外墙保温技术在住宅建筑中的应用

从节约能源、保护环境、改善建筑功能与质量为目的出发，采用外墙保温技术，加强围护结构的保温性，实现建筑节能65％的要求。     

大同市建筑节能的技术策略

将针对大同市寒冷地区的气候特点，利用建筑能耗分析软件DOE--2，建立典型建筑模型，分别从建筑体型系数、窗墙面积比、外围护结构传热系数以及大同市可利用天然冷热源和设备性能等方面对住宅节能的途径和方法进行分析探讨，进行在寒冷地区利用建筑节能的可行性研究。     

Organised structures in wall turbulence as deduced from stability theory-based methods

In earlier work, we have explored the relevance of hydrodynamic stability theory to fully developed turbulent wall flows. Using an extended Orr-Sommerfeld Equation, based on an anisotropic eddy-viscosity model, it was shown that there exists a wide range of unstable wave numbers (wall modes), which mimic some of the key features of turbulent wall flows. Here we present experimental confirmation for the same. There is good qualitative and quantitative agreement between theory and experiment. Once the dominant coherent structure is obtained from stability theory, control of turbulence would be the next logical step. As shown, the use of a compliant wall shows considerable promise. We also present some theoretical work for bypass transition (Klebanoff/K-modes), wherein the receptivity of a laminar boundary layer to a vortex sheet in the freestream has been studied. Further, it is shown that triadic interaction between K-modes, 2D TS waves and 3D TS waves can lead to rapid algebraic growth. A similar mechanism seems to carry over to inner wall structures in wall turbulence and perhaps this is the “root cause” for sustenance of turbulence.     

太阳能强化自然通风在长江流域的应用研究

介绍了武汉一间实验用被动式太阳房的太阳能强化自然通风。武汉为夏季湿热、冬季干冷的气候。该实验房专为长江流域的此类复合气候设计,且就近选取建筑材料。提出的一个多功能太阳能系统,探讨了一种室内通风的方法。通过实验结果的分析,证明了此种系统可以基本满足复合气候下的房间的全年舒适性要求。     

Dynamic behavior of HIPed Ti–6Al–4V

The overall dynamic properties of hot isostatically pressed (HIPed) Ti–6Al–4V were throughout investigated. MIL-T-9047G was chosen as a standard material for property comparison due to its best combination of strength and ductility. The elastic constants of HIPed Ti–6Al–4V were measured by resonant ultrasound spectroscopy (RUS) method. Three types of Hopkinson bar tests (constitutive relations tests, strain-controlled specimen tests and hat-shaped specimen tests) were conducted on HIPed material as well as on the standard material to evaluate the high-strain-rate properties of HIPed Ti–6Al–4V. Thick wall cylinder explosion test was conducted to compare the post-critical behavior of baseline material (MIL-T-9047G) and Ti–6Al–4V HIPed material. The texture effect in high-strain-rate properties was checked as the main difference between HIPed (texture free) and standard material (grains elongated along the rod axial direction). The results show that the nonmilled HIPed Ti–6Al–4V has similar yield strength and strain-hardening curve in comparison with the standard material in forging direction but has a lower ductility, which is similar to the ductility of standard material normal to forging direction. The same conclusion also generated from the strain controlled specimen tests. The results that obtained in hat-shaped specimen tests show that HIPed material starts shear localization relatively earlier than standard material. This result is somewhat contradicted with the ballistic testing results that show better ballistic performance for HIPed materials in all three types of penetration tests (flat-ended, conical and long-rod) [see Refs. Nesterenko VF, Indrakanti SS, Goldsmith W, Gu Y. In: Staudhammer KP, Murr LE, Meyers MA, editors. Fundamental issues and applications of shock-wave and high-strain-rate phenomena. Amsterdam: Elsevier Science; 2001. p. 593–600; Nesterenko VF, Indrakanti SS, Brar S, Gu Y. Shock compression of condensed matter. AIP Conf Proc 2000; 505(1): 419–22; Nesterenko VF, Indrakanti SS, Brar S, Gu Y. Key Eng. Mater. 2000; 177-180: 243–8; Nesterenko VF, Goldsmith W, Indrakanti SS, Gu Y. Int J Impact Eng 2003; 28(2): 137–60; Gu Y, Indrakanti SS, Nesterenko VF. Shock compression of condensed matter. AIP Conf Proc 2002; 620(1): 1294–7]. The explanation for this contradiction might be the influences coming from the texture, and other microstructure features such as phase content, grain size distribution and fast shear localization propagation path at the grain boundary and the phase interface.     

房屋建筑墙体开裂的原因及应对措施

根据近几年施工中的经验,分析了墙面裂纹产生的原因以及以往施工方法的得失,查阅有关资料,尝试着在砌筑及抹面砂浆中掺加膨胀剂,以砂浆自身适度膨胀抵消收缩裂纹.虽然这一方法尚不成熟,但确实值得同行们继续共同关注、探讨.     

冷弯型钢组合墙体抗剪承载力简化计算方法研究

对组合墙体抵抗水平剪力的受力机理进行了分析研究,在借鉴传统木结构房屋组合墙体抗剪承载力设计方法的基础上,分别用整体分析方法和剪力流分析方法对组合墙体上自攻螺钉受力进行分析,推导了单个自攻螺钉抗剪承载力与组合墙体抗剪承载力之间的关系,提出了冷弯型钢组合墙体的抗剪承载力计算公式及建议.并将本文公式计算结果与试验结果进行比较分析.结果表明:两种简化分析方法的计算结果均小于由组合墙体抗剪试验结果反算得到的抗剪承载力设计值,简化公式计算结果偏于安全,且剪力流分析方法较整体分析方法更为简便.本文提出的冷弯型钢组合墙体抗剪承载力计算公式,计算结果安全合理,计算过程简单实用,可供实际工程设计参考.     

企业内部网络信息安全与防御对策分析

计算机网络系统是支撑企业内外部各种信息传输、交互和共享的基本环境.但由于网络的互联性、开放性和网络系统本身的漏洞和缺欠,企业网每时每刻都面临来自内外部的威胁和攻击.本文主要分析了企业内部网络的安全隐患,并在此基础上提出了一些防御对策.     

大口径钻孔灌注桩的孔壁稳定研究分析

从钻孔灌注桩钻孔过程来看,由于地层土压力、孔隙水压力、地下水位及土体的蠕变等因素的影响,在成孔过程中或混凝土浇筑之前,孔壁处于不稳定状态之中,随时会出现滑裂或坍塌的危险。结合重阳大桥钻孔灌注桩工程,在分析孔壁稳定条件的基础上,进行不同土层的钻孔孔壁稳定性分析,同时分析孔内泥浆的稳定护壁作用及功能,建立孔壁稳定性数学分析模型,提出相应的护壁措施,防止孔壁的坍塌。     

开洞密肋复合墙体的受力性能研究

在课题组前期科研成果的基础上,通过对1/2模型开洞密肋复合墙体在水平单调荷载作用下的试验研究,并与标准未开洞密肋复合墙体进行对比分析,研究了开洞墙体的主要破坏特征;探讨开洞墙体的承载能力、刚度、变形能力、延性等受力性能;对开洞墙体进行钢筋应变分析;最后提出开洞复合墙体的刚度及受剪承载力的计算公式.试验及理论研究表明:开洞的密肋复合墙体的变形能力、延性好于标准不开洞密肋复合墙体,而刚度、承载力远远不及标准不开洞密肋复合墙体,设计时应加强外框柱和连梁的配筋以及墙板的竖向连接作用;钢筋应变分析表明外框柱、连梁对开洞墙体的受力性能贡献较大;提出的开洞墙体受剪承载力公式计算值比较接近试验值,适用于实际工程应用.