重庆地区南向外窗水平外遮阳的模拟研究

采用能耗模拟软件Energyplus对重庆地区南向外窗水平外遮阳进行模拟研究,包括单遮阳板适宜的外挑系数,多遮阳板(双遮阳板、三遮阳板)与单遮阳板的性能比较,遮阳板对照明电耗的影响,多遮阳板对室内采光的影响。单纯考虑太阳直射辐射时,单遮阳板的外挑系数宜控制在0.3左右。在相同外挑系数下,多遮阳板的遮挡效果优于单遮阳板。单遮阳板、多遮阳板基本不影响照明电耗。多遮阳板能够改善室内自然采光的均匀性。     

考虑累积损伤退化的钢材等效本构模型研究

在结构抗震分析中,钢材在循环荷载作用下的一维本构关系是利用杆系模型进行结构弹塑性地震响应分析的基础。为了更准确地模拟结构在强震作用下的反应,提出能够考虑累积损伤、刚度和强度退化的钢材等效本构模型,包括骨架曲线、滞回准则以及退化特征,利用损伤控制因子数学模型对钢构件、节点及结构的损伤退化全程进行描述。根据提出的等效本构模型并利用有限元软件ABAQUS提供的用户材料子程序UMAT,采用Fortran语言开发能够进行钢框架强震作用分析的损伤退化过程计算程序。采用等效本构模型对典型试验进行模拟分析,其结果与试验结果吻合良好,充分证明钢材等效本构模型用于钢构件在强震作用下弹塑性分析的准确性及可行性。     

升降式脚手架升降及防坠装置研究

高层建筑越来越多,施工过程中脚手架升降和防坠是一个很重要的问题,本文设计了一种简易的升降机构与防坠机构联动装置,实际应用表明性能良好,安全可靠。     

碳纤维布加固损伤旧木梁受弯承载力研究

木结构是我国古建筑的主要结构形式,长期使用后,木梁易发生老化损伤,导致其承载力、刚度明显降低,影响结构的正常使用.本文完成8根老化损伤旧木梁CFRP布加固试验,研究了不同层数的CFRP布加固矩形旧木梁的破坏形态、抗弯承载力、荷载-挠度曲线.研究结果表明,粘贴CFRP布加固老化旧木梁不仅能明显提高其受弯承载力,而且其破坏模式也由脆性受拉破坏转变为延性受压破坏.结合木梁在达到挠度限值时所承受的荷载往往小于其破坏时极限荷载的实际情况,基于截面等效替换原则,建立了木梁CFRP加固设计计算公式,计算结果与试验结果吻合较好,可为今后木梁加固改造时对不同荷载情况下所需CFRP用量进行设计.     

SR防渗体系在高寒高海拔地区水电站中的应用

西藏雪卡水电站上游铺盖在浇筑施工过程中隆起、接缝破坏,产生了渗漏现象,设计采用化学灌浆配合SR整体防渗体系的方法进行防渗治理,效果显著。本文对渗漏治理工艺及SR防渗体系的应用进行了详细阐述,为类似工程处理提供了借鉴。     

异形索桁架结构浮动式连接可行性研究

针对异形索桁架特殊的结构形式,从拉索结构适应温度变化、对主体结构产生影响、应力及挠度控制和造价几个方面出发,提出异形索桁架通常的硬性连接和新型的两种浮动式连接方式,并对这3种方案形式的构造和受力分别做了分析,利用通用的有限元程序,对3种方案的结构形式在各种工况条件下分别进行静力计算和对主体结构产生影响的分析,同时对3种结构形式的动力响应进行分析,系统地对3种连接方案的异形索桁架从温度变化、对结构产生的影响、挠度控制和工程造价方面分别做了对比性说明,对3种索桁架的动力特性做了具体对比,提出合理的建议,可作为今后索桁架节点设计的参考。     

单层厂房柱下独立基础设计中的问题

指出在单层厂房柱下独立基础的设计中存在忽略基础上部受拉的问题,提出了可以按照素混凝土结构进行基础设计。按照规范及对基础的受力分析推导出了简单的判断公式。用该公式可以容易地判断出基础上部是否需要配置抗弯钢筋。     

On the inhomogeneous hydration kinetics and stiffness evolution of HNBR‐MgO reactive elastomer composites

Swellable elastomers are widely used in oilfield industry for sealing and zonal isolation applications. These materials need to sustain a large amount of external load after swelling. A newly developed reactive hydrogenated nitrile butadiene rubber (HNBR) based elastomer composite with magnesium oxide (MgO) as filler can swell and stiffen when exposed to water, which makes it ideal for oil field applications. However, both the filler hydration and the stiffness evolution inside this composite material are observed to be highly inhomogeneous even for samples on the length scale of millimeters. To understand this coupled diffusion‐hydration process is critical for applications of these materials with larger length scales. In this work, the hydration kinetics and stiffness evolution of the HNBR‐MgO composite are quantitatively studied on microscopic level. The extent of MgO hydration along the thickness of the sample are measured at the different stage of swelling. These results are used to determine the diffusion coefficient of water inside the composite. The diffusivity increases orders of magnitude after the filler hydration. In addition, the modulus change is non‐proportional to the degree of filler hydration as demonstrated by instrumented grid indentation on the hydrated composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43420.     

Numerical simulation and experimental validation of liquid‐film‐flow characteristics in dip coating for non‐Newtonian fluids

The film‐flow problem in dip coating is simulated numerically for non‐Newtonian fluids based on Carreau–Yasuda (CY) and Herschel–Bulkley (HB) constitutive equations, with particular focus on coating‐film‐thickening phenomena and on the evolution of free surface and flow field under different sets of conditions. Finite element method (FEM) is combined with remeshing technique using a commercial code (Polyflow). Numerical predictions of the final film thickness and free surface for HB and CY fluids are successfully compared with experiments under the given conditions. Results show that the combination of FEM‐remeshing technique could be useful for dip‐coating design and optimization. Effects of coating fluid properties and withdrawal speed on film thickening and free surface shape and location are also discussed. Flow fields under different conditions are presented to analyze the evolution of the entire flow field and flow characteristics in detail. POLYM. ENG. SCI. 56:1070–1078, 2016. © 2016 Society of Plastics Engineers     

枸杞发酵液的抗衰老活性和皮肤安全性研究

采用枸杞为原料,德氏乳杆菌为菌种进行发酵获得枸杞发酵液。对枸杞发酵液的生理生化性质与成分进行检测,通过自由基清除实验与成纤维细胞增殖实验对枸杞发酵液的抗衰老活性进行检测,利用人体斑贴实验对枸杞发酵液的安全性进行评估。实验结果表明,枸杞发酵液为黏稠弱酸性液体,主要成分是多糖,具有较强的清除DPPH自由基和羟自由基的能力,在一定体积分数内可促进成纤维细胞增殖。