全文获取类型
收费全文 | 63篇 |
免费 | 3篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 3篇 |
地球物理 | 11篇 |
地质学 | 22篇 |
海洋学 | 10篇 |
天文学 | 16篇 |
自然地理 | 2篇 |
出版年
2024年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1974年 | 2篇 |
1973年 | 6篇 |
排序方式: 共有66条查询结果,搜索用时 984 毫秒
61.
Toshihiro Kawaguchi Masahiro Kawasaki Tsutomu Takayama Masahide Yamaguchi Jun'ichi Yokoyama 《Monthly notices of the Royal Astronomical Society》2008,388(3):1426-1432
Formation of primordial black holes (PBHs) on astrophysical mass scales is a natural consequence of inflationary cosmology, if the primordial perturbation spectrum has a large and negative running of the spectral index as observationally suggested today because double inflation is required to explain it and fluctuations on some astrophysical scales are enhanced in the field-oscillation regime in between. It is argued that PBHs thus produced can serve as intermediate-mass black holes (IMBHs), which act as the observed ultraluminous X-ray sources (ULXs) by choosing appropriate values of the model parameters in their natural ranges. Our scenario can be observationally tested in near future because the mass of PBHs is uniquely determined once we specify the values of the amplitude of the curvature perturbation, spectral index and its running on large scales. 相似文献
62.
Variations in stress and driving pore fluid pressure ratio using vein orientations along megasplay faults : Example from the Nobeoka Thrust,Southwest Japan
下载免费PDF全文
![点击此处可从《Island Arc》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Makoto Otsubo Ayumu Miyakawa Ryoji Kawasaki Katsushi Sato Asuka Yamaguchi Gaku Kimura 《Island Arc》2016,25(6):421-432
The Nobeoka Thrust of Southwest Japan is an on‐land example of an ancient megasplay fault that provides an excellent record of deformation and fluid flow at seismogenic depths. The present study reports: (i) temporal stress changes for the seismogenic period of the Nobeoka Thrust; and (ii) spatial heterogeneities in driving pressure ratios P* obtained from mineral veins around the Nobeoka Thrust fault zone. Many quartz veins that filled mode I cracks can be observed in the hanging wall and footwall of the thrust. Inversion for stress orientation suggests that normal faulting dominated in both the hanging wall and footwall, with similar stress axis orientations in both. The orientation of σ3 for the estimated stress regime is parallel to the slip direction of the Nobeoka Thrust. The detected normal‐faulting‐type stress regimes likely resulted from post‐seismic stress buildup after megathrust earthquakes. The hanging wall of the Nobeoka Thrust has smaller P* values than the footwall. Two possible explanations are proposed for the observed spatial variations in the driving pore fluid pressure ratio, P*: spatial variations in pore fluid pressure Pf are directly responsible for P* variations, or P* variations are controlled by differences in mechanical properties between the hanging wall and footwall. 相似文献
63.
G. Rostoker A.J. Chen F. Yasuhara S.-I. Akasofu K. Kawasaki 《Planetary and Space Science》1974,22(3):427-437
The magnetic perturbation patterns in the polar cap and auroral zone regions are obtained for extremely quiet days using two different techniques. It is shown that the form of the equivalent current flow pattern is extremely sensitive to the level of quietness, and that even so-called quiet days are at times disturbed by substorm activity. Certain characteristic equivalent flow not typically observed during substorms is noted in the polar cap, and this flow appears to be associated with effects associated with polar cap perturbations discussed by Svalgaard (1973). As well a region of equatorward flow appears at high latitudes near the dawn meridian, which appears to be Hall current driven by an eastward electric field. The dayside sub-auroral zone is dominated by the Sq-current system, while the nightside shows no significant current flow in the absence of substorm activity. 相似文献
64.
Mega T. Monden K. Ushio T. Okamoto K. Kawasaki Z.-I. Morimoto T. 《Geoscience and Remote Sensing Letters, IEEE》2007,4(3):392-396
A new high-resolution Ku-band Doppler radar for meteorological applications has been developed. With the new system design, the radar can accurately measure the radar reflectivity factor with 4-m resolution over a range from 40 m to several kilometers for 100-mW power using a pulse compression technique. Details of the system design, signal processing algorithm, and data acquisition procedures are described. To demonstrate the accuracy of the system, the radar reflectivity measurements are compared with the Joss-Waldvogel disdrometer measurements, and fairly good agreement is shown. The ability of the system to capture the backscattered signal and Doppler spectrum from rain volume at low altitude with high resolution is demonstrated for both convective- and stratiform-type rain events. 相似文献
65.
Temporal stress variations along a seismogenic megasplay fault in the subduction zone: An example from the Nobeoka Thrust,southwestern Japan
下载免费PDF全文
![点击此处可从《Island Arc》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ryoji Kawasaki Yoshitaka Hashimoto Makoto Otsubo Asuka Yamaguchi Yujin Kitamura Jun Kameda Yohei Hamada Rina Fukuchi Gaku Kimura 《Island Arc》2017,26(3)
The Nobeoka Thrust, an ancient megasplay fault in the Shimanto Belt, southwestern Japan, contains fault rocks from the seismogenic zone, providing an accessible analog of active megasplay faults in deep subduction settings. In this study, the paleostress along the Nobeoka Thrust was analyzed using multiple inversion techniques, including k‐means clustering of fault datasets acquired from drillcores that intersected the thrust. The six resultant stress orientation clusters can be divided into two general groups: stress solutions with north–south‐trending σ1 axes, and those with east–west‐trending σ1 axes. These groups are characterized by the temporal changes for the orientations of the σ1 and σ3 principal stress axes that involve alternation between horizontal and vertical. The findings are probably due to a change in stress state before and after earthquakes that occurred on the fault; similar changes have been observed in active tectonic settings, such as the 2011 Tohoku‐Oki earthquake (Japan). 相似文献
66.
Noriyuki Kawasaki Daiki Yamamoto Sohei Wada Changkun Park Hwayoung Kim Naoya Sakamoto Hisayoshi Yurimoto 《Meteoritics & planetary science》2024,59(4):630-639
Al–Mg mineral isochron studies using secondary ion mass spectrometry (SIMS) have revealed the initial 26Al/27Al ratios, (26Al/27Al)0, for individual Ca-Al-rich inclusions (CAIs) in meteorites. We find that the relative sensitivity factors of 27Al/24Mg ratio for SIMS analysis of hibonite, one of the major constituent minerals of CAIs, exhibit variations based on their chemical compositions. This underscores the critical need for using appropriate hibonite standards to obtain accurate Al−Mg data. We measured the Al−Mg mineral isochron for hibonite in a fine-grained CAI (FGI) from the Northwest Africa 8613 reduced CV chondrite by SIMS using synthesized hibonite standards with 27Al/24Mg of ~30, ~100, and ~400. The obtained mineral isochron of hibonite in the FGI yields (26Al/27Al)0 of (4.73 ± 0.09) × 10−5, which is identical to that previously obtained from the mineral isochron of spinel and melilite in the same FGI (Kawasaki et al., 2020). The uncertainties of (26Al/27Al)0 indicate that the constituent minerals in the FGI formed within ~0.02 Myr in the earliest solar system. The disequilibrium O-isotope distributions of the minerals in the FGI suggest that the O-isotope compositions of the nebular gas from which they condensed underwent a transitional change from 16O-rich to 16O-poor within ~0.02 Myr in the earliest solar system. Once formed, the FGI may have been removed from the forming region within ~0.02 Myr and transported to the accretion region of the parent body. 相似文献