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971.
Seasonal and interannual variability of carbon cycle in South China Sea: A three-dimensional physical-biogeochemical modeling study 总被引:5,自引:1,他引:4
Fei Chai Guimei Liu Huijie Xue Lei Shi Yi Chao Chun-Mao Tseng Wen-Chen Chou Kon-Kee Liu 《Journal of Oceanography》2009,65(5):703-720
The South China Sea (SCS) exhibits strong variations on seasonal to interannual time scale, and the changing Southeast Asian
Monsoon has direct impacts on the nutrients and phytoplankton dynamics, as well as the carbon cycle. A Pacific basin-wide
physical-biogeochemical model has been developed and used to investigate the physical variations, ecosystem responses, and
carbon cycle consequences. The Pacific basin-wide circulation model, based on the Regional Ocean Model Systems (ROMS) with
a 50-km spatial resolution, is driven with daily air-sea fluxes derived from the National Centers for Environmental Prediction
(NCEP) reanalysis between 1990 and 2004. The biogeochemical processes are simulated with the Carbon, Si(OH)4, Nitrogen Ecosystem (CoSINE) model consisting of multiple nutrients and plankton functional groups and detailed carbon cycle
dynamics. The ROMS-CoSINE model is capable of reproducing many observed features and their variability over the same period
at the SouthEast Asian Time-series Study (SEATS) station in the SCS. The integrated air-sea CO2 flux over the entire SCS reveals a strong seasonal cycle, serving as a source of CO2 to the atmosphere in spring, summer and autumn, but acting as a sink of CO2 for the atmosphere in winter. The annual mean sea-to-air CO2 flux averaged over the entire SCS is +0.33 moles CO2 m−2year−1, which indicates that the SCS is a weak source of CO2 to the atmosphere. Temperature has a stronger influence on the seasonal variation of pCO2 than biological activity, and is thus the dominant factor controlling the oceanic pCO2 in the SCS. The water temperature, seasonal upwelling and Kuroshio intrusion determine the pCO2 differences at coast of Vietnam and the northwestern region of the Luzon Island. The inverse relationship between the interannual
variability of Chl-a in summer near the coast of Vietnam and NINO3 SST (Sea Surface Temperature) index in January implies that the carbon cycle and primary productivity in the SCS is teleconnected
to the Pacific-East Asian large-scale climatic variability. 相似文献
972.
主要介绍丙烯酰胺型长效化学降阻剂降阻的原理、特点及其比其它降阻方法的优越性。也详细介绍使用这种长效化学降阻剂的施工方法和辽宁省部分地震台使用长效化学降阻剂的实际效果。 相似文献
973.
通过采用三星公司的S3C44B0X和嵌入式实时操作系统μC/OS-Ⅱ,提出了输液药品生产过程中的灭菌智能控制器的设计方案.按照输液药品的灭菌工艺流程要求和控制特点,介绍和论述控制仪的硬件结构、软件结构,重点介绍整个系统的软件设计,包括μC/OS-Ⅱ的移植、设备驱动程序开发、应用程序开发. 相似文献
974.
利用2015—2019年中国东部20个省份222个城市的地面O_3观测数据和全球再分析风场数据,研究了中国东部地区O_3的时空分布特征,以及在亚洲夏季风背景下污染上风方O_3光化学输送对下风方O_3质量浓度季节变化的影响。结果表明:中国东部地区O_3质量浓度夏季高、冬季低,O_3质量浓度按照东南、华东、东北、华北的顺序依次升高,位于中高纬度的华北、东北地区明显高于位于中低纬度的华东、华南地区。不同城市、不同季节O_3质量浓度日变化形态具有较好的一致性,都表现为夜晚低、清晨逐渐升高、下午至黄昏达到最大的单周期变化形态,具有典型的光化学控制特征。春季,亚洲夏季风开始影响中国东部地区,华东、华北、东北地区为大范围的O_3高值区;夏季,亚洲夏季风将O_3及其前体物由纬度较低的华南、华东地区向纬度较高的华北、东北地区不断输送和累积,并在夏季强紫外辐射作用下发生光化学反应,导致夏季华北、东北地区的O_3污染。 相似文献
975.
The polarimetric radar network in Jiangsu Province has just been operationalized since 2020. The first intense precipitation event observed by this polarimetric radar network and disdrometer occurred during August 28-29, 2020 and caused severe flooding and serious damage in eastern Jiangsu Province. The microphysics and kinetics for this heavy precipitation convective storm is diagnosed in this study, in order to promote the application of this polarimetric radar network. Drop size distribution (DSD) of this event is estimated from measurements of a ground disdrometer, and the corresponding three-dimensional atmospheric microphysical features are obtained from the multiple polarimetric radars. According to features of updraft and lighting, the evolution of the convective storm is divided into four stages: developing, mature with lightning, mature without lightning and dissipating. The DSD of this event is featured by a large number of raindrops and a considerable number of large raindrops. The microphysical characteristics are similar to those of warm-rain process, and ice-phase microphysical processes are active in the mature stages. The composite vertical structure of the convective storm indicates that deep ZDR and KDP columns coincide with strong updrafts during both mature stages. The hierarchical microphysical structure retrieved by the Hydrometeor Identification Algorithm (HID) shows that depositional growth has occurred above the melting level, and aggregation is the most widespread ice-phase process at the -10℃ level or higher. During negative lightning activity, the presence of strongest updrafts and a large amount of ice-phase graupel by riming between the 0℃ and -35℃ layers generate strong negative electric fields within the cloud. These convective storms are typical warm clouds with very high precipitation efficiency, which cause high concentration of raindrops, especially the presence of large raindrops within a short period of time. The ice-phase microphysical processes above the melting layer also play an important role in the triggering and enhancing of precipitation. 相似文献
976.
977.
978.
979.
BDS与GPS双系统组合定位时,每个子系统需要进行定权,不同系统间的差异性会导致定权不准确。为提升组合定位精度,本文提出一种基于抗差Helmert方差分量估计的组合定位算法(RH算法)。首先,建立Helmert方差分量后验估计模型,区分多类型、不同精度的观测值,实现系统间权值的动态分配;然后,构建基于IGGⅢ方案的改进等价权函数,调整含粗差观测量的权值,解决观测值易存在粗差导致Helmert模型收敛失真的问题;最后,通过测试实际采集的双系统观测数据,验证算法的有效性和准确性。 相似文献
980.
新疆西昆仑独尖山地区发育第四纪乌鲁克库勒组火山岩,根据岩石分布范围,将研究区内乌鲁克库勒组火山岩分为阿塔木帕下火山岩区和阿什库勒火山岩区,二者岩石组合相似,以爆发相凝灰质(角)砾岩、火山渣及溢流相玄武岩、玄武安山岩为主。岩石SiO2含量为60.42%~61.99%,Na2O+K2O为6.31%~7.10%,里特曼指数为2.22~2.67,固结指数8.27~14.36,铝质指数为0.63~0.73,岩石总体表现为偏铝质钾质钙碱性岩石系列特征。样品富集大离子亲石元素,亏损高场强元素,稀土元素配分曲线呈右陡倾型,显示出岛弧火山岩的特点。结合区域地质特征,乌鲁克库勒组火山岩形成时代为中新世,其岩浆主要来源于地幔,且岩石在形成过程中明显受到地壳物质混染,形成环境为大陆岛弧环境。 相似文献