Material removal and surface damage in EDM of Ti3SiC2 ceramic

Material removal and surface damage of Ti₃SiC₂ ceramic during electrical discharge machining (EDM) were investigated. Melting and decomposition were found to be the main material removal mechanisms during the machining process. Material removal rate was enhanced acceleratively with increasing discharge current, i_e, working voltage, u_i, but increased deceleratively with pulse duration, t_e. Microcracks in the surface and loose grains in the subsurface resulted from thermal shock were confirmed, and the surface damage in Ti₃SiC₂ ceramic led to a degradation of both strength and reliability.     

昆2井优快钻井及油气层保护技术

昆2井是一口位于柴北缘西段的昆特依凹陷潜伏Ⅰ号圈闭上的风险探井,设计井深为5950m。针对柴北缘深探井存在的主要技术难题,制定了昆2井的技术对策。通过对钻井设备的优选、井身结构的优化、钻头及钻具组合的优选、钻井参数及钻井液性能的优化、油气层保护技术的研究与应用,形成了一套适合于柴北缘的优快钻井技术,使昆2井的完钻井深达到5950m。与邻区的深探井平均水平相比,在井深增加888m、大尺寸井眼段更长的前提下,昆2井的钻井、完井周期分别缩短了98.75d、124.2d,钻机月速度增加了317m/台,平均机械钻速增加了0.82m/h。根据“理想充填新理论”,确定了保护油气层的最优复配暂堵方案,利用该方案所配制的钻井液其渗透率恢复值达到了87.5%以上,流变性能良好,滤失量低,对改善泥饼质量、增强井壁稳定性有明显的效果。     

小红楼

小红楼建于1921年，是一座三层的法式小洋楼。三十年代，它被英国百代唱片公司收购，抗日战争期间，一度被日本人占有，解放后，它成为中国唱片公司的所在地，伟大的中国国歌就诞生在这里。     

提高高炉煤比的措施与效果

分析了影响高炉煤比提高的主要因素，提出了提高高炉煤比的改进措施，通过技术攻关，高炉煤比在无富氧条件下达到了100kg／t以上，降本增效效果明显。     

Synthesis,characterization, and redox and electrochromic behaviors of poly(3-n-octyloxythiophene)

Poly(3-n-octyloxythiophene), a conjugated polymer, which possessed solubility in common organic solvents, was synthesized by electrochemical polymerization in the presence of lithium perchlorate as the supporting electrolyte and sodium dodecyl sulfate as the surfactant in an aqueous medium. Characterizations of the intermediate, monomer, and polymer were performed by NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and gel permeation chromatography. The process of electrochemical polymerization and the electrochemical redox behaviors were investigated by cyclic voltammetry and the potentiostatic method. A poly(3-n-octyloxythiophene) film that was deposited on a platinum electrode was found to exhibit electrochromic behaviors, and it switched electrochemically between blue–green oxidized and dark red reduced states. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

注入剖面五参数组合测井仪的改进

文章介绍了注入剖面五参数组合测井仪及对该仪器的改进与完善，特别是对流量计的结构进行了改进。流量计下端采用水阻尼和机械弹簧两种保护措施，有效地保护了涡轮；过芯加重改成通用加重下挂到涡轮流量计上，有效地减少了涡轮粘污，提高了组合测井仪的测井成功率。改进后测井成功率从60％提高到90％。同时。对数据处理与传输电路也进行了改进，新开发研制了PPM码数据传输体系，使组合仪耐温指标提高到175℃。     

国内中小皮化企业如何适应激烈的市场竞争

总结了目前国内中、小皮化企业中存在的主要问题 :自主开发能力差 ,造成产品品种单一、配套性差 ;新产品市场推广能力也较差 ,造成即使有好的产品 ,也无法打开市场 ;而普遍存在的制革厂欠款 ,皮化企业自身体制陈旧及国外皮化公司的进一步本土化策略 ,使国内皮化企业面临更严峻的挑战。根据自身多年经营皮化材料的经验 ,提出了切实可行的应对措施     

一种基于模式搜索的大尺寸测量移站坐标转换方法

针对空间大尺寸测量的移站坐标转换，提出了最小二乘坐标转换数学模型和基于模式搜索的参数求解方法，实验证明该方法具有理论正确性和实际可行性。     

智能控制在光电跟踪控制系统中的应用

描述了仿人智能用于光电跟踪控制系统的设计思想和方法。给出了利用这一设计方法在一大型光电跟踪镜上的控制结果。