材料期刊网

PLASMA SURFACE ALLOYING OF AGE HIGH SPEED STEEL

Z.H.Li , X.P.Liu , Y.Gao and Z.Xu Research Institute of Surface Engineering , Taiyuan University of Technology , Taiyuan 030024 , China

金属学报(英文版)

It, ageing high speed steel (AHSS) with high cobalt, has a strong ability of age hardening. However, it has two disadvantages, One is short of toughness, the other is its high price because of its too much alloy content especially cobalt. All of these effect on its widespread using. Now there is a new method without the two flows to form this steel in the surface of ingot iron by use of double glow plasma surface alloying technique.In this paper, the following three parts are introduced: the metallurgical process of this surface ageing high speed steel (SAHSS), the micro structure of the alloying layer, the alloy distribution in the layer. By using the designed source pole, the special alloying process, the required surface alloying content, just like the AHSS—Co23W11Mo7 can be achieved in the surface layer. This new method has wide prospect in the fields of tools, moulds and other wear resisting fields.

关键词: SAHSS , null , null

MARTENSITE AND REVERSE TRANSFORMATION IN PRESTRAINED TiNi SHAPE MEMORY ALLOY THIN FILM

X.P.Liu , M.Z.Cao , R.Yang

金属学报(英文版)

The effect of pre-strain on phase transformation of TiNi shape memory alloy film was studied by differential scanning calorimeter measurement(DSC).Compared with undeformed TiNi film,the reverse transformation of pre-strained specimens was elevated to a higher temperature on the first heating,but martensite and reverse transformation on subsequent thermal cycles occurred at a lower temperature.The evolution of transformation behavior in pre-strained TiNi film was related to the change of elastic strain energy,irreversible energy and internal stress field.

关键词: shape memory alloy , null , null

Magnetocaloric effect and size-effect related thermal hysteresis reduction in MnAs(1-x)P(x) compounds

Physica Status Solidi a-Applications and Materials Science

In MnAs(1-x)P(x) compounds (x = 0.006 and 0.01), prepared by mechanical alloying, the thermal hysteresis is greatly reduced from about 10-30K in MnAs-based compounds, prepared by conventional melting, to 2K for x = 0.01 (or 4K for x = 0.006). Such obvious hysteretic reduction is ascribed to the grain-size effect, largely due to the preparation method of mechanical alloying. Meanwhile, a maximum value of the magnetic-entropy change Delta S(M) of 11.3 J/kgK for a field change of 2 T is obtained at 294.5K for MnAs(0.994)P(0.006). The study on the MnAs(1-x)P(x) system and also the effect of the preparation technology may be beneficial for the realization of magnetic refrigerants for application at room temperature. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

关键词: magnetocaloric effect;mechanical alloying;thermal hysteresis;gd-5(si2ge2);transition;mnas

THE SYNTHESIS AND MAGNETOSTRICTION OF P rx Ce 1 x Fe 2 COMPOUNDS

Y.X.Li , G.Z.Xu , J.P.Qu , F.G.Liu and B.W.Wang Hebei University of Technology , Tianjin 300130 , China C.C.Tang.G.H.Wu and W.S.Zhan State Key Laboratory for Magnetism , Institute of Physics , CAS , Beijing 100080 , China C.Zhao Tianjin University , Tianjin 300072 , China S.X.Gao Hebei Normal University , Shijiazhuang 050091 , China

金属学报(英文版)

The synthesis and magnetic properties of Pr xCe 1 x Fe 2 have been investigated. The forma tion of Pr xCe 1 x Fe 2 is found to depend strongly on annealing temperature. Pure single phase compound can be synthesized at ambient pressure when x≤0 5. The main phase of the Laves structure can still be observed up to x=0 8. Magnetostriction increases with in creasing x and a largest saturation magnetostriction 200 ppm is observed for x=0.5.

关键词: magnetostriction , null , null

First-principles study on the electronic structure of dilute magnetic semiconductor Ga(1-x)Cr(x)P in zinc-blende phase

Physica Status Solidi B-Basic Research

We employ the full potential linearized augmented plane wave (FP-LAPW) method based on spin-polarized density functional theory (DFT) in order to investigate the structural, electronic, and magnetic properties of ordered dilute magnetic semiconductor (DMS) Ga(1-x)Cr(x)P in zinc-blende phase. The calculated electronic band structures and density of states of these DMSs are discussed. The results show that the ferromagnetic states are more favorable in energy than antiferromagnetic states. Ga(1-x)Cr(x)P for x = 0.125, 0.25, and 0.50 exhibits half-metallic (HM) characteristic with integral magnetic moment, and the sensitivity of half-metallicity of Ga(1-x)Cr(x)P as a function of lattice constant is also discussed. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

关键词: dilute magnetic semiconductors;density functional theory;electron;density of states;GaCrP;half-metallic ferromagnets;heusler alloys;doped gap;spin;gaas;ge;al;si

N-X共掺p型ZnO薄膜的研究进展

李万俊 , 孔春阳 , 秦国平 , 阮海波 , 杨天勇 , 梁薇薇 , 孟祥丹 , 赵永红

材料导报

获得高质量稳定的p型ZnO薄膜是实现ZnO基光电器件化的关键.目前,国际上公认V族元素中的N替代O位(No)是实现p型ZnO较理想的掺杂途径.但p-ZnO:N薄膜的导电性能会随着时间、光照、温度条件发生变化,稳定性不足.大量的理论和实验研究表明N基二元共掺( N-X)可以提高N在ZnO薄膜中的固溶度,浅化N的受主能级,且在很大程度上能够改善p型ZnO的导电性能,有利于获得稳定的p型ZnO薄膜.为此,从N基施主受主共掺、双受主共掺以及其它共掺方面综述了N-X共掺p型ZnO薄膜的研究现状.

关键词: p型ZnO薄膜 , N-X共掺 , 稳定性

固相反应合成Sr_(1+x)Zr_4P_(6-2x)Si_(2x)O_(24)磷酸盐粉体

姜斌 , 房明浩 , 彭鹏 , 卫礼贤 , 黄朝晖 , 刘艳改

稀有金属材料与工程

以SrCO_3、SiO_2、ZrO_2和(NH_4)H_2PO_4为实验原料,采用固相反应法制备出磷酸盐Sr_(1+x)Zr_4P_(6-2x)Si_(2x)O_(24)(x=0～0.4)粉体.XRD和SEM分析表明:在1100 ℃,4 h温度下煅烧能够合成单相Sr_(1+x)Zr_4P_(6-2x)Si_(2x)O_(24)(x=0～0.4)粉体,1100 ℃,4 h条件下制备的Sr_(1+x)Zr_4P_(6-2x)Si_(2x)O_(24)(x=0～0.4)粉体成球状,平均粒径在300～500 nm之间.在1100 ℃煅烧温度下适当延长保温时间,有利于Sr_(1+x)Zr_4P_(6-2x)Si_(2x)O_(24)(x=0～0.4)单相粉体的形成.

关键词: Sr_(1+x)Zr_4P_(6-2x)Si_(2x)O_(24) , 固相反应法 , 热膨胀系数

P53及其相关蛋白对X射线照射肝癌细胞周期的调节

刘辉 , 张红 , 刘兵 , 王小虎 , 郝冀芳 , 段昕

原子核物理评论 doi:10.3969/j.issn.1007-4627.2007.04.009

X射线照射人肝癌细胞HepG2,照射后细胞存活随照射剂量增大明显下降.流式细胞术分析,不同剂量组照射后24 h均发生G2期阻滞.照射后不同时间组的细胞周期分布也有不同,照射后12 h,有显著的S期延迟.Western Blot显示照射后24 h P53,MDM2,P21蛋白表达上升,并有时间效应:P53在照射后24 h之内始终维持较高表达,MDM2和P21分别在照射后6和12 h的表达最高.X射线照射通过影响P53及其相关蛋白的表达影响细胞周期.

关键词: X射线照射 , HepG2 , 细胞周期 , P53 , P53相关蛋白

APPLICATION OF MAXIMUM ENTROPY METHOD TO CALCULATE RDF OF Ni-P AMORPHOUS ALLOY FROM X-RAY DIFFRACTION DATA

LIANG Jianduan LIN Shuzhi Institute of Metal Research , Academia Sinica , Shenyang , China Professor , Institute of Metal Research , Academia Sinica , Shenyang , China

金属学报(英文版)

Experiments clarified that application of the maximum entropy method to calculate the RDF (radial distribution function)of the Ni-P amorphous alloy from fewer data of its X-ray diffraction data shows a higher resolution and good consistent with known results.It is be- lieved that this method is available for the analysis of amorphous structure.

关键词: maximum entropy , null , null

X射线荧光光谱法测定管线钢中Si,Mn,P,Nb,V和Ti

吴岩青

冶金分析 doi:10.3969/j.issn.1000-7571.2003.06.019

用X射线荧光光谱法测定了管线钢中Si,Mn,P,Nb,V,Ti的含量.钢样用车床加工至表面平整、光滑.采用强度校正模型,用计算机拟合工作曲线.所拟方法与常规湿法化学法测定结果相比较,取得满意的效果.

关键词: X射线荧光光谱法 , 管线钢