全文获取类型
收费全文 | 136篇 |
免费 | 0篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 16篇 |
地球物理 | 15篇 |
地质学 | 14篇 |
海洋学 | 5篇 |
天文学 | 74篇 |
综合类 | 1篇 |
自然地理 | 9篇 |
出版年
2020年 | 2篇 |
2019年 | 2篇 |
2017年 | 1篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 9篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1990年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1967年 | 1篇 |
排序方式: 共有136条查询结果,搜索用时 109 毫秒
21.
22.
Abstract The purpose of this article is to analyse whether the presence of surplus emission allowance trading jeopardizes the environmental target of an international environmental agreement. We argue that surplus emission allowance trading can be used as an implicit side-payment mechanism to actually bring about higher environmental protection compared with the situation without the trade option. We point to the existence of a fundamental trade-off between costs of compliance and the creation of dynamic incentives to develop cheaper reduction technologies. Implicit side payments, in terms of surplus emission allocations, may be needed in order to establish a compromise between these opposing demands. We identify the shortcomings and benefits of allowing fully flexible permit trading, including the allocation rule of grandfathering. 相似文献
23.
24.
Alan B. Binder Manfred A. Lange Heinz-Jürgen Brandt Susanne Kähler 《Earth, Moon, and Planets》1980,23(4):445-481
A synthesis of the majority of the available mare basalt data shows that basalts and glasses came from 28 different volcanic units. The compositions of the magmas of 12 of these units can be calculated with a high degree of confidence. Reasonable estimates can be made for the compositions of nine of the remaining units. In addition, the compositions of three general magma types can be obtained from data derived from the Luna 16, Luna 24, and Apollo 17 fines. The compositional data presented provide a firm basis for the further study of the characteristics of the mare basalt magma source region. 相似文献
25.
A. Mura S. Orsini E. Kallio S. Barabash A. Grigoriev H. Andersson M. Yamauchi N. Krupp K. Asamura C.C. Curtis B.R. Sandel M. Grande J.U. Kozyra S. McKenna-Lawlor R. D’Amicis S. Massetti P.C. Brandt R.A. Frahm 《Planetary and Space Science》2008,56(6):840-845
The Analyzer of Space Plasma and EneRgetic Atoms (ASPERA-3) on board Mars Express is designed to study the interaction between the solar wind and the atmosphere of Mars and to characterize the plasma and neutral gas environment in near-Mars space. Neutral Particle Detectors (NPD-1 and 2), which form part of the ASPERA-3 instrument suite, are Energetic Neutral Atom (ENA) detectors which use the time-of-flight (ToF) technique to resolve the energy of detected particles. In the present study, we perform a statistical analysis of NPD ToF data collected between 14 March 2004 and 17 June 2004 when Mars Express was located at the dayside of Mars looking toward the planet. After pre-processing and removal of UV contamination, the ToF spectra were fitted with simple analytical functions so as to derive a set of parameters. The behavior of these parameters, as a function of spacecraft position and attitude, is compared with a model, which describes ENA generation by charge exchange between shocked solar wind protons and extended Martian exosphere. The observations and the model agree well, indicating that the recorded signals are charge-exchanged shocked solar wind. 相似文献
26.
E. Kallio T.L. Zhang R. Jarvinen P. Janhunen J.-A. Sauvaud J.-J. Thocaven H. Andersson K. Brinkfeldt M. Holmström M. Yamauchi W. Baumjohann A.J. Coates D.O. Kataria K.C. Hsieh M. Grande T. Säles P. Riihelä N. Krupp J.G. Luhmann S. Orsini A. Mura M. Maggi P. Brandt K. Szego R.A. Frahm J.R. Sharber P. Bochsler 《Planetary and Space Science》2008,56(6):796-801
Plasma and magnetic field measurements made onboard the Venus Express on June 1, 2006, are analyzed and compared with predictions of a global model. It is shown that in the orbit studied, the plasma and magnetic field observations obtained near the North Pole under solar minimum conditions were qualitatively and, in many cases also, quantitatively in agreement with the general picture obtained using a global numerical quasi-neutral hybrid model of the solar wind interaction (HYB-Venus). In instances where the orbit of Venus Express crossed a boundary referred to as the magnetic pileup boundary (MPB), field line tracing supports the suggestion that the MPB separates the region that is magnetically connected to the fluctuating magnetosheath field from a region that is magnetically connected to the induced magnetotail lobes. 相似文献
27.
The decrease in the rms contrast of time-averaged images with the averaging time is compared between four data sets: (1) a
series of solar granulation images recorded at La Palma in 1993, (2) a series of artificial granulation images obtained in
numerical simulations by Rieutord et al. (Nuovo Cimento
25, 523, 2002), (3) a similar series computed by Steffen and his colleagues (see Wedemeyer et al. in Astron. Astrophys.
44, 1121, 2004), (4) a random field with some parameters typical of the granulation, constructed by Rast (Astron. Astrophys.
392, L13, 2002). In addition, (5) a sequence of images was obtained from real granulation images by using a temporal and spatial shuffling
procedure, and the contrast of the average of n images from this sequence as a function of n is analysed. The series (1) of real granulation images exhibits a considerably slower contrast decrease than do both the
series (3) of simulated granulation images and the series (4) of random fields. Starting from some relatively short averaging
times t, the behaviour of the contrast in series (3) and (4) resembles the t
−1/2 statistical law, whereas the shuffled series (5) obeys the n
−1/2 law from n=2 on. Series (2) demonstrates a peculiarly slow decline of contrast, which could be attributed to particular properties of
the boundary conditions used in the simulations. Comparisons between the analysed contrast-variation laws indicate quite definitely
that the brightness field of solar granulation contains a long-lived component, which could be associated with locally persistent
dark intergranular holes and/or with the presence of quasi-regular structures. The suggestion that the random field (4) successfully
reproduces the contrast-variation law for the real granulation (Rast in Astron. Astrophys.
392, L13, 2002) can be dismissed. 相似文献
28.
29.
30.