全文获取类型
收费全文 | 571篇 |
免费 | 13篇 |
国内免费 | 18篇 |
专业分类
测绘学 | 9篇 |
大气科学 | 95篇 |
地球物理 | 119篇 |
地质学 | 156篇 |
海洋学 | 173篇 |
天文学 | 27篇 |
综合类 | 9篇 |
自然地理 | 14篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 14篇 |
2020年 | 12篇 |
2019年 | 8篇 |
2018年 | 29篇 |
2017年 | 34篇 |
2016年 | 43篇 |
2015年 | 41篇 |
2014年 | 36篇 |
2013年 | 37篇 |
2012年 | 34篇 |
2011年 | 53篇 |
2010年 | 43篇 |
2009年 | 35篇 |
2008年 | 26篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 20篇 |
2004年 | 12篇 |
2003年 | 18篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有602条查询结果,搜索用时 31 毫秒
521.
Dongseon Kim Sang Hwa Choi Kyung Hee Kim JeongHee Shim Sinjae Yoo Chul Ho Kim 《Continental Shelf Research》2009,29(11-12):1426-1436
Nutrients, chlorophyll-a (Chl-a), and environmental conditions were extensively investigated in the northern East China Sea (ECS) near Cheju Island during five research cruises from 2003 to 2007. In the eastern part of the study area, surface waters were characterized only by the Tsushima Current Water (TCW) during all five cruises. However, the western surface waters changed with season and were characterized by the Yellow Sea Cold Water (YSCW) in spring, the Changjiang Diluted Water (CDW) in summer, and the Yellow Sea Mixed Water (YSMW) in autumn. In spring and autumn, relatively high concentrations of nitrate and phosphate were observed in the surface waters in the western part of the study area, where vertical mixing brought large supplies of nutrients from deep waters. Changes in wind direction occasionally varied the inflow of the Changjiang plume in summer, clearly causing the annual variation in surface nitrate and phosphate concentrations in summer. In summer, the surface distribution of nitrate and phosphate did not coincide with that of silicate in the study area, which probably resulted from the significant drop in the Si:N ratio in the Changjiang plume since construction of the Three Gorges Dam (TGD). Despite large temporal and spatial variations in surface Chl-a concentrations, depth-integrated Chl-a concentrations exhibited little variation temporally and spatially. In the study area, surface Chl-a concentration did not well reflect the standing stocks of phytoplankton. The vertical distribution of Chl-a showed large temporal and spatial variations, and the main factor controlling the vertical distribution of Chl-a in summer was the availability of nitrate. The thermohaline front may play an important role for accumulation of phytoplankton biomass in spring and autumn. 相似文献
522.
Assimilation of sea surface temperature in the Northwest Pacific Ocean and its marginal seas using the ensemble Kalman filter 总被引:2,自引:0,他引:2
Gwang-Ho Seo Byoung-Ju Choi Yang-Ki Cho Young Ho Kim Sangil Kim 《Ocean Science Journal》2010,45(4):225-242
Satellite-borne sea surface temperature (SST) data were assimilated with the ensemble Kalman filter (EnKF) in a Northwest Pacific Ocean circulation model to examine the effect of data assimilation. The model domain included the northwestern part of the Pacific Ocean and its marginal seas, such as the Yellow Sea and East/Japan Sea. The performance of the data assimilation was evaluated by comparing the simulated ocean state with that observed. Spatially averaged root-mean-squared errors in the SST and sea surface height (SSH) decreased by 0.44 °C and 4 cm, respectively, by the assimilation. The results of the numerical experiments substantiated the effectiveness of the SST assimilation via the EnKF for all marginal seas, as well as the Kuroshio region. The benefit of the data assimilation depended on the characteristics of each marginal sea. The variation of the SST in the East/Japan Sea and the Kuroshio extension (KE) region were improved 34% and those in the Yellow Sea 12.5%. The variation of the SSH was improved approximately 36% in the KE region. This large improvement was achieved in the deep-water regions because assimilation of SST data corrected the separation point of the western boundary currents, such as the Kuroshio and the East Korea Warm Current, and the associated horizontal surface currents. The SST assimilation via the EnKF also improved the subsurface temperature profiles. The effectiveness of SST assimilation was seasonally dependent, with the improvement being relatively larger in winter than in summer, which was related to the seasonal variation of the vertical mixing and stratification in the ocean surface layer. 相似文献
523.
In the late 1980s, dramatic increases in water use caused over‐exploitation of groundwater resources and deterioration of water quality in Seoul metropolitan city. To monitor changes in quantity of groundwater resources and their quality, the metropolitan government established a local groundwater monitoring network in 1997 consisting of 119 monitoring wells. Groundwater resources in the urban area were affected by various human activities, including underground construction such as subways, pumping for public or private water use, leaky sewer systems and pavements. The variation patterns of the groundwater levels were mainly classified into four types, reflecting natural recharge due to rainfall events during the wet season, artificial recharge from leaky sewer or water supply systems, and heavy groundwater pumping for drainage or flood control purposes at underground construction sites. Significantly decreasing trends of groundwater levels in the suburbs of Seoul indicate groundwater use for various agricultural activities. Subway construction lowered the water level by an average of 25 m. Electrical conductivity values showed a wide range, from 100 to 1800 µS/cm (mean 470 µS/cm). Groundwater temperature generally showed a stable pattern, except for some sensitive increases at relatively shallow monitoring wells. Detailed analysis of the monitored groundwater data would provide some helpful implications for optimal and efficient management of groundwater resources in this metropolitan city. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
524.
The spionid polychaete Paraprionospio pinnata (Ehlers 1901) has been widely reported from Korean waters. We examined some specimens belonging to the genus Paraprionospio that had been collected from Korean waters, and identified them as Paraprionospio coora Wilson, 1990, Paraprionospio cordifolia Yokoyama, 2007 and Paraprionospio patiens Yokoyama, 2007, which are new to the fauna of Korea. The present study suggests misidentification of the specimens that have been previously reported as P. pinnata from Korean waters. 相似文献
525.
Structure and seasonal variability of the deep mean circulation of the East Sea (Sea of Japan) 总被引:1,自引:0,他引:1
The horizontal structure of deep mean circulation and its seasonal variability in the Japan/East Sea (JES) were studied using
profiling float and moored current meter data. The deep circulation in the Japan Basin (JB) flows cyclonically, basically
following f/H contours. The correlation between the directions of deep current and f/H contour increases as |▿(f/H)| increases, reaching remarkably high correlation coefficient (>0.8) values in steep slope regions in the JB. In contrast
to the JB, the deep mean circulation in the Ulleung/Tsushima Basin (UTB) is generally weak and cyclonic accompanied by sub-basin-scale
cyclonic and anticyclonic eddies. The UTB shows a poorer correlation between directions of deep current and f/H contours than other basins. The time-space averaged deep mean current is about 2.8 cm/s and the volume transport in the deep
layer (800 m to bottom) in the JB reaches about 10 Sv (10 × 106 m3s−1), which is about four times greater than the inflow transport through the Tsushima Straits. A salient feature is that the
amplitude of deep mean current in the JB reveals a remarkable seasonal variation with a maximum in March and minimum in October.
The annual range of the seasonal variation is about 30% of the mean velocity, whereas that in the southern JES (UTB and Yamato
Basin) is weak. 相似文献
526.
Polybrominated diphenyl ethers (PBDEs) in marine sediments from industrialized bays of Korea 总被引:8,自引:0,他引:8
Concentrations of polybrominated diphenyl ethers (PBDEs) were determined in coastal sediments from heavily industrialized areas and major harbors in Korea. SummationPBDE(20) concentrations in sediments ranged from 2.03 to 2253ng/g dry weight. PBDE concentrations were higher at estuarine and inner bay locations close to industrial complexes and large harbors, indicating that the PBDE contamination in the sediments is due to local discharges from industrial complexes. Deca-BDE was the predominant congener and the concentrations were comparable to or higher than those reported from other countries. Non-parametric multidimensional scaling (MDS) ordination showed that deca-BDE technical mixture is the main source of PBDE contamination in Korean coastal waters, with minor contamination by octa-BDE product. This result is consistent with the consumption pattern of brominated flame-retardants (BFRs) in Korea. Significant correlations existed among BDEs 28, 47, 99, 100, 153, and 154; however, BDEs 183 and 209 showed little correlation with less highly brominated congeners. 相似文献
527.
Subramaniam Thatchaneshkanth Lee Hee-Jung Jeung Hee-Do Kang Hyun-Sil Kim Chul-Won Kim Hyung-Seop Cho Young-Ghan Choi Kwang-Sik 《Ocean Science Journal》2021,56(4):424-433
Ocean Science Journal - The Gray mussel Crenomytilus grayanus occurs in high density in the shallow rocky subtidal zone on the east coast of Korea, where the mussel dominates the shallow subtidal... 相似文献
528.
Kim Young Ok Choi Jungmin Kang Hyung-Ku Noh Jae Hoon Choi Dong Han Oh Kyung-Hee 《Ocean Science Journal》2021,56(1):69-77
Ocean Science Journal - As planktonic ciliates have been recognized as important players in marine microbial food webs, relevant studies have been conducted in the western coastal waters of the... 相似文献
529.
Kwon Yong Min Bae Seung Sub Choi Grace Lim Ji Yeon Jung Yoon-Hee Chung Dawoon 《Ocean Science Journal》2021,56(1):1-17
Ocean Science Journal - Studies on marine fungi (termed as ‘marine-derived fungi’ in this paper) have been significantly increasing worldwide because of the critical role displayed by... 相似文献
530.
Ocean Science Journal - Clove oil (CO) is an effective anesthetic. Many hatcheries and research studies use clove oil to immobilize fish for artificial reproduction and surgery to suppress their... 相似文献