检索结果-南通市图书馆

热处理对Mg-12Y-1Al合金组织及性能的影响

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

材料工程 2024年第3期52卷 129-136页

作者：聂敬敬潘玥袁杏夏先朝孙京丽李扬欣应韬肖旅上海航天精密机械研究所上海201600 上海交通大学上海200240

采用光学显微镜、X射线衍射仪及扫描电镜等研究固溶处理、时效处理后Mg-12Y-1Al合金的显微组织,利用拉伸实验分析热处理前后合金在室温及高温200℃下的力学性能,使用电化学方法测试热处理前后合金的耐腐蚀性能。结果表明:Mg-12Y-1Al合... 详细信息

采用光学显微镜、X射线衍射仪及扫描电镜等研究固溶处理、时效处理后Mg-12Y-1Al合金的显微组织,利用拉伸实验分析热处理前后合金在室温及高温200℃下的力学性能,使用电化学方法测试热处理前后合金的耐腐蚀性能。结果表明:Mg-12Y-1Al合金的铸态组织由α-Mg基体、Mg_(24)Y_(5)相和Al_(2)Y相组成。Mg-12Y-1Al具有优异的高温热稳定性,在520℃×16 h(T4)固溶处理后,晶粒没有长大,产生新的长周期有序堆垛相(LPSO);225℃×30 h(T6)时效处理对组织的影响不大。与室温下的性能相比,T4态合金在200℃下的极限抗拉强度没有降低,而伸长率由室温的1.3%提高至12.5%。此外,Mg-12Y-1Al合金经固溶及时效处理后耐腐蚀性能得到提升,腐蚀电流密度由铸态的2.799×10^(-5)A/cm^(2)降低至1.551×10^(-5)A/cm^(2)。

关键词： Mg-12Y-1Al合金热处理显微组织力学性能腐蚀行为

在线全文

学校读者我要写书评

暂无评论

新疆黑猪生态养殖的现状与建议

现代畜牧科技 2024年第9期 92-94页

作者：王丹张新银孙敬礼王煜舒新疆生产建设兵团第八师畜牧兽医工作站新疆石河子832000 石河子大学动物科技学院新疆石河子832000

目前,地方猪种商业化程度低、群体数量少,有些品种濒危灭绝或已经灭绝。随着人们对肉品质的要求越来越高,通过地方品种改良的“土猪”肉越来越受到大家的欢迎。新疆黑猪是新疆兵团培育成功的优良猪种,与西方瘦肉型猪种相比,具有肉质鲜... 详细信息

目前,地方猪种商业化程度低、群体数量少,有些品种濒危灭绝或已经灭绝。随着人们对肉品质的要求越来越高,通过地方品种改良的“土猪”肉越来越受到大家的欢迎。新疆黑猪是新疆兵团培育成功的优良猪种,与西方瘦肉型猪种相比,具有肉质鲜嫩香美、适应性强、耐粗饲等特性,可以满足我国日益提高的消费能力和易养少病的需求。该文介绍了新疆黑猪的几种养殖模式,以及如何更好的开展新疆黑猪的养殖,满足优质化猪肉市场需求,逐步完善新疆黑猪产业发展的产业链。该文从新疆黑猪产地、保种、延伸产业链发展等方面进行介绍和分析,提出新疆黑猪产业发展的对策和建议。

关键词：新疆黑猪保种生态养殖产业

维普期刊数据库博看期刊

人羊膜间充质干细胞对大鼠子宫瘢痕的修复作用

在线全文

学校读者我要写书评

暂无评论

基础医学与临床 2024年第7期44卷 1002-1007页

作者：宋佳赵峰张婷徐静孙静莉陈震宇北部战区总医院妇产科辽宁沈阳110016 中国医科大学干细胞与再生医学研究室辽宁沈阳110122 锦州医科大学妇产科学系辽宁锦州121001

目的探究人羊膜间充质干细胞(hAMSCs)对大鼠子宫瘢痕的修复作用。方法分离培养hAMSCs,选雌性SPF级SD大鼠行子宫壁全层切开术,术中注射hAMSCs,于术后第30天对子宫切开部位进行组织学检查。用ImageJ图像分析软件进行分析比较各组子宫肌层... 详细信息

目的探究人羊膜间充质干细胞(hAMSCs)对大鼠子宫瘢痕的修复作用。方法分离培养hAMSCs,选雌性SPF级SD大鼠行子宫壁全层切开术,术中注射hAMSCs,于术后第30天对子宫切开部位进行组织学检查。用ImageJ图像分析软件进行分析比较各组子宫肌层厚度、纤维化面积百分比。免疫组化法分别检测子宫肌层α平滑肌肌动蛋白(α-SMA)、转化生长因子β1(TGF-β1)、肿瘤增殖抗原Ki-67(Ki-67)阳性面积百分比。结果与磷酸缓冲盐溶液(PBS)组相比,hAMSCs组子宫肌层明显增厚、纤维化面积减少,α-SMA、Ki-67阳性表达明显增加(P<0.05),而TGF-β1阳性表达明显减少(P<0.05)。。结论人羊膜间充质干细胞(hAMSCs)可能通过减少瘢痕纤维化的形成、促进子宫瘢痕处平滑肌细胞的增殖等作用机制促进子宫切口组织修复。

关键词：人羊膜间充质干细胞剖宫产子宫瘢痕

A Fault Detection Mechanism in Erasure-Code Byzantine Fault-Tolerance Quorum

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2006年第6期11卷 1453-1456页

作者： LIU Gang ZHOU jingli sun Yufen QIN Leihua College of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China

Fault-tolerance is increasingly significant for large-scale storage systems in which Byzantine failure of storage nodes may happen. Traditional Byzantine Quorum systems that tolerate Byzantine failures by using replication have two main limitations： low space-efficiency and static quorum variables. We propose an Erasure-code Byzantine Fault-tolerance Quorum that can provide high reliability with far lower storage overhead than replication by adopting erasure code as redundancy scheme. Through read/write operations of clients and diagnose operation of supervisor, our Quorum system can detect Byzantine nodes, and dynamically adjust system size and fault threshold. Simulation results show that our method improves performance for the Quorum with relatively small quorums.

关键词： fault detection erasure code Byzantine fault-tolerance Quorum

Interfacial charge effects of supported-metal-cluster heterostructures on azo hydrogenation catalyzation

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3853-3862页

作者： Zhenhua Gu jingli Zhang Zijun Zhang Qingxue Mu Liangchong Yu Taolei sun Lei Shen Guanbin Gao State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases School of ChemistryChemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China

The impact of interfacial charge on catalytic performance of supported-metal-cluster(SMC)heterostructures remains unclear,hindering efforts to develop high-performance SMC *** we systematically investigated interfacial charge effects of SMCs using a model system of graphene-supported gold-nanoclusters(AuNCs/rGO)for azo *** types of SMCs with different interfacial charges were synthesized by anchoring electropositive 2-aminoethanethiol(CSH),amphoteric cysteine(Cys),and electronegative 3-mercaptopropionic-acid(MPA)onto AuNCs/rGO,*** three SMCs exhibited high and selective catalytic activity to azo-hydrogenation in four representative azo *** catalytic activity of Cys@AuNCs/rGO was lower than that of CSH@AuNCs/rGO but higher than that of MPA@AuNCs/***,the cyclic stability of Cys@AuNCs/rGO was inferior to that of both CSH@AuNCs/rGO and MPA@AuNCs/*** mechanistic studies revealed that amino ligands modified CSH@AuNCs and Cys@AuNCs agglomerated into large-size gold nanoparticles on rGO surface during catalytic reaction under NaBH_(4) action,leading to reduced efficiency and cyclic ***,non-amino ligand modified MPA@AuNCs only partially detached from rGO surface without agglomeration,resulting in better cyclic *** of amino groups in ligands such as modifying-NH_(3)^(+)group in Cys into imine to form N-isobutyryl-L-cysteine(NIBC)substantially improved the cyclic stability while maintaining the high activity in the NIBC@AuNCs/rGO catalyst *** work provides an approach for developing a highly-active and stable SMC heterostructure catalyst via manipulating interfacial charges in SMC.

关键词： interfacial charge effect supported-metal-cluster catalyst azo hydrogenation graphene supported gold nanoclusters

Characterizing leaf-deposited particles: Single-particle mass spectral analysis and comparison with naturally fallen particles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Environmental Science and Ecotechnology 2024年第5期21卷 318-328页

作者： Dele Chen Hua-Yun Xiao Ningxiao sun jingli Yan Shan Yin School of Agriculture and Biology Shanghai Jiao Tong University800 Dongchuan Rd.Shanghai 200240China Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station Ministry of Science and TechnologyMinistry of Education800 Dongchuan Rd.Shanghai 200240China Shanghai Urban Forest Ecosystem Research Station National Forestry and Grassland Administration800 Dongchuan Rd.Shanghai 200240China

The size and composition of particulate matter(PM)are pivotal in determining its adverse health *** is important to understand PM's retention by plants to facilitate its atmospheric ***,the distinctions between the size and composition of naturally fallen PM(NFPM)and leaf-deposited PM(LDPM)are not *** we utilize a single-particle aerosol mass spectrometer,coupled with a PM resuspension chamber,to analyze these *** find that LDPM particles are 6.8 e97.3%larger than *** a neural network algorithm based on adaptive resonance theory,we have identified distinct compositional profiles:NFPM predominantly consists of organic carbon(OC;31.2%)and potassium-rich components(19.1%),whereas LDPM are largely composed of crustal species(53.9e60.6%).Interestingly,coniferous species retain higher OC content(11.5e13.7%)compared to broadleaved species(0.5e1.2%),while the levoglucosan content exhibit an opposite *** study highlights the active role of tree leaves in modifying PM composition beyond mere passive capture,advocating for a strategic approach to species selection in urban greening initiatives to enhance PM *** insights provide guidance for urban planners and environmentalists in implementing nature-based solutions to improve urban air quality.

关键词： Particulate matter Dry deposition Phytoremediation Size distribution Chemical composition Source apportionment

Sparse identification-assisted exploration of the atomic-scale deformation mechanism in multiphase CoCrFeNi high-entropy alloys

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第4期67卷 1124-1132页

作者： XIAO Lu GUO XiaoXiang sun YuTong WANG Gang LONG WeiMin LIAW Peter K. REN jingli School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Institute of Materials Shanghai UniversityShanghai 200444China SKL of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(HEAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase HEA was prepared using molecular dynamics simulation involving melt and quench *** HEA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-packed structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi HEA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

寒区军人子女出生缺陷的流行病学调查与影响因素分析

在线全文

学校读者我要写书评

暂无评论

陆军军医大学学报 2023年第15期45卷 1666-1670,F0003页

作者：张玉孙静莉北部战区总医院妇产科沈阳110000

目的分析寒区军人子女全孕期出生缺陷的发生情况,探讨其流行病学特征和影响因素。方法采用病例对照研究,选取2017-2020年北部战区总医院分娩登记的所有军人胎儿1 883例(妊娠满12周至产后7 d,包括活产、死产及死胎、引产)为医院层面出... 详细信息

目的分析寒区军人子女全孕期出生缺陷的发生情况,探讨其流行病学特征和影响因素。方法采用病例对照研究,选取2017-2020年北部战区总医院分娩登记的所有军人胎儿1 883例(妊娠满12周至产后7 d,包括活产、死产及死胎、引产)为医院层面出生缺陷监测对象,选取沈阳及其周边部分驻地军人于2017-2020年分娩的胎儿2 198例(妊娠满12周以上,包括活产、死产及死胎、引产)为人群层面出生缺陷监测对象,通过填写《寒区军人子女出生缺陷流行病学调查表》收集数据,分析医院监测和人群监测下全孕期出生缺陷发生率、顺位及其影响因素。结果 (1)2017-2020年医院监测下寒区军人子女全孕期出生缺陷发生率为175.25/万(33/1 883),医院监测下寒区地方群众子女全孕期出生缺陷发生率为175.47/万(480/27 355),人群监测下寒区军人子女全孕期出生缺陷发生率为218.38/万(48/2 198)。(2)医院监测和人群监测下出生缺陷的前3顺位为外耳畸形、并指(趾)和/或多指(趾)、先天性心脏病。(3)出生缺陷儿母亲文化程度及牛奶摄入量≥500 mL/周比例均低于正常新生儿母亲(P<0.05)。双亲一方或双方存在雷达暴露、无线电波暴露和高电磁辐射暴露的缺陷儿出生率高于正常双亲(P<0.05)。多因素Logistic回归分析显示,母亲文化程度在大专及以下(OR=2.218)、双亲一方或双方有雷达暴露(OR=2.179)、无线电波暴露(OR=3.446)、高电磁辐射暴露(OR=2.687)是寒区军人子女发生出生缺陷的危险因素,母亲牛奶摄入量≥500 mL/周(OR=0.546)是保护性因素。结论寒区军人子女全孕期出生缺陷发生率与本地地方群众基本相同,出生缺陷发生顺位前3位分别是外耳畸形、并指(趾)和/或多指(趾)、先天性心脏病。母亲文化程度低,双亲的雷达、无线电波和高电磁辐射暴露是寒区军人子女发生出生缺陷的危险因素。

关键词：寒区军人出生缺陷医院监测人群监测

在线全文

学校读者我要写书评

暂无评论

三种常用不锈钢的耐局部腐蚀性能

材料研究学报 2017年第9期31卷 666-670,665,671页

作者：孙京丽邹丹金晶李莉刘海英上海航天设备制造总厂上海200245 上海航天精密机械研究所上海201600

研究了微量元素含量不同的1Cr18Ni9Ti、304、316L三种奥氏体不锈钢的耐局部腐蚀性能,包括晶间腐蚀、点蚀和应力腐蚀。结果表明,Ti元素的添加和较低的含C量都能改善抗晶间腐蚀性能;Cr和N含量最高的固溶态304不锈钢最耐点蚀;Ni含量最高的... 详细信息

研究了微量元素含量不同的1Cr18Ni9Ti、304、316L三种奥氏体不锈钢的耐局部腐蚀性能,包括晶间腐蚀、点蚀和应力腐蚀。结果表明,Ti元素的添加和较低的含C量都能改善抗晶间腐蚀性能;Cr和N含量最高的固溶态304不锈钢最耐点蚀;Ni含量最高的固溶态316L在42%沸腾氯化镁溶液中抗应力腐蚀性能最优。

关键词：材料失效与保护局部腐蚀动电位法硫酸.硫酸铜腐蚀法慢应变速率法微量元素