Study of statistically correcting model CMAQ-MOS for forecasting regional air quality

Based on analysis of the air pollution observational data at 8 observation sites in Beijing including outer suburbs during the period from September 2004 to March 2005, this paper reveals synchronal and in-phase characteristics in the spatial and temporal variation of air pollutants on a city-proper scale at deferent sites; describes seasonal differences of the pollutant emission influence between the heating and non-heating periods, also significantly local differences of the pollutant emission influence between the urban district and outer suburbs, i.e. the spatial and temporal distribution of air pollutant is closely related with that of the pollutant emission intensity. This study shows that due to complexity of the spatial and temporal distribution of pollution emission sources, the new generation Community Multi-scale Air Quality (CMAQ) model developed by the EPA of USA produced forecasts, as other models did, with a systematic error of significantly lower than observations, albeit the model has better capability than previous models had in predicting the spatial distribution and variation tendency of multi-sort pollutants. The reason might be that the CMAQ adopts average amount of pollutant emission inventory, so that the model is difficult to objectively and finely describe the distribution and variation of pollution emission sources intensity on different spatial and temporal scales in the areas, in which the pollution is to be forecast. In order to correct the systematic prediction error resulting from the average pollutant emission inventory in CMAQ, this study proposes a new way of combining dynamics and statistics and establishes a statistically correcting model CMAQ-MOS for forecasts of regional air quality by utilizing the relationship of CMAQ outputs with corresponding observations, and tests the forecast capability. The investigation of experiments presents that CMAQ-MOS reduces the systematic errors of CMAQ because of the uncertainty of pollution emission inventory and improves the forecast level of air quality. Also this work employed a way of combining point and area forecasting, i.e. taking the products of CMAQ for a center site to forecast air pollution for other sites in vicinity with the scheme of model products "reanalysis" and average over the "area".     

基于SHAP值机器学习的江西暖季暴雨预报因子重要性分析

机器学习模型（Machine Learning,ML）的不可解释性给其在气象业务中的应用带来了挑战。模型解释和可视化是解决这一问题的有效途径。文中将SHAP值应用于天气预报ML模型解释,研究了江西省暖季暴雨模型的预报因子对预报结果的影响。分别选取2016—2020年、2021—2022年4—9月ECWMF（European Centre for Medium-Range Weather Forecasts）高分辨率数值模式物理量及国家站降水观测数据进行XGBoost 建模与模型解释。结果表明,全局重要性排名前4位依次是总降水（重要性42.70%）、850 hPa比湿（重要性11.17%）、925 hPa相对湿度（重要性10.44%）、500 hPa相对湿度（重要性 9.16%）。个例分析表明,命中个例中高重要性物理因子在暴雨区的 SHAP 值较大,漏报（空报）个例在漏报（空报）区域高重要性物理因子的SHAP值偏小（偏大）。SHAP值从全局和局部可定量给出ML模型有物理意义的解释,解释结果与天气学原理和业务经验较一致,有利于ML在气象业务中的深入应用。     

信阳市燃气混气站断裂活动性和场地稳定性系统研究

运用多学科、多手段相结合的方法，从区域构造稳定性、构造岩研究、构造裂隙统计分析、红外相位法位移监测，高密度电阻率法、钻探验证、年代学研究、新构造运动分析、遥感图像解译、地震安全性评价、数值模拟、工程地质条件分析等方面入手，对信阳市燃气混气站的断裂活动性和场地稳定性进行了全面而系统的论证；指出场区断裂规模小，第四纪无大规模差异升降运动，无活动断裂通过，邻区地震活动小且弱，区域构造稳定性高，应力平缓，工程地质条件良好，是一个稳定的“岛区”，井指出系统而全面的综合研究方法是研究工程稳定性项目行之有效的手段。     

吉林夹皮沟金矿稳定同位素地质及找矿方向

吉林夹皮沟金矿床成因,多年来一直存在变质热液和岩浆热液之争。在金矿带北侧海西期花岗岩内和南侧白山镇一带变质岩地区进行外围找矿始终没有突破性进展。在前人研究基础上,通过一些补测工作对夹皮沟金矿稳定同位素地质给予新的认识。Ｓ和Ｃ、Ｈ、Ｏ流体主要来自地幔,部分Ｓ和Ｓｉ、Ｐｂ、Ａｕ主要来自花岗岩和古老变质层状岩系,成矿远景区应重点选定在夹皮沟—大砬子深大断裂两侧中生代脉岩体附近。     

有色示踪剂模拟槽实验图像分析法

图像分析法是处理有色示踪剂模拟槽实验结果的常用方法之一。本文以食用亮蓝为示踪剂,从污染物的检测精度和污染羽描绘的准确度两个方面将图像分析法与传统取样法进行对比,并利用Matlab编程对模拟槽内的污染物贮存质量进行定量计算。结果表明,与传统取样法结果相比：图像分析法的检测精度可提高1个数量级;污染羽的描绘准确度至少可提高3%左右,在实验所设置的非均质条件下可提高17%左右。利用自行编制的Matlab程序对本实验模拟槽内贮存亮蓝质量进行计算可得,当剖分格数为3 700²（1 369万）时,亮蓝贮存质量的计算值最接近实测值,最小误差仅为0.5%。综合来讲,图像分析法是一种准确度高、空间分辨率高的信息采集和处理手段,可实现对非均质地层中有色示踪剂运移过程更为精细的描述。     

三元复合驱采出污水回注渗透率的影响因素分析

基于大庆油田三元复合驱采出污水回注对地层存在的损害现象,研究了污水回注渗透率的影响因素。采用室内水驱实验方法,对三元复合驱采出污水中悬浮物、油、碱、聚合物等因素进行了分析,阐述了各种成分对渗透率的影响机理。结果表明,悬浮物颗粒会堵塞孔隙喉道,油产生的“贾敏效应”将增大油水流动阻力,碱与岩石及黏土矿物问的物理化学作用会使地层结垢,聚合物在岩芯中的吸附和滞留共同造成地层渗透率的下降。因此,建议将三元复合驱采出污水中悬浮物、油、碱、聚合物等处理合格后再进行回注,以减轻对地层的损害。     

资阳地区震旦系古岩溶储层特征及测井评价

位于四川盆地的资阳地区在震旦系灯影组中发现了继威远震旦系气藏之后的又一大型气藏。区内７口钻井揭露的地层显示本区灯影组主要由一套震层状白云岩民,基质岩块具低孔低渗特点,有效的储集空间是由受古岩溶作用产生的溶蚀孔洞和构造作用产徨的裂缝共同构成,溶洞具有数量多,大洞多,发育集中的特点,裂缝具有成因,多期次,多产状的特点,对这套以缝洞型为玉的储层,由常规测井资料计算单一的物性参数（如孔隙度等）的方法难以其     

西藏南木林普洛岗岩体锆石定年和Hf同位素特征及其地质意义

对冈底斯中段南木林县普洛岗乡花岗岩岩体进行了原位锆石LA-ICP-MS U-Pb定年和Hf同位素分析。2个花岗岩样品加权平均年龄分别为(44.3±1.1)和(44.5±1.1) Ma,代表该岩体的岩浆结晶年龄为始新世。岩石地球化学资料显示,花岗岩SiO₂质量分数为60.53％~65.28%,K₂O+Na₂O质量分数为6.53％~7.98%,Al₂O₃质量分数为15.52％~16.13%,铝饱和指数为0.86~0.91,属于准铝质高钾钙碱性系列花岗岩类。花岗岩轻稀土元素相对较富集,具有明显的Eu负异常,微量元素中亏损Nb、Ta、Ti和富集Rb、Th、U、Pb。锆石Hf同位素初始比值ε_Hf(t)值为8.8~11.1,¹⁷⁶Hf/¹⁷⁷Hf 为0.282 994~0.283 060,Hf同位素地壳模式年龄为422~557 Ma,反映了其岩浆来源于新生地壳物质的部分熔融。普洛岗乡花岗岩的形成与新特提斯洋向北俯冲、俯冲板片折返断离有关。     

The effects of soil sand contents on characteristics of humic acids along soil profiles

It is generally accepted that the compositions and properties of soil organic matter (SOM) are influenced by many factors. In order to reveal the effects of soil texture on characteristics and dynamics of SOM and its sub-fraction, humic acid (HA), along two soil profiles, a yellow soil profile and a purplish soil profile, under the same climate and vegetation conditions were determined. Results indicate that the decomposition and humification degrees of SOM and HA of the purplish soils are higher than those of the corresponding yellow soils indicated by A/O–A ratios of HAs, TOCs and HA yields of bulk soil samples, nevertheless, the development degree of the purplish soil is lower than that of the yellow soil. The variations of E₄/E₆ ratios of HAs along the soil profiles indicate the overall molecular sizes of HAs decreased downward along the soil profiles. A/O–A ratios of HAs decreased downward along both the soil profiles indicate that humification processes decrease downward along both the soil profiles. Leaching of SOM shows significant effects on the distribution and characteristics of HAs in the yellow soil profile but the purplish soil profile, which is consistent with the higher hydrophobicity of HAs in purplish soils, shows that the distribution characteristics of SOM along the soil profiles are a complex result of the combination of soil texture and characteristics of SOM itself. The remarkably different sand contents are concluded tentatively as one of reasons to the different distributions and dynamics of HAs along the soil profiles, however, to profoundly understand the evolution and transport of SOM along soil profiles needs more researches.     

Pretreatment of high strength waste emulsions by combined vibratory shear enhanced process with Fenton oxidation

Pretreatment of waste emulsions with high organic content by a combined process of vibratory shear enhanced process and Fenton’s oxidation prior to biological treatment was investigated. Vibrating membrane had shown good performance in chemical oxygen demand and oil removals and the mitigation of concentration polarization. However, the permeate after filtration processing still contained high content of organics. Thus, additional Fenton oxidation was applied to reduce the organic loading, and improve the biodegradability of the wastewater. The optimal molar ratio of ferrous iron to hydrogen peroxide was 0.05 obtained from the jar-test experiments. Removal of organics was enhanced by increasing hydrogen peroxide dosage, while efficiency of hydrogen peroxide reached maximum of 1.11(w/w) at the hydrogen peroxide dosage of 6.8 g/L. Furthermore, the biological experiments indicated that the high concentration of organics could inhibit microbial activity, which decreased the chemical oxygen demand degradation rates. The adaptive period of the microbe was greatly shortened using Fenton’s reagent at the low dosages. The improvement of the biodegradability could be explained by partial mineralization and chemical transformation of parent organic compounds after Fenton oxidation.