全文获取类型
收费全文 | 257篇 |
免费 | 6篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 10篇 |
地球物理 | 22篇 |
地质学 | 69篇 |
海洋学 | 21篇 |
天文学 | 100篇 |
综合类 | 2篇 |
自然地理 | 38篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 5篇 |
2013年 | 7篇 |
2012年 | 9篇 |
2011年 | 17篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 15篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 18篇 |
2004年 | 25篇 |
2003年 | 17篇 |
2002年 | 20篇 |
2001年 | 13篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 5篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有263条查询结果,搜索用时 15 毫秒
81.
Chris Blake Michael B. Pracy Warrick J. Couch Kenji Bekki Ian Lewis Karl Glazebrook Ivan K. Baldry Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Matthew Colless Chris Collins Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Carole Jackson Ofer Lahav Stuart Lumsden Steve Maddox Darren Madgwick Peder Norberg John A. Peacock Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2004,355(3):713-727
82.
83.
84.
Will J. Percival Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Carole Jackson Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Stephen Moody Peder Norberg John A. Peacock Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2001,327(4):1297-1306
The 2dF Galaxy Redshift Survey has now measured in excess of 160 000 galaxy redshifts. This paper presents the power spectrum of the galaxy distribution, calculated using a direct Fourier transform based technique. We argue that, within the k -space region , the shape of this spectrum should be close to that of the linear density perturbations convolved with the window function of the survey. This window function and its convolving effect on the power spectrum estimate are analysed in detail. By convolving model spectra, we are able to fit the power-spectrum data and provide a measure of the matter content of the Universe. Our results show that models containing baryon oscillations are mildly preferred over featureless power spectra. Analysis of the data yields 68 per cent confidence limits on the total matter density times the Hubble parameter , and the baryon fraction , assuming scale-invariant primordial fluctuations. 相似文献
85.
Michelle A Ramsay Richard P.J Swannell Warren A Shipton Norman C Duke Russell T Hill 《Marine pollution bulletin》2000,41(7-12):413-419
Bioremediation was conducted in the field on a mature Rhizophora stylosa mangrove stand on land to be reclaimed near Fisherman’s Landing Wharf, Gladstone Australia. Gippsland crude oil was added to six large plots (>40 m2) and three plots were left untreated as controls. Bioremediation was used to treat three oiled plots and the remaining three were maintained as oiled only plots. The bioremediation strategy consisted of actively aerating the sediment and adding a slow-release fertilizer in order to promote oil biodegradation by indigenous micro-organisms. Oil addition stimulated the numbers of alkane-degrading bacteria slightly to levels of 104–105/g sediment. Bioremediation of the oiled sediment had a marked effect on the alkane-degrading population, increasing the population size by three orders of magnitude from 105 to 108 cells/g of sediment. An effect of bioremediation on the growth of aromatic-degraders was detected with numbers of aromatic-degraders increasing from 104 to 106 cells/g of sediment. Active aeration and nutrient addition significantly stimulated the growth of hydrocarbon-degraders in oiled mangrove sediment in the field. 相似文献
86.
SYNCONVERGENT, DUCTILE N-DIRECTED SHEARING ON THE WESTERN MARGIN OF THE NANGA PARBAT SYNTAXIS, N. PAKISTAN1 BurgJ P ,ChaudryMN ,GhazanfarM ,etal.StructuralevidenceforbackslidingoftheKohistanarcinthecollisionalsystemofnorthwestPakistan[J] .Geology 1996 ,2 4 ( 8) ,739~ 74 2 .
2 ChamberlainCP ,ZeitlerPK ,EricksonE .ConstraintsonthetectonicevolutionofthenorthwesternHimalayafromgeochronologicandpetrologicstudiesofBabusarPass,Pakistan[J] .Journa… 相似文献
87.
Rahul Sharma B. Nagendernath A. B. Valsangkar G. Parthiban K. M. Sivakolundu Gavin Walker 《Marine Georesources & Geotechnology》2000,18(3):209-221
As a part of the Environmental Impact Assessment studies for nodule mining, a long-term program has been initiated in the Central Indian Basin. Multidisciplinary studies on geological, biological, physical, and chemical parameters were carried out in an area selected on the basis of baseline data collected in the first phase of the program. A benthic disturbance was simulated with a hydraulic device also used in the previous experiments in the Pacific Ocean. A site of 3,000 ×200 m was repeatedly disturbed by a combination of fluidizing pump and suction pump to dislodge and discharge sediment from the seafloor into the water column 5 m above the seafloor. During 9 days of operation, 26 tows were carried out for 47 h of disturbance, resuspending about 6,000 m 3 of sediment along an 88-km line. Data for postdisturbance impact assessment were collected with sediment traps, deep-towed cameras, seafloor samples, and conductivity-temperature depth sensor (CTD)-rosette observations. Seafloor data, sediment samples, and water column studies were aimed at evaluating the impact of benthic disturbance, on the basis of pre- and postdisturbance data collected during the experiment. Observations show that vertical mixing of sediment as well as its lateral movement and resedimentation because of plume migration alters various parameters and leads to changes in the environment around the area. 相似文献
88.
Gavin Ramsay Mark Cropper Kinwah Wu K. O. Mason Pasi Hakala 《Monthly notices of the Royal Astronomical Society》2000,311(1):75-84
We have detected the optical counterpart of the proposed double degenerate polar RX J1914+24. The I -band light curve is modulated on the 9.5-min period seen in X-rays. There is no evidence for any other periods. No significant modulation is seen in J . The infrared colours of RX J1914+24 are not consistent with a main-sequence dwarf secondary star. Our ASCA spectrum of RX J1914+24 is typical of a heavily absorbed polar and our ASCA light curve also shows only the 9.5-min period. We find that the folded I band and X-ray light curves are out of phase. We attribute the I -band flux to the irradiated face of the donor star. The long-term X-ray light curve shows a variation in the observed flux of up to an order of magnitude. These observations strengthen the view that RX J1914+24 is indeed the first double degenerate polar to be detected. In this light, we discuss the synchronizing mechanisms in such a close binary and other system parameters. 相似文献
89.
Gavin Kenny 《Climatic change》2011,106(3):441-462
Assessments of adaptation in agriculture have evolved considerably from early, top-down, impact assessments. These early assessments,
internationally and in New Zealand, provided a limited view of ‘smart farmer’ adaptation. While impact assessment provides
some useful insights, experience with vulnerability and adaptation assessment provides a more appropriate foundation for understanding
and characterising practical smart farmer adaptation. Findings are presented from 8 years of engagement with farmers in eastern
regions of New Zealand. A comprehensive farm resilience picture has emerged from this work. This picture reflects a strong
belief from real-world smart farmers that there is sufficient knowledge and experience to adapt to climate change. Proactive
farmers are already reading multiple signals, including changes in climate, and are responding. The farm resilience picture
provides a foundation for exploring alternative adaptation options and pathways for agriculture. These are presented and discussed
in response to two proposed climate change scenarios, a high carbon world scenario and a rapidly decarbonising world scenario.
Knowledge intensive, low input systems are consistent with the resilience picture drawn from farmers. Such systems are also
consistent with a rapidly decarbonising world scenario and, it is argued, are likely to become increasingly attractive under
a high carbon world scenario. A smart farming approach, focused on resilience, provides the basis for development of a response
capacity, with potentially significant co-benefits in terms of adaptation and mitigation to climate change. Wider issues and
needs to support the further development of farm resilience, and more widely landscape or regional resilience, are identified
and discussed. It is apparent from this work that ongoing engagement with smart farmers, focused on resilience, can contribute
significantly to development of a coordinated ‘bottom up’ and ‘top down’ response capacity. Addressing the psychology of change
is a fundamental need to ensure wider engagement. 相似文献
90.
Copenhagen 2009 was a major moment in the development of climate change as an issue. But climate sceptics before and during this event, sought to influence the nature of debate, and for this reason, the way Copenhagen was covered in the mass media was particularly important. This paper outlines the contours of contrarian arguments and claims, and assesses their reflection in the coverage at Copenhagen. The focus is on television, and extends to the assessment of internet - both modes of mass communication underrepresented in the existing literature. The results suggest a higher profile for contrarians and scepticism than is perhaps healthy, and speak to the role of these mass media, now and in the future, particularly with regard to the issue of public comprehension of the issues involved. 相似文献