全文获取类型
收费全文 | 162篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
大气科学 | 5篇 |
地球物理 | 47篇 |
地质学 | 35篇 |
海洋学 | 23篇 |
天文学 | 51篇 |
综合类 | 1篇 |
自然地理 | 9篇 |
出版年
2023年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 13篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有171条查询结果,搜索用时 250 毫秒
51.
Alexandre Raphael Cabral Harilaos Tsikos Yasuyuki Muramatsu Tomoko Sekiya 《Chemie der Erde / Geochemistry》2011,71(3):297-301
A reconnaissance bulk geochemical study was carried out on ten samples from the Palaeoproterozoic Hotazel iron formation, South Africa, with emphasis on iodine and bromine abundances. Very low-absolute contents recorded for both halogens, i.e. 0.08–0.26 μg/g for I and 0.35–1.23 μg/g for Br, indicate that they should largely have been lost during burial diagenesis. Bulk I/Br ratios (0.08–0.50), however, show marginal variation across the selected sample set and broadly resemble those that typify recent marine sediments containing organic matter. The possibility emerges that both elements are organic matter-sourced and may thus provide a potential proxy for the role of biological processes during deposition and diagenesis of Precambrian iron formations. 相似文献
52.
Unprecedented rates of landslide and surface erosion along a newly constructed road in Yunnan, China
Field measurements conducted 4 years after the construction of a new portion of the Weixi?CShangri-La road in Yunnan, China, reveal that unprecedented rates of mass wasting occurred along the road with much of this sediment directly impacting the headwaters of the Mekong River. Landslide erosion (including dry ravel) exceeded 33,000 t ha?1 year?1 along the most severely eroded sections of the road and averaged more than 9,600 t ha?1 year?1 along the surveyed 23.5 km of road; these values are the highest ever reported for road-related landslides. While surface erosion was only about 7% of the total erosion from the road, it is still more than an order of magnitude higher than typical surface erosion rates from disturbed lands in Southeast Asia. Combined landslide and surface erosion from this road delivered an estimated 19 times more sediment to the river than the remaining 99.6% of the contributing catchment. These sediment inputs are aggrading local channels, promoting downstream sediment transport, degrading aquatic habitat, and creating the possibility for a future debris flood or hyperconcentrated flow. 相似文献
53.
54.
Y.T. Hong B. Hong Q.H. Lin Y. Shibata Y.X. Zhu X.T. Leng Y. Wang 《Quaternary Science Reviews》2009,28(9-10):840-849
A peat cellulose δ18O record spanning around 14,000 years from the Hani peat mire in northeastern China reveals several abrupt temperature anomalies in the period from the last deglaciation through the Holocene. The timing of these anomalies coincides well with the notable cooling events recorded respectively using the GISP2 ice core and ice-rafted sediment of the North Atlantic Ocean, such as the Older Dryas, Inter-Allerød, Younger Dryas, and the nine ice-rafted debris events. The results demonstrate that this repeating pattern of abrupt temperature deterioration is not limited to the North Atlantic area at high latitude but also exists in the western North Pacific region at middle latitude. The synchronous temperature anomalies possibly are resulted from the joint effects of meltwater discharge into the North Atlantic Ocean and reduced solar activity. In the period from around 8600 to 8200 cal. yrs BP the Hani peat record shows a broad δ18O peak that may reflect compound climate signals resulting from the two kinds of forcing factors: the temperature drop related to reduced solar activity at around 8600–8250 cal. yrs BP, and the temperature anomaly attributed to the meltwater effect at around 8220 ± 70 cal. yrs BP. This result may provide palaeo-temperature evidence for existence of the sharp “8.2 k” event in the western North Pacific region. In addition, our results have revealed that in the period from the last deglaciation through the Holocene the synchronous temperature anomalies before and after the “8.2 k” event seem to be related to meltwater outflow and reduced solar activity, respectively. It is important that the all temperature anomalies—whether because of reduced solar activity in the late Holocene or from meltwater discharge in the early Holocene—are accompanied by an abrupt decline in the Indian Ocean summer monsoon and abrupt strengthening of the East Asian summer monsoon. It is likely that reduced solar activity and meltwater outflow appear to modulate Earth system changes in the same direction. The influences could be compounded. Reduced solar activity and meltwater outburst both appear to act as triggers for occurrence of the El Niño phenomenon in the equatorial Pacific Ocean, which may result in broad teleconnections between the temperature anomaly in the Northern Hemisphere and abrupt variation of the Asian monsoon. 相似文献
55.
V. I. Slysh M. V. Popov B. Z. Kanevskii A. I. Smirnov A. V. Kovalenko Yu. P. Ilyasov V. V. Oreshko B. A. Poperechenko H. Hirabayashi K. M. Shibata E. B. Fomalont 《Astronomy Letters》2001,27(5):277-283
The 64-m radio telescope equipped with an S-2 recording system in the town of Kalyazin was involved in an international fine-structure survey of quasars and active galactic nuclei carried out with a ground-based—space radio interferometer. The HALCA Japanese satellite in an orbit with an altitude of up to 24 000 km with an 8-m antenna was used as a space element of the interferometer. A radio image of the inner region of the CSS-type quasar 3C 147 was obtained with an angular resolution of ~0.3 mas at 6 cm. The image exhibits a core and several jet components mostly arranged in the main jet direction, but one of the components moves across the jet. No evidence was found for the superluminal separation of jet components. The estimated brightness temperature,~1011 K, is consistent with the theoretical limit imposed by synchro-Compton radiation. 相似文献
56.
Kazunari Shibata Takara Nishikawa Reizaburo Kitai Yoshinori Suematsu 《Solar physics》1982,75(1-2):99-118
We present a spicule model whose eruption occurs as a result of the sudden pressure enhancement at the bright point located at the root of the spicule. To show this, one dimensional (constant cross sectional) and time dependent hydrodynamic equations are solved numerically in the realistic solar atmosphere extending from the photosphere to the corona. Adiabatic motion is assumed. The pressure enhancement by a bright point at the base of the model atmosphere generates a shock wave. The shock gets stronger as it passes upward through the chromosphere and eventually collides with the chromosphere-corona interface which is a kind of a contact discontinuity. As the result, the interface begins to move upward. We identify the matter following behind this interface as the solar spicule. The model explains many observed features, such as the height and the density of the spicules, although such features have been hitherto considered not to be explained easily by shock theories. 相似文献
57.
58.
59.
S. Takechi T. Miyachi M. Fujii N. Hasebe K. Nogami H. Ohashi S. Sasaki H. Shibata T. Iwai E. Grün R. Srama N. Okada 《Journal of Atmospheric and Solar》2009,71(2):191-193
A cosmic dust detector for installation on a satellite is currently being developed using piezoelectric lead zirconate titanate (PZT), which can possess both functions of the collector and the transducer. The characteristics of the PZT detector have been studied by bombarding it with hypervelocity particles supplied by a Van de Graaff accelerator. The front surface of the detector used in this study was covered with a white paint to reduce any increase in the temperature due to the solar radiation. There was a linear relationship between the rise time of the signal produced by the detector and the particle's velocities, which were above 10 km/s on impact. This implies that individual particle velocities on impact can be inferred through the empirical formula derived from the data obtained from the PZT detector. 相似文献
60.
Bing Hong CongQiang Liu QingHua Lin Shibata Yasuyuki XueTian Leng Yu Wang YongXuan Zhu YeTang Hong 《中国科学D辑(英文版)》2009,52(7):952-964
From the last deglaciation to the Holocene, the Greenland Ice Core (GISP2) δ 18O records as well as the records of ice-rafted debris on the surface of the North Atlantic have revealed a succession of sudden cooling events on the centennial to millennial scales. However, the temperature proxy records are rarely studied systematically and directly to ensure that this air temperature cooling pattern simultaneously existed in the East Asian Region, in addition to the repeated pattern occurring in the Greater Atlantic Region. A peat cellulose δ 18O temperature proxy record proximately existing for 14000 years was picked up from the Hani peat in Jilin Province, China. It suggests by comparison that the sudden cooling events, such as the Older Dryas, Inter-Allerød, Younger Dryas, and nine ice-rafted debris events of the North Atlantic, are almost entirely reiterated in the temperature signals of Hani peat cellulose δ 18O. These cooling events show that the repeatedly occurring temperature cooling pattern not only appeared in the North Atlantic Region in the high latitudes, but also in the Northwest Pacific Region in the middle latitudes. The climate change events marking the start of the Holocene Epoch, the Holocene Megathermal, the “8.2 kyr” event, the “4.2 kyr” event, the Medieval Warm Period, and the Little Ice Age are further discussed. The sensitivity response of Hani peat cellulose δ 18O to the land surface temperature and the reason for the age accuracy of peat cellulose 14C are also discussed based on the characteristics of the peat bog environment. 相似文献