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551.
CifNet网络多井数据管理系统 总被引:2,自引:0,他引:2
针对目前油田研究院、测井公司等单位已有的百兆或千兆光纤局域网环境,建立了一整套网络多井数据管理方法,研制开发了相应的软件系统CifNet。系统的关键技术包括:1.利用广义测井曲线理论和Cif格式构建高效、低成本的网络多井数据管理体系;2.采用TCP/IP编程技术实现稳定的C/S网络结构的数据高效访问和传输;3.利用Unix的安全机制充分保障多井数据在存储、查询和调用过程中的安全。CifNet系统很好地解决了如何在这些单位任何一间办公室或研究人员家中访问整个油田任意工区任意井的测井资料问题。本文同时指出了CifNet系统的广宽应用前景。 相似文献
552.
对复式河道漫滩水流进行了研究,建立了摩阻因子与一维明渠流摩阻因子的关系,揭示出滩地的量纲为一涡粘性系数随着摩阻因子的增加而增加,并将二次流的影响表达成与雷诺切应力相同的形式,从而将其归入表观切应力中,由量纲为一表观涡粘性系数确定,后者可通过量纲为一表观涡粘性系数与摩阻因子之间的一个关系加以计算,该关系类似于量纲为一涡粘性系数与摩阻因子之间的关系。对光滑边界上对称的漫滩水流进行了计算,计算结果与实验资料吻合良好。 相似文献
553.
山西省是我国地震、洪涝、气象和地质灾害及农作物生物灾害等众灾频发的地区.研究表明,山西断陷盆地带的形成与发展,为这些灾害的孕育发生创造了有利环境和条件,致使盆地地区成为山西地震、洪涝、气象和地质灾害及农业生物灾害等众灾频发,且相互作用、相互强化最严重的地区;加之盆地地区恰是山西人口、工农业生产和社会经济财产最集中的部位,两方面因素的共同影响,使得该地区成为山西最严重的灾害高风险区. 为了减轻山西省的自然灾害,保障其社会经济可持续发展,必须将盆地地区作为山西省的减灾重点区域,并进行综合减灾. 相似文献
554.
Palaeozoic amalgamation of Central Europe: new results from recent geological and geophysical investigations 总被引:3,自引:0,他引:3
Multidisciplinary studies of geotransects across the North European Plain and Southern North Sea, and geological reexamination of the Variscides of the North Bohemian Massif, permit a new 3-D reassessment of the relationships between the principal crustal blocks abutting Baltica along the Trans-European Suture Zone (TESZ). Accretion was in three stages: Cambrian accretion of the Bruno–Silesian, Lysogory and Malopolska terranes; end-Ordovician/early Silurian accretion of Avalonia; and early Carboniferous accretion of the Armorican Terrane Assemblage (ATA). Palaeozoic plume-influenced metabasite geochemistry in the Bohemian Massif explains the progressive rifting away of peri-Gondwanan crustal blocks before their accretion to Baltica. Geophysical data, faunal and provenance information from boreholes, and dated small inliers and cores confirm that Avalonian crust extends beyond the Anglo-Brabant Deformation Belt eastwards to northwest Poland. The location and dip of reflectors along the TESZ and beneath the North European Plain suggest that Avalonian crust overrode the Baltica passive margin, marked by a high-velocity lower crustal layer, on shallowly southwest-dipping thrust planes forming the Heligoland–Pomerania Deformation Belt. The “Variscan orocline” of southwest Poland masks two junctions between the Armorican Terrane Assemblage (ATA) and previously accreted crustal blocks. To the east is a dextrally transpressive contact with the Bruno–Silesian and Malopolska blocks, accreted in the Cambrian, while to the north is a thrust contact with easternmost Avalonia, deeply buried beneath younger sedimentary cover. In the northeast Bohemian and Rhenohercynian Massifs Devonian “early Variscide” deformation dominated by WNW and NW-directed thrusting, records closure of Ordovician–Devonian seaways between detached “islands” of the ATA and Avalonia. 相似文献
555.
Hung Lee Jinling Wang Chris Rizos Dorota Grejner-Brzezinska Charles Toth 《GPS Solutions》2002,6(1-2):34-46
This paper discusses the introduction of pseudolites (ground-based GPS-like signal transmitters) into existing integrated
GPS/INS systems in order to provide higher availability, integrity, and accuracy in a local area. Even though integrated GPS/INS
systems can overcome inherent drawbacks of each component system (line-of-sight requirement for GPS, and INS errors that grow
with time), performance is nevertheless degraded under adverse operational circumstances. Some typical examples are when the
duration of satellite signal blockage exceeds an INS bridging level, resulting in large accumulated INS errors that cannot
be calibrated by GPS. Such a scenario, unfortunately, is a common occurrence for certain kinematic applications. To address
such shortcomings, both pseudolite/INS and GPS/pseudolite/INS integration schemes are proposed here. Typically, the former
is applicable for indoor positioning where the GPS signal is unavailable for use. The latter would be appropriate for system
augmentation when the number and geometry of visible satellites is not sufficient for accurate positioning or attitude determination.
In this paper, some technical issues concerned with implementing these two integration schemes are described, including the
measurement model, and the appropriate integration filter for INS error estimation and correction through GPS and pseudolite
(PL) carrier phase measurements. In addition, the results from the processing of simulated measurements, as well as field
experiments, are presented in order to characterize the system performance. As a result, it has been established that the
GPS/PL/INS and PL/INS integration schemes would make it possible to ensure centimeter-level positioning accuracy even if the
number of GPS signals is insufficient, or completely unavailable.
Electronic Publication 相似文献
556.
Walter W. Chen Ban-jwu Shih Yi-Chih Chen Jui-Huang Hung Howard H. Hwang 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):1209-1214
In order to study the damage patterns of natural gas and water pipelines in the Ji-Ji earthquake, a GIS database and analysis procedures were established. Repair statistics was obtained from major natural gas companies and the Taiwan Water Supply Corporation (TWSC), and entered into the system. Then, repair rates (RR) were calculated. Previously, damage was analyzed without considering the corresponding pipeline material and diameters. In this study, new attempts were made to collect more data including those related to the composition of pipelines to provide a more detailed analysis of the relationship between earthquake forces and the resulting damage. Statistical analysis was also conducted to understand the correlation between RR and seismic parameters such as the peak ground acceleration, peak ground velocity, and spectrum intensity. 相似文献
557.
558.
Estimation of the sensible heat flux of a semi-arid area using surface radiative temperature measurements 总被引:1,自引:1,他引:0
In the framework of an international field program for the study of semi-arid areas, observations were done in the region called La Crau in southern France. In this paper, the use of the surface radiative temperature for the determination of the sensible heat flux is addressed. We found that, once proper values of the roughness length of momentum (z
0) and heat (z
0h) are set, the sensible heat flux can be reliably predicted with a one-layer resistance model using standard observations of wind speed and air temperature, together with the surface temperature. The latter quantity has to be known with a precision better than ±2°C. From our observations, the value of the parameterB
–1k
–1 In (z
0
z
0h) was found to be 9.2, which falls between values quoted by Brutsaert (1982) for grass and bluff bodies. 相似文献
559.
The interpretation of the observed-ray burstV/V
max statistic in terms of spatial distributions is model-dependent. Detection of-ray bursts requires the counting rate in one or more detectors to exceed a thresholdC
lim determined from a time-dependent background rateB(t). The sampling depth of the burst detector is thus time-dependent, and, if burst sources are non-uniform in space, the observedV/V
max distribution will be affected byB(t). We demonstrate this effect with a simple geometric distribution of standard candles and argue thatV/V
max statistic without information on threshold variations is insufficient for rigorous data analysis. Peak count rates and threshold values must be given separately for all events in order to facilitate a meaningful comparison of observations with theoretical distribution models. 相似文献
560.
The Radioheliograph Group 《Solar physics》1989,120(1):193-204
A multi-frequency capability has been added to the north-south array of the Nançay Radioheliograph, providing observations at up to five frequencies between 150 and 450 MHz with time resolution 0.1 s. The projected position, brightness and dimension of sources in the solar corona can thus be studied as a function of height. Two-dimensional information is obtained at 164 MHz using the east-west and north-south arrays. In addition, the quiescent corona can be mapped in two dimensions at all observed frequencies by earth rotation synthesis. The paper describes the new aspects of the antennae, the receiver frontend, the data acquisition and the calibration procedure. The performances of the instrument are illustrated with multi-frequency observations of solar fast-drift bursts, continuum emission and maps of the quiet corona.Meudon: Y. Avignon, J. Bonmartin, A. Bouteille, B. Clavelier, E. Hulot, M. P. Issartel, A. Kerdraon, K.-L. Klein, P. Lantos, C. Mercier, M. Pick, A. Raoult, D. Rigaud, G. Trottet, N. Vilmer. Nançay: C. Chantelat, M. Chapuis, Y. Chapuis, A. Coffre, C. Couteret, B. Darchy, P. Guéniau, D. Lalardie, P. Picard, R. Tocqueville. 相似文献