水稻免耕原茬带水压耙试验

针对水田翻耕整地作业繁杂、费时费力、耗水量大等问题。选择具有代表性的稻田进行免耕原茬带水压耙试验。结果表明，这种压耙方法，简便易行，节水100m^3/667m^2，节支17.4元/667m^2，增产13.6kg/667m^2，增收17.68元/667m^2。是抗旱种稻的一项重要技术措施。     

Modulation of leaf conductance by root to shoot signaling under water stress in Arabidopsis

Signal communication between root and shoot plays a crucial role in plant resistance to water stress. While many studies on root to shoot signals have been carried out in many plant species, no information is available for the model plant, Arabidopsis, whose adoption has great significance for further probing the molecular aspects of long distance stress signals. Here, we introduced the establishment of techniques for investigations of root to shoot signals in Arabidopsis. Stomatal movements in relation to root signals were probed by using these techniques. The results show that Arabidopsis is a suitable plant species for partial roots drying (PRD) experiments. In the PRD system, while no significant differences were found in leaf water potential between well-watered and stressed plants, water stress led to a decrease in leaf conductance, which suggests a regulation of stomatal movements by root to shoot signals. While water stress caused a significant increase in the concentration of sap abscisic acid (ABA) of xylem, no increase in xylem sap pH was observed. Moreover, the increase in the ABA content of xylem coincided with the decrease in leaf conductance, which suggests a possible role of ABA in the regulation of stomatal movements. Infrared temperature images showed that leaf temperatures of PRD plant were higher compared with those of well-watered plants, which further indicates that stomatal movements can be modulated by root signals. The confirmation of root to shoot signaling in Arabidopsis has established a basis for further investigation into the molecular mechanisms of the root to shoot signaling under water stress.     

YC大厦后浇带渗水原因分析

根据工程实例分析了基础地下室工程后浇带渗水产生原因,进行有效的修补,从而保证了工程质量.     

水压式沼气池的几点小改进

原水压式沼气池(以下简称原池)用草粪原料时,由于草粪上浮缺水,发酵不充分,不仅产气少、换料也很困难。为了解决这些问题,开发利用山区丰富的草粪资源,我们对水压式沼气池几经改进。获得初步的成功,产气低、出料难问题基本得到解决,     

反料流新型水压式沼气池

遵循国家标准，结合本地农户在生产、生活方面的新需求。我们设计、建造了一批反料流新型水压式沼气池，现介绍如下.     

侵蚀坡耕地土壤强度变化特征

Undisturbed soil cores were taken from different slope positions （upslope, backslope and footslope） and soil depths （0-15, 20-35 and 100-115 cm） in a soil catena derived from Quaternary red clay to determine the spatial changes in soil strength along the eroded slope and to ewluate an indicator to determine soil strength during compaction. Precompression stress, as an indicator of soil strength, significantly increased from topsoil layer to subsoil layer （P 〈0.05） and was affected by slope position. In the subsoil layer （20-35 cm）, the precompression stress at the footslope position was significantly greater than at the backslope and upslope positions （P 〈0.05）, while there were no significant differences at 0-15 and 100-115 cm. Precompression stress followed the spatial wriation of soil clay content with soil depth and had a significant linear relationship with soil porosity （r^2 = 0.40, P 〈 0.01）. Also, soil cohesion increased with increasing soil clay content. The precompression stress was significantly related to the applied stress corresponding to the highest change of pore water pressure （r^2 = 0.69, P 〈 0.01）. These results suggested that soil strength induced by soil erosion and soil management wried spatially along the slope and the maximum change in pore water pressure during compaction could be an easy indicator to describe soil strength.     

改进型农村家用水压式沼气池简介

198 4年 ,《农村家用水压式沼气池标准图集》颁布实施 ,极大地推动了我国农村户用沼气池的发展 ,对规范沼气建设及提高建池质量发挥了极其重要的作用。时至今日 ,其技术上的缺陷日益暴露出来 ,为此 ,笔者针对国标水压式沼气池存在的技术问题 ,做了一些技术改进。现介绍如下。1　改进池的结构改进的池型结构见图 1。图 1　改进型水压式沼气池结构示意图1 进料口　 2 进料管　 3 发酵间　 4 贮气间　 5 人孔反盖　 6 导气管7 出料器　 8 水压间　 9 出料孔　 10 贮肥间　 11 分流板　 12 塑料地膜2　特点2 1　改变了形体尺寸众所周知 ,…     

新型活动罩水压式沼气发生装置及施工方法

沼气，作为无污染的再生能源，得到政府高度重视并在农村大力开发和推广使用。现行水压式沼气池建造成本虽低，但施工难、出料难、维护难、气密性差。本文介绍的新一代活动罩水压式沼气发生装置，继承了水压式沼气的主要优点、克服了“三难一差”的缺陷，实现了沼气池建造技术新飞跃。