湟水上游农户对自然灾害的感知及响应

随着全球气候变暖,自然灾害发生的频率和强度也在日益加强,对农业生产造成了极大危害.湟水流域是青海省主要的农牧交错区,农业发展历史悠久,河谷地区是主要的农业生产区.本文选择湟水上游3个不同海拔高度的自然村对其农户进行了调查,通过对340份问卷进行分析发现:(1)冰雹、干旱、虫灾、低温冷害等四种灾害是湟水谷地上游农户感知到的近十年以来发生最频繁的自然灾害.虫灾是农户感知最为强烈的以往不常见的灾种.(2)在湟水上游,随着海拔的升高,农业生产受自然灾害的影响程度增大.(3)农户为了防灾而做出更换作物品种而做出的选择在空间上呈现出:距离城镇越近,不假思索直接采用的比例越高;距离城镇越远,在选择上表现出较为谨慎和保守.     

小波变换用于沙漠化土地景观格局的分析

用基于小波变换提供的新型噪声清除、多尺度边缘检测方法对位于内蒙古、辽宁、吉林三省(区)的科尔沁农牧交错区沙地景观空间格局遥感图象进行分析和研究,以掌握自然过程和人为活动的规律·实例表明,本文提供的自适应和多带多分辨小波变换方法得到了可行验证·据分析可知沙地农牧交错区的景观格局呈现出不规则的聚集度和不均匀性特征,这些特征是尺度效应的结果·这一结果为其它农牧交错区沙地的开发和利用活动提供了建设性的意见·     

东北农牧交错区景观空间格局

利用遥感与地理信息系统技术对我国东北农牧交错区景观格局与成因进行了系统研究.结果表明:(1)东北农牧交错区可划分为2个一级景观类型,9个二级景观类型和69个三级景观类型.一级景观中自然景观约占总面积的57.1%,人工景观约占42.9%.(2)本区是一个以农业为主的农、林、牧结合的交错区,农、林、牧比例大体为3∶2∶1.(3)在大尺度景观背景下,山地和低山丘陵景观均呈条带状连续分布格局,大体沿东北—西南向贯穿于整个景观中;沙地景观集中分布于中南部;高平原、平原自然植被景观、人工建筑景观和人工林景观面积均很小.(4)在中小尺度水平上,景观格局主要体现在三级景观类型的空间布局上,并在不同的区域表现出不同的分布特征.     

陕北城镇体系结构分形特征研究

以2012年陕北非农业人口和陕西省交通地图为主要数据,借助分形理论对陕北城镇体系等级规模、空间结构和空间集聚特征进行量化研究。结果表明:延安和榆林城镇等级规模较为集中,分布较为均衡,中间位序城镇较多;陕北城镇之间交通通达性较好,各城镇之间具备开展经济协作的基础设施条件,两市的城镇体系在空间上分布比较集中,城镇主要分布于沟谷河流沿线,形成城镇体系的主要发展轴线;陕北城镇体系的空间分布从中心向四周密度递减,城镇体系呈现集聚分布状态。     

1987-2010年和林格尔县农牧交错带土地利用与景观动态变化研究

以1987年和2010年和林格尔县农牧交错区土地覆盖数据为基础,借助土地利用转移矩阵和景观格局指数分析法,对近23年的时间内和林格尔县农牧交错区的土地覆盖类型和景观格局的变化趋势进行了定量分析,结果表明:(1)、经过近23年时间后,和林格尔县农牧交错带整体向东北方向移动,而且面积急剧减小;(2)、用Fragstats3.4计算得出和林格尔县农牧交错区景观破碎化程度有所改善、景观多样性呈下降趋势以及人类对当地土地的改造干扰程度增加.     

淮河上游地区城市与河流关系的时空演化研究

以淮河上游地区为研究范围,运用实地考察、历史文献和GIS技术,分析从秦代至今2200多年来城市与河流的关系,揭示城市与河流时空演化特征.结果表明:第一,城市选址多在河流沿岸或干支流交汇处;第二,历史上城市分布呈现从北往南发展,北部城市数量多,城市分布密度大,南部数量少,分布密度小;第三,秦至西汉时期城市数量增长速度快,东汉至魏晋时期城市稳定发展,至南北朝时期城市数量达到顶峰,之后一直到元代,城市数量整体处于下降趋势.明朝城市数量有所恢复,呈现出现代城市的分布形态.清代以后城市数量有所上升.     

NECT上农牧交错区耕地变化及其驱动力分析

从中国东北样带（ＮＥＣＴ）内的农牧交错区选择典型样点作为研究单元,经分析得出该区域属样带上近年来耕地变化最明显的区域;在此基础上,对可能影响耕地变化的自然气侯因素和人口、社会经济因素等分别进行相关分析,进而得出该区域近年来耕地变化的主要驱动力,初步结论为：人口是农牧交错区对耕地变化影响最大的驱动力,次之为经济发展,再次为技术水平。     

基于地理加权回归的江南市镇发展动力机制分析(1736-1949年)

为揭示18世纪中叶至20世纪中叶江南市镇分布演变的驱动力并展现其时空演变过程,分别以1736—1850年和1851—1949年的市镇数量为因变量,以其所对应的人口数量、人口密度、河流密度和海拔中位数为自变量,建立了江南市镇数量演变的时空模型(GWR模型);再将市镇核密度图和产业区图进行叠加,以观察产业因素对市镇发展的影响.研究结果表明:(1)1736—1850年,江南地区市镇分布存在空间集聚性;1851—1949年,集聚性有所降低. (2)江南人口增长较为稳定地驱动全局市镇数量增长. (3)1736—1850年,河流密度显著地驱动了江南东部地区的市镇增长. (4)1851—1949年, 江南东部部分地区河流密度与本地市镇数量增长之间转为负相关关系. (5)1851—1949年,环太湖地区及江南西北地区的河流密度显著地驱动市镇数量增长. (6)未能纳入GWR模型分析的区域中所出现的市镇数量爆发性增长现象与当地植棉业密切相关.     

黄河流域淘宝村的时空演化特征及空间组织类型演变

在大数据背景下,基于阿里研究院发布的淘宝村数据,运用网络关注度、空间分类法及核密度分析法等对2013-2019年黄河流域淘宝村进行时空演化特征及空间组织类型分析.研究发现:(1)从时间维度看,研究期内淘宝村的数量呈指数增长,表现出自上游到下游阶梯状递减的分布规律.(2)从网络关注度看,呈现"一个高值集聚区+两个低值集聚区"的分布态势,"一个高值集聚区"集中分布在郓城县、鄄城县和牡丹区,"两个低值集聚区"是以博兴县和惠民县为中心和以洛龙区为中心.(3)从产业类型看,按主营产品和服务类型及区位可分为七大类,即城市近郊农贸型、城镇边缘农贸型、独立发展的农贸型、城市近郊工贸型、城镇边缘工贸型、独立发展的工贸型和城市近郊纯贸易型.(4)从空间分布来看,2013、2015、2017和2019年4个时间断面上黄河流域淘宝村的空间格局具有由点状扩散到面域联动的演变态势;空间上呈现出"一核两翼"的分布态势,其中"一核"主要集中分布在博兴县、鄄城县和牡丹区且逐渐向四周递减,"两翼"指在东北部、西南部形成两个较低的集聚区.(5)从空间组织类型来看,主要为同类型扩散、衍生扩散和独立发展3种类型,其中同类型扩散多分布在下游地区,衍生扩散类型多分布在中、下游地区,独立发展型淘宝村多分布在上、中游地区.     

陕南地区农田生态系统碳源/汇时空差异

对陕南农田生态系统碳源/汇进行研究,结论如下:碳汇量快速提高,碳源量变化平稳,净碳量与碳汇表现一致;碳汇量、碳源量、净碳汇量、净碳密度的空间分布基本一致,汉江河谷地带最高,沿河谷向两边递减,大巴山高于秦岭山地;丹江河谷中间地段峡谷深切,是各指标低值区,低值区外围环形分布的系列盆地各指标值较高;综合考虑农作物优生条件和农业比较利益,河谷地带适合大面积种植水果、蔬菜、玉米、水稻,丘陵坡地可适当种植油菜和薯类;发展生态农业,减少化肥施用量可达到减源增汇效果。     

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…     

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。     

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

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.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.