玉米/大豆不同间作模式下土面蒸发规律试验研究   总被引：9，自引：1，他引：8  

高阳  段爱旺  刘祖贵  陈金平  王和洲  刘战东 《农业工程学报》2008,24(7):44-48

为了准确估算间作农田土壤水分动态变化过程,制定合理的灌溉制度,该文采用微型蒸渗仪测定了玉米/大豆不同间作模式下不同位置处的土面蒸发量,分析了相对土面蒸发强度与表层土壤含水率的关系以及相对土面蒸发强度与叶面积指数的关系.结果表明:玉米/大豆间作模式下,不同位置处的土面蒸发量存在差异,2:3间作的累积蒸发量大于1:3间作;相对土面蒸发强度与表层土壤含水率呈指数递增关系,与叶面积指数呈指数递减关系.  相似文献   

掺沙对盐渍化土壤水盐分布及其蒸发特性的影响     

孙池涛  邓亚鹏  孙玉霞  毛伟兵  米兆荣  张倩  张明明 《排灌机械工程学报》2022,40(3):287-293

为了探明盐渍土水盐分布和土壤蒸发特性对掺沙的响应特征,以山东省滨州市无棣县"渤海粮仓"科技示范区土壤为研究对象,分析了不同掺沙量(沙-土质量比为0,10％,30％,50％和70％,分别以处理CK,T1,T2,T3和T4表示)对盐渍土水盐运移特征和土壤蒸发的影响.结果表明,0～5000 min,处理T1和T2表层0～1 ...  相似文献   

面向储罐碳排放溯源的油品蒸发及油气扩散研究进展     

黄维秋  许雪  娄井杰  张高  鄢永兵  陈风  吴春燕 《油气储运》2022,(2):135-145

储罐油品蒸发及油气扩散行为会对大气环境、社会经济、罐区安全等造成不利影响.以面向储罐碳排放溯源的油气蒸发扩散研究为脉络,从理论、实验及模拟3方面归纳总结了储罐油气蒸发扩散的研究现状及研究成果:通过理论分析揭示了罐内气液相变、气相中的油气传质及气体扩散的潜在机理;通过对现场实测及风洞实验成果进行分析,发现实验研究主要集中...  相似文献   

光响应性阳离子表面活性剂PCDA-C6-NH3+的合成及其对液滴蒸发行为的调控     

张浩  胡君 《农药学学报》2020,22(2):265-269

农药的有效利用与农药液滴在植物叶片上的蒸发过程息息相关。传统表面活性剂虽然可以改变液滴的蒸发模式或速率,但并不能根据外界环境变化对蒸发过程进行主动调节。为实现"自主调控"农药液滴蒸发的目的,本文设计合成了一种含丁二炔官能团的光响应性阳离子表面活性剂(PCDA-C6-NH3+),利用紫外光刺激改变其在液滴中的聚集状态,调控液滴的蒸发过程。该表面活性剂以10,12-二十五碳二炔酸(PCDA)作为骨架,通过酰胺化反应引入末端氨基并质子化后得到。采用紫外-可见光谱研究了PCDA-C6-NH3+的拓扑化学聚合反应,并利用静态表面张力和动态接触角分析了其紫外光照前后的表面活性和蒸发行为。该研究为实现液滴"自主调控"蒸发过程提供了一种新思路,对提高农药利用率具有重要意义。  相似文献   

玉屏风多糖脂质体的制备及表征研究     

张勇军  巴娟  巫辅达  王少杰  蒲文珺  邓桦  杨鸿 《动物医学进展》2019,(7):52-55

优选玉屏风多糖脂质体的最佳工艺并对其进行表征验证。采用逆向蒸发法制备玉屏风多糖脂质体,以膜材比、脂药比和超声时间为考察因素,包封率为评价指标,采用L9(34)正交试验设计优选制备条件,以超速离心法测定包封率,体外释药试验验证,纳米颗粒分析仪和透射电镜测定其粒径大小与形态。制备玉屏风多糖脂质体的最佳工艺为膜材比8∶1,脂药比4∶1,超声时间90s,包封率88.38%,24h累积释放率73.45%,平均粒径132.65nm。制备的玉屏风多糖脂质体具有较高的包封率与良好的缓释作用,粒径和形态较均匀,重现性好。  相似文献   

Analysis for dry and wet years with the WIMISA model of tree-crop competition for windbreak systems in the Sahel     

M. Mayus  H. Van Keulen  L. Stroosnijder 《Agroforestry Systems》1998,43(1-3):203-215

A modelling approach was chosen for analyzing the effects of competition between windbreaks and crops for soil water and radiation in the Sahel. The model has a high spatial and temporal resolution to account for the heterogeneity in a windbreak-cropping system. The model was parameterised for millet (Pennisetum glaucum (L.) R. Br.), the tree species Bauhinia rufescens Lam. and soil characteristics and weather data of Sadoré, Niger. Simulations were run for two wet years (1992 and 1993) and for a dry cropping season (1989). Simulations showed a strong yield reduction up to 2 m from the windbreak due to shading and/or water competition. For Sahelian sites with no access to groundwater, competition for water between trees and crops is likely to occur in the beginning of the rainy season. Water competition was surprisingly highest in the wet year 1992, intermediate in the dry year 1987 and lowest in the wet year 1993. Simulation results indicate that light and water competition depends on rainfall distribution and the period between the seasonal onset of tree and crop growth. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Energy partitioning influenced by tree spacing   总被引：1，自引：0，他引：1  

M. R. Irvine  B. A. Gardiner  A. P. Morse 《Agroforestry Systems》1998,39(3):211-224

An energy partitioning experiment was set-up within an experimental agroforest site at Cloich forest, near Edinburgh. Measurements of turbulent heat fluxes were made – during non stress conditions – both directly by eddy-covariance techniques and in the case of latent heat flux indirectly through closure of the energy budget equation. These measurements were made simultaneously in the thinned plots (one plot at a time) and a reference plot to eliminate differences due to external atmospheric conditions. Observed values of Bowen ratio ranged from 1 to 3.5, with significantly lower values in the thinned plots compared with those measured in the reference plot. On separation of the Bowen ratio into its two components, it was found that sensible heat flux remained constant between plots. The latent heat flux, however, increased as the tree density was reduced. A simple model of the evaporation from the forest plots based on the Penman-Monteith equation and incorporating an under-storey component was developed and was able to accurately replicate the observed results. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

柯夫达潜水蒸发公式中参数的推求     

齐仁贵  苏跃振 《灌溉排水学报》1998,(2)

采用迭代法求解柯氏潜水蒸发量计算公式中的参数。该方法快捷、方便,且计算精度较高,可在计算机上实现。  相似文献   

太阳能-热泵供热弱放射性废水蒸发排放的模拟试验研究     

张璧光  霍光青 《北京林业大学学报》1998,20(5):38-41

该文介绍了用太阳能－热泵供热,蒸发排放净化后的弱放射性废水（简称净化水）的模拟试验研究,分析了环境参数（温度、相对湿度）、供风温度及供热量对蒸发量与蒸发能耗的影响,还与韩国的类似设备进行了性能对比．试验证明此种处理净化水的方法是经济、有效可行的  相似文献   

天山北坡平原区水面蒸发的实验研究   总被引：14，自引：0，他引：14  

周金龙  姚斐 《干旱区研究》1999,16(1):40-43

本文以新疆地勘局昌吉地下水均衡试验场２０ｍ６３水面蒸发池水面蒸发量及常规气象观测资料为基础,应用灰色关联分析方法分析了各气象要素对水面蒸发量的影响程度,给出了Ｅ６０１蒸发四和Φ２０蒸发器水面蒸发折算系数,建立了计算水面蒸发量的经验公式。  相似文献