机制砂对混凝土拌和物含气特性影响规律研究

针对不同砂率、石粉含量、细度模数、颗粒级配的混凝土拌和物含气量展开试验研究，分析了机制砂对混凝土拌和物含气特性的影响规律。研究结果表明：混凝土拌和物含气量随砂率在一定范围成递增关系，随石粉含量、细度模数增大成递减关系；0.15～0.3 mm粒径范围的颗粒含量减少时，混凝土的含气量明显降低，0.3～0.6 mm粒径范围的颗粒含量增大时，混凝土的含气量显著增加，0.6～1.18 mm粒径范围的颗粒含量对含气量影响较小。研究结论可为机制砂混凝土配合比提供参考依据。     

太阳能-空气源热泵牧草干燥系统制热性能研究

以太阳能-空气源热泵牧草干燥系统为研究对象，通过系统不同工作模式的温升、恒温制热试验及带载试验，分析了温升速率、单位温升能耗、COP及除湿效率。研究结果表明：联合制热模式与太阳能单独制热相比，单位温升耗电量降低了86.2%,温升速率提高了99～112倍。联合制热模式与热泵单独制热试验相比，在温升过程中温升速率降低了7.7%～17.6%,单位温升耗电量降低8.0%;在恒温制热过程中，前者COP比后者提高了6.5%～11.1%,耗电量降低了5.8%～10.7%;在升温制热过程中前者COP比后者提高了6.0%～10.4%,耗电量降低了6.6%～11.1%。联合干燥模式比热泵单独干燥模式的SMER值高19.8%～36.2%。     

喷灌用镁合金管道成形工艺

研究了镁合金挤压模具及工艺参数．根据镁合金特点设计了4孔分流挤压模具，选择MB2镁合金在1250T卧式挤压机上进行了挤压试验．通过试验得到的主要工艺参数为：镁棒预热温度为548～698K，模具预热温度530～673K，挤压筒温度573～723K，挤压速度0．067～0．083m／s及挤压比40～60，与铝合金管相比，3种规格的镁合金管具有良好的力学性能和机械性能，可完全满足喷灌工程的需要．     

温室番茄滴灌灌水指标试验研究

研究了日光温室中番茄的需水量、需水规律、产量与耗水量的关系。对日光温室番茄进行了滴灌灌水制度的研究。根据番茄不同生育期的生理特性及其需水特性确定其相应适宜的土壤含水率范围（占田间持水量的百分比）为：苗期45％～55％，开花坐果期55～75％，坐果期65-85％。不同生育期的灌水定额为：苗期10～15mm，开花坐果期15-25mm，结果期20-30mm。     

建立灌排一体蓄水小区的试验研究

建立灌排一体蓄水小区的试验研究李守玉，蒋虎，杨培枢，宫清云（黑龙江省水利科研所哈尔滨１５００８０）三江平原位于黑龙江省东部，在东经１３０°～１３５°、北纬４５°～４８°之间，总面积１１万ｋｍ２，现有耕地面积３３３万ｈｍ２，其中平川低洼地１５３万ｈｍ２...     

三峡工程运用对洞庭湖区滨湖城市

三峡水库蓄水运行后,长江下游径流过程不同于建库前.按三峡水库供水期（5月1日～6月10日）；三峡水库洪水期（6月～9月）；三峡水库枯水期（12月～次年4月），三种情况，分析研究了由于水库调节径流过程改变，供水期与枯水期下泄量加大，洪水期腰峰过程延长，从而引起洞庭湖区相应时期水位抬高，持续时间延长，给滨湖城市排涝带来的负面影响。     

三峡工程对洞庭湖区滨湖城市排涝的影响

三峡水库蓄水运行后，长江下游径流过程将不同于建库前。按三峡水库供水期（5月1日～6月10日）、洪水期（6月～9月）、枯水期（12月～次年4月）3种情况，分析研究了由于水库调节径流过程改变，供水期与枯水期下泄流量加大，洪水期腰峰过程延长等原因，从而引起的洞庭湖区相应时期水位抬高且持续时间延长，给滨湖城市排涝带来的负面影响。     

半轴齿轮加堵碳氮共渗工艺

一、前言120、150型拖拉机的半轴齿轮（见图1），其材料为20CrMnTi，要求表面硬度为58～64HRC，心部硬度35～48HRC，金相组织为碳化物l～6级，马氏体、残余奥氏体1～5级，铁素体l～4级。半轴齿轮小瑞花键孔壁薄，而且长度占总长的一半左右，由于这种结构特点，使得小端在拉孔和热处理后都有不同程度的收缩，尤其在热处理后最为严重，致使花健精度达不到技术要求，不能装配使用。对此，专业技术人员进行了大量的试验研究，总结出以下几种生产工艺。一是花键孔镀银防渗工艺，在渗碳淬火后用推刀或拉刀精加工花键。二是先渗碳缓冷，然后加…     

减粘降阻仿生犁壁的研究

在仿生表面改形和表面改性研究基础上，根据机引犁壁工作特性，研制出具有减粘降阻功能的仿生犁壁。实验室试验及田间运行结果表明，该犁壁可比普通犁壁减少油耗５．６％～１２．６％，降低犁耕阻力１５％～１８％，并具有较好的脱土性和耐磨性     

土豆间作“开心棉”一亩收入三千元

土豆间作“开心棉”一亩收入三千元河北省乐亭县徐家店乡”两高一优”农业农民研究协会，经过三年试验示范，探索出一条地膜土豆间作“开心棉”的种植新模式。一般亩产土豆２０００～２５００公斤，皮棉１００～１２０公斤，两者合计收人３０００元，比单作棉田增加效益２...     

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。