苜蓿干燥方法及其对成品品质的影响

对我国目前主要的苜蓿干燥方法进行了综述，对各种不同的干燥方法对苜蓿草产品的品质影响进行了分析和探讨。     

苜蓿叶、茎秆与压裂茎秆干燥特性对比

在薄层干燥试验台上进行薄层干燥试验，分别研究了苜蓿叶、茎秆、压裂茎秆在不同条件下的干燥特性，并对其进行对比，为苗蓿干燥时干燥工艺的确定提供一定的理论依据。     

利用蛋白质组学技术探究叶绿素含量对植物生长的影响

本研究基于蛋白质组学技术,结合主成分分析和偏最小二乘法判别分析等方法探究叶绿素含量对植物生长的影响。依次收集冷处理前、冷处理后和复性3个阶段的水稻幼苗叶片,测定叶绿素含量,同时进行蛋白质组学分析。将蛋白质组与叶绿素含量的变化结合进行差异蛋白质组学分析,通过通路分析富集出淀粉蔗糖代谢、糖酵解途径等7个代谢途径,筛选出与叶绿素含量强相关的近30种酶。通过探寻与叶绿素含量变化相关的代谢途径,从蛋白质组学角度证明叶绿素含量可以作为植物生长健康状况的重要指标。     

微波干燥过程数学模型建立与分析

介绍微波的定义、应用现状以及微波干燥的特点,通过一系列数学推导给出微波干燥过程的数学模型,并对其中的一些问题进行讨论.     

烟剂对大棚藜麦菜光合作用和叶绿素含量的影响

在藜麦菜的温室大棚种植中,用12%百菌清烟剂与12%速克灵烟剂防治病害较为常用。为了研究这两种烟剂对藜麦菜的叶绿素含量和光合作用的影响,施用烟剂后第3天和第5天分别进行藜麦菜叶片叶绿素含量和光合速率的检测。结果显示,施用烟剂可以提高藜麦叶绿素的含量,提高光合速率,进而提高生产率。     

氧化铝气流干燥过程数值模拟

根据两相流理论,通过分析气流干燥特点,建立含湿氧化铝颗粒直管气流干燥过程的一维数学模型.对模型进行数值模拟,模拟结果与实验测试值较吻合,该模型可用于含湿氧化铝颗粒直管气流干燥过程的各参数预测.     

EM浸种处理对玉米叶色值的影响

以玉米品种农大108为试验材料,用SPAD-502仪分别测定了不同浓度EM稀释液浸种处理后的叶色值.试验结果表明利用不同浓度EM(有效微生物群)稀释液浸种及在玉米拔节期叶面喷施并灌根,可显著提高玉米叶片的叶绿素含量.并遴选出玉米施用EM的最佳浓度为500倍稀释液.     

电热热风循环干燥炉新型炉体结构解析

新型炉体结构是指炉体侧板为薄钢板弯曲成型，板块式组合结构，而原结构为整体钢结构构架，内外侧用钢板覆盖。另外，加热系统均分为几个加热单元，加热腔嵌在炉体内。而原结构为一个加热单元放置在炉顶中部，统一加热。新型结构对比旧式结构最大的优点就是节省钢材、加热均匀、降低噪音。     

油茶幼苗叶片叶绿素含量的检测分析

充分利用我国木本油料资源,对保障粮油安全,改善生态环境等具有重要意义.文章采用植物遗传育种学、生物统计学等方法,调查测定油茶叶片相关性状,比较分析不同油茶品种幼苗叶片不同部位叶绿素含量,以期为快速鉴别油茶适应性提供依据,为利用杂交育种培育高光效油茶新品种奠定基础.     

菊花热风烘房的流场模拟及结构优化

采用多孔介质模型对结构优化前后菊花热风烘房烘干室的流场进行了数值模拟研究,根据引风罩角度与长度提出了9种优化方案,考察了不同引风罩下烘干室气流组织的分布特性.结果表明:烘干室原始结构在进风口局部区域风速过大,前后、上下空间内风速较小,气流组织分布不均匀.相比原始结构,9种优化方案中,引风罩θ=20°,L= 150 mm...     

Evaluation of a hot oil immersion drying method for the upgrading of crushed low-rank coal

Coal is the most abundant fuel on earth, and low-rank coal (LRC) such as sub-bituminous coal and lignite makes up about half of all coal deposits. LRC is inconvenient to use due to its low caloric value and high content of moisture together with the strong tendency of spontaneous combustion due to these oxygen rich coals, etc. Solving these problems would substantially improve the efficiency of LRC usage. In this study, we describe a drying technique utilizing hot oil immersion. This upgrading process may be executed easily under relatively low temperature condition due to the difference of heat capacity and thereby pressure gradient between coal and heating oil. This results in greatly reducing its energy cost. Drying tests of Indonesian lignite were performed with refined waste oil and B-C heavy oil, which were heated to 120°C, 130°C or 140°C. Following 10 min of treatment, the moisture content of the upgraded coal was improved from 32% to 2.0–3.2%, and its high heating value from 3,000 kcal/kg to 6,000 kcal/kg.     

Effects of rolling parameters on work-roll temperature distribution in the hot rolling of steels

Temperature variations of work-rolls in the process of hot rolling of slabs were analyzed by solving heat conduction equation with time-dependent boundary conditions. The Raylieght-Ritz and the finite-element methods were employed to solve the governing equation. To improve the accuracy, the thermal relationship between rolling metal and work-rolls was taken into account as well as the effects of different parameters such as interface heat transfer coefficient, rolling speed, and slab initial temperature were considered in the calculations. To verify the employed model, a comparison was made between the predicted and the recorded time-temperature history and good agreement was observed. Modelling results show that the interface heat transfer coefficient and rolling speed are important factors that vary effectively the temperature field within the work-roll. In addition, the interface heat transfer coefficient is affected by the other parameters and factors such as flow stress behavior of the metal being rolled and initial temperature of metal. Therefore, in order to determine an accurate temperature field within the work-rolls, flow behavior and temperature distribution in the rolling metal should also be calculated at the same time.     

风对大型港口机械的脉动效应研究

大型港口机械工作于码头前沿或近岸海域,风的影响不容忽视.传统港口机械的设计过程中风载按静载处理,忽略了风的脉动效应.因此在有限元建模的基础上,结合根据Shinozuka方法模拟的脉动风载荷,预测大型港口机械在工作状态和非工作状态的动态响应,并与传统将风载处理成静载的方法进行对比.研究结果表明:工作状态下,风的脉动效应对结构最大应力的幅值影响不大,其主要影响体现在最大应力点的空间分布,对最大应力数值影响不大,对支座反力的影响亦不明显;非工作状态下,风的脉动效应将引起支反力的大幅波动,此时平均值已不能充分衡量结构的安全性,必须同时关注其标准差与时间历程.     

Effects of amplitude modulation on perception of wind turbine noise

Wind turbine noise is considered to be easily detectable and highly annoying at relatively lower sound levels than other noise sources. Many previous studies attributed this characteristic to amplitude modulation. However, it is unclear whether amplitude modulation is the main cause of these properties of wind turbine noise. Therefore, the aim of the current study is to identify the relationship between amplitude modulation and these two properties of wind turbine noise. For this investigation, two experiments were conducted. In the first experiment, 12 participants determined the detection thresholds of six target sounds in the presence of background noise. In the second experiment, 12 participants matched the loudness of modified sounds without amplitude modulation to that of target sounds with amplitude modulation. The results showed that the detection threshold was lowered as the modulation depth increased; additionally, sounds with amplitude modulation had higher subjective loudness than those without amplitude modulation.     

用流式细胞仪研究秋茄叶柄薄壁细胞大小及叶绿素含量与海水盐度的关系

采用快速离析方法和流式细胞仪研究了红树植物秋茄成熟叶柄薄壁细胞的大小和叶绿素含量与海水盐度之间的关系。结果表明 ,海水盐度为 0 .8%～ 2 .0 %时 ,随着盐度的升高 ,叶柄薄壁细胞大小和单位体积叶绿素含量的变化趋势与叶肉细胞一致。海水盐度为 0 .8%～ 1.0 %时 ,随着盐度升高 ,向有利于提高光合作用强度的方向发展 ;海水盐度在 1.0 %～ 2 .0 %之间时 ,随着盐度的升高 ,向加强生理干旱适应性方向发展。海水盐度高于2 .0 %时 ,叶柄薄壁细胞的大小和单位体积薄壁组织叶绿素含量随盐度的变化趋势与叶肉细胞不同 ,原因尚待进一步研究。实验结果表明 ,借助快速离析方法 ,使用流式细胞仪研究器官细胞相关特性是可行的 ,为从形态学角度研究红树植物耐盐机理提供了可能 ,扩大了流式细胞仪的应用领域     

浅谈砝码对烘干法水分测定仪装置和测量结果的影响及不确定度评定

水分测定仪是目前实现食品、药品、谷物水分含量快速检测的唯一测量仪器。砝码是其必备的测量设备之一。根据水分测定仪的显示方式和衡量装置的不同,目前市场上的烘干法水分测定仪分为模拟显示水分测定仪和数字显示水分测定仪。本文详细阐述砝码在烘干法水分测定仪运用,进一步阐述烘干法水分测定仪测量结果不确定度评定。     

风廓线仪在低空风切变探测中的应用

低空风切变是航空器起飞、着陆阶段威胁飞行安全的危险因素。文章根据首都机场风廓线探测资料,按照雷雨型、锋面型、逆温型、低空急流型和其他型,对产生的低空风切变过程进行了分类和统计;并利用风廓线探测资料,个例分析了几种产生低空风切变的风场特点。