Preparation and Characterization of Carboxymethyl Chitosan and β-Cyclodextrin Microspheres by Spray Drying

Three kinds of carboxymethyl chitosan/β-cyclodextrin microspheres loaded with theophylline were prepared by spray drying intended for pulmonary delivery. Mucociliotoxicity, permeation rate, and drug release characteristics of the product were investigated. The microspheres obtained by spray drying were found to be spherical with smooth or wrinkled surfaces. The mean particle size was between 3.39 and 6.06 µm. The microspheres demonstrated high product yield (43.7-50.2%), high drug loading (13.7-38.1%), and high encapsulation efficiency (86.9-92.8%). FT-IR indicated that there were interactions of theophylline with carboxymethyl chitosan matrix. Further studies on mucociliotoxicity and permeation confirmed that microspheres had better adaptability and high permeation rate. In vitro drug release from the microspheres was not related to the drug/polymer ratios.     

Computer aided kinetic modeling with KMT and KME

The complexity of many chemical and refining reaction systems and the thus-derived tedious and time-consuming process of building the associated kinetic models have been major obstacles in the use of fundamental kinetics in the solution of chemical engineering problems. This review summarizes work aimed at removing theses obstacles. Our recent work that has led to the enhancement of the Kinetic Modeler's Toolbox (KMT) and the development of the Kinetic Model Editor (KME) presents an end-to-end solution to the kinetic modeling process, including automated feedstock modeling, reaction network construction, kinetic rate estimation, model programming, process system configurations, model customizations, compilations, model execution and results analysis.     

钾基CO2吸收剂的碳酸化反应特性

对钾基CO2吸收剂的碳酸化反应机理进行研究.利用热重分析、XRD、扫描电镜和氮吸附仪进行试验.结果表明:分析纯碳酸钾的组分为K2CO3·1.5H2O,碳酸化反应速率缓慢;先将分析纯碳酸钾样品脱除结晶水后再进行碳酸化反应时,K2CO3与气氛中的水蒸气迅速生成K2CO3·1.5H2O,不利于碳酸化反应的进行;由KHCO3分解产生的K2CO3却表现出优越的碳酸化反应性能,20 min内转化率高达85%以上,经过多次循环试验后吸收剂仍保持很高的活性.从微观角度分析了两种改性钾基CO2吸收剂碳酸化反应机理差异的原因,通过拟合计算得到了这3种钾基吸收剂的碳酸化反应速率常数,为干法K2CO3/KHCO3循环脱除CO2的研究提供了一定的基础数据.     

管道安装工程中管路及附件匹配性问题研究

在管道设备安装工程中，常出现到货管材与管路附件不匹配的问题，究其原因，主要是目前国内使用的管材与管路附件标准繁杂、兼容性不高所致。为此，文章从管材及管件、阀门、管路法兰三方面分析了现行国内外标准之间、国标与行标之间存在的差异，并提出防止管材与管路附件不匹配的措施。     

首尔地面公交系统改革的成功经验

随着经济、人口的快速发展,首尔开展了一次针对地面公交系统的成功而深刻的变革。其中包括组建以公众参与为基础的公交系统改革公民委员会,形成了“以线路连接为导向的公交系统”,采用新型公交智能卡、票价新制度以及信息一体化的管理系统。     

Composite group vector space method for estimating melting and boiling point of pure organic compound

Composition Group Vector Space (CGVS) method for estimating melting and boiling point T _m , T _b of organic compound has been proposed, and the principle of this method has been elucidated. The models for estimating T _m , T _b have been established and the numerical values of relative parameters have been presented. The average percentage deviations of T _m , T _b estimation are 7.53 and 1.58, respectively, which show that the present method demonstrates significant improvement in applicability to predict the above properties, compared to conventional group methods.     

浅谈在线配粉条件下专用粉质量控制

浅述了在线配粉条件下,通过严格生产管理及改良剂应用等相关措施,控制好专用粉质量的措施.包括落实ISO质量管理体系,加强原料的质量控制和预粉、粉路的测定,生产过程中要注意小麦清理与着水、生产设备和现场管理、员工的技术水平因素等.