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。     

基于EEMD-LSTM模型的尾矿库风险预测模型研究

为了提高尾矿库风险预警能力,针对尾矿库稳定性受多种风险因素影响,以及风险变化的非线性,提出1种融合集合经验模态分解(EEMD)和长短期记忆(LSTM)的尾矿库风险预测模型。首先,采用皮尔逊相关系数分析尾矿库风险因素之间的相关性;然后,使用EEMD方法分解非线性的位移序列;最后,构建LSTM网络模型预测位移变化。以某尾矿库为例,将EEMD-LSTM模型与EEMD-BP模型、LSTM模型对比分析,评估模型的有效性。研究结果表明：EEMD-LSTM模型对尾矿库风险的预测精度明显提高,对防范化解尾矿库安全风险具有重要意义。     

大跨径钢管混凝土拱桥结构稳定与动力性能研究

为研究大跨径钢管混凝土拱桥结构稳定与动力性能,以某竖直双吊杆简支拱为工程背景,从拱桥吊杆设计形式和不同动力模型角度出发,研究系杆拱桥影响线特征以及不同列车激励下对桥跨结构的冲击系数。利用有限元软件ANSYS与UM(Universal Mechanism)动力学分析软件联合建模,进行仿真分析。结果表明：斜吊杆拱、网状吊杆拱刚度大、挠曲性能较好;3种吊杆设计中网状吊杆拱的稳定系数相对较大;车辆运行速度越快,对桥跨结构冲击系数越大;单节机车造成的冲击系数大于编组动车组,冲击系数随车质量的增大而减小。研究结果可为设计阶段桥型选择工作提供参考。     

典型固定燃烧源颗粒物成分谱特征研究

为了研究典型固定燃烧源颗粒物成分谱特征,于2013年在河北省应用固定源稀释采样系统采集燃煤电厂、燃煤锅炉、水泥窑及焦化厂炼焦炉等固定燃烧源排放的颗粒物(PM_(10)和PM_(2.5))样品。采样点设置在脱硫除尘器后,稀释比控制在20倍,采样流量为16.7L/min,采集3~4 h,每种颗粒物采集3个平行样品。应用ICP-MS、离子色谱仪和DRI碳质分析仪对PM_(10)和PM_(2.5)样品中的元素组分、水溶性离子及OC/EC组分质量分数进行了分析。结果表明,采用循环流化床锅炉的燃煤电厂排放的PM_(10)中主要组分为Al、Ca、SO_4~(2-)、OC,其质量分数分别为12.1%±5.3%、20.4%±7.3%、9.7%±3.1%、26.7%±8.2%,PM_(2.5)主要组分为Al(11.4%±4.7%)、Ca(17.9%±5.8%)、SO_4~(2-)(11.5%±2.8%)、OC(30.4%±10.8%);采用煤粉炉锅炉的燃煤电厂排放的PM_(10)中主要组分为Al、Ca、SO_4~(2-),其质量分数分别为18.9%±6.4%、12.8%±4.3%、6.2%±2.3%,PM_(2.5)主要组分为Al(9.5%±3.7%)、Ca(12.8%±5.5%)、SO_4~(2-)(10.8%±3.6%)。燃煤锅炉排放的颗粒物中主要组分为Na、Ca、Al、Fe、S、SO_4~(2-)、OC,水泥窑窑尾烟气颗粒物中Na、S、Ca、SO_4~(2-)、Mg~(2+)、OC质量分数较高,炼焦炉排放的颗粒物中主要组分为S、SO_4~(2-)、NH_4~+、OC。4类固定燃烧源PM_(10)和PM_(2.5)成分谱中各成分的相关系数均在0.9以上,但分歧系数分析结果表明PM_(10)和PM_(2.5)颗粒物成分谱差异性较大。     

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。     

Sediment analysis to support the recent glacial origin of DDT pollution in Lake Iseo (Northern Italy)

In the present study, a depth-related distribution of Persistent Organic Pollutants (POPs) in sediments of Lake Iseo, one of the major southern Alpine Italian lakes, is reported in order to further test the hypothesis of melting Alpine glaciers as a secondary source of contamination. In a previous paper, a “glacier contamination hypothesis” was suggested to explain the unexpected contamination of the biota of Lake Iseo, mainly fed by the Alpine melting ice.The sediment core analyses covered around the last 50 years. The organic matter profile evaluated as a Loss-On-Ignition percentage indicated transition of the basin from an oligotrophic to a mesotrophic status at around the early 1970s, but there was no evidence of the shift to eutrophy in the 1980s. Among DDTs, pp’DDE was the predominant metabolite, accounting on average for 79.4% of the total DDT concentrations and ranging from 6.4 to 447.5 ng g⁻¹ d.w. PCBs ranged from 5.0 to 163.7 ng g⁻¹ d.w. The maximum PCB concentrations were found in sediment layers corresponding to the 1970s when the highest production and use of these compounds occurred in Italy. In contrast, concentrations of DDTs showed a sharp increase from the early 1990s, long after their agricultural use was banned in Italy. This delayed pollution provides support for the hypothesis that the recent retreat of glaciers represents a secondary pollution source for old pesticides that were stored in the ice at the time of their use in agriculture.