共查询到20条相似文献，搜索用时 62 毫秒
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响应面法优化苹果真空冷冻干燥的工艺参数 总被引：1，自引：0，他引：1
为提高苹果真空冷冻干燥的单位时间内的生产率,针对其真空干燥工艺中3个主要干燥因素(干燥真空度、物料厚度和干燥温度),利用响应面分析法,对工艺参数进行优化.试验数据采用Design-Expert软件进行多元回归分析,建立了干燥因素与单位时间内生产率之间的函数模型.通过响应面分析,确定苹果的较佳真空干燥工艺条件为:干燥室真空度71.12Pa、物料厚度11.45mm、加热板温度35.35℃,在此优化干燥条件下苹果的单位时间内的生产率为107.2 g/(h·m2). 相似文献
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红外玉米穗干燥试验研究 总被引：1，自引：0，他引：1
为研究红外辐射干燥条件下收获期玉米穗干燥的水分迁移规律,利用自制红外玉米穗干燥试验台对玉米穗进行了恒温和变温干燥试验,探讨了多种温度条件下玉米穗的红外辐射干燥特性及对干燥后玉米穗外观品质的影响规律。结果表明:初始含水率、干燥温度、干燥用时和辐射距离是影响玉米穗干燥效率和外观品质的主要因素;当恒温干燥玉米穗的干燥温度为58℃、辐射距离为150mm时,干燥速率达2.25%/h,且玉米籽粒的外观品质最好;变温干燥玉米穗时,较佳的干燥温度范围为55~65℃,且采用逐渐升温干燥时的干燥品质较好。本研究为研制红外辐射玉米穗干燥机研发奠定了坚实基础。 相似文献
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稻谷干燥缓苏特性与裂纹产生规律研究 总被引：2，自引：0，他引：2
利用声发射系统监测稻谷籽粒热风干燥过程中微裂纹的形成和发展;对稻谷进行了不同条件的热风干燥-缓苏实验,分析了不同缓苏工艺对干燥特性及裂纹率的影响,并探究了现象产生的原因。结果表明:稻谷在干燥过程中一直有微裂纹产生或发展,缓苏工艺可有效抑制干燥后的稻谷籽粒产生宏观裂纹,降低净干燥时间;恒温干燥温度以40、45℃为宜;等温度干燥-缓苏条件下,干燥温度可提高到50℃,裂纹率增值合格;在低温干燥-高温缓苏工艺中,当缓苏温度比干燥温度高15℃时,干燥时间最短,产品裂纹率增值不超过3%,随缓苏温度提高,所需的缓苏时间越短。研究结果可为节能高效的稻谷干燥工艺研究提供借鉴。 相似文献
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甘薯全粉滚筒干燥生产工 总被引：1，自引：0，他引：1
选用甘薯(徐薯23)为原料进行滚筒干燥加工工艺的研究,以甘薯全粉的堆积密度及色差值为指标,采用响应面分析法,研究了进料温度、进料质量分数、滚筒转速、滚筒表面温度对滚筒干燥工艺的影响.确定的甘薯全粉滚筒干燥工艺最佳组合为:进料温度42℃,进料质量分数13.6%,滚筒转速3.0r/min,滚筒表面温度143℃.该条件下生产的甘薯全粉堆积密度为0.51g/mL,多项验证试验值在95%的置信区间内很好地符合了预测值,说明利用该模型在实践中进行预测是可行的. 相似文献
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冲孔网板双循环穿流热风干燥试验台设计 总被引：1，自引：0，他引：1
根据果蔬干燥特性和穿流带式干燥的原理及特点,在分析穿流干燥工艺的基础上,建立双循环穿流干燥试验台.该试验台为上下穿流循环系统,各系统均可独立运行,穿流风速0～10 m/s,温度30～150℃,相对湿度0～100％,可实现自动进风和排湿、能耗显示、各参数显示及记录等功能.在该试验台进行了红辣椒干燥试验,研究了前期干燥温度、后期干燥温度和铺料厚度因素对干燥单位能耗的影响,得出前期干燥温度70℃(20 min)+60℃ (40 min),后期干燥温度55℃,铺料厚度14 cm的干燥工艺可获得最少单位能耗. 相似文献
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Overland water and salt flows in a set of rice paddies 总被引：1，自引：0，他引：1
E. Playn O. Prez-Coveta A. Martínez-Cob J. Herrero P. García-Navarro B. Latorre P. Brufau J. Garcs 《Agricultural Water Management》2008,95(6):645-658
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. 相似文献
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车用发动机润滑油失效规律与更换周期研究 总被引：7，自引：0，他引：7
研究在正常使用条件下１０Ｗ／３０－ＱＣ级润滑油用于某型车用发动机时所表现的失效规律,确认期服从两参数Ｗｅｉｂｕｌｌ分布,并给出分布的尺度参数η和形状参数ｍ之最佳线性无偏估计（ＢＬＵＥ）同时,还为定量分析,计算车用发动机润滑油的使用可靠性和合理确定其更换周期提供了一套可供借鉴的方法,并给出了具体的计算实例。 相似文献
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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。 相似文献
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对《种子法》存在问题的探讨 总被引：1，自引：0，他引：1
李鹏 《农业机械化与电气化》2011,(6):129-130
《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。 相似文献
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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。 相似文献
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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。 相似文献
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赵国杰 《农业机械化与电气化》2011,(4):106-107
乡（镇）农技推广体系是农业发展的关键。介绍朝阳市农业技术推广体系的现状,针对目前体制及运行机制、服务手段等方面存在的问题,提出适合朝阳市乡（镇）农技推广体系改革与发展的对策,以期对全省农技推广体系改革和发展起到一些借鉴作用。 相似文献
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苑庆刚 《农业机械化与电气化》2010,(3):52-54
草莓果味酸甜爽口,营养价值高,为人们所喜爱的应市鲜果之一。由于草莓易受损伤和微生物侵染,因此其采收、贮藏过程极为重要。介绍草莓采收过程中的注意事项以及11种贮藏保鲜技术的实施步骤和操作方法,推介9种加工方式,为草莓产业化提供技术支持。 相似文献
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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. 相似文献