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31.
Theo Brauers Hans-Peter Dorn Helmut Koch Annette B. Kraus Christian Plass-Dülmer 《Journal of Atmospheric Chemistry》1998,31(1-2):33-52
Meteorological data, ozone mixing ratios, and photolysis frequencies for the period August 2 to August 24, 1994, are presented and discussed in support of the field campaign POPCORN (Photochemistry of Plant Emitted Compounds and OH Radicals in Northeastern Germany). Measurements of temperature, ozone, and wind speed at different heights are used to evaluate micro-meteorological parameters. The observations provide information about local influences on the air mass composition. The analysis of radio sonde data of nearby stations provides the height of the planetary boundary layer. 相似文献
32.
Chineke Theo Chidiezie 《大气科学》1997,21(5):638-640
本文目的在于描述热带湿润气候中局地天气预报的各种方法。文中所给的结果在大多数情况下是可靠的。 相似文献
33.
A brief introduction is given of the Grid–point 9–layer Atmospheric General Circulation Model (AGCM) developed at the Institute
of Atmospheric Physics (IAP), Chinese Academy of Sciences. The results of the 1980–1989 Atmospheric Model Inter-Comparison
Program (AMIP) run were compared with observed European Centre for Medium-Range weather Forecasts (ECMWF) temperature data
for the same period. The statistical analysis, and Grids Analysis and Display System (GrADS) results have shown that the model
holds a great promise in predicting the African climate with considerable accuracy, within and across the seasons. This is
a great hope for climate research in Africa which is data-sparse region.
On leave from School of Physical Sciences, Imo State University, PMB 2000 Owerri, Nigeria. 相似文献
34.
Theo Rauch 《Geoforum》1984,15(2):209-229
This article argues that the current explanations (polarization and polarization reversal theories) for the existing and widening regional disparities found in the developing countries are unsatisfactory and lead to unhelpful policy initiatives. It accepts the existance of polarisation and equalization mechanisms but argues that the influence of the historically and spatially differentiated socio-economic structure is the proper focus of attention. 相似文献
35.
John D. Monnier Stefan Kraus Michael J. Ireland Fabien Baron Amelia Bayo Jean-Philippe Berger Michelle Creech-Eakman Ruobing Dong Gaspard Duchêne Catherine Espaillat Chris Haniff Sebastian Hönig Andrea Isella Attila Juhasz Lucas Labadie Sylvestre Lacour Stephanie Leifer Antoine Merand Ernest Michael Stefano Minardi Christoph Mordasini David Mozurkewich Johan Olofsson Claudia Paladini Romain Petrov Jörg-Uwe Pott Stephen Ridgway Stephen Rinehart Keivan Stassun Jean Surdej Theo ten Brummelaar Neal Turner Peter Tuthill Kerry Vahala Gerard van Belle Gautam Vasisht Ed Wishnow John Young Zhaohuan Zhu 《Experimental Astronomy》2018,46(3):517-529
The Planet Formation Imager (PFI, www.planetformationimager.org) is a next-generation infrared interferometer array with the primary goal of imaging the active phases of planet formation in nearby star forming regions. PFI will be sensitive to warm dust emission using mid-infrared capabilities made possible by precise fringe tracking in the near-infrared. An L/M band combiner will be especially sensitive to thermal emission from young exoplanets (and their disks) with a high spectral resolution mode to probe the kinematics of CO and H2O gas. In this paper, we give an overview of the main science goals of PFI, define a baseline PFI architecture that can achieve those goals, point at remaining technical challenges, and suggest activities today that will help make the Planet Formation Imager facility a reality. 相似文献
36.
亚——非季风区非绝热加热与夏季环流关系的诊断研究 总被引:4,自引:0,他引:4
基于热力适应理论,本文利用 NCEP/ NCAR再分析资料对撒哈拉沙漠、青藏高原和孟加拉湾地区的非绝热加热与夏季环流进行了诊断研究。在非洲撒哈拉沙漠地区,以感热输送为主的加热仅局限于近地面层,边界层以上的大气则以辐射冷却占优势。因而除了边界层内存在着浅薄的正涡度和微弱的上升运动以外,整个对流层几乎都维持负涡度并盛行下沉运动。对于青藏高原地区,强大的表面感热通量引起的垂直扩散是近地面大气加热的主要分量,与大尺度上升运动相关的凝结潜热对低层大气的加热也有一定的贡献。长波辐射造成的对流层中、上层大气的冷却则主要由深对流潜热释放来补偿。夏季高原地区总非绝热加热是正值,且最大加热率出现在边界层内。低空大气辐合产生正涡度,而中、高层大气辐散伴有较强的负涡度。因而高原盛行上升运动,最大上升运动位于近地面层。夏季孟加拉湾地区的深对流凝结潜热释放远大于长波辐的冷却作用,因而整个对流层几乎都保持较强的非绝热加热。400hPa层附近的最大加热率引起300-400hPa最强的上升运动。对流层上层是负涡度区,而中、低层为正涡度区。结果还表明,垂直和水平辐散环流与大气的热源和热汇区密切相联:在高层,辐散气流从热源区流向热汇区;在低层则相 相似文献
37.
Pauline van den Berg Theo Arentze Harry Timmermans 《Journal of Geographical Systems》2012,14(2):125-141
Recently, there has been an increasing interest in the role of social networks in spatial-choice and travel behavior. It has
been acknowledged that social activities and the travel for these activities can emerge from individuals’ social networks
and that social activities are responsible for an important portion of travel demand. The influence of information and communication
technologies (ICT’s) is also important in this respect. The purpose of the paper is to examine the effects of characteristics
of egos and ego-alter relationships on the frequency of social interaction by different communication modes, using multilevel
path analysis. The analyses are based on social network data collected in 2008 in the Eindhoven region in the Netherlands
among 116 respondents. The results indicate a complementary relationship between contact frequencies by different modes. The
contact frequencies of the different modes, especially face-to-face and telephone, can also be largely explained by the ego’s
personal characteristics and the type of relationship and the distance between ego and alter. 相似文献
38.
The tilt correction servo for the Sydney University Stellar Interferometer (SUSI) consists of a 'pyramid' detector and piezo-electrically controlled tilt mirrors. The system measures image position and re-centers it with a sample frequency of 1000 Hz thereby holding the two beams of the interferometer parallel with a standard deviation of 0.164 ± 0.025 arcseconds. With an aperture size of 0.06 metres this implies less than a 2% loss in the visibility measurements made by SUSI. The servo has been used to magnitude 6.5 stars and is predicted to have a limiting magnitude of 7.5 and possibly as high as 8.5. The system not only corrects for the tilt introduced by the atmosphere but will supply a good estimate of seeing conditions using the same optical path through the atmosphere as the visibility measurements of the interferometer. 相似文献
39.
Using a filter radiometer, the meridional profile of the NO2 photolysis frequency, J(NO2), was measured between 50° N and 30° S during the cruise ANTVII/1 September/October 1988 of the research vessel Polarstern on the Atlantic Ocean. Simultaneously, global broadband irradiance and acrosol were monitored. Clean marine background air with low aerosol loads (b
sp=(1–2)×10-5 m-1) was encountered at the latitudes 25° N–30° N and 18° S–27° S, respectively. Under these conditions and an almost cloudless sky J(NO2) reached 7.3×10-3 s-1 (2 sr) for a zenith angle of 30°. Between 30° N and 30° S, the latitudinal variation of the J(NO2) noontime maxima was less than ± 10%, while the mean value at noon was 7.8×10-3 s-1. For the set of all data between 50° N and 30° S, a nearly linear correlation of J(NO2) vs. global broadland irradiance was found. The slope of (8.24±0.03)×10-5 s-1/mW cm-2 agrees within 10% with observations in Jülich (51° N, 6.2° E). 相似文献
40.
A non-linear non-hydrostatic model (MIT-gcm) is used to study the generation and propagation of internal tides. The model domain covers a continental slope and neighbouring parts of the deep ocean and shelf. Uniformity in the along-slope direction is assumed. We focus on the non-linear evolution of the internal tide once generated. In particular, we show that in the main region of generation, over the upper part of the slope, small-scale features occur, indicative of breaking and mixing. Far from the generation region, non-linear processes are important in the reflection of the beam at the bottom, where higher harmonics are generated. This implies an energy transfer toward higher frequencies and the resulting shape of the energy spectra is consistent with observations. Turbulent and mixing processes are analysed by employing an adiabatic sorting method; thus, we calculate the development in time of the available potential energy, the variation in the background potential energy due to irreversible processes, and the distribution of the Cox number (the local turbulent diffusivity normalized by the background diffusivity) over the slope. With rotation, the transfer of energy to higher harmonics is reduced. 相似文献