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Theoretical and numerical research on the dynamic launch response of carbon fiber composite cartridges

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Defence Technology（防务技术） 2024年第3期33卷 426-436页

作者： Ruijie Zhang hui xu Chenlei Huang Kun Liu Zhilin Wu School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina

Understanding the dynamic response of composite material cartridges during the firing process is of great significance for improving their reliability and safety.A theoretical model describing the dynamic response of composite material cartridges is established based on the thick-walled cylinder theory and rate-dependent constitutive model of composite *** correctness of the theoretical model is validated through finite element simulations of cartridge *** influence of chamber pressure and cartridge wall thickness on the cartridge's deformation process and stress distribution is *** results indicate that the primary deformation of composite material cartridges inside the chamber is elastic *** to metal cartridges,composite material cartridges require higher pressure for touching-chamber and are more prone to developing gaps after unloading to ensure smooth *** the deformation process,the touching-chamber behavior of the cartridge can improve the stress *** the same chamber pressure,the touching-chamber behavior can reduce the circumferential stress by approximately 30%.The inner wall surface of the cartridge is a critical area that requires *** touching-chamber behavior can be facilitated by appropriately reducing the cartridge wall thickness while ensuring overall *** study can provide guidance for the optimization design of composite material cartridges.

关键词： Composite material cartridges Dynamic response Thick-walled cylinder theory Finite element simulation Toughing-chamber behavior

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基于软硬件技术的传感器信号线性化处理研究

传感器与微系统 2008年第12期27卷 36-38页

作者：许宝卉李言西安理工大学陕西西安710048 运城学院山西运城044000

传感器信号的非线性程度直接影响测量系统的精度,因而,必须对其进行线性化。针对传感器特性和转换电路的非线性可以采用硬件的方法进行线性化;而对其他因素的影响,可以采用智能系统,用最小二乘法进行曲线拟合、神经网络法数据融合等软... 详细信息

传感器信号的非线性程度直接影响测量系统的精度,因而,必须对其进行线性化。针对传感器特性和转换电路的非线性可以采用硬件的方法进行线性化;而对其他因素的影响,可以采用智能系统,用最小二乘法进行曲线拟合、神经网络法数据融合等软件编程来实现;或者根据具体问题将二者结合。实验证明:这些都是实现线性化的好措施。

关键词：传感器线性化曲线拟合神经网络

Numerical Simulation of Droplet Generation in Coaxial Microchannels

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Fluid Dynamics & Materials Processing 2024年第3期20卷 487-504页

作者： Zongjun Yin Rong Su hui xu School of Mechanical Engineering Anhui Institute of Information TechnologyWuhu241100China

In this study,numerical simulations of the pinching-off phenomena displayed by the dispersed phase in a continuous phase have been conducted using COMSOL Multiphysics(level-set method).Four flow patterns,namely“drop flow”,“jet flow”,“squeeze flow”,and“co-flow”,have been obtained for different flow velocity ratios,channel diameter ratios,density ratios,viscosity ratios,and surface *** flow pattern map of two-phase flow in coaxial microchannels has been obtained accordingly,and the associated droplet generation process has been critically discussed considering the related frequency,diameter,and pinch-off *** particular,it is shown that the larger the flow velocity ratio,the smaller the diameter of generated droplets and the shorter the pinch-off *** pinch-off length of a droplet is influenced by the channel diameter ratio and density *** changes in viscosity ratio have a negligible influence on the droplet generation pinching *** an increase in surface tension,the frequency of generation and pinch-off length of droplets decrease,but for small surface tension the generation diameter of droplet increases.

关键词： Droplet generation characteristics coaxial microchannels flow patterns pinch-off length

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关于西藏高校科研创新团队建设的思考

西藏大学学报（社会科学版） 2013年第4期28卷 130-134,138页

作者：徐宝慧西藏大学理学院西藏拉萨850000

文章针对高等学校肩负的人才培养、科学研究、服务社会、文化传承创新等功能,分析了西藏高校科研创新团队建设的意义及建设现状。认为应从充分认识团队的作用、构建西藏高校创新团队支撑体系、形成结构合理的人才梯队、注重在创新团队... 详细信息

文章针对高等学校肩负的人才培养、科学研究、服务社会、文化传承创新等功能,分析了西藏高校科研创新团队建设的意义及建设现状。认为应从充分认识团队的作用、构建西藏高校创新团队支撑体系、形成结构合理的人才梯队、注重在创新团队带头人的培养上进行创新等方面来加强西藏高校创新团队建设,并为创新团队提供良好的制度和环境。

关键词：西藏高校创新团队建设

ZnO Additive Boosts Charging Speed and Cycling Stability of Electrolytic Zn–Mn Batteries

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Nano-Micro Letters 2024年第4期16卷 293-304页

作者： Jin Wu Yang Tang Haohang xu Guandie Ma Jinhong Jiang Changpeng Xian Maowen xu Shu‑Juan bao Hao Chen Institute for Clean Energy&Advanced Materials School of Materials and EnergySouthwest UniversityChongqing 400715People’s Republic of China

Electrolytic aqueous zinc-manganese(Zn–Mn) batteries have the advantage of high discharge voltage and high capacity due to two-electron reactions. However, the pitfall of electrolytic Zn–Mn batteries is the sluggish deposition reaction kinetics of manganese oxide during the charge process and short cycle life. We show that, incorporating ZnO electrolyte additive can form a neutral and highly viscous gel-like electrolyte and render a new form of electrolytic Zn–Mn batteries with significantly improved charging capabilities. Specifically, the ZnO gel-like electrolyte activates the zinc sulfate hydroxide hydrate assisted Mn^(2+) deposition reaction and induces phase and structure change of the deposited manganese oxide(Zn_(2)Mn_(3)O_8·H_(2)O nanorods array), resulting in a significant enhancement of the charge capability and discharge efficiency. The charge capacity increases to 2.5 mAh cm^(-2) after 1 h constant-voltage charging at 2.0 V vs. Zn/Zn^(2+), and the capacity can retain for up to 2000 cycles with negligible attenuation. This research lays the foundation for the advancement of electrolytic Zn–Mn batteries with enhanced charging capability.

关键词： Electrolytic aqueous zinc-manganese batteries Electrolyte pH value ZnO electrolyte additive Fast constant-voltage charging ability

Ultralow-phase-noise and broadband frequency-hopping coupled optoelectronic oscillator under quiet point operation

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Photonics Research 2024年第8期12卷 1785-1793页

作者： hui LIU MINGYANG GUO TIAN ZHANG JIAN DAI KUN xu State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Advancements in microwave photonics have yielded novel approaches for generating high-purity microwave *** these,optoelectronic oscillators(OEOs)and coupled optoelectronic oscillators(COEOs)have demonstrated the capability to generate frequency-independent microwaves with exceptionally low phase ***,the tunability of the oscillators is rather limited due to the necessity for narrowband electronic bandpass filters,presenting challenges in achieving both wide and rapid tuning ***,we present a COEO featuring ultralow phase noise,flexible tuning capability,and high *** is achieved through a quiet point(QP)-operated harmonic mode-locked fiber laser,which effectively mitigates optical amplifier noise and supermode competition,thus significantly diminishing the necessity for ultra-narrow electronic *** to the liberated tuning ability,we present an oscillator that can be tuned from 2 GHz to 18 GHz,with phase noise as low as-140 d Bc/Hz at 10 k Hz under the QP *** then illustrate the practical application of the proposed oscillator in generating frequency-hopping signals with consistent spurious modes less than-85 d Bc,absolute phase noise below-135 d Bc/Hz at 10 k Hz,hopping resolution of 1.25 MHz,and fractional frequency stability below 6.1×10^(-12)at 1 s averaging time when locked to a *** presented COEO structure emerges as a compelling solution for agile and low-noise microwave sources in advanced wireless communication and radar systems.

关键词： optoelectronic tuning amplifier

Exploring the impact of economic growth and energy consumption on SO2 emissions in China based on the Environmental Kuznets Curve hypothesis

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Petroleum Science 2024年第4期21卷 2892-2900页

作者： Bing-Jie xu Yi-Fei Shen hui Qiao Zhi Gao Faculty of Business City University of Macau Rural Development Institute Chinese Academy of Social Sciences School of Marxism Shenzhen Polytechnic University

This study aims to analysis the influence of economic growth(EG) and energy consumption(EC) on sulfur dioxide emissions(SE) in China. Accordingly, this study explores the link between EG, EC, and SE for 30 provinces in China over the span of 2000-2019. This study also analyzes cross-sectional dependence tests, panel unit root tests, Westerlund panel cointegration tests, Dumitrescu-Hurlin(D-H) causality tests. According to the test results, there is an inverted U-shaped association between EG and SE,and the assumption of the Environmental Kuznets Curve(EKC) is verified. The signs of EG and EC in the fixed effect(FE) and random effect(RE) methods are in line with those in the dynamic ordinary least squares(DOLS), fully modified ordinary least squares(FMOLS) and autoregressive distributed lag(ARDL)estimators. Moreover, the results verified that EC can obviously positive impact the SE. To reduce SE in China, government and policymakers can improve air quality by developing cleaner energy sources and improving energy efficiency. This requires the comprehensive use of policies, regulations, economic incentives, and public participation to promote sustainable development.

关键词： SO 2 emissions Economic growth Energy consumption EKC China

Effects of Fe solid solute on grain boundaries of bi-crystal Cu: A molecular dynamics simulation

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Nano Materials Science 2024年第1期6卷 86-95页

作者： Shuohan Yang Hongwei bao huizhong Bai Yan Li Haodong xu Fei Ma State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049ShaanxiChina

Grain boundaries(GBs)play a crucial role on the structural stability and mechanical properties of Cu and its *** this work,molecular dynamics(MD)simulations are employed to study the effects of Fe solutes on the formation energy,excess volume,dislocations and melting behaviors of GBs in CuFe *** is illustrated that Fe solute affects the structural stability of Cu GBs substantially,the formation energy of GBs is reduced,but the thickness and melting point of GBs are increased,that is,the structural stability of Cu GBs is significantly improved owing to the Fe solutes.A strong scaling law exists between the formation energy,excess volume,thickness and melting point of ***,Fe solid solute plays an important role in the characteristics of GBs in bi-crystal Cu.

关键词： CuFe alloy Grain boundary Structural stability MD simulations

Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

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Nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie Zhao Jin-hui Chen xu-Guang Huang Yu-Gang Ma Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)