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111.
北京地区PM10浓度空间分布特征的综合变分分析   总被引:7,自引:0,他引:7       下载免费PDF全文
利用2003年10月北京地区PM10浓度流动观测资料和同期MODIS AOD(Aerosol Optical Depth)高分辨率遥感资料,采用卫星遥感地面观测变分订正处理方法,综合分析了北京地区PM10浓度的空间分布特征以及机动车排放的影响效应。动态观测试验结果表明:北京城区大部分为轻污染区, 北京近郊区PM10浓度高值区沿环路呈环状分布,其中北京西南部、南部和东北部污染较严重,北京城郊街区PM10的空间分布受机动车排放的影响较大。MODIS卫星遥感资料分析表明:北京城区及近郊区AOD值较远郊区高得多,AOD空间分布场中存在虚假高值区,AOD非均匀分布特征不明显。采取点面结合综合观测研究思路,运用卫星遥感地面观测综合变分分析方法,可以取得客观订正的显著效果。经地面实测PM10浓度变分订正后的AOD变分场可以较高分辨率信息描述北京地区AOD的非均匀分布特征,弥补地面PM10浓度观测的缺陷。  相似文献   
112.
113.
黄淮平原农业干旱预警系统研究   总被引:1,自引:0,他引:1  
采用区域气候模式与土壤水分模型相结合的技术,建立黄淮平原农业干旱预警系统。系统的气候模式采用NCAR的区域气候模式(RegCM2),为土壤水分模型提供所需的气象要素场数值预报。土壤水分模型采用适合于黄淮平原冬小麦、夏玉米等作物的土壤水分平衡方程。试运行结果表明,利用区域气候模式和土壤水分模型构建的区域性土壤水分模型,土壤水分预报的平均相对误差在15%以下,可以较好地模拟出土壤水分变化和干旱分布状况,可用于土壤水分预报和干旱监测。  相似文献   
114.
首次在测站稀少的高原地区引入经变分技术处理的 TOVS卫星资料 ,通过动力诊断探讨了解决高原地区测站少、数值预报模式初始场信息误差大的技术关键问题 ,提出了采用TOVS反演资料在高原地区增加模式初始场信息的构思 ,并应用变分法处理 TOVS反演资料 ,显著地提高了高原初始场信息的可靠性 ;并从动力诊断分析角度 ,进一步证实了 TOVS反演资料的应用有利于提高高原动力系统特征的描述能力 ,并显著改善水汽输送通道分布及其层结稳定度等有关初始场信息的客观性  相似文献   
115.
青藏高原云对地气系统净辐射强迫的气候研究   总被引:1,自引:0,他引:1  
利用地球辐射平衡试验(ERBE)和国际卫星云气候计划(ISCCP)提供的地气系统行星反射率、长波射出辐射(OLR)和云量资料,计算了青藏高原地区云对地气系统净辐射的强迫,并讨论其与总云量及地气系统晴天净辐射的关系。结果表明:高原各季净辐射云强迫与总云量有较好的非线性关系,其中以暖季更明显;各月净辐射云强迫与地气系统晴天净辐射的曲线相关很明显,各条曲线均存在一个与净辐射云强迫零值相对应的晴天净辐射值  相似文献   
116.
Qihao Weng 《GeoJournal》2000,51(3):191-202
The formation and evolution of agricultural land uses in the Zhujiang Delta of South China are examined in the light of the dynamics of people and the environment and their interplay. The origin and propagation of agriculture are found to have a close relationship with the climate and sea level changes in the Holocene era. The development of rice cultivation, horticulture, and dike-pond system exemplifies human-environment interactions in a specified geographical and social context, which are manifested by the impact of environmental changes and population growth on agricultural innovations. The technologies of dike building and land reclamation, which represent local farmers effort to build a new and harmonious relationship with the changed environment, were critical to the agricultural success and sustainability. Imprudent use of a new agricultural technology could damage the environment, as evidenced by a frequent flooding that followed inappropriate dike building and premature reclamation. Diverse agricultural land uses are as a result of the adaptation of agricultural technology innovations to the environmental conditions.  相似文献   
117.
福建物探、化探工作起步于20世纪50年代。近半个世纪以来,福建省地质工作者利用物探、化探、遥感等技术在区域地质,深部地质,矿产地质,水文地质、工程地质,环境地质,医学地质,农业地质等领域取得了丰硕成果,但还存在一定差距。为进一步提高福建省物探、化探、遥感等技术水平和扩大应用领域,对今后工作提出几点建议和对策。  相似文献   
118.
社会信任作为非正式制度环境的核心构成要素对区域创业活动有复杂而重要的影响。由于社会距离、交往对象的不同,社会信任在表现形式和作用机制方面差异明显,但现有研究鲜有关注社会信任不同维度对区域创业的影响。论文从普遍信任、亲缘信任、制度信任3个维度构建社会信任框架,利用中国家庭跟踪调查(CFPS)2012、2014、2016、2018年4期面板数据和企业工商注册信息微观数据进行实证分析,研究发现:(1)在全国尺度,亲缘信任显著提高了区域创业活跃度,而普遍信任、制度信任对区域创业活跃度的作用不明显。(2)交互效应结果显示,普遍信任、亲缘信任与经济发展之间存在替代效应;普遍信任与政府干预互为补充,政府干预越弱,普遍信任对区域创业的激励作用越强;而制度信任与政府干预表现为相互促进的互动关系,共同促进了区域创业活跃度。(3)分样本异质性检验表明,东部地区创业活跃度对社会信任的依赖度较弱;中西部地区创业活跃度受到普遍信任、亲缘信任的积极影响;政商关系良好城市的创业活跃度受到制度信任的促进作用,创业政策红利得到有效释放;在政商关系普通城市,普遍信任能够显著促进创业,激发创业活力。研究证实了不同维度社会信任...  相似文献   
119.
The Earth Observation (EO) data with their advantages in spectral, spatial and temporal resolutions have demonstrated their great value in providing information about many of the components that comprise environmental systems and ecosystems for decades that are crucial to the understating of public health issues. This literature review shows that in conjunction with in situ data collection, EO data have been used to observe, monitor, measure and model many environmental variables that are associated with disease vectors. Furthermore, satellite derived aerosol optical depth has been increasingly employed to estimate ground-level PM2.5 concentrations, which have been found to associate with various health outcomes such as cardiovascular and respiratory diseases. It is suggested that Landsat-like imagery data may provide important data sources to analyse and understand contagious and infectious diseases at the local and regional scales, which are tied to urbanisation and associated impacts on the environment. There is also a great need of data products from coarse resolution imagery, such as those from moderate resolution imaging spectrometer, multiangle imaging spectroradiometer and geostationary operational environmental satellite , to model and characterise infectious diseases at the continental and global scales. The infectious diseases at greater geographical scales have become unprecedentedly significant as global climate change and the process of globalisation intensify. The relationship between infectious diseases and environmental characteristic have been explored by using statistical, geostatistical and physical models, with recent emphasis on the use of machine-learning techniques such as artificial neural networks. Lastly, we suggest that the planned HyspIRI mission is crucial for observing, measuring and modelling environmental variables impacting various diseases as it will improve both spectral resolution and revisit time, thus contributing to better prediction of occurrence of infectious diseases, target intervention and tracking of epidemic events.  相似文献   
120.
We present the main results from the second model intercomparison within the GEWEX (Global Energy and Water cycle EXperiment) Atmospheric Boundary Layer Study (GABLS). The target is to examine the diurnal cycle over land in today??s numerical weather prediction and climate models for operational and research purposes. The set-up of the case is based on observations taken during the Cooperative Atmosphere-Surface Exchange Study-1999 (CASES-99), which was held in Kansas, USA in the early autumn with a strong diurnal cycle with no clouds present. The models are forced with a constant geostrophic wind, prescribed surface temperature and large-scale divergence. Results from 30 different model simulations and one large-eddy simulation (LES) are analyzed and compared with observations. Even though the surface temperature is prescribed, the models give variable near-surface air temperatures. This, in turn, gives rise to differences in low-level stability affecting the turbulence and the turbulent heat fluxes. The increase in modelled upward sensible heat flux during the morning transition is typically too weak and the growth of the convective boundary layer before noon is too slow. This is related to weak modelled near-surface winds during the morning hours. The agreement between the models, the LES and observations is the best during the late afternoon. From this intercomparison study, we find that modelling the diurnal cycle is still a big challenge. For the convective part of the diurnal cycle, some of the first-order schemes perform somewhat better while the turbulent kinetic energy (TKE) schemes tend to be slightly better during nighttime conditions. Finer vertical resolution tends to improve results to some extent, but is certainly not the solution to all the deficiencies identified.  相似文献   
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