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251.
作为半封闭狭长海湾,铁山湾受风暴潮灾害的影响较为严重。根据多年观测资料和数值模型对铁山湾内的风暴潮水位特征进行了研究。观测资料表明海湾内风暴潮峰值水位受天文潮相位影响较为显著,然后基于ADCIRC风暴潮模型和1409号“威马逊”台风参数,定量评估了天文潮对风暴潮水位的影响。模拟结果表明当考虑天文潮作用时,会显著提高模拟结果精度,然后通过数值实验研究了风暴潮与不同相位天文潮相互作用时的水位变化特征。数值实验结果表明天文潮-风暴潮相互作用引起的非线性水位在涨潮阶段不明显,在高潮位时非线性水位达到负值最大;在落潮时达到正值最大。风暴潮增水峰值由于受到这种非线性效应的影响,在高潮位时数值最小。海湾内非线性作用要远大于外部,非线性效应越强,总水位峰值相对于天文潮高潮位的延迟时间也就越长。  相似文献   
252.
渤海PL油田是位于渤海湾盆地的大型河流相油田,在其注水开发过程中,亟需准确认识注水井与生产井之间的砂体连通性,以便优化和调整注采井网,提高采收率.针对油田砂体横向变化快,纵向上薄砂体发育的特点,利用丰富的压力、水淹等生产动态资料及相位转换后赋予地质意义的地震资料综合分析砂体的连通性,进一步完善和修正了早期以地质及测井资料确定的砂体连通性分析成果,并引入注采连通率概念,用来定量表示井组范围内注水井与生产井之间的砂体的连通性.该套方法在PL油田注水优化及井网调整研究中得到了充分的体现,对其它河流相注水开发油田井组范围内井间砂体连通性研究具有一定的借鉴作用.  相似文献   
253.
为了满足定量解释的需要,地震资料处理必须是高分辨率、振幅保持和相位控制的.面向海洋地震资料的相位控制处理技术包括利用远场信号进行确定性零相位化、Q补偿、预测反褶积及剩余相位校正等.利用模拟远场信号求取确定性去气泡及零相位化算子.此文基于相位控制处理,讨论了海洋地震资料的相位和极性判别方法,探讨了大于24 ms算子长度的预测反褶积对于保持信号形状的必要性,介绍了东海三维地震资料相位控制流程.  相似文献   
254.
The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers (PWIs) in addition to the de- tection of forward-scattering optical properties.  相似文献   
255.
The pathway of the East Asian winter monsoon(EAWM) that usually leads to the out-of-phase pattern of surface air temperature between northern and southern East Asia is an important feature in the variability of the EAWM besides its strength.Using the European Centre for Medium-Range Weather Forecasts 40-year(ERA40) reanalysis dataset,this study investigates the pathway-related stationary wave activity to explore the mechanism of the interannual variations in the EAWM pathway.It reveals that when the southern pathway of the EAWM is strong,the phase of the climatological stationary wave tends to be shifted westward significantly in both the horizontal and vertical directions by an anomalous wavenumber 2 pattern at mid-latitudes,whereas the changes are relatively small in the subtropics.The horizontal changes in the stationary wave phase facilitate a north-south-oriented East Asian trough in the middle troposphere that eventually produces the strong southern pathway of the EAWM.The vertical changes in the stationary wave,in contrast,feature a westward-tilted phase line with height over the North Pacific,indicating enhanced upward propagation of waves into the stratosphere.This result suggests that the phase of stationary waves at mid-latitudes dominate the interannual variations in the EAWM pathway.Moreover,it supports our previous interpretation of the possible role of the North Pacific sea surface temperature(SST) in the EAWM pathway variability.It also implies that the excitation of anomalous mid-latitude stationary waves may be the key in the response of the EAWM pathway to the North Pacific SST.  相似文献   
256.
The deep‐sea bivalve Acesta oophaga lives attached to the anterior end of the vestimentiferan tubeworm, Lamellibrachia luymesi, at cold methane seeps. The bivalve is found almost exclusively on female tubeworms, where it consumes the lipid‐rich eggs of L. luymesi that are spawned year round (Biological Bulletin, 209, 2005, 87). It is apparent that A. oophaga benefits directly from this close association, but the consequences for the tubeworm host may be more complicated than just a simple predator–prey interaction. Since A. oophaga completely surrounds the tube opening and plume of the worm, it is likely that its presence would limit oxygen uptake by L. luymesi, thereby inhibiting worm growth and reproduction. We hypothesized that occupied tubeworms would compensate for this by growing larger plumes for oxygen uptake. To explore the effects of bivalve presence/absence on female tubeworms, several morphological features, including body size, plume length, tube diameter, and tube segment length, as well as instantaneous fecundity, were compared. Results suggest that the mere presence of A. oophaga has a significant impact on the morphology of its host worm, as all measures of worm size, except for tube segment length, were significantly greater with clams present. Additionally, instantaneous fecundity was 3.5 times higher in occupied worms, implying that tubeworms are not oxygen‐deprived or energy limited as a result of bivalve presence. Our findings suggest that the association between these two deep‐sea organisms may be a more complex form of symbiosis than the simple predator–prey relationship, as previously thought.  相似文献   
257.
东海表层水体中的多环芳烃及其沉积通量估算   总被引:2,自引:0,他引:2  
以东海陆架水体中溶解态多环芳烃(PAHs)含量为基础,引入颗粒相-水相间的物质吸附系数(Koc)计算悬浮颗粒物中PAHs有机碳归一化含量,结合陆架沉积物有机碳的年埋藏通量,估算东海陆架沉积物中PAHs沉积通量。结果显示:水体中溶解态的15种PAHs总含量为(701±392)ng/L,变化范围为412~1 032ng/L,PAHs组成以3环为主。计算得到的悬浮颗粒物中15种PAHs有机碳归一化含量为20~28μg/g,对应的PAHs沉积通量为150~210t/a。估算结果与实测沉积物中PAHs含量和沉积通量结果基本吻合,表明实验室模拟实验获取的化合物Koc值适用于东海颗粒相-水相间的分配模型,证实悬浮颗粒物有机碳含量在控制PAHs两相分布过程中起着重要作用。同时,该方法为海洋沉积物中PAHs沉积通量的估算提供一种新途径。  相似文献   
258.
风廓线雷达垂直径向速度应用初探   总被引:2,自引:1,他引:1  
王令  王国荣  古月  李宏宇  马莉  郭金兰  乔林 《气象》2014,40(3):290-296
利用北京风廓线雷达五波束探测中的垂直波束资料,进行了垂直速度在预报中的应用研究。通过对垂直速度的分级显示,配合地面气象记录,对不同的天气个例进行分析,结果表明:平稳晴空的天气风廓线雷达所测量的垂直速度很小,基本上在±1m·s~(-1)范围内;而有降水时,风廓线雷达所测得边界层的垂直速度基本上都是朝向地面的,不同相态降水粒子的垂直下落速度有明显的差别。分析表明风廓线雷达垂直速度的探测对研究晴空大气的垂直运动、判断降水粒子相态和降水预报有应用价值。  相似文献   
259.
Using numerical simulation data of the forward differential propagation shift (ΦDP) of polarimetric radar,the principle and performing steps of noise reduction by wavelet analysis are introduced in detail.Profiting from the multiscale analysis,various types of noises can be identified according to their characteristics in different scales,and suppressed in different resolutions by a penalty threshold strategy through which a fixed threshold value is applied,a default threshold strategy through which the threshold value is determined by the noise intensity,or a ΦDP penalty threshold strategy through which a special value is designed for ΦDP de-noising.Then,a hard-or soft-threshold function,depending on the de-noising purpose,is selected to reconstruct the signal.Combining the three noise suppression strategies and the two signal reconstruction functions,and without loss of generality,two schemes are presented to verify the de-noising effect by dbN wavelets:(1) the penalty threshold strategy with the soft threshold function scheme (PSS); (2) the ΦDP penalty threshold strategy with the soft threshold function scheme (PPSS).Furthermore,the wavelet de-noising is compared with the mean,median,Kalman,and finite impulse response (FIR) methods with simulation data and two actual cases.The results suggest that both of the two schemes perform well,especially when ΦDP data are simultaneously polluted by various scales and types of noises.A slight difference is that the PSS method can retain more detail,and the PPSS can smooth the signal more successfully.  相似文献   
260.
在系统收集山东已完成的1∶5万、1∶20万和1∶25万区域地质资料基础上,通过编制山东省1∶25万实际材料图和建造构造图、1∶50万大地构造相五要素工作底图和1∶50万大地构造相图,全面介绍了大地构造相的定义、研究内容、指导思想、基本原则与编图程序。采用大地构造相编图作为大陆动力学研究的主要方法,是揭示不同陆块之间相互作用、形成过程和演化历史、研究山东大陆块体离散、会聚、碰撞、造山的大陆动力学过程的主要载体和具体表达形式。进而对山东大地构造相进行了划分,共划出华北陆块区、秦祁昆造山系和中国东部陆缘弧盆系相系3大相系,鲁西陆块、渤海陆块、大别苏鲁结合带、威海弧盆系、胶辽岩浆弧和华北裂谷盆地6个大相以及20个相和59个亚相,明确了其鉴别标志。对陆块区、造山系和陆缘弧盆系相系以及大相、相的基本特征进行了描述;简要总结了大地构造相与成矿尤其是金矿的关系,探讨了不同矿床与大地构造相的成因联系。  相似文献   
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