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THERMAL AND THERMO-ELASTIC-PLASTIC RESPONSE OF CERAMIC-METAL FUNCTIONALLY GRADED MATERIALS—THERMAL SHOCK PROBLEM

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Acta Mechanica Solida Sinica 1997年第2期10卷 148-156页

作者： Zhai, PC zhang, qj Yuan, RZ WUHAN UNIV TECHNOL STATE KEY LAB MAT SYNTH & PROCWUHAN 430070PEOPLES R CHINA

The thermal and thermo-elastic-plastic response of newly developed ceramic-metal functionally graded materials under a thermal shock load is studied. The materials are heated at the ceramic surface with a sudden high-intensity heat flux input, and cooled at the metal surface with a flowing liquid nitrogen. Emphasis is placed on two aspects: (1) the influence of the graded composition of the materials on the temperature and stress response; and (2) the optimum design of the graded composition from a unified viewpoint of the heat insulation property and stress relaxation property. Moreover, a comparison between the thermoelastic stress and the thermo-elastic-plastic stress is also made to indicate the plasticity effect.

关键词： functionally graded materials thermal shock thermo-elastic-plastic response

INSTANTANEOUS THERMAL EXPANSION BEHAVIOR OF HETEROGENEOUS MATERIALS WITH A WORK-HARDENING ELASTOPLASTIC MATRIX AND ELASTIC SPHEROIDAL INHOMOGENEITIES

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Acta Mechanica Solida Sinica 1995年第3期8卷 202-219页

作者： zhang, qj NAN, CW YUAN, RZ WUHAN UNIV TECHNOL STATE KEY LAB MAT SYNTH & PROCWUHAN 430071PEOPLES R CHINA

The instantaneous thermal expansion behavior of-two-phase heterogeneous materials subjected to a uniform temperature change is explored in the present study. The matrix phase is assumed to be a work-hardening ductile metal and the dispersive phase is assumed to consist of either aligned or randomly-oriented, elastic,, spheroidal inhomogeneities. The plastic flow and decreasing stiffness of the matrix during Eshelby's transformation strain of the equivalent inclusions are accounted for by using the deformation theory of plasticity. The explicit results of the instantaneous overall thermal expansion coefficients and the critical inelastic temperature changes are presented for aligned disc- and fiber-inclusions. For the spherical and randomly-oriented spheroidal inclusion, the present study demonstrates that when the yielding of the composites is governed by the average matrix stress, the overall response is always elastic in spite of the temperature change.

关键词： WORK-HARDENING PLASTIC FLOW AVERAGE MATRIX STRESS

A THEORY OF EFFECTIVE THERMAL CONDUCTIVITY FOR MATRIX-INCLUSION-MICROCRACK THREE-PHASE HETEROGENEOUS MATERIALS BASED ON MICROMECHANICS

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Acta Mechanica Solida Sinica 2000年第2期13卷 179-187页

作者： zhang, qj Zhai, PC Li, Y Wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China

The effective thermal conductivity of matrix-inclusion-microcrack three-phase heterogeneous materials is investigated with a self-consistent micromechanical method (SCM) and a random microstructure finite element method(RMFEM). In the SCM, microcracks are assumed to be randomly distributed and penny-shaped and inclusions to be spherical, the crack effect is accounted for by introducing a crack density parameter, the effective thermal conductivity is derived which relates the macroscopic behavior to the crack density parameter. In the RMFEM, the highly irregular microstructure of the heterogeneous media is accurately described, the interaction among the matrix-inclusion-microcracks is exactly treated, the inclusion shape effect and crack size effect are considered. A Ni/ZrO2 particulate composite material containing randomly distributed, penny-shaped cracks is examined as an example. The main results obtained are: (1) the effective thermal conductivity is sensitive to the crack density and exhibits essentially a linear relationship with the density parameter: (2) the inclusion shape has a significant effect on the effective thermal conductivity and a polygon-shaped inclusion is more effective in increasing or decreasing the effective thermal conductivity than a sphere-shaped one; and (3) the SCM and RMFEM are compared and the two methods give the same effective property in the case in which the matrix thermal conductivity A, is greater than the inclusion one lambda(2). In the inverse case of lambda(1) < lambda(2), the two methods as the as the inclusion volume fraction and crack density are low and differ as they are high. A reasonable explanation for the agreement and deviation between the two methods in the case of lambda(1) < lambda(2) is made.

关键词： effective thermal conductivity heterogeneous materials microcracks micromechanics

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反常失眠症人格特征的病例对照研究

中南大学学报（医学版） 2017年第8期42卷 958-965页

作者：廖静萍朱仕超张麒王定玺李小麟四川大学华西医院护理系成都610041 四川大学华西医院感染管理科成都610041 四川大学华西医院睡眠医学中心成都610041 四川大学华西医院中西医结合科成都610041

目的:比较反常失眠症患者与原发性失眠症患者及睡眠正常者的人格特征。方法:采用1:1:1配对病例对照研究,收集2013年3月至12月于四川大学华西医院睡眠医学中心就诊的63位反常失眠症患者为病例组,为每1例病例组患者配1例原发性失眠症患者... 详细信息

目的:比较反常失眠症患者与原发性失眠症患者及睡眠正常者的人格特征。方法:采用1:1:1配对病例对照研究,收集2013年3月至12月于四川大学华西医院睡眠医学中心就诊的63位反常失眠症患者为病例组,为每1例病例组患者配1例原发性失眠症患者和1例睡眠正常的健康对照。所有受试者完成艾森克人格问卷。结果:病例组艾森克人格问卷精神质维度、内外向维度、神经质维度得分分别为52.1±10.2,49.6±9.8,56.0±12.0。病例组有精神质或精神质倾向者的比例(31.7%)高于原发性失眠对照组(7.9%)(χ~2=11.228,P0.0125)。结论:反常失眠症患者整体上人格特征未达到明显病态的水平,有明显高于正常人和原发性失眠患者的精神质倾向,性格较原发性失眠患者更倾向于外向,在神经质特征上与原发性失眠患者相当,均异于正常人。

关键词：反常失眠原发性失眠人格精神质内外向神经质

电针对实验性糖尿病周围神经病变大鼠坐骨神经传导速度和超微结构的影响

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中国组织工程研究与临床康复 2007年第16期11卷 3069-3073页

作者：张秋娟施茵张云云东红升郑敏上海中医药大学附属岳阳中西医结合医院上海市200437

目的:观察电针对实验性糖尿病周围神经病变大鼠坐骨神经传导速度及神经纤维超微结构的影响。方法:实验于2005-01/12在上海中医药大学附属岳阳中西医结合医院中心实验室完成。选用清洁级雄性Wistar大鼠100只,按随机数字表法选取15只作为... 详细信息

目的:观察电针对实验性糖尿病周围神经病变大鼠坐骨神经传导速度及神经纤维超微结构的影响。方法:实验于2005-01/12在上海中医药大学附属岳阳中西医结合医院中心实验室完成。选用清洁级雄性Wistar大鼠100只,按随机数字表法选取15只作为正常对照组。在链脲佐菌素制备实验性糖尿病大鼠(n=85)基础上制备实验性糖尿病周围神经病变大鼠模型,以空腹血糖≥15mmol/L,坐骨神经感觉神经传导速度,运动神经传导速度明显减慢、摆尾温度阈值升高及坐骨神经有髓纤维形态学改变为造模成功的标准。在确认实验性糖尿病周围神经病变大鼠模型成功的基础上,采用随机数字表法抽取60只大鼠,分为3组,即电针经(组、电针非经(组、模型对照组,每组20只。①电针经(组:取肾俞(双)、足三里(双)(,将大鼠固定,针刺0.5cm,并接电针治疗仪,连续波,频率2Hz,20min/次,隔日1次,共治疗12次。②电针非经(组:将大鼠尾尖作为刺激点,具体方法和治疗次数同上。③模型对照组:不作任何治疗,只作与电针经(组相同的固定。④正常对照组:作与电针经(组相同的固定。造模后4周,以神经电生理法测试各组大鼠的运动神经、感觉神经传导速度;造模后8周,应用透射电镜观察各组大鼠的坐骨神经组织超微结构。结果:实验过程中模型对照组、电针非经(组及电针经(组大鼠分别死亡5,4,1只,因此进入结果分析每组分别抽取15只进行指标检测。①各组大鼠造模4周时的坐骨神经传导速度比较:模型对照组的运动神经传导速度、感觉神经传导速度显著低于正常对照组(31.37±3.70,18.17±9.54;41.30±1.15,44.22±8.80)m/s(P0.05)。②各组大鼠造模8周时的坐骨神经超微结构比较:模型对照组大鼠坐骨神经有髓神经纤维髓鞘结构模糊、松散、排列紊乱,出现空泡状缺损。电针非经(组大鼠坐骨神经有髓神经纤维髓鞘结构松散、排列紊乱,出现断裂或空泡状缺损。电针经(组大鼠坐骨神经髓纤维髓鞘结构损伤脱失的程度较模型对照组有所减轻,但未达到正常对照组水平。结论:电针对糖尿病周围神经病变具有一定的防治作用,其作用可能是通过改善糖尿病周围神经病变大鼠周围神经有髓纤维的形态及功能而实现的。

关键词：糖尿病神经病变/中医疗法电针坐骨神经/超微结构神经传导疾病模型,动物

Method for Estimating the State of Health of Lithium-ion Batteries Based on Differential Thermal Voltammetry and Sparrow Search Algorithm-Elman Neural Network

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Energy Engineering 2025年第1期122卷 203-220页

作者： Yu zhang Daoyu zhang TiezhouWu School of Electrical and Electronic Engineering Hubei University of TechnologyWuhan430068China

Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery ***,current SOH estimation methods often overlook the valuable temperature information that can effectively characterize battery aging during capacity ***,the Elman neural network,which is commonly employed for SOH estimation,exhibits several drawbacks,including slow training speed,a tendency to become trapped in local minima,and the initialization of weights and thresholds using pseudo-random numbers,leading to unstable model *** address these issues,this study addresses the challenge of precise and effective SOH detection by proposing a method for estimating the SOH of lithium-ion batteries based on differential thermal voltammetry(DTV)and an SSA-Elman neural ***,two health features(HFs)considering temperature factors and battery voltage are extracted fromthe differential thermal voltammetry curves and incremental capacity ***,the Sparrow Search Algorithm(SSA)is employed to optimize the initial weights and thresholds of the Elman neural network,forming the SSA-Elman neural network *** validate the performance,various neural networks,including the proposed SSA-Elman network,are tested using the Oxford battery aging *** experimental results demonstrate that the method developed in this study achieves superior accuracy and robustness,with a mean absolute error(MAE)of less than 0.9%and a rootmean square error(RMSE)below 1.4%.

关键词： Lithium-ion battery state of health differential thermal voltammetry Sparrow Search Algorithm

A Lightweight Multiscale Feature Fusion Network for Solar Cell Defect Detection

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Computers, Materials & Continua 2025年第1期82卷 521-542页

作者： Xiaoyun Chen Lanyao zhang Xiaoling Chen Yigang Cen Linna zhang Fugui zhang School of Mechanical Engineering Guizhou UniversityGuiyang550025China School of Computer Science and Technology Beijing Jiaotong UniversityBeijing100044China

Solar cell defect detection is crucial for quality inspection in photovoltaic power generation *** the production process,defect samples occur infrequently and exhibit random shapes and sizes,which makes it challenging to collect defective ***,the complex surface background of polysilicon cell wafers complicates the accurate identification and localization of defective *** paper proposes a novel Lightweight Multiscale Feature Fusion network(LMFF)to address these *** network comprises a feature extraction network,a multi-scale feature fusion module(MFF),and a segmentation ***,a feature extraction network is proposed to obtain multi-scale feature outputs,and a multi-scale feature fusion module(MFF)is used to fuse multi-scale feature information *** order to capture finer-grained multi-scale information from the fusion features,we propose a multi-scale attention module(MSA)in the segmentation network to enhance the network’s ability for small target ***,depthwise separable convolutions are introduced to construct depthwise separable residual blocks(DSR)to reduce the model’s parameter ***,to validate the proposed method’s defect segmentation and localization performance,we constructed three solar cell defect detection datasets:SolarCells,SolarCells-S,and *** and SolarCells-S are monocrystalline silicon datasets,and PVEL-S is a polycrystalline silicon *** results show that the IOU of our method on these three datasets can reach 68.5%,51.0%,and 92.7%,respectively,and the F1-Score can reach 81.3%,67.5%,and 96.2%,respectively,which surpasses other commonly usedmethods and verifies the effectiveness of our LMFF network.

关键词： Defect segmentation multi-scale feature fusion multi-scale attention depthwise separable residual block

Bilevel Optimal Scheduling of Island Integrated Energy System Considering Multifactor Pricing

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Energy Engineering 2025年第1期122卷 349-378页

作者： Xin zhang Mingming Yao Daiwen He Jihong zhang Peihong Yang Xiaoming zhang School of Automation and Electrical Engineering Inner Mongolia University of Science and TechnologyBaotou014010China

In this paper,a bilevel optimization model of an integrated energy operator(IEO)–load aggregator(LA)is constructed to address the coordinate optimization challenge of multiple stakeholder island integrated energy system(IIES).The upper level represents the integrated energy operator,and the lower level is the electricity-heatgas load *** to the benefit conflict between the upper and lower levels of the IIES,a dynamic pricing mechanism for coordinating the interests of the upper and lower levels is proposed,combined with factors such as the carbon emissions of the IIES,as well as the lower load interruption *** price of selling energy can be dynamically adjusted to the lower LA in the mechanism,according to the information on carbon emissions and load interruption *** benefits and win-win situations are achieved between the upper and lower ***,CPLEX is used to iteratively solve the bilevel optimization *** optimal solution is selected according to the joint optimal discrimination *** results indicate that the sourceload coordinate operation can reduce the upper and lower operation *** the proposed pricingmechanism,the carbon emissions and load interruption power of IEO-LA are reduced by 9.78%and 70.19%,respectively,and the capture power of the carbon capture equipment is improved by 36.24%.The validity of the proposed model and method is verified.

关键词： Bilevel optimal scheduling load aggregator integrated energy operator carbon emission dynamic pricing mechanism

Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun zhang Shengtao Gao Xingzhao zhang Dacheng Ma Chuanlei Zhu Jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)