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Carbides precipitation and their evolution of Cr15Co10Mo5-alloyed heat-resistant bearing steel after tempering at different temperatures

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Journal of Iron and Steel Research International 2019年第10期26卷 1096-1105页

作者： mao-guo Xiao Xin-yang Lü Dong-hui Li Shao-hong Li Kun-yu Zhao mao-sheng yang School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing 100081China

The carbides precipitation and their evolution at elevated tempering temperature in Crl5Col0Mo5-alloyed heat-resistant bearing steel were investigated by means of the transmission electron *** results show that there is no carbide precipitated from the martensitic matrix when the sample was tempered at 480℃.However,when the sample was tempered at 540℃,a large number of stable spherical M6C carbides precipitated in the test ***,there are three types of carbides precipitated from the matrix including M6C,M2C and M23C6 carbides when the tempering temperature reached 600℃.The mechanical properties also present a correlation with the evolution of carbides during tempering at different *** indicates that the strengthening mechanism of the steel is mainly attributed to the precipitation of carbides and their evolution,including the morphologies and types of carbides at different *** addition,the austenitic layers with a thickness of about 30 nm have been obtained between the martensite laths after tempering at 600℃.The austenitic layers will produce transformation-induced plasticity effects to improve the toughness of the steel.

关键词： High-temperature bearing steel Carbide evolution Phase diagram Diffusion coefficient Secondary hardening Austenitic layer

Wear Behavior and Mechanism of a Sliding Pair of 0.1C-3Cr-2W-V Nitrided Steel Rubbing against an Aluminum Bronze Alloy

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Journal of Iron and Steel Research International 2016年第3期23卷 281-288页

作者： Guang-hong WANG sheng-guan QU Zhi-hua XIONG Fu-qiang LAI Xiao-qiang LI mao-sheng yang School of Mechanical and Automotive Engineering South China University of Technology Institute of Special Steel Central Iron and Steel Research Institute

Wear behavior and mechanism of plasma nitrided steel oscillating against a heat-treated and an untreated aluminum bronze alloy were investigated using an Optimol SRV *** influence of heat treatment on the mechanical properties of the alloy was ***,the wear debris was also examined to understand the wear *** results show that a 220-230μm nitrided layer,which was harder than the substrate,was obtained on the steel *** tensile strength and hardness of the alloy are found to be significantly improved by the heat treatment associated with low impact *** heat treatment of the alloy did not obviously decrease the friction coefficient of the nitrided steel-bronze ***,the wear loss of the nitrided steel increased when it mated with the treated bronze by a severe three-body *** nitrided steel was mainly damaged by fatigue *** plane contact conditions,the wear debris was mainly generated from the bronze part and can escape from the interface before being oxidized,leading to the phase structure of all the debris being copper rather than copper oxides.

关键词： steel plasma nitriding aluminum bronze sliding wear three-body abrasion

Effects of traditional heat treatment and a novel deep cryogenic treatment on microstructure and mechanical properties of low-carbon high-alloy martensitic bearing steel

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Journal of Iron and Steel Research International 2021年第3期28卷 370-382页

作者： Dong-hui Li Wen-chao He Xu Zhang mao-guo Xiao Shao-hong Li Kun-yu Zhao mao-sheng yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093YunnanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing100081China

The effects of traditional heat treatment(quenching and then tempering)and deep cryogenic treatment on the microstructure and mechanical properties of a low-carbon high-alloy martensitic bearing steel were studied by Rockwell hardness test,X-ray diffractometry,scanning electron microscopy and transmission electron *** results show that the deep cryogenic treatment promotes the transformation of the retained austenite to martensite during cooling,which leads to the hardness of the sample after deep cryogenic treatment higher than that at the quenched ***,the carbon content in the martensite matrix after different treatments was calculated and the results indicated that deep cryogenic treatment can promote the segregation of carbon atoms in martensite to *** segregated carbon atoms act as and grow into nuclei for the formation of fine carbide particles during subsequent *** this resulted in the fact that the hardness of the tempered experimental steel after deep cryogenic treatment is higher than that without deep cryogenic treatment.

关键词： Heat treatment High-alloy martensitic bearing steel Deep cryogenic treatment Carbide Retained austenite

Effect of deep cryogenic treatment on martensitic lath refinement and nano-twins formation of low carbon bearing steel

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Journal of Iron and Steel Research International 2020年第1期27卷 105-113页

作者： Xin-yang Lü Zhi-wei Wu Xiao He Jun Li Shao-hong Li mao-sheng yang Kun-yu Zhao Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing 100081China

The effect of heat treatment and deep cryogenic treatment on microstructural evolution of low carbon martensitic bearing steel was *** experimental results showed that the lath martensite was obtained by quenching and a few twins as substructures formed in some martensitic *** rudiment of sub-interfaces of martensitic lath was formed in the highdensity dislocation regions after deep cryogenic treatment;meanwhile,the number of twins increased,especially in the highdensity dislocation *** phenomenon is due to the increase in internal stress caused by cryogenic *** tempering,the rudiment of sub-interface further evolved into the martensitic lath boundary,and thus the original martensitic laths were *** twins formed by cryogenic treatment did not disappear after *** addition,small quantities of annealing twins formed in tempering *** laths morphology and substructures in different stages of the heat and deep cryogenic treatment were observed by tninsmission electron microscopy.

关键词： Low carbon bearing steel-Deep cryogenic treatment Internal stress Sub-interface Nano-twin

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肠道菌群微环境与结直肠癌的关系研究进展

世界华人消化杂志 2016年第36期24卷 4759-4765页

作者：秧茂盛周密吉首大学医学院转化医学研究中心湖南省吉首市416000 重庆医科大学附属第一医院药学部重庆市400016

肠道菌群是目前研究的热点领域,现有的研究结果提示:肠道菌群可能与代谢性疾病、免疫性疾病、神经系统疾病、认知与行为失常、癌症等多种疾病相关.本文检索和分析了近10余年来有关肠道菌群及其微环境与结直肠癌(colorectal cancer,CRC)... 详细信息

肠道菌群是目前研究的热点领域,现有的研究结果提示:肠道菌群可能与代谢性疾病、免疫性疾病、神经系统疾病、认知与行为失常、癌症等多种疾病相关.本文检索和分析了近10余年来有关肠道菌群及其微环境与结直肠癌(colorectal cancer,CRC)关系的研究成果,从肠道菌群及其微环境与CRC的定义、健康与CRC状态下的肠道菌群构成、肠道菌群的失调方式、肠道菌群微环境与CRC的相关性、肠道菌群微环境与CRC的病理生理机制等5个方面进行了综述,期望能够为揭示肠道菌群微环境在CRC的发生与发展病理机制中的作用,以及以肠道菌群微环境为靶向的、新的CRC预防和治疗手段的研发提供思路和线索.

关键词：结直肠癌肠道菌群肠道菌群微环境病理机制细菌毒素

急性胰腺炎与肝功能异常之间的“因-果”关系研究进展

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世界华人消化杂志 2017年第22期25卷 1995-1999页

作者：秧茂盛张红晴吉首大学医学院转化医学研究中心湖南省吉首市416000

急性胰腺炎(acute pancreatitis,AP)与肝功能异常之间的关系问题是一个全新的临床课题,现有的研究结果暗示:AP易累及肝脏,肝功能受损也可影响胰腺.AP与肝功能异常之间可能存在着一定的互为"因-果"的关系.本文检索和分析了近十年来有关A... 详细信息

急性胰腺炎(acute pancreatitis,AP)与肝功能异常之间的关系问题是一个全新的临床课题,现有的研究结果暗示:AP易累及肝脏,肝功能受损也可影响胰腺.AP与肝功能异常之间可能存在着一定的互为"因-果"的关系.本文检索和分析了近十年来有关AP与肝功能异常之间关系的文献报道,从AP与肝功能异常的概念、AP诱发的肝功能异常及其机制、肝功能异常诱发的胰腺炎及其机制、胰腺炎与肝功能损伤之间的相互关系及临床意义等方面进行了综述,期望能够为对临床预防和治疗"AP"或"肝功能异常"提供新的思考,并为探索"AP"或"肝功能异常"的病理机制提供新的研究方向.

关键词：急性胰腺炎肝功能异常 “因-果”关系

Genetic dissection of developmental behavior of crop growth rate and its relationships with yield and yield related traits in rice

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Genetic dissection of developmental behavior of crop growth ...

非肽类β-分泌酶1(BACE1)抑制剂的研究进展

湖北省遗传学会、江西省遗传学会2006年学术年会暨学术讨论会

作者： Shao-Bo Li, Zhi-Hong Zhang, Ying Hu, Chen-Yu Li, Xuan Jiang, Ting mao, yang-sheng Li, Ying-Guo Zhu Key Laboratory of the Education Ministry of China for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China

Crop growth rate is a dynamic character that determines the final yield in cereal crops. The objective of the current study is to reveal its genetic basis and to genetically understand its relationships with grain yield and yield related traits like heading date, grain-filling duration, 1000-grain weight and plant height in rice (Oryza saliva L.). With 258 recombinant inbred lines (RILs) derived from a cross between cv. Lemont and cv. Teqing, time-related QTL mapping was conducted. Eight QTL for crop growth rate were identified at four consecutive growth periods. These QTL individually explained 5-29% of the trait variation. The Teqing alleles increased the trait values at all the four QTL detected before heading, while Lemont contributed alleles to increase the trait values at three of the other four QTL mapped after heading, which was in agreement with the observation that Teqing was the high-value parent before heading, while Lemont became the high-value parent after heading. No common QTL was observed at different growth periods. These results implied that crop growth rate of rice might be controlled by different genes (QTL) during different time intervals. A total of 22 QTL were identified for the other five traits, and the amount of variation explained by individual QTL ranged from 3% to 26%. The interval RM25-CSU754 on chromosome 8 was identified to produce a major effect on multiple traits such as crop growth rate Ⅳ, grain yield, heading date, grain-filling duration, plant heights Ⅱ and Ⅳ, which provided a genetic explanation for the close correlations among the traits. The implications of the results for further improvement in rice yield potential were discussed.

关键词： Crop growth rate Heading date Grain-filling duration Time-related QTL mapping

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中国药物化学杂志 2016年第6期26卷 498-508页

作者：李慧宁李凤然程卯生刘洋沈阳药科大学基于靶点的药物设计与研究教育部重点实验室辽宁沈阳110016

β-分泌酶1(β-site APP cleaving enzyme 1,BACE1)是存在于中枢神经系统的天冬氨酸蛋白酶,能够催化β-淀粉样多肽(Aβ)形成中的第一步也是关键一步的反应,因而被认为是调节认知障碍、治疗阿尔兹海默症(AD)的关键靶点。自2000年BACE1的... 详细信息

β-分泌酶1(β-site APP cleaving enzyme 1,BACE1)是存在于中枢神经系统的天冬氨酸蛋白酶,能够催化β-淀粉样多肽(Aβ)形成中的第一步也是关键一步的反应,因而被认为是调节认知障碍、治疗阿尔兹海默症(AD)的关键靶点。自2000年BACE1的结构被解析出来后,其抑制剂的研究始终是药物化学领域的热点。随着高通量筛选和基于片段的药物发现等技术的广泛应用,大量非肽类小分子BACE1抑制剂被设计与合成,并且部分化合物已经进入了临床研究阶段。本文对近5年来非肽类BACE1抑制剂的研究进展进行综述。

关键词： β-分泌酶1 非肽类BACE1抑制剂 β-淀粉样多肽

纳米载体SWCNT投递Bcl-2 siRNA促进U251细胞凋亡

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中国临床解剖学杂志 2017年第5期35卷 521-525页

作者：胡晓芳邱仁杰余磊刘茂生杨琳王国保遵义医学院珠海校区人体解剖与组织胚胎学教研室广东珠海519041 南方医科大学广东省组织构建与检测重点实验室广州510515 江西中医药大学科技学院江西南昌330004 南方医科大学南方医院肾内科广州510515

目的设计和构建特异性siRNA纳米载体SWCNT-siRNA,通过体外实验,研究其对脑胶质瘤的作用。方法设计合成特异性Bcl-2 siRNA,利用超声技术合成SWCNT-siRNA复合物,动态散射粒度分析仪进行粒径分析;体外培养U251胶质瘤细胞,SWCNT-siRNA复合... 详细信息

目的设计和构建特异性siRNA纳米载体SWCNT-siRNA,通过体外实验,研究其对脑胶质瘤的作用。方法设计合成特异性Bcl-2 siRNA,利用超声技术合成SWCNT-siRNA复合物,动态散射粒度分析仪进行粒径分析;体外培养U251胶质瘤细胞,SWCNT-siRNA复合物处理细胞后,激光共聚焦显微镜追踪siRNA进入细胞的分布。PCR检测靶基因Bcl-2沉默情况,Annexin-V FITC与PI联合标记细胞后,流式细胞仪检测细胞凋亡。结果通过粒径分析证明siRNA成功缠绕到SWCNT上形成稳定的复合物siRNA-SWCNT。利用激光共聚焦显微镜对标记红色荧光的siRNA进行追踪,发现siRNA成功投递到细胞内。PCR验证了被投递到胞浆的siRNA很好的沉默目标基因Bcl-2。通过流式细胞仪分析发现,与对照组比较发现其可以抑制肿瘤细胞生长,促进肿瘤细胞早期凋亡。结论 SWCNT作为纳米载体投递Bcl-2 siRNA进入U251胶质瘤细胞,通过降解Bcl-2 mRNA抑制Bcl-2的表达并促进胶质瘤细胞的凋亡。

关键词：脑胶质瘤 siRNA 碳纳米管 Bcl-2 U251