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431.
J. Goldstein 《Space Science Reviews》2006,124(1-4):203-216
The plasmasphere is the cold, dense innermost region of the magnetosphere that is populated by upflow of ionospheric plasma
along geomagnetic field lines. Driven directly by dayside magnetopause reconnection, enhanced sunward convection erodes the
outer layers of the plasmasphere. Erosion causes the plasmasphere outer boundary, the plasmapause, to move inward on the nightside
and outward on the dayside to form plumes of dense plasma extending sunward into the outer magnetosphere. Coupling between
the inner magnetosphere and ionosphere can significantly modify the convection field, either enhancing sunward flows near
dusk or shielding them on the night side. The plasmaspheric configuration plays a crucial role in the inner magnetosphere;
wave-particle interactions inside the plasmasphere can cause scattering and loss of warmer space plasmas such as the ring
current and radiation belts. 相似文献
432.
Normarc M改型下滑信标辐射场型的分析和比较 总被引:2,自引:0,他引:2
金辽 《中国民航学院学报》2000,18(3):30-34,47
分析了Normarc M改型下滑信标的CSB和SBO信号的辐射场型,并把它与另外三种通用设备的相关辐射场型进行了比较。 相似文献
433.
R. Hollmann R.W. Mueller A. Gratzki 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,37(12):2166-II
In the phase of redefinition of the EUMETSAT ground segment seven so called Satellite Application Facilities (SAF) each of them serving dedicated user groups have been established in Europe. The SAF on climate monitoring (CM-SAF) will deliver a comprehensive set of climate variables, including from different cloud products, radiation budget at the top of the atmosphere, surface radiation budget and tropospheric humidity. A consistent dataset of cloud and radiation products in a high spatial resolution on a uniform grid is derived. The CM-SAF is a joint project of the German Meteorological Service, EUMETSAT and five other European Meteorological Services. It is dedicated to produce climate datasets using data from instruments onboard of METEOSAT Second Generation and polar orbiting satellites NOAA and METOP. After the development phase, the CM-SAF has started its initial operational phase in the end of 2003. In this context, the algorithms have been implemented at the processing centres and the processing of satellite data from the polar orbiting satellites of NOAA has commenced. This paper gives an overview of the first products of surface radiative fluxes and their validation with selected surface sites. 相似文献
434.
Radiation exposure estimates for crew members on the surface of Mars may vary widely because of the large variations in terrain altitude. The maximum altitude difference between the highest (top of Olympus Mons) and the lowest (bottom of the Hellas impact basin) points on Mars is about 32 km. In this work estimates of radiation exposures as a function of altitude, from the Hellas impact basin to Olympus Mons, are made for a solar particle event proton radiation environment comparable to the Carrington event of 1859. We assume that the proton energy distribution for this Carrington-type event is similar to that of the Band Function fit of the February 1956 event. In this work we use the HZETRN 2010 radiation transport code, originally developed at NASA Langley Research Center, and the Computerized Anatomical Male and Female human geometry models to estimate exposures for aluminum shield areal densities similar to those provided by a spacesuit, surface lander, and permanent habitat as a function of altitude in the Mars atmosphere. Comparisons of the predicted organ exposures with current NASA Permissible Exposure Limits (PELs) are made. 相似文献
435.
Progress in helicopter infrared signature suppression 总被引:2,自引:1,他引:1
Due to their low-attitude and relatively low-speed fight profiles, helicopters are subjected to serious threats from radio, infrared(IR), visual, and aural detection and tracking. Among these threats, infrared detection and tracking are regarded as more crucial for the survivability of helicopters. In order to meet the requirements of infrared stealth, several different types of infrared suppressor(IRS) for helicopters have been developed. This paper reviews contemporary developments in this discipline, with particular emphasis on infrared signature suppression, advances in mixer-ejectors and prediction for helicopters. In addition, several remaining challenges, such as advanced IRS, emissivity optimization technique, helicopter infrared characterization, etc., are proposed, as an initial guide and stimulation for future research. In the future, the comprehensive infrared suppression in the 3–5 lm and 8–14 lm bands will doubtfully become the emphasis of helicopter stealth. Multidisciplinary optimization of a complete infrared suppression system deserves further investigation. 相似文献
436.
单边膨胀喷管(Single Expansion Ramp Nozzle,SERN)是1种新型的排气喷管,具有可以有效抑制航空发动机排气系统的红外辐射和雷达反射截面积、后体阻力小、质量轻、增加飞机的敏捷性和可操控性等优点。运用计算流体力学/红外辐射(CFD/IR)数值模拟的方法,采用标准k-ε湍流模型和标准壁面函数,研究了轴对称喷管、单边膨胀喷管和开缝冷却单边膨胀喷管的排气系统与机身融合后的红外辐射特性空间分布规律。结果表明:单边膨胀喷管大幅度降低了排气系统尾向红外辐射峰值,其降幅达到60%以上,说明了单边膨胀喷管与后机身融合、遮挡内部高温部件,从而降低了尾向红外辐射的卓越红外抑制效果。 相似文献
437.
438.
C.J. Rodriguez-Solano U. HugentoblerP. Steigenberger 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
One of the major uncertainty sources affecting Global Positioning System (GPS) satellite orbits is the direct solar radiation pressure. In this paper a new model for the solar radiation pressure on GPS satellites is presented that is based on a box-wing satellite model, and assumes nominal attitude. The box-wing model is based on the physical interaction between solar radiation and satellite surfaces, and can be adjusted to fit the GPS tracking data. 相似文献
439.
440.