柠檬汁在奶酪制作中的应用

分别用生物酶法，微生物发酵法和生物化学法制备感观性能良好的熟化奶酪。实验结果表明，以柠檬汁作为制作奶酪的天然生化凝乳剂，完全中以与发酵微生物和凝乳酶相媲美。它不仅凝乳性能好，而且用其制成的奶酪富有营养，感官性能好。     

极谱法测定克氏氮

用极谱仪测定克氏消化液中氨的含量是一种既简单、又迅速的方法。消化液被稀释,并用吸管吸到加有醋酸缓冲液的甲醛溶液中,甲醛与氨反映产生的(乌洛托品)在-1.04V电压下通过电化学法测定。通过对三种不同的样品(牛奶、面包、槚如树坚果)进行分析,其克氏氮测定值的平均相对标准误差为3.4%;对同一消化液进行重复分析,其相对标准误差是1.5%。     

红枣核桃酸奶的贮藏品质及胃肠液环境下抗氧化研究

以红枣、核桃、新鲜牛奶为主要原料制备红枣核桃酸奶,以不添加红枣汁与核桃粉的同批鲜奶自制普通酸奶为对照,分别测定不同贮藏时期红枣核桃酸奶和对照酸奶的理化指标,以及两种酸奶在贮藏期和胃、肠液模拟环境下对DPPH、ABTS自由基的清除能力。结果表明,贮藏期间红枣核桃酸奶在活菌数、酸度以及抗氧化能力方面均显著优于对照酸奶(P<0.05),持水力低于对照酸奶(P<0.05),且贮藏21 d后,红枣核桃酸奶的DPPH和ABTS自由基清除率分别为88.65%、72.46%,对照酸奶为53.10%、69.44%。然而,两种酸奶经延长冷藏时间或在胃肠液环境处理后均会导致自由基清除能力降低,但红枣核桃酸奶在总体上仍然优于对照酸奶。因此,红枣核桃酸奶是一种新型的功能性乳品。     

Trichloroethylene uptake into fruits and vegetables: three-year field monitoring study

Trichloroethylene (TCE) contaminated groundwater migrating into communities surrounding Hill Air Force Base (HAFB) in northern Utah prompted a multiyear monitoring program (2001-2003) to examine the extent of TCE uptake and transfer into edible fruits. During the initial sampling in fall 2001, TCE was detected in a small fraction of the 167 fruit and tree core samples collected from 17 private residences. Samples were analyzed using headspace gas chromatography (GC) with electron capture detection (ECD) with limited confirmation by mass spectrometry (MS) in selected ion monitoring mode. In fall 2002, over 300 samples were collected from the same general locations sampled in 2001. No TCE was found in any of the fruit or vegetable samples above the method detection limit (MDL) for the headspace GC/MS method (approximately 0.1 microg/ kg fresh weight, depending on sample size), but TCE was again detected in several fruit tree trunk core samples. The detection of TCE in fruit in 2001, but not in 2002, may have been due to improvements in the analytical procedure or changes in the environmental conditions impacting transfer to fruit. The 2003 monitoring focused on repeated sampling over several months at five locations that were selected to represent the range of exposure scenarios evaluated during the previous years. No TCE was identified in any of the fruit above the MDL during 2003, however TCE was again found in tree core samples as observed in 2001 and 2002.     

超高压输电线路风偏故障及防范措施分析

近年来,我国电力行业取得了较快的发展,电力系统的稳定运行是确保电能正常供应的基础。输电线路作为电力系统重要的组成部分,通畅的输电线路为电力系统的运行提供了良好的保障。我国由于幅员辽阔,输电线路点多面广,所处环境恶劣,受自然条件影响较大。特别是在强风作用下,极易趣导致风偏故障的发生,而且在天气和地形影响下,风偏故障还不易进行判断和处理,导致近年来风偏闪络频繁发生。所以需要加强对输电线路风偏故障的分析,从而采取必要的防范措施,确保电网能够安全、可靠的运行。     

打造不可替代的烟草物联网

物流产业是国民经济发展的动脉和基础产业,被喻为经济发展的加速器,其发展水平成为衡量一个国家现代化程度和综合国力的重要指标。烟草物流是烟草行业的核心业务,建设现代烟草物流,打造中国烟草物联网是卷烟上水平的重要任务,是中国烟草提升核心竞争力的重要支撑。     

Trichloroethylene uptake by apple and peach trees and transfer to fruit

A greenhouse study was conducted to quantify 14C-trichloroethylene (TCE) uptake and transfer into the edible fruit of apple and peach trees. Trees were subsurface irrigated with solutions of 14C [TCE] that bracketed groundwater concentrations (5 and 500 microg/L) found in residential areas surrounding Hill Air Force Base, UT, where trace amounts of TCE had been found in several fruits during a preliminary field survey. Nondosed control trees were grown within the canopy of the dosed trees and in a separate greenhouse. Tissue samples were analyzed for 14C and TCE using combustion/liquid scintillation counting (LSC) and headspace/gas chromatography/mass spectrometry (HS/GC/MS). Tissue was also extracted and analyzed by GC/MS for dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and trichloroethanol (TCEt), three specific TCE metabolites that have been previously identified in laboratory and field studies. No 14C was detected in the nonexposed control trees. Exposed trees contained levels of 14C that were proportional to the exposure concentration. 14C concentrations were greatest in leaves followed by branches and fruits. At the end of the study, TCE was detected only in roots implying that the 14C in the leaves, branches, and fruit was associated with unidentified nonvolatile TCE transformation products and/or is nonextractable. However, TCAA and DCAA were positively identified only in leaves collected during the first year from an apple tree exposed to the high dose treatment. Additional data for other chemicals and fruittrees are needed to better understand the potential transfer of organic compounds to edible fruit.     

新型饲料添加剂——稳定性固态氯化胆碱的研究

研究出了有效而经济实用的合成，制造一种新型的饲料添加剂－稳定性固态氯化胆碱产品的生产工艺流程。经在饲料的生产，储藏极化条件下测定，此稳定性固态氯化胆碱新产品的理化性能显著好于现有饲用氯化胆碱产品，不仅吸水（湿）率低，物理性能稳定，而且对饲料中的维生素具有保护作用。     

埋栅TCO薄膜的制备及在太阳电池上的应用

提出新型金属埋栅结构来改良透明导电氧化物薄膜(TCO)的光电性能,并分别采用AZO和ITO这2种TCO材料制备和对比3类薄膜(单层TCO薄膜、TCO/金属薄膜/TCO以及TCO/金属栅线/TCO三明治结构的薄膜)的光学和电学性能.本文制备的新型叠层AZO/Mg栅线/AZO和ITO/Ag栅线/ITO结构在300～1200...     

压榨法制取鳄梨食用油脂的研究

分析了两种布隆迪产鳄梨（Ｎａｂａｌ,Ｆｕｅｒｔｅ）的组成成分,探讨和研究了从鳄梨鲜果肉中制取食用油脂的压榨工艺。结果表明：使用某些固体添加剂能显著提高压榨效果和油脂得率,其中以沙粒（添加３０％～４０％）的使用效果最佳;而且活性炭与活性土ＴＯＮＳＩＬ复配脱色的效果好。