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多碎片移除过程中的路径优化
空间碎片 移除 路径优化 蚁群算法
2018/5/4
采用蚁群优化算法对多碎片移除过程中的路径优化问题进行研究，然后采用改进的最速下降法对移除每块碎片的时间进行合理优化，进一步降低总的速度增量需求.对比轨道高度、轨道倾角或者升交点赤经的顺序后发现，采用蚁群算法优化之后的顺序移除碎片可以大大节省轨道转移所需要的速度增量.选取中国空间活动产生的三组碎片进行优化计算，结果显示在相同的任务时间内，优化后的顺序可能不同于轨道高度、倾角和赤经的顺序，并且优化顺序...
Graviton mass bounds from space-based gravitational-wave observations of massive black hole populations
Graviton mass bounds space-based gravitational-wave observations massive black hole populations
2011/10/17
Space-based gravitational-wave detectors, such as LISA or a similar ESA-led mission, will offer unique opportunities to test general relativity. We study the bounds that space-based detectors could pl...
Joint downscale fluxes of energy and potential enstrophy in rotating stratified Boussinesq flows
Turbulent ows Strati ed ows Rotating ows
2011/10/14
We employ a coarse-graining approach to analyze nonlinear cascades in Boussinesq flows using high-resolution simulation data. We derive budgets which resolve the evolution of energy and potential enst...
Oscillations of relativistic axisymmetric tori and implications for modelling kHz-QPOs in neutron-star X-ray binaries
X-rays: binaries – relativity – stars: neutron
2011/10/8
We perform a global linear perturbative analysis, and investigate the oscillation properties of relativistic, non-selfgravitating tori orbiting around neutron stars in the slow rotation limit approxim...
Magnetic Fields, Relativistic Particles, and Shock Waves in Cluster Outskirts
Magnetic Fields Relativistic Particles Shock Waves Cluster Outskirts
2011/10/20
It is only now, with low-frequency radio telescopes, long exposures with high-resolution X-ray satellites and gamma-ray telescopes, that we are beginning to learn about the physics in the periphery of...
A More General Model for the Intrinsic Scatter in Type Ia Supernova Distance Moduli
General Model Intrinsic Scatter Supernova Distance Moduli
2011/10/13
We describe a new formalism to fit the parameters $\alpha$ and $\beta$ that are used in the SALT2 model to determine the standard magnitudes of Type Ia supernovae. The new formalism describes the intr...
From the Blazar Sequence to the Blazar Envelope: Revisiting the Relativistic Jet Dichotomy in Radio-loud AGN
Blazar Envelope Revisiting Relativistic Jet Dichotomy Radio-loud AGN
2011/10/21
We revisit the concept of a blazar sequence that relates the synchrotron peak frequency ({\nu}peak) in blazars with synchrotron peak luminosity (Lpeak, in {\nu}L{\nu}) using a large sample of radio-lo...
Stability Constraints on Classical de Sitter Vacua
Stability Constraints Classical Sitter Vacua
2011/10/17
We present further no-go theorems for classical de Sitter vacua in Type II string theory, i.e., de Sitter constructions that do not invoke non-perturbative effects or explicit supersymmetry breaking l...
Extending the effective-one-body Hamiltonian of black-hole binaries to include next-to-next-to-leading spin-orbit couplings
Extending Hamiltonian black-hole binaries couplings
2011/10/17
In the effective-one-body (EOB) approach the dynamics of two compact objects of masses m1 and m2 and spins S1 and S2 is mapped into the dynamics of one test particle of mass mu = m1 m2/(m1+m2) and spi...
Quasisteady Configurations of Conductive Intracluster Media
Quasisteady Configurations Conductive Intracluster Media
2011/10/8
The radial distributions of temperature, density, and gas entropy among cool-core clusters tend to be quite similar, suggesting that they have entered a quasi-steady state. If that state is regulated ...
We present here the All Sky Transmission MONitor (ASTMON), designed to perform a continuous monitoring of the surface brightness of the complete night-sky in several bands. The data acquired are used ...
Deep sub electron noise readout in CCD systems using digital filtering techniques
CCD spectroscopy dark matter sub electron noise
2011/9/28
Scientific CCDs designed in thick high resistivity silicon (Si) are excellent detectors for astronomy, high energy and nuclear physics, and instrumentation. Many applications can benefit from CCDs ult...
Inhomogeneities in molecular layers of Mira atmospheres
Techniques: interferometric – Techniques: photometric – Stars: AGB and post-AGB – Stars: atmospheres – Stars: fun- damental parameters – Stars: mass-loss
2011/9/28
We obtained K-band spectro-interferometric observations of the Miras R Cnc, X Hya, W Vel, and RW Vel with a spectral resolution of 1500 using the VLTI/AMBER instrument. We obtained concurrent JHKL pho...
Application of speckle and (multi-object) multi-frame blind deconvolution techniques on imaging and imaging spectropolarimetric data
Sun: photosphere – Sun: spectropolarimeters
2011/9/27
We test the effects of reconstruction techniques on 2D data to determine the best approach. We obtained a time-series of spectropolarimetric data in the Fe I line at 630.25 nm with the Goettingen Fabr...