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341.
Won-Gi Min Dongsung Kim Hyun Soo Rho Sang Bum Chi Seung-Kyu Son 《Ocean Science Journal》2018,53(2):315-336
This study was carried out as part of a baseline long-term environmental project in the proposed mining areas for an environmental impact assessment of future mining in the Clarion-Clipperton Fracture Zone (CCFZ). The community structure and distributional pattern of meiobenthos were investigated in the deep-sea bottom of the Clarion-Clipperton Fracture Zone of the northeastern Pacific in July 1998, 1999, 2001, 2003 and August 2004, 2005. Twenty one meiobenthic groups were found at the stations in the study area. The most abundant meiobenthos comprised nematodes followed by benthic foraminiferans and harpacticoid copepods. The maximum density of meiobenthos was 306 ind/10 cm2 at the station located at 11°N (water depth, 4833 m), and the minimum density was 6 ind/10 cm2 at the station located at 14°N (water depth, 5037 m). Oligotrophic conditions in the CCFZ seem to directly reflect the lower standing stocks of meiobenthos in the CCFZ compared to other deep-sea plains of similar depth. The latitudinal distribution pattern of meiobenthos in the study area seemed to be related with surface water primary productivity, which was connected to the water circulation pattern of the Pacific Ocean near the Equator, diverging at 8ºN latitude and converging at 5°N. The horizontal distribution of meiobenthic organisms in the study area showed high densities at the stations within 135–136°W. The densities of meiobenthic organismas within the CCFZ were high at stations with few manganese nodules on the sediment surface at low-latitude sites. In 1998, the observed relative high values of meiobenthic abundance were at stations from 5° to 6°N. Other stations from 7° to 10°N showed no significant fluctuations during the interannual sampling periods. It is considered that the inter-annual fluctuation of meiobenthos abundance is intimately related with a regime shift that may have occurred in the north Pacific between 1998 and 1999, the El Niño period. Vertical distribution of meiobenthic organisms showed the highest individual numbers in the surface sediment layers of 0~2 cm depth and a steep decreasing trend as sediment becomes deeper at the stations of high latitude located in 16~17°N. Size distribution analyses showed that organisms that fit into the sieve mesh size of 0.063 mm were abundant. 相似文献
342.
In this work,we study a direction dependent power spectrum in anisotropic Finsler spacetime. We use this direction dependent power spectrum to address the low-l power observed in WMAP and PLANCK data. The angular power spectrum of the temperature fluctuations has a lower amplitude in comparison to the ΛCDM model in the multipole range l = 2-40. Our theoretical model gives a correction to the isotropic angular power spectrum C_l~T~T ldue to the breaking of rotational invariance of the primordial power spectrum. We estimate best-fit model parameters along with the six ΛCDM cosmological parameters using the PLANCK likelihood code in Cosmo MC software. We find that this modified angular power spectrum fits the CMB temperature data in the multipole range l = 2-10 to a good extent but fails for the whole multipole range l = 2-40. 相似文献
343.
α-Glucosidase inhibitors are used therapeutically to treat type-2 diabetes mellitus. Through a bioassay-guided fractionation technique, three carotenoids,(all-E)-lutein,(all-E)-zeaxanthin and(9-Z)-zeaxanthin, were purified from the green alga Chlorella ellipsoidea, in which(all-E)-lutein and(9-Z)-zeaxanthin had potent α-glucosidase inhibitory activity. IC_(50) values of(all-E)-lutein and(9-Z)-zeaxanthin were 70 and 53.5 μmol L~(-1) against Saccharomyces cerevisiae α-glucosidase, respectively, with non-competitive inhibition. In addition, IC_(50) values of(9-Z)-zeaxanthin against Bacillus stearothermophilus and rat-intestinal α-glucosidase were 805.1 and 671.2 μmol L~(-1), respectively. The K_i values of(all-E)-lutein and(9-Z)-zeaxanthin against S. cerevisiae α-glucosidase were 78.1 and 16.5 μmol L~(-1), respectively. Therefore, C. ellipsoidea carotenoids might be utilized as a novel candidate to prevent type-2 diabetes mellitus related disorders in food and medical industry. 相似文献
344.
Yeon S. Chang Jong Dae Do Weon Mu Jeong Sang Kwon Hyun Won-Dae Baek Jae Ho Choi Jae-Youll Jin 《Ocean Science Journal》2020,55(1):1-16
Beach erosion is a serious problem that can be aggravated by human-made structures, and the modeling of breaking waves near the coast and around coastal st 相似文献
345.
346.
Large vortices with scales ranging from hundreds meters to tens of kilometers are generallyfound in the atmospheric convective boundary layer(CBL).These vortices play important roles in the vertical transport of momentum,heat,water vaporand other tracers in the boundary layer.On the basis of the view of interaction between theconvection in CBL and the gravity waves in the upper stable layer the authors developed aconvection-wave theory on the formation of large vortices.According to the theory thewavenumber spectrum of the large vortices mainly depends on the atmospheric conditions in bothof the upper and lower layers,such as wind speed,wind direction shear,stratification as well astemperature jump.In the present paper satellite image and weather data in a case of cold air outbreak over warmocean are analyzed to study every stage of the convective processes,such as cloud street,convective cell as well as their transformation.According to the theory the wavenumbercompositions for cloud street and convective cell are calculated,respectively,on the basis of theatmospheric conditions at every stage.The distributions of vertical motions,convergent band anddisturbed interface are obtained and compared with the cloud patterns in the convective processes.Thus the study seems to offer a likely explanation for the origin of large vortices in CBL. 相似文献
347.
348.
本文用数值试验方法,讨论了对于较小尺度山脉过山波和背风坡积云形成的关系.证明了在中层大气层结稳定、水平风速较强的条件下,过山波可能成为背风坡积云形成的启动机制. 相似文献
349.
350.
Sang Longkang 《地球科学》1986,(1)
作者在地质调查基础上,对取自玲珑花岗岩、包体和胶东群变质岩的25个有代表性的样品,用费氏台测定了113个斜长石颗粒。本文根据测定资料的统计分析,探讨了玲珑花岗岩斜长石成分、有序度、双晶类型、演化规律及其成因意义,并将玲珑花岗岩与金喆佑、舟桥三男(1972)建立的不同时代花岗岩模式进行了对比。上述研究的初步结果认为玲珑花岗岩属于元古代交代-深熔成因。 相似文献