硅氧烷乳液聚合过程中大颗粒形成机理研究：Ⅰ.阳离子型乳液的耐电解质…

探讨了二甲基聚硅氧烷阳离子型乳液耐电解质稳定性的影响因素。结果表明，加入少量的非离子型表面活性剂与阳离子型乳化剂并用进行乳液聚合，可以保护乳液粒子，防止由于电解质引的乳液粒子的相互凝聚而形成大颗粒。     

硅氧烷乳液聚合过程中大颗粒形成机理的研究：Ⅱ.聚硅氧烷乳液的耐酸碱…

研究了阴离子型与阳离子型聚硅氧烷乳液的耐酸碱稳定性，发现阴离子型乳液对酸碱都相当稳定，在乳液制备过程中，酸性催化剂不会引起乳液颗粒的凝聚；而阳离子型乳液的耐酸三稳定性性差，尤其是引起乳液颗粒慢速凝聚的碱浓度下限值很低，碱是制备阳离子型乳液的化剂，碱引起乳液颗粒的慢速凝聚是阳离子型乳液中大颗粒形成的主要原因，在乳液聚合过程中所发生的相当部分的乳化剂从水相向有机硅相的转移也是影响阳离子型乳液稳定性的一     

FIA-ICP/AES法分析茶叶浸取液中多元素的形态

本文报道了分析茶叶浸取液中[Zn、Mn、Fe、Al及Mg]形态的新方法。研究了以C-18柱为分离柱的流动注射与ICP/AES的联用技术。     

Using nitrile-derivatized amino acids as infrared probes of local environment

It is well-known that the C=N stretching vibration in acetonitrile is sensitive to solvent. Therefore, we proposed in this contribution to use this vibrational mode to report local environment of a particular amino acid in proteins or local environmental changes upon binding or folding. We have studied the solvent-induced frequency shift of two nitrile-derivatized amino acids, which are, AlaCN and PheCN, in H(2)O and tetrahydrofuran (THF), respectively. Here, THF was used to approximate a protein's hydrophobic interior because of its low dielectric constant. As expected, the C=N stretching vibrations of both AlaCN and PheCN shift as much as approximately 10 cm(-1) toward higher frequency when THF was replaced with H2O, indicative of the sensitivity of this vibration to solvation. To further test the utility of nitrile-derivatized amino acids as probes of the environment within a peptide, we have studied the binding between calmodulin (CaM) and a peptide from the CaM binding domain of skeletal muscle myosin light chain kinase (MLCK(579-595)), which contains a single PheCN. MLCK(579-595) binds to CaM in a helical conformation. When the PheCN was substituted on the polar side of the helix, which was partially exposed to water, the C=N stretching vibration is similar to that of PheCN in water. In constrast, when PheCN is introduced at a site that becomes buried in the interior of the protein, the C=N stretch is similar to that of PheCN in THF. Together, these results suggest that the C=N stretching vibration of nitrile-derivatized amino acids can indeed be used as local internal environmental markers, especially for protein conformational studies.     

Analysis of Petroleum Distillates from Fire Debris Using Supercritical Fluid Extraction with a Two‐Level Orthogonal Array Experimental Design

A supercritical fluid extraction (SFE) method was developed in the present study as an effective sample pretreatment technique of petroleum distillates from fire debris. Three petroleum distillates were used as target analytes, including 95 unleaded gasoline, kerosene, and premium diesel. An orthogonal array (L16) experimental design was adopted to separately evaluate primary SFE experimental factors. The SFE efficiencies of petroleum distillates at various extraction conditions were examined and the optimized SFE conditions were identified. Experimental results demonstrated that the optimized SFE method not only provided an effective extraction method for the spiked sample, but also successfully recovered residues of petroleum distillates from fire debris.     

Sizable concentration-dependent frequency shifts in solution NMR using sensitive probes

With the growing use of high fields and ultrasensitive probes, radiation damping emerges as a significant feedback interaction in modern solution NMR. Motivated by recent observations of mysterious concentration-dependent frequency shifts, experiments carried out on a cryoprobe at 600 MHz have revealed a time-averaged frequency shift of up to +83/-81 Hz. The sizable frequency shifts arise from deviations in the phase of the radiation damping field from perfect orthogonality relative to the net transverse magnetization. The frequency shift is shown to depend on the longitudinal magnetization and probe tuning conditions through experiments and numerical simulations. Such unexpected shifts in the solvent precession frequency provide a physical explanation for the empirical practice of adjusting the irradiation frequency of the saturating B1 field in solvent presaturation to achieve optimal suppression. Additional applications of the radiation damping induced frequency shift to solvent suppression and NMR methodology are discussed.     

双亲嵌段聚合物的合成与应用

本文介绍了双亲嵌段聚合物的合成方法，包括共溶剂法、聚合后功能化法、胶束聚合法、自由基界面聚合法等，以及双亲嵌段聚合物在乳液聚合、三次采油、医用高分子材料等方面的应用。     

三硒化二铒Er_2Se_3的合成与结构

采用高温固相反应和化学气相传输法合成三硒化二铒。晶体属于四方晶系，Ｍ_ｒ＝５７１．４０，空间群为Ｐ４／ｎｍｍ，ａ＝３．９８４（１），ｃ＝８．２２８（３），Ｖ＝１３０．５９（７），Ｚ＝１，Ｄ_ｃ＝７，２７ｇ／ｃｍ￣３，Ｆ（０００）＝２３８，μ（ＭｏＫα）＝５２８．８６ｃｍ￣（－１），对于１８７个Ｉ≥３σ（Ｉ）的独立衍射点，最后偏离因子Ｒ＝０．０６６，Ｒ_ｗ＝０．０７８。化合物Ｅｒ_２Ｓｅ_３的晶体结构是由Ｅｒ配位多面体的双层状结构通过共用Ｓｅ（２）原子，沿ｃ轴方向堆积而形成的三维结构。     

BaF（Cl,Br）：Sm^2＋的光谱烧孔与光激励发光过程

Ｘ射线辐照前后，在ＢａＦ（Ｃｌ，Ｂｒ）：Ｓｍ＾２＋中以５６０ｎｍ的Ｎｄ：ＹＡＧ脉冲光在液氮温度下进行了双光子烧孔实验和光激励发光实验，结果表明，Ｓｍ＾２＋掺杂的碱土金属氟卤化物光谱烧孔过程中伴随着光激励发光过程，这一过程直接影响光谱烧孔过程的进行。     

硫酸溶液中Ag+离子对Mn2+离子阳极氧化的催化作用

Anodic oxidation of Mn2+ and Ag+ ions and anodic oxidation of Mn2+ ion on platinum electrode in H2SO4 solution catalyzed by Ag+ ion are studied by using RRDE and triangle voltammetry techniques. Mn2+ ion is oxidized on the anode surface with adsorped OH group to form a certain compound containing Mn3+, which causes Mn2+difficult to be oxidized directly on anode. Near the potential of oxygen evolution from H2O decomposition, Ag+ ion is oxidized to form Ag2+ ion. This is the main reaction on anode because of its reversability. At higher potential silver oxide is formed on the anode. The oxide catalyzes the decomposition of H2O strongly. The anodic oxidation of Mn2+ion catalyzed by Ag+ takes place and Ag2+ ion and silver oxide are no longer the product of Ag+ anodic oxidation when Mn2+ exists in solution at the potential for Ag+ anodic oxidation. It is confirmed that the catalysis reaction is homogeneous and very fast.