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941.
《The Journal of geography》2012,111(1):12-17
Abstract Geographic information systems (GIS) are computer-based tools for geographic data analysis and spatial visualization. They have become one of the information and communications technologies for education at all levels. This article reviews the current status of GIS in schools, analyzes the requirements of a GIS-based learning environment from constructivist perspectives, and discusses the major issues in the design of a constructivist GIS-based learning environment based on experience from the development of World Explorer, a GIS-based learning environment that provides a theme-oriented data and information base, supports multiple representations and multiple linkages of information, and facilitates interactive learning and knowledge construction. 相似文献
942.
《The Journal of geography》2012,111(6):301-303
Abstract Teaching geography within a field-based, environmental-problem-solving framework integrates geographic knowledge and practice and introduces high school students to skills required to undertake geographic research. A five-day field investigation on coastal geography was designed for juniors at a science high school in New Jersey. The goal of the field investigation was to allow students to engage in problem-solving, gather field data, apply geographic concepts and tools, and foster the ability to think critically. The purpose of the investigation was to identify the spatial distribution of litter on a beach and interpret the distribution based on physical and human processes. The field site is a 400-m-long shoreline reach in Raritan Bay, New Jersey. Students defined the term “litter” for purposes of the investigation, developed a classification system, and mapped the location and type of litter on the beach. Three sampling grids were established across the beach from the dune crest to the waterline. Students conducted topographic surveys of the sampling grids, collected litter in each grid cell, and counted, classified, and weighed the litter. Data gathered were reduced, analyzed, and interpreted based on the published literature. Findings were presented at a formal presentation on the last day of the investigation. Students submitted a written report and presented the results of the investigation at a student conference two months later. Field investigations can expose students to different methods of data sampling and measurement. Collaboration between secondary schools and universities can result in successful learning initiatives that allow students the opportunity to experience the role of a practicing professional. 相似文献
943.
《The Journal of geography》2012,111(5):214-228
This study aims to provide an understanding of the main obstacles to conducting GIS-based projects in secondary schools and to determine the effects of these projects on students, teachers, and schools. The study was conducted in three public high schools in Turkey. The students first surveyed over 4,015 people in their school districts to understand the main social, environ- mental, and economic problems in their area, then conducted nine different GIS-based projects to help design solutions to these problems. As seen in the study, GIS is a very important teaching and learning tool for secondary schools; however, its effective use depends on planning, motivation, support, resources, time, and enthusiasm, especially for teachers. 相似文献
944.
945.
S.L.Shvartsev 《地学前缘》2009,16(6):257
自从地球上有水出现,就持续存在水-岩体系的平衡-不平衡。这一体系内部是不协调的,这就决定了它在地质历史的长河中自发地连续发展的可能性,并导致完全新的矿物相和水的不同地球化学类型的生成。在地壳中这一体系持续在一个热力学分支的线性域中,远离平衡而发育。它积聚太阳能,形成非生物成因耗散结构。它在连续发育惯性中起特殊作用,然后发育为一种生命物质。前进自组织将向该体系倾斜的趋向,定义为无机物质发育的基础之一。还有其他的一组体系都从这个体系中继承了它大多数的性质。水-岩体系的演化导致了次生矿物相和水的地球化学新类型的形成。随着演化程度加深,体系在成分上、结构上逐渐变得复杂,形成新的地球化学介质,它们又反过来控制新矿物相的生成从而对自身的性质产生影响。这一过程在地质历史上是永恒的。这便是矿物界自组织的要点,即包括发生、生长及新结构形体的时-空弥散以及矿物、地球化学介质的形成,最后是新的有机物质和生命的起源。 相似文献
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947.
948.
Throughfall and stemflow vary seasonally in different land‐use types in a lower montane tropical region of Panama
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Catriona M.O. Macinnis‐Ng Eric E. Flores Henry Müller Luitgard Schwendenmann 《水文研究》2014,28(4):2174-2184
Catchment hydrology is influenced by land‐use change through alteration of rainfall partitioning processes. We compared rainfall partitioning (throughfall, stemflow and interception) and soil water content in three land‐use types (primary forest, secondary forest and agriculture) in the Santa Fe region of Panama. Seasonal patterns were typified by larger volumes of throughfall and stemflow in the wet season, and the size of precipitation events was the main driver of variation in rainfall redistribution. Land‐use‐related differences in rainfall partitioning were difficult to identify due to the high variability of throughfall. However, annual throughfall in agricultural sites made up a larger proportion of gross precipitation than throughfall in forest sites (94 ± 1, 83 ± 6 and 81 ± 1% for agriculture, primary and secondary forests, respectively). Proportional throughfall (% of gross precipitation becoming throughfall) was consistent throughout the year for primary forest, but for secondary forest, it was larger in the dry season than the wet season. Furthermore, proportional stemflow in the dry season was larger in secondary forest than primary forest. Stemflow, measured only in primary and secondary forests, ranged between 0.9 and 3.2% of gross precipitation. Relative soil moisture content in agricultural plots was generally elevated during the first half of the dry season in comparison to primary and secondary forests. Because throughfall is elevated in agricultural plots, we suggest careful management of the spatial distribution and spread of this land‐use type to mitigate potential negative impacts in the form of floods and high erosion rates in the catchment. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
949.
利用50余口井的储层实验资料,对苏北盆地主力勘探地区海安凹陷和高邮凹陷泰州组砂岩储层进行孔隙类型和有利储层评价。综合研究表明:海安凹陷和高邮凹陷泰州组发育三角洲、浊积扇、扇三角洲等成因类型砂体,这些砂体由成分和结构成熟度较低的长石岩屑砂岩和岩屑长石砂岩组成,并且砂岩储层发育次生孔隙,原生孔隙较少;海安凹陷泰州组储层第一个次生孔隙发育段为2 300~2 500m,系大量碳酸盐胶结物、长石和岩屑颗粒遭受强烈溶蚀而成,孔隙度为12%~25%,第二个次生孔隙发育段为2 600~3 200m;高邮凹陷泰州组储层孔隙演化与海安凹陷有一定差异,其只存在1个次生孔隙发育段(2 400~2 900m),孔隙发育程度与海安凹陷的第一个次生孔隙带相似;泰州组砂岩储层中次生孔隙的形成主要与沉积物中有机质演化产生的有机酸、酚以及碳酸有关;大部分次生孔隙是由粒间碳酸盐胶结物溶蚀产生;海安凹陷有利储层主要分布在西北部和东部三角洲前缘砂体和滑塌浊积扇砂体中,高邮凹陷有利储层主要分布在南部扇三角洲前缘砂体中,储层埋藏浅、物性好,均以Ⅰ和Ⅱ类储层为主,是有利的勘探地区。 相似文献
950.
塔里木盆地奥陶系烃源岩二次生烃研究 总被引:1,自引:0,他引:1
为研究海相烃源岩二次生烃规律和塔里木盆地生排烃规律,以塔里木盆地奥陶系烃源岩为研究对象,首先通过构造-热演化史和生烃史研究得出,塔里木盆地典型构造单元奥陶系烃源岩具有二次生烃的特征,并且起始成熟度和生烃期次不同.然后选取自然条件下演化至不同起始成熟度的奥陶系海相烃源岩,采用热压模拟实验方法系统研究其二次生烃规律.研究表... 相似文献