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861.
<正> 1.引言 军用飞机电子设备舱中的各种电器设备需要用一定量的冷却空气进行冷却。为此需将供给电子设备舱的总供气量按所要求的比例分配给各设备。保证分配比的方法通常是在通入各电子设备的供气支管中加一相应的限流孔,由限流孔孔径的大小控制流量的多少。可见,确定满足流量要求的限流孔孔径是解决这一问题的关键。关于限流孔孔径的确定,目前尚未看到其计算方法,以往主要靠试验进行试凑。众所周知,这种试凑方法费时费力,很不经济,是一种不得已的方法。因此,笔者力图从解析角度入手,找出限流孔孔径与所 相似文献
862.
The results of studying a dispersed airflow around a single porous cylinder are presented. The flow field of carrying medium outside the cylinder is described within the framework of the Navier-Stokes equations for incompressible gas; inside the porous cylinder the Darcy-Brinkman extended equations for averaged velocity are used. The numerical solution of the medium equations is achieved in the FLUENT package. In the found field of carrying medium velocities the suspended particle trajectories are calculated. Also given are the dependences of the particle inertial deposition effectiveness on the Stokes number at various values of the Darcy number. 相似文献
863.
Calorimeters play an important role in cosmic-ray physics and, in particular, in experiments, which are carried out in the
atmosphere with balloons and on satellites in space. This paper presents a method of energy measurement for protons (at energy
higher than 20 GeV) with the help of a thin discrete calorimeter (using as an example the position-sensitive silicon-tungsten
calorimeter of the PAMELA experiment) developed based on the data of simulation by the Monte-Carlo method and on the results
of test experiment at an accelerator in charged particle beams. The method is based on measurement of the total released energy
and on the criterion of event selection, which characterizes the beginning of particle cascade development in the calorimeter.
The influence of insertion of additional parameters on the energy resolution obtained with the help of this method is also
studied. 相似文献
864.
865.
S. G. Parafes’ 《Russian Aeronautics (Iz VUZ)》2010,53(2):126-133
An approach to the solution of a number of practical important problems of flight vehicle thin-walled structure design based
on a unified mathematical identification technique is proposed. These problems include estimation of functional performance
of existing structures, development of unconventional promising structures, structure design by a prototype and some others.
The original mathematical identification technique contains an identification criterion, identification procedures and methods
for formation of structure standards. 相似文献
866.
A technique for numerical calculations of the coefficients of temperature restitution and heat transfer on the surface streamlined by a high-speed constant-composition flow is suggested. The data obtained in the course of numerical studies of local coefficients of temperature restitution and heat transfer on this surface in the presence and absence of the longitudinal pressure gradient are given. The nonmonotonic variation of the coefficient of restitution along the streamlined surface length is established. We are the first who succeeded in obtaining the data on influence of both the adverse and accelerating longitudinal pressure gradients upon the coefficients of temperature restitution and heat transfer in a high-speed turbulent gas flow. Also obtained are some data on the influence of inaccurate determination of restitution coefficients upon heat transfer. 相似文献
867.
Making use of the Boltzmann kinetic equation, an approach to a more accurate calculation of transport coefficients is considered; the approach is based on the modification of the Lennard-Jones potential and efficient numerical algorithm for calculating the Ω-integrals. The calculation data on the transport coefficients are compared with the experimental data obtained by other researchers. 相似文献
868.
869.
V. V. Tret’yakov 《Russian Aeronautics (Iz VUZ)》2007,50(4):395-401
The results of calculating a flow and concentrations of droplet-liquid and vaporous fuel in the combustion chamber injector module are presented. The numerical model used takes into account polydispersity of a fuel flame and a multistage nature of fuel atomization. A significant influence of the swirler design on the fuel droplet deposition on the module walls and distribution of droplet-liquid and vaporous fuel concentrations is revealed. 相似文献
870.
B. Kh. Perel’shtein R. A. Kil’deev E. B. Mats B. M. Osipov A. S. Khamzin E. A. Titova 《Russian Aeronautics (Iz VUZ)》2007,50(4):430-435
The air heat pump (HP) driven from GTP, created on the basis of aircraft GTE removed from service, is considered. The heat pump uses ambient air from negative (?40 °C) to positive (+15 °C) temperature values as a low-grade heat source and provides heating temperature in a range from 100 to 250 °C with the performance factor 2.5–3.2. The high technological burning of gas decreases its consumption for heating on the average by a factor of 1.5 in comparison with an ordinary boiler-house. Cold HP exhaust within the range of ? 50 … ? 80 °C is fed both to a drive GTP and an integrated electric energy generating GTP, this increasing their specific power by a factor of 1.2–1.4 and efficiency up to a factor of 1.05–1.1. In standard HPs designed for operation with low-grade heat sources from +5 to +10°C, the heating temperature does not exceed +60 … +65 °C for the performance factors indicated. 相似文献