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41.
M. Karlický 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
The paper presents a summary of results from two different simulations which study the tearing, coalescence and fragmentation of current sheets, the associated production of energetic electrons and of plasma waves from these electrons which could explain drifting pulsation structures observed at radio wavelengths. Using a 2.5-D particle-in-cell (PIC) model of the current sheet it is shown that due to the tearing mode instability the current sheet tears into plasmoids and these plasmoids later on coalesce into larger ones. During these processes electrons are accelerated and they produce observable electromagnetic waves. Furthermore, the 3-D PIC model with two current sheets extended in the electric current direction shows their fast fragmentation associated with the exponential dissipation of the free magnetic field energy. An example of the drifting pulsating structure which is considered to be a radio signature of the above mentioned processes in solar flares is shown. 相似文献
42.
A. Chilingarian R. Mirzoyan M. Zazyan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
Cosmic Ray research on Mt. Aragats began in 1934 with the measurements of East–West anisotropy by the group from Leningrad Physics-Technical Institute and Norair Kocharian from Yerevan State University. Stimulated by the results of their experiments in 1942 Artem and Abraham Alikhanyan brothers organized a scientific expedition to Aragats. Since that time physicists were studying Cosmic Ray fluxes on Mt. Aragats with various particle detectors: mass spectrometers, calorimeters, transition radiation detectors, and huge particle detector arrays detecting protons and nuclei accelerated in most violent explosions in Galaxy. Latest activities at Mt. Aragats include Space Weather research with networks of particle detectors located in Armenia and abroad, and detectors of Space Education center in Yerevan. 相似文献
43.
Egidio Landi Degl’Innocenti 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
A century has elapsed since the first observation of the polarimetric profile of a line of the solar spectrum. Since then, dramatic progress has been made in the instrumentation, which is now reaching unprecedented levels of sensitivity in the measurement of polarization signals in solar spectral lines. At the same time, the theoretical framework needed for the interpretation of polarimetric observations has steadily evolved from the pioneering methods, based on simple formulae, to the sophisticated structure that is nowadays used with success in the interpretation of solar observations. The present paper is intended to give a historical perspective of the evolution of this research field and of its major achievements, with particular emphasis on the role played by the magnetic field in determining the polarimetric shapes of spectral lines. 相似文献
44.
Benjamin Lenoir Agnès Lévy Bernard Foulon Brahim Lamine Bruno Christophe Serge Reynaud 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Radio tracking of interplanetary probes is an important tool for navigation purposes as well as for testing the laws of physics or exploring planetary environments. The addition of an accelerometer on board a spacecraft provides orbit determination specialists and physicists with an additional observable of great interest: it measures the value of the non-gravitational acceleration acting on the spacecraft, i.e. the departure of the probe from geodesic motion. 相似文献
45.
We analyzed UVCS/SOHO data and compared the H I Lyα (121.6 nm) and O VI (103.2 nm, 103.7 nm) emission in the polar and equatorial
coronal holes. We found that the emission lines have similar characteristics in these two types of coronal holes. Both types
show evidence for superradially diverging boundaries. The latitudinal distribution of the O VI line ratio may indicate that
the equatorial coronal hole has O+5 outflow velocities lower than in the polar coronal holes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
46.
Deborah L. Domingue Patrick L. Koehn Rosemary M. Killen Ann L. Sprague Menelaos Sarantos Andrew F. Cheng Eric T. Bradley William E. McClintock 《Space Science Reviews》2007,131(1-4):161-186
The existence of a surface-bounded exosphere about Mercury was discovered through the Mariner 10 airglow and occultation experiments.
Most of what is currently known or understood about this very tenuous atmosphere, however, comes from ground-based telescopic
observations. It is likely that only a subset of the exospheric constituents have been identified, but their variable abundance
with location, time, and space weather events demonstrate that Mercury’s exosphere is part of a complex system involving the
planet’s surface, magnetosphere, and the surrounding space environment (the solar wind and interplanetary magnetic field).
This paper reviews the current hypotheses and supporting observations concerning the processes that form and support the exosphere.
The outstanding questions and issues regarding Mercury’s exosphere stem from our current lack of knowledge concerning the
surface composition, the magnetic field behavior within the local space environment, and the character of the local space
environment. 相似文献
47.
论述了计算物理与数学实验的关系,以及数学实验对计算物理的重要性,并通过实例说明,利用数学实验方法可以简化计算,突出物理概念,使问题得到更好的解决。 相似文献
48.
The progress on Chinese Space Solar Telescope (SST) in 2002-2004 is introduced. The documentations on plans and outlines based on the standards of Chinese aerospace industry for SST mission has been fulfilled. The key technical problems of SST satellite platform and payloads are tackled during pre-study stage of the mission. The laboratory assembly and calibration of the main optical telescope of 1.2 m spherical mirror and 1 m plain mirror have been carried out with the accuracy of λ/40 and λ/30, respectively. The prototype at 17.1 nm for extreme ultraviolet telescope is under development and manufacture with a diameter of 13 cm. Its primary and secondary mirrors have a manufacturing error of 5 nm with a roughness degree of less than 0.5 nm and a multiplayer reflection factor of better than 20%. The on-board scientific data processing unit has been developed. Prototypes for other payloads such as H. and white light telescope, wide band spectroscopy in high energy and solar and interplanetary radio spectrometer have been developed accordingly. 相似文献
49.
Progress on Microgravity Sciences in China 总被引:1,自引:1,他引:1
The main progress of the research activities on microgravity fluid physics, combustion, biotechnology research and fundamental Physics in China are briefly summarized in the present paper. The major space missions and experimental results obtained on board the Chinese recoverable/nonrecoverable satellites and the Chinese manned spaceship named "Shen Zhou" are presented summarily. The recent main activities of the ground-based studies in China are introduced in brief. 相似文献
50.