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121.
122.
矿区处于博罗霍洛山主脊,属斑岩型铜钼矿床。斑岩体本身为矿体,钼矿在岩体内,铜矿在外接触带。通过矿区北部勘查地球化学工作表明,Mo、Cu、Pb、Ag、As原生地球化学异常规模大、连续性好,形态规则,梯度大。As、Sb、Ag具前缘特征。除Mo、Cu外,Pb、Ag具主成矿元素特征。原生异常纵向分带具轴向分带特征,分带序列有一定的典型意义。从地质、地球化学异常特征、小岩体地球化学特征以及金属预测资源初步计算认为该矿床很有远景。  相似文献   
123.
A new and simple method based on a nonlinearly mathematical optimization concept has been proposed in this research to interpret magnetic anomalies due to vertical faults and thin dikes. This proposed interpretative method consists of three main steps. The first step is to formulate nonlinearly constrained optimization problems to describe the geophysical problems related to the studied structures. The second step is to suggest an interior penalty function in order to convert these nonlinearly constrained optimization problems into nonlinearly unconstrained optimization ones. The third step is to solve the converted nonlinearly unconstrained optimization problems by using the famous Hooke and Jeevess algorithm in order to estimate the geophysical parameters of the studied structures such as: depth, amplitude coefficient, and index parameter. The Hooke and Jeevess algorithm is purposely chosen for being robust and also its application to magnetic data converges rapidly towards the optimal estimation of parameters. This method was first tested on theoretical models with different random noise, where a very close agreement was obtained between the assumed and evaluated parameters. The validity of this new method was also tested on practical field examples taken from Australia, India, United States, and Brazil, where available magnetic data existed and was previously analyzed by different interpretative methods. The agreement between the results obtained by our developed method and those obtained by the other geophysical methods is good. The advantages of this newly proposed method, compared with the other published interpretative methods, also have been discussed and demonstrated.  相似文献   
124.
An analysis of high-resolution precipitation data for 1978-2006 indicates that the precipitation over southern China in June experienced a low-value period in 1980-1989 and a high-value period in 1992-2001.It also reveals that exceptional heavy(light) precipitation occurred in June 2005(2004) since 1951.For these variations on both interdecadal and interannual timescales,fairly uniform anomalies of precipitation appeared over Vietnam,southern China,and southeastern China.Corresponding to positive(negative) precipitation anomalies,anomalous southeasterly(northwesterly) flow at 850 hPa reached Vietnam and anomalous southwesterly(northeasterly) flow expanded to the coastal regions of southern and southeastern China.Precedent to the positive(negative) precipitation anomalies during 1992-2001(1980-1989),positive(negative) anomalies of sea surface temperature appeared over the extratropical northwestern Pacific in the winter and spring seasons,associated with a strong(weak) extension of the warm Kuroshio Current that affects the coastal region of eastern China.The above-normal precipitation in June 2005 was associated with the pseudo-ENSO event in the previous winter,and the below-normal precipitation in June 2004 was associated with negative anomalies of sea surface temperature over the equatorial central Pacific and positive anomalies over the equatorial western and eastern Pacific.  相似文献   
125.
对大地高、正高与正常高的关系进行阐述,对机场工程场址条件较为困难时使用区域似大地水准面精化的方式满足大比例尺测图的可能性进行叙述,对"移去-恢复法"的计算方法、误差来源与精度评定方法进行论述,在实际算例中使用不同的EGM模型、不同的残差拟合方法所得到的结果进行比对,提出适合于机场工程大比例尺测图用控制网点正常高值拟合的方法。  相似文献   
126.
根据介休市气象局1954年-2006年的气温资料,分析了介休市近53年来的温度变化。结果表明:近53年来介休市气温呈上升趋势,上升速度显著高于全国水平,上世纪90年代中期以来这种趋势尤为明显;以20世纪90年代中期为界,近53年来介休市气候分冷、暖两个阶段,前为冷期,后为暖期。  相似文献   
127.
采用CAM3(Community Atmosphere Model Version3)模式中海气湍流通量参数化原方案和改进方案,利用观测海温驱动CAM3模式进行气候模拟,以分析模式对厄尔尼诺事件影响气候变化的模拟能力。结果表明,采用CAM3模式海气湍流通量参数化改进方案,模式能够更好地模拟出由厄尔尼诺事件引起的北太平洋和北美地区大气环流的变化,尤其是对厄尔尼诺年冬季阿留申低压强度和与PNA遥相关型有关的500hPa位势高度异常的模拟。  相似文献   
128.
宋燕  李智才  朱临洪  张世英 《气象》2008,34(2):61-68
采用EOF分解和合成分析方法研究了1960-2003年山西夏季降水异常之北少(多)南多(少)型(第二类雨型)和山西省气温的变化异常.结果表明,两者具有较好的对应关系.分析了第二类异常雨型的时空分布,并给出相应的典型年份.EOF时间系数变化特征揭示了山西夏季降水第二类雨型有显著的年际振荡.利用合成分析,从500hPa位势高度场、纬向风、850hPa风场、700hPa水汽场和水汽输送场等物理量场研究了山西夏季第二类雨型的环流异常特征.结果表明,第二类雨型与弱的东亚夏季风相关联,北多南少和北少南多是弱夏季风的不同表现.山西省夏季降水北多南少年副高呈带状分布,位置偏北,强度较强;中高纬度地区异常波列呈大圆路径分布,在高纬度地区存在纬向排列的- -波列,同时在东亚大陆沿岸存在经向排列的- -波列.并且华北北部有西风异常,北支锋区偏北,由西南向东北水汽输送较强.北少南多年与之相反.海温场分析表明,第二类雨型与中北太平洋海温异常紧密相关.  相似文献   
129.
A fault was traced along the southwestern margin of the Shatsky Rise. It extends to land where it crosses the Mountainous Crimea. Interpretation and analysis of marine seismic and magnetic survey data, as well as geological data on land, allow stating that the fault originated during the rift evolution stage of the East Black Sea Basin. Currently, the fault is in the sea and is a channel for migrating hydrocarbon fluids. Another fault was traced from the West Caucasus into the sea, where it separates the Shatsky Rise into two structural units.  相似文献   
130.
Aeromagnetic anomalies over Bastar craton and Pranhita-Godavari (P-G) basin in the south of central India could be attributed to NW-SE striking mafic intrusives in both the areas at variable depths. Such intrusions can be explained considering the collision of the Bastar and Dharwar cratons by the end of the Archaean and the development of tensile regimes that followed in the Paleoproterozoic, facilitating intrusions of mafic dykes into the continental crust. The P-G basin area, being a zone of crustal weakness along the contact of the Bastar and Dharwar cratons, also experienced extensional tectonics. The inferred remanent magnetization of these dykes dips upwards and it is such that the dykes are oriented towards the east of the magnetic north at the time of their formation compared to their present NW-SE strike. Assuming that there was no imprint of magnetization of a later date, it is concluded that the Indian plate was located in the southern hemisphere, either independently or as part of a supercontinent, for some span of time during Paleoproterozoic and was involved in complex path of movement and rotation subsequently. The paper presents a case study of the utility of aeromagnetic anomalies in qualitatively deducing the palaeopositions of the landmasses from the interpreted remanent magnetism of buried intrusive bodies.  相似文献   
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