Detection of acylated homoserine lactones in gram-negative proteolytic psychrotrophic bacteria isolated from cooled raw milk

Through a mechanism called quorum sensing, bacteria are able to express specific genes in response to population density. Cell-to-cell communication in bacteria is mediated by signal molecules such as acylated homoserine lactones (AHLs). This work aimed to detect AHL production in Gram-negative psychrotrophic bacteria isolated from raw milk. A total of 84.9% of the bacteria were identified as AHL producers eliciting a diversity of responses in the AHL-monitor systems. These results demonstrate that AHL-production is common among psychrotrophic bacteria isolated from milk, and indicate that quorum sensing may play an important role in the spoilage of this product.     

《动态网站开发》课程教学改革探索

《动态网站开发》课程是中职学校计算机专业的核心课程,传统的授课方式以讲授理论为主,实际操作较少,这种方式很难适应现在中职学校的教学,必须打破传统的教学理念,对《动态网站开发》课程进行改革。     

基于模块化模型的自适应预失真技术

系统地比较和分析了OFDM传输系统里高功率放大器（HPA）预失真方法的优缺点,提出一种基于模块化模型的有记忆高功率放大器自适应数字预失真方法,该方法分别基于Wiener、Hammerstein和Wiener-Hammerstein模型各自构成一个有记忆HPA的自适应预失真器。从而避免了因分别估计Wiener-Hammerstein模型各个环节特性参数所带来的复杂性。使得有记忆高功率放大器的预失真设计变得简单了。     

高性能电极接头栓的研制

研制了高粘结强度、低电阻率、高渗透性能接头栓,并说明了改进的目标和方向。研究了电极接头栓的使用性能、主要作用和选用接头栓补救电极和接头连接质量的优点;研究了电极接头栓的原料选择、原料配比、添加剂和发泡剂的选取;确定了电极接头栓的生产技术要求和生产工艺流程。试验证明,研制的高性能接头栓具有高粘结、强固结、有效补强的作用。     

不同种类牙膏对牙龈卟啉单胞菌的抑制作用

牙龈卟啉单胞菌是引起牙周炎的重要病原菌。本研究选取市售常见13种牙膏,利用药物敏感试验方法对牙龈卟啉单胞菌的抑菌性能进行测定。结果表明,中药牙膏对牙龈卟啉单胞菌均有不同程度的抑制作用;氟化物牙膏对牙龈卟啉单胞菌有一定的抑制效果,但作用较小;而普通牙膏对该菌无抑制作用。为了防治牙龈卟啉单胞菌引起的牙周炎,要慎重选择牙膏种类。     

液力偶合器用铝合金材料的超声波检测

铝硅合金ZAlSi9Mg(代号ZL104)具有优良的力学性能,在大气和淡水中不宜腐蚀、耐磨耐热、塑性成形能力强、铸造性能和切削加工性能好、不易产生“咬死”现象,是一种优良的绿色环保材料[1],被笔者公司广泛用于液力机械产品中的涡轮、泵轮、离合器等高速运转部件,降低了经济成本,也     

串联法氧化铝生产中的合流脱硅

合流脱硅是简化联合法生产流程、降低能耗的有效措施。因此。国内外业界做了大量卓有成效的工作。串联法的工艺特点，更宜于采用合流脱硅。试验结果表明，串联法采用常压合流脱硅流程可以达到所需要的硅量指数。文中还对合流脱硅的硅量指数、合流点、合流脱硅温度、赤泥种子和添加石灰乳等问题进行了讨论。     

Model checking response times in Networked Automation Systems using jitter bounds

Response time (RT) of Networked Automation Systems (NAS) is affected by timing imperfections induced due to the network, computing and hardware components. Guaranteeing RT in the presence of such timing imperfections is essential for building dependable NAS, and to avoid costly upgrades after deployment in industries.This investigation proposes a methodology and work-flow that combines modelling, simulation, verification, experiments, and software tools to verify the RT of the NAS during the design, rather than after deployment. The RT evaluation work-flow has three phases: model building, modelling and verification. During the model building phase component reaction times are specified and their timing performance is measured by combining experiments with simulation. During the modelling phase, component based mathematical models that capture the network architecture and inter-connection are proposed. Composition of the component models gives the NAS model required for studying the RT performance on system level. Finally, in the verification step, the NAS formal models are abstracted as UPPAAL timed automata with their timing interfaces. To model timing interfaces, the action patterns, and their timing wrapper are proposed. The formal model of high level of abstraction is used to verify the total response time of the NAS where the reactions to be verified are specified using a subset of timed computation tree logic (TCTL) in UPPAAL model checker. The proposed approach is illustrated on an industrial steam boiler deployment.     

基于Cortex-A8智能家居系统的设计与实现

本文设计了一套低成本无线智能家居系统的解决方案,具有安全,可靠,稳定的显著特点,以及智能家居系统市场的广大前景.本文还阐明了系统的体系结构,详细介绍了系统软件和硬件部分的设计与实现。并对关键技术(GPRS、24L01)的流程做了详细的阐述。     

基于手绘艺术作品的文化创意服务与交易平台的分析与设计

进入21世纪,文化创意产业从概念逐步变为现实,也带来了巨大的经济效益。而文化创意产业不断产生新的文化创意作品,如何把这些文化创意作品更好的为社会服务?如何进行文化创意作品的在线交易?本文重点以手绘艺术作品为例进行了研究,通过制作手绘艺术作品的网站从而实现在线交易作品的目的。