火电机组高压抗燃油系统检修及缺陷处理

目前大、中型汽轮发电机组,广泛采用以抗燃油为液体工质的数字电流调节系统(DEH系统),高压抗燃油系统(EH系统)是汽轮机DEH系统的重要组成部分,根据DL/T 838《发电企业设备检修导则》电力行业标准的要求,EH系统为A类设备,并按A级检修项目定期进行大修.EH系统较为庞大,设备类型较多,专业性较强,通过大修可恢复功能、消除缺陷,确保机组安全、稳定运行.     

高校岗位绩效考核信息管理系统设计与实现

高校岗位绩效考核管理涉及的数据量大、流程较多,设计开发了支持其网上运行的缋效考核信息管理系统,实现了岗位绩效管理信息存储处理和全流程控制,满足了高校发展战略和人力资源配置的辅助分析决策需要.     

新型巷道堆垛式立体车库的虚拟设计

提出了一种新型巷道堆垛式立体车库的方案,阐述了其工作原理及存取车过程.运用模块化的设计思想,将车库分为提升机、堆垛机及泊车位三大模块,分别在Solidworks里进行了建模,并组装成虚拟样机.以所存车辆的长、宽、高为原始参数,对虚拟样机进行参数驱动,最终完成了立体车库的虚拟设计,缩短了设计周期,提高了设计效率和可靠性.     

机械装备构件轻量化主要技术途径的探讨

在对机械装备构件轻量化的基本原则和主要技术依据进行概括的基础上,就机械装备构件轻量化强度设计技术进行探讨,分别在简单拉伸、弯曲、扭转、疲劳等受力状态下,对简单形状构件轻量化强度设计判据进行分析,并进一步得到构件轻量化强度设计通用判据;对铁、钛、铝、镁、钴等金属基体合金轻量化性能指标进行比较,并进一步提出逐步建立构件轻量化材料性能指标体系的设想;对机械装备构件轻量化成形工艺和表面改性技术的作用进行概括,并提出通过工艺技术提高构件材料的强度(或屈服强度)、提高构件截面形状的抗弯截面系数(或抗扭截面系数)、提高表面层材料的强度(或屈服强度)和改变构件表面为压应力状态等工艺途径来达到构件轻量化目的。     

吉沙水电站低压引水隧洞围岩地质条件分析

在吉沙水电站低压引水隧洞开挖过程中,根据实际揭露的围岩性状,及时对围岩分类进行调整,为引水隧洞安全施工及优化设计提供了可靠的地质资料。电站多年运行实践表明,地质人员对该隧洞围岩工程地质条件分析与实际情况基本吻合,对围岩类别的划分及地质参数的建议值是合理的。     

A Comparative Study of the Performance of Public Water Rights Allocation in China

Pubic water rights allocation, in which water resources are allocated to users administratively as shared public property, is an effective and powerful policy for water resource management. Dozens of public water right allocation systems have been established in China since 1998 without any unified standard across the country. An indicator-based assessment approach, based on equity, efficiency and sustainability, is proposed in this study to evaluate the performance of public water rights allocation systems in China in a quantitative way. The approach was applied in 11 river basins of China in which water rights have been defined. The results show that the performance of the allocation systems depends on the spatial density and exploitation ratio of the water resources. The performance of allocated water rights systems is better in river basins with greater resource densities and smaller water exploitation ratios. This assessment approach is very useful for evaluating policy options for public water rights allocation with appropriate consideration of the local conditions of the river basins.     

Development of a compact filament-discharge multi-cusp H- ion source

A 14 MeV medical cyclotron with the external ion source has been designed and is being constructed at China Institute of Atomic Energy. The H(-) ion will be accelerated by this machine and the proton beam will be extracted by carbon strippers in dual opposite direction. The compact multi-cusp H(-) ion source has been developed for the cyclotron. The 79.5 mm long ion source is 48 mm in diameter, which is consisting of a special shape filament, ten columns of permanent magnets providing a multi-cusp field, and a three-electrode extraction system. So far, the 3 mA∕25 keV H(-) beam with an emittance of 0.3 π mm mrad has been obtained from the ion source. The paper gives the design details and the beam test results. Further experimental study is under way and an extracted beam of 5 mA is expected.     

Characterizing natural dissolved organic matter in a freshly submerged catchment (Three Gorges Dam, China) using UV absorption, fluorescence spectroscopy and PARAFAC

This study applied parallel factor analysis (PARAFAC) to fluorescence excitation-emission matrices (EEMs) of natural water samples in a freshly submerged catchment in the upper reach of Three Gorges Dam (China). Two fluorescent natural dissolved organic matter (NDOM) components (humic/fulvic-like) were uncovered and were positively correlated with selected water quality parameters, i.e. dissolved oxygen concentration, dissolved organic carbon concentration, dissolved Kjeldahl nitrogen concentration and total (dissolved plus particulate) phosphorus concentration, respectively. To other water quality parameters (i.e. total nitrogen, particulate nitrogen, particulate phosphorus, dissolved phosphorus, dissolved nitrate, pH, and chemical oxygen demand), either the two components did not show any correlation or only one component showed correlation. In particular, particulate N correlated significantly to the fulvic acid, but not to the humic acid. Meanwhile, two conventional spectroscopic indices i.e. specific UV absorbance at 254 nm (SUVA254) and fluorescence index (FI) indicated that the whole NDOM in the waters were low in aromaticity and predominantly derived from aquatic microbial processes. Given together, it concludes that N and P did not function equally in the NDOM production, and the two components were not derived from the same microbial processes. The EEMs-PARAFAC has proven to be of potential as an effective tool in investigation of the interlink between NDOM and nutrients which may be utilized as an indicator of water environment.     

黑龙江省水田发展北扩战略研究

从黑龙江省北部地区种植结构调整、农民增产增收以及为黑龙江省水田发展谋取新的增长空间出发,在黑河市爱辉区高寒高纬度水田种植试验取得成功的基础上,提出在第四、第五积温带进行水稻种植的条件完全具备,确定了水田北扩的范围为北纬48°~51°之间的黑河市6个县区、大兴安岭的呼玛三卡地区和伊春市的嘉荫县,并提出了水田北扩的初步设想。     

IEEE802.11p下删余卷积编码译码方法的研究

应用于智能交通系统的无线接入协议IEEE802.11p,其物理层卷积编码的码率可通过对(2,1,7)卷积编码器的删余来实现。讨论了删余位置的图案和算法,分析了在删余位置插入不同哑元时维特比译码后误码率的统计特性。仿真的同时比较了固定哑元下不同码率所引入的误比特率。