Photocatalytic properties of [polymerized n-butyl-o-titanate + hydrogen peroxide] complex on the decomposition of water

The electronic structure of the [pol-Ti(OBu)₄ + H₂O₂] complex, which is formed during the photolysis of water over [pol-Ti(OBu)₄ + CH₃OH] complex on silica gel, is elucidated in detail from the photocatalytic standpoint by DV-Xα cluster calculations. The numerical results reveal the appearance of a localized state (active site) similar to that of the [pol-Ti(OBu)₄ + CH₃OH] complex. The [TiOBu)(OH)(OH)₄]²⁻ cluster, which substitutes a hydroxyl group for the (OOH) group, exhibits an electronic structure very close to that of the [Ti(OBu)(OMe)(OH)₄]²⁻ cluster (A₁ or A₂), which was studied previously. A reduction in photocatalytic activity for the water decomposition is discussed.     

Binuclear hydroxo-monopentahalophenyl complexes of palladium(II)

The novel binuclear hydroxo-bridged complexes trans-[R(PPh₃)Pd(μ-OH)₂Pd(PPh₃)R] and cis-[R(PPh₃)Pd(μ-OH)(μ-pz)Pd(PPh₃)R] (R = C₆F₅ or C₆Cl₅; pz = pyrazolate) have been prepared, and their structures assigned on the basis of NMR data.     

The Proton-Resonance-Frequency-Shift Method Compared with Molecular Diffusion for Quantitative Measurement of Two-Dimensional Time-Dependent Temperature Distribution in a Phantom

Noninvasive thermometry methods with magnetic resonance imaging usually explore the temperature dependence of the molecular diffusion coefficient of water. A method based on the temperature dependence of the proton resonance frequency is proposed in this study and compared with the diffusion method. The comparison was made with a gel phantom with muscle characteristics and for a voxel size of 0.8 × 0.8 × 10 mm³. The root-mean-square deviation of the temperature images obtained with simulations of the thermal process is between 0.1 and 0.15°C for the proton-resonance-shift-based method with an acquisition time of 1 minute and 0.9-1°C for the diffusion-based method with an acquisition time of 4.5 minutes. Unfortunately, the proton-resonance-shift method is very sensitive to the drift of the external magnetic field and therefore a method of external references was proposed to correct for this drift. The method proves to be adequate as long as the thermal be of interest do not take more than 1 hour.     

反相液相色谱中溶剂强度规律的研究

 以溶质计量置换保留模型 (SDM R)为依据 ,通过研究 3种正链醇同系物溶剂置换剂对 14种正链醇同系物溶质色谱保留行为的影响 ,发现计量置换参数Z(对应 1mol溶质被吸附时从溶质与固定相接触处释放出的溶剂的总摩尔数 )、lgI(与 1mol溶质对固定相亲和势有关的常数 )和 j(与 1mol溶剂对固定相亲和势有关的常数 )均随着同系物置换剂相对分子质量的增大而减小 ,并呈现出线性变化 ,表明溶剂强度与溶剂分子的大小有关 ,分子愈大 ,溶剂洗脱能力愈强 ,并遵循同系物规律。     

Synthesis,crystal structure and magnetic properties of the cyano-bridged heteropolynuclear complex [{(Cu(dien))2Co(CN)6}n][Cu(dien)(H2O)Co(CN)6]n·5nH2O

The reaction of [Cu(dien)(H₂O)](NO₃)₂ with K₃[Co(CN)₆] leads to the cyano-bridged heteropolynuclear complex, [{(Cu(dien))₂Co(CN)₆}_n][Cu(dien)(H₂O)Co(CN)₆]_n·5nH₂O, {Cu₃Co₂}, whose crystal structure has been solved. The structure consists of two distinct ionic units, namely one-dimensional cationic chains [{(Cu(dien))₂Co(CN)₆}_n]ⁿ⁺, and discrete binuclear anionic entities [(H₂O)(dien)Cu–NC–Co(CN)₅]⁻. The cryomagnetic investigation of the title compound reveals a very weak antiferromagnetic coupling between the Cu(II) ions within the cationic chain (J=−1.02 cm⁻¹, g=2.14). The complete elimination of the water molecules from the isomorphous {Cu₃Co₂}, {Cu₃Fe₂} and {Cu₃Cr₂} complexes causes the modification of the magnetic properties. The most dramatic one is observed with the Cu(II)–Fe(III) system, where the magnetic behavior changes from ferro- to antiferromagnetic. The dehydrated chromium derivative preserves the ferromagnetic coupling, which is observed at lower temperatures (below 30 K) in comparison with the parent compound (below 150 K).     

用于变性蛋白质复性及同时纯化的简易型色谱柱的研制及其应用

研制出一种简易型色谱柱并通过装填大颗粒的疏水色谱填料对色谱柱的性能进行了考察,该柱的外形和操作如同传统的液相色谱柱,但它却在生物大分子分离方面有着和高效液相色谱相似的分辨率。另外,只要给该柱装填合适的固定相,比如疏水相互作用色谱固定相,便可用于蛋白质的复性及同时纯化。实验考察了该色谱柱的结构、操作和性能,包括柱压、柱寿命及对蛋白质的分辨率等。以溶菌酶为模型蛋白质,实验测得其在初始浓度为50.0 g/L时的质量回收率和活性回收率分别为(96.6±1.3)%和(101.1±6.0)%。这种简易型色谱柱价格低廉     

A Thermochemical Study on Complex Nickel（Ⅲ）L—α—Histidine

The formation enthalpy ofcomplex nickel(Ⅱ）-histidine(His)in water was determined by means of microcalorimetry in the temperature range of 298.15-323.15K.The standard enthalpy of the formation of Ni(His)2^2 (aq) was calculated.On the basis of the experimental and the calculated results,three thermodynamic parameters(the activation enthaly,the activation entropy and the activation free energy),the rate constants,three kinetic parameters(the apparent activation energy,the pre-exponential constant and the reaction order)of the formation reaction of the title complex were obtained.     

高效液相色谱法同时测定扁桃仁中的水溶性维生素C,B1,B2和B6

建立了用高效液相色谱同时测定扁桃仁中4种水溶性维生素C,B1,B2和B6的方法。以酸水解法处理样品,在Inertsil ODS-3柱(25 cm×4.6 mm i.d., 5.0 μm)上,以0.05 mol/L KH2PO4 (pH 6.0)-甲醇(体积比为70∶30)为流动相进行等度洗脱,检测波长265 nm条件下,对陕西蒲城扁桃仁中的水溶性维生素C,B1,B2和B6的含量进行了同时测定。4种水溶性维生素在其质量浓度为5.0~50 mg/L时线性良好(r=0.9990~0.9997);添加水平为5.0~20.0 mg/kg时,平均回收率为91.77%～99.30%,相对标准偏差(n=3)为0.31%～1.98%。测得陕西蒲城产扁桃仁中维生素B2的含量为4.27～4.53 mg/kg,维生素B1的含量为0.799～0.838 mg/kg,未检出维生素C和维生素B6。该法简便、快速,准确性和重现性均较好,对果仁中水溶性维生素的测定具有一定的参考价值。