全文获取类型
收费全文 | 71篇 |
免费 | 12篇 |
国内免费 | 79篇 |
专业分类
测绘学 | 5篇 |
大气科学 | 27篇 |
地球物理 | 26篇 |
地质学 | 61篇 |
海洋学 | 18篇 |
天文学 | 4篇 |
综合类 | 17篇 |
自然地理 | 4篇 |
出版年
2024年 | 2篇 |
2023年 | 23篇 |
2022年 | 11篇 |
2021年 | 6篇 |
2020年 | 11篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
排序方式: 共有162条查询结果,搜索用时 281 毫秒
31.
32.
Ye PU Hongbo LIU Ruojing YAN Hao YANG Kun XIA Yiyuan LI Li DONG Lijuan LI He WANG Yan NIE Mirong SONG Jinbo XIE Shuwen ZHAO Kangjun CHEN Bin WANG Jianghao LI Ling ZUO 《大气科学进展》2020,37(10):1081-1092
This paper describes the datasets from the Scenario Model Intercomparison Project(ScenarioMIP) simulation experiments run with the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System Model,GridPoint version 3(CAS FGOALS-g3). FGOALS-g3 is driven by eight shared socioeconomic pathways(SSPs) with different sets of future emission, concentration, and land-use scenarios. All Tier 1 and 2 experiments were carried out and were initialized using historical runs. A branch run method ... 相似文献
33.
WANG Qing-yan YIN Kun CHEN Bao-yi JI Sheng-li College of Construction Engineering Jilin University Changchun Jilin China 《东北亚地学研究》2005,(Z1)
Hydraulic impact perforator is powerful tools for trenchless project. It has advantages in cabinet structure, low cost, long life and easy protected. Compared with pneumatic DTH, the hydraulic impact spear worked under high pressure and using uncompressible fluid thusgreater impact energy and higher efficiency can be supported. The authors founded the dynamic simulation model of HDI-146 hydraulic impact spear. The project for solving the differential equation was suggested also. By means of virtual machine technology, the dynamic mechanism of HDI-146 can be explored and tutoring us to optimize the structural parameters can be made. 相似文献
34.
Analysis of Wave Loads on A Semi-Submersible Platform 总被引:10,自引:0,他引:10
For the global and structural fatigue strength analysis of a semi-submersible platform, wave loads under design conditions are calculated by use of the three-dimensional boundary element method. Methods for calculating the forward-speed free-surface Green function are discussed and a computer program with this Green function is developed. According to the special rules, the wave loads under several typical design conditions of the platform are calculated. The maximum vertical bending moment, torsion moment and horizontal split force are determined from a series of contour maps of wave loads for the wave period of 5 to 18 seconds at a certain interval and the wave phase of 0°to 360°at a certain interval. The wave height is determined by the function of wave period with a given exceedance probability. The maximum wave loads under the combination of wave parameters are used as the input of hydrodynamic pressure in the three-dimensional finite element analysis process. The transfer functions of wave loads 相似文献
35.
Scour of the Seabed Under A Pipeline in Oscillating Flow 总被引:3,自引:0,他引:3
The scour of the seabed under a pipeline is studied experimentally in this paper. Tests are carried out in a U-shaped oscillatory water tunnel with a box imbedded in the bottom of the test section. By use of the standard sand, clay and plastic grain as the seabed material, the influence of the bed material on the scour is studied. The relationship between the critical initial gap-to-diameter ratio above which no scour occurs and the parameters of the oscillating flow is obtained. The self-burial phenomenon, which occurs for the pipeline not fixed to two sidewalls of the test section, is not observed for the fixed pipeline. The effect of the pipe on sand wave formation is discussed. The maximum equilibrium scour depths for different initial gap-to-diameter ratios, different Kc numbers and different bed sands are also given in this paper. 相似文献
36.
WANG Qing-yan YIN Kun CHEN Bao-yi JI Sheng-li 《东北亚地学研究》2005,8(1):138-141
Hydraulic impact perforator is powerful tools for trenchless project. It has advantages in cabinet structure, low cost, long life and easy protected. Compared with pneumatic DTH, the hydraulic impact spear worked under high pressure and using uncompressible fluid thusgreater impact energy and higher efficiency can be supported. The authors founded the dynamic simulation model of HDI-146 hydraulic impact spear. The project for solving the differential equation was suggested also. By means of virtual machine technology, the dynamic mechanism of HDI-146 can be explored and tutoring us to optimize the structural parameters can be made. 相似文献
37.
<正>1 Introduction Magnetotelluric(MT)is a geophysics method for oil exploration,which measures the surface orthogonal electric and magnetic fields base on the electromagnetic induction and natural electromagnetic fields.The data process and inversion methods are developed.The static shift effect is a very common phenomenon in 相似文献
38.
HUANGFU Yuhui ZHANG Jinyou ZHANG Shuichang WANG Xiaomei HE Kun GUAN Ping ZHANG Huanxu ZHANG Bin WANG Huajian 《《地质学报》英文版》2023,97(5):1568-1586
In this study, organic geochemical and petrological analyses were conducted on 111 shale samples from a well to understand the retention, intraformational migration and segmented accumulation(shale oil enrichment in different intervals is unconnected) features of shale oil within the organic-rich shale in the Qingshankou Formation of the Gulong Sag. Our study shows that retained petroleum characteristics in the investigated succession are mainly influenced by three factors: organic richness, int... 相似文献
39.
Xiaoya Tang Sichen Tong Guoxian Huang Guangxiang Xu Xinghua Li Kun Lei Shiming Yao 《国际泥沙研究》2021,36(2):177-189
Construction of large dams is attractive because of their great benefits in flood control,hydropower generation,water resources utilization,navigation improvement,etc.However,dam construction may bring some negative impacts on sediment transport and channel dynamics adjustments.Due to the effects of recent water and soil conservation projects,sediment retention in the newly constructed large upstream reservoirs,and other factors,the sedimentation in the Three Gorges Reservoir(TGR)is quite different from the amount previously predicted in the demonstration stage.Consequently,based on the measured data,characteristics of sedimentation and the related channel deformation in the TGR were analyzed.The results imply that sediment transport tended to be reduced after the Three Gorges Project(TGP).Sedimentation slowed dramatically after 2013 and indicated obvious seasonal characteristics.Due to the rising water level in the TGR in the flood season,the yearly sediment export ratio(Eratio)was prone to decrease.The water level near the dam site should be reasonably regulated according to the flow discharge to improve the sediment delivery capacity and reduce sedimentation in the TGR,and to try to avoid situations where the flood retention time is close to 444 h.The depositional belt was discontinuous in the TGR and was mainly distributed in the broad reaches,and only slight erosion or deposition occurred in the gorge reaches.Sedimentation in the broad and gorge reaches accounted for 93.8% and 6.2% of the total sedimentation,respectively.The estuarine reach located in the fluctuating backwater area experienced alternate erosion-deposition,with a slight accumulative deposition in the curved reach.Sedimentation mainly occurred in the perennial backwater area.The insight gained in this study can be conducive to directly understanding of large reservoir sedimentation and mechanism of channel adjustment in the reservoir region in the main channel of large river. 相似文献
40.
Temporal Variations of the Frontal and Monsoon Storm Rainfall during the First Rainy Season in South China 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《大气和海洋科学快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The temporal variations in storm rainfall during the first rainy season (FRS) in South China (SC) are investigated in this study. The results show that the inter-annual variations in storm rainfall during the FRS in SC seem to be mainly influenced by the frequency of storm rainfall, while both frequency and intensity affect the inter-decadal variations in the total storm rainfall. Using the definitions for the beginning and ending dates of the FRS, and the onset dates of the summer monsoon in SC, the FRS is further divided into two sub-periods, i.e., the frontal and monsoon rainfall periods. The inter-annual and inter-decadal variations in storm rainfall during these two periods are investigated here. The results reveal a significant out-of-phase correlation between the frontal and monsoon storm rainfall, especially on the inter-decadal timescale, the physical mechanism for which requires further investigation. 相似文献