DONG Danyang
,
LIU Changsheng
,
ZHANG Bin
钢铁研究学报(英文版)
Based on the Miedema′s formation heat model for binary alloys and the Toop′s asymmetric model for ternary alloys, the formation heat, excess entropy, and activity coefficients of silicon ranging from 1 900 K to 4 100 K in the FeSiC melt formed during the laser cladding high silicon coatings process were calculated. The results indicated that all values of lnγ0Si, εCSi, ρSiSi and ρCSi are negative in the temperature range and these values increase as the temperature increases. And all values of εSiSi and ρSiCSi are positive and these values decrease with increasing temperature. The isoactivity lines of silicon are distributed axisymmetrically to the incident laser beam in the melt pool vertical to the laser scanning direction. And the isoactivity lines of silicon in the front of the melt pool along the laser scanning direction are more intensive than those in the back of the melt pool. The activity of silicon on the bottom of the melt pool is lower than that in the effecting center of laser beam on the top surface of the melt pool and it may be the important reason for the formation of the silicides and excellent metallurgical bonding between the laser cladding coating and the substrate.
关键词:
laser cladding;silicon steel;high silicon content coating;thermodynamic calculation;Miedema′s formation heat model
Physical Review B
In a recent publication [S. Dong et al., Phys. Rev. Lett. 103, 127201 (2009)], two (related) mechanisms were proposed to understand the intrinsic exchange bias present in oxides heterostructures involving G-type antiferromagnetic perovskites. The first mechanism is driven by the Dzyaloshinskii-Moriya interaction, which is a spin-orbit coupling effect. The second is induced by the ferroelectric polarization, and it is only active in heterostructures involving multiferroics. Using the SrRuO(3)/SrMnO(3) superlattice as a model system, density-functional calculations are here performed to verify the two proposals. This proof-of-principle calculation provides convincing evidence that qualitatively supports both proposals.
关键词:
thin-films;weak ferromagnetism;superlattices;anisotropy;bifeo3;srruo3;model
Canying CAI
,
Qibin YANG
,
Hongrong LIU
材料科学技术（英）
Assuming that the wave function , the Schrodinger equation can be written as . Neglecting the last two terms, an analytical expression of electron dynamical diffraction was derived by Qibin YANG et al. In this paper, the analytical expression is modified by further considering the second-order differential term . When the accelerating voltage is not very high, or the sample is not very thin, the reciprocal vector ɡ is large, the modification of the second-order differential is necessary; otherwise it can be neglected.
关键词:
Electron dynamical diffraction
,
null
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
Fresenius Environmental Bulletin
The relationship between existence of microbes and early corrosion behavior of mild steel in fresh waters was studied using immersion tests, electrochemical measurements and surface analysis techniques. In the field immersion test at Dan Jiangkou reservoir in China, mild steel had less corrosion weight loss in the upper layer of water, where more microbes existed. The accumulation of microbes on the surface of coupons was thought to slow down the corrosion rate by restricting the oxygen diffusion and other factors. This hypothesis was confirmed by the electrochemical measurements and immersion test in natural freshwater. The results of the Scanning Electron Microscopy (SEM) and Fourier Transform Infra-red (FT-IR) spectra further confirmed that the existence of microbes could affect the formation of the corrosion products. Furthermore, the surface film formed in microbes-contained freshwater was thicker and with more complex corrosion products.
关键词:
Corrosion;freshwater;eutrophication;microbes;mild steel;microbiologically influenced corrosion;biocorrosion
衷诚武
,
叶奇
,
简炜炜
钛工业进展
doi:10.3969/j.issn.1009-9964.2007.02.006
通过有机镀膜技术,对镁合金表面进行改性.对有机镀膜处理后的镁合金表面的接触角,表面自由能进行了测定.研究了不同有机镀液,在恒电流作用下,有机镀膜时间对镁合金表面性能的影响.结果表明,经过TTN溶液有机镀膜后,镁合金板表现出亲水性,其表面能比未处理镁合金板的表面自由能要高;而经过DHN和DAN溶液有机镀膜后,镁合金板表现出良好的疏水性,其表面能比未处理镁合金板的表面自由能要低,在二者中DHN处理后的疏水效果最好.实现了对镁合金表面疏水、亲水表面改性,能够很好的扩大镁合金在工业中的应用领域.
关键词:
镁合金
,
有机镀膜
,
亲水薄膜
,
疏水薄膜
张金艳
,
肖小明
,
蒋艳
,
谭年元
应用化学
doi:10.3724/SP.J.1095.2010.90729
在微波辐射和无催化剂条件下,由吡啶2,6-二甲酸与乙二胺反应合成了2,6-二(2′-咪唑啉-2′-基)吡啶(L),采用常规加热法合成其配合物[CrL2][NO3]3. 用核磁共振、红外光谱、元素分析、热重分析和摩尔电导率测试技术对其进行表征分析. 通过紫外吸收光谱和黏度测试,分别考察了配体及配合物与DNA的键合常数及其作用方式. 结果表明,配体L以氢键和沟面作用方式与DAN键合,而配合物以氢键和静电作用模式与DNA键合. 密度泛函理论(DFT)计算结果较好的解释了L及[CrL2]3+与DNA的相互作用模式.
关键词:
二(咪唑啉基)吡啶
,
铬配合物
,
DNA
,
微波辐射
,
DFT
颜慧成
,
郭征
,
张孟亭
,
张洪平
钢铁研究学报
引入变量m(冲量密度)和Yang-Mills型规范变换m=u+gradφ,将原始变量的N-S方程转化为规范-不变量形式,用自由质点法处理Voronoi元,对连铸结晶器弯月面处保护渣流动行为进行数学模拟.输出振动周期内的动态流场,然后结合一组试验数据进行计算,计算结果与实际情况相吻合,进而讨论了渣圈对液渣流动行为的影响,为研究结晶器弯月面处保护渣的行为和铸坯振痕的形成提供了一定的依据.
关键词:
连续铸钢
,
保护渣
,
流动行为
,
数学模拟
章明川
,
张楚
,
林郁郁
,
徐旭常
工程热物理学报
根据快速流化床的基本流动特性、A 型噎塞和 C 型噎塞的特征与定义,建立了一个统一,自恰的快速床模型一分相共存模型.模型以 A 型噎塞的修正Yang公式为‘本构方程',合理预报了快速床的最小固体流率Gsm,以及在固体流率不变的条件下降低操作气速时床层由A型噎塞向C型噎塞的连续过渡.模型中的稀相有效气流速度函数幂次n为可调参数,根据 C 型噎塞速度预报的Yousfi and Gau公式,初步确定模型参数n=4.
关键词:
快速流态化
,
噎塞速度
,
A 型噎塞
,
C 型噎塞
,
分相共存模型
