Improved photocatalytic efficiency and stability of CdS/ZnO shell/core nanoarrays with high coverage and enhanced interface combination

Photocatalytic hydrogen production of CdS/ZnO shell/core nanoarrays were investigated by combining the sensitization and calcining techniques. Long single crystal ZnO nanoarrays hydrothermally grown on FTO were fully covered with CdS using an optimized chemical bath deposition method. Heating treatment not only improved the interface connection and CdS crystallinity but also formed a (Cd_0.8Zn_0.2)S buffer layer between ZnO and CdS. The CdS/ZnO shell/core arrays showed gradually enhanced photocatalytic activity with raising the calcining temperature. This is predominantly attributed to the improved CdS crystallinity and the resultant (Cd_0.8Zn_0.2)S. The (Cd_0.8Zn_0.2)S buffer layer formed by calcining shows dramatic effect on the photocatalytic activity and stability. The CdS/ZnO shell/core arrays calcined at 550 °C exhibits the optimized photocurrent density of 5.1 mA cm^?2 and a photocatalytic stability over 12 h under visible-light irradiation.     

TD-LTE主设备节能新技术简介

如何在节能减排的大背景下,不断开拓新思路、运用新技术,在不影响网络质量的情况下尽可能的提升设备能效是网络发展的必由之路,本文重点介绍了应用于TD-LTE主设备的几种节能新技术,通过对4G系统架构的分析,从硬件和软件2个方面着重阐述了新技术的原理及节能效果。     

卷烟生产企业能源管理系统设计与应用

能源管理系统是融合系统节能思想、现代自动化及信息技术,并以客观信息为基础的先进能源管理理念与技术。能源管理系统对卷烟生产企业的节能降耗和提高能源管理水平都具有明显的效果。重点描述了卷烟生产企业EMS的目标、功能以及管理机制,以强化卷烟生产企业的能源管理。     

基于MOSS的二级学院教学管理系统的设计与实现

介绍基于MOSS 2010搭建的二级学院教学管理系统的设计与实现,并介绍文档多人编辑、机房叠加日历等特色功能。该系统能够显著提高工作效率,增强团队沟通协作能力。     

基于ARM与FPGA的电流扰动发生器

本文描述了一种基于嵌入式处理器(ARM)和现场可编程门阵列(FPGA)的电流扰动发生器,研究了采用ARM和FPGA构建其控制系统的实现方法。该电流扰动发生器采用单极倍频CPS-SPWM技术,每相主拓扑由2个双级H桥功率单元在逆变侧级联构成,有效提高了输出电压等级范围与等效开关频率,并能够精确输出基波与2~50次任意谐波,为测试APF等被试设备的工作性能与运行状况提供了现场测试环境。通过工业样机试验,证明了该拓扑结构的良好性及实现方法的有效性。     

改进集成深层自编码器在轴承故障诊断中的应用

针对滚动轴承振动信号故障特征难以自动提取和故障类别难以自动准确识别的问题,提出一种改进集成深层自编码器(IEDAE)方法.首先,改进自编码器的损失函数并设计3种小波卷积自编码器;其次,利用区分自编码器、小波卷积自编码器等5种自编码器构造相应的深层自编码器,并设计“跨层”连接以缓解深层网络的梯度消失现象,实现对轴承振动信号的无监督预训练和有监督微调;最后,通过加权平均法输出识别结果,以保证诊断结果的准确性和稳定性.实验结果表明,改进集成深层自编码器方法能有效地对滚动轴承进行多种工况和多种故障程度的识别,较好地摆脱了对人工特征提取的依赖,特征提取能力和识别能力优于现有其他方法.     

Harmonic analysis in DC electrified transit railway systems consisting of uncontrolled bridge rectifiers with commutation impedances

Abstract

The paper presents a new formulation of harmonic current injection of the 6‐pulse uncontrolled bridge rectifier with commutation impedance. In cooperation with a train simulator developed earlier, the proposed harmonic source model is applied in a harmonic analysis program to comprehensively simulate the harmonic penetration in the Blue Line of Taipei Rapid Transit Systems (TRTS). Both frequency scans and harmonic distortion calculations were performed for various system component models. Simulation results indicated that both the voltage and current harmonic distortions in the Blue Line of TRTS were improved by use of 24‐pulse rectifiers. The application of further harmonic suppression schemes in traction networks to alleviate the harmonic distortions can be achieved using the simulated results.     

Single Beacon Cruise Positioning Algorithm in Wireless Sensor Networks

Node localization is important in WSNs （Wireless sensor networks） applications. We present a new cruise positioning algorithm, where a single beacon node cruises an entire network, broadcasting its position periodically with fixed signal strength. Meawhile, an unknown node obtains the location and the corresponding distance of the beacon node. Two possible position coordinate sets for the unknown node can then be calculated, and the coordinate mean of the point set with a small variance is an unbiased estimator of the unknown node＇s coordinate. The positioning algorithm＇s computation is simple, positioning accuracy is not limited by a physical distance measuring tool, and there are no restrictions on the path of motion, which makes it more realistic. An algorithm simulation is presented to compare the original and cruise location algorithm. Numerical results show that the cruise localization algorithm can achieve good positioning accuracy.     

Find truth in the hands of the few: acquiring specific knowledge with crowdsourcing

Crowdsourcing has been a helpful mechanism to leverage human intelligence to acquire useful knowledge.However, when we aggregate the crowd knowledge based on the currently developed voting algorithms, it often results in common knowledge that may not be expected. In this paper, we consider the problem of collecting specific knowledge via crowdsourcing. With the help of using external knowledge base such as WordNet, we incorporate the semantic relations between the alternative answers into a probabilisticmodel to determine which answer is more specific. We formulate the probabilistic model considering both worker’s ability and task’s difficulty from the basic assumption, and solve it by the expectation-maximization (EM) algorithm. To increase algorithm compatibility, we also refine our method into semi-supervised one. Experimental results show that our approach is robust with hyper-parameters and achieves better improvement thanmajority voting and other algorithms when more specific answers are expected, especially for sparse data.