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991.
本文讨论复试水准网平差中的几个实际问题,即平差方法的选择,定权的必要精度和验后估计的必要多余观测数等。通过理论分析与实际试算得出了一些有益的结论。 相似文献
992.
A limited area model has been applied to study the impact of satellite-derived relative humidity data on the predic-tion of onset vortex of monsoon 1979.The results show that inclusion of satellite-derived relative humidity data im-proved the prediction of track of the cyclonic circulation and the rainfall rates in the region of the vortex. 相似文献
993.
本文提出了一种适合于跨断层形变测量数据处理的相对分析平差原理,并应用突变论方法分析了相对位移突变及其稳定性问题,实例验证了方法的正确性。 相似文献
994.
Tectonic forces from the relative movements between plates are transmitted into the continental crust, and then they create
the earthquake generating stress field there. The space-time distribution of the seismic activity including the small earthquakes
in a region reflects the variation of the stress field in the region.
According to this idea, the characteristics of the stress fields in the various regions of East Asia have been analyzed in
detail in this paper based on a lot of solutions of focal mechanisms and data of seismic activity during the last 500 years.
The results indicate that the tectonic forces from the subduction of the Pacific Ocean plate underneath the Eurasian plate
control the stress field in the region from North China to the northern part of the North-South Seismic Belt.
The variation of the regional stress field shown by the variation of seismic activity in some regions of Japan has also been
discussed based on characteristics of variation of the seimicity of small earthquakes.
Synchronous variations of seismicity in the past 100 years or so in West China and in the boundary region between the Indo-Australian
and Eurasian plates implicate that there is the transmission of tectonic forces into West China through the collision between
the Indo-Australian and Eurasian plates. The active seismic activity in the boundary region between the Indo-Australian and
the Eurasian plates and in West China is continuing consistently.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 287–294, 1991. 相似文献
995.
According to conditions of seismogeological structure and the data on seismicity in the area from the west of Beijing to the
Shanxi-Hebei-Nei Mongol border region, the tectonic stress field and the seismic stress field in this area are studied by
using the finite element method and the dislocation theory. In the light of the distribution features of these stress fields
and the characteristics of recent activity of small earthquakes, it is inferred that there are two relative stress concentration
zones in the area, they are (1) the zone which is bounded on the south by the Heishansi fault, on the west by the Niuxinchuan-Sihuizhuang
fault and on the north by the Liangjiazhuang fault; and (2) the zone with a NW long axis, which is surrounded by the intersection
zone of the Tianzhenbei, Jiucaigou-Huangtugudui, and Zhanggao faults. Of these, in the first relative stress concentration
zone, a strong earthquake will be more probable to occur in future to the west of Huailai at the place where the Xiahuayuan,
Hunjingdong and Sangganhe faults converge together but do not intersect, or in its surrounding area.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 307–318, 1991.
The English version of this paper is improved by Dr. Zhixin Zhao. 相似文献
996.
N. Sundararajan I. Arun Kumar N. L. Mohan S. V. Seshagiri Rao 《Pure and Applied Geophysics》1990,133(1):117-126
Self-potential anomalies due to two-dimensional inclined sheet of finite depth extent are analysed from their horizontal and vertical derivatives via the Hilbert transform. The depths to the top and bottom of the sheet and the inclination are obtained by means of simple mathematical expressions. The method is applied to a theoretical example and to a field S.P. anomaly over a sulphide deposit in the Kalava fault zone of Cuddapah basin, India. The presence of random noise is analysed for various levels and its effect is discussed. This interpretation process can be automated for all practical purposes by simple programming. 相似文献
997.
廖华 《大地测量与地球动力学》1996,(1)
讨论了多个粗差的定位方法──“向前、向后”探测法,并编制了相应的平差计算程序,对鲜水河断裂带上具有代表意义的虾拉沱小测边网和老乾宁小测边网进行了粗差探测与自动剔除,结果表明效果显著,方法简单、有效。 相似文献
998.
对2012—2013年GRAPES_TYM模式热带气旋路径预报结果进行检验,结果表明:模式对所有类型路径预报在24h、48h和72h预报时效的平均距离误差分别为94.3km,143.7km和260.8km,并且存在偏北的系统性偏差;对于南海TC,模式对TC移向预报较实况偏右,移速误差较小,移向偏差是路径偏差的主要原因;另外统计得到模式对TC移向的预报偏差与对其环境引导气流预报偏差有密切的关系,以1213号台风"启德"为例进一步通过移向误差诊断方程探讨了环境引导气流预报偏差(包括环境风场预报偏差、环境引导气流半径偏差及环境引导气流厚度偏差)对TC移向偏差的影响,而环境引导气流预报误差来源与模式对大尺度天气系统、TC大小及强度的预报偏差有关。 相似文献
999.
为了解和掌握上级指导产品对石家庄市空气质量预报的适用性,进一步提高石家庄市空气质量预报的准确性,利用国家气象中心(NMC)、北京区域气象中心(BJ)和河北省气象局(HB)空气质量预报产品,对石家庄市夏季4种主要污染物PM_(2.5)、PM_(10)、O_3和SO_2的预报进行了对比检验,结果表明:1)NMC对4种污染物的预报效果均逊于HB和BJ的,对PM_(10)、PM_(2.5)和SO_2的预报值明显较实况偏大,尤其在发生重污染天气时,对PM_(10)和PM_(2.5)的空报率高达90%以上;2)HB对PM_(10)和SO_2的预报效果好于BJ的,对SO_2的预报值与实况值均在一个等级范围内,发生重污染天气时,对PM_(10)的预报效果好于BJ的,预报值更接近于实况,但对重污染向优、良转折天气的预报值偏高;3)BJ预报PM_(2.5)和O_3的效果好于HB的,对O_3的0级误差级别预报准确率高达90.5%,对PM_(2.5)优到轻度污染等级的预报效果较好,但对重污染天气的预报值低于实况。 相似文献
1000.
珠江口盆地陆架坡折带海底滑坡及其影响因素 总被引:3,自引:1,他引:2
为了解海底滑坡在陆架坡折演化过程中所起的作用并分析影响海底滑坡发育的因素,以最新采集的二维和三维地震资料为基础,综合运用了地貌分析和地震解释技术,通过对滑坡的地貌形态特征及地震响应特征进行详细刻画,在珠江口盆地陆架坡折带新近纪地层中识别出多处海底滑坡,明确了其分布范围并建立了滑坡发育的地质模式。分析认为,珠江口盆地相对海平面变化和流体活动的综合作用是导致研究区海底不稳定的主要因素。海底滑坡发源于海底峡谷的朔源侵蚀,向上陆坡扩展并终止于陆架坡折带。 相似文献