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排序方式: 共有337条查询结果,搜索用时 15 毫秒
91.
近年来,由于我国地震的频频发生,部分钢筋混土框架结构的严重破坏和倒塌,特别是许多工业厂房,虽然是严格按照国家规范设计建造的,但是在罕遇地震作用下,该类厂房仍然受到了较大的破坏[2]。对单体多层混凝土框架工业厂房震害预测的步骤进行了简述,并结合某开发区一个算例进行了对比分析,针对多层混凝土框架工业厂房的特点,提出抗震设计建议,为抗震设计、加固提供一定的借鉴作用。 相似文献
92.
对目前我国房屋建筑中一种最为广泛应用的结构形式房屋——多层砌体房屋进行震害预测分析研究,简要介绍六种常用的多层砌体震害预测方法,易损性概率分析法或称为半经验半理论法、强度判别法、延性系数判别法、模糊类比法、人工神经网络法和结构理论计算法,在详细调查房屋基本情况的基础上,综合考虑以上几种方法,提出相应的震害预测的分析方法。对郑东新区砌体房屋进行震害预测,做出该地区的震害矩阵,并给出该地区砌体房屋在地震作用下的破坏程度及相应震害面积。 相似文献
93.
楼板对钢筋混凝土框架结构受力性能影响 总被引:1,自引:0,他引:1
汶川8级地震震害调查发现,这次地震中现浇钢筋混凝土框架结构多发生"强梁弱柱"型破坏,这与规范中"强柱弱梁"抗震设计原则相悖。为探究其原因,采用ABAQUS软件对钢筋混凝土带楼板框架和空框架结构进行了侧向加载情况的性能分析。通过对比纵向梁端钢筋应力变化和柱端钢筋应力变化,以及分析不同侧向位移对应的楼板钢筋的应力变化情况,指出楼板对梁端抗负弯矩能力的增强有很大贡献。研究了节点类型、楼板钢筋材性、侧向位移、梁高、梁跨和板厚等因素对纵向梁端处楼板有效宽度的影响规律,提出了负弯矩作用下梁端处楼板有效宽度的取值方法。 相似文献
94.
遥感技术在城市建筑震害预测中的应用研究 总被引:1,自引:0,他引:1
长期以来,在城市的震害预测研究工作中,建筑物属性信息的主要获取方法是基于人工调查的传统方式。近年来,随着遥感技术的发展,尤其是高分辨率民用遥感卫星的成功发射,使得利用遥感技术进行城市震害预测成为可能。鉴于传统的信息获取方式存在的费时费力,数据获取周期长,数据信息时效性差等缺点,以郑州市中牟县的部分住宅区为例,对高分辨率遥感影像在城市震害预测中的应用做了相应研究。 相似文献
95.
Junhong Yang Xuyang Cui Yuanzheng Feng Guangning Jing Ligai Kang Mengyuan Luo 《International Journal of Green Energy》2017,14(15):1269-1276
Microalgae have been identified as a superior feedstock for biodiesel production and varied tubular photobioreactors are developed for high efficient and scale-up microalgae cultivation. This article presented a novel concentric double tubes using aeration through radial pores along the length direction of inner tube. Experiments on microalgae cultivation were carried out in the novel photobioreactor, and two control groups including concentric double tubes with axial aeration at both ends and common tubular. The biomass productivity of novel photobioreactor increased by 43.6% and 107.4%, respectively, compared with concentric double tubes with axial aeration at both ends and common tubular without aeration. The values of pH shifted from 7.5 to 9.0 for novel photobioreactor, but 7.5 to 8.8 for common tubular, and 7.5 to 9.6 for concentric double tubes with axial aeration. The dissolved oxygen concentration fluctuated between 6.0 and 7.0 mg·L?1 for novel photobioreactor, but rose from 6.6 to 10.2 mg·L?1 for the common tubular, and 6.9 to 8.1 mg·L?1 for the concentric with axial aeration. Results show that the aeration style of novel photobioreactor can make efficient local mixing and maintain smaller range of pH and lower level of dissolved oxygen in case of higher biomass concentration. Moreover, compared with the two control groups, the novel concentric double tubes have advantages on the light/dark cycle frequency, which may be benefit for microalgae cultivation. The novel concentric double tubes presented in this work can give some inspiration for high efficiency microalgae cultivation. 相似文献
96.
Li Yuxin Zhong Mingqing He Xianzhi Zhang Ruoyu Fu Yu You Ruolan Tao Feiyan Fang Lei Li Yuanyuan Zhai Qingfeng 《Environmental science and pollution research international》2023,30(9):22176-22187
Environmental Science and Pollution Research - Titanium nanoparticles and pyrethroid pesticides are now being widely used in industrial, agriculture, and biomedical applications. In recent years,... 相似文献
97.
98.
Transfer of metals from soil to vegetables in an area near a smelter in Nanning, China 总被引:32,自引:0,他引:32
A field survey was conducted to investigate the metal contamination in soils and vegetables, and to evaluate the possible health risks to local population through foodchain transfer near a smelter in Nanning, southern China. Contamination levels in soils and vegetables with cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu) were measured, and transfer factors (TF) from soils to vegetable plants and its health risk (risk index, RI) were calculated accordingly. Results showed that both soils and vegetables from villages 1 and 2 (V1 and V2, 1500 m and 500 m from the smelter) were heavily contaminated, compared to a village 50 km from the smelter. Geometric mean of Cd and Pb concentrations in vegetables for V1 and V2, respectively, were 0.15 and 0.24 mg Cd kg(-1) and 0.45 and 0.38 mg Pb kg(-1) (on fresh weight basis). Oral intake of Cd and Pb through vegetables poses high health risk to local residents. Risk indices for V1 and V2, respectively, were 3.87 and 7.42 for Cd, and 1.44 and 13.5 for Pb. The complexity of metal contamination and their health risks are also discussed. 相似文献
99.
Guofang Zhai Teruko Sato Teruki Fukuzono Saburo Ikeda Kentaro Yoshida 《Journal of the American Water Resources Association》2006,42(4):927-940
ABSTRACT: This study aimed to clarify public preferences for flood control measures in Japan, willingness to pay (WTP), and the main factors involved in WTP by applying the contingent valuation method. Findings showed that most residents surveyed expected some flood control measures, and revealed a diversity of interest in river management. WTP levels for different measures ranged from a mean of ¥2,887 to ¥4,861 and from a median of ¥1,000 to ¥2,000. However, WTP for additional flood risk reduction beyond initial levels was found to be zero. This was considered to be because WTP for flood risk reduction must be determined within a multi‐risk context. WTP for flood control measures may increase with per capita income, individual preparedness, and/or experience with flooding, but may decrease with distance from a river, acceptability of flood risk, and provision of environmental information. Furthermore, perception of flood risk may increase WTP, while perception of other risks may decrease it. Methods of dealing with environmental risk that were proposed in the survey may have affected WTP levels. 相似文献
100.