In_(1-x)Ga_xAs液相外延片组分一致性的控制方法

用电子探针微区分析和阴极荧光研究了LPE生长In_(1-x)Ga_xAs(x～0.47)时用逐次降低生长起始温度T_g的方法生长的外延片.结果表明,采用这种方法可以多次使用生长溶液,得到组分一致性比较好的In_(1-x)Ga_xAs(x～0.47)外延片.     

支持电解质对无水甲醇电氧化途径的影响

利用原位红外光谱证实了当NaClO_4作为支持电解质时,在铂电极上水对甲醇电氧化途径有着重要影响.纯的无水甲醇电氧化时没有CO生成,只有当水的质量分数超过60%时,CO作为甲醇电氧化的中间体的可能性才较大,同时生成CO_2的量也增大.本文试图利用SPAIRS(single potential alteration infrared spectroscopy)技术进一步探讨不同支持电解质     

配合物{(n-Bu)2Sn[(η5-C5H5)Fe(η5-C5H4)COO]2}2的合成、谱学表征及晶体结构

合成了新型配合物{(n-Bu)₂Sn[(η⁵-C₅H₅)Fe(η⁵-C₅H₄)COO]₂}₂，用元素分析、红外光谱和核磁共振谱( ¹H、¹³C、¹¹⁹Sn)进行了表征，并用X-射线单晶衍射分析法测定其晶体结构。晶体属单斜晶系，空间群P2₁/c，晶胞参数a=11.753(4)?，b=21.133(7)?，c=23.374(9)?，β=101.62(3)°，V=5687(4)?³，Z=4，D_c=1.614Mg·m^-3，μ(MoKα)=1.912mm^-1，F(000)=2800，最终可靠因子R₁=0.0827，wR₂=0.2085。配合物分子呈中心对称，是具有Sn₂O₂中心内环的二聚体结构;每个锡原子与5个O原子和2个C原子形成扭曲的五角双锥几何构型，其中5个O原子为赤道配位原子，而C-Sn-C为配合物的轴。     

配合物[Cu(HPHAc)2(py)2](H2PHAc=苯羟乙酸，py=吡啶)的合成和晶体结构

The novel copper(Ⅱ) complex with α-hydroxyphenylacetic acid (H₂PHAc) and pyridine (py) ligands, [Cu(HPHAc)₂(py)₂], has been synthesized and characterized by elemental analysis and IR spectroscopy. Its crystal structure was determined by single crystal X-ray diffraction techniques. The crystal belongs to monoclinic with space group C2/c. The cell parameters are: a=1.712 5(3) nm, b=1.533 2(2) nm, c=0.963 42(14) nm, β=111.866(2)°, V=2.347 6(6) nm³, and D_c=1.483 Mg·m^-3, Z=4, F(000)=1 084. The structure was refined to final R₁=0.071 4, wR₂=0.166 1. The complex has a six-coordinated distorted octahedral geometry, in which copper(Ⅱ) ion coordinates with two carboxylic oxygen atoms and two hydroxyl oxygen atoms from the two α-hydroxyphenylacetic acid ligands, two nitrogen atoms from the two pyridine ligands. The analysis of the crystal structure indicates that the complex has a one-dimensional chain structure, which is formed by intermolecular hydrogen bonds. CCDC: 255346.     

二维网状铜(Ⅱ)配位聚合物{Cu(μ2-C10H8N2O3)( μ2-C6H12N4)1/2}n的合成和晶体结构

The novel copper(Ⅱ) coordination polymer with 2-oxo-propionic acid benzoyl hydrazone and hexamethylenetetramine ligands, {Cu(μ₂-C₁₀H₈N₂O₃)( μ₂-C₆H₁₂N₄)_1/2}_n (C₁₀H₈N₂O₃^2- is the dinegative ion of 2-oxo-propionicacid benzoyl hydrazone), has been synthesized and characterized by elemental analysis and IR spectroscopy. The crystal structure was determined by single crystal X-ray diffraction analysis. The results show that the crystal of the title coordination polymer belongs to monoclinic space group C2/c, the cell parameters are as follows: a=1.787 5(2) nm, b=0.730 93(9) nm, c=2.038 2(2) nm, β=92.890(2)°, and V=2.659 6(5) nm³, Z=8, D_c=1.687 Mg·m^-3, μ(Mo Kα)=1.659 mm^-1, F(000)=1 384, R=0.031 1, wR=0.079 0 for 2 454 observed reflections (I>2σ(I)) out of 2887 unique reflections. In this copper(Ⅱ) coordination polymer, each copper(Ⅱ) ion is five-coordinated with a geometry of distorted square-pyramid. Two oxygen atoms of the carboxyl of each C₁₀H₈N₂O₃^2- acts as a bridge to bond two neighboring copper(Ⅱ) ions, leading to an infinite one-dimensional chainlike coordination polymer. Each chain is linked by coordinated hexamethylenetetramines with its neighbors to form an infinite two-dimensional network structure. CCDC: 255347.     

配体尺度对配合物结构及光催化降解活性的调节:从零维到一维的Cu(Ⅱ)配合物

合成了桥联吡啶类配体2,6-二(3′-吡啶乙炔基)-4-甲基苯胺(L1)和未见文献报道的尺度更短的桥联吡啶配体2,6-二(3′-吡啶基)-4-甲基苯胺(L2),在常温下分别将其与一水合醋酸铜(Cu(OAc)2·H2O,OAc-=CH3CO2-)进行配位反应获得零维的配位大环分子[Cu2(L1)(OAc)4]2(1)和一维的配位聚合物{[Cu2(L2)(OAc)4]·2CH2Cl2·CH3CN}n(2)。对获得的2个配合物进行了X射线单晶衍射、傅里叶红外光谱、元素分析等方面的结构表征。对比其结构可以发现,配合物1和2中均存在{Cu2(OAc)4}的二核铜簇,不同的是2个配合物中配体的配位取向不同:配位大环化合物1中的配体L1以U型构型与二核铜簇形成了“2+2”的平面配位大环结构,而化合物2中的配体L2则以Z型构型连接相邻的二核铜簇形成一维链状结构。2个化合物的结构差异是由于配体的尺度导致的,更短的尺度使得配位氮原子取向发生改变而产生不同的配位构型,这显示了结构调控中配体尺度的影响作用。通过测定配体与配合物在固态下的荧光发射性质,证实了铜的引入会猝灭配体自身的荧光发射;同时,采用亚甲基蓝(MB)为底物的光催化降解实验证明,大环配位分子的光催化降解活性明显优于一维配位聚合物,两者的催化活性均远远强于醋酸铜本身的催化活性。     

THE PREPARATION AND CHARACTERIZATION OF SBR／PS CORE-SHELL PARTICLES BY GAMMA IRRADIATION

A kind of core(SBR)-shell(PS) particles was synthesized by using SBR latex and grafting with St under gamma irradiation. The influences of absorbed dose and dose rate on the grafting yield of PS on SBR seed latex have been investigated. Results show there was a transition layer which contained the SBR/PS graft copolymer between the SBR core and PS shell. Dynamic laser scattering (DLS) and differential scanning calorimetry (DSC) results confirm the existence of grafted polystyrene, and transmission electron microscope (TEM) observation verifies the core-shell structure of SBR-g-PS latex. Such SBR/PS core-shell latex could be processed easily to ultrafine rubber powders by using spray drying and expected to be used as an impact modifier for PS.     

由CBr4分子动力学研究观察到的可能的新相

通过分子动力学模拟考察并分析了１０８个分子组成的分子簇相变的结构、能量和动力学行为。结果表明，分子簇经历了由低温单斜相到新相的转变，该相变包含平动和转动相变。     

三维结构的邻近效应校正

针对三维曝光图形的结构特点,结合重复增量扫描方式,分别从水平和深度两个方向进行邻近效应校正。水平方向通过预先建立校正过程中需要的各种规则表,使所需参数可以通过查表获得,快速、准确地实现了邻近效应校正,深度方向的校正则是从吸收能量密度与曝光剂量的关系上考虑。利用SDS-3电子束曝光机完成了校正实验。AFM图显示,邻近效应已大大降低,可满足三维加工精度的要求。所提出的扫描方式和校正方法为电子束曝光的三维加工和邻近效应校正提供了一种新方法。     

不同沉积方式SiO2薄膜的自然时效特性

SiO2薄膜是光学薄膜领域内常用的重要低折射率材料之一。文中采用不同沉积技术在Si基底上制备了SiO2薄膜,并研究了它们光学特性的自然时效特性。采用不同贮存时间的椭偏光谱表征SiO2薄膜的光学特性,随着时间的增加,EB-SiO2薄膜和IAD-SiO2薄膜的物理厚度和光学厚度随着增加,但IBS-SiO2薄膜随着减小,变化率分别为1.0%,2.3%和-0.2%。当贮存时间达到120天时,IBS-SiO2薄膜、EB-SiO2薄膜和IAD-SiO2薄膜的物理厚度和光学厚度趋于稳定。实验结果表明,IBS-SiO2薄膜的光学特性稳定性最好,在最外层保护薄膜选择中,应尽可能选择离子束溅射技术沉积SiO2薄膜。