Synthesis and Crystal Structure of RE[CH_2(CH_2)_4CONC_4H_9]_3(NO_3)_3(RE=Dy,La)

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＲＥ［ＣＨ２（ＣＨ２）４ＣＯＮＣ４Ｈ９］３（ＮＯ３）３（ＲＥ＝Ｄｙ，Ｌａ）ＷａｎｇＨａｎｚｈａｎｇ（王汉章），ＸｕＱｉｎｇｆｅｎｇ（徐庆锋），ＱｉａｎＰｕ（钱朴）ＳｕｎＪｉａｎｐｉｎｇ（孙建...     

砷化镓声电荷转移延迟线的设计与工艺研究

由于声电荷转移(ACT)这一新颖的高速缓冲抽样技术的发明,使得新一代高速高频信号处理器件的实现成为可能。本文研究了第二代平面结构的ACT器件转移沟道的电位分布特性,给出了平面结构ACT延迟线的设计,并研究了ACT器件的工艺实现。     

电流模精密整流电路

由电压型运算放大器组成的精密整流电路要严格地匹配电阻才能获得精密全波整流波形．本文给出一种具有CCⅡ电路特性由运算放大器AD844所构成的电流模精密整流电路．无需匹配电阻就可输出良好的精密全波整流波形．且具有输入电压范围大，频带宽等特点．     

近红外仿灸仪的研制与临床应用

近红外仿灸仪,也称为经络灸疗仪,是采用我国传统医学与现代科学技术相结合而研制成的一种新型中医治疗、保健仪器,可以用于治疗多种疾病。本仪器根据艾灸燃烧时所辐射的光谱,运用仿真技术进行模拟,根除了传统灸法燃烧缓慢、效率不高、烟雾较大、刺鼻熏眼、易于灼伤、操作不便等缺点,充分发挥了我国传统灸法的温经通络、补气活血、化瘀消肿,祛湿止痛的功效。     

Embedded deterministic test for low-cost manufacturing

You have probably heard that BIST takes too long and its fault coverage is low, and that deterministic test requires too many patterns. This article shows how on-chip compression and decompression techniques provide high fault coverage with low test times.     

掺杂聚苯胺的表面接枝共聚改性

化学氧化法制备的聚苯胺表面的亲水性差，本文在本征态和不同酸掺杂志聚苯胺的表面上接枝共聚丙烯丙烯酸和丙烯酰胺，明显地改善了聚苯胺的表面亲水性。结果显示，聚苯胺表面经过等离子体处理后，有利于丙烯酸和丙烯酰胺在聚苯胺表面上的接枝共聚，随着接枝量增多，导电率则随之有所下降，此外，利用ＳＥＭ和反射ＩＲ表征了改性反聚苯胺表面的形态和结构。     

项目成功的几个关键原则

从项目和项目管理的定义和概念出发，提出了一个运作成功的项目应该遵循以下几个关键的管理原则。     

Flood frequency and routing processes at a confluence of the middle Yellow River in China

Floods cause environmental hazards and influence on socio‐economic activities. In this study, we evaluated the historic flood frequency at a confluence in the middle Yellow River, China. A non‐parametric, multivariate, empirical, orthogonal function matrix model, which consists of time correlation coefficients of flood discharge at different gauge stations and flood events was used for the analysis of flood frequency. The model addresses the characteristics of confluent floods such as frequency and the probability in multiple tributary rivers. Flood frequency analysis is often coupled with studies of hydrological routing processes that reduce the flood capacity of the rivers. Flood routing to the confluence were simulated using kinematic wave theory. Results of this flood frequency analysis showed that flooding frequency has intensified in the past 500 years, especially during the 19th century. Flooding in streams above the confluence was more frequent than in streams below the confluence. Over the last 2000 years, concurrent flooding in multiple tributary rivers accounted for 67.5% of the total flooding in the middle Yellow River. Simulation of flood routing processes shows that the decreased flooding capacity and elevated river bed of the shrunken main channel leads to an increased flood wave propagation time (24–52.3 h) in the study area after 1995. The model indicates that human activities, such as constructions of the Sanmenxia Dam, have changed flood routing boundary conditions and have contributed to the increased flood frequency at the confluence. Copyright © 2007 John Wiley & Sons, Ltd.     

乙二醇合成工艺的研究进展

对国内外乙二醇合成的传统工艺:直接水合法、催化水合法和碳酸乙烯酯法进行了介绍;对乙二醇合成的新工艺,包括乙二醇和碳酸二甲酯联产法和C1化学法的工艺流程和发展前景进行了综述,其中,C1化学法主要分为乙烯合成法、合成气合成法和甲醛、甲醇合成法。作为合成气合成法之一的合成气偶联合成法,具有工艺要求不高、反应条件温和等优点,是目前最有希望大规模工业化生产乙二醇的工艺路线。     

隔壁精馏塔分离芳烃混合物的模拟研究

采用隔壁精馏塔分离苯-甲苯-对二甲苯物系,用Aspen Plus软件模拟了隔壁精馏塔内温度分布及液相组成分布,考察了汽相和液相分配比对产品纯度的影响。对隔壁精馏塔模拟得到的优化操作条件为:隔壁精馏塔的理论板数为30块,侧线采出在第14块理论板,进料段为15块理论板,在进料段的第7块理论板进料,进料组成n(苯)∶n(甲苯)∶n(对二甲苯)为1∶3∶1,回流比为8.8,液相分配比为2.96,汽相分配比为0.83。在此条件下,各组分的摩尔分数大于98.5%,与实验结果基本吻合。当进料组成n(苯)∶n(甲苯)∶n(对二甲苯)为1∶3∶1时,采用隔壁精馏塔可比常规两塔流程节能27.18%。