118 research outputs found
Anomaly analysis of Hawking radiation from Kaluza-Klein black hole with squashed horizon
Considering gravitational and gauge anomalies at the horizon, a new method
that to derive Hawking radiations from black holes has been developed by
Wilczek et al. In this paper, we apply this method to non-rotating and rotating
Kaluza-Klein black holes with squashed horizon, respectively. For the rotating
case, we found that, after the dimensional reduction, an effective U(1) gauge
field is generated by an angular isometry. The results show that the gauge
current and energy-momentum tensor fluxes are exactly equivalent to Hawking
radiation from the event horizon.Comment: 15 pages, no figures, the improved version, accepted by Eur. Phys. J.
Structural Strength and Service Life of the Extrusion Forming Die for Agricultural Engine Piston Heads
Three-tier high-strength prestressed combination concave dies are designed to manifacture highpower corn combine harvester engine piston heads. This design integrates the advantages of traditional casting or hot die forging and warm extrusion. The following key parameters, viz radial dimensions of each mating layer, axial bonding and radial contact interaction, are obtained by theoretical calculation. Nonlinear analysis of the contact interaction was carried out, and the die contact condition was studied at no-load and full-load. Based on the Archard wear theory, thermomechanical bonding was studied in operation of the die. Through numerical simulation of the die wear in each operation cycle, the univariate linear regression equation of the die service life was derived, and the reliability of this equation was verified. The results show that the die contact is both stable and reliable if the radial contact interaction of the inner and outer layers is ÎŽâ= 1.9716 mm and ÎŽâ= 1.3870 mm, respectively. With the nitriding layer thickness of 0.24 mm, the extrusion die service life in the production of piston heads corresponds to 6357 pieces.Đ Đ°Đ·ŃĐ°Đ±ĐŸŃĐ°ĐœŃ ŃŃĐ”Ń
ŃŃŃŃŃĐœŃĐ” ĐČŃŃĐŸĐșĐŸĐżŃĐŸŃĐœŃĐ” ĐżŃДЎĐČĐ°ŃĐžŃДлŃĐœĐŸ-ĐœĐ°ĐżŃŃĐ¶Đ”ĐœĐœŃĐ” ĐŒĐœĐŸĐłĐŸĐŒĐ”ŃŃĐœŃĐ” ĐČĐŸĐłĐœŃŃŃĐ” ĐłĐŸĐ»ĐŸĐČĐșĐž ĐŽĐ»Ń ĐžĐ·ĐłĐŸŃĐŸĐČĐ»Đ”ĐœĐžŃ ĐŽĐœĐžŃ ĐżĐŸŃŃĐœŃ ĐŽĐČОгаŃĐ”Đ»Ń ĐŒĐŸŃĐœĐŸĐłĐŸ ĐșŃĐșŃŃŃĐ·ĐŸŃĐ±ĐŸŃĐŸŃĐœĐŸĐłĐŸ ĐșĐŸĐŒĐ±Đ°ĐčĐœĐ°. ĐĐŸĐœŃŃŃŃĐșŃĐžŃ ŃĐŸĐ”ĐŽĐžĐœŃĐ”Ń ĐČ ŃДбД ĐżŃĐ”ĐžĐŒŃŃĐ”ŃŃĐČĐ° лОŃŃŃ ĐžĐ»Đž ĐłĐŸŃŃŃĐ”Đč ĐșĐŸĐČĐșĐž Đž ĐłĐŸŃŃŃĐ”Đč ŃĐșŃŃŃŃзОО. РаЎОалŃĐœŃĐ” ŃĐ°Đ·ĐŒĐ”ŃŃ ĐșĐ°Đ¶ĐŽĐŸĐłĐŸ ŃĐŸĐ”ĐŽĐžĐœŃĐ”ĐŒĐŸĐłĐŸ ŃĐ»ĐŸŃ, ĐŸŃĐ”ĐČĐŸĐ” ŃŃĐ”ĐżĐ»Đ”ĐœĐžĐ” Đž ŃаЎОалŃĐœĐŸĐ” ĐșĐŸĐœŃĐ°ĐșŃĐœĐŸĐ” ĐČĐ·Đ°ĐžĐŒĐŸĐŽĐ”ĐčŃŃĐČОД ŃĐ°ŃŃŃĐžŃĐ°ĐœŃ ŃĐ”ĐŸŃĐ”ŃĐžŃĐ”ŃĐșĐž. ĐŃĐżĐŸĐ»ĐœĐ”Đœ ĐœĐ”Đ»ĐžĐœĐ”ĐčĐœŃĐč Đ°ĐœĐ°Đ»ĐžĐ· ĐșĐŸĐœŃĐ°ĐșŃĐœĐŸĐłĐŸ ĐČĐ·Đ°ĐžĐŒĐŸĐŽĐ”ĐčŃŃĐČĐžŃ, ОзŃŃĐ”ĐœŃ ŃŃĐ»ĐŸĐČĐžŃ ĐșĐŸĐœŃĐ°ĐșŃĐžŃĐŸĐČĐ°ĐœĐžŃ ĐČ ĐłĐŸĐ»ĐŸĐČĐșĐ” ĐżŃĐž ĐœŃлДĐČĐŸĐč Đž ĐżĐŸĐ»ĐœĐŸĐč ĐœĐ°ĐłŃŃĐ·ĐșĐ”. ĐĐ° ĐŸŃĐœĐŸĐČĐ°ĐœĐžĐž ŃĐ”ĐŸŃОО ĐžĐ·ĐœĐŸŃĐ° ĐŃŃĐ°ŃĐŽĐ° ĐČŃĐżĐŸĐ»ĐœĐ”ĐœĐ° ĐŸŃĐ”ĐœĐșĐ° ŃĐ”ŃĐŒĐŸĐŒĐ”Ń
Đ°ĐœĐžŃĐ”ŃĐșĐŸĐłĐŸ ŃŃĐ”ĐżĐ»Đ”ĐœĐžŃ ĐČ ĐżŃĐŸŃĐ”ŃŃĐ” ŃĐșŃплŃĐ°ŃĐ°ŃОО ĐłĐŸĐ»ĐŸĐČĐșĐž. ĐŃŃĐ”ĐŒ ŃĐžŃĐ»Đ”ĐœĐœĐŸĐłĐŸ ĐŒĐŸĐŽĐ”Đ»ĐžŃĐŸĐČĐ°ĐœĐžŃ ĐžĐ·ĐœĐŸŃĐ° ĐłĐŸĐ»ĐŸĐČĐșĐž ĐČ ĐșĐ°Đ¶ĐŽĐŸĐŒ ŃĐ°Đ±ĐŸŃĐ”ĐŒ ŃĐžĐșлД ĐżĐŸĐ»ŃŃĐ”ĐœĐŸ ĐŸĐŽĐœĐŸĐżĐ°ŃĐ°ĐŒĐ”ŃŃĐžŃĐ”ŃĐșĐŸĐ” ŃŃĐ°ĐČĐœĐ”ĐœĐžĐ” Đ»ĐžĐœĐ”ĐčĐœĐŸĐč ŃДгŃĐ”ŃŃОО ĐŽĐ»Ń ŃŃĐŸĐșĐ° ДД ŃĐ»ŃжбŃ; ĐżŃĐŸĐČĐ”ŃĐ”ĐœĐ° ĐŽĐŸŃŃĐŸĐČĐ”ŃĐœĐŸŃŃŃ ĐŽĐ°ĐœĐœĐŸĐłĐŸ ŃŃĐ°ĐČĐœĐ”ĐœĐžŃ. ĐĐŸĐșĐ°Đ·Đ°ĐœĐŸ, ŃŃĐŸ ĐșĐŸĐœŃĐ°ĐșŃ ĐČ ĐłĐŸĐ»ĐŸĐČĐșĐ” ŃŃŃĐŸĐčŃĐžĐČ Đž ĐœĐ°ĐŽĐ”Đ¶Đ”Đœ, ĐżŃĐž ŃаЎОалŃĐœĐŸĐŒ ĐșĐŸĐœŃĐ°ĐșŃĐœĐŸĐŒ ĐČĐ·Đ°ĐžĐŒĐŸĐŽĐ”ĐčŃŃĐČОО ĐČĐœŃŃŃĐ”ĐœĐœĐ”ĐłĐŸ Đž ĐœĐ°ŃŃĐ¶ĐœĐŸĐłĐŸ ŃĐ»ĐŸĐ”ĐČ ÎŽâ= 1.9716 ĐŒĐŒ Đž ÎŽâ= 1.3870 ĐŒĐŒ ŃĐŸĐŸŃĐČĐ”ŃŃŃĐČĐ”ĐœĐœĐŸ. ĐŃĐž ŃĐŸĐ»ŃĐžĐœĐ” ĐœĐžŃŃĐžĐŽĐœĐŸĐłĐŸ ŃĐ»ĐŸŃ 0,24 ĐŒĐŒ ŃŃĐŸĐș ŃĐ»ŃĐ¶Đ±Ń ŃĐșŃŃŃŃĐ·ĐžĐŸĐœĐœĐŸĐč ĐłĐŸĐ»ĐŸĐČĐșĐž ĐČ ĐżŃĐŸĐžĐ·ĐČĐŸĐŽŃŃĐČĐ” ĐŽĐœĐžŃ ĐżĐŸŃŃĐœŃ ŃĐŸĐŸŃĐČĐ”ŃŃŃĐČŃĐ”Ń 6357 ОзЎДлОŃĐŒ
Corrections to Hawking-like Radiation for a Friedmann-Robertson-Walker Universe
Recently, a Hamilton-Jacobi method beyond semiclassical approximation in
black hole physics was developed by \emph{Banerjee} and
\emph{Majhi}\cite{beyond0}. In this paper, we generalize their analysis of
black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is
shown that all the higher order quantum corrections in the single particle
action are proportional to the usual semiclassical contribution. The
corrections to the Hawking-like temperature and entropy of apparent horizon for
FRW universe are also obtained. In the corrected entropy, the area law involves
logarithmic area correction together with the standard inverse power of area
term.Comment: 10 pages, no figures, comments are welcome; v2: references added and
some typoes corrected, to appear in Euro.Phys.J.C; v3:a defect corrected. We
thank Dr.Elias Vagenas for pointing out a defect of our pape
The ARGO-YBJ Experiment Progresses and Future Extension
Gamma ray source detection above 30TeV is an encouraging approach for finding
galactic cosmic ray origins. All sky survey for gamma ray sources using wide
field of view detector is essential for population accumulation for various
types of sources above 100GeV. To target the goals, the ARGO-YBJ experiment has
been established. Significant progresses have been made in the experiment. A
large air shower detector array in an area of 1km2 is proposed to boost the
sensitivity. Hybrid detection with multi-techniques will allow a good
discrimination between different types of primary particles, including photons
and protons, thus enable an energy spectrum measurement for individual specie.
Fluorescence light detector array will extend the spectrum measurement above
100PeV where the second knee is located. An energy scale determined by balloon
experiments at 10TeV will be propagated to ultra high energy cosmic ray
experiments
High Altitude test of RPCs for the ARGO-YBJ experiment
A 50 m**2 RPC carpet was operated at the YangBaJing Cosmic Ray Laboratory
(Tibet) located 4300 m a.s.l. The performance of RPCs in detecting Extensive
Air Showers was studied. Efficiency and time resolution measurements at the
pressure and temperature conditions typical of high mountain laboratories, are
reported.Comment: 16 pages, 10 figures, submitted to Nucl. Instr. Met
Quantifying atmospheric nitrogen deposition through a nationwide monitoring network across China
A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3â in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3â47.0 ÎŒg N mâ3) and dry plus wet/bulk deposition fluxes (2.9â83.3 kg N haâ1 yrâ1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N haâ1 yrâ1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health
Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV
The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3
magnetic muon spectrometer for zenith angles ranging from 0 degree to 58
degree. Due to the large exposure of about 150 m2 sr d, and the excellent
momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in
the vertical direction is achieved.
The ratio of positive to negative muons is studied between 20 GeV and 500
GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003
(stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure
Metabolite analysis for the comparison of irrigated and non-irrigated field grown tomato of varying genotype
ARGO-YBJ constraints on very high energy emission from GRBs
The ARGO-YBJ (Astrophysical Radiation Ground-based Observatory at YangBaJing)
experiment is designed for very high energy -astronomy and cosmic ray
researches. Due to the full coverage of a large area () with
resistive plate chambers at a very high altitude (4300 m a.s.l.), the ARGO-YBJ
detector is used to search for transient phenomena, such as Gamma-ray bursts
(GRBs). Because the ARGO-YBJ detector has a large field of view (2 sr)
and is operated with a high duty cycle (90%), it is well suited for GRB
surveying and can be operated in searches for high energy GRBs following alarms
set by satellite-borne observations at lower energies. In this paper, the
sensitivity of the ARGO-YBJ detector for GRB detection is estimated. Upper
limits to fluence with 99% confidence level for 26 GRBs inside the field of
view from June 2006 to January 2009 are set in the two energy ranges 10100
GeV and 10 GeV1 TeV.Comment: accepted for publication in Astroparticle Physic
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