基于新空气质量标准的全国大气环境承载力评价

随着中国环境问题特别是大气环境问题的凸显,环境承载能力研究成为国内各界关注的热点。采用大气污染物年均质量浓度与新的空气质量标准比较的方法即超标倍数法,对全国330个地级城市进行大气环境承载力评价。评价结果表明,有70%的城市大气环境超载,大气环境承载形势严峻。超载最严重地区为京津冀及周边区域,长三角地区、中部大部分地区。PM2.5为大多数重点城市超载的首要污染物。通过对比大气环境承载指数与污染物排放总量、污染排放强度、人口、第二产业、地形、气象等因素的相关关系发现,不同地区主要影响因素不同,应该采取分区域、季节等差别化手段控制污染物排放,提高环境承载能力。     

考虑水温变化的变降解系数在北京市北运河水质模拟中的应用

综合降解系数是水质模拟预测、水环境容量计算中的关键参数之一,并且受温度影响较大。首先基于北京市北运河代表站2010年逐日水温资料,根据描述氨氮降解系数与温度之间数量关系的经验公式,得到随水温变化的动态降解系数以及年均水温对应的恒定降解系数,并采用模型试错法进行修正。然后基于MIKE11模型,模拟了采用变降解系数和恒定降解系数2种情景下北运河榆林庄断面氨氮浓度的变化。结果表明:2种情景均能较好地模拟氨氮浓度的年变化趋势,但采用变降解系数下大多月份模拟得到的月均质量浓度相对实测值误差较小,尤其是4—12月各月平均质量浓度模拟误差控制在15%以内,全年日均质量浓度模拟误差不足4%,模型表现更为稳定。     

采用微电极测定溶解氧有效扩散系数的研究

生物载体内部溶解氧的传质是影响载体同步硝化反硝化性能的重要因素.介绍了一种以溶解氧微电极为测试工具,获得球形生物载体内部溶解氧扩散系数的方法.采用自制的溶解氧微电极检测沿载体半径方向上的溶解氧分布,结合扩散-反应方程拟合获得载体内部的溶解氧有效扩散系数.结果表明,在载体填充率为25%的情况下,连续流球形载体反应器可实现同步硝化反硝化,对有机物的去除负荷达到5.6 kg/(m³·d).沿载体半径方向里层1/2区域范围内溶解氧消耗为零,载体内能够形成明显的缺氧/厌氧区.溶解氧分布曲线的拟合结果表明,载体内部溶解氧有效扩散系数为0.017?2　m²/d,传质过程以紊动传质为主.     

Multi-metric evaluation of the models WARM,CropSyst, and WOFOST for rice

WARM (Water Accounting Rice Model) simulates paddy rice (Oryza sativa L.), based on temperature-driven development and radiation-driven crop growth. It also simulates: biomass partitioning, floodwater effect on temperature, spikelet sterility, floodwater and chemicals management, and soil hydrology. Biomass estimates from WARM were evaluated and compared with the ones from two generic crop models (CropSyst, WOFOST). The test-area was the Po Valley (Italy). Data collected at six sites from 1989 to 2004 from rice crops grown under flooded and non-limiting conditions were split into a calibration (to estimate some model parameters) and a validation set. For model evaluation, a fuzzy-logic based multiple-metrics indicator (MQI) was used: 0 (best) ≤ MQI ≤ 1 (worst). WARM estimates compared well with the actual data (mean MQI = 0.037 against 0.167 and 0.173 with CropSyst and WOFOST, respectively). On an average, the three models performed similarly for individual validation metrics such as modelling efficiency (EF > 0.90) and correlation coefficient (R > 0.98). WARM performed best in a weighed measure of the Akaike Information Criterion: (worst) 0<wk<1$0<w_k<1$ (best), considering estimation accuracy and number of parameters required to achieve it (mean wk=0.983$w_k=0.983$ against 0.007 and ∼0.000 with CropSyst and WOFOST, respectively). WARM results were sensitive to 30% of the model parameters (ratio being lower with both CropSyst, <10%, and WOFOST, <20%), but appeared the easiest model to use because of the lowest number of crop parameters required (10 against 15 and 34 with CropSyst and WOFOST, respectively). This study provides a concrete example of the possibilities offered using a range of assessment metrics to evaluate model estimates, predictive capabilities, and complexity.     

重点环保城市二氧化硫扩散特性的研究

根据高、中、低架源排放污染物与地面环境质量的关系和《全国污染物排放申报登记》数据分析得出的每年各环保重点城市由高、中、低烟囱排放的二氧化硫,以及由1996年度《全国环境质量报告书》中给出的二氧化硫年均浓度,得出每个城市的年平均扩散系数。依据各城市的年平均扩散系数计算结果,将各城市划为不利于污染物扩散、较不利于污染物扩散、较利于污染物扩散和利于污染物扩散的4种类型,本方法在制订二氧化硫排放总量控制方案时,具有指导意义。      

确定二氧化硫总量控制目标方法的研究

分析了城市二氧化硫地面浓度来源,提出了高、中、低架源对地面浓度贡献的理论,由城市污染源排放结构导出该城市的年平均扩散系数,确定城市二氧化硫地面环境质量控制目标,从而可以得出各城市二氧化硫总量控制目标值      

氯代芳香化合物的KOW与对数拓扑指数和路径指数的相关性

本文用１ｇＫｏｗ表征氯代芳香化合物的生物降解能力,并分别以对数拓扑指数（ＬＴＩ）和路径指数（ＰＩ）为自变量,建立了新的预测模型。结果表明,回归方程的预测值与实验值十分吻合,相关系数接近于１,平均标准偏差小于０．１。     

回采工作面安全性灰色评价模型分辨系数p对评价结果的影响分析

阐述了对回采工作面安全性进行客观而准确评价的重要性。灰色关联理论应用于安全评价过程中 ,就其分辨系数 p选择所存在的问题进行了理论分析 ,并用实例验证了分辨系数对评价结果的影响 ,得出了分辨系数 p必须大于 0 .4的结论。这对灰色关联理论在安全评价中的应用研究 ,具有一定的参考价值。     

中国高新技术产业的地理格局与地理集中

与传统产业相比,高新技术产业对地理集中具有更加强烈的内在要求,这导致其地理格局与传统产业具有明显的差别。在产业集中指数等相关理论方法和实证分析的基础上,力图从地理学视角,结合高新技术产业的时间序列数据和2008年断面数据,从整体产业和分行业研究了高新技术产业地理格局和地理集中的现状和变动趋势。研究发现,我国高新技术产业高度集中在沿海省区和陕、川两省,省区间差距悬殊;高新技术产业产值份额同经济发展显著相关。时间序列分析表明：长时间尺度产业集中持续增强,近年来趋于稳定;地理格局逐渐清晰,核心省区凸显。不同行业由于产业性质、发展基础、资源需求和市场群体的差异,有其各自的集中态势和演变趋势。     

The use of hard- and soft-modelling to predict radiostrontium solid-liquid distribution coefficients in soils

The solid-liquid distribution coefficient (K_d) is the parameter that governs the incorporation of contaminants in soils. Its estimation allows the prediction of the fate of contaminants in the short- and long-term after a contamination event. Here, the K_d of radiostrontium (K_d(Sr)), a radionuclide of significant environmental interest, was predicted by hard models, which are based on knowledge of the mechanisms governing its sorption, and by soft models based on Partial Least Squares (PLS), using a large data set with the main soil parameters. The two approaches were tested and compared for 30 soils in Spain. Correlations between the predicted and experimental values of K_d(Sr) obtained using hard- and soft-modelling showed slopes close to 1 and regression coefficients higher than 0.95, which confirms that both approaches are able to obtain satisfactory estimates for K_d(Sr) from soil parameters.