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431.
R Navarro-González A Negrón-Mendoza M E Aguirre-Calderón C Ponnamperuma 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1989,9(6):57-61
The gamma-irradiation of 0.1 M, O2-free, aqueous HCN was studied in the presence of ferrocyanide or ferricyanide in the concentration range 10(-3) - 10(-5) M. This study was carried out in order to get an insight into the possible role that cyanocomplexes of iron may have played in promoting prebiotic syntheses via the free-radical oligomerization of HCN. It was found that ferrocyanide or ferricyanide have no effect on the irradiation of 0.1 M HCN solutions at concentrations < or = 10(-4) M. At high concentrations, 10(-3) M, they lead to a marked decrease in the conversion of HCN. There was no significant difference due to the oxidation state of iron used, particularly at high doses > or = 100 kGy. 相似文献
432.
433.
Cáceres M 《Aerospace America》2005,43(8):10-12
The article provides an overview of funding for space exploration to the Moon and Mars under NASA's direction, and presents an argument for the creation of a commercial space industry. 相似文献
434.
R Navarro-González C Ponnamperuma 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1995,15(3):357-364
We have studied the effect of iron in the free-radical oligomerization of hydrogen cyanide and acetic acid, and found that iron(II) and iron(III) readily reduces or oxidizes free radicals, respectively. The transient species produced by these reactions do not induce a chain oligomerization process and, therefore, they protect the solute molecules from degradation. Analysis of the available kinetic data for the reactions of a variety of transition metal ions with free radicals indicate that transition metal ions behave similarly to iron. Since Fe, Zn and Mo are essential to all living organisms, and there seems to be no apparent difference in chemical reactivity among transition metal ions towards free radicals, we suggest that these metal ions probably protected the biomolecules from degradation induced by free-radical reactions in the later stages of chemical evolution. 相似文献
435.
Gy. Molnár 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(4):323-326
The paper deals with a new method for simultaneous determination of cloud top height and effective cloud cover, using infrared radiance data of satellite-borne instruments. These cloud properties derived from the Selective Chopper Radiometer on the Nimbus 5 satellite are compared with nearly simultaneous observations by radiosondes and with satellite images. Encouraging results for Central-Europe during January, April, July, August and October 1974, as well as numerical simulations indicate that the method proposed here, would be useful also for global application. Another advantage of the described procedure are the small amount of computing time, and that no other data are required than 3 of infrared channel values, for each sounded spot. 相似文献
436.
437.
Y Honda R Navarro-González C Ponnamperuma 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1989,9(6):63-66
A CH4-N2-H2OV gas mixture was subjected to a high voltage (20 kV), high frequency (0.3 MHz) electric discharge. The energy input in the electric discharge was varied from 0.016 to 3.048 MJ mol-1. The chemical yields (G), expressed as the number of molecules formed or destroyed per 100 eV of energy input were calculated for several products. The G values calculated at the lowest energy input were (-CH4) = 6.48; (-N2) = 2.51; (C2H2) = 1.16; (HCN) = 0.215; (CH3CHO) = 0.115; (CH3CH2CHO) = 0.00161; (CH3(CH2)2CHO) = 0.0165; ((CH2CO2H)2) = 0.0000339; (CH4 --> Solid material) = 0.196; (N2 --> Solid material) = 0.00355. This is the first report in prebiotic studies in which the G values of various products in electric discharge experiments are determined. This type of study is needed in order to get a better insight into the relative role of electric discharges on the primitive Earth. 相似文献
438.
Cornelis de Jager 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(7):303-306
A coronal explosion is a density wave observed in X-ray images of solar flares. The wave occurs at the end of the impulsive phase, which is the time at which the flare's thermal energy content has reached its maximum value. It starts in a small area from where it spreads out, mainly into one hemisphere, with velocities that tend to rapidly decrease with time, and which are between ~ 103 and a few tens of km s?1. We interpret them as magneto-hydrodynamic waves that (mainly) move downward from the low corona into denser regions. 相似文献
439.
P. Lála 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(6):57-67
The computer program used mainly for determination of orbits of the Interkosmos satellites is described. Examples of results are given for Geos B and Interkosmos 17 satellites. 相似文献
440.
M.M. Császár 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(4):309-312
Two procedure are presented for quantitative estimation of cloud cover (N), type of clouds (C), as well as base of clouds (Cb) and top of clouds (Ct) by using radiosonde data as well as satellite cloud pictures and radiation data. The data obtained in this way can be used as input data in the model for the estimation of the vertical profile of longwave radiative cooling. 相似文献