共查询到18条相似文献,搜索用时 109 毫秒
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基于空气质量数据不足及波动较大的情况,将灰色GM(1,1)模型与人工神经网络模型组合并改进,建立改进型灰色神经网络组合模型。利用天津市2001—2008年PM10、SO2和NO2年均值作为原始数据预测2009—2010年PM10、SO2和NO2的浓度以进行模型精度检验,最后利用该模型预测2011—2015年天津市空气质量状况。结果表明,与灰色GM(1,1)模型、传统灰色神经网络组合模型相比,所建立的改进型灰色神经网络组合模型相对模拟误差小,预测结果更为可靠,可以用于空气质量预测。 相似文献
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在对淮南市窑河洼区环境水文地质调研基础上,对拟建窑河洼电厂灰场及邻区的浅层地下水环境质量现状进行了模糊数学评价。基于地下水水质模型,以F^-作为模拟因子,对地下水F^-浓度变化进行了数值模拟,对其5a后的污染范围和程度进行了预测评价。结果表明,模型较为可靠、合理,灰场建成后对场区及邻区地下水环境质量的短期影响不大,这为电厂灰场选址决策及电厂灰场建设后,可能引起地下水污染的范围和程度预测提供了科学依据。 相似文献
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运用灰色系统理论对城市环境噪声分析与预测 总被引:2,自引:0,他引:2
利用灰色系统理论的灰色关联度分析法,对影响佛山市禅城区区域环境噪声的影响因子进行定量分析,结果表明,影响佛山市禅城区区域环境噪声的第一位因素是机动车辆密度;同时建立了城市区域环境噪声的灰色GM(1,1)预测模型,短期预测精度很高,未来5年禅城区区域环境噪声呈平稳下降趋势.为规划防治城市区域环境噪声提供科学依据. 相似文献
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影响环境质量变化的因素是“灰色”的.如何“白化”一个国家或地区的环境质量及影响因素,定量分析不同因素对环境质量的影响作用,这是环境经济学研究主要内容之一.Commoner把“环境压力”作为环境质量概念,定义为每年排入环境的污染物数量,以反映环境质量退化的程度.胡鞍钢在Commoner方程基础上提出了“环境变迁曲线”,其主要参数为每亿元国民收入能源消费量.本文试运用近来应用广泛的GM(1,1)模式的建模思想,建立了预测中国每亿元国民收入能源消费量之GM(1,1)包络预测模型. 相似文献
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本文简要介绍了系统动力学,分析了城市水污染控制系统的特点,然后以洛阳城市为例,建立了该城市排污控制子系统的SD模型。该模型以8个水平变量为核心,共选择了157个参、变量,其中待估参、变量的确定运用了历史统计、类比、选用规划值以及灰色系统GM(1,1)模型预测等手段。并对摸型做了有效性检验,其结果是令人满意的。在模型的实际应用中,选定了6个决策点和决策变量组作为决策变量,依此设计了6个策略。经对所有策略的运行结果分析,从中得出反映该系统最佳运行状态的策略5,该策略可作为决策者的供选方案。 相似文献
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Polychlorinated dibenzo-p-dioxins and dibenzofurans emissions from open burning of crop residues in China between 1997 and 2004 总被引:1,自引:0,他引:1
Annual emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from open burning of crop residues in each province of China mainland between 1997 and 2004 were estimated to be ranged from 1.38x10(3) to 1.52x10(3) g I-TEQ/yr, with the average of 1.50+/-0.08x10(3) g I-TEQ/yr, which contributed to approximately 10% approximately 20% of the total emissions in China. The PCDD/F emissions mainly occurred in the largest crop-producing provinces, especially in those of higher economic levels. The major sources of PCDD/F emissions from open burning in China were found to be cereal residues (i.e. rice, wheat, and corn), which accounted about 70% of the total emissions. Moreover, the first-order one-variable grey differential equation model (GM (1,1) model) for annual emissions of PCDD/Fs was established based on grey system theory. The GM (1,1) model was proved to be robust to predict the annual PCDD/F emissions from crop residue field burning in forthcoming years. 相似文献
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Xu Zhicun Liu Lianyi Wu Lifeng 《Environmental science and pollution research international》2021,28(13):15659-15672
Environmental Science and Pollution Research - Non-equigap GM(1,1) model with conformable fractional accumulation (CFNGM(1,1)) is proposed to analyze the relationship between energy consumption and... 相似文献
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Meng Xiangmei Wu Lifeng 《Environmental science and pollution research international》2021,28(23):29253-29264
Environmental Science and Pollution Research - Considering the shortage of per capita water resources in China, the paper established a fractional order accumulated grey prediction model (FGM(1,1))... 相似文献
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利用灰色系统理论的灰色关联度分析法,对影响佛山市禅城区区域环境噪声的影响因子进行定量分析,结果表明,影响佛山市禅城区区域环境噪声的第一位因素是机动车辆密度;同时建立了城市区域环境噪声的灰色GM(1,1)预测模型,短期预测精度很高,未来5年禅城区区域环境噪声呈平稳下降趋势.为规划防治城市区域环境噪声提供科学依据. 相似文献
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Harry J. White William H. Cole 《Journal of the Air & Waste Management Association (1995)》2013,63(3):239-245
This paper presents an evaluation of four gaussian (GM, HIWAY, AIRPOL-4, CALINE-2), and three numerical (DANARD, MROAD 2, ROADS) models with the tracer gas data collected in the General Motors experiment. Various statistical techniques are employed to quantify the predictive capability of each of the above models. In general, the three numerical models performed rather poorly compared to the gaussian models. For this data set, the model with the best performance in accurately predicting the measured concentrations was the GM model followed in order by AIRPOL-4, HIWAY, CALINE-2, DANARD, MR0AD2, and ROADS. Although the GM model provides by far a better simulation than any of the models tested here, it is skewed toward underprediction. As a screening tool for regulatory purposes, however, HIWAY model would be useful since this model has the highest percentage in the category of overprediction if the concentration data in the range of 50th percentile through 100th percentile are included in the analysis. The present version of the HIWAY model for stable and parallel wind-road conditions warrants modifications to improve its predictive capability. Current studies indicate that the modified HIWAY model can be used with greater confidence by the regulatory agencies. 相似文献
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Nathalie Colbach 《Environmental science and pollution research international》2009,16(3):348-360
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Lee SM Lee JW Park KR Hong EJ Jeung EB Kim MK Kang HY Choi IG 《Journal of environmental science and health. Part. B》2006,41(4):385-397
The white rot fungus Stereum hirsutum was used to degrade methoxychlor [2,2,2-trichloro-1,1-bis(4-methoxyphenyl)ethane] in culture and the degraded products were extensively determined. The estrogenic activity of the degraded products of methoxychlor was examined using cell proliferation and pS2 gene expression assays in MCF-7 cells. S. hirsutum showed high resistance to methoxychlor 100 ppm, and the mycelial growth was fully completed within 8 days of incubation at 30 degrees C. Methoxychlor in liquid culture medium was gradually converted into 2,2-dichloro-1,1-bis(4-methoxyphenyl)ethane, 2,2-dichloro-1,1-bis(4-methoxyphenyl)ethylene, 2-chloro-1,1-bis(4-methoxyphenyl) ethane, 2-chloro-1,1-bis(4-methoxyphenyl) ethylene, and 1,1-bis(4-methoxyphenyl)ethylene, indicating that methoxychlor is dominantly degraded by dechlorination and dehydrogenation. MCF-7 cells were demonstrated to proliferate actively at the 10-5 M concentration of methoxychlor. However, cell proliferation was significantly inhibited by the incubation with methoxychlor culture media containing S. hirsutum. In addition, the expression level of pS2 mRNA was increased at the concentration (10-5 M) of methoxychlor. The reductive effect of S. hirsutum for methoxychlor was clear but not significant as in the proliferation assay. 相似文献