喇嘛甸油田聚驱抽油机井管杆偏磨断脱状况分析及技术对策

从现场抽油杆偏磨状况知道，抽油杆本体或接箍偏磨严重，这是因为它们与油管壁有接触，出现接触的原因是在井下杆管的受力不可能达到理想状况的，抽油杆在井下运动过程中，与油管不同心，从而造成油管与抽油杆发生接触。为避免杆管偏磨，采取技术对策：（1）降低阻力；（2）提高杆管的强度。     

Preparation and characterization of the porous ceramics from fly ash

Porous ceramics was made from coal fly ash, and the microstructure and other properties were characterized as a function of the amount of the pore-forming agent and firing temperature. The results indicated that the proper sintering temperature for the useful ceramic materials is 1 250℃, and a liquid-phase was involved in the densification process.     

有线电视HFC接入网络的改造与优化

目前,国内大多数有线电视网络已在不同程度上进行了HFC的建设,网络质量有了大幅度提高,但在相当长的时间内还会存在同轴电缆接入网的改造和优化问题,其主要目的是: (1)扩展频带资源,提高信号质量,减少网络故障; (2)优化HFC用户接入网络,提高网络的可靠性、安全性和可管理性;     

用维多利亚褐煤制造工业碳素制品

用维多利亚褐煤制造工业碳素制品维多利亚具有丰富的褐煤资源，估计超过２０００亿吨，其中约３３０亿吨可采用目前的露天开采技术开采。这些资源大约是澳大利亚全部矿物能源储量的２５％。因此，它是澳大利亚用于能源供应的主要的国家财富之一。尽管目前大部分褐煤用于发...     

西南第一条冷轧带肋钢筋生产线建成投产

重庆长江钢厂最近建成投产西南地区第一家冷轧带肋钢筋生产线。该生产线设计能力为年产4000tφ4～φ5.5mm的冷轧带肋钢筋,总投资约60万元。冷轧带肋钢筋是80年代国外新兴的建设钢材,该产品具有强度高,塑性好,与混凝土的粘结力强(其握裹力比混凝土与光圆钢筋之间的握裹力大20倍),广泛用于民用建筑的楼、墙、板,以及高速公路和机场跑道,与光     

基于特征像分析的光学镜头MTF测试方法的研究

光学镜头的MTF(ModulationTransferFunction)是一个准确、客观并且定量的成像质量评价指标.采用基于特征像分析的MTF测试方法,重点对刀口法进行改进,提出自适应平均行数算法和微倾刀口法.通过MATLAB进行实验仿真,获得的值与IMATEST模拟仿真的值在空间频率较低时误差控制在5%以内.实验结果证明了MTF计算值的可靠性;该方法具有数据处理简单、成本低、操作简便等优点.     

龙固矿井井底煤仓仓顶硐室结构形式研究

龙固矿井井底煤仓仓顶硐室位于不稳定岩层中,胶带机设备的外形尺寸及布置形式导致仓顶硐室断面较大,不利于支护结构和施工的安全。该文主要介绍了仓顶硐室优化后的结构形式及支护情况。     

Effect of La2O3 on electrical friction and wear properties of Cu-graphite composites

Sliding friction and wear experiments using Cu-La2O3-graphite composites against Cu-5 wt.%Ag alloy ring were conducted at a constant sliding speed of 10 m/s, a current density of 10 A/cm2 and a load of 2.5 N/cm2. These composites with different La2O3 and graphite contents were fabricated by hot-pressing. Physical and mechanical properties of the composites were examined. Morphologies of the worn surface of composites were observed using optical microscopy. X-ray photoelectron spectroscopy spectra were used to study compositions of the lubricating film. The results showed that with the increasing addition of La2O3, hardness, flexural strength and electrical resistivity increased, but the relative density dropped. The friction coefficient increased with the increasing addition of La2O3. Composite containing 3 vol.% of La2O3 and 37 vol.% of graphite showed the best wear resistance. The main wear mechanisms of composites were abrasive wear, oxidative wear and adhesive wear.     

MoS2夹层化合物的制备与应用

MoS2为层状结构,层间为较弱的范德华力,因此可将无机、有机离子或基团插入其层间形成具有特定性能和功用的MoS2夹层化合物。综述了MoS2夹层化合物的制备方法。介绍了剥层/重堆法制备MoS2夹层化合物的机理、客体物质的种类及MoS2夹层化合物的性能与应用,并展望了MoS2夹层化合物的发展前景。