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471.
本文推导了球体、椭球体空间斜墨卡托(SOM)投影公式;指出了空间投影的特点和用途,给出了可实际应用的SOM投影正反解公式计算程序包;分析了真(垂直)卫星地面轨迹投影线附近的变形情况,提出了一种正形多项式快速算法,提高了SOM投影正反解计算速度;最后给出了SOM投影与传统地图投影(例如高斯、等角园锥投影)的转换程序包。 相似文献
472.
空间直角坐标直接计算高斯平面直角坐标公式 总被引:2,自引:0,他引:2
本文首先导出了由空间直角坐标直接解算大地纬度的精确而简明的实用公式。在此基础上,导出了由空间直角坐标直接计算高斯平面直角坐标公式。 相似文献
473.
The main problem in the orbit determination of the space debris population orbiting our planet is identifying which separate
sets of data belong to the same physical object. The observations of a given object during a passage above an observing station
are collectively called a Too Short Arc (TSA): data from a TSA cannot allow for a complete determination of an orbit. Therefore, we have to solve first the identification
problem, finding two or more TSAs belonging to the same physical object and an orbit fitting all the observations. This problem
is well known for the determination of orbits of asteroids: we shall show how to apply the methods developed for preliminary
orbit determination of heliocentric objects to geocentric objects. We shall focus on the definition of an admissible region for space debris, both in the case of optical observations and radar observations; then we shall outline a strategy to perform
a full orbit determination. 相似文献
474.
Christopher M. Moreno 《GeoJournal》2009,74(3):219-226
Through a critical analysis of Darren Aronofsky’s filmic adaptation of Hubert Selby’s Jr.’s Requiem for a Dream (2000), this article explores different relational understandings of drug using bodies and spaces of addiction. In an attempt to
move away from modernist readings of addiction I look to different relational and ethical understandings of bodies and assemblages
offered in the work of Gilles Deleuze and Felix Guattari. By approaching the subject of drug addiction through the film and
Deleuzian–Guattarian philosophy, this article presents different insights and alternative political and ethical imaginaries
of what drug bodies and spaces are and do. 相似文献
475.
476.
数字城市空间管治体系模式的探讨 总被引:5,自引:0,他引:5
周立 《地球信息科学学报》2003,5(3):22-25
本文结合数字城市的特点 ,探讨了数字城市空间管治新模式。从数字城市环境中 ,城市管理所面临的全球化、多元化、信息化、网络化、智能化等背景 ,论证了数字城市空间管治宏观需求以及发展的必然性 ,提出数字城市空间管治内涵和空间准入、空间管制主要任务。依据数字城市空间管治信息采集平台、信息资源管理平台、空间管治决策服务平台、决策应用平台的任务目标 ,构建了数字城市空间管治体系结构。 相似文献
477.
A series of experiments was conducted on the decomposition of natural and chemically mixed chlorites to examine the stable hydrous phases in the MgO–FeO–Al2O3–SiO2–H2O (MFASH) system under 5–12 GPa and 700–1100 °C. The upper pressure and temperature limits of the stability region of chlorite are consistent with those observed in previous studies. The hydrous aluminum bearing pyroxene (phase HAPY) and Mg-sursassite (Sur) were observed just above the temperature stability region of chlorite (Chl); clinohumite (cHm) was observed coexisting with phase HAPY at 6 GPa and 800 °C and coexisting with the 23-Å phase at 7 GPa and 800 °C, which may suggest the transportation of water through Chl → (HAPY → cHm) → 23-Å phase along a relatively warm slab. The 23-Å phase has a wider stability region in the pure MASH system (up to 12 GPa and 1100 °C) than it does in the MFASH system (7–10 GPa, up to 1000 °C). The stability of the 23-Å phase beyond the chlorite breakdown pressure indicates that it may play an important role in transporting water into the deep Earth and even into the mantle transition zone. 相似文献
478.
479.
城市化是当今时代社会经济发展的主旋律与经济发展实现现代化的主要目标之一。在经济发达地区,工业化水平高、城镇密集、交通发达、土地利用空间高度集约化,也是沿海地区城市化的重要特点。然而,每个城市的用地空间在城市化过程中存在着非理性的扩展现象,甚至有些大城市地区用地失控的现象;使之城市边缘地区过度郊区化,无限制的蔓延扩展,开发区泛滥,造成生态环境恶化,非理性化的城市建设成本不断增加,社会与环境治理成本也不断加大。提出在经济发达地区内,大都市用地空间理性扩展的5个原则与5种解决的办法,在中国土地资源十分有限的国情条件下,大都市建设做到用地空间理性扩展以及城市化健康发展将起到重要的指导作用,具有十分重要的实践意义与学术价值。 相似文献
480.
The water flow and sediment transport equations have been linearized and analytically solved under the hypothesis of quasi-equilibrium conditions. This solution permits to reconstruct the river bathymetry from planimetric data, the only ones available from satellite images for most of the large rivers of the world. The linearized quasi-equilibrium solution provides a criterion to evaluate the accuracy of the approximate (uniform-flow) model, compared to the regular (steady-flow) model. For non-equilibrium conditions, a further constraint on time resolution should be added, which is however generally satisfied for long-term morphological simulations. The uniform-flow solution presents many advantages which become crucial for long-term numerical computations at watershed scale. The article provides a detailed numerical comparison of the accuracy and resolution of both steady- and uniform-flow models, with an application to the evolution of the lower Zambezi River, which confirms the theoretical criterion. The accuracy of the uniform-flow solution appears to improve when the river is schematized with a coarse computational grid although, of course, with a corresponding loss of spatial resolution. 相似文献