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131.
结合高光谱数据反演吉林石头口门水库悬浮物含量和透明度 总被引:5,自引:1,他引:5
水中悬浮物含量是评价水环境质量的一个重要参数,它可影响水体透明度、混浊度、水色等光学性质,决定太阳光照在水下的分布和浮游植物对光照的利用,并最终影响水体的初级生产力.本文利用长春市石头口门水库的高光谱实测数据和水质采样分析数据,尝试通过一阶微分法建立悬浮物估测模型,再用估测结果反演透明度信息.结果表明:用590nm处的一阶微分光谱值建立的悬浮物估测模型的决定系数R2和均方根误差(RMSE)分别为0.76、9.09 mg/L,验证模型的R2和RMSE分别为0.79、7.15 mg/L;石头口门水库上游严重的水土流失导致透明度受悬浮物含量影响较大,两者存在明显的指数关系,相关系数r为-0.80,用悬浮物含量建立的透明度估测模型的R2和RMSE分别为0.79和0.12 m,验证模型的R2和RMSE分别为0.82、0.11 m.显著水平均为p<0.01.研究结果表明,该方法用于石头口门水库悬浮物含量和透明度的定量遥感结果较理想. 相似文献
132.
The analysis of disk core from the Maoping 800 m bore hole(阮小平)(李方全)TheanalysisofdiskcorefromtheMaoping800mborehole¥Xiao-Ping... 相似文献
133.
X射线荧光光谱熔融片法测定超导材料原子数配比 总被引:2,自引:0,他引:2
报道了用X射线荧光光谱测定铋钾钡系超导材料原子配比的方法。测量样片用熔融法制备,测定各组分的质量分数后计算原子配比并推出材料的分子式。 相似文献
134.
135.
Disk clusters are developed to represent the shape of granular materials more precisely (compared to circular particles) and to minimise excessive rolling. Investigating the behaviour of dynamic disk-based discontinuous deformation analysis (DDA) with disk clusters is very important to evaluate the applicability of disk-based DDA to dynamic problems in geomechanics. In this paper, the accuracy of disk-based DDA under dynamic conditions is studied by a comprehensive sensitivity analysis. The results obtained by disk-based DDA are compared with the analytical solutions of a disk cluster on an incline subjected to gravitational force only, and three different accelerations of increasing complexity with sinusoidal input functions as well as gravitational load. In this research, the effects of time step size and interface friction angles on the results are studied. Overall, most of the error for both velocity and displacement occurs at the beginning of the solution. With increasing friction angle, the initial perturbation of the solution increases in the case of sliding under gravitational force only, and decreases in the case of sliding under dynamic loads. This study shows that disk-based DDA predicts accurately the velocities and displacements derived with respect to the frictional resistance offered by the inclines. 相似文献
136.
We self-consistently obtain shock locations in an accretion flow by using an analytical method. One can obtain the spectral
properties, quasi-periodic oscillation frequencies and the outflow rates when the inflow parameters are known. Since temperature
of the CENBOL decides the spectral states of the black hole, and also the outflow rate, the outflow rate is directly related
to the spectral states. 相似文献
137.
N. R. Sibgatullin 《Astronomy Letters》2002,28(2):83-88
We derive a formula for the nodal precession frequency and the Keplerian period of a particle at an arbitrary orbital inclination (with a minimum latitudinal angle reached at the orbit) in the post-Newtonian approximation in the external field of an oblate rotating neutron star (NS). We also derive formulas for the nodal precession and periastron rotation frequencies of slightly inclined low-eccentricity orbits in the field of a rapidly rotating NS in the form of asymptotic expansions whose first terms are given by the Okazaki-Kato formulas. The NS gravitational field is described by the exact solution of the Einstein equation that includes the NS quadrupole moment induced by rapid rotation. Convenient asymptotic formulas are given for the metric coefficients of the corresponding space-time in the form of Kerr metric perturbations in Boyer-Lindquist coordinates. 相似文献
138.
A morphological analysis study of open clusters’ properties has been achieved for a sample of 160 UBVCCD open star clusters of approximately 128,000 stars near the galactic plane. The data was obtained and reduced from Tadross (2001) using the same reduction procedures, which makes this catalogue the largest homogeneous source of open clusters’ parameters. 相似文献
139.
Disk wind in young binaries with low-mass secondary components: Optical observational manifestations
We consider a model of a young binary with a low-mass secondary component. Mass accretion from the remnants of the protostellar
cloud onto the binary components is assumed to take place in accordance with current models; i.e., it proceeds mainly onto
the low-mass component. The accretion is accompanied by mass outflow (disk wind), whose low-velocity component can be partially
captured by the primary component. As a result, an asymmetric common envelope is formed. Its densest part is involved in the
orbital motion of the secondary and can periodically shield the primary component of the binary from the observer. Assuming
a standard dust-to-gas ratio for the disk wind (1: 100), we calculated the possible photometric effects from such eclipses
and showed that they could be observed even at moderate accretion rates onto the low-mass binary component, ∼10−8–10−9
M
⊙ per year. In this case, the parameters of the minima depend on the model of the disk wind, on the ratio of its characteristic
velocity to the orbital velocity of the secondary, and on its orbital inclination to the line of sight. These results can
form the basis for interpreting a wide range of phenomena observed in young stars, such as the activity cycles in UX Ori stars,
the unusually broad minima in some young eclipsing systems, etc., and for searching for substellar objects and massive protoplanets.
In addition, the peripheral parts of the gas and dust disk around a young binary can fall within the shadow zone produced
by the opaque part of the common envelope. In such cases, a shadow from the common envelope must be observed on the disk;
this shadow must move over the disk following the orbital motion of the low-mass component. Detection and investigation of
such structures in the images of protoplanetary disks may become a method of searching for protoplanets and studying binaries
at early stages of their evolution. 相似文献
140.