全文获取类型
收费全文 | 49篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 9篇 |
地球物理 | 17篇 |
地质学 | 14篇 |
海洋学 | 5篇 |
天文学 | 1篇 |
自然地理 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1983年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有50条查询结果,搜索用时 15 毫秒
1.
The Holocene history of the Danube Delta has been studied using 14C analyses of faunal material. The principal phases of development include: (1) initial Letea Caroarman spit, 11,700–9800 yr B.P. in its central part, 8800-5500 yr B.P. in its southern part; (2) Sf. Gheorghe I Delta, 8900-7200 yr B.P.; (3) Sulina Delta, 7200-2000 yr B.P., and (4) Sf. Gheorghe II Delta-Chilia Delta 2000 yr B.P.-present. Other smaller-scale features have also been dated, including secondary deltas (Co?na and Sinoe Deltas) and littoral bars. Age determinations carried out on whole samples were erratic and it was found that individual species had to be separated and dated. In all cases, the older dates were of transported material whereas the younger dates gave the true age of the formation. 相似文献
2.
Belyaev Yu. R. Panin A. V. Kiryuhina A. D. Koshurnikov A. V. Kramynin A. M. Pavlov M. A. Konstantinov E. A. Kurbanov R. N. Zakharov A. L. Sychev N. V. 《Doklady Earth Sciences》2022,506(1):S84-S93
Doklady Earth Sciences - A complex of works including geomorphological deciphering, field survey, drilling, electric prospecting, and dating of deposits using the radiocarbon method and optically... 相似文献
3.
Water Resources - The runoff of glacial melt water into the river system of the Volga and farther into the Caspian Sea is evaluated for the epoch of the last glaciation. Melt water entered the... 相似文献
4.
Water Resources - Large paleochannels, which are common in the floodplains and terraces of rivers in the Volga Basin, are indicators of an appreciable increase in river flow in the past and can be... 相似文献
5.
K. A. Goncharov O. A. Golovin A. Yu. Kochetkov M. A. Balykin K. N. Korzhov Yu. V. Panin V. A. Antonov 《Solar System Research》2013,47(7):554-560
In this paper, methods of control for the temperature of the loop heat pipe evaporator by an external thermal action on elements of the pipe construction are described. 相似文献
6.
A. Y. Sidorchuk A. V. Panin O. K. Borisova S. A. Elias J. P. Syvistki 《International Journal of Earth Sciences》2000,89(3):541-549
The relicts of large meandering palaeochannels are found throughout the territory of the periglacial zone of the Last (Valdai=Weichselian) Glaciation on the Russian Plain. Channel widths of macromeanders can be 15 times larger than the recent meanders of the same rivers. Palaeolandscape and palaeohydrological reconstructions show that these periglacial river channels were formed under conditions of high spring water flow, up to eight times greater than the modern discharges, when the flow coefficient was close to 0.9-1.0 due to presence of permafrost, summers were dry and streams lacked ground water supply. Permafrost degradation increased soil permeability in spring and increased ground water flow in summer, causing a decrease of annual flow (due mainly to the flood flow decrease in spring). As a result, large periglacial channels were abandoned and transformed into lakes and bogs. Late Holocene channels have much smaller channel widths and meander lengths. These were formed under conditions of lower annual flows and much steadier flow regime. 相似文献
7.
Irina Popescu Gilles Lericolais Nicolae Panin Marc De Batist Hervé Gillet 《Geo-Marine Letters》2007,27(2-4):173-183
This study is a synthesis of gas-related features in recent sediments across the western Black Sea basin. The investigation
is based on an extensive seismic dataset, and integrates published information from previous local studies. Our data reveal
widespread occurrences of seismic facies indicating free gas in sediments and gas escape in the water column. The presence
of gas hydrates is inferred from bottom-simulating reflections (BSRs). The distribution of the gas facies shows (1) major
gas accumulations close to the seafloor in the coastal area and along the shelfbreak, (2) ubiquitous gas migration from the
deeper subsurface on the shelf and (3) gas hydrate occurrences on the lower slope (below 750 m water depth). The coastal and
shelfbreak shallow gas areas correspond to the highstand and lowstand depocentres, respectively. Gas in these areas most likely
results from in situ degradation of biogenic methane, probably with a contribution of deep gas in the shelfbreak accumulation.
On the western shelf, vertical gas migration appears to originate from a source of Eocene age or older and, in some cases,
it is clearly related to known deep oil and gas fields. Gas release at the seafloor is abundant at water depths shallower
than 725 m, which corresponds to the minimum theoretical depth for methane hydrate stability, but occurs only exceptionally
at water depths where hydrates can form. As such, gas entering the hydrate stability field appears to form hydrates, acting
as a buffer for gas migration towards the seafloor and subsequent escape. 相似文献
8.
9.
G. N. Panin A. E. Nasonov Th. Foken H. Lohse 《Theoretical and Applied Climatology》2006,85(3-4):123-129
Summary This paper demonstrates that typical air–sea interaction models can be transferred to shallow water conditions and lakes including
a depth dependent function. As depth decreases, it is assumed that exchange conditions increase. From our results it follows
that the model without the shallow water correction underestimates the latent and sensible heat fluxes of a lake by about
20%. This was shown through the comparison of the model with eddy covariance data for a shallow lake during the LITFASS-98
experiment in Germany. Furthermore, data selection according to the fetch and footprint conditions is presented. These models
are also useful for gap filling procedures at measuring stations over lakes with limited fetch conditions in selected directions. 相似文献
10.
Inhomogeneity of the Land Surface and Problems in theParameterization of Surface Fluxes in Natural Conditions 总被引:1,自引:0,他引:1
Summary Eddy correlation techniques to determine the turbulent fluxes of heat, moisture and momentum in the near-surface atmospheric
layer rely on the Monin-Obukhov similarity theory, which requires stationarity and horizontal homogeneity. Experiments at
specially selected sites over land and particularly over sea are used to develop this concept. Recent experiments, deliberately
conducted in non-ideal conditions, show an underestimation of turbulent fluxes. Results from the field experiments FIFE, KUREX,
TARTEX and SADE, point to a relationship between the underestimation of turbulent fluxes and terrain inhomogeneity. In order
to systematically correct for this effect a scheme is suggested which uses fetch lengths of different types of surface in
the sites surrounding the environment. In addition, horizontal differences in atmospheric stability above different surfaces
are included in the correction scheme. This scheme might be useful for the design of validation experiments in non-homogeneous
terrain.
Received April 9, 1997 Revised July 16, 1997 相似文献