信息超市

秸秆定向复合板制备让秸秆"变废为宝"最近,西北农林科技大学教授郭康权和博士研究生漆楚生经过3年的试验,研制出了"棉秆束/高密度聚乙烯定向复合板制备",通过碾压、干燥、铺装、热压等工序将棉秆、     

信息超市

秸秆定向复合板制备让秸秆＂变废为宝＂ 最近,西北农林科技大学教授郭康权和博士研究生漆楚生经过3年的试验,研制出了＂棉秆束/高密度聚乙烯定向复合板制备＂,通过碾压、干燥、铺装、热压等工序将棉秆、麦秸、玉米秆、高粱秆等秸秆制成复合板材。这种板材生产成本低、产品性能好、表面美观、应用前景广泛，研究成果已申请国家发明专利。     

棉秆重组方材制备工艺与试验

以棉秆为原料,通过单因素试验研究密度、施胶量和热压温度对棉秆重组方材力学性能的影响.结果表明,在试验范围内,棉秆重组方材的抗弯弹性模量、抗弯强度和顺纹抗压强度随着密度(0.5、0.6和0.7 g/cm3)和施胶量(添加量为绝干棉秆束质量的8％、10％和12％)的增加而增大,随着热压温度的升高(由160℃C升到180℃℃C)先增大后有所减小(由180℃升到200℃).在其他工艺条件相同的情况下,酚醛胶棉秆重组方材的力学性能明显好于三聚氰胺改性脲醛胶棉秆重组方材.与人工林木材比较,密度为0.7 g/cm3的棉秆重组方材,其力学性能和人工林杨木的成熟材相当.     

工艺参数对棉秆重组方材尺寸稳定性的影响研究

尺寸稳定性是衡量棉秆重组方材质量的重要指标之一。为此,通过正交试验研究了密度、施胶量、热压温度和时间4个工艺参数对棉秆重组方材尺寸稳定性的影响。结果表明:在试验范围内,棉秆重组方材的干缩湿胀性表现出很强的方向性,方材上下方向的尺寸干缩率和吸湿膨胀率均小于前后方向;棉秆重组方材上下、前后方向的干缩率和吸湿膨胀率随着方材密度的增加而增大;随着施胶量的增加、热压温度和时间的升高和延长而有所降低。     

黄糊精/秸秆纤维复合材料弯曲性能分

利用模压方法制备了黄糊精/秸秆纤维复合材料,并利用试验方法研究黄糊精/秸秆纤维复合材料的弯曲性能.研究结果表明:在试验条件下,通过对黄糊精/秸秆纤维复合材料弯曲强度和弯曲弹性模量的极差分析发现最优组合相同,即热压温度A=170℃、热压压力B=9.8 MPa、热压时间C=20 min、黄糊精质量D=30 g,并对最优组合进行了试验验证,得出其弯曲强度为15.34 MPa,弯曲弹性模量为2 522.78 MPa.通过对复合材料的弯曲强度和弯曲弹性模量的方差分析发现,热压时间是不显著因素,而热压压力是显著因素.     

海苔片热压粘合工艺参数试验优化

针对现有夹心海苔生产采用单张海苔片逐张加工导致两张海苔片难以准确对齐、夹心料浪费严重、生产效率低等问题，提出一种采用热压粘合将单张海苔片粘合成带状海苔片的加工方法，对这种海苔片热压粘合工艺进行试验研究及参数优化。首先研究了热压温度、热压时间和酒精体积分数对粘合后海苔片韧性和粘附力的影响；然后通过二次回归正交试验及响应面分析，研究了各因素对评价指标的影响规律并建立了各影响因素与评价指标间的数学模型；最后通过对数学模型的求解，进行了海苔片热压粘合工艺参数优化，并对优化结果进行了试验验证。结果表明，热压温度、热压时间和酒精体积分数均对海苔片的韧性和粘附力有极显著的影响(P<0.01),随着热压温度的升高，海苔片韧性降低，粘附力增大；增长热压时间，粘附力增大，但韧性呈现先降后升的趋势；随着酒精体积分数的增加，海苔片韧性逐渐降低，粘附力先升高后降低。优化结果表明，热压粘合的最佳参数组合为：热压温度208.39℃、热压时间2.91 s、酒精体积分数61.52%,此时海苔片韧性可达8.86 N·mm,粘附力为1.36 N。验证试验显示，试验结果与优化结果基本一致，说明所建参数优化模型可靠，优化...     

废植物油脂与废聚乙烯塑料共裂解制备燃油研究

研究在高压反应釜中,利用Zr O2/Al2O3/Ti O2多晶泡沫陶瓷催化剂,催化废植物油脂与废聚乙烯塑料共裂解制备燃油。考察了温度、时间、催化剂添加比例、物料质量比等因素对废植物油脂与废聚乙烯塑料共裂解制备燃油的影响。得到适宜的制备条件为反应温度430℃、反应时间40 min、催化剂质量分数15%、物料质量比1∶1,在此条件下,液体产物产率为65.9%。GC-MS分析表明,裂解液体中饱和烃类产物峰面积比例接近100%,其中97.85%为直链烷烃,并初步推断了废植物油脂与废聚乙烯塑料共裂解机理。产物的部分燃料油性能测定结果表明,裂解燃油热值明显高于生物柴油与0号柴油,密度和运动黏度符合0号柴油的标准,冷凝点和冷滤点均优于生物柴油,低温流动性好。     

疏解棉秆的热风干燥特性及其数学模型

棉秆重组材具有与木质人造板相媲美的优异性能,是棉秆资源利用的新途径。为此,对棉秆重组材生产的重要前处理工序—干燥工艺及疏解棉秆的热风干燥特性进行了研究,可为棉秆重组材的干燥工艺参数的选择和干燥设备的设计提供依据。利用数字型洞道干燥试验装置进行了单因素试验和正交试验,探讨不同热风温度、风速、疏解棉秆的初始干基含水率以及铺装质量对干燥速率的影响,得到改良的Page模型,可以描述疏解棉秆的热风干燥曲线,并分析了模型常数与各因素的关系。     

凹凸棒石改性甘蔗渣/麦秸木质陶瓷制备与性能

为资源化利用甘蔗渣和麦秸等废弃物,以甘蔗渣、麦秸以及凹凸棒石为原料,以酚醛树脂为黏结剂,采用混合后热压再烧结的工艺制备凹凸棒石改性甘蔗渣/麦秸木质陶瓷,试验制备出了各温度点下的木质陶瓷材料并对其真密度、体积密度、显气孔率、抗弯强度、电阻率等性能进行了测试,对该材料的性能、形成机理及规律进行了分析,初步揭示了原料选择、原料配比、温度等参数对制备过程及材料性能的影响。试验结果证明了通过该工艺用甘蔗渣（麦秸）和凹凸棒石制备木质陶瓷的可行性,同时也表明烧结温度对材料性能影响很大,坯体在700～800℃保护气氛下煅烧可提高传统木质陶瓷的强度而不影响木质陶瓷导电性。试验为甘蔗渣（麦秸）等植物残渣以及凹凸棒石的利用提供了新的途径。     

基于响应面法的棉秆压捆试验研究

针对棉秆压缩打捆密度低、压缩打捆装备可靠性差等问题,采用设计的棉秆压捆试验平台,将棉秆含水率、棉秆切断长度、棉秆喂入量和压缩活塞压缩频率作为试验因素,以压缩活塞端面压力、压缩室压力和棉秆压捆密度作为试验性能指标进行棉秆压缩打捆单因素和中心组合试验,建立各试验因素和试验性能指标之间的回归方程,确定各试验因素对性能指标的影响规律,并进行优化计算,对优化结果进行试验验证。结果表明:棉秆压缩打捆的最优组合为棉秆含水率30%,棉秆切断长度25 cm,棉秆喂入量2.15 kg/s,压缩活塞压缩频率110次/min,压缩活塞端面压力13.84 kN,压缩室压力3.36 kN,棉秆打捆密度145.83 kg/m~3,为棉秆压缩打捆机械的设计提供理论指导。     

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。