全文获取类型
收费全文 | 355篇 |
免费 | 82篇 |
国内免费 | 172篇 |
专业分类
测绘学 | 33篇 |
大气科学 | 413篇 |
地球物理 | 55篇 |
地质学 | 25篇 |
海洋学 | 7篇 |
天文学 | 56篇 |
综合类 | 12篇 |
自然地理 | 8篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 17篇 |
2020年 | 15篇 |
2019年 | 27篇 |
2018年 | 21篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 23篇 |
2014年 | 25篇 |
2013年 | 20篇 |
2012年 | 29篇 |
2011年 | 25篇 |
2010年 | 16篇 |
2009年 | 36篇 |
2008年 | 15篇 |
2007年 | 29篇 |
2006年 | 27篇 |
2005年 | 27篇 |
2004年 | 23篇 |
2003年 | 17篇 |
2002年 | 28篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 17篇 |
1998年 | 21篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
排序方式: 共有609条查询结果,搜索用时 15 毫秒
31.
大气CO2浓度增加,大气辐射平衡调整,将影响到大气的辐射加热,对季风环流的产生影响.CMIP6结果显示,大气CO2浓度增加,可减弱季风区主雨季对流层高,低层的辐射加热,加强对流层中层的辐射加热.各季风区加热响应的峰值层次不同:亚洲季风区平均层次最高(500-775 hPa),北非,南美,澳洲季风区次之(550-600 ... 相似文献
32.
A. Ben-Zvi M. Langerman 《Stochastic Environmental Research and Risk Assessment (SERRA)》1989,3(3):203-216
A comparison is carried out between historical records of the flow measured in Kinneret watershed during and prior to the time of cloud seeding for rainfall enhancement. Precipitation series for the control area of the meteorological experimentation serve as a reference for the comparison. The fluctuations of the flow, which would have occurred unless the effect of the seeding, are estimated by a linear regression on the precipitation as the control. The regression parameters are calibrated separately for the unseeded and for the seeded time series. The model with the parameters calibrated for the unseeded series is applied on the rainfall recorded during the seeded time, and vice versa. The difference between the measured and the computed data is attributed to the effect of cloud seeding. Similar comparisons are carried out with respect to rainfall series recorded at the target area and at the edge of the enhanced area.The results indicate that the flow from the affected sector of the watershed has been enhanced, with respect to the control, by 31×106
m
3/year, at a significance level of 31. This enhancement is 5% of the volume which is generated in that area. The rates found with respect to the rainfall at the edge are higher than those found with respect to the control, while those with respect to the rainfall at the center of the target area are lower. 相似文献
33.
34.
青藏高原地区云对地面有效辐射的影响:Ⅱ.强迫作用 总被引:2,自引:0,他引:2
本文利用1982年8月-1983年7月青藏高原地面热源观测试验资料,讨论了与云对地面有效辐射强迫作用有关的参数的计算问题,并对这些参数的计算结果进行了分析。结果表明:晴空、全云条件下的地面有效辐射和云对地面有效辐射强迫作用的年平均日变化振幅有明显的地域差异;云对地面有效辐射的强迫作用春夏大,秋冬小,甘孜、拉萨、那曲和改则4站平均的年平均值为-27.2W/m^2。? 相似文献
35.
Peng Wang Lei Liu Xichuan Liu Shuai Hu Shijun Zhao Wenming Ji Taichang Gao 《地球科学进展》1986,35(7):704-714
The accurate observation of the microphysical structure of cloud and precipitation plays an important role in understanding the formation of clouds and precipitation. In-situ measurement using measuring instruments carried by meteorological balloons is an effective way to obtain the microphysical properties of cloud and precipitation particles, which is a supplementary means for aircraft to observe cloud and precipitation particles. This observation method plays a more and more important role in in-situ measurement. According to the difference of the working principle of the existing balloon-borne cloud and precipitation particles probes, the detectors can be divided into particle impact-sampling sensors, particle imaging sensors, light-scattering sensors, light intensity attenuation sensors and charge measurement sensors. The working principles, key technologies and main advantages and disadvantages of typical instruments were summarized, and their applications to detailed cloud structure acquisition, cloud remote sensing method establishment, cloud and precipitation physical process research and parameterization, and scientific observation of thunderstorm clouds were briefly introduced. Finally, the development trend of balloon-borne cloud precipitation particle detectors was prospected, which will provide reference for related technical research and equipment development. 相似文献
36.
The use of cloud tracking techniques and storm identification procedures is proposed in this paper with the aim of predicting the evolution of cloud entities associated with the highest rainfall probability within a given meteorological scenario. Suitable algorithms for this kind of analysis are based on the processing of digital images in the thermal infrared (IR) band from geostationary satellites: a selection of such algorithms is described in some detail together with a few real case applications. Three heavy rainfall events have been selected for this purpose with reference to the extreme meteorological situation observed during Fall 1992 and 1993 over the Mediterranean area. A window from 30 to 60 °N and from 20 °W to 30 °E has been identified for the analysis of data from the radiometer on board the ESA Meteosat platform. In conclusion, the suitability of cloud tracking techniques for predicting the probability of heavy rainfall events is discussed provided that the former are associated with proper modeling of small scale rainfall distribution. 相似文献
37.
38.
The influence of various cloud parameters and the interactions with the ground albedo and the solar zenith angle have been studied by means of model simulations. The radiative transfer model suitable for a cloudy atmosphere as well as for a clear atmosphere has been developed on the basis of the Discrete Ordinate Method. This study leads to a general understanding for cloudy atmospheres: in the presence of a uniform cloud, the cloud scattering is dominant to molecular and aerosol scattering, and it is also wavelength-independent; the ratio of transmitted irradiance in a cloudy atmosphere to that in the background clear atmosphere is independent of cloud height and solar zenith angle. That’s to say, the radiation downwelling out of a cloud is quite isotropic; it decreases approximately exponentially with the cloud optical depth at a rate related to the ground albedo; the reflected irradiance at the top of the atmosphere is dependent on cloud optical depth as well as on solar zenith angle, but not on ground albedo for clouds of not very thin optical depth. 相似文献
39.
中国大陆卫星反演云参数的评估 总被引:29,自引:6,他引:29
该文选取1983年7月和1984年1月份代表夏季和冬季,利用中国地面气象月报的云量资料以及多年平均的地面观测云气修资料,与中国大陆地区ISCCP卫星反演的去量和云状资料进行了对比分析。参照大气环流和云天气气候特征,从卫星得到的从云状是比较合理的,但干旱沙漠地区的高云量的估计不足,低云估计偏多。 相似文献
40.