Characterization of humic substances of different origin by means of mass spectrometry and neural networks

Mass spectrometry fingerprinting of humic acids extracted from different soils has been carried out using laser desorption/ionization mass spectrometry (LDI-TOF MS). LDI-TOF MS provides characteristic mass spectra fingerprints for the humic acids of different origin. The information given in the fingerprints was evaluated for natural grouping trends in the samples by neural networks computing tools, such as self-organizing feature map (SOFM). This approach is efficient for recognizing patterns in the humic acids samples independently of their characteristic variability; variability characterizing natural products such as humic substances. The use of multi-layer perceptron artificial neural networks gave a successful classification of the samples.     

深圳市新一代暴雨强度公式的研制

首先构造了深圳市新一代暴雨强度公式研制的路线图，重点是利用深圳市气象局1954-2003年50年间的暴雨记录，用指数分布和P-Ⅲ分布进行分布曲线拟合和选优，得到了理论上的雨强-历时-重现期三联表，在此基础上再分别采用最优法、二分搜索法和广义逆法等3种方法求解分公式和总公式参数，根据误差最小的原则确定最优方法。结果表明：由指数分布拟合分布曲线，经过上述步骤求解得到的公式参数，误差最小，符合相关国标要求。     

Prediction of potential areas of species distributions based on presence-only data

We introduce a methodology to infer zones of high potential for the habitat of a species, useful for management of biodiversity, conservation, biogeography, ecology, or sustainable use. Inference is based on a set of sites where the presence of the species has been reported. Each site is associated with covariate values, measured on discrete scales. We compute the predictive probability that the species is present at each node of a regular grid. Possible spatial bias for sites of presence is accounted for. Since the resulting posterior distribution does not have a closed form, a Markov chain Monte Carlo (MCMC) algorithm is implemented. However, we also describe an approximation to the posterior distribution, which avoids MCMC. Relevant features of the approach are that specific notions of data acquisition such as sampling intensity and detectability are accounted for, and that available a priori information regarding areas of distribution of the species is incorporated in a clear-cut way. These concepts, arising in the presence-only context, are not addressed in alternative methods. We also consider an uncertainty map, which measures the variability for the predictive probability at each node on the grid. A simulation study is carried out to test and compare our approach with other standard methods. Two case studies are also presented.     

大气环境及腐蚀性

根据近年来国内外对大气环境和腐蚀性的研究成果．描述了大气环境及腐蚀性的研究状况．介绍了国际标准化组织的分类分级标准和我国大气环境的腐蚀性的分类分级的探讨性研究以及大气腐蚀图的研究。     

Development of fire risk visualization tool based on heat map

At present, relatively few tools are able to visualize regional fire risks both dynamically and efficiently. As a general method of density clustering and visualization, heat maps can be used to analyze the spatial distribution characteristics of fire risks. In this study, based on combining a transformed sigmoid function with a heat map method, a transformed sigmoid risk model (TSRM) was proposed. A numerical mapping method between fire risk values and colors was established based on an RGB color model. By using HTML 5 and JavaScript, a fire risk visualization tool (FRVT) was developed based on the TSRM. Baidu Map was used as the geographic information system engine for the FRVT by calling its JavaScript application program interface. To validate the TSRM and FRVT with case studies, 16,448 historical fires from 2013 to 2017 in Changsha, China, were gathered and visualized. The visualization results indicated that the high-risk areas were mainly distributed in urban areas, and that the medium-risk and low-risk areas were primarily distributed in rural areas. The FRVT can also be applied to visualize and analyze process-related fire risks from a regional perspective. In further research, it will be important to update the FRVT, e.g., to visualize the fire risks posed by the transportation of hazardous materials.     

基于地学信息图谱的合肥市城市扩展时空特征及驱动力分析

利用多时相遥感影像,借助ArcGIS平台,采用空间形态分析、等扇分析、等距分析及分形分析等方法,以城市扩展强度、紧凑度、分形维数、重心坐标、扩展弹性系数等为指标,基于地学信息图谱分析了1987~2011年合肥市城市扩展时空特征及其驱动力。结果表明：合肥市在经历了轴向放射状扩展、双核组团扩展及轴间填充后,城市形态由不规则团块状向星楔形、连体双星形转变;24 a间,城市用地面积增长了22415 km2,城市规模扩大了455倍;2000年以前基本保持中、低速扩展,进入21世纪后,开始高速扩展;城市空间主要沿交通线向西南、东南、东、东北等方向非均衡延展,城市扩展最强烈的区域约在距城区中心8 km处,城市重心不断向南偏西方向转移;扩展过程中,城市紧凑度呈“W”型波动,分形维数呈“M”型波动,扩展弹性系数呈“∧”型波动,城市形态最终向着稳定、合理化方向发展;自然环境、经济发展、人口增长、交通建设、政府行为等是合肥市城市扩展的主要驱动力量     

古堆泉域岩溶地下水水化学特征及成因

古堆泉为山西省著名岩溶大泉之一,是唯一的中低温温泉,具有悠久的开发观赏历史,凝聚着丰厚的人文积淀.以古堆泉域岩溶地下水为研究对象,通过系统地样品采集与同位素分析,综合运用水化学（Durov图、离子比例、Gibbs图和氢氧同位素）同位素方法分析地下水水化学特征和地下水系统径流特征.古堆泉域岩溶地下水的⁸⁷ Sr/⁸⁶ Sr值在0.709~0.717之间,Mg/（Mg+Ca）值在0.27~0.74之间.通过分析Sr同位素组成和Mg/（Mg+Ca）、1/Sr变化特征,得出古堆泉域岩溶地下水为深部热水与浅部冷水的混合水,中条山南梁泉岩溶水子系统呈现碳酸盐岩地层径流特征,佛岭山-高显海头泉岩溶水子系统和侯马盆地深循环子系统呈现碳酸盐岩地层与火成岩地层径流特征,塔儿山-九原山古堆泉岩溶水子系统呈现碳酸盐岩地层与古老硅铝质岩地层径流特征.通过2014年样品与2021年相同位置取样点的氢氧同位素比对分析,得出古堆泉口水样变化原因是其受三泉水库补给随时间的积累的结果,三泉水库的变化原因是受引黄水的影响.研究区岩溶地下水水化学类型可分为SO₄-Na、SO₄-Ca、HCO₃-Na、HCO₃-Mg、HCO₃-Ca和Cl-Na型.岩溶地下水水化学类型从HCO₃-Ca·Mg→HCO₃·SO₄-Ca·Mg→SO₄·HCO₃-Na·Ca→SO₄·Cl-Na·Ca呈现明显的水化学成分分带.     

Adding virtual measuring stations to a network for urban air pollution mapping

Maps of pollutants concentration are usually generated by means of interpolation and extrapolation methods. The quality of the results depends mainly of the number of permanent or temporary measuring stations. This paper deals with a method for the virtual densification of the network of stations. The method creates "virtual measuring stations". It aims at improving the quality of interpolation by increasing the number of data on pollutant concentration. The virtual stations are determined by the means of a classification method applied to each pixel of the area under concern. Discriminating elements are pollutants emission classes, land cover types, urban morphological indicators created to this purpose and distance to major roads. A first implementation was made for particulate matter (PM) for the city of Strasbourg (France) using thin-plates spline interpolation method in Arcview 9 GIS. The relative Root Mean Square Error decreases from 49% for five input stations down to 15% for the virtual stations.     

Loft features reveal the functioning of the young pigeon’s navigational system

It is thought that young homing pigeons are able to use information acquired en route for their initial homeward orientation. However, the cues involved and mechanisms utilised are under discussion. Blocking light-dependent route-specific information during the first leg of an outward journey detour, together with analysis of pigeons that were raised under different loft conditions, allowed us to correctly evaluate the functioning of this mechanism and, more generally, the navigational map of birds. Pigeons from the same stock were raised and kept in two different lofts. The birds in the experimental groups were transported to the release sites via detours, and light-dependent information was denied during the first half of the outward journey (no compass information was available). Control birds were transported by the most direct route and had access to all available information. In general, the results showed that the low-loft birds preferred to use magnetic compass cues, whereas the high-loft birds preferred to use navigational map cues to collect information of the first part of the outward journey. The impairments observed in the homing performances of the experimental groups highlight the reliability of information collected inside the map area. Relevant to an understanding of the route-reversal mechanism was the evidence that this mechanism is able to function in the absence of compass information (birds raised in a wind-exposed loft show a detour effect). In systems where directional information could be provided by multiple sources, processing and extracting accurate course trajectories through a common mechanism may prove more efficient and reliable.     

基于ArcGIS Server ADF的流域水环境专题图研究

专题地图是流域水环境信息的良好表达形式和信息载体,文章运用地理信息系统二次开发软件-ArcGIS Server ADF研究并实现水环境专题图展示功能。通过流域水环境信息专题地图可以表达水环境监测评价结果,能将水环境质量的空间规律直观显示,实现水环境质量评价信息的可视化,并表示其动态变化和发展趋势,揭示发展规律,以供有关专家、决策者获取各类重要信息,进行环保政策的研究分析和决策。