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高温下HMX热分解反应分子动力学模拟

原子与分子物理学报 2025年第2期42卷 105-110页

作者：陈芳贾方硕陈瑶李天浩郭国琦董羚中北大学化学与化工学院太原030051

本文采用ReaxFF-lg反应分子动力学方法研究了奥克托金(HMX)在六种不同温度下的初始反应热分解过程,验证了ReaxFF-lg势函数对HMX体系的适用性,计算了不同温度下HMX体系势能、总物种演化趋势、初始反应产物以及指前因子和活化能.结果表明,... 详细信息

本文采用ReaxFF-lg反应分子动力学方法研究了奥克托金(HMX)在六种不同温度下的初始反应热分解过程,验证了ReaxFF-lg势函数对HMX体系的适用性,计算了不同温度下HMX体系势能、总物种演化趋势、初始反应产物以及指前因子和活化能.结果表明,HMX热分解过程主要有三种初始分解机理:N-NO_(2)键的断裂,HONO的解离和主环上C-N键的断裂,计算得到的初始分解阶段活化能Ea和指前因子ln(A),与实验值相吻合.

关键词： HMX 反应分子动力学(RMD) ReaxFF-lg 热分解温度

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Particle Paths of Lagrangian Velocity Distribution Simulating Yin-Yang Balance in Ancient Tai-Chi Diagram

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Journal of Thermal Science 2007年第2期16卷 140-144页

作者： Tzu-fang chen Department of Mechanical and Industrial Engineering Concordia UniversityMontrealQuebecCanada H3G 1M8

The particle paths of the Lagrangian flow field simulate very well the interface curve of the Yin-Yang balance in the ancient Tal-Chi diagram. There are four forms called the ＂four states＂ in the Tai-Chi diagram. Of the four states, under Yang are the Major Yang and the Minor Yin, and under Yin are the Major Yin and the Minor Yang. The present study provides the proper positions of the four states in the ancient Tal-Chi diagram. The Fu Xi＇s Eight Trigrams Chart located along the ancient Tai-Chi diagram is also developed in the present study. The interface curve of Yin-Yang in the ancient Tai-Chi diagram has never been described mathematically. It can now be formulated by the equations describing the particle paths in the Lagrangian flow field.

关键词： Lagrangian flow field particle path Yln-Yang balance ancient Tal-Chi diagram Fu Xi's Eight Trigrams Chart

Particle image velocimetry for combustion measurements:Applications and developments

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Chinese Journal of Aeronautics 2018年第7期31卷 1407-1427页

作者： fang chen Hong LIU School of Aeronautics and Astronautics Shanghai Jiao Tong University

In the last several decades, Particle Image Velocimetry（PIV） has reached a high degree of maturity as a laser diagnostic technique based on tracer particles, with significant improvements in accuracy, resolution, dynamic range, and as an extension to combustion measurements. To assess the recent developments and to project the future trends of using the PIV technique for combustion measurements, we review many key issues for measuring combustion flow fields. We introduce the representative applications of a supersonic combustor and swirling burner and summarize the promising prospects and further development requirements of PIV measurements in combustion flow fields.

关键词： Combustion Diagnostics Tracer panicles Velocietry

Chronic toxicity and cytotoxicity of synthetic pyrethroid insecticide cis-bifenthrin

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Journal of Environmental Sciences 2009年第12期21卷 1710-1715页

作者： WANG Cui chen fang ZHANG Quan fang Zhuo College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China College of Environmental Science and Engineering Zhejiang Gongshang University Hangzhou 310035 China

With the increasing use of synthetic pyrethroids （SPs）, the significance of ecological safety and health risk is an emerging concern, In this study, we evaluated the chronic aquatic toxicity of eis-bifenthrin （cis-BF） in Daphnia magna and its cytotoxicity in Chinese hamster ovary （CHO） cells as well as human cervical carcinoma （Hela） ceils. Chronic aquatic toxicity tests showed that cis-BF could significantly affect the reproduction of D. magna. The lowest observed effective concentration and the non-observed effective concentration of cis-BF to D. magna were 0.02 and 0.01 μg/L, respectively, and the chronic value was 0.014 μg/L. The intrinsic rate of natural increase was significantly decreased （p 〈 0.05） to 0.02 μg/L. The cytotoxicity assay demonstrated that cis-BF decreased cell viability in CHO and Hela cells in a concentration- and time-dependent manner. The IC50 values for Hela and CHO cells were 4.0 × 10^-5 and 3.2 × 10^-5 mol/L, respectively. Together, these results indicated that cis-BF induced chronic toxicity in both aquatic invertebrate animals and mammalian cells. These findings assist in understanding the impact of SPs on health and environmental safety. Considering the wide spectrum of SPs, a more comprehensive understanding of the negative effects is indispensible for planning future application and regulation of these pesticides.

关键词： cis-bifenthrin Daphnia magna chronic toxicity cytotoxicity

A k⋅p Effective Hamiltonian Generator

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Chinese Physics Letters 2021年第7期38卷 85-89页

作者： Yi Jiang Zhong fang chen fang Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Kavli Institute for Theoretical Sciences Chinese Academy of SciencesBeijing 100190China

A k⋅p effective Hamiltonian is important for theoretical analysis in condensed matter *** on the kdotp-symmetry package,we develop an upgraded package named as *** generator takes in arbitrary magnetic symmetries with their representations and returns symmetry-allowed k⋅p *** this package,we calculate k⋅p Hamiltonians for irreducible co-representations in 1651 magnetic space groups up to the third order,and their linear coupling to external fields including the electromagnetic field and the strain *** hope that the package will facilitate related research in the future.

关键词： Hamiltonian symmetry allowed

Design optimization of 3.9GHz fundamental power coupler for the SHINE project

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Nuclear Science and Techniques 2021年第11期32卷 174-190页

作者： Zhen-Yu Ma Jin-fang chen Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

The third harmonic superconducting cryomodule is being designed for the Shanghai High repetition rate XFEL and Extreme light facility(SHINE)project,which is under *** contrast to the European X-ray Free Electron Laser(E-XFEL)project,the 3.9 GHz cryomodules in the SHINE project will operate in the continuous wave regime with higher radio frequency average power for both cavities and *** propose a 3.9 GHz fundamental power coupler with an adjustable antenna length,for satisfying the SHINE project ***,we describe the 3.9 GHz fundamental power coupler's design considerations and power requirements for various operating modes of the SHINE *** also present the results of the radio frequency simulation and optimization,including the studies on multipacting and thermal analysis of the proposed 3.9 GHz coupler.

关键词： 3.9 GHz fundamental power coupler Third harmonic cavity Superconducting cryomodule XFEL and extreme light facility(SHINE)Linac

Necessary condition and sufficient condition for affine frames

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Science China Mathematics 2005年第10期48卷 1369-1378页

作者： SHI Xianliang chen fang College of Mathematics and Computer Science Hunan Normal University Changsha 410081 China College of Mathematics and Computer Science Hunan Normal University Changsha 410081 China

The main goal of this paper is to establish a set of necessary conditions for affine frames. These conditions are also sufficient for tight frames.

关键词： affine frame, necessary condition.

Confidence limits for the mean of exponential distribution in any time-sequential samples

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Science China Mathematics 2005年第9期48卷 1182-1193页

作者： chen Jiading fang Xiangzhong School of Mathematical Sciences LMAM Peking University Beijing 100871 China School of Mathematical Sciences LMAM Peking University Beijing 100871 China

We present the general results determining confidence limits for the mean of exponential distribution in any time-sequential samples, which are obtained in any sequential life tests with replacement or without replace... 详细信息

关键词： confidence limits, time-sequential samples, exponential distribution.

Hepatitis B virus pre-S/S variants in liver diseases

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World Journal of Gastroenterology 2018年第14期24卷 1507-1520页

作者： Bing-fang chen School of Medicine Fu-Jen Catholic University

Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.

关键词： hepatitis B virus pre-S/S mutant pre-S deletion splice variant spPS1 chronic hepatitis liver cirrhosis hepatocellular carcinoma