取代乙酸配体对乙炔二聚反应催化剂性能的影响

研究了取代乙酸配体作为Ｎｉｅｕｌａｎ催化剂对乙炔二聚反应性能的影响。结果表明，不同功能结构数目的影响，结果表明，不同功能结构数目的的氨羧配体均使催化剂的选择性提高。乙炔转化率略有下降，巯基乙酸配体的加入，则改变了乙炔二聚反应的机理，得到以乙醛为主的产物。     

Carbon dioxide reduction under visible light: a comparison of cadmium sulfide and titania photocatalysts

1. Download : Download high-res image (135KB)
2. Download : Download full-size image

     

氯化1-乙基-3-甲基烷基咪唑分子结构及其氢键作用能的密度泛函研究

采用量子化学密度范函方法计算研究了氯化1-乙基-3-甲基咪唑盐（[EMIM]C1）正负离子间相互作用的平衡构型和Cl^-离子从不同方位与咪唑阳离子的结合能．计算发现Cl^-可在咪唑环平面上结合形成离子键，其结合能为．368．97kJ／mol，还可与环上的三个H原子形成氢键，其氢键键长和结合能分别为0．2000nm／-378．03kJ／mol、0．2339nm／-344，69kJ／mol和0．2301nm／-346，01kJ／mol．结合能包括氢键作用能和正负离子的静电作用能，后者为主要贡献．从理论上展示了该离子液体的氢键结构．     

气相色谱法测定三聚氰氯的研究

气相色谱法测定三聚氰氯的研究李秀梅赵树岚＊田锦霞＊孙维星（东北师范大学化学系长春１３００２４）关键词气相色谱法三聚氰氯三聚氰氯（ＣＮＣｌ）３是活性染料的重要中间体及合成树脂、橡胶、塑料等的防老剂，也常用于除草剂、增白剂、药物、炸药等的生产中。传统的分...     

Synthesis of cationic water-soluble esters of chlorin e6

Two esters of chlorin e₆ have been synthesized by esterification with aminoalcohols via the formation of acid chloride using oxalyl chloride and converted to the corresponding cationic water-soluble esters of chlorin e₆. The visible absorption and circular dichroism spectra have revealed that these two cationic chlorin e₆ esters synthesized are readily soluble in water as a monomer.     

An optimized method for determination of intracellular glutathione in mouse macrophage cultures by fluorimetric high-performance liquid chromatography

We have optimized a method for the determination of intracellular glutathione by high-performance liquid chromatography, using fluorimetric detection. To minimize artifacts and provide an accurate determination of intracellular glutathione, cell extracts were prepared using extraction conditions specifically designed to inhibit autoxidation and enzymatic degradation of glutathione. The sensitivity of the method was enhanced by adjusting the dansyl chloride derivatization reaction with regard to parameters such as pH, reaction time and dansyl chloride concentration. Both oxidized and reduced forms of glutathione were quantified using the refined method in extracts of oxidatively stressed J774A.1 mouse macrophage cells and reflected an expected shift in cellular redox status.     

Thermodynamic properties of electrolyte solutions: An EMF study of the activity coefficients of KCl in the system KCl−KNO3−H2O at 25, 35 and 45°C

Electromotive force measurements were carried out on the system KCl–KNO₃–H₂O at constant total ionic strengths of 0.5, 1.0, 2.0 and 3.0 mol-kg^–1 and at 25, 35 and 45°C using a cell consisting of a potassium ionselective electrode and a Ag/AgCl electrode. The Harned coefficients and the Pitzer binary and ternary interaction parameters for the system have been evaluated at each temperature. The osmotic coefficients, excess free energies of mixing and heats of mixing of the system have been predicted at each of the experimental temperatures and ionic strengths. The solubility data at 25°C are also interpreted.     

反相乳液聚合制备壳聚糖接枝共聚物及应用

以壳聚糖、丙烯酰胺、甲基丙烯酰氧乙基三甲基氯化铵为原料,硝酸铈铵为引发剂,Span-20为乳化剂,通过反相乳液聚合技术,合成壳聚糖阳离子接枝共聚物。分析讨论了乳化剂用量、引发剂浓度、油水体积比、单体配比、反应时间、反应温度对共聚物接枝率的影响,并采用正交试验方法对合成条件进行了优化。研究了其对重金属离子Cu2 、Cd2 、Zn2 的吸附性能。结果表明,在Cu2 、Cd2 、Zn2 的混合离子体系中,该共聚物对Cu2 、Zn2 有选择性吸附。     

SYNERGISTIC MODIFICATION OF EPDM AND CROSSLINKING AGENT IN IMMISCIBLE BLENDS OF POLYVINYL CHLORIDE WITH LOW DENSITY POLYETHYLENE

The synergism of ethylene-propylene-diene monomer copolymer （EPDM） and dicumyl peroxide （DCP, a crosslinking agent） in low density polyethylene （LDPE）/poly（vinyl chloride） （PVC） blends was investigated. When EDPM and DCP are added to the blends simultaneously, the tensile properties could be improved significantly, especially for the blends with LDPE matrix. For example, incorporation of 10/1 （mass ratio） EPDM/DCP improves the tensile strength of the LDPE/PVC （mass ratio 80/20） blend from 7.9 MPa to 8.5 MPa and the elongation at break from 25% to 503%. Results from selective extraction, phase-contrast microscopy and thermal analysis reveal that the improvement in the tensile properties of the blends with LDPE matrix is principally due to the formation of a fine crosslinking network of the LDPE and EPDM phase. The outstanding modification effect of EPDM is explained by its dual functions： molecular entanglement with LDPE and the enhanced efficiency of DCP in the blends.     

Apparent molar volumes of aqueous calcium chloride to 250°C, 400 bars,and from molalities of 0.242 to 6.150

Relative densities of CaCl ₂ (aq) with 0.22ml(mol-kg^–1)6.150 were measured with vibrating- tube densimeters between 25 and 250°C and near 70 and 400 bars. Apparent molar volumes V calculated from the measured density differences were represented with the Pitzer ioninteraction treatment, with appropriate expressions chosen for the temperature and pressure dependence of the virial coefficients of the model. It was found that the partial molar volume at infinite dilution V ^o , and the second and third virial coefficients B ^V and C ^V , were necessary to represent V near the estimated experimental uncertainty. The ionic-strength dependent ^(1)v term in the B ^V coefficient was included in the fit. The representation for V has been integrated with respect to pressure to establish the pressure dependence of excess free energies over the temperature range studied. The volumetric data indicate that the logarithm of the mean ionic activity coefficient, ln ±(CaCl ₂ ), increases by a maximum of 0.3 at 400 bars, 250°C, and 6 mol-kg^–1 as compared with its value at saturation pressure.