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.     

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。     

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.     

电液比例控制技术在工程船舶中的应用

以长江及沿海航道铺排工程船(长雁1号)液压系统的工程项目为背景,采用电液比例控制技术设计了一种新型的电液比例控制系统,通过对移船马达速度的控制实现了移船的移位和准确定位,同时液压系统的能耗也大大降低.     

Experimental Study on Energy Consumption of Combined Conventional and Dehumidification Drying

Conventional drying, dehumidification drying, and combined conventional-dehumidification drying of wood were experimentally studied in this article. The results showed that the energy consumption in the dehumidification drying is the least but its drying time is the longest. The energy consumption in the combined drying is more than that in the dehumidification drying but less than that in the conventional drying, and the drying time is half of that in the dehumidification drying. The advantages of the combined conventional and dehumidification drying are discussed from the experiments results.     

Study of the Mössbauer effect on rare-earth borided surface layers on pure iron

Journal of Materials Science Letters -     

用于氢化的铜铬氧化物催化剂的研究

通过铜铬氧化物催化剂用于豆油的选择氢化,研究了制备方法及氢化条件对催化剂活性的影响.在所用的五种催化剂中,以Adkins法制备的催化剂活性最好,碳酸氢铵法次之.文中还对催化剂焙烧气氛、焙烧温度、焙烧时间、铜铬原子比对催化剂活性的影响以及氢化温度、催化剂用量、搅拌速度、氢流速等对反应的影响进行了较详细的讨论.