8,891 research outputs found
Vacuum induced transparency and photon number resolved Autler-Townes splitting in a three-level system
We study the absorption spectrum of a probe field by a {\Lambda}-type
three-level system, which is coupled to a quantized control field through the
two upper energy levels. The probe field is applied to the ground and the
second excited states. When the quantized control field is in vacuum, we derive
a threshold condition to discern vacuum induced transparency (VIT) and vacuum
induced Autler- Townes splitting (ATS). We also find that the parameter change
from VIT to vacuum induced ATS is very similar to that from broken PT symmetry
to PT symmetry. Moreover, we find the photon number resolved spectrum in the
parameter regime of vacuum induced ATS when the mean photon number of the
quantized control field is changed from zero (vacuum) to a finite number.
However, there is no photon number resolved spectrum in the parameter regime of
VIT even that the quantized control field contains the finite number of
photons. Finally, we further discuss possible experimental realization
Institutional changes and the Shifting Power Network
In this paper, the authors introduce the issue of institution as a factor of considerable significance. Based on field investigation and historical geography analysis, inquiring port plans, policy documents, laws and regulations as the basic historical data, the authors try to review the process of developing Wusong Port in the twentieth century and analyse the dynamic mechanism of its evolution from the perspective of institutional changes. The first section of this paper provides an overview of the development trajectory of Wusong Port, which focuses on its functions and locations changes. The second section briefly discusses the shifting power network that had historically governed the port and analyses relationship between the port and the city. The impact of administrative zoning adjustment is particularly mentioned, since the changes of the function of Wusong port were always accompanied by it. The third section explores the planning of the Wusong port in different historical periods. This article provides evidence that government-led port exploitation plays a great role in the fundamental change of Wusong Port -- from a naval port, to a commercial port, to an industrial port, and finally an international cruise port
Contact parameters identification of a cannon cradle and its bushing based on FDA and ELM
An identification method based on functional data analysis (FDA) and extreme learning machine (ELM) is presented to identify the contact parameters of a cannon cradle and its bushing. A virtual prototype of the cannon is built in ADAMS. The response curves of muzzle vertical acceleration with different contact parameters of the cradle and its bushing are obtained by simulation experiments and used for FDA as sample data. Features of the sample data are extracted by FDA and functional principle component analysis (FPCA), and the features and contact parameters are used to train the ELM. Simulation data and test data are used to verify the proposed method. The presented method is also proved to be feasible and effective by comparing actual muzzle vertical acceleration curve and the muzzle vertical acceleration curve from the virtual prototype with respect to the test data identification results
NLO QCD corrections to Single Top and W associated production at the LHC with forward detector acceptances
In this paper we study the Single Top and W boson associated photoproduction
via the main reaction at
the 14 TeV Large Hadron Collider (LHC) up to next-to-leading order (NLO) QCD
level assuming a typical LHC multipurpose forward detector. We use the
Five-Flavor-Number Schemes (5FNS) with massless bottom quark assumption in the
whole calculation. Our results show that the QCD NLO corrections can reduce the
scale uncertainty. The typical K-factors are in the range of 1.15 to 1.2 which
lead to the QCD NLO corrections of 15 to 20 correspond to the
leading-order (LO) predictions with our chosen parameters.Comment: 41pages, 12figures. arXiv admin note: text overlap with
arXiv:1106.2890 by other author
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