New method in synthesis of nano uranyl(VI) Schiff base complexes: Characterization and electrochemical studies

This study presents a new method in synthesis of nano uranyl Schiff base complexes. In this method slow addition of dilute uranyl(VI) acetate solution to dilute Schiff base solution following the reflux for about 24 h, yields nano uranyl(VI) Schiff base complexes. Characterization of Schiff base ligands and nano uranyl complexes has been done using ¹H NMR, IR, UV–vis spectroscopy, elemental analysis. Schiff base ligands were synthesized by the condensation of one mole 3,4-diaminobenzophenone and two moles salicylaldehyde or substituted salicylaldehyde (3-OMe, 4-OMe, 5-OMe, 5-Br, 5-Cl). The electrochemical properties of the uranyl(IV) complexes were investigated by cyclic voltammetry. A good correlation was observed between the oxidation potentials and the electron withdrawing character of the substituents on the Schiff base ligands, according to the following trend: 5-MeO < H < 5-Br ≈ 5-Cl. Also the effect of the position of the substituted groups of Schiff base on the anodic potentials is as follows: 5-OMe < 3-OMe < 4-OMe.     

广西壮族自治区城镇污泥特性与处置方向

通过对广西壮族自治区13个地级市的城镇污水处理厂污泥进行实地采样和测定,分析了污泥中的有机质、氮、磷、钾、重金属等含量及其热值水平。结果表明,广西地区的城镇污泥中养分(有机质、氮、磷、钾)含量较高,符合农用泥质、园林绿化用泥质和林地用泥质标准;对于污泥中的重金属含量,除个别城市污泥中的Zn含量超标外,其他均无超标现象;另外,污泥热值水平较低,尚不具备开展焚烧处置的泥质条件。从目前来看,无害化处理后进行土地利用是比较适合广西地区城镇污泥的处置技术路线。     

基于TIN的露天矿区地形精细模型构建研究

准确构建露天矿区三维地形模型，客观反映露天矿在开采过程中的地形动态变化特征，对于提高露天矿生产管理效率和信息化水平具有重要意义。根据露天矿地形特点，提出了以凸壳算法为基础的建模方法。该方法中，以空间特征为约束条件构建三维地形精细模型。以三维地形精细模型为基准，针对地理信息软件ArcGIS中三维体积计算的局限性，提出了一种土方量计算的改进算法。以宝日希勒露天矿为例，结合矿区地形碎部点测绘数据，进行了三维地形精细模型构建。研究表明：该建模方法提升了三维地形模型的构建效率，同时以边为着眼点对三维地形模型进行优化，提高了模型的几何精度。通过对比分析不同时期露天矿三维地形模型的体积变化和形状变化情况，可为露天矿开采动态量化评估提供可靠依据。     

Conservation controls in Melbourne

Controls to protect the historic environment have developed relatively late in Australian cities. The earliest and subsequently most comprehensive evolved in the state of Victoria, especially in the inner suburbs of the state capital, Melbourne. These controls have two basic forms; specific site registration and protection and broader planning control. While the controls have developed amidst some criticism and opposition, they appear currently to be well accepted and to be making a positive impact.     

Spatial prediction of landslide susceptibility using data mining-based kernel logistic regression,naive Bayes and RBFNetwork models for the Long County area (China)

The main goal of this study is to assess and compare three advanced machine learning techniques, namely, kernel logistic regression (KLR), naïve Bayes (NB), and radial basis function network (RBFNetwork) models for landslide susceptibility modeling in Long County, China. First, a total of 171 landslide locations were identified within the study area using historical reports, aerial photographs, and extensive field surveys. All the landslides were randomly separated into two parts with a ratio of 70/30 for training and validation purposes. Second, 12 landslide conditioning factors were prepared for landslide susceptibility modeling, including slope aspect, slope angle, plan curvature, profile curvature, elevation, distance to faults, distance to rivers, distance to roads, lithology, NDVI (normalized difference vegetation index), land use, and rainfall. Third, the correlations between the conditioning factors and the occurrence of landslides were analyzed using normalized frequency ratios. A multicollinearity analysis of the landslide conditioning factors was carried out using tolerances and variance inflation factor (VIF) methods. Feature selection was performed using the chi-squared statistic with a 10-fold cross-validation technique to assess the predictive capabilities of the landslide conditioning factors. Then, the landslide conditioning factors with null predictive ability were excluded in order to optimize the landslide models. Finally, the trained KLR, NB, and RBFNetwork models were used to construct landslide susceptibility maps. The receiver operating characteristics (ROC) curve, the area under the curve (AUC), and several statistical measures, such as accuracy (ACC), F-measure, mean absolute error (MAE), and root mean squared error (RMSE), were used for the assessment, validation, and comparison of the resulting models in order to choose the best model in this study. The validation results show that all three models exhibit reasonably good performance, and the KLR model exhibits the most stable and best performance. The KLR model, which has a success rate of 0.847 and a prediction rate of 0.749, is a promising technique for landslide susceptibility mapping. Given the outcomes of the study, all three models could be used efficiently for landslide susceptibility analysis.

     

跨流域调水的大尺度分布式水文模型研究与应用

变化环境下区域分布式水循环模拟研究,是地球系统科学中的重大科学问题,也是区域水安全和水资源风险管理需求的重要应用基础。本文开展了以南水北调中线工程联系的跨汉江、黄河和海河多个流域的区域水循环模拟、环境变化影响与水安全研究。重点论述了跨流域调水的大尺度分布式水文模型(LDTVGM)的研究与展望。目的是探讨变化环境下跨流域调水的分布式水循环模型的建立,发展区域水循环动力学-非线性系统-多源不确定性分析与综合的理论与影响评估方法,为分析应对气候变化和高强度人类活动影响的区域水资源安全及应对措施的风险管理,提供科学依据。     

Contribution of vortex Rossby wave to spiral rainband formation in tropical cyclones

The contribution of the vortex Rossby wave （VRW） to framework of a barotropic non-divergent TC-like vortex model. the spiral rainband in the tropical cyclones （TCs） is studied in the The spectral function expanding method is used to analyze the disturbance evolution of a defined basic state vortex. The results show that the numerical solution of the model is a superposition of the continuous spectrum component （non-normal modes） and the discrete spectrum component （normal modes）. Only the eyewall and the rainbands in the inner core-region in a TC are related to the VRW normal modes, whereas the continuous spectrum wave components play an important role in the formation of secondary-, principal-, and distant- rainbands, especially the outer rainband, through an indirect way. The continuous spectrum can promote the development of the TC circulation for the occurrence of a mesoscale instability. The convection under a favorable moisture condition will trigger the inertial-gravitational wave to cause the formation of unstable spiral bandliked-disturbances outside of the eyewall. The complicated interaction between the basic state-vortex and the VRW disturbances will cause a positive feedback between the TC circulation and the rainband.     

State-sponsored and spontaneous urbanization in Fujian province of China, 1982–2010

This paper examines unbalanced urbanization process in Fujian province from 1982 to 2010 from the perspective of dual-track urbanization. The analysis is mainly based on 67 county-level units. The spontaneous track of urbanization is a new process of urbanization in China emerged in the reform period. It plays an important role in linking urban and rural areas but also creates problems of rural-urban integration and social cohesion. This paper examines the relative roles of spontaneous and state-sponsored urbanization and their impacts on the spatial pattern and structure of urbanization in Fujian. It is found that rural to urban migration plays the most significant role while state-sponsored urbanization and rural urbanization play equal roles in the process of urbanization. There was a significant shift of state-sponsored urbanization from county-level cities and counties to urban areas of central cities, Fuzhou and Xiamen, and from inland area to coastal area after 1990. There have also been significant shift and growth of temporary population towards the central cities in the reform period. The shift from small towns to large urban areas is clear in both tracks of urbanization.     

Spatial Pattern of Chinese Tourism Development and Its Mechanism Based on Different Spatial-temporal Scales:Taking the Panel Data of China Mainland(1996-2010) for Example

By taking the panel data of China mainland from 1996 to 2010 for an example, this paper used ESDA, gravity center and standard deviation ellipse to analyze the spatial differences, combined with the impulse response function to propose the infl uence mechanism of spatial evolution. The results showed that the provincial tourism economy generally showed a random spatial distribution and the spatial differences had narrowed from 1996 to 2010. The differences of tourism development in east China are the largest, and differences of the middle China are the smallest. The gravity center of Chinese provincial tourism has shifted to the northwest, the HH district concentrated in the Yangtze River Delta and its surroundings, the LL district concentrated in west Chinese. The high-value areas of city tourism economy are broadly distributed in the right of line "Heihe–Tengchong", mainly concentrated in four plates. Compared with spatial differences of provincial tourism economy, those of city tourism economy were more signifi cant. Regional tourism resources and social economic factors are the two major factors that infl uence spatial differences of tourism economy, the objective rule and policy and institution also have a great impact on regional tourism development differences. Special events may have a certain impact on the pattern of the original; however, it cannot change the spatial pattern completely.