2450MHz频率下含盐凝胶琼脂的介电特性

本文通过对水分含量９９％的含盐琼脂（盐浓度：０．１,０．２,０．３,０．４,０．５,１,１．５,２）的介电特性值测定,研究了在１０～７５℃范围中盐浓度对高水分凝胶琼脂在介电特性所产生的影响,并进一步讨论了食品微波加热中,采用含盐琼脂在介电性质上对真实食品进行模拟的可能性,扩大在液晶感温法进行食品内温度分布研究的适用范围。     

长春农作物微波辐射特性的研究

对长春地区农作物及背景土壤的微波辐射特性进行了测量和研究,从１９９１年以来,使用长春地理所研制的多频段微波辐地测量窕测量窕作物的微波辐射特性,了窕作物辐射亮温与土壤温度,窕作物长势等各参数之间的对应关系。     

微波消解-FAAS测定虾肉中钙的质量分数

采用微波消解-火焰原子吸收光谱法（flame atomic absorption spectrometry,FAAS）测定虾肉中钙（ca）元素的质量分数,对微波消解前处理的条件进行了研究。试验结果显示,最佳的微波消解体系为取样量0．500g,以硝酸（HNO,）作为消解溶剂,用量5．0mL,最适微波消解程序为多步消解程序D,包含3个步骤：1）功率400W,比例100％,升温5min,消解温度120℃,保持5min;2）功率800W,比例100％,升温5min,消解温度150℃,保持10min;3）功率800W,比例100％,升温10min,消解温度180℃,保持10min。样品消解液在常温或冷藏条件下保存48h之内的稳定性良好。经微波消解前处理后虾肉样品中”（ca）的相对标准偏差（relative standard deviation,RSD）为5．284％,加标回收率为91％-98％。微波消解-FAAS测定虾肉中的w（Ca）具有样品处理时间短、试剂用量少、结果准确和安全性高等优点。     

大型海藻干燥技术研究进展

干燥是海藻储存、加工、生产的重要方法之一,不同的干燥方式对海藻脱水效率、能耗和品质影响很大。本文对藻类传统干燥和新型干燥技术的特点、研究及应用现状进行了分析。研究表明,太阳能干燥技术能够充分做到干燥过程中绿色、环保,与空气热泵构成组合干燥模式,可解决太阳能不连续的问题;过热蒸汽干燥效率高、能耗低,藻类干燥后复水性好;真空冷冻干燥产品品质好,能最大限度保持藻类的营养和功能性成分;远红外加热技术对海带进行干燥,与同风速的热风干燥相比,可显著缩短干燥时间,降低能耗;微波真空干燥技术干燥江蓠,在保持品质的基础上干燥时间较热风干燥减少70%。本文同时对藻类干燥技术与设备存在的问题进行了总结,对国内藻类干燥技术及装备的发展趋势进行了展望并提出了措施与建议。     

三种赤潮微藻基因组DNA快速制备方法的研究

采用超声波法、煮沸法和微波法3种方法分别对塔玛亚历山大藻、环状异帽藻和角毛藻进行细胞破碎及快速制备基因组DNA的研究。通过细胞计数和DNA浓度测定的手段对三种方法进行了比较,以选择适合不同藻种的细胞破碎方法。结果表明,塔玛亚历山大藻和环状异帽藻用超声波法破碎效果较好;角毛藻用微波法较好。对用该三种方法制备的基因组DNA做了PCR扩增,电泳检测表明,与CTAB法扩增效果一样。本文建立的微藻DNA快速制备方法有望应用在赤潮藻类的快速分子鉴定方面。     

可食性鲜花色、香和形永久保持的机理及应用研究

为解决目前鲜花保鲜中存在的色、香、形等问题，选用玫瑰花、荷花为试材，采用微波、生物大分子涂膜等技术，研究了可食性鲜花色、香、形永久保持的机理。结果表明：魔芋多糖、β-环状糊精、柠檬酸等物质及高火短时的微波条件对鲜花的色泽、香气、外形有很好的稳定作用，同时花材的浸泡时间，浸泡液的浓度等因素也有一定影响。并在此基础上研制成可食性永贮玫瑰花和荷花。     

An evaluation of the net radiation sub-model in the ASCE standardized reference evapotranspiration equation: Implications for evapotranspiration prediction

Net radiation (R_n) is a key component of the surface energy balance, but it is expensive and difficult to measure accurately. For these reasons, R_n is often predicted in evapotranspiration (ET) calculations with a model requiring measurements of incoming shortwave radiation, air temperature, and vapor pressure. We compared R_n predictions from the R_n sub-model used in the American Society of Civil Engineers (ASCE) standardized reference ET equation to mean R_n measurements from five 4-component reference net radiometers. The radiometers were part of a recent comparison study of multiple net radiometer models conducted over irrigated and clipped turfgrass in northern Utah (Blonquist et al., 2009). In the R_n model, net shortwave radiation is determined by direct measurement of solar radiation and an assumed value of albedo for the surface (0.23 for fully vegetated surfaces), and net longwave radiation is calculated with a Brunt (1932, 1952) approach for predicting net surface emissivity, calculated from near surface vapor pressure. Additionally, the ratio of measured incoming shortwave radiation to predicted clear-sky shortwave radiation is used as a surrogate variable for cloud cover in the net longwave radiation calculation. Relative to the reference R_n measurements (average of five 4-component net radiometers), modeled R_n was high during the day by an average of 8.6% and high in magnitude (more negative) at night by an average of 13.4% over hourly time intervals. Daily total R_n calculated by summing the hourly model predictions was always higher than the reference measurements, by an average of 8.1%, whereas daily total R_n calculated from the model over daily time intervals was closer to the reference measurements, 2% high on average. The model R_n error during the day was partly caused by the assumption in the model that surface albedo is a constant value of 0.23. Measurements showed albedo ranged from approximately 0.21 at solar noon to 0.30 near the beginning and end of the day, with a mean value of 0.23. However, most of the model R_n error was due to the prediction of net longwave radiation, where the empirical equation in the model typically yielded values that were too low in magnitude (less negative), by approximately 20% on average, but the error was dependent on time of day. The R_n error at night was largely caused by the inability to measure the surrogate for cloud cover at night, which relies on measurement of solar radiation from a previous time period of sufficient solar zenith angle. All five of the net radiometer models tested in the comparison study matched the mean of the reference net radiometers better than the ASCE model. When modeled hourly R_n was used to calculate ET over hourly time intervals, or when hourly ET values were summed to yield daily ET, ET was typically high, by 6% on average, relative to ET calculated from measured reference R_n. When modeled R_n was calculated over daily time intervals and used to calculate ET over daily time intervals, ET was more accurate, 1% high on average, relative to ET calculated over daily time intervals from measured reference R_n. While new models for R_n are being developed, the sub-model in the ASCE standardized reference ET equation has been in use for the past two decades in thousands of ET stations. As newer models are developed we hope to use this data set to evaluate them.     

微波法制玉米秸秆活性炭工艺条件及性能研究

以玉米秸秆为原料、ZnCl2为活化剂、微波为能源制备活性炭,通过正交试验,获得制备玉米秸秆活性炭的最佳工艺条件。将产品应用于甲醛气体的去除,并与市售活性炭进行了性能比较。发现在甲醛浓度为1．94-1．97mg／m^3的条件下,试验产品的穿透时间（tB）为12min,比市售活性炭提高20％,且吸附速度更快。     

鲢、狭鳕鱼糜微波加热凝胶形成的动力学分析

以鲢（Hypophthalmichthys mollitrix）和狭鳕（Theragra chalcogramma）鱼糜为对象,在微波、水浴两种加热条件下,对鱼糜及鱼糜大豆蛋白复合素材试样的凝胶特性——破断力值加以测定,进而考察不同加热方式下两种鱼糜的凝胶形成速度以及微波加热所需的活化能,并对试样能量吸收值进行了比较。结果表明：（1）鲢、狭鳕鱼糜微波加热凝胶形成速度比传统水浴加热高两个数量级,不同鱼种的鱼麋微波加热凝胶形成速度有一定的差异性（P〉0．05）。（2）微波加热下,欲达到相同的破断力值,鲢需要高于狭鳕1倍的活化能,两者对应的复合素材的活化能均小于相应的单一鱼糜试样。（3）与水浴加热相比,在能量吸收值相同的情况下,微波加热试样能达到更高凝胶破断力值。     

马铃薯生全粉中不饱和脂肪酸微波萃取工艺参数优化及应用

为了优化马铃薯生全粉不饱和脂肪酸的微波萃取工艺,该试验采用软件Design-Expert 8.05分析以及响应面法来优化马铃薯生全粉中不饱和脂肪酸微波萃取工艺,得出马铃薯生全粉中不饱和脂肪酸的萃取模型P=0.000 10.01,R2=0.939 8,并确定马铃薯生全粉中不饱和脂肪酸最佳萃取工艺:萃取温度81℃,萃取时间11 min,萃取溶剂中丙酮占比0.802 5,料液比3.25∶1,各因素对不饱和脂肪酸质量分数影响大小分别为:丙酮占比料液比萃取温度萃取时间,实测不饱和脂肪酸质量分数为1.081 mg/g和拟合方程的预测值1.084 mg/g基本一致。将该优化方案应用于热风干燥温度对马铃薯生全粉中不饱和脂肪酸含量影响的分析中,结果表明:随着干燥温度的升高,亚油酸质量分数显著增加(P0.05),总不饱和脂肪酸质量分数增加(P0.05)。优化试验为热风干燥条件对马铃薯品质影响的研究提供了理论依据。