35CrMo旋转接头激光表面硬化技术的试验研究

用L9(34)正交试验法研究35CrMo旋转接头激光相变硬化工艺参数优化组合,分析了旋转接头激光相变硬化方法.试验结果表明:激光相变硬化层硬度比渗氮淬火提高了30%,耐磨性提高了1倍,表面残余应力为压应力;满足了旋转接头工作要求,为改进旋转接头表面处理方法提供了依据.     

柴油机三大精密偶件密封性对供油特性的影响

柴油机喷油泵的柱塞、出油阀和针阀这三大精密偶件的磨损程度直接影响到柴油机的供油规律和各种综合性能。为此,采用二次回归正交设计的方法,通过大量的试验数据,建立了精密偶件的磨损量与供油量之间的定量关系式,从而更直观、清楚地了解到三大精密偶件的密封性对供油量影响程度的主次关系。     

农业"三新技术"农机化配套项目的应用

为进一步提高粮食生产科技含量,稳定粮食生产能力,近几年来浙江省确定在全省667khm2商品粮基地中实施以农业新品种、新技术和新农机为主要内容的“三新技术”配套项目。上虞市于2002年度获得了该项目的建设计划,并按照省定要求,联系本地实际,及时制定了项目实施方案,落实地方配套资金,签订项目承包合同,加强项目的管理,确保了项目的建设质量,产生了良好的社会和经济效益。该项目的实施既促进了农业龙头企业的生产发展,又起到了较好的示范和带动作用,也为提高上虞市部分农产品的经济效益提供了较好的条件,有着广阔的市场发展前景。     

水分亏缺对覆膜玉米生长发育及产量的影响

通过系统的覆膜玉米亏水灌溉试验 ,研究了不同生育期内不同程度的水分亏缺对覆膜玉米生长发育、光合作用、产量及水分利用效率等的影响。结果表明 ,拔节期受旱对玉米株高及叶面积指数影响最大 ,抽雄后的水分亏缺对玉米生长发育影响不明显。各处理产量资料表明 ,覆膜春玉米的需水临界期为抽雄开花期 ,此期轻度的水分亏缺可造成产量大幅度下降 :灌浆期较抽雄开花期玉米产量对水分亏缺敏感程度低 ,但在这个阶段的水分亏缺也可使玉米减产 ;拔节期玉米产量对水分胁迫敏感程度较差 ,该阶段为对玉米进行水分亏缺处理的适宜时期     

基于PDM犁的智能CAD设计系统

讨论基于产品数据管理(PDM)犁的智能CAD设计系统基本框架及其3个组成部分：设计专家系统、产品数据管理和犁的计算机辅助设计。研究了各部分的功能和技术实现，设计专家系统用于犁的参数化设计过程中参数的选择和装配图装配合理性的判断，PDM主要管理犁的辅助设计相关的数据和文件以及专家系统知识。在此基础上，介绍了集成专家系统和产品数据管理犁的计算机辅助设计软件开发。     

秸秆揉切机用刀片磨损的研究

对9RZ-60型揉切机用刀片进行了磨损试验,探讨了刀片材料、作业对象、装机位置和刃口形式对刀片磨损的影响,对65Mn、T10和Crl2MoV三种材料的刀片磨损表面形貌进行了微观分析,指出加工羊草时,刀片材料为主要影响因素,加工玉米秸和豆秸时,刃口形式为主要影响因素。刀片加工秸秆的磨损形式是以抛光磨损为主,辅之以硬杂质造成的磨料磨损。     

Managing secondary dryland salinity: Options and challenges

Salt occurs naturally at high levels in the subsoils of most Australian agricultural land. As a result of clearing native vegetation, groundwater tables have risen, mobilising the stored salt and causing adverse impacts on farmland, infrastructure, water resources, and biodiversity. The main action required to prevent groundwater tables from rising is establishment of perennial plants, either herbaceous (pastures or crops) or woody (trees and shrubs). Recent technical and economic research has emphasised how difficult it will be to establish sufficient perennials to get control of groundwater tables. Where watertables are already shallow, the options for farmers are salt-tolerant plants (e.g. saltbush for grazing) or engineering (e.g. deep open drains). The existing options for farm-level salinity management are reviewed, with mixed but somewhat disappointing findings regarding their suitability for addressing salinity. However, there are also a number of good prospects for development of new and better options for plant-based management of salinity, and these are described.     

Hydraulic-hydrological simulations of canal-command for irrigation water management

A modelling system that combines the hydraulic simulations of the canal and hydrological simulations of the irrigated command is introduced. It uses MIKE 11 and MIKE SHE, two well-established modelling systems, for the hydraulic and hydrological simulations respectively. In addition, it also has an irrigation scheduling module and a crop growth module. The modelling system is applied to the Mahanadi Reservoir Irrigation Scheme, a large irrigation project in Central India. The results show that presently a significant amount of water is wasted in the command during the monsoon season. It is demonstrated that the minimization of this wastage could lead to a substantial crop production in the subsequent dry season. Furthermore, the simulations illustrate the versatility of the modelling system for planning and analysing the various aspects of an irrigation project.     

湖南省节水灌溉分区与规划

将模糊聚类方法用于湖南省节水灌溉分区，建立了湖南省节水灌溉区划模型，将系统动力学的动态仿真原理用于节水灌溉发展规划，建立了节水灌溉发展规划的动态仿真模型。据此，提出了湖南省节水灌溉区划，并对各分区及全省“九五”期间节水浇灌发展作了详细规划。     

Evaluating factors influencing farmers' satisfaction with their irrigation system

The logit technique is used to analyze the relationship between dichotomous reactions of satisfaction (satisfied/dissatisfied) with the irrigation system and certain independent variables. The result shows that five important variables — water availability on time, fertilizer availability, landholding size, farmers' participation in irrigation activities and location of farmland along the canal — significantly determine satisfaction.