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Academic literature on the topic 'Van der Waals frequencies'

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Published: 4 June 2021
Last updated: 20 February 2023

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Journal articles on the topic "Van der Waals frequencies"

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Liu, Yulei, Fengqiang Qian, and Lizhong Xu. "Four field coupled dynamics for a micro resonant gas sensor." Journal of Vibroengineering 18, no. 2 (March 31, 2016): 717–30. http://dx.doi.org/10.21595/jve.2015.16307.

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In a micro resonant gas sensor, the electrostatic excitation is used widely. For a micro resonant gas sensor with electrostatic excitation, four physical fields are involved. In this paper, for the micro resonant gas sensor, the four-field coupled dynamics equation is proposed. It includes mechanical force field, chemical density field, electrostatic force field, and the van der Waals force field. Using the method of multiple scales, the coupled dynamics equation is resolved. The effects of the four physical fields on the natural frequencies for the micro resonant gas sensor are investigated. Results show that the effects of the Van der Waals force on the natural frequencies of the micro resonant gas sensor depend on the mechanical parameters and the bias voltages; the sensitivity of the natural frequencies to the gas adsorption depends on the mechanical parameters, the bias voltages, and the Van der Waals force.
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Schuller, F. "Dispersion Potentials between Atoms and Dielectric Bodies." Zeitschrift für Naturforschung A 49, no. 9 (September 1, 1994): 885–89. http://dx.doi.org/10.1515/zna-1994-0911.

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Abstract We derive a formula for the van der Waals interaction between an atom and a dielectric surface for both ground and excited state potentials. We compare our result with previously derived expressions involving the dielectric constant at purely imaginary frequencies. We also study the relationship between atom-dielectric and ordinary atom-atom van der Waals interaction.
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Hsu, Ming-Hung. "Dynamic analysis of multi-walled carbon nanotubes using the differential quadrature method." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 224, no. 3 (October 26, 2009): 731–44. http://dx.doi.org/10.1243/09544062jmes1719.

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This work describes a novel modelling scheme to elucidate the frequencies of carbon nanotubes via continuum mechanics by considering the van der Waals force interaction based on differential quadrature simulations, in which nanobeam-bending paradigms are utilized. Exactly how the surrounding elastic medium, length-to-radius ratio, and van der Waals forces of the carbon nanotubes affect the frequencies is also investigated. The proposed modelling scheme is highly promising for advanced carbon nanotube applications. Further elucidation of the vibration mechanism of carbon nanotubes embedded in an elastic medium in this work significantly contributes to efforts to design nano oscillators.
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Xu, Lizhong, Yulei Liu, and Xiaorui Fu. "Effects of the van der Waals Force on the Dynamics Performance for a Micro Resonant Pressure Sensor." Shock and Vibration 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/3426196.

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The micro resonant pressure sensor outputs the frequency signals where the distortion does not take place in a long distance transmission. As the dimensions of the sensor decrease, the effects of the van der Waals forces should be considered. Here, a coupled dynamic model of the micro resonant pressure sensor is proposed and its coupled dynamic equation is given in which the van der Waals force is considered. By the equation, the effects of the van der Waals force on the natural frequencies and vibration amplitudes of the micro resonant pressure sensor are investigated. Results show that the natural frequency and the vibrating amplitudes of the micro resonant pressure sensor are affected significantly by van der Waals force for a small clearance between the film and the base plate, a small initial tension stress of the film, and some other conditions.
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Li, Renfu, and George A. Kardomateas. "Vibration Characteristics of Multiwalled Carbon Nanotubes Embedded in Elastic Media by a Nonlocal Elastic Shell Model." Journal of Applied Mechanics 74, no. 6 (January 2, 2007): 1087–94. http://dx.doi.org/10.1115/1.2722305.

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In this paper, the vibrational behavior of the multiwalled carbon nanotubes (MWCNTs) embedded in elastic media is investigated by a nonlocal shell model. The nonlocal shell model is formulated by considering the small length scales effects, the interaction of van der Waals forces between two adjacent tubes and the reaction from the surrounding media, and a set of governing equations of motion for the MWCNTs are accordingly derived. In contrast to the beam models in the literature, which would only predict the resonant frequencies of bending vibrational modes by taking the MWCNT as a whole beam, the current shell model can find the resonant frequencies of three modes being classified as radial, axial, and circumferential for each nanotube of a MWCNT. Big influences from the small length scales and the van der Waals’ forces are observed. Among these, noteworthy is the reduction in the radial frequencies due to the van der Waals’ force interaction between two adjacent nanotubes. The numerical results also show that when the spring constant k0 of the surrounding elastic medium reaches a certain value, the lowest resonant frequency of the double walled carbon nanotube drops dramatically.
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Sokolov, N. D. "Van der Waals interaction and hydrogen bond effects on molecular vibrational frequencies." Chemical Physics 104, no. 3 (May 1986): 371–81. http://dx.doi.org/10.1016/0301-0104(86)85026-1.

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Tian, Mei Ling, Jin Bao Wang, Xiao Qiao He, and Yu Zhou Sun. "Vibration Properties of Multi-Layered Graphene Sheets." Advanced Materials Research 287-290 (July 2011): 81–85. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.81.

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Based on an explicit formula used for describing the van der Waals (vdW) interaction between any two layers of multi-layered graphene sheets (MLGSs), the vibration properties of five- and eight-layered graphene sheets are analyzed with considering the influence of vdW interaction on the natural frequences. The present study shows that for a given combination n and m the lowest natural frequency (classical natural frequency) of a MLGSs is independent of vdW interaction, but that it is very significant for the influence of vdW interaction on the other higher frequencies (resonant frequencies). The different vibration modes, including in-phase and anti-phase ones, are given for exhibiting clearly the influence of vdW interaction.
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Dubnikova, Faina, and Assa Lifshitz. "Formation of Van Der Waals Complexes in Concerted Unimolecular Elimination Processes." ISRN Physical Chemistry 2012 (April 9, 2012): 1–7. http://dx.doi.org/10.5402/2012/431367.

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Potential energy surfaces for three unimolecular elimination reactions: , , and were calculated using a variety of quantum chemical methods. It was shown that, in all the three cases, the transition state in the first step of the reaction leads to the production of the complex intermediates based on van der Waals interactions. In addition to the fact that the three complexes appear as intermediates on the potential energy surfaces, which means that they are not free entities, the entropy values of the two elimination products are far above those of the complexes due to their additional Sackur-Tetrode entropy. Moreover, the three vibrational frequencies of the H2O group in the (CH3)3COH complex and the H–Cl and H–F stretch frequencies in CH3CF3 and CH3CH2CH2Cl are quite different (see the various tables). The energy levels of the complexes were found to be below those of the corresponding decomposition products. Rate constants for the elimination processes were calculated from the potential energy surfaces using transition-state theory and were compared to available experimental data.
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Zheng, Zebo, Ningsheng Xu, Stefano L. Oscurato, Michele Tamagnone, Fengsheng Sun, Yinzhu Jiang, Yanlin Ke, et al. "A mid-infrared biaxial hyperbolic van der Waals crystal." Science Advances 5, no. 5 (May 2019): eaav8690. http://dx.doi.org/10.1126/sciadv.aav8690.

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Hyperbolic media have attracted much attention in the photonics community due to their ability to confine light to arbitrarily small volumes and their potential applications to super-resolution technologies. The two-dimensional counterparts of these media can be achieved with hyperbolic metasurfaces that support in-plane hyperbolic guided modes upon nanopatterning, which, however, poses notable fabrication challenges and limits the achievable confinement. We show that thin flakes of a van der Waals crystal, α-MoO3, can support naturally in-plane hyperbolic polariton guided modes at mid-infrared frequencies without the need for patterning. This is possible because α-MoO3 is a biaxial hyperbolic crystal with three different Reststrahlen bands, each corresponding to a different crystalline axis. These findings can pave the way toward a new paradigm to manipulate and confine light in planar photonic devices.
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Senthilkumar, V. "Axial vibration of double-walled carbon nanotubes using double-nanorod model with van der Waals force under Pasternak medium and magnetic effects." Vietnam Journal of Mechanics 44, no. 1 (March 30, 2022): 29–43. http://dx.doi.org/10.15625/0866-7136/16582.

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The present study investigates the axial vibration of double-walled nanotubes. Using the nanorod continuum model with the van der Waals effect, the vibrational frequencies are studied. Aydogdu (Journal of Vibration and Control, Vol. 21, Issue 16, (2015), 3132-3154) proposed a reliable model for the study of axial vibration in a double-walled nanotube. This model provided a detailed investigation of axial vibration using van der Waals effects. But sometimes, the wrong equation might lead to erroneous scientific results. The incorrect term for axial vibration in the double-walled nanotube model is taken care of in the present study for the correct scientific inferences. Effectively, the axial vibrational frequencies appear without decoupling the continuum model as for primary and secondary nanotubes. The semi-analytical method estimates the axial vibrational frequencies of the double-walled nanotube as a coupled model. Two different boundary conditions like clamped-clamped and clamped-free support, are considered in this computation. The Pasternak medium support and magnetic effects influence the vibrational frequencies of the first and second nanotube for the first time. The Pasternak constant and magnetic parameters don't vary with the length of the nanotube for axial vibration. It means that still more understanding requires in modeling the Pasternak medium and magnetic force for the double-nanotube to model axial vibration.
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Dissertations / Theses on the topic "Van der Waals frequencies"

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Bieske, Evan John, and n/a. "The Electronic Spectroscopy of Neutral and Ionic Clusters." Griffith University. School of Science, 1989. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20051109.112502.

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This thesis is concerned with weakly bound neutral and ionic clusters. Spectra of the region near the S1fS0 electronic origin of four neutral van der Waals molecules - aniline-argon, phenol-argon, chlorobenzene-argon and fluorobenzene-argon - were obtained using resonance enhanced multiphoton ionization (REMPI). These spectra indicate that Fermi resonances between van der Waals stretching and bending motions are important in these molecules. Effective Hamiltonians are constructed that describe well the low frequency vibrations. In order to better discuss the low frequency van der Waals motions of aromatics bound to one and two rare gas atoms a simple model for the vibrations is developed. The model enables expression of van der Waals frequencies in terms of fundamental molecular properties and enables facile comparison of effective force constants in a variety of van der Waals molecules. The model is successfully employed to explain van der Waals vibrational structure associated with the origin region of aniline-(argon)2 using van der Waals potential parameters derived from the aniline-(argon)1 spectrum. REMPI and emission spectra of larger clusters of aniline and argon are also reported and discussed. Using atom-atom potentials, equilibrium structures for aniline-(argon)n (n=l, 2, 3) are calculated. The calculations prove useful in the analysis of the spectra.The BfX transitions of the cation complexes fluorobenzene+-argon and chlorobenzene+-argon have been investigated. The cations were prepared by resonance enhanced multiphoton ionization of the neutral van der Waals molecules. A time delayed tunable dye laser was then used to dissociate the cations, loss of an argon atom being the dominant process. When the second laser was tuned to a cation resonance the dissociation cross section increased markedly, allowing characterization of BfX transition. The resulting spectra are presented and discussed.
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Bieske, Evan John. "The Electronic Spectroscopy of Neutral and Ionic Clusters." Thesis, Griffith University, 1989. http://hdl.handle.net/10072/367202.

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This thesis is concerned with weakly bound neutral and ionic clusters. Spectra of the region near the S1fS0 electronic origin of four neutral van der Waals molecules - aniline-argon, phenol-argon, chlorobenzene-argon and fluorobenzene-argon - were obtained using resonance enhanced multiphoton ionization (REMPI). These spectra indicate that Fermi resonances between van der Waals stretching and bending motions are important in these molecules. Effective Hamiltonians are constructed that describe well the low frequency vibrations. In order to better discuss the low frequency van der Waals motions of aromatics bound to one and two rare gas atoms a simple model for the vibrations is developed. The model enables expression of van der Waals frequencies in terms of fundamental molecular properties and enables facile comparison of effective force constants in a variety of van der Waals molecules. The model is successfully employed to explain van der Waals vibrational structure associated with the origin region of aniline-(argon)2 using van der Waals potential parameters derived from the aniline-(argon)1 spectrum. REMPI and emission spectra of larger clusters of aniline and argon are also reported and discussed. Using atom-atom potentials, equilibrium structures for aniline-(argon)n (n=l, 2, 3) are calculated. The calculations prove useful in the analysis of the spectra.The BfX transitions of the cation complexes fluorobenzene+-argon and chlorobenzene+-argon have been investigated. The cations were prepared by resonance enhanced multiphoton ionization of the neutral van der Waals molecules. A time delayed tunable dye laser was then used to dissociate the cations, loss of an argon atom being the dominant process. When the second laser was tuned to a cation resonance the dissociation cross section increased markedly, allowing characterization of BfX transition. The resulting spectra are presented and discussed.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Science
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Bezzi, Luca. "Materiali 2D van der Waals." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.

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Dalla scoperta del grafene, molte ricerche sono state condotte sui cosiddetti “materiali 2D”. Questo elaborato si focalizza sulle proprietà strutturali, elettroniche, ottiche ed eccitoniche di due materiali bidimensionali, ossia il grafene il disolfuro di molibdeno (MoS2-1H), quest’ultimo un importante semiconduttore. Le proprietà di questi materiali sono diverse rispetto alla loro controparte massiva (bulk) grafite e MoS2-2H, e un loro confronto è stato preso in considerazione. Come metodo di indagine sono state scelte simulazioni quanto- meccaniche ab initio dei sistemi in esame, un approccio che, negli ultimi decenni, sta avendo un impatto sempre più importante sulla fisica, sulla chimica dello stato solido e sulla scienza dei materiali, promuovendo non solo una comprensione più profonda, ma anche la possibilità di contribuire in modo significativo alla progettazione di materiali per nuove tecnologie. Questo importante passo avanti è stato possibile grazie a: (i) una descrizione migliorata ed efficiente degli effetti elettronici a molti corpi (many-body) nella teoria del funzionale della densità (DFT), nonché lo sviluppo di metodi post-DFT per lo studio di proprietà specifiche; (ii) un’accurata implementazione di questi metodi in software altamente efficienti, stabili e versatili, capaci di sfruttare il potenziale delle architetture informatiche moderne. Tra i possibili software ab initio basati su DFT, abbiamo scelto il pacchetto di simulazione di Vienna ab initio VASP, considerato un gold standard per questo tipo di indagini. I risultati ottenuti per le varie proprietà di bulk e di superficie (bidimensionale) dei materiali scelti sono in ottimo accordo con dati ottenuti in precedenza, sia a livello teorico, sia sperimentale. Questo elaborato getta quindi le basi per futuri studi nel campo dei materiali 2D per comprendere, analizzare, ingegnerizzare nuovi materiali con proprietà desiderabili e per sviluppare nuove applicazioni degli stessi.
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Boddison-Chouinard, Justin. "Fabricating van der Waals Heterostructures." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38511.

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The isolation of single layer graphene in 2004 by Geim and Novoselov introduced a method that researchers could extend to other van der Waals materials. Interesting and new properties arise when we reduce a crystal to two dimensions where they are often different from their bulk counterpart. Due to the van der Waals bonding between layers, these single sheets of crystal can be combined and stacked with diferent sheets to create novel materials. With the goal to study the interesting physics associated to these stacks, the focus of this work is on the fabrication and characterization of van der Waals heterostructures. In this work, we first present a brief history of 2D materials, the fabrication of heterostructures, and the various tools used to characterize these materials. We then give a description of the custom-built instrument that was used to assemble various 2D heterostructures followed by the findings associated with the optimization of the cleanliness of the stack's interface and surface. Finally, we discuss the results related to the twisting of adjacent layers of stacked MoS2 and its relation to the interlayer coupling between said layers.
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Tiller, Andrew R. "Spectra of Van der Waals complexes." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333415.

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Mauro, Diego. "Electronic properties of Van der Waals heterostructures." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10565/.

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L’interazione spin-orbita (SOI) nel grafene è attualmente oggetto di intensa ricerca grazie alla recente scoperta di una nuova classe di materiali chiamati isolanti topologici. Questi materiali, la cui esistenza è strettamente legata alla presenza di una forte SOI, sono caratterizzati dall’interessante proprietà di avere un bulk isolante ed allo stesso tempo superfici conduttrici. La scoperta teorica degli isolanti topologici la si deve ad un lavoro nato con l’intento di studiare l’influenza dell’interazione spin-orbita sulle proprietà del grafene. Poichè questa interazione nel grafene è però intrinsecamente troppo piccola, non è mai stato possibile effettuare verifiche sperimentali. Per questa ragione, vari lavori di ricerca hanno recentemente proposto tecniche volte ad aumentare questa interazione. Sebbene alcuni di questi studi abbiano mostrato un effettivo aumento dell’interazione spin-orbita rispetto al piccolo valore intrinseco, sfortunatamente hanno anche evidenziato una consistente riduzione della qualità del grafene. L’obbiettivo che ci si pone in questa tesi è di determinare se sia possibile aumentare l’interazione spin-orbita nel grafene preservandone allo stesso tempo le qualità. La soluzione proposta in questo lavoro si basa sull’utilizzo di due materiali semiconduttori, diselenio di tungsteno WSe2 e solfuro di molibdeno MoS2, utilizzati da substrato su cui sopra verrà posizionato il grafene formando così un’eterostruttura -nota anche di “van der Waal” (vdW)-. Il motivo di questa scelta è dovuto al fatto che questi materiali, appartenenti alla famiglia dei metalli di transizione dicalcogenuri (TMDS), mostrano una struttura reticolare simile a quella del grafene, rendendoli ideali per formare eterostrutture e ancora più importante, presentano una SOI estremamente grande. Sostanzialmente l’idea è quindi di sfruttare questa grande interazione spin-orbita del substrato per indurla nel grafene aumentandone così il suo piccolo valore intrinseco.
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Klein, Andreas. "Energietransferprozesse in matrixisolierten van-der-Waals-Komplexen." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=962344761.

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Odeyemi, Tinuade A. "Numerical Modelling of van der Waals Fluids." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/22661.

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Many problems in fluid mechanics and material sciences deal with liquid-vapour flows. In these flows, the ideal gas assumption is not accurate and the van der Waals equation of state is usually used. This equation of state is non-convex and causes the solution domain to have two hyperbolic regions separated by an elliptic region. Therefore, the governing equations of these flows have a mixed elliptic-hyperbolic nature. Numerical oscillations usually appear with standard finite-difference space discretization schemes, and they persist when the order of accuracy of the semi-discrete scheme is increased. In this study, we propose to use a Chebyshev pseudospectral method for solving the governing equations. A comparison of the results of this method with very high-order (up to tenth-order accurate) finite difference schemes is presented, which shows that the proposed method leads to a lower level of numerical oscillations than other high-order finite difference schemes, and also does not exhibit fast-traveling packages of short waves which are usually observed in high-order finite difference methods. The proposed method can thus successfully capture various complex regimes of waves and phase transitions in both elliptic and hyperbolic regimes
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Marsden, Alexander J. "Van der Waals epitaxy in graphene heterostructures." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/77193/.

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Graphene — a two-dimensional sheet of carbon atoms — has surged into recent interest with its host of remarkable properties and its ultimate thinness. However, graphene combined with other materials is starting to attract more attention. These heterostructures can be important for production routes, incorporating graphene into existing technologies, or for modifying its intrinsic properties. This thesis aims to examine the role of van der Waals epitaxy within these heterostructures. First, the graphene-copper interaction during chemical vapour deposition of graphene is investigated. Graphene is found to grow with a mismatch epitaxy of 8 relative to the [001] direction of the Cu(100) surface, despite a mismatch in symmetry and lattice parameter between two. Further, the electronic structure of both graphene and copper is unchanged by the interaction. This highlights the weak interaction between the two, owing to its van der Waals nature. Functionalised graphene is another important heterostructure, and is intensively studied for both graphene production routes and for altering graphene’s properties. Here, it is the change to the homogeneous graphene surface that makes it interesting for van der Waals epitaxy. The effect of functionalisation of graphene with atomic oxygen and nitrogen is presented next. In both cases, only small amounts of functionalisation ( 5 at%) is sufficient to significantly deteriorate the -band structure of the graphene through localisation. For small amounts of nitrogen functionalisation, and greater amounts of oxygen functionalisation, extended topological defects are formed in the graphene lattice. Unlike epoxide oxygen groups, these disruptions to the pristine graphene are found to be irreversible by annealing. Next, the interaction between graphene and the organic semiconducting molecule vanadyl-phthalocyanine (VOPc) is presented. As a result of the van der Waals nature of the graphene surface, VOPc molecules can form crystals microns in size when deposited onto a substrate with an elevated temperature of 155 C; at ambient temperatures, the crystals are only tens of nanometres across. In contrast, the functionalised graphene oxide surface prevents large crystal growth, even at elevated temperatures, because surface functionalities inhibit molecule diffusion. This highlights the importance of graphene as a substrate for molecular crystal growth, even when the growth is not epitaxial. Finally, the supramolecular assembly of trimesic acid (TMA) and terephthalic acid (TPA) is presented. Despite their chemical similarity they display different behaviour as they transition from monolayers to three-dimensional structures: for TMA, the epitaxial chicken wire structure seen at a monolayer templates up through the layers as molecules stack, until a thickness of 20 nm, when random in-plane orientations appear; on the other hand, TPA forms a brickwork structure at the monolayer, which quickly transitions to fibre-like crystals with a bulk structure for the thin films. However, the TPA orientation is still determined by the epitaxy with the graphene substrate, although this is significantly weaker than for TMA.
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Connelly, James Patrick. "Microwave studies of Van der Waals complexes." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:3865eb1d-d288-44c9-8d42-84f7ff2c0608.

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This thesis describes the commissioning and development of a pulsed supersonic nozzle, Fourier-transform microwave spectrometer and its application to the study of several weakly bound van der Waals complexes. A pulsed supersonic expansion, Fourier-transform microwave spectrometer based on the Flygare design with a number of modifications has been constructed with an operating range of 6-18 GHz. A homodyne detection circuit mixing signals to modulus values between dc and 1 MHz is used, requiring two measurements to determine absolute transition frequencies. Transition frequencies are measured from the power spectrum by determining the first derivative zero crossing point in a least squares fitting procedure. Semiautomation of many of the spectrometer operations has been achieved allowing unattended data collection over scans of up to 300 MHz. The microwave spectrum of Ar2-OCS and Ar2-OC34S has been observed and analysed using conventional Watson S reduction hamiltonian parameters. Effective structural parameters are derived and used in a harmonic force field analysis, based on the centrifugal distortion constants, to compare the trimer interations with a model based on the sum of dimer interactions. A series of complexes containing the nitrogen molecule undergoing tunnelling motions have been studied. Hyperfine matrix elements for the first order nuclear quadrupole interaction are derived for the coupled identical nuclei case appropriate to the rapid tunnelling motions observed. The microwave spectrum of N2-OCS is described. Tunnelling and nuclear spin statistical effects for two symmetry states are observed arising from the interchange of nitrogen nuclei. Rotational and quadrupole constants are derived; an accidental near degeneracy of two rotational levels allows the off-diagonal quadrupole coupling constant to be determined from second order effects. A tunnelling hamiltonian fitting the quadrupole coupling constants to an angular potential has been used to calculate the tunnelling frequency and barrier to N2 rotation. The microwave spectrum of N2-O3 and a preliminary spectrum of N2-SO3 have been observed. Rotation-inversion motions of the O3 and SO2 moieties must be considered in addition to the N2 tunnelling to fit the spectrum. Tunnelling frequencies for the O3/SO2 and geared motions with the N2 are derived as well as structural parameters. Modifications for production of refractory molecules and complexes by laser ablation have been made. A modified nozzle employing rods of material is used with the ablation process taking place in the nozzle throat. Modifications to obtain an expansion along the axis of the microwave cavity employ a hemispherical Fabry-Perot cavity configuration. The system has been tested on a number of diatomic molecules including PbS and CuCl.
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Books on the topic "Van der Waals frequencies"

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Parsegian, V. Adrian. Van der Waals forces. New York: Cambridge University Press, 2005.

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1926-, Rowlinson J. S., and I︠A︡velov B. E, eds. Van der Waals and molecular science. Oxford: Clarendon Press, 1996.

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Kipnis, Aleksandr I͡Akovlevich. Van der Waals and molecular sciences. Oxford: Clarendon Press, 1996.

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Holwill, Matthew. Nanomechanics in van der Waals Heterostructures. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-18529-9.

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Sily Van-der-Vaalʹsa. Moskva: "Nauka," Glav. red. fiziko-matematicheskoĭ lit-ry, 1988.

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NATO Advanced Research Workshop on Dynamics of Polyatomic Van der Waals Complexes (1989 Castéra-Verduzan, France). Dynamics of polyatomic Van der Waals complexes. New York: Plenum Press, 1990.

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Halberstadt, Nadine. Dynamics of Polyatomic Van der Waals Complexes. Boston, MA: Springer US, 1991.

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Halberstadt, Nadine, and Kenneth C. Janda, eds. Dynamics of Polyatomic Van der Waals Complexes. New York, NY: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4684-8009-2.

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M, Smirnov B. Cluster ions and Van der Waals molecules. Philadelphia: Gordon and Breach Science Publishers, 1992.

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Kok, Auke. De verrader: Leven en dood van Anton van der Waals. 2nd ed. Amsterdam: Arbeiderspers, 1995.

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Book chapters on the topic "Van der Waals frequencies"

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Haroche, S., A. Anderson, E. Hinds, W. Jhe, and D. Meschede. "Atomic Physics in Confined Space: Suppressing Spontaneous Emission at Optical Frequencies and Measuring the Van der Waals Atom-Surface Interaction." In Laser Spectroscopy VIII, 30–35. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-540-47973-4_8.

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Tsuchiya, Taku. "Van der Waals Force." In Encyclopedia of Earth Sciences Series, 1–2. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-39193-9_329-1.

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Tsuchiya, Taku. "Van der Waals Force." In Encyclopedia of Earth Sciences Series, 1473–74. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-39312-4_329.

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Bruylants, Gilles. "Van Der Waals Forces." In Encyclopedia of Astrobiology, 1728–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_1647.

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Zhang, Xiang-Jun. "Van der Waals Forces." In Encyclopedia of Tribology, 3945–47. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-0-387-92897-5_457.

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Arndt, T. "Van-der-Waals-Kräfte." In Springer Reference Medizin, 2429–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-48986-4_3207.

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Gooch, Jan W. "Van der Waals Forces." In Encyclopedic Dictionary of Polymers, 788. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_12442.

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Bruylants, Gilles. "Van der Waals Forces." In Encyclopedia of Astrobiology, 2583–85. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_1647.

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Tadros, Tharwat. "Van der Waals Attraction." In Encyclopedia of Colloid and Interface Science, 1395–96. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-20665-8_159.

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Arndt, T. "Van-der-Waals-Kräfte." In Lexikon der Medizinischen Laboratoriumsdiagnostik, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-49054-9_3207-1.

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Conference papers on the topic "Van der Waals frequencies"

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Caruntu, Dumitru I., and Iris Alvarado. "Influence of van der Waals Forces on Electrostatically Actuated MEMS/NEMS Circular Plates." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63798.

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This paper deals with electrostatically actuated micro and nano-electromechanical (MEMS/NEMS) circular plates. The system under investigation consists of two bodies, a deformable and conductive circular plate placed above a fixed, rigid and conductive ground plate. The deformable circular plate is electrostatically actuated by applying an AC voltage between the two plates. Nonlinear parametric resonance and pull-in occur at certain frequencies and relatively large AC voltage, respectively. Such phenomena are useful for applications such as sensors, actuators, switches, micro-pumps, micro-tweezers, chemical and mass sensing, and micro-mirrors. A mathematical model of clamped circular MEMS/NEMS electrostatically actuated plates has been developed. Since the model is in the micro- and nano-scale, surface forces, van der Waals and/or Casimir, acting on the plate are included. A perturbation method, the Method of Multiple Scales (MMS), is used for investigating the case of weakly nonlinear MEMS/NEMS circular plates. Two time scales, fast and slow, are considered in this work. The amplitude-frequency and phase-frequency response of the plate in the case of primary resonance are obtained and discussed.
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Behfar, K., R. Naghdabadi, A. Vafai, and H. E. Estekanchi. "Nanoscale Vibrational Analysis of an Embedded Multi-Layered Graphene Sheet." In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58629.

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In this paper, nanoscale vibrational analysis of a multilayered graphene sheet embedded in an elastic medium is investigated and the corresponding resonant modes and frequencies are determined. It is known that the elastic moduli of a graphene sheet in two orientations x, y are different, so the graphene sheet is assumed to be a general form of an orthotropic plate. The orthotropic sheets stacking at the top of each other bond with carbon-carbon van der Waals forces, also the whole multi-layered graphene sheet is influenced by polymer-carbon van der Waals forces from the surrounding elastic medium.
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Asadi, Ehsan, Ali Karimzade, and Mehrdad Farid. "Investigation of the Fundamental Frequency of Double Walled Carbon Nanotubes Using Molecular Mechanics Approach by an Averaging Van Der Waals Forces Modeling." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62962.

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Carbon nanotubes have received a lot of attention since their introduction in 1991 because of novel properties that show substantial promises for use in many applications. Their usage depends on the strength of our knowledge of their properties. In this work, molecular mechanics approach is used to study the mechanical properties of multi-wall carbon nanotubes. In particular this paper investigates fundamental frequency of double walled carbon nanotubes. Carbon nanotubes are big and long molecules that can be regarded as mechanical structures. In modeling of multi-walled carbon nanotubes, two distinct atomic bonds are required to be modeled, i.e. covalent bonds between the neighboring carbon atoms in the same layer and Van der Waals bonds between close atoms in neighboring layers. In this approach, for modeling of each wall; covalent bonds are modeled by beam joints such that atoms are considered to be concentrated masses at the ends. Interactions of neighboring walls that are mainly due to Van der Waals forces are treated to be truss rods in modeling. The most challenging aspect of modeling is to define truss rod properties as they are highly nonlinear. We utilized an averaging method for finding truss rod properties. Finite Element Method is employed to obtain Fundamental frequencies. Results are compared to available researches and a close agreement is observed. Results indicate that by increasing aspect ratio, fundamental frequency of double walled nanotubes decrease. In addition, double walled carbon nanotubes have higher fundamental frequencies at clamp-clamp in comparison to clamp-free condition; however, this difference becomes negligible as aspect ratio increases.
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Alipi, Marcos, and Dumitru I. Caruntu. "Frequency Response of Parametric Resonance of Electrostatically Actuated Bio-MEMS Circular Membranes." In ASME 2022 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/detc2022-91044.

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Abstract This paper deals with the amplitude-frequency response of parametric resonance of electrostatically actuated Bio-MEMS circular membrane resonators. The system consists of a flexible clamped circular membrane over a parallel fixed ground plate. Between the membrane and the ground plate is an alternating current (AC) voltage. The magnitude of the AC voltage is in the range of soft excitation. The AC frequency used to actuate the Bio-MEMS is near the first natural frequency of the membrane. Since the electrostatic force is proportional to the square of the voltage, this actuation leads to parametric resonance of Bio-MEMS circular membranes. The equation of motion includes Casimir and Van deer Waals forces. Two methods of investigation are utilized in this paper, the method of multiple scales (MMS), and the reduced order model (ROM). They are used to analytically and numerically solve the differential equations of motion for amplitude-frequency response of Bio-MEMS membrane resonators. The effects of Casimir force, Van der Waals force, voltage, and damping on the amplitude-frequency response of the system are also reported. The results show that the increase of Casimir and Van der Waals parameters increase the softening effect of the response, i.e., the response shifts towards lower frequencies and amplitudes. The results also showed that an increase in the damping parameter decreased the escape band of the response, while increasing the voltage parameter had the opposite effect increasing the size of the escape band.
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Koperski, J., J. B. Atkinson, and L. Krause. "Laser spectroscopy of HgRG and Hg2 molecules in supersonic beams." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1993. http://dx.doi.org/10.1364/oam.1993.mr.1.

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Fluorescence of HgHe, HgNe, HgAr, and Hg2 van der Waals molecules was excited in a pulsed expansion beam by pulsed radiation from a frequency-doubled dye laser. The vibrational structures in the excitation spectra resulting from dye-laser scans were registered with a transient digitizer. The HgRG spectra each consist of two vibrational progressions, one on the long-wavelength side and one on the short-wavelength side of 253.7 nm atomic Hg line. Standard vibrational analyses yielded the frequencies, anharmonicities and dissociation energies for the ground- and excited states of the molecules, which are compared with data reported elsewhere. Although there is general agreement with previous spectroscopic results, there are some discrepancies for the HgAr spectrum [1], and also for the Hg2, spectrum [2].
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Mahmoodi, S. Nima, Amin Salehi-Khojin, and Mehdi Ahmadian. "Nonlinear Force Analysis of Atomic Force Microscopy." In ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/detc2011-48482.

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The objective of this work is to highlight and discuss some critical conditions in which the imprecision of atomic force microscopy (AFM) system will be intensified. To precisely address these issues, we developed a complete close form solution for a non-linear motion of AFM system subjected to non-linear contact and van der Waals forces. Galerkin method and multiple time scale approach are used to solve the governing non-linear differential equation of the AFM system. A nonlinear frequency-response equation is then obtained as a function of displacement excitation, resonance frequency and associated response amplitude. By simulation of the AFM response under different tip-sample interaction force and distance, it is shown that jump phenomenon takes place due to the non-linear motion of microcantilever at certain operating frequencies. This case can be avoided via operating the AFM in a right frequency region; however the error associated with it must be compensated by a post-processing of collected data.
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Eslami, Sohrab, Nader Jalili, Ali Passian, Laurene Tetard, and Thomas Thundat. "Nonlinear Interaction Force Analysis of Microcantilevers Utilized in Atomic Force Microscopy." In ASME 2009 Dynamic Systems and Control Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/dscc2009-2712.

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This paper presents an Euler-Bernoulli microcantilever beam model utilized in non-contact Atomic Force Microscopy (AFM) systems. A distributed-parameters modeling is considered for such system. The motions of the microcantilever are studied in a general Cartesian coordinate with an excitation at the base such that beam end with a tip mass is subject to a general force. This general force comprising of two attractive and repulsive parts with high power terms is taken as the atomic intermolecular one which has a relation with the displacement between the tip mass and the surface such that the total general force will be in the form of an implicit nonlinear equation. It is most desired to observe the effects of the base excitation in high frequencies on the tip van der Waals interaction force. Hence, the general force will produce a peak in the FFT spectrum corresponding to the frequency of the base.
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CAPOZZIELLO, S., V. F. CARDONE, S. CARLONI, and A. TROISI. "VAN DER WAALS QUINTESSENCE." In Proceedings of the International Conference. WORLD SCIENTIFIC, 2004. http://dx.doi.org/10.1142/9789812702999_0038.

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Neundorf, Dörte. "Van-der-Waals-interaction constant." In The 13th international conference on spectral line shapes. AIP, 1997. http://dx.doi.org/10.1063/1.51852.

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Liu, Chang-Hua. "van der Waals materials integrated nanophotonics." In Plasmonics: Design, Materials, Fabrication, Characterization, and Applications XVIII, edited by Takuo Tanaka and Din Ping Tsai. SPIE, 2020. http://dx.doi.org/10.1117/12.2567598.

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Reports on the topic "Van der Waals frequencies"

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Klots, C. E. (Physics and chemistry of van der Waals particles). Office of Scientific and Technical Information (OSTI), October 1990. http://dx.doi.org/10.2172/6608231.

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Mak, Kin Fai. Understanding Topological Pseudospin Transport in Van Der Waals' Materials. Office of Scientific and Technical Information (OSTI), May 2021. http://dx.doi.org/10.2172/1782672.

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Kim, Philip. Nano Electronics on Atomically Controlled van der Waals Quantum Heterostructures. Fort Belvoir, VA: Defense Technical Information Center, March 2015. http://dx.doi.org/10.21236/ada616377.

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Sandler, S. I. The generalized van der Waals theory of pure fluids and mixtures. Office of Scientific and Technical Information (OSTI), June 1990. http://dx.doi.org/10.2172/6382645.

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Sandler, S. I. (The generalized van der Waals theory of pure fluids and mixtures). Office of Scientific and Technical Information (OSTI), September 1989. http://dx.doi.org/10.2172/5610422.

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O'Hara, D. J. Molecular Beam Epitaxy and High-Pressure Studies of van der Waals Magnets. Office of Scientific and Technical Information (OSTI), August 2019. http://dx.doi.org/10.2172/1562380.

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Menezes, W. J. C., and M. B. Knickelbein. Metal cluster-rare gas van der Waals complexes: Microscopic models of physisorption. Office of Scientific and Technical Information (OSTI), March 1994. http://dx.doi.org/10.2172/10132910.

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Gwo, Dz-Hung. Tunable far infrared laser spectroscopy of van der Waals bonds: Ar-NH sub 3. Office of Scientific and Technical Information (OSTI), November 1989. http://dx.doi.org/10.2172/7188608.

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French, Roger H., Nicole F. Steinmetz, and Yingfang Ma. Long Range van der Waals - London Dispersion Interactions For Biomolecular and Inorganic Nanoscale Assembly. Office of Scientific and Technical Information (OSTI), March 2018. http://dx.doi.org/10.2172/1431216.

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Busarow, K. L. Tunable far infrared laser spectroscopy of Van der Waals molecules in a planar supersonic jet expansion. Office of Scientific and Technical Information (OSTI), December 1990. http://dx.doi.org/10.2172/5610416.

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