全文获取类型
收费全文 | 91篇 |
免费 | 1篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 3篇 |
大气科学 | 6篇 |
地球物理 | 16篇 |
地质学 | 18篇 |
海洋学 | 22篇 |
天文学 | 24篇 |
自然地理 | 7篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 7篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 10篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1986年 | 2篇 |
1983年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有96条查询结果,搜索用时 15 毫秒
71.
K. Iwasawa G. Matt A.C. Fabian S. Bianchi W.N. Brandt M. Guainazzi T. Murayama Y. Taniguchi 《Monthly notices of the Royal Astronomical Society》2001,326(1):119-125
We report on the BeppoSAX detection of a hard X-ray excess in the X-ray spectrum of the classical high-ionization Seyfert 2 galaxy Tol 0109–383. The X-ray emission of this source observed below 7 keV is dominated by reflection from both cold and ionized gas, as seen in the ASCA data. The excess hard X-ray emission is presumably caused by the central source absorbed by an optically thick obscuring torus with N H ∼2×1024 cm−2 . The strong cold X-ray reflection, if it is produced at the inner surface of the torus, is consistent with the picture where much of the inner nucleus of Tol 0109–383 is exposed to direct view, as indicated by optical and infrared properties. However, the X-ray absorption must occur at small radii in order to hide the central X-ray source but leave the optical high-ionization emission-line region unobscured. This may also be the case for objects such as the Seyfert 1 galaxy Mrk231. 相似文献
72.
Yoshinobu Tsuji Hideo Matsutomi Fumihiko Imamura Minoru Takeo Yoshiaki Kawata Masafumi Matsuyama Tomoyuki Takahashi Sunarjo Prih Harjadi 《Pure and Applied Geophysics》1995,144(3-4):481-524
A field survey of the 1992 Flores Island earthquake tsunami was conducted during December 29, 1992 to January 5, 1993 along the north coast of the eastern part of Flores Island. We visited over 40 villages, measured tsunami heights, and interviewed the inhabitants. It was clarified that the first wave attacked the coast within five minutes at most of the surveyed villages. The crust was uplifted west of the Cape of Batumanuk, and subsided east of it. In the residential area of Wuring, which is located on a sand spit with ground height of 2 meters, most wooden houses built on stilts collapsed and 87 people were killed even though the tsunami height reached only 3.2 meters. In the two villages on Babi Island, the tsunami swept away all wooden houses and killed 263 of 1,093 inhabitants. Tsunami height at Riang-Kroko village on the northeastern end of Flores Island reached 26.2 meters and 137 of the 406 inhabitants were killed by the tsumani. Evidence of landslides was detected at a few points on the coast of Hading Bay, and the huge tsunami was probably formed by earthquake-induced landslides. The relationship between tsunami height and mortality was checked for seven villages. The efficiencies of trees arranged in front of coastal villages, and coral reefs in dissipating the tsunami energy are discussed. 相似文献
73.
Masahiro Takenobu Masafumi Miyata Yu Otake Takehiko Sato 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2019,13(3):195-204
ABSTRACTThe Partial Factor Method (PFM) based on the Level 1 reliability design method was introduced in 2007 to the Technical Standards for Port and Harbour Facilities (TSPHF-2007) in Japan. After nearly 10 years of practical use of TSPHF-2007, the design standard has been revised based on requests from the practitioners who recommend the transition from the PFM to the Load Resistance Factor Design (LRFD). In this paper, we discuss the setting method of the target failure probability to determine the partial factors based on code calibration. Furthermore, we examine the impacts of implementing the LRFD concept to the TSPHF by taking the sliding and overturning of a gravity type quay wall as an example to represent port and harbour facilities. We found no practical difference in caisson width derived using the LRFD and the PFM, whereas the degree of matching of the target failure probability was somewhat more precise for the PFM. This finding indicates that the LRFD is a more reasonable design method than the PFM in terms of the simplicity of the performance function itself and the ease of engineering interpretation during the design procedure. 相似文献
74.
Arne P. Willner Axel Gerdes Hans-Joachim Massonne Alexander Schmidt Masafumi Sudo Stuart N. Thomson Graciela Vujovich 《Contributions to Mineralogy and Petrology》2011,162(2):303-327
The Guarguaraz Complex in West Argentina formed during collision between the microplate Chilenia and South America. It is
composed of neritic clastic metasediments with intercalations of metabasic and ultrabasic rocks of oceanic origin. Prograde
garnet growth in metapelite and metabasite occurred between 1.2 GPa, 470°C and 1.4 GPa, 530°C, when the penetrative s2-foliation was formed. The average age of garnet crystallization of 390 ± 2 Ma (2σ) was determined from three four-point Lu–Hf
mineral isochrones from metapelite and metabasite samples and represents the time of collision. Peak pressure conditions are
followed by a decompression path with slight heating at 0.5 GPa, 560°C. Fluid release during decompression caused equilibration
of mineral compositions at the rims and also aided Ar diffusion. An 40Ar/39Ar plateau age of white mica at 353 ± 1 Ma (1σ) indicates the time of cooling below 350–400°C. These temperatures were attained
at pressures of 0.2–0.3 GPa, indicative of an average exhumation rate of ≥1 mm/a for the period 390–353 Ma. Late hydrous influx
at 0.1–0.3 GPa caused pervasive growth of sericite and chlorite and reset the Ar/Ar ages of earlier coarse-grained white mica.
At 284–295 Ma, the entire basement cooled below 280°C (fission track ages of zircon) after abundant post-collisional granitoid
intrusion. The deeply buried epicontinental sedimentary rocks, the high peak pressure referring to a low metamorphic geotherm
of 10–12°C/km, and the decompression/heating path are characteristics of material buried and exhumed within a (micro) continent–continent
collisional setting. 相似文献
75.
Sea surface height anomaly maps of realistic eddy activity were obtained by applying space-time optimum interpolation to altimeter
data. Analysis error and rate of reconstructing eddy signals were investigated by taking account of: 1) dependency on orbit
configurations of single and multiple altimeters; 2) dependency on space-time scales of realistic, dominant eddies; and 3)
effect of space-time scales of eddy propagation. Large-scale sea surface height anomalies are subtracted from altimeter data
by applying an along-track filter to allow easy handling of eddy signals. The space-time scales of the first-guess error in
the optimum interpolation are statistically evaluated by fitting a space-time anisotropic Gaussian function to space-time-distributed
correlation coefficients of sea surface height using the TOPEX data. The results of the optimum interpolation clarify the
followings: 1) ERS has a better capability of reconstructing eddy signals than TOPEX. Comparison of maps from multi-altimeter
data shows that TOPEX+ERS has a better capability than Jason−1+TOPEX in lower latitudes and vice versa in higher latitudes,
though the differences are small. 2) The small space-time scale yields a low reconstruction rate in marginal seas and alongside
the equator. The persistent timescale is large, and westward propagation is dominant in the subtropical and subarctic regions,
where the reconstruction rates are high. 3) The optimum interpolation, taking account of eddy propagation, provides higher
reconstruction rates than that taking no account of the propagation. The effect of propagation on the optimum interpolation
is greater when it is applied to single-altimeter data than to multi-altimeter data.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
76.
K–Ar geochronology of a Quaternary monogenetic volcano group in Ojika Jima District, Southwest Japan
Masafumi Sudo Kozo Uto Yoshiyuki Tatsumi Kazunori Matsui 《Bulletin of Volcanology》1998,60(3):171-186
An unspiked K–Ar dating method using a mass-fractionation correction procedure was applied to a Quaternary independent group
of monogenetic volcanoes, Ojikajima Volcano Group, located in northwestern Kyushu in Southwest Japan, in order to clarify
in detail secular variations in eruptive volume, locations of eruptive vents, and magma compositions in a single monogenetic
volcano group. The major results were as follows: (a) K–Ar ages of monogenetic volcanoes distribute from 1.08 to 0.30 Ma,
with voluminous peaks at approximately 1.0 and 0.6 Ma. (b) The volcanic activity commenced in the central part of the field,
expanded to the whole field at approximately 0.6 Ma, and then shrank to the central area. (3) Concentrations of incompatible
elements, such as Ba, K, and Nb, increase with decreasing age, whereas P, Y, and Zr concentrations remain constant. These
concentrations suggest gradual decrease in the degree of partial melting from an identical mantle source with residual garnet.
Received: 15 December 1997 / Accepted: 23 May 1998 相似文献
77.
Mónica Vásquez Uwe Altenberger Rolf L. Romer Masafumi Sudo Juan Manuel Moreno-Murillo 《Journal of South American Earth Sciences》2010,29(2):171-186
The Eastern Cordillera of the Colombian Andes represents an inverted Cretaceous basin where Cretaceous magmatism is characterized by rare mafic dykes and sills. We use 40Ar/39Ar, Sr–Nd–Pb isotopes, as well as major and trace elements analyses of Cretaceous intrusions from both flanks of the Eastern Cordillera in combination with structural data to document the complex evolution of the basin. Magmatism, which is diachronous and geochemically diverse, seems to be related to mantle melting beneath the most subsiding segments of each sub-basin during enhanced extensional tectonics. The mafic intrusions display two different compositional series: an alkaline one with OIB-like pattern and a tholeiitic one with MORB-like features. This indicates at least two diverse mantle sources. Trace-element patterns suggest that the intrusions were emplaced in an extensional setting. 40Ar/39Ar dating on primary plagioclase and hornblende provides plateau ages between ~136 and ~74 Ma.The geochemical and temporal diversities show that the emplacement of the magmas was tectonically controlled, each sub-basin reflecting an individual subsidence event. 相似文献
78.
Toyoda Takahiro Fujii Yosuke Kuragano Tsurane Kosugi Naohiro Sasano Daisuke Kamachi Masafumi Ishikawa Yoichi Masuda Shuhei Sato Kanako Awaji Toshiyuki Hernandez Fabrice Ferry Nicolas Guinehut Stéphanie Martin Matthew Andrew Peterson K. Good Simon A. Valdivieso Maria Haines Keith Storto Andrea Masina Simona Köhl Armin Yin Yonghong Shi Li Alves Oscar Smith Gregory Chang You-Soon Vernieres Guillaume Wang Xiaochun Forget Gael Heimbach Patrick Wang Ou Fukumori Ichiro Lee Tong Zuo Hao Balmaseda Magdalena 《Climate Dynamics》2017,49(3):891-907
Climate Dynamics - The interannual-decadal variability of the wintertime mixed layer depths (MLDs) over the North Pacific is investigated from an empirical orthogonal function (EOF) analysis of an... 相似文献
79.
Alexander C. Brandt Qiqin Zhang Maximo Larry Lopez Caceres Hideki Murayama 《水文研究》2020,34(15):3235-3251
Warm winters and high precipitation in north-eastern Japan generate snow covers of more than three meters depth and densities of up to 0.55 g cm−3. Under these conditions, rain/snow ratio and snowmelt have increased significantly in the last decade under increasing warm winters. This study aims at understanding the effect of rain-on-snow and snowmelt on soil moisture under thick snow covers in mid-winter, taking into account that snowmelt in spring is an important source of water for forests and agriculture. The study combines three components of the Hydrosphere (precipitation, snow cover and soil moisture) in order to trace water mobility in winter, since soil temperatures remained positive in winter at nearly 0.3°C. The results showed that soil moisture increased after snowmelt and especially after rain-on-snow events in mid-winter 2018/2019. Rain-on-snow events were firstly buffered by fresh snow, increasing the snow water equivalent (SWE), followed by water soil infiltration once the water storage capacity of the snowpack was reached. The largest increase of soil moisture was 2.35 vol%. Early snowmelt increased soil moisture with rates between 0.02 and 0.035 vol% hr−1 while, rain-on-snow events infiltrated snow and soil faster than snowmelt and resulted in rates of up to 1.06 vol% hr−1. These results showed the strong connection of rain, snow and soil in winter and introduce possible hydrological scenarios in the forest ecosystems of the heavy snowfall regions of north-eastern Japan. Effects of rain-on-snow events and snowmelt on soil moisture were estimated for the period 2012–2018. Rain/snow ratio showed that only 30% of the total precipitation in the winter season 2011/2012 was rain events while it was 50% for the winter 2018/2019. Increasing climate warming and weakening of the Siberian winter monsoons will probably increase rain/snow ratio and the number of rain-on-snow events in the near future. 相似文献
80.
Masafumi Kamachi Tsurane Kuragano Noriya Yoshiok Jiang Zhu Francesco Uboldi 《大气科学进展》2001,18(5):767-786
l. IntroductionLinear dynamics ls domlnant as a response to atmospheric forcing in the equatrialregion. In the mid-- to high--latitudes, ocean represents nonlinear phenomena such as strongcurrents and meso--scale eddies. Heat and water fluxes are also important. The resultantscales of the phenomena are rather small. We developed, for the mid-- to high--latitudes, anocean data assimilation system COMPASS--K: Comprehensive Ocean ModeIing, Prediction,Analysis and Synthesis System in the K… 相似文献