纳米材料的发展及其展望

介绍了纳米材料的研究现状及特点,对纳米组装材料,纳米结构材料、等纳米材料的研究进行了评述,并对２１世纪纳米材料的发展新动向提出展望。     

Building service life economic loss assessment under sequential seismic events

Aftershocks have been shown to exacerbate earthquake‐induced financial losses by causing further damage to structural and nonstructural components in buildings that have already been affected by a mainshock event and increasing the duration of disrupted functionality. Whereas seismic loss assessment under isolated events has been addressed thoroughly in previous studies, comparatively less has been accomplished in the area of loss assessment under sequences of mainshock‐aftershock ground motions. The main objective of the current study is to formulate a comprehensive framework for quantifying financial losses under sequential seismic events. The proposed framework is capable of accounting for the uncertainties in the state of structure due to accumulation of earthquake‐induced damage, the time‐dependent nature of seismic hazard in the post‐mainshock environment, and the uncertainties in the occurrence of mainshock and aftershock events. Application of the proposed framework to a 4‐story reinforced concrete moment frame shows that consideration of aftershocks could increase lifecycle earthquake‐induced losses by up to 30% compared with mainshock‐only assessments.     

2017年8月9日精河6.6级地震灾害损失及灾后恢复重建经费评估

2017年8月9日新疆精河发生6.6级地震,地震造成36人受伤,各类房屋建筑、公共服务设施、基础设施等遭受不同程度的破坏。通过实地抽样调查,按照国家标准的原则和方法,评估出此次地震造成的直接经济损失为429964万元,灾后恢复重建经费约需538461万元。     

Optimum selection of design parameters for transportation of offshore structures

A probabilistic framework is presented to select the design significant wave height and design transverse rotation for typical barges used in the Gulf of Mexico for marine transportation of structural elements and/or systems. The selection of design transverse rotation is based on optimization procedure that trade-off between the performance of the barge subjected to a meteorological-oceanographic (metocean) hazard along the route and losses by structural damage. For this purpose probabilistic models to estimate the metocean hazard for marine transportation are shown. Afterwards, the design rotation is linked to the design of significant wave height and to the return period associated with such wave conditions. The formulation is applied to an offshore transportation route in the Gulf of Mexico.     

余氯排海浓度预测及渔业损失计算

在潮流数值模拟的基础上,建立余氯的二维输运-扩散模型.并将模型应用于胶南发电厂温排水工程,预测了胶南发电厂温排水中余氯排海后在海洋中的浓度分布,并计算其造成的渔业损失量,为我国以自然水为冷却用水的企业确定水体加氯浓度和制定冷却水余氯排放标准提供科学依据,并为电厂的渔业资源补偿提供参考.     

Groundwater as an environmental constraint of longwall coal mining

Groundwater impacts are a common reason for opposition to longwall mining. Most impacts are due to subsidence-related fracturing. Although upper aquifers are protected from drainage to the mine by a confining zone, water levels decline due to fracture dilation, and drawdown expands outward a few hundred meters. Recovery of water levels is common.     

腾冲全新世未来火山喷发灾害损失预测初探

介绍腾冲全新世火山喷发灾害损失静态预测的方法、喷发灾害等级、预测范围划分、各类地面财富、火山喷发、经济损失及人员伤亡预测。地面财富包括房屋建筑、工矿企业、水库、电站、公路、桥梁、森林等 ,给出了预测结果     

新疆近20a风灾研究

风灾是新疆的主要气象灾害之一。新疆风灾每年平均造成24亿元的经济损失。依据大风对农牧业所造成的灾害事件的损失,对风灾时空变化进行评估,其重要意义在于给出了描述大风灾害损失等级划分的量化标准。研究得出:新疆风灾可比损失值随着工农业生产总值的增长而增加,而且增长速度比经济增长速度快;阿克苏、喀什风灾次数较多,强度最大,巴州重大风灾受灾次数最多,是风灾防范和灾后救助的重点地区,和田、吐鲁番因次数较多,强度较大,哈密强度较大,是风灾防范和灾后救助的次重点地区;风灾在作物生长和收获的季节4、5、6、8月份危害最大;建议增加防治风灾投入,改善生态环境,加快退耕还林、退耕还草进程,把阿克苏、喀什、巴州等作为风灾重点防范区,和田、吐鲁番、哈密作为风灾防范和灾后救助的次重点地区,4、5、6、8月份作为重点防范季节。     

Factors affecting channel infiltration of floodwaters in Nahal Zin basin,Negev desert,Israel

Although floods in arid environments have been documented, considerable uncertainties still exist as to the floodwater and in‐channel infiltration relationships. In desert alluvial channels, the prime cause of flood discharge attenuation is water loss by infiltration into the alluvium. The present study documents flows in Nahal Zin, Israel, their infiltration into the channel bed, and the resultant change in the alluvium moisture content. The study uses a systematic combination of two experimental scales, the cross‐section scale and the reach scale. Direct measurements of moisture distribution in the active channel during floods were made using time domain reflectometry. Twelve flow events were recorded. Flow patterns and their respective alluvium moisture content were analysed. A trench was dug in the alluvium for the study of alluvium properties and time domain reflectometry sensor installation. The alluvium was characterized in terms of size distribution and sediment stratigraphy, structure, and composition. Two main alluvial structures (closed and open) affected the advance of the wetting front and water losses. Alluvial units with an open structure (clast‐supported) reached their maximum moisture content faster than closed structure units (matrix‐supported). Small‐sized particles and matrix‐supported layers reduced infiltration rate. The measured velocities of the wetting front were 0.33 and 2.88 m h^?1 for small and large floods respectively. The wetting front moved downward. Lateral movement was negligible. Copyright © 2016 John Wiley & Sons, Ltd.