排序方式: 共有49条查询结果,搜索用时 535 毫秒
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以实际观测为依据,以七台河地区地质条件为背景,给出该区塌陷变形,诸如不均匀沉降、地面倾斜、曲率变化、移动等力学量的估算。 相似文献
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An S Li H Guan B Zhou C Wang Z Deng Z Zhi Y Liu Y Xu C Fang S Jiang J Li H 《Ambio》2007,36(4):335-342
Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% costal wetlands) because of the wetland reclamation during China's long history of civilization, and the population pressure and the misguided policies over the last 50 years. Recently, with an improved understanding that healthy wetland ecosystems play a vital role in her sustainable economic development, China started major efforts in wetland conservation, as signified by the policy to return reclaimed croplands to wetlands, the funding of billions of dollars to restore degraded wetlands, and the national plan to place 90% of natural wetlands under protection by 2030. This paper describes the current status of the natural wetlands in China, reviews past problems, and discusses current efforts and future challenges in protecting China's natural wetlands. 相似文献
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关于如何减轻我国村镇居住建筑地震灾害的建议 总被引:10,自引:2,他引:8
本文在考察了我国七省、市近200个村、镇后指出,我国农村正在兴起一个居住建筑更新换代的高潮,但是几乎所有的村镇建筑都忽视对地震的预防,没有进行必要的抗震性能设计。如果全国村、镇房屋抗震性能低下的隐患如不加以迅速纠正,在未来可能的地震中必将造成极其惨重的损失。为此呼呈政府领导应该重视这一现实,并迅速抓住目前这一村、镇建筑大发展的时机,全面实行抗震设计,消除隐患。 相似文献
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BI Xiao-yi WANG Peng~* JIANG Hong XU Huan-yan SHI Shu-jie HUANG Jun-li Research Center for Green Chemistry Technology School of Municipal Environmental Engineering Harbin Institute of Technology Harbin China. 《环境科学学报(英文版)》2007,(12)
The catalyst of CuO_x/Al_2O_3 was prepared by the dipping-sedimentation method usingγ-Al_2O_3 as a supporter.CuO and Cu_2O were loaded on the surface of Al_2O_3,characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).In the presence of CuO_x/Al_2O_3,the microwave-induced chlorine dioxide(ClO_2) catalytic oxidation process was conducted for the treatment of synthetic wastewater containing 100 mg/L phenol.The factors influencing phenol removal were investigated and the results showed that microwave-induced ClO_2-CuO_x/Al_2O_3 process could effectively degrade contaminants in a short reaction time with a low oxidant dosage,extensive pH range.Under a given condition(ClO_2 concentration 80 mg/L,microwave power 50 W,contact time 5 min,catalyst dosage 50 g/L,pH 9),phenol removal percentage approached 92.24%,corresponding to 79.13% of COD_(Cr) removal.The removal of phenol by microwave-induced ClO_2-CuO_x/Al_2O_3 catalytic oxidation process was a complicated non-homogeneous solid/water reaction, which fitted pseudo-first-order by kinetics.Compared with traditional ClO_2 oxidation,ClO_2 catalytic oxidation and microwave-induced ClO_2 oxidation,microwave-induced ClO_2 catalytic oxidation system could significantly enhance the degradation efficiency.It provides an effective technology for the removal of phenol wastewater. 相似文献
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壬基酚是环境内分泌干扰物质中具有代表性的物质,非离子表面活性剂壬基酚聚氧乙烯醚在环境中的降解产物,对生物体造成很大危害。目前检测水样中壬基酚的主要方法是采用GC—MS和HPLC,预处理主要采用固相萃取和液一液萃取。研究表明自来水厂的常规处理工艺对于水中壬基酚的去除有限;近年来倍受关注的深度处理工艺如活性炭吸附等物理方法... 相似文献
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