Preparation of Dodecyl Dimethyl Benzyl Ammonium Bromide-Doped Cubic CaCO<Subscript>3</Subscript> with Antibacterial Properties

CaCl₂ encapsulated was placed in the hydrothermal reactor of an aqueous solution of Na₂CO₃ and dodecyl dimethyl benzyl ammonium bromide for synthesis of two samples of calcium carbonate by an improved hydrothermal method and one-pot method. Their crystal structure, morphology, chemical composition, and thermal stability of the synthesized samples of calcium carbonate were investigated by XRD, FTIR, SEM, EDS and TGDSC. The sterilization activity of the as-prepared samples was evaluated by killing of Sarcina lutea bacteria. The results indicated that the regular cube capsule-assisted calcium carbonate prepared by hydrothermal process was doped with dodecyl dimethyl benzyl ammonium bromide. Under the same condition, the spindle-shaped calcium carbonate synthesized the one-pot method was not doped with dodecyl dimethyl benzyl ammonium bromide. Among the samples of calcium carbonate, capsule-assisted calcium carbonate had shown better antibacterial effect for Sarcina lutea: in 48 h after its inhibition a zone diameter was 12.3 mm.     

Poly（ethylene glycol）-supported Liquid-phase Parallel Synthesis of Di（aryloxyacetyl）thiosemicarbazides

An efficient poly(ethylene glycol) (PEG)-supported liquid-phase parallel approach to di(aryloxyacetyl)thiosemicarbazides is described. PEG-bound phenol reacted with chloroacetic acid to afford PEG-bound phenyloxyacetic acid, which was readily converted into corresponding phenyloxyacetyl chloride. Subsequent nucleophilic substitution with ammonium thiocyanate followed by addition of aryloxyacetic acid hydrazides gave PEG-bound di(aryloxyacetyl)thiosemicarbazides, which were easily cleaved to give the resulting library of 1-aryloxyacetyl-4-(4‘-methoxylcarbonylphenyloxyacetyl)thiosemicarbazides in good to high yield and high purity.     

Separation and determination of active components in Radix Salviae miltiorrhizae and its medicinal preparations by nonaqueous capillary electrophoresis

A nonaqueous capillary electrophoresis (NACE) method was developed for simultaneous assay of three bioactive components (1: cryptotanshinone; 2: tanshinone IIA, and 3: tanshinone I) in Radix Salviae miltiorrhizae and in its herbal preparations for the first time. After optimization of separation conditions, a buffer of 250 mmol L(-1) ammonium acetate containing 30% acetonitrile and 1.0% acetic acid (V:V) in methanol was selected for separating the three analytes, but baseline separation of tanshinon I and tanshinone IIA was not obtained. Therefore second-order derivative electropherograms were applied for resolving overlapping peaks. Regression equations revealed good linear relationships (correlation coefficients 0.9943-0.9991) between peak heights in second-order derivative electropherograms and concentrations of the three analytes. The relative standard deviations (RSD) of the migration times and the peak height of the three constituents were in the range of 0.81 -0.88% and 0.34-1.13% (intra-day), 1.57-1.86% and 3.05-5.52% (inter-day), respectively. The recoveries of three constituents ranged from 90.2 to 108.5%. The results indicated that baseline separation of the analytes was sometimes hard to obtain and second-order derivative electropherograms were applicable for the resolving and analysis of overlapping peaks.     

CARBONIUM CYCLIZATION-STUDIES ON LIGNANS CONTAINING THE DIBENZOCYCLOOCTADIENE SYSTEM.Ⅰ

Schisandrin(1)under the Ritter reaction conditions (conc.H₂SO₄/CH₃CN)gave trace amounts of the expected acetamido derivatives(2 a, 2 b).The main product is 5 a, from intramolecular car-bonium cyclization.     

高效液相色谱检测动物肌肉组织中7种喹诺酮类药物的残留

本研究建立了同时检测动物肌肉组织中环丙沙星、单诺沙星、恩诺沙星、沙拉沙星、二氟沙星、恶喹酸、氟甲喹7种喹诺酮类药物的HPLC-FLD检测方法。动物组织样品用磷酸盐水溶液提取,HLB固相萃取柱净化,采用甲酸水溶液-乙腈体系作为流动相,梯度洗脱,程序波长荧光检测器检测。方法的线性范围为0.3~100μg/L,相关系数(r)大于0.9989;检出限为0.1~0.3μg/kg,定量限为0.3~1.0μg/kg;7种喹诺酮类药物在鸡肉和猪肉的平均回收率分别为70.4%~102.1%和79.6%~105.8%;相对标准偏差分别为1.1%~8.9%和1.3%~9.3%。     

Capacity Titration Technique for Determining the Solid Diffusion Coefficient of Intercalary Species within Insertion-host Materials

Investigation on the solid diffusion process of intercalary species within insertion-host materials plays an important role in the energy storage and output of secondary batteries1. To determine the solid diffusion coefficient, several electrochemical techniques have been developed such as galvanostatic intermittent titration (GITT)2,3, electrochemical impedance spectroscopy (EIS)4,5, potential intermittent titration technique (PITT)6, and potential step chronoamperometry (PSCA)7, potenti…     

硅氧烷乳液聚合的研究Ⅲ.八甲基环四硅氧烷在阳离子乳液聚合过程中乳液颗粒的形成

八甲基环四硅氧烷(D_4)在阳离子乳液聚合过程中,首先被乳化成颗粒较大的“过渡粒子”,在这里以D_4的水解开环和加聚反应为主,然后转变为颗粒较小的稳定乳液粒子。聚合物端基≡SiOH的缩合反应主要在乳液粒子中进行。     

攀枝花地区野生番石榴叶提取物中Zn、Mg、Cr、V等微量元素分析

采用电感耦合等离子体发射光谱仪(ICP-AES)同时测定了攀枝花地区野生番石榴叶水和乙醇提取物中Zn、Mg、Cr、V等微量元素的含量。结果表明,攀枝花地区野生番石榴叶中富含Zn、Mg、Cr、V等微量元素,水提取物和不同浓度乙醇提取物中Zn、Mg、Cr、V等微量元素含量不同。     

环戊烯阳离子聚合反应

使用不同阳离子引发剂聚合环戊烯，得到了低聚合度的ＣＰ齐聚物。ＩＲ和＾１ＨＮＭＲ研究发现齐聚物链端碳阳离子通过质子消去反应生成了相应的不饱和端基，这种通过质子消去机现发生的链转移反应和生成稳定叔碳阳离子的１，２－Ｈ转移反应导致了聚合反应的氏聚合度。ＣＰ在甲苯中不发生聚合反应而是通过链转移反应与甲苯生成偶合产物。     

液相烧结碳化硅晶界内氮化反应的研究

碳化硅 ( Si C)由于其高度的共价键结合特性而具有高硬度、耐磨性和高化学稳定性等优异性能而成为热机、高温环境和化学化工等领域的研究应用对象 .碳化硅材料的无压烧结最早是由 Prochazka[1] 实现的 .2 0世纪 80年代初期 ,Omori[2 ] 通过采用氧化物 ( Al2 O3,Y2 O3和稀土氧化物等 )添加剂的手段大大降低了无压烧结的温度 .这些氧化物具有较低的共熔点 ,在高温下易形成液相 ,从而促进了碳化硅的晶粒重排和晶体生长 .2 0世纪 90年代以来 ,氮化物和氧化物的混合添加剂 (如 Al N- Y2 O3) [3]被广泛应用于碳化硅的液相烧结 .这是因为氮在…