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China's energy consumption in the building sector: A Statistical Yearbook-Energy Balance Sheet based splitting method
China's energy consumption in the building sector (BEC) is not counted as a separate type of energy consumption, but divided and mixed in other sectors in China's statistical system. This led to the lack of historical data on China's BEC. Moreover, previous researches' shortages such as unsystematic research on BEC, various estimation methods with complex calculation process, and difficulties in data acquisition resulted in âheterogeneousâ of current BEC in China. Aiming to these deficiencies, this study proposes a set of China building energy consumption calculation method (CBECM) by splitting out the building related energy consumption mixed in other sectors in the composition of China Statistical Yearbook-Energy Balance Sheet. Then, China's BEC from 2000 to 2014 are estimated using CBECM and compared with other studies. Results show that, from 2000 to 2014, China's BEC increased 1.7 times, rising from 301 to 814 million tons of standard coal consumed, with the BEC percentage of total energy consumption stayed relatively stable between 17.7% and 20.3%. By comparison, we find that our results are reliable and the CBECM has the following advantages over other methods: data source is authoritative, calculation process is concise, and it is easy to obtain time series data on BEC etc. The CBECM is particularly suitable for the provincial government to calculate the local BEC, even in the circumstance with statistical yearbook available only
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Boiling two-phase pressure drop in small diameter tubes
An experimental study of two-phase pressure drop in small diameter tubes is described in this paper. Stainless steel tubes of internal diameter and length of 4.26 mm, 500 mm and 2.01 mm, 211 mm were used. The working fluid was R134a and the range covered was: mass flux 100 â 500 kg/m2s; system pressure 8-14 bar and exit quality up to 0.9. The heat flux applied to the tubes ranged from 13 â 150 kW/m2. The effect of diameter on pressure drop is discussed in this paper and a detailed presentation of the results of the comparison with existing pressure drop correlations, some particularly developed for small tubes, is given
Characterizing Some Gaia Alerts with LAMOST and SDSS
Gaia is regularly producing Alerts on objects where photometric variability
has been detected. The physical nature of these objects has often to be
determined with the complementary observations from ground-based facilities. We
have compared the list of Gaia Alerts (until 20181101) with archival LAMOST and
SDSS spectroscopic data. The date of the ground-based observation rarely
corresponds to the date of the Alert, but this allows at least the
identification of the source if it is persistent, or the host galaxy if the
object was only transient like a supernova. A list of Gaia Nuclear Transients
from Kostrzewa-Rutkowska et al. (2018) has been included in this search also.
We found 26 Gaia Alerts with spectra in LAMOST+SDSS labelled as stars (12 with
multi-epoch spectra). A majority of them are CVs. Similarly 206 Gaia Alerts
have associated spectra labelled as galaxies (49 with multi-epoch spectra).
Those spectra were generally obtained on a date different from the Alert date,
are mostly emission-line galaxies, leading to the suspicion that most of the
Alerts were due to a SN. As for the GNT list, we found 55 associated spectra
labelled as galaxies (13 with multi-epoch spectra). In two galaxies, Gaia17aal
and GNTJ170213+2543, was the date of the spectroscopic observation close enough
to the Alert date: we find a trace of the SN itself in their LAMOST spectrum,
both classified here as a type Ia SN. The GNT sample has a higher proportion of
AGNs, suggesting that some of the detected variations are also due to the AGN
itself. Similar for Quasars, we found 30 Gaia Alerts but 68 GNT cases have
single epoch quasar spectra, while 12 plus 23 have multi-epoch spectra. For ten
out of these 35, their multi-epoch spectra show appearance or disappearance of
the broad Balmer lines and also variations in the continuum, qualifying them as
"Changing Look Quasars".Comment: Accepted for publication in APSS, 14 pages, 8 figures, 2 table
Atomic Entanglement vs Photonic Visibility for Quantum Criticality of Hybrid System
To characterize the novel quantum phase transition for a hybrid system
consisting of an array of coupled cavities and two-level atoms doped in each
cavity, we study the atomic entanglement and photonic visibility in comparison
with the quantum fluctuation of total excitations. Analytical and numerical
simulation results show the happen of quantum critical phenomenon similar to
the Mott insulator to superfluid transition. Here, the contour lines
respectively representing the atomic entanglement, photonic visibility and
excitation variance in the phase diagram are consistent in the vicinity of the
non-analytic locus of atomic concurrences.Comment: 4 pages, 2 figure
High temperature plastic deformation constitutive model of Mg-Zn-Zr-Y alloy
In order to accurately predict the flow stress of Mg-Zn-Zr-Y alloy at high temperature, the hot compression test of Mg-Zn-Zr-Y alloy was carried out on Gleeble-1500 thermal / mechanical simulator. The deformation temperature was 523 K, 573 K, 623 K, and the strain rate was 0,01 ~ 1 s-1. By obtaining the true stress-strain curve, the strain compensation factor Z parameter was introduced into the Arrhenius equation to establish a more accurate strain coupling constitutive model. The results show that the theoretical value of the peak stress calculated by the constitutive model is in good agreement with the experimental results, and the average relative error is 5,67 %, which verifies the feasibility of the model
High temperature plastic deformation constitutive model of Mg-Zn-Zr-Y alloy
In order to accurately predict the flow stress of Mg-Zn-Zr-Y alloy at high temperature, the hot compression test of Mg-Zn-Zr-Y alloy was carried out on Gleeble-1500 thermal / mechanical simulator. The deformation temperature was 523 K, 573 K, 623 K, and the strain rate was 0,01 ~ 1 s-1. By obtaining the true stress-strain curve, the strain compensation factor Z parameter was introduced into the Arrhenius equation to establish a more accurate strain coupling constitutive model. The results show that the theoretical value of the peak stress calculated by the constitutive model is in good agreement with the experimental results, and the average relative error is 5,67 %, which verifies the feasibility of the model
HST and LAMOST discover a dual active galactic nucleus in J0038+4128
We report the discovery of a kiloparsec-scale dual active galactic nucleus
(AGN) in J0038+4128. From the Hubble Space Telescope (HST) Wide Field Planetary
Camera (WFPC2) images, we find two optical nuclei with a projection separation
of 4.7 kpc (3.44 arcsec). The southern component (J0038+4128S) is
spectroscopically observed with the HST Goddard High Resolution Spectrograph in
the UV range and is found to be a Seyfert 1 galaxy with a broad Ly alpha
emission line. The northern component (J0038+4128N) is spectroscopically
observed during the Large Sky Area Multi-Object Fibre Spectroscopic Telescope
(also named the Guoshoujing Telescope) pilot survey in the optical range. The
observed line ratios as well as the consistency of redshift of the nucleus
emission lines and the host galaxy's absorption lines indicate that J0038+4128N
is a Seyfert 2 galaxy with narrow lines only. These results thus confirm that
J0038+4128 is a Seyfert 1-Seyfert 2 AGN pair. The HST WFPC2 F336W/U-band image
of J0038+4128 also reveals for the first time for a dual AGN system two pairs
of bi-symmetric arms, as are expected from the numerical simulations of such
system. Being one of a few confirmed kiloparsec-scale dual AGNs exhibiting a
clear morphological structure of the host galaxies, J0038+4128 provides an
unique opportunity to study the co-evolution of the host galaxies and their
central supermassive black holes undergoing a merging process.Comment: 6 pages, 4 figures, 2 tables, Accepted for publication in MNRAS
Letter
Design of a five-axis ultra-precision micro-milling machineâUltraMill. Part 2: Integrated dynamic modelling, design optimisation and analysis
Using computer models to predict the dynamic performance of ultra-precision machine tools can help manufacturers to substantially reduce the lead time and cost of developing new machines. However, the use of electronic drives on such machines is becoming widespread, the machine dynamic performance depending not only on the mechanical structure and components but also on the control system and electronic drives. Bench-top ultra-precision machine tools are highly desirable for the micro-manufacturing of high-accuracy micro-mechanical components. However, the development is still at the nascent stage and hence lacks standardised guidelines. Part 2 of this two-part paper proposes an integrated approach, which permits analysis and optimisation of the entire machine dynamic performance at the early design stage. Based on the proposed approach, the modelling and simulation process of a novel five-axis bench-top ultra-precision micro-milling machine toolâUltraMillâis presented. The modelling and simulation cover the dynamics of the machine structure, the moving components, the control system and the machining process and are used to predict the entire machine performance of two typical configurations
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