Lactic acid production from dining‐hall food waste by Lactobacillus plantarum using response surface methodology

BACKGROUND: Food waste generally has a high starch content and is rich in nutritional compounds, including lipids and proteins. It therefore represents a potential renewable resource. In this study, dining‐hall food waste was used as a substrate for lactic acid production, and response surface methodology was employed to optimise the fermentation conditions. RESULTS: Lactic acid biosynthesis was significantly affected by the interaction of protease and temperature. Protease, temperature and CaCO₃ had significant linear effects on lactic acid production, while α‐amylase and yeast extract had insignificant effects. The optimal conditions were found to be an α‐amylase activity of 13.86 U g^?1 dried food waste, a protease activity of 2.12 U g^?1 dried food waste, a temperature of 29.31 °C and a CaCO₃ concentration of 62.67 g L^?1, which resulted in a maximum lactic acid concentration of 98.51 g L^?1 (88.75% yield). An increase in inoculum size would be appropriate for accelerating the depletion of initial soluble carbohydrate to enhance the efficiency of α‐amylase in dining‐hall food waste fermentation. CONCLUSION: A suitable regression model for lactic acid production was developed based on the experimental results. Dining‐hall food waste was found to be a good substrate for lactic acid fermentation with high product yield and without nutrient supplementation. Copyright © 2008 Society of Chemical Industry     

基于VHDL实现单精度浮点数的加／减法运算

研究了单精度浮点数加／减法的结构及其设计方法，并在Aldec公司的Active—HDL软件环境下，采用VHDL语言进行设计，并进行了仿真验证，计算精度可以达到10^-7。     

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.     

关于传统与现代设计理念的思考

中国传统的思维方式深深地影响了中国传统陶瓷艺术设计，中国传统陶瓷艺术设计的历史脉络清晰，深入到设计思维系统的深层，才有助于我们对当前的陶瓷设计作出有效的转化。现代陶瓷设计的观念是对传统陶瓷文化的延续和发展，深入挖掘传统思维方式的源头活水，才是发展中国现代陶瓷设计的关键。     

百色盆地林蓬浅层稠油油藏热采开发的可行性研究

百色盆地林蓬油藏为一浅、薄、低产、低渗的普通稠油构造油藏。通过对油藏特征、原油热物性、热采数值模拟初步分析及热米开发经济效益的初步评价，认为林蓬油藏利用我国现有的热采技术投入开发具有可行性，并提出了具体实施方案和工作意见．     

提高E^2PROM中NMOS管源漏穿通电压的实验研究

为了提高Ｅ＾２ＰＲＯＭ中Ｎ管源漏穿通电压，用实验的方法对制造工艺进行了研究。结果表明，高能量注入是提高ＶＰＴ的有效手段，但受到ｐｎ结击穿的限制，只适用于低区短沟Ｎ管；ＤＤＤ工艺大幅度高ＶＰＴ，但ｐｎ结击穿电压低于２０Ｖ，不能应用于高压ＭＯＳ管；采用适量的防穿通注入和适当增大沟道长度为最理想的工艺途径。     

控制棒钴吸收体的活度分布

应用单组中子微扰理论,对辐照后控制棒钴吸收体内活度分布进行理论分析,得到活度分布计算的解析表达式。对高通量工程试验堆(HFETR)首次出堆的2根控制棒钴吸收体进行数值计算。利用钴靶活度水下测量装置进行这2根钴吸收体活度分布的实验测量。计算与实验测量结果相符。通过理论计算所得到的活度分布可作为辐照后~(60)Co同位素分装依据。本文得到的控制棒相对价值曲线理论计算值与实验测量结果符合良好。