基于GPRS的风电并网稳定控制系统

研究了风电场并网存在的稳定问题,针对风电场通信通道的特殊性,研制了基于GPRS的风电场并网稳定控制系统,实现了风电并网的有功潮流和无功电压的综合自动控制.系统应用GPRS实现了如下通信功能:数据缓冲功能、心跳报文功能、自动重拨功能、数据标识功能、软硬件看门狗功能.该系统的主要功能包括:过载切机;低压切机;高频切机;系统运行状态接近稳定极限时,若风机出力波动幅度持续较大,切除风电机组;根据系统关键断面潮流的情况实时调整风机出力的上限;依据风电场并网节点母线电压水平,控制风电场无功补偿设备的投切.最后,介绍了风电场并网稳定控制系统在阜新电网的应用.     

多分辨HHT在STATCOM并补线路故障位置识别中的应用

引入多分辨分析方法对Hilbert-Huang变换(HHT)进行改进:根据信号的特征尺度对信号筛分后进行经验模态分解(EMD)处理,然后对固有模态函数(IMF)分量进行Hilbert变换,求取各分量的瞬时频率和幅值。通过对信号按不同时间尺度进行滤波,有效消除模态混叠;同时对信号进行分段样条拟合,减少计算量。用多分辨HHT方法对含静止同步补偿器(STATCOM)的并补线路保护在稳态和故障暂态时的测量信号以及在不同故障位置时的谐波进行仿真分析,结果表明:STATCOM会使故障时保护安装处的电压谐波含量明显增大;谐波分量的特征与故障回路中是否包含STATCOM有关,故障回路包含STATCOM时特征谐波的幅值很大,否则幅值很小。将该谐波特征用于STATCOM并补线路的故障位置识别,可以自适应地判断故障点的位置,与距离保护相结合,可以有效地解决距离保护用于并补线路时的超越误动和欠范围拒动问题。     

CO2腐蚀数据库的设计和实现

在Microsoft Win XP中文版操作系统支持下，应用Visual FoxPro6.0中文版数据库管理系统设计和实现了一个全中文的综合性腐蚀数据库.库内包括影响CO2腐蚀的各种影响因素的腐蚀数据.数据库功能包括数据编辑、检索浏览、库维护以及打印等功能.使用Visual FoxPro6.0自带的编程语言编制数据库管理系统和用户界面，软件支持环境简单，使用操作简便.      

Q370R压力容器板热处理工艺的研究

论述了Q370R压力容器板的生产工艺,并研究了热处理工艺对Q370R压力容器板性能的影响.结果表明,钢板经870℃×10mm处理后,即可满足性能要求.     

A new method for mining deformation monitoring with GPS-RTK

Based on ranging intersection theory, a new method which is simple and easy to operate was proposed for data collection in the mine surface deformation monitoring with GPS-RTK centering rod measurements. It can fully eliminate the inevitable shaking error and the vertical deflection, and to some extent weaken the multipath effect on the estimates of coordinates in a relatively short period of time, using high-frequency observations. The results show that three-dimensional coordinates with a height accuracy better than 1 cm, horizontal accuracy better than 2-4 cm can be achieved through only 15-30 s continuous observation by 20 Hz high-frequency and effectively improve the measurement accuracy and efficiency of RTK, fully satisfying the high-speed and high-precision data acquisition in mine surface subsidence deformation monitoring.     

国家主权财富基金的投资特点及其对国际货币体系与金融市场的影响

国家主权财富基金按来源可分为两类,一类来源于资源性商品出口所得外汇,一类则是以国家的官方外汇储备转移为基础而建立的.主权财富基金的目的主要有三个:平滑经济周期、分散风险和取得相对外汇储备更高的收益率.主权财富基金的投资组合表现出来的特点是本土性倾向、以北美和欧洲为主要国际投资区域、偏重大盘股和金融行业,并表现出多元化趋势.从其投资和运行特点来看,主权财富基金更可能维持甚至促进现有的国际货币体系的延续,而对金融市场则更有可能产生积极的稳定作用.     

Rainfall Assimilation Using a New Four-Dimensional Variational Method: A Single-Point Observation Experiment

Accurate forecast of rainstorms associated with the mei-yu front has been an important issue for the Chinese economy and society.In July 1998 a heavy rainstorm hit the Yangzi River valley and received widespread attention from the public because it caused catastrophic damage in China.Several numerical studies have shown that many forecast models,including Pennsylvania State University National Center for Atmospheric Research's fifth-generation mesoscale model (MM5),failed to simulate the heavy precipitation over the Yangzi River valley.This study demonstrates that with the optimal initial conditions from the dimension-reduced projection four-dimensional variational data assimilation (DRP-4DVar) system,MM5 can successfully reproduce these observed rainfall amounts and can capture many important mesoscale features,including the southwestward shear line and the low-level jet stream.The study also indicates that the failure of previous forecasts can be mainly attributed to the lack of mesoscale details in the initial conditions of the models.     

Facile Synthesis of Gold Nanoparticle-loaded Carbon Nanofiber Composites and Their Electrocatalytic Activity Towards Dopamine, Ascorbic Acid and Uric Acid

A facile approach for the synthesis of gold nanoparticle-loaded carbon nanofiber(Au/CNF) composites was developed. When applied to electrochemistry, these composites showed attractive performances such as high conductivity and facile electron transfer kinetics. Under physiological conditions, the Au/CNF composite modified electrode exhibits highly electrocatalytic activity for the oxidation of dopamine, ascorbic acid and uric acid. Owing to the good selectivity for the simultaneous detection of these three species, the novel composites are promising for the development of effective electrochemical biosensors.     

Lectin Conjugated Gold Nanoparticle-based Colorimetric Assay for Studying the Interactions of Antibiotic with Living Cell

The interactions of antibiotic with living cells were studied by lectin conjugated gold nanoparticles(GNPs)based colorimetric assay. Because of the high affinity of lectin for saccharides, the lectin conjugated GNPs are able to employ as indicators for monitoring the antibiotic induced changes of glycosyl complexes. The interactions of a well known antibiotiC., tunicamycin, with two different cell lines, HeLa and SHG-44, were selected to establish this assay.In the presence of tunicamycin, the dose-and time-dependence on the decreasing of binding affinity of lectin conjugated GNPs with living cells were demonstrated by conventional microscopic and UV-Vis spectroscopic studies. The experimental result demonstrates that our approach can be used to identify antibiotic induced expression difference of glycosyl complexes on different cellular surfaces and determine drug activity quantitatively. For further confirming the capability of the GNP-based assay, the system was also studied by confocal laser scanning microscopy(CLSM)and classic flow cytometry(FCM) assay, and satisfactory results were obtained.     

Electrochemical analysis of dye adsorption on aligned carbon nanofiber arrays coated with TiO2 nanoneedles for dye-sensitized solar cell

An electrochemical method has been developed to analyze dye absorption on the aligned carbon nanofiber arrays coated with TiO2 nanoneedles for dyesensitized solar cell. The unique nanostructure with the roughness factor of 90.6 provides a large effective surface area for dye adsorption. The experimental results showed that the dye molecules cover 39.7% of the TiO2 surface area which influences the performance of dye-sensitized solar cell. The electrochemical method provides the information of the coverage of dye molecules which is a key issue to optimize solar cell performance.