一种结构动力学分析的实用方法(英文)

本文把多自由度线性动力系统的传递函数(TF)及脉冲响应函数(IRF)[1]*之间的关系简化为公式(3)、(4)*形式.对于由基础(其传递函数Ho已知)和两个质量块(其中一个与基础刚性连接,另外一个弹性连接,见图1及公式6)组成的系统,本文推导了系统的设计公式.为了展示这种方法的应用,本文利用了不同的传递函数Ho值分析了在脉冲载作用下若干种结构支力分析问题,这些结构包括具有及不具有基础隔震的系统(图1;公式(3);(6)*)、位于地基上的具有隔震装置的板.利用这种方法不需要振型展开,从而不需要求固有振型及不需要进行标准化.*表示参考本文的参考文献     

Thermal analysis of the cryostat feed through for the ITER Tokamak TF feeder

In Tokamaks,the toroidal field (TF) coil feeder is an important component that is used to supply the cryogens and electrical power for the TF coils.As a part of the TF feeder,the cryostat-feed through (CFT) is subject to low temperatures of 9 and 80 K inside and room temperature of 300 K outside.Based on the features of the International Thermonuclear Experimental Reactor TF feeder,the thermal performance of the CFT under the nominal conditions is studied.Taking into account the conductive,convective and radiation heat transfer,the finite element model of the CFT is built.Transient thermal analysis is performed to determine the temperatures of the CFT on the 9th day of cooldown.The model is assessed by comparing the cooling curves of the CFT after 9 days.If the simulation and experimental results are the same,the finite element model can be considered as calibrated.The model predicts that the cooling time will be approximately 26 days and the temperature distribution and heat load of the main components are obtained when the CFT reaches thermal equilibrium.This study provides a valid quantitative characterization of the CFT design.     

Test and Analysis of China's First Short Conductor Sample for ITER Toroidal Field Coils

In the framework of the ITER Qualification Tests, the first China TF conductor sample (CNTF1) was tested at the SULTAN facility. The sample was made of two TF conductor sections manufactured from identical internal stannum strands provided by the Oxford Superconducting Technology Company (OST). In order to evaluate the conductor performance, the current sharing temperature (Tcs) was measured at specified electromagnetic load cycling steps. Both conductor sections of the CNTF1 sample showed identical performance. Tcs was 7.2 K before cycling loading, and 6.9 K even after 950 cycles, without significant degradation, which substantially exceeds the ITER requirement of 5.7 K. The tests of the CNTF1 conductor sample showed that the electromagnetic cyclic load exhibited a negligible effect on the conductor performance. The coupling time constant for AC loss was 214 ms and 71.52ms before and after the cycling load, respectively. The test results of the sample are compared with the strand performance and parameter model analysis.     

TF Desba控制系统在热网自控工程中的应用

介绍了TF Desba控制系统的特点、基本功能、硬件结构及其在集中供热热网自控工程中的应用状况。     

用于TF/TA仿真试验的数字地形模型研究

采用数字仿真方法进行TF/TA实验时,需要生成飞行器在实战中可能遭遇到的各种真实地形场景。为了借助计算机模拟方法产生所需各种复杂多变的数字高程模型,提出了改进分形几何法和数学函数法来自动生成数字地形模型的方法。前一种方法可以根据需要控制地形的光滑度,可以为视景仿真系统提供具有细部特征的真实感地形;第二种方法产生的几种典型地形突出了不同地域的地形特点,多用于TF/TA算法的验证。大量的仿真结果说明了这些方法的可行性。     

基于时频单源点的欠定混合矩阵估计

主要研究了欠定盲源分离中的混合矩阵估计问题。提出了一种检测时频单源点的新方法,通过比较归一化的观测信号时频点的实部和虚部向量来检测时频单源点。与其他时频单源点检测方法相比,该方法简单而有效,同时降低了对检测条件的要求。采用K-means方法估计混合矩阵,通过去除聚类后每一类数据中偏离中心方向较远的数据点,进一步提高了混合矩阵的估计精度。仿真实验表明,与已有欠定混合矩阵估计算法相比,提出的方法有更高的估计精度。     

XML数据的查询技术

XML规范已成为当前网络应用(包括数字图书馆、Web服务以及电子商务)中事实上的数据表达、交换的标准.针对XML数据的查询在当前XML数据管理研究中占有重要的地位,也是当前XML数据处理研究领域的热点方向,相关的研究文献有很多.根据查询模式描述的不同,将当前XML查询技术归入两大类:XML Query方式和XML IR方式.后者又进而可分以为3个子类:XML IR/keyword方式、XML IR/fragment和XML IR/query方式,并从中挑选出3个研究者关注的问题进行了简述,它们是:Twig查询模式的处理、SLCA(smallest lowest common ancestor)节点的获取以及对所获取的XML片段相似性的度量.以方便普通用户使用为准则探讨了相关XML查询技术的优、缺点,将如下4个问题作为需要进一步关注的研究内容:结构化关键字查询及相应的结构相似性度量方法,如何消除XML Query查询处理模式(包含XML IR/query)和XML IR/keyword查询处理模式间数据冗余的问题,XML Query查询方式的理论探讨及其实现以及针对特定应用的XML数据的有效管理.     

Deep Web下基于中文分词的聚类算法

随着Deep Web飞速的发展,使用商业网站上所提供的查询接口从Web数据库中获取高质量数据并对这些数据进行分析加工处理显得尤为重要。通过动态提交关键词,利用查询接口得到检索页面,对检索页面中的中文信息进行抽取并进行分词处理,对分词的结果进行统计分析,通过引入DF进行降维得到特征项,使用TF/IDF计算得到特征项的权重向量矩阵,对权重矩阵进行聚类从而实现文档的分类。通过仿真实验检验了本算法的合理性和可行性。     

Fabrication of new joints for SST-1 TF coil winding packs

The Toroidal Field (TF) magnet system of SST-1 has sixteen NbTi/Cu based coils with about one hundred Inter-Pancake (IP) and Inter-Coil (IC) joints. New box type helium leak tight, low DC resistance joints have been designed, fabricated and tested at 5 K temperature and 10 kA DC transport current. The prototype of this joint has been validated in laboratory as well as on spare TF coil winding pack. Moreover, the performance of these joints has been realised and validated on actual sixteen TF winding packs, the joint resistance of ～0.5 nΩ repeatedly measured on hundreds of IP joints. The quality of terminations and joints was ensured at various stages of fabrication. The quality of joint box material was ensured by visual inspection, chemical analysis, radiography test, ultrasonic test, eddy current test, etc. This paper describes joint design drivers, joint design detail, prototype joint fabrication processes, quality assurance (QA)/quality control (QC) adopted during prototype and actual joint fabrication process, joint resistance measurement on actual TF coils and analysis of measured joint resistance in detail.     

LC-MS/MS法定量测定人血浆中TF及其代谢产物M1，M2

A sensitive liquid chromatography-electrospray ionization-tandem mass spectrometric(LC-MS/MS) method for the simultaneous determination of TF and its metabolites M1 and M2 in human plasma were developed and validated. The plasma TF, M1, M2 were extracted using a solid phase extraction(SPE), and the sample extract was injected onto the LC-MS/MS system. The limits of quantitation(LLOQ) for TF, M1, M2 are 1 ng•L^－1. This method allowes the reproducible and accurate quantification with the concentration range of 1-500 ng•L^－1. This method can be applied to the quantitation of TF, M1, M2 in human plasma.