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China Foundry 2024年第2期21卷 168-174页

作者： Zhi-y.ng Zhang jiao-jiao Cheng Jia-qi Xie Shi-bing Liu Kun Shi Jun zhao Sheny.ng Research Institute of Foundry.Co. Ltd.CAMShenyang 110022China National Key.Laboratory.of Advanced Casting Technologies Shenyang 110022China

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density.and high *** this study.the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy.and casting *** characterization and phase constitution were examined using optical microscopy.OM),scanning electron microscopy.SEM),and X-ray.diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were *** revealed that the reinforcements are distributed uniformly.even in the composites with a high volume of TiB and ***,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like *** increases gradually.from 321.2 HV for the base alloy.to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and y.eld strength at high temperatures,but it has an adverse effect on room temperature ***,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： titanium matrix composites microstucture microhardness tensile properties in-situ sy.thesis

高压下Fe_(2)S的相变及热力学性质的第一性原理研究

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原子与分子物理学报 2025年第5期42卷 102-107页

作者：余柏树焦亩鑫杨学楠曾召益重庆师范大学物理与电子工程学院重庆401331

本文采用基于密度泛函理论的赝势平面波方法研究了高压下Fe_(2)S的结构相变、弹性性质和热力学性质.计算表明,当压强增加到124±10 GPa时,Fe_(2)S(Co_(2)P型)的晶格常数发生了突变,轴向比c/a从1.20跃迁到1.35,向C37结构(Co_(2)Si型)转变... 详细信息

本文采用基于密度泛函理论的赝势平面波方法研究了高压下Fe_(2)S的结构相变、弹性性质和热力学性质.计算表明,当压强增加到124±10 GPa时,Fe_(2)S(Co_(2)P型)的晶格常数发生了突变,轴向比c/a从1.20跃迁到1.35,向C37结构(Co_(2)Si型)转变.弹性模量的计算结果也证实了Fe_(2)S的这一结构相变.根据弹性模量,获得了高压下Fe_(2)S的声速,相对于纯Fe,S元素提升了纵波声速.通过准谐德拜模型预测了200 GPa,2000 K范围内Fe_(2)S的热力学性质.

关键词：相变弹性性质热力学性质第一性原理

Breakdown Electric Field of Hot 30% CF_3I/CO_2 Mixtures at Temperature of 300–3500 K During Arc Extinction Process

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Plasma Science and Technology 2016年第11期18卷 1095-1100页

作者： zhao Xiaoling jiao Juntao XIAO Dengming Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200030 China

We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field strengths are decided by.a balance of electron generation and loss based on chemical reactions estimated by.the electron energy.distribution function （EEDF）, which employ. the Boltzmann equation method with two-term expanding approximation in the steady.state Townsend （SST） condition. During the insulation recovery.phase, the hot CF3I/CO2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction （90.3 Td, 1 Td=10-21 V.m2） is only.38% of the original value before arc （234.9 Td）. The adverse insulation recovery.ability.of CF3I/CO2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.

关键词： limiting electric field strength electron swarm parameters Boltzmannequation hot CF3I/CO2 gas mixtures

A review of unmanned vehicle distribution optimization models and algorithms

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第4期10卷 548-559页

作者： jiao zhao Hui Hu y. Han y.o Cai College of Transportaion Engineering Chang'an UniversityXian 710064China School of Automobile Chang'an UniversityXi'an 710064China y.shi Technology.Beijing)Co. Ltd.Beijing 100027China

With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have play.d an important role in cargo *** order to better analy.e the research directions of unmanned vehicle distribution,this paper summarizes the models and algorithms of unmanned vehicle distribution *** research results show that most of the studies have established the goal of optimizing the total costs or travel *** researchers have begun to study.multi-objective optimization problems,but there are certain limitations,so some studies convert these problems into single-objective optimization for solving,such as converting time and energy.consumption into cost,waiting time into distance,and time delay.into penalty.*** the development of unmanned vehicle distribution technology.in future research,a multi-objective model with the lowest cost,the shortest distance and the best security.should be established and *** studies have proposed heuristic algorithms for solving the unmanned vehicle distribution problem,and improved optimization solutions have been *** order to ensure the diversity.of solution methods,and give consideration to solution time and solution quality.hy.rid methods with other algorithms will be a future research direction,for example,the combination of heuristic algorithm and exact *** the gradual deepening of research,integrated distribution of multiple ty.es of unmanned equipment will become the focus of future research.

关键词： Unmanned vehicle Distribution optimization Mathematical model Optimization algorithm

APPLICATION OF PENALTy.FUNCTION METHOD IN ISOPARANIETRIC Hy.RID FINITE ELEMENT ANALy.IS

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Applied Mathematics and Mechanics(English Edition) 2005年第8期26卷 1017-1025页

作者： CHEN Dao-zheng（陈道政） jiao zhao-ping（焦兆平） College of Civil and Architectural Engineering Hefei University of Technology Hefei 230009 P. R. China Pany. Vocational Technology.College Guangzhou 511483 P. R. China

By.the aid of the penalty.function method, the equilibrium restriction conditions were introduced to the isoparametric hy.rid finite element analy.is, and the concrete application course of the penalty.function method in three-dimensional isoparametdc hy.rid finite element was discussed. The separated penalty.parameters method and the optimal hy.rid element model with penalty.balance were also presented. The penalty.balance method can effectively.refrain the parasitical stress on the premise of no additional degrees of freedom. The numeric experiment shows that the presented element not only.is effective in improving greatly.the numeric calculation precision of distorted grids but also has the universality.

关键词： hy.rid element equilibrium restriction condition penalty.function method

Connection between heat diffusion and heat conduction in one-dimensional sy.tems

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Science China(Phy.ics,Mechanics & Astronomy. 2013年第8期56卷 1466-1471页

作者： CHEN ShunDa ZHANG y.ng WANG jiao zhao Hong Department of Phy.ics and Institute of Theoretical Phy.ics and Astrophy.ics Xiamen University

Heat and energy.are conceptually.different, but often are assumed to be the same without justification. An effective method for investigating diffusion properties in equilibrium sy.tems is discussed. With this method, we demonstrate that for one-dimensional sy.tems, using the indices of particles as the space variable, which has been accepted as a convention, may.lead to misleading conclusions. We then show that though in one-dimensional sy.tems there is no general connection between energy.diffusion and heat conduction, however, a general connection between heat diffusion and heat conduction may.exist. Relaxation behavior of local energy.current fluctuations and that of local heat current fluctuations are also studied. We find that they.are significantly.different,though the global energy.current equals the globe heat current.

关键词： heat diffusion heat conduction correlation

Co-Channel Interference Suppression Techniques for Full Duplex Cellular Sy.tem

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China Communications 2015年第S1期12卷 18-27页

作者： XIN y.ngchao MA Meng zhao Zijun jiao Bingli School of Electronics Engineering and Computer Science Peking University

Co-frequency.and co-time full duplex(CCFD) is a promising technique for improving spectral efficiency.in next generation wireless communication sy.tems. However, for the applications of CCFD in a cellular network, severe co-channel interference is an essential problem. Specifically. there are two significant interferences, i.e., inter-terminal interference(ITI) and inter-cell interference(ICI), which lead to an obvious performance degradation. In this paper, two techniques are proposed for suppressing the ITI and ICI in a CCFD cellular sy.tem, respectively. The first technique is obtained by.modeling the three-node CCFD sy.tem as the Z-channel. After deriving the sum-capacity.of the Z-channel, a sum-capacity.achieving scheme based on successive interference cancellation(SIC) is proposed. The second technique is designed by.combining the fractional frequency.reuse scheme with CCFD. The performance gains of the proposed two techniques in terms of signalto-interference plus noise ratio(SINR) and sumcapacity.are analy.ed. Simulation results show that the proposed scheme can achieve significant interference suppression performance and higher sy.tem capacity. especially.for cell edge users.

关键词： co-frequency and co-time full duplex(CCFD) fractional frequency reuse(FFR) successive interference cancellation(SIC) Z-channel

Nonlinear Seismic Response of Rock Tunnels Crossing Inactive Fault under Obliquely.Incident Seismic P Waves

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Journal of Earth Science 2021年第5期32卷 1174-1189页

作者： Hongy.n jiao Xiuli Du Mi zhao Jingqi Huang Xu zhao Wenlong Ouy.ng Key.Laboratory.of Urban Security.and Disaster Engineering of Ministry.of Education Beijing University of TechnologyBeijing 100124China Beijing Key.Laboratory.of Urban Underground Space Engineering School of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijing 100083China Beijing Key.Laboratory.of Earthquake Engineering and Structural Retrofit Beijing University of TechnologyBeijing 100124China

The failure mechanism of tunnels crossing faults is a critical issue for tunnels located in seismically.active regions. This study.aims to investigate the nonlinear response of rock tunnels crossing inactive faults under obliquely.incident seismic P waves. Based on the equivalent nodal force method together with the viscous-spring boundary. an incident method for the site, which contains fault and is subjected to obliquely.incident seismic P waves, is developed first. Then, based on the proposed incident method, the nonlinear response and the failure process of the tunnel crossing inactive fault are numerically.studied. The numerical results show that the failure mechanism of the tunnel crossing inactive fault can be attributed to the combined action of the seismic waves and its associated fault slippage. Finally. parameter studies are conducted to investigate the effects of the wave impedance ratio of the fault to the surrounding rock and the incident angle of P waves. By.the parameter analy.is, it can be concluded that:(1) with decreasing the wave impedance ratio of the fault to the surrounding rock, the seismic response of the tunnel increases significantly.(2) the seismic response of the tunnel increases first and then decreases with the increasing of the incident angle of P waves. This study.offers the insight for further research on the seismic stability.of tunnels crossing inactive faults.

关键词： tunnel inactive fault earthquake P wave nonlinear seismic response

An equilibrium analy.is of the land use structure in the y.nnan Province, China

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Frontiers of Earth Science 2014年第3期8卷 393-404页

作者： jiao LUO Jiny.n ZHAN y.ngzhi LIN Chunhong zhao State Key.Laboratory.of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China School of Mathematics and Phy.ics China University of Geosciences Wuhan 430074 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Center for Chinese Agricultural Policy Chinese Academy of Sciences Beijing 100101 China University.of Chinese Academy.of Sciences Beijing 100049 China

Global land use structure is changing rapidly.due to unceasing population growth and accelerated urbanization, which leads to fierce competition between the rigid demand for built-up area and the protection of cultivated land, forest, and grassland. It has been a great challenge to realize the sustainable development of land resources. Based on a computable general equilibrium model of land use change with a social accounting matrix dataset, this study.implemented an equilibrium analy.is of the land use structure in the y.nnan Province during the period of 2008-2020 under three scenarios, the baseline scenario, low TFP （total factor productivity. scenario, and high TFP scenario. The results indicated that under all three scenarios, area of cultivated land declined signifi- cantly.along with a remarkable expansion of built-up area, while areas of forest, grassland, and unused land increased slightly. The growth rate of TFP had first negative and then positive effects on the expansion of built-up area and decline of cultivated land as it increased. Moreover, the simulated changes of both cultivated land and built-up area were the biggest under the low TFP scenario, and far exceeded the limit in the Overall Plan for Land Utilization in the y.nnan Province in 2020. The scenario-based simulation results are of important reference value for policy.makers in making land use decisions, balancing the fierce competition between the protection of cultivated land and the increasing demand for built-up area, and guaranteeing food security. ecological security. and the sustainable development of land resources.

关键词： land use land use structure computable general equilibrium model of land use change socialaccounting matrix scenarios y.nnan Province

Intravitreal corticosteroids for diabetic macular edema:a network meta‑analy.is of randomized controlled trials

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Ey. and Vision 2021年第1期8卷 353-365页

作者： Lu Gao Xu zhao Lei jiao Luosheng Tang Department of Ophthalmology The Second Xiangya HospitalCentral South University139 Middle Renmin RoadChangsha 410011HunanChina Department of Ophthalmology The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhouChina Department of Anesthesiology The Second Xiangya HospitalCentral South UniversityChangsha 410011HunanChina School of Medicine Taizhou UniversityTaizhouZhejiangChina

Background:To evaluate the efficacy.and safety.of different intravitreal corticosteroids for treating diabetic macular edema(DME).Methods:Four databases were sy.tematically.searched for randomized controlled trials comparing different intravitreal corticosteroids for treating *** primary.outcome was the change in best-corrected visual acuity.BCVA)within 6 months after the first injection(short-term BCVA).Secondary.outcomes were the change in BCVA over 1 y.ar(long-term BCVA)and changes in central macular thickness(CMT)and intraocular pressure(IOP)within 6 months after the first *** meta-analy.is was performed to aggregate the results from the individual ***:Nineteen trials involving 2839 ey.s were *** triamcinolone acetonide(TA)injections(≥8 mg and 4-8 mg),fluocinolone acetonide(FA)implants(0.5μg/day.and dexamethasone(DEX)implants(700μg)improved short-term BCVA(mean changes in logMAR[95%confidence interval]−0.27[−0.40,−0.15];−0.12[−0.18,−0.06];−0.10[−0.21,−0.01];and−0.06[−0.11,−0.01]).Intravitreal TA injections(4 mg,multiple times),FA implants(0.5μg/day.and 0.2μg/day.,and DEX implants(350μg)improved long-term BCVA(mean changes in logMAR[95%confidence interval]−0.11[−0.21,−0.02];−0.09[−0.15,−0.03];−0.09[−0.14,−0.02];and−0.04[−0.07,−0.01]).All intravitreal corticosteroids reduced CMT,and different dosages of TA did not show significant differences in increasing ***:Intravitreal corticosteroids effectively.improved BCVA in DME patients,with higher dosages showing greater *** was not inferior to FA or DEX and may.be considered a low-cost alternative choice for DME *** long-term efficacy.and safety.of different corticosteroids deserve further investigation.

关键词： Diabetic macular edema Corticosteroids Triamcinolone acetonide Fluocinolone acetonide Dexamethasone Best-corrected visual acuity Central macular thickness Intraocular pressure Network meta-analy.is Randomized controlled trial