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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
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Vibration & Noise Analysis on Double-ring Gear Reducer 总被引:1,自引:0,他引:1
Double-ring gear reducer with Central inputting shaft is studied. The basic structure of reducer as well as testing equipment, probe spot and testing method of Structure-borne noise and air-borne noise is presented. Based on frequency spectrum of each point, amplitude spectrum of structure-borne noise and testing results of air-borne noise, the authors analyze the vibration characters and latent faults of double-ring gear reducer, coming to the value and the cause of the noise, providing theoretical basis for proper design of the double-ring gear reducer and method of reducing its vibration and noise. 相似文献
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YANG Zhong-ren RAO Cheng ZOU Jian PENG Zhen-liane Ministry of Education Chongqing Chin 《保鲜与加工》2004,(2):32-35
Dong village is very valuable for research work because of its special regional and national character and rich cultural implication. In this paper, some information about the location, form and features of Dong village is given. Then, the relationship between the culture and the settlement is analyzed, which provides a clue for understanding Dong village and will be beneficial to creating modern human settlements. 相似文献
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LIN Yuan-hu LI Run-fang SHI Tai-he LIANG Zheng LIN Teng-jiao Goods SWPI ngqing Chin 《保鲜与加工》2004,(8):1-6
It is difficult to calculate the penetration rate (ROP) of percussion drilling. In the early research, the empirical or semiempirical formulae of the ROP are derived from the laboratory or field data collected by the researchers. However, the ROP value of the formulae is not as accurate as that in the field. Benefiting from the dynamic model, the geometric structure model and the theory of the roller cone bit, the mathematical model of the hammer bit, the mathematical model of the true bottom hole and the mathematical model between the tooth and the rock of the hammer bit are established. Hence the ROP of the air percussion drilling can be predicted by simulation. Field tests show the models are reliable and the results are coincident with that in the field. The research can help to redesign the hammer bit and optimize the drilling parameters. 相似文献
48.
黄土高原北部垄膜沟植田间集雨高效栽培技术研究 总被引:1,自引:0,他引:1
DUAN Yu TUO De-bao ZHAO Pei-yi LI Huan-chun Inner Mongolia Academy of Agricultural Animal Husbandry Sciences Huhhote China 《华北农学报》2006,(Z3)
在黄土高原北部,采用起垄覆膜(垄上覆膜种植马铃薯,垄沟种植谷子)的垄沟间作田间集雨补灌栽培并结合增施氮、磷、钾化肥,具有显著的增产、增收效果。该技术可大大提高化肥的增产效果和肥料利用率,有明显的集雨增墒效果,同时采用起垄覆膜种植马铃薯与垄沟种植谷子能够合理利用有限的工程集雨,有利于充分利用有限的降水资源,进行节约化农业经营。 相似文献
49.
鄂尔多斯高原北部沙区主要植被类型下土壤要素的空间分析 总被引:1,自引:0,他引:1
鄂尔多斯北部沙区存在着极为显著的风沙地貌,在此格局基础之上,特别是在植被与土壤的相互响应过程中,二者的相互关系逐渐密切,这种反馈作用使得该区域的植被与土壤要素形成的空间分布格局具有一定的耦合性。研究这种关系可以为该地区保护植被和合理利用土地资源提供科学依据。 相似文献
50.
山西地膜棉花高产优质综合农艺措施数学模型的研究 总被引:5,自引:0,他引:5
本文采用五因素五水平二次回归旋转设计的方法,研究了山西不同生态棉区皮棉产量与密度、氮、磷、钾施肥量及化控次数(用量)关系的数学模型。分析了不同因素的影响效应,明确了各栽培措施的主次。通过模拟进优待选了不同产量等级的优化农艺措施组合方案,为不同生态棉区制定棉花高产优质决策方案提供依据。 相似文献