全文获取类型
收费全文 | 388篇 |
免费 | 7篇 |
国内免费 | 11篇 |
专业分类
测绘学 | 9篇 |
大气科学 | 15篇 |
地球物理 | 130篇 |
地质学 | 127篇 |
海洋学 | 22篇 |
天文学 | 76篇 |
综合类 | 6篇 |
自然地理 | 21篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 2篇 |
2018年 | 11篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 20篇 |
2012年 | 15篇 |
2011年 | 30篇 |
2010年 | 15篇 |
2009年 | 27篇 |
2008年 | 17篇 |
2007年 | 19篇 |
2006年 | 12篇 |
2005年 | 10篇 |
2004年 | 16篇 |
2003年 | 8篇 |
2002年 | 9篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1988年 | 2篇 |
1987年 | 7篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1961年 | 1篇 |
1960年 | 2篇 |
排序方式: 共有406条查询结果,搜索用时 296 毫秒
381.
Airborne Fungal Spores of Subalpine Zone of the Karkonosze and Izerskie Mountains (Poland) 总被引:4,自引:1,他引:3
The incidence of the airborne fungal spores was determined in the air of subalpine zone of the Karkonosze Mountains and of the Izerskie Mountains in the borderland between Poland and the Czech Republic. The experiment was conducted in 2011 and 2012 at three to four week intervals from May to October. Air samples were taken from three locations in the Karkonosze Mts. and one from the Izerskie Mts. To examine the air, the Air Ideal 3P sampler and acidified PDA medium were used. The results show that Cladosporium cladosporioides was the most abundant spore type in all the sampling locations (up to 30%), followed by Alternaria alternata (16%-20%), Fusarium (up to 10%) and Sclerotinia sclerotiorium (up to 6%). The lower spore counts were recorded in May samples, compared to the other months. In this case the snow cover, that was still present in the area at the beginning of May, may be the reason for the lower, compared to June, July and August samplings, CFU (Colony Forming Unit) counts in that month.. The influx of air masses from SE, S and SW sectors in the area under study may affect dissemination of the plant-pathogenic fungi from the Czech Republic and from the South of Europe in general. 相似文献
382.
383.
384.
Andrzej Aniszewski 《Acta Geophysica》2009,57(2):435-453
The paper addresses the 2D mathematical equation of conservative contaminant transport in an aquifer for chosen contaminants.
The contaminants (chlorides and sulfates) are subject to instantaneous reversible part of sorption process. The term of instantaneous
reversible sorption in the presented equation has been described by the non-linear Freundlich adsorption isotherm, widely
applied in practice in relation to static processes (for local equilibrium). The numerical solution (using the finite difference
method) has been based on the previously calculated values of longitudinal and transverse dispersion coefficients and the
non-linear adsorption parameters for the chosen contaminants. Based on this model, the values of chloride and sulfate concentration
isolines have been calculated and compared with the measured maximal concentrations in the chosen natural aquifer (installed
piezometers). Additionally, the values of chloride concentrations have been calculated taking into account the influence of
radioactive decay term, using the numerical value of the firstorder decay rate constant for an adopted theoretical radionuclide. 相似文献
385.
Bonnie A. Stevens Andrzej J. Maciejewski 《Celestial Mechanics and Dynamical Astronomy》2002,82(2):111-112
Preface
Preface 相似文献386.
INTRODUCTIONTheHuangheRiverwellknownworldwideforitshighsedimentdischargeisChina’ssecondlargestriver,whoserunoffismainlysuppliedbyprecipitationovertheupperreaches.However,thematerialfromsoilerosionintheLoessPlateauinthemiddlereachesisamajorcontributort… 相似文献
387.
Gaussian beams in anisotropic elastic media 总被引:2,自引:0,他引:2
Andrzej Hanyga 《Geophysical Journal International》1986,85(3):473-504
388.
Ryszard K. Borwka Andrzej Osadczuk Andrzej Witkowski Brygida Wawrzyniak-Wydrowska Tomasz Duda 《Quaternary International》2005,130(1):87
Analyses on 27 sediment cores taken from the bottom of the Szczecin Lagoon allowed environmental reconstruction of the postglacial main stages of basin development, based on detailed sedimentological, geochemical, diatomological and malacological studies of selected key cores. Studies revealed that during the Late Glacial and Holocene this area developed in several stages. In the Late Glacial the whole study area constituted a low alluvial plain. At the turn from Younger Dryas to Holocene the alluvial plain was cut through by the Odra river to a level of 10–11 m below sea level (b.s.l.). Along with the first phases of the Holocene marine transgression at the southern Baltic Sea's coasts the accumulation of the limnic-swampy deposits began in this lower part of the Odra valley. At ca. 6–6.5 ka BP the transgression proceeded and Littorina Sea waters flooded the area. At that time the Szczecin Lagoon constituted a marine embayment in which series of sands, partly rich in malacofauna, was deposited. The development of the Swina barrier resulted in the isolation of the embayment from the direct inflow of Baltic Sea waters. 相似文献
389.
Estimation of the Maximum Earthquake Magnitude, <Emphasis Type="Italic">m</Emphasis><Subscript>max</Subscript> 总被引:1,自引:0,他引:1
This paper provides a generic equation for the evaluation of the maximum earthquake magnitude mmax for a given seismogenic zone or entire region. The equation is capable of generating solutions in different forms, depending on the assumptions of the statistical distribution model and/or the available information regarding past seismicity. It includes the cases (i) when earthquake magnitudes are distributed according to the doubly-truncated Gutenberg-Richter relation, (ii) when the empirical magnitude distribution deviates moderately from the Gutenberg-Richter relation, and (iii) when no specific type of magnitude distribution is assumed. Both synthetic, Monte-Carlo simulated seismic event catalogues, and actual data from Southern California, are used to demonstrate the procedures given for the evaluation of mmax.The three estimates of mmax for Southern California, obtained by the three procedures mentioned above, are respectively: 8.32 ± 0.43, 8.31 ± 0.42 and 8.34 ± 0.45. All three estimates are nearly identical, although higher than the value 7.99 obtained by Field et al. (1999). In general, since the third procedure is non-parametric and does not require specification of the functional form of the magnitude distribution, its estimate of the maximum earthquake magnitude mmax is considered more reliable than the other two which are based on the Gutenberg-Richter relation. 相似文献
390.
Tetsuya Watanabe Hirohisa Haka Toshifumi Shimizu Eijiro Hiei Robert D. Bentley James Lang Kenneth J. H. Phillips C. David Pike Andrzej Fludra Barbara J. I. Bromage John T. Mariska 《Solar physics》1995,157(1-2):169-184
Solar active-region temperatures have been determined from the full-Sun spectra of helium-like sulphur (Sxv) observed by the Bragg Crystal Spectrometer on board theYohkoh satellite. The average temperature deduced from Sxv is demonstrated to vary with the solar activity level: A temperature of 2.5 × 106 K is derived from the spectra taken during low solar activity, similar to the general corona, while 4 × 106 K is obtained during a higher activity phase. For the latter, the high-temperature tail of the differential emission measure of active regions is found most likely due to the superposition of numerous flare-like events (micro/nano-flares). 相似文献