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161.
Historical enclosure era property-related maps can tell us a great deal about the life and times of communities in the past. This study offers a unique approach to studying the historical landscape by applying GIS techniques to the examination of an eighteenth-century English village. Using novel GIS applications relying on historical maps, the study explores various aspects of the village’s physical and social characteristics. In doing so, the study forges effective linkages between cultural and landscape variables to reveal aspects of the historical landscape in eighteenth-century Britain previously inaccessible to researchers. This, in turn, provides a much more comprehensive and sophisticated template for future use by historical geographers in a number of contexts.  相似文献   
162.
比奥固结理论在堆载预压加固工程场地中运用   总被引:4,自引:2,他引:4  
徐书平  刘祖德 《岩土力学》2003,24(2):307-310
运用平面应变比奥固结有限单元法,对南京某钢铁厂江边原料厂采用堆载预压结合塑料排水板处理的软土地基进行了计算,得到了较为理想的效果。计算中将塑料排水板合理地简化成等效砂墙,理论计算结果与实测结果吻合较好。验证了计算方法是合理可行的。  相似文献   
163.
In the northern part of Tunisia, close to Testour/Slouguia, new observations and updated biostratigraphy make it possible to highlight the relation between the Triassic saliferous mass and the surrounding Mesozoic beds (T. M.). Near the (T. M.) boundary, the formations observed consist dominantly of Triassic evaporites reworked in the Early and Late Albian deep-water sedimentary deposits. Throughout the studied area, Jurassic rocks are absent. We propose to interpret the Chitana-Ed Djebs structure originally emplaced as gravitational stretch masses in a passive margin in the same way as the salt bodies of widespread salt province in the Gulf of Mexico. A reconstructed schematic position of the Chitana-Ed Djebs salt body displays a scenario of setting of the salt mass on a submarine palaeo-slope. Moreover, the starting clues of the paroxysmal event of the Late Mesozoic tectonic inversion clearly fossilized through the discordance of the Middle Eocene–Early Lutetian limestone on the Albian series.  相似文献   
164.
煤岩动静力学参数关系试验研究   总被引:1,自引:0,他引:1  
煤岩的动、静力学参数关系的试验研究,对研究煤岩的位移和变形特征及工程支护设计具有重要意义。将取自新河煤矿3煤的煤样加工成Φ50 mm×100 mm的圆柱体标准试件;采用500 kHz频率的纵横波换能器分别进行纵横波速度测试;在MTS815.03电液伺服试验机上进行单轴压缩试验,得到静态弹性模量和泊松比。试验结果表明:煤岩动弹性模量与横波速度相关性强于与纵波速度的相关性,煤岩介质的纵波对孔隙和裂隙发育程度的敏感程度要比横波高;煤岩试件Ed/Es比值主要集中在1.4~1.7,室内煤岩试件动、静弹性模量和动静泊松比之间存在较好的线性相关关系。  相似文献   
165.
汕尾市雾霾天气的能见度多时间尺度特征分析   总被引:3,自引:0,他引:3  
根据汕尾气象台1961~2003年共43 a的常规气象观测资料,对汕尾市雾霾天气的能见度多时间尺度特征进行了分析.结果表明,汕尾市雾霾天气能见度的时次变化都是在08时次出现最多,在08~14时次逐渐减少,在14时次出现最少;霾天气逐月变化不明显,轻雾和雾主要出现在冬春季节,以春季为多;霾在80年代后出现次数明显增多,而雾则在70年代以后出现次数多,但雾天气年代变化不明显,主要原因可能是城市污染的逐年加重,引起雾霾天气次数明显增多.  相似文献   
166.
杨彦明  陈婧  熊峰  张云  马援  贾昕晔  贾彦杰 《地震》2019,39(2):97-109
收集了2010—2011年华北克拉通西部块体北缘及邻区布设的36个流动地震台和2009—2016年内蒙古自治区数字地震台网17个宽频带固定地震台站的远震事件波形数据, 采用接收函数H-κ算法分析获得了53个基岩台站下方的地壳厚度和泊松比结果。 此外, 结合已有的81个台站的研究成果, 给出华北克拉通西部块体北缘及邻区地壳厚度与泊松比分布特征。 综合分析认为, 研究区地壳厚度在整体上呈现自东向西渐变的特征, 最厚的地方出现在华北克拉通西端的阿拉善地块(~48.7±3.0 km)。 研究区平均泊松比为0.27, 泊松比高值异常出现在河套断陷带, 意味着可能具有较高的地壳温度或者存在壳内部分熔融。 研究区内不同构造单元呈现出显著的地壳厚度和泊松比分布特征的差异性, 意味着在华北克拉通构造演化过程中, 不同地区经历了不同的地壳改造过程。  相似文献   
167.
In this study, three high frequent occurrence regions of tropical cyclones(TCs), i.e., the northern South China Sea(the region S), the south Philippine Sea(the region P) and the region east of Taiwan Island(the region E), are defined with frequency of TC's occurrence at each grid for a 45-year period(1965–2009), where the frequency of occurrence(FO) of TCs is triple the mean value of the whole western North Pacific. Over the region S, there are decreasing trends in the FO of TCs, the number of TCs' tracks going though this region and the number of TCs' genesis in this region. Over the region P, the FO and tracks demonstrate decadal variation with periods of 10–12 year, while over the region E, a significant 4–5 years' oscillation appears in both FO and tracks. It is demonstrated that the differences of TCs' variation in these three different regions are mainly caused by the variation of the Western Pacific Subtropical High(WPSH) at different time scales. The westward shift of WPSH is responsible for the northwesterly anomaly over the region S which inhibits westward TC movement into the region S. On the decadal timescale, the WPSH stretches northwestward because of the anomalous anticyclone over the northwestern part of the region P, and steers more TCs reaching the region P in the greater FO years of the region P. The retreating of the WPSH on the interannual time scale is the main reason for the FO's oscillation over the region E.  相似文献   
168.
城市化极大地改变了城市下垫面的性质,这有可能增加灰霾天气发生的概率和强度.利用Landsat-7 ETM+和HJ-1A卫星多光谱遥感数据,通过人工解译获得2002年和2012年武汉市土地利用情况,并对武汉市土地利用规划图进行数字化和尺度转换.在此基础上,针对武汉市典型灰霾天气过程,对不同土地类型(历史、现状和规划)利用WRF-NAQPMS空气质量数值模式进行了不同情景的模拟.同时,对比分析和揭示了不同情境下,大气风场和主要大气污染物浓度场的变化,解析了下垫面对灰霾天气的影响.可为从灰霾天气防治的角度完善城市土地规划和建设提供科学依据.  相似文献   
169.
This study presents a massively parallel spatial computing approach that uses general-purpose graphics processing units (GPUs) to accelerate Ripley’s K function for univariate spatial point pattern analysis. Ripley’s K function is a representative spatial point pattern analysis approach that allows for quantitatively evaluating the spatial dispersion characteristics of point patterns. However, considerable computation is often required when analyzing large spatial data using Ripley’s K function. In this study, we developed a massively parallel approach of Ripley’s K function for accelerating spatial point pattern analysis. GPUs serve as a massively parallel platform that is built on many-core architecture for speeding up Ripley’s K function. Variable-grained domain decomposition and thread-level synchronization based on shared memory are parallel strategies designed to exploit concurrency in the spatial algorithm of Ripley’s K function for efficient parallelization. Experimental results demonstrate that substantial acceleration is obtained for Ripley’s K function parallelized within GPU environments.  相似文献   
170.
MANDELBROT enunciated the uncertainty of the length of a coastline in his paper “How long is the coastline of Britain?” published in Science in 1967. The fractal concept was presented for the first time in that paper and has been applied to many fields ever since. Although fractal dimensions of lots of phenomena were calculated by the box-counting method, the quantitative influence of series of square grids on them is ignored. The issue is systematically discussed as a case study of the mountains of China‘s Mainland in this paper. And some significant conclusions are drawn as follows: 1) Although the fractal character objectively exists in the mountains of China‘s Mainland, and it does not vary with the changes of series of square grids, the fractal dimensions of the mountains of China‘s Mainland are different with these changes. 2) The fractal dimensions of the mountains of China‘s Mainlandvary with the average lengths of sides of series of square grids. The fractal dimension of the mountains of China‘s Mainland is the function of the average length of side of square grid. They conform to the formula D=f(r) (where D is the fractal dimension, and r is the average length of side of square grid). 3) Different dots of data collection can affect the fractal dimension of the mountains of China‘s Mainland. 4) The same range of length of side of square grid and dots of data collection can ensure the comparison of fractal dimensions of the mountains of China‘ s Mainland. The research is helpful to get the more understanding of fractal and fractal dimension, and ensure that the fractal studies would be scientific.  相似文献   
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