低压金属有机化合物气相外延生长的 （Al_x Ga_（1-x））_（0 .5 1）In_（0 .49）P折射率测量（英文）

采用测量反射谱方法确定了低压金属有机化合物气相外延生长的GaAs衬底匹配(Al_xGa_(1-x))_(0.51)In_(0.49)P外延材料的折射率。实验中测量的反射谱波长范围为05-2.5μm。在拟合实验数据过程中采用了单振子模型。折射率数据用于分析应变量子阱GaInP/AlGaInP可见光激光二极管波导，计算出的器件远场图与实验数据吻合很好。

不同尺寸分布的自组织In_(0.55)Al_(0.45)As/Al_(0.5)Ga_(0.5)As量子点的静压光谱

在15K测量了不同尺寸分布的In_(0.55)Al_(0.45)As/Al_(0.5)Ga_(0.5)As量子点的静压我致发光，静压范围为0--1.3GPa。常压下观察到三个发光峰，分别来源于不同尺寸的量子点(横向直径分别为26、52和62nm)的发光。它产的压力系数分别为82、94和98meV/GPa,都小于In_(0.55)Al_(0.45)As体材料带边的压力系数，特别是尺寸为26nm的小量子点比In_(0.55)Al_(0.45)As体材料带边小17%，并且压力系数随量子点尺寸的变小而减小。理论计算表明有效质量的增在和Γ-X混合是量子点压力系数变小的主要原因，并得到横向直径为26和52nm的小量子点的Γ－X混合势为15和10meV。根据实验还确定In_(0.55)Al_(0.45)As/Al_(0.5)Ga_(0.5)As量子点系统X能带具有Ⅱ类结构，并且估算出价带不连续量为0.15±0.02。

In_(0.5)Ga_(0.5)P/GaAs 材料系中有序结构的研究

于2010-11-23批量导入

有序Ga（0.5）In（0.5）P光致发光的研究

国家自然科学基金

MOCVD和GSMBE生长Ga（0.5）In（0.5）P 外延层中有序结构的研究

用MOCVD在(100)、GSMBE在(100)和(111)B GaAs上生长了GaInP外延层.PL测试表明,(100)衬底上GaIn PL 峰的能量比计算的带隙分别小43(GSMBE生长)和104meV(M(CVD生长).用Kurtz等人的模型对MOCVD和GSMBE生长的GaInP中有序度的不同进行了解释.并讨论了衬底晶向对GaInP中有序程度的影响.

自发有序Ga（0.5）In（0.5）P合金的静压光致发光研究

于2010-11-23批量导入

自发有序Ga（0.5）In（0.5）P合金的喇曼光谱研究

于2010-11-23批量导入

Microstructure, thermal stability and mechanical properties of the novel (W1-xAlx)C-Co (x=0.2, 0.33, 0.4, 0.5) cemented carbide

Bulk novel cemented carbides (W1-xAlx)C-10.1 vol% Co (x = 0.2, 0.33, 0.4, 0.5) are prepared by mechanical alloying and hot-pressing sintering. Hot-pressing (HP) is used to fabricate the bulk bodies of the hard alloys. The novel cemented carbides have good mechanical properties compared with WC-Co. The density and operating cost of the novel material is much lower than a WC-Co system. The material is easy to process and the processing leads to nano-scaled, rounded, particles in the bulk material. The hardness of (W1-xAlx)C-10.1 vol% Co (x = 0.2, 0.33, 0.4, 0.5) hard material is 20.37, 21.16, 21.59 and 22.16 GPa, and the bending strength is 1257, 1238, 1211 and 1293 MPa, with the aluminum content varying from 20% to 50%. The relationship between the microstructure and the mechanical properties of the novel hard alloy is also discussed.

High-pressure sintering study of a novel hard material (W0.5Al0.5)C-0.5 without binder metal

A novel hard material of (W0.5Al0.5)C-0.5 has been successfully sintered under high-pressure (4.5 GPa). The influence of sintering time and temperature on the microstructure, Vickers microhardness and density of the as-prepared specimens are well described. Interestingly, sintering temperature has an amazing influence on the hardness, density and microstructure of the specimen while the sintering time does not. It is found that the most suitable sintering condition from our work is 1600 degrees C and 10 min under pressure of 4.5 GPa. The hardness and relative density of the as-prepared sample can reach 2340 kg mm(-2) and 98.62%, respectively. The cell parameters of the sintered specimen is found to be little smaller than that of the powder, which we propose is related to the high pressure.

Synthesis, reactive mechanism and thermal stability of W1-xAlxC (x=0.33, 0.5, 0.75, 0.86) nanocrystalline

W1-xAlxC (x = 0.33, 0.50, 0.75, 0.86) solid solutions have been synthesized directly by ball-milling tungsten powder, aluminum powder and activated carbon. The structural development of W0.5Al0.5C phase with the milling times up to 160 h has been followed using X-ray diffraction. X-ray photoelectron spectra demonstrate that Al atom takes the place of W. High temperature annealing experiment reveals that Al is stable in hexagonal structure to 1873 K. Transmission electron microscopy image shows that the grain size of the prepared powders is about 5 nm.

Na_(0.5)La_(0.5)TiO_3的水热法合成及其表征

通过控制反应物摩尔比、晶化温度和时间以及体系的碱度等重要因素 ,用水热法在温和的条件下合成了Na0 .5La0 .5TiO3 ;结构分析表明单相的Na0 .5La0 .5TiO3 是具有立方对称性的钙钛矿型化合物 ,晶胞参数为 3 .875 ;初步认为该化合物合成过程为溶解 -沉淀机理。

Effect of La/Ce ratio on the structure and electrochemical characteristics of La0.7-xCexMg0.3Ni2.8Co0.5 (x=0. 1-0.5) hydrogen storage alloys

The effect of La/Ce ratio on the structure and electrochemical characteristics of the La0.7-xCexMg0.3Ni2.8Co0.5 (x = 0.1, 0.2, 0.3, 0.4, 0.5) alloys has been studied systematically. The result of the Rietveld analyses shows that, except for small amount of impurity phases including LaNi and LaNi2, all these alloys mainly consist of two phases: the La(La, Mg)(2)Ni-9 phase with the rhombohedral PuNi3-type structure and the LaNi5 phase with the hexagonal CaCU5-type structure. The abundance of the La(La, Mg)(2)Ni-9 phase decreases with increasing cerium content whereas the LaNi5 phase increases with increasing Ce content, moreover, both the a and cell volumes of the two phases decrease with the increase of Ce content. The maximum discharge capacity decreases from 367.5 mAh g(-1) (x = 0.1) to 68.3 mAh g(-1) (x = 0.5) but the cycling life gradually improve. As the discharge current density is 1200 mA g(-1), the HRD increases from 55.4% (x = 0.1) to 67.5% (x = 0.3) and then decreases to 52.1% (x = 0.5). The cell volume reduction with increasing x is detrimental to hydrogen diffusion D and accordingly decreases the low temperature dischargeability of the La0.7-xCexMg0.3Ni2.8Co0.5 (x = 0.1-0.5) alloy electrodes.