2,163 research outputs found
Event patterns extracted from anisotropic spectra of charged particles produced in Pb-Pb collisions at 2.76 TeV
Event patterns extracted from anisotropic spectra of charged particles
produced in lead-lead collisions at 2.76 TeV are investigated. We use an
inverse power-law resulted from the QCD calculus to describe the transverse
momentum spectrum in the hard scattering process, and a revised Erlang
distribution resulted from a multisource thermal model to describe the
transverse momentum spectrum and anisotropic flow in the soft excitation
process. The pseudorapidity distribution is described by a three-Gaussian
function which is a revision of the Landau hydrodynamic model. Thus, the event
patterns at the kinetic freeze-out are displayed by the scatter plots of the
considered particles in the three-dimensional velocity, momentum, and rapidity
spaces.Comment: 19 pages, 8 figures, The European Physical Journal A, accepte
Relationship between Human Body Anthropometric Measurements and Basal Metabolic Rate
Through the use of 3D body measurement technology and cardiopulmonary function test equipment, obtaining the body size data and basal metabolic rate of 116 young healthy subjects, this study aims to find the relationship between the size of human body and basal metabolic rate. Factor analysis, univariate analysis, and linear regression analysis were performed on 13 observed items (selected from 152 human data) by SPSS data analysis software. The 13 observed items include the largest abdominal circumference, waist circumference, chest circumference (horizontal), thigh circumference, hip circumference, weight, total shoulder width, neck circumference, height, waist height, high cervical point, hip height, and chest height. The results indicate that girth and height factors are correlated with the predicted basal metabolic rate as well as the measured basal metabolic rate. The predicted basal metabolic rate is significantly correlated with weight, height, hip circumference, and neck circumference. The measured basal metabolic rate is significantly correlated with the neck circumference as well as height
Full-spectrum noise prediction of the high-speed train head under multi-physics coupling excitations based on statistical energy analysis
The force between wheels and rails of the high-speed train was firstly extracted and applied into the computational model of radiation noises of wheels and rail respectively. As a result, the radiation noise of wheels and rails was obtained. As can be seen from the result, radiation noises of wheels had an obvious directivity on the body surface, while radiation noises of rails had an obvious periodicity on the body surface. With the increase of the analyzed frequency, both directivity and periodicity were shown more obviously. Then the aerodynamic model of the high-speed train was established, and the pressure and velocity distributions on the train surface were computed. The maximum pressure was at the tip of the nose of the high-speed train, the maximum velocity was at the transition of the cabin, and more serious eddy was in the rear of the high speed train. Based on the computed pressure distribution, the aerodynamic noise was distributed evenly on the entire body surface, which was gradually increased with the increasing analyzed frequency. Finally, the wheel radiation noise, rail radiation noise and aerodynamic noise were extracted as excitations and applied into the SEA (Statistical Energy Analysis) model of the high-speed train, in order to compute its full-spectrum noise under multi-physics coupling excitations. The computational result was compared with the experimental result. It was presented that the difference of average sound pressure level (SPL) was 2.8Â dB between the experimental and numerical simulations within the entire analytical frequency band. The SEA model with considering the multi-physics coupling was effective
Event patterns from negative pion spectra in proton-proton and nucleus-nucleus collisions at SPS
Rapidity-dependent transverse momentum spectra of negatively charged pions
measured at different rapidities in proton-proton collisions at the Super
Proton Synchrotron (SPS) at various energies within its Beam Energy Scan (BES)
program are investigated by using one- and two-component standard distributions
where the chemical potential and spin property of particles are implemented.
The rapidity spectra are described by a double-Gaussian distribution. At the
stage of kinetic freeze-out, the event patterns are structured by the scatter
plots in the three-dimensional subspaces of velocity, momentum and rapidity.
The results of the studies of the rapidity-independent transverse mass spectra
measured at mid-rapidity in proton-proton collisions are compared with those
based on the similar transverse mass spectra measured in the most central
beryllium-beryllium, argon-scandium and lead-lead collisions from the SPS at
its BES energies.Comment: 17 pages, 9 figure
The Role of Digital-Media-Based Pedagogical Aids in Elementary Entomology: An Innovative and Sustainable Approach
It has been challenging for city school pupils to learn about insects, given the lack of live insects. To overcome this challenge, the objective of this study is to propose the use of emerging digital media, namely three-dimensional printing (3DP) technologies, to create reusable, fake, “live” insects. In this study, we designed two 3D-printed pedagogical aids to support elementary entomology. The first aid was a set of cards showing photos of the 3D-printed insect prototype, which could help the learners in close observation of the insect body’s regions and parts, and the second 3D-printed aid was a construction kit mimicking physical insects, which were made of an enlarged 3D-printed insect prototype. The two aids were used in our field experiment to examine the effectiveness in learning and motivation. A total of 153 pupils were grouped into three groups (one using the existing multimedia e-book, one using the first 3DP aid, and one using the second aid). The results confirm that the digital media application—in this case, 3DP technologies—were able to compensate for the lack of the live insects. These results raised our confidence in using a customized size 3D-printed insect prototype to enhance rudimentary entomology inside the classroom. If the 3DP technologies are used properly, they could offer an innovative and sustainable solution
Network nonlocality sharing via weak measurements in the generalized star network configuration
Network nonlocality exhibits completely novel quantum correlations compared
to standard quantum nonlocality. It has been shown that network nonlocality can
be shared in a generalized bilocal scenario via weak measurements [Phys. Rev.
A. 105, 042436 (2022)]. In this paper, we investigate network nonlocality
sharing via weak measurements in a generalized star-shaped network
configuration with arbitrary numbers of unbiased dichotomic input , which
includes branches and adds (-1) more parties in each branch to the
original star network scenario. It is shown that network
nonlocality sharing among all observers can be revealed from simultaneous
violation of inequalities in the () and ()
scenarios for any branches. The noise resistance of network nonlocality
sharing with a precise noise model is also analyzed.Comment: 8 pages, 3 figures. update new result
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