全文获取类型
收费全文 | 346篇 |
免费 | 33篇 |
国内免费 | 33篇 |
专业分类
测绘学 | 7篇 |
大气科学 | 42篇 |
地球物理 | 153篇 |
地质学 | 145篇 |
海洋学 | 18篇 |
天文学 | 26篇 |
综合类 | 4篇 |
自然地理 | 17篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 20篇 |
2017年 | 6篇 |
2016年 | 15篇 |
2015年 | 11篇 |
2014年 | 17篇 |
2013年 | 25篇 |
2012年 | 13篇 |
2011年 | 12篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 20篇 |
2007年 | 17篇 |
2006年 | 17篇 |
2005年 | 7篇 |
2004年 | 16篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 20篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1954年 | 1篇 |
1953年 | 1篇 |
排序方式: 共有412条查询结果,搜索用时 15 毫秒
61.
62.
Dam overtopping risk assessment considering inspection program 总被引:1,自引:2,他引:1
Jan-Tai Kuo Yung-Chia Hsu Yeou-Koung Tung Keh-Chia Yeh Jian-De Wu 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(3):303-313
Safety inspection of large dams in Taiwan is conducted every 5 years. The practice does not take into consideration uncertainty
of dam conditions. The goal of this study is to determine the optimal dam inspection interval under the consideration of overtopping
risk incorporating uncertainty gate availability. In earlier studies, assessment of overtopping risk only considered the uncertainties
in reservoir properties and natural randomness of hydrologic events without giving much thought to the availability of spillway
gates. As a result, the overtopping risk could be underestimated. In this study, an innovative concept is proposed to evaluate
dam overtopping by taking into account spillway gate availability. The framework consists of three parts: (1) evaluation of
conditional overtopping risk for different numbers of malfunctioning spillway gates; (2) evaluation of spillway gate availability;
and (3) dam inspection scheduling. Furthermore, considerations are given to overtopping risk, inspection cost, and dam break
cost for determining the optimal inspection schedule. The methodology is applied to the Shihmen Reservoir in Taiwan and to
evaluate its time-dependent overtopping risk. Results show that overtopping risk considering the availability of the spillway
gates is higher than the one without considering the availability of the spillway gates. 相似文献
63.
64.
65.
Borehole gravity has been used in mineral exPloration recently with the advent of slim-hole gravime-ters. It is logical to Perform inversion to utilize the information in the newly acquired data. The i... 相似文献
66.
67.
Ching-Hui Tsai Shu-Kun Hsu Yi-Ching Yeh Chao-Shing Lee Kanyuan Xia 《Marine Geophysical Researches》2004,25(1-2):63-78
Magnetic data suggest that the distribution of the oceanic crust in the northern South China Sea (SCS) may extend to about 21 °N and 118.5 °E. To examine the crustal features of the corresponding continent–ocean transition zone, we have studied the crustal structures of the northern continental margin of the SCS. We have also performed gravity modeling by using a simple four-layer crustal model to understand the geometry of the Moho surface and the crustal thicknesses beneath this transition zone. In general, we can distinguish the crustal structures of the study area into the continental crust, the thinned continental crust, and the oceanic crust. However, some volcanic intrusions or extrusions exist. Our results indicate the existence of oceanic crust in the northernmost SCS as observed by magnetic data. Accordingly, we have moved the continent–ocean boundary (COB) in the northeastern SCS from about 19 °N and 119.5 °E to 21 °N and 118.5 °E. Morphologically, the new COB is located along the base of the continental slope. The southeastward thinning of the continental crust in the study area is prominent. The average value of crustal thinning factor of the thinned continental crust zone is about 1.3–1.5. In the study region, the Moho depths generally vary from ca. 28 km to ca. 12 km and the crustal thicknesses vary from ca. 24 km to ca. 6 km; a regional maximum exists around the Dongsha Island. Our gravity modeling has shown that the oceanic crust in the northern SCS is slightly thicker than normal oceanic crust. This situation could be ascribed to the post-spreading volcanism or underplating in this region. 相似文献
68.
69.
A mesoscale mountain such as the Central Mountain Range (CMR) of Taiwan can considerably affect the motion and the structure of an approaching tropical cyclone in very complicated ways. Many studies have presented and explained the mechanism for the change of moving speed, track deflection, or track discontinuity. In the past, the tracks of Typhoon Mary (1965), Tropical Cyclone Polly (1993), and Typhoon Haitang (2005) have a looping motion prior to making landfall on Taiwan. When the looping occurs, the timing and the intensity of the typhoon to affect Taiwan can be very different from the one moving with smooth track. It is very important to have a correct forecast for disaster mitigation operations. However, the mechanism causing such looping has not been fully understood. In this study, the case of Typhoon Haitang is examined. The radar reflectivity diagrams are used to illustrate looping in its track. By applying piecewise potential vorticity inversion analysis and numerical model simulations, it is shown that the looping motion of Typhoon Haitang near Taiwan resulted from the CMR terrain effect. When Typhoon Haitang approaches Taiwan and its circulation encounters the CMR, the terrain induces a cyclonic vortex in the lee side of the mountain over southeast of Taiwan. This terrain-induced vortex interacts with Typhoon Haitang in a way similar to the binary vortex interaction. The two vortex centers rotate around their system center, which causes looping of Typhoon Haitang. 相似文献
70.
Y. -K. Tung K. -C. Yeh J. -C. Yang 《Stochastic Environmental Research and Risk Assessment (SERRA)》1997,11(2):145-171
Hydrologic regionalization is a useful tool that allows for the transfer of hydrological information from gaged sites to ungaged
sites. This study developed regional regression equations that relate the two parameters in Nash's IUH model to the basin
characteristics for 42 major watersheds in Taiwan. In the process of developing the regional equations, different regression
procedures including the conventional univariate regression, multivariate regression, and seemingly unrelated regression were
used. Multivariate regression and seeming unrelated regression were applied because there exists a rather strong correlation
between the Nash's IUH parameters. Furthermore, a validation study was conducted to examine the predictability of regional
equations derived by different regression procedures. The study indicates that hydrologic regionalization involving several
dependent variables should consider their correlations in the process of establishing the regional equations. The consideration
of such correlation will enhance the predictability of resulting regional equations as compared with the ones from the conventional
univariate regression procedure. 相似文献