石英玻璃热膨胀性能的高温分子动力学研究

采用基于第一性原理的COMPASS力场对石英玻璃的热膨胀性能作了分子动力学研究。结果分析表明Si-O键长与Si-O-Si键角是导致结构随温度变化的主要因素，两者的变化趋势和变化速率决定了材料热膨胀的不规则性。此外，还根据四面体体积随温度的变化粗略估算了四面体间隙的变化，对负热膨胀现象做了进一步讨论。     

一起COMPASS产品故障的分析与处理

通过对一起COMPASS产品内部异常响声故障的现场分析、判断、处理过程的总结,指出了COMPASS产品内部存在的结构和装配工艺弱点,提请该产品的所有用户共同关注这类问题,一旦发现类似现象必须及时检查处理,以确保设备及电网的安全运行。     

A double-filter-structure based COMPASS/INS deep integrated navigation system implementation and tracking performance evaluation

Beidou or COMPASS is a Chinese GNSS(global navigation satellite system).Like the GPS receiver,the COMPASS receiver also faces the challenge of choosing an optimal bandwidth to satisfy both anti-jamming capability and dynamics adaptation simultaneously.GPS/INS(inertial navigation system)deep integrated navigation system has solved this problem by fusing GPS baseband signal and INS information in a deeply coupled mode.In this study,a COMPASS B3 frequency is considered and a traditional federated GPS/INS deep integration model is used to derive a single-filter-structure based COMPASS/INS deep integration model.Besides,a double-filter-structure based COMPASS/INS deep integration model is proposed.The simulation results show a better carrier tracking performance,especially a better dynamics adaptation.The impact of IMU errors and vehicle’s dynamics on carrier tracking performance of the double-filter-structure based COMPASS/INS deep integrated navigation system are evaluated in simulated and field environments.Simulation and field test results are in accordance with the theory analysis.     

Discharge studies in micromegas detectors in a 150 GeV/c pion beam

A detailed study of several Micromegas detectors prototyped for the COMPASS and CLAS12 experiments is presented. Using a 150 GeV/c pion beam, the discharge probability was measured for several detector variants including bulk and non-bulk Micromegas. A detector equipped with an additional GEM foil as pre-amplification stage was also tested. A resistive coating of the readout strips was found to reduce the amplitude of the discharge by at least two orders of magnitude which was below the detection limit of the experimental setup. The effects of the micro-mesh type and material were investigated as well as the influence of the drift gap. Response in the presence of a 1.5 T transverse magnetic field was also studied. The measurements presented were performed during a RD51 beam test period.     

珠海市陆海统一高精度高程网的建设与实现

珠海市陆海统一高精度高程网的建设与实现,是利用域内收集到的526个重力资料以及25个高精度GPS水准数据,采用第二类Helmert凝集法建立的1㎝级精度似大地水准面。高程网的精度可满足四等水准甚至三等水准的要求。这将改变传统的平面和高程测量分离的作业模式,实现平面高程测量同步一体化的现代化方法。     

射频识别与北斗卫星导航系统在物联网中的应用

物联网是上个世纪末提出的新概念,其发展历史比较短。本文是基于家电物联网项目的技术应用,以三洋荣 事达企业的实际物流配送为原型,将无线射频识别（RFID）技术以标签的形式用于对物品进行唯一标识,并采用帧时隙算法解 决RFID 系统中应答碰撞的问题,保证在读取RFID 标签发出的信号时做到既不丢失也不重复。将北斗卫星导航系统用在对 在途车辆及货物的跟踪定位上,降低货物丢失的风险,降低产品成本,提高企业利润。     

移动式比相法配电网接地故障定位同步采集的实现

根据移动式比相法的定位原理,提出应用北斗导航系统的秒脉冲(1 pulse/s)及UTC来实现零序电压电流的异地同步采集。1 pulse/s及UTC可为采集工作分别提供同步触发信号及时间标定。为验证1 pulse/s信号的同步性,设计了一种基于ARM(Advanced RISC Machines)技术的软硬件平台,实现了不同北斗授时模块1 pulse/s接口精度的测试。选用2.4 GHz射频收发芯片nRF2401来实现移动式零序电流互感器高压端和低压端间数据的无线传输,提出一种预备-触发模式的程序设计方案,以实现三相电流的同步采样。实验室试验验证了所述方法的可行性。     

北斗卫星导航定位系统在地质测绘中的应用

文中介绍了北斗卫星导航系统的基本原理,主要技术特征优势及在地质勘探测绘方面的主要应用.通过实例阐述了北斗导航系统实时动态定位功能在地质测绘中的应用,分析了北斗卫星导航系统的发展前景.     

一种宽频带宽角度圆极化微带天线的设计

设计了一种实用型宽频带圆极化微带天线,在容性探针顶部附加圆形贴片进行耦合馈电的基础上,通过平衡馈电提高了天线的阻抗带宽(VSWR<=2)和在宽角度内实现了圆极化(AR<=3 dB)．利用有限元积分软件CST对天线的参数进行优化仿真,通过实验测试表明：仿真与实测吻合较好,满足实际应用的需求．     

基于准则法的飞机薄壁结构可靠性优化设计

针对传统的安全因数法考虑载荷和强度不确定性因素对飞机安全性的影响太笼统,无法从根本上减轻飞机结构质量的问题,提出一种飞机结构可靠性优化设计方法.根据应力-强度干涉模型计算结构单元的可靠度,建立以单元满可靠度为准则的优化模型,实现包含可靠性约束的结构尺寸优化.该功能已经加入到COMPASS中.算例结果表明该方法能够减轻结构质量,改善结构可靠度.该方法为开展飞机结构不确定性设计提供技术手段.