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34.
Eugene I. Smith 《Earth, Moon, and Planets》1973,6(1-2):3-31
Over 300 previously unrecognized volcanic domes were identified on Lunar Orbiter photographs using the following criteria:
(1) the recognition of land forms on the Moon similar in morphology to terrestrial volcanic domes, (2) structural control,
(3) geomorphic discordance, and (4) the recognition of land forms modified by dome-like swellings. Many terrestrial volcanic
domes are similar in morphology to lunar domes. This analogy suggests that some lunar hills are in fact extrusive volcanic
domes. Many of the domes identified in this paper seem to be related to basins and craters, and with the exception of local
tectonic grid control few domes are related to any observable Moon-wide pattern. Domes are not uniquely found on maria. Dome
formation probably spans a wide range of lunar time and activity in areas where domes are located may be continuing to the
present as revealed by the close correlation of dome distribution with the distribution of lunar transient events. The overall
morphology of a lunar dome is a poor indicator of the composition of the rock that forms the dome.
Contribution No. 33 Planetary Geology Group, University of New Mexico. 相似文献
35.
Eugene Rabe 《Celestial Mechanics and Dynamical Astronomy》1973,8(2):177-179
As previously shown (Rabe, 1970), two classes of small periodic librations exist, in the plane, elliptic restricted problem, for an infinite sequence of easily specified oscillation frequenciesZ
j
. The present paper considers the dependence ofZ on the eccentricitye of the primary motion, in addition to its dependence on the mass parameter , and determines the resulting relations between ande, for any given periodic frequencyZ
j
. These relationships are obtained from the conditionD (Z
j
,, e)=0, where the basic determinantD has been expanded up to terms of orderZ
20, 5, ande
4.Presented at the Conference on Celestial Mechanics, Oberwolfach, Germany, August 27–September 2, 1972. 相似文献
36.
Variation in surface turbulence and the gas transfer velocity over a tidal cycle in a macro-tidal estuary 总被引:2,自引:0,他引:2
Christopher?J.?ZappaEmail author Peter?A.?Raymond Eugene?A.?Terray Wade?R.?McGillis 《Estuaries and Coasts》2003,26(6):1401-1415
The gradient flux technique, which measures the gas transfer velocity (k), and new observational techniques that probe turbulence in the aqueous surface boundary layers were conducted over a tidal
cycle in the Plum Island Sound, Massachusetts. Efforts were aimed at testing new methods in an estuarine system and to determine
if turbulence created by tidal velocity can be responsible for the short-term variability ink. Measurements were made during a low wind day, at a site with tidal excursions of 2.7 m and a range in tidal velocity of
nearly 1 m s−1. Estimates ofk using the gradient flux technique were made simultaneously with the Controlled Flux Technique (CFT), infrared imagery, and
high-resolution turbulence measurements, which measure the surface renewal rate, turbulent scales, and the turbulent dissipation
rate, respectively. All measurements were conducted from a small mobile catamaran that minimizes air- and water-side flow
distortions. Infrared imagery showed considerable variability in the turbulent scales that affect air-water gas exchange.
These measurements were consistent with variation in the surface renewal rate (range 0.02 to 2 s−1), the turbulent dissipation rate (range 10−7 to 10−5 W kg−1), andk (range 2.2 to 12.0 cm hr−1). During this low wind day, all variables were shown to correlate with tidal speed. Taken collectively our results indicate
the promise of these methods for determining short-term variability in gas transfer and near surface turbulence in estuaries
and demonstrate that turbulent transport associated with tidal velocity is a potentially important factor with respect to
gas exchange in coastal systems. 相似文献
37.
Numerical Simulation of the 1918 Puerto Rico Tsunami 总被引:1,自引:0,他引:1
The Caribbean Sea region is well known for its hurricanes, and less known for tsunamis. As part of its responsibilities in hazard assessment and mitigation, the U.S.A. Federal Emergency Management Agency, and the Puerto Rico Civil Defense, funded a pilot study to perform a numerical simulation of the 1918 Puerto Rico tsunami, one of the most deadly in the region. As part of the study a review has been made of the tectonic and tsunamigenic environment around Puerto Rico, the fault parameters for the 1918 event have been estimated, and a numerical simulation has been done using a tsunami propagation and runup model obtained through the Tsunami Inundation Modeling for Exchange (TIME) program. Model results have been compared with the observed runup values all along the west coast of Puerto Rico. 相似文献
38.
R. Eugene Turner 《Estuaries and Coasts》1978,1(1):65-68
Results from the reverse-flow concentration method used to determine community plankton respiration vary significantly because of metabolic inactivation or losses of a portion of the concentrated sample during the filtering process. These losses seem to be nearly constant at concentrations greater than 150X. The within sample coefficient of variation is 20–40% and is primarily a result of clumping and inadequate mixing before subsampling. A rapid processing of the samples is critical for best results. 相似文献
39.
From experimental data it is shown that there is a relationship between measured wind speed and associated micropressure levels. It is also shown that turbulent eddies associated with the wind vanish within distances of five to six times their size, and that these eddies exhibit normal dispersion. These results confirm, at the atmospheric scales, results previously observed only in model experiments. 相似文献
40.
Particulate dispersion from sources within a 10- to 13-m tall pine forest was studied experimentally at Brookhaven National Laboratory using stained ragweed pollen and other tracers ranging from 14 to 58 m in size. Forty-seven continuous point source releases lasting from 22 to 55 min were made at heights from 1.75 to 14.0 m from locations having a long fetch through the forest. In most experiments, differently colored ragweed pollen were emitted simultaneously from three locations. In other tests, several particle types were released from a single point. The sampling network consisted of 119 rotoslide samplers at heights from 0.5 to 21.0 m at 57 positions within and at the edge of the forest. Deposition to the ground was sampled by greased microscope slides at each position. Meteorological measurements were taken in and near the forest.Data were classified by particle characteristics, source height and meteorological parameters. Concentration patterns were illustrated on scale diagrams of the sampling grid. Changes in centerline and crosswind integrated concentrations, plume width and height, mass flux, deposition and deposition velocity were studied as a function of distance, particle size and wind speed. Results were compared to those obtained from similar releases over open terrain.In the forest, vertical predominates over lateral dispersion and considerable interchange occurs through the canopy. Flow is channelled somewhat by vegetation density differences but is generally in the direction of the mean wind above the forest. No systematic turning of the wind with height was observed. Most particles are lost to the foliage rather than to the ground and large particles are lost more rapidly than smaller ones. Rate of change in mass flux is similar to that over open terrain and is greater with light than with stronger wind speeds.This research was carried out under the auspices of the New York State Museum and Science Service and the U.S. Atomic Energy Commission (now Energy Research and Development Administration) and was partially supported by Research Grant No. R-800677 from the Division of Meteorology, U.S. Environmental Protection Agency. 相似文献