检索结果-南通市图书馆

An interface shear damage model of chromium coating/steel substrate under thermal erosion load

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第2期17卷 405-415页

作者： xiao-long Li Yong Zang Yong Lian Min-yu Ma Lei mu Qin Qin School of Mechanical Engineering University of Science and Technology BeijingBeijing100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory for Corrosion Erosion and Surface TechnologyBeijing100083China

The Cr-plated coating inside a gun barrel can effectively improve the barrel’s erosion resistance and thus increase the service ***,due to the cyclic thermal load caused by high-temperature gunpowder,micro-element damage tends to occur within the Cr coating/steel substrate interface,leading to a gradual deterioration in macro-mechanical properties for the material in the related *** order to mimic this cyclic thermal load and,thereby,study the thermal erosion behavior of the Cr coating on the barrel’s inner wall,a laser emitter is utilized in the current *** the help of in-situ tensile test and finite element simulation results,a shear stress distribution law of the Cr coating/steel substrate and a change law of the interface ultimate shear strength are *** have shown that the Cr coating/steel substrate interface’s ultimate shear strength has a significant weakening effect due to increasing *** this study,the interfacial ultimate shear strength decreases from 2.57 GPa(no erosion)to 1.02 GPa(laser power is 160 W).The data from this experiment is employed to establish a Cr coating/steel substrate interface shear damage *** this model is used to predict the flaking process of Cr coating by finite element *** simulation results show that the increase of coating crack spacing and coating thickness will increase the service life of gun barrel.

关键词： Cr coating/steel substrate Thermal erosion Finite element simulation Ultimate shear strength Interface shear damage model

The molecular basis of heat stress responses in plants

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2023年第10期16卷 1612-1634页

作者： Yi Kan xiao-Rui mu Jin Gao Hong-Xuan Lin Youshun Lin National Key Laboratory of Plant Molecular Genetics CAS Centre for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China Joint Center for Single Cell Biology School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghai 200240China University of the Chinese Academy of Sciences Beijing 100049China Guangdong Laboratory for Lingnan Modern Agriculture Guangzhou 510642China

Global warming impacts crop production and threatens food *** temperatures are sensed by different cell *** increases are classified as either mild warm temperatures or excessively hot temperatures,which are perceived by distinct signaling pathways in *** temperatures induce thermomorphogenesis,while high-temperature stress triggers heat acclimation and has destructive effects on plant growth and *** this review,we systematically summarize the heat-responsive genetic networks in Arabidopsis and crop plants based on recent *** addition,we highlight the strategies used to improve grain yield under heat stress from a source-sink *** also discuss the remaining issues regarding the characteristics of thermosensors and the urgency required to explore the basis of acclimation under multifactorial stress combination.

关键词： global warming thermosensing heat stress thermomorphogenesis heat stress responses heat acclimation

Numerical simulation:preparation of La_2O_3 in a jet pyrolysis reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2015年第8期34卷 600-606页

作者： Chao Lv Zi-mu Zhang Qiu-yue Zhao Zhi-He Dou Ting-An Zhang Hong-Liang Zhao Key Laboratory of Ecological Utilization of multi-metal Intergrown Ores of Ministry of Education School of Materials and Metallurgy Northeastern University Department of Mathematics Northeast Petroleum University at Qinhuangdao

Based on the technique for preparing La Cl3 via direct pyrolysis of rare earth chloride solution, a jet pyrolysis reactor was designed and the intra-reactor temperature and chemical reactions were numerically simulated using computational fluid dynamics(CFD) *** results show that the flow rate variation at the fuel inlet does not largely affect the temperature in the reactor, while the increase in external pressure at the material inlet rapidly decreases the average temperature, Venturi temperature, and outlet temperature. The CH4 and O2inside the reactor are combusted completely, and when the material inlet pressure is \90 Pa, the La Cl3 is fully pyrogenated. The contents of CO2, La2O3, and HCl fluctuate near the Venturi tube and finally stabilize. La2O3 content at the outlet is in a top-to-bottom gradient.

关键词： Jet-flow Pyrolysis Chemical reaction Numerical sim

Loss of ozone on sulfate and sulfide doped ice surfaces

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2000年第2期12卷 64-68页

作者： mu, Yu-Jing Zhang, xiao-Shan Liu, Ye Yang, Wen-Xiang Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The sticking coefficients of ozone on ice surface and solid solution of sulfate and sulfide were measured over a temperature range from 200K to 260K. Experiments were performed in a horizontal flow tube. Results indicate that the sticking coefficients of ozone on ice are in the range from 1 3×10 -7 to 2 7×10 -6 , and it will become larger as temperature increases; the sticking coefficients of ozone on eight kinds of 0.1mol/L sulfate doped ice are in the range from 1 8×10 -7 to 6 9×10 -6 ; the sticking coefficients of ozone on four kinds of 0 1 mol/L sulfide doped ice are in the range from 3 2×10 -7 to 2 1×10 -5 . Ozone loss on these particles was evaluated.

关键词： sticking coefficient ozone ice flow\|tube sulfate sulfide CLC number: X132 Document code: A

Excellent Color Sensitivity of Butterfly Wing Scales to Liquid Mediums

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2016年第3期13卷 355-363页

作者： Zhiwu Han Meng Yang Bo Li Zhengzhi mu Shichao Niu Junqiu Zhang xiao Yang Key Laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun 130022 China State Key Laboratory of Automotive Simulation and Control Jilin University Changchun 130022 China Hangzhou Branch of Technical Institute of Physics and Chemistry Chinese Academy of Sciences Hangzhou 310018 China School of Mechanical Engineering Hangzhou Dianzi University Hangzhou 310018 China

The ultrastructure characteristic and vivid colors of butterfly wing scales have attracted considerable attention recently. Surprisingly, these hyperfine structures also endow butterfly Trogonoptera brookiana wing scales the excellent color sensitive property to liquid mediums. In this work, the characteristic features of this excellent functional surface and the mechanism of its highly sensitive response characteristics were investigated. Firstly, the extraordinary and ordered nanostructures of this butterfly wing scales were characterized by a Field Emission Scanning Electron Microscope （FESEM）. Then, the ultra-depth three-dimensional （3D） microscope was used to observe the sensitive discoloration effect of the scales to liquid mediums. Afterwards, the highly spectral sensitive feature was identified by a mini spectrometer. In addition, the mechanism of this color sensitive effect of butterfly wing scales was revealed through modelling, calculation and simulation. It was found that this sensitivity is caused by the combined action of the microscale scales and the ultra-fine nanoscale structures in scale surface. On one hand, the arched and bended cover scales were stretched and superimposed by the filled ether solution. So, the color of the scales became reddish brown in an instant. On the other hand, the change of the fill mediums with different reflective index induced the modification of the surface interference, resulting in the peak shift of the reflectance spectrum. More importantly, the results of simulation and theoretical calculation were both in agreement with the experimental results. It illustrated that the butterfly TrogonOptera brookiana wings have repeatable sensitivity to liquid mediums, and obvious discoloration sensitive effect. This spectral sensitivity of butterfly wing scales has great prospect and meaning for the basic research and application of cheap, environmentally free and biodegradable sensitive element for water quality monitoring and

关键词： color sensitivity micro and nanostructures butterfly wing scales bionics

Semiparametric Analysis of Longitudinal Data with Informative Observation Times

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2011年第1期27卷 29-42页

作者： Liu-quan Sun xiao-yun mu Zhi-hua Sun Xing-wei Tong Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China School of mathematical Sciences Beijing Normal University Beijing 100875 China

In many longitudinal studies, observation times as well as censoring times may be correlated with longitudinal responses. This paper considers a multiplicative random effects model for the longitudinal response where these correlations may exist and a joint modeling approach is proposed via a shared latent variable. For inference about regression parameters, estimating equation approaches are developed and asymptotic properties of the proposed estimators are established. The finite sample behavior of the methods is examined through simulation studies and an application to a data set from a bladder cancer study is provided for illustration.

关键词： Estimating equations Informative observation times Joint modeling Latent variables,Longitudinal data

Fatigue Strength Improvement of Welded Joint by Ultrasonic Peening in Ultra-Fine Grain Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2003年第3期10卷 64-66页

作者： TIAN Zhi-ling ZOU Gang HE Chang-hong ZHANG xiao-mu Central Iron and Steel Research Institute

The influence of rare earths (RE) on carbides in high carbon steel weld metal was studied by transmission electron microscope (TEM) and energy dispersive X ray microanalysis (EDX). It is found that rare earth markedly affects the quantity, morphology and distribution of carbides. The precipitating mechanism of carbides was proposed in which rare earth compounds with high surface energy serve as the nucleation sites for carbides in superheated liquid metal and the induced carbides are precipitated extensively and distributed evenly. The preferential precipitation of carbides decreases the carbon content in matrix, which is transformed into low carbon lath martensite after welds are chilled to room temperature.

关键词： rare earth metal carbide weld

Prediction of freestanding semiconducting bilayer borophenes

在线全文

学校读者我要写书评

暂无评论

Nano Research 2022年第6期15卷 5752-5757页

作者： Yuan-Yuan Ma xiao-Yun Zhao Wenyan Zan yuewen mu Zhuhua Zhang Si-Dian Li Institute of Molecular Science Shanxi UniversityTaiyuan 030006China Fenyang College of Shanxi Medical University Fenyang 032200China Department of Applied Chemistry Yuncheng UniversityYuncheng 044000China State Key Laboratory of Mechanics and Control of Mechanical Structures and Key Laboratory for Intelligent Nano Materials and Devices of Ministry of EducationNanjing University of Aeronautics and AstronauticsNanjing 210016China

Supported bilayerα-borophene(BL-αborophene)on Ag(111)substrate has been synthesized in recent *** on the experimentally observed quasi-planar C_(6v)B_(36)(1),its monolayer assemblyα^(+)-borophene B_(11)(P6/mmm)(2),and extensive global minimum searches augmented with density functional theory calculations,we predict herein freestanding BL-α^(+)borophenes B_(22)(Cmmm)(3)and B_(22)(C2/m)(4)which,as the most stable BL borophenes reported to date,are composed of interwoven boron triple chains as boron analogs of monolayer graphene(5)consisting of interwoven carbon single *** nearly degenerate eclipsed B_(22)(3)and staggered B_(22)(4)with the hexagonal hole density ofη=1/12 and interlayer bonding density of u=1/4 appear to be two-dimensional semiconductors with the indirect band gaps of 0.952 and 1.144 eV,*** bonding analyses reveal one delocalized 12c-2eπbond over each hexagonal hole in both the B_(22)(3)and B_(22)(4),similar to the situation in monolayer graphene which contains one delocalized 6c-2eπbond over each C_(6)***,these BL-α^(+)borophenes appear to remain highly stable on Ag(111)substrate,presenting the possibility to form supported BL-α+borophenes.

关键词： boron nanomaterials blayer borophenes structures bonding semiconductors

Post-miosis changes in the anterior chamber structures in primary and lens-induced secondary chronic angle-closure glaucoma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2019年第4期12卷 675-680页

作者： mu Li xiao-Qin Yan Gai-Yun Li Hong Zhang Department of Ophthalmology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Retinal Department Shanxi Eye Hospital

To evaluate post-miosis changes in the anterior chamber structures in various angle-closure glaucomas(ACG). Totally 14 eyes of primary chronic angle-closure glaucoma(PCACG), 12 eyes of lens-induced secondary chronic angleclosure glaucoma(LSACG) and 14 healthy eyes were recruited. After miosis, for PCACG group, intraocular pressure(IOP) and anterior chamber depth(ACD) changed not significantly, while anterior chamber angle widened significantly. LSACG group showed a significant increase in IOP, decrease in ACD, and narrowing in anterior chamber angle. Healthy eyes showed significant decreases in IOP and anterior chamber parameters. Thus, miosis could widen the anterior chamber angle of patients with PCACG, while increase the narrowing of anterior chamber angle and IOP of patients with LSACG. We should pay attention to the distinction between PCACG and LSACG patients and the proper administration of pilocarpine in the treatment of patients with chronic ACG.

关键词： miosis chronic angle-closure glaucoma anterior chamber structure intraocular pressure optical coherence tomography