条件中位数L_1-模最近邻估计的渐近性质

本文在－混合随机变量的条件下，讨论了基于几个观察值的条件中位数的L1－模最近邻估计的渐近性质，得到了独立同分布时类似的结论．     

透水性沥青面层材料设计新法及应用

本文提出了一种根据主骨料空隙率设计透水性面层沥青混合料级配的新方法，根据这一方法设计的透水性沥青面层具有良好的路面使用功能，应用前景广阔。     

石膏制品防水防潮剂的研制与开发

本文提出采用高分子有机材料配合，生产石膏制品防水防潮剂的生产方法和工艺。该剂还可以应用到氧化镁系列板材，同时提出开发珠光或彩色防水防潮剂，能达到满足的装饰效果，值提开发推广。     

Analogue implementation of a neural network controller for UPSinverter applications

An analogue neural-network controller for UPS inverter applications is presented. The proposed neural-network controller is trained off-line using patterns obtained from a simulated controller, which had an idealized load-current-reference. Simulation results show that the proposed neural-network controller can achieve low total harmonic distortion under nonlinear loading condition and good dynamic responses under transient loading condition. To verify the performance of the proposed NN controller, a hardware inverter with an analogue neural network (NN) controller (using mainly operational amplifiers and resistors) is built. Additionally, for comparison purposes, a PI controller with optimized parameters is built. Experimental results confirm the simulation results and show the superior performance of the NN controller especially under rectifier-type loading condition. Implementing the analogue neural-network controller using programmable integrated circuits is also discussed     

A low-power, linear, permanent-magnet generator/energy storagesystem

This paper describes the design, analysis and characterization of a linear permanent magnet generator and capacitive energy storage system for generating electrical power from a single stroke of a salient-pole armature. It is suitable for applications that require relatively low levels of electrical power, such as remote electronic locks. An electromagnetic analysis of the generator is described, and a design optimization methodology for the system is presented. Finally, the performance of a prototype is validated against measurements     

我国车用无铅汽油的质量状况及分析

对1998－2001年间生产领域和流通领域的近500批次汽油产品检验数据进行了总结和分析，表明我国汽油的实物质量正在不断提高，但从环保要求出发还需不断向国际水平靠扰，尤其应进一步降低烯烃含量，硫含量。     

Fivefold symmetry in real and reciprocal spaces

Tetrahedrally close-packed structures with juxtaposed pentagonal antiprisms, such as the μ, C14 Laves and the newly found C phases, were studied by means of HREM and SAD. It was found that each bright spot in the structural image corresponds to an antiprism. Differently oriented domains of these phases intergrow frequently with a fairly good match at the interphase boundary. All diffraction patterns of these phases show a fivefold distribution of spot-pairs, and it is shown that this fivefold symmetry comes from the pentagons and spot-pairs from two pentagonal prisms superposed in antisymmetrical positions.     

Fluidised pellet bed bioreactor: a promising technology for onsite wastewater treatment and reuse.

A pilot-scale fluidised pellet bed (FPB) bioreactor, which combines chemical coagulation, biological degradation, particle pelletisation and separation in one unit, was applied for onsite wastewater treatment and reuse. As a result of rational use of inorganic coagulant and organic polymer and moderate mechanical agitation, spherical particles were generated in the upflow column and a well-fluidised bed was formed. With a continuous supply of dissolved oxygen through a recycling loop, an aerobic condition was kept in the bottom section of the FPB column. Under such conditions the pellets in the FPB column showed the following characteristics: (1) compact structure and high density; (2) rich in microorganisms; and (3) high MLSS and MLVSS concentrations. Therefore, the FPB bioreactor achieved more than 90% removal of SS, COD, BOD and TP from raw domestic wastewater within a total hydraulic retention time (HRT) of only about 30 minutes. It also showed nitrification and denitrification ability and the TN removal could be about 50% as the recycling ratio was increased to 1:1. The treated water quality is generally competitive with the secondary effluent from a conventional activated sludge process. With these advantages the FPB bioreactor is recommendable as a compact system for onsite wastewater treatment and reuse.     

高职教育只有特色办学才有竞争力

在我国虽然高等职业教育发展势头强劲,但仍属于新生事物。面对高等教育激烈的竞争态势,如何扬长避短,办出自己的特色,是诸多新建高职院校应致力思考的一个重要问题。     

粗苯放散气体回收系统的开工调试经验

介绍了焦化厂粗苯放散气体回收系统开工调试的经验。