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61.
红外动态图像生成技术概念研究 总被引:4,自引:0,他引:4
红外动态图像生成技术的基本概念包括基本术语及其定义。为了描述红外动态图像生成技术的特性,通常采用如光源类型、光谱波段、阵列规模、空间分辨率、填充因子、时间常数、帧频、闪烁、温度范围、串扰、均匀性、发射率、辐射对比度、动态范围、温度分辨率、调制传递函数、几何畸变及最大温度和最大辐射强度等概念。介绍了描述红外动态图像生成系统性能的基本概念的定义。转换器的指标定义对于转换器的设计和性能指标的测试都有重要的意义。 相似文献
62.
Given a constant of motion for the one-dimensional harmonic oscillator with linear dissipation in the velocity, the problem to get the Hamiltonian for this system is pointed out, and the quantization up to second order in the perturbation approach is used to determine the modification on the eigenvalues when dissipation is taken into consideration. This quantization is realized using the constant of motion instead of the Hamiltonian.
PACS: 03.20.+i, 03.30.+p, 03.65.−w,03.65.Ca 相似文献
63.
The bunching system of the ATLAS positive ion injector (PII) has been improved by relocating the harmonic buncher to a point
significantly closer to the second stage sine-wave buncher and the injector LINAC. The longitudinal optics design has also
been modified and now employs a virtual waist from the harmonic buncher feeding the second stage sine-wave buncher. This geometry
improves the handling of space charge for high-current beams, significantly increases the capture fraction into the primary
rf bucket and reduces the capture fraction of the unwanted parasitic rf bucket. Total capture and transport through the PII
has been demonstrated as high as 80% of the injected dc beam while the population of the parasitic, unwanted rf bucket is
typically less than 3% of the total transported beam. To remove this small residual parasitic component a new traveling-wave
transmission-line chopper has been developed reducing both transverse and longitudinal emittance growth from the chopping
process. This work was supported by the U.S. Department of Energy under contract W-31-109-ENG-38. 相似文献
64.
We present a design technique of retarders suitable for nonlinear optical systems. A thin sample of LiNbO3 crystal is utilized as a retarder for wide-ranging applications. Analysis shows that the same crystal can be used for single-wave or two-wave retardations, changing the orientation of the crystal only. As an application, the retarder is used to polarize two waves orthogonal, as necessary for difference frequency mixing in an AgGaSe2 crystal. 相似文献
65.
本文将文献[9]中给出的一维广义函数的集值导数的某些结果,推广到n维情形,并给出一些与优化有关的其他结果. 相似文献
66.
This paper presents detailed information on the experience gained during the attempts to model a set of transitional flows
due to boundary layer separation. These flows are developed on a flat plate with a semi-circular leading edge and they have
been coded by the ERCOFTAC Special Interest Group on Transition, as T3L flows. Different freestream velocities and turbulence
intensities configure these transitional flows and, by consequence, govern the transition mechanism, resulting in larger or
smaller transitional regions. The modeling of the T3L flows has been performed by adopting a low-Reynolds number second-moment
closure turbulence model. The results showed satisfactory agreement with the experimental measurements, although some difficulties
regarding successful convergence have been faced. The final conclusion is that turbulence modeling can present quite accurate
results for transitional flows without any additional use of ad-hoc modifications or additional equations based on various
transition models and intermittency transport modeling. 相似文献
67.
S. Sarkar A. D. Thakur C. V. Tomy G. Balakrishnan D. McK Paul S. Ramakrishnan A. K. Grover 《Pramana》2006,66(1):193-207
New experimental data are presented on the scan rate dependence of the magnetization hysteresis width ΔM(H) (∞ critical current densityJ
c(H)) in isothermalMH scans in a weakly pinned single crystal of Ca3Rh4Sn13, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE). We observe an interesting
modulation in the field dependence of a parameter which purports to measure the dynamical annealing of the disordered bundles
of vortices injected through the sample edges towards the destined equilibrium vortex state at a givenH. These data, in conjunction with the earlier observations made while studying the thermomagnetic history dependence inJ
c(H) in the tracing of the minor hysteresis loops, imply that the partially disordered state heals towards the more ordered state
between the peak field of the SMP anomaly and the onset field of the PE. The vortex phase diagram in the given crystal of
Ca3Rh4Sn13 has been updated in the context of the notion of the phase coexistence of the ordered and disordered regions between the
onset field of the SMP anomaly and the spinodal line located just prior to the irreversibility line. A multi-critical point
and a critical point in the (H,T) region of the Bragg glass phase have been marked in this phase diagram and the observed behavior is discussed in the light
of recent data on multi-critical point in the vortex phase diagram in a single crystal of Nb. 相似文献
68.
利用可积系统的思想,借助三维Minkowski空间L3的矩阵模型,研究了L3中具有调和逆平均曲率的类空曲面和洛伦兹调和逆平均曲率类时曲面的可积性及其形变. 相似文献
69.
D. H. Armitage 《Journal of Approximation Theory》2002,118(2):225-234
For each compact subset K of
N let
(K) denote the space of functions that are harmonic on some neighbourhood of K. The space
(K) is equipped with the topology of uniform convergence on K. Let Ω be an open subset of
N such that 0Ω and
N\Ω is connected. It is shown that there exists a series ∑Hn, where Hn is a homogeneous harmonic polynomial of degree n on
N, such that (i) ∑Hn converges on some ball of centre 0 to a function that is continuous on Ω and harmonic on Ω, (ii) the partial sums of ∑Hn are dense in
(K) for every compact subset K of
N\Ω with connected complement. Some refinements are given and our results are compared with an analogous theorem concerning overconvergence of power series. 相似文献
70.
This paper investigates second best policies to regulate nitrogen leaching. When the policy maker controls the total nitrogen use, an overall tax is superior to an action equivalent overall quota. When the goal is to regulate the expected level of nitrogen leaching, expected profit of a risk neutral farmer is greater under an overall tax than under an overall quota under a reasonable condition. The welfare ranking of action equivalent taxes and quotas for a risk averse farmer is generally ambiguous. In the numerical analyses, overall taxes turned out to be superior to overall quotas with both targets, despite a very high value of absolute risk aversion, 0.01. These results suggest that an overall tax is probably a superior policy to an overall quota to regulate expected total nitrogen use or expected nitrogen leaching for risk neutral and most of risk averse farmers. 相似文献