苦荞麦麸皮总黄酮提取工艺及其数学模型研究

为充分利用荞麦资源，该文测定了苦荞麦麸皮总黄酮的含量，对苦荞麦麸皮总黄酮的提取工艺及其数学模型进行了研究。试验结果表明：苦荞麦麸皮总黄酮的含量为6.01%；乙醇提取法的最佳工艺条件为乙醇浓度80%，提取温度80℃，料液比1∶50，提取时间2.5 h，该工艺条件下总黄酮提取率达94.01%；建立了以总黄酮提取率为目标值，以各提取工艺参数为因子的二次多项式模型，经验证计算值与试验值拟合良好。     

芝麻叶中总黄酮的最佳提取工艺研究

该文测定了芝麻叶中总黄酮的含量，并对芝麻叶黄酮的提取工艺进行了研究。重点探讨了采用乙醇提取法和微波处理与乙醇提取相结合的方法提取芝麻叶黄酮类化合物的最佳工艺条件。试验结果表明：芝麻叶中总黄酮的含量为0.98%；乙醇提取法的最适工艺参数是浸提剂乙醇浓度为80%、浸提温度为80℃、料液比为1∶25、浸提时间为2.5 h，如此条件可使黄酮提取率达95.6%；微波处理与乙醇提取相结合的方法的最适工艺参数是微波功率200 W、微波处理时间70s，乙醇浓度为80%、浸提温度为80℃、料液比为1∶25、浸提时间为30 min，这种工艺可使黄酮提取率达95.8%。     

勐库大叶茶中总黄酮最佳提取工艺的研究

黄酮类化合物具有多种药理作用,勐库大叶茶中含有丰富的黄酮类物质。本试验采用乙醇恒温浸提的方法提取勐库大叶茶中的总黄酮,并结合正交试验选择出最佳的提取工艺条件。结果表明4因素对勐库大叶茶中总黄酮提取得率影响的主次顺序为乙醇浓度>固液比>提取温度>提取时间,最佳提取工艺条件为乙醇浓度70%、料液比1g:30 mL、提取温度85℃、提取时间2.0 h,在此条件下总黄酮的提取率为2.096%。     

丹参糖蛋白的提取精制及其理化性质研究

采用单因子试验和L9(34)正交试验设计,研究料液比、提取时间、提取温度和NaCl浓度对丹参糖蛋白提取率的影响。结果表明,提取物是糖含量为26.24%、蛋白质含量为37.34%的通过O-糖肽键连接的酸性糖蛋白;最佳提取工艺条件:料液比1∶20,提取温度70°C,提取时间4 h,0.1 mol/L的NaCl;Sevage法脱蛋白7次,80%乙醇醇析,可得精制糖蛋白5.03%。     

响应面法优化块菌多糖的超声波辅助提取工艺

利用响应面分析法对超声波辅助提取块菌多糖的工艺进行优化。在单因素试验的基础上,以超声时间、功率、温度和液料比为自变量,以多糖提取率和多糖含量共为响应值,进行Box-Behnken中心组合试验,回归分析确定最优工艺条件。分析各个因素的显著性和交互作用后,得出最优工艺条件为:超声功率140 W、处理时间36min、处理温度50℃、液料比40∶1,多糖理论提取率为18.42%,实际提取率为18.15%,相对误差为1.47%;多糖理论含量为74.70%,实际含量73.89%,相对误差为1.08%。     

几种植物精油的提取工艺优化及抑菌效果初步研究

确定几种植物精油的最佳提取工艺,检测植物精油抑菌效果,为精油的开发利用提供参考。以水蒸气蒸馏法提取精油,分析烘干时间、烘干温度、料液比对甜橙精油提取率的影响,分析料液比、烘干温度、蒸馏温度对香樟精油提取率的影响;检测精油的抑菌效果、保鲜效果。初步结论:甜橙精油最佳提取工艺为烘干时间3 h、烘干温度70℃、料液比1∶7,提取率可达5.08%;香樟精油最佳提取工艺为烘干时间150 min、蒸馏温度90℃、料液比1∶5,提取率可达0.60%;薄荷精油和香樟精油对细菌有抑制作用,甜橙精油和大蒜精油对真菌与细菌均有抑制作用,大蒜精油抑菌效果最佳;精油对果蔬具有保鲜效果;精油空气清新剂杀菌效果依次为甜橙薄荷香樟。     

杜仲叶绿原酸的微波提取及高速逆流色谱分离纯化

以杜仲叶为原料,正交试验优化了微波辅助提取绿原酸的工艺条件。应用高速逆流色谱（HSCCC）分离制备高纯度杜仲叶绿原酸,通过质谱技术与核磁共振技术进行结构鉴定。结果表明,杜仲叶最佳提取工艺条件为微波辅助50%的丙酮水溶液浸提,料液比1∶30,提取时间25min,提取功率400W,绿原酸的提取率达2.28%;高速逆流色谱法...     

苦荞茶中黄酮提取工艺优化及不同品牌苦荞茶黄酮含量比较

研究苦荞茶中黄酮提取的最佳工艺,比较不同类型苦荞茶的黄酮含量。通过单因素试验考察乙醇溶液体积分数、料液比、提取时间和提取温度4个因素对黄酮得率的影响。通过正交试验确定最佳提取工艺,并在此基础上对不同类型苦荞茶黄酮含量进行比较。结果表明:各因素对苦荞茶中黄酮类物质得率的影响由大到小分别为温度、提取时间、乙醇溶液体积分数和料液比。优化得到苦荞茶中黄酮类物质的最佳提取工艺条件为:乙醇溶液体积分数70%,料液比1∶25,提取时间4 h,温度70℃,此条件下苦荞茶中总黄酮得率为1.98%;基于该条件下,分析8个品牌19种苦荞茶(11种造粒茶、6种全麦茶、2种全株茶)的黄酮含量,结果表明三类苦荞茶总黄酮含量平均值高低依次是全株茶造粒茶全麦茶;同类型苦荞茶之间,总黄酮含量差异最大的是造粒茶,其次是全麦茶,最小的是全株茶。     

超声法协同表面活性剂提取苦瓜多糖的工艺研究

以多糖提取率为指标,应用单因素试验方法考查表面活性剂、液料比、超声功率、超声温度、超声时间对苦瓜中总多糖提取率的影响,并通过正交实验优化提取工艺。结果表明,表面活性剂(吐温80)的用量为9μL,最佳工艺条件是:提取温度60℃,液料比1∶35,提取功率70%,提取时间30 min。     

超声法协同表面活性剂提取苦瓜多糖的工艺研究

以多糖提取率为指标,应用单因素试验方法考查表面活性剂、液料比、超声功率、超声温度、超声时间对苦瓜中总多糖提取率的影响,并通过正交实验优化提取工艺。结果表明,表面活性剂(吐温80)的用量为9μL,最佳工艺条件是:提取温度60℃,液料比1∶35,提取功率70%,提取时间30 min。     

Physical Properties of the Soils of Sibay City of the Republic of Bashkortostan

Eurasian Soil Science - The results of the study of the properties of urban soils of the city of Sibay located in the mining region of the Republic of Bashkortostan are presented. A specific...     

食用仙人掌萎蔫气象条件分析

塑料大棚内种植的食用仙人掌在土壤墒情较好时也有萎蔫现象发生，通过试验观测和对仙人掌生理习性的分析，发现阴雨过后天气突然放晴温度急剧上升易使仙人掌发生萎蔫现象，并提出了田间管理的应对措施。     

Heterogeneity of Organic Matter of Aggregates of Protocalcic Chernozems

Eurasian Soil Science - Layers were step-by-step removed from macroaggregates (2–1 mm in diameter) of Protocalcic Chernozems via successive abrasion in a revolving rotator during 5, 10, 15,...     

青海省耕地资源开发利用分析及对策研究

分析论述了青海省耕地资源开发利用的现状、特点和问题。在此基础上,提出了对青海省耕地资源进行研究的框架体系和思路,同时基于GIS/RS技术设计了相关的技术路线。最后依据所做设计对青海省耕地资源开发利用做了初步分析,并进行了相关的对策研究分析。     

Characterization of physical and chemical properties of Varzea soils of Goias State of Brazil

Abstract

Brazil has approximately 30 million hectares of lowland areas, known locally as “Varzea,”; distributed throughout the country. Soils in these areas have the potential to support agricultural production, but very little is known about their fertility. The current experiment was undertaken to characterize the chemical and physical properties of representative “Varzea”; soils collected at 0–20, 20–40, 40–60, and 60–80 cm depth intervals from 23 sites in Goias State of Brazil. Organic matter contents averaged 42 g/kg in the surface 20 cm of soil and should make a significant contribution to overall nutrient availability. Soil pH increased slightly with depth from a mean value of 5.2 in the surface 20 cm of soil to a mean value of 5.4 in the 60–80 cm depth interval. Several soils had exchangeable Al values ≥ 1.0 cmol Al/kg, but soil Al saturation was generally less than the 60% level frequently associated with Al toxicity. However, cereal and legume production could benefit from lime addition in many of these soils. Although base saturation was fairly low in some soils, exchangeable Ca and Mg levels were, in general, adequate throughout the profile. Extractable P levels were adequate in most surface soil samples. Extractable K levels in these soils were generally low, and the application of K fertilizers should be beneficial, especially in conjunction with lime addition. The high clay content “Varzea”; soils of the Brazilian lowlands have some drainage problems but generally exhibit favorable chemical properties for crop production when compared to soils of the well‐drained Cerrados.     

Estimation of potential nitrogen-fixing activity of agrophytocenoses soils of the subtropical zone of Russia

An estimation of potential nitrogen-fixing activity of various soil types under agrophytocenoses of tea, filbert, peach, and pawpaw which grow in the area of Greater Sochi is given. High indicators of nitrogen fixation activity in the soil in the course of vegetation were characteristic of agrocenoses of pawpaw, peach, and filbert. The lowest level of nitrogen fixation was noted in the soil of a tea plantation. A negative correlation dependence of potential nitrogen-fixing activity on the acidity of the soil solution was established. A study of the seasonal dynamics of the activity of nitrogen fixation of soils of agrocenoses of the subtropical zone of Russia made it possible to distinguish a less active winter and more active spring-summer-autumn periods.     

Kinetics of Popping of Popcorn

The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements.     

物联网安全及解决措施

物联网是一个集信息通信、数据交换、传感器技术与软件工程于一体的综合性产业,探讨和分析了物联网的结构体系与发展中遇到的安全问题。     

荔枝种子结构的扫描电镜观察

荔枝种子从果实中剥离出来后, 即使在室内条件下, 也极易失水干缩, 潮湿环境中又易发霉而腐烂。扫描电镜观察表明: 种皮上布满纹孔, 水分散失面积很大; 种脐部为疏松的海绵组织, 且营养丰富。据此, 生产上应对种子彻底清洗, 并保存于适当湿度的环境中, 以提高其发芽率。