabatiques Li2." Paris 6, 2001. http://www.theses.fr/2001PA066564.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Wang, Gang. "CORRELATIONS RELATIVE TO THE REACTION PLANE AT THE RELATIVISTIC HEAVY ION COLLIDER BASED ON TRANSVERSE DEFLECTION OF SPECTATOR NEUTRONS." Kent State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=kent1144770985.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Eerola, Isabelle, and Felicia Wahlén. "Emojier – Ett lingua franca för den digitala tidsåldern : men hur användbart är det egentligen?" Thesis, Högskolan Kristianstad, Fakulteten för ekonomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-19534.

Full text
Abstract:
Emojier har kommit att bli en stor del i hur vi interagerar med varandra, både online och offline och dagligen innehåller närmare 40 procent av alla sms i västvärlden en eller flera emojier. 2009 valde Unicode Consortium att implementera emojier i sin standard och därefter valde Apple som första kommersiella företag att lägga till emojier i sitt tangentbord. Tidigare undersökningar har delade meningar om huruvida det är en skillnad i användandet av emojier mellan yngre och äldre åldersgrupper. Forskningen har främst fokuserat på användningen av emojier online i sociala kanaler, därav finns det bristfällig forskning om hur emojier upplevs i en interaktion som sker offline. Syftet med denna studie är att undersöka hur emojier upplevs offline via sms i iOS gränssnitt av emojier, detta görs genom en jämförelse mellan två åldersgrupper: 20–30 år samt 50–60 år. Studien har också syftet att undersöka möjliga förbättringar till iOS gränssnitt av emojier för att främja god användbarhet. Studiens kvalitativa ansats innebär ostrukturerade observationer och semi-strukturerade intervjuer. Resultaten visar på både likheter och skillnader mellan åldersgrupperna om hur de upplever emojier i en interaktion som sker via sms. Det framkommer också brister i användningen av gränssnittet som motverkar en god användbarhet där informanterna får ge förslag till en förbättring av gränssnittet.
Emojis have become a major part of how we interact with each other, online as well as offline and almost 40 percent of all text messages in the Western world contains one or more emojis. In 2009, the Unicode Consortium chose to implement emojis in their standard which entailed that Apple became the first commercial company to add emojis to their keyboard. Previous studies have different opinions on whether or not there is a difference in the use of emojis between younger and older various age-groups. Former studies have mainly focused on the use of emojis in social channels online, however, there is little research on how emojis are experienced in an offline interaction. The aim of this study is to investigate how emojis are experienced offline through text messages in iOS interface of emojis, this is done by comparing two age-groups: informants between the ages of 20-30 and 50-60. Moreover, this study aims to explore the possibilities of improvements of the iOS interface of emojis in order to further improve user experience. The qualitative approach of the study involves unstructured observations and semistructured interviews. The results show both similarities and differences between the age-groups on how they experience emojis when interacting through text messages. It also appears shortcomings in the use of the interface which undermine good usability.
APA, Harvard, Vancouver, ISO, and other styles
7

GOSSELIN, ANNIE. "Mise au point d'une source d'ions de recul pompee par ganil-sme en vue d'etudier des collisions ions-atomes a tres base energie : application aux collisions ar#8#++he." Caen, 1993. http://www.theses.fr/1993CAEN2006.

Full text
Abstract:
Dans le but d'etudier les collisions ions-atomes a basse energie, nous avons realise une source d'ions de recul. Ces ions de recul sont produits par impact de faisceaux issus de la sortie moyenne energie du ganil sur une cible gazeuse. Un dispositif electrostatique et magnetique permet d'extraire, de guider et de selectionner ces ions de recul. Nous indiquons la facon d'operer afin de former des faisceaux les plus intenses possible, de bonne qualite optique tout en conservant une faible dispersion en energie. Afin d'etudier les collisions de ces ions avec une cible gazeuse formee par un jet supersonique, nous avons mis au point trois dispositifs d'analyse qui permettent les mesures des sections efficaces totales, partielles, differentielles en angle, d'echange de charge. A l'aide de deux de ces dispositifs, nous avons mesure les sections efficaces totales de simple capture pour les collisions ar#q#++he pour 6q12 pour une energie de collision de 300 qev ainsi que pour q=6 et 8 pour des energies de collision de 50 a 300 qev. Ensuite, nous avons mesure les sections efficaces partielles de simple capture pour la collision ar#8#++he pour des energies de collisions de 50 a 300 qev. Nous avons egalement effectue une etude de cette collision avec les modeles theoriques a notre disposition afin d'effectuer une comparaison avec nos resultats experimentaux
APA, Harvard, Vancouver, ISO, and other styles
8

Daněček, Vít. "Zálohovaný napájecí zdroj pro lékařský přístroj s managementem po I2C." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217249.

Full text
Abstract:
Object my master’s thesis is the design a Medical device uninterruptible power supply with managment system utilizing I2C bus. Norm EN 61000-3-2 define electric parameters for medical device power supply. In case of power supply for medial equipment is expressive accent on increased electric strength. This power supply have usually primary and secondary power circuit. Primary power circuit form line accumulator, which supplies needed output to the load and recharge reserve battery. Secondary is formed battery-pack, which serve as back-up power supply at drop-out prime circle. They have a minimum weight, small proportions, large overall effectivity also charging battery-pack and monitoring battery-pack charging condition. Result whole those master’s thesis is design Medical device uninterruptible power supply with managment system utilizing I2C bus and realization board layout. Resulting characteristics designed supply unit are: Output voltages are 5V/ 3 A , 12V/ 1,5 A and -12V/ 0,1 A. Managment support information about: Line adapter/ battery pack switch, battery-pack charging condition and actuall tempera-ture battery-pack.
APA, Harvard, Vancouver, ISO, and other styles
9

Fischer, Andreas C. "Integration and Fabrication Techniques for 3D Micro- and Nanodevices." Doctoral thesis, KTH, Mikro- och nanosystemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107125.

Full text
Abstract:
The development of micro and nano-electromechanical systems (MEMS and NEMS) with entirely new or improved functionalities is typically based on novel or improved designs, materials and fabrication methods. However, today’s micro- and nano-fabrication is restrained by manufacturing paradigms that have been established by the integrated circuit (IC) industry over the past few decades. The exclusive use of IC manufacturing technologies leads to limited material choices, limited design flexibility and consequently to sub-optimal MEMS and NEMS devices. The work presented in this thesis breaks new ground with a multitude of novel approaches for the integration of non-standard materials that enable the fabrication of 3D micro and nanoelectromechanical systems. The objective of this thesis is to highlight methods that make use of non-standard materials with superior characteristics or methods that use standard materials and fabrication techniques in a novel context. The overall goal is to propose suitable and cost-efficient fabrication and integration methods, which can easily be made available to the industry. The first part of the thesis deals with the integration of bulk wire materials. A novel approach for the integration of at least partly ferromagnetic bulk wire materials has been implemented for the fabrication of high aspect ratio through silicon vias. Standard wire bonding technology, a very mature back-end technology, has been adapted for yet another through silicon via fabrication method and applications including liquid and vacuum packaging as well as microactuators based on shape memory alloy wires. As this thesis reveals, wire bonding, as a versatile and highly efficient technology, can be utilized for applications far beyond traditional interconnections in electronics packaging. The second part presents two approaches for the 3D heterogeneous integration based on layer transfer. Highly efficient monocrystalline silicon/ germanium is integrated on wafer-level for the fabrication of uncooled thermal image sensors and monolayer-graphene is integrated on chip-level for the use in diaphragm-based pressure sensors. The last part introduces a novel additive fabrication method for layer-bylayer printing of 3D silicon micro- and nano-structures. This method combines existing technologies, including focused ion beam implantation and chemical vapor deposition of silicon, in order to establish a high-resolution fabrication process that is related to popular 3D printing techniques.

QC 20121207

APA, Harvard, Vancouver, ISO, and other styles
10

楊適存. "The preparation and photoluminescence of Y2O3 phosphors doped Eu3+ and Sm3+ ions." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/90331068833081839777.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Sm3+ IONS"

1

United States. National Aeronautics and Space Administration., ed. Determination of solar flare accelerated ion angular distributions from SMM gamma-ray and neutron measurements and Determination of the ³He/H ratio in the solar photosphere from SMM gamma-ray measurements: Final technical report, NASA grant NAG 5-945 (07/01/87 to 08/31/89). [Washington, DC: National Aeronautics and Space Administration, 1990.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Determination of solar flare accelerated ion angular distributions from SMM gamma-ray and neutron measurements and Determination of the ³He/H ratio in the solar photosphere from SMM gamma-ray measurements: Final technical report, NASA grant NAG 5-945 (07/01/87 to 08/31/89). [Washington, DC: National Aeronautics and Space Administration, 1990.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Sm3+ IONS"

1

Wåhlin, E. K., J. S. Thompson, G. H. Dunn, R. A. Phaneuf, D. C. Gregory, and A. C. H. Smith. "Electron-impact excitation of multiply-charged ions using energy loss in merged beams: e + Si3 + (3s2S1/2) → e + Si3+ (3p2P1/2,3/2)." In Atomic Physics of Highly Charged Ions, 35–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76658-9_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Holze, Rudolf. "Transference numbers of Sm3+ ion in aqueous electrolyte solutions." In Electrochemistry, 1863. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49251-2_1650.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Holze, Rudolf. "Single ion conductivities of Sm3+ ion in aqueous electrolyte solutions at infinite dilution." In Electrochemistry, 2101. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49251-2_1883.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Holze, Rudolf. "Single ion conductivities of Sc3+ ion in aqueous electrolyte solutions at infinite dilution." In Electrochemistry, 2099. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49251-2_1881.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mandal, Satish Kumar, Savita, Pradip Kumar Priya, Ram Pratap Yadav, Hari Pratap Bhasker, Raj Kumar Anand, and Amreesh Chandra. "A Detailed Study of Structural, Dielectric and Luminescence Properties of Sm3+ Doped BiFeO3 Nanoceramics." In Materials Science: A Field of Diverse Industrial Applications, 110–19. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815051247123010008.

Full text
Abstract:
Observation of at least two coexisting switchable ferroic states viz., ferromagnetic, ferroelectric, and/or ferroelastic at room temperature with promising coupling among order parameters, has made BiFeO3 a highly explored material in the field of multiferroics and/or magnetoelectric multiferroics, which creates the possibility for its application in various technological devices such as spintronics, spin-valve, DRAM, actuators, sensors, solar-cells photovoltaic, etc. Intrinsically, its low coupling coefficients, difficulty to prepare in pure phase in bulk, high leakage current, etc. have restricted BiFeO3 from technological reliability. However, the effect of doping with iso- and alio-valent ions, nanostructure, thin-film-form and nanoparticles, etc., has been carried out to improve its physical properties by several research groups over the decades. In this chapter, the structural, luminescence, and dielectric properties of samarium (Sm3+) doped BiFeO3 nanoceramics synthesized using a modified gelcombustion route are discussed in detail. The effect of Sm3+ doping in BiFeO3 is explored using the X-ray diffraction (XRD) technique. The XRD studies exhibit a possible structural phase transition above Sm3+ doping of 15% from rhombohedral (R3c) space group to the orthorhombic (Pbnm) space group. The dielectric study shows interesting behavior accompanied by structural transition. Our study suggests that Sm3+ doping plays an important role in governing the structural, luminescence, and dielectric properties of BiFeO3 samples.
APA, Harvard, Vancouver, ISO, and other styles
6

Ramya, Emusani. "Green Synthesis of Metal Nanostructures and Its Nonlinear Optical Properties." In Nonlinear Optics [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99449.

Full text
Abstract:
Simple green synthesis of metal nanoparticles (Ag NPs) was prepared by using Raphanussativus leaf extract. This extract acts as reduce and stabilizing agent. The formation of silver NPs was confirmed and characterized by XRD, UV–visible absorption spectrum, TEM, and FTIR. The luminescence enhancement and quenching of Eu3+and Sm3+ ions were observed in the presence of silver NPs. The luminescence enhancement is owing to arise in the electric-dipole transition with alteration of the field around Ln3+ ions. Nonlinear studies in femtosecond (fs) and picosecond (ps) time scales have been studied by using the Z-scan technique. Third-order nonlinear optical susceptibility of silver nanoparticles was obtained with Degenerate Four-Wave Mixing (DFWM) in the fs regime. The lifetimes of lanthanum complexes were increased by the concentration of silver NPs and decreased for further silver. The high enhanced luminescence and nonlinear studies of green synthesized silver nanoparticles can be used in optics and bio applications.
APA, Harvard, Vancouver, ISO, and other styles
7

Rai, S. "Effect of Nanostructure-Materials on Optical Properties of Some Rare Earth ions (Eu3+ ,Sm3+&Tb3+) Doped in Silica Matrix." In Advanced Materials and Nano Systems: Theory and Experiment - Part 2, 108–19. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815049961122020011.

Full text
Abstract:
Nanoparticles of CdS incorporated in Rare Earth doped silica xerogel (RE3+:SiO2) matrix have been prepared by sol-gel method to study its various aspect. The prepared materials have been characterized by physical and optical technique, such as XRD, SEM, TEM and Photoluminescence (PL). We can conclude from TEM that the particle size of the materials 8 nm and an average particle dimension of 5 nm. It is also found consistent with the theoretical calculation performed based on the Scherrer equation and effective mass approximation (EMA) model. The optical properties of these materials depend on various parameters such as dimension and surface characteristics, doping and interaction with the surrounding environment. Enhancements of Rare Earth (RE) ions luminescence have been observed with the presence of CdS NPs in RE3+:SiO2 matrix. A twenty time more intense dominating orange peaks (616 nm) from the characteristic peak of Eu3+ ions are observed for CdS/Eu3+:SiO2 matrix compared to the sample without CdS NPs. The efficient energy transfer (ET) from CdS NPs to RE ions is primarily responsible for this boost in the luminescence intensity. The emission intensity in PL spectra decreases with raise in the concentration of CdS NPs. With an increase in CdS NPs concentration in RE3+:SiO2 matrix, the emission intensity decreases possibly due to the increase in the concentration of “oxygen vacancy ”and “Si hanging” in the matrix of the silica xerogel. Thus, photoluminescence properties of the material are greatly influenced by site symmetry and hence the concentration of dopant ions.
APA, Harvard, Vancouver, ISO, and other styles
8

V. Kalinina, Marina, Daria A. Dyuskina, Irina G. Polyakova, Sergey V. Mjakin, Maxim Yu. Arsent’ev, and Olga A. Shilova. "Synthesis and Investigation of Ceramic Materials for Medium-Temperature Solid Oxide Fuel Cells." In Smart and Advanced Ceramics and Applications [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105108.

Full text
Abstract:
Finely dispersed (СeO2)1-x(Sm2O3)x (x = 0.02; 0.05; 0.10); La1-xSrxNiO3, La1-xSrxCoO3 and La1-xSrxFe0.7Ni0.3O3 (x = 0.30; 0.40) mesoporous xerogel powders are synthesized by co-crystallization of the corresponding nitrates with ultrasonic processing and used to obtain nanoscale ceramic materials with cubic fluorite-like, orthorhombic, and perovskite-like tetragonal crystal structure, respectively, with CSR ∼ 64–81 nm (1300°C). Physicochemical characterization of the obtained ceramics revealed that (СeO2)1-x(Sm2O3)x features with open porosity 2–6%, while for La1-xSrxNiO3, La1-xSrxCoO3, and La1-xSrxFe0.7Ni0.3O3, this value is about 21–29%. Ceria-based materials possess a predominantly ionic conductivity (ion transport numbers ti = 0.82–0.71 in the temperature range 300–700°C, σ700°С = 1.3·10−2 S/cm) determined by the formation of mobile oxygen vacancies upon heterovalent substitution of Sm3+ for Се4+. For solid solutions based on lanthanum nickelate and cobaltite, a mixed electronic-ionic conductivity (σ700°С = 0.80·10−1 S/cm) with ion transport numbers (te = 0.98–0.90, ti = 0.02–0.10) was obtained. The obtained ceramic materials are shown to be promising as solid oxide electrolytes and electrodes for medium-temperature fuel cells.
APA, Harvard, Vancouver, ISO, and other styles
9

Malchukova, Eugenia. "Influence of the Doping Ion Nature and Content on Defect Creation Processes under the Effect of Ionizing Radiation in Aluminoborosilicate Glasses." In Recent Techniques and Applications in Ionizing Radiation Research. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.92317.

Full text
Abstract:
Effects of ionizing irradiation on defect creation processes have been studied in rare earth (RE)-doped (RE = Sm, Gd, Eu, Ce, Nd) aluminoborosilicate glass with use of the electron paramagnetic resonance (EPR) and optical spectroscopy. As a function of RE ion nature, we observe that doping significantly influences the nature of the defects produced during irradiation and more specifically the relative proportions between hole and electron defect centers. Strong decrease of defect production efficiency under ionizing radiation independence on both the RE doping content and on the relative stability of the RE different oxidation states is also clearly revealed. The results could be explained by dynamical reversible trapping of the electron-hole pairs produced during irradiation on the different RE charge states as well as by RE segregation and pre-existing defects speciation in ABS glass structure.
APA, Harvard, Vancouver, ISO, and other styles
10

Hernandez-Avila, Juan, Edgar Omar Serrano-Mejía, Eleazar Salinas-Rodríguez, Eduardo Cerecedo-Sáenz, María Isabel Reyes-Valderrama, María del Pilar Gutiérrez-Amador, and Ventura Rodríguez-Lugo. "Use of Porous no Metallic Minerals to Remove Heavy Metals, Precious Metals and Rare Earths, by Cationic Exchange." In Trace Metals in the Environment - New Approaches and Recent Advances. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.88742.

Full text
Abstract:
This chapter is related with the preliminary study of some non-metallic minerals to evaluate their cationic exchange capacity, to remove heavy and precious metals, as well as rare earths elements. The minerals and materials used to execute the ion metals removal were bentonite, phosphorite, and diatomite. The chapter shows the physicochemical behavior of all these minerals, which were used to remove the mentioned elements from solutions coming from ore leaching. It was found that in all cases, the removal of heavy and precious metals, as well as rare earths elements reached over 90%. Although, there were minimal differences in efficiency for all minerals used (bentonite, phosphorite, and diatomite), it could be pointed that the phosphorite has the best results going from 99.43% of removal of Gd, to 99.95–100% for the case of Ce, Nd, La, Yb, Eu, Er, Sm, Tb, Ge, Pd, Pt, and Au.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Sm3+ IONS"

1

Jha, Nitin S., K. Linganna, C. K. Jayasankar, and Ajoy K. Kar. "Sm3+ ions Doped Phosphate Glasses for Multiband Visible Laser Applications." In CLEO: Applications and Technology. Washington, D.C.: OSA, 2015. http://dx.doi.org/10.1364/cleo_at.2015.jth2a.23.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kumi-Barimah, E., Y. Chen, R. Tenwick, G. Sharma, and A. Jha. "Optical properties and energy transfer of fluorotellurite glasses doped with Sm3+ and Sm3+:Yb3+ in visible and near-infrared wavelength under three different excitation sources." In Novel Optical Materials and Applications. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/noma.2022.notu3f.4.

Full text
Abstract:
Fluorotellurite based glasses have been investigated for numerous optical applications such as lasers, fibre optic, waveguide, and Raman gain devices. The fluorotellurite materials exhibit unique high linear and nonlinear refractive indices ( please add data), extended UV- and IR transparency (0.35 to 5.0µm). Above all the glass host promotes the retention of large concentrations of RE3+-ions in an environment of depleted OH-ions which is advantageous from the point of view of enhanced spectroscopic properties for light amplification in visible and near-IR.
APA, Harvard, Vancouver, ISO, and other styles
3

Madhukar Reddy, Chintala, Sd D. Zulifiqar Ali Ahamed, and B. D. Deva Prasad Raju. "Spectroscopic and Laser Properties of Sm3+ Ions Doped Lithium Fluoroborate Glasses." In International Conference on Fibre Optics and Photonics. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/photonics.2012.w3a.5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Karthikeyan, P., S. Arunkumar, P. Suthanthirakumar, and K. Marimuthu. "Spectroscopic investigations on Sm3+ ions doped zinc telluro-borate glasses for laser applications." In DAE SOLID STATE PHYSICS SYMPOSIUM 2018. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5113078.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mariyappan, M., S. Arunkumar, and K. Marimuthu. "Influence of modifiers on the spectroscopic properties of Sm3+ ions doped sodium fluoroborate glasses." In NANOFORUM 2014. AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4917870.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

M., Shwetha, and B. Eraiah. "Influence of samarium ions (Sm3+) on the optical properties of lithium zinc phosphate glasses." In 2ND INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC 2017). Author(s), 2018. http://dx.doi.org/10.1063/1.5032849.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Rao, K. Venkata, S. Babu, B. Venkata Rao, and Y. C. Ratnakaram. "Visible properties of Sm3+ ions in chloro-fluoro-borate glasses for reddish - orange emission." In DAE SOLID STATE PHYSICS SYMPOSIUM 2015. Author(s), 2016. http://dx.doi.org/10.1063/1.4947835.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Babu, S., A. Balakrishna, and Y. C. Ratnakaram. "Spectrometric analysis of different fluorophosphate glasses doped with Sm3+ ions for reddish-orange laser emission." In SOLID STATE PHYSICS: Proceedings of the 58th DAE Solid State Physics Symposium 2013. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4872734.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Mariyappan, M., P. Suthanthirakumar, S. Arunkumar, and K. Marimuthu. "Structural and optical studies on Sm3+ ions doped bismuth fluoroborate glasses for visible laser applications." In DAE SOLID STATE PHYSICS SYMPOSIUM 2017. Author(s), 2018. http://dx.doi.org/10.1063/1.5028818.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Krishna, V. Vinay, J. Suresh Krishna, M. Hemalatha, D. Siva Raju, and Ch Linga Raju. "Effect of Sm3+ ions on structural and thermal properties of PVA+PEG nano polymer films." In INTERNATIONAL CONFERENCE ON MULTIFUNCTIONAL MATERIALS (ICMM-2019). AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0022582.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Sm3+ IONS"

1

Lehotay, Steven J., and Aviv Amirav. Fast, practical, and effective approach for the analysis of hazardous chemicals in the food supply. United States Department of Agriculture, April 2007. http://dx.doi.org/10.32747/2007.7695587.bard.

Full text
Abstract:
Background to the topic: For food safety and security reasons, hundreds of pesticides, veterinary drugs, and environmental pollutants should be monitored in the food supply, but current methods are too time-consuming, laborious, and expensive. As a result, only a tiny fraction of the food is tested for a limited number of contaminants. Original proposal objectives: Our main original goal was to develop fast, practical, and effective new approaches for the analysis of hazardous chemicals in the food supply. We proposed to extend the QuEChERS approach to more pesticides, veterinary drugs and pollutants, further develop GC-MS and LC-MS with SMB and combine QuEChERS with GC-SMB-MS and LC-SMB-EI-MS to provide the “ultimate” approach for the analysis of hazardous chemicals in food. Major conclusions, solutions and achievements: The original QuEChERS method was validated for more than 200 pesticide residues in a variety of food crops. For the few basic pesticides for which the method gave lower recoveries, an extensive solvent suitability study was conducted, and a buffering modification was made to improve results for difficult analytes. Furthermore, evaluation of the QuEChERS approach for fatty matrices, including olives and its oil, was performed. The QuEChERS concept was also extended to acrylamide analysis in foods. Other advanced techniques to improve speed, ease, and effectiveness of chemical residue analysis were also successfully developed and/or evaluated, which include: a simple and inexpensive solvent-in-silicone-tube extraction approach for highly sensitive detection of nonpolar pesticides in GC; ruggedness testing of low-pressure GC-MS for 3-fold faster separations; optimization and extensive evaluation of analyte protectants in GC-MS; and use of prototypical commercial automated direct sample introduction devices for GC-MS. GC-MS with SMB was further developed and combined with the Varian 1200 GCMS/ MS system, resulting in a new type of GC-MS with advanced capabilities. Careful attention was given to the subject of GC-MS sensitivity and its LOD for difficult to analyze samples such as thermally labile pesticides or those with weak or no molecular ions, and record low LOD were demonstrated and discussed. The new approach of electron ionization LC-MS with SMB was developed, its key components of sample vaporization nozzle and flythrough ion source were improved and was evaluated with a range of samples, including carbamate pesticides. A new method and software based on IAA were developed and tested on a range of pesticides in agricultural matrices. This IAA method and software in combination with GC-MS and SMB provide extremely high confidence in sample identification. A new type of comprehensive GCxGC (based on flow modulation) was uniquely combined with GC-MS with SMB, and we demonstrated improved pesticide separation and identification in complex agricultural matrices using this novel approach. An improved device for aroma sample collection and introduction (SnifProbe) was further developed and favorably compared with SPME for coffee aroma sampling. Implications, both scientific and agricultural: We succeeded in achieving significant improvements in the analysis of hazardous chemicals in the food supply, from easy sample preparation approaches, through sample analysis by advanced new types of GC-MS and LCMS techniques, all the way to improved data analysis by lowering LOD and providing greater confidence in chemical identification. As a result, the combination of the QuEChERS approach, new and superior instrumentation, and the novel monitoring methods that were developed will enable vastly reduced time and cost of analysis, increased analytical scope, and a higher monitoring rate. This provides better enforcement, an added impetus for farmers to use good agricultural practices, improved food safety and security, increased trade, and greater consumer confidence in the food supply.
APA, Harvard, Vancouver, ISO, and other styles
2

Gorney, D. J. An Alternative Interpretation of Ion Ring Distribution Observed by the S3-3 Satellite. Fort Belvoir, VA: Defense Technical Information Center, May 1985. http://dx.doi.org/10.21236/ada157655.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Wisniewski, Michael, Samir Droby, John Norelli, Dov Prusky, and Vera Hershkovitz. Genetic and transcriptomic analysis of postharvest decay resistance in Malus sieversii and the identification of pathogenicity effectors in Penicillium expansum. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597928.bard.

Full text
Abstract:
Use of Lqh2 mutants (produced at TAU) and rNav1.2a mutants (produced at the US side) for identifying receptor site-3: Based on the fact that binding of scorpion alpha-toxins is voltage-dependent, which suggests toxin binding at the mobile voltage-sensing region, we analyzed which of the toxin bioactive domains (Core-domain or NC-domain) interacts with the DIV Gating-module of rNav1.2a. This analysis was based on the assumption that the dissociation of toxin mutants upon depolarization would vary from that of the unmodified toxin should the substitutions affect a site of interaction with the channel Gating-module. Using a series of toxin mutants (mutations at both domains) and two channel mutants that were shown to reduce the sensitivity to scorpion alpha-toxins, and by comparison of depolarization-driven dissociation of Lqh2 derivatives off their binding site at rNav1.2a mutant channels we found that the toxin Core-domain interacts with the Gating-module of DIV. Details of the experiments and results appear in Guret al (2011). Mapping receptor site 3 at Nav1.2a by extensive channel mutagenesis (Seattle): Since previous studies with photoaffinity labeling and antibody mapping implicated domains I and IV in scorpion alpha-toxin binding, Nav1.2 channel mutants containing substitutions at these extracellular regions were expressed and tested for receptor function by whole-cell voltage clamp. Of a large number of channel mutants, T1560A, F1610A, and E1613A in domain IV had ~5.9-, ~10.7-, and ~3.9-fold lower affinities for the scorpion toxin Lqh2, respectively, and mutant E1613R had 73-fold lower affinity. Toxin dissociation was accelerated by depolarization for both wild-type and mutants, and the rates of dissociation were also increased by mutations T1560A, F1610A and E1613A. In contrast, association rates for these three mutant channels at negative membrane potentials were not significantly changed and were not voltage-dependent. These results indicated that Thr1560 in the S1-S2 loop, Phe1610 in the S3 segment, and Glu1613 in the S3-S4 loop in domain IV participate in toxin binding. T393A in the SS2-S6 loop in domain I also showed a ~3.4-fold lower affinity for Lqh2, indicating that this extracellular loop may form a secondary component of the toxin binding site. Analysis with the Rosetta-Membrane algorithm revealed a three-dimensional model of Lqh2 binding to the voltage sensor in a resting state. In this model, amino acid residues in an extracellular cleft formed by the S1-S2 and S3-S4 loops in domain IV that are important for toxin binding interact with amino acid residues on two faces of the wedge-shaped Lqh2 molecule that are important for toxin action. The conserved gating charges in the S4 transmembrane segment are in an inward position and likely form ion pairs with negatively charged amino acid residues in the S2 and S3 segments (Wang et al 2011; Gurevitz 2012; Gurevitzet al 2013).
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Sm3+ IONS' for particular source types:
Journal articles Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography