材料期刊网

Oscillation Characteristics of Molten Metal Free Surface Under Compound Magnetic Field

DENG Anyuan , WANG Engang , XU Yongyi , ZHANG Xingwu , HE Jicheng

钢铁研究学报(英文版)

The free surface waves of a molten lowmelting point Sn32%Pb52%Bi alloy under the imposition of an AC and a static magnetic field were visualized and recorded by use of a laser displacement sensor and a high speed video camera. The Fourier analysis method was used to analyze the oscillation characteristics. The results show that at the center of the free surface, the azimuthal and radial oscillation mode can be found simultaneously owing to AC magnetic field. With increasing coil current intensity, the amplitude and the main frequencies of the oscillations increase, and the azimuthal fluctuation at the center of the free surface is also enhanced. The fluctuation characteristics are closely related to the turbulent flow induced by the alternating electromagnetic force. A series of regular traveling waves can be observed on free surface, and the main frequencies of oscillations at threephase points decrease owing to superposing AC and static magnetic field. The static magnetic field can remarkably control the unstable swinging behavior of free surface. With increasing static magnetic flux density, the amplitude of oscillations at the center of free surface decreases firstly, and then increases, but the fluctuation amplitude at the triplephase point always reduces and keeps within 1 mm, and the azimuthal waves at the center of free surface are weakened. Especially at 144 T, the radial waves are dominant. The static magnetic flux density should be controlled in an appropriate range to obtain more stable free surface. With compound magnetic field, even if the static magnetic flux density is above 10 T, the free surface still vibrates with lower amplitude and dominant frequency.

关键词: continuous casting , compound magnetic field , free surface , fluctuation

Effect of Structure Parameters on Power and Magnetic Field in Electromagnetic SoftContact Continuous Casting System

DENG Anyuan , WANG Engang , HE Jicheng

钢铁研究学报(英文版)

To design a power source system and mold for electromagnetic softcontact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic softcontact continuous casting system with partialsegment type mold, the power consumption is much more than that with a fullsegment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 mm, the reasonable slit number, width, and length are about 24-32, 05-10 mm, and 160 mm, respectively.

关键词: continuous casting;softcontact mold;electromagnetic field;electric power;structure parameter

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

En24钢在海水中的应力腐蚀

王正

中国腐蚀与防护学报

用恒位移弯曲试验,慢应变速率试验、动电位扫描和浸蚀试验研究了En24钢在海水中的应力腐蚀特性。结果表明,En24钢的环境敏感断裂倾向随强度降低而降低;强度低于临界值,则不出现应力腐蚀裂缝。外加电位对En24钢的环境敏感特性有重要影响,裂缝扩展平台速度于-900mV处出现极小值。依据裂缝扩展动力学、断口形貌、物理冶金参数和电化学等方面的判据,认为En24钢在海水中的应力腐蚀与电位密切相关。低于-900mV,属氢致开裂;高于-900mV,则由阳极溶解过程所制约;在一定电位范围内,不排除两种机理共同作用的可能性。

关键词:

可膨胀石墨改性APP/PER/EN防火涂料热降解行为

王震宇 , 韩恩厚 , 柯伟

复合材料学报 doi:10.3321/j.issn:1000-3851.2005.05.008

采用可膨胀石墨(EG)对APP/PER/EN防火体系进行改性,制备成一种新型EG改性APP/PER/EN防火涂料.运用示差热分析(DTA)、热重分析(TG)、扫描电镜分析(SEM)、能谱分析(EDS)和隔热性能试验分析研究APP/PER/EN防火涂料和EG改性防火涂料的热降解行为、残余炭体元素含量、成炭率和隔热性能.EG改性防火涂料的APP-PER-EN之间的化学反应膨胀过程与可膨胀石墨物理膨胀过程作用温度范围接近,能产生很好的协同配合作用.膨胀石墨提高了APP/PER/EN防火涂料炭质层的成炭率、抗氧化性和热稳定性.EG添加量过高(≥15%)会造成燃烧后期炭质层脱离基材.10%EG(质量分数)添加量能有效提高APP/PER/EN防火涂料的隔热防火性能.

关键词: 可膨胀石墨(EG) , 热降解行为 , APP/PER/EN防火涂料 , EG改性防火涂料

半导体纳米材料Zn(en)3 Se,ZnSe及其光学性能研究

李国强 , 陈日耀 , 郑曦 , 陈震

功能材料

以有机溶剂热技术制备片状Zn(en)3Se(en为乙二胺)纳米材料,DTG、IR、XRD分析结果表明该化合物中乙二胺与中心离子Zn2+通过配位键相结合;以制得的纳米Zn(en)3Se为母体,在氮气氛中煅烧至980℃,热分解制得棒状纳米ZnSe;以TEM、ED初步研究了两者的形貌、结构;以提拉法分别将Zn(en)3Se、ZnSe纳米材料涂布在ITO导电玻璃上,制得纳米颗粒/ITO复合膜,并研究其光学特性.结果表明,Zn(en)3Se属立方晶系,呈片状结构;ZnSe属六方纤锌矿型,棒直径在40nm左右;可能的生长机理是乙二胺作为模板分子,首先嵌入到ZnSe无机结构框架中,接着受热分解逃逸出无机框架形成一维纳米棒.PL分析表明Zn(en)3Se的荧光红移至448nm处.

关键词: 一维纳米材料 , 溶剂热法 , 金属硫族化合物 , 半导体 , 光致发光

EN及SEM在铝锌铟合金活化机理研究中的应用

文九巴 , 卢现稳 , 马景灵 , 李元侦

功能材料

采用扫描电镜(SEM)及电化学噪声(EN)分析了Al-5Zn-0.03In-1Mg-0.05Ti-X合金腐蚀前后的金相结构、表面形态,探讨了合金初始活化过程.结果表明晶界上存在富AlZnMg及富AlZnMgIn两种偏析相,这些阳极第二相处诱发的孔蚀为合金初始活化的主要方式.对电化学噪声进行小波分解可以清晰地分辨合金表层第二相初始腐蚀的时间段.

关键词: 铝基牺牲阳极 , 电化学噪声 , SEM , 活化机理

[Mn(en)3]2·Sn2Se4Te2的结构和光吸收性能

韩克飞 , 夏芸 , 王平 , 郭洪猷

材料研究学报 doi:10.3321/j.issn:1005-3093.2003.04.011

按照K2Se:K2Te2:MnCl2@4H2O:SnCl2 2H2O:Se:乙二胺(en)＝3.8:1:2:2:6:270的摩尔比配料,采用溶剂热法使原料混合物在180℃反应7 d,得到黑色块状晶体[Mn(en)3]2@Sn2Se4Te2.属于三斜晶系,空间群为P-1,晶胞参数a＝0.91428(7)nm,b＝1.02781(7)nm,c＝1.15745(8)nm,α＝94.632(2)°,β＝100.944(2)°,γ＝115.918(1)°,V＝0.94382(12)nm3,Z＝1.晶体由[Mn(en)3]2+和(Sn2Se4Te2)4-堆积而成.具有Zintl结构的特征半导体[Mn(en)3]2@Sn2Se4Te2的光学能隙(Eg)为2.2 eV.当温度低于190℃时,[Mn(en)3]2@Sn2Se4Te2晶体是稳定的.详细讨论了这类化合物的组成对晶体结构和光吸收性能的影响.

关键词: 无机非金属材料,[Mn(en)3]2@Sn2Se4Te2,溶剂热法合成,晶体结构,反射光谱

有机溶剂热生长技术制备Zn(en)2S、ZnS纳米棒及其光学性能的研究

李国强 , 何晓云 , 钟惠妹 , 张燕琼 , 陈日耀 , 郑曦 , 陈震

人工晶体学报 doi:10.3969/j.issn.1000-985X.2005.04.038

以有机溶剂热生长技术(organic solvothermal technique)制备Zn(en)2S(en为乙二胺)纳米棒,以IP、XRD 、TG等测试表明该化合物中乙二胺与中心离子Zn2+通过配位键结合.以TEM、ED初步研究了该纳米材料的形貌、结构;以制得的纳米Zn(en)2S为母体,在氮气氛中,煅烧在900℃,制得棒状纳米ZnS;溶胶提拉法,在导电玻璃(ITO)基本上制备出Zn S Zn(en)2S纳米微粒/ITO复合膜,并研究其光学特性.结果表明,二者均为纳米棒构型, Zn(en)2S属立方晶系,棒直径约为30nm;ZnS属六方纤锌矿型,棒直径较大,在60nm左右.PL分析表明Zn(en)2S的荧光红移至452nm处.

关键词: 一维纳米材料 , 有机溶剂热生长技术 , 纳米棒 , 光致发光

[Pt(en)(5-Fu)2]Cl2配合物的合成及抗肿瘤活性

钟文远 , 崔永春 , 范春兰 , 胡智兴 , 李玛琳

贵金属 doi:10.3969/j.issn.1004-0676.2004.02.005

为寻求高效低毒的新型顺铂类抗肿瘤药物,用K2PtCl4、乙二胺(en)、氟尿嘧啶(5-Fu)为原料,设计合成了顺铂类似物[pt(en)(5-Fu)2]C12配合物,由元素分析、红外光谱和质谱分析初步证实了其化学结构,用改良MTT、SRB法,选用K562、A549、Bel-7402、BIU-87、Bcap-37细胞株对其进行体外抗肿瘤活性测定.结果表明,所合成的配合物除在浓度为0.01、0.1 μg/mL时对K562细胞株抗肿瘤活性大于顺铂和氟尿嘧啶外,其它情况下的抗肿瘤活性均小于顺铂和氟尿嘧啶.该配合物仍有进一步研究的价值.

关键词: 药学 , 铂(Ⅱ)配合物 , 合成 , 抗肿瘤活性