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Effect of strain,strain rate and temperature on workability of AZ80 wrought magnesium alloy

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中国有色金属学会会刊：英文版 2012年第S3期22卷 650-655页

作者： Lü Wen-quan quan Guo-zheng YU Chun-tang ZHAO Lei ZHOU Jie College of Materials Science and Engineering Chongqing University

The hot deformation behavior of AZ80 wrought magnesium alloy was studied in the temperature range of 523-673 K and the strain rate range of 0.01-10 s-1 using hot compression *** the flow stresses behavior,the processing maps were calculated and analyzed according to the dynamic materials *** stable,metastable and unstable regimes were *** optimum processing conditions were suggested as following:the DRX regions in Domain #1-0.25,Domain #2-0.25,Domain #1-0.45,Domain #2-0.45,Domain #3-0.45,Domain #1-0.65 and Domain #1-0.85,and the DRV regions in Domain #3-0.25 and Domain #*** each "safe" DRX domain,it is preferable to conduct hot working in the small region around efficiency peak *** strain has a great influence on the processing *** whole area of the "safe" domains increases with the increase of true strain from 0.25 to 0.65,while it decreases with the increase of true strain from 0.65 to *** results of kinetic analysis reveal that the values of apparent activation energy in all the domains are higher than that for self-diffusion in pure magnesium (135kJ/mol),and the deformation mechanism in all the domains is likely to be cross-slip.

关键词： AZ80 magnesium alloy strain rate kinetic analysis processing map flow behavior

Correction to Hawking Radiation Characteristics of Stationary Demianski-Newman Black Hole

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Communications in Theoretical Physics 2006年第6期45卷 1026-1030页

作者： JIANG Qing-quan YANG Shu-zheng Institute of Theoretical Physics China West Normal University Nanchong 637002 China

The pure thermal spectrum in dragging coordinate system and the tunneling radiation characteristics across the event horizon for stationary Demianski-Newman black hole are researched. The result shows that the tunneling rate of the particle is relevant to Bekenstein-Hawking entropy, and the derived radiate spectrum is not strictly pure thermal, but is consistent with underlying unitary theory. Finally, we use the obtained results to reduce to stationary Kerr black hole and static Schwarzschild black hole, and lind that only when ignoring the spectrum at higher energies is the tunneling radiation spectrum consistent with Hawking pure thermal one.

关键词： Demianski-Newman black hole energy conservation angular momentum conservation tunneling rate Bekenstein-Hawking entropy

粤北喀斯特地区不同年龄油茶林土壤细菌群落动态变化特征

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林业科学研究 2024年第4期37卷 95-107页

作者：郑全胜吴斌白拉曲珍叶飞王雨冯汉华广东省林业调查规划院广东广州510520 广州大学大湾区环境研究院珠江三角洲水质安全与保护教育部重点实验室广东广州510006

[目的]明确油茶种植年限对喀斯特地区土壤微生物群落的影响。[方法]以乐昌市富树山油茶种植基地分别种植了2、3和7年的油茶林土壤为研究对象,利用高通量测序技术和分子生态网络的分析方法对土壤细菌群落进行研究。[结果]油茶种植年限的... 详细信息

[目的]明确油茶种植年限对喀斯特地区土壤微生物群落的影响。[方法]以乐昌市富树山油茶种植基地分别种植了2、3和7年的油茶林土壤为研究对象,利用高通量测序技术和分子生态网络的分析方法对土壤细菌群落进行研究。[结果]油茶种植年限的增加会导致土壤中铵态氮和总氮的积累,虽然不会显著改变土壤中细菌群落的生物多样性,但会导致土壤细菌群落结构的改变。同时发现土壤水分是影响2、3年龄油茶林土壤细菌群落的关键环境因子,而种植7年油茶林的土壤细菌群落主要受pH的影响。此外,相比种植2~3年的油茶林,种植7年的油茶林土壤细菌类群之间的联系更为紧密,但同时出现了细菌网络模块化的缺失和关键物种的演变的现象。[结论]本研究揭示了粤北石漠化地区不同种植年限油茶纯林的土壤细菌群落动态变化特征,为维持油茶林土壤生态系统功能的实践管理提供了理论依据。

关键词：喀斯特地区油茶林细菌群落高通量测序网络分析

内质网-线粒体互扰在功能性消化不良中的机制及疏肝健脾类中药的干预现状

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中国临床药理学杂志 2024年第15期40卷 2292-2295页

作者：郭军武正权王争艳张慧君李生财田旭东甘肃省中医院脾胃病科甘肃兰州730020

胃肠动力障碍是导致功能性消化不良(FD)发生的核心因素,其特征为胃肠道神经-Cajal间质细胞-平滑肌网络的破环。肝郁脾虚病机与内质网应激(ERs)-线粒体自噬稳态失衡相似,线粒体自噬紊乱是脾虚的生物学基础,肝郁是ERs的宏观体现,调控ERs-... 详细信息

胃肠动力障碍是导致功能性消化不良(FD)发生的核心因素,其特征为胃肠道神经-Cajal间质细胞-平滑肌网络的破环。肝郁脾虚病机与内质网应激(ERs)-线粒体自噬稳态失衡相似,线粒体自噬紊乱是脾虚的生物学基础,肝郁是ERs的宏观体现,调控ERs-线粒体自噬途径是防治FD的重要途径。本文从“肝脾相关”理论切入,结合胃肠动力障碍发生过程中内质网和线粒体的变化,揭示肝郁脾虚病机与ERs-线粒体自噬的相关性,阐明疏肝健脾法促胃肠动力的机制,为FD胃肠动力障碍的治疗提供新观点。

关键词：内质网应激线粒体自噬功能性消化不良肝郁脾虚

The thermodynamically directed dendrite-free lithium metal batteries on LiZn alloy surface

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Nano Research 2023年第6期16卷 8354-8359页

作者： Huanqin zheng Xu Cheng quan zheng Jianjun Zhang Tao Li Erqing Xie Ying Xu School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China School of Materials and Energy Lanzhou UniversityLanzhou 730000China Southeast Research Institute of Lanzhou University Fujian 351100China

Metical lithium(Li)is one of the most promising alternatives as an anode in next-generation high energy batteries for its high theoretical specific capacity and low redox ***,severe Li dendrite growth leading to poor stability and safety issues hinders its practical ***,three-dimensional carbon cloth(CC)with full zinc oxide quantum dots(ZnO QDs)covering is rationally chosen as the substrate for the suppression of Li *** to the spontaneous reaction between ZnO QDs and molten Li,LiZn alloy is formed and covered on CC,which endows substrate with high affinity for Li adsorption and suitable barrier energy for Li *** thermodynamic regulation on substrate is beneficial for homogeneous Li nucleation and deposition,thus enabling high stability for over 1,900 h at ultrahigh current density of 10 mA∙cm^(−2) in symmetrical cell and delivering superior performance in full batteries.

关键词： LiZn alloy adsorption energy diffusion barrier dendrite-free Li metal batteries

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基于多尺度双注意力网络的植物病虫害识别

计算机仿真 2024年第4期41卷 175-179页

作者：常开心侯彦东陈政权李泉龙河南大学人工智能学院河南郑州450000 河南大学计算机与信息工程学院河南开封475000

植物病虫害问题是农业上的重大难题,准确识别植物病虫害是农业病虫害预防和治理的关键步骤。经验丰富的植物病理专家通过观察叶片状态来进行诊断,不仅费时、费力,对于农民来说还需要付很大的成本来联系专家。因此,在ResNet模型的基础上... 详细信息

植物病虫害问题是农业上的重大难题,准确识别植物病虫害是农业病虫害预防和治理的关键步骤。经验丰富的植物病理专家通过观察叶片状态来进行诊断,不仅费时、费力,对于农民来说还需要付很大的成本来联系专家。因此,在ResNet模型的基础上设计了一种高效的多尺度双注意力模型(Multiscale Dual Attention Network)的植物病虫害识别方法。首先,通过多尺度卷积获取不同尺度的子特征图,然后,使用空间注意力和通道注意力对输入叶片重要特征进行加权处理。深度提取叶片图像中重要的全局特征和局部特征,快速准确的对植物病害进行识别。实验结果表明,在AI Challenge2018的植物病害数据集中,MDANet获得了90.2%的准确率,与其它卷积神经网络模型相比有着明显的优势。

关键词：病虫害识别多尺度注意力机制卷积神经网络

Mechanical buckling induced periodic kinking/stripe microstructures in mechanically peeled graphite fla es from HOPG

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Acta Mechanica Sinica 2015年第4期31卷 494-499页

作者： Manrui Ren Ze Liu quan-shui zheng Jefferson Zhe Liu Department of Engineering Mechanics and Center for Nano and Micro Mechanics Tsinghua University Department of Mechanical and Aerospace Engineering Monash University

Mechanical exfoliation is a widely used method to isolate high quality graphene layers from bulk graphite. In our recent experiments, some ordered microstructures, consisting of a periodic alternation of kinks and stripes, were observed in thin graphite flakes that were mechanically peeled from highly oriented pyrolytic graphite. In this paper, a theoretical model is presented to attribute the formation of such ordered structures to the alternation of two mechanical processes during the exfoliation：（1） peeling of a graphite flake and （2） mechanical buckling of the flake being sub- jected to bending. In this model, the width of the stripes L is determined by thickness h of the flakes, surface energy Y, and critical buckling strain ecr. Using some appropriate values of y and ecr that are within the ranges determined by other inde- pendent experiments and simulations, the predicted relations between the stripe width and the flake thickness agree reason- ably well with our experimental measurements. Conversely, measuring the L-h relations of the periodic microstructures in thin graphite flakes could help determine the critical mechan- ical buckling strain εcr and the interface energy γ.

关键词： HOPG Mechanical exfoliation Periodic microstructures Kinking Mechanical buckling

Influence of propagation direction on operation performance of rotating detonation combustor with turbine guide vane

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Defence Technology（防务技术） 2021年第5期17卷 1617-1624页

作者： Wan-li Wei Yu-wen Wu Chun-sheng Weng quan zheng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle ***,the performance of gas-turbine engine can be further improved with this combustion *** the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally *** and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the ***-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion *** experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation *** and counterclockwise propagation directions of RDW are *** clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is *** the oblique shock wave propagates across the TGV,the pressure oscillations reduces *** addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.

关键词： Rotating detonation combustor Propagation direction Turbine guide vane Operation performance

模拟压水堆一回路环境下冷应变对321不锈钢高温电化学行为和应力腐蚀开裂行为的影响

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原子能科学技术 2024年第8期58卷 1671-1678页

作者：李东兴曹晗高俊宣郑全张鹏钟巍华杨文中国原子能科学研究院反应堆工程技术研究所北京102413

321不锈钢是常用的压水堆结构材料之一,在成型加工和服役期间易因各种因素发生冷应变,使其性能发生改变。本文在模拟压水堆一回路水化学环境中,测量了不同冷应变量321不锈钢的电化学阻抗谱,并用热应变样品作为对比;采用慢应变速率拉伸... 详细信息

321不锈钢是常用的压水堆结构材料之一,在成型加工和服役期间易因各种因素发生冷应变,使其性能发生改变。本文在模拟压水堆一回路水化学环境中,测量了不同冷应变量321不锈钢的电化学阻抗谱,并用热应变样品作为对比;采用慢应变速率拉伸测试了冷应变试样应力腐蚀开裂性能。使用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)对样品微观特征进行了分析。XRD分析表明,冷应变使基体发生了由奥氏体到马氏体的转变,而高温抑制了这一过程。随着应变程度的增大(至20%),电荷转移电阻增大,膜电阻随马氏体含量的升高而降低。裂纹萌生实验结果表明,马氏体优先发生氧化腐蚀,保护了奥氏体基体,抑制了应力腐蚀裂纹萌生。

关键词：压水堆 321不锈钢冷应变高温电化学应力腐蚀开裂

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