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961.
湖北东岳地区位于豫、鄂两省交界处,西靠陕西(图1)。构造位置处于东秦岭中部地区。区内下、中寒武统剖面连续,出露良好,尤其是中寒武统地层分布广泛,为一套不纯的碳酸盐岩沉积。过去由于在该套地层中始终未获得大古化石,也没有根据盆地碳酸盐岩特有的鉴定标志,如微体化石、特有的动物群和沉积构造,而是仅仅根据其缺乏化石,颜色较深、岩性粒度较细,把它作为陆棚边缘相或盆 相似文献
962.
A new exsolved copper-iron-sulfur phase in sphalerite has been found in the Dajing cassiterite- sulfidecopper-silver-tin deposit, Inner Mongolia, China. After investigating the optical properties, chemical composi-tion, crystal structure and exsolved Characters of the exsolved phase, the authors present important evidencefor its being a new exsolved copper-iron-sulfur phase mineral. Its formation mechenism is discussed in consider-ing heating experiments, phase equilibrium data and the geology of the deposit. 相似文献
963.
1989年大同—阳高地震的地质环境与地震构造 总被引:6,自引:1,他引:6
1989年10月18日的大同—阳高地震发生于大同盆地的册田凹陷。册田凹陷走向北东东,其南缘的六棱山断裂为凹陷的主干断裂,是这次地震的控震断裂。该凹陷内发育北东向和北西向两组断裂,其中大王村断裂和团堡断裂规模最大。这两条断裂大部份隐伏于新生代沉积层之下。电法勘探、钻探、泉的分布及地貌现象均显示其展布位置。在北东东向区域压应力场的作用下,这两条断裂成为此次地震的发震断层。震源机制解结果和烈度分布特点支持上述结论。 相似文献
964.
965.
966.
新构造运动在塔里木盆地演化中作用 总被引:6,自引:1,他引:6
在第四纪以来的新构造运动的影响下,塔里木盆地逐渐向封闭的干旱盆地演化。由于波动式的新构造运动在每阶段表现的形式有差异,因而盆地的演化也相应表现出明显的阶段性。该盆地新构造运动大致经历了上新世末—早更新世、早更新世末—中更新世以及晚更新世三个阶段,其中以早更新世末的一次构造运动对盆地的地貌影响最大。新构造运动是由印度板块和欧亚板块挤压引起的,故塔里木盆地与青藏高原的演化阶段在时间上大致吻合。 相似文献
967.
The reduction of the microhardness and the crystal constants of some non-metallic materials, such as calcite, dolomite, antigorite,
etc., are observed after a short time of hydrogen permeating treatment at low pressure. It means that hydrogen diffusion can
cause their strength dropping or weakening. The hydrogen, which is produced under the earth by various chemical reactions
or accumulated when the earth formed, is migrating up continuously along faults, causing weakening of rocks and faults at
the same time. So it is possible that rocks and faults break under lower tectonic stress condition. Hydrogen anomalies are
passive reflection, precursor and accompaniment of fault activities or earthquakes on the face of it, but hydrogen migrating
has active influence on faults and its moving.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 229–235, 1992. 相似文献
968.
The spatial distribution characteristics of shallow fissures of a landslide in the Wenchuan earthquake area 总被引:1,自引:1,他引:0
Shallow fissures, being the main infiltration paths of fluid on the surface of a slope, played an important role in the whole process of a landslide. However, the spatial distribution characteristics of fissures in the slope are difficult to be determined. In this study, we attempted to characterize the variation pattern of slope fissures along depth in the Wenchuan earthquake area in Sichuan Province by combining engineering geological investigation, geomorphologic analysis and geophysical investigation. The geophysical methods that were used in this study include Multichannel Analysis of Surface Wave (MASW), Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT). The results suggested that geophysical parameters (shear wave velocity, electromagnetic signals attenuation and resistivity) could provide valuable information for the spatial network of shallow fissures. Through the verification by engineering geological survey and geophysical sensitivity analysis, this work highlighted that MASW was the most appropriate technique to delineate the propagation of shallow fissures in a gravel soil slope. 相似文献
969.
Identifying suitable habitats of three ungulates in Arjinshan National Nature Reserve,China 总被引:1,自引:0,他引:1
Xu-kun Su Shi-kui Dong Shi-liang Liu Yu Wu Xue-xia Wang Yong Zhang Xiao-yu Wu 《山地科学学报》2016,13(1):157-168
Arjinshan National Nature Reserve (ANNR) is one of 3 refuges of the endemic ungulates Tibetan wild ass (Equus kiang), Chiru (Pantholops hodgsonii) and wild yak (Bos mutus) that are endangered by natural and anthropogenic factors in the Qinghai-Tibetan Plateau (QTP). Identifying habitat suitability is critical for species protection management. We used a GIS-based niche model to delimit and classify habitat suitability using an integrated assessment system, which included 9 biotic and abiotic factors. We divided the research area into 4 habitat types for these ungulates: (1) high suitability habitat; (2) moderate suitability habitat; (3) low suitability habitat; and (4) unsuitable area. Results suggested that chiru have the most areas of high and moderate suitability habitats while Tibetan wild ass had the largest areas of low suitability habitat and unsuitable area. Wild yak had the largest area of moderate and low suitability habitat, but high suitability habitats for wild yak were smaller than those of other 2 ungulates. There was overlap of high-quality habitat for the three kinds of ungulates in the vicinity of Kardun inspection station, which could be regarded as the core area for the coexistence and conservation of these endangered ungulate populations. 相似文献
970.
Landslide susceptibility assessment of the region affected by the 25 April 2015 Gorkha earthquake of Nepal 总被引:3,自引:2,他引:1
Amar Deep Regmi Megh Raj Dhital Jian-qiang Zhang Li-jun Su Xiao-qing Chen 《山地科学学报》2016,13(11):1941-1957
Nepal was hit by a 7.8 magnitude earthquake on 25th April, 2015. The main shock and many large aftershocks generated a large number of coseismic landslips in central Nepal. We have developed a landslide susceptibility map of the affected region based on the coseismic landslides collected from remotely sensed data and fieldwork, using bivariate statistical model with different landslide causative factors. From the investigation, it is observed that most of the coseismic landslides are independent of previous landslides. Out of 3,716 mapped landslides, we used 80% of them to develop a susceptibility map and the remaining 20% were taken for validating the model. A total of 11 different landslide-influencing parameters were considered. These include slope gradient, slope aspect, plan curvature, elevation, relative relief, Peak Ground Acceleration (PGA), distance from epicenters of the mainshock and major aftershocks, lithology, distance of the landslide from the fault, fold, and drainage line. The success rate of 87.66% and the prediction rate of 86.87% indicate that the model is in good agreement between the developed susceptibility map and the existing landslides data. PGA, lithology, slope angle and elevation have played a major role in triggering the coseismic mass movements. This susceptibility map can be used for relocating the people in the affected regions as well as for future land development. 相似文献