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Physical Review D 2014年第11期90卷 114028-114028页

作者： Zhen-Jun Xiao Ya Li Dong-Ting Lin Ying-Ying Fan Ai-Jun Ma Department of Physics and Institute of Theoretical Physics Nanjing Normal University NanjingJiangsu 210023 People’s Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People’s Republic of China College of Physics and Electronic Engineering Xinyang Normal University Xinyang Henan 464000 People’s Republic of China

In this paper, we calculate the branching ratios and CP-violating asymmetries of the five B¯s0→(π0η(′),η(′)η(′)) decays, by employing the perturbative QCD (pQCD) factorization approach and with the inclusion of all currently known next-to-leading order (NLO) contributions. We find that (a) the NLO contributions can provide about 100% enhancements to the LO pQCD predictions for the decay rates of B¯s0→ηη′ and η′η′ decays, but result in small changes to Br(B¯s→π0η(′)) and Br(B¯s→ηη); (b) the newly known NLO twist-2 and twist-3 contributions to the relevant form factors can provide about 10% enhancements to the decay rates of the considered decays; (c) for B¯s→π0η(′) decays, their direct CP-violating asymmetries Afdir could be enhanced significantly by the inclusion of the NLO contributions; and (d) the pQCD predictions for Br(B¯s→ηη(′)) and Br(B¯s→η′η′) can be as large as 4×10−5, which may be measurable at LHCb or the forthcoming Super-B experiments.

关键词： BOSONS CP violation (Nuclear physics) BRANCHING ratios (Nuclear physics) PARTICLE decays PERTURBATIVE quantum chromodynamics DECAY rates (Radioactivity) STANDARD model (Nuclear physics)

黏弹性溶剂中胶体流变行为的多粒子碰撞动力学模拟

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黏弹性溶剂中胶体流变行为的多粒子碰撞动力学模拟

2014年大分子体系理论、模拟与计算研讨会

作者： Shichen Ji Xiaojia Zhang Roland G. Winkler Gerhard Gompper Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources School of Chemistry and Chemical EngineeringGuangxi Normal UniversityGuilin 541004China Theoretical Soft Matter and Biophysics Institute of Complex Systems and Institute for Advanced SimulationForschungszentrum JülichD-52425 JülichGermany Theoretical Soft Matter and BiophysicsInstitute of Complex Systems and Institute for Advanced SimulationForschungszentrum JülichD-52425 JülichGermany

Chaotic diffusion of complex trajectory and its quantum signature

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arXiv 2019年

作者： Zhao, Wen-Lei Wang, Jiaozi Wang, Qian Tong, Peiqing School of Science Jiangxi University of Science and Technology Ganzhou341000 China Department of Modern Physics University of Science and Technology of China Hefei230026 China Department of Physics Zhejiang Normal University Jinhua321004 China Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing210023 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

We investigate both the quantum and classical dynamics of a non-Hermitian system via a kicked rotor model with PT symmetry. In non-Hermitian case, the classical trajectory is assumed to be complex. We find the normal diffusion for the real part of momentum and the exponentially-fast diffusion for the imaginary part of momentum. Due to the exponentially-fast increase of some trajectories, there is a threshold time for the breakdown of classical diffusion. Our theoretical prediction of such a threshold time is in good agreement with numerical results. The quantum signature of the chaotic diffusion of the complex trajectories is reflected by the dynamics of the out-of-time-order correlators (OTOC) in the semiclassical regime. We find that the growth of the OTOC exhibits a sharp transition to infinitely large at a critical time which exponentially increases with the increase of the threshold time of the classical diffusion. For the quantum dynamics, both the mean momentum and mean square of momentum exhibits the staircase growth with time when the system parameter is in the neighborhood of the PT symmetry breaking. If the system parameter is very larger than the PT symmetry breaking point, the acceleration mode results in the directed spreading of the wavepackets as well as the ballistic diffusion in momentum space. Copyright © 2019, The Authors. All rights reserved.

关键词： Momentum

Construction of dimeric hTSPO protein model using homology modeling and molecular dynamics

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Journal of Physics: Conference Series 2021年第1期1932卷

作者： Hien T T Lai Toan T Nguyen Key Laboratory for Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University - Hanoi 334 Nguyen Trai street Thanh Xuan district Hanoi Vietnam

A model for the dimeric form of the human TSPO (hTSPO) protein is constructed homologically using the RsTSPO dimer template. Then, Molecular dynamics simulation of 1μs is carried out on the model to investigate its stability as well as to study its various physicochemical properties. Our model shows good stability, with various important conserved residues involving in monomer–monomer interactions, in good agreements with available experimental data. Several functioning motifs are well demonstrated. This model hence can serve as a good basis for further study of this system as well as for discoveries of candidate radioligands targeting TSPO protein as a biotracer for medical imaging of brain inflamation.

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Computational study of the effect of protonation states of PSA protein zinc fingers on its DNA binding

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Journal of Physics: Conference Series 2019年第1期1274卷

作者： Nguyen Viet Duc Ly Hai Nguyen Hien T. T. Lai Toan T. Nguyen VNU Key Laboratory for Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University 334 Nguyen Trai street Thanh Xuan Hanoi 11416 VIETNAM

In this study, we investigate the binding of the Zinc finger (ZF) structure on a short DNA molecule. The zinc finger of a protein where a Zn2+ ion binds to 4 cysteine or histidine amino acids in a tetrahedral structure is a very common motif of nucleic acid binding proteins. This structure is ubiquitous and the corresponding interaction model is present in 3% of the genes of human genome. ZF has been shown to be extremely useful in various therapeutic and research capacities, as well as in biotechnology. A recent computational study has shown that isolated zinc finger structure is stable if the cysteine amino acids are in deprotonated state. Here, we investigate how this deprotonated state influences protein structure, dynamics, and function in binding of ZF to short DNA molecules using molecular dynamics simulations in sub-microsecond range. Our results show that the Zn2+ ion and the deprotonated state of cysteine is essential for mechanical stabilization of the functional, folded conformation. Not only this state stabilizes the ZF structure, it also stabilizes the DNA-binding structure. Our result has potential impact on better design of zinc fingers for various biotechnological applications.

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Automatic Term Recognition Method for Military Domain

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Journal of Physics: Conference Series 2021年第1期2078卷

作者： Ani Song Xiaoxia Jia Wei Jiang North China Institute of Computing Technology Beijing 100083 China National key Laboratory for Complex Systems Simulation. Department of Systems General Design. Institute of Systems Engineering. AMS. Beijing 100083 China

With the development of military intelligence, higher requirements are put forward for automatic term recognition in military field. In view of the characteristics of flexible and diverse naming of military requirement documents without annotated corpus, the method of this paper uses the existing military domain core database, and matches the data set and core database by Aho-Corasic algorithm and word segmentation technology, so that the terms to be recognized in the data set can be divided into three types. The possible rules of word formation of military terms are summarized and phrases that conform to the rules of word formation are found in the documents as the term candidate set. The core library and TF-IDF method are used to calculate the value of the candidate terms, and the candidate terms whose value is greater than the threshold are selected iteratively as the real terms. The experimental results show that the F1 value of this method reaches 0.719, which is better than the traditional C-value method. Therefore, the method proposed in this paper can achieve better automatic term recognition effect for military requirement documents without annotation.

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Influence of fatty alcohol mixing ratios on the physicochemical properties of stearyl-cetyl alcohol-polysorbate 60-water ternary system: Insights from experiments and computer simulations

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arXiv 2021年

作者： Hoang, Vu Dang Cong, Cao Phuong Tran, Hung Huu Nguyen, Hue Minh Thi Nguyen, Toan T. Department of Analytical Chemistry and Toxicology Hanoi University of Pharmacy 13-15 Le Thanh Tong street Hanoi Viet Nam Key Laboratory for Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University 334 Nguyen Trai street Thanh Xuan Hanoi120401 Viet Nam Faculty of Chemistry and Center for Computational Science Hanoi National University of Education 136 Xuan Thuy street Cau Giay Hanoi Viet Nam

The structure and stability of ternary systems prepared with polysorbate 60 and various combinations of cetyl (C16) and stearyl (C18) alcohols were examined as they aged over 3 months at 25◦C. Rheological results showed that the consistency of these systems increased initially during roughly the first week of aging, which was succeeded by little changes in consistency (systems containing from 30% to 70% C18, with the 50% C18 system showing the highest consistencies) or significant breakdown of structure (remaining systems). The formation and/or disintegration of all ternary systems were also detected by microscopy and differential scanning calorimetry experiments. This study emphasizes the fact that the structure and consistency of ternary systems are dominantly controlled by the swelling capacity of the lamellar gel phase. Molecular dynamics simulations were performed to provide details on the molecular mechanism of stability. Computational results support the hypothesis experimentally proposed for the stability of the mixed system being due to an increase flexibility of the alcohol with a longer hydrocarbon chain. Computational results are in excellent agreement with experimental conclusions. Additionally, they show that in the mixed system, alcohols with shorter hydrocarbon chain become more rigid. These molecular details could not be available in experimental measurements. Copyright © 2021, The Authors. All rights reserved.

关键词： Molecular dynamics

Network shell structure based on hub and non-hub nodes

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arXiv 2024年

作者： Dong, Gaogao Sun, Nannan Wang, Fan Lambiotte, Renaud School of Mathematical Sciences Jiangsu University Jiangsu Zhenjiang212013 China Emergency Management Institute Jiangsu University Jiangsu Zhenjiang212013 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Jiangsu Zhenjiang210023 China Department of Physics Bar-Ilan University Ramat-Gan52900 Israel Mathematical Institute University of Oxford Woodstock Rd OxfordOX2 6GG United Kingdom

The shell structure holds significant importance in various domains such as information dissemination, supply chain management, and transportation. This study focuses on investigating the shell structure of hub and non-hub nodes, which play important roles in these domains. Our framework explores the topology of Erdös-Rényi (ER) and Scale-Free (SF) networks, considering source node selection strategies dependent on the nodes’ degrees. We define the shell l in a network as the set of nodes at a distance l from a given node and represent rl as the fraction of nodes outside shell l. Statistical properties of the shells are examined for a selected node, taking into account the node’s degree. For a network with a given degree distribution, we analytically derive the degree distribution and average degree of nodes outside shell l as functions of rl. Moreover, we discover that rl follows an iterative functional form rl = φ(rl−1), where φ is expressed in terms of the generating function of the original degree distribution of the network. Copyright © 2024, The Authors. All rights reserved.

关键词： Shells (structures)

Investigating molecular mechanism for the stability of ternary systems containing cetrimide, fatty alcohol and water by using computer simulation

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arXiv 2019年

作者： Hoang, Vu Dang Tran, Hung Huu Phuong, Cao Cong Thi Nguyen, Hue Minh Nguyen, Toan T. Department of Analytical Chemistry and Toxicology Hanoi University of Pharmacy 13-15 Le Thanh Tong Hoan Kiem Hanoi Viet Nam Faculty of Chemistry Center for Computational Science Hanoi National University of Education 136 Xuan Thuy Street Cau Giay Hanoi Viet Nam Faculty of Physics VNU Key Laboratory on Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University 334 Nguyen Trai Street Thanh Xuan Hanoi Viet Nam

Computer simulations using atomistic model are carried out to investigate the stability of ternary systems of pure or mixed fatty alcohols, cetrimide, and water. These semi−solid oil-in-water systems are used as the main component of pharmaceutical creams. Experiments show that the mixed alcohol systems are more stable than pure ones. The current experimental hypothesis is that this is the result of the length mismatch of the alkyl chains. This leads to higher configurational entropy of the chain tip of the longer alcohol molecules. Our simulation results support this hypothesis. The results also show that the shorter alcohol molecules become stiffer with higher values of the deuterium order parameters and smaller area per molecule. The magnitude in fluctuations in the area per molecule also increases in mixed systems, indicating a higher configurational entropy. Analysis of the molecular structure of simulated systems also shows good agreements with experimental data. Copyright © 2019, The Authors. All rights reserved.

关键词： Molecules

Directed momentum current induced by the PT -symmetric driving

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arXiv 2019年

作者： Zhao, Wen-Lei Wang, Jiaozi Wang, Xiaohui Tong, Peiqing School of Science Jiangxi University of Science and Technology Ganzhou341000 China Department of Modern Physics University of Science and Technology of China Hefei230026 China School of Information Engineering Jiangxi University of Science and Technology Ganzhou341000 China Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing210023 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

We investigate the directed momentum current in the quantum kicked rotor model with PT symmetric deriving potential. For the quantum non-resonance case, the values of quasi-energy become to be complex when the strength of imaginary part of the kicking potential exceeds a threshold value, which demonstrates the appearance of the spontaneous PT symmetry breaking. In the vicinity of the transition point, the momentum current exhibits a staircase growth with time. Each platform of the momentum current corresponds to the mean momentum of some eigenstates of the Floquet operator whose imaginary parts of the quasi-energy are significantly large. Above the transition point, the momentum current increases linearly with time. Interestingly, its acceleration rate exhibits a kind of "quantized" increment with the kicking strength. We propose a modified classical acceleration mode of the kicked rotor model to explain such an intriguing phenomenon. Our theoretical prediction is in good agreement with numerical results. Copyright © 2019, The Authors. All rights reserved.

关键词： Momentum