地铁与建筑物合建中不同固有频率钢弹簧浮置板轨道的适用性分析

以基于车辆-轨道耦合动力理论的地铁-钢弹簧浮置板耦合动力模型为基础,按照钢弹簧底座位置上力相互协调的原则,建立隧道-建筑物-地基二维有限元模型。然后从分析合建结构的自振特性和钢弹簧支反力的频谱特征入手,采用1/3倍频程振级评价法探讨不同固有频率钢弹簧浮置板轨道在不同合建结构形式中的适用性。研究结果表明:①地铁与建筑物合建结构的竖向自由振动20～80Hz的参振质量比例较高,可达50%以上,而4～10Hz竖向参振质量却差异较大,这与结构尺寸和刚度有关;②4～10Hz钢弹簧浮置板都可有效削减合建结构20～80Hz的竖向振动能量,但会放大浮置板固有频率附近的振动能量;③地铁低频振动传播容易在合建结构内引起共振,因此钢弹簧浮置板固有频率应避开合建结构4～10Hz内竖向参振质量较大且较集中的频段。     

西江引水工程综合自动化系统总体设计

为保证西江引水系统的安全、可靠和经济运行,设计建立了包括取水泵站、配水泵站、管网、调度中心等在内的综合自动化系统,通过实时在线测控和预警预测管理,确保了全线流量平衡和管网安全.介绍了西江引水综合自动化系统的主要构成及基本特性,对类似城市远距离供水自动化测控和保障系统的建立具有指导意义.     

地下游泳池高大模板配置与安装

某地下游泳池顶板支模架高度、支模净空等达到了国家规定的危险性较大的分部分项工程标准,为确保安全施工并保证质量,对高大模板支撑体系进行专项设计并验算,采用扣件式钢管满堂支模架体系,确定了模板选型、支撑形式、间距、步距及节点做法,通过软件验算符合要求。     

为了那片青杨(下)——青海原子城国家级爱国主义教育示范基地纪念园景观设计解读

作为风景园林学中一种非常重要而特殊的设计类型,纪念性景观因其强烈的政治性、时代性和主题性特征成为社会性思想传达的主要载体,因此往往能够产生重大和深远的社会效应和影响力,是风景园林设计创作永恒的研究课题之一.试以历经3年创作周期的青海原子城国家级爱国主义教育基地景观设计实践过程为线索,论述了高海拔恶劣的特殊生境下景观设计的变通途径,深度探讨了属于中国地域性的和当代性的纪念性景观的设计模式及其可能的拓展之道.     

合肥新桥国际机场航站楼转换节点受力性能试验研究

为研究合肥新桥国际机场航站楼屋盖大跨度刚架转换节点的受力性能,对2个转换节点模型进行了静力加载试验研究。试验测定了转换节点模型的荷载-位移曲线、面外位移,以及各关键位置的应变,得到了转换节点的破坏模式,并建立了有限元模型,将试验结果与有限元计算结果进行了对比和分析。研究结果表明：在设计荷载作用下试件处于弹性状态,证明了设计的合理性和安全性;在极限荷载作用下,试件ZHJD-1为焊缝断裂的脆性破坏,试件ZHJD-2为钢管的压屈破坏;试验结果与有限元结果吻合较好,初始缺陷对转换节点的受力性能影响不敏感。     

干熄焦炉壳制作安装施工技术

干熄焦壳体制作、安装是整个干熄焦施工过程的主要组成部分,其中壳体制作、安装要求按分段、排版、定尺、下料、组装、焊接、安装这一程序依次进行。主要讲述壳体的分段要领、制作方法及要求、安装工艺、注意事项。     

大调谐质量比减振结构中巨梁层竖向地震响应分析

基于随机振动分析方法对大调谐质量比减振结构及普通巨型框架结构中巨梁层竖向地震响应问题进行探讨,并从实际构造的角度为解决大跨度巨梁层竖向动力响应过大问题提供设计建议。研究结果表明:巨梁层上最大竖向地震响应分布于中段附近;巨梁层于建筑上的位置越高,其竖向地震响应越大;相比其他巨梁层,大跨度巨梁层竖向地震响应同比增大;在大跨度巨梁层上设置子框架可对该巨梁层竖向地震响应起到抑制作用。     

Effects of gamma irradiation for sterilization on aqueous dispersions of length sorted carbon nanotubes

There is currently great interest in the potential use of carbon nanotubes as delivery vessels for nanotherapeutics and other medical applications. However, no data are available on the effects of sterilization methods on the properties of nanotube dispersions, the form in which most medical applications will be processed. Here we show the effects of gamma irradiation from a ⁶⁰Co source on the dispersion and optical properties of single-wall carbon nanotubes in aqueous dispersion. Samples of different length-refined populations were sealed in ampoules and exposed to a dose of approximately 28 kGy, a level sufficient to ensure sterility of the dispersions. In contrast to literature results for solid-phase nanotube samples, the effects of gamma irradiation on the dispersion and optical properties of the nanotube samples were found to be minimal. Based on these results, gamma irradiation appears sufficiently non-destructive to be industrially useful for the sterilization of nanotube dispersions.     

Catalyst-free growth of nanographene films on various substrates

We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition (r-PECVD) system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy (STM) confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films.     

Self-Assembly and Ordering of C60 on the WO2/W（110） Surface

The growth and ordering of C₆₀ molecules on the WO₂/W(110) surface have been studied by low-temperature scanning tunnelling microscopy and spectroscopy (STM and STS), low-energy electron diffraction (LEED), and density functional theory (DFT) calculations. The results indicate the growth of a well-ordered C₆₀ layer on the WO₂/W(110) surface in which the molecules form a close-packed hexagonal structure with a unit cell parameter equal to 0.95 nm. The nucleation of the C₆₀ layer starts at the substrate’s inner step edges. Low-temperature STM of C₆₀ molecules performed at 78 K demonstrates well-resolved molecular orbitals within individual molecules. In the C₆₀ monolayer on the WO₂/W(110) surface, the molecules are aligned in one direction due to intermolecular interaction, as shown by the ordered molecular orbitals of individual C₆₀. STS data obtained from the C₆₀ monolayer on the WO₂/W(110) surface are in good agreement with DFT calculations.