Articles de revues : « Compound Nucleus Formation probability »

1

Wang, N., et M. Liu. « Extraction of probability of compound-nucleus formation ». Nuclear Physics A 834, n^o 1-4 (mars 2010) : 212c—216c. http://dx.doi.org/10.1016/j.nuclphysa.2009.12.043.

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Budaca, R., A. Sandulescu et M. Mirea. « Quasifission mass distributions in the synthesis of 274Hs with 26Mg and 36S projectiles ». Modern Physics Letters A 30, n^o 26 (13 août 2015) : 1550129. http://dx.doi.org/10.1142/s0217732315501291.

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The potential energy landscape for the [Formula: see text] synthesis is evaluated in the framework of the macroscopic–microscopic model. The fragmentation potential calculated in a configuration space characterized by five degrees of freedom associated to elongation, mass asymmetry, necking, and left/right deformations reveals the existence of several minima and some pronounced valleys. The valleys correspond mainly to the [Formula: see text] and [Formula: see text] quasifission channels, but also for some paths in the formation of the compound nuclear system. In this context, two different paths are obtained for the [Formula: see text] and [Formula: see text] entrance channels. The [Formula: see text] path leads to the formation of an isomeric minimum that decays by fission. The [Formula: see text] path evidences a larger probability for the formation of the compound nucleus. Therefore, the two distributions obtained for the associated quasifission processes are very different.

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Albertsson, Martin, B. Gillis Carlsson, Thomas Døssing, Jørgen Randrup, Dirk Rudolph et Sven Åberg. « Formation of ²⁵⁸Rf in drift plus diffusion dynamics ». EPJ Web of Conferences 306 (2024) : 01014. http://dx.doi.org/10.1051/epjconf/202430601014.

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We present calculations on the formation of 258Rf in the reaction 50Ti+208Pb within the Langevin framework. The initital stage after contact of the colliding nuclei is dominated by a drift in the center-of-mass direction, while the subsequent process of forming a compound nucleus is diffusion dominated. The probability for the composite system to diffuse over the inner saddle is obtained by performing Metropolis random walks in a five-dimensional potential-energy landscape.

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Maydanyuk, Sergei P., Gyorgy Wolf et Kostiantyn A. Shaulsky. « Synthesis of Elements in Compact Stars in Pycnonuclear Reactions with Carbon Isotopes : Quasibound States vs. States of Zero-Points Vibrations ». Universe 9, n^o 8 (29 juillet 2023) : 354. http://dx.doi.org/10.3390/universe9080354.

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(1) Purpose: Conditions of formation of compound nuclear systems needed for synthesis of heavy nuclei in pycnonuclear reactions in compact stars are studied on a quantum mechanical basis. (2) Methods: The method of multiple internal reflections is applied for pycnonuclear reactions in compact stars with new calculations of quasibound spectra and spectra of zero-point vibrations. (3) Results: Peculiarities of the method are analyzed for reaction with isotopes of Carbon. The developed method takes into account continuity and conservation of quantum flux (describing pycnonuclear reaction) inside the full spacial region of reaction, including the nuclear region. This gives the appearance of new states (called quasibound states) in which compound nuclear systems of Magnesium are formed with the largest probability. These states have not been studied yet in synthesis of elements in stars. Energy spectra of zero-point vibrations and spectra of quasibound states are estimated with high precision for reactions with isotopes of Carbon. For the first time, the influence of plasma screening on quasibound states and states of zero-point vibrations in pycnonuclear reactions has been studied. (4) Conclusions: The probability of formation of a compound nucleus in quasibound states in pycnonuclear reaction is essentially larger than the probability of formation of this system in states of zero-point vibrations studied by Zel’dovich and followers. Therefore, synthesis of Magnesium from isotopes of Carbon is more probable through the quasibound states than through the states of zero-point vibrations in compact stars. Energy spectra of zero-point vibrations are changed essentially after taking plasma screening into account. Analysis shows that from all studied isotopes of Magnesium, only 24Mg is stable after synthesis at an energy of relative motion of 4.881 MeV of the incident nuclei 12C.

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NASIROV, AVAZBEK, GIORGIO GIARDINA, GIUSEPPE MANDAGLIO, MARINA MANGANARO et AKHTAM MUMINOV. « MECHANISMS PRODUCING FISSIONLIKE BINARY FRAGMENTS IN HEAVY ION COLLISIONS ». International Journal of Modern Physics E 19, n^o 05n06 (juin 2010) : 997–1008. http://dx.doi.org/10.1142/s0218301310015448.

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The mixing of the quasifission component to the fissionlike cross section causes ambiguity in the quantitative estimation of the complete fusion cross section from the observed angular and mass distributions of the binary products. We show that the partial cross section of quasifission component of binary fragments covers the whole range of the angular momentum values leading to capture. The calculated angular momentum distributions for the compound nucleus and dinuclear system going to quasifission may overlap: competition between complete fusion and quasifission takes place at all values of initial orbital angular momentum. Quasifission components formed at large angular momentum of the dinuclear system can show isotropic angular distribution and their mass distribution can be in mass symmetric region similar to the characteristics of fusion-fission components. As result the unintentional inclusion of the quasifission contribution into the fusion-fission fragment yields can lead to overestimation of the probability of the compound nucleus formation.

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Li, Ning, et Wei Zeng Chen. « Investigation and Simulation on Amorphous Formation and Growth ». Applied Mechanics and Materials 138-139 (novembre 2011) : 727–31. http://dx.doi.org/10.4028/www.scientific.net/amm.138-139.727.

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The amorphous formation mechanism was studied from the viewpoint of the crystallography. The experimental results showed that the heterogeneity atoms with chemical bonds had a higher capability of forming into compounds than that of congener atoms. It was proposed that the banded structure was induced by the variation of active atoms with a proper thickness, alternated depletion and enrichment of anions in the diffusion layer due to generation and evolution of hydrogen gas. The chemical force plays an important part in the formation. The factors working on chemical reaction affect the formation in the same. A number of steady motes are in a high speed movement, and collide with each other in all probability. The formation of amorphous alloys is the result of massive nucleus appearance, which was proposed from the crystallography in this paper. The cause of the chaotic distribution is of the suppression of each nucleus growth. The short-range order atomic structure is of the atomic nucleus growth orientation. And the long-range disorder structure is of the massive nucleus suppression growth.

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Li, Ning, et Wei Zeng Chen. « Investigation and Simulation on Amorphous Formation and Growth ». Advanced Materials Research 346 (septembre 2011) : 136–40. http://dx.doi.org/10.4028/www.scientific.net/amr.346.136.

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The amorphous formation mechanism was studied from the viewpoint of the crystallography. The experimental results showed that the heterogeneity atoms with chemical bonds had a higher capability of forming into compounds than that of congener atoms. It was proposed that the banded structure was induced by the variation of active atoms with a proper thickness, alternated depletion and enrichment of anions in the diffusion layer due to generation and evolution of hydrogen gas. The chemical force plays an important part in the formation. The factors working on chemical reaction affect the formation in the same. A number of steady motes are in a high speed movement, and collide with each other in all probability. The formation of amorphous alloys is the result of massive nucleus appearance, which was proposed from the crystallography in this paper. The cause of the chaotic distribution is of the suppression of each nucleus growth. The short-range order atomic structure is of the atomic nucleus growth orientation. And the long-range disorder structure is of the massive nucleus suppression growth.

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Ansari, Ahmad, et Nader Ghahramany. « Production cross-sections of superheavy elements using nearly double magic nuclei as projectile ». International Journal of Modern Physics E 26, n^o 07 (juillet 2017) : 1750050. http://dx.doi.org/10.1142/s0218301317500501.

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In our new approach, evaporation residue cross-sections for new superheavy nuclei with atomic numbers [Formula: see text] are estimated by calculation of vital characteristics of superheavy nuclei synthesis such as the fission barrier height, the compound nucleus formation probability and the survival probability of the residue nuclei. Our presented estimation is in good agreement with available experimental data. In addition, this new approach allowed us to predict the evaporation residue cross-sections for superheavy nuclei with [Formula: see text] and 120 via introducing synthesis box and compare our results with other models. It is shown that the fission barrier heights of two nuclei with [Formula: see text] and 120 are comparable with their corresponding neutron separation energies. It is suggested that for the synthesis of new superheavy nuclei, it is proper to use nearly double magic nuclei such as [Formula: see text] as our projectile, so that the fission barrier heights remain high.

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Khuukhenkhuu, Gonchigdorj, Myagmarjav Odsuren, Yury Gledenov, Guohui Zhang, Battur Batchimeg, Jargalsaikhan Munkhsaikhan, Chinzorig Saikhanbayar, Enkhbold Sansarbayar et Milana Sedysheva. « An evaluation of the alpha-cluster formation factor in (n, α) reactions ». EPJ Web of Conferences 239 (2020) : 03007. http://dx.doi.org/10.1051/epjconf/202023903007.

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In this work we suggest some methods based on the statistical and knock-on models, for evaluation of the α-clustering factor or α-clustering probability in (n, α) reactions induced by slow and fast neutrons. The main purpose of this study is to compare the values of the α-clustering factors obtained by the compound and direct mechanisms for the same nuclear reactions. Also, our results are compared with values estimated by other authors.

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Macías, Mario A., Nerith-Rocio Elejalde, Estefanía Butassi, Susana Zacchino et Jaime Portilla. « Studies via X-ray analysis on intermolecular interactions and energy frameworks based on the effects of substituents of three 4-aryl-2-methyl-1H-imidazoles of different electronic nature and their in vitro antifungal evaluation ». Acta Crystallographica Section C Structural Chemistry 74, n^o 11 (23 octobre 2018) : 1447–58. http://dx.doi.org/10.1107/s2053229618014109.

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The crystal structures of 2-methyl-4-phenyl-1H-imidazole, C10H10N2, (3a), 4-(4-chlorophenyl)-2-methyl-1H-imidazole hemihydrate, C10H9ClN2·0.5H2O, (3b), and 4-(4-methoxyphenyl)-2-methyl-1H-imidazole, C11H12N2O, (3c), have been analyzed. It was found that the electron-donating/withdrawing tendency of the substituent groups in the aryl ring influence the acid–base properties of the 2-methylimidazole nucleus, changing the strength of the intermolecular N—H...N interactions. This behaviour not only influences the crystal structure but also seems to have an important effect on the antifungal activity. Considering the substituent groups, that is, H in (3a), Cl in (3b) and OMe in (3c), the formation of strong N—H...N connections has the probability (3a) > (3b) > (3c), while compound (3c) proves to be more active than (3a) and (3b) at all concentrations against C. neoformans.

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11

Shaulskyi, K. A., et S. P. Maydanyuk. « Quantum design in the study of pycnonuclear reactions in compact stars and new quasibound states ». Nuclear Physics and Atomic Energy 24, n^o 2 (25 juin 2023) : 93–105. http://dx.doi.org/10.15407/jnpae2023.02.093.

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Quantum effects in pycnonuclear reactions in compact stars at zero temperatures are studied with high precision. The reaction 16O + 16O was analyzed using the method of multiple internal reflections. The study of such reactions requires full consideration of quantum fluxes in the internal nuclear region. This reduces the rate and number of pycnonuclear reactions up to 1.8 times. This leads to the appearance of new states (which we call quasibound states) where the compound nuclear system is formed with maximal probability. As shown, the minimal energy of such a state is slightly higher than the energy of zero-mode oscillations in the lattice nodes in the pycnonuclear reaction, however, the probability of the formation of a compound system in a quasibound state is significantly greater than the corresponding probability in a state of zero-mode oscillations. It is reasonable to say that the frequency of reactions in quasi-bound states is more likely than in states of zero-mode oscillations. This can lead to significant changes in estimates of reaction rates in stars.

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12

Pahlavani, M. R., et S. A. Alavi. « Effects of level density parameter on the superheavy production in cold fusion ». Modern Physics Letters A 29, n^o 40 (28 décembre 2014) : 1450214. http://dx.doi.org/10.1142/s0217732314502149.

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By using semiclassical method and considering Woods–Saxon and Coulomb potentials, the level density parameter a was calculated for three superheavy nuclei 270110, 278112 and 290116. Obtained results showed that the value of level density parameter of these nuclei is near to the simple relation a ≈ A/10. In framework of the dinuclear system model, the effects of level density parameter on the probability of the formation of a compound nucleus, the ratio of neutron emission width and fission width, and evaporation residue cross-section of three cold fusion reactions 62 Ni +208 Pb , 70 Zn +208 Pb and 82 Se +208 Pb , leading to superheavy elements were investigated. The findings indicate that the level density parameter play a significant role in calculations of heavy-ion fusion–fission reactions. The obtained results in the case of a = A/12 have larger values in comparison with calculated level density parameter with Woods–Saxon potential (a WS ) and a = A/10. The theoretical results of the evaporation residue cross-section are very sensitive to the choice of level density parameter. The calculated values with a WS are in good agreement with experimental values.

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Gonzalez Carmona, Juan Manuel, Alexander Ruden Muñoz, Christian Barbosa, Carolina Ortega Portilla et Federico Sequeda Osorio. « Computational Study of Allotropic Structures of Carbon by Density Functional Theory (DTF) ». Ingeniería y Ciencia 10, n^o 19 (janvier 2014) : 145–62. http://dx.doi.org/10.17230/ingciencia.10.19.7.

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In this paper using Density Functional Theory (DFT), the principal carbonallo tropic crystalline structures (Diamond, graphite, nanotube y fullerene-C60) were simulated. The results shows diamond sp3 bonds formation between carbon atomsand low reactivity, indicating low probability of lateral compound formation and high mechanical properties. Interplanar weakness was evidentin graphite structure, which is related to solid lubrication process. Carbon-Carbon metallic bonds and polarizations at the edges of the structure were observed in Armchair Carbon Nanotube, stabilizing the system which allows the nanotube continuous growth. In fullerene C60structureaFaraday nano-gauge behavior was confirmed, together withlowprobability of interatomic polarization, indicating high structural stability. Besides Total Energy (TE) and Nuclear Repulsion Energy (NRE) values were used to perform energetic comparisons between different structures, allowing the study of electronic stability and their relationship to mechanical properties.

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Yuhara, Daisuke, Brian C. Barnes, Donguk Suh, Brandon C. Knott, Gregg T. Beckham, Kenji Yasuoka, David T. Wu et Amadeu K. Sum. « Nucleation rate analysis of methane hydrate from molecular dynamics simulations ». Faraday Discussions 179 (2015) : 463–74. http://dx.doi.org/10.1039/c4fd00219a.

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Clathrate hydrates are solid crystalline structures most commonly formed from solutions that have nucleated to form a mixed solid composed of water and gas. Understanding the mechanism of clathrate hydrate nucleation is essential to grasp the fundamental chemistry of these complex structures and their applications. Molecular dynamics (MD) simulation is an ideal method to study nucleation at the molecular level because the size of the critical nucleus and formation rate occur on the nano scale. Various analysis methods for nucleation have been developed through MD to analyze nucleation. In particular, the mean first-passage time (MFPT) and survival probability (SP) methods have proven to be effective in procuring the nucleation rate and critical nucleus size for monatomic systems. This study assesses the MFPT and SP methods, previously used for monatomic systems, when applied to analyzing clathrate hydrate nucleation. Because clathrate hydrate nucleation is relatively difficult to observe in MD simulations (due to its high free energy barrier), these methods have yet to be applied to clathrate hydrate systems. In this study, we have analyzed the nucleation rate and critical nucleus size of methane hydrate using MFPT and SP methods from data generated by MD simulations at 255 K and 50 MPa. MFPT was modified for clathrate hydrate from the original version by adding the maximum likelihood estimate and growth effect term. The nucleation rates calculated by MFPT and SP methods are within 5%, and the critical nucleus size estimated by the MFPT method was 50% higher, than values obtained through other more rigorous but computationally expensive estimates. These methods can also be extended to the analysis of other clathrate hydrates.

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Nilsson, E. D., et M. Kulmala. « Aerosol formation over the Boreal forest in Hyytiälä, Finland : monthly frequency and annual cycles – the roles of air mass characteristics and synoptic scale meteorology ». Atmospheric Chemistry and Physics Discussions 6, n^o 5 (18 octobre 2006) : 10425–62. http://dx.doi.org/10.5194/acpd-6-10425-2006.

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Abstract. New atmospheric particles with diameters of 3–10 nm and their subsequent growth to cloud condensation nucleus have been observed at various places in the European boundary layer. These events have been observed simultaneously within wide geographical areas (over 1000 km) in connection to specific weather systems, the cold air behind cyclones. Here we show that atmospheric aerosol formation (i.e. nucleation and initial growth) is favoured by the outbreak of cold Arctic air over northern Europe. Aerosol formation was about twice as common in Arctic air as in sub-Polar air, and even more so compared to other air masses. The most important general factor favouring aerosol formation in Arctic air and marine air was weaker competing condensational sink (CS) for the precursor gases (less pre-existing aerosols), while high CS prevented aerosol formation in heated sub-Polar air and mid-latitude air. High SO2 levels favoured nucleation in continental air and high UV-B radiation in sub-tropical air. The critical factor that determined if aerosol formation would start on a day with Arctic air was the UV-B radiation. The same applied to sub-Polar air and continental air, while increased SO2 concentration could trigger formation in heated sub-Polar and mid-latitude air, and reduced CS could cause formation in mid-latitude, marine or mixed/transient air. We speculate that strong emissions of volatile organic compounds from the Boreal forest and strong boundary layer dynamics may have caused aerosol formation in sub-Polar air masses and air in transition from a marine to a continental character. The monthly frequency of Arctic air masses and the probability for photo-chemically driven aerosol formation explains the observed annual cycle in monthly particle formation frequency as well as much of the inter annual variability. The same cyclones that transport cold, clean air from the Arctic to Europe will also transport warm polluted air in the other direction, which help cause the Arctic Haze phenomena. The cyclones have a key role for the atmospheric aerosol life cycle in mid to high latitudes. Due to the observed growth to the size of CCN in one to two days, there is a potential feed back from the effects on the CCN population and cloud albedo even within the same weather system, but also on the climatic time scale.

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Yeremin, A. V. « Regularities of formation and survival probability of compound nuclei in the region of Z ≥ 82 : Study of complete-fusion reactions with heavy ions using the kinematic separator VASSILISSA ». Physics of Particles and Nuclei 38, n^o 4 (juillet 2007) : 492–524. http://dx.doi.org/10.1134/s1063779607040041.

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Sano, M., M. Wakai et Y. Yamamoto. « Formation and Fragmentation of Double- Compound Nucleus ». Progress of Theoretical Physics 87, n^o 4 (1 avril 1992) : 957–67. http://dx.doi.org/10.1143/ptp/87.4.957.

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Yamamoto, Y., M. Sano et M. Wakai. « Formation and Fragmentation of Double- Compound Nucleus ». Progress of Theoretical Physics Supplement 117 (17 mai 2013) : 265–79. http://dx.doi.org/10.1143/ptp.117.265.

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19

Katsuma, Masahiko. « Carbon burning rates on the compound nucleus formation ». EPJ Web of Conferences 260 (2022) : 11014. http://dx.doi.org/10.1051/epjconf/202226011014.

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The 12C+12C reaction rates based on the compound nucleus formation seem to be concordant with the standard rates. The resonant contribution in 12C+12C is also discussed. To put the rates on firm ground, the resonances below Ec.m. = 3 MeV will have to be studied further.

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Carlson, B. V., F. T. Dalmolin, M. Dutra, T. J. Santos, S. R. Souza et R. Donangelo. « Formation and decay of a hot compound nucleus ». EPJ Web of Conferences 69 (2014) : 00012. http://dx.doi.org/10.1051/epjconf/20136900012.

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Yamamoto, Yasuo, Mitsuo Sano et Masamichi Wakai. « Formation and Fragmentation of Double-Λ Compound Nucleus ». Progress of Theoretical Physics Supplement 117 (1994) : 265–79. http://dx.doi.org/10.1143/ptps.117.265.

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Deppman, A., J. D. T. Arruda-Neto, E. De Sanctis et N. Bianchi. « Clustering-related aspects in the compound nucleus formation ». Il Nuovo Cimento A 109, n^o 8 (août 1996) : 1197–205. http://dx.doi.org/10.1007/bf02798822.

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Suzuki, Takakazu. « The influence of total pressure in the reactor and carrier gas on the chemical vapor deposition of Al from tri-isobutyl aluminum ». Journal of Materials Research 12, n^o 7 (juillet 1997) : 1866–71. http://dx.doi.org/10.1557/jmr.1997.0256.

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The influence of total pressure in the chamber and carrier gases on the chemical vapor deposition of aluminum using tri-isobutyl aluminum was studied. The superior penetrability of chemical vapor deposition is expected to make it effective for aluminum deposition onto complex-shaped materials such as turbo-charger rotors, fibrous preform, and multifilament. It may also be a suitable method for the development of fiber-reinforced composite materials. The apparatus was composed of a raw material gas supply system, a three-zone electric furnace, a reaction chamber, an auto pressure controller, and an exhaust system. Aluminum was deposited onto a graphite fiber in the quartz reactor. The results show that, in the diffusion rate-determining stage of aluminum thermal decomposition, the rate of deposition for aluminum shows a marked increase as the pressure increases; in contrast, in the reaction rate-determining stage, this tendency is limited. This can be explained by the fact that, as the total pressure decreases, the gas diffusion coefficient becomes larger, and there is an increase in the uniformity of film formation. On the other hand, as the carrier gas flow rate increases, the amount of raw material supplied increases; consequently, a higher rate of deposition is obtained. Moreover, in the diffusion rate-determining stage, there is a tendency for an increase in flow rate to elevate the probability of arrival of the raw material, and, in combination with high temperatures, for nucleus generation to be accelerated and the average diameter of aluminum granules to become smaller. In the reaction rate-determining stage, there appears to be hardly any dependency of granule diameter on the flow rate. When Ar or He is used as the carrier gas, under the same conditions argon, rather than helium, is seen to increase the rate of deposition.

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Liang, J. F., J. D. Bierman, M. P. Kelly, A. A. Sonzogni, R. Vandenbosch et J. P. S. van Schagen. « Dissipative effects in the formation of the156Er compound nucleus ». Physical Review C 56, n^o 2 (1 août 1997) : 908–17. http://dx.doi.org/10.1103/physrevc.56.908.

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Bian, Bao-An, Feng-Shou Zhang et Hong-Yu Zhou. « Entrance channel mass asymmetry dependence of compound nucleus formation ». Physics Letters B 665, n^o 4 (juillet 2008) : 314–17. http://dx.doi.org/10.1016/j.physletb.2008.06.006.

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ŚWIATECKI, W. J., K. SIWEK-WILCZYŃSKA et J. WILCZYŃSKI. « CALCULATIONS OF CROSS SECTIONS FOR THE SYNTHESIS OF SUPER-HEAVY NUCLEI IN COLD FUSION REACTIONS ». International Journal of Modern Physics E 13, n^o 01 (février 2004) : 261–67. http://dx.doi.org/10.1142/s021830130400203x.

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The fusion cross sections are considered to be given by the product of three factors: the cross section to overcome the Coulomb barrier, the probability for the resulting system to reach the compound nucleus configuration by diffusion, and the probability for the compound nucleus to survive fission. The first and third factors are treated by more or less conventional equations, and the second by Brownian diffusion in one dimension. Adjusting one free parameter in the theory one can reproduce the twelve measured cross sections to within a factor of two.

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BIAN, BAO-AN, FENG-SHOU ZHANG et SAI-SAI DU. « SHELL CORRECTION ENERGY AND THE ENTRANCE CHANNEL EFFECT ON THE FORMATION OF SUPERHEAVY NUCLEI ». International Journal of Modern Physics E 17, supp01 (décembre 2008) : 80–96. http://dx.doi.org/10.1142/s021830130801177x.

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Based on the improved isospin dependent molecular dynamics model in which the shell correction energy of the system is calculated by using deformed two-center shell model and the surface energy of the system is improved by introducing a switch function that combines the surface energies of projectile and target with the one of the compound nucleus. The effects of the shell correction energy on synthesis of superheavy nuclei and the fusion cross sections in asymmetric and nearly symmetric reaction systems leading to the same compound nuclei 62 Zn , 76 Kr , and 202 Pb are studied. The entrance channel mass asymmetry dependence of compound nucleus formation is found by analyzing the shell correction energies, Coulomb barriers and fusion cross sections. The experimental data are described quantitatively by the present model. It is found that the compound nucleus formation is favorable for the systems with larger mass asymmetry.

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Chopra, Sahila, Arshdeep Kaur et Raj K. Gupta. « Compound nucleus formation probabilityPCNdefined within the dynamical cluster-decay model ». EPJ Web of Conferences 86 (2015) : 00006. http://dx.doi.org/10.1051/epjconf/20158600006.

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Antonenko, N. V., E. A. Cherepanov, A. K. Nasirov, V. P. Permjakov et V. V. Volkov. « Compound nucleus formation in reactions between massive nuclei : Fusion barrier ». Physical Review C 51, n^o 5 (1 mai 1995) : 2635–45. http://dx.doi.org/10.1103/physrevc.51.2635.

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Yamazaki, Toshimitsu, et Hirokazu Tamura. « Double-lambda compound nucleus and the formation of double hypernuclei ». Czechoslovak Journal of Physics 42, n^o 11 (novembre 1992) : 1137–42. http://dx.doi.org/10.1007/bf01591398.

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Blocki, J. P., H. Feldmeier et W. J. Swiatecki. « Dynamical hindrance to compound-nucleus formation in heavy-ion reactions ». Nuclear Physics A 459, n^o 1 (octobre 1986) : 145–72. http://dx.doi.org/10.1016/0375-9474(86)90061-8.

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Van Geertruyden, A., et Ch Leclercq-Willain. « Compound nucleus formation, fast fission phenomena and deep inelastic reactions ». Nuclear Physics A 459, n^o 1 (octobre 1986) : 173–95. http://dx.doi.org/10.1016/0375-9474(86)90062-x.

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van Geertruyden, A., et Ch Leclercq-Willain. « Compound nucleus formation, fast fission phenomena and deep inelastic reactions ». Nuclear Physics A 459, n^o 1 (octobre 1986) : 196–226. http://dx.doi.org/10.1016/0375-9474(86)90063-1.

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Bezzina, L. T., E. C. Simpson, D. J. Hinde et M. Dasgupta. « Observation of suppression of heavy-ion fusion by slow quasifission ». EPJ Web of Conferences 306 (2024) : 01029. http://dx.doi.org/10.1051/epjconf/202430601029.

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The formation of superheavy elements (SHEs) by nuclear fusion can be conceptually divided into two steps: capture, and compound nucleus formation. Once captured, the two nuclei may reseparate before fusing to form a compact compound nucleus. This outcome is called quasifission. Fusion-fission, in many cases, leads to reactions outcomes inseparable from quasifission. Evaporation residue (ER) measurements are therefore the most reliable, direct experimental signature of fusion. ER cross section measurements forming the same compound nucleus, 220Th, using 16O, 40Ar, 48Ca, 82Se and 124Sn-induced reactions [1–4] revealed [1] that fusion was severely suppressed for the more symmetric reactions relative to the 16O-induced reaction. Here two new reactions forming 220Th using 28Si, 34S projectiles provide conclusive evidence that the ER cross section is exponentially suppressed as a function of ZpZt. The fission characteristics show no mass-angle correlation, demonstrating that here ER cross sections are suppressed by slow quasifission.

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Sun, Jie, Le Xin Zhou, Xiao Hong Li et Ming Xia. « Preparation and Property of Antibacterial Nucleus with the Combination of Nano-Silver and Antibiotics ». Key Engineering Materials 905 (4 janvier 2022) : 282–87. http://dx.doi.org/10.4028/www.scientific.net/kem.905.282.

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To improve the yield and quality of pearls in freshwater pearl culture and the survival rates after nucleus implanting surgery, pearl farmers used artificial pearl nuclear transplantation techniques to raise pearls. To address the common problem of Staphylococcus aureus and Escherichia coli infection in oyster farming, a new prophylactic method by using compound antibiotics to prepare the medicine coated pearl nucleus was put forward based on existing research results of the nanosilver antibacterial nucleus. Single-factor experiment, multi-factor experiment, orthogonal experiment, SPSS analysis of variance was used to optimize the antibacterial formulation on the assumption that the contaminated probability of these two pathogenic bacteria was the same. The result showed that the optimal ratio of compound antibiotics was 0.0075g/ml of the flavomycin solution and 0.01g/mL of the terramycin solution; the inhibition zones diameter of both pathogenic bacteria was more than 2.6cm in vitro, which was higher than the nanosilver antibacterial nucleus of 0.9cm in vitro. Indicating that the addition of this compound antibiotic formula for the nanosilver antibacterial nucleus could reduce the usage of antibiotics under the premise of maintaining antibacterial effectiveness, and could preferably inhibit the pathogenic microorganisms in the postoperative infection period. This also indicates that compound antibiotics coated antibacterial nanosilver nucleus would be applied more widely.

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Antonenko, N. V., et R. V. Jolos. « Mechanism of enhanced yield of light particles in compound nucleus formation ». Zeitschrift f�r Physik A : Hadrons and Nuclei 339, n^o 4 (décembre 1991) : 453–63. http://dx.doi.org/10.1007/bf01288429.

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D’ARRIGO, A., G. GIARDINA, A. LAMBERTO, D. O. EREMENKO, O. V. FOTINA, S. Yu PLATONOV, O. A. YUMINOV et F. MALAGUTI. « THE PROBABILITY OF POPULATING THE SECOND POTENTIAL WELL STATES IN FISSION DYNAMICS ». International Journal of Modern Physics E 04, n^o 02 (juin 1995) : 443–55. http://dx.doi.org/10.1142/s021830139500016x.

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We study the probability of populating the second well states in the de-excitation of the compound nucleus during the competition between fission and emission of light particles. We consider the cases of underdamped and overdamped fission processes caused by a different influence of nuclear dissipation. The probability dependencies on the second well depth and the excitation energy are also analyzed.

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Nicolis, N. G., J. L. Barreto, D. G. Sarantites, R. J. Charity, L. G. Sobotka, D. W. Stracener, D. C. Hensley et al. « Decay of 160Er* in 16O + 144Nd and 64Ni + 96Zr Fusion Reactions ». HNPS Proceedings 7 (5 décembre 2019) : 137. http://dx.doi.org/10.12681/hnps.2410.

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The population of evaporation residue entry states in the decay of the compound nucleus 160Er*(54 MeV) is investigated in a cross-bombardment employing the reactions 160 + 144Nd and 64Ni + 96Zr. Evaporation residue cross sections and entry state 7-ray fold distributions of the dominant exit channels were obtained for each reaction, using a 4π 7-ray detection system. An entrance-channel dependence of the 7-ray fold distributions of the xn products is observed. This effect is described successfully by the statistical model making use of compound nucleus angular momentum distributions obtained with a fusion model that provides a good description of the bombarding energy dependence of fusion data for both reactions. In accordance with recent findings on the decay of 164Yb*, it is suggested that the observed differences in the population of the dominant exit channels originate from the primary spin distributions rather than a possible dependence of the compound nucleus decay on the formation mode.

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AGGARWAL, MAMTA. « NEUTRON EMISSION SPECTRA AND LEVEL DENSITY OF HOT ROTATING 132Sn ». International Journal of Modern Physics E 17, n^o 06 (juin 2008) : 1091–105. http://dx.doi.org/10.1142/s0218301308010295.

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The neutron emission spectrum of the highly excited compound nuclear system 132 Sn is investigated at high spin. The doubly magic nucleus 132 Sn undergoes a shape transition at high angular momentum which affects the nuclear level density and neutron emission probability considerably. The interplay of temperature, shape, deformation and rotational degrees of freedom and their influence on neutron emission is emphasized. We predict an enhancement of nucleonic emission at those spins where the nucleus suffers a transition from a spherical to deformed shape.

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Yan, Xinlin, Shi Hou, Cheng Xing, Yuanyuan Zhang, Jiajia Chang, Junhai Xiao et Feng Lin. « Design, Synthesis, and Biological Evaluation of the Quorum-Sensing Inhibitors of Pseudomonas aeruginosa PAO1 ». Molecules 29, n^o 10 (8 mai 2024) : 2211. http://dx.doi.org/10.3390/molecules29102211.

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Due to the resistance of Gram-negative bacteria Pseudomonas aeruginosa PAO1 to most clinically relevant antimicrobials, the use of traditional antibiotic treatments in hospitals is challenging. The formation of biofilms, which is regulated by the quorum-sensing (QS) system of Pseudomonas aeruginosa (PA), is an important cause of drug resistance. There are three main QS systems in P. aeruginosa: the las system, the rhl system, and the pqs system. The inhibitors of the las system are the most studied. Previously, the compound AOZ-1 was found to have a certain inhibitory effect on the las system when screened. In this study, twenty-four compounds were designed and synthesized by modifying the Linker and Rings of AOZ-1. Using C. violaceum CV026 as a reporter strain, this study first assessed the inhibitory effects of new compounds against QS, and their SAR was investigated. Then, based on the SAR analysis of compound AOZ-1 derivatives, the parent core of AOZ-1 was replaced to explore the structural diversity. Then, nine new compounds were designed and synthesized with a new nucleus core component of 3-amino-tetrahydro-l,3-oxazin-2-one. The compound Y-31 (IC50 = 91.55 ± 3.35 µM) was found to inhibit the QS of C. violaceum CV026. Its inhibitory effect on C. violaceum CV026 was better than that of compound AOZ-1 (IC50 > 200 µM). Furthermore, biofilm formation is one of the important causes of Pseudomonas aeruginosa PAO1 resistance. In this study, it was found that compound Y-31, with a new nucleus core component of 3-amino-tetrahydro-l,3-oxazin-2-one, had the highest biofilm inhibition rate (40.44%). The compound Y-31 has a certain inhibitory effect on the production of PAO1 virulence factors (pyocyanin, rhamnolipid, and elastase) and swarming. When the concentration of compound Y-31 was 162.5 µM, the inhibition rates of pyocyanin, rhamnolipid, and elastase were 22.48%, 6.13%, and 22.67%, respectively. In vivo, the lifetime of wildtype Caenorhabditis elegans N2 infected with P. aeruginosa PAO1 was markedly extended by the new parent nucleus Y-31. This study also performed cytotoxicity experiments and in vivo pharmacokinetics experiments on the compound Y-31. In conclusion, this study identified a compound, Y-31, with a new nucleus core component of 3-amino-tetrahydro-l,3-oxazin-2-one, which is a potential agent for treating P. aeruginosa PAO1 that is resistant to antibiotics and offers a way to discover novel antibacterial medications.

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SIWEK-WILCZYŃSKA, K., I. SKWIRA et J. WILCZYŃSKI. « SHELL CORRECTION ENERGIES IN CALCULATIONS OF THE SURVIVAL PROBABILITY ». International Journal of Modern Physics E 14, n^o 03 (avril 2005) : 333–39. http://dx.doi.org/10.1142/s0218301305003089.

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Analysis of existing data on experimental fission barriers for about 90 nuclei shows that the shell correction energy practically vanishes at the barrier configuration. Statistical model calculations, with shell effects accounted for by the Ignatyuk formula, were carried out for the decay of the 248 Cf compound nucleus assuming the ground state shell corrections of Möller et al., and the vanishing shell correction energy at the barrier. The results are consistent with existing experimental data on fusion- and xn evaporation-residue cross sections in the 12 C +236 U reaction.

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Shabanova, Galina, Victoria Taranenkova, Oksana Myrgorod et Oleksandr Pirohov. « On the Existence of Ternary Compounds in the CaO-BaO-Al<sub>2</sub>O<sub>3</sub> ; System ». Materials Science Forum 1100 (19 octobre 2023) : 129–38. http://dx.doi.org/10.4028/p-mkga4l.

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In this article in order to verify the probability of the formation of the compound CaBaAl4O8, a thermodynamic analysis of the following possible solid-phase reactions of its formation was carried out: formation of CaBaAl4O8 from the initial components - calcium carbon dioxide, barium carbon dioxide and aluminum oxide; the probability of formation of dual compounds CaAl2O4 and BaAl2O4 from the same raw materials (since the compound CaBaAl4O8 is located on the BaAl2O4-CaAl2O4 conjugate) and the possibility of formation of the compound CaBaAl4O8 from binary compounds CaAl2O4 and BaAl2O4. As a result of our experimental studies, the existence of ternary compounds Вa3CaAl2O7 and ВaCa2Al8O15 was confirmed, and it was found that the Вa3CaAl2O7 compound exists in the system at least up to a temperature of 1400 °C. Thus, our studies have determined an increase in the temperature limits of its existence, in contrast to the data of previous researchers, who indicated 1250 °C as the upper temperature of existence of Вa3CaAl2O7.

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Volkov, V. V. « The mechanism of compound nucleus formation in complete fusion of two massive nuclei ». Physics of Atomic Nuclei 66, n^o 6 (juin 2003) : 1065–70. http://dx.doi.org/10.1134/1.1586419.

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Malhotra, Neelam, R. Aroumougame, D. R. Saroha et Raj K. Gupta. « Model for fusion and cool compound nucleus formation based on the fragmentation theory ». Physical Review C 33, n^o 1 (1 janvier 1986) : 156–64. http://dx.doi.org/10.1103/physrevc.33.156.

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Dietrich, F. S. « On the accuracy of techniques for determining neutron compound-nucleus formation cross sections ». EPJ Web of Conferences 2 (2010) : 01001. http://dx.doi.org/10.1051/epjconf/20100201001.

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Antonenko, N. V., et R. V. Jolos. « Mechanism of enhanced yield of light particles in compound nucleus formation : Diffusion description ». Zeitschrift f�ur Physik A Hadrons and Nuclei 341, n^o 4 (décembre 1992) : 459–63. http://dx.doi.org/10.1007/bf01301390.

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Khryachkov, Vitaly, Andrei Goverdovskii, Vladimir Ketlerov, Vecheslav Mitrofanov et Alexei Sergachev. « Investigation of the heavy nuclei fission with anomalously high values of the fission fragments total kinetic energy ». EPJ Web of Conferences 169 (2018) : 00011. http://dx.doi.org/10.1051/epjconf/201816900011.

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Binary fission of 232Th and 238U induced by fast neutrons were under intent investigation in the IPPE during recent years. These measurements were performed with a twin ionization chamber with Frisch grids. Signals from the detector were digitized for further processing with a specially developed software. It results in information of kinetic energies, masses, directions and Bragg curves of registered fission fragments. Total statistics of a few million fission events were collected during each experiment. It was discovered that for several combinations of fission fragment masses their total kinetic energy was very close to total free energy of the fissioning system. The probability of such fission events for the fast neutron induced fission was found to be much higher than for spontaneous fission of 252Cf and thermal neutron induced fission of 235U. For experiments with 238U target the energy of incident neutrons were 5 MeV and 6.5 MeV. Close analysis of dependence of fission fragment distribution on compound nucleus excitation energy gave us some explanation of the phenomenon. It could be a process in highly excited compound nucleus which leads the fissioning system from the scission point into the fusion valley with high probability.

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DU, SAI-SAI, et FENG-SHOU ZHANG. « ENTRANCE CHANNEL EFFECT AND FUSION CROSS SECTIONS IN THE SYNTHESIS OF HEAVY AND SUPERHEAVY NUCLEI ». International Journal of Modern Physics E 19, n^o 08n09 (septembre 2010) : 1603–15. http://dx.doi.org/10.1142/s0218301310016016.

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The entrance channel effect, mainly involved the mass asymmetry, the neutron-excess and the collision orientation of the combined system, are presented by summarizing the recent theoretical results about the fusion reactions leading to the same compound nuclei and the neutron-rich fusion reactions in the synthesis of heavy and superheavy nuclei through various models. It is concluded that the system with large mass asymmetry and neutron-rich nuclear reactions is favorable for the compound nucleus formation.

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Miura, Hitoshi, Seiji Yasuda et Taishi Nakamoto. « Fragment-collision model for compound chondrule formation : Estimation of collision probability ». Icarus 194, n^o 2 (avril 2008) : 811–21. http://dx.doi.org/10.1016/j.icarus.2007.11.005.

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Kurniadi, Rizal, Abdul Waris et Sparisoma Viridi. « Monte Carlo simulation based toy model for fission process ». International Journal of Modern Physics C 27, n^o 03 (23 février 2016) : 1650030. http://dx.doi.org/10.1142/s0129183116500303.

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Nuclear fission has been modeled notoriously using two approaches method, macroscopic and microscopic. This work will propose another approach, where the nucleus is treated as a toy model. The aim is to see the usefulness of particle distribution in fission yield calculation. Inasmuch nucleus is a toy, then the Fission Toy Model (FTM) does not represent real process in nature completely. The fission event in FTM is represented by one random number. The number is assumed as width of distribution probability of nucleon position in compound nuclei when fission process is started. By adopting the nucleon density approximation, the Gaussian distribution is chosen as particle distribution. This distribution function generates random number that randomizes distance between particles and a central point. The scission process is started by smashing compound nucleus central point into two parts that are left central and right central points. The yield is determined from portion of nuclei distribution which is proportional with portion of mass numbers. By using modified FTM, characteristic of particle distribution in each fission event could be formed before fission process. These characteristics could be used to make prediction about real nucleons interaction in fission process. The results of FTM calculation give information that the [Formula: see text] value seems as energy.

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