高压共轨系统中的燃油温度变化及其影响

为说明高压流动燃油温度对喷油量的影响,进行了高压共轨系统中燃油温度变化及其影响研究,建立了燃油不同的发热和热交换数学模型,构建了高压泵、共轨管和喷油器的燃油温度模型,运用液压流体仿真软件AMESim构建高压共轨系统燃油热仿真计算模型;结合试验数据,验证了高压共轨系统燃油热模型的有效性,分析了不同燃油初始温度下不同部件出口燃油温度的变化。在高压泵转速分别为400r/min和1 600r/min时,高压油泵出口温度增加幅度分别约为4.5℃和23.3℃;在共轨管压力从55MPa增大到140MPa时,共轨管出口的燃油温度仅在35℃~55℃之间变化;在共轨压力为140MPa时,喷孔出口温度变化范围在90℃~110℃之间。燃油温度20℃、40℃时的压力变化较小,燃油温度0℃、60℃时的压力变化较大;在低共轨压力时燃油温度引起的喷油量变化大,高共轨压力时燃油温度引起的喷油量变化小。     

磁性介孔TiO2/氧化石墨烯复合材料的制备及其对U(Ⅵ)的吸附

以氧化石墨烯（GO）、纳米Fe₃O₄、钛酸四丁酯（TBOT）为原料,合成了磁性介孔TiO₂/GO（Fe₃O₄@TiO₂/GO）复合材料,用其处理浓度为10 mg·L-1的含U（Ⅵ）废水。研究了Fe₃O₄@TiO₂/GO复合材料中GO含量、溶液初始pH值、Fe₃O₄@TiO₂/GO复合材料投加量、反应时间、U（Ⅵ）初始浓度及共存离子对U（Ⅵ）吸附的影响。结果表明:在pH值为6、GO质量分数为60wt%、Fe₃O₄@TiO₂/GO复合材料投加量为10 mg的条件下,Fe₃O₄@TiO₂/GO复合材料对U（Ⅵ）的吸附效果最佳,较同等条件下磁性介孔Fe₃O₄@TiO₂复合材料和GO的吸附量分别高了10.99 mg·g-1和1.91 mg·g-1。Fe₃O₄@TiO₂/GO复合材料对U（Ⅵ）的吸附180 min即达到平衡,准二级动力学模型和Freundlich吸附等温模型能很好地描述其吸附过程。解吸实验表明,经5次吸附-解吸后,U（Ⅵ）的吸附率仍高达90.86%,说明Fe₃O₄@TiO₂/GO复合材料具有较高的循环利用性能。      

地铁运营线路既有普通扣件地段更换谐振式浮轨扣件施工工艺

本文以地铁施工中的轨道工程施工为背景,介绍如何在地铁运营线路既有普通扣件地段更换谐振式浮轨扣件。     

我国轨道交通环境问题研究现状

目前我国正大力发展轨道交通,主要是地铁和轻轨,同时产生了一系列的环境问题。针对人群密集的地铁微环境空气质量和轻轨的噪声问题,讨论了我国轨道交通环境问题的主要表现及研究现状,并提出了建议。     

Environmentally Smart Design: Designing for Social Wellbeing Across the City and in the Workplace

Sustainable need not mean more expensive. Health problems caused by sedentary lifestyles, pollution and injuries from road accidents come at great financial cost — not just for individuals, but also for employers and indeed national governments. Built environments designed to keep people active and away from harm are thus economically beneficial, too. Alisdair McGregor, Ann Marie Aguilar and Victoria Lockhart of Arup cite some of the company's recent schemes in New York and London that have successfully encouraged cycling, strolling and other healthy behaviours, while also avoiding contributing to climate change.     

A New Type I Peritrophic Membrane Protein from Larval Holotrichia oblita (Coleoptera: Melolonthidae) Binds to Chitin

Peritrophic membranes (PMs) are composed of chitin and protein. Chitin and protein play important roles in the structural formation and function of the PM. A new type I PM protein, HoCBP76, was identified from the Holotrichia oblita. HoCBP76 was shown as a 62.3 kDa protein by SDS-PAGE analysis and appeard to be associated with the PM throughout its entire length. In H. oblita larvae, the midgut is the only tissue where HoCBP76 could be detected during the feeding period of the larvae. The predicted amino acid sequence indicates that it contains seven tandem chitin binding domains belonging to the peritrophin-A family. HoCBP76 has chitin binding activity and is strongly associated with the PM. The HoCBP76 was not a mucin-like glycoprotein, and the consensus of conserved cysteines appeared to be CX_13–17CX₅CX₉CX₁₂CX₇C. Western blot analysis showed that the abundance of HoCBP76 in the anterior, middle and posterior regions of the midgut was similar, indicating that HoCBP76 was secreted by the whole midgut epithelium, and confirmed the H. oblita PM belonged to the Type I PM. Immunolocalization analysis showed that HoCBP76 was mainly localized in the PM. The HoCBP76 is the first PM protein found in the H. oblita; however, its biochemical and physiological functions require further investigation.     

Analysis of 235U Enrichment by Chemical Exchange in U(IV)‐U(VI) System on Anionite

Abstract

A theoretical study about ²³⁵U enrichment by the chemical exchange method in U(IV)‐U(VI) system on anion‐exchange resins is presented. The ²³⁵U isotope concentration profiles along the band were numerically calculated using an accurate mathematical model and simulations were carried out for the situation of product and waste withdrawal and feed supply. By means of numerical simulation, an estimation of the migration time, necessary for a desired enrichment degree, was obtained. The required migration distance, the production of uranium 3 at.% ²³⁵U per year and the plant configuration are calculated for different operating conditions. An analysis of the process scale for various experimental conditions is also presented.     

兼做试验压环的U型管换热器的管板设计

从国外引进的U型管换热器管板兼做法兰的结构转变成按GB151-1999进行设计这种兼做法兰的U型管换热器管板,既经济又方便使用很有参考价值.     

Preparation of amorphous poly(ethylene terephthalate) from U‐polymer via a copolymerization process

U‐Polymer, a kind of polyarylate, was synthesized by interfacial polycondensation method with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and bisphenol A (BPA) as raw materials. The structure of the U‐Polymer was characterized by IR and ¹H–NMR spectra. Then, an amorphous poly(ethylene terephthalate) (APET) was prepared with the introduction of the U‐Polymer to the PET sequence to improve thermal and mechanical behaviors of PET via the polymerization process. The structure and property of the APET were characterized by DSC and DMA. The results showed that the APET exhibits amorphism, transparency, higher glass‐transition temperature (T_g), and higher storage modulus than that of PET. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1653–1657, 2001     

近年美国染料工业概况

美国染料工业持续下滑,染料产量由2000年的16.6万吨下降到2003年的11.9万吨,占世界染料总量的9.7%,生产的染料有24%出口;其价格连续走低;染料的消费量也逐年下滑,2003年的表观消费量为18.4万吨,折百约为13.2万吨,消费量为世界消费总量的12.7%,其中进口量超过50%,在进口染料中超过40%来自中国和印度。在美国进行化学合成的染料只有酸性和活性,其余均为进口原染料进行加工或商品化,占染料生产量的75%～80%。经过6年的分化重组,美国染料生产商的主体是德司达、汽巴和科莱恩等跨国公司。纺织印染工业萎缩和进口冲击、染料产品利润空间的急剧缩小、环境因素是造成美国染料工业不景气的主要原因。