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Applied Mathematics and Mechanics(English Edition) 2019年第4期40卷 549-562页

作者： qiang LYU Jingjing li Nenghui zhang Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Department of Mechanics College of Sciences Shanghai University

The quasi-static and dynamic responses of a thermoviscoelastic Timoshenko beam subject to thermal loads are analyzed. First, based on the small geometric deformation assumption and Boltzmann constitutive relation, the governing equations for the beam are presented. Second, an extended differential quadrature method(DQM)in the spatial domain and a differential method in the temporal domain are combined to transform the integro-partial-differential governing equations into the ordinary differential equations. Third, the accuracy of the present discrete method is verified by elastic/viscoelastic examples, and the effects of thermal load parameters, material and geometrical parameters on the quasi-static and dynamic responses of the beam are discussed. Numerical results show that the thermal function parameter has a great effect on quasi-static and dynamic responses of the beam. Compared with the thermal relaxation time, the initial vibrational responses of the beam are more sensitive to the mechanical relaxation time of the thermoviscoelastic material.

关键词： Timoshenko beam thermoviscoelasticity thermal load dynamic response,differential quadrature method(DQM)

Design and heat transfer analysis of a compound multi-layer insulations for use in high temperature cylinder thermal protection systems

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Science China(Technological Sciences) 2018年第7期61卷 994-1002页

作者： CHEN MengJun zhang Ping li qiang MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science & Technology School of Mechanical and Electrical Engineering Guilin University of Electronic Technology

Thermal protection systems are very essential for high temperature thermal conductivity measurement system to reduce the heat loss to environment at the range of 600-1800 K. A compound multi-layer insulations structure which composed of inner carbon fibrous materials and outer alternately arranged alumina fibrous materials and high reflectivity foils is proposed for use in high temperature cylinder thermal protection systems. A coupled conductive and radiation governing equations is presented for heat transfer analysis of the structure. The finite volume method and the discrete ordinate method are used to solve the goveming equations. The optimization structure of the compound multi-layer insulations is investigated by considering the pressure of the gas, the density of the carbon fibrous materials, the density of the alumina fibrous materials, the number of reflective foil layers and the emissivity of reflective foils. The results show that the compound structure has the best thermal insulation performance when the pressure of the gas is below 0.01 kPa, the density of carbon fibrous materials is 180 kg m^-3, the density of alumina fibrous materials is 256 kg m^-3 and the number of reflective foil layers is 39. In addition, the thermal insulation performance is much better when the emissivity of reflective foils is lower.

关键词： compound insulation heat transfer carbon fibrous alumina fibrous

Composition demixing effect on cathodic arc ion plating

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Journal of University of Science and Technology Beijing 2006年第2期13卷 125-130页

作者： Jun zhang li li lipeng zhang Shilu Zhao qiang Guo Department of Materials Science and Engineering. Shenyang University Shenyang 110044 China State Key Laboratory of Materials Modification by Laser Ion and Electron Beams Dalian 116024 China

The composition demixing effect has been found often in alloy coatings deposited by cathodic arc ion plating using various alloy cathode targets. The characteristics of composition demixing phenomena were summarized. Beginning with the ionization zone near the surface of the cathode target, a physical model in terms of the ions generated in the ionization zone and their movement in the plating room modified by bias electric field was proposed. Based on the concept of electric charge state, the simulation calculation of the composition demixing effect was carried out. The percentage of atoms of an element in coating and from the alloy target was demonstrated by direct comparison. The influences of the composition change of the alloy target and the bias electric field on the composition demixing effect were discussed in detail. It is also proposed that the average charge states of the elements may be used to calculate the composition demixing effect and to design the composition of the alloy target.

关键词： cathodic arc ion plating alloy coating composition demixing

Effect of cypermethrin insecticide on the microbial community in cucumber phyllosphere

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Journal of Environmental Sciences 2008年第11期20卷 1356-1362页

作者： zhang baoguo zhang Hongxun JIN Bo TANG ling YANG Jianzhou li Baoju ZHUANG Guoqiang BAI Zhihui Research Centre for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China School of Earth and Environmental Science University of Adelaide Adelaide SA 5005 Australia Graduate University of Chinese Academy of Sciences Beijing 100085 China Institute of Vegetables and Flowers Chinese Academy of Agricultural Sciences Beijing 100081 China

Cucumber (Cucumis sativus) is one of the most widely used vegetable in the world,and different pesticides have been extensively used for controlling the insects and disease pathogens of this ***,little is known about how the pesticides affect the microbial community in cucumber *** study was the first attempt to assess the impact of pyrethroid insecticide cyperemethrin on the microbial communities of cucumber phyllosphere using biochemical and genetic *** fatty ac...

关键词： cucumber cypermethrin insecticide microbial community phyllosphere phospholipid fatty acid (PLFA) T-RFLP

Influence of lanthanum on inclusions and as-cast microstructures in a low-alloy high-strength steel

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Journal of Iron and Steel Research International 2023年第12期30卷 2471-2481页

作者： Can liu Ji zhang qiang Ren li-feng zhang School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

Advanced high-strength steel ingots with total lanthanum(TLa)contents of 0,15×10^(–6),86×10^(–6)and 360×10^(–6)were prepared through laboratory *** modification of inclusions and the variation of the as-cast microstructure with the content of lanthanum in the high-strength steel were *** result showed that with the increase in the TLa content in the steel from 0 to 360×10^(–6),the modification path of inclusions in the as-cast steel was Al2O_(3)and calcium aluminate→LaAlO_(3)→La_(2)O_(2)S→La_(2)O_(2)S–La2O_(3).The addition of La in the high-strength steel significantly refined the solidification *** the increase in the TLa content in the steel from 0 to 360×10^(–6),the ratio of the equiaxed crystal region in the macrostructure increased from 30.1%to 50.7%,the proportion of the high-angle grain boundary in the microstructure increased from 36.9%to 69.8%,and the area fraction of the acicular ferrite and the bainite increased from 0 to 93.3%.Inclusions of LaAlO_(3),La_(2)O_(2)S and La2O_(3)in the La-containing steel could act as heterogeneous nucleation cores ofα-Fe during the *** the increase in the TLa content in the steel,the number density of inclusions that could act as effective heterogeneous nucleation cores in the steel gradually increased,which enlarged the ratio of the equiaxed crystal region and the proportion of intragranular acicular ferrite,and refined the as-cast microstructure of the high-strength steel.

关键词： Advanced high-strength steel Lanthanum Inclusion Heterogeneous nucleation As-cast microstructure

Control of Ultra Low Titanium in Ultra Low Carbon Al-Si Killed Steel

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Journal of Iron and Steel Research International 2013年第4期20卷 20-25页

作者： zhang Feng li Guang-qiang Silicon Steel Department Baoshan Iron and Steel Co.Ltd. Key Laboratory forFerrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and Technology

Titanium is the impurity in some special steel *** existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various ***,titanium should be removed to the *** on the industrial production of ultra low carbon Al-Si killed steel,the physical-chemical behavior of titanium was investigated in vacuum degassing refining（RH）process with and without *** influences of titanium content in hot metal,ladle slag composition,and ladle slag quantity,etc,on titanium content of refined liquid steel were *** results showed that the partition ratio of titanium between ladle slag and liquid steel is in inverse proportion to the 4/3square of aluminum *** maximum partition ratio of titanium between top slag and liquid steel can be obtained by adjusting an optimum slag composition including contents of FeOxand Al2O3and the slag basicity,and the suitable range of them should be controlled higher than 6%,less than 20%,and within 1.5to 3.0,***,desulfurization refining by RH decreases the partition ratio of titanium between ladle slag and liquid steel *** ensure the titanium content stably less than 15×10-6 in a 300tladle,the titanium content in hot metal must be less than 500×10-6 and the thickness of basic oxygen furnace（BOF）slag carrying over must be less than 50mm.

关键词： titanium desulfurization RH refining ultra low carbon steel Al-Si killed steel

Effect of methylimidazolium-based ionic liquids on vapor–liquid equilibrium behavior of tert-butyl alcohol + water azeotropic mixture at 101.3 kPa

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Chinese Journal of Chemical Engineering 2016年第3期24卷 365-372页

作者： Zhigang zhang qiang zhang Tao zhang Qinqin zhang Wenxiu li liaoning Provincial Key Laboratory of Chemical Separation Technology Shenyang University of Chemical Technology

Three ionic liquids(ILs),1-ethyl-3-methylimidazolium bromine([EMIM]Br),1-butyl-3-methylimidazolium bromine([BMIM]Br),and 1-hexyl-3-methylimidazolium bromine([HMIM]Br),were used as the solvent for separation of {tert-butyl alcohol(TBA)+ water} ***–liquid equilibrium(VLE)data for {TBA + water + IL}ternary systems were measured at 101.3 k *** results indicate that all the three ILs produce an obvious effect on the VLE behavior of {TBA + water} system and eliminate the azeotropy in the whole concentration range.[EMIM]Br is the best solvent for the separation of {TBA + water} system by extractive distillation among the three *** experimental VLE data for the ternary systems are correlated with the NRTL model equation with good *** are given with activity coefficients of water and TBA,and the experimental VLE-temperature data for {TBA or water + IL} binary systems.

关键词： Azeotrope Ionic liquids Vapor-liquid equilibrium Relative volatility NRTL model

Emerging energy chemistry in lithium-sulfur pouch cells

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Science China Chemistry 2021年第3期64卷 337-338页

作者： Bo-Quan li qiang zhang Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

On pursuing high-energy-density energy storage systems beyond the current lithium-ion battery technique, lithium-sulfur(li-S) batteries have attracted worldwide attention due to their ultrahigh theoretical energy density up to 500 Wh kg-1[1]. The unique li-S chemistry based on the conversion reactions between solid sulfur, dissolved lithium polysulfides, and solid lithium sulfide affords thermodynamic advantages including high cathode specific capacity and low anode potential [2].

关键词： battery lithium energy

Total Electricity Consumption Forecasting Based on Temperature Composite Index and Mixed-Frequency Models

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Data Intelligence 2023年第3期5卷 750-766页

作者： Xuerong li Wei Shang Xun zhang baoguo Shan Xiang Wang Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China MOE Social Science Laboratory of Digital Economic Forecasts and Policy Simulation at UCAS State Grid Energy Research Institute CO. LTDBeijing 102209China

The total electricity consumption(TEC)can accurately reflect the operation of the national economy,and the forecasting of the TEC can help predict the economic development trend,as well as provide insights for the formulation of macro ***,high-frequency and massive multi-source data provide a new way to predict the *** this paper,a"seasonal-cumulative temperature index"is constructed based on high-frequency temperature data,and a mixed-frequency prediction model based on multi-source big data(Mixed Data Sampling with Monthly Temperature and Daily Temperature index,MIDAS-MT-DT)is *** results show that the MIDAS-MT-DT model achieves higher prediction accuracy,and the"seasonal-cumulative temperature index"can improve prediction accuracy.

关键词： Total electricity consumption seasonal effect temperature big data high-frequency big data mixedfrequency prediction model

Age-specific mortality and fecundity of a spider mite under diet restriction and delayed mating

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Insect Science 2022年第3期29卷 889-899页

作者： Guang-Yun li Zhi-qiang zhang Centre for Biodiversity and Biosecurity School of Biological SciencesUniversity of AucklandAucklandNew Zealand Manaaki Whenua-Landcare Research AucklandNew Zealand Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqingChina

Numerous experimental life-history studies on aging are mainly baised on two classical models—fruit fly Drosophila melanogaster(Meigen)and nematode Caenorhab-ditis elegans(Maupas)—with relatively little attention given to other organisms with different life-history ***-spotted spider mite Tetranychus urticae Koch(Acari:Tetranychidae)differs from many other arthropods in that the females continue their growth in the early adult stage and can reproduce sexually and *** this study,the influences of dietary restriction and delayed mating on the aging patterns of the spider mite were examined with the prevailing survival and reproduction trade-off hypothesis of aging being *** sex-specific responses of the spider mites were *** females showed longevity extension on diet restriction(fasting for 2 days in every 4 days)compared with their counterparts being fed ad libitum,and after delayed mating for 9 days,while the males displayed a decrease in lifespan when experiencing diet restriction but were not significantly influenced by delayed *** analysis was used to investigate the relationship between mite survival and reproduction traits,including longevity,female lifetime reproduction,age at first reproduction,early reproductive efforts and late reproductive efforts,yielding no evidence for trade-offs between these life-history *** additive effects of dietary restriction and delayed mating in lifespan extension of female spider mites were confirmed,proving that diet restriction is a robust anti-aging intervention,and that later onset of reproduction can prolong adult lifespan in females.

关键词： age-specific mortality delayed mating diet restriction reproduction sex difference trade-off