Synthetic Application for Analysis Methods of the Planar Mechanism Overconstraints     

AN Pei wen  HUANG Mao lin 《保鲜与加工》2002,(5):21-24

Overconstraints exist widely in planar closed chain mechanisms and mechanical systems result in a series of detrimental influences on behavior of machines, and attention is given to them by machine designer. Some analysis methods of overconstraints in planar closed chain mechanisms are presented, and more study due to the faultiness of these methods. In accordance with faultiness of two common kind of methods, formulas method and loop analysis method of degrees of freedom, and by combining these two methods, an useful mechanism overconstraints analysis method which is convenient for computer aided overconstraints analysis is gained via research on the two methods thoroughly and systematically, and some new views about mechanism overconstraints analysis are presented.  相似文献   

高度对色斑法测量雨滴粒径影响的试验研究   总被引：2，自引：0，他引：2  

李红  任志远  袁寿其  朱兴业  汤跃 《中国农村水利水电》2006,(1):16-17,19

以前的色斑法雨滴率定只考虑色斑直径与雨滴真实粒径的关系，忽略了高度对率定的影响。在大量试验的基础上，通过回归分析，得到了以色斑直径和高度为变量的率定公式。研究表明，水滴下落高度小于5m时需考虑高度的影响；高度大于5m时，高度的影响可以忽略。通过相关性分析，公式的拟合性较好，对以后的色宽法测量雨滴粒径有指导意义。  相似文献   

电控喷油器流量特性试验台的设计与试验   总被引：2，自引：0，他引：2  

尹丛勃  张振东  刘志远  王玉顺 《农机化研究》2007,(12):194-196

论述了开发电控喷油器微机测试系统的意义;为检测电喷发动机喷油性能,介绍了所以8098为核心的喷油器流量试验台;阐述了喷油器流量试验台设计思想、硬件结构和软件设计方法.以高阻型喷油器为例,在整个流量范围内对其进行测试,并对测试数据加以分析总结,得出了该喷油器流量特性的一些重要参数.目前,电控喷油器微机测试系统已投入使用,取得了良好的实际效果.  相似文献   

阜新县节水农业分区研究   总被引：1，自引：0，他引：1  

商艾华  郭维东  黄毅  杨建青  安禹 《节水灌溉》2006,(3):13-15,20

针对阜新县水资源紧缺的现状，在综合分析全县气候、土壤、水资源现状、农业种植制度和经济发展水平等因素的基础上，对阜新县节水型农业分区进行了研究，为确保分区指标的科学性、系统性，采用模糊数学聚类分析方法，探讨节水农业的地域分布规律，进行节水农业分区，以阜新县为例对因地制宜地发展东北半干旱地区的节水农业分区进行有益的探索。  相似文献   

基于WebGIS的农业状况管理信息系统研究     

郑伟  赵英娜  曾志远 《农机化研究》2004,(4):190-191

分析了WebGIS和农业状况信息的特点，并提出了基于WebGIS的农业状况管理信息系统的设计方案。  相似文献   

国外水泵研究现状概述   总被引：7，自引：3，他引：7  

严敬  杨小林 《排灌机械》2003,21(5):1-3

以丰富的材料为基础，概括性地评价了西方近年中在水泵技术各研究领域，如流场计算、汽蚀机理、振动、无泄漏密封等方面的研究现状及成果，这些资料将为国内水泵技术人员的产品开发、科研活动提供有益的启发和借鉴。  相似文献   

马铃薯收获机设计试验研究     

杨世成  安宏宇 《农机化研究》2007,(11):161-163

张家口地区马铃薯种植面积广,畜力犁收获时效率低,漏收和破损较为严重,外购的马铃薯收获机不适合当地农民的种植方式.为此,设计了马铃薯收获机.该机可实现马铃薯挖掘、薯土分离和薯秧分离.同时,对该机部分关键零件进行了设计,对样机在玉米茬地和马铃薯地的工作性能进行了试验研究.试验结果满足当地农民的使用要求,试验数据对设计多行马铃薯收获机具有参考和借鉴作用.  相似文献   

增压对非道路柴油机主要零部件的影响     

楼狄明  于伟峥  胡志远 《拖拉机与农用运输车》2007,34(6):43-45,48

对4102非道路柴油机的主要零部件进行了精确的建模,确定了主要的载荷工况,分别对曲轴及连杆在增压前后两种情况下进行了有限元分析以及强度计算,并对计算结果进行了分析比较,找出了增压后零部件的薄弱部位,提出了适当的改进措施。  相似文献   

Mechanism of Fuzilizhong decoction alleviating inflammatory damage of rats with non-alcoholic fatty liver disease     

MA Wei  YANG Jia-yao  AN Liu  ZOU Qi  ZHANG Xiao  LIU Nian 《园艺学报》2021,36(12):2258-2263

AIM To observe the effect of Fuzilizhong decoction on the inflammatory damage of non-alcoholic fatty liver disease （NAFLD） rats and to explore its mechanism. METHODS SPF male SD rats were randomly divided into 6 groups： control group, model group, high dose （20 mg·kg^-1·d^-1）, middle dose （10 mg·kg^-1·d^-1）, low dose （5 mg·kg^-1·d^-1） Fuzilizhong decoction group and Yishanfu （30 mg·kg^-1·d^-1）group, 8 rats in each group. A NAFLD rat modelwas established by intragastric administration of fat emulsion for 4 weeks. Then the drug was given for 4 weeks in each treatment group. HE staining was performed to observe the histopathological changes of the rat liver.The serum levels of interleukin-2（IL-2）, IL-6 and tumor necrosis factor-α（TNF-α） were measured by ELISA. The expression of toll like receptor 4（TLR4） and NF-κB p65 in liver tissues at mRNA and protein levels was determined by RT-qPCR and Western bolt,respectively. RESULTS Compared with control group, the inflammatory damage of liver tissue was more serious, the serum levels of IL-2, IL-6 and TNF-α, the mRNA expression TLR4 and NF-κB p65 in liver tissues were significantly increased in model group（P<0.05）. However, compared with model group, the liver pathological changes in each treatment group were significantly relieved, the serum levels of IL-2, IL-6 and TNF-α, the mRNA expression of TLR4 and NF-κB p65 in liver tissues were significantly reduced（P<0.05）.In addition, the changes of TLR4 and p-NF-κB p65 protein levels in liver tissue were consistent with the changes of TLR4 and NF-κB p65 mRNA. CONCLUSION Fuzilizhong decoction attenuates the inflammatory damages of NAFLD in rats by inhibiting TLR4/NF-κB p65 signaling pathway.  相似文献   

MicroRNA-9-5p mediates sympathetic overactivity by targeting KCNN3 in paraventricular nucleus of rats with T2D     

XU Jia-qi  AN Mei-ling  YUAN Yue  HAO Yi-fan  WANG Xiu-wen  ZHANG Min  WEI Xiao-wei  LI Hua  WANG Ren-jun 《园艺学报》2021,36(12):2148-2158

AIM To investigate whether microRNA-9-5p （miR-9-5p） mediates sympathetic overactivity by targeting KCNN3 （potassium intermediate/small conductance calcium-activated channel, subfamily N, member 3） gene,which encoded small-conductance calcium-activated potassium channel 3 （SK3） protein, in paraventricular nucleus （PVN） of rats with type 2 diabetes mellitus （T2D）. METHODS A rat model of T2D was established by high-fat diet combined with intraperitoneal injection of 30 mg/kg streptozotocin. The levels of miR-9-5p and KCNN3 mRNA in PVN were detected by real-time PCR. The relationship between KCNN3 and miR-9-5p was predicted by TargetScan. Recombinant adeno-associated virus （rAAV）-miR-9-5p or KCNN3 were bilaterally microinjected into the PVN to observe the changes in plasma glucose levels and sympathetic drive indicators. The number of FosB and SK3 positive cells was measured by immunofluorescence staining. The protein expression of SK3 was determined by Western blot. The relationship between KCNN3 and miR-9-5p were confirmed by cell transfection and dual-luciferase reporter assay. RESULTS Compared with the rats in diabetes control （DC） group, the blood glucose, sympathetic drive indexes and the level of miR-9-5p in PVN were significantly increased, while the SK3 expression in PVN was obviously reduced in the diabetes mellitus （DM） rats. After microinjecion of rAAV-miR-9-5p in PVN, the sympathetic drive indexes, blood glucose, and the number of FosB-positive cells were increased significantly, but the SK3 protein expression was significantly reduced （P<0.05）. However, up-regulation of KCNN3 in PVN had the opposite effect. These responses were obviously enhanced in DM rats compared with DC rats. The results of cell transfection and dual-luciferase reporter assay demonstrated that miR-9-5p bound to the 3’-UTR of KCNN3 and inhibit its expression. CONCLUSION miR-9-5p was up-regulated in PVN of the rats with T2D, and it may mediate sympathoexcitation by targeting KCNN3.  相似文献