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1. Detection of Very High-energy Gamma-Ray Emission from the Radio Galaxy M87 with LHAASO

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. C. Chu, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, T. T. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, O. A. Hannuksela, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, C. Huang, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Y. Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, H. B. Jiang, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Khangulyan, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, K. C. Y. Ng, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, L. H. Wan, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, and X. Zuo

Subjects
Active galactic nuclei, High energy astrophysics, Astrophysics, QB460-466
Abstract

The nearby radio galaxy M87 is a very high-energy (VHE) gamma-ray emitter established by observations with ground-based gamma-ray detectors. Here we report the long-term monitoring of M87 from 2021 to 2024 with the Large High Altitude Air Shower Observatory (LHAASO). M87 has been detected by LHAASO with a statistical significance ∼ 9 σ . The observed energy spectrum extends to 20 TeV, with a possible hardening at ∼20 TeV and then a clear softening at higher energies. Assuming that the intrinsic spectrum is described by a single power law up to 20 TeV, a tight upper bound on the extragalactic background light intensity is obtained. A strong VHE flare lasting 8 days, with a rise time of ${\tau }_{r}^{\mathrm{rise}}=1.05\pm 0.49$ days and decay time of ${\tau }_{d}^{\mathrm{decay}}=2.17\pm 0.58$ days, was found in early 2022. A possible GeV flare is seen also in Fermi Large Area Telescope data during the VHE flare period. The variability time as short as 1 day seen in the LHAASO data suggests a compact emission region with a size of ∼3 × 10 ^15 δ cm ( δ being the Doppler factor of the emitting region), corresponding to a few Schwarzschild radii of the central supermassive black hole in M87. The continuous monitoring of the source reveals a duty cycle of ∼1% for VHE flares with a flux above 10 ^−11 erg cm ^−2 s ^−1 .

Published
2024
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2. Discovery of Very High Energy Gamma-Ray Emissions from the Low-luminosity AGN NGC 4278 by LHAASO

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, X. Zuo, and The LHAASO Collaboration

Subjects
High energy astrophysics, Gamma-ray astronomy, Low-luminosity active galactic nuclei, LINER galaxies, Blazars, Fanaroff-Riley radio galaxies, Astrophysics, QB460-466
Abstract

The first source catalog of the Large High Altitude Air Shower Observatory (LHAASO) reported the detection of a very high energy gamma-ray source, 1LHAASO J1219+2915. This Letter presents a further detailed study of the spectral and temporal behavior of this pointlike source. The best-fit position of the TeV source (R.A. = 185.°05 ± 0.°04, decl. = 29.°25 ± 0.°03) is compatible with NGC 4278 within ∼0.°03. Variation analysis shows an indication of variability on a timescale of a few months in the TeV band, which is consistent with low-frequency observations. Based on these observations, we report the detection of TeV γ -ray emissions from this low-luminosity active galactic nucleus. The observation by LHAASO's Water Cherenkov Detector Array during the active period has a significance level of 8.8 σ with a best-fit photon spectral index Γ = 2.56 ± 0.14 and a flux f _1–10 TeV = (7.0 ± 1.1 _sta ± 0.35 _syst ) × 10 ^−13 photons cm ^−2 s ^−1 , or approximately 5% of the Crab Nebula. The discovery of VHE gamma-ray emission from NGC 4278 indicates that compact, weak radio jets can efficiently accelerate particles and emit TeV photons.

Published
2024
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3. The First LHAASO Catalog of Gamma-Ray Sources

Author

Zhen Cao, F. Aharonian, Q. An, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, J. T. Cai, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. Y. He, X. B. He, Y. He, M. Heller, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Z. C. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, T. Ke, D. Kuleshov, K. Kurinov, B. B. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, Jian Li, Jie Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, R. Lu, Q. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, Z. W. Ou, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, A. Sáiz, D. Semikoz, C. Y. Shao, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Q. W. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, K. Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, F. Yang, F. F. Yang, H. W. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, L. X. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and (The LHAASO Collaboration)

Subjects
Gamma-ray astronomy, Gamma-ray observatories, Catalogs, Astrophysics, QB460-466
Abstract

We present the first catalog of very-high-energy and ultra-high-energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory. The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array from 2021 March to 2022 September and 933 days of data recorded by the Kilometer Squared Array from 2020 January to 2022 September. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering decl. from −20° to 80°. In total, the catalog contains 90 sources with an extended size smaller than 2° and a significance of detection at >5 σ . Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ( E > 100 TeV) emission at >4 σ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.

Published
2024
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4. Construction and on-site performance of the LHAASO WFCTA camera

Author

F. Aharonian, Q. An, Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and The LHAASO Collaboration

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here.

Published
2021
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5. Measurement of the central exclusive production of charged particle pairs in proton-proton collisions at s $$ \sqrt{s} $$ = 200 GeV with the STAR detector at RHIC

Author

The STAR collaboration, J. Adam, L. Adamczyk, J. R. Adams, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, A. Aparin, E. C. Aschenauer, M. U. Ashraf, F. G. Atetalla, A. Attri, G. S. Averichev, V. Bairathi, K. Barish, A. Behera, R. Bellwied, A. Bhasin, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. D. Brandenburg, A. V. Brandin, J. Butterworth, H. Caines, M. Calderón de la Barca Sánchez, D. Cebra, I. Chakaberia, P. Chaloupka, B. K. Chan, F-H. Chang, Z. Chang, N. Chankova-Bunzarova, A. Chatterjee, D. Chen, J. H. Chen, X. Chen, Z. Chen, J. Cheng, M. Cherney, M. Chevalier, S. Choudhury, W. Christie, X. Chu, H. J. Crawford, M. Csanád, M. Daugherity, T. G. Dedovich, I. M. Deppner, A. A. Derevschikov, L. Didenko, X. Dong, J. L. Drachenberg, J. C. Dunlop, T. Edmonds, N. Elsey, J. Engelage, G. Eppley, R. Esha, S. Esumi, O. Evdokimov, A. Ewigleben, O. Eyser, R. Fatemi, S. Fazio, P. Federic, J. Fedorisin, C. J. Feng, Y. Feng, P. Filip, E. Finch, Y. Fisyak, A. Francisco, L. Fulek, C. A. Gagliardi, T. Galatyuk, F. Geurts, A. Gibson, K. Gopal, D. Grosnick, W. Guryn, A. I. Hamad, A. Hamed, S. Harabasz, J. W. Harris, S. He, W. He, X. H. He, S. Heppelmann, N. Herrmann, E. Hoffman, L. Holub, Y. Hong, S. Horvat, Y. Hu, H. Z. Huang, S. L. Huang, T. Huang, X. Huang, T. J. Humanic, P. Huo, G. Igo, D. Isenhower, W. W. Jacobs, C. Jena, A. Jentsch, Y. JI, J. Jia, K. Jiang, S. Jowzaee, X. Ju, E. G. Judd, S. Kabana, M. L. Kabir, S. Kagamaster, D. Kalinkin, K. Kang, D. Kapukchyan, K. Kauder, H. W. Ke, D. Keane, A. Kechechyan, M. Kelsey, Y. V. Khyzhniak, D. P. Kikoła, C. Kim, B. Kimelman, D. Kincses, T. A. Kinghorn, I. Kisel, A. Kiselev, A. Kisiel, M. Kocan, L. Kochenda, L. K. Kosarzewski, L. Kramarik, P. Kravtsov, K. Krueger, N. Kulathunga Mudiyanselage, L. Kumar, R. Kunnawalkam Elayavalli, J. H. Kwasizur, R. Lacey, S. Lan, J. M. Landgraf, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, Y. H. Leung, C. Li, W. Li, X. Li, Y. Li, Y. Liang, R. Licenik, T. Lin, Y. Lin, M. A. Lisa, F. Liu, H. Liu, P. Liu, T. Liu, X. Liu, Y. Liu, Z. Liu, T. Ljubicic, W. J. Llope, R. S. Longacre, N. S. Lukow, S. Luo, X. Luo, G. L. Ma, L. Ma, R. Ma, Y. G. Ma, N. Magdy, R. Majka, D. Mallick, S. Margetis, C. Markert, H. S. Matis, J. A. Mazer, N. G. Minaev, S. Mioduszewski, B. Mohanty, M. M. Mondal, I. Mooney, Z. Moravcova, D. A. Morozov, M. Nagy, J. D. Nam, Md. Nasim, K. Nayak, D. Neff, J. M. Nelson, D. B. Nemes, M. Nie, G. Nigmatkulov, T. Niida, L. V. Nogach, T. Nonaka, A. S. Nunes, G. Odyniec, A. Ogawa, S. Oh, V. A. Okorokov, B. S. Page, R. Pak, A. Pandav, Y. Panebratsev, B. Pawlik, D. Pawlowska, H. Pei, C. Perkins, L. Pinsky, R. L. Pintér, J. Pluta, J. Porter, M. Posik, N. K. Pruthi, M. Przybycien, J. Putschke, H. Qiu, A. Quintero, S. K. Radhakrishnan, S. Ramachandran, R. L. Ray, R. Reed, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, L. Ruan, J. Rusnak, N. R. Sahoo, H. Sako, S. Salur, J. Sandweiss, S. Sato, W. B. Schmidke, N. Schmitz, B. R. Schweid, F. Seck, J. Seger, M. Sergeeva, R. Seto, P. Seyboth, N. Shah, E. Shahaliev, P. V. Shanmuganathan, M. Shao, F. Shen, W. Q. Shen, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. Sikora, M. Simko, J. Singh, S. Singha, N. Smirnov, W. Solyst, P. Sorensen, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, M. Stefaniak, D. J. Stewart, M. Strikhanov, B. Stringfellow, A. A. P. Suaide, M. Sumbera, B. Summa, X. M. Sun, X. Sun, Y. Sun, B. Surrow, D. N. Svirida, P. Szymanski, A. H. Tang, Z. Tang, A. Taranenko, T. Tarnowsky, J. H. Thomas, A. R. Timmins, D. Tlusty, M. Tokarev, C. A. Tomkiel, S. Trentalange, R. E. Tribble, P. Tribedy, S. K. Tripathy, O. D. Tsai, Z. Tu, T. Ullrich, D. G. Underwood, I. Upsal, G. Van Buren, J. Vanek, A. N. Vasiliev, I. Vassiliev, F. Videbæk, S. Vokal, S. A. Voloshin, F. Wang, G. Wang, J. S. Wang, P. Wang, Y. Wang, Z. Wang, J. C. Webb, P. C. Weidenkaff, L. Wen, G. D. Westfall, H. Wieman, S. W. Wissink, R. Witt, Y. Wu, Z. G. Xiao, G. Xie, W. Xie, H. Xu, N. Xu, Q. H. Xu, Y. F. Xu, Y. Xu, Z. Xu, C. Yang, Q. Yang, S. Yang, Y. Yang, Z. Yang, Z. Ye, L. Yi, K. Yip, H. Zbroszczyk, W. Zha, D. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. J. Zhang, Z. Zhang, J. Zhao, C. Zhong, C. Zhou, X. Zhu, Z. Zhu, M. Zurek, and M. Zyzak

Subjects
Diffraction, Forward physics, Hadron-Hadron scattering (experiments), Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We report on the measurement of the Central Exclusive Production of charged particle pairs h + h − (h = π, K, p) with the STAR detector at RHIC in proton-proton collisions at s $$ \sqrt{s} $$ = 200 GeV. The charged particle pairs produced in the reaction pp → p′ + h + h − + p′ are reconstructed from the tracks in the central detector and identified using the specific energy loss and the time of flight method, while the forward-scattered protons are measured in the Roman Pot system. Exclusivity of the event is guaranteed by requiring the transverse momentum balance of all four final-state particles. Differential cross sections are measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. They are measured in a fiducial region corresponding to the acceptance of the STAR detector and determined by the central particles’ transverse momenta and pseudorapidities as well as by the forward-scattered protons’ momenta. This fiducial region roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range 0.04 GeV2 < −t 1 , −t 2 < 0.2 GeV2, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range |η| < 0.7. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of π + π − and K + K − pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to π + π − production. For π + π − production, the fiducial cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the f 0(980), f 2(1270) and f 0(1500), with a possible small contribution from the f 0(1370). Fits to the extrapolated differential cross section as a function of t 1 and t 2 enable extraction of the exponential slope parameters in several bins of the invariant mass of π + π − pairs. These parameters are sensitive to the size of the interaction region.

Published
2020
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6. RESEARCH ON THE POLICIES AND LAWS OF INTERNATIONAL CIVILIAN REMOTE SENSING SATELLITES AND THEIR PROBLEMS

Author

X. P. Zhang, W. Y. Wan, G. Q. Zhou, T. Yue, and B. Chen

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

In the exploration of outer space and international space activities, civilian remote sensing satellites have made rapid development since the 1970s, and countries around the world have accelerated their civilian satellite development and its policy formulation as well. Regarding the regulations on the peaceful use of outer space and related space launches, the United Nations respectively formulated the "Five Treaties on Space" in the 1960s and 1970s to regulate the peaceful uses of outer space. However, in the development of civilian remote sensing satellites, orbital resources and application rules of remote sensing data, the implementation of "first-come, first-occupy" and "non-discriminatory access to remote sensing data" is mainly led by western developed countries, especially the space powers such as the United States and Russia. Based on the outer space policies and regulations, this article will make a comparative study of civilian remote sensing satellite development policies and related laws and regulations in major countries and regions in the world, so as to analyze the policies and legal principles of civilian remote sensing satellites, as well as its corresponding issues and problems.

Published
2020
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7. Application of GA-BP Neural Network Optimized by Grey Verhulst Model around Settlement Prediction of Foundation Pit

Author

C. Y. Liu, Y. Wang, X. M. Hu, Y. L. Han, X. P. Zhang, and L. Z. Du

Subjects
Geology, QE1-996.5
Abstract

Due to the limitation in the prediction of the foundation pit settlement, this paper proposed a new methodology which takes advantage of the grey Verhulst model and a genetic algorithm. In the previous study, excavation times are often the only factor to predict the settlement, which is mainly because the correspondence between real-time excavation depth and the excavation time is hard to determine. To solve this issue, the supporting times are precisely recorded and the excavation depth rate can be obtained through the excavation time length and excavation depth between two adjacent supports. After the correspondence between real-time excavation depth and the excavation time is obtained, the internal friction angle, cohesion, bulk density, Poisson’s ratio, void ratio, water level changes, permeability coefficient, number of supports, and excavation depth, which can influence the settlement, are taken to be considered in this study. For the application of the methodology, the settlement monitoring point of D4, which is near the bridge pier of the highway, is studied in this paper. The predicted values of the BP neural network, GA-BP neural network, BP neural network optimized by the grey Verhulst model, and GA-BP neural network optimized by the grey Verhulst model are detailed compared with the measured values. And the evaluation indexes of RMSE, MAE, MSE, MAPE, and R2 are calculated for these models. The results show that the grey Verhulst model can greatly improve the consistency between predicted values and measured values, while the accuracy and resolution is still low. The genetic algorithm (GA) can greatly improve the accuracy of the predicted values, while the GA-BP neural network shows low reflection to the fluctuation of measured values. The GA-BP neural network optimized by the grey Verhulst model, which has taken the advantages of GA and the grey Verhulst model, has extremely high accuracy and well consistency with the measured values.

Published
2021
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8. Stable isotope variations in precipitation: simulations and comparison with observations (Yunnan Plateau, High Asia)

Author

X. P. Zhang, H. D. Guan, and Z. A. Sun

Subjects
amount effect, mwl (meteoric water line), simulation, stable isotopes, yunnan plateau, Science
Abstract

Stable isotopes in precipitation, both liquid (rain) and solid (snow), can be suitable tracers for hydrological cycles because their concentrations reflect the cumulative record of physical phase changes. Distribution of stable isotopes in precipitation over High-Asian monsoon regions, including Yunnan Plateau is investigated. It has two noticeable features: firstly, the stable isotopes in precipitation distinctly decrease; and secondly, the stable isotopes in precipitation demonstrate smaller concentrations during rainy seasons and higher values during dry seasons. These features were found by the MUGCM simulation developed in the Melbourne Univertisty. Quantitative effect of the stable isotopes in precipitation takes place at different time scales, i.e. in diurnal, monthly or annual variations. Relative to observations, the simulated δ¹⁸O in precipitation shows stronger dependence on precipitation. In the diurnal course, the simulated regression equations of δ¹⁸O in precipitation versus precipitation amount are in good agreement with the observed values at Tengchong and Simao, except that the simulated δ¹⁸O/P curve slope is slightly smaller than the observed one at Mingzi. In the monthly and annual courses both, the simulated and observed δ¹⁸O/P slopes are smaller than it is in the diurnal course. For individual station, the local meteoric water line (LMWL) is simulated well at Mengzi and Tengchong. However, the simulated result does not reproduce truly the observed relationship between δD and δ¹⁸O in precipitation at Simao and Kunming where the LMWL inclination is larger 8.0, and a shift along the y-axis higher 10.0. In addition, all simulated LMWL slopes are higher the observed ones at four stations, suggesting that the GCM can overestimate the decreasing of Hydrogen Deuterium Oxide and, thus, underestimate the second-order parameter, i.e. the deuterium excess, in a particular region Yunnan.

Published
2015
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9. STUDY ON THE QUALITY CONTROL METHODS OF CLUSTER-BASED REMOTE SENSING IMAGE PROCESSING

Author

L. Xia, L. B. Zhao, X. P. Zhang, and X. M. Zhou

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

Along with the advances in technology, modern surveying technology developed rapidly, a series of high-tech equipments have been invited and developed. A lot of cluster-based Remote Sensing image processing systems, at home or abroad, have been produced and used in production, such as PixelFactory, PixelGrid, CIPS etc. Been popularized and used, processing technology and procedure have changed to be different from the old pattern, and traditional ways of quality control no longer meet the need of new technology. Above all, it is of vital importance for us to find new ways of procedure quality control for the geographical spatial data quality certification under new technology system. Based on the mainstream image fast processing systems – PixelFactory and PixelGrid, the nodes and methods of quality control during image processing will be studied in this paper, including image preprocessing, AT, DSM, DEM, ortho-rectification, mosaic etc. After that, the feasibility of quality control ways proposed will be verified by actual production project. All the advices can be used as references for large-scale application of new technology in information surveying system.

Published
2013
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10. Trends of streamflow, sediment load and their dynamic relation for the catchments in the middle reaches of the Yellow River over the past five decades

Author

Z. L. Gao, Y. L. Fu, Y. H. Li, J. X. Liu, N. Chen, and X. P. Zhang

Subjects
Technology, Environmental technology. Sanitary engineering, TD1-1066, Geography. Anthropology. Recreation, Environmental sciences, GE1-350
Abstract

To control severe soil erosion on the Loess Plateau, China, a great number of soil conservation measures have been implemented since 1950s and subsequently, the "Grain for Green" project was implemented in 1999. The measures and the project resulted in a large scale land use/cover change (LUCC). Understanding the impacts of the measures and the project on streamflow, sediment load and their dynamic relation is essential because the three elements are closely related to the sustainable catchment management strategy on the Loess Plateau. The data for seven selected catchments in the middle reaches of the Yellow River were used and standardized with the precipitation and the controlling area for analysis. The nonparametric Mann-Kendall test and the Pettitt test were employed to detect trends and change points of the annual streamflow and annual sediment load. Simple linear regressions for the monthly streamflow and sediment load from May to October were made to express their relationship. Based on the change point identification and the time when the project began to be implemented on the Loess Plateau, the complete time for the data records was divided into three periods to compare the change degrees of streamflow, sediment load and their relation for the catchments. Results show that there are three types of responses in streamflow, sediment load, and their dynamic relations for the seven catchments. The effects of the LUCC on streamflow, sediment load, and their relationships are greatest in the three transition zone catchments followed by the two rocky mountain catchments. The effects are much weaker in the two loess hilly-gully catchments. In general, the change degrees for sediment load are much greater than those for streamflow, which results from the decreased streamflow and weakening trend of their dynamic relation period by period in catchments.

Published
2012
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12. White-light-emitting diode based on a single-layer polymer

Author

B. Z. Wang, X. P. Zhang, and H. M. Liu

Subjects
Physics, QC1-999
Abstract

A broad-band light-emitting diode was achieved in a single-layer device based on pure poly(9,9′-dioctylfluorene-co-bis-N,N′-(4-butylphenyl)-bis-N,N′-phenyl-1,4-phenylenediamine) (PFB). Electromer emission was observed in the red with a center wavelength of about 620 nm in electroluminescence (EL) spectrum. This kind of emission exhibits strong dependence on the thickness of the PFB layer, so that the shape of the EL spectrum may be adjusted through changing the thickness of the active polymer layer to balance between the intrinsic PFB emission in the blue and the electromer emission in the red. Thus, white light emission may be achieved from such a single-layer single-material diode.

Published
2013
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16. Disruption of adipocyte HIF-1α improves atherosclerosis through the inhibition of ceramide generation

Author

Zhipeng Zhang, Pengcheng Wang, Changtao Jiang, Huiying Liu, X P Zhang, Yu Yan, Guangyi Zeng, Yongqiang Dong, Yangming Zhang, Yanli Pang, and Song-Yang Zhang

Subjects
Ceramide, medicine.medical_specialty, Chemistry, Cholesterol, Adipose tissue, medicine.disease, High cholesterol, chemistry.chemical_compound, Endocrinology, Internal medicine, Adipocyte, medicine, General Pharmacology, Toxicology and Pharmaceutics, Sphingomyelin, Dyslipidemia, Function (biology)
Abstract

s Atherosclerosis is a chronic multifactorial cardiovascular disease. A Western diet has been reported to affect atherosclerosis through regulation of adipose function. In high cholesterol diet-fed ApoE–/– mice, adipocyte HIF-1α deficiency or direct HIF-1α inhibition by the selective pharmacological HIF-1α inhibitor PX-478 alleviates high cholesterol diet-induced atherosclerosis by reducing adipose ceramide generation, which lowers cholesterol levels and reduces inflammatory responses, resulting in improved dyslipidemia and atherogenesis. Smpd3, the gene encoding neutral sphingomyelinase, is identified as a new target gene directly regulated by HIF-1α that is involved in ceramide generation. Epididymal adipose tissue injected with lentivirus-SMPD3 reverses the decrease in ceramides in adipocytes and eliminates the improvements on atherosclerosis in the adipocyte HIF-1α-deficient mice. Therefore, inhibitors of HIF-1α may constitute a novel approach to slow atherosclerotic progression.

Published
2022

19. A dynamic range extension system for LHAASO WCDA-1

Author

F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, null Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Dynamic range, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Extension (predicate logic), Measure (mathematics), Effective nuclear charge, Nuclear physics, Air shower, Nuclear Energy and Engineering, Orders of magnitude (time), Energy (signal processing)
Abstract

The main scientific goal of LHAASO-WCDA is to survey gamma-ray sources with energy from 100 GeV to 30 TeV. To observe high-energy shower events, especially to measure the energy spectrum of cosmic rays from 100 TeV to 10 PeV, a dynamic range extension system (WCDA++) is designed to use a 1.5-inch PMT with a dynamic range of four orders of magnitude for each cell in WCDA-1. The dynamic range is extended by using these PMTs to measure the effective charge density in the core region of air shower events, which is an important parameter for identifying the composition of primary particles. The system has been running for more than one year. In this paper, the details of the design and performance of WCDA++ are presented.

Published
2021

21. Constraints on heavy decaying dark matter from 570 days of LHAASO observations

Author

Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, E S, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, Y, Chen, H L, Cheng, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B, D'Ettorre Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, X T, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, W K, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, Q, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, W H, Huang, X T, Huang, X Y, Huang, Y, Huang, Z C, Huang, X L, Ji, H Y, Jia, K, Jia, K, Jiang, Z J, Jiang, M, Jin, M M, Kang, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, W J, Long, R, Lu, Q, Luo, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, Y C, Nan, Z W, Ou, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, A, Sáiz, C Y, Shao, L, Shao, O, Shchegolev, X D, Sheng, J Y, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R, Wang, R N, Wang, W, Wang, X G, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, X F, Wu, Y S, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, G G, Xin, Y L, Xin, Y, Xing, Z, Xiong, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, H W, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H, Yue, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, F, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S B, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, S, Ando, M, Chianese, D F G, Fiorillo, G, Miele, K C Y, Ng, and GRAPPA (ITFA, IoP, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics (astro-ph.CO), High Energy Physics - Phenomenology (hep-ph), General Physics and Astronomy, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Published
2022

23. [Prevalence and transmission of pyrazinamide-resistant

Author

B B, Liu, P L, Hu, Z H, Chen, S L, Yi, X P, Zhang, and Y H, Tan

Subjects
Mutation, Tuberculosis, Multidrug-Resistant, Antitubercular Agents, Prevalence, Humans, Microbial Sensitivity Tests, Mycobacterium tuberculosis, Rifampin, Tuberculosis, Lymph Node, Pyrazinamide, Ethambutol, Amidohydrolases
Published
2022

25. Fascial space priority approach for laparoscopic complete mesocolic excision (CME) plus central vascular ligation or extended lymphadenectomy (CVL/D3) in right-sided colon cancer (with video)

Author

Z C Zhang, H J Yang, X P Zhang, Y D Zhou, P Li, Yun Sun, and Q S Zeng

Subjects
Extended lymphadenectomy, medicine.medical_specialty, business.industry, Colorectal cancer, Gastroenterology, medicine.disease, Colorectal surgery, Surgery, Colonic Neoplasms, medicine, Humans, Lymph Node Excision, Laparoscopy, Fascial space, Ligation, business, Colectomy, Mesocolon, Abdominal surgery
Published
2021

27. Superior strength and strengthening mechanism of die attachment joints by using bimodal-sized Cu nanoparticle paste capable of low-temperature pressureless sintering

Author

Xue Wu, M. B. Zhou, Hai-Jun Huang, and X. P. Zhang

Subjects
010302 applied physics, Fabrication, business.product_category, Materials science, business.industry, Nanoparticle, Pressureless sintering, Condensed Matter Physics, Microstructure, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Semiconductor, Chemical engineering, Phase (matter), 0103 physical sciences, Shear strength, Die (manufacturing), Electrical and Electronic Engineering, business
Abstract

Recently, there has seen an increasing demand for reliable and cost-effective die attachment materials to be used in power electronics and third-generation semiconductors. The present work develops a facile yet efficient approach to fabrication of bimodal-sized Cu nanoparticles (NPs) by a one-step method and the Cu NP paste capable of low-temperature pressureless sintering for die attachment. The synthesized Cu NPs exhibit a special wrapping conformation of large Cu NPs (~ 160 nm) surrounded by a large number of small ones (~ 9 nm). The special wrapped structure of Cu NPs is heritable to Cu NP paste, which greatly increases initial density of Cu NPs and enables the paste to be sintered completely at low temperature without pressure. Sintered dummy die joints show very high shear strength of 48 and 54 MPa, respectively, after pressureless sintering at 260 and 280 °C for 20 min in nitrogen, which is attributed to the strengthening effect of sintered microstructures featured by a large amount of bulky Cu phase formed as a result of the heritable effect of large Cu particles in bimodal-sized Cu NPs. This pressureless sinterable Cu NP paste shows a great potential for use in die attachment of power electronics.

Published
2021

28. THE RELATIVE STABILITY OF PROTONATED BASE PAIRS BETWEEN XANTHINE AND DNA BASES

Author

Z. M. Qiu and X. P. Zhang

Subjects
Stereochemistry, Guanine, Base pair, Protonation, Thymine, Nucleobase, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Materials Chemistry, Proton affinity, Physical and Theoretical Chemistry, Cytosine, Natural bond orbital
Abstract

Base pairs involving protonated nucleobases play important roles in the DNA republication. Xanthine is an oxidative product of guanine. In this work, we employ density functional theory to investigate the protonation properties of xanthine (X), adenine (A), cytosine (C), guanine (G), and thymine (T). With regard to the proton affinity, we study the protonated base pairs between X and A, C, G, T. The quantum theory of atoms in molecule and the natural bond orbital analysis are employed to elucidate the interaction characteristics. The interaction energy and structural parameters show the relative stability of the protonated base pairs: X:AH+ > X:CH+ > X:GH+ > XH+:T. The occurrence of X(syn):AH+(anti) structure may lead to a G:C → T:A transition.

Published
2021

29. Quasi-isentropic compression of LiH above 400 GPa using magnetocumulative generator

Author

X. P. Zhang, Z. W. Gu, Z. Q. Xiao, F. L. Tan, X. Q. Ye, Y. J. Tong, X. S. Tang, Z. Y. Zhou, C. Cheng, J. Zhao, B. Q. Luo, J. M. Li, X. W. Kuang, J. H. Zhao, C. W. Sun, and C. L. Liu

Subjects
Instrumentation
Abstract

The knowledge of high-pressure behavior of LiH is significant for the validation of fundamental theoretical models and applications in thermonuclear materials and potential energy supplies. The compressibility of7LiH under isentropic compression at high pressure was investigated experimentally and theoretically. The experimental technique for quasi-isentropic compression with low-density materials was developed using the magnetocumulative generator CJ-100 and x-ray flash radiography. The x-ray images and extracted interface of the sample target in dynamic flash radiography experiments were obtained. According to each interface size of the target both before and after compression, the compression ratio of7LiH and reference material aluminum was obtained. The density of the reference and using its known isentropic curve provide the pressure in the reference. The pressure in7LiH was deduced from the pressure in the reference and using the calculated gradient correction factor. The quasi-isentropic data point at 438 GPa was obtained experimentally. A semiempirical three-term complete equation of state was constructed and validated for7LiH using the theory of Mie–Grüneisen–Debye with experimental data from the literature. The quasi-isentrope data point is reasonably consistent with the theoretical results. The quasi-isentropic experimental techniques and results broaden the existing research scope and are practical and helpful to further validate theoretical models in the future.

Published
2022

30. Progress of Underground Nuclear Astrophysics Experiment JUNA in China

Author

W. P. Liu, Z. H. Li, J. J. He, X. D. Tang, G. Lian, J. Su, Y. P. Shen, Z. An, F. Q. Chao, J. J. Chang, L. H. Chen, H. Chen, X. J. Chen, Y. H. Chen, Z. J. Chen, B. Q. Cui, X. C. Du, X. Fang, C. B. Fu, L. Gan, B. Guo, Z. Y. Han, X. Y. Guo, G. Z. He, J. R. He, A. Heger, S. Q. Hou, H. X. Huang, N. Huang, B. L. Jia, L. Y. Jiang, S. Kubono, J. M. Li, M. C. Li, K. A. Li, E. T. Li, T. Li, Y. J. Li, M. Lugaro, X. B. Luo, H. Y. Ma, S. B. Ma, D. M. Mei, W. Nan, W. K. Nan, N. C. Qi, Y. Z. Qian, J. C. Qin, J. Ren, C. S. Shang, L. T. Sun, W. L. Sun, W. P. Tan, I. Tanihata, S. Wang, P. Wang, Y. B. Wang, Q. Wu, S. W. Xu, S. Q. Yan, L. T. Yang, Y. Yang, X. Q. Yu, Q. Yue, S. Zeng, L. Zhang, H. Zhang, H. Y. Zhang, L. Y. Zhang, N. T. Zhang, P. Zhang, Q. W. Zhang, T. Zhang, X. P. Zhang, X. Z. Zhang, W. Zhao, J. F. Zhou, and Y. Zhou

Subjects
Atomic and Molecular Physics, and Optics
Published
2022

32. Metastasis to lateral lymph nodes with no mesenteric lymph node involvement in low rectal cancer: a retrospective case series

Author

X P Zhang, Yi Sun, Z C Zhang, Q S Zeng, Y D Zhou, and P Li

Subjects
medicine.medical_specialty, lcsh:Surgery, lcsh:RC254-282, Metastasis, 03 medical and health sciences, 0302 clinical medicine, medicine, Mesenteric lymph nodes, Humans, Prospective Studies, Prospective cohort study, Lymph node, Retrospective Studies, business.industry, Rectal Neoplasms, Research, lcsh:RD1-811, medicine.disease, Prognosis, lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens, Total mesorectal excision, Colorectal surgery, Dissection, medicine.anatomical_structure, Oncology, 030220 oncology & carcinogenesis, Lymph Node Excision, 030211 gastroenterology & hepatology, Surgery, Radiology, Lymph, Lymph Nodes, business
Abstract

Purpose The aim of this study is to examine the pattern of lymph node metastasis (lateral vs. mesenteric lymph nodes) in low rectal cancer. Methods This retrospective analysis included all patients undergoing laparoscopic total mesorectal excision plus lateral lymph node dissection for advanced low rectal cancer (up to 8 cm from the anal verge) during a period from July 1, 2017, to August 31, 2019, at the Department of Colorectal Surgery, Tianjin Union Medical Center. The decision to conduct lateral lymph node dissection was based on positive findings in preoperative imaging assessments. Results A total of 42 patients were included in data analysis. Surgery was successfully completed as planned, without conversion to open surgery in any case. A minimum of 10 mesenteric lymph nodes and 1 lateral lymph node on each side were dissected in all patients. Pathologic examination of resected specimens showed no metastasis to either mesenteric or lateral lymph nodes in 7 (16.7%) case, metastasis to both mesenteric and lateral lymph nodes in 26 (61.9%) cases, metastasis to mesenteric but not lateral lymph nodes in 4 (9.5%) cases, and metastasis to lateral but not mesenteric lymph nodes in 5 (11.9%) cases (n = 2 in the obturator region; n = 3 in the iliac artery region). Conclusion A clinically significant proportion of low rectal cancer patients have metastasis to lateral lymph nodes without involvement of mesenteric lymph nodes. More carefully planned prospective studies are needed to verify this preliminary finding.

Published
2020

33. Hierarchical phase separation behavior in a Ni-Si-Fe alloy

Author

X. P. Zhang, Gregory B. Thompson, W. Li, Sebastian Haas, Anna M. Manzoni, Florian Vogel, Uwe Glatzel, Xuyang Zhou, and E. Zaiser

Subjects
010302 applied physics, Materials science, Polymers and Plastics, Alloy, Metals and Alloys, Nanochemistry, 02 engineering and technology, Atom probe, engineering.material, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Electronic, Optical and Magnetic Materials, law.invention, Superalloy, Crystallography, law, Phase (matter), 0103 physical sciences, Ceramics and Composites, engineering, 0210 nano-technology, Ternary operation, Single crystal
Abstract

Improving the properties of durable high-temperature alloys is based on the fundamental understanding of the link between microstructure and three-dimensional (3D) nanochemistry. Here we utilize a complementary approach of transmission electron microscopy and atom probe tomography to link microstructure and 3D nanochemistry of a ternary single crystal Ni83.9Si13Fe3.1 (at.%) model alloy. The formation of a γ/γ' microstructure is revealed, containing primary and secondary γ' precipitates analogous to Ni-based superalloys. Subsequently, microstructural hierarchy is created by the formation of γ particles inside primary γ' precipitates. The correlated supersaturation with γ forming elements (Ni, Fe) of primary γ' precipitates was identified as driving force for the formation of γ particles. The influence of aging on the mechanical properties is reported and peak hardness is achieved after 24 h of aging at 923 K. Thermo-Calc equilibrium phase concentrations based on the TTNi8 database where found to be closer to the APT data than the TCNi8 based values. Our results suggest that improved stability of γ particles can be achieved by tailoring the phase chemistry and the lattice misfit.

Published
2020

37. Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR

Author

M S, Abdallah, B E, Aboona, J, Adam, L, Adamczyk, J R, Adams, J K, Adkins, G, Agakishiev, I, Aggarwal, M M, Aggarwal, Z, Ahammed, I, Alekseev, D M, Anderson, A, Aparin, E C, Aschenauer, M U, Ashraf, F G, Atetalla, A, Attri, G S, Averichev, V, Bairathi, W, Baker, J G, Ball Cap, K, Barish, A, Behera, R, Bellwied, P, Bhagat, A, Bhasin, J, Bielcik, J, Bielcikova, I G, Bordyuzhin, J D, Brandenburg, A V, Brandin, I, Bunzarov, X Z, Cai, H, Caines, M, Calderón de la Barca Sánchez, D, Cebra, I, Chakaberia, P, Chaloupka, B K, Chan, F-H, Chang, Z, Chang, N, Chankova-Bunzarova, A, Chatterjee, S, Chattopadhyay, D, Chen, J, Chen, J H, Chen, X, Chen, Z, Chen, J, Cheng, M, Chevalier, S, Choudhury, W, Christie, X, Chu, H J, Crawford, M, Csanád, M, Daugherity, T G, Dedovich, I M, Deppner, A A, Derevschikov, A, Dhamija, L, Di Carlo, L, Didenko, P, Dixit, X, Dong, J L, Drachenberg, E, Duckworth, J C, Dunlop, N, Elsey, J, Engelage, G, Eppley, S, Esumi, O, Evdokimov, A, Ewigleben, O, Eyser, R, Fatemi, F M, Fawzi, S, Fazio, P, Federic, J, Fedorisin, C J, Feng, Y, Feng, P, Filip, E, Finch, Y, Fisyak, A, Francisco, C, Fu, L, Fulek, C A, Gagliardi, T, Galatyuk, F, Geurts, N, Ghimire, A, Gibson, K, Gopal, X, Gou, D, Grosnick, A, Gupta, W, Guryn, A I, Hamad, A, Hamed, Y, Han, S, Harabasz, M D, Harasty, J W, Harris, H, Harrison, S, He, W, He, X H, He, Y, He, S, Heppelmann, N, Herrmann, E, Hoffman, L, Holub, Y, Hu, H, Huang, H Z, Huang, S L, Huang, T, Huang, X, Huang, Y, Huang, T J, Humanic, G, Igo, D, Isenhower, W W, Jacobs, C, Jena, A, Jentsch, Y, Ji, J, Jia, K, Jiang, X, Ju, E G, Judd, S, Kabana, M L, Kabir, S, Kagamaster, D, Kalinkin, K, Kang, D, Kapukchyan, K, Kauder, H W, Ke, D, Keane, A, Kechechyan, M, Kelsey, Y V, Khyzhniak, D P, Kikoła, C, Kim, B, Kimelman, D, Kincses, I, Kisel, A, Kiselev, A G, Knospe, H S, Ko, L, Kochenda, L K, Kosarzewski, L, Kramarik, P, Kravtsov, L, Kumar, S, Kumar, R, Kunnawalkam Elayavalli, J H, Kwasizur, R, Lacey, S, Lan, J M, Landgraf, J, Lauret, A, Lebedev, R, Lednicky, J H, Lee, Y H, Leung, N, Lewis, C, Li, W, Li, X, Li, Y, Li, X, Liang, Y, Liang, R, Licenik, T, Lin, Y, Lin, M A, Lisa, F, Liu, H, Liu, P, Liu, T, Liu, X, Liu, Y, Liu, Z, Liu, T, Ljubicic, W J, Llope, R S, Longacre, E, Loyd, N S, Lukow, X F, Luo, L, Ma, R, Ma, Y G, Ma, N, Magdy Abdelwahab Abdelrahman, D, Mallick, S, Margetis, C, Markert, H S, Matis, J A, Mazer, N G, Minaev, S, Mioduszewski, B, Mohanty, M M, Mondal, I, Mooney, D A, Morozov, A, Mukherjee, M, Nagy, J D, Nam, Md, Nasim, K, Nayak, D, Neff, J M, Nelson, D B, Nemes, M, Nie, G, Nigmatkulov, T, Niida, R, Nishitani, L V, Nogach, T, Nonaka, A S, Nunes, G, Odyniec, A, Ogawa, S, Oh, V A, Okorokov, B S, Page, R, Pak, J, Pan, A, Pandav, A K, Pandey, Y, Panebratsev, P, Parfenov, B, Pawlik, D, Pawlowska, C, Perkins, L, Pinsky, R L, Pintér, J, Pluta, B R, Pokhrel, G, Ponimatkin, J, Porter, M, Posik, V, Prozorova, N K, Pruthi, M, Przybycien, J, Putschke, H, Qiu, A, Quintero, C, Racz, S K, Radhakrishnan, N, Raha, R L, Ray, R, Reed, H G, Ritter, M, Robotkova, O V, Rogachevskiy, J L, Romero, D, Roy, L, Ruan, J, Rusnak, A K, Sahoo, N R, Sahoo, H, Sako, S, Salur, J, Sandweiss, S, Sato, W B, Schmidke, N, Schmitz, B R, Schweid, F, Seck, J, Seger, M, Sergeeva, R, Seto, P, Seyboth, N, Shah, E, Shahaliev, P V, Shanmuganathan, M, Shao, T, Shao, A I, Sheikh, D Y, Shen, S S, Shi, Y, Shi, Q Y, Shou, E P, Sichtermann, R, Sikora, M, Simko, J, Singh, S, Singha, M J, Skoby, N, Smirnov, Y, Söhngen, W, Solyst, P, Sorensen, H M, Spinka, B, Srivastava, T D S, Stanislaus, M, Stefaniak, D J, Stewart, M, Strikhanov, B, Stringfellow, A A P, Suaide, M, Sumbera, B, Summa, X M, Sun, X, Sun, Y, Sun, B, Surrow, D N, Svirida, Z W, Sweger, P, Szymanski, A H, Tang, Z, Tang, A, Taranenko, T, Tarnowsky, J H, Thomas, A R, Timmins, D, Tlusty, T, Todoroki, M, Tokarev, C A, Tomkiel, S, Trentalange, R E, Tribble, P, Tribedy, S K, Tripathy, T, Truhlar, B A, Trzeciak, O D, Tsai, Z, Tu, T, Ullrich, D G, Underwood, I, Upsal, G, Van Buren, J, Vanek, A N, Vasiliev, I, Vassiliev, V, Verkest, F, Videbæk, S, Vokal, S A, Voloshin, F, Wang, G, Wang, J S, Wang, P, Wang, X, Wang, Y, Wang, Z, Wang, J C, Webb, P C, Weidenkaff, L, Wen, G D, Westfall, H, Wieman, S W, Wissink, J, Wu, Y, Wu, B, Xi, Z G, Xiao, G, Xie, W, Xie, H, Xu, N, Xu, Q H, Xu, Y, Xu, Z, Xu, G, Yan, C, Yang, Q, Yang, S, Yang, Y, Yang, Z, Ye, L, Yi, K, Yip, Y, Yu, H, Zbroszczyk, W, Zha, C, Zhang, D, Zhang, J, Zhang, S, Zhang, X P, Zhang, Y, Zhang, Z J, Zhang, Z, Zhang, J, Zhao, C, Zhou, Y, Zhou, X, Zhu, M, Zurek, and M, Zyzak

Subjects
General Physics and Astronomy, CROMODINÂMICA QUÂNTICA
Abstract

The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-π^{0}s produced at forward pseudorapidities (2.6η4.0) in p+p, p+Al, and p+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back π^{0} pairs in p+Al and p+Au collisions compared to the p+p data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in p+Au relative to p+Al collisions exhibits a dependence of the saturation scale Q_{s}^{2} on the mass number A. A linear scaling of the suppression with A^{1/3} is observed with a slope of -0.09±0.01.

Published
2022

40. A study of grain boundary effects on the stress-induced martensitic transformation and superelasticity in NiTi alloy via atomistic simulation

Author

S. Liu, C. B. Ke, S. Cao, X. Ma, Y. F. Xu, and X. P. Zhang

Subjects
General Physics and Astronomy
Abstract

The stress-induced martensitic transformations and superelasticity behavior in the NiTi alloy with a single crystal model and a twist grain boundary bicrystal model at different temperatures are studied using molecular dynamics simulations. An atomic tracing method is proposed to identify specific numbers of B19′ martensite variants. Under uniaxial compressive loading, the stress-induced martensitic transformation takes place accompanied by the formation of M type II twins, and the deformation process can be divided into three distinct stages based on microstructure evolution and average atomic total energy. It is found that the twist grain boundary induces an increase in the martensite start temperature, which is consistent with the experimental results. There is no residual B19′ martensite at the end of the unloading process, and the irrecoverable strain mainly results from plastic deformation at the grain boundary through the analysis of atomic local shear strains and has hardly changed with increasing deformation temperature. Remarkably, the grain boundary brings about the acceleration of martensite nucleation and an earlier occurrence of stress plateau. Further simulation results manifest that the presence of the twist grain boundary leads to weakened temperature dependence of martensitic transformation stress and a reduction in the hysteresis loop area.

Published
2023

41. First Report of Muskmelon Fruit Rot Caused by Fusarium nanum in China

Author

X. P. Zhang, Q. Q. Dang, X. D. Cao, Y. G. Liu, Z. B. Bi, X. P. Zhu, and J. W. Xia

Subjects
Plant Science, Agronomy and Crop Science
Abstract

Muskmelon (Cucumis melo L.) is one of the most widely cultivated and economically important fruit crops in the world. However, many pathogens can cause decay of muskmelon fruit, including Fusarium asiaticum, F. equiseti, F. incarnatum and F. lateritium (Hao et al. 2021; Wang et al. 2019). Fusarium spp. are the most important pathogens affecting muskmelon fruit yield and quality (Wang et al. 2011). In August 2020, fruit rot symptoms were observed on ripening muskmelons (cv. Tianbao) in several fields in Jiyang District, Jinan City of Shandong Province, China. The incidences of infected muskmelon ranged from 15% to 30% and caused an average 20% yield loss. Symptoms appeared as pale brown, water-soaked lesions that were irregular in shape, with the lesion sizes ranging from a small spot (1 to 2 cm) to decay of the entire fruit. The core and surface of infected fruit were colonized and covered with white mycelia. Two infected muskmelons were collected from two fields, 7 km apart. Tissues removed from inside the infected fruit were surface disinfected with 75% ethanol for 30 s, and cultured on potato dextrose agar (PDA) at 25°C in the dark for 5 days. Four purified cultures were obtained using the single spore method. On carnation leaf agar (CLA), macroconidia were 1 to 5 septate, falcate, with a pronounced dorsiventral curvature with blunt to papillate apical cell, and barely to distinctly notched basal cell, measuring 12 to 35 × 3.5 to 6 μm. Microconidia and chlamydospores were not observed. These morphological characteristics were consistent with the description of Fusarium sp. Because these isolates had similar morphology, two representative isolates (XP9 and XP10) were selected for multilocus phylogenetic analyses. DNA was extracted from the representative isolates using a CTAB method. Nucleotide sequences of the internal transcribed spacers (ITS) (White et al. 1990), calmodulin (CAM), RNA polymerase II second largest subunit (RPB2), translation elongation factor 1-α gene (TEF1) (Xia et al. 2019) were amplified using specific primers, sequenced, and deposited in GenBank (ITS: MW391507 and MW391508, CAM: MW392787 and MW392788, RPB2: MW392795 and MW392796, TEF1: MW392791 and MW392792). The Fusarium MLST database pairwise alignment of ITS (546 bp), CAM (628 bp), RPB2 (902 bp) and TEF1 (718 bp) sequences from isolate XP9 showed 99.63%, 99.33%, 100.00% and 99.71% similarity with the corresponding sequences (GQ505685, GQ505508, GQ505774 and GQ505596) of the reference strain of F. nanum (NRRL 22244), respectively. The overlap of ITS, CAM, RPB2 and TEF1 sequences from XP9 and NRRL 22244 were 100.00%, 95.06%, 97.45% and 94.99%, respectively. Alignments of a combined dataset of ITS, CAM, RPB2 and TEF1 were made using MAFFT v. 7, and phylogenetic analyses were conducted in MEGA v. 7.0 using the maximum likelihood method. The muskmelon isolates (XP9 and XP10) clustered together with the F. nanum reference strain CGMCC3.19498 and NRRL 22244 (100% bootstrap) (Wang et al., 2019). To perform a pathogenicity test, 10 μl of conidial suspensions (1 × 106 conidia/ml) were injected into each muskmelon fruit using a syringe, and the control fruit was inoculated with 10 μl of sterile distilled water. There were ten replicated fruits for each treatment. The test was repeated three times. After 7 days at 25°C, the interior of the inoculated muskmelons begun to rot, and the rot lesion expanded from the core towards the surface of the fruit, then white mycelia were produced on the surface. Ten isolations were re-isolated from the infected tissues and identified by morphological and phylogenetic analyses and confirmed to fulfill Koch's postulates. No symptoms were observed on the control muskmelons. To our knowledge, this is the first report of muskmelon fruit rot caused by F. nanum in China. Considering the economic value of the muskmelon crop, correct identification can help farmers select appropriate field management measures for control of this disease.

Published
2023

42. Measurements of Proton High-Order Cumulants in sqrt[s_{NN}]=3 GeV Au+Au Collisions and Implications for the QCD Critical Point

Author

M S, Abdallah, B E, Aboona, J, Adam, L, Adamczyk, J R, Adams, J K, Adkins, G, Agakishiev, I, Aggarwal, M M, Aggarwal, Z, Ahammed, I, Alekseev, D M, Anderson, A, Aparin, E C, Aschenauer, M U, Ashraf, F G, Atetalla, A, Attri, G S, Averichev, V, Bairathi, W, Baker, J G, Ball Cap, K, Barish, A, Behera, R, Bellwied, P, Bhagat, A, Bhasin, J, Bielcik, J, Bielcikova, I G, Bordyuzhin, J D, Brandenburg, A V, Brandin, I, Bunzarov, X Z, Cai, H, Caines, M, Calderón de la Barca Sánchez, D, Cebra, I, Chakaberia, P, Chaloupka, B K, Chan, F-H, Chang, Z, Chang, N, Chankova-Bunzarova, A, Chatterjee, S, Chattopadhyay, D, Chen, J, Chen, J H, Chen, X, Chen, Z, Chen, J, Cheng, M, Chevalier, S, Choudhury, W, Christie, X, Chu, H J, Crawford, M, Csanád, M, Daugherity, T G, Dedovich, I M, Deppner, A A, Derevschikov, A, Dhamija, L, Di Carlo, L, Didenko, P, Dixit, X, Dong, J L, Drachenberg, E, Duckworth, J C, Dunlop, N, Elsey, J, Engelage, G, Eppley, S, Esumi, O, Evdokimov, A, Ewigleben, O, Eyser, R, Fatemi, F M, Fawzi, S, Fazio, P, Federic, J, Fedorisin, C J, Feng, Y, Feng, P, Filip, E, Finch, Y, Fisyak, A, Francisco, C, Fu, L, Fulek, C A, Gagliardi, T, Galatyuk, F, Geurts, N, Ghimire, A, Gibson, K, Gopal, X, Gou, D, Grosnick, A, Gupta, W, Guryn, A I, Hamad, A, Hamed, Y, Han, S, Harabasz, M D, Harasty, J W, Harris, H, Harrison, S, He, W, He, X H, He, Y, He, S, Heppelmann, N, Herrmann, E, Hoffman, L, Holub, Y, Hu, H, Huang, H Z, Huang, S L, Huang, T, Huang, X, Huang, Y, Huang, T J, Humanic, G, Igo, D, Isenhower, W W, Jacobs, C, Jena, A, Jentsch, Y, Ji, J, Jia, K, Jiang, X, Ju, E G, Judd, S, Kabana, M L, Kabir, S, Kagamaster, D, Kalinkin, K, Kang, D, Kapukchyan, K, Kauder, H W, Ke, D, Keane, A, Kechechyan, M, Kelsey, Y V, Khyzhniak, D P, Kikoła, C, Kim, B, Kimelman, D, Kincses, I, Kisel, A, Kiselev, A G, Knospe, H S, Ko, L, Kochenda, L K, Kosarzewski, L, Kramarik, P, Kravtsov, L, Kumar, S, Kumar, R, Kunnawalkam Elayavalli, J H, Kwasizur, R, Lacey, S, Lan, J M, Landgraf, J, Lauret, A, Lebedev, R, Lednicky, J H, Lee, Y H, Leung, N, Lewis, C, Li, W, Li, X, Li, Y, Li, X, Liang, Y, Liang, R, Licenik, T, Lin, Y, Lin, M A, Lisa, F, Liu, H, Liu, P, Liu, T, Liu, X, Liu, Y, Liu, Z, Liu, T, Ljubicic, W J, Llope, R S, Longacre, E, Loyd, N S, Lukow, X F, Luo, L, Ma, R, Ma, Y G, Ma, N, Magdy, D, Mallick, S, Margetis, C, Markert, H S, Matis, J A, Mazer, N G, Minaev, S, Mioduszewski, B, Mohanty, M M, Mondal, I, Mooney, D A, Morozov, A, Mukherjee, M, Nagy, J D, Nam, Md, Nasim, K, Nayak, D, Neff, J M, Nelson, D B, Nemes, M, Nie, G, Nigmatkulov, T, Niida, R, Nishitani, L V, Nogach, T, Nonaka, A S, Nunes, G, Odyniec, A, Ogawa, S, Oh, V A, Okorokov, B S, Page, R, Pak, J, Pan, A, Pandav, A K, Pandey, Y, Panebratsev, P, Parfenov, B, Pawlik, D, Pawlowska, C, Perkins, L, Pinsky, J, Pluta, B R, Pokhrel, G, Ponimatkin, J, Porter, M, Posik, V, Prozorova, N K, Pruthi, M, Przybycien, J, Putschke, H, Qiu, A, Quintero, C, Racz, S K, Radhakrishnan, N, Raha, R L, Ray, R, Reed, H G, Ritter, M, Robotkova, O V, Rogachevskiy, J L, Romero, D, Roy, L, Ruan, J, Rusnak, A K, Sahoo, N R, Sahoo, H, Sako, S, Salur, J, Sandweiss, S, Sato, W B, Schmidke, N, Schmitz, B R, Schweid, F, Seck, J, Seger, M, Sergeeva, R, Seto, P, Seyboth, N, Shah, E, Shahaliev, P V, Shanmuganathan, M, Shao, T, Shao, A I, Sheikh, D Y, Shen, S S, Shi, Y, Shi, Q Y, Shou, E P, Sichtermann, R, Sikora, M, Simko, J, Singh, S, Singha, M J, Skoby, N, Smirnov, Y, Söhngen, W, Solyst, Y, Song, P, Sorensen, H M, Spinka, B, Srivastava, T D S, Stanislaus, M, Stefaniak, D J, Stewart, M, Strikhanov, B, Stringfellow, A A P, Suaide, M, Sumbera, B, Summa, X M, Sun, X, Sun, Y, Sun, B, Surrow, D N, Svirida, Z W, Sweger, P, Szymanski, A H, Tang, Z, Tang, A, Taranenko, T, Tarnowsky, J H, Thomas, A R, Timmins, D, Tlusty, T, Todoroki, M, Tokarev, C A, Tomkiel, S, Trentalange, R E, Tribble, P, Tribedy, S K, Tripathy, T, Truhlar, B A, Trzeciak, O D, Tsai, Z, Tu, T, Ullrich, D G, Underwood, I, Upsal, G, Van Buren, J, Vanek, A N, Vasiliev, I, Vassiliev, V, Verkest, F, Videbæk, S, Vokal, S A, Voloshin, F, Wang, G, Wang, J S, Wang, P, Wang, X, Wang, Y, Wang, Z, Wang, J C, Webb, P C, Weidenkaff, L, Wen, G D, Westfall, H, Wieman, S W, Wissink, R, Witt, J, Wu, Y, Wu, B, Xi, Z G, Xiao, G, Xie, W, Xie, H, Xu, N, Xu, Q H, Xu, Y, Xu, Z, Xu, G, Yan, C, Yang, Q, Yang, S, Yang, Y, Yang, Z, Ye, L, Yi, K, Yip, Y, Yu, H, Zbroszczyk, W, Zha, C, Zhang, D, Zhang, J, Zhang, S, Zhang, X P, Zhang, Y, Zhang, Z J, Zhang, Z, Zhang, J, Zhao, C, Zhou, Y, Zhou, X, Zhu, M, Zurek, and M, Zyzak

Abstract

We report cumulants of the proton multiplicity distribution from dedicated fixed-target Au+Au collisions at sqrt[s_{NN}]=3.0 GeV, measured by the STAR experiment in the kinematic acceptance of rapidity (y) and transverse momentum (p_{T}) within -0.5y0 and 0.4p_{T}2.0 GeV/c. In the most central 0%-5% collisions, a proton cumulant ratio is measured to be C_{4}/C_{2}=-0.85±0.09 (stat)±0.82 (syst), which is 2σ below the Poisson baseline with respect to both the statistical and systematic uncertainties. The hadronic transport UrQMD model reproduces our C_{4}/C_{2} in the measured acceptance. Compared to higher energy results and the transport model calculations, the suppression in C_{4}/C_{2} is consistent with fluctuations driven by baryon number conservation and indicates an energy regime dominated by hadronic interactions. These data imply that the QCD critical region, if created in heavy-ion collisions, could only exist at energies higher than 3 GeV.

Published
2021

44. Fascial space priority approach for laparoscopic en bloc extended right hemicolectomy with pancreaticoduodenectomy for locally advanced colon cancer

Author

Q S Zeng, H J Yang, Y D Zhou, Z C Zhang, S X Liu, X P Zhang, P Li, and Yun Sun

Subjects
medicine.medical_specialty, medicine.diagnostic_test, Colorectal cancer, business.industry, General surgery, medicine.medical_treatment, Gastroenterology, MEDLINE, Pancreaticoduodenectomy, medicine.disease, Colorectal surgery, medicine, Surgery, Fascial space, business, Laparoscopy, Abdominal surgery, Colectomy
Published
2021

45. First Report of

Author

X P, Zhang, J W, Xia, J K, Liu, D, Zhao, L G, Kong, and X P, Zhu

Published
2021

47. Measurements of _{Λ}^{3}H and _{Λ}^{4}H Lifetimes and Yields in Au+Au Collisions in the High Baryon Density Region

Author

M S, Abdallah, B E, Aboona, J, Adam, L, Adamczyk, J R, Adams, J K, Adkins, G, Agakishiev, I, Aggarwal, M M, Aggarwal, Z, Ahammed, I, Alekseev, D M, Anderson, A, Aparin, E C, Aschenauer, M U, Ashraf, F G, Atetalla, A, Attri, G S, Averichev, V, Bairathi, W, Baker, J G, Ball Cap, K, Barish, A, Behera, R, Bellwied, P, Bhagat, A, Bhasin, J, Bielcik, J, Bielcikova, I G, Bordyuzhin, J D, Brandenburg, A V, Brandin, I, Bunzarov, X Z, Cai, H, Caines, M, Calderón de la Barca Sánchez, D, Cebra, I, Chakaberia, P, Chaloupka, B K, Chan, F-H, Chang, Z, Chang, N, Chankova-Bunzarova, A, Chatterjee, S, Chattopadhyay, D, Chen, J, Chen, J H, Chen, X, Chen, Z, Chen, J, Cheng, M, Chevalier, S, Choudhury, W, Christie, X, Chu, H J, Crawford, M, Csanád, M, Daugherity, T G, Dedovich, I M, Deppner, A A, Derevschikov, A, Dhamija, L, Di Carlo, L, Didenko, P, Dixit, X, Dong, J L, Drachenberg, E, Duckworth, J C, Dunlop, N, Elsey, J, Engelage, G, Eppley, S, Esumi, O, Evdokimov, A, Ewigleben, O, Eyser, R, Fatemi, F M, Fawzi, S, Fazio, P, Federic, J, Fedorisin, C J, Feng, Y, Feng, P, Filip, E, Finch, Y, Fisyak, A, Francisco, C, Fu, L, Fulek, C A, Gagliardi, T, Galatyuk, F, Geurts, N, Ghimire, A, Gibson, K, Gopal, X, Gou, D, Grosnick, A, Gupta, W, Guryn, A I, Hamad, A, Hamed, Y, Han, S, Harabasz, M D, Harasty, J W, Harris, H, Harrison, S, He, W, He, X H, He, Y, He, S, Heppelmann, N, Herrmann, E, Hoffman, L, Holub, Y, Hu, H, Huang, H Z, Huang, S L, Huang, T, Huang, X, Huang, Y, Huang, T J, Humanic, G, Igo, D, Isenhower, W W, Jacobs, C, Jena, A, Jentsch, Y, Ji, J, Jia, K, Jiang, X, Ju, E G, Judd, S, Kabana, M L, Kabir, S, Kagamaster, D, Kalinkin, K, Kang, D, Kapukchyan, K, Kauder, H W, Ke, D, Keane, A, Kechechyan, M, Kelsey, Y V, Khyzhniak, D P, Kikoła, C, Kim, B, Kimelman, D, Kincses, I, Kisel, A, Kiselev, A G, Knospe, H S, Ko, L, Kochenda, L K, Kosarzewski, L, Kramarik, P, Kravtsov, L, Kumar, S, Kumar, R, Kunnawalkam Elayavalli, J H, Kwasizur, R, Lacey, S, Lan, J M, Landgraf, J, Lauret, A, Lebedev, R, Lednicky, J H, Lee, Y H, Leung, N, Lewis, C, Li, W, Li, X, Li, Y, Li, X, Liang, Y, Liang, R, Licenik, T, Lin, Y, Lin, M A, Lisa, F, Liu, H, Liu, P, Liu, T, Liu, X, Liu, Y, Liu, Z, Liu, T, Ljubicic, W J, Llope, R S, Longacre, E, Loyd, N S, Lukow, X F, Luo, L, Ma, R, Ma, Y G, Ma, N, Magdy, D, Mallick, S, Margetis, C, Markert, H S, Matis, J A, Mazer, N G, Minaev, S, Mioduszewski, B, Mohanty, M M, Mondal, I, Mooney, D A, Morozov, A, Mukherjee, M, Nagy, J D, Nam, Md, Nasim, K, Nayak, D, Neff, J M, Nelson, D B, Nemes, M, Nie, G, Nigmatkulov, T, Niida, R, Nishitani, L V, Nogach, T, Nonaka, A S, Nunes, G, Odyniec, A, Ogawa, S, Oh, V A, Okorokov, B S, Page, R, Pak, J, Pan, A, Pandav, A K, Pandey, Y, Panebratsev, P, Parfenov, B, Pawlik, D, Pawlowska, C, Perkins, L, Pinsky, R L, Pintér, J, Pluta, B R, Pokhrel, G, Ponimatkin, J, Porter, M, Posik, V, Prozorova, N K, Pruthi, M, Przybycien, J, Putschke, H, Qiu, A, Quintero, C, Racz, S K, Radhakrishnan, N, Raha, R L, Ray, R, Reed, H G, Ritter, M, Robotkova, O V, Rogachevskiy, J L, Romero, D, Roy, L, Ruan, J, Rusnak, A K, Sahoo, N R, Sahoo, H, Sako, S, Salur, J, Sandweiss, S, Sato, W B, Schmidke, N, Schmitz, B R, Schweid, F, Seck, J, Seger, M, Sergeeva, R, Seto, P, Seyboth, N, Shah, E, Shahaliev, P V, Shanmuganathan, M, Shao, T, Shao, A I, Sheikh, D Y, Shen, S S, Shi, Y, Shi, Q Y, Shou, E P, Sichtermann, R, Sikora, M, Simko, J, Singh, S, Singha, M J, Skoby, N, Smirnov, Y, Söhngen, W, Solyst, P, Sorensen, H M, Spinka, B, Srivastava, T D S, Stanislaus, M, Stefaniak, D J, Stewart, M, Strikhanov, B, Stringfellow, A A P, Suaide, M, Sumbera, B, Summa, X M, Sun, X, Sun, Y, Sun, B, Surrow, D N, Svirida, Z W, Sweger, P, Szymanski, A H, Tang, Z, Tang, A, Taranenko, T, Tarnowsky, J H, Thomas, A R, Timmins, D, Tlusty, T, Todoroki, M, Tokarev, C A, Tomkiel, S, Trentalange, R E, Tribble, P, Tribedy, S K, Tripathy, T, Truhlar, B A, Trzeciak, O D, Tsai, Z, Tu, T, Ullrich, D G, Underwood, I, Upsal, G, Van Buren, J, Vanek, A N, Vasiliev, I, Vassiliev, V, Verkest, F, Videbaek, S, Vokal, S A, Voloshin, F, Wang, G, Wang, J S, Wang, P, Wang, X, Wang, Y, Wang, Z, Wang, J C, Webb, P C, Weidenkaff, L, Wen, G D, Westfall, H, Wieman, S W, Wissink, R, Witt, J, Wu, Y, Wu, B, Xi, Z G, Xiao, G, Xie, W, Xie, H, Xu, N, Xu, Q H, Xu, Y, Xu, Z, Xu, G, Yan, C, Yang, Q, Yang, S, Yang, Y, Yang, Z, Ye, L, Yi, K, Yip, Y, Yu, H, Zbroszczyk, W, Zha, C, Zhang, D, Zhang, J, Zhang, S, Zhang, X P, Zhang, Y, Zhang, Z J, Zhang, Z, Zhang, J, Zhao, C, Zhou, Y, Zhou, X, Zhu, M, Zurek, and M, Zyzak

Abstract

We report precision measurements of hypernuclei _{Λ}^{3}H and _{Λ}^{4}H lifetimes obtained from Au+Au collisions at sqrt[s_{NN}]=3.0 GeV and 7.2 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider, and the first measurement of _{Λ}^{3}H and _{Λ}^{4}H midrapidity yields in Au+Au collisions at sqrt[s_{NN}]=3.0 GeV. _{Λ}^{3}H and _{Λ}^{4}H, being the two simplest bound states composed of hyperons and nucleons, are cornerstones in the field of hypernuclear physics. Their lifetimes are measured to be 221±15(stat)±19(syst) ps for _{Λ}^{3}H and 218±6(stat)±13(syst) ps for _{Λ}^{4}H. The p_{T}-integrated yields of _{Λ}^{3}H and _{Λ}^{4}H are presented in different centrality and rapidity intervals. It is observed that the shape of the rapidity distribution of _{Λ}^{4}H is different for 0%-10% and 10%-50% centrality collisions. Thermal model calculations, using the canonical ensemble for strangeness, describes the _{Λ}^{3}H yield well, while underestimating the _{Λ}^{4}H yield. Transport models, combining baryonic mean-field and coalescence (jam) or utilizing dynamical cluster formation via baryonic interactions (phqmd) for light nuclei and hypernuclei production, approximately describe the measured _{Λ}^{3}H and _{Λ}^{4}H yields. Our measurements provide means to precisely assess our understanding of the fundamental baryonic interactions with strange quarks, which can impact our understanding of more complicated systems involving hyperons, such as the interior of neutron stars or exotic hypernuclei.

Published
2021

49. Prediction of acute myocardial infarction by multi-parameter coronary computed tomography angiography

Author

J. Wang, H.-W. Chen, L.-J. Zhou, X.-P. Zhang, B.-X. Chen, K.-D. Chen, and X.-M. Fang

Subjects
Fractional Flow Reserve, Myocardial, Computed Tomography Angiography, Predictive Value of Tests, Coronary Stenosis, Myocardial Infarction, Humans, Radiology, Nuclear Medicine and imaging, General Medicine, Coronary Artery Disease, Coronary Angiography, Coronary Vessels, Inosine Diphosphate, Retrospective Studies
Abstract

To investigate the performance of multi-parameter coronary computed tomography angiography (CCTA), including stenosis, plaque qualitative-quantitative characteristics, and fractional flow reserve derived from CCTA (FFRct), to predict acute myocardial infarction (AMI) and build a combined model.Thirty patients with AMI 90 days after CCTA and 120 matched patients without AMI were enrolled retrospectively. Multiple CCTA parameters were analysed and compared. Independent risk factors were obtained through univariate and multivariate regression analyses, after which a multi-parameter model was built.A total of 150 patients were analysed successfully. The multi-parameter CCTA model (area under the curve, 0.944; p0.001) had a higher predictive value than each single parameter (p0.001, all). Independent risk factors were intra-plaque dye penetration (IDP; odds ratio [OR], 8.373; p=0.002), lipid plaque volume (LPV; OR, 1.263; p0.001), and FFRct ≤0.83 (OR, 8.092; p=0.001).This one-stop multi-parameter CCTA model, comprising IDP, LPV, and FFRct as independent risk factors, has good performance to predict AMI.

Published
2021

50. Spectrophotometry of the lunar regolith using the Chang’E-3 Panoramic Camera (PCAM)

Author

T. Y. Xu, B. Hapke, X. P. Zhang, Y. Z. Wu, and X. P. Lu

Subjects
Space and Planetary Science, Astronomy and Astrophysics
Abstract

Aims. We present a multiband photometric study of the lunar mare surface based on in situ measurements using the Panoramic Camera on board the Chang'E-3 mission. We aim to obtain photometric properties and to investigate the differences in measuring sites in various conditions. Methods. Data were collected with a vast range of phase angles from 0.5° to 160°, probing 0–5° phases to constrain the opposition effect (OE) and phases above 120° to constrain the phase function. Stray light and spectral corrections were conducted to calibrate the regolith’s bidirectional reflectance distribution function. We employed the Hapke photometric model to describe the regolith’s photometric properties. Results. Phase functions and Hapke parameters at three measuring sites were retrieved. The mare regolith at the measuring sites had a single-scattering albedo (SSA) of 0.17-0.21 for the green channel and exhibited backscattering and a strong OE. The coherent backscatter opposition effect (CBOE) represented the majority of OE, with a proportion of around 80% for pristine regolith. The phase ratio curves were arch-shaped, and the arch positions of the curves were associated with grain size.

Published
2022

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