抗水氧腐蚀致密环境障涂层研究进展

环境障涂层（EBCs）涂敷在碳化硅陶瓷基复合材料（SiC-CMCs）表面,能够有效隔绝发动机腐蚀环境,避免基体的快速腐蚀失效,成为SiC-CMCs材料在航空航天发动机热端部件应用的关键。然而,涂层内不可避免地存在贯通孔隙,导致EBCs在发动机高温水氧环境下快速腐蚀失效。从EBCs材料特性、制备工艺及工艺参数等方面总结了国内外研究进展,阐述了孔隙结构对涂层抗高温水氧腐蚀性能的影响规律,分析了等离子体法制备的涂层中孔隙的形成机制,总结了提高涂层致密性的方法,并展望了获得高抗水氧腐蚀的致密EBCs的后续重点研究方向。     

新一代山梨醇类聚丙烯成核剂及其研发思路

对新一代成核剂Millad NX8000的物化性质、毒理性质进行了介绍,其合成工艺路线是经分子修饰得到的丙基山梨醇与丙基苯甲醛反应而得。通过四代山梨醇成核剂的研发过程研究,提出成核剂的一些研发思路,具体思路是以第四代成核剂分子结构为核心,进行分子结构改造设计,得到刚性结构更强,热稳定性更优的新成核剂品种。     

预应力SWRH82B盘条的生产实践

介绍了邢钢预应力SWRH82B盘条的生产工艺,盘条的化学成分、力学性能、显微组织等均达到了标准要求.     

基于信用透支的公平电子现金交易系统*

综合分析电子现金系统各种模型,针对目前电子现金交易系统存在的问题,提出了基于信用透支的公平电子现金交易协议。采用了多重签名算法,实现了银行与实时交易分离,提高系统的运行效率;并能够在发生经济纠纷时,根据纠纷双方提供的电子证据实施仲裁,保证交易公平性。     

建立稳定系统保证软件质量

软件工程的最直观问题是判定软件开发过程中是否已经出现了质量问题,软件质量量度的选择特别重要,收集哪些数据,如何使用数据一直是个难点.以过去成功项目为基础,提取必要的数据,使之规则化,并以此定义稳定系统的软件质量量度,根据该量度建立项目基线和控制范围,对项目当前状态进行评价,并给出偏差调整方法.本方法具有数据收集简单,操作性强,应用到实际的项目中,对软件质量状况判断比较准确的特点.     

建立稳定系统保证软件质量

软件工程的最直观问题是判定软件开发过程中是否已经出现了质量问题，软件质量量度的选择特别重要，收集哪些数据，如何使用数据一直是个难点。以过去成功项目为基础，提取必要的数据，使之规则化，并以此定义稳定系统的软件质量量度，根据该量度建立项目基线和控制范围，对项目当前状态进行评价，并给出偏差调整方法。本方法具有数据收集简单，操作性强，应用到实际的项目中，对软件质量状况判断比较准确的特点。     

Research on Reverse Recovery Transient of Parallel Thyristors for Fusion Power Supply

In nuclear fusion power supply systems, the thyristors often need to be connected in parallel for sustaining large current. However, research on the reverse recovery transient of parallel thyristors has not been reported yet. When several thyristors are connected in parallel,they cannot turn-off at the same moment, and thus the turn-off model based on a single thyristor is no longer suitable. In this paper, an analysis is presented for the reverse recovery transient of parallel thyristors. Parallel thyristors can be assumed as one virtual thyristor so that the reverse recovery current can be modeled by an exponential function. Through equivalent transformation of the rectifier circuit, the commutating over-voltage can be calculated based on Kirchhoff's equation. The reverse recovery current and commutation over-voltage waveforms are measured on an experiment platform for a high power rectifier supply. From the measurement results, it is concluded that the modeling method is acceptable.     

蚊虫驱避剂驱蚊酯的合成及应用

以丙烯酸乙酯、正丁胺、乙酰氯为原料制备驱蚊酯,收率85%,纯度99.6%;其结构经红外光谱确证;按照GB/T17322.10-1998对产品的驱蚊效果进行了检测,效果理想。     

Study of the EAST Fast Control Power Supply Based on Carrier Phase-Shift PWM

EAST(experimental advanced superconducting tokamak) fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply,which traces the displacement signal of plasma,and excites coils in a vacuum vessel to produce a magnetic field that realizes plasma stabilization.To meet the requirements of a large current and fast response,the multiple structure of the carrier phase-shift three-level inverter is presented,which realizes parallelled multi-inverters,raises the equivalent switching frequency of the inverters and improves the performance of output waves.In this work the design scheme is analyzed,and the output harmonic characteristic of parallel inverters is studied.The simulation and experimental results confirm that the scheme and control strategy is valid.The power supply system can supply a large current,and has a perfect performance on harmonic features as well as the ability of a fast response.