冷冻熟制面条保温加热及速冻节能加工工艺

为了降低生产耗能,提高能源的利用率,该文通过引入保温加热工序以及优化速冻工艺参数,得到冷冻面条的节能加工工艺。从质构特性、白度值、糊化特性以及水分状态等方面,结合感官和单位耗电量对冷冻面条工艺参数进行了优化。得到最佳工艺参数:煮制3 min保温加热4 min,在-40℃下速冻20 min。此工艺下的感官得分为85.5(75),单位质量耗电量为3.47 k W·h/kg。与原生产工艺相比:在色泽、表现状态、适口性、光滑性、食味、总分等感官指标上没有显著性差异(P0.05),在能耗方面降低17.18%(P0.05)。结果表明:在保证一定品质的前提下,通过保温加热和减少速冻时间来达到节能的目的是可行的。成本分析结果表明:使用节能工艺生产冷冻熟制面条可节省805元/t。以上研究结果为探索冷冻面条的节能工艺提供生产依据和参考。     

Assessment of soil structure repair due to wetting and drying cycles through 2D tomographic image analysis

Soil structure is very important in agriculture since it affects soil and plant root attributes, such as root system distribution, soil water and nutrient transport, and heat transfer. Degraded soil structures may be repaired by wetting and drying cycles due to changes in the soil pore system. Gamma-ray computed tomography (CT) was used as a tool to evaluate the effect of wetting/drying cycles on soil structure repair, using samples collected in aluminum cylinders. A first-generation tomograph with an ²⁴¹Am source and a 7.62 cm × 7.62 cm NaI(Tl) scintillation crystal detector coupled to a photomultiplier tube were employed. Image analysis and tomographic unit profiles showed that CT can provide an insight into sample structure in order to evaluate repairs and so improves the use of this tool in relation to the judgement of the quality of measured soil physical properties.     

微波干制南瓜片干燥规律及工艺优化研究

进行了微波干燥南瓜片干燥脱水与耗电试验，获得微波干燥南瓜片失水特性及耗电特性，并建立了微波干燥南瓜片干燥模型；进行了4因素4指标的二次正交回归试验，得出各指标(外观质量、复水系数、单位时间降水率及单位耗电量)的回归方程，采用了非线性规划对各指标进行目标优化，得出各目标函数的发射功率、切片厚度、前期时间、缓苏时间的最优组合，并对4因素对4指标影响的显著性分析、参数综合优化，提出了参数的最佳组合。     

灌溉水温对冻融土入渗规律的影响

在冬春灌溉期间,由于灌溉水源、灌溉方式、灌溉时间不同,当水流入农田时,将具有不同的水温。灌溉水温不同,在相同的灌溉水量条件下,其热容量不同,导致土壤温度分布不同,必将影响到冻土的入渗规律。该文通过土壤冻结期间积水入渗试验,获得了不同入渗水温条件下冻土的入渗规律。试验结果表明,入渗水温对冻土入渗规律的影响十分明显,冻土的入渗能力随入渗水温的升高而增强。研究结果对于季节性冻土壤区冬春灌溉合理灌水技术参数的确定提供依据     

Microbial response time to sugar and amino acid additions to soil

Soil microbial respiration is derived predominantly from the turnover of carbohydrates and proteins in soil. In most agricultural ecosystems, these C compounds enter soil mainly from rhizodeposition (root exudation and turnover). Our aim was to determine how long it takes for the microbial population to reach their maximum mineralization potential after the addition of low-molecular-weight (MW) rhizodeposits to the soil. We added sugar in the form of glucose and amino acids in the form of glycine to an arable, grazed grassland, Eucalyptus forest and boreal forest soil and monitored CO₂ efflux over a 6-h period. Artificial rainwater amended (zero C addition) or unamended soils were used as controls. The Michaelis-Menten substrate utilization profiles showed vastly different patterns of microbial mineralization capacity and substrate affinity between the soils. However, in all soils we showed that activation of the soil microbial community to C addition occurred almost instantaneously (?60 s) with the average time taken to reach half maximal CO₂ production being 14±8 min for glucose and 10±8 min for glycine. After reaching their maximal mineralization potential, the rate of CO₂ evolution remained constant for the remainder of the experiment. Our results showed that while substrate uptake and mineralization within the soil microbial biomass was activated quickly, subsequent adaptation and upregulation of its C processing capacity did not occur at least in the short term. The fast rate of microbial activation and substrate use we partially attribute to the large degree of functional redundancy that exists within the soil microbial community for processing rhizodeposits.     

不同干燥方法对生姜粉物理性质的影响

采用离心喷雾干燥、热风干燥、远红外干燥、真空冷冻干燥对安徽临泉产新鲜生姜进行干燥制粉，研究干燥制粉后的生姜粉的物理性质。结果表明：喷雾干燥的生姜粉容重较高，而得率、水合能力、吸油能力以及感官性能都是最差的；远红外干燥的生姜粉得率和容重最高，水合能力、吸油能力及感官性能较好；热风干燥的生姜粉水合能力最好，而得率、容重、吸油能力和感官性能都仅次于远红外干燥的姜粉；真空冷冻干燥的生姜粉得率和水合能力居中，容重最低，吸油能力和感官性能最好。     

谷物干燥节能技术

作者通过开发谷物干燥模拟研究实践和对国内外已有研究成果的分析,对谷物干燥中的节能技术按以下几方面作出了评述:1.数学模拟和优化技术在改进干燥机结构和工艺参数、降低能耗方面的应用,2.新型节能干燥工艺的开发,3.干燥机排气余热回收再利用,4.基于新机理上的干燥工艺。     

中国主要粮食作物产后损失特征及减损潜力研究

为减少作物产后损失,增加粮食供应数量。该文基于物质流分析方法以及农产品流动特征,建立了一套量化作物产后损失的计算方法,在已有数据基础上,重点分析了2010年中国三大粮食作物(水稻、小麦和玉米)产后(包括收获、运输、干燥和储藏)损失特征及其减损潜力。结果显示,中国作物产后损失率较高,水稻、小麦和玉米产后综合损失率分别为6.9%、7.8%和9.0%,三者平均损失率7.9%,高于发达国家作物产后损失水平。粮食产后损失中,储藏环节损失比重最高,损失比例达到40.3%,其次是收获环节,为31.4%,运输和干燥环节损失较小,分别为11.1%和17.2%。农户储藏和收获是作物产后减损的重点环节。情景分析结果显示,通过改进产后不同环节技术条件,可以有效减少作物产后损失,情景5(粮食产后环节技术条件达到最优)三大粮食作物产后损失率均可以降低到4.0%以下。由此可见,中国粮食作物产后减损存在较大潜力,减损重点应落在农户储粮环节以及作物收获环节。作物产后减损需要国家农业科技政策作保障,通过提升农户科学储粮意识以及提高作物机械收获水平和改进作物收获质量等综合措施,最终实现中国粮食作物产后损失的降低。研究结果为中国粮食产后减损政策和措施的制定及实施提供借鉴。     

采用太阳能集热器干燥玉米的研究

介绍了采用太阳能集热器干燥玉米的机理与实验装置的设计。在不同季节，采用太阳能集热器对玉米干燥过程进行了试验，测出了采用太阳能集热器干燥玉米的特性曲线，并对干燥曲线进行了分析与讨论；实验得出，采用太阳能集热器干燥玉米能满足玉米干燥的工艺要求，从而为大规模利用太阳能干燥玉米示范性工程的建设提供了科学依据。     

我国中草药干燥的现状及发展趋势

通过对我国中草药干燥现状及主要存在问题的分析，提出了中草药干燥的发展趋势，阐述了真空冷冻、微波、远红外、热泵等新型干燥技术的应用原理，中草药干燥前预处理的重要性，并对中草药干燥发展的现实意义及市场前景进行了讨论。