转型期测绘复合创新、知识服务型人才培养模式创新与质量保障     

柯福阳  赵显富  丁海勇  孙景领  祝善友  缪启龙 《测绘通报》2019,(4):138-142

审视分析当前测绘工程专业人才培养存在的问题，以"测绘4.0"与智能测绘对测绘人才的新要求为导向，南京信息工程大学遥感与测绘工程学院结合实际情况，依托优势特色，在培养方案制定、课程体系构建、教学手段和模式、评价方式、工程实训等人才培养方面进行一系列的创新与实践，构建了闭环的人才培养质量保证体系，人才培养成效和社会声誉显著，为测绘高校复合创新、知识服务型高级人才的培养提供了重要参考。  相似文献   

Paleoenvironmental implications of two relative indicator rodent taxa during the Pleistocene to Holocene transition in south‐eastern Washington state,USA          下载免费PDF全文

R. LEE LYMAN 《第四纪科学杂志》2014,29(7):691-697

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International wood trade and forest change: A global analysis     

Thomas Kastner  Karl-Heinz ErbSanderine Nonhebel 《Global Environmental Change》2011,21(3):947-956

Throughout history, humans have transformed natural forests into agricultural land, settlement areas and managed forests. Studies on the dynamics of forest change are one of the mainstays in land change science. The forest transition theory offers a powerful tool to analyze changes in human interference with forests. At the national level, a range of factors have been found to influence a country's forest change. The role of international wood product trade has, however, rarely been studied based on empirical data. We offer a global assessment of how this trade helps shape observed forest change, by relating forest stock change to net trade of wood products for the period 1997-2007 and by localizing the origin of wood consumed in a given nation. For many nations, traded wood products have a relevant impact on the course of ongoing forest transitions. We develop a general typology of how wood product trade can influence forest change and place various nations within this framework. We find that many wealthy nations with returning forests seem to accelerate this return by importing wood products. These imports appear to be provided by two main types of wood exporters: (a) by wealthy countries with low population densities and stable forests and (b) by relatively poor countries with declining forests, employing increasing population and welfare levels. We discuss these findings in the light of general theories on land use transitions and forest change and conclude by highlighting implications for national forest policies and global environmental governance, aiming at reducing negative impacts of wood products and enhancing the positive role they can play in replacing more fossil fuel intensive products.  相似文献   

The Campanian Ignimbrite (Y5) tephra at Crvena Stijena Rockshelter, Montenegro     

Mike W. Morley  Jamie C. Woodward 《Quaternary Research》2011,75(3):683-696

Clearly defined distal tephras are rare in rockshelter sediment records. Crvena Stijena, a Palaeolithic site in Montenegro, contains one of the longest (> 20 m) rockshelter sediment records in Europe with deposits ranging in age from Middle Pleistocene to mid-Holocene. A distinctive tephra is clearly exposed within the well stratified record approximately 6.5 m below the present land surface. We present geochemical data to confirm that this tephra is a distal equivalent of the Campanian Ignimbrite deposits and a product of the largest Late Pleistocene eruption in Europe. Originating in the Campanian volcanic province of southwest Italy, this tephra has been independently dated to 39.3 ka. It is a highly significant chronostratigraphic marker for southern Europe. Macrostratigraphic and microstratigraphic observations, allied with detailed particle size data, show that the tephra layer is in a primary depositional context and was transported into the rockshelter by aeolian processes. This site is unique because the tephra forms an abrupt boundary between the Middle and Upper Palaeolithic records. Before they can be used as chronostratigraphic markers in rockshelter and cave-mouth environments, it is essential to establish the stratigraphic integrity of distal tephras and the mechanisms and pathways involved in their transport and deposition.  相似文献   

A new approach for phase transitions in miscible multi-phase flow in porous media   总被引：1，自引：0，他引：1  

A. Lauser  C. Hager 《Advances in water resources》2011,34(8):957-966

The tightly coupled, strongly nonlinear nature of non-isothermal multi-phase flow in porous media poses a tough challenge for numerical simulation. This trait is even more pronounced, if miscibility is also considered. A primary reason why inclusion of miscibility tends to be problematic are the difficulties stemming from phase transitions: on the one hand, phase transitions need to be included since the presence or absence of fluid phases has a major impact on the flow behavior; on the other hand, convergence of the nonlinear solver may be severely affected if they are not handled robustly.In this work, we present a mathematically sound approach to include phase transitions in the nonlinear system of equations: first, the transition conditions are formulated as a set of local inequality constraints, which are then directly integrated into the nonlinear solver using a nonlinear complementarity function. Under this scheme, Newton-Raphson solvers exhibit considerably more robust convergence behaviour compared to some previous approaches, which is then illustrated by several numerical examples.  相似文献   

岩浆到热液演化的包裹体记录——以骑田岭花岗岩体为例   总被引：3，自引：2，他引：1  

单强  廖思平  卢焕章  李建康  杨武斌  罗勇 《岩石学报》2011,27(5):1511-1520

骑田岭花岗岩是燕山期花岗岩早期多阶段侵入复式岩体,岩石化学的研究表明它是富碱的、高分异的A型花岗岩,形成于板内拉张的构造环境。在其第二阶段中细粒黑云母花岗岩内广泛发育着厘米级至米级似伟晶岩囊状体和石英晶洞, 它们是富挥发份岩浆固结的产物,代表岩石形成过程经历了明显的岩浆-热液过渡阶段。包裹体显微岩相学研究在骑田岭黑云母花岗岩的石英中发现熔体-流体包裹体和流体包裹体共存,这一结果进一步证实骑田岭中细粒黑云母花岗岩中的似伟晶岩囊状体和石英晶洞是花岗质熔体在岩浆-热液过渡阶段的产物。显微测温结果显示,熔体-流体包裹体的捕获温度大于530℃,说明岩浆热液过渡阶段的温度不低于该温度;闪锌矿中流体包裹体的均一温度在285~417℃之间,盐度为11.7% NaCleqv,代表了成矿流体的温度和盐度;流体包裹体的均一温度为172~454℃,代表热液阶段流体的温度。从中细粒黑云母花岗岩到似伟晶岩囊状体再到石英晶洞,岩浆-热液体系经历了富挥份熔体→熔体+高盐度流体→高盐度流体→低盐度流体的完整演化过程,形成了CaCl₂-NaCl-H₂O-CO₂体系的岩浆热液流体。包裹体岩相学及激光拉曼探针分析结果显示,在流体包裹体和多晶熔体-流体包裹体中含有长石、方解石、金红石及金属氧化物等子矿物,暗示其所捕获的流体具有较强的成矿能力。  相似文献   

陕西陈耳金矿床不同构造－岩相带微量元素地球化学特征及构造控矿机理   总被引：1，自引：1，他引：0       下载免费PDF全文

李建波蒋振频  鲁勇花郭 磊 史兴俊 曾 涛 《中国地质》2011,38(6):1551-1561

通过对陈耳金矿床两类不同构造-岩相带微量元素分布特征分析,发现元素特别是成矿元素Au的含量从片理化带→破碎蚀变带→石英脉逐渐增强。构造-岩相带内变形岩石的石英Rf/φ法有限应变测量表明,片理化带应变强度最大,破碎蚀变带应变强度小,应变集中在韧性剪切带边部的片理化带内。R型聚类分析表明Au与Ag、Cu、Pb及Zn的相关系数远大于Au与Ni、Co元素的相关系数,甚至接近于1。研究认为:破碎蚀变带内由于应变软化导致脆性裂隙大量发育,易于成矿流体的迁入与淀积而强富集;片理化带由于应变集中,造成成矿流体的迁出而弱富集。韧性剪切带脆-韧性变形转换不仅控制了矿体就位空间,同时也决定着元素迁移的方向。  相似文献   

Triggering the low-carbon transition in the aftermath of the global financial crisis     

Jean-Charles Hourcade  Priyadarshi Shukla 《Climate Policy》2013,13(2):22-35

An assessment of the post-Kyoto climate change negotiations, and the altered role of climate finance post-financial crisis, is presented. First, the paradigm shift of the Cancun Agreements is examined from an historical perspective and it is shown that the impasse in the negotiations, caused by the underlying over-emphasis on burden sharing reductions in emissions, can be overcome. Second, using information from two modelling exercises, it is demonstrated how climate finance can encourage the decoupling of carbon emissions from economic growth and thereby help align the development pattern with global climate goals. Third, a framework to place carbon finance within current discussions is sketched regarding both the reformation of the world financial systems and the facilitation of a sustainable economic recovery that is beneficial for North and South while addressing the low-carbon transition. It is concluded that upgrading climate finance is the key to triggering the shift to a low-carbon society and a system is proposed in which an agreed social cost of carbon is used to support the establishment of carbon emissions certificates to reorient a significant portion of global savings towards low-carbon investments.

Policy relevance

Investments that align development and climate objectives are shown to substantially lower the social cost of carbon and deliver long-term carbon emissions reductions. These reductions are greater than those contributed by the sole carbon price signal generated by a world cap-and-trade system. Carbon finance, as a part of the broader reform of financial systems and overseas aid, can help overcome the dual adversity of climate and financial crisis contexts. The carbon certificate, with an upfront agreed social cost of carbon, can be used as its instrument. The portion of the banking system that intends to reorient a significant part of world savings towards low-carbon investments could thus issue such carbon certificates. By giving carbon assets the status of a reserve currency, the system could even respond to the need of emerging countries to diversify their foreign exchange reserves and trigger a wave of worldwide sustainable growth through infrastructure markets.  相似文献   

Winnie(9711)台风变性加强过程中的降水变化研究   总被引：9，自引：1，他引：8  

李英  陈联寿  雷小途 《大气科学》2013,37(3):623-633

热带气旋变性过程是其结构、强度及其风雨分布发生显著变化的过程,常导致预报失败。基于T106格点分析资料、日本气象厅TBB资料以及MM5V3数值模式结果,对9711号台风Winnie变性加强过程中的降水变化特征及其机理进行研究。结果表明,Winnie台风变性加强过程中降水分布非对称性明显,强降水带首先出现在台风环流北部,之后向南弯曲,其强降水中心绕台风中心从北部顺时针转向东北和东南部。这种降水变化一方面与Winnie与西风带高空槽相互作用过程中环境风垂直切变明显增大,且其指向顺时针旋转有关。此间台风垂直结构发生明显倾斜,变性前期涡旋环流随高度增加先向北倾斜,发展到最强时又趋于垂直,之后又向东南倾斜。强降水区出现在垂直切变的下风方、台风气柱倾斜方向一侧。另一方面还与台风环流内冷、暖平流活动紧密相关,强降水落区与低层暖平流输送位置关系密切。对流涡度矢量垂直分量反映了Winnie台风环流内中尺度锋区与风垂直切变的相互作用,800 hPa上的大值区对其强降水落区有较好的指示意义。  相似文献   

季风转换期东印度洋的赤道流系结构和水文特征          下载免费PDF全文

乔彬  刘子洲  张书颖  刘聪  李培良 《海洋科学进展》2014,32(3)

基于2013-04夏季风转换期间航次观测数据,对赤道东部印度洋3支东向强流及其水文特征进行分析。结果表明,沿赤道在表层存在Wyrtki急流,在温跃层深度存在赤道潜流,它们携带着阿拉伯海的高盐水向东输运,81°E断面上,核心流量分别为4.76Sv和12.18Sv;南赤道逆流核心在5°S附近,核心流量7.4Sv,并伴有高盐特性。  相似文献