Degradation of indole in aqueous solution using contact glow discharge plasma

Exhaustive indole oxidation in aqueous solution was studied using contact glow discharge plasma. The results indicated that the rate of indole degradation increases with the decrease in the solution conductivity. The degradation rate can be enhanced under the following situations. First, the increase in temperature. Second, introduce active carbon and hydrogen peroxide to the solution. Third, the degradation process is performed in alkaline or acidic media rather than the neutral media. Fourth, add Fe²⁺ to solution to undergo Fenton’s reaction. However, n-butanol was found decelerate the degradation of indole. Some major intermediates produced during the degradation were detected by using both HPLC and GC-MS.     

MATLAB PSB在电力系统暂态稳定中的仿真应用

运用MATLAB电力系统仿真程序SimPowerSystems构建了一个单机—无穷大系统模型,并在此基础上对电力系统稳定器、快速切除故障、故障限流器、单相自动重合闸等提高电力暂态稳定性措施的运行效果进行了仿真分析,可供师生在电力系统暂态分析课程教学过程中参考。     

胶结充填材料的强度特性与强度设计(Ⅲ)——胶结充填材料的强度特性

本文对低强度的胶结脱泥尾砂充填材料的特性,包括其力学模型、本构关系、破坏准则以及影响强度特性的主要因素等,在实验室实验的基础上进行了较为深入的研究,并得出了一些实用的重要结论。     

办公建筑的照度测量及分析

针对某些建筑后期装修与前期照明设计差异很大的问题,笔者通过对某办公建筑的两个典型房间进行实例照度分析,在对照度值和照明功率密度的对比分析中找出后期装修中存在的问题,并提出相应的对策.以期达到合理进行照度装修设计,节约能源的目的.     

矩形钢筋混凝土接地网地面电位的计算

用矩量法计算埋在二层土壤中含水平钢筋的矩形钢筋混凝土接地网在地面上产生的电位,并绘制地面电位、接触电压、跨步电压的三维分布图。由跨步电压分布图可见,钢筋混凝土接地网的跨步电压可能会产生2个峰值,一个在混凝土内部钢筋地网外部的边角附近;另一个在矩形混凝土外部的边角附近。文中给出的2个钢筋混凝土接地网的例子,跨步电压最大值均发生在混凝土外部的边角附近。对有混凝土的接地网,需同时考虑钢筋地网及混凝土外部附近地面上均可能存在跨步电压峰值,这2处地方应加强安全措施。     

乙烯装置急冷油系统减粘技术的研究

基于乙烯装置急冷油和急冷系统结垢物的组成分析，探讨了急冷油增粘和系统结垢的机理．研究了适用于急冷油系统的新型减粘剂RIPP-1420和减粘剂的注入技术。结果表明，RIPP-1420减粘剂和该注入技术能有效降低急冷油系统物料的粘度，减少结垢物的生成。     

Evaluation of the in vitro and in vivo performance of two sustained-release lithium carbonate matrix tablets. Effect of different diets on the bioavailability

Two sustained-release (SR) lithium carbonate (Li) matrix tablets, which use a hydrophilic (HP) matrix of hydroxypropylmethylcellulose (Methocel 4K MP) and a lipid (L) matrix of hydrogenated castor oil (Cutina HR) as sustaining agents, have been studied. In vitro performance through dissolution tests in different media was established. The L and HP formulations were affected by the composition of the dissolution media, and liberation was complete in 8 hr using a variable-pH medium that simulates the gastrointestinal (Gl) pH. Liberation was better described by the diffusional model of the square root of time for the L matrix and by zero-order kinetics for the HP matrix. Absolute bioavailability (BA) and food-induced changes on BA of both formulations were studied. The in vivo study design was a 4 x 4 Latin square involving 12 subjects who received two tablets of a 300-mg dose of SR formulations while fasting or with a standardized normal, high-fat, or high-fat/high-protein meal. The results for both formulations showed no differences in the disposition parameters and mean residence time when the tablets were administered with any type of diet. Changes in rate of absorption were found when both types of tablets were administered with any class of diet. The analysis of the ratio Cmax/AUC (area under the curve) evidenced that changes in Cmax were attributable to a higher rate of absorption for the HP matrix and to a higher amount absorbed for the L matrix. In the last, high-fat and high-fat/high-protein diets produced higher AUCs than under fasting condition. The SR Li tablets formulated with hydrogenated castor oil were affected more by high-fat food, probably because of the increase of pancreatic and biliary secretions promoted by the meal, which would affect the matrix itself. The HP matrix was also affected, but to a lesser extent. The magnitude of the change in Cmax observed with this matrix probably is not important from a clinical point of view. Absolute BA was very low for the lipid matrix; in addition, since it is more seriously affected by food, probably it is not a good choice for a drug such as lithium. The in vivo behavior of the HP matrix makes it advisable to invest in efforts to achieve increased BA. Comparing in vitro and in vivo results, the focus should be achieving sustained, but complete, in vitro liberation in not more than 3 hr, with simulation of the transit time through the stomach and small bowel since lithium ion is only absorbed to this point.     

Efficient Euclidean projections via Piecewise Root Finding and its application in gradient projection

Recently, the gradient (subgradient) projection method, especially by incorporating the idea of Nesterov's method, has aroused more and more attention and achieved great successes on constrained optimization problems arising in the field of machine learning, data mining and signal processing. In the gradient projection method, a critical step is how to efficiently project a vector onto a constraint set. In this paper, we propose a unified method called Piecewise Root Finding (PRF) to efficiently calculate Euclidean projections onto three typical constraint sets: ?₁-ball, Elastic Net (EN) and the Intersection of a Hyperplane and a Halfspace (IHH). In our PRF method, we first formulate a Euclidean projection problem as a root finding problem. Then, a Piecewise Root Finding algorithm is applied to find the root and global convergence is guaranteed. Finally, the Euclidean projection result is obtained as a function of the found root in a closed form. Moreover, the sparsity of the projected vector is considered, leading to reduced computational cost for projection onto the ?₁-ball and EN. Empirical studies demonstrate that our PRF algorithm is efficient by comparing it with several state of the art algorithms for Euclidean projections onto the three typical constraint sets mentioned above. Besides, we apply our efficient Euclidean projection algorithm (PRF) to the Gradient Projection with Nesterov's Method (GPNM), which efficiently solves the popular logistic regression problem with the ?₁-ball/EN/IHH constraint. Experimental results on real-world data sets indicate that GPNM has a fast convergence speed.     

On Constrained MMVC of Discrete‐Time First‐Order Linear Stochastic Systems with PSI I: The Critically Stable Case

This paper is devoted to the study of the modified minimal variance control (MMVC) of discrete‐time first‐order linear critically stable stochastic systems with prospective strong intervention (PSI) and control input constraints. Due to different evolutionary characteristics of systems with PSI, that is, the two modes of tending to infinity and having bounded oscillations, the discrete‐time first‐order linear critically stable systems can be partitioned into two types regarding the signs of a key system parameter a. A necessary and sufficient condition for the state mean convergence of a system with a = 1 is derived and the corresponding design of MMVC is formulated. For the critical stable system with a =? 1, its oscillation amplitudes of state means can be effectively suppressed or the means can converge under control. Finally, the effectiveness and advantages of the proposed control strategies comparing with MVC are confirmed by numerical simulations.     

分布式数据库数据复制技术的分析与应用

本文在分布式数据库系统的基础上，针对分布式数据库的数据存储方式进行了概述，细致地讲述了分布式数据库复制技术的几个关键内容，对Oracle、Sybase、SQL Server数据库的复制技术(方案)进行了综合分析比较，并结合实践经验提出了复制技术的方案选择策略，对复制技术的发展进行了展望。