面向长距离量子通信的双光子关联成像技术

量子时域鬼成像利用光子对的时间-频率关联性实现了50km光纤链路上的图像传送,有望应用于量子通信的协议中。然而,现有方案的成像质量较差,成像速度较慢,因此其应用性在一定程度上受到了限制。文章对已有成像方案进行了较大的改进,利用可编程滤波器数字设定待成像信息,进而实现了二维图像信息的自动化实时传送。实验结果证明,改进方案的成像质量和速度均有显著改善,有利于推动量子关联成像在量子通信领域的应用。     

γ-γ符合测量系统的新型前端读出电路研制

研制了一种新型前端读出电路，用于重离子治癌装置中符合测量原型系统的研究和测试。电路主要包括能量链、时间链和数据处理单元。能量链由截止频率7 MHz的抗混叠滤波器和模数转换器(ADC)组成，形成波形采样电路；时间链由高速比较器构成的定时甄别电路和时间数字转换器（TDC）组成；数据处理单元基于现场可编程门阵列(FPGA)设计实现。电路的线性度优于0.8%，噪声小于0.8 mV（RMS）。配合LaBr3单晶体条测试，能量分辨为4.5%（FWHM），在与LYSO晶体阵列配合测试时，位置映射散点图清晰。该前端读出电路性能优于CAMAC系统，具有较好的实际应用前景。     

Generating synthetic benchmark circuits for accelerated life testing of field programmable gate arrays using genetic algorithm and particle swarm optimization

Accelerated life testing (ALT) of a field programmable gate array (FPGA) requires it to be configured with a circuit that satisfies multiple criteria. Hand-crafting such a circuit is a herculean task as many components of the criteria are orthogonal to each other demanding a complex multivariate optimization. This paper presents an evolutionary algorithm aided by particle swarm optimization methodology to generate synthetic benchmark circuits (SBC) that can be used for ALT of FPGAs. The proposed algorithm was used to generate a SBC for ALT of a commercial FPGA. The generated SBC when compared with a hand-crafted one, demonstrated to be more suitable for ALT, measured in terms of meeting the multiple criteria. The SBC generated by the proposed technique utilizes 8.37% more resources; operates at a maximum frequency which is 40% higher; and has 7.75% higher switching activity than the hand-crafted one reported in the literature. The hand-crafted circuit is very specific to the particular device of that family of FPGAs, whereas the proposed algorithm is device-independent. In addition, it took several man months to hand-craft the SBC, whereas the proposed algorithm took less than half-a-day.     

基于约瑟夫森量子电压的交流功率测量系统及方法研究

基于约瑟夫森量子电压标准设计了交流功率差分测量系统。通过分析差分采样系统的误差分布及误差传递函数,提出换向差分测量方法,减小了差分采样系统的增益误差,提高了电压幅值测量准确度;通过分析衰减系数η,证明了采用换向差分测量较容易实现10-7量级电压幅值测量。通过评估差分采样系统零相位,结果证明了差分采样系统具有较好的相位测量稳定性。分析了交流功率差分测量系统的不确定度分量,评估了功率因数为1.0,0.5 L和0.5 C时的功率测量不确定度,通过与国家交流功率基准装置进行实验比对,证明了基于约瑟夫森量子电压交流功率测量系统不确定度评估的合理性。     

Identifying and Verifying Vulnerabilities through PLC Network Protocol and Memory Structure Analysis

Cyberattacks on the Industrial Control System (ICS) have recently been increasing, made more intelligent by advancing technologies. As such, cybersecurity for such systems is attracting attention. As a core element of control devices, the Programmable Logic Controller (PLC) in an ICS carries out on-site control over the ICS. A cyberattack on the PLC will cause damages on the overall ICS, with Stuxnet and Duqu as the most representative cases. Thus, cybersecurity for PLCs is considered essential, and many researchers carry out a variety of analyses on the vulnerabilities of PLCs as part of preemptive efforts against attacks. In this study, a vulnerability analysis was conducted on the XGB PLC. Security vulnerabilities were identified by analyzing the network protocols and memory structure of PLCs and were utilized to launch replay attack, memory modulation attack, and FTP/Web service account theft for the verification of the results. Based on the results, the attacks were proven to be able to cause the PLC to malfunction and disable it, and the identified vulnerabilities were defined.     

极端环境下储库控制系统的通信解决方案

在干旱、高温、潮湿、寒冷等环境中使用宽温的自动化产品一般都能达到要求,但在荒野等极端环境中,没有电力供应,没有网络通信的情况时有发生,进而对自动化系统造成致命性的影响。针对该问题,以土耳其地下天然气储库项目为例,提出了使用太阳能供电,运用卫星进行无线通信的方法实现自动化控制系统的正常运行,成功地解决了该问题。     

可编程序控制器(PC)在矿用提升机中的应用

分析了原矿井提升机电控系统存在的缺陷并阐述可编程序控制器 (PC)在矿用提升机中的应用及效果。     

PLC在液粘调速电控系统中的应用与设计

介绍一种经济型、高性能的矿井提升调速装置 ,给出系统提升控制过程工艺流程及程序设计。     

可编程序控制器在膜-生物反应器控制系统中的应用

膜-生物反应工艺过程的自动控制系统以可编程序控制器为中心，自动采集液位信号，对泵、阀进行自动控制。3个月的昼夜常规运行表明，系统能满足工艺过程自动控制要求，结构简单，操作便利，运行可靠、稳定。该自控系统可推广应用于同类型相关领域。