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31.
The aim of this study is to evaluate the current state of rural area development at the county level in the eastern coastal China. An evaluation index system including 18 factors was developed, and a rural development index (RDI) was constructed to evaluate rural development state in 2000, 2004, and 2008. The quantitative evaluation indicated the following results. 1) This study derived four dominating components by means of principal component analysis, which can explain 78.2% of the total information, namely agricultural production input, the basic condition of agriculture, the comparative effectiveness of grain production, and the household′s own basic conditions. 2) Since the turn of the new millennium, the rural area in the eastern coastal China has experienced a rapid development in general. Well developed, developed, moderately developed and undeveloped rural areas respectively occupied 29.32%, 22.33%, 21.91%, and 10.51% in 2008. 3) The countryside had maintained a sound momentum of developing trend between 2000 and 2008, while the rural development in the eastern coastal China lacked sustainability. And 4) industrialization, urbanization, original economic basis, and location are four major driving forces of the disparity of rural area development in the eastern coastal China. Given these results, the strategies and policies for the improvement of each rural group were put forward.  相似文献   
32.
Evaluating the role of fluvial transfer of terrestrial organic carbon (OC) and subsequent burial in the global carbon cycle requires the sources and fluxes of fluvial OC to be assessed, which remains poorly constrained in the Huanghe (Yellow River). Here, we report the elemental, stable isotopic, and radiocarbon activity of particulate organic carbon (POC) sampled at the outlet of Huanghe in 2012–2013. We show that the Huanghe riverine POC can be explained by binary mixing of fossil (POCfossil) and non‐fossil (POCnon‐fossil) components, the former may reach ~40% of the total POC. The Huanghe POCnon‐fossil is mostly sourced from C3 plants, with a mean residence time of c. 2200 years. The current human‐controlled hydrological regime strongly influenced the POC sources, transport modes, and fluxes. In 2012–2013, the Huanghe delivered 0.73 Tg (1 Tg = 1012 g) of POC to the sea, and about 28% of the annual POC flux occurred within a short human induced flood event. Globally, the Huanghe should be one of the largest rivers in the transfer and re‐burial of fossil OC. However, the fate of Huanghe fossil OC is still unconstrained and needs to be further investigated. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
33.
通过1∶25万邦多区幅地质调查,发现晚侏罗世—早白垩世则弄群中存在2个喷发-沉积不整合界面,将则弄群自然分成3个部分,对应3个火山喷发-沉积旋回。新创建扎列拿组、郎穷组和荣纳组。描述了3个组的定义及层型、次层型的岩性、岩相、古生物、同位素年代特征及其分布情况。  相似文献   
34.
黄河流域代表水文站径流和降水量变化的初步分析   总被引:9,自引:1,他引:9       下载免费PDF全文
通过对1995—1990年共36a黄河上游和中游两个代表站径流量和区域降水量资料的季节和年际变化趋势的分析,初步揭示了黄河不同流域降水量和径流量之间的关系,发现虽然黄河上游区域平均降水量距平的变化在夏季和秋季呈下降趋势,但代表黄河上游的兰州水文站径流量在夏季和秋季却呈现出明显的上升变化趋势,而黄河中游区域平均降水量距平的变化在夏季和秋季呈下降趋势,代表黄河中游的花园口水文站径流量在夏季和秋季也呈现出明显的下降变化趋势。因此,在比较长时间的气候趋势上,黄河中游地区径流量异常与降水量异常变化趋势是一致的,降水量异常是影响径流量异常的主要因子。而在黄河上游地区径流量异常与降水量异常变化趋势并不一致,降水量减少的同时径流量却增加,这可能与伴随着降水量减少的全球增暖所引起的高原冰川和积雪融化等因素有关。因此,影响黄河上游径流量的因素除了降水等自然因子外,其它因子诸如上游的径流量、人类活动、全球增暖等也同样会影响黄河上游的径流量。  相似文献   
35.
西藏西部日松地区多仁组、日松组的建立及其地质意义   总被引:2,自引:0,他引:2  
在班公湖-改则-革吉-带广布-套类复理石-复理石碎屑沉积,总体岩性单调,化石稀少,研究程度极低。对该套地层.尤其上部层位因缺乏年代依据,其时代归属及沉积上限一直争论较大,地层序列划分难以统一。在1:25万日土幅区域地质调查过程中对该套地层进行了详细研究,于中上部层位中采获了较丰富的古生物化石,其时代归属为晚侏罗世。据沉积建造、岩性组合及古地理、古生物面貌特征,宜将其从原木嘎岗日地层分区划出,归入班戈-八宿地层分区,创建为多仁组、日松组。  相似文献   
36.
黄河源区地表水资源变化及其影响因子   总被引:19,自引:3,他引:16  
利用1955~2005 年黄河源区玛多气象站和黄河沿水文站气象、水文资料, 分析了该区域地表水资源、气候及冻土演变规律, 揭示了地表水资源变化的成因。研究表明: 近51 年黄河源流量丰枯转化频繁, 但在总体上特别是进入20 世纪90 年代以来黄河源流量呈减少趋势, 流量年内分配表现为单峰型; 降水量对流量有着较为显著的影响, 且具有一定的持续性; 黄河源区气温的显著升高对于加大流域蒸发量导致流量补给的减少作用要大于其升高致使冰雪融水的补给作用, 其中春季气温回升的这一效应更为显著; 黄河源区冻土呈现出显著的退化趋势, 冻土厚度与流量总体上呈显著的正相关关系, 其不断减小削弱了自身天然隔水层的作用; 黄河源区蒸发量呈现出显著的增大趋势, 并导致流量的减少; 气候变化导致流量的减少量占总减少量的70%, 其余30%可能是由人类活动加剧造成的, 气候及冻土因子对流量的作用大小依次为冻土、降水、蒸发和气温, 显然多年冻土对于黄河源区地表水资源的形成和发育有着至关重要的作用。  相似文献   
37.
黄河源区水资源变化及其影响因子   总被引:1,自引:0,他引:1  
Taking the source region of the Yellow River as a study area and based on the data from Madoi Meteorological Station and Huangheyan Hydrological Station covering the period 1955-2005, this paper analyses the changing trends of surface water resources, climate and frozen ground and reveals their causes. Results show that there exist frequent fluctuations from high to low water flow in the 51-year period. In general, the discharge has shown a de- clining trend in the 51 years especially since the 1990s. The annual distribution shows one peak which, year on year is getting smaller. (1) Precipitation has a significant and sustained influence on discharge. (2) A sharp rise of temperature resulted in the increase of evaporation and the decrease of discharge, which has a greater effect than on ice-snow melting. (3) Frozen ground tends to be degraded markedly. There is a significant positive correlation be- tween the permafrost thickness and the discharge. (4) Evaporation rates are significantly increasing, leading to the decrease of discharge. 70% of the discharge reduction resulted from climate change, and the remaining 30% may have been caused by human activities.  相似文献   
38.
北京奥林匹克塔是北京标志性建筑之一,是北京市首例柔性高耸钢结构体,其变形特点没有历史数据可以借鉴,对其监测的本身就是带有研究性质的.其主体形变受基础、结构、周边环境以及气象等多种因素综合影响,监测主要是针对其结构和变形特点,利用北斗-全球导航定位系统(Global Positioning Sys-tem,GPS)联合解...  相似文献   
39.
In the later stage of Late Pleistocene, global climate entered into the climax period of Würm when temperature decreased remarkably and glaciers developed. Information from the East China Sea also confirm that the sea level fell by at least 130 m at that time (Emery, 1968). The Bohai Sea and Yellow Sea at the climax period were totally exposed, while the East China Sea and South China Sea shelf regions were exposed partly. The exposed shelf area exceeded 1 million km2 and became a salty desert where land plants could not survive. Such were the conditions which led to the desertization of the shelf region. Eolation was the major exogenetic force not only on land but also on the shelf region in the ice age. At the climax period of Würm, the northern part of China developed thick layers of loess deposits. The shelf region at that time had similar climatic conditions and sediments. Because the shelf region was not protected by vegetation in the ice age, intensive wind storms remoulded the primarily deposited strata to produce new sedimentary differentiation and new series of land sediments. Shallow-layer profiler records indicated the existence of many land sediment types, including dunes, dune-chains, desert bodies, thick layers of repose angle sediments and desertization derivatives. New data available show the shelf region adjoining China can be divided into six regions of desertization and its derivatives. Contribution No. 1846, from the Institute of Oceanology, Acadernia Sinica. Project sponsored by the National Natural Science Foundation of China.  相似文献   
40.
环渤海地区县域经济发展时空分异研究   总被引:1,自引:0,他引:1  
以县域为基本研究单元,应用统计分析法和空间分析法,以人均地区生产总值为指标,分析1996—2009年间环渤海地区县域经济的时空分异特征。结果表明,环渤海地区经济实力不断增强,产业结构呈现高级化趋势;县际经济发展水平差距大,部分县域人均GDP处于极端高水平;1996—2009年间,县域人均GDP的绝对差异增大而相对差异波动性缩小,省间差异是区域差异的主要组成部分;人均GDP空间自相关显著,经济发展热点区和冷点区的空间集聚特征增强。基于1996年各县人均GDP及1996—2009年间人均GDP增长差异,将环渤海地区划分为基础好增长较快型、基础中等增长较快型等6种类型。  相似文献   
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