护岸糙率对梯形河道行洪能力的影响研究

采用仿真草皮和三棱柱砖块模拟生态护岸,通过水槽试验研究了变流量和变底坡工况下梯形河道中护岸糙率的变化规律。通过数值模拟的方法,研究了非均匀流及不同宽深比情况下护岸糙率对河道水面线的影响。结果表明:河道综合糙率随水深的增加而增大,符合对数分布规律,改变流量或底坡对护岸糙率值影响不大;均匀流与非均匀条件下,河道水深均随着护岸糙率的增大而增加;非均匀流条件下,沿程综合糙率与沿程水深呈正相关;护岸糙率较大范围的变化,对宽深比较小的河道水深有较大影响,而对宽浅河道的行洪能力影响不大。     

有压平直管道内交汇柱系下游流场特性分析

为研究管道车作为一种交汇圆柱系式的钝体结构在有压管道流场绕流时,在柱系下游产生的流动分离和尾迹涡现象,运用理论分析与数值模拟相结合的方法,对柱系下游的流场特性进行了研究.数值模拟采用了LES-WALE湍流模型,其结果与物理试验结果比较证明了数值模拟的可行性.对数值模拟结果进行理论分析:首先,由于流动分离柱系后流场中速度分布整体上分为低速流区与高速流区2部分,低速流区主要分布在断面中心位置,高速流区分布在断面外围,呈近似环状分布;其次,流场沿程速度幅值方面,从交汇柱系下游近端断面到远端断面,其中部分低速流区域的整体速度幅值愈高,周围高速流区的速度幅值愈低,并且两区域流场随距交汇柱系距离的增加呈现趋同变化;最后,关于流场的压强特性方面,沿程压强整体呈下降趋势,断面Z6仅与同流量时管道流场断面平均压强相差3.4%.     

秸秆螺旋挤压脱水机叶片强度和变形的流固耦合分析

运用数值模拟方法,对秸秆螺旋挤压脱水机进行了流固耦合模拟分析,建立了秸秆浆料的流体模型,用Fluent软件模拟了不同出口压力条件下,螺旋挤压脱水机内部压力场分布,并据此对螺旋挤压脱水机的挤压性能进行了分析。同时,通过Workbench-Fluent单向流固耦合的方式,对螺旋叶片的强度和变形进行了分析,得出了出口压力和叶片强度的关系。     

大豆蛋白组织化挤压机结构设计、滞留时间测定及试验研究

蛋白质是人体必需的 3大营养物质之一，目前我国人均蛋白质摄取量比世界公认的标准约少 10g/天，而质量上的差距更大。根据目前国情，为了解决这一问题，应大力开发利用蛋白质资源和发展植物蛋白食品的生产。 　　用挤压法加工大豆组织蛋白，可充分利用榨油后的副产品——豆饼。由于挤压机使豆粉受强烈的高温、高压和剪切等作用，消除了大豆所含的多种有害物质，蛋白质更易于被人体消化吸收，淀粉的营养价值也有显著提高，产品成片状，具有多孔性和肉样组织，保水性好，有咀嚼感，类肉性强，易于保存。因此，利用挤压设备加工组织蛋白成本低…     

营养豆奶和豆粉的生产工艺

据营养调查显示，我国平均每人每日摄入蛋白质67g，低于维持人体健康75g的需要量。而大豆中蛋白质含量高达40％。因此，大力开发利用大豆等优质植物蛋白质是提高我国人民蛋白质供应量的一条非常有效的途径。为此，介绍了以大豆为原料生产豆粉，豆粉的工艺，并对生产过程中易产生的问题提出了解决办法。     

不同施肥处理对菜用大豆品质影响研究

研究不同施肥处理对菜用大豆的蛋白质、脂肪和可溶性糖含量的影响。结果表明：大豆脂肪含量与磷酸二铵施用量呈显著正相关;蛋白质含量与磷酸二铵施用量呈负相关;可溶性糖含量与磷酸二铵施用量呈正相关。同样施肥水平下,菜用大豆的蛋白质和可溶性糖含量高于普通大豆,而脂肪含量低于普通大豆。蛋白质含量与磷酸二铵施用量呈负相关,脂肪含量与磷酸二铵施用量呈显著正相关,可溶性糖含量与磷酸二铵施用量呈不显著的正相关。     

弧面凸轮等温挤压成形工艺仿真与参数优化

应用UG和DEFORM软件对弧面凸轮等温挤压成形过程进行了三维有限元模拟,分析了挤压温度、挤压速度、摩擦条件对挤压过程中温度场、应力场分布的影响规律。结果表明:挤压应力和挤压温度会随挤压速度等工艺参数的变化而变化,但它们的分布规律不变。在此基础上,优化了挤压工艺参数:挤压温度为750℃,冲压速度为10mm/s,摩擦因子为0.25。     

不同施肥处理对菜用大豆品质影响研究

研究不同施肥处理对菜用大豆的蛋白质、脂肪和可溶性糖含量的影响.结果表明:大豆脂肪含量与磷酸二铵施用量呈显著正相关:蛋白质含量与磷酸二铵施用量呈负相关;可溶性糖含量与磷酸二铵施用量呈正相关.同样施肥水平下,菜用大豆的蛋白质和可溶性糖含量高于普通大豆,而脂肪含量低于普通大豆.蛋白质含量与磷酸二铵施用量呈负相关,脂肪含量与磷酸二铵施用量呈显著正相关,可溶性糖含量与磷酸二铵施用量呈不显著的正相关.     

大豆籽粒静态压缩特性试验

为了研究大豆在收获、脱粒、输送等过程中的损伤机理及相关力学特性,在电子万能材料物理试验机上对不同品种、挤压方式、含水率和加载速度的大豆籽粒进行静态压缩特性试验.结果表明:加载速度、含水率、品种、挤压方式均对大豆籽粒破损、破裂时的压力峰值有显著影响.试验分析过程及结论对相关研究和大豆专用机具部件的设计具有明显的指导意义.     

新型双螺杆食品挤压机加工复合组织蛋白的研究

采用FTS－50新型双螺杆食品挤压机，对抗压加工复合组织蛋白进行了研究。通过流变试验，测试分析了大豆蛋白面团的动态流变性能，得出了含水量、温度、蛋白质含理对流变行为的影响规律；通过挤压试验，研究了工艺参数（螺杆转速、机筒温度、含水量）与系统参数（生产率、主机功率、比能耗、机头入口处面团温度）的关系，得出了回归方程和表面响应曲面；通过SEM照片分析，研究了挤压前后大豆蛋白质微观结构的变化。     

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。