一种用于IGBT模块的新型半桥驱动电路

介绍了一种高性能、高压集成新型半桥IGBT驱动电路.该驱动模块内部集成两路独立驱动和独特的故障"局域网"保护电路,驱动能力强,体积封装小,易于逆变器的小型化设计,并介绍了该驱动模块在便携式柴油发电机逆变电源中的应用,讨论了设计中应注意的问题.实验结果证明,该驱动电路结构简单,性能优越,能够实现对IGBT的可靠驱动和保护.     

PVC防水卷材的配方研究

研究了利用废旧软聚氯乙烯回收料(旧料)生产PVC塑料防水卷材的配方及其对卷材拉伸性能的影响。结果表明,PVC塑料卷材的拉伸强度和断裂伸长率随PVC树脂添加比例增加而提高,而相同添加量的SG-3型PVC树脂比SG-5型PVC树脂的拉伸性能高；在试验范围内,增塑剂用量增加,卷材的拉伸强度降低,伸长率先升后降；添加CPE能提高PVC卷材伸长率,但拉伸强度有所下降。当CaCO_3用量低于20份时,卷材的拉伸强度和伸长率随CaCO_3添加量增加而提高。PVC防水卷材的优选配方(质量份)：旧料85份,PVC树脂(SG-3型)15份,DOP 5份,CPE 3份,稳定剂(TLS)0．6份,其它助剂适量。     

A novel method for camera external parameters online calibration using dotted road line

On board camera is the most important information source for driver assistant application which is based on computer vision. One problem for on board camera is that the external parameters are easy to be changed when moving on the road. Traditional method either calibrates external parameters offline or calibrates external parameters semi-online, which both need human intervention. By observation, it is found that corner connection of dotted road lane can form two groups of parallel lines. Using this geometric characteristics and through theoretical derivation, a novel online camera external parameter calibration method is proposed which focus on the situation when vehicle is moving. The pro of this method is that it maintains relatively high calculation accuracy and more important, it does not require any human intervention in whole calibration process. Experimental and comparison results show that this method is simple and have accurate results which fully meet the requirements of practical application.     

基于BACnet/IP的设备与实时数据库通信实现

针对不同厂商、不同系统的楼宇自控设备互操作、互通信的局限性,分析了BACnet/IP技术和实时数据库,设计开发了一种基于BACnet/IP技术的实时数据库DasRdb的设备驱动程序。该设备驱动程序采用UDP通信方式,通过调用每个BACnet/IP设备的标准接口函数来驱动实时数据库DasRdb分别进行写操作和读操作,能够有效地实现BACnet/IP设备与实时数据库DasRdb之间的通信,从而使楼控设备的互操作成为可能。现场工程应用表明,该程序的运行契合BACnet的一致性要求,具有简单、高效、精确度高、实时性好的特点。     

Feasibility of Sludge Ozonation for Stabilization and Conditioning

A pilot-scale sludge treatment plant was built to investigate the feasibility of ozonation processes for waste activated sludge treatment. Ozonation of wastewater sludge resulted in mass reduction by mineralization as well as by supernatant and filtrate recycle. Another advantage of sludge ozonation is a significant improvement of settleability and dewaterability. Experimental results showed that mass reduction of 70% and volume reduction of 85% compared with the control sludge was achieved through the sludge ozonation at a dose of 0.5?gO₃/gDS. It is also interesting to note that the filterability deteriorates up to ozone dose of 0.2?gO₃/gDS and then improves considerably at a higher ozone dose. The filterability could be improved by chemical conditioning even at a low ozone dose. The economic feasibility by cost analysis reveals that ozonation processes can be more economical than other alternative processes for sludge treatment and disposal at small-sized wastewater treatment plants.     

ARM7处理器NUC710ADN扩充双网口设计

在ARM7处理器NUC710ADN的第一个网口的基础上,利用网口驱动芯片DM9000AEP扩充了第二个网口,使系统实现双网口通信。给出了硬件设计电路,对DM9000AEP的驱动程序在μClinux下的移植过程进行了描述,测试结果表明双网口都能正常可靠的工作,达到了ARM7处理器进行双网通信的功能要求。     

增压风机用高速无刷直流电机控制系统设计

根据增压用无刷直流电机的具体需求,设计了一套无刷直流电机H桥驱动电路;建立了无刷直流电机的数学模型,分析了变积分PID的优点;在Matlab环境下,设计了实际系统的变积分PID控制器;最后,将系统的运行数据上传至上位机,并对实际运行情况进行了分析。分析表明,控制系统设计较合理,并具有一定的参考价值。     

Non-conventional treatment of treated municipal wastewater for reverse osmosis

High-quality potable water can be produced at a reasonable cost if reverse osmosis (RO) technology is applied to renovate secondary/tertiary urban wastewater effluent. Such implementation would yield many advantages to Kuwait, namely: satisfying the increasing agricultural, industrial and domestic demands for good quality water that is free from viruses and bacteria and other microbials present preserving the natural strategic water resources; reducing the environmental pollution resulting from the direct discharge of secondary/tertiary municipal effluents to the sea; and meeting unexpected emergency cases of shortages in freshwater produced from the desalination of seawater for certain domestic applications. The main aims of this work are to assess the technical viability and the economic feasibility of implementing RO technology to renovate Kuwaiti wastewater treated effluent. The paper describes the design of pretreatment, experimental set-up, results, and data analysis of desalinating municipal wastewater by RO. The results indicate that wastewater can be treated to produce an excellent permeate quality almost devoid from salts and pollutants.     

提高Java数据库访问效率的策略研究

在开发基于Java的应用时,提高对数据库的访问效率是程序员重点要考虑的问题之一。研究、分析了Java通过JDBC访问数据库的四种访问类型,提出了在不同的使用过程中的选择方案。介绍了连接池等对数据库访问效率影响较大的预处理语句及数据库连接管理技术。探讨了当前使用最为普遍的Hibernate在配置连接池和使用缓存等方面的问题。     

一种闪存敏感的多级缓存管理方法

基于闪存的固态硬盘(solid state driver,简称SSD)已经广泛应用于各种移动设备、PC机和服务器.与磁盘相比,尽管SSD具有数据存取速度高、抗震、低功耗等优良特性,但SSD自身也存在读写不对称、价格昂贵等不利因素,这使得SSD 短期内不会完全取代磁盘.将SSD和磁盘组合构建混合系统,可以发挥不同的硬件特性,提升系统性能.基于 MLC 型 SSD 和 SLC 型 SSD 之间的特性差异,提出了一种闪存敏感的多级缓存管理策略——FAMC.FAMC将SSD用在内存和磁盘之间作扩展缓存,针对数据库系统、文件管理中数据访问的特点,有选择地将内存牺牲页缓存到不同类型的SSD.FAMC同时考虑写请求模式和负载类型对系统性能的影响,设计实现对SSD友好的数据管理策略.此外,FAMC基于不同的数据置换代价提出了适用于SSD的缓冲区管理算法.基于多级缓存存储系统对FAMC的性能进行了评测,实验结果表明,FAMC可以大幅度降低系统响应时间,减少磁盘I/O.