日光温室作物冠层夏季光照强度与空气温湿度

针对温室内不同时间、位置的环境参数存在变异性,且随天气与季节变化,日光温室冠层光照强度、空气温度和空气相对湿度的分布差异性问题,构建了基于无线传感器网络的环境监测系统。环境感知节点部署在作物冠层位置,集成了光照强度、空气温湿度等传感器。首先,基于实时采集的温室环境数据,采用反距离加权算法进行插值分析,得到环境参数的离散曲面;其次,通过基于质心坐标的K-means聚类算法,得到了温室内连通及非连通区域的代表性特征点;最后,采用半变异函数与变异系数方法对温室环境的空间变异性与时间变异性进行分析。实验结果表明,夏季日光温室在下午表现为高温与高光照,08:00、16:00的光照强度分别为12:00的24.2%、72.9%,08:00的空气温度（27.7℃）较12:00、16:00低约6.0℃,对应的空气湿度（90%）高约30%。晴天最大光照强度分别为阴天、雨天的1.4倍和4.6倍,晴天、阴天最高空气温度高于雨天（29.5℃）约6℃,最小空气相对湿度远低于雨天（84%）。夏季日光温室晴天与阴天表现为高温和低湿,雨天表现为高湿和低光照。各环境参数中,光照强度的空间变异性最强,变程为10.34m。空气温湿度的空间变异性较弱,整体分布均匀。光照强度、空气温度和空气相对湿度的时间变异性均为中等变异程度。环境参数的特征点及时空变化规律有助于日光温室传感器的高效部署,为揭示作物与环境的交互作用提供了基础。     

节能性目光温室冬季栽培关键技术

1温室调控日光温室在冬季主要以保温为主,分为内保温和外保温。（1）内保温。指在日光温室内部覆盖保温设施。在栽培畦上加盖地膜、小拱棚和草帘,有条件的农民可再设保温天幕,若遇连续阴、雨、雪天气,可人工辅助加温。当棚内温度过高时,可适当通风降温。主要通风方法是在日光温室顶端设置通风口通风,未设置通风口的,也应在目光温室中上部扒开薄膜通风。     

日光温室集散热增温蓄热系统的优化与试验研究

为研究设计适用于南疆和田地区日光温室冬季夜间增温蓄热设备,设计了日光温室集散热增温系统,改进了系统集散热器,测试了系统冬季夜间增温蓄热效果,分析了系统对日光温室空气温度、相对湿度以及0cm深土壤温度和15cm深土壤温度的影响和系统集放热效率。试验结果表明：系统在典型晴天试验温室较对照温室温度可以增温4.3℃,试验温室较对照温室平均相对湿度降低8.65%;阴天试验温室较对照温室平均温度增温2.4℃,平均相对湿度降低6.8%,且系统综合平均集热效率为52.6%,表明该日光温室增温系统在和田地区富余的光热资源条件下具有显著效果。     

日光温室内置式太阳能集热调温装置试验研究

为了提高冬季日光温室内的温度,研究开发了贮蓄太阳热能用于夜间温室内加温的太阳能集热调温试验装置.该装置垂直固定在日光温室内靠近北墙的钢筋拱架上,利用冬季晴天时北墙部位的太阳辐射热量使水增温,并把水储存在蓄热水箱内;夜间温室内温度降到一定程度时,利用所贮蓄的热量再给温室加温.试验结果表明:该装置白昼贮热与夜间加温效果明显,白昼集热可使水温提高20℃以上,夜间用蓄积的热量加温,可以使室内气温平均提高约1.7℃以上.     

日光温室后墙保温系统试验研究

为减少冬季日光温室加温能耗,基于空气流动原理设计了温室后墙保温系统。该系统利用风机将温室白天蓄积的热量储蓄在后墙的夹层中与后墙的保温室内,经过热量传导与交换,保证太阳能的高效利用。试验结果表明,在冬季白昼为晴朗、连阴雾霾天(极端天气)下蓄热温室夜间空气温度分别比对照温室平均高3.12和3.17℃,土壤温度分别比对照温室平均高3.2和2.78℃。日光温室蓄热能力的提高,实现了番茄的安全过冬生产。该研究成果对日光温室结构的改进、温度调控有重要意义。     

京郊地区多种类型日光温室温度对比试验

为进一步优化北京市密云区日光温室的结构，提高设施棚室的温度，以密云区现有的3种日光温室为基础，包括主动蓄热型日光温室（G1）、下沉型日光温室（G2）、当地传统的日光温室（G3），利用小气候综合观测仪的温度数据，对比分析了不同天气条件下3种日光温室生长季内的温度变化情况。结果表明：长周期条件下，G1、G2、G3的夜间平均气温分别为14.66、10.21和8.37 ℃；短周期条件下，G1、G2、G3的夜间平均气温分别为15.84、11.08和9.49 ℃；极端低温条件下，G1、G2、G3的夜间平均气温分别为10.63、7.54和6.24 ℃；典型晴天条件下，3座温室的夜间平均气温分别为17.83、11.48和9.16 ℃；典型阴天条件下，3座温室的夜间平均气温分别为9.64、7.03和6.04 ℃。G1型日光温室整体优于G2、G3型日光温室，在极端低温和典型阴天条件下都表现出了较好的保温储温性能，能够在较低温度下满足室内作物的生长要求。因此，主动蓄热型日光温室在北京市密云区具有较好的推广价值。     

不同方式封装的相变材料蓄热效果研究——基于日光温室

相变材料应用于日光温室中可以将温室白天多余的热量转移至夜间,起到调节温度的作用。为此,测试了经过两种不同方式封装后的相变材料在日光温室中的实际应用效果。通过与普通砖墙温室对照分析发现:两种类型相变材料温室均具有一定蓄热保温性能。内渗型相变材料温室比普通日光温室室温晴天夜间平均高0.9℃,阴天夜间平均高0.3℃;外挂型相变材料温室晴天比普通砖墙温室夜间温度平均高0.7℃。通过对两种类型相变材料温室综合应用效果比较发现,内渗型优于外挂型。此结果为相变材料在温室中的应用提供参考。     

基于风机盘管热风供热系统的温室热环境研究

为进一步提高温室供热系统整体供热效率,针对生物质锅炉作为热源、风机盘管作为末端散热装置的温室热风供热系统,建立了试验温室冬季夜间供暖条件下的室内热环境模拟CFD模型,对室内温度场分布进行了数值模拟并与试验结果进行对比。结果表明,二者所描述的温室内温度场的分布趋势相同,各点误差均小于3℃,计算均方根误差为0.66℃,验证了所建CFD模型的有效性。模拟结果表明：采用该热风供热系统可有效提高室内温度,植物生长区域温度范围为12~17℃,植物层温度分布均匀,无较大梯度变化。     

冬季日光温室电热膜和风机组合增温性能研究

针对北方越冬型日光温室在极端天气下需要临时增温的问题,根据热能方程,提出电热膜和轴流风机相结合的短时定向增温方式,并进行了性能试验研究。试验选取晴天、阴天和雨天等,以0.5h为1个测试周期,测试连续加热5、10min和间隔加热10min,在分别配合2台和4台风机的组合模式下,对比分析室内作物冠层平面温度分布情况。试验结果表明:在晴天和小雨天气下使用间隔加热10min和2台风机的加热策略,阴天使用连续加热10min和2台风机的加热策略,能够达到高效且均匀的增温目的,可为日光温室冬季的临时性增温提供指导。     

日光温室保温被卷放位置对温度环境的影响

温室保温被卷放位置影响着室内的太阳能得热及通过前屋面的散热,从而影响着温室温度。该研究以室外气象因子为模拟输入条件,分别模拟晴天、阴天不同保温被卷放位置对12 m跨度日光温室温度环境的影响。保温被卷放位置分别为保温被卷至前屋面一半与至顶2种方案。模拟结果显示：白天保温被卷至前屋面一半的室内空气温度高于保温被卷至屋顶的温度,而夜间2种方案室内空气温度差异不明显;晴天保温被卷至屋顶与卷至前屋面一半相比,可明显提高夜间墙体表面温度,但对后坡的夜间表面温度影响较小。该研究结果对温室生产中晴天、阴天保温被卷的合理放     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。