NdNi4M贮氢性能和电子结构关系研究

测量了ＮｄＮｉ４Ｍ（Ｍ＝Ｃｒ,Ｍｎ,Ｆｅ,Ｃｏ,Ｎｉ,Ｃｕ）的吸氢性能和晶体结构参数,同时采用ＳＣＦ－Ｘα－ＳＷ方法,计算了它们的电子结构,并对其性能和电子结构的关系进行了分析。体系费米能附近态密度峰的变化是影响贮氢合金性能的主要因素;吸氢平台与费米能Ｅｆ及电荷转移数有关,Ｅｆ越低,替代元素得到电荷的倾向越大,氢化物越稳定,吸氢平台压越低;Ｈ－Ｆ力与吸氢最有关,Ｈ－Ｆ力越小,合金吸氢量越大。     

熔盐电化学的新进展

本文主要介绍熔盐体系、熔盐电池、熔盐电沉积金属以及合金、电合成化合物材料等方面的新进展 ,预期熔盐电化学在能源、环境保护和资源利用等领域中的应用 .     

EDTA滴定法测定钢渣中游离氧化镁

以碘-乙醇溶液为催化剂,选择乙二醇作溶剂浸取钢渣中游离氧化镁,采用EDTA滴定法测定其中游离氧化镁的含量。试验中考察了碘-乙醇的最佳用量和K-B混合指示剂的最合适配比。结果表明:催化剂碘-乙醇溶液的添加量达碘与氧化镁的质量比为7.5比1,指示剂中酸性铬蓝K和萘酚绿B的比值为1比1.4时,滴定终点变色明显,滴定结果准确。在钢渣中加入纯氧化镁测定的平均回收率为96.5%,相对标准偏差(n=5)为1.3%。     

镍钛记忆合金自补偿磨粒磨损性能研究

研究了高临界温度镍钛记忆合金一维自补偿磨粒磨损特性.结果表明,在一定温度下,镍钛记忆合金在摩擦过程中具有形状恢复能力,从而产生一维磨损自补偿作用.超弹状态镍钛记忆合金具有热弹性马氏体相变、高阻尼、应力感生马氏体、超弹性、高应变硬化指数和时效弥散析出强化等特性,这使得硬度较低的镍钛合金的耐磨性能远优于硬度较高的淬火45#钢.利用超弹状态镍钛记忆合金的磨损自补偿作用可望开发出新型抗磨形状记忆合金产品.     

Metamorphic InAs(Sb)/InGaAs/InAlAs nanoheterostructures grown on GaAs for efficient mid-IR emitters

High-efficiency semiconductor lasers and light-emitting diodes operating in the 3–5?μm mid-infrared (mid-IR) spectral range are currently of great demand for a wide variety of applications, in particular, gas sensing, noninvasive medical tests, IR spectroscopy etc. III-V compounds with a lattice constant of about 6.1?Å are traditionally used for this spectral range. The attractive idea to fabricate such emitters on GaAs substrates by using In(Ga,Al)As compounds is restricted by either the minimum operating wavelength of ～8?μm in case of pseudomorphic AlGaAs-based quantum cascade lasers or requires utilization of thick metamorphic In_xAl_1-xAs buffer layers (MBLs) playing a key role in reducing the density of threading dislocations (TDs) in an active region, which otherwise result in a strong decay of the quantum efficiency of such mid-IR emitters. In this review we present the results of careful investigations of employing the convex-graded In_xAl_1-xAs MBLs for fabrication by molecular beam epitaxy on GaAs (001) substrates of In(Ga,Al)As heterostructures with a combined type-II/type-I InSb/InAs/InGaAs quantum well (QW) for efficient mid-IR emitters (3–3.6?μm). The issues of strain relaxation, elastic stress balance, efficiency of radiative and non-radiative recombination at T?=?10–300?K are discussed in relation to molecular beam epitaxy (MBE) growth conditions and designs of the structures. A wide complex of techniques including in-situ reflection high-energy electron diffraction, atomic force microscopy (AFM), scanning and transmission electron microscopies, X-ray diffractometry, reciprocal space mapping, selective area electron diffraction, as well as photoluminescence (PL) and Fourier-transformed infrared spectroscopy was used to study in detail structural and optical properties of the metamorphic QW structures. Optimization of the growth conditions (the substrate temperature, the As₄/III ratio) and elastic strain profiles governed by variation of an inverse step in the In content profile between the MBL and the InAlAs virtual substrate results in decrease in the TD density (down to 3?×?10⁷ cm^?2), increase of the thickness of the low-TD-density near-surface MBL region to 250–300?nm, the extremely low surface roughness with the RMS value of 1.6–2.4?nm, measured by AFM, as well as rather high 3.5?μm-PL intensity at temperatures up to 300?K in such structures. The obtained results indicate that the metamorphic InSb/In(Ga,Al)As QW heterostructures of proper design, grown under the optimum MBE conditions, are very promising for fabricating the efficient mid-IR emitters on a GaAs platform.     

动态压缩下Zr基非晶合金失效释能机理

为研究Zr 基非晶合金动态压缩条件下的失效释能机理,采用力学试验机、霍普金森杆、高速摄影、差示扫描量热分析(differential scanning calorimetry, DSC)、扫描电镜(scanning electron microscope, SEM)等,得到了材料应力应变曲线、高速摄影图像、失效式样微观形貌及DSC 曲线,根据实验数据计算了材料的晶化激活能,并拟合了材料的JH-2(Johnson-Holmquist Ⅱ)模型,对材料动态失效过程进行有限元数值模拟。实验结果表明,压缩条件下材料为脆性断裂,断口处观察到典型的脉状纹样及液滴状结构,材料失效过程伴随着释能现象;数值模拟结果表明,材料裂纹局部的瞬时内能大于材料晶化激活能。动态压缩下材料的失效释能机理即为材料破碎释放储存的弹性势能,并导致材料局部晶化释能,释能强度与应变率成正相关。     

锌-铟合金电极在浓KOH溶液中的电化学行为

应用动电位扫描,恒流放电等电化学方法研究含铟锌电极的电化学行为.用SEM和EDS观察放电后的Zn-In合金电极表面形貌,初步探讨了不同In含量的锌-铟合金电极在浓KOH溶液中电化学行为及其影响因素.结果表明,与纯锌电极相比,Zn-In合金的电极致钝电流增大,达到钝化的时间缩短,从而明显地提高了该电极的电化学活性.     

氢化物发生原子荧光法测定钢铁中微痕量碲

碲是钢铁的微痕量有害杂质,易引发晶间脆化和微裂纹,降低材料的力学与抗疲劳性能,危及船海装备的服役安全,需要准确快速的检测和控制。原标准方法GB/T 223.55—2008《钢铁及合金碲含量的测定示波极谱法》使用滴汞电极,存在局部汞富集与危及人员健康和水体环境的风险。伴随《关于汞的水俣公约》在国内外的全面生效,该方法已于2017年废止。钢铁中碲的检验迫切呼唤绿色环保、准确快速的分析方法。基于碲可被新生态氢还原为易挥发氢化物的特点,采用氢化物发生进样技术从基体溶液中高选择性地分离和富集碲,并联用原子荧光法测定钢铁中微痕量碲。实验优化了负高压、灯电流、观察高度、载气流量、屏蔽气流量等光谱仪的工作参数,研究确定了消解用酸、试液介质、溶液酸度、载流酸度与硼氢化钾浓度等氢化物发生条件,系统考察了铁基体与铬、镍、锰、铜、钼、钨、钛、硅、钒等共存离子的干扰效应及掩蔽方法。确定的条件参数如下,负高压：360 V,灯电流：70～80 mA,观察高度：7～8 mm,载气流量：700 mL·min^-1,屏蔽气流量：700～800 mL·min^-1,试液介质：15%盐...     

Effects of nickel on the crystallization of Zr70Cu20Ni10 amorphous alloy

Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) are employed to investigate the effects of nickel on the crystallization of the amorphous Zr₇₀Cu₂₀Ni₁₀ alloy. We have found that the crystallization process of the amorphous Zr₇₀Cu₂₀Ni₁₀ alloy is strongly influenced by the addition of nickel. Addition of 10 at% Ni to the Zr₇₀Cu₃₀ amorphous alloy makes the crystallization process proceed from a single-stage mode to a double-stage mode. The activation energy for crystallization of the amorphous Zr₇₀Cu₂₀Ni₁₀ alloy is calculated to be about 388kJ·mol^-1 on the basis of the Kissinger equation. The effects of nickel on the crystallization of the amorphous Zr₇₀Cu₂₀Ni₁₀ alloy are discussed in terms of the genetics of metals.     

爆炸压实制取W-Cu纳米复合材料的实验研究

采用机械合金化法制备了W-Cu合金粉末。将制备出的W-Cu合金粉末置于爆炸压制成型的装置中进行爆炸压实,得到了最高致密度达98%的W-Cu合金。利用X射线衍射(XRD)分析了W-Cu混合粉末的合金化过程,研究了W-Cu合金粉末的还原温度对压实坯致密度的影响。通过电子探针微量分析仪(EPMA)观察了样品内部的成分与元素分布,利用扫描电子显微镜(SEM)对样品断口形貌进行了观察,并对样品的维氏硬度和电导率进行了测量。结果表明,W-Cu合金化粉末在爆炸冲击波作用下能够结合成高致密体,复合材料具有高硬度、组织均匀、晶粒细小的特点。