β-AgVO3一维材料的制备及其光学性能

以AgNO3和 NH4VO3为原料,采用水热法,通过调控反应体系pH值,制备了β-AgVO3纳米线、亚微米线及微米棒.采用X射线衍射(XRD)和场发射扫描电子显微镜(FE-SEM)对样品的组成和表面形貌进行了表征.紫外-可见光吸收测试表明所制得的不同尺寸的β-AgVO3一维材料均具有较宽的紫外-可见光吸收范围,通过计算得出β-AgVO3纳米线、亚微米线及微米棒的光学带隙分别为2.21 eV,2.17 eV和2.12 eV.     

哺乳动物细胞光电行为的机理研究

研究了阿霉素、寡霉素和秋水仙素对细胞光电流的影响,发现细胞光电流的变化可适时表征药物对细胞的作用,且药物对细胞光电流的抑制率具有剂量和时间依赖性.据此提出了“光激励酶促反应加速模型”,并对哺乳动物细胞光电行为的机理进行了探讨.     

硅锆复合包覆BiVO4晶体的表征及其机理研究

利用正硅酸乙酯(TEOS)和氧氯化锆(ZrOCl2·8H2O)的水解反应并经高温煅烧后,在BiVO4晶体表面形成SiO2·ZrSiO4膜,以提高BiVO4的耐高温性.采用红外光谱仪、X射线衍射仪、差热分析仪对产品进行了表征,并得出结论:包覆SiO2·ZrSiO4膜后的BiVO4晶体,其耐热温度由680℃提高到1000℃,并对包覆机理进行了探讨.     

Improving the picture of atomic structure in nonoriented polymer domains using the pair distribution function: A study of polyamide 6

Investigations of the atomic structures within polyamides started over 80 years ago and continue today. These weakly ordered materials diffract X-rays poorly and typically require postprocessing to obtain idealized samples for structural studies. An important goal remains to develop techniques to study the local structure in its natural state, with atomic resolution, and with sensitivity to subtle changes due to synthesis conditions or other technologically relevant processing procedures. Here, we compare the structures of as-produced, nonoriented polyamide 6 ([C₆H₁₁NO] _n) from both hydrolytic and anionic processes. A total scattering pair distribution function approach is used to elucidate information about the atomic bonding, molecular conformation, chain packing, crystallite size, and ratio of ordered to disordered domain content. The results are compared with those from standard analytical methods.     

High transverse momentumη production in π− p, π+ p,andpp interactions at 280 GeV/c

The inclusive cross sections for η production by the interactions of 280 GeV/c momentum π^?, π⁺, and proton beams in hydrogen have been measured. The kinematical range covered is ?0.45<x _F <0.45, and 4.0<P _T <7.0 GeV/c for Feynmanx _F and transverse momentum respectively. The η to π⁰ cross section ratios are given for the three reactions. The ratio of π^? p to π⁺ p cross sections for η production in the above kinematic ranges is 1.22±0.08±0.11.     

Structure analysis of naturally occurring alkyl porphyrins by hydrogen chemical ionisation mass spectrometry

Chemical ionisation (CI) mass spectrometry with H₂ as reagent gas has been used to obtain spectra of a number of demetallated alkyl porphyrins from an oil shale and a bitumen. The spectra give more structural informa- tion than the electron impact spectra, by way of odd electron dipyrrolic fragment ions. Thus, the structural possibilities for a novel /c30 aetio porphyrin have been narrowed to two, although¹HNMR only reduced the possibilities to six. The spectra of four types of components containing a five, six, seven or methyl-substituted six membered exocyclic ring show, for example, that three out of four C₃₂ isomers can be distinguished. The technique offers promise as a tool in structural elucidation of other novel naturally occurring porphyrins.     

明胶基多孔碳球电极材料的制备及电化学性能研究

Gelatin-based porous carbon beads have been fabricated from gelatin micro-spheres by means of solidification, carbonization and chemical activation with KOH. The physical properties of gelatin-based porous carbon beads were studied by a t-plot method based on N₂ adsorption isotherms. The gelatin-based porous carbon beads activated at 800 ℃ exhibited the largest specific surface area and resulted in the highest capacitance. Carbon/carbon super-capacitors cells assembled with the electrode materials in 1.0 mol·L^-1 NEt₄BF₄ / acetonitrile electrolyte have also been studied. The electrochemical properties of gelatin-based porous carbon beads electrode were studied by using constant-current discharge tests. The results indicate that the gelatin-based porous carbon beads electrode is with good cycling stability and specific capacitance of 119.8 F·g^-1.     

Hydrogen catalysis and scavenging action of Pd-POSS nanoparticles

Prompted by the need for a self-supported, chemically stable, and functionally flexible catalytic nanoparticle system, we explore a system involving Pd clusters coated with a monolayer of polyhedral oligomeric silsesquioxane (POSS) cages. With an initial theoretical focus on hydrogen catalysis and sequestration in the Pd-POSS system, we report density functional theory (DFT) results on POSS binding energies to the Pd(1 1 0) surface, hydrogen storing ability of POSS, and possible pathways of hydrogen radicals from the catalyst surface to unsaturated bonds away from the surface.     

Separation of positional isomers of oxidation catalyst precursors

A series of polypyridyl ruthenium complexes of the general formula [Ru(tpy)(bpy')Cl]+ where tpy is 2,2':6',2"-terpyridine and bpy' is 4-carboxy-4'-methyl-2,2'-bipyridine (4-CO2H-4'-Mebpy), a proline derviative (4-CO-Pra-(Boc)(OMe)-4'-Mebpy), or 4-((diethoxyphosphinyl)methyl)-4'-methyl-2,2'-bipyridine (4-CH2PO3Et2-4'-Mebpy) are prepared. For each complex, two isomers exist, and these are separated chromatographically. The structure of the hexafluorophosphate salt of cis-[Ru(tpy)(4-CO2H-4'-Mebpy)Cl]+, cis-1, is determined by X-ray crystallography. The salt crystallizes in the monoclinic space group Cc with a = 12.4778(6) A, b = 12.6086(6) A, c = 20.1215(9) A, beta = 107.08200(1) degrees, Z = 4, R = 0.058, and Rw = 0.072. The structures of the remaining complexes are assigned by 1H NMR comparisons with cis-1. The complexes are potentially important precursors for the incorporation of RuIV=O2+ oxidants into polymers or peptides or for their adsorption onto oxide surfaces. Preliminary electrochemical results for the isomers of [Ru(tpy)(4-CH2PO3H2-4'-Mebpy)(H2O)]2+, 4, adsorbed on ITO (In2O3:Sn) surfaces add support to a recently proposed electron-transfer mechanism involving cross-surface proton-coupled electron transfer.