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351.
利用世界银行1970—2007年的112个国家(地区)的人均碳排放量和城市化率数据,基于SPSS与Eviews软件,分析城市化水平与人均碳排放量的关联机理。结果表明,随着城市化水平的上升,人均碳排放量逐步增加;40%的城市化率是人均碳排放变化的转折点;在相近城市化水平下,经济发展水平较高地区和化石能源主产区的人均碳排放高于其他地区。格兰杰因果检验表明,人均碳排放与城市化之间基本存在着格兰杰因果关系;地区之间的格兰杰因果检验结果既有共性,也有差异。 相似文献
352.
新疆罗布泊旅游资源特征 总被引:1,自引:0,他引:1
罗布泊曾为中国第二大内陆湖泊,随着自然环境的变迁以及塔里木河上游筑坝截流,使罗布泊无水流补给于1972年彻底干涸,干涸的罗布泊在卫星影像图上呈现出清晰的耳状环形图案,被称为神秘"地球之耳".在罗布泊古湖周围分布有龙城、白龙堆、阿齐克谷地等雅丹地貌,面积达约3 00km2,是我国仅次于柴达木盆的第二大雅丹地貌分布区,由于其位于塔里木盆地东部的荒漠地带,人迹罕至,是世界最神秘的雅丹地貌.除丰富的地质遗迹景观外,在罗布泊还分布有楼兰古城遗址、米兰古城遗址、贵族墓等众多绚丽多彩的人文景观资源.这里原始古朴,是一块充满神秘色彩的地方,是未来旅游开发的热点地区之一. 相似文献
353.
Asphaltenes are traditionally considered to be recalcitrant to microbial alteration. Resins and asphaltenes of seven biodegraded oils extracted from reservoir cores of two columns (Es3 and Es1) of the Lengdong oilfield in the Liaohe Basin, NE China, were studied to test this hypothesis. Elemental (C, H, N, O, S) and isotopic compositions (δ13C and δ15N) were measured, FT-IR was used to study the oxygenated functionalities of both resins and asphaltenes, and Py–GC–MS was used to elucidate how alkyl side chains of asphaltenes were altered during biodegradation. We conclude that the products of biodegradation, such as carboxylic acids, phenol and alcohols, may not only contribute to the resin fraction of crude oils, but also are linked with functionalities of resins and asphaltenes. The amount of asphaltenes increases because some resin molecules are enlarged and their polarity increased such that they can be precipitated by hexane as newly generated asphaltenes. Thus, the hydrocarbons that are progressively consumed during biodegradation can pull the δ13C of asphaltene fraction closer to the δ13C of the altered resins and hydrocarbons that were consumed. 相似文献
354.
近断层强地震动预测的一些基本问题讨论 总被引:2,自引:1,他引:1
近断层地震动的预测是当前地震工程中的一个关键科学问题。对预测中涉及的震源和三维地下结构建模、格林函数的计算和预测方法等基本问题做了探讨。分析了震源模型中全局和局部震源参数,给出一套震源建模方案;通过各种格林函数的对比分析,指出宽频带格林函数法是当前近断层地震动预测中最合适的方法。对近断层场地非线性分析的一些问题也进行了讨论。 相似文献
355.
The bottom simulating reflector (BSR) in gas hydrate-bearing sediments is a physical interface which is composed of solid, gas, and liquid and is influenced by temperature and pressure. Deep sea floor sediment is a porous, unconsolidated, fluid saturated media. Therefore, the reflection and transmission coefficients computed by the Zoeppritz equation based on elastic media do not match reality. In this paper, a two-phase media model is applied to study the reflection and transmission at the bottom simulating reflector in order to find an accurate wave propagation energy distribution and the relationship between reflection and transmission and fluid saturation on the BSR. The numerical experiments show that the type I compressional (fast) and shear waves are not sensitive to frequency variation and the velocities change slowly over the whole frequency range. However, type II compressional (slow) waves are more sensitive to frequency variation and the velocities change over a large range. We find that reflection and transmission coefficients change with the amount of hydrate and free gas. Frequency, pore fluid saturation, and incident angle have different impacts on the reflection and transmission coefficients. We can use these characteristics to estimate gas hydrate saturation or detect lithological variations in the gas hydrate-bearing sediments. 相似文献
356.
海洋天然气水合物可控源电磁法的响应特征:一维正演模拟 总被引:1,自引:1,他引:0
We discuss the feasibility of using controlled-source electromagnetic (CSEM) in the frequency domain for prospecting marine gas hydrates. Based on the Ocean Drilling Program (ODP) Leg 164 log data, we have established several 1-D resistivity models which have different gas hydrate concentrations. Meanwhile, we analyzed the electromagnetic response of marine gas hydrates in the frequency domain based on these models. We also studied the relationship between electrical field magnitude or phase and parameters such as receiver-transmitter distance and frequency. Our numerical modeling results provide us with a quantitative reference for exploration and resource evaluation of marine gas hydrates. 相似文献
357.
Double-square-root one-way wave equation prestack tau migration in heterogeneous media 总被引:1,自引:0,他引:1
In this paper, source‐receiver migration based on the double‐square‐root one‐way wave equation is modified to operate in the two‐way vertical traveltime (τ) domain. This tau migration method includes reasonable treatment for media with lateral inhomogeneity. It is implemented by recursive wavefield extrapolation with a frequency‐wavenumber domain phase shift in a constant background medium, followed by a phase correction in the frequency‐space domain, which accommodates moderate lateral velocity variations. More advanced τ‐domain double‐square‐root wave propagators have been conceptually discussed in this paper for migration in media with stronger lateral velocity variations. To address the problems that the full 3D double‐square‐root equation prestack tau migration could meet in practical applications, we present a method for downward continuing common‐azimuth data, which is based on a stationary‐phase approximation of the full 3D migration operator in the theoretical frame of prestack tau migration of cross‐line constant offset data. Migrations of synthetic data sets show that our tau migration approach has good performance in strong contrast media. The real data example demonstrates that common‐azimuth prestack tau migration has improved the delineation of the geological structures and stratigraphic configurations in a complex fault area. Prestack tau migration has some inherent robust characteristics usually associated with prestack time migration. It follows a velocity‐independent anti‐aliasing criterion that generally leads to reduction of the computation cost for typical vertical velocity variations. Moreover, this τ‐domain source‐receiver migration method has features that could be of help to speed up the convergence of the velocity estimation. 相似文献
358.
浅谈基层台站地面测报应急处理 总被引:1,自引:0,他引:1
为了保证探测业务在应急气象保障服务或突发事件中应能够反应迅速,并且连续、有效地开展工作,根据地面观测业务特点,对值班过程中可能出现的问题进行了总结,主要从硬件和工作流程制度等方面进行分析,本着早做准备,早做部署、科学指挥调度的原则,以期对观测业务的制定应急预案有所帮助。 相似文献
359.
中国东部次火山岩型铜银多金属矿床找矿规律 总被引:4,自引:2,他引:2
次火山岩型矿床与陆相火山岩、次火山岩为同源,同时期,同空间,同成因。总结了区域火山活动特征;区域构造与成矿关系;火山构造、火山机构与成矿关系;隐爆角砾岩与成矿关系等成矿规律。 相似文献
360.