紫杉醇C-13侧链的合成进展

(2R,3S)-N-苯甲酰基-3-苯基异丝氨酸是合成抗癌药物紫杉醇的重要原料,它的制备方法反映出手性物质的一些特点和发展方向。本文从化学法和生物酶法两方面综述了该物质的合成方法,并对其中一些有代表性和应用前景的方法进行了重点介绍。     

暂态电压稳定与新型动态无功补偿装置

大型互联电网因缺乏快速动态无功支撑将面临潜在的暂态电压稳定威胁。本文介绍了新一代动态无功补偿器--链式静止同步补偿器(Static Synchronous Compensator,STATCOM)的作用及其与传统的SVC在性能、运行损耗、价格方面的比较,并介绍了我国自行研制的上海西郊变电站±50Mvar STATCOM关键技术、示范工程的建设及运行情况,给出了分相瞬时电流控制的实时仿真结果。     

带有非边界扫描器件的混装电路的扫描链优化配置

在混装电路中,由不同的非边界扫描器件所组成的簇所需要的测试向量的数目可能是不同的,根据不同的簇所需要的测试向量的不同,可以将整个测试过程分为不同的测试阶段,每个测试阶段过后都会有一个或者多个扫描芯片处于bypass状态,而此时其长度只有1,也就是说每一个扫描链的长度是随着测试矢量的移出而变化的,整个扫描链的配置过程中,需要考虑这样两个问题：如何将扫描芯片分配给各条扫描链以及如何排列各条扫描链中扫描芯片的顺序,提出了一种如何配置单链的方法,即优化配置扫描芯片在扫描链中的顺序,这种方法同样可以被应用到多链.     

Irradiated Ch/GG/PVP-based stimuli-responsive hydrogels for controlled drug release

Hydrogels based on gamma (γ) irradiated chitosan (pre-irradiated), guar gum, and polyvinyl pyrrolidone were crosslinked with various concentrations of (3-mercapto propyl)trimethoxysilane and fabricated by solution casting technique for the drug delivery applications. High molecular weight chitosan (Ch) possesses lower solubility and higher viscosity, these problems overcame by γ irradiation, which also generated hydrophilicity and effect of irradiated Ch on controlled drug release was assessed. FTIR analysis showed the development of chemical and physical interactions and confirmed the incorporation of characteristic peaks. SEM micrographs revealed porous structure of the prepared hydrogels. Swelling analysis of the hydrogels was performed in distilled water, buffer, and electrolyte mediums. All the hydrogel samples showed higher swelling at acidic pH and lower swelling at neutral and basic pH. These pH-responsive characteristics made these RCGP hydrogels an important contender for injectable controlled drug release. The ampicillin sodium drug was loaded and in vitro controlled release mechanism was evaluated in the PBS, SIF, and SGF which shown out of all prepared hydrogels (RCGP-1, RCGP-2, and RCGP-3), RCGP-1 has exhibited 87.4% release in PBS and 81.3% in SIF in 180 min.     

复杂环境下的深基坑钻爆实践

阐述了深孔台阶控制爆破结合谨慎爆破技术在复杂环境深基坑开挖工程中的应用及相应的减震工艺;通过对爆破施工全过程的跟踪监测,证实减震措施是非常有效的。在保证电厂、油库及支护管桩安全的同时,大大加快了工程进度,可供类似工程参考。     

An investigation into the antiwear,antioxidation, and anticorrosion behaviour of some derivatives of 2,5-dimercapto -1,3,4-thiadiaxole

It appears that the comprehensive performance of 2,5-dimercapto-1,3,4-thiadiazole derivatives is dependent upon both the type and the structure of the chains attached to the carbon atoms in the 2 and 5 positions of the thiadiazole ring. For the side chain of the monosulphide type R-S-, the type and location of substituents have an important influence on additive performance. In the case of the side chain of the disulphide type, X-SS-, the presence of the phosphorus-containing group has a significant effect on multifunctionality.     

一种面向边缘环境的多实例服务链在线部署算法

边缘设备的资源有限性促使部署边缘服务需要深入理解网络功能的资源消耗情况.通过无线路由器上容器化网络功能部署实验得出,除了处理业务流的计算开销外,网络功能实例间的通信也会消耗大量CPU资源.基于该发现,考虑在近距离和相对低负载的对等边缘设备上分布式地部署网络功能实例,在满足时延约束的条件下均衡流量,从而最小化边缘设备负载...     

两性疏水改性瓜尔胶的实验研究

在溶解性良好的阴离子瓜尔胶(MAG)基础上引入自制的水溶性阳离子疏水长链单体,赋予其动态物理交联及静电桥作用,形成一种两性疏水瓜尔胶(MAG-N22).室内实验表明,MAG-N22有更高的黏度,0.6％达到114 mPa·s,明显高于瓜尔胶原粉(GG)与MAG.MAG-N22微观网络结构测试显示0.4％,0.5％ 水溶...     

SCANGIN:一种降低扫描测试中动态功耗的方法

通过调整扫描链上扫描单元顺序与逻辑门插入相结合,以减少扫描移入阶段扫描链上不必要的状态跳变,从而达到降低测试中电路动态功耗的目的．在ISCAS’89基准电路上进行的实验表明,该方法最多能将扫描移入阶段峰值功耗降低94．5％,平均功耗降低93．8％,而面积开销可以忽略不计．     

服务供应链深度优先扩散构建算法

用服务关系网刻画服务实体问服务关系的耦合情况;然后论述了计算服务链数量的定理并证明;最后提出在赋权服务关系网中的服务供应链深度优先的扩散构建算法,分析了算法的最坏时间复杂性。