Uncertainty assessment for watershed water quality modeling: A Probabilistic Collocation Method based approach

Watershed water quality models are increasingly used in management. However, simulations by such complex models often involve significant uncertainty, especially those for non-conventional pollutants which are often poorly monitored. This study first proposed an integrated framework for watershed water quality modeling. Within this framework, Probabilistic Collocation Method (PCM) was then applied to a WARMF model of diazinon pollution to assess the modeling uncertainty. Based on PCM, a global sensitivity analysis method named PCM-VD (VD stands for variance decomposition) was also developed, which quantifies variance contribution of all uncertain parameters. The study results validated the applicability of PCM and PCM-VD to the WARMF model. The PCM-based approach is much more efficient, regarding computational time, than conventional Monte Carlo methods. It has also been demonstrated that analysis using the PCM-based approach could provide insights into data collection, model structure improvement and management practices. It was concluded that the PCM-based approach could play an important role in watershed water quality modeling, as an alternative to conventional Monte Carlo methods to account for parametric uncertainty and uncertainty propagation.     

新疆乌苏5.1级地震前波速比异常震例研究

利用天山中段数字化地震波资料,采用多台和达法,计算2006年11月23日新疆乌苏5.1级地震前后波速比的变化情况,得到如下结果:(1)在空间分布上,乌苏5.1级地震前,波速比形成一个近似椭圆形低值异常区,且椭圆长半轴约为70 km,短半轴约为55 km,椭圆走向NW,地震就发生在该椭圆区域的西北部边缘;(2)在时间进程...     

陆面蒸散量观测方法比较分析及其影响因素研究

陆面蒸散是陆面水分平衡的主要分量,也是地球系统水分消耗的主要途径,但陆面蒸散量测量技术一直没有得到很好地解决.利用LOPEX试验区内陇中黄土高原定西陆面过程综合观测站的历史观测资料,在参考对照蒸发皿观测的水面蒸发量的基础上,对蒸渗计法、涡动相关法、彭曼方法等3种方法观测的陆面蒸散量的年变化特征进行了比较分析,发现各观测...     

示波极谱法测量电锌液中微量镍

提出在丁二酮肟-亚硝酸钠-氨水-氯化铵体系中,准确测定电锌液中微量镍的新方法:克服原子吸收光谱法测定微量镍回收率偏低问题。     

开拓创新 解决问题——评戴伟华先生《文化生态与中国古代文学论丛》

戴伟华先生的《文化生态与中国古代文学论丛》在文化生态与文学关系的视野下探讨中国古代文学的生成、发展和表现形态,创新研究方法,再析经典名篇,归纳诗学现象,观点独到鲜明,取材精当,论证严密,是中国古代文学研究的又一创获。     

改革开放以来吉林省产业结构演进特征分析

运用产业结构演进评价指标和分析模型,定量研究了1978年以来吉林省产业结构演进的特征。研究表明:1978年以来,吉林省与全国的产业结构趋同严重,相似指数均在0.97以上;吉林省产值结构与就业结构不对称,就业结构与产业结构的总差距在缓慢增大;产业结构转换速度经历了先降后升的过程,近30年发展趋势表明吉林省的产业结构正处在向高级化演进的过程中,产业结构转换方向合理。2000年以来吉林省相对于全国的经济增长率有所提高,竞争力有所提升,但经济增长主要依靠第二产业的带动,产业结构仍需进一步调整优化。     

江苏南京定林寺斜塔纠偏及地基加固技术

通过江苏南京定林寺斜塔成功纠偏及地基加固工程,使原来的最大倾斜度7°59’纠偏至5°36’,纠偏角度为2°23’,仍保持了世界上现存第一斜塔的要求。该工程主要采用"塔式古建筑组合控制纠偏技术",为砖石古塔的加固纠偏及保护提供了新的思路。     

量热法在玻璃晶化动力学中的应用

通常以Ｊｏｈｎｓｏｎ—Ｍｅｈｌ—Ａｖｒａｍｉ（ＪＭＡ）方程为基础，采用等温及非等温量热法（ＤＳＣ和ＤＴＡ）研究相变动力学。结果表明，ＪＭＡ方程能很好地适用于等温法，但对非等温过程，则要满足一些条件，这常引起不同作者的争论。本文比较了七种利用量热技术研究玻璃的非等温晶化动力学的方法，分析了其理论依据及推导过程，讨论了它们的可靠性和适用范围。     

A parallel mesh-free contaminant transport model based on the Analytic Element and Streamline Methods

This paper introduces a new method for simulating large-scale subsurface contaminant transport that combines an Analytic Element Method (AEM) groundwater flow solution with a split-operator Streamline Method for modeling reactive transport. The key feature of the method is the manner in which the vertically integrated AEM flow solution is used to construct three-dimensional particle tracks that define the geometry of the Streamline Method. The inherently parallel nature of the algorithm supports the development of reactive transport models for spatial domains much larger than current grid-based methods. The applicability of the new approach is verified for cases with negligible transverse dispersion through comparisons to analytic solutions and existing numerical solutions, and parallel performance is demonstrated through a realistic test problem based on the regional-scale transport of agricultural contaminants from spatially distributed sources.     

深变质岩区遥感地质填图方法研究

通过深变质岩区遥感影像特征的分析研究,以影像群、影像组为基础,建立了变质岩影像岩石填图单位,进行了研究区变质表壳岩和变质深成岩的遥感地质解译,总结了变质岩区遥感地质填图的方法技术。该方法对1:25万区域地质调查中变质岩区填图具有重要的指导意义