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931.
We study the spatial orientation of 5 169 galaxies that have radial velocity 3 000 to 5 000 km s−1. The ‘position angle–inclination’ method is used to find the spin vector and the projections of spin vector of the galaxy
rotation axes. The spatial isotropic distribution is assumed to examine the non-random effects. For this, we have performed
chi-square, Fourier, and auto-correlation tests. We found a random alignment of spin vectors of total galaxies with respect
to the equatorial coordinate system. The spin vector projections of total galaxies is found to be oriented tangentially with
respect to the equatorial center. The spiral galaxies show a similar orientation as shown by the total sample. Five subsamples
of barred spiral (late-type) galaxies show a preferred alignment. However, early-type barred spirals show a random orientation.
A weak morphological dependence is noticed in the subsamples of late type barred spirals. A comparison with the previous works
and the possible explanation of the results will be presented. 相似文献
932.
An analytical study to evaluate quantitatively weak zoning of a garnet from a high-grade kinzigite has been performed with an electron microprobe. The technique consists of the reconstruction of a profile step-by-step by successive analyses performed during relatively long counting times (30 s), along a radial profile of 2,500 μm length. The successive analytical data along this profile are statistically treated by Fisher's test and compared with the χ2 values (Pearson's law). These statistical tests were applied to assess microprobe stability and analysis homogeneity, and as a consequence to assure high credibility of the radial variations of the garnet. From core to rim, and for each element, zoning appears as the radial juxtaposition of stationary Poissonian samples. These samples being associated, the garnet appears to be constituted of successive concentric domains with stationary compositions. Different substitutions between Mg, Fe, Mn and Ca are evidenced. Such an analytical approach to chemical zoning can be useful for understanding growth mechanisms, and the possible diffusion reactions with the environment at each growth step. In addition, such a procedure can be used to evaluate accurately the fluid content of cordierite, and to appreciate the nature of the fluids concerned. As an example, the fluid content of a cordierite from a similar high-grade kinzigite has been evaluated. 相似文献
933.
A. A. Deshpande R. Ramachandran G. Srinivasan 《Journal of Astrophysics and Astronomy》1995,16(1):53-67
A detailed statistical analysis of pulsarcurrent is presented. The conclusions reached are the following: (1) The birthrate of pulsars is about one in 75 ± 15 years. (2)
There is evidence forinjection of pulsars into the population of solitary pulsars. Such an injection is particularly pronounced in the magnetic field range
12 < logB < 12.6. (3) This is interpreted as due torecycled pulsars being released into the population. (4) We tentatively conclude that as much as 10 – 15% of all pulsars may have been born
and processed in binary systems. 相似文献
934.
何安明 《地球科学与环境学报》1990,(2)
本文采用Bose量子统计方法,对地幔矿物的激子热传导问题进行了详细讨论,得到了激子热导率K_(ex)的表达式,并指出在高压和高温下,激活能A对激子热导率的变化速率有重要影响。讨论结果表明,激子热传导作用有可能在下地幔发生,但它却不是热传导的主要机制。 相似文献
935.
F. J. Bloore 《Mathematical Geology》1977,9(2):113-122
A theory of pebble erosion is presented, based on the assumption that the rate of erosion at a point on the surface is a function Vof the curvature there. It is proved that for physically reasonable functions V,the sphere is the only shape of pebble which can maintain its proportions as it wears away. An argument is given which leads
to a particular form for the function Vand a few qualitative consequences of this form are indicated. The surface of the pebble at time tmay be described using spherical polar coordinates θ, Φ by the radius function r (θ, Φ, t). This function is given by a highly nonlinear partial differential equation. However, in the case of the erosion
of a deformed sphere, when terms which are of second order or higher in the deformation are neglected, the equation becomes
linear and is a version of the diffusion equation. The stability of the spherical shape against deformations of the various
harmonic types is then easily analyzed. 相似文献
936.
937.
The commonly measured value of in the relaxed eddy accumulationmethod of about 0.56is shown to arise from the non-Gaussiannature of turbulence. Fourth-orderGram–Charlier functions forthe two-dimensional probability distributionsof variation in the horizontal component of wind velocityand concentrations of water vapour, carbondioxide and methane with respect to thevertical component of wind velocity are used to examinethe value of .An analytical solution for ispresented in terms of fourth-order moments.Under mean conditions, this solution givesa value for of0.557. Variation of is shown to be controlledprimarily by the ratio of the mean ofc'w3 (where c'is relevant to the entity of interest andw' is vertical component of windvelocity) to the correlationcoefficient between the entity concentrationand vertical component of wind velocity. 相似文献
938.
岩石样品元素点异常概率统计方法 总被引:2,自引:0,他引:2
本文提供了一种处理分散岩石样品地质地球化学信息的方法,介绍了方法的基本公式及作用,并给出了实例表格数据供参考。 相似文献
939.
A hydroclimatic threshold for landslide initiation on the North Shore Mountains of Vancouver, British Columbia 总被引:5,自引:0,他引:5
Landslides triggered by rainfall are the cause of thousands of deaths worldwide every year. One possible approach to limit the socioeconomic consequences of such events is the development of climatic thresholds for landslide initiation. In this paper, we propose a method that incorporates antecedent rainfall and streamflow data to develop a landslide initiation threshold for the North Shore Mountains of Vancouver, British Columbia. Hydroclimatic data were gathered for 18 storms that triggered landslides and 18 storms that did not. Discriminant function analysis separated the landslide-triggering storms from those storms that did not trigger landslides and selected the most meaningful variables that allow this separation. Discriminant functions were also developed for the landslide-triggering and nonlandslide-triggering storms. The difference of the discriminant scores, ΔCS, for both groups is a measure of landslide susceptibility during a storm. The variables identified that optimize the separation of the two storm groups are 4-week rainfall prior to a significant storm, 6-h rainfall during a storm, and the number of hours 1 m3/s discharge was exceeded at Mackay Creek during a storm. Three thresholds were identified. The Landslide Warning Threshold (LWT) is reached when ΔCS is −1. The Conditional Landslide Initiation Threshold (CTLI) is reached when ΔCS is zero, and it implies that landslides are likely if 4 mm/h rainfall intensity is exceeded at which point the Imminent Landslide Initiation Threshold (ITLI) is reached. The LWT allows time for the issuance of a landslide advisory and to move personnel out of hazardous areas. The methodology proposed in this paper can be transferred to other regions worldwide where type and quality of data are appropriate for this type of analysis. 相似文献
940.