全文获取类型
收费全文 | 223篇 |
免费 | 148篇 |
国内免费 | 226篇 |
专业分类
测绘学 | 9篇 |
大气科学 | 421篇 |
地球物理 | 45篇 |
地质学 | 37篇 |
海洋学 | 58篇 |
天文学 | 2篇 |
综合类 | 7篇 |
自然地理 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 21篇 |
2019年 | 24篇 |
2018年 | 21篇 |
2017年 | 21篇 |
2016年 | 22篇 |
2015年 | 22篇 |
2014年 | 32篇 |
2013年 | 22篇 |
2012年 | 16篇 |
2011年 | 26篇 |
2010年 | 14篇 |
2009年 | 31篇 |
2008年 | 20篇 |
2007年 | 27篇 |
2006年 | 29篇 |
2005年 | 28篇 |
2004年 | 22篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 13篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 16篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 6篇 |
1977年 | 1篇 |
排序方式: 共有597条查询结果,搜索用时 15 毫秒
61.
A Simulating Study on Resolvable-Scale Microphysical Parameterization in a Mesoscale Model 总被引:3,自引:1,他引:2
The Penn State/ NCAR Mesoscale Model (MM5) is used to simulate the precipitation event that oc-curred during 1-2 May 1994 to the south of the Yangtze River. In five experiments the Kain-Fritsch scheme is made use of for the subgrid-scale convective precipitation, but five different resolvable-scale microphysical parameterization schemes are employed. They are the simple super-saturation removal scheme, the warm rain scheme of Hsie et al. (1984), the simple ice scheme of Dudhia (1989), the complex mixed-phase scheme developed by Reisner et al. (1993). and the GSFC microphysical scheme with graupel. Our interest is how the various resolvable-scale schemes affect the domain-averaged precipitation, the pre-cipitation distribution, the sea level pressure, the cloud water and the cloud ice.Through a series of experiments about a warm sector rainfall case, results show that although the dif-ferent resolvable-scale scheme is used, the differences of the precipitation characteristics among all five runs are not very obvious. However, the precipitation is over-predicted and the strong mesoscale low is produced by the simple super-saturation removal scheme. The warm rain scheme with the inclusion of condensation and evaporation under-predicts the precipitation and allows the cloud water to reach the 300 hPa level The scheme of the addition of graupel increases the resolvable-scale precipitation by about 20%–30%. The inclusion of supercooled liquid water in the grid-scale scheme does not affect significantly the results. 相似文献
62.
该文利用GMS多通道气象卫星资料推导得到的降水资料估算出的加热率, 作为非绝热的非线性正规模初始化过程中的非绝热强迫项, 进行风压场的初值调整, 再采用一个与模式中的对流参数化方案相反的逆运算方案, 进行水汽场的初值调整.以保证初始时刻按模式的物理参数化方案计算得到的加热率与由卫星推导的加热率一致. 这一方法在非绝热的非线性正规模初值化的框架中, 使初始时刻的水汽场得到调整.既实现了传统的初始化目标, 又提高了模式对降水的短时预报效果.对华南的两个个例的试验结果表明该文的方法是有效的. 相似文献
63.
Large-Eddy Simulation and Parametrization of the Effects of Shear on Shallow Cumulus Convection 总被引:1,自引:0,他引:1
A. R. Brown 《Boundary-Layer Meteorology》1999,91(1):65-80
Large-eddy simulations are performed of ensembles of shallow convective clouds under varying shear. The scalar transports are shown to be largely unaffected by shear, while the momentum transport is strongly affected. The parametrization of the momentum fluxes is discussed. The cross-cloud pressure gradient, commonly neglected in shallow cumulus parametrizations, is shown to be a dominant term in the in-cloud momentum budget. The performance of two possible representations of this pressure gradient, each previously proposed for use in deep convection parametrizations, is assessed. 相似文献
64.
积云对流参数化对一交梅雨锋暴雨过程影响的模拟检验 总被引:12,自引:10,他引:2
应用1988年版日本谱模式JSM,对比分析了Arakawa-Sckawa-Schubert、Kain-Fritsch、KuoAnthes和Gadd-Keers等几种积云对流参数化方案在梅雨锋暴雨对流系统模拟中的表现。 相似文献
65.
Treatments of the boundary layer in a five-layer primitive equation model with mixed P—σcoordinates are improved by incorporating similarity theory,which is widely used at present.Twokinds of parameterization schemes of the boundary layer are designed,and static test and numericalsimulation are performed.It is found that the iterative scheme can fairly improve the simulation ofthe mean climate field in July.The abnormally strong heat low over the Tibetan Plateau isweakened to some extent. 相似文献
66.
67.
R. S. Lindzen 《Pure and Applied Geophysics》1988,126(1):123-135
A simple parameterization of cumulonimbus convective heating is presented. The model is primarily based on preserving a moisture budget and on detraining cloud air at levels corresponding to the neutral buoyancy of the air converged at low levels. Results are compared with data from the western Pacific and GATE. Agreement is good. Suggestions are offered for improving the model and extending it to other regions. 相似文献
68.
本文利用一个三维中尺度模式,分别采用两种不同的湿过程处理方案FPA和NCA模拟同一个洋面冷锋个例,以考察模拟结果对湿过程参数化方案的敏感性。两种方案的区别在于前一种使用了次网格湿对流参数化而后者没有。通过比较分别使用FPA和NCA方案所进行的模拟FPS和NCS,发现冷锋结构在两者间出现较大差异。从850 hPa等压面|Δθe|等值线图所显示的结构看,NCS中冷锋呈现为一长一短两条锋带,而FPS中冷锋仅呈现为一条锋带。在相应的冷锋横向垂直剖面中,NCS中存在两个相邻的锋面垂直环流,而FPS中只有一个。另外,NCS中对流不稳定的冷锋区出现垂直运动过分发展的现象,而FPS中不存在这个问题。通过与卫星云图比较,我们注意到,NCS中尽管出现了垂直运动过分发展的现象,但相对于FPS而言,其模拟的冷锋结构与实际较为接近,成功地模拟出云图上显示的双冷锋结构。NCS中垂直运动过分发展的一个重要原因是模式中采用的静力平衡近似。FPS中次网格对流参数化方案的使用,通过减少甚至消除对流不稳定度,一方面使垂直运动的过分发展倾向受到约束,另一方面也可能使在对流不稳定层结下的锋区环境中本应出现的中尺度结构失去了形成的机会。 相似文献
69.
作者简单介绍了国内预报员较为熟悉的欧洲中期天气预报中心,美国国家气象中心和日本气象厅三个中期预报模式的性能及预报效果,包括近几年颇为流行的半拉格朗日时间积分方案,物理过程参数化方案的完善和改进,中期数值预报业务模式的发展趋势等。 相似文献
70.
The survey for the HEIFE(Atmosphere-Land Surface Processes Experiment at Heihe RiverBasin,Western China)is given in the paper.The following basic subjects for land-surface process-es in arid areas are studied:(1)the general characteristics of the energy budget on ground surfacein arid areas;(2)the parameterization of the land surface processes;(3)the interaction betweenoasis and its desert circumstances,a special phenomenon in arid areas.The analysis shows that thesensible heat flux in the surface energy budget is in the majority,and the latent heat flux may beneglected.The influence of atmospheric stratification stability on the turbulent transfer of energyand substance must be considered in parameterization of land surface processes in arid areas.The“cold island effect”phenomenon in oasis and the“humidity inversion”phenomenon in desert nearoasis are the result of the interaction between them.The results would improve the understandingof land surface processes in arid areas. 相似文献