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281.
A new water quality assessment model was built based on projection pursuit technique. A great quantity of sample data was applied to increase the model's precision. A new genetic algorithm combined with conditional optimization method was proposed and applied to the model optimization, which could deal with global optimization problem with various restrictions effectively. The case study shows that this model can give an appropriate assessment of water quality. Moreover, it can determine the index weights in an objective way or provide information for decision makers, which is difficult for other assessment methods. 相似文献
282.
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284.
数字海洋中海量多源异构空间数据集成研究 总被引:1,自引:0,他引:1
针对目前海量多源异构空间数据在组织、管理、集成方面的困难以及传统方法在数据转化过程中造成的数据损耗等问题,结合海洋空间数据的特征,提出一种新的海量多源异构空间数据无缝集成技术(SIMMHS)。该技术针对底层海洋空间数据的海量性和异构性,利用FLEX和XML技术,以XML为数据转换格式,使用XML Schema建立了公共模型,利用虚拟空间数据搜索引擎作为中介实现平台,实现了对海量多源异构空间数据的无缝集成。结合数字海洋上海示范区建设项目的实际应用,有效集成了海量多源异构的空间数据,以方便用户的快速浏览查询、系统的三维展示和数据的实时更新。 相似文献
285.
Additive manufacturing based on optimized mask video projection for improved accuracy and resolution
Additive manufacturing (AM) processes based on mask image projection such as digital micro-mirror devices (DMD) have the potential to be fast and inexpensive. More and more research and commercial systems have been developed based on such digital devices. However, the accuracy and resolution of the related AM processes are constrained by the limited number of mirrors in a DMD. In this paper, a novel AM process based on the mask video projection has been presented. For each layer, a set of mask images instead of a single image are planned based on the principle of the optimized pixel blending. The planned images are then projected in synchronization with the small movement of the building platform. A mask image planning method has been presented for the formulated optimization problem. Experimental results have verified that the mask video projection process can significantly improve the accuracy and resolution of built components. 相似文献
286.
Gang Xiao Baosheng Jin Mingjiang Ni Kefa Cen Yong Chi Zhongxin Tan 《Frontiers of Environmental Science & Engineering in China》2011,5(2):193-204
Considering high-moisture municipal solid waste (MSW) of China, a steam dried MSW gasification and melting process was proposed,
the feasibility was tested, and the mass and energy balance was analyzed. Preliminary experiments were conducted using a fixed-bed
drying apparatus, a 200 kg per day fluidized-bed gasifier, and a swirl melting furnace. Moisture percentage was reduced from
50% to 20% roughly when MSW was dried by slightly superheated steam of 150°C–350°C within 40 min. When the temperature was
less than 250°C, no incondensable gas was produced during the drying process. The gasifier ran at 550°C–700°Cwith an air equivalence
ratio (ER) of 0.2–0.4. The temperature of the swirl melting furnace reached about 1240°C when the gasification ER was 0.3
and the total ER was 1.1. At these conditions, the fly ash concentration in the flue gas was 1.7 g·(Nm3)−1, which meant over 95% fly ash was trapped in the furnace and discharged as slag. 85% of Ni and Cr were bound in the slag,
as well as 60% of Cu. The mass and energy balance analysis indicates that the boiler heat efficiency of an industrial MSW
incineration plant reaches 86.97% when MSW is dried by steam of 200°C. The boiler heat efficiency is sensitive to three important
parameters, including the temperature of preheated MSW, the moisture percentage of dried MS Wand the fly ash percentage in
the total ash. 相似文献
287.
Yuheng Feng Xuguang Jiang Yong Chi Xiaodong Li Hongmei Zhu 《Frontiers of Environmental Science & Engineering in China》2011,5(2):186-192
In China, safe disposal of hazardous waste is more and more a necessity, urged by rapid economic development. The pyrolysis
and combustion characteristics of a residue from producing monopotassium phosphate (monopotassium phosphate residue), considered
as a hazardous waste, were studied using a thermogravimetric, coupled with Fourier transform infrared analyzer (TG-FTIR).
Both pyrolysis and combustion runs can be subdivided into three stages: drying, thermal decomposition, and final devolatilization.
The average weight loss rate during fast thermal decomposition stage in pyrolysis is higher than combustion. Acetic acid,
methane, pentane, (acetyl) cyclopropane, 2,4,6-trichlorophenol, CO, and CO2 were distinguished in the pyrolysis process, while CO2 was the dominant combustion product. 相似文献
288.
危险废物对生态环境和人类健康构成严重的危害。水泥窑协同处理危险废物能同时实现减量化、无害化以及资源化,是最有效的处理危险废物的方法。大连东泰产业废弃物处理有限公司利用水泥窑协同处理危险废物。实现废物处置与水泥生产的优化组合。 相似文献
289.