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881.
湖北省自然保护区建设十分迅速,目前已发展到50余个,占全省国土面积的5.85%。系统分析了湖北省自然保护区的发展态势,并针对保护工作中存在的问题,提出了今后的发展思路与建议。 相似文献
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China produces almost half of ceramic tiles in the world. However, serious air pollution and high energy consumption in the preparation of ceramic press-powders by traditional wet process (WP) have become major barriers for the sustainable development of ceramic tile manufacturing industry. A novel cleaner production process, named by the authors as Droplet-Powder Granulation Process (DPGP), was proposed and tested in this work. Droplet-powder granulator, a key facility of DPGP, was designed. In the granulator, ceramic suspension was directly sprayed to form fine suspension droplets and ceramic dry powder was simultaneously jetted and dispersed to enwrap, insulate and adsorb the suspension droplets so as to form coarse granules that were then rolled, tamped and dried into press-powders. Lab experiments of preparing press-powders by DPGP were carried out. The as-prepared DPGP press-powders consist of solid granules with nearly spherical shape and approximately normal grain size distribution, and present favorable flowability and relatively high bulk density, with the similar properties of the press-powders as those prepared by WP. Moreover, as compared with WP, DPGP can reduce both pollutant emission of 98% dust, 65% sulfur oxides and 71% nitrogen oxides and resource consumption of 24% energy and 69% water. Therefore, DPGP is an innovative approach for cleaner production of ceramic press-powders. 相似文献
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885.
Jin Y. Fan Jin J. Geng Hong Q. Ren Xiao R. Wang Chao Han 《Journal of environmental science and health. Part. B》2013,48(10):844-850
Roundup® is a glyphosate-based herbicide containing a mixture of surfactants. This paper evaluates the toxic effects of Roundup® and its main constituents on the goldfish, Carassius auratus, after 7 days exposure. Fish were exposed to 0.16, 0.032 and 0.0064 mg/L of Roundup® [containing 41% isopropylamine salt of glyphosate (G.I.S) and 18% polyoxyethylene amine (POEA)], G.I.S, and POEA. Their livers were taken for determining reactive oxygen species (ROS), superoxide dismutase (SOD) activity, malondialdehye (MDA) content and acetylcholinesterase (AChE) activity. Hydroxyl radical (·OH) could be induced by exposing Roundup® at a rate of 43%–111%, G.I.S at 90%–124% and POEA at142%–157%. A decreased SOD activity was observed in fish exposed to G.I.S and POEA. The contents of MDA significantly increased when exposed to Roundup® at all concentrations, 0.16 mg/L G.I.S and 0.032 mg/L POEA. The exposure led to an inhibition of AChE in livers overall during the experimental periods. POEA was more toxic than Roundup® or G.I.S during this experiment. AChE and ·OH are supposed to be sensitive biomarkers of the exposure of Roundup® and its main constituents to C. auratus. 相似文献
886.
尝试用时间序列分析中的自适应滤波法对江河灾害性洪水进行预测,认为加权因子个数和自适应常数的确定是关键。以荆江沙市站1950~1995年的年最高水位资料为研究对象,借助计算机编程与计算,确定了最优加权因子个数和自适应常数,建立了适合于该站未来年最高水位的预测模型。预测结果与误差分析表明,自适应滤波法用于江河洪水预测是可行的。 相似文献
887.
资源代际管理与可持续发展 总被引:17,自引:0,他引:17
代际均衡发展是可持续发展战略的重要方面,代际均衡发展的物质基础是代际财富均衡。自然资源是代际财富均衡分配的主要内容,需要进行资源代际管理来保证可持续发展战略的实现。 相似文献
888.
C. L. Hwang J. L. Williams R. Shojalashkari L. T. Fan 《Journal of the American Water Resources Association》1973,9(6):1159-1181
ABSTRACT: A river basin-wide water quality management system is considered. The river receives thermal as well as organic wastes. At-source treatment of these pollutants is imposed to control the basin-wide water quality. The related water quality standards are: the minimum DO concentration, the maximum allowable BOD concentration, the maximum allowable stream temperature, and the allowable rise in stream temperature. The general dynamic mathematical model representing water quality in streams and the thermal effects on BOD and DO concentrations is presented. The model is highly nonlinear in nature. The optimal management problem involving the model is solved by a recently developed nonlinear propgramming technique - the generalized reduced gradient (GRG) method. Comparison of results obtained by the GRG method vs. dynamic programming, and of results using a more realistic mathematical model vs. a simple model are presented. The analysis procedure can be applied to designing new and examining existing water quality programs, and to study the influence of alternate policies and constraints. 相似文献
889.
This study assesses the relative dominance of vision and hearing in judgments of environments, and examines whether the sound sensitivity of the judge alters relative sensory dominance. Six sets of four composite (auditory-plus-visual) videotaped environmental displays were created from unisensory visual and auditory components with known levels of evoked affect. These displays, in a 2 (high, low) × 2 (high, low) Pleasure and/or Arousal format, were presented to 70 participants. The results indicate that visual cues dominate auditory cues in judgments of Pleasure, but that the degree of dominance is highly variable. Arousal judgments were not consistently related to visual or auditory cues. Sound sensitivity does not appear to influence the relative dominance of vision. 相似文献
890.
城市地铁安全施工第三方监测的研究与实施 总被引:12,自引:3,他引:12
实施城市地铁施工第三方监测是保证施工安全和工程质量十分重要的举措 ,有效地避免了施工过程中可能发生的事故。笔者以深圳地铁一期工程为例 ,详细阐述该工程中实施第三方监测的内容、第三方监测分析管理信息系统的研究和开发 ,包括地铁施工过程中对线路及沿线两侧建筑物倾斜和沉降、道路及各种管线沉降、土体位移、水位变化、桥梁墩台位移、隧道收敛及拱顶下沉等进行及时的监测、分析和信息反馈 ,从地铁工程第三方监测分析管理信息系统的内容、主要功能、系统结构等方面论述该系统的设计及开发。第三方监测及其管理的信息化 ,对全国其他城市的地铁施工安全 ,具有借鉴作用。 相似文献