Al—12.7%Si共晶中硅相的形态与分枝特征

用SEM考察了生长速度R=30～2500μm/s时Al-12.7％Si共晶中硅相的形态与分枝特征。对深腐蚀样品的观察表明,共晶硅相具有连续生长、成束分布特征,随生长速度R增大,共晶硅逐渐由粗大片状向片状、条状转变。硅相生长与分枝特征与局部生长条件密切相关,从整体上看,随生长速度增大,晶体学生长与分枝特征减弱。     

废旧锂离子电池正极有价金属的分离和提取方法

介绍了废旧锂离子电池回收处理的意义和必要性,对溶剂萃取法、化学沉淀法、电沉积法、络合离子交换法等提取和分离正极中钴、铝、镍、锂等有价金属的研究现状进行了评述。     

膜建筑的起源、发展与展望

主要介绍了膜建筑的起源、发展,总结了膜建筑的主要特点,展望了膜建筑的未来。     

In vitro corrosion behaviour of Mg alloys in a phosphate buffered solution for bone implant application

The corrosion behaviour of Mg–Mn and Mg–Mn–Zn magnesium alloy in a phosphate buffered simulated body fluid (SBF) has been investigated by electrochemical testing and weight loss experiment for bone implant application. Long passivation stage and noble breakdown potential in the polarization curves indicated that a passive layer could be rapidly formed on the surface of magnesium alloy in the phosphate buffered SBF, which in turn can protect magnesium from fast corrosion. Surfaces of the immersed magnesium alloy were characterized by SEM, EDS, SAXS and XPS. Results have shown that Mg–Mn and Mg–Mn–Zn alloy were covered completely by an amorphous Mg-containing phosphate reaction layer after 24 h immersion. The corrosion behaviour of magnesium alloys can be described by the dissolving of magnesium through the reaction between magnesium and solution and the precipitating of Mg-containing phosphate on the magnesium surface. Weight loss rate and weight gain rate results have indicated that magnesium alloys were corroded seriously at the first 48 h while Mg-containing phosphate precipitated fast on the surface of magnesium alloy. After 48–96 h immersion, the corrosion reaction and the precipitation reaction reach a stable stage, displaying that the phosphate layer on magnesium surface, especially Zn-containing phosphate layer could provide effective protection for magnesium alloy.     

Water permeation across nanochannels with defects

Defects are common in fabricated nanochannels. In this paper, water permeation across a single-walled carbon nanotube with defects was studied using molecular dynamics simulations. It is found that the impact on water permeation is negligible when the density of the defects is small, while a significant reduction in water permeation is observed when the density of the defects is high. These findings should be helpful in both understanding water permeation across nanochannels and designing efficient artificial nanochannel.     

AB5型低钴含铁贮氢合金电极材料的研究进展

综述了近年来人们对提高AB5型低钴含铁贮氢合金综合性能所进行的探索.重点介绍了近年来国内外低钴含铁稀土系贮氢合金在合金成分设计、制备工艺及热处理方面的研究进展.利用Fe与Cu,Cr,Si,Zn,Sn等元素部分或全部取代贮氢含金中的Co元素,在多数情况下虽会略降低贮氢合金的最大放电容量,但能够显著提高循环稳定性.最后阐明了低钴稀土系贮氢合金的发展前景.     

PHASE CONSTITUTE AND MICROGRAPHY OF REACTION SYNTHESIS OF Al+Ti+C SYSTEM

ＰＨＡＳＥＣＯＮＳＴＩＴＵＴＥＡＮＤＭＩＣＲＯＧＲＡＰＨＹＯＦＲＥＡＣＴＩＯＮＳＹＮＴＨＥＳＩＳＯＦＡｌ＋Ｔｉ＋ＣＳＹＳＴＥＭ￥ＺＨＡＮＧＥｒｌｉｎ;ＺＥＮＧＳｏｎｇｙａｎ;ＺＥＮＧＸｉａｏｃｈｕｎ;ＬＩＱｉｎｇｃｈｕｎ（Ｈａｒｂｉｎｉｎｓｔｉｔｕｔ...     

A study on the kinetic process of reaction synthesis of TiC: Part II. Theoretical analyses and numerical calculation

Based on the experimental results, a mathematical kinetic model of the reaction process to synthesize TiC particles has been built, and a reaction rate expression is developed in this article based on the following mechanism: a Ti-rich Al-Ti complex layer is formed around carbon particles and titanium atoms diffuse from melt, across the layer, to react with carbon to form TiC; the TiC particles precipitate out of melt and diffuse all over the melt. The calculated results have shown that there are four major effect elements—the temperature of the system, the aluminum content of the preform, the thickness of the titanium-rich layer, and the size of carbon particle—to decrease the aluminum content, the thickness of titanium-rich layer, and the size of carbon particle and to increase the temperature, accelerate the reaction rate, and reduce the complete reaction time. In the end, some experiments have been done to investigate the effect of temperature, size of C powder, and Al content on the reaction. The experimental results were in good agreement with the numerical calculated result.     

太赫兹Si/SiGe量子级联激光器的能带设计

使用nextnano3模拟软件计算Si/Si1-xGex/Si量子阱的能带结构,对Si/SiGe量子级联激光器有源区的能带结构进行设计,结果表明使用Ge组分为0.27～0.3,量子阱宽度为3nm的SiGe合金与垒宽为3nm的Si层构成对称应变级联异质结构,有利于优化THz Si/SiGe量子级联激光器结构.     

半绝缘InP（Fe）的低温氯化物VPE生长

介绍了一种半绝缘ＩｎＰ（Ｆｅ）的低温氯化物气相外延（ＶＰＥ）生长方法，生长温度为５５０℃，可为金属有机气相淀积的量子阱结构二次外延半绝缘ＩｎＰ（Ｆｅ）盖层。４０μｍ层厚时电阻率超过５×１０８Ωｃｍ，临界击穿电压达到１０Ｖ以上。用这种方法制备的激光器阈值电流达８０ｍＡ，较平板式的降低３倍，远场图样平行和垂直结平面方向光功率曲线对称性良好，远场发散角，器件测试得到较好光谱。目前尚未见到其它类似报道。