Mediating and inducing quantum correlation between two separated qubits by one-dimensional plasmonic waveguide

We investigate the dynamics of quantum correlation between two separated qubits trapped in one-dimensional plasmonic waveguide. It is found that for a class of initial states, the quantum discord shows a sudden change phenomenon during the dynamical evolution. Furthermore, we demonstrate that the quantum discord can be enhanced if a proper product of the plasmon wave number and two qubits distance is chosen. Finally, we find that the non-zero quantum discord between two qubits can be created for the states without initial quantum discord during the time evolution of the system.     

打印机概述

打印机是微型机系统的重要外部输出设备之一,可以把在微型机上设计的文档打印成令人赏心悦目的印刷品.本文主要介绍打印机的一些基础知识.     

基于改进LS-SVR的超磁致伸缩作动器模型辨识

提出了基于遗忘因子矩形窗的最小二乘支持向量机回归( LS - SVR)方法.该方法先将矩形窗方法与传统的LSSVR相结合,用有限个过去的数据做LS - SVR的样本,随着时间增加不断在样本中丢弃旧数据加入新数据,保持样本总数不变;然后在此基础上添加了遗忘因子,在丢弃旧样本的同时兼顾了历史数据的影响.改进后的LS - SVR方法提高了运算速度,同时也提高了辨识的精度.通过仿真实例验证了该方法的有效性和可行性.将此方法应用到超磁致伸缩作动器的在线模型辨识上,取得了较好的辨识结果.     

一种高效无线传感器网络认证及密钥协商方案

随着无线传感器网络在社会各个领域的渗透,其安全机制的研究一直是无线传感器网络的研究热点。在分析了无线传感器网络中认证及密钥协商方案设计时应满足条件的基础上,基于单向HASH函数和对称密码算法,设计了无线传感器网络中传感器节点间一种高效的认证及密钥协商方案。并从互认证、会话密钥、可抵御攻击等方面对该方案的安全性进行了分析,说明了该方案的安全性能较好,可有效抵御典型攻击行为;详细比较该方案和现有类似方案的运行性能,结果表明,该方案在存储容量需求、计算复杂性和通信带宽需求方面均优于现有方案。     

Delphi环境下目标规划图解法算法程序的开发

作为目标规划算法平台的一个重要组成部分,研究了多目标线性规划中的目标规划图解法算法程序的开发,以方便该方法在各领域的应用。首先,介绍了目标规划的原理、建立目标规划模型的步骤。然后,介绍目标规划图解法的计算步骤以及在Del-phi环境下开发目标规划图解法的流程和具体方法。最后,通过实例对目标规划图解法算法程序的正确性进行了验证。所开发的算法程序直观简捷,方便工程人员的使用。     

一种改进WebGIS实时监控的通用框架

针对传统WebGIS实时监控应用中面临的主要问题,引入AJAX和SVG技术进行改进,并对这两种技术在WebGIS实时监控中的应用及其优点进行了分析,最后给出了一种通用框架模型.     

基于织物结构特征和小波变换的快速疵点检测

给出了一种利用小波为分析工具,基于织物采样图像进行疵点检测的新方法.首先对织物疵点图片进行了奇偶行列采样抽取,得到奇偶两幅子图像并使得图像的总数据变为原来的二分之一,然后再进行小波变换.在进行小波变换时,采用邻域插值,使得紧支撑小波滤波器的系数序列得到缩短,并可以由原来的滤波器系数计算出缩短后的滤波器系数.实验结果表明该方法可以在保证检测效果准确性的同时,大幅减少数据计算量、提升检测速度.     

基于信令降频码方法的信令寻径式光纤交换机的研究

信令寻径式高速光纤交换机需要使用大量"串/并"转换器件提取信令来实现对信道的控制,这使得交换机的底板面积十分庞大,无法检测BGA封装焊接质量;针对以上问题,提出了一种使用特殊的降频码对信令进行编码,成倍地降低信令的频率,采用普通的FPGA器件即可提取信令,取代了大量占线的"串/并"转换器件,减少了PCB面积和降低了成本;并在此基础上给出了高速光纤交换机的解决方案;目前,基于信令降频码方法的信令寻径式光纤交换机已经调试成功,性能稳定,运行状态良好。     

Adaptive robust posture control of a parallel manipulator driven by pneumatic muscles

Rather severe parametric uncertainties and uncertain nonlinearities exist in the dynamic modeling of a parallel manipulator driven by pneumatic muscles. Those uncertainties not only come from the time-varying friction forces and the static force modeling errors of pneumatic muscles but also from the inherent complex nonlinearities and unknown disturbances of the parallel manipulator. In this paper, a discontinuous projection-based adaptive robust control strategy is adopted to compensate for both the parametric uncertainties and uncertain nonlinearities of a three-pneumatic-muscles-driven parallel manipulator to achieve precise posture trajectory tracking control. The resulting controller effectively handles the effects of various parameter variations and the hard-to-model nonlinearities such as the friction forces of the pneumatic muscles. Simulation and experimental results are obtained to illustrate the effectiveness of the proposed adaptive robust controller.     

Amine Coordinated Electron-Rich Palladium Nanoparticles for Electrochemical Hydrogenation of Benzaldehyde

Electrocatalytic hydrogenation (ECH) is a burgeoning strategy for the sustainable utilization of hydrogen. However, how to effectively suppress the competitive hydrogen evolution reaction (HER) is a big challenge to ECH catalysis. In this study, amine (NH₂ R)-coordinated Pd nanoparticles loaded on carbon felt (Pd@CF) as a catalyst is successfully synthesized by a one-step solvothermal reduction method using oleylamine as the reducing agent. An exceptional ECH reactivity on benzaldehyde is achieved on the optimal Pd@CF catalyst in terms of a high conversion (89.7%) and selectivity toward benzyl alcohol (89.8%) at −0.4 V in 60 min. Notably, the Faradaic efficiency for producing benzyl alcohol is up to 90.2%, much higher than that catalyzed by Pd@CF-without N-group (41.1%) and thecommercial Pd/C (20.9%). The excellent ECH performance of Pd@CF can be attributed to the enriched electrons on Pd surface resulted from the introduction of NH₂ R groups, which strengthens both the adsorption of benzaldehyde and the adsorbed hydrogen (H_ads) on Pd, preventing the combination of H_ads to form H₂, that is, inhibiting the HER. This study gives a new insight into design principles of highly efficient electrocatalysts for the hydrogenation of unsaturated aldehydes molecules.