数控车床刀架常见故障诊断与分析     

陈安安  熊杰 《湖南农机》2016,(8):15-16

文章介绍了数控车床四工位刀架的基本结构和工作原理，面向数控车床刀架的常见故障现象，对故障原因进行了全面分析，并针对不同的故障原因，提出了具体维修方法。  相似文献   

论民营医疗机构的市场准入规制——以法经济学为视角     

陈蓉 《湖南农业大学学报(自然科学版)》2016,(5):140-144

随着市场经济的深化发展，多元化医疗服务竞争机制的形成需要民营医疗机构市场准入。在我国鼓励社会资本办医政策下，民营医疗机构有了一定发展，但却存在逐利性和市场退出制度缺失等问题。引发这些现象的主要原因是医患信息不对称、医疗服务负外部性、供给诱导需求、医疗公共产品短缺等市场失灵现象。基于此，为确保医疗事业发展和医疗安全，政府应以从严规制与从宽规制相结合的方式，对民营医疗机构市场准入适度干预，建立民营医疗机构市场准入法律制度，明确其市场准入条件和准入范围，建立市场退出制度，以促进和引导民营医疗机构健康、快速和稳定发展。  相似文献   

梧州市意园冲滑坡变形破坏模式分析与稳定性评价   总被引：3，自引：0，他引：3  

杨军  郭纯青 《水土保持通报》2006,26(6):111-115

在对意园冲滑坡地段地质环境背景调查的基础上,分别研究了滑坡形态特征、分布范围及稳定状态,分析出滑坡的变形破坏模式及其变形破坏机理和过程。通过稳定性计算得到意园冲滑坡地段稳定性评价,并针对该滑坡体的变形破坏机理、威胁现状提出了治理对策,以达到消除灾害隐患的最终目的。  相似文献   

Analysis of salt rock underground deposit failure probability in operation period based on response surface method     

LIU Jian  SONG Juan  ZHANG Qiang yong  JIA Chao  LI Shu cai 《保鲜与加工》2011,(12):144-150

For the safety of salt rock underground deposit, uncertainties and their influences are considered, and failure probability during operation period is analyzed. Based on finite element model, equation of limit state surface is transformed into explicit equation by response surface method. Combined with Monte Carlo method, computation efficiency is improved. The deposit could be simulated as a series-parallel system. The element with highest failure probability is determined first, then failure mode and system reliability are computed. Taking Jintan underground gas deposit as an example, the analysis indicates that as storage pressure increases, failure probability of middle part of deposit decreases firstly, then increases gradually when storage pressure accumulates to a certain extent. The failure probabilities of upper part and underside of deposit increase as storage pressure increases. During operation period, controlled failure mode is shear failure of upper part and underside of deposit under high storage pressure. In conclusion, the storage pressure during operation period should be controlled strictly.  相似文献   

基于土壤压缩破坏理论的挖掘铲的设计与分析     

郑厚贵  张周强  徐武彬  魏塬  关意昭  徐开元 《农机化研究》2011,33(11)

对影响木薯收获的因素进行分析,借鉴马铃薯收获机挖掘铲的设计思想,在铲面受力分析的基础上,引入了土壤压缩和破坏理论,建立了运动条件下挖掘铲的碎土性能分析模型。应用Matlab软件对该模型进行了数值计算,并对平面挖掘铲进行了碎土性能分析,得到了最佳的平面铲倾角,提高了木薯挖掘铲的碎土性能,为木薯挖掘铲的设计提供了理论参考。  相似文献   

数控机床常见故障诊断及排除方法     

杨晓苗 《湖南农机》2011,38(1):25-26

数控机床具有机、电、液集于一身的、技术密集和知识密集的特点,是一种自动化程度高、结构复杂且又昂贵的先进设备.在生产中,数控机床不可避免地会发生不同程度、不同类型的故障,导致不能正常工作.文章介绍了数控系统常见故障的诊断技术,数控系统的常见故障分析及排除方法,并列举了部分故障排除实例.  相似文献   

反光式突起路标功能失效ANASYS分析     

盛玉刚  夏红亮  吕婷婷 《森林工程》2011,(4):58-61,96

根据目前道路上安装的反光式突起路标存在破坏率高、反光功能失效快等问题,在调查数据基础上,分析得出反光式突起路标的主要破坏形式为脱落、压碎、凹陷、反光性能衰减等,破坏主要原因有基体材料抗压强度不够、机体与路面粘结不牢固等。在此基础上,运用ANSYS软件,建立有限元分析模型,将影响因素分为静荷载与动荷载两种情况分别加载到有限元分析模型上进行力学分析,模拟得出突起路标的主要应力集中点在突起路标表面四个边缘区域与钉脚与基座衔接段。将ANSYS分析数据导入Fe-Safe软件,模拟得出突起路标在荷载作用150482次后发生破坏,疲劳寿命系数为0.613,屈服极限为603Mpa。  相似文献   

Feline chronic kidney disease: can we move from treatment to prevention?     

White JD  Malik R  Norris JM 《Veterinary journal (London, England : 1997)》2011,(3):317-322

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Brain-natriuretic peptide and cyclic guanosine monophosphate as biomarkers of myxomatous mitral valve disease in dogs     

Sophia G. Moesgaard  Torkel Falk  Tom Teerlink  Halldóra H. Guðmundsdóttir  Sif Sigurðardóttir  Caroline E. Rasmussen  Lisbeth H. Olsen 《Veterinary journal (London, England : 1997)》2011,189(3):349-352

Elevations in the plasma concentrations of natriuretic peptides correlate with increased severity of myxomatous mitral valve disease (MMVD) in dogs. This study correlates the severity of MMVD with the plasma concentrations of the biomarkers N-terminal fragment of the pro-brain-natriuretic peptide (NT-proBNP) and its second messenger, cyclic guanosine monophosphate (cGMP). Furthermore, the l-arginine:asymmetric dimethylarginine (ADMA) ratio was measured as an index of nitric oxide availability. The study included 75 dogs sub-divided into five groups based on severity of MMVD as assessed by clinical examination and echocardiography.Plasma NT-proBNP and cGMP concentrations increased with increasing valve dysfunction and were significantly elevated in dogs with heart failure. The cGMP:NT-proBNP ratio decreased significantly in dogs with heart failure, suggesting the development of natriuretic peptide resistance. Although the l-arginine:ADMA ratio decreased with increasingly severe MMVD, this was largely due to the older age of the dogs with heart failure.  相似文献   

The Kidney in Critically Ill Small Animals     

Katharine F. Lunn 《Veterinary Clinics of North America: Small Animal Practice》2011,41(4):727-744

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