几种苯甲酰胺类抗精神病药物的手性色谱拆分及其对映体含量的测定

采用直链淀粉-三(5-氯-2-甲基苯基氨基甲酸酯)手性固定相(CSP),以0.1%二乙胺正己烷和0.1%二乙胺乙醇为流动相梯度洗脱,以舒必利、阿米舒必利和莫沙必利为目标物,利用高效液相色谱法研究了这3种苯甲酰胺类药物的手性色谱分离行为。分别考察了流动相组成、添加剂及柱温对3种药物对映体分离的影响,从热力学和结构上探讨了色谱拆分的机理。结果表明: 在优化的色谱条件下,舒必利、阿米舒必利和莫沙必利对映体的分离度Rs＞1.5;计算了3种药物对映体的色谱保留因子k和分离因子α,以及与CSP相互作用的热力学函数,其相互作用大小依次为舒必利＞阿米舒必利＞莫沙必利。已将该方法成功地应用于上述3种药物片剂和血清中其对映体的测定,方法简便、准确、可靠。     

A light-through-side cell and co-used furnace designed for micro-Raman spectra study on volatile melts

A new type of sample cell specially designed for micro-Raman spectra study on volatile melts is described.The cell is made of quartz.The lower section of the cell is circular ring-shaped and the one-end-closed hole in the cell is used for locating the heating body.The tube attached to the cell lid for placing the thermal couple is inserted into the sample,which ensures that the temperature measurement accuracy is good.The cell can be sealed for reducing the effect of the composition change caused by the inhomogeneous volatilization.During the Raman spectra scanning,the laser beam is transmitted into the cell through the side but not the top.Meanwhile,a furnace has been designed to match the cell.The heating body is closely coupled with the sample cell, and there is a hole on the side wall of the furnace for the entrance of the microlens.The assembly has performed well in the tested Raman spectrum measurement of molten NaNO₃ at 602℃.     

Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3‐dihydroxybenzoic acid, and one purified humic acid material were used in this study. Under the experimental conditions, the UV peaks of salicylic acid and 2,3‐dihydroxybenzoic acid were well separated from the peaks of humic acid in the chromatogram. Concentrations of the two small organic acids could be accurately determined from their peak areas. The concentration of humic acid in the mixture could then be derived from mass balance calculations. The measured results agreed well with the nominal concentrations. The detection limits are 0.05 mg/L and 0.01 mg/L for salicylic acid and 2,3‐dihydroxybenzoic acid, respectively. Applicability of the method to natural samples was tested using groundwater, glacier, and river water samples (both original and spiked with salicylic acid and 2,3‐dihydroxybenzoic acid) with a total organic carbon concentration ranging from 2.1 to 179.5 mg C/L. The results obtained are promising, especially for groundwater samples and river water samples with a total organic carbon concentration below 9 mg C/L.     

碳化硼纳米线的制备和结构

以碳纳米管为模板，通过加热碳纳米管与硼粉的混合物，获得了笔直的硼碳纳米线.对纳米线的结构和成分进行研究，结果表明纳米线主要为B4C纳米线.在部分B4C纳米线的端部存在Ni颗粒，这些端部具有Ni颗粒的纳米线构成了纳米磁针.讨论了B4C纳米线的生长机制，B4C纳米线的生长主要为硼原子在碳纳米管中扩散并发生化学反应，使得碳纳米管晶格结构发生重组，形成B4C纳米线.反应后，硼原子部分取代了碳纳米管中碳原子，修补了碳纳米管中的晶格缺陷，获得了形态笔直的B4C纳米线.     

Isotropic-nematic phase transition in athermal solutions of rod-coil diblock copolymers

We present a hybrid method to investigate the isotropic-nematic (I-N) transition in athermal solutions of rod-coil copolymers. This method incorporates the scaled-particle theory for semiflexible chains with two-chain Monte Carlo simulation for the osmotic second virial coefficient and for the angle-dependent excluded volume. We compare the theoretical prediction with Monte Carlo simulations for fused rod-coil copolymers and find good agreement for both the equation of state and the orientational order parameter. The theory is also used to examine the effects of the bond length, the chain length, and the chain composition on orientational ordering in athermal solutions of rod-coil block copolymers. It predicts I-N transition in rod-coil copolymers with fixed rod length but a variable flexible tail in good agreement with experiments.     

Analogy in the adsorption of random copolymers and homopolymers at solid-liquid interface: a Monte Carlo simulation study

The adsorption of random copolymers at solid-liquid interface from a nonselective solvent has been studied by Monte Carlo simulation in a cubic lattice. The polymeric molecules are modeled as self-avoiding linear chains composed of two types of segments A and B. The effects of copolymer composition (A/B ratio), segment-surface interaction, and bulk concentration are examined on the thermodynamic and structural adsorption properties including surface coverage, adsorption amount, adsorption layer thickness, and microscopic density distribution. At a given newly introduced effective adsorption energy, random copolymers are found to behave quantitatively as homopolymers regardless of the copolymer composition and surface affinity. This remarkable analogy provides an efficient way in predicting the adsorption of random copolymers from homopolymers.     

Liquid–liquid equilibria for the quaternary system methyl isobutyl ketone–water–phenol–hydroquinone

Liquid–liquid equilibria data of the quaternary system methyl isobutyl ketone (MIBK)–water–phenol–hydroquinone were measured at 25 °C under atmosphere pressure. The experimental data were correlated with the UNIQUAC and NRTL activity coefficient models on the base of the fixed binary interaction parameters that were obtained from two sub-ternary systems MIBK–water–phenol and MIBK–water–hydroquinone. The root mean square deviations (RMSD) show that the regressed results for the quaternary system were in good agreement with the experimental data for both UNIQUAC and NRTL models. The comparison between experimental and calculated distribution coefficient values of phenol and hydroquinone shows that a relative deviation of less than 5% is obtained.     

镧掺杂粘土源含铜氧化物催化剂的制备、表征及催化性能

采用共沉淀和水热法合成了不同阴离子粘土前驱型复合氧化物催化材料,样品经XRD,FTIR,TPR,TG-DSC,SEM进行表征.同时考察了铜含量在掺杂和不掺杂稀土时对甲烷催化燃烧的影响,结果发现随含铜量增加催化活性增加;未掺杂La的催化剂在高温下出现失活现象,而掺杂型催化剂稳定性良好.同时,制备方法对催化剂的性能有显著影响,在不同制备前驱物pH的条件下,使用共沉淀和水热法合成的阴离子粘土材料,合成时的pH均对催化剂的活性影响较大;同时焙烧温度对催化活性有不同程度的影响.     

Two Novel Alkaloids from Zanthoxylum nitidum

Two novel alkaloids, 4,5‐dihydroxy‐1‐methyl‐3‐oxo‐2‐(trichloromethyl)‐3H‐indolium chloride ( 1 ) and 4‐(2‐methoxyethyl)‐N,N‐dimethylbenzenamine ( 2 ), were isolated from the EtOH extract of the roots of Zanthoxylum nitidum. Their structures were identified on the basis of spectroscopic and mass‐spectrometric analyses.