长距离曲线顶管在杭州河坊街工程中的应用

对杭州市重点工程—杭州河坊街长距离曲线顶管进行了总结和介绍 ,可为同类工程借鉴和参考     

浅谈综采工作面过陷落柱方法

通过分析陷落柱的形成机理,提出过陷落柱的有效方法,以加快综采工作面过陷落柱的速度.     

双时基频率校准电路

提供精确的时间基准是精密仪器和高精度设备计时和工作的关键技术之一。文中采用两套晶振电路，通过分频产生高频和低频两个频率信号，采用编码的方法对两个频率信号在每一个时钟周期内进行动态校核，只有两个晶振的频率在允许的精度范围内，或同时增大（缩小）相同的倍数，校核后频率信号才是正确的，且能给系统提供精确的时间基准。该方法能有效防止系统的时钟周期因意外的原因伸长或缩短。整个电路可以作为精密仪器或高精度设备的一个模块电路。     

地源热泵——辐射地板联供试验

通过地源热泵－辐射地板系统冬夏联供试验，讨论了该系统作为新型环保节能空调方式的可行性及优越性，并对运行中出现的问题进行分析。     

I/OIMAGESYSTEM微波中继应用

微波中继的应用非常广泛 ,目前在二维、三维施工中跨越障碍物时 ,一般都使用微波中继站来传输命令和数据。文章就微波中继及I/OIMAGESYSTEM“蛇形排列”先进功能的实际应用进行了详细的阐述 ,同时提出了使用微波中继站应注意的问题。     

电站锅炉制粉系统的爆炸原因与防范对策

火力发电厂制粉系统爆炸事故时有发生 ,重大设备损坏 ,造成了严重的经济损失。本文通过分析研究 ,找出制粉系统爆炸的原因 ,从措施上、煤的质量控制上及制粉系统结构改造上提出了防范的对策。     

钨合金废料的资源再生利用技术

钨是一种稀有金属，钨合金具有高的强度、硬度，较好的耐高温性、耐密性和良好的电性能。广泛应用于航空航天工业、兵器工业、核工业、信息产业、汽车工业和钢铁工业等行业。目前，钨资源短缺，钨合金价格高、用量大，因此各国都把废弃的钨合金作为宝贵的第二钨资源加以再生利用。本文综述了钨合金的再生利用现状，分别总结了硬质合金、高比重合金、钨铜合金和钨材的再生利用技术，并利用生态环境材料的观点。对每种再生利用技术作了简单的评价。     

Cholesterol‐imprinted polymer receptor prepared by a hybrid imprinting method

A novel cholesterol‐imprinted polymer (CMIP‐H) was prepared by a hybrid method of covalent imprinting and non‐covalent imprinting. This approach involves the copolymerization of a template‐containing monomer, cholesteryl 2‐hydroxyethyl methacrylate carbonate, and a cross‐linker, followed by hydrolysis to afford a flexible guest‐binding site accompanied with the easy and efficient removal of a ‘sacrificial spacer’. The effect of solvent on the binding capacity of CMIP‐H towards cholesterol was studied, indicating that a good binding capacity towards cholesterol could be achieved in a less‐polar solvent. The binding experiments of CMIP‐H towards a series of structural analogues of cholesterol, including cholesterol acetate, progesterone and stigmasterol, were carried out in hexane. The results showed that CMIP‐H almost did not bind cholesterol acetate at all because the hydrogen‐bonding site is blocked. It exhibited a similar binding towards both cholesterol and stigmasterol, but much higher binding towards progesterone. Copyright © 2005 Society of Chemical Industry     

Study of a BGO calorimeter using electron and hadron beams from 1 to 50 GeV

A calorimeter of 25 bismuth germanate (BGO) crystals equipped with silicon photodiode readout has been tested at the CERN SPS in the energy range 1–50 GeV. The response for electrons has been shown to be linear in this energy range and the rms resolution obtained ( ) is approximately 1%, for E > 4 GeV. The electron/pion separation was found to be better than 1:500 in the energy range 1–20 GeV. Data on lateral and longitudinal shower development were compared with the results of a Monte Carlo simulation using the SLAC-EGS program and found to be in good agreement.     

Ultra-wideband bandpass filter with hybrid microstrip/CPW structure

A novel ultra-wideband (UWB) bandpass filter (BPF) is presented using the hybrid microstrip and coplanar waveguide (CPW) structure. A CPW nonuniform resonator or multiple-mode resonator (MMR) is constructed to produce its first three resonant modes occurring around the lower end, center, and higher end of the UWB band. Then, a microstrip/CPW surface-to-surface coupled line is formed and modeled to allocate the enhanced coupling peak around the center of this UWB band, i.e., 6.85GHz. As such, a five-pole UWB BPF is built up and realized with the passband covering the entire UWB band (3.1-10.6GHz). A predicted frequency response is finally verified by the experiment. In addition, the designed UWB filter, with a single resonator, only occupies one full-wavelength in length or 16.9mm.