王强
,
马明臻
,
张新宇
,
刘日平
,
D.M.Herlach
金属学报
doi:10.3321/j.issn:0412-1961.2008.12.002
利用静电悬浮设备成功地实现了Zr50Cu50合金熔体的深过冷与凝固,并测得了在近200 K的过冷度范围内的晶体生长速度.随过冷度的增加,初生ZrCu相的晶体生长速度几乎呈线性增大,但在整个测量的过冷度范围之内,其生长速度极低,比一般的金属、Si和Ge等的生长速度低两个数量级以上.
关键词:
Zr50Cu50合金
,
过冷凝固
,
晶体生长速度
俞善庆
,
张小平
,
马敏伟
材料研究学报
透明薄膜是一种光谱选择性材料,探明该膜系的光谱选择度,对于开发新型能源材料具有重要意义。作者研究了在Al 和Ag 基膜上分别沉积SiO,SnO_2,CeO_2,ZnS 和CdS 介质膜,组成D/M 非对称膜系,测定了它们在320—1000nm 波长范围内的光谱透过率。证明各种介质膜对于金属基膜光谱选择度的影响基本相似,但对于透过率峰值的影响却明显不同;一般说来,介质膜对于Ag 膜的光谱透过率会产生较大的增益,而且介质膜愈厚,增透性愈好。实验结果表明,采用D/M 非对称膜系,有可能研制出光谱选择度满意的透明热反射镜材料。
关键词:
光谱透光性
,
transparent heat-mirror films
,
unsym-metrical optical systems
孙瑶
,
汪洪
航空材料学报
doi:10.11868/j.issn.1005-5053.2015.4.005
采用射频反应溅射制备SiNx薄膜,作为以Ag膜为功能层的D/M/D结构透明导电膜中的电介质膜,并研究射频功率、气压以及N2流量对SiNx薄膜光学常数的影响.结果表明,SiNx薄膜具有非晶态结构,光学常数在300～ 2500nm波长范围内符合正常色散关系.椭偏测试及Cauchy模型拟合结果表明,折射率随功率、气压以及N2流量升高而降低,SiNx光学常数最佳的工艺条件为功率300W,气压0.16Pa,N2与Ar流量比例1∶1,此时薄膜折射率为2.02,消光系数为0,最接近具有化学计量比的Si3N4薄膜的光学常数.按此工艺制备的SiNx膜在优化厚度为44nm的条件下作为20nm厚度Ag膜的电介质膜,当只有表面SiNx膜时,Ag膜透光率由29.17％提高至55.01％,当Ag膜上下均制备SiNx膜时,透光率进一步提高至66.12％.
关键词:
SiNx膜
,
Ag膜
,
折射率
,
椭偏仪
,
透光率
Yong LIU
,
Baiyun HUANG
,
Kechao ZHOU
,
Hongwu OUYANG
,
Yuehui HE
材料科学技术（英）
In order to overcome the shortcomings of conventional hot pressing, a novel near net-shape technique, called radial hot pressing, for P/M parts with large height-to-diameter (H/D) ratio was introduced. Effects of processing parameters on the microstructures and density of P/M TiAl base alloy valves were studied. Results show that the radial hot pressing is an effective technique for manufacturing valves with a H/D ratio of about 10:1, and the perfect joint interface between the Mo sheet and the parts is helpful for subsequent HIPing.
关键词:
Near net-shape technique
,
null
,
null
赵德文
,
郭长武
,
刘相华
,
王国栋
,
徐辉
,
戴建明
钢铁
开展了在空气和氮气两种气氛下，采用Gleeble-1500热模拟机与普通电炉两种加热方式、不同加热温度、加热时间对D2、M2、S5钢脱碳层深度影响的试验研究。依据试验结果，结合现场实际制定了较为合理的生产工艺并在现场成功应用，使上述模具扁钢脱碳层指标达到了美国ASTM-A681技术标准。
关键词:
脱碳层深度
,
模具扁钢
,
ASTM-A681
楼永通
,
宋伟华
,
罗菊芬
,
吕海峰
,
王寿根
,
徐荣安
,
贺持缓
,
李国良
,
陶维正
膜科学与技术
doi:10.3969/j.issn.1007-8924.2004.05.010
在中试基础上建立1200 m3/d电镀镍漂洗水膜法回收工程,采用三级膜分离技术浓缩电镀废水并回收水和镍.一级处理量50 m3/h,浓缩10倍;二级处理量5 m3/h,浓缩5倍;三级处理量1m3/h,浓缩2倍以上,共浓缩100倍以上.一级膜分离系统对镍的截留率为98%;二级、三级膜分离系统对镍截留率均在99%以上.从2001年1月至2002年12月,共运行了2年.三级膜分离系统的通量均有不同程度的下降,一级下降约20%,二级下降约25%,三级下降约40%.整个系统运行良好,基本上实现了电镀废水的资源化.
关键词:
电镀废水
,
膜分离技术
,
截留率
,
通量
Physical Review B
In the investigation of the optical and magnetic properties of the semiconductors containing transition-metal ions, the one-electron orbital cannot be treated with a pure d orbital because of a strong covalence. This paper presents the energy matrix of the d*(8) and d*(2) (d* means a modified d function) system, in which the covalence is described by two covalent factors. The differences between the matrix diagonal elements of the t(2)(m)e(n) term of the d*(8) system and the t(2)(6-m)e(4-n) term of the d*(2) system vary with m and n. The d(N) electron system can be explained with the d(10-N) hole system because the difference between the energy matrix of the d(N) and d(10-N) systems has a fixed value. However, this kind of simple relation does not exist for the d*(N) and d*(10-N) systems when the covalence is considered. A numerical calculation shows that the variation of the energy levels with the covalence for Ni2+ in the d*(8) electron system is larger than that in the d*(2) hole system. The calculated energy levels obtained from the d*(8) matrix are in good agreement with the experimental data of the Ni2+ ion for ZnS:Ni and ZnSe:Ni. This suggests that the d*(8) electron system instead of the d*(2) hole system should be used in the investigation of optical and magnetic properties of semiconductor containing Ni2+ ions.
关键词:
zns-ni;absorption;vanadium;impurities;spectra;ions
