高压电路防污闪带电清洗维护技术可行性研究

比较全面地论述了带电清洗中的高压带电清洗剂、高压带电清洗工具、高压带电施工工艺和高压带电安全措施等内容。     

Modeling of material removal rate in electric discharge grinding process

The mechanism of material removal in electric discharge grinding (EDG) is very complex due to interdependence of mechanical and thermal energies responsible for material removal. Therefore, on the basis of conceived process physics for material removal, an attempt has been made to predict the material removal rate (MRR). The proposed mathematical model is based on the fundamental principles of material removal in electric discharge machining (EDM) and conventional grinding processes. The inter-dependence of the thermal and mechanical phenomena has been realized by scanning electron microscopy (SEM) characterization of the samples machined at different processing conditions. The key input process parameters like pulse on time, pulse current, gap voltage, duty cycle, pulse off time, frequency, depth of cut, wheel speed and table speed are co-related with MRR for three distinct idealized processing conditions. The constant showing the extent of interdependence of two phenomena were evaluated by experimental data. The obtained expressions of MRR have been validated for processing conditions other than those used for obtaining constants. It was found that the discharge energy plays prominent role in material removal. The percentage difference in experimental findings and theoretical predictions was found to be less than 3%.     

Channel estimation for MIMO-OFDM systems using steepest-descent algorithm

In this paper, the channel estimation methods to resolve the error floor for SUI-5 channel are investigated. Since the pilot allocation is solid with FUSC model, the author can＇t modify it exhaustively. So only the author can do is to combine the preamble and pilot carrier to resolve the problem. Here the authors introduce steepest descent algorithm combine preamble and pilot well for consult. Simulation result show that novel algorithm can decrease the error floor for SUI_5 channel drastically and improve the performance for slow fading or fast fading channel. The authors also conclude that pilot only scheme exits error floor when the coherent bandwidth of channel is narrow, and preamble only scheme can decrease the error floor drastically when the coherent bandwidth of channel is narrow, however it can＇t trace the fast fading channel.     

基于MAPGIS软件的管线探测数据建库的应用与实现

以桂林市供水管网探测数据建库为例，概略叙述MAPGIS管网管理地理信息系统中数据建库方法和步骤，认为GIS技术在建立科学化的管网管理模式和增强企业的经济效益和社会效益方面将起到巨大作用。     

深圳河湾水系生态需水的污水资源化

以深圳河湾水系为例,探讨以污水资源化再生水满足城市水系生态需水的方法。该方法统一考虑河流的水量水质需求,计算不同截污率和补水水质条件下河流的生态需水量;根据生态用水的供需平衡情况,确定污水资源化规模与水质要求。在此基础上,设计污水资源化的处理工艺以及再生水厂等的分布;并通过数学模型预测补水方案对水环境改善的效果。本研究为面向城市水系生态补水的污水资源化工程规划提供了科学的方法。     

论通信动力系统运维效益的量化方法

为了实现通信动力系统运维管理部门的量化考核与绩效改进,文章提出了基于成本与网络风险损失的动力运维效益量化方法,直接计算单位成本的有效电度,并提供网络风险损失系数取值的建议。     

Development of a tool to monitor static balance of construction workers for proactive fall safety management

The construction industry around the globe is afflicted with an exorbitant rate of fatal and non-fatal falls. To lower the propensity of the falls, researchers and safety experts have recommended to supplement the traditional passive fall safety measures with some active measures (such as early identification of task/environmental hazards and personal risk factors). Unfortunately, at present, there is no readily available onsite tool which could identify workers with poor postural controls. This study aimed to develop a static balance monitoring tool for proactive tracking of construction workers on-site using a wearable inertial measurement unit (WIMU) and a smartphone. To this end, a three-phase project was conducted. Firstly, a validation study was conducted to examine the validity of using WIMUs to detect task/fatigue-induced changes in static balance during a 20-second static balance test. The results of the study revealed that WIMUs could detect the post-task subtle changes in static balance with reference to the findings of a force-plate (considered as industrial standard). Secondly, since there were no existing static balance classification methods, five experts were engaged to establish balance classification thresholds using the fuzzy set theory. Thirdly, a mobile phone application was developed for the managers/foremen for onsite balance monitoring of the construction workers using the 20-second test at different times of the day and establishing their corresponding balance performance profiles. This would assist early identification of fall prone workers, plan mitigation schemes before a fall accident happens and ultimately help reduce falls in the construction industry.     

Fabrication of high-performance Y2O3 stabilized hafnium dioxide refractories

Y₂O₃ stabilized HfO₂ ceramics with 5 mol% and 8 mol% Y₂O₃, respectively, were successfully fabricated by pressureless sintering at 1600 °C for 1 h. The phase distribution and transformation, microstructure, and relative density were investigated for Y₂O₃ stabilized HfO₂ ceramics. Cubic phase was observed in the Y₂O₃ stabilized hafnium dioxide while pure HfO₂ showed monoclinical phase only. The SEM images of fractured surface indicated two kinds of structures existed in modified HfO₂, the solid solution region and uniform polygon grains, and some holes caused by Kirkendall effect. Refractoriness test showed that high temperature volumetric stability of the material can be effectively enhanced by adding Y₂O₃ into HfO₂.     

移动接入层拆环优化方法探讨

随着近几年移动网络的迅速扩大,对接入层进行拆环优化已成为一项必须且重要的工作。本文分析了目前最为常用的拆环优化方法的弊端,并介绍了几种更合理的方法,以供读者分享和探讨。     

汽车内部装饰材料醛类物质的HPLC法测定和分析

采用恒温测试箱法加热汽车内部装饰材料1 h,使其释放出醛类物质,利用DNPH(2,4-二硝基苯肼)管对恒温测试箱内气体进行醛类物质的采样,用HPLC法(高效液相色谱法)进行分析。检出限低于2.0μg/m3。选择五种汽车内部装饰材料,进行醛类物质甲醛和乙醛含量的测定,并对结果进行了分析和讨论。