材料期刊网

Fire and Corrosion Resistances of Intumescent Nano-coating Containing Nano-SiO₂ in Salt Spray Condition

Zhenyu Wang Enhou Han Fuchun Liu Wei Ke

材料科学技术（英文）

The nano-concentrates and fiame retardant nano-coating were prepared in thhis study. The effect of nano-SiO₂ on the corrosion resistance and fire resistance of ammonium polyphosphate-pentaerythritol-melamine (APP-PER-MEL) coating was investigated by differential thermal analysis (DTA), scanning electron microscopy
(SEM), effective thermal conductivity (λ/d), X-ray photoelectron spectroscopy (XPS) and fire protection test. The chemical action and endothermic effect of ammonium polyphosphate, pentaerythritol and melamine in traditional flame retardant coating were damaged by salt spray condition, whereas the flame-retardant additives in the nano-coating demonstrated the good chemical interaction in salt spray condition. The uniformly dispersed nano-SiO₂ particles could improve corrosion resistance of the coating, and hence nano-coating could remain the good fire-resistant properties even after 500 h salt spray test.

关键词: Nano-SiO₂

HAN液晶盒中开关时间对形变场弛豫过程的影响

李晓吉 , 郑桂丽 , 张志东

液晶与显示 doi:10.3788/YJYXS20132801.0025

在HAN液晶盒撤掉外加电压的过程(即弛豫过程)中,假定电压的开关时间为有限的,把电压处理为时间的指数衰减函数.在这一假定下,对撤掉外加电压后HAN液晶盒中指向矢的分布情况进行研究,得到了对HAN液晶盒的弛豫过程有影响的电压开关时间的范围.

关键词: HAN液晶盒 , 有限开关时间 , 驰豫过程 , 动力学理论

La对Fe-P-N合金Snoek-Ke-K■ster峰的影响

戢景文 , 魏全金 , 张国福 , 赖祖涵 , 陈廷国

金属学报

研究了F? P—N合金加?对Snoek—Ke-Koster(SKK)峰的影响,发现与合金含La,P的原子浓度比(C_(La)/C_p)有关:对于C_(La)/C_p较大(例如4.56和2.6)的合金,La有明显增强SKK阻?效应:对于C_(La)/C_p=0.27的P过饱和合金,La对SKK峰无明显影响。

关键词: 内耗 , Snoek-Ke-Koster peak , Fe-P-La-N alloy

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

电场诱导纳米结构HAN液晶盒中新型有序重构过程的描述

陈思博 , 王永超 , 周璇 , 张志东

液晶与显示 doi:10.3788/YJYXS20163109.0853

基于 Landau-de Gennes 理论，利用松弛迭代的方法，研究了包含－1/2向错线的混合排列(HAN)液晶盒中，平行于向错线的电场所诱导的结构转变。结果表明，盒厚固定时，电场诱导五种结构转变过程；电场固定时，盒厚变化产生三类结构转变方式。力曲线上的极小值确定了液晶系统发生结构转变的临界盒厚。

关键词: 有序重构 , Landau-de Gennes理论 , -1/2 向错 , 力曲线

HAN-IPS液晶盒的引流效应

郑桂丽 , 姜丽 , 张志东

液晶与显示 doi:10.3969/j.issn.1007-2780.2010.06.001

根据Erickson-Leslie流体动力学理论,研究了混合排列向列相-共面转换液晶盒的引流效应.在强锚定边界条件下,经过理论推导,得出液晶指向矢与流速的关系方程,进一步通过数值计算得出指向矢分布与时间的关系.发现引流效应加快了指向矢达到平衡态的速度,而且破坏了指向矢分布的瞬态对称性,特别在加电压的初始几毫秒这种现象非常明显.

关键词: 混合排列向列相 , 共面转换 , 引流效应 , 指向矢分布

Congratulations to Prof. Dr. WEI Shoukun's 100th Birthday

金属学报(英文版)

关键词:

Dedicated to Prof. Dr. WEI Shoukun's 100th birthday

稀有金属（英文版）

关键词:

SNOEK-Ke-K■STER PEAK OF INTERNAL FRICTION IN Fe-P-N ALLOYS

Y.Y.Che , G. Y.Zeng , Y. C. Xu and J. W , Ji(College of Science , Northeastern University , Shenyang 110006 , China)

金属学报(英文版)

The internal friction and precipitate phases of the deformed Fe-P-N alloys have been investigated. It has been found that the ratio of depends on the content of P and the relation holds if the content of N is lower than 30wt.ppm and the content of P is lower than 640wt.ppm. It shows that the intercept K2 is related to the presence of the atomic pairs and clusters of P in the alloy matrix.

关键词: internal friction , null

Interfacial diffusion in Cu with a gradient nanostructured surface layer

Acta Materialia

A graded microstructure was produced in the surface layer of a pure Cu sample by means of surface mechanical attrition treatment (SMAT) [Wang K, Tao NR, Liu G, Lu J, Lu K. Acta Mater 2006;54:5281.]. The diffusion behavior of (63)Ni in such a surface layer was investigated by the radiotracer technique at temperatures <438 K. It is shown that the effective diffusivity in the top 10 mu m surface layer is more than 2 orders of magnitude higher than that along conventional high-angle grain boundaries (HAGB) in Cu of similar purity. The diffusion rate increases gradually with increasing depth up to 30-50 mu m, and then decreases with further increasing depth. The enhanced diffusivities reveal higher-energy states of various interfaces in the SMAT surface layer. The excess free energy of HAGB in this layer is estimated to be similar to 30% higher than that of conventional grain boundaries. An apparent retardation of the effective diffusion rate in the top 25 mu m surface layer is induced by tracer leakage into numerous twin-boundary-like interfaces, while the gradual decrease in interface excess free energy correlates with the observed decrease in diffusivity in the subsurface layer at depths exceeding 50 mu m. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

关键词: Nanostructured material;Surface mechanical attrition treatment;Diffusion;Grain boundaries;Twin boundaries;grain-boundary diffusion;mechanical attrition treatment;severe;plastic-deformation;nanocrystalline copper;self-diffusion;nickel;alloys;bulk;temperatures;segregation