高强超薄壁冷弯型钢低层住宅抗震设计方法

结合国内外已完成的冷弯薄壁型钢龙骨式复合墙体静力和动力试验研究成果,提出了冷弯薄壁型钢复合墙体的骨架曲线和恢复力模型。基于已经完成的屈服强度550 MPa高强超薄壁冷弯型钢足尺结构模型振动台试验,对结构在多遇和罕遇地震作用下的抗震分析方法进行了对比。结果表明：多遇地震作用下结构的弹性分析可采用底部剪力法、反应谱法和弹性时程分析法;罕遇地震作用下结构分析可采用静力非线性（推覆）分析和非线性时程分析法。依据GB 50011-2010《建筑抗震设计规范》的基本规定,提出了低层冷弯薄壁型钢龙骨体系结构的抗震设计实用方法建议。     

动静加载下煤的破坏特性及机制的试验研究

动静加载下煤的破坏特性及机制是研究动载冲击地压机制的基础问题,利用改进的霍普金森杆对该问题进行试验研究。首先,通过试验结果的回归分析发现煤在动静加载下有其不同于均质致密岩石的独特的破坏特性。然后,通过对试验结果的讨论对动静加载煤的破坏机制进行分析,发现较多裂隙的存在是导致独特破坏特性的主要原因。破坏模式以裂隙脆性扩展为主;动载的作用主要是使裂隙扩展,进而发生破坏;而静载的作用主要是改变原生裂隙的数量和裂隙尖端的蓄能。最后,基于试验结果对动静加载下煤的冲击危险性进行分析,得出动静加载下煤具有临界静载和最优动载;并将动静载荷下煤的强度作为动载抵抗指数,用来反映抵抗动载能力的强弱;将碎片的分维值作为动载冲击能量指数,用来衡量动载冲击破坏的剧烈程度。     

江苏省地域性民用建筑装饰工程室内环境污染特征与控制

文章在对江苏省地域性室内环境污染大量监测数据统计分析基础上,全面分析了江苏省室内环境污染的新特征,提出了民用建筑室内装饰工程室内环境污染控制新措施,提请全社会重视建筑装饰工程室内环境污染,确保民众身体健康.     

节理岩体蠕变特性的数值模拟研究

利用FLAC3D软件建立不同结构面角度的三维规则齿形结构面模型,进行不同应力水平条件下的结构面剪切蠕变试验.试验结果表明,不同剪应力级别下,试样的齿状突起物所发挥的作用并不相同,随着剪应力级别的增大,发挥抵抗作用的齿状突起物逐渐减少,起到抗剪作用的突起物越来越少.对于相同角度的结构面试件,当法向应力水平高时,剪切蠕变变形大,剪切应力加载的级数明显增加;对不同角度的结构面,在相同的试验条件下,角度越大,剪切蠕变变形越小,结构面角度较大的试样剪应力加载的级数也更多.     

风化砂不同掺入率对膨胀土特性影响的研究

针对目前膨胀土改良措施中存在的问题,提出了一种新的改良方法——在膨胀土中掺入风化砂,对膨胀土实施物理改良。对风化砂不同掺入率的膨胀土进行颗分试验,液、塑限试验,活性指数试验,相对密度试验。试验表明:随着掺砂比例的增大,活性指数急剧下降,液性指数发生了降低;对风化砂不同掺入率改良膨胀土进行的自由膨胀率、有荷膨胀率、无荷膨胀率和膨胀力试验表明,随着掺砂比例的增加,膨胀土的膨胀性得到显著的抑制;最后对掺砂膨胀土进行了直剪试验、无侧限抗压强度试验、CBR试验和回弹模量试验,探讨不同掺砂率对强度指标的影响及其变化规律。试验研究结果表明,掺砂能较好地改良膨胀土的基本工程性质指标,有效抑制膨胀土的膨胀特性,改善膨胀土的力学强度性能,掺砂后膨胀土的各项指标均可达到路基填料的要求。     

浅议建筑内用施工电梯的特点与应用

近年来,随着经济的不断发展,我国建筑业也获得更大的发展空间,与此同时,基本建筑物的规模不断增加,建筑结构也愈发复杂,高度和面积也在不断增加,这也为建筑工程施工带来了更大的难度。为了满足建筑工程施工需要,建筑起重设备在施工现场的应用也日益频繁,并且逐渐成为了建筑施工中不可或缺的重要设备,尤其是施工用升降机能够从垂直方向上层层停靠,而且能同时承载人和货物,获得了广泛的运用。建筑内用施工电梯对传统意义上的升降梯进行了改进,具有更高的稳定性和安全性,受到了人们的广泛关注。文章主要针对施工内用电梯的特点与应用的相关问题进行简单的探讨。     

Hydrodynamic characteristics of a new permeable pavement material produced from recycled concrete and organic matter

The aim of the present study was to evaluate the hydrodynamic characteristics of a new material to be used for permeable and purifying pavements in urban areas. The new material is a mixture of crushed concrete, to provide structural support, and a compost mix intended to retain and biologically treat stormwater pollutants. The first part of this study was to evaluate the hydraulic conductivity of the material at different mixing ratios to define the range of materials suitable for urban drainage applications. The second part of the study involved using tracing experiments to quantify the effects of the pollutant transport mechanisms occurring during the water infiltration process. These experiments were conducted under steady state flows condition using a conservative tracer (NaCl). The results demonstrate that while the addition of compost significantly reduced the permeability of the concrete mix, it was still suitable for use as a paving material in an urban environment. The increased residence time of the stormwater pollutants due to the addition of the compost mix was shown to have a positive effect on the biological treatment of the stormwater pollution.     

恒粘剂硫酸联胺对天然橡胶硫化特性的影响

研究恒粘剂硫酸联胺对天然橡胶(NR)硫化特性的影响。结果表明:在NR中加入恒粘剂硫酸联胺,胶料的t_(10)缩短,t_(90)延长;随着硫化温度的升高,NR和恒粘天然橡胶(CVNR)胶料的t_(10)和t_(90)缩短,NR胶料的t_(10)对温度的依赖性小于CVNR胶料,t_(90)对温度的依赖性大于CVNR胶料;NR胶料的t_(10)对t_(90)的影响灵敏度大于CVNR胶料;NR和CVNR胶料的M_H随硫化温度的升高而减小。     

Compression and filtration characteristics of yeast-immobilized beads prepared using different calcium concentrations

Yeast cells were immobilized on calcium alginate beads prepared using different calcium concentrations. The compression properties of the immobilized beads (e.g., softness index and retardation time for compression) were strongly affected by the calcium concentration. The effects of the bead properties on filtration characteristics, such as cake porosity, specific cake filtration resistance, cake compression creeping effect and cake compressibility, were analysed using a dead-end filtration system. The filtration curve of yeast-immobilized beads had an “S” shape, similar to that of soft gel particles. The cake compression behaviour and variation in cake properties were directly reflected on the curve trend. The Voigt in the series model was employed to describe variation in cake porosity with time during a compression. The yeast immobilization increased the bead softness; therefore, the porosity of a cake formed by yeast-immobilized beads was lower than that formed by pure calcium alginate beads. The cakes formed by yeast-immobilized beads possessed a high compressibility of approximately 1.0 and a high softness index of approximately 1.5. The beads prepared using lower calcium concentrations had higher softness, shorter retardation times for compression, higher cake compressibility, lower cake porosity and higher specific cake filtration resistance. The results demonstrated that immobilizing yeast cells on calcium alginate beads is beneficial for retaining higher yeast activity than that of freely suspended yeast. However, the activity levels of yeast immobilized using different calcium concentrations were nearly the same after 3 h. Therefore, using high concentrations of calcium for yeast immobilization is beneficial for improving yeast activity and filtration characteristics.     

Preparation processes and characterizations of alumina-coated alumina support layers and alumina-coated natural material-based support layers for microfiltration

Recently, porous ceramic membranes have become a subject of significant interest due to their outstanding thermal and chemical stability. To reduce the high manufacturing costs of these porous ceramic membranes, recent research has focused on the utilization of inexpensive natural materials. However, there have not been any well-established direct comparisons of the membrane properties between typical alumina-based membranes and novel natural material-based membranes. Therefore, we compared alumina-coated alumina support layers (with average pore sizes ranging from 0.10 µm ~0.18 µm), alumina-coated diatomite-kaolin composite support layers (with an average pore size of 0.12 µm), and alumina-coated pyrophyllite-diatomite composite support layers (with an average pore size of 0.11 µm) via the dip-coating method and subsequent heat treatment ranging from 1200 °C–1400 °C for 1 h. The pure water permeability of the alumina-coated diatomite-kaolin composite support layer and the alumina-coated pyrophyllite-diatomite composite support layer was found to be approximately 2.0×10² L m⁻² h⁻¹ bar⁻¹, which is similar to that of an alumina-coated alumina support layer. Therefore, we suggest that the average pore size of an alumina-coated natural material-based support layer can be effectively controlled while exhibiting acceptable water permeability.