预应力薄腹梁质量事故的分析及鉴定     

张国志  王晓军 《东北林业大学学报》1994,22(4):115-119

阐述了某工程由于施工原因，导致预应力混凝土工字形屋面梁强度不足的预制构件的检验鉴定过程和方法。采用回弹法推定混凝土实际强度；通过静载试验测试构件的实际挠度、抗裂和承载能力。分析了导致混凝土强度不足的原因。  相似文献   

秦皇岛装船原油管道能耗指标测算     

汪冈伟  宋建河  赵晓智  肖明 《油气储运》2002,21(10):41-44

针对秦皇岛原油装船线装船量急剧下降的情况，从分析油电消耗着手，推导出油电指标的测算公式，探讨成本与装船计划的关系。确定了维持成本运行的最低年装船量，并提出了相应降低能耗的措施。  相似文献   

无缝烟夹不同针尖处理对烤后烟叶孔径的影响   总被引：1，自引：1，他引：0  

吴小平 《现代农业科技》2015,(7)

为优化无缝烟夹装置设计,充分发挥无缝烟夹装烟方式的优势,对不同直径、不同形状针尖及不同方向的无缝烟夹烤后烟叶的针孔面积进行了比较研究。结果表明:不同直径烟针相比,3 mm直径无缝烟夹烤后针孔面积小于5 mm直径无缝烟夹;无缝烟夹在3 mm直径条件下,扁形针尖平行处理烤后针孔面积最小;在5 mm直径条件下,圆形针尖平行处理烤后针孔面积最小。  相似文献   

青核桃去皮过程的受力分析     

郑甲红  吴东泽  梁金生  牛硕雅  安碾粮 《农机化研究》2015,(8):153-156

青核桃在去皮方面不断进取的同时,存在着共同的问题是去掉的青皮被打成泥状,对核桃和环境都造成再次污染。为此,将通过模拟青核桃去皮过程的受力进行试验,分别从青核桃的尺寸、加载方向及加载速度等可能影响青核桃去皮过程的因素进行分析研究,为使青皮脱掉后不会被打成泥状,而是呈块状脱出奠定实验基础。  相似文献   

CALCULATION OF ULTIMATE STRESS OF UNBONDED PRESTRESSED TENDONS IN UNSYMMETRICAL DEFLECTED BEAMS     

Pan Li Institute of Building Structures  China Academy of Building Research 《保鲜与加工》1989,(3)

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Experimental Study on the Deformation Characteristics of Fine-Sandstone Under the Loading and Unloading Conditions     

XU Jiang  WANG Wei-zhong  YANG Xiu-gui  WANG Hongl Disaster Control Engineering Under the State Ministry of Education  Chongqing University  Chongqing  Chin 《保鲜与加工》2004,(12):60-62

The deformation characteristics of the fine-sandstone is studied under the loading and unloading conditions at the three different deformation-rates and the two different stress-levels. The experimental results show that there is really the plastic-loop in the deformation curve for the loading deformation curve is different from the unloading deformation curve. But the plastic-loop is nearly unchangeable since the second circulate loading. The residual-deformation is be almost zero since the second circulate loading, and that the slope of the deformation curve increases as the deformation-rate increases, and that the residual-deformation increases as the stress-levels increases.  相似文献   

Data Loading Technology of Data Warehouse     

XIONG Zhong yang  ZHANG Yu fang  WU Zhong fu 《保鲜与加工》2002,(2):106-108

Data warehouse is not the simply data accumulation of operational database. For exerting the function of data warehouse, the construction of data warehouse should be convenient for the data mining and business intelligent work, supply information access, analyze, and share for decision maker. The key to constructing a successful data warehouse is to fully understand the demand of end users from beginning to the end, search and storage data surround users motive closely. This paper first analyzes the data warehouse characteristic and the sort of data component, emphasizes in effective data loading methods and strategies from operational database to data warehouse, gives five sorts data loading methods.  相似文献   

EFFECT OF HIGH LOADS IN THE BRIDGE LOAD SPECTRUM ON FATIGUE CRACK GROWTH OF 16 Mn STEEL     

Zhong An  Shen Xianrong 《保鲜与加工》1995,(2):15-22

This paper studies an effect of high loads in Rayleigh distribution random load-ing on fatigue crack growth wi th 16 Mn steel compact tenion specimen,The results show that thehigh loads in the load spectrum close to service load of steel bridges accelerate crack growth and re-duce crack growth life,Lives predicted with constant amplitude da/dn data and equivalent loads arequite in agreement with test lives.  相似文献   

EFFECT OF HIGH LOAD RATE AND OCCURRENCE IN RANDOM LOADING ON FATIGUE CRACK GROWTH     

Zhong An  Fang Jin 《保鲜与加工》1995,(3):8-20

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Evolvement of Plastic-loop of Fine-sandstone Under the Loading and Unloading Conditions     

WANG Hong  XU Jiang  YANG Xiu-gui 《保鲜与加工》2006,(4):80-82

The deformation characteristics and the plastic-loop of the fine-sandstone is studied under the loading and(unloading) condition at the three different deformation-rates and the two different stress-levels,the results show: 1) There is really the plastic-loop in the deformation curve for the loading deformation curve is different form the unloading deformation curve.But the plastic-loop is nearly unchangeable since the second circulate loading.2) There is different for every imitational parameter between the first deformation curve and the second deformation curve at the different stress-levels and the different deformation-rates,but every imitational parameters become more and more invariable gradually since the second circulate curve.3) With the change of the deformation-rates and stress-levels,the imitational(parameters) will change with it.4) The imitational parameters are different for loading section and unloading section of the fine-sandstone deformation curve at the same circulate curve under the same deformation-rate and stress-level.  相似文献