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131.
A seabed-type of breakwater applicable to very soft ground without the need for soil improvement is newly developed. This type of soft-ground breakwater is expected to ensure sufficient lateral resistance and prevent excessive consolidation settlement due to self-weight of the breakwater. In this paper, lateral and consolidation behaviors of soft-ground breakwater were investigated by performing model tests and finite element simulations. The results revealed that the bottom wall and buoyant box, which are the main features of soft-ground breakwater, contribute to the increase in lateral resistance and to the control of the consolidation settlements, respectively, and that Terzaghi's consolidation theory could be conservatively adopted in deriving the consolidation settlements of soft-ground breakwater proposed herein. 相似文献
132.
Internal soil moisture response to rainfall-induced slope failures and debris discharge 总被引:2,自引:0,他引:2
Ching-Chuan Huang Chien-Li Lo Jia-Shiun Jang Lih-Kang Hwu 《Engineering Geology》2008,101(3-4):134-145
Predictions of rainfall-induced fast-moving mass flow and/or debris flows require better knowledge of the mechanism controlling the debris discharge of slopes in debris source areas. A series of rainfall tests on 0.32 m-deep, 0.7 m-high, 1.35 m-wide sandy slopes resting on a bi-linear impermeable rigid base was performed. Soil moisture content and solid discharge measurements were performed to gain insights into the rainfall-induced retrogressive slope failure. The solid (or debris) discharge is a result of the wash-out of the fluidized slope toe by the interflow along the soil–bedrock interface. Characteristics of the failure process for the slopes are represented by mass wasting curves or ‘solid discharge (Qs) vs. time (t)’ curves which are functions of the rainfall intensity and/or the cumulative rainfall. The mass wasting curves have inflection points representing transitions from minor toe failures into remarkable retrogressive failures. The first inflection point of the soil moisture (ω) vs. t curve measured at the soil–bedrock interface signaling the arrival of the descending ‘wet front’, may serve as a precursor for predicting the onset of an abrupt solid discharge induced by shallow slope failures. The time of peak water content measured at the soil–bedrock interface may approximate the time of 5% total solid volume discharge. Up to the time of 5% of total slope volume discharge, a fully saturated state (Sr 100%) was never observed at the 0.2 m-below-surface zone; however, it was observed along the soil–bedrock interface at near-toe zone of the slope, regardless of the intensity of rainfall investigated. Retrogressive failures were essentially associated with nonuniformly distributed water content in the slope. For both the 0.2 m-below-surface zone and the soil–bedrock interface, a more uniform distribution of Sr along the full height of the slope was found for slopes subjected to high rainfall intensities of 47 and 65 mm/h than that for the slope subjected to a low rainfall intensity of 23 mm/h. At the inflection point of the Qs vs. t curve and 5% of total solid volume discharge, values of Sr at a certain distance from the toe for the soil–bedrock interface were higher than those measured at the same distance from the toe for the 0.2 m-below-surface zone, indicating the effect of infiltration-induced interflow along the soil–bedrock interface and its effects on the fluidization of the slope toe and the retrogressive failure of the slope. 相似文献
133.
134.
Hae Jin Jeong Se Hyeon Jang Nam Seon Kang Yeong Du Yoo Min Jeong Kim Kyung Ha Lee Eun Young Yoon éric Potvin Yeong Jong Hwang Jong Im Kim Kyeong Ah Seong 《Ocean Science Journal》2012,47(1):1-18
Species belonging to the genus Bysmatrum are peridinoid, thecate, photosynthetic dinoflagellates. The plate formula of Bysmatrum spp., arranged in a Kofoidian series, is almost identical to that of Scrippsiella spp. Bysmatrum spp., which were originally classified as Scrippsiella spp., but were transferred to the genus Bysmatrum spp. because of separation of the intercalary plates 2a and 3a by plate 3??. Whether this transfer from Scrippsiella spp. to Bysmatrum spp. is reasonable should be genetically confirmed. Dinoflagellates were isolated from 2 solar saltons located in western Korea in 2009?C2010 and 3 clonal cultures from Sooseong solar saltons and 2 clonal cultures from Garolim solar saltons were successfully established. All of these dinoflagellates were identified as Bysmatrum caponii based on morphology analysis by light and electron microscopy. The plates of all Korean strains of B. caponii were arranged in a Kofoidian series of Po, X, 4??, 3a, 7??, 6c, 4s, 5?, 0 (p), and 24??. When properly aligned, the ribosomal DNA (rDNA) sequences of the 3 Sooseong strains of B. caponii were identical, as were those of the 2 Garolim strains. Furthermore, the sequences of the 3 Sooseong strains were 0.01% different from those of the Garolim strains. However, the sequences of SSU rDNA of these Korean B. caponii strains were 9% different from that of Bysmatrum subsalsum and > 10% from that of any other dinoflagellate thus far reported. In the phylogenetic trees generated using SSU and LSU rDNA sequences, these Korean B. caponii strains formed a clade with B. subsalsum which was clearly divergent from the Scrippsiella clade. However, this Bysmatrum clade was phylogenetically close to the Protoperidinium and/or Peridinium clades. The results of the present study suggest that Bysmatrum spp. are markedly different genetically from Scrippsiella spp.. 相似文献
135.
This study investigates a freshwater budget in the Yellow and East China Seas (YECS) using a global f general circulation
model with a regional focus on the YECS. A freshwater budget analysis finds that major freshwater contributors over the YECS
change seasonally. In summer, freshwater inflow from Changjiang and positive precipitation minus evaporation (P-E) dominates
freshwater outflow across the boundaries around the YECS, resulting in net freshwater gain in the YECS. In winter, evaporation,
intensified by strong winds, dominates freshwater inflow from Changjiang and precipitation, while net freshwater transport
across the boundaries around the YECS is negligible, causing freshwater loss in total over the YECS. Although P-E has often
been assumed to be negligible by supposing that the annual mean of precipitation is nearly equal to that of evaporation, this
study suggests that P-E needs to be included in the seasonal freshwater budget in the YECS. 相似文献
136.
Evaluation of statistical gap fillings for continuous energy flux (evapotranspiration) measurements for two different land cover types 总被引:1,自引:0,他引:1
137.
Innovative water management is the first priority for the Saemangeum Project, a national project for a building global city as a frontrunner of green growth because there has been a big debate concerning the environmental problems (water quality, destruction of mud flats and so on). This study aims at identifying the change of water quality with time and analyzing the cause of its tendency. Results of this study verify that the importance of water quality is required when preparing water infrastructure for smart water use and may use for establishing a proper management plan in the Mangyeong River basins of the Saemangeum. 相似文献
138.
Risk-based assessment of arsenic-affected aquacultural water in blackfoot disease hyperendemic areas
Cheng-Shin Jang Kao-Hung Lin Chen-Wuing Liu Ming-Chao Lin 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(5):603-612
This work explored a risk-based arsenic (As) regulation in farmed pond water by ingesting tilapia (Oreochromis mossambicus) in blackfoot disease hyperendemic areas and discussed a rational As regulation in pond water. Monte Carlo analysis was used
to propagate the parameter uncertainty and to assess probabilistically regulation risks. A dynamic scheme of groundwater management
was proposed that curves of utilization ratios against As concentrations in groundwater were established based on the risk-based
regulation. The 5th to 95th percentiles of risks range from 3.5 × 10−7 to 6.0 × 10−5 via ingesting the farmed tilapia under the current As regulation in farmed pond water in Taiwan, 50 μg/L. To compare to inorganic
As regulation in drinking water, the current As regulation in farmed pond water does not pose a great threat to human health,
but it is unsafe. Therefore, this study suggests that the regulation of As in farmed pond water is revised to be 25 μg/L. 相似文献
139.
Abstract Paleostress of the Joseon Supergroup in the northeastern part of the Ogcheon Belt, South Korea, is reconstructed in the Jecheon–Danyang area with the help of calcite twinning. In the study area, the average twin thickness and intensity increase with the total twin strain increase. From the appearance of twins, the average twin thickness and intensity, and the total twin strain, it is estimated that calcite twins were produced under temperatures lower than 200°C. The maximum shortening axis in the study area changes orientation from northeast–southwest to NNW–SSE or northwest–southeast, and finally to north–south. We suggest these three distinct stages with different orientations of the maximum shortening axis can be correlated with: (i) the Paleozoic to Early Jurassic Songrim orogeny; (ii) the Early Jurassic to Late Jurassic Daebo orogeny; and (iii) the Cretaceous Bulgugsa orogeny. 相似文献
140.
Ocean Science Journal - To understand and clarify the geographic variations of the Korean sea raven, Hemitripterus villosus, we investigated the molecular and morphometric characteristics of 147... 相似文献