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1. chinaXiv:201903.00228 [pdf]

Correlation Analysis for γ-ray and Broad Line Emissions of Fermi Blazars

L. X. Zhang; J. H. Fan; Y.H. Yuan
Subjects: Astronomy >> Astrophysical processes

In a standard model of active galactic nuclei (AGNs), there is a supermassively central black hole surrounded by an accretion disk with the jet coming out perpendic-ularly to the disk plane. Theoretical works suggest that there is a connection between the jet and the accretion disk. To investigate such a connection, people use the cor-relation between the radio emission ( or γ-ray emission) and the broad line emission.However, it is well known that the radio (or γ-ray ) emission is strongly beamed in blazars. In this sense, we should consider the beaming effect when we discuss the jet–accretion disk connection. In this work, we compiled a sample of 202 Fermi/LAT blazars with available broad line emissions. Out of the 202 sources, 66 have known Doppler factors. The corre-lation between γ-ray and broad-line emission, and that between radio and broad-line emission are investigated by removing the effects of redshift and beaming boosting for the whole sample and the subclasses, flat spectrum radio quasars (FSRQs) and BL Lacertae objects (BL Lacs) respectively. We obtained a strong positive correlation between γ-ray and broad-line emission and between radio and broad-line emis-sion for the 202 blazars; It’s worth noting that the correlation still exists after removing redshift effect. For the 66 sources with Doppler factors, there is also a strong positive correlation between γ-rays and broad-line emission after remov-ing the Doppler factors, as well as that between radio and broadlineemission.Ouranalysissuggestthat1. Therearestrongcorrelationsbetween theγ-rayandthe broad line emission for the whole blazar sample and their subclasses. The correlations exist when the redshift effect is removed for the whole sample and their subclasses,confirming the results by Ghisellini et al. (2014) and Chen (2018). 2. For the 66 blazars with available Doppler factors,a strong correlation between the broad line emission and the Doppler factor is found. The correlation between the γ-ray and the broad line emission exists after the Doppler factor effect is removed. Similar results also obtained between radio and broad-line emission. 3. Our analysis suggests a robust connection between the accretion process and the jet.

submitted time 2019-03-25 From cooperative journals:《天文研究与技术》 Hits10972Downloads787 Comment 0

2. chinaXiv:201705.00616 [pdf]

Investigation of the biofouling properties of several algae on different textured chemical modified silicone surfaces

Xu, JH [Xu, Jihai][ 1,2 ]; Zhao, WJ [Zhao, Wenjie][ 1 ]; Peng, SS [Peng, Shusen][ 1 ]; Zeng, ZX [Zeng, Zhixiang][ 1 ]; Zhang, X [Zhang, Xin][ 1 ]; Wu, XD [Wu, Xuedong][ 1 ]; Xue, QJ [Xue, Qunji][ 1 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Engineered pillars, pits and grooves spaced 3, 6, 9 and 12 m apart were fabricated on siloxane modified acrylic resin films. The effect of feature size, geometry, and wettability on the settlement of different algae was evaluated. These films showed various antifouling performances to Ulothrix, Closterium and Navic- ula. For Navicula (length: 10–12 m), the feature size and geometry displayed a substantial correlation with the antifouling properties. The film with pillars spaced 3 m reduced Navicula settlement by 73% compared to the control surface. For Closterium (length: 45–55 m), their responses were governed by the same underlying thermodynamic principles as wettability, the largest reduction in Closterium, 81%, was obtained on the surface with grooves spaced 12 m apart. For Ulothrix (length: 5–8 mm), the surface also showed the best antifouling performance, the reduction ratio of the settlement on the surface with grooves spaced 12 m apart could even reach 92%. At last, physical fouling deterrent mechanisms for the films with various textures were analyzed in detail. The feature size and geometry display a substantial correlation with the antifouling properties when the size of fouling algae is close to the textures. With the increasing size for algae, antifouling performance was getting better on surface with pillars or grooves because the algae are bridged between two or more features other than stabilizing its entire mass on one single feature or able to settle between features.

submitted time 2017-05-02 Hits15726Downloads1126 Comment 0

3. chinaXiv:201705.00438 [pdf]

A single-phase Ba9Lu2Si6O24:Eu2+, Ce3+, Mn2+ phosphor with tunable full-color emission for NUV-based white LED applications

Zhang, CH [Zhang, Changhua][ 1,2 ]; Liu, YF [Liu, Yongfu][ 2 ]; Zhang, JH [Zhang, Jiahua][ 3 ]; Zhang, X [Zhang, Xia][ 3 ]; Zhang, JX [Zhang, Jianxin][ 2,4 ]; Cheng, ZX [Cheng, Zhixuan][ 1 ]; Jiang, J [Jiang, Jun][ 2 ]; Jiang, HC [Jiang, Haochuan][ 2 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

We obtained a single phase BLS:Eu2+, Ce3+, Mn2+ phosphor by solid-state reactions. Eu2+, Ce3+, and Mn2+ gives rise to the blue, green, and red emission, respectively. The Mn2+ red emission can be effectively enhanced via energy transfers from both Eu2+ and Ce3+. Thus a tunable full color emission from 410 to 750 nm was realized in this single phosphor. The Eu2+ ! Mn2+ energy transfer mechanism was investigated by the fluorescence decay curves. This single phosphor exhibits an efficient excitation band covering from 390 to 410 nm, which matches well with the emission light of the efficient NUV chips. The optimized BLS:Eu2+, Ce3+, Mn2+ phosphor shows a high quantum efficient of $62% and a good color stability. When this single phosphor was combined with a 395 nm NUV-chip, an ideal white LED with a high color render index (CRI) of 85 and a correlated color temperature (CCT) of 6300 K was obtained. This demonstrates the promising application of the BLS:Eu2+, Ce3+, Mn2+ single phosphor for the NUV-based white LEDs.

submitted time 2017-05-02 Hits864Downloads549 Comment 0

4. chinaXiv:201703.00578 [pdf]

Electron irradiation-induced defects in Mo-diluted FeCrNi austenitic alloy during void swelling incubation

B. Y. Wang; E Y Lu; C. X. Zhang; Q Xu; S. X. Jin; P. Zhang; X. Z. Cao
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

The microstructural features and the effect of Mo addition during incubation period in FeCrNi austenitic alloy were investigated using positron annihilation technique and micro-Vickers Hardness. The electron irradiation, which could induce vacancy defects in material, was performed at room temperature up to the dose of 1.70-4 and 50-4 dpa, respectively. The defect concentration was estimated about 10-4-10-7 though standard trapping model. The added Mo could trap vacancies to form Mo-vacancy complexes, which may suppress the migration and growth of vacancy defects during electron irradiation. In addition, the microstructural evolution during electron radiation resulted in hardening, while the added Mo might to improve the hardening property of the alloy.

submitted time 2017-03-26 Hits1500Downloads792 Comment 0

5. chinaXiv:201703.00577 [pdf]

Effect of Cu content on the defect evolution in Fe-Cu alloys investigated by PALS

X. Z. Cao; X. Lai; G. D. Cheng; S. X. Jin; X. Zhang; P. Zhang; B. Y. Wang
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

The effect of Cu content on the evolution of defects in Fe-x%Cu alloys (x= 0.15, 0.3, and 0.6) were investigated using Positron Annihilation Lifetime Spectroscopy. The vacancy-type and Cu-vacancy complexes defects were respectively produced by quenching from 1173 K and cold-rolled deformation followed by isochronal annealing. The isochronal annealing results obtained by PALS showed that Cu-vacancy complexes delayed the complete recovery of vacancy-type defects and the complete recovery temperature increased with the content of Cu in 30% deformed Fe-Cu alloys. The increment of Cu content also restrained the migration of vacancies in as-quenched Fe-Cu alloys.

submitted time 2017-03-26 Hits1327Downloads736 Comment 0

6. chinaXiv:201703.00574 [pdf]

Electron irradiation-induced defects in Mo-diluted FeCrNi austenitic alloy during void swelling incubation

B. Y. Wang; E. Y. Lu; C. X. Zhang; Q. Xu; S. X. Jin; P. Zhang; X. Z. Cao
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

Abstract. The microstructural features and the effect of Mo addition in FeCrNi austenitic alloy during incubation period were investigated using positron annihilation technique and micro-Vickers Hardness. The electron irradiation, which could induce vacancy defects in material, was performed at room temperature up to the dose of 1.70-4 and 50-4 dpa, respectively. The defect concentration was estimated about 10-4-10-7 though the standard trapping model. The added Mo atoms could trap vacancies to form Mo-vacancy complexes, which may restrain the migration and growth of vacancy defects during electron irradiation. In addition, the microstructural evolution during electron radiation resulted in hardening, while the added Mo might improve the hardening property of the alloy.

submitted time 2017-03-26 Hits1165Downloads695 Comment 0

7. chinaXiv:201703.00511 [pdf]

Enhanced plasticity in Zr-Cu-Ag-Al-Be bulk metallic glasses

Q. P. Cao; J. B. Jin; Y. Ma; X. Z. Cao; B. Y. Wang; S. X. Qu; X. D. Wang; D. X. Zhang; J. Z. Jiang
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

The dependences of bending plasticity on compositional adjustment and structural relaxation in Zr-Cu-Ag-Al-Be bulk metallic glasses (BMGs) were systematically studied. We reveal that with the increase in the Zr content, the plasticity is enhanced at the expense of glass forming ability and the shear transformation zone (STZ) volume becomes larger, while structural relaxation results in the embrittlement accompanied with the further enlarged STZ volume. Average positron lifetime, representing average free volume, drops with the increase in the Zr content and structural relaxation. The results indicate that neither STZ volume nor average positron lifetime can solely describe the plastic deformability of BMGs. Analyzing positron annihilation lifetime spectra, a bimodal distribution of open volume size is observed. The smaller open volume shrinks with increased concentration and the larger open volume expands with decreased concentration due to the increase in the Zr content, while structural elaxation only reduces the size of smaller open volume. The effects of open volume size distribution on the STZ activation and shear band propagation have been discussed. It has been demonstrated that combining the STZ volume with open volume size distribution can explain the plasticity evolution with the composition and structural relaxation, which sheds light on understanding the deformation mechanism of BMGs.

submitted time 2017-03-23 Hits1608Downloads882 Comment 0

8. chinaXiv:201703.00510 [pdf]

Thermal evolution of vacancy-type defects in quenched FeCrNi alloys

C. X. Zhang; X. Z. Cao; Y. H. Li; S. X. Jin; E. Y. Lu; H. W. T; P. Zhang; B. Y. Wang; ?
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

The effect of isochronal annealing on vacancy-type defects in quenched FeCrNi alloys and SUS316 has been investigated by positron annihilation techniques. Vacancy-type defects gather and grow with the annealing temperature increasing to 523 K, and the vacancy-type defects annihilated gradually in FeCrNi alloys at the annealing temperature increasing. The results indicate that the addition of Mo and nonmetal elements is not the key reasons that determined the annihilated temperature of vacancy-type defects. It’s worth noting that the vacancy-type defects annihilated and dislocation-type defects formed in all sample alloys after 673 K annealing treatment. In addition, the density of defects in Mo diluted FeCrNi model alloy is lower than that in FeCrNi model alloy due to the Mo-vacancy complexes formed in Mo diluted FeCrNi model alloy. The long lifetime of vacancy-type defects in commercial stainless steel SUS316 is smaller than that in FeCrNi model alloys because the mobility of vacancy-type defects changed by nonmetal elements. In addition, vacancy-type and dislocation defects detected contribute to the S and W parameters of positron annihilation in the whole annealing treatment.

submitted time 2017-03-23 Hits1450Downloads891 Comment 0

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