凸轮转子叶片泵中凸轮曲线的CAD

利用机构反转原理和位移旋转矩阵，提出了一种快速、精确设计凸轮廓线的计算机辅助设计方法。     

计算机在美国棉花生产中的应用

从60年代开始,国际上已兴起各种作物生产或产量形成的模拟,把特定的气候因素与作物的产量相联系;自70年代起,人们开始把农业气候资源中的太阳辐射和温度等作为驱动变量,模拟作物的光合作用、呼吸作用和植株的生长等,随着时间的推移,逐渐     

中国大豆发育动态的计算机模型

利用1980～1982年,黑河3号等10个大豆品种在全国19个省26个点34个播期种植的生物气候资料,在计算机上建立了大豆播种至出苗和出苗至成熟两个发育阶段的发育动态的计算机模型,起名“大豆发育动态的正态模型”.大豆发育的正态模型不仅各项参数有明确的生物学意义,而且模拟精度比传统的“积温模型”有明显提高.     

Sediment Load in Runoff Under Laboratory and Field Simulated Rainfall

Soil erosion is one of the most important problems in the Loess Plateau of China affecting sustainable agriculture. Near Luoyang (Henan Province, China), field plots were constructed to measure soil erosion rates under conventional tillage practices using field-simulated rainfall.Field rainfall experiments were carried out to compare previous results from laboratory rainfall simulations on the same soil for interrill conditions. Although in the laboratory experiments, a strong correlation was found betweenthe stream power of the runoff water and the unit sediment load, this sediment transport equation overestimated the field rainfall simulation results. Another sediment transport equation derived by Nearing et al. for rill erosion was in better agreement with the results of the field experiments, although it also overestimated these values. The measured sediment load values during the field rainfall simulations were also lower than those found during field experiments on the same soil but with a loosened surface layer. This difference indicates the importance of soil physical condition of surfce like soil structure and aggregate size, which may contribute to the discrepancy between the field and laboratory experiment results.