国外棕地研究进展

"棕地"一词最早出现在英国的规划文献中,20世纪90年代初开始成为美国官方用语。近年,棕地问题已成为了一个十分严肃的城市发展问题,交织了经济、社会、发展与环境保护的矛盾。为了推动棕地领域内的研究,在整理与分析国外相关文献资料的基础上,针对国外在棕地的定义、基本特征、分类、治理和开发价值评估、环境风险与责任、政策与法律法规、利益相关者及其关系以及棕地的治理与开发对策等方面的研究成果进行了述评。     

Petrogenesis of the Yangchang Mo‐bearing granite in the Xilamulun metallogenic belt,NE China: geochemistry,zircon U–Pb ages and Sr–Nd–Pb isotopes

The Yangchang granite‐hosted Mo deposit is typical of the Xilamulun metallogenic belt, which is one of the important Mo–Pb–Zn–Ag producers in China. A combination of major and trace element, Sr, Nd and Pb isotope, and zircon U–Pb age data are reported for the Yangchang batholith to constrain its petrogenesis and Mo mineralization. Zircon LA‐ICPMS U–Pb dating yields mean ages of 138 ± 2 and 132 ± 2 Ma for monzogranite and granite porphyry, respectively. The monzogranites and granite porphyries are calc‐alkaline with K₂O/Na₂O ratios of 0.75–0.92 and 1.75–4.42, respectively. They are all enriched in large‐ion lithophile elements (LILEs) and depleted in high‐field‐strength elements (HFSEs) with negative Nb and Ta anomalies in primitive‐mantle‐normalized trace element diagrams. The monzogranites have relatively high Sr (380–499 ppm) and Y (14–18 ppm) concentrations, and the granite porphyries have lower Sr (31–71 ppm) and Y (5–11 ppm) concentrations than those of monzogranites. The monzogranites and granite porphyries have relatively low initial Sr isotope ratios of 0.704573–0.705627 and 0.704281, respectively, and similar ²⁰⁶Pb/²⁰⁴Pb ratios of 18.75–18.98 and 18.48–18.71, respectively. In contrast, the ε_Nd(t) value (−3.7) of granite porphyry is lower than those of monzogranites (−1.5 to −2.7) with Nd model ages of about 1.0 Ga. These geochemical features suggest that the monzogranite and granite porphyries were derived from juvenile crustal rocks related to subduction of the Paleo‐Pacific plate under east China. Copyright © 2013 John Wiley & Sons, Ltd.     

格尔木水井水氡测值异常与地震活动的关系

根据格尔木台观测井的水文地质条件、水氡观测存在的主要干扰因素和年动态变化特征等方面因素,对格尔木地震台水井的水氡观测出现的趋势、突变异常进行了分析。结果表明,格尔木水氡趋势变化与气温有关、水氡突降与流量变化有关,更重要的是存在与格尔木水文地质条件有关的信息,反映了岩石应力—应变、区域构造和地震活动的相关信息。     

基于投影寻踪学习网络算法的植物群落高分遥感分类研究

传统的植物群落调查方法主要是野外样地调查和抽样统计,其对于地形复杂的区域难以做到对数据的全面调查;将遥感技术应用于植物群落调查,可实现数据的全面获取,以及对植物群落的快速分类。在深圳市植物群落野外样地调查的基础上,本文应用高分辨率Pléiades影像,结合光谱、地形及纹理信息,采用投影寻踪学习网络的方法,实现了深圳市东部地区植物分类。在实验中,选取人工林和次生林中典型群落样本,将投影寻踪与学习网络算法结合应用于植被分类,通过分类结果与经典监督分类方法比较表明,该算法应用于植物群落分类是可行的;并且该算法分类精度高,更新速度快,能满足深圳市重点项目基本生态控制线专项调查的要求。     

地质课程在地理科学中的作用及影响

分别从地质课程在地理科学中的作用和影响2个方面进行分析,总结了地质课程在地理科学中的作用:它是学习其他地理学科的基础、有利于分析当地的产业结构、为经济发展提供保证.并从地质年代的研究、矿床的寻找、地质灾害的预防、旅游业的发展这几个方面分析了地质课程在地理科学中的影响.     

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An Electronic Chart Display and Information System

This article introduces the most advanced form of electronic chart display and information systems (ECDIS) which complies with the performance standards for ECDIS established by the International Maritime Organization (IMO) and International Hydrographic Organization (IHO). It also describes the key features and the important functions of ECDIS, which we developed. This system is different from the productions developed by C-map, Seven-cs, offshore, and others. It is more suitable for China Marine Safety Administration Bureau to manage the navigation marks real-time. Using this system charts were located and accessed rapidly, and displayed smoothly. This article also discusses in ECDIS application system how to dynamically access and desert charts data in a limited memory (limited computer memory and resource). We constructed a tridimensional structure to manage a large amount of charts data. Vertically, according to the scale range, all charts were divided into eight levels, and a data structure called as “Multiple Scale Quad-tree” was constructed. And horizontally, a grid (every unit has a fixed size) was given to a certain scale level. We call this data structure a “Regular Page.” We explore the implementation of such a structure on the worldwide charts management utilizing quad-trees. Then we discuss the future development of ECDIS and its application system in marine agencies in China.     

有限样本类别城市高光谱数据SVM分类应用分析

对比分析线性核函数和非线性核函数支持向量机算法在样本类别不足情况下城市高光谱影像分类中的应用。选用张掖地区高光谱影像作为试验区,依据高分影像和地面调研信息获取参考样本数据,利用非线性核函数和线性核函数的支持向量机进行影像分类,获取每一类别的分类后验概率图,对分类后验概率图采用0.2,0.4,0.6,0.8,0.9的后验概率截断,分析不同截断概率下的地物分类精度变化情况,结果表明：线性核函数和非线性核函数SVM方法的结论相似,随着截断概率的增加,分类结果中用户精度提高或保持稳定,制图精度下降或保持稳定,总体分类精度先提高后降低,但波动幅度不大。所以,SVM的后验概率可以用于指导类别不足时城市高光谱影像的分类。通过分析各类地物的混淆矩阵,可知,非线性核函数的SVM方法比线性核函数SVM方法更敏感,在低后验概率下就可以准确提取出未分类信息,而线性核函数SVM在高后验概率下才能提取出未分类信息,而且还混入了许多训练过的类别信息。所以,非线性核函数SVM方法的分类精度更稳定,利用后验概率提取未分类信息的可信度更高。     

Photochemical activity and characterization of the complex of humic acids with iron(III)

This study examined the effects of humic acids (HA) and Fe(III)–HA complex on the photodegradation of atrazine, one of the most widely used herbicides. It was shown that the photolysis of atrazine proceeded via first-order reaction kinetics and that atrazine photodegradation was inhibited by the presence of HA, whereas the rate for atrazine photolysis was promoted in solutions containing both HA and Fe(III). Interactions of Fe(III) with HA were characterized by SEM, EDX, UV–Vis and FTIR, revealing that Fe(III)–HA complex was formed by ligand exchange between oxygen groups of HA and Fe(III). Using fluorescence spectrometry the stability constant (K_c) and the fraction of fluorophores available for complexation (f) were obtained as log K_c = 4.28 and f = 74%. Photoformed Fe(II) by ligand-to-metal charge-transfer (LMCT) within the Fe(III)–HA complex was the most important factor involved in photolysis of atrazine, since Fe(II) was the reactant to generate hydroxyl radical. Thus, the rate of atrazine photodegradation in natural sunlit waters is dependent on both the amount of iron present and the interaction between HA and iron.