392 research outputs found
Morphological Dependence of Star Formation Properties for the Galaxies in the Merging Galaxy Cluster A2255
The merging cluster of galaxies A2255 is covered by the Sloan Digital Sky
Survey (SDSS) survey. In this paper we perform a morphological classification
on the basis of the SDSS imaging and spectral data, and investigate the
morphological dependence of the star formation rates (SFRs) for these member
galaxies. As we expect, a tight correlation between the normalized SFR by
stellar mass (SFR/M) and the H equivalent width is found for the
late-type galaxies in A2255. The correlation of SFR/M with the continuum
break strength at 4000 \AA is also confirmed. The SFR/M - M correlation
is found for both the early- and late-type galaxies, indicating that the star
formation activity tends to be suppressed when the assembled stellar mass
M) increases, and this correlation is tighter and steeper for the late-type
cluster galaxies. Compared with the mass range of field spiral galaxies, only
two massive late-type galaxies with M M are survived in
A2255, suggesting that the gas disks of massive spiral galaxies could have been
tidally stripped during cluster formation. Additionally, the SFR variation with
the projected radial distance are found to be heavily dependent upon galaxy
morphology: the early-type galaxies have a very weak inner decrease in
SFR/M, while the inner late-type galaxies tend to have higher SFR/M
values than the outer late-types. This may suggest that the galaxy-scale
turbulence stimulated by the merging of subclusters might have played different
roles on early- and late-type galaxies, which leads to a suppression of the
star formation activity for E/S0 galaxies and a SFR enhancement for spiral and
irregular galaxies.Comment: 21 pages, including 7 EPS figures and 1 tables, uses aastex.cls,
Accepted by the A
Analyses of representative elementary volume for coal using X-ray μ-CT and FIB-SEM and its application in permeability predication model
We acknowledge financial support from the National Natural Science Foundation of China (41872123; 41830427), the Petro China Innovation Foundation (2018D-5007-0101), the Key research and development project of Xinjiang Uygur Autonomous Region (2017B03019-1), the Royal Society Edinburgh through the international cost share scheme and National Natural Science Foundation China (NSFC 41711530129).Peer reviewedPostprin
Prediction of Water Consumption in Hospitals Based on a Modified Grey GM (0, 1∣sin) Model of Oscillation Sequence: The Example of Wuhan City
Water shortage is one of the main factors limiting urban construction and development. Scientific forecasting of water consumption is an important approach for the rational allocation of water resources. Taking the hospitals in Wuhan City as an example and basing the analysis on the characteristics of actual water consumption, we proposed a modified grey GM (0, 1∣sin) model of oscillation sequence. Using the grey theory, the variable weight-strengthening buffer operator (VWSBO) was introduced into this model to weaken the interference of the disturbance term on the data sequence. The actual quarterly total water consumption data for hospitals in Wuhan City during the period from 2010 to 2012 were used to verify the effectiveness and practicality of this modified grey GM (0, 1∣sin) model in predicting water consumption. In terms of the model’s fitting performance, the mean absolute percentage error (MAPE) of the modified model was 3.77%, indicating a higher prediction accuracy than the traditional grey GM (0, 1∣sin) model of oscillation sequences. Therefore, the modified grey GM (0, 1∣sin) model we established in this study can provide a scientific reference for administrative departments to forecast water consumption
Imaged based fractal characterization of micro-fracture structure in coal
We acknowledge financial support from the National Natural Science Foundation of China (41830427; 41472137), the Petro China Innovation Foundation (2018D-5007-0101), the Key research and development project of Xinjiang Uygur Autonomous Region (2017B03019-1), the Royal Society Edinburgh and National Natural Science Foundation China (NSFC 41711530129), and the Foreign Experts’ Recruiting Program from the State Administration of Foreign Experts Affairs P.R. China.Peer reviewedPostprin
Investigations of CO2-water wettability of coal : NMR relaxation method
Acknowledgments We acknowledge financial support from the National Natural Science Foundation of China (41472137), the Key Research and Development Projects of The Xinjiang Uygur Autonomous Region (2017B03019-01), and the National Major Research Program for Science and Technology of China (2016ZX05043-001), and the Royal Society Edinburgh and National Natural Science Foundation China (NSFC 41711530129).Peer reviewedPostprin
Family and Individual Risk and Protective Factors of Depression among Chinese Migrant Children with Oppositional Defiant Disorder Symptoms
Migrant children reached 35.81 million in China and were vulnerable to serious emotional problems including depression. The present study aimed to identify the family and individual risk and protective factors for depression in an at-risk sample of Chinese migrant children. Participants were 368 children (9.47 ± 1.46 years old, 73.4% boys) who had at least one symptom of Oppositional Defiant Disorder symptoms (ODD) and their parents in Mainland China. Risk and protective factors within both family (i.e., family maltreatment and family functioning) and individual (i.e., automatic thoughts and resilience) perspectives. Family maltreatment and negative automatic thoughts served as risk factors in relation to children's depression. Further, automatic thoughts mediated the relationship between family maltreatment and children's depression. Family functioning (cohesion, but bot adaptability) and individual resilience could buffer the effects of risk factors in the Structure Emotion Model such that both cohesion and resilience moderated the relationship between family maltreatment and children's automatic thoughts only. Our findings highlighted the urgent need to decrease risk factors and increase protective factors of both family and child individual characteristics in prevention and intervention depression among migrant children with ODD symptoms in China
Evolution of Galaxy Luminosity Function and Luminosity Function by Density Environment at 0.03<z<0.5
Using galaxy sample observed by the BATC large-field multi-color sky survey
and galaxy data of SDSS in the overlapped fields, we study the dependence of
the restframe -band galaxy luminosity function on redshift and on
large-scale environment. The large-scale environment is defined by isodensity
contour with density contrast \delta\rho/\rho. The data set is a composite
sample of 69,671 galaxies with redshifts 0.03 < z < 0.5 and r < 21.5 mag. The
redshifts are composed by three parts: 1) spectroscopic redshifts in SDSS for
local and most luminous galaxies; 2) 20-color photometric redshifts derived
from BATC and SDSS; 3) 5-color photometric redshifts in SDSS. We find that the
faint-end slope \alpha steepens slightly from -1.21 at z ~ 0.06 to -1.35 at z ~
0.4, which is the natural consequence of the hierarchical formation of
galaxies. The luminosity function also differs with different environments. The
value of \alpha changes from -1.21 at underdense regions to -1.37 at overdense
regions and the corresponding M* brightens from -22.26 to -22.64. This suggests
that the fraction of faint galaxies is larger in high density regions than in
low density regions.Comment: 7 pages, 9 figures, accepted by Ap
A Matrix Ensemble Kalman Filter-based Multi-arm Neural Network to Adequately Approximate Deep Neural Networks
Deep Learners (DLs) are the state-of-art predictive mechanism with
applications in many fields requiring complex high dimensional data processing.
Although conventional DLs get trained via gradient descent with
back-propagation, Kalman Filter (KF)-based techniques that do not need gradient
computation have been developed to approximate DLs. We propose a multi-arm
extension of a KF-based DL approximator that can mimic DL when the sample size
is too small to train a multi-arm DL. The proposed Matrix Ensemble Kalman
Filter-based multi-arm ANN (MEnKF-ANN) also performs explicit model stacking
that becomes relevant when the training sample has an unequal-size feature set.
Our proposed technique can approximate Long Short-term Memory (LSTM) Networks
and attach uncertainty to the predictions obtained from these LSTMs with
desirable coverage. We demonstrate how MEnKF-ANN can "adequately" approximate
an LSTM network trained to classify what carbohydrate substrates are digested
and utilized by a microbiome sample whose genomic sequences consist of
polysaccharide utilization loci (PULs) and their encoded genes.Comment: 18 pages, 6 Figures, and 6 Table
Size Distribution and Fractal Characteristics of Coal Pores through Nuclear Magnetic Resonance Cryoporometry
This research was funded by the National Natural Science Foundation of China (Grant no. 41602170), the Research Program for Excellent Doctoral Dissertation Supervisor of Beijing (grant no. YB20101141501), the Key Project of Coal-based Science and Technology in Shanxi Province-CBM accumulation model and reservoir evaluation in Shanxi province (grant no. MQ2014-01) and the Fundamental Research Funds for Central Universities (grant no. 35832015136).Peer reviewedPostprin
The Progenitor of Supernova 2004dj in a Star Cluster
The progenitor of type II-plateau supernova (SN) 2004dj is identified with a
supergiant in a compact star cluster known as "Sandage Star 96" (S96) in the
nearby spiral galaxy NGC 2403, which was fortuitously imaged as part of the
Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolor Sky Survey from Feb 1995
to Dec 2003 prior to SN 2004dj. The superior photometry of BATC images for S96,
taken with 14 intermediate-band filters covering 3000-10000\AA, unambiguously
establishes the star cluster nature of S96 with an age of Myr, a
reddening of mag and a total mass of M. The compact star cluster nature of S96 is also consistent
with the lack of light variations in the past decade. The SN progenitor is
estimated to have a main-sequence mass of 12M. The comparison
of our intermediate-band data of S96 with the post-outburst photometry obtained
as the SN has significantly dimmed, may hopefully conclusively establish the
nature of the progenitor.Comment: 4 pages; 3 figures. To accept for Publications in ApJ Letters, but
slightly longer in this perprin
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