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211.
在调研了上海化学工业生产工艺的基础上,结合将来上海化学的原料和产品,着重提出了一些清洁生产工艺的建议和规划。在异氰酸酯、甲基丙烯酸甲酯、叔丁胺、苯胺、亚氨基二乙酸、碳四、苯二酚等项目方面提出了相应的建议。 相似文献
212.
Frederick M. Fisher Kenneth L. Dickson John H. Rodgers Keith Anderson John Slocomb 《Journal of the American Water Resources Association》1988,24(5):1017-1026
ABSTRACT: A method to partition the variation in concentrations of water chemistry parameters in a river is described. The approach consists of fitting a family of curves for each chemical parameter. Each curve indicates the response of the parameter to river flow for a particular time period or location. An analysis of covariance is then used to identify statistically significant differences between curves. Such differences result largely from two factors: (1) the discharge of effluents and (2) river flow-concentration relationships. The deviations from the fitted curves indicate month-to-month variations unrelated to river flow that are controlled by factors such as temperature-related seasonal patterns. Underlying statistical assumptions are discussed with respect to water chemistry data. The technique is applied to a data set consisting of monthly samples of 22 water chemistry parameters from the Sulphur River of Texas and Arkansas. Several patterns of response to river flow and to two effluent discharges were revealed. 相似文献
213.
James V. Bonta 《Journal of the American Water Resources Association》2000,36(4):869-887
ABSTRACT: Prior to PL95–87 little research had been conducted to determine the impacts of mining and reclamation practices on sediment concentrations and yields on a watershed scale. Furthermore, it was unknown whether sediment yield and other variables would return to undisturbed levels after reclamation. Therefore, three small watersheds, with differing lithologies and soils, were monitored for runoff and suspended sediment concentrations during three phases of watershed disturbances: undisturbed watershed condition, mining and reclamation disturbances, and post‐reclaimed condition. Profound increases in suspended‐sediment concentrations, load rates, and yields due to mining and reclamation activities, and subsequent drastic decreases after reclamation were documented. Even with increases in runoff potential, reductions in suspended‐sediment concentrations and load rates to below or near undisturbed‐watershed levels is possible by using the mulch‐crimping technique and by removing diversions. Maximum concentrations and load rates occurred during times of active disturbances that exposed loose soil and spoil to high‐intensity rains. Sediment concentrations remained elevated compared with the undisturbed watershed when diversions were not well maintained and overtopped, and when they were not removed for final reclamation. Diversions are useful for vegetation establishment, but should be maintained until they are removed for final reclamation after good vegetative cover is established. 相似文献
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215.
Yuan Cheng Qinqin Yu Jiumeng Liu Youwen Sun Linlin Liang Zhenyu Du Guannan Geng Wanli Ma Hong Qi Qiang Zhang Kebin He 《Frontiers of Environmental Science & Engineering》2022,16(2):18
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218.
R. G. Clawson B. G. Lockaby R. B. Rummer 《Journal of the American Water Resources Association》1999,35(5):1081-1088
ABSTRACT: Floodplain forests directly influence water quality by serving as sinks, sources, or transformers of nutrients. Increases in the demand for timber raise the question of how silvicultural disturbance may affect this function. The objective of this research was to compare biogeochemical relationships between undisturbed vs. disturbed conditions in a floodplain forest. A randomized complete block design consisting of three blocks and two treatments (partial harvest and undisturbed) was installed on the Flint River floodplain, Georgia. The partial cut was conducted during September-October 1993. Automated water samplers were situated to sample during flood events as sheet flow entered and exited treatment plots during the 1994, 1995 and 1996 flood seasons. Prevs. post-contact comparisons indicated that the undisturbed floodplain has minimal influence on water chemistry at this scale of measurement. Although the partial harvest on an 8-ha scale had minimal effect upon sheetfiow water chemistry for three years following harvest, the data suggest that harvests may stimulate a minor increase in Ca and K sink activity. 相似文献
219.
介孔TiO2纤维的制备及其光催化性能 总被引:3,自引:1,他引:2
采用溶胶-凝胶和水蒸气活化热处理技术制备了介孔TiO2纤维,考察了各种因素对介孔TiO2纤维光催化活性的影响,并对介孔TiO2纤维结构进行了表征。介孔TiO2纤维的最佳制备条件:n(TBOT)∶n(C6H10O3)∶n(H2O)∶n(C3H8O)=1∶0.4∶2.0∶16,搅拌时间80min,Si与Ti的摩尔比为0.15,采用分段程序升温工艺,活化温度为700℃。所得介孔TiO2纤维比表面积为127.7m2/g,最可几孔径为7.3nm,具有极高的热稳定性及抗晶型转变能力,反应时间75min时活性艳红X-3B降解率为99.3%。 相似文献
220.