F.C.Zhang 1)
,
B.T.Hu 1)
,
L.X.Zhang 1) and C.F.Lin 2) 1) Department of Materials Science and Engineering
,
Yanshan University
,
Qinhuangdao 066004
,
China 2) Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China
金属学报(英文版)
Nano silicon particles can be become nano fibre under low energy electron beam bombarding. The formation of the nano silicon fibre include two stages. At first, on the nano silicon particle surface many silicon atoms are gasified, then these silicon atoms deposit in the place where have more charge on account of the static electrical absorption and the point effect of the charge accumulation , these atoms grow into non crystalline silicon fibres. The second stage is the non crystalline silicon fibres crystallizing. Its crystallizing temperature is about 180℃. The growth mechanism of the nano silicon fibre is vapour solid mode.
关键词:
nano fibre
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null
,
null
Chinese Physics Letters
The magnetic properties of 1 T-TaS2 and 1 T-Fe-0.07 Ta-0.93 S-2 have been studied, Experimental results show that the phase transition temperature of 1 T-TaS2 is a function of the magnetic field, At low temperatures, both compounds are in a mixed state of charge density wave -spin density wave due to the coherent superposition of antiferromagnetic coupling.
关键词:
density
孙长征
,
宇波
,
魏进家
工程热物理学报
通过分析气相、液相、管壁之间的关系,将气液混输管道中的流型划分为五种,并总结了各流型的特点及气液相和管壁间的几何关系;在对Baker、Brill、Beggs-Brill、Taitel、段塞特征分析(SCA)等流型判别方法进行分析的基础上,提出了一种综合使用SCA、Taitel和Brill三种方法的流型判别方法 S-T-B法.经算例验证,该方法对气液两相混输的流型判断准确性较高,可以作为气液混输工艺计算过程中确定流型的方法.
关键词:
气液混输
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流型
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段塞特征分析法
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S-T-B
史瑞民
,
王治
,
郑燕
,
卢建敏
功能材料
doi:10.3969/j.issn.1001-9731.2017.04.026
研究了不同退火温度下形成的纳米晶Fe74.5Cu1Nb2Si17.5B5合金经过磁场退火后,其饱和磁致伸缩系数λs、矫顽力Hc和μi-T曲线的变化.研究表明,经过磁场退火后,纳米晶合金的矫顽力出现不同程度的降低,温度在350℃以下时,初始磁导率表现出明显的提高,这些性能的改善归因于合金饱和磁致伸缩的减小.
关键词:
纳米晶合金
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磁场退火
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磁致伸缩
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矫顽力
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μi-T曲线
Physical Review B
The magnetic properties and phase transitions of 1T-TaS2 and 1T-Fe0.07Ta0.93S2 have been studied in the interval of 1.5-300 K and over the range of 100 Oe-60 kOe. Experimental results show that at high temperatures the compounds are in a diamagnetic state and the commensurate-charge-density-wave-triclinic-nearly-commensurate transition temperature of 1T-TaS2 decreases with increasing magnetic field. The amount of variation is a function of the magnetic field. At low temperatures both 1T-TaS2 and 1T-Fe0.07Ta0.93S2 are in a paramagnetic state owing to the localized moments that come from the single Anderson-Mott localization state. The curves of magnetization versus temperature do not follow the Curie law or Curie-Weiss law, but can be described fairly well as M = M(0) + gamma T--n. The fitting parameters of experimental curves show that a part of the neighboring moment appears as antiferromagnetic coupling due to exchange interaction between the moments. The magnetic-field dependence of magnetization exhibits a complicated feature at low temperature. It shows that the compounds may undergo a phase transition at the maximum value of magnetization and then they are probably in a mixed charge-density-wave-spin-density-wave (CDW-SDW) state or SDW state due to the coherent superposition of the antiferromagnetic coupling.
关键词:
metal-insulator-transition;density-wave domains;high magnetic-fields;charge-density;doped 1t-tas2;coexistence;microscopy;systems;silicon;2h-tas2
Wenli PEI
,
Fazeng LIAN
,
Guiqin ZHOU
,
Jinguo LI
材料科学技术（英文）
In this article, the quenched Nd4.5Fe75Co1Si1B18.5 ribbons were prepared, and the structures and properties were investigated. The results show that the change of structures of Nd4.5Fe75Co1Si1B18.5 quenched amorphous ribbons is Am-->Am' +Fe3B+ Nd2Fe23B3+ Nd2Fe14B-->Fe-3 B+Nd2Fe14B when it is heated. The effect of crystallizing treatment temperature and time on the magnetic properties of the quenched alloy was studied. The magnetic properties of 16 m/s quenched ribbons for 710 degrees Cx1200 s crystallizing treatment reach H-i(c)=238.6 kA/m, B-r=0.8987 T and (BH)(max)=51.39 kJ/m(3). The grain size is about D-Fe3B=32 nm and D-Nd2Fe14B=22 nm.
关键词:
材料科学技术（英文）
In this article, the quenched Nd4.5Fe75Co1Si1B18.5 ribbons were prepared, and the structures and properties were investigated. The results show that the change of structures of Nd4.5Fe75Co1Si1B18.5 quenched amorphous ribbons is Am-->Am' +Fe3B+ Nd2Fe23B3+ Nd2Fe14B-->Fe-3 B+Nd2Fe14B when it is heated. The effect of crystallizing treatment temperature and time on the magnetic properties of the quenched alloy was studied. The magnetic properties of 16 m/s quenched ribbons for 710 degrees Cx1200 s crystallizing treatment reach H-i(c)=238.6 kA/m, B-r=0.8987 T and (BH)(max)=51.39 kJ/m(3). The grain size is about D-Fe3B=32 nm and D-Nd2Fe14B=22 nm.
关键词:
Physica B-Condensed Matter
The superposition model has been applied to the studies of the zero-field splitting b(2)(0) for AgGaS2: Cr+ crystal and the uniaxial stress EPR data for ZnS: Cr+ crystal. These studies show that for [CrS4](7-) groups in crystals, the intrinsic parameter (b)over-bar(2)(R-0) approximate to -0.035(8)cm(-1) with the reference distance R-0 approximate to 2.378(20) Angstrom and the power-law exponent t(2) approximate to 14(4). To our knowledge, this is the first time that the superposition model parameters (b)over-bar(2) and t(2) are given for Cr+-S2- combination (or other Crc-X combinations). (C) 1999 Published by Elsevier Science B.V. All rights reserved.
关键词:
electron paramagnetic resonance;superposition model;Cr+ ion;AgGaS2;ZnS;zero-field splittings;crystals;transition;mn-2+;fe-3+
Communications in Theoretical Physics
For the first time, by taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as all the levels and the admixtures of wavefunctions within d(3) electronic configuration, the values of parameters in expressions of Raman and optical-branch terms of thermal shifts (TS) due to EPI for three levels, T-4(2) band and T-4(1) band of ruby have been evaluated; the contributions to TS of T-4(2) and T-4(1) broad bands from thermal expansion have also been. calculated; and then, the TS of the peak energies of 'T2 and 4 Ti broad bands have been calculated. The results are in satisfactory agreement with observed data. The values of single-electron reduced matrix elements representing the strengths of EPI of T-4(2) and T-4(1) bands have respectively been determined. For TS of the peak energies of T-4(2) and T-4(1) bands, it is found that the contribution to TS from the second-order term in EPI Hamiltonian is dominant; TS due to EPI of acoustic branches are over two times as much as those of optical branches, and both of them increase rapidly with temperature; the neighbor-level term is insignificant; the contribution to TS from thermal expansion is specially important, and all the three terms of TS of T-4(2) or T-4(1) band axe red shifts.
关键词:
crystal fields;optical spectral bands;electron-phonon interaction;thermal expansion;thermal shift;theoretical calculations;high-pressure;field;spectroscopy;spectra
韩伟
,
吕彩琴
,
张翼
金属功能材料
在温度为473～623 K、应变速率为0.1 s-1～0.001 s-1的条件下对7B04-T6铝合金板材进行温拉伸实验,研究该材料在所选定温度和应变速率下的流变应力变化数据.分别对Fields and Backofen方程和加入软化因子"s"的流变应力数学方程进行修正,建立该材料的两个流变应力数学模型.两模型中,Fields and Backofen模型在峰值应力之前能更好地反映流变应力的变化;加入软化因子的流变应力模型在峰值应力之后软化阶段能更好地反映流变应力的变化.
关键词:
铝合金
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温拉伸
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流变应力
