Electronic structures and properties of Ti, Zr and Hf metals

Ａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅａｎｄａｍｂｉｅｎｔｐｒｅｓｓｕｒｅ ,ｔｈｅｓｔａｂｌｅｃｒｙｓｔａｌｌｉｎｅｓｔａｔｅｏｆｔｈｅｅａｒｌｙｔｒａｎｓｉｔｉｏｎｍｅｔａｌｓＴｉ,ＺｒａｎｄＨｆｉｓａｈｅｘａｇｏｎａｌｃｌｏｓｅ ｐａｃｋｅｄ(ｈｃｐ)ｓｔｒｕｃｔｕｒｅ (αｐｈａｓｅ) .Ａｔｈｉｇｈｔｅｍｐｅｒａｔｕｒｅ ,ａｌｌｔｈｅｓｅｔｈｒｅｅｍｅｔａｌｓｕｎｄｅｒｇｏａｐｈａｓｅｔｒａｎｓｆｏｒｍａ ｔｉｏｎｉｎｔｏａｂｏｄｙ ｃｅｎｔｅｒｅｄｃｕｂｉｃ (ｂｃｃ)ｓｔｒｕｃｔｕｒｅ (βｐｈａｓｅ) …     

Structures and properties of Sc and Y metals

Ａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅａｎｄａｍｂｉｅｎｔｐｒｅｓｓｕｒｅ ,ｔｈｅｓｔａ ｂｌｅｃｒｙｓｔａｌｌｉｎｅｓｔａｔｅｏｆＳｃａｎｄＹｈａｓａｈｅｘａｇｏｎａｌｃｏｌｓｅ ｐａｃｋｅｄ(ｈｃｐ)ｓｔｒｕｃｔｕｒｅ(αｐｈａｓｅ) .Ａｔｈｉｇｈｔｅｍｐｅｒａｔｕｒｅ ,ｂｏｔｈｍｅｔａｌｓｕｎｄｅｒｇｏａｐｈａｓｅｔｒａｎｓｆｏｒｍａｔｉｏｎｉｎｔｏａｂｏｄｙ ｃｅｎｔｅｒｅｄｃｕｂｉｃ(ｂｃｃ)ｓｔｒｕｃｔｕｒｅ( βｐｈａｓｅ) .Ｔｈｅｐｈａｓｅｓｔａ ｂｉｌｉｔｙａｎｄｐｈａｓｅｔｒａｎｓｆｏｒｍａ…     

Electronic structures and physical properties of pure aluminum metal

By one-atom theory, the electronic structure of pure Al metal with f.c.c, structure has been determined to be [Ne](3s_c)~(1.8790)(3p_c)~(0.4982)(3s_f 3p_f)~(0.6228). According to this electronic structure, the potential curve, lattice constant, cohesive energy, elastisity, and the temperature dependence of the linear thermal expansion coefficients have been calculated. The electronic structures and characteristic properties of Al metals with b. c. c., h.c.p. structures and liquid have been studied. It is argued that the pure Al metal with f. c.c. structure can exist naturally, but with b. c. c.and h. c.p. structures cannot.##属性不符     

电子废弃物资源化处理技术

介绍了电子废弃物的组成及其特点,分析了其具有潜在的环境污染性和可作为再生资源进行回收利用的双重性质,对其中电子元器件的拆解技术及有价金属和塑料的资源化回收处理方法进行了详细阐述,指出了采用机械全自动或者机械半自动结合人工的拆解方法与机械物理法相结合回收其中的有价金属是当前工业上广泛采用的电子废弃物处理方法。     

微生物法回收电子废弃物中贵金属的研究进展

电子废弃物的资源化处理是当今社会的一项重要内容。概述了微生物法回收贵金属的作用机理,阐述了利用微生物回收电子废弃物中贵金属的研究现状,并对现有的菌体研究现状进行了分析,对微生物法回收贵金属的发展前景进行了展望。提出现阶段主要任务是筛选和培养出可以回收电子废弃物中贵金属的其他微生物,并对培养条件进行优化,以缩短浸取时间,提高贵金属的回收率。     

Low temperature doping of ZnO nanostructures

Doping of ZnO nanostructures was investigated by using a low temperature electrochemical process. Various dopant materials have been studied, including transition metals, group I, and group VII elements. The structure, composition, and optical properties of the doped ZnO nanostructures were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence, and x-ray diffraction. It was demonstrated that dopant elements were incorporated into the ZnO structures. The effects of dopant incorporation on the structure and properties of ZnO were also investigated. This low temperature approach is compatible with current micro-fabrication techniques and promising for large-scale production of doped ZnO nanostructures for optical and electronic applications.     

Preparation and application of gallium-based conductive materials in the very recent years

Gallium and its alloys are a group of metallic materials with low-melting points at or around room temperature. Apart from the good electrical conductivity, the unique liquid state endows those metals with excellent compliance and self-healing capacity,which present great value in the development of flexible and stretchable electronics. Constrained by the high surface tension and low viscosity, however, liquid metals cannot be applied to some common microelectronics manufacturing technologies such as micro-electro mechanics in the preceding years, which impedes their mass production in electronic devices. To address these issues and broaden the applications of liquid metals in electronics devices, numerous efforts have been taken and great progress has been made especially in the very recent years. This review summaries the recent development of liquid metal-based conductive materials from the aspects of preparation or modification methods and their accommodative fabrication techniques in flexible electronic applications. Further outlook including expectations and challenges of liquid metal-based conductive materials are also presented.     

以喹啉为端基的双酰胺型柔性化合物的合成及配位性能研究

以8-氨基喹啉、己二酸及硫代二丙酸为主要原料,合成了2个新的柔性化合物:N,N′-二(喹啉-8-基)己二酰胺(3a)、N,N′-二(喹啉-8-基)-4-硫杂庚二酰胺(3b),通过元素分析、红外光谱、核磁共振等方法对其结构进行了表征,并研究了这2种化合物与过渡金属的配位性能。结果表明,化合物(3b)可与M(NO3)(M=Co、Ni、Cu、Zn)反应形成配合物,该系列配合物的组成为[M(3b)(NO3)2](M=Co、Ni、Cu、Zn)。而化合物(3a)则不宜与这些金属发生配位反应。     

废弃印刷线路板资源化中的微生物

电子产品更新速度加快导致大量电子废弃物产生。废弃印刷线路板是金属资源和污染物的集合体,故其资源化和无害化备受关注。废弃印刷线路板的金属赋存状态、材料特性和结构特点与金属矿物有明显差异。废弃印刷线路板资源化常用微生物有嗜酸菌、产氰微生物和真菌。其中嗜酸菌和真菌多用于基本金属的浸出,产氰微生物多用于贵金属的浸出。嗜酸菌主要通过直接-间接作用机理回收金属;产氰微生物通过产生的氰化物浸出金属;真菌通过产生的有机酸对金属可进行酸解、络合、还原和生物富集。微生物回收废弃印刷线路板中零价金属的作用机理尚未达成共识,该机理的解析将成为研究热点。     

雌二醇衍生物的定量结构-活性关系

应用半经验量子化学AM1法得到了16种雌二醇衍生物的优势构象，利用量子化学算法和分子图形学技术获得电子结构、几何结构和拓扑结构参数，并将这些参数与雌二醇衍生物对微管蛋白的报制活性相关联。结果表明：雌二醇衍生物对微管蛋白的抑制活性与氨原子（或氧原子或双键）指示数、分子成键能及32号氢原子净电荷的相关性较好，成功地建立了16种雌二醇衍生物的构效关系式。     

First-Principles Studies the Lattice Constants and the Electronic Structures of Diluted Magnetic Semiconductors （In,Mn）As

Lattice constants and electronic structures of diluted magnetic semiconductors （ In, Mn ） As were investigated using the first principles LMTO-ASA band calculation by assuming supercell structures. Three concentrations of the 3 d impurities were studied （ x = 1/2, 1/4, 1/8）. The effect of varying Mn coucentrations on the lattice constants and the electronic structures are shown.     

基于Matlab的紧束缚近似下面心立方晶格s态能带三维分析

鉴于许多金属如金、银、铜及半导体材料硅、锗等的晶格结构属于面心立方晶格,因此研究面心立方晶格的能带结构对金属与半导体材料性质的认识有着重要的意义.利用Matlab对面心立方晶格在紧束缚近似下的s态能带的等能面进行计算机模拟,得到简约布里渊区内的不同能量值等能面的三维清晰图像.其中,既有类似近自由电子的准球面,也有与实验获得的金属费米面相似的曲面,直观地展现了面心立方单晶s态能带在状态空间的结构形态.     

Medium-range order clusters in metal melts

Structures of molten metals Cu and Al, alloys Cu-Al, Al-Ni, Al-Fe and, Al-Si were investigated by using high temperature X-ray diffractometer. It has been found that there are not only short-range order structures (SRO) but also medium range order structures (MRO) in Cu-Al, Al-Ni, Al-Fe alloy melts. There are only short-range order structures in the pure metals Cu and Al and Al-Si alloy melts at different temperatures. It has also been found that the presence and the disappearance of the MRO structures in molten metals are a function of temperature. Moreover, the pre-peak in the structure factor is an indication of MRO in molten metals. There is a pre-peak in each structure factor S( Q) of Al-Fe alloy melt containing 14 wt% Fe, 16 wt% Fe and 19 wt% Fe at 1550℃, showing that there are the medium range order structures in these alloy melts. For Al-35wt% Ni alloy, the pre-peak exists in S(Q) when the temperature is lower than 1300?, and it is weakened drastically when the temperature surpasses 1300℃. The     

内嵌乙硅烷的推拉型有机分子的二阶非线性光学性质的理论研究

用密度泛函理论方法计算了系列含乙硅烷的推拉型有机分子的结构、电子性质和非线性光学（ NLO）性质。该系列分子具有典型的电子供体－共轭桥－电子受体结构,其中乙硅烷的饱和Si Si键嵌入共轭桥,改变了共轭体系的电子性质,导致分子的电子吸收光谱、偶极矩、极化率、超极化率、结晶行为等发生显著改变。在比较研究该系列化合物电子结构的基础上,提出了进一步优化其NLO响应的方法。     

稀土元素在铝合金真空钎焊中的作用

研究了真空钎焊时在钎料中加入微量稀土元素Ｌａ、Ｃｅ,能显著提高Ａ１－Ｓｉ基钎料对ＬＤ３０铝 合金的润湿性和真空钎焊接头质量;明显改善钎缝微观组织,使晶粒细化,并使中间相分布更均匀, 改变第二相ＣｕＡｌ_２、Ｍｇ_２ Ｓｉ的网状分布,使之变薄变细;促进铝合金基体与钎料中合金元素的相互 扩散和均匀分布;从而使钎焊接头强度明显提高．     

Thermoelectric Properties and Electronic Structure of Ca_3Co_2O_6

1　IntroductionIthasbeengenerallyacceptedthatthethermoelectricefficiencyofoxidesislowerthanthatoftheconventionalthermoelectricmaterialbecauseoftheirhighioniccharacter,whichgenerallycausesastronglocalizationofelectronsandhenceleadstoaverylowcarriermobility…     

电子鼻与电子舌在饮料品质评价中的应用

随着传感技术的发展,电子鼻与电子舌以其独特的优越性广泛应用于食品的品质评价中.阐述了电子鼻与电子舌的结构组成及其在饮料的种类识别、品质控制、定量分析和感官评价等方面的应用,并指出了其在发展过程中需要解决的问题.     

采用磁选和重选回收废旧电路板中的金属

采用磁选和重选联合工艺回收废旧印刷电路板中Fe、Cu、Al、Pb、Zn、Sn和Ni等金属。结果表明,采用干法磁选工艺,可回收的铁磁性物质约占废旧电路板质量分数的8．23％,重液分选可使金属与非金属有效分离,采用磁选和重选联合工艺可使Fe、Cu、Pb、Zn、Ni和Sn的回收率分别达到约100％、80％、65％、75％、88％和56％。     

Material Properties and Tensile Behaviors of Polypropylene Geogrid and Geonet for Reinforcement of Soil Structures

The properties and tensile behaviors of polypropylene(PP) geogrids and geonets for reinforce ment of soil structures are investigated.Mass per unit area of the geogrids and geonets was weighed using an electronic balance and aperture sizes of the geonets were exactly measured using a computer,Laboratory tests were performed using a small tensile machine capable of monitoring tensile force and displacement.Tensile failure behaviors were described,and tensile index properties such as tensile strength,maximum tensile strain,tensile forces corresponding to different strains in the geogrids and gronets were obtained.The characterization of these indexes is discussed.     

聚酰亚胺几何结构和电子结构的分子模拟

依据密度泛函(DFT)理论,利用PW 91方法,对聚酰亚胺二、三和四聚体进行模拟,研究其几何结构和电子结构.模拟结果表明,聚酰亚胺二、三和四聚体中间片断的键长、键角基本一致,采用低聚物中间片断结构,可以表征整个高分子聚合物结构,随着聚合度N的增加,总能量降低,能隙减小.