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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)

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

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

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)

Non-Rigid Metal–Oxygen Bonding Empowered Nitrate Reduction on Ruthenium Catalysts

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SSRN

SSRN 2024年

作者： Wang, Suwen Zhuang, Zechao Xu, Jiawei Fu, Cheng Qiu, Zhen Feng, Huajun Xiang, Hai Chen, Zuliang Li, Hui Zhang, Lei Li, Yongfu Cai, Yanjiang Ma, Tianyi Yu, Bing State Key Laboratory of Subtropical Silviculture Zhejiang A&F University Hangzhou311300 China Zhejiang A&F University Hangzhou311300 China Department of Chemistry Tsinghua University Beijing100084 China Jiangsu Key Laboratory of Numerical Simulation of Large Scale Complex Systems School of Chemistry and Materials Science Nanjing Normal University Nanjing210023 China Fujian Key Laboratory of Pollution Control and Resource Reuse School of Environmental and Resource Sciences Fujian Normal University Fujian Province Fuzhou350007 China School of Science RMIT University MelbourneVIC3000 Australia Centre for Translational Atomaterials

Electrocatalytic nitrate reduction (NitRR) offers exciting potential for mass production of ammonia (NH3) from renewables. However, the rigidity of metal−ligand bonds in most electrocatalysts renders them unable to survive the structural transformations required for NitRR. Herein, we establish a type of non-rigid metal−oxygen bonds by employing graphene oxide (GO) sheets as a 'micron-scale' ligand for transition metals (TM). Because of being confined to the interfaces between GO and TM, the oxygenated groups in GO can associate with and dissociate from the TM in response to reaction dynamics. As a proof-of-concept demonstration, an electrocatalyst was developed by dispersing nanoscale ruthenium (Ru) on graphene oxide (GO) and utilizing two-dimensional MXene to compensate for the low electrical conductivity of GO. This electrocatalyst exhibits a maximum NH3 yield of over 5 mg cm−2 h−1, with almost 100% current-to-NH3 efficiency, far outperforming the performance of most reported Ru-based materials. What's even more remarkable is the achievement of a record-breaking performance: a 200-hour stable electrolysis with a NH3 yield of 40.2 mg cm−2 h−1, using a membrane electrode reactor. Our experimental and theoretical investigations further reveal the non-rigidity of the Ru–O bonds and how they self-regulate to adapt to diverse intermediates involved in NitRR. This work provides an approach to fabricate a high-performance electrocatalyst featuring reversible and non-rigid metal−oxygen bonds, opening new possibilities for practical nitrate electrolysis. © 2024, The Authors. All rights reserved.

关键词： Electrocatalysis

Superexponential diffusion in nonlinear non-Hermitian systems

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Physical Review A 2020年第6期102卷 062213-062213页

作者： Wen-Lei Zhao Longwen Zhou Jie Liu Peiqing Tong Kaiqian Huang School of Science Jiangxi University of Science and Technology Ganzhou 341000 China Department of Physics College of Information Science and Engineering Ocean University of China Qingdao 266100 China Graduate School of China Academy of Engineering Physics Beijing 100193 China CAPT HEDPS and IFSA Collaborative Innovation Center of the Ministry of Education Peking University Beijing 100871 China Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu 210023 China Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials SPTE South China Normal University Guangzhou 510006 China

We investigate the quantum diffusion of a periodically kicked particle subjected to both nonlinearity-induced self-interactions and PT-symmetric potentials. We find that, due to the interplay between the nonlinearity and non-Hermiticity, the expectation value of the mean square of momentum scales with time in a superexponential form 〈p2(t)〉∝exp[βexp(αt)], which is faster than any known rates of quantum diffusion. In the PT-symmetry-breaking phase, the intensity of a state increases exponentially with time, leading to the exponential growth of the interaction strength. The feedback of the intensity-dependent nonlinearity further turns the interaction energy into the kinetic energy, resulting in a superexponential growth of the mean energy. These theoretical predictions are in good agreement with numerical simulations in a PT-symmetric nonlinear kicked particle. Our discovery establishes a mechanism of diffusion in interacting and dissipative quantum systems. Important implications and possible experimental observations are discussed.

关键词： Anderson localization Atomic, optical & lattice clocks Diffusion Nonlinear optics Quantum transport Spatiotemporal chaos Wave chaos

Study ofBs⟶ϕℓ+ℓ−Decays in the PQCD Factorization Approach with Lattice QCD Input

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Advances in High Energy Physics 2021年第1期2021卷

作者： Su-Ping Jin Zhen-Jun Xiao Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu 210023 *** Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 ***

In this paper, we studied systematically the semileptonic decays B s ⟶ ϕ l + l − with l − = ( e − , μ − , τ − ) by using the perturbative QCD (PQCD) and the “PQCD+Lattice” factorization approach, respectively. We first evaluated all relevant form factors F i ( q 2 ) in the low- q 2 region using the PQCD approach, and we also took the available lattice QCD results at the high- q 2 region as additional input to improve the extrapolation of F i ( q 2 ) from the low- q 2 region to the endpoint . We then calculated the branching ratios and many other physical observables , , S 3,4,7 , and A 5,6,8,9 and the clean angular observables P 1,2,3 and . From our studies, we find the following points: (a) the PQCD and “PQCD+Lattice” predictions of are about 7 × 10 −7 , which agree well with the LHCb measured values and the QCD sum rule prediction within still large errors; (b) we defined and calculated the ratios of the branching ratios and ; (c) the PQCD and “PQCD+Lattice” predictions of the longitudinal polarization F L , the CP-averaged angular coefficients S 3,4,7 , and the CP asymmetry angular coefficients A 5,6,8,9 agree with the LHCb measurements in all considered bins within the still large experimental errors; and (d) for those currently still unknown observables , and , we suggest LHCb and Belle-II Collaboration to measure them in their experiments.

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Option to survive or surrender: Carbon asset management and optimization in thermal power enterprises from China

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arXiv 2021年

作者： Liu, Yue Tian, Lixin Xie, Zhuyun Zhen, Zaili Sun, Huaping School of Geography Nanjing Normal University Nanjing Jiangsu210042 China School of Finance and Economics Jiangsu University Zhenjiang Jiangsu212013 China Energy Development and Environmental Protection Strategy Research Center Jiangsu University Zhenjiang Jiangsu212013 China Energy Interdependency Behavior and Strategy Research Center School of Mathematical Science Nanjing Normal University Nanjing Jiangsu210042 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210042 China

Carbon emission right allowance is a double-edged sword, one edge is to reduce emission as its original design intention, another edge has in practice slain many less developed coal-consuming enterprises, especially for those in thermal power industry. Partially governed on the hilt in hands of the authority, body of this sword is the prices of carbon emission right. How should the thermal power plants dance on the blade motivates this research. Considering the impact of price fluctuations of carbon emission right allowance, we investigate the operation of Chinese thermal power plant by modeling the decision-making with optimal stopping problem, which is established on the stochastic environment with carbon emission allowance price process simulated by geometric Brownian motion. Under the overall goal of maximizing the ultimate profitability, the optimal stopping indicates the timing of suspend or halt of production, hence the optimal stopping boundary curve implies the edge of life and death with regard to this enterprise. Applying this methodology, real cases of failure and survival of several Chinese representative thermal power plants were analyzed to explore the industry ecotope, which leads to the findings that: 1) The survival environment of existed thermal power plants becomes severer when facing more pressure from the newborn carbon-finance market. 2) Boundaries of survival environment is mainly drawn by the technical improvements for rising the utilization rate of carbon emission. Based on the same optimal stopping model, outlook of this industry is drawn with a demarcation surface defining the vivosphere of thermal power plants with different levels of profitability. This finding provides benchmarks for those enterprises struggling for survival and policy makers scheming better supervision and necessary intervene. © 2021, CC BY-NC-SA.

关键词： Carbon

Streaming Algorithms for the k-Submodular Cover Problem

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arXiv 2023年

作者： Wang, Wenqi Gutin, Gregory Mao, Yaping Du, Donglei Zhang, Xiaoyan School of Mathematical Science Institute of Mathematics Nanjing Normal University Key Laboratory of Ministry of Education Numerical Simulation of Large Scale Complex Systems Nanjing210023 China Royal Holloway University of London Egham SurreyTW20 0EX United Kingdom School of Mathematics and Statistics Academy of Plateau Science and Sustainability Qinghai Normal University Qinghai Xining810008 China Faculty of Management University of New Brunswick FrederictonNBE3B9Y2 Canada

Given a natural number k ≥ 2, we consider the k-submodular cover problem (k-SC). The objective is to find a minimum cost subset of a ground set X subject to the value of a k-submodular utility function being at least a certain predetermined value τ. For this problem, we design a bicriteria algorithm with a cost at most O(1/ǫ) times the optimal value, while the utility is at least (1 − ǫ)τ/r, where r depends on the monotonicity of g. © 2023, CC BY.

关键词： Approximation algorithms

Generation of orthogonal curvilinear grids on the sphere surface based on Laplace-Beltrami equations

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IOP Conference Series: Earth and Environmental Science 2014年第1期19卷

作者： Fuqiang Lu Zhiyao Song Xin Fang Key Laboratory of Virtual Geographic Environment (Ministry of Education) Nanjing Normal UniversityNanjing Jiangsu Province 210046 China AA(Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Nanjing 210046 China

In this paper, Laplace-Beltrami equations are used to generate orthogonal curvilinear grids on the sphere for ocean models. In addition to overcoming the pole-problem, the grid configuration has quasi-uniform cell-size on the whole sphere. Some quantities such as the grid length along two directions, the angle deviation from orthogonality, the area of the cell to evaluate the quality of the grid, which demonstrate the grid produced is fit to be a model grid on which the finite difference method or finite volume method can be implemented for numerical simulating of global atmosphere and ocean dynamics on large scale.

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