32,876 research outputs found
Evaluation of heating effects on atoms trapped in an optical trap
We solve a stochastic master equation based on the theory of Savard et al. [T. A. Savard. K. M. O'Hara, and J. E. Thomas, Phys, Rev. A 56, R1095 (1997)] for heating arising from fluctuations in the trapping laser intensity. We compare with recent experiments of Ye et al. [J. Ye, D. W. Vernooy, and H. J. Kimble, Phys. Rev. Lett. 83, 4987 (1999)], and find good agreement with the experimental measurements of the distribution of trap occupancy times. The major cause of trap loss arises from the broadening of the energy distribution of the trapped atom, rather than the mean heating rate, which is a very much smaller effect
An experimental approach to quantify strain transfer efficiency of fibre bragg grating sensors to host structures
This paper developed a method to evaluate the strain transfer efficiency of
fibre Bragg grating sensors to host structures. Various coatings were applied to
fibre Bragg grating sensors after being fabricated. They were epoxy, silane
agent and polypropylene, representing different surface properties. A neat epoxy
resin plate was used as the host in which the coated fibre sensors were embedded
in the central layer. The tensile strain output from the FBGs was compared with
that obtained from electrical strain gauges which were attached on the surface
of the specimen. A calculating method based on the measured strains was
developed to quantify the strain transfer function of different surface
coatings. The strain transfer coefficient obtained from the proposed method
provided a direct indicator to evaluate the strain transfer efficiency of
different coatings used on the FBG sensors, under either short or long-term
loading. The results demonstrated that the fibre sensor without any coating
possessed the best strain transfer, whereas, the worst strain transfer was
created by polypropylene coating. Coatings play a most influential role in
strain measurements using FBG sensors
Acoustic Attenuation by Two-dimensional Arrays of Rigid Cylinders
In this Letter, we present a theoretical analysis of the acoustic
transmission through two-dimensional arrays of straight rigid cylinders placed
parallelly in the air. Both periodic and completely random arrangements of the
cylinders are considered. The results for the sound attenuation through the
periodic arrays are shown to be in a remarkable agreement with the reported
experimental data. As the arrangement of the cylinders is randomized, the
transmission is significantly reduced for a wider range of frequencies. For the
periodic arrays, the acoustic band structures are computed by the plane-wave
expansion method and are also shown to agree with previous results.Comment: 4 pages, 3 figure
Can Machine Learning, as a RegTech Compliance Tool, lighten the Regulatory Burden for Charitable Organisations in the United Kingdom?
Purpose: The purpose of this article is to explore the extent to which machine learning can be used as solution to lighten the compliance and regulatory burden on charitable organisations in the United Kingdom.
Design/methodology/approach: The subject is approached through the analysis of data, literature, and domestic and international regulation. The first part of the article summarises the extent of current regulatory obligations faced by charities, these are then, in the second part, set against the potential technological solutions provided by machine learning as at July 2021.
Findings: It is suggested that charities can utilise machine learning as a smart technological solution to ease the regulatory burden they face in a growing and impactful sector.
Originality: The work is original because it is the first to specifically explore how machine learning as a technological advance can assist charities in meeting the regulatory compliance challenge
Abelian bosonization approach to quantum impurity problems
Using Abelian Bosonization, we develop a simple and powerful method to
calculate the correlation functions of the two channel Kondo model and its
variants. The method can also be used to identify all the possible boundary
fixed points and their maximum symmetry, to calculate straightforwardly the
finite size spectra, to demonstrate the physical picture at the boundary
explicitly. Comparisons with Non-Abelian Bosonization method are made. Some
fixed points corresponding to 4 pieces of bulk fermions coupled to s=1/2
impurity are listed.Comment: 12 pages, REVTEX, 1 Table, no figures. To appear in Phys. Rev. Letts.
July 21, 199
Controlling Insider Dealing Through Criminal Enforcement in China
The enforcement of the new Securities Law (SL 2020) of the People’s Republic of China (PRC) in March 2020 presents a perfect opportunity to review the criminal enforcement of insider dealing cases in China’s securities market and to provide feasible suggestions for improvement for a more coherent and streamlined insider dealing regulatory framework in the PRC.
Through analysing the previous literature on public interest theories and economic theories of regulation, this article examines the necessity to regulate insider dealing in China with criminal law to ensure fairness and avoid monopolies in its securities market. The article reviews the criminalising of severe insider dealing cases in China from the Nanking National Government in the 1920s to the inception of the securities market of the PRC in the 1990s to the present day. The investigation, prosecution, enforcement, and trial of criminal offences of insider dealing in China are thoroughly examined.
The article finds a tendency for over reliance on the investigation and the administrative judgement of the China Securities Regulatory Commission (CSRC) in criminal investigation, prosecution, and trial in the PRC.
The article is one of the first articles to critically and thoroughly analyse the criminal enforcement of insider dealing in China following the recent enforcement of China’s new Securities Law in March 2020
Real-time cavity QED with single atoms
We report the first measurement of the real-time evolution of the complex field amplitude brought on by single atom transits. We show the variation in time of both quadrature amplitudes (simultaneously recorded) of the light transmitted through the cavity, as well the resultant optical phase for a single atom transit event. In this particular measurement, the cavity and laser were both detuned by 10 MHz from the Cs resonance
Modulation of the high mobility two-dimensional electrons in Si/SiGe using atomic-layer-deposited gate dielectric
Metal-oxide-semiconductor field-effect transistors (MOSFET's) using
atomic-layer-deposited (ALD) AlO as the gate dielectric are fabricated
on the Si/SiGe heterostructures. The low-temperature carrier
density of a two-dimensional electron system (2DES) in the strained Si quantum
well can be controllably tuned from 2.5cm to
4.5cm, virtually without any gate leakage current.
Magnetotransport data show the homogeneous depletion of 2DES under gate biases.
The characteristic of vertical modulation using ALD dielectric is shown to be
better than that using Schottky barrier or the SiO dielectric formed by
plasma-enhanced chemical-vapor-deposition(PECVD).Comment: 3 pages Revtex4, 4 figure
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