1,682 research outputs found
Analysis of Quality Influencing Factors and Coping Strategies in Site Construction Stage of Prefabricated Building
Limited to the current industry, the personnel, knowledge, and technology reserves of prefabricated buildings are not sufficient, which directly affects the engineering quality of prefabricated buildings. In particular, the quality control of the prefabricated building site construction stage is the most critical. In view of the on-site construction stage of prefabricated buildings, this paper sorts out the influencing factors of project quality from three aspects of personnel, technology and management, and from the three aspects of personnel quality, construction technology and whole process management, the coping strategies of engineering quality problems are put forward. It can effectively improve the detailed management and control of quality problems in the construction stage of the prefabricated building, and help the rapid development of the prefabricated building industry
Data Processing Pipeline for Pointing Observations of Lunar-based Ultraviolet Telescope
We describe the data processing pipeline developed to reduce the pointing
observation data of Lunar-based Ultraviolet Telescope (LUT), which belongs to
the Chang'e-3 mission of the Chinese Lunar Exploration Program. The pointing
observation program of LUT is dedicated to monitor variable objects in a
near-ultraviolet (245-345 nm) band. LUT works in lunar daytime for sufficient
power supply, so some special data processing strategies have been developed
for the pipeline. The procedures of the pipeline include stray light removing,
astrometry, flat fielding employing superflat technique, source extraction and
cosmic rays rejection, aperture and PSF photometry, aperture correction, and
catalogues archiving, etc. It has been intensively tested and works smoothly
with observation data. The photometric accuracy is typically ~0.02 mag for LUT
10 mag stars (30 s exposure), with errors come from background noises,
residuals of stray light removing, and flat fielding related errors. The
accuracy degrades to be ~0.2 mag for stars of 13.5 mag which is the 5{\sigma}
detection limit of LUT.Comment: 10 pages, 7 figures, 4 tables. Minor changes and some expounding
words added. Version accepted for publication in Astrophysics and Space
Science (Ap&SS
Charmless two-body meson decays in perturbative QCD factorization approach
The perturbative QCD (PQCD) approach based on factorization has made a
great achievement for the QCD calculation of the hadronic B decays. Regulating
the endpoint divergence by the transverse momentum of quarks in the
propagators, one can do the perturbation calculation for kinds of diagrams
including the annihilation type diagrams. In this paper, we review the current
status of PQCD factorization calculation of two-body charmless decays up to the next-to-leading order (NLO) QCD corrections. two new power
suppressed terms in decaying amplitudes are also taken into account. By using
the universal input (non-perturbative) parameters, we collected the branching
ratios and asymmetry parameters for all the charmless two body
decays, calculated in the PQCD approach up to the NLO, including some power
suppressed terms in decaying amplitudes. The results are compared with the ones
from QCD factorization approach, soft-collinear effective theory approach and
the current experimental measurements. For most considered B meson decays, the
PQCD results for branching ratios agree well with other approaches and the
experimental data. The PQCD predictions for the asymmetry parameters
for many of the decay channels do not agree with other approaches, but have a
better agreement with the experimental data. The longstanding puzzle
about the pattern of the direct CP asymmetries of the penguin-dominated decays can be understood after the inclusion of the NLO contributions
in PQCD. The NLO corrections and power suppressed terms play an important role
in the color suppressed and pure annihilation type decay modes. These rare
decays are more sensitive to different types of corrections, providing
opportunity to examine the factorization approach with the more precise
experimental measurements.Comment: 51 pages, 4 figures, 11 tables, references added, typos remove
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