材料期刊网

ADVANCED QUALITY CONCEPTS AND COMPOSITE RELIABILITY THROUGH STATISTICAL PROCESS CONTROL

D. Evans (CCLRC , Rutherford Appleton Laboratory , Chilton , Oxon. OX14 2HQ U.K.)

金属学报(英文版)

The physical properties of thermosetting resins and resin based composites may be influenced by changes in any one of the mang formulating or process related variables involved in their manufacture. When resins and composite materials are required to perform in aggressive environments, reliable and predicable performance is essential and therefore these materials must be prepared and tested in accorkance with a strictquality plan. This paper outlines the elements of statistical process control (S.P.C.)as it may be applied to non-metallic materials and discusses the concept of Capability Index (Cp).

关键词: physical property , null , null , null

高稳定性Tl2Ba2CaCu2Ox薄膜DC-SQUID

王晶 , 韩冰 , 徐凤枝 , 赵士平 , 陈赓华 , 杨乾声 , 阎少林 , 方兰 , 何明 , 路荣涛

低温物理学报 doi:10.3969/j.issn.1000-3258.1999.04.013

与YBCO薄膜相比,Tl2Ba2CaCu2Ox薄膜具有更高的Tc和更好的抗湿性能,所以Tl2Ba2CaCu2Ox薄膜器件不仅在液氮温度下具有更好的稳定性,而且在室温下具有更长的存放寿命.我们用磁控溅射的方法分别在24°和36.8°的STO双晶衬底上外延出Tl2Ba2CaCu2Ox薄膜并制备成晶界结DC-SQUID,比较了二者由于晶界夹角不同而产生的性能差异,并给出可工作在95K的DC-SQUID干涉曲线;对工作在77K的Tl2Ba2CaCu2Ox和YBCO薄膜双晶DC-SQUID,比较了二者在噪声特性及临界电流和结电阻随温度变化等特性,并对结果作了讨论.

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Pressure effects on spectra of tunable laser crystal GSGG : Cr3+ IV: Pressure-induced shifts of R-1 line, R-2 line, and U band at 300 K

Communications in Theoretical Physics

By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R-1 line, R-2 line, and U band of GSGG:Cr3+ at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-of degree \t(2)(2)(T-3(1))e(4)T(2)> and \t(2)(3) 2E> base-wavefunctions in the wavefunctions of R-1 level of GSGG:Cr3+ at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R-1 line and R-2 line but also the PS of R-1 line and R-2 line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R-1 line (or R-2 line) and the PS Of R-1 line (or R-2 line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R-1 line (or R-2 line). In the range of about 15 kbar similar to 45 kbar, the mergence and/or order-reversal between t(2)(2)(T-3(1))e(4)T(2) levels and t(2)(32)T(1) levels take place, which cause the fluctuation of the rate of PS for t(2)(2)(T-3(1))e(4)T(2) (or t(2)(3) T-2(1)) with pressure. At 300 K, both the temperature-dependent contribution to R-1 line (or R-2 line or U band) from EPI and the temperature-independent one are important.

关键词: high-pressure effect;spin-orbit interaction;electron-phonon;interaction;d orbital;coupling between t(2)(2)(3T(1))e(4)T(2) and;t(2)(32)E;tunable laser crystal;theoretical calculations;temperature-dependence;thermal broadenings;garnet crystals;cr3+ ions;r-line;cr-3+;luminescence;ruby;spectroscopy

The effects of ultrasound on the direct electrosynthesis of solid K2FeO4 and the anodic behaviors of Fe in 14 M KOH solution

Journal of Solid State Electrochemistry

The effects of ultrasound on the direct electrosynthesis of solid K2FeO4 and the anodic behaviors of pure iron were investigated, and the physical properties of samples were characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The experimental results showed that the existence of ultrasound can decrease the formation potential of ferrate(VI) and the passivation extent of iron anode, and this leads to higher current efficiency for the direct electrosynthesis of solid ferrate(VI) at 65 degrees C in 14 M KOH solution. It was also found that, in the experimental scope suitable ultrasonic power (14.6 W), shorter electrolysis duration and smaller electrolysis current can improve the apparent current efficiency of the electrosynthesis, and the largest current efficiency under suitable experimental conditions reached 77.2%.

关键词: K2FeO4;ultrasound;electrosynthesis;pure iron;efficiency;super-iron battery;direct electrochemical preparation;potassium;ferrate(vi);fe(vi) ferrate;charge-transfer;dissolution;sonoelectrochemistry;sonochemistry;electrolyte;frequency

2D配位聚合物{[Eu(pdc)(ox)0.5(H2O)4]·2H2O}n的结构和荧光性质

王宏胜 , 夏军 , 张万强

人工晶体学报

用氯化铕和2,4-吡啶二甲酸在水热条件下反应合成了一个二维铕稀土配位聚合物{[Eu (pdc) (ox)05(H2O)4]·2H2O}n(1)(H2pdc=2,4-吡啶二甲酸;ox=草酸根阴离子),草酸根离子由部分2,4-吡啶二甲酸分解产生.X-射线单晶衍射分析表明,该配位聚合物属单斜晶系,P121/c1 (No.14)空间群,晶胞参数为a=1.53047(15) nm,b=1.10973(9) nm,c =0.85494(15) nm,β=102.81(1)°,α=y =90°.Eu3+为九配位,除了与一个pdc阴离子配体和一个ox阴离子配体螫合配位外,还与四个水分子配位.pdc阴离子通过2-位羧基以μ2-桥联方式连接两个Eu3+,吡啶环上的氮原子与其中一个Eu3+配位,4-位羧基没有参与配位.草酸根阴离子以螯合方式连接两个Eu3+.配体pdc和ox与Eu3+通过配位键连接形成了少见的2D之字形平面,该配合物在紫外光的激发下显示鲜艳的红色荧光,表明该配位聚合物具有良好的荧光性质,热重分析表明该配位聚合物具有较好的热稳定性.

关键词: 2,4-吡啶二甲酸 , 铕 , 配位聚合物 , 荧光性质

厚度小于100nm的Tl2Ba2CaCu2Ox高温超导薄膜

路荣涛 , 方兰 , 何明 , 赵新杰 , 马永昌 , 周铁戈 , 贾颖新 , 王建伟 , 路昕 , 阎少林

低温物理学报 doi:10.3969/j.issn.1000-3258.2003.z2.050

采用直流磁控溅射和在纯氩气中后热处理的方法,在LaAlO3(001)衬底上生长出厚度小于100nm的Tl2Ba2CaCu2Ox(Tl-2212)超导薄膜.在77K和零磁场下,100nm厚的薄膜具有105.3K的超导转变温度和2.33×106A/cm2的临界电流密度.这些值与较厚的Tl-2212薄膜的最好值相符.30nm厚的薄膜仍具有大于100K的转变温度,并具有光滑致密的表面形貌和外延生长的晶体结构.20nm厚的薄膜仍显示出正常态的金属行为和充分的超导转变.当厚度小于20nm时,薄膜的表面形貌和超导电性明显变坏,6nm厚的薄膜在15K低温下,未发现超导转变.从这个意义上看,20nm为我们所研究的Tl-2212薄膜的临界厚度.

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Ti/SnO2+Sb2Ox/PbO2耐酸阳极的寿命及电催化性能

宋秀丽 , 李付合 , 梁镇海

人工晶体学报

用电沉积法制备了Ti/SnO2+ S2Ox/PbO2耐酸阳极,采用交流阻抗法测定了电极的导电性,利用加速寿命实验测定了电极的加速使用寿命,同时引入循环伏安新方法定量考察不同sb掺杂物质的量分数对电极表面分形维数的影响,并且讨论了电极在酸性溶液中的析氧电催化性能.结果表明,sb掺杂物质的量分数在0.02和0.10时Ti/SnO2+ Sb2Ox/PbO2电极的分形维数较高,表明电极表面粗糙程度较大,析氧电催化性能较好,是优良的高析氧电位下的阳极材料,适用于阳极氧化获得产品的电极过程.Sb掺杂物质的量分数为0.06时Ti/SnO2+ Sb2Ox/PbO2电极的导电性最好,加速使用寿命达到89 h.因此.Ti/SnO2+ Sb2Ox/PbO2电极是酸性溶液中较好的阳极材料.

关键词: 耐酸阳极 , 电催化性能 , 交流阻抗法 , 分形维数

O2在U和U-Nb合金表面吸附的XPS研究

伏晓国 , 刘柯钊 , 汪小琳 , 柏朝茂 , 赵正平 , 蒋春丽

金属学报

采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa.s),而O2在金属Nb上的饱和吸附量仅约为10 L.

关键词: 合金 , null , null

O2在U和U-Nb合金表面吸附的XPS研究

伏晓国 , 刘柯钊 , 汪小琳 , 柏朝茂 , 赵正平 , 蒋春丽

金属学报 doi:10.3321/j.issn:0412-1961.2001.06.004

采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa@s),而O2在金属Nb上的饱和吸附量仅约为10 L.

关键词: O2 , U , U-Nb合金 , 表面吸附 , X射线光电子谱

Ag/Bi2Sr2CaCu2Ox复合材料摩擦学特性

董丽荣 , 李长生 , 王旻璐 , 彭义

复合材料学报

采用固态反应法合成超导体Bi2Sr2CaCu2Ox(Bi2212),使用摩擦实验机从液氮温度至室温对其摩擦学特性进行研究.研究表明:室温Bi2212与不锈钢盘对摩时摩擦系数约为0.35,当温度降至超导转变温度以下(液氮温度),摩擦系数大幅度降低至0.11,非常稳定.为改善Bi2212常温摩擦性能,添加Ag制备出Ag/Bi2212超导复合材料,XRD、SEM和EDS分析表明,Ag未进入Bi2212晶格,保证了Bi2212的超导电性,Ag的添加提高了复合材料密度和韧性,在正常载荷和滑行速度下Ag质量分数为10%时摩擦系数为0.2,15%Ag/Bi2212磨损率最低,为9.5× 10-5mm3(N·m)-1.分布基体中的Ag能有效抑制裂纹萌生和扩展并在摩擦作用下向表面转移,在摩擦表面形成一层Ag转移膜,其低剪切强度起到很好的润滑作用,同时将摩擦产生的热量及时传导出去,使复合材料表现出良好的减摩耐磨性能.

关键词: Bi2212 , Ag , 复合材料 , 超导转变温度 , 摩擦学特性