新疆土地荒漠化灾害及其对策

新疆生态环境脆弱，土地荒漠化十分严重。在遥感、地理信息系统等技术支持下，研究新疆土地荒漠化的孕灾机理及过程，建立土地荒漠化灾害扔监测及预警系统，对于新疆生态环境建设具有重要意义。新疆的土地荒漠化有多种表现形式，土壤盐渍化、土壤风蚀、土地沙漠化等是重要的几种荒漠化类型。以位于塔里木盆地的塔里木河下游阿拉干地区为例，该区土地沙质荒漠化的面积百分率已由20世纪50年代末期的86．98％，上升到90年代后期的94．78％。受土地荒漠化的影响，与荒漠化相关的灾害主要发生在4个地理区域，干旱、大风、沙尘暴等自然灾害频繁发生，严重地影响到区域的生态安全。荒漠化及其灾害的综合治理是生态环境建设的重要方略。     

基于三生空间的山区村庄建设用地开发边界划定——以贵州省仁怀市五马镇为例

划定村庄建设用地开发边界有利于山区耕地、生态环境保护,也为山区村庄建设用地合理规划布局提供参考。选取贵州省仁怀市五马镇为研究区,运用层次分析法和GIS空间分析法进行生态敏感性综合评价,划定生态敏感区。将生态敏感区、永久基本农田、法定保护区、自然灾害易发区和非村庄建设用地作为限定因子,划出山区村庄建设用地开发边界。研究显示:划定的五马镇村庄建设用地开发边界内允许开发建设区面积为24. 41 km~2,占土地总面积的19. 03%,主要分布在五马镇中部河谷地带以及西北部地区。山区村庄建设用地开发受自然限制明显,划定的村庄建设用地开发边界内的允许开发建设面积较平原区偏小。     

GEE支持下的1988—2022年淮北市土地利用变化及其对生态系统服务价值的影响

淮北矿区是全国重要的煤炭生产基地之一，其在安徽省经济发展中占据重要地位，分析该区域土地利用变化对生态系统服务价值（ESV）的影响具有重要意义。本文以淮北市为研究区，基于谷歌地球引擎云平台和分类决策树算法，对研究区内1988—2022年的Landsat影像进行分类，得到7个时期的土地利用分类数据，进而分析该市土地利用变化情况及其对ESV的影响。研究结果表明：（1）1988—2022年淮北市建设用地面积不断扩张至初始的8倍，而林地和草地面积则不断递减，主要转为建设用地和耕地，且水体面积在波动中不断增加，主要与采煤沉陷有关；（2）林地和草地退缩以及建设用地扩张导致了研究区ESV总值不断减少，已减少50%，影响了ESV的空间分布；（3）ESV对耕地较敏感，且其他土地利用系数敏感性均小于1，说明在研究以耕地为主的淮北市时，应当对ESV当量因子进行针对性改进。本文结果为推进淮北矿区可持续发展和高效合理配置土地资源提供了技术支持和科学依据。     

中国北方农牧交错区沙质荒漠化灾害监测评价模型

沙质荒漠化灾害是我国北方农牧交错区最为严重的灾害之一。选择科尔沁和毛乌素两个典型的农牧交错带作为研究区，基于沙质荒漠化灾害背景(图象、图形和统计)GIS数据库，对沙质荒漠化灾害进行判别、预测及对灾情进行综合评估的建模研究，在此基础上，初步建立了我国沙质荒漠化灾害监测综合评价模型。运用该模型对上述两个试验区的沙质荒漠化灾害进行模拟与分析，结果表明：乌审旗、抗锦旗为沙质荒漠化极重度区，奈曼、库伦、开鲁为重度区，昌图县为中度区，通辽为轻度区，对沙质荒漠化影响大小依次为自然因素、经济因素和社会因素。沙质荒漠化灾害危险度评价的结果表明，在毛乌素地区的南部灾害严重，危险度为重度，西部程度较轻，为中度偏轻，东部与北部程度稍重，为中度偏重，但乌审旗的沙质荒漠化灾害程度被低估了，应为重度。     

沈阳市内五区开发强度时空演变及影响因素研究

以沈阳市内五区作为研究区域，通过构建开发强度模型，对2005—2020年开发强度时空演变规律及影响因素进行探究.结果表明：开发强度总体呈现先快速下降、后平稳发展的变化态势，2009年后受政策调控，开发趋于合理，地区间差异逐渐减小；开发强度表现出中心高四周低的空间格局，圈层式发展特征显著；开发强度空间集聚性明显，表现出中部热点集聚和边缘冷点集聚的“核心-边缘”特征；人均城乡用地面积、城市用地弹性增长系数以及地均GDP是影响开发强度的主要因素.     

矿业密集区地表热环境时空演变特征及驱动力分析

矿产资源是人类赖以生存的重要物质基础,矿业开采在促进地方经济、文化等快速发展的同时,会对区域地表热环境造成一定影响。在遥感和GIS技术的支持下,准确和快速地获取地表温度(Land Surface Temperature,LST)及矿业用地信息,结合迁安市矿业开发过程特点,借助“黄蓝—差值影像法”、叠加分析法和剖面分析法等方法,系统分析了2000―2018年间,迁安市矿业密集区马兰庄镇的地表热环境时空演变特征及驱动力。结果表明：贯穿典型矿业用地的4条温度剖面线的波谷(低温区)均位于绿地和水域,波峰(高温区)均位于矿区采场裸岩、未进行生态修复的排土场矿渣和尾矿库内尾砂。2000―2018年马兰庄镇的高温区面积占比从2000年的25.11%,上升到2008年的39.93%,再下降到2018年的28.71%；矿业用地占比从2000年的25.78%,上升到2008年的38.78%,再下降到2018年的27.94%；矿业用地和高温区变化趋势基本一致,并且矿业用地与高温区空间位置基本重合。研究结果将深化矿业密集区地表热环境时空演变特征规律的认识,为制定缓解高温聚集效应策略提供定量参考依据。     

闽台土地利用时空格局对比研究

以闽台为研究对象，对两地土地利用时空格局进行对比研究，结果表明：从空间格局上看，闽台土地利用类型齐全，闽台两地皆以林地为主，耕地次之，各地类面积和区域差异较大.福建的林地、未利用土地面积比重高于台湾，耕地、建设用地相反.福建林地比重由西向东，由北往南逐渐减少，台湾反之，福建耕地及建设用地比重由西向东、由北往南逐渐增加，而台湾则由东向西，由南北往中部依次上升;从时间变化上看，闽台耕地均以递减为主，闽台建设用地均以递增为主.     

矿业区域经济可持续发展初步研究--以陕西省黄陵县为例

目的 探讨黄土高原矿产资源富集、经济基础薄弱及生态环境脆弱的典型矿业区域矿产资源开发与区域经济持续增长的耦合关系。方法 依据实地调查资料和历年统计数据，运用区域开发的矿产资源需求生命周期理论和实证研究方法。结果 黄陵县是一个典型的矿业区域，县域矿产资源开发与经济增长均呈倒“U”字型结构，受国家政策、市场压力、产业结构调整等因素影响，现阶段县域经济正处于繁荣期向衰退期的转变阶段。结论 利用县域煤炭、旅游、农业等资源的综合优势，通过产业结构调整，培育和发展煤炭深加工、旅游业及苹果业等多元化、多层次的产业结构是促进黄陵县域经济持续协调发展的关键。     

浅析安徽省荒漠化土地的治理与开发

根据安徽省荒漠化监测和普查结果，从荒漠化地区的气候条件、土壤资源、治理成效等方面，分析了荒漠化治理开发的优势和有利条件，并结合荒漠化地区的实际情况，提出荒漠化治理开发的思路和策略以及与荒漠化治理开发相配套的组织、技术和管理等措施。     

基于GIS和RS的三明市荆东生态工业区土地开发生态适宜度和景观结构分析

土地开发生态适宜度分析是生态工业区规划的重要基础．基于GIS和RS技术，通过水土保持与地质安全、工程建设适宜度分析、建设用地适宜度、自然生态服务功能评价对三明市荆东生态工业区土地开发生态适宜度进行了综合分析．分析表明，现状土地自然禀赋条件较好的用地面积比例为34．95％，需经较大规模工程改造可用于城市建设用地的比例约49．3％；位于地质灾害潜在风险高易、中易发生区的不适宜进行建设用地面积约为15．6％．在土地开发适宜度分析的基础上，从景观生态学的角度，对不同的规划方案进行了比较分析．     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to