水力脉冲式钻井工具的研制与应用

水力脉冲式钻井是利用特定的工具使钻井管柱中的连续流转变为脉冲射流,从而改变井底流场的压力状况,进而提高机械钻速的一种钻井新工艺。在分析水力脉冲产生机理的基础上,探讨了基于瞬变流理论的机械阻断式水力脉冲破岩机理,介绍了SLPMC机械阻断式水力脉冲工具的工作原理及结构特点,简单叙述了该工具在胜利油田进行的2口井的现场试验情况。该钻井工具对于提高机械钻速和降低钻井成本具有一定的积极意义。     

中小企业创业资源的形成机制研究

创业资源是创业的基础,创业过程的规律性和市场配置资源的基础作用影响和决定中小企业创业资源的内在功能和形成方式。对中小企业资源的形成机制进行了分析探讨,并分析了它们之间的内在关系。     

快速搜寻卫星数字压缩信号

在没有专业仪器，没有明确参照物的条件下，如何快速定位接收天线，搜索到卫星信号，是电视工程技术人员经常遇到的问题，本文就此问题提出了一个新的解决办法，即利用已知卫星的位置来定位其它卫星的位置。     

The Adhesion and Formation Mechanism of Blast Furnace Gunning Layer

1 Introduction Gunning refractories are unshaped refractories commonly used in iron and steel industry for the main- tenance of furnace linings. The specific way of gunning processing requires the refractory to have specific rheo- logical properties so as…     

The sinuous antenna-A dual polarized feed for reflector-based searching systems

The sinuous antennas have a numerous applications in military and civil systems such as direction finding systems and reflector feeds due to their superior broadband characteristics and simultaneous polarization capability. In this paper, design, construction and measurements of planar sinuous antennas are investigated for 1–5 GHz frequency range. Feeding sections of this antenna are realized by using microstrip tapered baluns. We have determined the microstrip tapered balun dimensions using Ansoft HFSS-simulation program. The performances of the manufactured antenna are measured using HP vector network analyzer. Polarization patterns and return loss characteristics of the designed antenna that have been measured in anechoic chamber, are presented.     

步进梁式炉的运动研究

对国内引进的、用于粉末冶金的步进梁式炉的运动,以图解法和解析法进行了分析,并对运动参数进行了理论推导和计算。本研究结果,对解决步进粱式炉的运动故障以及进行新型设计提供了有效的理论分析和计算依据。     

Monoalkyl Esters of Isoalkylphosphonic Acid as Extractants in Rare Earth Separation

Four monoalkyl esters of isoalkylphosphonic acids have been studied for the chromatographic separation ofrare earths (RE).The relationship between distribution ratios and acid concentration of the eluants forsamarium and ytterbium has been explored.The characteristics of these extractants loaded onto macroreticularpoly (methyl methacrylate) resin beads for the separation of lanthanum,cerium,praseodymium and neodymiumhave been compared.Among the extractants studied,mono(1-methylheptyl) ester of isooctylphosphonic acidwas found to be the best for RE separation.The acidity for separation is lower than any known P-containingextractants for the same purpose.For instance,with 1.73 mol·L~(-1) nitric acid as eluent,thulium,ytterbium andlutetium can be separated quantitatively.The extractant-loaded resins possess high column efficiency with goodkinetic characteristics.The extraction mechanism was also explored.     

生物降解塑料的研究现状及问题

生物降解塑料这一领域的研究和发展正成为人们普遍关注的焦点。生物降解塑料根据其降解机理和破坏形式，可分为完全生物降解塑料和生物崩坏性(致劣性)塑料两种。这种新型塑料涉及化工、高分子、生物学等多门学科，属于一项高新技术。尽管各国投入了较大的人力、物力，但至今还未普遍达到实用阶段，在研究开发、市场、应用等方面还存在许多问题。     

兴企之要 惟在用人

阐述了人力资源管理在企业发展中的重要作用;对如何引入竞争机制、知人善任、建立科学的激励机制和约束机制、改革管理体制等方面进行了论述。     

石油价格机制改革之对策

文章在阐述我国石油价格形成机制的演变过程的基础上,针对我国目前石油定价机制所导致的诸如石油价格变动滞后以及由此带来的市场信号失灵等问题思考了相应的改革对策,提出了调整政府价格管理职能、建立平等竞争的市场规则、完善稳定油价的调控体系以及加快建立石油战略储备等7个方面的建议。