基于模块化结构的电气化铁路统一电能质量控制器

提出了2种基于模块化结构的铁道统一电能质量控制器主电路拓扑,2种拓扑交流侧均采用链式结构,具有良好的谐波特性。针对链式结构变流器存在的直流电压平衡问题,建立了所述拓扑中电容电压的数学模型,并对现有各种直流电压平衡控制策略的优缺点及存在有功功率双向流动的背靠背变流器的适用性进行了分析。结果表明,电容电压中的直流分量分别与吸收和发出有功功率侧变流器的调制比成正相关和反相关的关系。最后,给出了铁道统一电能质量控制器装置级控制策略,并通过仿真实例证明了所述拓扑和控制策略的正确性。     

基于递变能量线性约束的X射线图像质量评价方法

X射线图像质量评价是射线检测正确与否的关键问题,传统的人工主观评价方法效率低,实时性差,常用的对比度、清晰度等考核指标,受成像过程的散射及噪声影响,存在一定的局限性.为此论文提出基于递变能量线性约束的X射线图像质量评价方法.文章首先通过分析递变能量成像过程中图像序列的灰度变化规律,提出序列间灰度增益分布图,并依据成像器件的线性最优成像,从分布图中提取线性散布度评价图像质量;进一步针对过曝光影响散布度评价失败问题,综合线性散布度和平均对比度,构建了新的图像质量综合评价标准,实现射线图像质量评价.最后通过实验验证了论文方法的可行性,能够有效避免传统单一评价指标的局限性.     

Advances of electronic nose and its application in fresh foods: A review

ABSTRACT

The science and technology aspects of electronic nose (E-nose) has been developed rapidly in last decade (2006–2016). This paper reviews of the publications that that cover the developments in science and technological aspects of electronic nose together with its application in fresh foods. The first part of this review covers the sensing and pattern recognition system (PR) of E-nose. The second part covers the application of E-nose in classification, flavor detection, and evaluation of spoilage in fresh foods area. With more new sensor materials to be found and more combination between E-nose and other analysis technologies, the usages of E-nose in fresh foods will have wider prospects.     

Intramuscular lipids of Mertolenga-PDO beef, Mertolenga-PDO veal and “Vitela Tradicional do Montado”-PGI veal

Three quality branded meats (n = 68), “Vitela Tradicional do Montado”-PGI veal, Mertolenga-PDO veal and Mertolenga-PDO beef were analysed for cholesterol (HPLC-UV), α-tocopherol (HPLC-FD), fatty acid composition (GC-FID), including conjugated linoleic acid (CLA) isomeric profile (Ag⁺-HPLC), and nutritional value of lipids. All the meats analysed had similar contents (P > 0.05) of cholesterol, α-tocopherol and intramuscular fat. In contrast, the percentage of 18:0 was lower for PGI veal, and that of 18:1 c9 was higher in PDO veal, whilst the percentage of 18:2 n−6 was higher in PDO beef, relative to other two meats. The content of total CLA and the percentage of its t11,c13 isomer were higher, and the n−6/n−3 ratio was lower, in PDO veal, relative to the other two meats. The data suggested that PGI veal has higher variability for most fatty acids than the other two types of meat. Finally, a discriminant analysis was conducted and the three meat types were well discriminated using the meat fatty acid profile as variables.     

臭氧处理对小麦粉及其面条品质特性影响的研究进展

臭氧处理是一种新型绿色的食品加工技术.综述了臭氧的工业化生产方式,臭氧处理对小麦粉微生物的抑制及真菌毒素的降解作用、对小麦粉粒度分布和微观形态、营养物质及加工特性的影响,以及对臭氧化小麦粉制得的小麦面条的微生物及货架期、理化特性及感官特性的影响,并浅析了相关影响机制,为深入了解臭氧的作用机制及其在小麦粉和面条制品的生产...     

提高"江津白酒"质量的研究与生产实践

“江津白酒”乃川法小曲白酒。通过对发酵周期、发酵池材料、晾糟设备等的研究与改进,选育生香酵母菌种,采用丢糟做培养基、培养固体香醅进行串蒸、分段摘酒、分级贮存等工艺,制定了白酒中有关微量成分的最佳比例,完善了勾兑工艺。开发的“金江津”系列酒,彻底解决了川法小曲酒因工艺问题造成口感方面苦涩味重的难题,大幅度提高了产品质量,其酒的乙酸乙酯含量达到150mg／100mL以上。     

Extension of shelf-life of whole-wheat flour by gamma radiation

The effect of low-dose gamma irradiation (0.25–1.00 kGy) on pre-packed whole-wheat flour (atta) was assessed in terms of physico-chemical properties, nutritional quality, chapati-making quality and sensory attributes. Semi-pilot scale storage studies on irradiated pre-packed whole-wheat flour revealed that there was no adverse effect of irradiation and storage up to 6 months of whole-wheat flour treated at doses up to 1.00 kGy on total proteins, fat, carbohydrates, vitamin B₁ and B₂ content, colour index, sedimentation value, dough properties, total bacterial and mould count. Storage of wheat flour resulted in slight increase in moisture, free fatty acids, damaged starch, reducing sugars and slight decrease in gelatinization viscosity.
However, irradiation as such had no effect on any of these parameters. Irradiation at 0.25 kGy was sufficient to extend the shelf-life of atta up to 6 months without any significant change in the nutritional, functional attributes. Chapaties made from irradiated atta (0.25 kGy) were preferred even after 6 months storage, compared with the control.     

大豆多肽豆酸奶的的研制

研究使用不同直投式发酵剂以及添加大豆多肽作为促进剂对豆酸奶产品感官品质和酸度的影响,初步探讨大豆多肽在豆酸奶中的应用.实验结果表明,在200mL的豆酸奶中选择Hansen YF-L811作为发酵剂,其添加量为0.02 g,蔗糖添加量为5～7 g,大豆多肽为1 g时,可获得感官品质较好的大豆多肽酸奶产品.制品中酸度的变化与大豆多肽添加量存在密切联系.添加大豆多肽作为促进剂,在豆酸奶的应用中具有一定的可行性.     

水刺非织造布专用涤纶短纤维的开发

分析了水刺工艺和水刺产品品质对原料涤纶短纤维的质量要求,介绍了调整生产工艺的方法以及用调整后的工艺生产的纤维质量。新开发的水刺专用短纤维品质优良,可较好地满足水刺工艺和产品的要求。     

Microbiological quality of Australian sheep meat in 2004

The third national baseline microbiological survey of Australian sheep carcases and frozen boneless sheep meat was conducted in 2004. Carcases (n=1117) sampled at 20 slaughter establishments were found to have a mean log total viable count (TVC, 25°C) of 2.28 cfu/cm(2) and Escherichia coli was isolated from 43.0% carcases with a mean log 0.03cfu/cm(2) on positive samples. In samples from 10 boning (fabrication) plants (n=560) the mean log TVC for frozen boneless sheep meat was 1.85cfu/g and the mean log count for the 8.2% of samples with detectable E. coli was 1.39cfu/g. E. coli O157:H7 was isolated from 6/1117 carcases and from 1/560 boneless samples. Salmonella was isolated from 0/1117 carcases and from 3/560 samples of boneless product. Campylobacter sp. were isolated from 4/1117 carcases and from 1/560 boneless samples. Coagulase positive staphylococci were isolated from 23.4% to 32.7% of carcases and boneless sheep meat samples, respectively, with positive samples having a mean log count of 0.93cfu/cm(2) and 1.14cfu/g, respectively. The low level of bacteria described here is consistent with a very low risk to human health due to bacterial hazards in Australian sheep meat.