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Enhancing high-temperature tensile properties of Ni/Ni-W laminated composites for MEMS devices

Journal of Materials Science & Technology 2023年第7期138卷 129-137页

作者： Zhe-Xuan Wang Fei Liang guang-ping zhang Bin zhang Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationSchool of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

There is an increasing demand for materials with excellent mechanical performance for Micro-Electro-Mechanical System(MEMS)devices serving at elevated ***,how to enhance the high-temperature strength of the materials without losing their plasticity is a pending ***,the Ni/Ni-W laminated composites with different monolayer thicknesses and the same ratio of the constituent layer thicknesses were fabricated successfully by using the dual-bath electrodeposition *** microstructure stability and tensile properties of annealed Ni/Ni-W laminated composites with different monolayer thicknesses were investigated at 400℃.The results show that the annealed Ni0.5/Ni-W0.05 laminated composites have both high yield strength(450 MPa)and excellent elongation to failure(25.1%)at 400℃,being superior to that of the monotonic Ni(179 MPa and 17.7%).Such a high strength of the laminated composite at 400℃ results from the contribution of the intrinsically high strength of the Ni-W layers with excellent thermal stability,the thickness-constrained effect on grain growth of Ni layers and the interface coupling effect of heterogeneous *** good plasticity may be derived from the heterogeneous laminated structure and the decrease in the constituent layer thickness,providing a good co-deformation *** mechanisms for the high tensile strength and good plasticity of the Ni/Ni-W laminated composites at 400℃ were analyzed *** findings reveal a potential strategy to fabricate MEMS components with excellent high-temperature tensile properties through tailoring the microstructure thermal stability and the constituent layer scale.

关键词： Laminated composites MEMS Strength Plasticity High temperature

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A unified model for determining fracture strain of metal films on flexible substrates

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Journal of Materials Science & Technology 2020年第19期54卷 87-94页

作者： Xu-ping Wu Xue-Mei Luo Hong-Lei Chen Ji-Peng Zou guang-ping zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of Chin1Shenyang 110016China

Failure strain determination of polymer-supported thin films is a key for the design of the flexible devices.A theoretical model R/R0=(L/L0)2(R,L are the electrical resistance and the length of the stretched film,respectively.R0,L0 are the corresponding initial values.)has been widely used to determine the fracture strain of thin films on flexible ***,this equation loses its function in some special ***,a simple and universal theoretical model was proposed to determine the fracture strain of metal thin films on flexible substrates in more generally *** this model,we investigated the thicknessdependent failure strains of Cu-5 at.%Al films with thickness of 10 nm,200 nm,1000 nm,and Ti films with thickness of 50 nm,100 nm,300 *** model was also employed to study the published data *** results showed that the new model provided a fairly good prediction of the failure strains of different films.

关键词： Thin films Fracture Electrical resistance Microstructure Flexible substrate

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Effects of Grain Size and Cryogenic Temperature on the Strain Hardening Behavior of VCoNi Medium‑Entropy Alloys

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Acta Metallurgica Sinica(English Letters) 2023年第6期36卷 973-986页

作者： Guo‑Dong Liu Xue‑Mei Luo Ji‑Peng Zou Bin zhang guang‑ping zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationSchool of Materials Science and EngineeringNortheastern UniversityShenyang 110819China

The mechanical behavior of VCoNi medium-entropy alloys with five different grain sizes at three different temperatures was *** VCoNi alloys with different grain sizes exhibit a traditional strength–ductility trade-off at 77 K,194 K and 293 *** the yield strength and the uniform elongation of the VCoNi alloys with similar grain size increase with decreasing the deformation temperature from 293 to 77 *** strain hardening rate recovery characterized by an evident up-turn behavior at stage II is observed in VCoNi alloys with the grain size above 11.1μ*** is found that the extent of the strain hardening rate recovery increases with increasing grain size or decreasing deformation *** may mainly result from the faster increase in the dislocation multiplication rate caused by the decrease in the dislocation mean free path,the decrease in the absorption of dislocations by grain boundaries and the dynamic recovery from the cross-slip with increasing grain size,as well as the suppressed dynamic recovery at cryogenic *** critical grain sizes for the occurrence of the recovery of strain hardening rate are determined to be around 9.5μm,8.3μm and 3μm for alloys deformed at 293 K,194 K and 77 K,*** basic mechanism for the strain hardening behavior of the VCoNi alloys associated with grain size and deformation temperature is analyzed.

关键词： Medium-entropy alloy Strain hardening rate Cryogenic temperature Grain size Slip band refinement

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Evaluation of Tensile and Fatigue Properties of Metals Using Small Specimens

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Acta Metallurgica Sinica(English Letters) 2023年第1期36卷 147-157页

作者： Wen‑Ke Yang Zhu‑Man Song Xue‑Mei Luo guang‑ping zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Small specimens are increasingly being used in getting mechanical properties directly when there are limited materials to facilitate standard specimens,which play a great role in the rapid measurement of mechanical properties and residual life assessment of in-service reactor *** tensile and fatigue properties of the small specimens are investigated extensively,theoretical models for describing the mechanical properties of small specimens need to be ***,we conduct a systematic investigation of tensile and fatigue properties of pure Cu specimens with thicknesses ranging from 3 to 0.2 *** results show that the decrease in uniform elongation of the 0.2 mm-thick specimens is mainly due to the efects of grain boundary and free surface on the strain hardening rate.A modifed theoretical model correlated with the ratio of the surface grain layer thickness to the grain size is proposed to predict variation in yield strength of the small specimens more ***,the mechanism for the diference in fatigue life between the 0.2 mm-thick specimen and other thicker specimens is *** Basquin equation-based model is presented as a potential way to evaluate the fatigue life of metals using small specimens.

关键词： Size efect Small specimen Tensile property Fatigue life

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Achieving very high cycle fatigue performance of Au thin films for flexible electronic applications

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Journal of Materials Science & Technology 2021年第30期89卷 107-113页

作者： Hong-Lei Chen Xue-Mei Luo Dong Wang Peter Schaaf guang-ping zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Institute of Materials Engineering and Institute of Micro-and Nanotechnologies MacroNano® TU IlmenauGustav-Kirchhoff-Str.598693 IlmenauGermany

The fatigue damage behavior of the nanocrystalline Au films on polyimide substrates was *** was found that the very high-cycle fatigue damage resistance of the Au film was significantly enhanced by at least a factor of~2 in supported loading through adding an ultrathin Ti interlayer at the Au film/polyimide *** a better fatigue damage resistance is mainly ascribed to the effective suppression of voiding at the Au film/polyimide interface through modulation of the Au/Ti interface,and thus the propensity of the cyclic strain localization and grain boundary cracking is *** finding may provide a potential strategy for the design of flexible devices with ultra-long fatigue life.

关键词： Thin films Ti interlayer Fatigue Extrusion Interface

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Dynamics and Thermodynamics of Porous HMX-like Material Under Shock

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Communications in Theoretical Physics 2009年第11期52卷 901-908页

作者： XU Ai-Guo zhang guang-Cai zhang ping PAN Xiao-Fei ZHU Jian-Shi National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P.O.Box 8009-26 Beijing 100088 China

Strong shock may induce complex processes in porous materials. We use the newly developed materialpoint-method to simulate such processes in an HMX-like material. To pick out relevant information, morphological characterization is used to treat with the temperature map. Via the Minkowski funetional analysis the dynamics and thermodynamics of the shock wave reaction on porous HMX-like material are studied. The geometrical and topological properties of the ＂hot-spots＂ are revealed. Numerical results indicate that, shocks in porous materials are not simple jump states as classically viewed, but rather are a complex sequence of compressions and rarefactions. They cover a broad spectrum of states. We can use coarse-grained description to the wave series. A threshold value of temperature presents a Turing pattern dynamical procedure. A higher porosity is generally preferred when the energetic material needs a higher temperature for initiation. The technique of data analysis can be used to other physical quantities, for example, density, particle velocity, some specific stress, etc. From a series of studies along the line, one may get a large quantity of information for desiring the fabrication of material and choosing shock strength according to what needed is scattered or connected ＂hot-spots＂. PACS numbers： ***, 05 Key words： porous material 70.-a, 05.40.-a, *** shock wave, Minkowski functionals

关键词： porous material shock wave Minkowski functionals

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Multiple gastric adenocarcinoma of fundic gland type: A case report

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World Journal of Clinical Cases 2019年第18期7卷 2871-2878页

作者： Ou Chen Ze-Yong Shao Xiong Qiu guang-ping zhang Department of Gastroenterology Ya’an People’s HospitalYa’an 625000Sichuan ProvinceChina Department of Pathology Ya’an People’s HospitalYa’an 625000Sichuan ProvinceChina 不详

BACKGROUND In recent years, there have been reports of a new histological type of gastric cancer, termed gastric adenocarcinoma of the fundic gland (GA-FG). This disease entity presents differentiation towards the fundic gland, especially chief cellpredominant differentiation (GA-FG-CCP). GA-FG-CCP easily invades into the submucosa but rarely shows metastasis. The reports mostly describe primarily single lesions. Herein, we report a case with multiple lesions, and summarize the clinicopathologic characteristics of multiple cases. CASE SUMMARY A 55-year-old woman underwent upper gastrointestinal endoscopy screening. Two whitish lesions on the anterior wall of the gastric corpus and the gastric fundus were detected. The patient had previously received Helicobacter pylori eradication therapy. The mucosa was characterized as grade C-2 atrophic gastritis. We diagnosed the patient with multiple GA-FG (GA-FG-CCP) by hematoxylin and eosin (HE) staining and immunohistochemical staining of the endoscopic biopsy. Upon performing endoscopic submucosal dissection (ESD), one lesion was not found, but the scar from the biopsy was visible;the mucularis mucosa of the biopsy and ESD-resected specimen were intact. The two lesions showed no lymphatic nor venous invasion. The resection performed appeared to be relatively curative. CONCLUSION Cases of multiple GA-FG-CCP are very rare in clinical practice. Most of its clinicopathologic characteristics are similar to those of a single lesion. Our case provides diagnostic and therapeutic information about GA-FG-CCP with multiple lesions.

关键词： Gastric adenocarcinoma of the fundic gland Multiple lesions Pepsinogen-I Endoscopic submucosal dissection Case report

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Study on fast calibration of a ULA's gain and phase error

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Journal of Marine Science and Application 2007年第2期6卷 64-69页

作者： ZHU guang-ping SUN Hui zhang Ming-hui College of Underwater Acoustic Engineering Harbin Engineering University Harbin 150001 China

Array calibration is important in engineering practice. In this paper, fast calibration methods for a ULA's gain and phase errors both in far and near fields are proposed. In the far field, using a single sound source without exact orientation, this method horizontally rotates the array exactly once, performs eigen value decomposition for the covariance matrix of received data, then computes the gain and phase error according to the formulas. In the near field, using the same single sound source, it is necessary to rotate the array horizontally at most three times, build equations according to geometric relations, then solve them. Using the formula proposed in this paper, spherical waves are modified into plane waves. Then eigen values decomposition is performed. These two calibration methods were shown to be valid by simulation and are fast, accurate and easy to use. Finally, an analysis of factors influencing estimation precision is given.

关键词： ULA single sound source gain and phase error eigen values decomposition

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Low-Bias Conductance Mechanism of Diarylethene Isomers:a First-Principle Study

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Chinese Journal of Chemical Physics 2020年第6期33卷 697-702,I0002页

作者： Ming-lang Wang guang-ping zhang Xiao-xiao Fu Chuan-kui Wang School of Physics and Electronics Shandong Normal UniversityJinan 250358China

The structure-property relationship of diarylethene(DAE)-derivative molecular isomers,which involve ring-closed and ring-open forms,is investigated by employing the nonequilibrium Green’s function formalism combined with density functional *** junctions are formed by the isomers connecting to Au(111)electrodes through flanked pyridine *** difference in electronic structures caused by different geometry structures for the two isomers,particularly the interatomic alternative single bond and double bond of the ring-closed molecule,contributes to the vastly different low-bias conductance *** lowest unoccupied molecular orbital(LUMO)of the isomers is the main channel for electron *** addition,more electrons transferred to the ring-closed molecular junction in the equilibrium condition,thereby decreasing the LUMO energy to near the Fermi energy,which may contribute to a larger conductance value at the Fermi *** findings are helpful for understanding the mechanism of low-bias conductance and are conducive to the design of high-performance molecular switching based on diarylethene or diarylethene-derivative molecules.

关键词： Molecular electronics Molecular switching Density functional theory Nonequilibrium Green’s function

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Screening and Identifying Hepatotoxic Components in Polygoni multiflori Radix and Polygoni multiflori Radix Praeparata

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World Journal of Traditional Chinese Medicine 2019年第3期5卷 173-179页

作者： guang-ping zhang Hai-Jing zhang Teng-Fei Chen Hong-ping Hou ping Su Yun-Hang Gao Yi-Fei Yang Zu-guang Ye Atomized Inhalation Preparation Research Center Institute of Chinese Materia Medica China Academy of Chinese Medical Sciences

Objective: In this study, the hepatotoxic components of Polygoni multiflori Radix and Polygoni multiflori Radix Praeparata(known as Heshouwu [HSW] and Zhiheshouwu [ZHSW] in China, respectively) were screened, isolated, and identified. Materials and Methods: The ethanol extracts of HSW and ZHSW were separated into 80 fractions according to their polarity in the preparation liquid phase. Chang liver cell line was used to screen the toxic components of HSW and ZHSW in vitro. The obtained toxic mixture was further collected, isolated, and identified to confirm the hepatotoxic compounds of HSW and ZHSW. Results: The identifid hepatotoxic compounds include 2,3,5,4’-tetrah ydroxystilbene-2-O-β-D-glucoside, emodin, physcion-8-O-β-d-glucoside, physcion, and citreorosein, the fist two among them were the main components of HSW and ZHSW. After processing of HSW, the contents of 2,3,5,4’-tetrahydroxystilbene-2-O-β-D-glucoside and emodin in ZHSW were signifiantly decreased. Conclusions: The traditional processing with herb has signifiant effects on the components, especially the toxic components, in the extract of HSW and is an effective method to reduce its toxicity.

关键词： 2,3,5,4’-tetra-hydroxystilbene-2-O-β-D-glucoside emodin hepatotoxicity Polygoni multiflori Radix Polygoni multiflori Radix Praeparata

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