Mifare系列射频卡读写器的研制

Mifare系列射频卡具有高度安全、高可靠性及分区的存储结构等特点，其应用范围越来越广，支持一卡多用场合。本文介绍了射频卡及其读写器工作原理，给出了该读卡器的硬件结构和主程序流程图。     

中频弯管工艺中测温的分析及应用

根据中频弯管工艺的特点和辐射测温原原理，提出了适于这一特殊情况的比色（双色）红外测温仪，对影响测温的目标面积与距离系数的关系，管材表面的处理，测温仪的安放位置，水雾的处理，加热区温度分布状况及加热区位置变化等因素进行了详细分析，并提出了相应的解决办法。     

单相多线圈中频变压器DC/DC控制方法研究

多端直流电网是未来分布式输配电网的关键技术,不同电压等级的直流电网通过中频变压器隔离互联。目前变压器采用多电平移相控制技术因触发不同步存在器件发热不均衡、可靠性不稳定等问题。针对现有技术缺陷,提出了一种单相多线圈中频变压器级联式DC/DC控制方法,拓扑结构主要包括控制器、滤波电感和多线圈变压器。将单相变压器的每一绕组拆分为多个线圈,再将每个线圈的半桥控制模块串联,这样可以有效改善功率器件电压和电流的应力,实现电容电压自动均衡。MATLAB/Simulink仿真结果表明所设计的拓扑结构和控制方法是可行的。     

Atom transfer radical polymerization (ATRP): A versatile and forceful tool for functional membranes

The progress in atom transfer radical polymerization (ATRP) provides an effective means for the design and preparation of functional membranes. Polymeric membranes with different macromolecular architectures applied in fuel cells, including block and graft copolymers are conveniently prepared via ATRP. Moreover, ATRP has also been widely used to introduce functionality onto the membrane surface to enhance its use in specific applications, such as antifouling, stimuli-responsive, adsorption function and pervaporation. In this review, the recent design and synthesis of advanced functional membranes via the ATRP technique are discussed in detail and their especial advantages are highlighted by selected examples extract the principles for preparation or modification of membranes using the ATRP methodology.     

射频识别读写设备应用设计

主要结合对射频识别原理和组成的分析采用符合ISO/IEC 14443A标准的Philips公司MIFARE技术的MFRC500射频集成电路芯片、ATMEL89C5l单片机芯片及辅助电子元器件等来实现射频卡读写设备的设计。该设计首先对射频IC卡读写设备原理进行分析,再根据其原理完成硬件电路设计和软件功能实现,最后在此基础上配置相应的通信协议,来具体实现射频IC卡读写设备的各种操作接口以供射频识别系统的应用。     

高通量氧化铝微滤膜的制备

在前有工作基础上进一步研究了氧化铝微滤膜纯水通量影响因素及其提高方法，发现制膜液粘度对纯水通量有重要影响，提高制服膜液粘度可提高膜纯水通量２￣３倍。采用有机高分子溶液预涂载体可进一步提高纯水通量３０％￣４０％。随烧结温度升高纯水通量先增后减。     

Removal of Salmonella Enteritidis from commercial unpasteurized liquid egg white using pilot scale cross flow tangential microfiltration

Effectiveness of a cross flow microfiltration (MF) process for removal of a cocktail of Salmonella enterica serovar Enteritidis species from commercial unpasteurized liquid egg white (LEW) from a local egg breaking plant, while maintaining its functional properties was evaluated. To facilitate MF, LEW was wedge screened, homogenized and then diluted (1:2 w/w) with distilled water containing 0.5% sodium chloride. Diluted unpasteurized LEW was inoculated with five strains of S. Enteritidis (ATCC 4931, ATCC BAA-708, ATCC 49215, ATCC 49218, and ATCC BAA-1045) to a level of approximately 10⁷ CFU/mL of LEW and microfiltered using a ceramic membrane. Process parameters influencing egg white functional properties and pathogen removal efficiency were evaluated. Average permeates flux increased by almost 126% when pH of LEW was adjusted from pH 8 to pH 7 at 25 °C. Microbial removal efficiency was at least, on average, 6.8 Log₁₀ CFU/mL (limit of detection ≤ 0.5 Log₁₀ CFU/mL). Functional property analysis indicated that the MF process did not alter the foaming power of LEW.     

白姑鱼和小黄鱼肉中挥发性风味物质的鉴定

采用新型固相萃取整体捕集剂（Mono-Trap）结合气相色谱-质谱-嗅闻技术对白姑鱼和小黄鱼肉的挥发性风味物质进行鉴定,分别得到42 种和49 种挥发性成分。进一步通过芳香萃取物稀释分析法分别从白姑鱼和小黄鱼肉挥发物中筛选出12 种和6 种挥发物,其中9 种挥发物经质谱和线性保留指数鉴定。进一步结合校准频率（modified frequency,MF）法,各筛选出2 种鱼肉中排名前10的气味物质。白姑鱼中香气稀释（flavor dilution,FD）因子最高为40的化合物为三甲胺、2-辛烯-1-醇、壬醛及金属味未知化合物。结合MF排名,得到三甲胺和2-辛烯-1-醇对白姑鱼贡献较大;小黄鱼中FD因子最高为40的化合物为己醛和2-辛烯-1-醇,但结合MF排名,对其气味贡献较大的是三甲胺和未知烧烤味化合物。6-甲基-5-庚烯-2-酮为2 种鱼中均鉴定出的一种带金属味或血腥味成分,根据MF排名,该化合物对白姑鱼影响更大。2,3-戊二酮、1-戊烯-3-醇为小黄鱼中MF较靠前的物质,结合三甲胺和未知烧烤味化合物以及白姑鱼中未鉴定到的二甲基二硫醚,这些挥发物可能是造成其与白姑鱼气味感知差异的原因。     

常用造纸湿强剂的作用机理及研究现状

湿强剂在造纸业中得到广泛的应用,其重要性被越来越多的人们所关注,对各种湿强剂主要包括脲醛树脂、三聚氰胺甲醛树脂、聚酰胺环氧氯丙烷等的作用机理和研究现状进行了综述。并简要介绍了现存湿强剂的不足,对我国湿强剂的发展做了展望。     

Effectiveness of Cross-Flow Microfiltration for Removal of Microorganisms Associated with Unpasteurized Liquid Egg White from Process Plant

ABSTRACT:  Thermal preservation is used by the egg industry to ensure the microbiological safety of liquid egg white (LEW); however, it does not eliminate all microorganisms and impairs some of the delicate functional properties of LEW. In this study, a pilot-scale cross-flow microfiltration (MF) process was designed to remove the natural microflora present in commercial LEW, obtained from a local egg-breaking plant, while maintaining the nutritional and functional properties of the LEW. LEW, containing approximately 10^{6 ± 1.7} colony forming units (CFU) per milliliter of total aerobic bacteria, was microfiltered using a ceramic membrane with a nominal pore size of 1.4 μm, at a cross-flow velocity of 6 m/s. To facilitate MF, LEW was screened, homogenized, and then diluted (1 : 2, w/w) with distilled water containing 0.5% sodium chloride. Homogenized LEW was found to have a threefold lower viscosity than unhomogenized LEW. Influence of MF temperature (25 and 40 °C) and pH (6 and 9) on permeate flux, transmission of egg white nutrients across the membrane, and microbial removal efficiency were evaluated. The pH had a significantly greater influence on permeate flux than temperature. Permeate flux increased by almost 148% when pH of LEW was adjusted from pH 9 to pH 6 at 40 °C. Influence of temperature on permeate flux, at a constant pH, however, was found to be inconclusive. Microbial removal efficiency was at least 5 log₁₀ CFU/mL. Total protein and SDS-PAGE analysis indicated that this MF process did not alter the protein composition of the permeate, compared to that of the feed LEW, and that the foaming properties of LEW were retained in the postfiltered samples.