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Formation of adiabatic shear band and deformation mechanisms during warm compression of Ti–6Al–4V alloy

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Rare Metals 2016年第8期35卷 598-605页

作者： Jiao Luo Lin-Feng Wang Miao-Quan Li Chang-jian Ge xiao-xiao Ma Yong-Ting yang School of Materials Science and Engineering Northwestern Polytechnical UniversityXi'an 710072China

Adiabatic shear band （ASB） was narrow region where softening occurred and concentrated plastic defor- mation took place. In present study, the effects of height reduction and deformation temperature on ASB were investigated by means of optical microscopy （OM） and scanning electron microscopy （SEM）. And the deformation mechanisms within the shear band were discussed thor- oughly with the help of transmission electron microscopy （TEM）. There is a critical strain for the formation of ASB during warm compression of Ti-6AI-4V alloy. The width of ASB increases with height reduction increasing. Elon- gated alpha grains within shear band grow up with defor- mation temperature increasing. Some ultrafine grains that confirm the occurrence of dynamic recrystallization are observed within shear band during warm compression of Ti-6AI-4V alloy.

关键词： Titanium alloy Adiabatic shear band Deformation mechanisms Dynamic recrystallization

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优质牧草新品种选育方法研究进展

草业学报 2024年第6期33卷 187-202页

作者：亓雯雯马红媛李亚晓杜艳孙梦丹武海涛中国科学院东北地理与农业生态研究所吉林长春130102 中国科学院大学北京100049 中国科学院近代物理研究所甘肃兰州730000

作为草食家畜最优良和天然的饲料,牧草是草食畜牧业发展的基础和保障,是大食物观下重要的粮食资源。牧草新品种的选育是草牧业可持续发展的重要基础,在促进畜产品稳产保供能力提升及草牧业高质量发展中起着重要作用。随着对优质牧草新... 详细信息

作为草食家畜最优良和天然的饲料,牧草是草食畜牧业发展的基础和保障,是大食物观下重要的粮食资源。牧草新品种的选育是草牧业可持续发展的重要基础,在促进畜产品稳产保供能力提升及草牧业高质量发展中起着重要作用。随着对优质牧草新品种需求增加,牧草育种技术从常规育种手段进入分子育种时代,牧草新品种培育取得重大突破。本研究对国内外近100年来的牧草育种技术进行了系统的综述,包括驯化育种、杂交育种、诱变育种、倍性育种等常规育种技术,转基因、分子设计育种等基因工程育种技术,以及近年来发展起来的基因编辑技术,同时阐述了不同育种技术取得的成就和存在的问题,并对今后的牧草育种工作提出了以下展望:1)深入挖掘牧草自然资源,加强种质资源收集利用;2)以需求为导向丰富牧草新品种的育种目标,注重牧草品质的改良和抗性品种培育,充分发挥牧草的生产、生态和生活等“三生”功能;3)将常规育种手段与现代生物技术相结合,突破牧草育种瓶颈,加强优质牧草特别是羊草和苜蓿等新品种选育。旨在推动我国进入生物育种新时代,为牧草种质资源创新和优质牧草新品种选育提供参考,为建立优质高产人工草地提供技术支持,从而满足我国畜牧业日益增长的饲草需求。

关键词：羊草苜蓿种质资源分子育种诱变育种细胞工程

Inclusion variations and calcium treatment optimization in pipeline steel production

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International Journal of Minerals,Metallurgy and Materials 2011年第5期18卷 527-534页

作者： jian-hua Liu Hua-jie Wu yan-ping Bao Min Wang Research Institute of Metallurgy Engineering University of Science and Technology Beijing Beijing 100083 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

SiCa line and SiCaBaFe alloy were injected into liquid pipeline steel at the end of LF refining as calcium treatment,and samples were taken from the ladles,mould,and *** of Ca content and inclusions shows that Ca content in steel decreases obviously in the following process after calcium treatment;the compositions,morphology,and sizes of inclusions also vary much in the production;primary inclusions in the ladles prior to calcium treatment are mainly Al2O3 inclusions,but they turn to fine irregular CaS-CaO-Al2O3 compound inclusions after the treatment,then become fine globular CaO-Al2O3 inclusions in the mould,and finally change to a few larger irregular CaS-CaO-Al2O3 complex inclusions in the *** study reveals that inclusion variations are related with the preferential reactions among Ca,Al2O3,and S and the precipitation of S in CaO-Al2O3 inclusions with high sulfur *** evaluation standards for calcium treatment in high-grade pipeline steel were put forward according to the inclusion variations and requirements of pipeline steel on inclusion controlling,and the calcium process was studied and optimized.

关键词： pipeline steel refining inclusions calcium treatment thermodynamics precipitation

Effect of Aging on the Microstructure and Mechanical Properties of 1460 Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 454-459页

作者： Juan Ma De-Sheng yan Li-jian Rong Yi-Yi Li Institute of Metal Research Chinese Academy of Sciences

Effects of the aging temperature on the hardening response, the tensile properties and the precipitate micro- structure evolution of 1460 alloy were studied in this work. It was found that Al3 （Sc, Zr） and δ′ （Al3Li） phases were precipitated from the matrix at the very early aging stage, while the precipitation of T1 （Al2CuLi） and θ′ （Al2Cu） was much slower than that of the δ′ phase. When aging at higher temperature （160 and 190 ℃）, the δ′, T1 and θ′ phases tended to form simultaneously and grow up very quickly. Conversely, the δ′ and θ″ （Al2Cu） phases were precipitated separately and more dispersive at lower aging temperature （130 ℃）. Taken together, the alloy aged at 160 ℃ exhibited improved mechanical properties owing to the uniform dispersion of the fine T1 precipitates.

关键词： Al-Li alloy Precipitate Precipitation hardening process Mechanical property

Morphological Studies on Sn-O Coordination Driving Self-assembly of Well-defined Organotin-containing Block Copolymers

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Chinese Journal of Polymer Science 2014年第12期32卷 1655-1665页

作者： jian jiang Wei yan 柳凌艳 Wei-xing Chang 李靖 The State Key Laboratory of Elemento-Organic Chemistry Nankai University Collaborative Innovation Center of Chemical Science and Engineering

A tin-oxygen coordination driving self-assembly was developed in the block copolymers containing organotin, which were prepared by the radical addition-fraction transfer（RAFT） method and characterized by the gel-permeation chromatography（GPC） and 1H-NMR. And the self-assemblies of these block copolymers with various chain length ratios in the different concentrations in CHCl3 were stable according to the results of DLS and TEM. Additionally, it was also given an insight investigation on the regulation of self-assembly of the block copolymers by adding dibutyltin dichloride and a possible mechanism was proposed.

关键词： Organotin RAFT Sn-O coordination Self-assembly.

Zinner＇s syndrome： clinical features and imaging diagnosis

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Asian Journal of Andrology 2018年第3期20卷 316-317页

作者： xiao-Song jiang Huan-Jun Wang Jin-Hua Lin yan Guo Can-Hui Sun Ling Lin jian Guan Department of Radiology Guangdong Women and Children Hospital Guangzhou 511400 China Department of Radiology The First Affiliated Hospital of Sun Yat-sen University Guangzhou 510080 China UItrosounic Department The First Affiliated Hospital of Sun Yat-sen University Guangzhou 510080 China

Dear Editor, Zinner＇s syndrome is an uncommon urogenital malformation of congenital seminal vesicle cyst associated with ipsilateral renal agenesis. It is considered to be the anomaly development in early embryogene... 详细信息

关键词： IPSILATERAL RENAL AGENESIS

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调控睡眠-觉醒的分子细胞和脑网络机制探讨

生命科学 2024年第3期36卷 399-410页

作者：尹楚慧高稚凡刘晏君杜镜鉴余立晗曾燕梅宇飞武汉科技大学脑科学先进技术研究院武汉430065 职业危害识别与控制湖北省重点实验室武汉430065 武汉科技大学医学院武汉430065

睡眠是影响人体健康的重要因素,睡眠失调易引起多种生理和心理疾病。睡眠稳态既受外界因素(昼夜变化、饮食和温度)影响,亦受内在系统(分子钟和促睡眠/觉醒神经元)调控。细胞内有CLOCK、PER、CRY、NPAS2和BMAL1等分子周期性变化控制生物... 详细信息

睡眠是影响人体健康的重要因素,睡眠失调易引起多种生理和心理疾病。睡眠稳态既受外界因素(昼夜变化、饮食和温度)影响,亦受内在系统(分子钟和促睡眠/觉醒神经元)调控。细胞内有CLOCK、PER、CRY、NPAS2和BMAL1等分子周期性变化控制生物节律;脑内有基底前脑、丘脑、下丘脑、脑桥和延髓等神经元群体特异性地抑制或促进睡眠与觉醒,各核团之间通过突触连接形成神经网络启动和维持觉醒、非快速眼动睡眠和快速眼动睡眠。睡眠障碍普遍存在,本综述将针对调控生物体睡眠-觉醒的分子、细胞和脑网络机制展开讨论,为防治睡眠障碍类疾病提供新的思路。

关键词：睡眠觉醒脑网络昼夜节律快速眼动睡眠

阴山地块固阳地区新太古代TTG片麻岩成因及构造意义:锆石U-Pb年代学、地球化学和Lu-Hf同位素约束

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岩石学报 2024年第11期40卷 3465-3483页

作者：赵辰王笑刘锦张健陈井胜张超崔丹丹崔育菘中国地质调查局沈阳地质调查中心沈阳110034 东北地质科技创新中心沈阳110034 香港大学地球科学系中国香港吉林大学地球科学学院长春130061 辽宁省地质矿产调查院有限责任公司沈阳110000

作为太古宙基底保存较完整的地区,华北克拉通阴山地块出露大量的新太古代岩石组合,主要包括表壳岩、TTG片麻岩(英云闪长质片麻岩-奥长花岗质片麻岩-花岗闪长质片麻岩)、钾质花岗岩和闪长岩(赞岐岩)等。前人对阴山地块新太古代TTG片麻岩... 详细信息

作为太古宙基底保存较完整的地区,华北克拉通阴山地块出露大量的新太古代岩石组合,主要包括表壳岩、TTG片麻岩(英云闪长质片麻岩-奥长花岗质片麻岩-花岗闪长质片麻岩)、钾质花岗岩和闪长岩(赞岐岩)等。前人对阴山地块新太古代TTG片麻岩开展了一系列的工作,但有关其岩石成因、构造背景以及新太古代地壳生长机制仍然存在较大争议。本次工作在内蒙古固阳西部的花岗-绿岩带中新识别出一套TTG片麻岩组合,并对其进行了岩石学、同位素年代学和岩石地球化学的综合研究。LA-ICP-MS锆石U-Pb定年结果显示TTG片麻岩组合形成时代为2550~2524Ma;Lu-Hf同位素分析结果显示其εHf(t)值为+0.54~+4.96,t C DM模式年龄为2985~2715Ma,这与阴山地块目前最古老的奥长花岗质片麻岩(2.7Ga)的岩浆年龄近一致,说明其可能来源于2.7Ga新生镁铁质地壳的部分熔融。全岩地球化学分析结果显示,该TTG片麻岩组合具有较高的SiO 2(63.32%~70.80%)和Al 2O 3(15.19%~16.55%)含量,以及较高的Sr(410×10^(-6)~1532×10^(-6))和较低的Y(2.61×10^(-6)~14.04×10^(-6))含量,同时具有相对较高的(La/Yb)N(10.31~56.85)和Sr/Y(44.32~349.1)比值,并相对富集轻稀土元素(LREEs)和大离子亲石元素(LILEs),这些均与典型的埃达克质岩石地球化学特征相似。另外,该TTG片麻岩样品具有相对较低的MgO(0.60%~2.60%)、Ni(3.12×10^(-6)~11.12×10^(-6))、Cr(3.77×10^(-6)~18.11×10^(-6))含量和Mg#(34.88~53.45),说明其来源于加厚的大陆下地壳埃达克质岩浆。因此,本文认为在2.55~2.52Ga,固阳新太古代TTG片麻岩可能由加厚的镁铁质下地壳部分熔融形成的。结合前人的研究结果,进一步推断阴山地块在新太古代可能经历两期岩浆事件:第一期岩浆事件发生在2.7Ga,形成加厚的镁铁质地壳和少量的~2.7Ga TTG岩石;第二期岩浆事件发生在2.55~2.50Ga,形成阴山地块大面积的新太古代TTG岩石和其他花岗质岩石组合。综上,我们认为以地幔柱为主导的地球动力学机制可以较好地解释阴山地块加厚镁铁质下地壳部分熔融和TTG岩浆的形成过程。

关键词：华北克拉通阴山地块埃达克质岩石 TTG片麻岩地幔柱

Haploid Induction via In vitro Gynogenesis in Tomato(Solanum lycopersicum L.)

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Journal of Integrative Agriculture 2014年第10期13卷 2122-2131页

作者： ZHAO He WANG xiao-xuan DU Yong-chen ZHU De-wei GUO yan-mei GAO jian-chang LI Fei John C Snyder Institute of Vegetables and Flowers Chinese Academy of Agricultural Sciences Department of Horticulture University of Kentucky

In order to determine the potential for haploid induction via in vitro gynogenesis in tomato, the ovules and protoplasts of embryo sacs from the hybrids Zhongza 101 and Zhongza 105 were cultured. An efficient method of ovule isolation was established in this study. Using this method, 100-150 ovules could be isolated from one ovary. Isolated ovules were cultured on three induction media to induce gynogenesis in vitro. During culture, ovules were enlarged markedly, with opaque white color. When observed microscopically, there were cell divisions and cell clumps in embryo sacs. Subsequently, the cell clumps in embryo sacs ceased growth, likely because the integument grew faster than embryo sacs did and hindered the fiarther development of embryo sacs. Therefore, subsequent callus morphogenesis might be originated from the integument. Thousands ofcalli from the two tomato varieties were obtained. Five diploid plants were regenerated after 15 months of subculturing. To eliminate the hindering effect of integument on embryo sac cells, the protoplasts of embryo sacs were prepared and cultured. After 48 hours of culture, the protoplasts of embryo sacs doubled in size and gradually formed clusters of cells. These results suggested that gynogenesis might be a potential way for haploid induction in tomato.

关键词： Solanum lycopersicum ovule protoplast of embryo sac macrospore in vitro gynogenesis haploid