绢云母质无机紫外屏蔽剂在聚丙烯中的应用

用自制的绢云母质无机紫外屏蔽剂改性聚丙烯(PP),对光老化后的PP复合材料进行力学性能测试。结果表明:绢云母质无机紫外屏蔽剂可以显著改善PP复合材料的耐光老化性,同时提高复合材料的综合力学性能;其最佳添加量是20%。     

一种节能的无线磁敏传感节点车辆检测算法

提出一种无线磁敏传感节点进行车辆检测的新算法,即自适应窗口距离算法。利用磁敏信号背景窗口与当前窗口的信号特征距离检测车辆信号的端点,在地磁场背景中分离出车辆到来与车辆离开事件而进行道路车辆检测,降低了长型慢速车辆的冗检率及快速车辆的漏检率。基于无线传感网络应用中对算法节能的要求,本算法应用可变化周期的“Duty-cycling”策略,在基本不影响检测准确率的情况下,降低节点能耗。选用Honeywell HMC1051Z及NVEGMR磁敏传感器采集样本库进行仿真,结果表明本算法较ATA算法具有更高的检测准确率（97％以上）,且鲁棒性更强,节能性更好,节点的寿命更长。     

基于有限元方法的液体火箭发动机机架优化设计

采用ANSYS有限元分析软件提供的优化方法对液体火箭发动机机架的优化问题进行了分析,提出了机架优化设计的一般流程,使用ANSYS的APDL语言编写了机架优化设计分析程序,通过对优化程序的研究,获得了某型号发动机机架的最优化结果,优化后的质量比初始设计质量大大的减轻.     

阻燃材料测试与表征方法概述

介绍几种常用的阻燃材料测试方法,包括水平和垂直燃烧法、氧指数法、NBS烟箱法、热分析法、锥形量热仪法,重点介绍了锥形量热仪法及其在阻燃材料研究中的应用。指出将多种测试方法结合使用可以更好地评价材料的阻燃性能。     

基于双核酞菁铜为中性载体的水杨酸根选择性电极的研究

合成了一种双核酞菁铜的衍生物,并将其用于离子选择性电极的敏感材料,制备出了基于该载体的水杨酸根离子(Sal-)选择性电极.该电极对Sal-呈现出良好的选择性和近能斯特电位响应性能.电极斜率为-56.5 mV/dec,线性范围为1.0×10-1～2.2×10-6mol/L,检测下限8.9×10-7mol/L.该电极用于了阿司匹林药片中水杨酸含量的分析,结果令人满意.     

基于铜(Ⅱ)席夫碱配合物为中性载体的高选择性水杨酸根传感器的研究

该文合成了双水杨醛缩4,4,-二氨二苯甲烷铜(Ⅱ)金属有机配合物,并以此配合物为中性载体,制得PVC膜离子选择性电极.该电极在pH值为4.0～8.5范围内对水杨酸根离子有较好的Nernst响应,且呈现反Hofmeister序列行为.电极具有良好的选择性、稳定性和重现性,其线性范围为2.7×10-5～1.0×10-1 mol/L.通过UV-Vis、交流阻抗技术分析了电极响应机理,将该电极初步应用于药品分析中,其测定结果与经典滴定法测定结果基本一致.     

水分胁迫条件下葡萄生理生化反应研究进展

从水分胁迫对葡萄叶、根的形态及气孔行为、光合作用、呼吸作用、质膜透性、氮代谢、碳水化合物代谢、活性氧代谢、内源激素变化等生理生化方面的研究进行了综述,为全面研究葡萄抗旱机理及进一步制定抗旱措施奠定理论基础.     

Rapid and sensitive detection of Salmonella Typhimurium on eggshells by using wireless biosensors

This article presents rapid, sensitive, direct detection of Salmonella Typhimurium on eggshells by using wireless magnetoelastic (ME) biosensors. The biosensor consists of a freestanding, strip-shaped ME resonator as the signal transducer and the E2 phage as the biomolecular recognition element that selectively binds with Salmonella Typhimurium. This ME biosensor is a type of mass-sensitive biosensor that can be wirelessly actuated into mechanical resonance by an externally applied timevarying magnetic field. When the biosensor binds with Salmonella Typhimurium, the mass of the sensor increases, resulting in a decrease in the sensor's resonant frequency. Multiple E2 phage-coated biosensors (measurement sensors) were placed on eggshells spiked with Salmonella Typhimurium of various concentrations (1.6 to 1.6 × 10(7) CFU/cm(2)). Control sensors without phage were also used to compensate for environmental effects and nonspecific binding. After 20 min in a humidity-controlled chamber (95%) to allow binding of the bacteria to the sensors to occur, the resonant frequency of the sensors was wirelessly measured and compared with their initial resonant frequency. The resonant frequency change of the measurement sensors was found to be statistically different from that of the control sensors down to 1.6 × 10(2) CFU/cm(2), the detection limit for this work. In addition, scanning electron microscopy imaging verified that the measured resonant frequency changes were directly related to the number of bound cells on the sensor surface. The total assay time of the presented methodology was approximately 30 min, facilitating rapid detection of Salmonella Typhimurium without any preceding sampling procedures.     

Quantification and reduction of organic sulfur compound formation in a commercial wood pulping process

This study experimentally quantified the formation of organic sulfur compounds in a commercial SuperBatch kraft pulping process using a laboratory pilot-scale digester. The results indicate that wood chips not only can adsorb HS- but also methyl mercaptan (MM) in the black liquor used for pretreatment during the two pretreatment stages. The absorption rate of MM is much faster than that of HS-. In the third stage of SuperBatch pulping, the rate of formation of MM and dimethyl sulfide (DMS) is very similar to that found in conventional batch kraft pulping processes. The study examined the applicability of the phase transition cooking (PTC) concept for reducing organic sulfur compounds in pulping, previously developed in laboratory batch pulping using a bomb-type digester, in a SuperBatch process. It was confirmed that there is a phase transition point (PTP) corresponding to PTC in SuperBatch pulping beyond which further delignification significantly increases the formation of volatile organic sulfur compounds. The results indicate that a 40% reduction of TRS formation can be achieved by using PTC.