影响浓香型酒甜味因素的探讨

绵甜是浓香型大曲酒的主要特点。影响浓香型大曲酒甜味的因素有：（1）多元醇类、a-联酮类及醛类物质的量比;（2）发酵速度：曲和入窖温度;配料加入池酸度;（3）发酵周期;（4）原料、菌种及菌种数;（5）接酒操作;（6）白酒的贮存处理;（7）勾调处理等。     

鹌鹑蛋功能特性及其影响因素

测定了鹌鹑蛋乳化性、起泡性、持水性等功能特性,并探讨了蔗糖、温度、pH值、氯化钠等因素对蛋白起泡性及其稳定性和蛋黄乳化性的影响。结果表明,鹌鹑蛋白的起泡性为7.33%,泡沫稳定性为63.49%,乳化性为41.51%,持水性约17.14%;鹌鹑蛋黄的起泡性为10%,泡沫稳定性为59.73%,乳化性为46.82%;鹌鹑全蛋液的起泡性为11%,泡沫稳定性为63.95%,乳化性为43.99%,持水性约18.28%。蔗糖能在一定范围内提高泡沫稳定性,适当加热可改善蛋白起泡性,蛋白起泡性随NaCl增加而有较大幅度提高。鹌鹑蛋黄乳化性随蔗糖浓度增大而提高,10～60℃内随温度升高而提高,加入氯化钠能明显提高蛋黄乳化性。pH值对蛋白起泡性和泡沫稳定性、蛋黄乳化性的影响均呈动态变化。     

Microbial Assessment in School Foodservices and Recommendations for Food Safety Improvement

ABSTRACT:  This study evaluated microbial food safety in school foodservices. Five school foodservices were randomly selected, and samples from water, cooking utensils, tableware, foodservice surroundings, and linen were collected in summer and winter ( N = 420). Tap and drinking water samples were collected, samples of food contact surfaces were collected by swab-kit, and samples for foodservice workers' hands and gloves were prepared by glove juice method. Aerobic plate count (APC) and coliform bacterial populations were enumerated on plate count agar (PCA) and desoxycholate lactose agar, respectively. The presence of Escherichia coli , Salmonella , Listeria monocytogenes , and Staphylococcus aureus was also examined by biochemical identification tests. In addition, PCA agar for APCs and Baird-Parker agar for S . aureus were used to enumerate airborne microorganisms. Higher APCs (< 0 to 5.1 log CFU/mL) than acceptable level were generally observed in water samples, while low coliform counts were found in the samples. High APCs were enumerated in cooking utensils, foodservice workers, tableware, and foodservice surroundings, and coliforms were also found in the samples for both seasons. The presence of Salmonella was found from only 10% of plastic glove samples (summer), and the presence of L . monocytogenes was not observed in all samples. S . aureus was detected in some of water, cooking utensils, tableware, employees, and foodservice surroundings, and E . coli was observed in cooking utensils (10% to 20%; summer). No obvious airborne bacteria were detected. These results showed that sanitation practice in school foodservices should be improved, and the results may be useful in microbial assessment of school foodservices.     

一起罕见的电容式电流互感器缺陷的发现和分析

介绍和诊断了一起罕见的因电容式电流互感器末屏没有处于等电位体的缺陷导致油色谱测试结果中乙炔含量超标的故障.不能通过状态检修例行试验中的介损测试结果有效地发现和诊断此类故障;在油色谱跟踪试验中,在氢气和总烃含量还没有明显增长即远没有超标的情况下,就出现很大的乙炔含量,这与一般绝缘故障的发展规律相违背.解体发现,故障原因是对缠绕末屏的铜编织带的设计缺陷使得末屏没有处于整体的等电位体.如果在色谱测试结果中氢气和甲烷含量尚无明显增长的情况下就直接出现乙炔含量,这说明电容式电流互感器有可能出现了此类故障.     

基于概率统计方法的东北地区风电运行特性研究

风电的快速发展,装机规模的不断增大,给电网带来的问题日益增多.应用了2年来的东北电网全区风电场出力数据,分析了东北区域风电出力同时率、概率分布、负荷相关性等特性指标,为科学认识电网风电运行特性提供参考.     

基于FRANC2D的中央裂纹平板断裂力学分析

针对用于断裂力学分析的通用有限元程序和专业有限元程序进行了分析,介绍了FRANC2D程序的建模、断裂力学分析过程。以含有中央裂纹平板为研究对象,验证了FRANC2D用于计算KⅠ值的可行性;通过网格粗细模型结果比较发现,用FRANC2D分析时,网格大小对计算结果影响不大,采用较粗网格就能得到满意的结果。通过对应力强度因子KⅠ、J积分法、应变能释放率G值有限元和理论结果比较,FRANC2D计算精度满足工程需要。     

用相因子判断法分析多缝衍射

采用波前相因子判断法并考虑到光栅孔径的影响来分析多缝的衍射。得出多缝衍射的波前函数、像面上多缝衍射振幅和光强公式,并模拟出像面衍射振幅分布和光强分布,最后得出中央主极大的半角宽度。结果表明该研究为多缝衍射分析提供了一种新的分析方法。     

浅析胶辊表面粗糙度不匀对纺纱质量的影响

分析了胶辊表面粗糙度不匀产生的原因 ,并运用试验数据就纺纱胶辊不同的表面粗糙度值对不同品种纱的适应性进行了论述 ,说明了表面粗糙度不匀对成纱质量的影响及解决方法     

Can we identify key characteristics associated with grazing-management dairy systems from survey data?

Discriminant analysis was used to identify farms using confinement and grazing-production systems from mail survey data of 2074 dairy farmers in Pennsylvania, Vermont, Virginia, and North Carolina. Survey respondents included 45.1% of the farms using confinement management; 13.5% of farms practicing intensive grazing, defined as moving cows to new pasture at least every 3 d; and 41.4% of farms using nonintensive grazing. Farmers using confinement management had significantly more cows, higher milk production, more crop acreage, higher debt, used automatic takeoff milking units (ATO), fed total mixed rations (TMR), and were more satisfied. In general, dairy farmers who grazed their milking cows had smaller herds, fewer acres, but had more acres per cow and made less use of technology. However, farmers practicing intensive grazing were significantly younger, more educated, less experienced, more likely to use computers, and farmed less acreage than other graziers or farmers on confinement farms. The discriminant function correctly classified 70% of the total sample when divided into confinement and overall grazing categories. However, the discriminant function correctly classified only 36% of intensive-grazing farms in comparison to confinement farms. Significant variables identified using ordinary least squares as being related to confinement management were milk per cow, acres of corn, use of ATO and TMR, debt greater than 40%, and residence in North Carolina. Significant variables associated with grazing management were acres of pasture, future use of pasture, education, and residence in Vermont. The analysis indicated that the discriminant function could correctly classify confinement and nonintensive-grazing management but was unable to reliably differentiate between confinement and intensive-grazing farms.     

Vatless manufacturing of low-moisture part-skim mozzarella cheese from highly concentrated skim milk microfiltration retentates

Low-moisture, part-skim (LMPS) Mozzarella cheeses were made from concentration factor (CF) 6, 7, 8, and 9, pH 6.0 skim milk microfiltration (MF) retentates using a vatless cheese-making process. The compositional and proteolytic effects of cheese made from 4 CF retentates were evaluated as well as their functional properties (meltability and stretchability). Pasteurized skim milk was microfiltered using a 0.1-microm ceramic membrane at 50 degrees C to a retentate CF of 6, 7, 8, and 9. An appropriate amount of cream was added to achieve a constant casein:fat ratio in the 4 cheesemilks. The ratio of rennet to casein was also kept constant in the 4 cheesemilks. The compositional characteristics of the cheeses made from MF retentates did not vary with retentate CF and were within the legal range for LMPS Mozzarella cheese. The observed reduction in whey drained was greater than 90% in the cheese making from the 4 CF retentates studied. The development of proteolytic and functional characteristics was slower in the MF cheeses than in the commercial samples that were used for comparison due to the absence of starter culture, the lower level of rennet used, and the inhibition of cheese proteolysis due to the inhibitory effect of residual whey proteins retained in the MF retentates, particularly high molecular weight fractions.