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Pichel WG Veenstra TS Churnside JH Arabini E Friedman KS Foley DG Brainard RE Kiefer D Ogle S Clemente-Colón P Li X 《Marine pollution bulletin》2012,65(1-3):28-41
Marine debris, particularly debris that is composed of lost or abandoned fishing gear, is recognized as a serious threat to marine life, vessels, and coral reefs. The goal of the GhostNet project is the detection of derelict nets at sea through the use of weather and ocean models, drifting buoys and satellite imagery to locate convergent areas where nets are likely to collect, followed by airborne surveys with trained observers and remote sensing instruments to spot individual derelict nets. These components of GhostNet were first tested together in the field during a 14-day marine debris survey of the Gulf of Alaska in July and August 2003. Model, buoy, and satellite data were used in flight planning. A manned aircraft survey with visible and IR cameras and a LIDAR instrument located debris in the targeted locations, including 102 individual pieces of debris of anthropogenic or terrestrial origin. 相似文献
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Sediment and sea surface microlayer samples near an open-net salmon farm in Nova Scotia, were analysed for copper. Copper is a constituent of the feed and is an active ingredient of anti-foulants. The salmon farm was placed in fallow after 15years of production. Sampling was pursued over 27months. Elevated copper concentrations in the sediments indicated the farm site as a source. Bubble flotation due to gas-emitting sediments from eutrophication is a likely process for accumulating copper in the sea surface microlayer at enriched concentrations. Elevated and enriched concentrations in the sea surface microlayer over distance from the farm site led, as a result of wind-drift, to an enlarged farm footprint. The levels of copper in both sediments and sea surface microlayer exceeded guidelines for protection of marine life. Over the 27months period, copper levels persisted in the sediments and decreased gradually in the sea surface microlayer. 相似文献
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在加拿大瓦比贡(Wabigoon)和乌奇(Uchi)太古代绿岩带进行的实例研究证明,利用压碎台分析可以准确和重复地测定含CO_2的气液包体。这些包体可作为中温热液金-石英-碳酸盐-硫化物矿床的判断特征。单独利用该法不能区别勘查区中不同品位的矿脉,但在利用压碎分析初步确定局部变质流体的成分后,在野外可廉价、准确地鉴定采自可能含金的中温热液矿床的样品。压碎台最适用于沉积物的地球化学测量,其石英中的特征气液包体可提供比与金有关的异常宽得多的勘查靶区。在中温热液矿脉的围岩中,可迅速无误地测出含CO_2的气液包体晕。晕的延伸范围与蚀变矿物组合一致,所以,在野外露头稀少或强烈风化的地区,压碎分析可圈定供进一步详查的靶区。 相似文献
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Pichel WG Churnside JH Veenstra TS Foley DG Friedman KS Brainard RE Nicoll JB Zheng Q Clemente-Colón P 《Marine pollution bulletin》2007,54(8):1207-1211
Floating marine debris, particularly derelict fishing gear, is a hazard to fish, marine mammals, turtles, sea birds, coral reefs, and even human activities. To ameliorate the economic and environmental impact of marine debris, we need to efficiently locate and retrieve dangerous debris at sea. Guided by satellite-derived information, we made four flights north of Hawaii in March and April 2005. During these aerial surveys, we observed over 1800 individual pieces of debris, including 122 derelict fishing nets. The largest debris concentrations were found just north of the North Pacific Transition Zone Chlorophyll Front (TZCF) within the North Pacific Subtropical Convergence Zone (STCZ). Debris densities were significantly correlated with sea-surface temperature (SST), chlorophyll-a concentration (Chla), and the gradient of Chla. A Debris Estimated Likelihood Index (DELI) was developed to predict where high concentrations of debris would be most likely in the North Pacific during spring and early summer. 相似文献
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In 2002, 13 years after the Exxon Valdez spill, mussels and clams were examined for lingering oil exposure and damage. Known oil patches were sampled at four locations, and compared to nearby reference areas (same bay), and were also compared to "hot reference" sites to verify the methods used (Cordova harbor and fresh diesel spill at Port Chalmers). Passive samplers deployed for a month at the sites, along with tissue samples, confirmed that the oiled sites were oiled (fingerprinting back to Exxon Valdez oil) and that reference sites were clean. The highest PAH loads were detected in sub-surface interstitial waters at oiled sites. Exposure at the surface was generally low level, and probably intermittent. DNA damage was assessed in blood cells using sensitive comet analyses. DNA strand breakage was detected in both mussels and clams, with the highest level of damage detected at "hot reference" sites of Cordova harbor and Port Chalmers. Bioavailability and DNA damage at the oiled sties was low, indicating there has been substantial progress in recovery from the spill 13 years before, yet low level bioavailability and damage were still detectable. 相似文献