节水压采区农业种植结构多目标优化研究——以衡水市为例

针对节水压采区水资源紧缺、种植结构不合理、灌溉定额较大等问题,提出了基于作物水分生产函数的多目标种植结构优化模型。以衡水市为例,以种植结构和灌水量为优化变量,以经济效益最大和总灌溉水量最小为优化目标,建立了多目标优化模型,通过改进的NSGA-II算法进行优化计算,得出了不同灌溉水价水平下对应的种植结构和灌水量调整方案。结果表明,小麦种植面积比现状种植面积有所减少,玉米、花生等耗水量小的作物面积有所增加。通过优化,合理提高灌溉水价可促进高耗水作物种植面积的减少,扩大低耗水作物种植面积。     

塑料大棚温室沼气池圈坑式水压间的设计建议

塑料大棚温室沼气池圈坑式水压间的设计建议姜锋唐作英（山东省科学院能源研究所２５００１４）孙恕善（山东省农业厅农村能源办公室）我国农村户用三联通水压式沼气池，具有结构简单、施工方便、产气积肥等多种功能。同厕所、猪圈相结合，形成养殖—沼气—种植生态系统良...     

石家庄市推广节水小麦品种、实现节水压采目标的措施探讨

结合工作实践,简要论述了石家庄市推广节水小麦品种、实现节水压采目标的具体措施,供参考。     

蛋鸡的四种饮水用具介绍

正养鸡用的饮水器,可分为槽式、塔式、乳头、杯式等几种,都要求在鸡舍内配套水箱,且对水压与水质均有要求,还须按产品说明书安装与使用(以请技术工人安装为好)。槽式饮水器槽式饮水器是一种最普通的饮水装置。其优点是结构简单,供水可靠;缺点是水易     

浅谈泵房供水管理的几点建议

从抓泵房供水水压、抓泵房供水人员的技能和选泵房供水负责人、抓机电维修和保养方法介绍了泵房供水管理。     

常见沼气池建设存在的问题和解决办法

底层出料水压式户用沼气池,在平安县已推广五年,取得了较好的建池成效。但有的地方在建筑施工中,没有严格按标准施工,或者长期不保养池内壁,使部分沼气池出现了一些质量问题,导致沼气池漏水、漏气。不能运行或反复维修,这样即浪费了人力、物力、财力,又影响了沼气效益的发挥,通过这几年的实践摸索,在沼气池建设方面存在如下几点问题和解决办法。     

Canopy Temperature Depression as a Potential Selection Criterion for Drought Resistance in Wheat

Field studies were conducted at Bushland, Texas, USA, in 2004 to examine usefulness of canopy temperature depression （CTD）, the difference of air-canopy temperature, in screening wheat （Triticum aestivum L.） genotypes for yield under dryland and irrigated. Forty winter wheat genotypes were grown under irrigation and dryland. CTDs were recorded after heading between 1 330 and 1 530 h on 6 clear days for dryland and 9 days for irrigation. Drought susceptible index （DSI） for each genotype was calculated using mean yield under dryland and irrigated conditions. Genotypes exhibited great differences in CTD under each environment. The dryland CTDs averaged 1.33℃ ranging from -0.67 to 2.57℃, and the average irrigation CTD were 4.59℃ ranging from 3.21 to 5.62℃. A low yield reduction was observed under dryland conditions relative to irrigated conditions for high-CTD genotypes. CTD values were highly negatively correlated with DSI under dryland, and genotypes of CTDs = 1.3℃ in dryland condition were identified as drought resistant. For 21 genotypes classified as drought resistant by DSI, their CTDs were 1.68℃ for dryland and 4.35℃ for irrigation on average; for 19 genotypes classified as drought susceptible by DSI, average CTD was 0.94℃ in dryland and 4.85℃ in irrigation. The high-yield genotypes consistently had high CTD values, and the low-yield ones had low CTD values for all measurements in dryland. After heading, genotypes maintained consistent ranking for CTD. Regression results for CTD and yield suggested that the best time for taking CTD measurement was 3-4 weeks after heading in irrigation but any time before senescence in dryland. Crop water stress index （CWSI） calculated from CTD data was highly correlated with CWSI calculated from yield, which suggesting traditional costly CWSI measurement may be improved by using portable infrared thermometers. Most importantly, grain yield was highly correlated with CTD under dryland （R^2 = 0.79-0.86） and irrigation （R^2 = 0.46-0.58） conditions. These results clearly indicated grain yield and water stress can be predicted by taking CTD values in field, which can be used by breeding programs as a potential selection criterion for grain yield and drought resistance in wheat, but a second study year is needed to confirm further.     

临夏槐树关水库输水管道布置与设计

输水管道工程始于水库输水泄洪洞的输水叉管末端控制蝶阀，沿槐树关河左岸或右岸布置至原槐树关水源地（铁寨）引水枢纽为上段，线路长18.735千米，然后从原铁寨引水枢纽布置至原大夏河罗家堡水源地为下段，线路长17.86千米。全线线路总长36.6千米。     

农村家用沼气池修建常识问答

1.关于修建沼气池的标准有哪些。怎样修建沼气池,修建沼气池使用什么材料,沼气池修好了怎么判断它的质量是否符合使用要求,这些问题在下面的国家标准中即能找到答案.关于修建沼气池的标准有：GB4750农村家用水压式沼气池标准图集,GB4751农村家用水压式沼气池质量验收标准,GB4752农村家用水压式沼气池施工操作规程,GB7637农村家用沼气管路施工安装操作规程,GB9958农村家用沼气发酵工艺规程,GB7959粪便无害化卫生标准,DB21/T-835-94北方农村能源生态模式标准.     

简便实用的砖模卡具

近年来,我们推广的户用水压式沼气池,基本上采用混凝土浇注结构或混凝土池墙加砖拱盖结构。在建池施工中,多数都使用钢制或木制模具进行整体浇注。实践证明这两种模具在使用过程中都存在明显的缺点。而采用砖模的建池过程一般都有没有专用卡具,只是边砌砖边用尺量一下,尤其是用砖拱盖,由于没有专用卡具结果造成拱盖的形状不符合曲率半径尺寸。建池模具、卡具的不理想、不完备,造成了建池速度和质量等方面的严重问题。