HSC/HPC高温爆裂机理研究进展

对高温下HSC/HPC的爆裂机理以及相关抑制措施对HSC/HPC抗爆裂性能和高温后剩余性能的影响进行了研究综述,并简要介绍了由爆裂引起的HSC混凝土构件耐火极限计算方法,指出了其中存在的某些有待完善的问题,并展望了今后的研究发展趋势,以期指导实践。     

澳斯麦特法炼铜过程的热力学研究

采用HSC Chemistry 5.0热力学分析软件,对硫化铜精矿澳炉熔炼提取金属铜过程的吉布斯自由能与温度关系进行了研究,重点分析了澳炉熔炼、电炉渣净化沉降及澳炉吹炼过程,研究结果为云南锡业澳炉炼铜法提供一定的理论依据和基础数据。     

Experimental and analytical investigation of reinforced high strength concrete continuous beams strengthened with fiber reinforced polymer

Carbon and glass fiber reinforced polymer (CFRP and GFRP) are two materials suitable for strengthening the reinforced concrete (RC) beams. Although many in situ RC beams are of continuous constructions, there has been very limited research on the behavior of such beams with externally applied FRP laminate. In addition, most design guidelines were developed for simply supported beams with external FRP laminates. This paper presents an experimental program conducted to study the flexural behavior and redistribution in moment of reinforced high strength concrete (RHSC) continuous beams strengthened with CFRP and GFRP sheets. Test results showed that with increasing the number of CFRP sheet layers, the ultimate strength increases, while the ductility, moment redistribution, and ultimate strain of CFRP sheet decrease. Also, by using the GFRP sheet in strengthening the continuous beam reduced loss in ductility and moment redistribution but it did not significantly increase ultimate strength of beam. The moment enhancement ratio of the strengthened continuous beams was significantly higher than the ultimate load enhancement ratio in the same beam. An analytical model for moment–curvature and load capacity are developed and used for the tested continuous beams in current and other similar studies. The stress–strain curves of concrete, steel and FRP were considered as integrity model. Stress–strain model of concrete is extended from Oztekin et al.’s model by modifying the ultimate strain. Also, new parameters of equivalent stress block are obtained for flexural calculation of RHSC beams. Good agreement between experiment and prediction values is achieved.     

Rail safety and rail privatisation in Britain

British Rail (BR), the former unified main line railway operator in Great Britain, was divided into about 100 separate organisations and privatised from April 1994. There was concern in the run-up to privatisation that the fragmentation of the system and the entry of new operators might compromise safety. This paper investigates what has happened to safety by analysing data on almost all fatal railway accidents, together with the most important non-fatal train accidents, from 1967 to 2003, with additional brief analyses back to 1946. BR had achieved downward trends in the mean numbers of accidents per train-kilometre for all the main classes of accident in the 27 years up to 1993, and the paper takes the extrapolation of these favourable trends as the yardstick by which to judge the safety performance of the privatised railway. The paper finds that the privatised railway had fewer accidents than this yardstick for all classes of accident. Only one indicator is adverse: the number of fatalities in train collisions and derailments is higher than expected, because of the severity of the accident at Ladbroke Grove in 1999. The principal conclusion is that there is no evidence that privatisation caused railway safety to deteriorate.     

数字技术在棒材成品飞剪电控系统的应用

为了解决棒材成品飞剪剪切倍尺精度不高,成材率和定尺率低,切损大,没有实现优化剪切等问题,在技术改造中采用了全数字电控系统,使飞剪剪切精度提高,由原来的剪切误差200 mm缩小到100 mm以内,有效提高了成材率和定尺率,对于现场备件储备和维护都比较方便,有效的提高了设备作业率.     

浅谈采用HSC新型灌浆材料进行隧洞阻水灌浆的方法

大伙房水库输水工程六河标段,围岩破碎、地下水丰富,开挖后仍然有大量渗、漏水,对二次混凝土衬砌施工产生了很大影响,为保证二次混凝土施工的质量,对严重渗、漏水部位采用HSC新型灌浆材料进行二次隧洞灌浆的方法,并成功抑制了大量渗、漏水的发生.     

分层软小区无线接入网及其性能分析

基于分布式天线系统的概念,提出了一种新型的无线接入网络结构--分层软小区(HSC)无线网络.该网络采用集中统一的资源管理策略,由软件控制多个天线端口形成软小区服务于移动终端,同时,按照资源的正交划分形成地域上重叠的多层不同大小和形状的软小区,以适应不同的用户场景.分析表明,分层软小区无线网络的系统容量、干扰、阻塞率等性能都比传统蜂窝网络有较大的提高.     

内燃机内甲烷水蒸气重整特性分析

为了较为系统地认识甲烷水蒸气重整反应对内燃机性能的影响。应用HSC 5.1软件对甲烷水蒸气重整反应在不同反应温度和水碳比的工况下进行分析,然后应用Chemkin-pro程序,计算了在相同供热量下甲烷水蒸气重整气在不同物质的量比下比CH_4的燃CH_4消耗降低率。结果表明,提高反应温度和水碳比可提高CH_4的转化率;当温度为700℃、水碳比为3时,发热量提高了13.58%,在供热相同情况下,燃CH_4消耗量可减少11.96%,CH_4的转化率越高,循环效率越高;重整气效率比纯天然气高,随着物质的量比降低,重整气优势降低。     

基于高速切削刀具与刀具系统的研究

根据高速切削高效率、高质量的加工目的,分析高速切削的特点,提出高速切削加工对刀具系统的要求,并提出刀具的选择要点,以及提高工艺系统刚性与安全性的要求,以提高切削效率和加工质量。     

Magnetic manipulation device for the optimization of cell processing conditions

Variability in human cell phenotypes make it's advancements in optimized cell processing necessary for personalized cell therapy. Here we propose a strategy of palm-top sized device to assist physically manipulating cells for optimizing cell preparations. For the design of such a device, we combined two conventional approaches: multi-well plate formatting and magnetic cell handling using magnetite cationic liposomes (MCLs). From our previous works, we showed the labeling applications of MCL on adhesive cells for various tissue engineering approaches. To feasibly transfer cells in multi-well plate, we here evaluated the magnetic response of MCL-labeled suspension type cells. The cell handling performance of Jurkat cells proved to be faster and more robust compared to MACS (Magnetic Cell Sorting) bead methods. To further confirm our strategy, prototype palm-top sized device “magnetic manipulation device (MMD)” was designed. In the device, the actual cell transportation efficacy of Jurkat cells was satisfying. Moreover, as a model of the most distributed clinical cell processing, primary peripheral blood mononuclear cells (PBMCs) from different volunteers were evaluated. By MMD, individual PBMCs indicated to have optimum Interleukin-2 (IL-2) concentrations for the expansion. Such huge differences of individual cells indicated that MMD, our proposing efficient and self-contained support tool, could assist the feasible and cost-effective optimization of cell processing in clinical facilities.