余伟
,
武会宾
,
王立军
,
霍松波
,
祝瑞荣
,
林国强
钢铁
N610E级石油储备罐用钢（12MnNiVR）常用加热调质处理工艺生产。利用OM、TEM等试验方法,研究了石油储罐用钢N610E直接淬火后,不同回火温度对组织和力学性能的影响。结果表明：直接淬火钢经655℃回火,钢板具有最佳综合力学性能,其抗拉强度640 MPa,屈服强度570 MPa,伸长率22%,-20℃冲击功273 J,不同回火温度的N610E钢韧脆转变温度均在-60℃以下。随回火温度的升高,板条贝氏体回复作用逐渐加强,位错通过运动、合并、重组,相邻板条合并,组织粗化;回火后钢的力学性能变化趋势的非单调性,归因于回火过程贝氏体中位错亚结构的回复软化与碳的脱溶及第二相的析出强化机制综合作用。
关键词:
直接淬火
,
回火
,
组织
,
力学性能
,
石油储罐钢
杨天佑
,
王铁固
,
田静
,
常景玲
,
秦广雍
原子核物理评论
研究了30 keV N+注入E.coli诱发的辐射超敏感效应/增强的辐射性(HRS/IRR)及该效应诱发时E.coli细胞内抗氧化物酶(SOD和CAT)的诱导表达,探讨了细胞内抗氧化物酶的诱导与HRS/IRR诱发之间的关联.研究结果显示,HRS诱发剂量范围内(0-5×1014 N+/cm2),E.coli细胞内超氧化物岐化酶(SOD)的酶活基本维持在10 Us/mg的较低水平,过氧化氢敏(CAT)酶活也都低于8 Us/mg;IRR诱发的剂量范围内(5×1014-10×1014N+/cm2),SOD和CAT活性升高并分别达到了58 Us/mg和26 Uc/mg的最高水平.研究结果初步表明,低能离子注入E.coli HRS/IRR的诱发与细胞内抗氧化物酶的诱导关系密切.
关键词:
N+注入
,
辐射超敏感效应
,
增强的辐射性
,
超氧化物岐化酶
,
过氧化氢酶
臧超飞
,
何豫生
,
沈庆飞
,
昌俊
,
李春光
,
张国华
,
罗胜
,
齐志
,
尹道乐
,
丁克俭
低温物理学报
doi:10.3969/j.issn.1000-3258.2001.04.008
我们应用脉冲电流的方法测量了Bi2Sr2CaCu2O8单晶在4特斯拉强场下的大电流时等温E-J特性.我们观察到在大电流时,样品电阻率ρ迅速增大,随着电流的继续上升,经过一段正曲率增长阶段,几乎达到饱和值,最后经过一段负曲率上升,达到正常态,显示出完整的S形.应用尹道乐等人的统一物质方程理论,给出了实验曲线较好的数值拟合.根据拟合结果,讨论了理论中各个参量的物理意义.
关键词:
Journal of Vacuum Science & Technology a-Vacuum Surfaces and Films
Cr-Si-N films were deposited using a hybrid coating system combining arc ion plating and magnetron sputtering. The authors investigated the influence of N-2 flux rate and negative bias voltage on the microstructure and properties of Cr-Si-N films, e. g., chemical composition, film morphology, phase structure, residual stress, and microhardness. The results showed that all the Cr-Si-N films were close to stoichiometry. The N-2 flux rate had no important influence on the microstructure and properties of the Cr-Si-N films. Applying a negative bias voltage resulted in significant decrease in macroparticle densities and smoother film surface. Also the film microstructure transformed from apparent columnar to nanocomposite microstructure. The maximum microhardness obtained ranged from 45 to 50 GPa at a bias voltage ranging from -50 to -100 V. The microhardness enhancement could be ascribed to the mixed effect of grain size diminishment and residual compressive stress. (c) 2008 American Vacuum Society.
关键词:
cathodic arc plasma;mechanical-properties;sputtering techniques;substrate bias;nanocomposite films;ion-bombardment;thin-films;deposition;temperature;hardness
Journal of Alloys and Compounds
Cr(N)-beta-Cr2N nanoparticles were prepared by arc-discharge process in a mixture of argon, hydrogen and nitrogen gases. The nanoparticles are composed of the two components, i,e. Cr(N) solid-solution nanoparticles (polyhedral shape) and beta-Cr2N nitrogen-deficiency nanoparticles (cuboidal shape). Both the nanoparticles share a similar shell-core structure: the shell consists of chromium oxide Cr-2(CrO4)(3) or Cr-O (20 at% Cr), and the complex of Cr and N-O, as well as the core of Cr(N) solid-solution or beta-Cr2N. Moreover, the nanoparticles have a blocking temperature of 29 K and a narrow size distribution. The weak ferromagnetism can be interpreted in terms of the presence of non-compensated surface spins. For the field-cooled (FC) magnetization with the field of 0.01 T, a perfect Curie-Weiss fit of the data above 50 K indicates paramagnetic characteristics of the nanoparticles. This is supported by the hysteresis loops at 5 and 295 K. The paramagnetic Curie temperature of -124 K suggests the type of dominant interaction is antiferromagnetic. (c) 2006 Published by Elsevier B.V.
关键词:
arc-discharge;nanoparticles;blocking temperature;Curie-Weiss law;fe-co(c) nanocapsules;chromium;temperature;fabrication;particles;oxidation;diborane;nitrides;coatings;metals
