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71.
72.
Since the adoption of the 1969CLC and the 1971FC, the international oil-spill compensation regime has improved compensation for loss and damage caused by tanker oil spills. However, this regime has inherent limitations, such as protracted compensation payments and controversies over the scope and type of economic losses, including environmental damages, and the cost of environmental restoration. Therefore, given large oil-spill incidents, such as the Erika, Prestige, and Hebei Spirit, each government, respectively, has addressed compensation by enacting special laws or establishing domestic programs. This article contains a historical and legal analysis of the Hebei Spirit incident and discusses the limitations and necessary improvements to the international oil-spill compensation regime. 相似文献
73.
In consideration of large uncertainties in severe convective weather forecast, ensemble forecasting is a dynamic method developed to quantitatively estimate forecast uncertainty. Based on ensemble output, joint probability is a post-processing method to delineate key areas where weather event may actually occur by taking account of the uncertainty of several important physical parameters. An investigation of the environments of little rainfall convection and strong rainfall convection from April to September (warm season) during 2009-2015 was presented using daily disastrous weather data, precipitation data of 80 stations in Anhui province and NCEP Final Analysis (FNL) data. Through ingredients-based forecasting methodology and statistical analysis,four convective parameters characterizing two types of convection were obtained, respectively, which were used to establish joint probability forecasting together with their corresponding thresholds. Using the ECMWF ensemble forecast and observations from April to September during 2016-2017, systematic verification mainly based on ROC and case study of different weather processes were conducted. The results demonstrate that joint probability method is capable of discriminating little rainfall convection and non-convection with comparable performance for different lead times, which is more favorable to identifying the occurrence of strong rainfall convection. The joint probability of little rainfall convection is a good indication for the occurrence of regional or local convection, but may produce some false alarms. The joint probability of strong rainfall convection is good at indicating regional concentrated short-term heavy precipitation as well as local heavy rainfall. There are also individual missing reports in this method, and in practice, 10% can be roughly used as joint probability threshold to achieve relative high TS score. Overall, ensemble-based joint probability method can provide practical short-term probabilistic guidance for severe convective weather. 相似文献
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75.
老寨湾金矿控矿层位时代及控矿因素新认识 总被引:2,自引:0,他引:2
矿区主要金矿化层为下奥陶统老寨组(O1l),而非下泥盆统坡松冲组。金矿化主要受断裂构造+岩浆活动+不整合面+岩性等多因素的综合控制,矿体富集的空间部位与断裂构造及深部岩浆活动有密切的关系。丰富和扩展了滇东南地区加里东不整合面控矿理论的内涵,明确矿区深部及外围找矿空间。 相似文献
76.
Local and Spatial Joint Frequency Uncertainty and its Application to Rock Mass Characterisation 总被引:1,自引:1,他引:0
Stability is a key issue in any mining or tunnelling activity. Joint frequency constitutes an important input into stability
analyses. Three techniques are used herein to quantify the local and spatial joint frequency uncertainty, or possible joint
frequencies given joint frequency data, at unsampled locations. Rock quality designation is estimated from the predicted joint
frequencies. The first method is based on kriging with subsequent Poisson sampling. The second method transforms the data
to near-Gaussian variables and uses the turning band method to generate a range of possible joint frequencies. The third method
assumes that the data are Poisson distributed and models the log-intensity of these data with a spatially smooth Gaussian
prior distribution. Intensities are obtained and Poisson variables are generated to examine the expected joint frequency and
associated variability. The joint frequency data is from an iron ore in the northern part of Norway. The methods are tested
at unsampled locations and validated at sampled locations. All three methods perform quite well when predicting sampled points.
The probability that the joint frequency exceeds 5 joints per metre is also estimated to illustrate a more realistic utilisation.
The obtained probability map highlights zones in the ore where stability problems have occurred. It is therefore concluded
that the methods work and that more emphasis should have been placed on these kinds of analyses when the mine was planned.
By using simulation instead of estimation, it is possible to obtain a clear picture of possible joint frequency values or
ranges, i.e. the uncertainty. 相似文献
77.
瑞利面波垂直-水平振幅比(或ZH振幅比)是一个随频率变化的函数,对于台站下方浅层地壳结构非常敏感,且具有和频散资料不同的深度敏感核,是传统频散反演方法的一个很好的补充,从而可以将基阶瑞利面波的ZH振幅比和面波频散数据联合起来更好地反演获得观测台站下方的速度结构.本文提出了基于邻域算法的面波频散曲线与ZH振幅比联合反演方法,我们进行了基于理论模型的模拟测试,证明了联合反演是一种更为可靠的反演方法,且能更好地约束浅层地壳结构.相比于频散曲线单独反演,联合反演不仅可以精确反演获得地壳的Vs结构,对分层地壳的Vp/Vs也能很好地约束.然后我们将联合反演算法应用于实际测量数据,获得了中国西南昆明台(KMI)下方更为准确的地壳横波速度结构及Vp/Vs模型. 相似文献
78.
为了更好理解2013年四川芦山MS7.0级地震的发生过程及其与发震构造和地表多种观测资料的动力学关联,本文综合重新定位的余震分布与地质、地球物理信息构建3D发震构造模型,采用水平层状介质模型,并以震区GPS、水准、强震动等同震位移/形变观测资料为约束,联合反演了芦山主震的同震滑动分布.其中,断层解译结果表明震源区包含5条相关断层F1-F5,通过对所有可能的断层组合模型进行反演分析,显示采用F1+F3+F4+F5的组合模型反演效果相对最好,是最可能的发震断层模型.反演得到的芦山主震矩震级为MW6.5,其中同震滑动主要分布在NW倾的主断层F1的断坡周围,最大值为0.86 m,滑动角92.88°,纯逆冲型;F1上方反倾的次级断层F3上最大滑动量为0.37 m,滑动角119.92°,表现出以逆冲为主兼右滑的斜向反冲作用;而沿另一条反倾的次级断层F4的最大滑动量为0.40 m,滑动角97.98°,几乎为纯逆冲作用.此外,震区还存在一个NW缓倾深度为5~8 km的浅部滑脱面F5,它分隔了浅部沉积盖层与深部变质基底,限制了其下方F1、F3及F4等断层的同震破裂继续向更浅部扩展.主震时深部F1和F3断层夹持的冲起构造发生了上冲运动,除了使浅层和地表产生响应运动及变形外,还引起冲起构造顶面即F5底面的NE段和SW段分别产生了NE和SWW向调节滑动,最大值0.25 m.总之,基于文中构建的F1+F3+F4+F5的发震断层模型,反演结果能很好拟合地表多种观测资料,还能解释地表GPS观测的同震"左旋"运动与地震学观测的震源断层逆冲运动的"不协调性". 相似文献
79.
PP波和PS波联合反演方法作为有效的地震技术,比单纯纵波反演精度要高,能够提高地震储层识别的精度.以Russell近似理论为基础,推导了新的转换波AVO近似公式,双层模型界面的反射特征数值模拟显示,新公式具有较高的近似精度,且具备直接反演流体因子f、剪切模量μ和密度ρ等参数的优势,有效避免间接反演带来的误差.结合纵横波联合反演理论,提出了基于贝叶斯理论的新型联合反演算法.在实际应用中,对纵波和转换波角道集进行同相轴匹配处理,综合利用纵波和转换波资料携带的信息,实现基于Russell近似的多波联合反演.模型数据和实际资料测试结果表明,反演结果与真实值或测井结果匹配度较高,证实该方法真实有效. 相似文献
80.
基于Bayes反演理论(Tarantola,1987,2005),在接收函数非线性复谱比反演方法基础上(刘启元等,1996),本文讨论了接收函数与地震环境噪声Rayleigh波相速度频散的联合反演.本文采用修正后的快速广义反射/透射系数方法(Pei et al., 2008,2009) 计算Rayleigh波相速度频散, 并引入地壳泊松比的全局性搜索.数值检验表明:(1)接收函数与环境噪声的联合反演能够有效地解决反演结果对初始模型依赖的问题,即使对地壳速度结构仅有非常粗略的初始估计(例如,垂向均匀模型),本文方法仍能给出模型参数的可靠估计;(2)由于环境噪声与接收函数在频带上的适配性明显优于地震面波,接收函数与环境噪声的非线性联合反演能更好地约束台站下方近地表的速度结构;对于周期范围为2~40s的环境噪声相速度频散,利用本文方法能够可靠推测台站下方0~80 km深度范围的S波速度结构, 其浅表速度结构的分辨率可达到1 km; (3)本文方法能够可靠地估计地壳泊松比,泊松比的全局性搜索有助于合理解释接收函数和环境噪声的面波频散数据.利用本文方法对川西台阵KWC05台站观测的接收函数与环境噪声的联合反演表明,该台站下方地壳厚度为44 km,上地壳具有明显的高速结构,24~42 km范围的中下地壳具有低速结构.该台站下方地壳的平均泊松比为0.262,壳内低速带的泊松比为0.27. 相似文献