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91.
TheJiulongRiver,composedoftheWestStream,theNorthStreamandtheSouthStream(seeFig.1)isthesecondlargestriverinFujianProvince.ItsestuarineplainintervenesbetweenthetwqcitiesofXiamenandZhangzhou,withsouthern-subtropicoceanicmonsoonclimate-SofartherehasnotbeensystematicresearchontheLateQuaternarysea1evelchangesinthearea,andthispaperisintendedtodosomethingaboutit.DIAToMZoNESANDBIoFACIESOFZK5BoREHOLETheBoreholeZK5islocatedtothenortheastofHaichengTown,withcoordinateof24"24,32*N,ll7'5…  相似文献   
92.
从山东省地震局数字信息服务的沿革、数字科技信息网的建设、及对数字化信息资源建设与服务的再认识等方面,展示了山东省地震局数字科技信息服务平台。该平台突出防震减灾和地区特色,整合信息资源,建立了更加完备的数字化信息网站,全面提升了山东省地震局数字科技信息的服务水平,以全新的服务模式实现了全方位、多层次的数字化信息管理服务。  相似文献   
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A detailed study was carried out on a piece of land that had been struck by lightning during the violent rainstorm that raged over the Island of S?o Miguel (Azores Archipelago) in late October 2006. Temperature and gas measurements (CO2, CO, H2S and CH4) were performed in four study trenches, dug in an area of ∼3 m2, where an underground fire had been initiated by the impact with a lightning stroke, followed by the emission of a column of gases and smoke. The soil under study was originally a well-pedogenized about 80 cm thick bed, made of volcanic clayey to silty tephra fallouts and contained 5.5–9.7% of organic matter. The underground fire was monitored for one week and revealed a peak release of 404 ppm CO and 3.4% CO2 originating from a horizon located about 45 cm under the soil surface. Measurements of temperature, performed one week after the impact, indicated a maximum value of 326°C inside the soil, while 516.5°C were measured on the surface of a lava block interred about 20 cm under the surface. Subsequently, a stratigraphic and sedimentologic study proved the role of the grain-size of the soil and of the organic matter content of the different horizons of the impact area, in determining the ratio between anoxic/oxidised combustion conditions and in the progress of the process itself. It was also noticed that combustion was not total all over in the soil bed and that the process had slightly migrated toward SW during the observation period. The combustion process went on for about ten days, in spite of several other violent rainstorms, until it was artificially extinguished through the excavations made to obtain study trenches. This particular circumstance evidenced the potential natural hazard represented by this kind of atmospheric event, especially in a land where the volcanic nature of the soil may easily mislead inexperienced observers and, consequently, delay proper action.  相似文献   
95.
黄果树风景名胜区旅游环境容量研究   总被引:1,自引:0,他引:1  
王剑  彭建 《中国岩溶》2007,26(2):183-188
选择我国典型的喀斯特风景名胜区— — 黄果树景区为例,通过分析主要制约因子,定量研究了该景区的旅游环境容量。研究表明,黄果树风景区的空间环境容量为21 933人次/日,生态环境容量为51 354人次/日,经济环境容量为98 716人次/日。空间环境容量成为制约景区提高接待规模的主要限制因子,平日一般不会出现超载的问题,周末存在局部超载的情况,而在黄金周等旅游高峰期,接待规模远远超出其旅游环境容量,景区常常出现整体性超载。针对这些问题,作者提出了游客分流、及时发布旅游接待信息以及加强未成熟景区的开发等措施,以缓解黄果树景区的旅游环境容量问题。   相似文献   
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An early warning system can be an effective measure to reduce the damage caused by landslides by facilitating the timely evacuation of residents from a landslide-prone area. Early detection of landslide triggering across a broad range of natural terrain types can be accomplished by monitoring rainfall and the physical property changes of soils in real time or near-real time. This study involved the installation of a real-time monitoring system to observe physical property changes in soils in a valley during rainfall events. This monitoring included the measurement of volumetric water content, which was compared with the results of laboratory flume tests to identify landslide indicators in the soils. The response of volumetric water content to rainfall events is more immediate than that of pore-water pressure, and volumetric water content retains its maximum value for some time before slope failure. Therefore, an alternative method for landslide monitoring can be based on the observation of volumetric water content and its changes over time at shallow soil depths. Although no landslide occurred, the field monitoring results showed a directly proportional relationship between the effective cumulative rainfall and the gradient of volumetric water content per unit time (t/t max). This preliminary study thus related slope failure to the volumetric water content gradient as a function of rainfall. Laboratory results showed that a high amount of rainfall and a high gradient of volumetric water content could induce slope failure. Based on these results, it is possible to suggest a threshold value of the volumetric water content gradient demarcating the conditions for slope stability and slope failure. This threshold can thus serve as the basis of an early warning system for landslides considering both rainfall and soil properties.  相似文献   
98.
马国民  吕恩春 《探矿工程》2011,38(10):80-82
近年来,欠平衡钻井(UBD)和控制压力钻井(MPD)因能大幅度提高机械钻速、有效降低井下复杂情况的发生、减少非生产时间而得到了飞速发展,国内外也对两项技术制定了相关标准。从石油行业标准I、ADC标准、API标准入手,着重讨论欠平衡钻井和控制压力钻井的标准现状,探讨建立控制压力标准应包含的主要内容。  相似文献   
99.
The Lanhualing tungsten-molybdenum deposit is a skarn-type deposit located in Ningguo county, Anhui province. This deposit is mainly hosted in the Yinzhubu Formation and the Yanwashan Formation of Ordovician, and genetically related to the Lanhualing granite. The Lanhualing granite belongs to high-K calc-alkaline series with high alkali (Na2O+K2O=4.00%-7.03%), SiO2 (67.87%-74.92%) and MgO (0.62%-1.23%) contents. The granitic rocks show right-dipping chondrite normalized REE patterns with weak δEu anomalies. The granitic rocks are relatively enriched in large ion lithophile elements (LILE) and depleted in high field strength elements (HFSE). The ore-bearing granite was dated at 148.17±0.94 Ma by LA-ICP-MS zircon U-Pb method. The late Yanshanian is the main tungsten mineralization epoch in the South Anhui-north Jiangxi area; and indeed, the Dongyuan, Zhuxi, Yangchuling, Dahutang and other large and super-large tungsten deposits were formed in this period. Geochemical Characteristics of the Lanhualing granite indicate a crustal source but with mantle input under tectonic regime of compression thickening. ©, 2015, Science Press. All right reserved.  相似文献   
100.
Natural Resources Research - Fractal and multifractal models, including the concentration-area (C–A) fractal model, spectrum-area (S–A) multifractal model, and local singularity...  相似文献   
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