浅谈我国农药残留监测现状及其治理措施

20世纪以来，随着工业化、现代化和社会经济的迅速发展，加上人类对资源的不合理开发，生态环境与资源问题日益突出。目前，我国农业产业化和农业标准化生产程度不高，农产品质量安全水平较低，由于农业生产者片面追求短期经济效益，农药的用量居高不下，而农药在生产、销售、运输、使用、储存和废弃等各个环节都可能造成污染。     

大力发展农业机械化 加快实现农业现代化

农业机械化是农业现代化的重要组成部分，是农业和农村经济持续快速发展的保证。农业机械化不仅能够促进农村产业结构的调整，促进农村剩余劳动力转移，而且能保证农村生产的稳定，大幅度地提高农业生产率，提高土地产出率。保证粮食产量再上新台阶，离不开农业机械化；在搞好粮食生产的同时，发展农业产业化达到富国裕民目标，同样也离不开农业机械化。因此，我们要从根本上把发展农业机械化和实现农业现代化有机的结合起来，不要一提到农业，就认为是农业技术部门和水利部门的事情，而把农机排除在外。很难设想，也不可能存在没有农业机械…     

世界农业发展的新格局与新趋势

我国农业是世界农业的一个重要组成部分，对世界农业发展曾做出而且也正在做出重大的贡献，世界农业发展离不开中国农业。同时，我国农业发展也不可能游离于世界农业之外。借鉴其他国家农业发展的成功经验，也是促进我国农业发展的重要方面。一部世界农业发展史，所展现的其实就是各国农业相互借鉴、互相融合、共同进步的历程。当今世界，经济全球化和世界一体化以前所未有的速度推进，各国之间农业交流与合作的广度和深度也盛况空前。     

对农业产业化的认识

江泽民同志在党的十五大报告中指出，坚持把农业放在经济工作的首位，积极发展农业产业化经营，形成生产、加工、销售有机结合和相互促进的机制，推进农业向商品化、专业化、现代化转变。这是我党在世纪之交对农业发展提出的重要指导方针。如何认真贯彻落实党的十五大精神...     

把握精神实质 加大工作力度努力做好农业机械化促进法贯彻实施工作——农业部农机化管理司王智才司长在全国农业机械化促进法培训班上的讲话

一、充分认识贯彻实施《农业机械化促进法》的重要性和紧迫性。统筹城乡经济社会发展，建设现代农业，发展农村经济，增加农民收入，是全面建设小康社会的重大任务。农业是国民经济的基础，没有农民的小康，就不可能实现全面的小康；没有农村现代化，就不可能有全国现代化。全面建设小康社会，重点在农村，难点在农业。农业基础薄弱，农业生产力还不高，农业机械化发展滞后，不能满足农业、农村经济结构战略性调整和农民生产、生活的迫切需求，不少地方的农业生产仍然主要依靠畜力和手工劳动，影响了农业生产效率和效益的提高，已成为农业发展中亟待解决的突出问题之一。要从根本上解决这个问题，必须转变观念，创新工作思路和工作方法，既要充分利用市场机制，又要加强国家的政策扶持和各级政府的引导推动，依法促进农业机械化发展。农机管理部门作为《农业机械化促进法》实施的主体部门，要充分认识《农业机械化促进法》颁布实施的重大意义，增强贯彻实施、依法做好农业机械化促进工作的责任感和紧迫感。     

推进农机服务产业化是实现农业机械化的加速器

江泽民同志在十五大报告中指出，积极发展农业产业化经营，形成生产、加工、销售有机结合和相互促进的机制，推进农业向商品化、专业化、现代化转变。这一论述，对于推进我国农业的持续健康发展，具有极其重要的意义。发展农业产业化，进而实现农业现代化的实质是农业生产力的现代化，农业机械化作为农业现代化的载体，是农业现代化的依托。下面就为什么要发展农机服务产业化、农机服务产业化的经营模式及如何推进农机服务产业化等有关问题，结合莱州市的农机化发展状况进行探讨。１　推进农机服务产业化的必要性１．１　农机服务产业化是家…     

推进农业产业化经营是新形势下农业和农村经济发展的必然趋势

当前我国农业发展进入新阶段，主要农产品供给实现了由长期短缺到总量基本平衡、丰年有余的历史跨越，同时也出现了农产品卖难、价格下跌、农民增收困难等新问题。我国加入世界贸易组织，农业和农村经济将直接参与更加激烈的国际市场竞争。面对国际国内出现的新形势，我们必须找到一条既符合我国国情又符合市场经济要求的实现农业现代化的具体形式和途径。农业产业化经营是在家庭经营的基础上，以市场为导向，以效益为中心，通过一定的组织形式和利益机制，把农业产前、产中、产后各个环节，把千家万户与大市场，把生产、加工、销售联结起来…     

基于混合激励机制的种业供应链协调性研究

主要研究了针对种业供应链的供应商与分销商间的契约实务.应用简单报童原理,构建并分析了含有奖励和惩罚性质的单个供应商对单个分销商的两级供应链的多种契约模型.基于无需求分布的假设,指出纯奖励机制优于基本系统而又不能有效协调供应链的局限性,并构建一个混合(奖励和惩罚)机制,以实现供应链协调的可行性.最后以民营益群种业的西瓜种子销售为案例,结合模型进行实证分析,为描述并优化种业供应链协调过程提供了参考和依据.     

我国农业补贴政策的演变及优化方向

农业补贴政策是农业政策的重要组成部分之一，对农业发展过程中的生产、销售、贸易以及农业生产结构等的调整具有重要作用。近年来，虽然我国农业补贴力度不断提升，但仍存在农业补贴强度相对较低、结构需进一步优化等问题。分析并结合我国农业发展的现状和需求，提出我国农业补贴政策应向农业科技成果转化、农业保险模式、农业旅游经济以及农业生物质能源等方向进行调整和优化。      

谈县级农机维修、销售网点管理

农机维修、销售网点能方便农机户对农机进行维护保养，对改善和提高农机技术状态，促进农村经济的发展，起到了一定的作用，但这些网点存在很多问题，因此加强对农机维修销售网点的管理势在必行。     

Equity of water distribution along secondary canals in Punjab,Pakistan

Equity in the distribution of irrigation water has long been an operational objective for the management of the large canal systems in the north and west of the Indian subcontinent. How well that operational objective continues to be met is the central concern of the research reported in this paper. Detailed studies of canal operations were conducted on three distributaries in the Lower Chenab Canal system in Punjab Province, Pakistan. Mananwala and Lagar Distributaries off-take in the head reach of the Gugera Branch Canal and Pir Mahal Distributary is at the very tail of this Branch. Flow conditions for these distributaries and of selected outlets served by each were measured daily throughout 1988, and data were converted to discharges. These field observations show that discharge variation at the head of distributaries greatly exceeds the original design criteria. The data also indicate that two design assumptions for outlets are no longer valid: continuous full supply water level in the distributary and outlet modular flow conditions. Field measurements confirm that the distribution of surface water among the outlets of all three distributaries is substantially inequitable. Outlets in the channels' head reaches commonly draw 3 to 6 times greater share of total supplies than do tail outlets. Although all three selected distributaries are perennial canals, some outlets remained dry for up to 90% of the total operational days in a year. Finally, evaluation of field data also shows that better operational procedures at the distributary level can substantially improve water supply conditions in the tail reaches.     

Automatic extraction of tank outlets in a sub-watershed using digital elevation models

Watersheds contain many sub-watersheds (SWS) and the existence of a number of “small reservoirs” also called “tanks”, located near the outlet points of the SWS, that serve as water-harvesting and storage structures, is common today. Estimation of the volume of water collected in these tanks, and determining the spatial and temporal distribution of the available water at various locations in the watershed are the two main aspects in agricultural land-use management. While, geographic information systems (GIS)-based approaches are used in estimating the volumes of water, routing is carried out in passing these volumes through the channels to the outlet of the main watershed. Extraction or determination of the location of the outlets of these tanks therefore, becomes essential to know the points where the water is available and wherefrom it could be distributed appropriately. An algorithm was developed for automatic identification or location of tank outlets as well as tank boundaries, wherein the advantages of digital elevation models (DEM), that have become an essential and integral part of distributed, i.e. GIS-based approaches in hydrological modelling, are used beneficially and to overcome the difficulty in locating these tank outlets manually. The details of the algorithm are reported in this paper. A program in ‘C’ has been developed and the algorithm is tested in the study area of Kalyanakere SWS, Karnataka, India and the results of the algorithm match excellently with the field data.     

多孔管允许最大长度的计算

导出了不同地面坡度的多孔管允许最大长度公式，这一成果可用于喷灌及微灌工程的规划设计。     

Application of a hydraulic model for testing management decisions at distributary level

Summary This study was conducted on the Lagar Distributary of Gugera Branch of Lower Chenab Canal, Punjab, Pakistan. A computer model MISTRAL was adopted for evaluating management options. The study showed that the model can be used as a decision support tool for prioritizing management options. The model suggests that under current physical conditions of this distributary the combination of rotation between the distributaries and along the distributary canals can improve the equity of water discharge. For example, in case of Lagar Distributary the discharge of tail outlets can be increased threefold by introducing rotation between the tail of the distributary and an offtaking minor canal. A small decrease in the discharge of the minor would result from adopting this option. A combination of rotations between this and neighboring distributaries and along the Lagar itself can increase the discharge of tail outlets up to seven times. The results of the model indicate that operational changes can improve the discharge of tail outlets to some extent, but the improvement of physical conditions of the distributary is needed to achieve equity conditions, as specified in the design.     

渠道平均流量计算公式探讨

提出流经配水渠道的平均流量应与各配水口在渠道上的分布及其所控制的面积有关 ,并推导了他们之间的关系。采用簸箕李灌区的实际资料 ,比较了计算结果 ,验证了上述结论的合理性。     

The effect of standing water above drains on the water table height midway between drains

Wesseling (1964) stated that standing water above drains as a result of submerged outlets creates a radial flow in the vicinity of the drains which promotes flow conditions so that a smaller rise of the water table height midway between drains results. Wesseling (1979) concluded the same for standing water above drains as the result of too high entrance resistance. Standing water above drains may also be due to overpressure in the drains as a result of too small pipe diameter or to irregular drain slopes. With the exception of submerged outlets the resulting water table rise midway between drains is however in the same order of the water table rise above the drain as can be derived from theoretical analysis. This conclusion was confirmed by measurements at an experimental field where the standing water above drains, as a result of overpressure, and the water table midway between drains were monitored in a field located at the northwest of the Nile Delta. In spite of the low discharge rates, overpressure was observed in the drains. It was mainly attributed to irregular drain slopes. The analysis of field data showed that the water table midway between drains rises at least the same as the water table height above the drains. Since overpressure in drains causes a decrease of the dewatering zone, a careful and accurate installation is of utmost importance for the proper functioning of a drainage system.     

叶片形状对离心泵作透平性能影响研究

为了更好的研究叶轮出口形状对离心泵作透平性能的影响,以一台比转数为65的离心泵作为研究对象,结合数值模拟和模型试验对比分析了不同叶片形状（叶片出口倒圆、叶片出口修挫等）对于泵作透平性能的影响。通过对比原模型计算结果与试验结果对比可知,所采用的数值计算方法具有较高的精度,在设计工况附近,预测值的相对误差为3%,而在小流量工况和大流量工况分别为5%以及8%,且能够准确地模拟出不同流量下的外特性变化情况;通过对比不同叶片形状模型计算结果可知,各个流量下叶片出口修挫的模型扬程和效率都最高,而原模型获得的扬程和效率最低。     

地下滴灌灌水器负压吸泥影响因素试验研究

为了探究引起地下滴灌系统灌水器负压吸泥的影响因素,通过对比试验,研究分析了土壤类型、单次灌水量、灌溉次数、灌水器类型、保水剂和灌水间隔等6个因素对灌水器负压吸泥的影响规律。结果表明,1流量可调式灌水器出水孔外部及内部存在负压吸泥并引起堵塞情况。外部出水孔有3个被堵塞的所占比例最多,为26.7%;泥沙分布主要集中在灌水器出水孔的内侧附近,有极少部分泥沙甚至可以越过内凸边缘,进入灌水器内圈。2压力补偿式灌水器抗负压吸泥的能力强于流量可调式灌水器,压力补偿式灌水器外部出水口及内部未发现有泥沙,而流量可调式灌水器外部出水口及内部有泥沙;灌水器在红壤土中比黄沙土中更容易出现负压吸泥情况,灌水器在红壤土中的内部泥沙量是黄沙土中的1.12~1.76倍。3灌溉方式(单次灌水量、灌溉次数、灌水间隔)对灌水器负压吸泥的影响显著。单次灌水量小的灌水器内部泥沙量较多,灌水器单次灌水量为170 m L内部泥沙量是250 m L的1.61~2.94倍;灌溉次数与负压吸泥量成正比,灌溉次数为16次的内部泥沙量是8次的3.48~5.41倍;在同一灌溉次数的条件下,灌水间隔长度与负压吸泥量成正比。4保水剂能够有效阻隔泥沙进入灌水器内部,在添加了保水剂的灌水器中,其内部未出现负压吸泥的现象。     

基于径向基神经网络优化汽车除霜性能研究

为了提高汽车的除霜性能,在出风口处增加横格栅,然后选择出风口的长度尺寸和出风角度作为设计变量,使用径向基函数神经网络找到设计变量的最优组合方案。经过优化后,前挡风玻璃上的风速分配更合理,并消灭了除霜死角,在20 min时,前挡风玻璃玻璃的霜层基本完全除净,汽车空调的除霜性能得到明显的提高。     

Adjusted friction correction factors for center-pivots with an end-gun

A new method for calculating total friction head loss in center-pivots with an operational end-gun was developed. The proposed methodology is based on adjusting the previous friction correction factors for center-pivots with end-guns in order to correct their paradoxes and shortcomings. Equations presented in the current work are developed for center-pivots with a finite number of outlets along the lateral and constant outlet spacing and discharge as well as constant discharge and variable spacing. The proposed formulas depend on the number of outlets along the supply pipeline, the exponent of velocity term in the friction formula used and the distance that water is jetted by the end-gun. All equations reduce to the well-established equations for the friction correction factor when the end-gun is turned off. The equations presented here compare well to the stepwise friction calculation method, yet correct slight errors in the way that these friction correction factors were calculated in the past.