烯基锡化合物的区域和立体选择性合成进展

烯基锡化合物是取代烯烃的重要合成原料和中间体,在有机合成中有着十分广泛的应用.文章综述了区域和立体选择性地合成Z型或E型的烯基锡化合物的方法.     

工程装备的腐蚀与防护对策

叙述了工程装备在不同工作环境中的腐蚀失效形式，详细分析了其大气腐蚀、水介质腐蚀、土壤腐蚀等腐蚀形式产生的原因、腐蚀机理及行为，并从工程装备的选材和结构设计、电化学保护、施加高效防腐涂层等方面入手，制定了相应的防腐技术对策，从而达到提高工程装备使用寿命和可靠性的目的。     

A Study on the Surface Structures of Viscose-based Activated Carbon Fiber by FT-IR Spectroscopy and XPS

Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at temperatures between 450℃ and 900℃ in N_2 artmosphere. Then, in a successive activation stage, the product carbonized at 600℃ was activated in steam at 450-900℃ for 30 min, and at 600℃ for 5-30 min. The other carbonization products were activated at 600 and 900℃ for 30 min respectively. The products activated at 900℃ were then activated at 450℃ for 30 min again. The starting materiah carbonized products and all activation products were examined by FT-IR spectroscopy and some products were examined by X-ray photoelectron spectroscope (XPS). And the yields of the carbonized and activated products were calculated. By analysing these spectra, the amount of oxygen-containing functional groups of the activated products attained under various activation time, various activation temperature and     

Switched Capacitor Network Analysis by Means of TCM

The totally coded method (TCM) reveals the same objective law, which governs the gain calculating for signal flow graph as Mason formula does. This algorithm is carried out merely in the domain of code operation. Based on pure code algorithm, it is more efficient because figure searching is no longer necessary. The code-series (CS), which are organized from node association table, have the holoinformation nature, so that both the content and the sign of each gain-term can be determined via the coded method. The principle of this method is obvious and it is suited for computer programming. The capability of the computeraided analysis for Switched Capacitor (SCN) can be enhanced.     

Meshing Theoretical Study and Simulation on Cylindrical Tri-sine Oscillating Tooth Gear Drive

The structure of cylindrical tri-sine oscillating tooth gear drive is presented. Based on the space meshing theory, equations of meshing and tooth profile are established and its meshing theory is studied. Using Pro/E, this system is modeled and simulated,which is compared with the above-established equations.     

Kinetics of Chlorine Decay in Water Distribution Systems

A combined first and second-order model, which includes bulk decay and wall decay, was developed to describe chlorine decay in water distribution systems. In the model the bulk decay has complex relationships with total organic carbon (TOC), the initial chlorine concentration and the temperature. Except for the initial stages they can be simplified into a linear increase with TOC, a linear decrease with initial chlorine concentration and an exponential relationship with the temperature. The model also explains why chlorine decays rapidly in the initial stages. The parameters of model are determined by deriving the best fitness with experimental data. And the accuracy of model has been verified by using the experimental data and the monitoring data in a distribution system.     

Finite Element Analysis and OADs Optimization of the Temperature in the Plane-strain Orthogonal Metal Cutting Process

IntroductionDuringthemetalremoving process,a greatdealofheatwillbe generatedbythemechanicalworkbeingconvertedintoheatthroughthe plasticdeformationinvolvedduringchipformationandalsoduetofrictionalworkbetweenthetool,chipandworkpiece[1] .Thisheatmaybeveryharmfultothemachine ,toolandtheworkpiecesbeingmachined ,socontrollingthequantityofcuttingheatisaveryimportant probleminmachiningprocess.Overthese years ,manyimprovementsinmanufacturingtechnologiesrequiredinthemodelingandsimulationofmetalcutting p…     

网络文化与高校思想政治教育

在互联网时代,网络文化给高校政治思想教育提供了难得的机遇,但也带来了新的挑战。网络已成为一种重要的思想交流手段,利用好网络,发挥它的积极作用,将成为今后高校思想政治工作的一项重点。     

金属基复合材料的热膨胀

在过去几十年里，研究人员倾注了大量的精力来研究金属基复合材料，取得了很多的成果，热膨胀作为这类材料重要的、基本属性之一也得到了广泛深入的研究，本文主要论述了金属基复合材料的热膨胀研究现状，以及典型的金属基复合材料热膨胀系数模型，并预测了今后的发展方向。     

夫朗和费双矩孔衍射图样的分析

利用Mathematica软件 ,通过夫朗和费衍射公式计算双矩孔的衍射光强 ,并且绘制出了衍射图样 .