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Evolution of microstructure and texture of AZ80 magnesium alloy under hot torsion with constant decreasing temperature rate

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Journal of Magnesium and Alloys 2024年第4期12卷 1619-1637页

作者： Yongbiao Yang Jinxuan Guo Cuiying Wang Wenxuan Jiang zhimin Zhang Qiang Wang xing Zhang College of Materials Science and Engineering North University of ChinaLane 3Xueyuan RoadTaiyuanShanxi 030051China North Hongyang mechanical and electronic limited company of Henan Province China

Hot torsion tests for AZ80 magnesium alloy were carried out in the temperature range of 380℃-260℃,with a constant decreasing temperature rate of 10℃/s in order to weaken the basal texture and refine the *** results indicated that the average grain sizes were refined forming gradient structure with increasing specimen radial position from center(12.2-5.4μm),and that the initial basal texture intensity of the extruded magnesium alloy was weakened from 46.2 to ***,the extension twins(ETs)could be disintegrated from the twins forming separated twins with smaller ***,ETs with the same twin variant intersecting with each other could be coalesced forming grains with similar orientation,while ETs with different twin variants were separated by twins boundaries contributing to grain ***,in addition to the conventional continuous dynamic recrystallized(CDRX)grains with 30˚orientation rotated around C-axis of the parent grains,CDRXed grains with 30˚rotation around a-axis and random rotation axis were also ***,the CDRX evolution induced twins were also elaborated,exhibiting the complex competition between CDRX and *** torsion deformation with constant decreasing temperatures rate is an effective way of grain refinement and texture modification.

关键词： Texture Microstructure Hot torsion Decreasing temperature AZ80

Dynamically switchable porphyrin-based molecular tweezer for on-off fullerene recognition

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Chinese Chemical Letters 2024年第6期35卷 283-287页

作者： zhimin Sun Xin-Hui Guo Yue Zhao Qing-Yu Meng Li-Juan xing He-Lue Sun College of Chemistry and Materials Science Hebei Key Laboratory of Organic Functional MoleculesHebei Normal UniversityShijiazhuang 050024China

Herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes *** syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene *** exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational ***,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the ***,the association-disassociation process can be switched reversibly and repeatedly.

关键词： Molecular tweezer Fullerene recognition Supramolecular chemistry Conformation conversion Coordination

Effect of annealing temperature on structure and electrochemical properties of LiCoO_2 cathode thin films

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Rare Metals 2006年第Z2期25卷 189-192页

作者： YANG zhimin xing Guangjian YANG Jian MAO Changhui DU Jun Advanced Electronic Materials Institute General Research Institute for Nonferrous Metals Beijing 100088 China Advanced Electronic Materials Institute General Research Institute for Nonferrous Metals Beijing 100088 China Department of Materials Science and Engineering Beijing Institute of Petrochemical Technology Beijing 102617 China Advanced Electronic Materials Institute General Research Institute for Nonferrous Metals Beijing 100088 China Advanced Electronic Materials Institute General Research Institute for Nonferrous Metals Beijing 100088 China Advanced Electronic Materials Institute General Research Institute for Nonferrous Metals Beijing 100088 China

LiCoO2 thin films, which can be used as a cathode material in microbatteries, were deposited using radio frequency (r.f.) magnetron sputtering system from a LiCoO2 target and in an O2+Ar atmosphere. The films were characterized by various methods such as XRD, SEM and AFM. The LiCoO2 films were annealed in air at 300, 500, 700 and 800 ℃ respectively. The effect of the annealing temperature on the structure, the surface morphology and the electrochemical properties of the films were investigated. The LiCoO2 thin film deposited at room temperature is amorphous and has smaller grain size. With increasing of annealing temperature, the crystallinity of the films is promoted. When the annealing temperature increases to 700 ℃, the films have a perfect crystalline LiCoO2 phase. The LiCoO2 thin film without annealing has no discharge plateau and small discharge capacity (about 27 μAh·cm-2μm). The discharge capacity increases with the increasing of annealing temperature and reaches 47 μAh·cm-2μm for the film annealed with 700 ℃, which also shows the typical discharge plateau of 3.9 V. The cycle performance of LiCoO2 thin films of as grown and annealed at different temperatures were studied. In the case of the film without thermal treatment, the capacity fading is much faster than that of the film annealed at different temperature, showing about 40% capacity loss only after 25 cycles. However, in the case of the film annealed at 700 ℃, the capacity reaches to steady state gradually and maintained constantly with cycling. After 25 times cycling, the discharge capacity of the film annealed at 700 ℃ decreases to about 36.9 μAh·cm-2·μm, only 0.8% capacity loss per cycle.

关键词： LiCoO2 thin film annealing temperature structure electrochemical properties

Low-firing and temperature stability regulation of tri-rutile MgTa_(2)O_(6)microwave dielectric ceramics

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1935-1943页

作者： Chengzhi Xu Hongyu Yang Hongcheng Yang Linzhuang xing Yuan Wang zhimin Li Enzhu Li Guorui Zhao School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710071China Academy of Advanced Interdisciplinary Research Xidian UniversityXi’an 710071China School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China National Engineering Research Center of Electromagnetic Radiation Control Materials and Key Laboratory of Multi-Spectral Absorbing Materials and Structures of Ministry of Education University of Electronic Science and Technology of ChinaChengdu 610054China Songshan Lake Materials Laboratory A1 Building University Innovation ParkDongguan 523808China

A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this *** good low-firing effects are presented due to the high matching relevance between Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass and MgTa_(2)O_(6)*** pure tri-rutile MgTa_(2)O_(6)structure remains unchanged,and high sintering compactness can also be achieved at 1150℃.We found that the Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass not only greatly improves the low-temperature sintering characteristics of MgTa_(2)O_(6)ceramics but also maintains a high(quality factor(Q)×resonance frequency(f))value while still improving the temperature ***,great microwave dielectric characteristics when added with 2wt%Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass can be achieved at 1150℃:dielectric constant,ε_(r)=26.1;Q×f=34267 GHz;temperature coefficient of resonance frequency,τ_(f)=-8.7×10^(-6)/℃.

关键词： MgTa_(2)O_(6) ceramic microwave dielectric characteristics glass

A New Analytical Model for the Flow Stress of Twin-roll Casting Magnesium Sheet at Elevated Temperatures

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Journal of Materials Science & Technology 2010年第5期26卷 461-466页

作者： zhimin Liu,Shuming xing ,Peiwei Bao,Nan Li,Shuqing Yao and Milan Zhang School of Mechanical,Electronic and Control Engineering,Beijing Jiaotong University,Beijing 100044,China School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China

To evaluate the flow stress of the twin-roll casting magnesium sheet in high temperature forming processes,a new analytical model was proposed by analyzing stress-strain curves measured under various temperatures and strain *** model can be parameterized to reflect the volume fraction of semi-sold grain and sold grains undergoing *** applying the new model,the result showed that the simulated stress-strain curves fit the experiment data very *** curve fitting can be employed for any magnesium sheet when the deformation conditions are *** evolution indicated that it affected the stress-strain curves *** mechanisms of dynamic recrystallization（DRX） depended on the operating deformation mechanisms,which changed with *** the volume fraction and grain size of DRX changed with the Zener-Hollomon parameter and temperatures.

关键词： Twin-roll casting Semi-sold grains Twinning

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人文关怀护理在胃癌放疗患者中的应用效果

中国民康医学 2022年第1期34卷 173-176页

作者：邢志民濮阳市第五人民医院门急诊科河南濮阳457000

目的:探讨人文关怀护理在胃癌放疗患者中的应用效果。方法:回顾性分析2018年10月至2020年10月该院收治的90例胃癌患者的临床资料,按照护理方法不同将患者分为对照组与观察组各45例。对照组采用常规护理,观察组采用人文关怀护理。比较两... 详细信息

目的:探讨人文关怀护理在胃癌放疗患者中的应用效果。方法:回顾性分析2018年10月至2020年10月该院收治的90例胃癌患者的临床资料,按照护理方法不同将患者分为对照组与观察组各45例。对照组采用常规护理,观察组采用人文关怀护理。比较两组患者焦虑自评量表(SAS)、抑郁自评量表(SDS)、生活质量综合评定问卷(GQOLI-74)评分、不良事件发生率,以及护理满意度。结果:观察组SAS、SDS评分均低于对照组,GQOLI-74中躯体功能、社会功能、心理功能评分均高于对照组,差异有统计学意义(P<0.05);观察组不良事件发生率为4.44%(2/45),低于对照组的22.22%(10/45),差异有统计学意义(P<0.05);观察组护理满意度为95.56%(43/45),高于对照组的75.56%(34/45),差异有统计学意义(P<0.05)。结论:对胃癌放疗患者应用人文关怀护理,可缓解其负面情绪,降低不良事件发生率,提高护理满意度及生命质量。

关键词：人文关怀护理胃癌放疗心理状态生命质量满意度

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海砂中氯离子含量的影响因素研究

建筑材料学报 2016年第5期19卷 921-925,932页

作者：刘伟蒲正霖孙红芳贺智敏邢锋深圳大学广东省滨海土木工程耐久性重点实验室广东深圳518060 宁波大学建筑工程与环境学院浙江宁波315211

试验研究了砂水比、海水氯离子含量、海砂含水率及颗粒粒径等因素对海砂中氯离子含量的影响.结果表明:海砂中氯离子含量分别与海水氯离子含量及海砂含水率显著线性相关;堆积状态下的海砂,其含水率沿堆积高度呈递减规律,含水率稳定值对... 详细信息

试验研究了砂水比、海水氯离子含量、海砂含水率及颗粒粒径等因素对海砂中氯离子含量的影响.结果表明:海砂中氯离子含量分别与海水氯离子含量及海砂含水率显著线性相关;堆积状态下的海砂,其含水率沿堆积高度呈递减规律,含水率稳定值对应的临界高度约为40cm;海水氯离子含量、海砂含水率及颗粒粒径等因素对海砂氯离子含量的影响规律均可用相应的数学关系来表征.

关键词：海砂海水氯离子含量含水率颗粒粒径

慢性心衰患者采用依伐布雷定联合美托洛尔的临床疗效

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中国继续医学教育 2018年第19期10卷 112-114页

作者：邢智敏鸡西市人民医院心血管内科黑龙江鸡西158100

目的针对慢性心衰患者采用依伐布雷定与美托洛尔联合治疗的效果进行分析研究。方法收集2015年1月—2016年1月的30例慢性心衰患者有关资料进行分析研究,随机将患者平均分为三组,每组各有10例患者,A组患者采用依伐布雷定治疗,B组患者采用... 详细信息

目的针对慢性心衰患者采用依伐布雷定与美托洛尔联合治疗的效果进行分析研究。方法收集2015年1月—2016年1月的30例慢性心衰患者有关资料进行分析研究,随机将患者平均分为三组,每组各有10例患者,A组患者采用依伐布雷定治疗,B组患者采用美托洛尔治疗,C组患者采用上述两种药物联合治疗的方法,对三组患者的治疗效果进行比较。结果治疗后,C组患者的治疗总有效率及心率变化明显比A、B两组患者好,药物不良反应发生率最低,差异具有统计意义(P<0.05)。结论慢性心衰患者采用依伐布雷定与美托洛尔联合治疗,可使患者治疗总有效率明显提升,并调节改善患者的心率变化,临床应用价值较高。

关键词：美托洛尔依伐布雷定心力衰竭心率变化药物治疗临床效果

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微波通信中的故障定位与排除案例分析

广播与电视技术 2017年第12期44卷 123-124页

作者：邢志民河北省广播电视微波总站河北050000

广电系统、电力系统等领域都有大量应用微波通信,运行中难免会出现通信方面的故障。如何快速准确的定位故障,排除故障,对于广电系统、电力系统、民航系统等领域的安全具有非常重要的作用和意义。本文以案例介绍实践维护中遇到的微波电... 详细信息

广电系统、电力系统等领域都有大量应用微波通信,运行中难免会出现通信方面的故障。如何快速准确的定位故障,排除故障,对于广电系统、电力系统、民航系统等领域的安全具有非常重要的作用和意义。本文以案例介绍实践维护中遇到的微波电路典型故障的定位与排除,以期能为微波电路维护提供可参考的借鉴。

关键词：微波频谱分析故障定位