斯堪尼亚将向中联重科交付新一批重卡底盘

近日,中联重科向斯堪尼亚订购了375台重型卡车底盘用于混凝土泵车上装。该订单将在2012年4月交付。斯堪尼亚凭借独有的模块化生产系统,为中联重科量身定制一款坚固的卡车底盘,以最大程度的满足其对车身和操控方面的需求。该卡车底盘可以以最大扭矩每天连续工作14 h。     

二次系统等电位接地网的敷设在沙梁水电站中的应用

针对水电站发生接地故障时,大的短路电流在电站主接地网上产生巨大的相对电位差,会对二次设备产生磁性干扰,影响电气二次设备的正常运行,甚至损毁设备的情况。通过敷设二次系统等电位接地网,使二次电气设备地电位相等,阻止主接地网不均匀电位对于二次设备的危害,确保电网的可靠安全运行。结合沙梁水电站的工程敷设情况,分析该水电站二次系统等电位接地网敷设的基本原则、注意问题及实施方案,提出电气二次系统等电位接地网敷设方面的工程建议。     

超宽带通信技术的研究现状与发展前景

超宽带通信具有系统容量大、数据传输速率高、抗多径能力强、成本低、功耗低、信号衰减较小、定位精度高、穿透力强等优点,是下一代无线通信的革命性技术之一。文章简述了UWB技术的理论依据及技术方案;探讨了UWB关键技术的研究现状;阐述了UWB技术的研究方向与发展前景,指出随着研究工作的不断深入,将逐步找到UWB技术现有问题的解决方案,其技术将更加成熟,这项新技术必将在通信领域和电子领域得到广泛的应用,发展前景十分广阔。     

页岩气勘探开发技术综述

松辽盆地大量含油气泥页岩的开发正在进入新的阶段。虽然我国传统意义上的泥页岩裂隙气藏等并不被划入完整意义上的页岩气,但其开发技术却与页岩气的开发有着不可分割的借鉴价值。本文通过对当今世界页岩气开发技术的梳理,力求为吉林探区的泥页岩气开发提供参考。     

全家便利店的营销策略制定——上海地区为例

当今日本便利店在我国的规模已大到惊人,仅上海一条普通的街巷就会有两到三家不同品牌的日本便利店,并且其数量仍在不断增长。截止2016年上半年,全家便利店仅在上海地区就超过1000家,远远超过罗森、7-11、好德等,在消费者心中站稳脚跟。全家在上海之所以能够发展到现在一家独大的地位,靠的是它自身一套独特有完整的营销策略。     

绘画的危机

本文从三个递进的层面探讨了绘画中的一些危机问题,首先提出对绘画专业前景问题的担忧,其次论述了画家通过作品所传递的思想观念价值的重要性,最后论述绘画不断细化、专业化的弊端和缺陷,希望通过对前辈大师的学习和其他领域的探寻来完善和促进绘画的发展,各个专业都需要建立在人类知识的完整性上才能不断发展,才能不至于造成狭隘。绘画发展到今天已经有一部厚厚的艺术史做见证,除了时代性的无可替代和独特性,我们能做的是要比前人更全面、更彻底、更专心和精确的探索这个世界。     

Study on purification and application of novel precipitant for ceria-based polishing powder

Novel precipitant prepared through carbonation with MgCl2 wastewater generated from rare earth extraction separation process and low-price dolomite as raw materials was studied in this paper. The purification methods of novel precipitant by adding appropriate oxidizing agent were studied. It was found that optimal purification result could be achieved with sodium hypochlorite as iron removal reagent and the iron removal rate could reach up to 90% when the adding amount was 0.1 vol.%. During the preparation, the particle size and distribution of ceria-based polishing powder were affected obviously by the parameters such as concentration, reaction temperature and feeding rate. The results showed that ceria-based polishing powder with D50 =2.5-3.5 μm and the particle size distribution of 0.65-0.75 μm could be prepared when the concentration of CeCl3 was 0.6 mol/L, the reaction temperature was maintained at 50 °C and the feeding speed was controlled at 25 ml/min. Compared with commercial powder, the self-made polishing powder had roughly the same cutting amount, but the surface finish of polished glass was better than that of commercial polishing powder.