用于保护位置隐私的邻近检测算法

现有保护位置隐私的邻近检测算法通常根据网格大小对用户位置进行量化计算,会降低算法结果的准确性。针对该问题,提出2种准确安全的邻近检测算法。用户将自己的位置分成网格内坐标以及网格编号两部分,并将其分别加密后发送给服务器,服务器利用加密后的网格内坐标在整个地图中筛选出所有满足查询的网格,用户根据服务器的返回结果判断用户之间是否邻近。实验结果表明,算法1速度快,传输信息少,算法2更加安全,但计算和通信开销较大,并且需查询与被查询用户同时在线。用户可根据对服务器的信任程度、查询性能和应用场景需求进行算法选择。     

吸水膨胀橡塑密封材料的研究

研究了用物理共混法制备吸水膨胀橡塑材料的一些特性，对在不同CPE／SBR配比下吸水膨胀橡塑材料的吸水性能和力学性能及其影响因素进行了研究。根据不同的工艺参数，对产品性能进行测试，选择最佳配方，制造出性能优良的吸水膨胀橡塑材料。     

人工骨料在混凝土中的应用研究

为了充分利用尾矿资源,促进天津地区人工骨料的应用,针对蓟县尾矿资源的开发利用进行了初步研究,内容包括不同种类骨料的性能及其混凝土的立方体抗压强度和抗冻性试验,实验结果表明,利用尾矿资源生产的人工骨料可以满足工程需要。     

AutoCAD辅助施工测量放线

在大面积地下室工程轴线和圆弧曲线的测量控制中使用了AutoCAD绘图软件，简化工程测量内业翻样，将繁复的计算转换为直观的“图解法”，数据直接从图上量出，使测量放线变得快速、准确。     

电流模式n阶MOCCII—RC的全通滤波器设计

本文提出了一种新的基于MOCCII的n阶等电容和等电阻全通电流模式滤波器综合方法.通过对,n阶全通滤波传输函数进行分析将其分解成一系列能用无损积分器实现的表达式,南低阶向高阶进行电路综合.该滤波电路包含n 2个有源器件、2n 4个接地无源元件,整个电路的部分无源元件灵敏度之和与全部元源元件灵敏度之和为0.文中对一个3阶全通滤波器进行了PSPICE模拟验证.     

羟化含氟嵌段共聚物的合成及其自组装行为研究

用α-溴代丙酸乙酯（EPN—B）／氯化亚铜（CuCl）／联二吡啶（bpy）作为催化引发体系,环己酮为溶剂,进行甲基丙烯酸2,2,2-三氟乙酯（TFEMA）的原子转移自由基聚合（ATRP）,得到单分散PTFEMA—X预聚体。并以此预聚体为大分子引发剂引发甲基丙烯酸-β-羟乙酯聚合,得到分子质量可控、分子质量分布窄的聚甲基丙烯酸2,2,2-三氟乙酯-b-聚甲基丙烯酸-β-羟乙酯嵌段共聚物,用FTIR、^1H—NMR、GPC等对产物的结构与性能进行了表征。同时利用动态激光光散射（DLS）对嵌段共聚物的自组装行为进行了研究。     

放电等离子烧结(SPS)制备金属材料研究进展

综述了放电等离子烧结(SPS)技术在制备纳米/超细晶、大块非晶、准晶、金属间化合物、功能梯度材料、多孔材料、硬质合金等多种金属材料中的应用情况.重点阐述烧结过程中的致密化机理,焦耳热生成机制,关于等离子活化效应的争议,电流、温度、位移量和应力分布的不均匀性及其影响,粉末的预处理工艺及其对性能的影响.并总结了SPS技术现存问题及发展趋势.     

基于S3C2410的嵌入式网络接口设计

本文详细阐述了一种基于ARM芯片S3C2410的嵌入式网络接口设计方案,成功实现了与工业级网络接口芯片CS8900A的网络互联,并详细介绍了网络接口的硬件电路设计和软件设计流程。     

Experimental investigation and simulation of gas-liquid-liquid reactive extraction process for the production of hydrogen peroxide

The gas-liquid-liquid reactive extraction system for the production of hydrogen peroxide via anthraquinone route was investigated. The oxidation of the hydrogenated anthraquinone working solution by oxygen and the extraction of hydrogen peroxide from the working solution with deionized water were carried out simultaneously in a sieve plate column of 50 mm in diameter. The effects of the superficial velocity of oxygen on the conversion of 2-ethylanthrahydroquinone and the extraction efficiency of hydrogen peroxide were investigated, separately. The results showed that the oxidation and the extraction do not hamper each other, on the contrary, the presence of gas in the column can promote the transfer of hydrogen peroxide from the organic phase to the aqueous phase, therefore, the conversion of 2-ethylanthrahydroquinone and the extraction efficiency of hydrogen peroxide increased with the increase of gas superficial velocity. In addition, a mathematical model for the simulation of the gas-liquid-liquid reactive extraction process was developed. The predicted values were compared with the experimental data at different conditions and the agreement was found to be quite satisfactory for the production of hydrogen peroxide in a sieve plate column.     

Piezoresistive TiB2/silicone rubber composites for circuit breakers

Piezoresistive composites with high hardness and conductivity are required for circuit breakers for multi-cycle operation under large current flow. Based on the simulation results for the mechanical behavior of piezoresistive composites, we developed piezoresistive composites with conductive TiB₂ ceramic materials and silicone rubber. TiB₂ up to 70 vol.% was embedded into the polymer matrix without any mechanical deterioration while the electrical resistance was decreased with increasing TiB₂ content. Piezoresistive composites with 70 vol.% TiB₂ particles exhibited a resistance of 1.7 Ω at a pressure of 1.1 MPa. A circuit breaker with the fabricated piezoresistive composites acted as a switch with a response time of around 2 ms.