Quality assurance of Chinese herbal medicines: Procedure for multiple‐herb extraction

A quality assurance (QA) procedure for multiple‐herb extraction, which takes into account the existence of common chemical markers and multiple‐herb‐extraction effects, has been developed for producing Chinese herbal medicines (CHMs) of consistent quality. The experimental method for determining related correlation function of the multiple‐herb‐extraction effect was designed. A systematic solution strategy was also developed to appropriately decompose the multiple‐herb extraction system into several subsystems for obtaining solution(s) and determining the overall behavior of the system. An example of QA of Danshen–Gegen (DG) decoction was used to demonstrate the QA procedure. An H9c2 cell assay was used to test the efficacy of consistent quality DG decoctions prepared by different herb combinations with different material costs of herbs. It was observed that a multiple‐herb‐extraction effect was present in the aqueous extraction of Danshensu and this effect was depended on the extraction solvent. The possible mechanism of this multiple‐herb‐extraction effect in the aqueous DG extraction was speculated to be the change of initial pH value of the aqueous extraction solvent by an unknown component from Gegen. The experimental chemical marker concentrations fell within ±10% of the specified chemical marker compositions by using the amount of herb from each herb class as predicted by the QA model. Furthermore, an H9c2 cell assay was used to test the efficacy of three consistent quality DG extracts, which were produced by different herb combinations with different material costs of herbs. The results showed that the three DG extracts provided consistent biological efficacy against menadione‐induced toxicity. This study extended a recently developed QA procedure of single‐herb extraction to multiple‐herb extraction. It provides a solution of QA in extraction, which is one of the most important unresolved problems in the modernization of traditional Chinese medicines. With this modified model and the companion experiments, the amount of herbs needed from different quality classes to produce a multiple‐herb formula CHM product decoction with consistent quality can be exactly determined. © 2014 American Institute of Chemical Engineers AIChE J 60: 4014–4026, 2014     

Preparation of anion exchange membrane based on homogeneous quaternization of bromomethylated poly(arylene ether sulfone)

This article presented the synthetic and preparation route of quaternary ammonium functionalized anion exchange membranes (AEMs), which were derived from an engineering plastics polymer, poly(arylene ether sulfone) with 3,3′,5,5′‐tetramethyl‐4,4′‐dihydroxybipheny moiety (PAES‐TM). The benzylmethyl groups on the main‐chain of PAES‐TM were converted to the bromomethyl groups via a radical reaction, thereby avoiding complicated chloromethylation, which required carcinogenic reagents. The chemical structure of the bromomethylated PAES was characterized by ¹H NMR spectrum. Following a homogeneous quaternization with trimethylamine in the solution, a series of flexible and tough membranes were obtained by a solution casting and anion exchange process. The ion exchange capacity values were ranging from 1.03 to 1.37 meq g^?1. The properties of the membranes, including water uptake, hydroxide conductivity, and methanol permeability were evaluated in detail. The AEM showed a high conductivity above 10^?2 S cm^?1 at room temperature and extremely low methanol permeability of 4.16–4.94 × 10^?8 cm² s^?1. The high hydroxide conductivity of TMPAES‐140‐NOH could be attributed to the nano‐scale phase‐separated morphology in the membrane, which was confirmed by their transmission electron microscopy images. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40256.     

基于PLC的燃煤锅炉脱硝控制系统

聚酯生产装置共有5台58 600MJ的燃煤锅炉,为了使锅炉烟气中的NOx达标排放,在烟气排放前增加了脱硝装置,脱硝工艺采用选择性非催化还原法,以S7-300 PLC作为其控制核心,采用WinCC设计操作站的监控和数据采集系统,重点给出了模拟量的输入与转换、PID控制回路和氨水流量累积过程的组态和程序代码。     

封闭王水溶解联合ICP-MS法测定地质样品中痕量金

探讨了采用封闭王水溶解联合电感耦合等离子体质谱法测定地质样品中痕量金的方法。经实验验证,本方法不仅能显著提高金的溶出度,而且操作简便、快速、结果可靠。尤其适用于地质样品中痕量金含量的测定。     

NR/SiO_2复合体系结合胶及动态力学性能研究

研究了白炭黑用量和Si69原位改性对NR/SiO2复合体系结合胶含量及其与动态力学性能之间关系的影响。结果表明,随着白炭黑用量的增大,2种复合体系(NR/SiO2/Si69和NR/SiO2)结合胶含量均呈现先增大后减小的趋势。当白炭黑用量达到临界值时,复合体系结合胶含量最大,此时Payne效应开始显现。当白炭黑用量超过临界值时,复合体系结合胶含量减小,形成完善的填料网络结构,出现明显的Payne效应。与NR/SiO2复合体系相比,NR/SiO2/Si69复合体系结合胶含量大大提高,白炭黑用量的临界值也相应提高,Payne效应减弱。     

发射光谱法测定土壤中的痕量银

在地球化学样品调查工作中,土壤中痕量银的测试是整个测试工作的重要组成部分。以往大多数采用发射光谱法,但离散性较大。通过对实验条件的选择和优化,尤其是对缓冲溶液改进后,各项性能指标有所提高,方法的回收率在96%～105%,检出限为0.018μg/g;对标准样品GBW07401进行11次重复测定,相对标准偏差为6.08%,测量范围为0.050～1μg/g。同时方法改进后,工作成本降低,效率有所提高。     

Flow control with electrode bank arrangements by electrohydrodynamics force for heat transfer enhancement in a porous medium

Active flow control with electrohydrodynamics (EHD) force in the channel flow has been numerically investigated for enhancing heat transfer. This study focuses on the effect of electrode bank arrangements and the number of electrodes on corona wind and fluid flow for heat transfer onto a porous medium. Aligned and staggered configurations of electrode banks are compared. The numerical results show that electric field intensity depends on electrical voltage and the number of electrodes. Shear flow is increased with larger numbers of electrodes and in the aligned configuration, resulting in the enhancement of vortex strength. The swirling flow from staggered configurations spread wider than that of aligned configurations, but the aligned configuration produced more turbulence. In addition, the temperature distribution in the channel flow is increased with increasing numbers of electrodes. With the effect of swirling flow, airflow above the porous sample surface is faster leads the heat to more transfer to the porous sample surface. This causes the temperature of porous medium to increase rapidly so the convective heat transfer coefficient on porous medium surface is increased. Finally, the modified case of the numerical results is validated against the experimental results. The experimental flow visualization is based on the incense smoke technique, in order to verify the accuracy of the swirling flow pattern subjected to the electric field. It is shown that the comparison results in both techniques are in good agreement.     

Selective oxidation behavior of an ignition-proof Mg-Y-Ca-Ce alloy

A Mg-Y-Ca-Ce magnesium alloy was optimized for high ignition-proof property, which did not burn in air at 1233 K up to 30 min. Oxidation behavior of the alloy was investigated by X-ray diffraction (XRD...     

工厂环境下移动智能终端系统的研发与应用

以移动互联网为代表的信息技术在智能制造中发挥着越来越重要的作用,移动智能终端联通了制造流程中各个环节和岗位,使得管理层与一线工人间的沟通变得扁平化,提高了数据获取的实时性和有效性。本文分析了移动智能终端系统在制造行业应用中遇到的问题,诸如与现有系统融合、对工厂环境的适应能力、对软硬件平台的适应能力、信息安全保障等,并提出了完整的解决方案。最后实现了一套用于生产质量和设备管理的移动智能终端系统,并成功在大型离散制造企业实施,提高了企业的生产效率,为移动智能终端在制造业推广提供了经验。