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First Passage Density of Brownian Motion with Two-sided Piecewise Linear Boundaries

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1505-1520页

作者： zhen YU Mao Zai tian Center for Applied Statistics School of StatisticsRenmin University of ChinaBeijing 100872P.R.China School of Mathematics and Data Science Changji UniversityChangji 831100P.R.China

The first passage time has many applications in fields like finance,econometrics,statistics,and ***,explicit formulas for the first passage density have only been obtained for a few *** paper derives an explicit formula for the first passage density of Brownian motion with twosided piecewise continuous boundaries which may have some points of *** are used to obtain a simplified formula for estimating the first passage ***,the results are also generalized to the case of two-sided general nonlinear *** can be easily carried out with Monte Carlo method and it is demonstrated for several typical two-sided boundaries that the proposed approximation method offers a highly accurate approximation of first passage density.

关键词： Boundary non-crossing probability first density passage density two-sided piecewise continuous boundaries Brownian motion

Quantum nonlocality evolution for two entangled mesoscopic fields under decoherence

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Communications in Theoretical Physics 2024年第1期76卷 24-28页

作者： Zhao-Song Tan Shou-Bang Yang zhen-biao Yang Shi-biao zheng Fujian Key Laboratory of Quantum Information and Quantum Optics Fuzhou UniversityFuzhouFujian 350116China

Investigation of the nonlocality evolution of entangled mesoscopic fields under decoherence not only is important for understanding the quantum–classical transition,but also has relevance to quantum communication and quantum computation protocols based on continuous *** to previous formulations of Bell inequalities,the system loses nonlocal features far before the disappearance of *** here construct a new version of Bell signal based on rotated and displaced on–off correlations,with which the Bell inequality is violated as long as there remains entanglement and the field state components keep ***,the nonlocal character revealed by our formulation decays much slower compared with those based on previous *** importantly,there exists a wide regime where the Bell inequality is restored with previous formulations but remains to be violated based on our correlation operators.

关键词： entangled mesoscopic fields rotated and displaced on-off correlations Bell inequality nonlocality evolution

Experimental observation of spontaneous symmetry breaking in a quantum phase transition

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 34-39页

作者： Wen Ning Ri-Hua zheng Jia-Hao Lu Fan Wu zhen-biao Yang Shi-biao zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350108China Hefei National Laboratory Hefei 230088China

Spontaneous symmetry breaking(SSB)plays a central role in understanding a large variety of phenomena associated with phase transitions,such as superfluid and *** far,the transition from a symmetric vacuum to a macroscopically ordered phase has been substantially *** process bridging these two distinct phases is critical to understanding how a classical world emerges from a quantum phase transition,but so far remains unexplored in *** here report an experimental demonstration of such a process with a quantum Rabi model engineered with a superconducting *** move the system from the normal phase to the superradiant phase featuring two symmetry-breaking field components,one of which is observed to emerge as the classical *** results demonstrate that the environment-induced decoherence plays a critical role in the SSB.

关键词： quantum phase transition Rabi model spontaneous symmetry breaking superconducting circuit Schrodinger cat states

Self-supported NiFe-LDH nanosheets on NiMo-based nanorods as high-performance bifunctional electrocatalysts for overall water splitting at industrial-level current densities

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Nano Research 2024年第5期17卷 3769-3776页

作者： Yan Zhang biao Feng MingLei Yan zhen Shen Yiqun Chen Jingyi tian Fengfei Xu Guanghai Chen Xizhang Wang Lijun Yang Qiang Wu zheng Hu Key Laboratory of Mesoscopic Chemistry of Ministry of Education(MOE)and Jiangsu Provincial Lab for Nanotechnology School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa’an 625014China

Efficient,durable and economic electrocatalysts are crucial for commercializing water electrolysis ***,we report an advanced bifunctional electrocatalyst for alkaline water splitting by growing NiFe-layered double hydroxide(NiFe-LDH)nanosheet arrays on the conductive NiMo-based nanorods deposited on Ni foam to form a three-dimensional(3D)architecture,which exhibits exceptional performances for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In overall water splitting,only the low operation voltages of 1.45/1.61 V are required to reach the current density of 10/500 mA·cm^(-2),and the continuous water splitting at an industrial-level current density of 500 mA·cm^(-2) shows a negligible degradation(1.8%)of the cell voltage over 1000 *** outstanding performance is ascribed to the synergism of the HER-active NiMo-based nanorods and the OER-active NiFe-LDH nanosheet arrays of the hybridized 3D ***,the dense NiFe-LDH nanosheet arrays enhance the local pH on cathode by retarding OH-diffusion and enlarge the electrochemically active surface area on anode,while the conductive NiMo-based nanorods on Ni foam much decrease the charge-transfer resistances of both *** study provides an efficient strategy to explore advanced bifunctional electrocatalysts for overall water splitting by rationally hybridizing HER-and OER-active components.

关键词： alkaline water splitting bifunctional electrocatalysts layered double hydroxides high durability industrial current densities

Data-driven rational design of single-atom materials for hydrogen evolution and sensing

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Nano Research 2024年第4期17卷 3352-3358页

作者： Lei Zhou Pengfei tian Bowei Zhang Fu-zhen Xuan Shanghai Key Laboratory of Intelligent Sensing and Detection Technology East China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety of Ministry of Education East China University of Science and TechnologyShanghai 200237China

Herein we proposed a data-driven high-throughput principle to screen high-performance single-atom materials for hydrogen evolution reaction(HER)and hydrogen sensing by combing the theoretical computations and a topology-based multi-scale convolution kernel machine learning *** the rational training by 25 groups of data and prediction of all 168 groups of single-atom materials for HER and sensing,respectively,a high prediction accuracy(>0.931 R^(2) score)was achieved by our *** show that the promising HER catalysts include Pt atoms in C_(4) and Sc atoms in C_(1)N_(3) coordination ***,Y atoms in C_(4) coordination environment and Cd atoms in C_(2)N_(2)-ortho coordination environment were predicted with great potential as hydrogen sensing *** method provides a way to accelerate the discovery of innovative materials by avoiding the time-consuming empirical principles in experiments.

关键词： machine learning single-atom materials sensing hydrogen evolution

Metal–Organic Framework‑Based Photodetectors

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Nano-Micro Letters 2024年第11期16卷 675-703页

作者： Jin‑biao Zhang Yi‑Bo tian Zhi‑Gang Gu Jian Zhang State Key Laboratory of Structural Chemistry Structure of MatterFujian Institute of ResearchChinese Academy of SciencesFuzhouFujian 350002People’s Republic of China College of Chemistry and Materials Science Fujian Nornal UniversityFuzhou 350007FujianPeople’s Republic of China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108FujianPeople’s Republic of China University of Chinese Academy of Science Beijing 100049People’s Republic of China

The unique and interesting physical and chemical properties of metal–organic framework(MOF)materials have recently attracted extensive attention in a new generation of photoelectric *** this review,we summarized and discussed the research progress on MOF-based *** methods of preparing MOF-based photodetectors and various types of MOF single crystals and thin film as well as MOF composites are introduced in ***,the photodetectors applications for X-ray,ultraviolet and infrared light,biological detectors,and circularly polarized light photodetectors are ***,summaries and challenges are provided for this important research field.

关键词： Metal-organic frameworks Semiconductor Photodetectors

Epileptic brain network mechanisms and neuroimaging techniques for the brain network

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Neural Regeneration Research 2024年第12期19卷 2637-2648页

作者： Yi Guo Zhonghua Lin zhen Fan Xin tian Department of Neurology Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Sichuan Provincial Center for Mental Health Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Department of Geriatrics Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Department of Neurology Chongqing Key Laboratory of NeurologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina

Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal *** more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical *** increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tra ctography,diffusion kurtosis imaging-based fiber tractography,fiber ball imagingbased tra ctography,electroencephalography,functional magnetic resonance imaging,magnetoencephalography,positron emission tomography,molecular imaging,and functional ultrasound imaging have been extensively used to delineate epileptic *** this review,we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy,and extensively analyze the imaging mechanisms,advantages,limitations,and clinical application ranges of each technique.A greater focus on emerging advanced technologies,new data analysis software,a combination of multiple techniques,and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions.

关键词： electrophysiological techniques epilepsy functional brain network functional magnetic resonance imaging functional near-infrared spectroscopy machine leaning molecular imaging neuroimaging techniques structural brain network virtual epileptic models

Effect of Preload Force on Heat Generation of Li(Ni_(0.8)Co_(0.1)Mn_(0.1))O_(2)/SiO_(x)-C System Batteries:The Discharge Process

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Journal of Thermal Science 2024年第5期33卷 1809-1825页

作者： LIN Chunjing LAI zhenxing BAI Guangli MA biao WEI zhen QI Chuang LIU Shiqiang Key Laboratory of Advanced Manufacturing Technology for Automobile Parts Ministry of EducationChongqing University of TechnologyChongqing 400054China China Auto Research New Energy Vehicle Inspection Center(tianjin)Co Tianjin 300300China

Lithium-ion batteries(LIBs)undergo various degradation phenomena such as material decomposition,structural change and uneven lithium ion distribution during long-term cycles,which would affect their performance and *** order to improve the performance of the LIBs during their life cycle,preload force is preset when the batteries are *** preload forces will in turn affect the cycle life and heat generation of the *** order to address this issue,this work carries out charge/discharge cycle tests on a NCM811 battery under different preload *** calorimetry tests are performed to investigate the battery heat generation under different states of health(SOHs)and preload *** on the test results,an empirical prediction model for heat generation power as a function of SOH is *** show that when the preload force is 5 N·m,the battery capacity decreases in the slowest rate and the average heat generation power is the *** in peaks of the incremental capacity curve can be used to characterize the loss of lithium at the electrode,which in turn characterizes the change of heat generation power of the *** average heat generation power is mainly affected by the SOH,going through a period of trough with the decrease of the SOH and continuing to increase after crossing the critical *** general,these findings emphasize the relationship between preload force,SOH and heat generation power,which is helpful for the judgment of optimal preload to improve the efficiency of LIBs.

关键词： lithium ion battery cyclic aging preload force heat generation characteristic

Trends and characteristics in pre-hospital emergency care in Beijing from 2008 to 2017

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Chinese Medical Journal 2020年第11期133卷 1268-1275页

作者： Wei Huang tian-Bing Wang Ying-Dong He Huan Zhang Xiao-Hua Zhou Hui Liu Jin-Jun Zhang zhen-biao tian Bao-Guo Jiang Departm ent of Trauma Rescue Center Peking University People's HospitalBeijing 100044China Department of Trauma and Orthopaedics Peking University People's HospitalBeijing 100044China Key Laboratory of Trauma and Neural Regeneration(Peking University) Ministry of EducationBeijing 100044China Department of Epidemiology and Biostatistics School of Public HealthPeking University Health Science CenterBeijingChina Medical Informatics Center Peking UniversityBeijing 100191China Beijing Emergency Center Beijing 100031China Beijing Red Cross Emergency Center Beijing 100085China

Background: We aimed to describe and analyze the pre-hospital emergency medical service (EMS) in Beijing and provide information for the government and medical institutions to optimize ***: We collected all pre-hospital emergency data in Beijing from 2008 to 2017. The chief complaint in each case was classified according to the Medical Priority Dispatch System (MPDS). The sites’ administrative districts were determined through geo-encoding of addresses and then classified into four functional regions. We analyzed the demand for EMS, emergency response times (ERT), and disease spectrum for Beijing as a whole, and for each functional ***: A total of 4,192,870 pre-hospital EMS cases met the inclusion criteria, with a significant increase (P < 0.001) of 51.60% from 2008 to 2017. EMS demand was positively associated with population (r= 0.946,P < 0.001). The pre-hospital EMS demand rate was 1907.05 in 2008 and 2172.23 in 2017 per 100,000, with no significant change (P = 0.57). ERT increased significantly (P = 0.001), from 19.18 min in 2008 to 24.51 min in 2016. According to MPDS classifications, the demand for pre-hospital care increased for 14 diseases, remained stable for 19, and decreased for only 1 disease. Cases of injury-related disease increased significantly from approximately 90,000 in 2017, accounting for 20% of all pre-hospital EMS cases, and the demand rate decreased in the core region but increased in the sub-urban regions. Cases of heart problems and stroke/transient ischemic attack also increased significantly in the four functional regions, with the highest demand rate in the Core Functional ***: More resources and effort should be devoted to pre-hospital EMS according to the increased pre-hospital EMS demand and prolonged ERT in Beijing over our 10-year study period. Changes in disease spectrum and differences between functional regions should also be considered.

关键词： China Emergency medical services Emergency response time