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1.
In most ectotherms, environmental temperature has differential effects on growth and differentiation. For example, amphibian size at maturity decreases with increasing temperature. To address how radiant heat in the form of far-infrared radiation (FIR) may affect development of the aquatic ectotherm Xenopus laevis, we continuously irradiated swimming larvae as they developed into young adults. Here we report evidence that FIR promotes growth of these organisms in an aqueous environment.  相似文献   
2.
SN 1006 is one of the supernova remnants (SNRs) with relatively low-temperature electrons, considering the young age of just 1000 years. We carried out SN 1006 mapping observations with the X-ray Imaging Spectrometers (XIS) and the Hard X-ray Detector (HXD) onboard Suzaku, the fifth Japanese X-ray satellite. Thanks to the excellent spectral resolution of XIS in the soft X-ray band, H-like and He-like oxygen emission lines were clearly detected, and we could make a map of the line intensity, and as well as a flux and the photon index of nonthermal component. We found that these parameters have spatial dependences from region to region in the SNR; the north region is bright in nonthermal, while dim in thermal; the east region is bright in both nonthermal and thermal; the inner region shows dim nonthermal and bright thermal emission. The photon index is the smallest in the north region.  相似文献   
3.
Forced vibration analysis including a vortex lattice prediction given an external aerodynamic force is conducted in this paper based on a standing wave formulation. The starting point of the standing wave formulation is a set of blade disk normal modes that incorporate all forms of the blade, disk, and shroud elastic coupling. The Küssner gust function was used in a few previous investigations of forced vibration based on the standing wave formulation. However, it was found to be valid only for low engine-order excitation. Therefore, a two-dimensional unsteady vortex lattice method is employed in this paper to predict the gust excitation up to higher engine-order excitation. Thus, the present unsteady vortex lattice analytical model is capable of capturing compressibility and higher engine-order excitation. It features advantages in terms of its computational time and level of accuracy. The effects of mistuning a cascaded blade are also examined in the present aeroelastic analysis to determine the possible advantages obtained by doing this. Numerical results for the mistuned bladed disk are presented regarding its forced response characteristics. In a low engine-order excitation condition, it is shown that similar predictions are obtained between the present and earlier analyses. The maximum discrepancy in the blade amplitude is 70% for a single-blade mistuned rotor and 62.6% for an alternately mistuned rotor, in the worst case, compared to a completely tuned rotor. Single-peak frequencies are presented and analyzed in the higher engine-order excitation levels.  相似文献   
4.
Numerical simulation of unsteady flow control over an oscillating NACA0012 airfoil is investigated. Flow actuation of a turbulent flow over the airfoil is provided by low current DC surface glow discharge plasma actuator which is analytically modeled as an ion pressure force produced in the cathode sheath region. The modeled plasma actuator has an induced pressure force of about 2 k Pa under a typical experiment condition and is placed on the airfoil surface at 0% chord length and/or at 10% chord length. The plasma actuator at deep-stall angles(from 5° to 25°) is able to slightly delay a dynamic stall and to weaken a pressure fluctuation in down-stroke motion. As a result, the wake region is reduced. The actuation effect varies with different plasma pulse frequencies, actuator locations and reduced frequencies. A lift coefficient can increase up to 70% by a selective operation of the plasma actuator with various plasma frequencies and locations as the angle of attack changes. Active flow control which is a key advantageous feature of the plasma actuator reveals that a dynamic stall phenomenon can be controlled by the surface plasma actuator with less power consumption if a careful control scheme of the plasma actuator is employed with the optimized plasma pulse frequency and actuator location corresponding to a dynamic change in reduced frequency.  相似文献   
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In order to better understand the characteristics of Yohkoh Soft X-ray Telescope (SXT) mirror, we have analyzed the in-flight overexposed image (the starburst image) obtained during the solar flare observation. It has been revealed from our study that the intensity distribution inside the shadows shown in the scattering difference image contains little of the scattered component of the PSF and matches almost correctly the extension of the PSF core profile. Also it is found that the scattering wing of the SXT PSF is connected smoothly to the PSF core within the distance of about 100–200 arcsec from the peak. With numerical simulations we have shown that an increase in energy affects not only the level of scattering wing, but also both the shape and the absolute level of the PSF core. The results have revealed, however, that the energy dependence for the SXT PSF cannot be easily estimated with the data obtained from one filter alone, which implies that the data analysis using multiple filters will enable us to determine the absolute amount of scattered component as well as the energy dependence of the SXT PSF. Details on the analysis of starburst image and the results from numerical simulations will be introduced and discussed thoroughly.  相似文献   
8.
The remote sensing of precipitation, especially rain by the spaceborne weather radar is an important subject which has not been realized. The system design and examination of the spaceborne weather radar which is called as the spaceborne microwave rain-scatterometer are performed by considering user's requirements to observe rain, the restrictions derived from the interface with satellite and the state of the art and the possibility of spaceborne microwave technology. Characteristic parameters for spaceborne microwave rain-scatterometer are determined based on the user's requirements for the system. Functions and performances of each subsystem (antenna, transmitters, receivers and data transmission processor) with the detailed block diagram of the total system of spaceborne microwave rain-scatterometer are shown. All of the critical items of hardware in the development of spaceborne microwave rain-scatterometer are also discussed.  相似文献   
9.
In most ectotherms, environmental temperature has differential effects on growth and differentiation. For example, amphibian size at maturity decreases with increasing temperature. To address how radiant heat in the form of far-infrared radiation (FIR) may affect development of the aquatic ectotherm Xenopus laevis, we continuously irradiated swimming larvae as they developed into young adults. Here we report evidence that FIR promotes growth of these organisms in an aqueous environment.  相似文献   
10.
The discontinuous Galerkin (DG) finite element method has been popular as a numerical technique for solving the conservation laws, In the present study, in order to investigate the shock wave structures in highly thermal nonequilibrium, an explicit modal cell-based DG scheme is developed for solving the conservation laws in conjunction with nonlinear coupled constitutive relations (NCCR). Convergent iterative methods for solving alge- braic constitutive relations are also implemented in the DG scheme. It is shown that the new scheme works well for all Mach numbers, for example, Ma = 15.  相似文献   
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