Two New Butenolide Derivatives from Erigeron acer

IntroductionThe genusErigeron(Compositae)is widelydistributed in Asia,North America and Europe.Thereare about35species distributed in China,some ofwhich have a long history of application in Chinese folkmedicine[1].Sesquiterpenes have been reported as the…     

Pulse Plating of Zn-Co Alloy Coatings

Pulse plating of Zn-Co alloys was studied using square pulse containing reverse current.The surface morphologies of Zn-Co alloy deposits were examined using scanning elecron microscopy （SEM）, and an attendant energy dispersive X-ray analyzer （EDA） was used to analyze the composition of Zn-Co alloy deposits. Results obtained showed that the average current density and reverse current density amongst all the variables investigated had very strong effects on the cobalt content and surface morphologies of Zn-Co alloy deposits. It is possible to elecrodeposit Zn-Co alloy coatings with a very wide cobalt content range of 10-90 wt% by modulating pulse parameters.     

THE ADSORPTION BEHAVIORS OF 2,6-DICHLOROPHENOL ONTO HYPERCROSSLINKED RESINS

1. INTRODUCTION Chlorophenolic compounds are very toxic, and many are known or suspected human carcinogens. They have been widely used for many industrial purposes. The removals of chlorophenols are of high industrial and environmental interest [1~2]. The adsorption resin is another adsorbent widely employed for isolation and purification of organic substances, treatment of wastewaters, solid phase extraction, and so on. A variety of materials has been developed and tested, such as Amber…     

Electrokinetic control of fluid in plastified laser-printed poly(ethylene terephthalate)-toner microchips

The application of plastified laser-printed poly(ethylene terephthalate)(PET)-toner microchips to capillary electrophoresis was investigated. Electroosmotic flow was observed in the direction of the cathode for the buffer system studied (phosphate, pH 3–10). Average electroosmotic mobilities of 1.71×10^–4 to 4.35×10^–4 cm² V^–1 s^–1 were observed from pH 3 to 10. This variation suggests that silica fillers in the toner and on the surface of the polymer dominate the zeta potential of the material, which is also confirmed by XPS measurements. Dopamine and catechol were used as model analytes for microchip electrophoresis in combination with electrochemical detection. Results show that these two analytes can be efficiently separated and detected electrochemically with the plastified laser-printed PET-toner microchips.     

基于消息传递接口的空中爆炸问题的并行计算

研究了用于处理三维多物质欧拉网格的模糊界面技术以及算法存在的数据相关性问题,提出了解决数据相关性的方法。采用基于消息传递接口(MPI)模式,设计出了相应的MMIC-3D并行程序,得到了无限空气介质中爆炸的三维数值模拟结果,计算结果与实际的实验现象及规律基本吻合。在共享存储的全对称多处理机(SMP)上进行了测试,得到了理想的加速比。     

西昌经久工业园区环境现状监测研究

以国标法为检测标准,对西昌经久工业园区区域地表水、环境空气主要污染指标进行检测与监测。通过现场监测、室内分析和数据处理表明:西昌经久工业园区区域地表水、环境空气主要污染指标达到国家环境要求。     

基于层次分析法的战时气象资料质量评估

采用层次分析法(Analytic Hierarchy Process,AHP),以战时气象资料的及时性、准确性、可用性、全面性、相关性和连续性等6项指标建立战时气象资料质量评估层次结构模型,构造出两两判断矩阵,并以3个气象台提供的不同气象资料为例,通过进行层次单排序及一致性检验、层次总排序及一致性检验,最终得出质量最佳的气象资料.通过气象资料质量的综合评估,为气象台及时、全面地发现组织气象观探测、预报保障、装备性能与维护、信息传输网络等方面的问题,以及为针对问题采取相应的对策提供指导,也为战时气象资料质量的提高程度的评价提供量化依据.     

一类不确定非线性系统的多约束鲁棒H∞控制

针对一类不确定的T-S模糊模型,给出了反馈控制器存在的充分条件,该控制器使得闭环极点被配置在给定的线性矩阵不等式(LMI)区域内,同时满足系统对H∞范数和方差约束的要求.基于这一条件和并行分布补偿技术(PDC),借助于LMI和凸优化方法,得出一个全局鲁棒H∞控制器的解析式.最后,通过一个仿真例子,说明该方法的可行性.     

基于超声分子束和普通充气的聚变等离子体密度反馈实验研究

本文介绍了全超导托卡马克装置EAST实验中等离子体密度反馈的方法和结果. EAST密度反馈采用普通充气 (gas puffing) 和超声分子束 (supersonic molecule beam injection, SMBI) 在放电过程中反馈进气, 获得稳定、预期的等离子体密度. 典型的一天放电实验中, 每次放电的充气量和壁滞留的变化可分为两个阶段: 第一阶段为初始约20次放电, 该阶段充气量非常高且呈指数趋势下降, 粒子滞留率为80%–90%, 壁滞留迅速上升. 第二阶段为随后的约50次放电, 该阶段充气量较小且保持稳定, 粒子滞留率为50%–70%, 壁滞留缓慢上升. SMBI的加料效率为15%–30%, 延迟时间小于5 ms. 因此使用SMBI 进行密度反馈效果优于gas puffing反馈, 相同条件下前者充气量较后者减少了～ 30%, 壁滞留减少了～ 40%, 再循环系数也相应减少. gas puffing反馈时, 采用脉宽调制模式效果优于脉幅调制模式. SMBI密度反馈可以作为未来EAST长脉冲高参数放电的主要手段之一. 关键词： 密度反馈 超声分子束 再循环 壁滞留     

制造商检验的最优质量水平及影响因素研究

为提高我国食品质量安全水平,对小型、分散的单个供应商和一个制造商构成的食品供应链中,制造商对原材料和最终食品进行质量检测的情况,建立了以供应商和制造商各自的质量水平为决策变量的优化模型,分析了最优质量水平的影响因素和影响效应.并依据结论提出相应建议,如提高消费者对优劣食品的识别能力,发挥制造商在供应链中的监督检验作用等.