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701.
702.
抗生素药生产废水处理工艺改进研究 总被引:1,自引:0,他引:1
企业抗生素废水经原有工艺处理后污染物指标偏高,且不稳定。工艺通过采用增加初沉池和二沉池、污泥回用等改进措施,COD、氨氮等排放浓度下降且稳定排放,改进效果明显。 相似文献
703.
根据2004—2009年大气中SO2污染物的监测数据,通过灰色GM(1,1)模型预测了未来6年秦皇岛市大气中SO2的变化趋势。结果显示,灰色系统GM(1,1)模型合理,精度较高,相对误差为-1.875%~1.228%,与环保部门公布的数据吻合程度较好。 相似文献
704.
Bin He Taikan Oki Fubao Sun Daisuke Komori Shinjiro Kanae Yi Wang Hyungjun Kim Dai Yamazaki 《Journal of environmental management》2011
Artificial Neural Network (ANN) is a flexible and popular tool for predicting the non-linear behavior in the environmental system. Here, the feed-forward ANN model was used to investigate the relationship among the land use, fertilizer, and hydrometerological conditions in 59 river basins over Japan and then applied to estimate the monthly river total nitrogen concentration (TNC). It was shown by the sensitivity analysis, that precipitation, temperature, river discharge, forest area and urban area have high relationships with TNC. The ANN structure having eight inputs and one hidden layer with seven nodes gives the best estimate of TNC. The 1:1 scatter plots of predicted versus measured TNC were closely aligned and provided coefficients of errors of 0.98 and 0.93 for ANNs calibration and validation, respectively. From the results obtained, the ANN model gave satisfactory predictions of stream TNC and appears to be a useful tool for prediction of TNC in Japanese streams. It indicates that the ANN model was able to provide accurate estimates of nitrogen concentration in streams. Its application to such environmental data will encourage further studies on prediction of stream TNC in ungauged rivers and provide a useful tool for water resource and environment managers to obtain a quick preliminary assessment of TNC variations. 相似文献
705.
The explosion and deflagration-to-detonation transition (DDT) in epoxy propane (E.P.) vapor/air mixture clouds under weak ignition conditions has been studied in an experimental tube of diameter 199 mm and length 29.6 m. E.P. vapor clouds were formed by injecting liquid E.P. into the experimental tube and evaporating of the fine E.P. droplets. The dimension and the evaporating process of the E.P. droplet were measured and analyzed. The E.P. vapor/air mixture clouds were ignited by an electric spark with an ignition energy of 40 J. The characteristics and the stages of the DDT process in the E.P. vapor/air mixtures have been studied and analyzed. A self-sustained detonation wave formed, as was evident from the existence of a transverse wave and a cellular structure. Moreover, a retonation wave formed during the DDT process in the E.P. vapor/air mixture. The influence of the E.P. vapor concentration on the DDT process has been studied. The minimum E.P. vapor concentration for the occurrence of the DDT in the E.P. vapor/air mixture has been evaluated and the variation of DDT distance with E.P. vapor concentration has been analyzed. 相似文献
706.
707.
贵州省境内乌江干流水质现状分析 总被引:1,自引:0,他引:1
根据贵州省环境监测部门资料显示乌江已成为贵州省水污染程度最为严重的流域,突出的问题是总磷、氟化物超标。本文用最小二乘法模型和t检验方法对贵州省境内乌江干流2006—2013年水质状况进行分析,结果表明乌江干流总磷、氨氮、氟化物,高锰盐指数浓度变化趋式为"无趋势",乌江干流水质稳定,并提出流域污染防治的对策和建议。 相似文献
708.
东三旗台Sacks体应变干扰分析与震例研究 总被引:4,自引:0,他引:4
本文对北京市昌平区东三旗台Sacks体应变观测值与固体潮、气压、水位、降雨关系进行了初步分析。通过干扰因素分析,为提高地震预报的准确性提供了参考依据。同时,进行了有关震例研究,希望通过总结震例,为今后利用Sacks体应变观测探索地震预报实践建立科学的分析处理方法。 相似文献
709.
Alkylphenols (APs), the breakdown products of alkylphenol polyethoxylates that are widely used as surfactants, have been proven to exert estrogenic effects. With industrial development, higher concentrations of APs are discharged into aquatic environments. Nonylphenol (NP), the most noxious AP, is included in the blacklist of several countries. The toxicity of NP to the alga Cyclotella caspia and the biodegradation of NP by C. caspia were studied in the laboratory. The median effective concentration at 96 hr (96 hr EC50 ) of NP for C. caspia was found to be 0.18 mg/L. Five toxicity and three degradation indices were selected for toxicity and biodegradation experiments, respectively, in five or three concentrations of NP set by the 96 hr EC50 of NP. The algal growth rate and chlorophyll a contents decreased as NP concentration increased. The main manifestations of morphological deformity of the cells included volume expansion and the presence of cytoplasmic inclusions (lipid droplets). The abnormality rate of the cells increased with NP concentration and time, and was 100% at 0.22 and 0.26 mg/L of NP after 192 hr of culture. Superoxide dismutase activity initially increased and then declined at a higher NP toxicity of greater than 0.18 mg/L. After 192 hr of culture, the biodegradation rates of NP by C. caspia with initial concentrations of 0.14, 0.18, and 0.22 mg/L were 37.7%, 31.7%, and 6.5%, respectively. The kinetic equation of C. caspia biodegradation on NP was correlated with algal growth rate and initial NP concentration. 相似文献
710.
根据指标构建的科学性、系统性等原则,构建了城市群经济与环境协调发展指标体系,利用因子分析法测算出经济与环境综合发展水平,在此基础上,建立了经济与环境协调发展评价模型,并以秦唐沧城市群为例进行了实证分析。结果表明:2002年-2011年间秦皇岛经济与环境协调发展度高于唐山和沧州,协调发展类型由初步协调向良好协调转变;唐山经济与环境协调发展度呈波浪式上升,由中度失调向中等协调转变;沧州经济与环境协调发展度处于末位,由中度失调向中等协调转变。 相似文献