挤压膨化对玉米秸秆中木质素含量的影响

通过五因素五水平正交旋转组合试验,研究了挤压膨化系统参数(模孔间隙、螺杆末端至模板内表面的距离、套筒温度、螺杆转速和物料含水率)对挤压膨化后的玉米秸秆木质素含量的影响规律,为秸秆纤维生产酒精挤压膨化预处理工艺提供了参考依据.     

挤压膨化参数对玉米秸秆纤维成分含量的影响

针对秸秆纤维制取酒精过程中纤维利用率低问题,利用小型单螺杆秸秆挤压机,采用五因素五水平正交旋转组合试验方法,研究了挤压膨化系统参数:模孔环隙B、螺杆末端至模板内表面的距离δ、套筒温度T、螺杆转速N和物料含水率W,对玉米秸秆纤维(纤维素、半纤维素和木质素)成分比例的影响规律,得出最优参数组合为:B=4 mm、δ=5 mm、T=120℃、N=90 r/min、W=20%,纤维成分含量为:纤维素35.11%,半纤维素31.83%,木质素6.77%.研究结果为秸秆纤维制取酒精的挤压膨化预处理工艺提供参考.     

基于人工神经网络的秸秆螺旋挤压成形机系统建模

秸秆螺旋挤压成形机理比较复杂,系统模型难以进行描述.为此,以物料含水率、螺杆头部与喷孔的出口间隙、物料的粒度为输入样本,生产率为输出样本,利用BP神经网络,建立了秸秆螺旋挤压成形机的系统模型.仿真结果表明:训练好的网络模型具有较高的精度,可以对特定条件进行输出预测,为系统参数优化提供参考.     

挤压系统参数对秸秆挤压膨化机度电产量的影响

秸秆饲料在替代粮食、降低饲养成本方面起着非常重要的作用,它不仅关系到我国资源的合理利用、畜牧业的发展和人民生活的改善,而且关系到环境保护这个千秋大业。为此,通过五因素五水平正交旋转组合试验,研究了挤压膨化系统各参数(套筒温度、螺杆转速、螺杆末端至模板内表面的距离、模孔间隙)和物料含水率对度电产量的影响规律,得出回归方程;并对回归方程得出的最佳参数进行了验证性试验,为实际中应用膨化秸秆生产饲料提供参考。     

挤压膨化参数对玉米秸秆纤维成分含量的影响

针对秸秆纤维制取酒精过程中纤维利用率低问题,利用小型单螺杆秸秆挤压机,采用五因素五水平正交旋转组合试验方法,研究了挤压膨化系统参数：模孔环隙B、螺杆末端至模板内表面的距离δ、套筒温度Τ、螺杆转速N和物料含水率W,对玉米秸秆纤维（纤维素、半纤维素和木质素）成分比例的影响规律,得出最优参数组合为：B=4mm、δ=5mm、T=120℃、N=90r/min、W=20%,纤维成分含量为：纤维素35.11%,半纤维素31.83%,木质素6.77%。研究结果为秸秆纤维制取酒精的挤压膨化预处理工艺提供参考。     

基于人工神经网络的秸秆挤压膨化工艺参数优化

以秸秆挤压膨化的4个工艺参数—秸秆含水率、秸秆粒度、喷嘴出口间隙和螺杆螺距为输入,以生产率为输出,建立了4×9×1结构的BP神经网络模型。训练学习后,用经验数据对所建的模型进行检验,结果表明,该网络模型具有较高的精度。同时,确定了一组最优工艺参数。     

小型单螺杆膨化机加工参数的优化

研究了豆粕挤压膨化系统诸参数(物料含水率、螺杆转速、模孔孔径)对膨化指数的影响规律,及挤压膨化系统最佳参数。试验结果表明,影响试验指标的主要因素是模孔孔径,试验因素主次排列为模孔孔径、物料含水率、螺杆转速。其较优组合模孔孔径为2.31mm,物料含水率为37%,转速为563r/min。     

基于APDL的挤压膨化锥形螺杆的参数化建模

作为挤压膨化机关键部件的螺杆,其结构对膨化物料的性状有着十分重要的影响.所以,能否设计出结构合理的螺杆将直接影响挤压膨化机的性能.为此,利用ANSYS二次开发功能,实现秸秆粗纤维饲料挤压膨化机变根径、变螺距锥形螺杆的参数化建模,为利用ANSYS对各种结构的螺杆进行分析和优化设计奠定了基础.     

玉米粗淀粉挤出物制取葡萄糖浆的响应面分析

以单螺杆挤压系统参数套筒温度、原料含水率、模孔直径、螺杆转速和轴头间隙为试验因子,以玉米粗淀粉挤出物糖化液葡萄糖当量值(DE值)和出品率为响应值,采用五元二次正交回归旋转组合试验设计,寻找符合生产实际的较优数学模型。结果表明,所得回归模型拟合情况良好,达到设计要求。通过典型分析,确定DE值和出品率的最佳工艺参数分别为:套筒温57℃、挤压原料含水21%、模孔直径6mm、螺杆转速248r/min和轴头间隙6mm,或者套筒温度72℃、挤压原料含水21%、模孔直径12mm、螺杆转速192 r/min和轴头间隙17mm。同时,对系统参数和考察指标进行了相关性分析,结果表明:原料含水率与DE和出品率相关性最大;其次为轴头间隙和模孔直径。     

挤压蒸煮小麦作啤酒辅料的糖化试验

通过二次正交旋转组分试验,研究了小麦啤酒辅料挤压蒸煮系统参数(模孔孔径、套筒温度、小麦含水率、螺杆转速和模板内表面至螺杆末端端面的距离)对麦汁主要考察指标(麦汁过滤速度、碘值、浸出物收得率)的影响规律.研究结果表明,挤压蒸煮小麦可以作啤酒辅料,当模孔孔径为12 mm、套筒温度为60℃、小麦含水率20%、螺杆转速为200 r/win、模板内表面至螺杆末端端面的距离为15 mm时,麦汁浸出物收得率为74.38%,高于传统不挤压小麦辅料.     

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。