全文获取类型
收费全文 | 426篇 |
免费 | 10篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 26篇 |
大气科学 | 48篇 |
地球物理 | 87篇 |
地质学 | 134篇 |
海洋学 | 31篇 |
天文学 | 79篇 |
综合类 | 3篇 |
自然地理 | 32篇 |
出版年
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 6篇 |
2011年 | 21篇 |
2010年 | 10篇 |
2009年 | 17篇 |
2008年 | 17篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 14篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1994年 | 14篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1924年 | 2篇 |
1923年 | 2篇 |
排序方式: 共有440条查询结果,搜索用时 15 毫秒
41.
Eric Huff A.E. Schulz Martin White David J. Schlegel Michael S. Warren 《Astroparticle Physics》2007,26(6):351-366
The coupling of photons and baryons by Thomson scattering in the early universe imprints features in both the cosmic microwave background (CMB) and matter power spectra. The former have been used to constrain a host of cosmological parameters, the latter have the potential to strongly constrain the expansion history of the universe and dark energy. Key to this program is the means to localize the primordial features in observations of galaxy spectra which necessarily involve galaxy bias, non-linear evolution and redshift space distortions. We present calculations, based on mock catalogs produced from high-resolution N-body simulations, which show the range of behaviors we might expect of galaxies in the real universe. We investigate physically motivated fitting forms which include the effects of non-linearity, galaxy bias and redshift space distortions and discuss methods for analysis of upcoming data. In agreement with earlier work, we find that a survey of several Gpc3 would constrain the sound horizon at z 1 to about 1%. 相似文献
42.
43.
P. Rodríguez-Gil B. T. Gänsicke H.-J. Hagen S. Araujo-Betancor A. Aungwerojwit C. Allende Prieto D. Boyd J. Casares D. Engels O. Giannakis E. T. Harlaftis J. Kube H. Lehto I. G. Martínez-Pais R. Schwarz W. Skidmore A. Staude M. A. P. Torres 《Monthly notices of the Royal Astronomical Society》2007,377(4):1747-1762
44.
45.
46.
47.
Laurent Gindre‐Chanu John K. Warren Cai Puigdefabregas Ian R. Sharp David C. P. Peacock Roger Swart Ragnar Poulsen Hercinda Ferreira Lourenco Henrique 《Sedimentology》2015,62(1):204-233
The widespread and dissected nature of the Angolan gypsiferous salt residuals offers a uniquely detailed view of the lateral and vertical relations inherent to secondary evaporite textures, which typify exhumed salt masses worldwide. Such secondary textures are sometimes misinterpreted as primary evaporite textures. Thin, metre‐scale and patchy, dome‐like gypsum accumulations are well‐exposed within strongly incised present‐day river valleys along the eastern margin of the Namibe and Benguela basins (south‐west Angola). These sections are time equivalent to the main basinward subsurface evaporites (Aptian Loeme Formation) which mostly consist of halite. The gypsum (here called the Bambata Formation) is interpreted to represent the final residual product of fractional dissolution and recrystallization of the halite mass that occurred during Late Cretaceous margin uplift and continues today. This halite underwent multiple episodes of diagenetic alteration between its deposition and its final exhumation, leading to the formation of various secondary gypsum fabrics and solution‐related karst and breccia textures that typify the current evaporite outcrop. Four different diagenetic gypsum fabrics are defined: thinly bedded alabastrine, nodular alabastrine, displacive selenite rosettes and fibrous satin‐spar gypsum. Current arid conditions are responsible for a thin weathered crust developed at the top of the outcropping gypsum, but the fabrics in the main core of the current at‐surface evaporite unit mostly formed during the telogenetic stage of uplift prior to complete subaerial exposure. Alteration occurred as various dissolving and rehydrating saline minerals encountered shallow aquifers in the active phreatic and vadose zones. Geomorphological and petrographic analyses, mostly based on the cross‐cutting relations and crystallographic patterns in the outcrop, are used to propose a sequence of formation of these different fabrics. 相似文献
48.
49.
Marjolijn Haasnoot Jan H. Kwakkel Warren E. Walker Judith ter Maat 《Global Environmental Change》2013,23(2):485-498
A new paradigm for planning under conditions of deep uncertainty has emerged in the literature. According to this paradigm, a planner should create a strategic vision of the future, commit to short-term actions, and establish a framework to guide future actions. A plan that embodies these ideas allows for its dynamic adaptation over time to meet changing circumstances. We propose a method for decisionmaking under uncertain global and regional changes called ‘Dynamic Adaptive Policy Pathways’. We base our approach on two complementary approaches for designing adaptive plans: ‘Adaptive Policymaking’ and ‘Adaptation Pathways’. Adaptive Policymaking is a theoretical approach describing a planning process with different types of actions (e.g. ‘mitigating actions’ and ‘hedging actions’) and signposts to monitor to see if adaptation is needed. In contrast, Adaptation Pathways provides an analytical approach for exploring and sequencing a set of possible actions based on alternative external developments over time. We illustrate the Dynamic Adaptive Policy Pathways approach by producing an adaptive plan for long-term water management of the Rhine Delta in the Netherlands that takes into account the deep uncertainties about the future arising from social, political, technological, economic, and climate changes. The results suggest that it is worthwhile to further test and use the approach. 相似文献
50.