基于插桩技术的动态测试研究与实现

为了动态进行白盒、黑盒测试,设计实现了基于源代码插桩的动态测试工具,该工具包含了源代码的预处理方法、插桩库设计、插桩策略以及统计分析等内容。通过对源代码的语法、词法分析,对其插桩能获取最高的准确度,并且设计在函数执行,结束之前统一将桩信息写入桩文件中,减少了大量的I/O操作。最终,通过测试用例的执行获得了覆盖率、执行时间、复杂度等测试数据,正确地得到了测试用例优劣性的指标。     

一种应用于电子封装的热匹配工艺设计

作为组件封装材料,铝合金与芯片和电路基板之间存在热膨胀不匹配问题.采用热匹配工艺设计,选择合适的热匹配材料,为铝合金盒体与LTCC基板热膨胀匹配提供了一种理想解决方案.根据匹配设计理念,利用Abaqus有限元软件对热匹配材料及铝盒体的结构进行了仿真和优化,并与加工出试验样品的测试结果进行了对比,验证了模拟结果,为铝合金...     

Charge‐Transport Behavior in Aligned Carbon Nanotubes: A Quantum‐Chemical Investigation

Correlated quantum‐chemical calculations are applied to analyze the amplitude of the electronic‐transfer integrals that describe charge transport in interacting carbon nanotubes (CNTs) by investigating the influences of: i) the relative positions of the CNTs, ii) the size of the CNTs, and iii) their chemical impurities. Our results indicate that the mobility of the charge carrier is extremely sensitive to the molecular packing and the presence of chemical impurities. The largest splitting for the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels is in the case of perfectly cofacial conformations where hexagons face hexagons in the dimer structure. We found that the diameter of the CNT determines the type of transporting carrier: for CNTs with large diameters hole transport dominates, while for thin CNTs electron transport dominates. In general, the carrier mobility for the perfect CNTs (n ≥ 3) is less pronounced than that of C₆₀ due to their relatively small strain. B‐ and N‐doped CNTs exhibit considerably larger mobilities owing to the possibility of metallic behavior. These results provide a plausible explanation for the high mobility found experimentally in a field‐effect transistor (FET) made from a large‐area, well‐aligned CNT array. In addition, these hole‐rich and electron‐rich dopants imply potential applications in nanoelectronics.     

电力线通信室内互联技术电磁发射测试与分析

对高速宽带电力线通信（BPL）在室内互联场景下的应用进行了分析和测试,特别详细描述BPL产品的电磁发射测量。最后根据测试结果给出了BPL室内互联的应用建议,并对BPL产品的电磁兼容标准进行了初步探讨。     

Characterization and Studies on Hydro Dynamically Stable Operation of an Angular Jet SOG for COIL

Chemical oxygen-iodine Laser (COIL) is one of the fast emerging high power laser source for near Infrared (λ=1.315μm) laser generation. The heart of the system is the singlet oxygen generator (SOG) which is a pumping source for this laser. A Jet type SOG with a novel approach was designed and fabricated. Singlet oxygen was taken out of the SOG at an angle of 40° thus avoiding the carry over of droplets, which is one of the major drawbacks of horizontal system. The preliminary results have been reported in our earlier publication. The present paper discusses the performance of this generator for various operational conditions viz. diluent's gas nitrogen / helium, basic hydrogen peroxide composition, generator pressure and gas velocity. Further, conditions for the stable operation from generator as well as chlorine injection point of view have been identified.     

基于液体选择填充光子晶体光纤的波分解复用器研究

设计了一种基于液体选择填充三芯光子晶体光纤的1.31/1.55um波分解复用器。中间为缺失一个空气孔的普通二氧化硅纤芯,左右两纤芯填充了不同折射率的液体材料。根据光纤的消逝场耦合的模式理论,不对称相邻波导存在波长相关耦合。不同填充折射率的两纤芯与中间纤芯分别耦合,构成两个不同响应波长的光滤波器。通过选择合适光纤长度,可实现不同波长光的分离。采用全矢量有限元法分析了光纤的传输特性,讨论了填充不同折射率液体时波导间的模式耦合,得到了其匹配波长与耦合长度。基于光束传播法仿真发现,长度为4.88 mm的光纤能实现1.31/1.55 um波长光的解复用。     

基于用户浏览行为的个性化教学系统

网络教育已成为现代教育技术主流的发展方向。提出了二层树状结构模型,并在此基础上,设计了一个基于基于浏览行为的个性化推荐系统(BB IRS)。系统可以通过离线和在线方式对用户的访问日志和交互数据分别进行挖掘,并通过根据用户的浏览速度计算用户对页面的兴趣度,根据该兴趣度是否大于阈值,系统采用不同的推荐策略。     

Enhanced solder joint bonding strength of electronic packaging with electrowetting effect

This paper reports a novel method to enhance solder ball or solder ring bonding strength by using electrowetting-on-dielectric (EWOD) effect. With a low melting point, the metal Sn has been widely used in electronic packaging technology. Since Sn will be molten into liquid when the temperature is increased above the melting point, the method for treating liquid can be herein employed. Contact angle of the molten Pb-free balls or ring structure on silicon substrate have been experimentally changed by applying electric field across the thin dielectric film between the molten solder and the conductive silicon substrate. The contact area between the solder and the substrate is enlarged due to the decrease of the contact angle. Our testing results on the EWOD enhanced packaging structures of solder balls, flip-chip and solder ring hermetic package generally show about 50% enhancement in bonding shear strength. The significantly enhanced solder link bonding strength is hopeful for improving packaging reliability and is promising to be used in high performance silicon based electronic or microelectromechanic SiP (system in package) technologies.     

基于Hough变换的天基激光测距轨迹提取算法

天基目标测量具有全天时、不受大气干扰等优点.但与地面人卫测距相比,天基待测目标运动速度快且缺乏距离预报等先验信息,导致传统测距方法无法有效提取目标距离轨迹.为此,文章提出了一种基于Hough变换的激光测距距离轨迹提取算法,利用目标回波点之间的线性相关性将直线检测算法引入回波轨迹的提取,具有适应天基探测特性、抗噪声能力强等特点.实 验结果表明,使用该方法提取的目标距离轨迹均方根误差优于2.72 m.上述方法可以准确地提取高速移动目标的距离轨迹,为后续空间非合作目标的距离轨迹提取提供了新的途径.     

基于FPGA的宽带数字接收机的数据率转换的实现方法

本文对数字系统设计的方法进行了阐述 ,着重讨论了用FPGA实现宽带数字接收机的数据率转换的方法 ,最后给出了计算机仿真结果