聚四甲基丙二胺-二氯二乙醚季铵盐的合成及其对积层线路板镀铜的影响

设计并合成新化合物聚四甲基丙二胺-2,2'-二氯二乙醚季铵盐,系统研究了其对积层线路板镀铜的影响。通过红外光谱、核磁共振氢谱和凝胶色谱表征该化合物结构和分子量分布,分析该化合物对线路板通孔镀铜的影响。研究结果显示,将此缩聚物添加至电解液后,孔铜生长快,孔铜厚度厚,面铜厚度合理,成品率提高至98%,电镀时间减少30%。     

Two-dimensional coupled vibration and equivalent circuit of longitudinal-longitudinal orthogonal composite vibration direction converter

With the advantages of transmitting energy from multiple directions to one direction and transforming vibration from one source to multiple directions, the two-dimensional vibra?tion direction converter has important applications in power ultrasonic technology. However, for the complexity of using the wave equation to design and analysis the two-dimensional vibration direction converter, a concise equivalent circuit for the converter is investigated. By introducing the two-dimensional mechanical coupling coefficient and the longitudinal force transform coef?ficient, and using the electromechanical analogy principle, the equivalent circuit and resonance frequency equation of the two-dimensional vibration direction converter vibrating in anti-phase and in-phase two-dimensional coupled vibration are deduced. The resonance frequencies of the vibration direction converters of two different materials are calculated by using the proposed frequency equation, which are in agreement with the results from the finite element method and the experimental test. It provides a concise method for the design and applications of such ultrasonic vibration system.     

具有双荧光发射的螺吡喃的合成与性质研究

设计合成了未见文献报道的含有双官能团的螺吡喃类化合物1,通过红外光谱、核磁共振氢谱、碳谱和高分辨质谱对其结构进行了确证。紫外可见吸收光谱表明化合物在有机溶剂中的光致变色性良好;化合物的乙醇溶液在365 nm光激发时产生双荧光发射,分别为闭环体和开环体所对应的的荧光峰。本文首次从场效应角度推测了螺吡喃吲哚林N原子上含有极性基团时开环体稳定的原因。     

3种现场快速水质检测仪的性价对比

选择了市场上口碑好、占有率高的3款便携式水质现场应急检测设备,通过准确度、精密度、检测时长及价格等指标,以权重积分法对3款仪器进行了比选,结果表明德国MN公司的PF-12型便携式多参数分光光度计的综合性能最优.     

Deployment strategy for static chargers in WRSN

The traditional deployment strategy of static chargers in wireless rechargeable sensor networks (WRSN) covers all the area.The basic idea is to cover all the positions of nodes.A mathematical model of distance between a charger and the farthest node was established,the relationship between the number of nodes and the mathematical expectation of minimum radius of charging was analyzed,and deployment strategy for static chargers was proposed.The method based on the locations of all nodes that need to be charged in the area,used the smallest enclosing circle (SEC) algorithm and finds the optimal location of the charger through Euclidean delivery boy algorithm.It will decrease charging radius,reduce the minimum required transmitted power,thereby saving the average charging energy consumption.The experimental results demonstrated that the less the number locations that the nodes existed,the more energy will be saved.     

基于FFT的二维并行长码捕获算法

导航伪随机长码周期一般为7天,在时间不确定度为±1 s,码速率为10.23 MHz的情况下,需要搜索码片数最多达20 460 000个,普通方法难以实现短时间内捕获。通过增加硬件资源消耗及减少相干积分时间能加快捕获速度,但由于硬件资源有限,而减少相干积分时间会导致捕获灵敏度降低。为了在有限的硬件资源下,不影响捕获灵敏度而又能快速实现捕获,研究了一种基于快速傅里叶变换(FFT)的二维并行搜索算法。通过与传统基于FFT的码相位并行多普勒串行搜索及匹配滤波+FFT方法在捕获时间、灵敏度及硬件资源3方面对比,验证了基于FFT的二维并行捕获方法在长码捕获中具有捕获速度快、捕获灵敏度较高、硬件资源的利用更加合理等优势。     

一类新的 pqr长2阶广义分圆序列的线性复杂度

具有良好随机性质的伪随机序列在流密码和通信领域中有着广泛的应用。本文构造出一类新的长为pqr的2阶广义分圆序列,并且计算其线性复杂度和极小多项式。结果显示这种序列具有高线性复杂度。     

云环境下的 CRUAC访问控制模型

提出了云计算环境下的CRUAC访问控制模型。该模型以使用控制模型为基础,引入了角色的概念,并将约束信息加入到决策判定因素中。该模型能够解决使用控制模型中将权限直接分配给用户所带来的系统开发、重用和系统安全管理等复杂性问题,并且为云用户访问不同云服务器上的资源提供了一种解决方案,能够较好地满足云计算环境对访问控制的需求。     

印刷带状偶极子天线与经典三维柱状偶极子天线的等效理论研究

相对于传统的柱状偶极子,印制偶极子天线更适合应用于现代通讯系统.本文通过引入边缘场效应,对传统的基于感应电动势法的柱状电偶极子辐射阻抗公式进行修正,并在此基础上将其推广至印制偶极子天线中.此外,本文还采用合成渐进法,基于物理概念,推导出平面偶极子天线的谐振频率及谐振频率处辐射电阻的两个计算机辅助计算公式.数值计算及验证表明,两个公式的精度均在2%以内,可以用于指导工程设计.