Influence of the Flood-Control-Projects on the Hydrodynamic State of the Rivers Confluence in Chongqing     

Chen JingQiu  Zhao WanXing  Ji ZheGang  Wen Cen  Liu XueLan 《保鲜与加工》2005,(4):47-51

Though the Flood-Control-Projects along Yantze River and Jialing River in Chongqing may well improve the urban traffic and construction,it may change the river hydrodynamic characters.There may be two consequences,one is to reduce the size of cross section and the other is to change the river shape,such as the curvature radius.The phenomena of the local backwater and velocity variety are obvious,which result in some problems for the navigation: sediment,transport and so on.In this paper, the study object is the Flood-Control-Projects and Yangtse River and Jialing River,and the aim is to study the influence of the Flood-Control-Projects on the hydrodynamic state of the two rivers.Using the numerical technique,with the two rivers hydrodynamic model the flow field's change of river after completion of Flood-Control-Projects is simulated and the reasons caused by the change are analyzed.  相似文献   

Behavior and Design of High-strength Bolt in Tensile Connection     

CHENG Rui  CUI Ji  LONG Li-ping 《保鲜与加工》2002,(4):25-30

The tensile strength of high strength bolt is affected by many factors, including prying force. The prying force can result in the increment of bolt force, for which the connection failed ahead of time. Several methods are presented for calculating the prying force. In the China's "Code for Design of Steel Structure" (GB50017), there is no formula for calculation of prying force and a factor of 0.8 is considered in formula for tensile strength of bolt for taking the prying force into account. It is proposed that the design value of tensile resistance for high strength bolt should be increased.  相似文献   

Calculation and Measurement of Electric Field along Polluted Cylindrical Insulator     

Zhang Jianhui  Gu Leguan  Su Caixin  Xu Guoyu 《保鲜与加工》1994,(6):24-29

In this paper,the electrical field distribution along the polluted cylindrical insu-lator before a nd after the local a re appea rs is calculated with the optim lzed pa rtially cha rge simula-tinn method and measured with the pockels device. Based on the calculating and measuring results,the in fluen ce of the electric field distri bu tion on the propagation of local a re in the flashover ofcyIlndrical insufator under various conditions is analyzed systematieally.  相似文献   

利用多种抗源选育小麦远丰139的研究     

任志龙  张宏  王康峰  王亚娟  蔡东明  吉万全  宋玉莲 《中国农学通报》2006,22(7):228-231

为了选育持久抗耐多种病害的小麦核心抗病种质,以奥地利黑麦、中间偃麦草和野生二粒小麦为抗源,采用单交、复合杂交、回交、阶梯式杂交等多种组配方式,将基因逐步累加、聚合到一起。选育中以不丢失抗性基因为前提,以抗旱耐寒为适应性选择的基本标准。育成的小麦新品系远丰139半冬性,耐寒、抗旱,株型结构好,产量高,品质好。经西北农林科技大学植保系鉴定对条锈病免疫,对白粉病和叶枯病高抗,中抗赤霉病。经农业部谷物品质检测中心分析,品质达到国标精制级面条用小麦粉标准。2005年陕西省区试较对照小偃22增产5.6%。  相似文献   

ADAPTIVE MOMENT-ROTATION FUNCTIONS FOR SEMIRIGID STEEL FRAMES     

Chen Lin Department.of Mechanical Electrical EngineeringCui Ji  Wu Huibi Dept.of Civi Elngineering 《保鲜与加工》1992,(1)

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The Algorithm of Searching out the Least and Most Loops by Making Use of Direction Factor     

FU Zhi hong  YU Ji hui  SU Xiang feng 《保鲜与加工》2002,(3):64

Based upon the conception of the least loop,the most loop and direction factor presented by the author firstly,the algorithm of searching out the least and most loops has been designed.By building the adjoining matrix, confirming the start-point of searching,vectorizing the searching sides,calculating the direction factor of adjoining sides,we can search out the next side of the least loop or the most loop rapidly.With a valid searching side being confirmed at every searching and the searching scope being reduced by forming degenerate graph,the time compexity of the algorithm is much less. In the research of the automatic calculating system of construction quantities, the problem of houses partition and out-wall partition had been solved succesfully by utilizing this searching algorithm.  相似文献   

稻谷固定床深层干燥的计算机模拟   总被引：3，自引：0，他引：3  

李娟玲  陈坤杰  杨明毅  姬长英 《农业机械学报》2001,32(6):59-62

针对稻谷固定床深层间歇干燥过程中的加热和缓苏两个阶段建立了数学模型，用C语言编制了相应的运算程序。用该模型计算了不同干燥介质温度和湿度、不同粮食初始含水率和温度条件下，不同层厚处稻谷的含水率和温度，计算结果与试验结果基本相符。  相似文献   

基于虚拟仪器的农产品"身份证"数字识别系统   总被引：1，自引：0，他引：1  

钱稷  钱东平  周娟 《农机化研究》2007,(12):160-162

介绍了基于虚拟仪器图形化语言LABVIEW开发的农产品"身份证"数字识别系统,采用CCD摄像机对农产品"身份证"编号进行采集,通过PCI-1411彩色图像采集卡将图像传输到计算机并进行图像处理,最后应用美国NI公司的OCR软件包对处理好的编号进行识别.结果表明,该系统抗干扰能力强且精度高.  相似文献   

泵站中钢筋混凝土梁加固的变形计算     

胡吉  石启印 《排灌机械》2005,23(4):49-52

基于试验研究资料的分析,对于大型泵站中具有合适锚固的CFRP片材加固受弯构件变形计算方法进行研究,认为加固梁的弯矩-曲率曲线符合三线型规律（混凝土开裂前,混凝土开裂后,受拉钢筋屈服后）.通过解析分析,得到试验梁在通常两点加载条件下的任一加载阶段的弯矩及变形计算公式,与相应条件试验梁的试验测试结果吻合,可为泵站工程设计规程的制定提供参考。  相似文献   

可视化编程技术在发动机外特性曲线绘制中的应用   总被引：1，自引：0，他引：1  

孙振军  陈福恩  姬鹏 《农业装备与车辆工程》2005,(10):20-22

通过对汽车发动机外特性的理论分析,在处理汽车发动机外特性曲线时,建立了一种适合处理发动机外特性曲线的三次样条函数拟合的数学模型,在C Builder可视化开发平台上,编制了汽车发动机外特性曲线绘制程序.利用三次样条函数插值法对实验数据进行拟合,实现了发动机外特性曲线绘制的自动化.  相似文献