基于HJ-1A卫星超光谱数据的太湖叶绿素a浓度及悬浮物浓度反演

通过对2010年5月2日太湖HJ-1A卫星超光谱影像的几何纠正和6S模型辐射校正,以及水体实测光谱数据和影像光谱数据分析,将太湖28个水体采样点光谱数据分别进行归一化处理和一阶微分处理后,选取和水质参数相关系数最大的波段或波段组合建立反演模型,获得太湖叶绿素a浓度以及悬浮物浓度的空间分布图.研究表明,超光谱影像B73波...     

A pattern-oriented modelling approach to simulating populations of grey partridge

A number of wildlife species including the grey partridge (Perdix perdix) have shown dramatic post-war population declines. Multiple drivers have been proposed as reasons for the declines, for example agrochemical use and intensification of agricultural practices, climate, predation, and changes in landscape structure. These drivers may interact in non-linear ways and are inherently spatio-temporal in nature. Therefore models used to investigate mechanisms should be spatio-temporal, of proper scale, and have a high degree of biological realism. Here we describe the development and testing of an agent-based model (ABM) of grey partridge using a well documented pre-decline historical data set in conjunction with a pattern-oriented modelling (POM) approach. Model development was an iterative process of defining performance criteria, testing model behaviour, and reformulating as necessary to emulate system properties whilst ensuring that internal mechanisms were biologically realistic. The model was documented using ODdox, a new protocol for describing large agent-based models. Parameter fitting in the model was achieved to within ±2% accuracy for 15 out of 17 field data patterns used, and within 5% for the remaining two. Tests of interactions between input parameters showed that 62% of parameter pairs tested had significant interactions underlining the complex nature of the model structure. Sensitivity analysis identified chick mortality as being the most sensitive factor, followed by adult losses to hunting and adult overwinter mortality, agreeing in general with previous partridge models. However, the ABM used here could separate individual drivers, providing a better understanding of the underlying mechanisms behind population regulation, and allowing factors to be compared directly. The ABM used is rich in output signals allowing detailed testing and refinement of the model. This approach is particularly suited to systems such as the partridge system where data for comparison to model outputs is readily available. Despite the accurate fit between historical data and model output, making use of the predictive power of the approach the model requires further calibration and testing under modern field conditions.     

中部地区承接国际产业转移效率及驱动机理研究——基于超效率DEA模型和面板回归分析

为研究我国中部6省近15a承接国际产业转移成效,探索提高承接国际产业转移水平路径,从投入产出角度构建了承接国际产业转移效率测度指标体系,采用EMS3.1软件测度了我国中部6省80个地级单元2000~2014年承接国际产业转移效率的时空分异特征,结合GeoDa095i软件分析了中部地区承接国际产业转移效率的时空分异格局及空间关联性;在分析影响承接国际产业转移效率机制的基础上,采用固定效应模型对我国中部6省承接国际产业转移效率的影响因素进行定量分析。结果表明:(1)2000~2014年间处于DEA有效的地市数量逐渐增加,处于波动上升的地市有52个,呈现下降趋势的有28个,省会城市及其周边地区DEA效率值相对高于其他地区;(2)中部地区承接国际产业转移效率空间分异显著,具有明显的空间群聚效应;(3)产业支撑因子、产业吸引因子、产业发展因子对中部地区承接国际产业转移效率影响较为显著,而产业鉴别因子影响相对较弱。影响因素回归系数由大到小分别为二、三产业从业人员比重、客运总量、职工平均工资、人均GDP、年末金融机构存款余额研究与试验发展(RD)经费支出。基于研究结果对中部地区承接国际产业转移提出了相应对策建议。     

徐州市电磁辐射环境的污染现状调查及评价

调查了徐州市电磁辐射污染源的状况,分析了其电磁辐射环境质量的现状,并对全市电磁辐射环境质量进行了评价,指出了分析工作中存在的问题,提出了防治对策。     

马斯京根模型参数估计的新方法

提出了马斯京投模型参数估计的一种新方法—加速遗传算法,分析了该算法控制参数的优化特性,总结出了这些参数的简便设置技术．应用实例表明,该方法简便、直观、通用、适应性强,它可广泛应用于各种自然灾害模型的优化问题之中。     

Lessons from the 2006 Louisiana health and population survey

The 2005 hurricane season caused extensive damage and induced a mass migration of approximately 1.1 million people from southern Louisiana in the United States. Current and accurate estimates of population size and demographics and an assessment of the critical needs for public services were required to guide recovery efforts. Since forecasts using pre-hurricane data may produce inaccurate estimates of the post-hurricane population, a household survey in 18 hurricane-affected parishes was conducted to provide timely and credible information on the size of these populations, their demographics and their condition. This paper describes the methods used, the challenges encountered, and the key factors for successful implementation. This post-disaster survey was unique because it identified the needs of the people in the affected parishes and quantified the number of people with these needs. Consequently, this survey established new population and health indicator baselines that otherwise would have not been available to guide the relief and recovery efforts in southern Louisiana.     

矩形喷嘴PM2.5惯性冲击采样器的研制

惯性冲击器是最重要的颗粒物采样器之一,被广泛用于大气颗粒物的分级采样。设计了一种中流量的矩形喷嘴PM2.5惯性冲击采样器。根据Marple准则设计了冲击器的结构参数,用CFX软件进行了惯性冲击器内部气固两相流场的CFD模拟,得出了惯性冲击器的最优结构参数。根据得出的最优设计参数,进行了PM2.5惯性冲击器样机的结构设计,并在实验室用APS气溶胶空气动力学粒度仪进行了标定。实验标定和CFD数值模拟的结果基本吻合,当采样流量为100L/min,冲击器的切割粒径dp50=2.55μm,切割锐度σg=1.4,满足设计要求。     

Data-directed modelling of Daphnia dynamics in a long-term micro-ecosystem experiment

The micro-ecosystem under consideration consists of three compartments forming a closed chain in which water circulates. Three trophic levels are represented in different compartments: autotrophs (algae, mainly Chlorella vulgaris), herbivores (Daphnia magna) and microbial decomposers. From a 20 years experiment with this system, data has been selected for this study. The dynamics of algae and Daphnia magna in only one of the compartments were modeled by different systems of differential and difference equations. We describe the successive steps in the process of model development, and the fitting of parameters using a Nelder-Mead simplex calibration method. Identification problems were overcome by taking values for physiological parameters in agreement with the literature. It turned out that a logistic type of model gives the best result for the structured Daphnia population because of the set up of the experiment: algae grow and reproduce in the upstream compartment. For this reason well-known plant–herbivore models did not comply with the data. The results of the parameter estimation procedure are discussed. The estimated grazing rate by Daphnia was smaller than expected. Possibly the Daphnia fed also on detritus and decomposing algae which were not measured.     

Towards automatic and robust adjustment of human behavioral parameters in a pedestrian stream model to measured data

People die or get injured at mass events when the crowd gets out of control. Urbanization and the increasing popularity of mass events, from soccer games to religious celebrations, enforce this trend. Thus, there is a strong need to better control crowd behavior. Here, simulation of pedestrian streams can be very helpful: Simulations allow a user to run through a number of scenarios in a critical situation and thereby to investigate adequate measures to improve security. In order to make realistic, reliable predictions, a model must be able to reproduce the data known from experiments quantitatively. Therefore, automatic and fast calibration methods are needed that can easily adapt model parameters to different scenarios. Also, the model must be robust. Small changes or measurement errors in the crucial input parameters must not lead to disproportionally large changes in the simulation outcome and thus potentially useless results. In this paper we present two methods to automatically calibrate pedestrian simulations to the socio-cultural parameters captured through measured fundamental diagrams. We then introduce a concept of robustness to compare the two methods. In particular, we propose a quantitative estimation of parameter quality and a method of parameter selection based on a criterion for robustness. We discuss the results of our test scenarios and, based on our experience, propose further steps.     

污水处理厂提标改造工程实例及运行效果分析

成都天府新区直管区某城市污水处理厂选用AAOA+MBR工艺进行提标改造,通过多点进水,调整回流比,改变碳源补充物质投加方式、投加量等技术改良和参数优化,使出水优质优于设计标准,为老城镇污水处理厂提标改造提供参考。