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Searching for events in Chinese ancient records to explain the increase in ^(14)C from AD 774–775 and AD 993–994

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Research in Astronomy and Astrophysics 2015年第9期15卷 1504-1512页

作者： Ya-Ting Chai yuan-chuan zou School of Physics Huazhong University of Science and Technology Department of Physics Hong Kong University

According to analysis of the ^14C content in two Japanese trees, that grew over a period of approximately 3000 years, with high time resolution, Miyake et al. found a rapid increase at AD 774-775 and another one at AD 993-994. These increases correspond to high-energy events that happened within those years and radi- ated ＂）,-ray energy of about 7x 1034 erg toward the Earth. The origin of these events is a mystery. Such strong events should have an unusual optical counterpart, and have been recorded in historical literatures. We searched Chinese historical materi- als around AD 744-775 and AD 993-994, but no remarkable event was found except for a violent thunderstorm in AD 775. However, the possibility of a thunderstorm containing so much energy is unlikely. We conclude that the events, which caused the 14C increase, are still unclear. These events most probably had no optical counterpart, and a short gamma-ray burst, giant flare of a soft gamma-ray repeater or a terrestrial γ-ray flash could all be candidates.

关键词： astroparticle -- ^14C -- gamma rays: general -- astronomical history --astrobiology

Tail Emission from a Ring-like Jet: Its Application to Shallow Decays of Early Afterglows and GRB 050709

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Chinese Journal of Astronomy and Astrophysics 2006年第5期6卷 551-554页

作者： yuan-chuan zou Zi-Gao Dai Department of Astronomy Nanjing University Nanjing 210093

Similar to the case of pulsars the magnetic axis and the spin axis of gamma-ray burst sources may not lie on the same line. This may cause the formation of a ring-like jet due to collimation of the precessing magnetic axis. We analyze the tail emission from such a jet, and find that it has a shallow decay phase with a temporal index of - 1/2 if the Lorentz factor of the ejecta is not very high, which is consistent with the shallow decay phase of some early X-ray afterglow detected by Swift. The ring-like jet has a tail cusp with sharp rising and very sharp decay. This effect can provide an explanation for the re-brightening and sharp decay of the X-ray afterglow＇of GRB 050709.

关键词： gamma rays bursts - X-rays general

Gradient microstructure and superior strength-ductility synergy of AZ61 magnesium alloy bars processed by radial forging with different deformation temperatures

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Journal of Materials Science & Technology 2024年第3期170卷 65-77页

作者： Jingfeng zou Lifeng Ma Yanchun Zhu Ling Qin yuan yuan School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Heavy Machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Engineering University of HullCottingham RdHull HU67RXUK National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

Gradient microstructure modification is a cost-efficient strategy for high strength without compromising ductility,which is urgently needed in the fundamental science of engineering *** this study,heterogeneous structures of AZ61 alloy bars with anisotropic gradients(with different grain size distributions from the surface to the center)were observed to exhibit strong strength-ductility synergies under different deformation tem *** results reveal that the grain refinement process under mediumlow temperature deformation conditions(≤350℃)consists of four transition stages along the radial direction,i.e.,twin activations and deformation band formations,dislocation cells and pile-ups,ultrafine sub-grains,and randomly orientated quasi-micron *** deformation temperatures have a great influence on twin activations and deformation band formations,and the high temperature can easily provoke the initiation of non-basal *** deformation bands were determined as a primary nucleation site due to their highly unstable dislocation hindrance *** in combination with the Radial forging(RF)deformation process,the differences of dynamic precipitates can be attributed to microstructural difference and solubility limit of Al at different tem *** summarizing the tensile test results,the sample forged at 350℃exhibited the best strength-ductility synergy,exhibiting the highest elongation(EL)of 23.2%with a 251 MPa yield strength(YS)and 394 MPa ultimate tensile strength(UTS)in center region,and combined with the highest strength value of 256 MPa YS and 420 MPa UTS in the center region,while the EL was slightly degraded to 19.8%.

关键词： Gradient microstructure Radial forging Strength-ductility synergy Magnesium alloy Strengthening mechanism

Mismatch loss analysis of solar array output power on stratospheric airship during flight

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Chinese Journal of Aeronautics 2024年第2期37卷 371-384页

作者： Siyu LIU Kangwen SUN Haoquan LIANG Xinzhe JI Tong zou chuan SHAN School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Yunnan Innovation Institute Beihang UniversityKunming 650233China Institute of Unmanned System Beihang UniversityBeijing 100191China

Stratospheric airships are long-endurance aerostats and have broad *** of the energy required for their operation is obtained from solar radiation,which makes accurate calculation of the energy output from the solar array crucial to the design and flight planning of the ***,the status of each photovoltaic module in the solar array may differ due to the airship curvature,resulting in mismatch losses and lowered output power,which has not been widely *** this paper,an irradiation model and a thermal model are established based on the actual arrangement of the *** output power model is established considering the non-uniform radiation in the *** mismatch losses of the array are analyzed under different flight *** output power of the solar array is decreased by up to 31.6%compared to the ideal ***,the proportion of mismatch losses increases with latitude,but the maximum mismatch loss power occurs at ***,an array reconfiguration method is proposed based on the irradiance dispersion index and position dispersion *** reconfigured array increases output power by 11.5%and can maintain energy balance in continuous *** results can be used to correct the overestimation of the output power during the airship design or to guide the configuration of the solar array.

关键词： Stratospheric airship Solar panels Solar energy Non-uniform irradiation Mismatch loss assessment Reconfiguration

Early afterglows from radially structured outflows and the application to X-ray shallow decays

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Research in Astronomy and Astrophysics 2009年第8期9卷 911-920页

作者： Xue-Wen Liu Xue-Feng Wu yuan-chuan zou Tan Lu Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Joint Center for Particle Nuclear Physics and Cosmology （J-CPNPC） Nanjing 210093 China Department of Astronomy ＆ Astrophysics Pennsylvania State University University Park PA 16802 USA Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

In the fireball model, it is more physically realistic that ganuna-ray burst （GRB） ejecta have a range of bulk Lorentz factors （assuming M ∝ Г^-8）. The low Lorentz factor part of the ejecta will catch up with the high Lorentz factor part when the latter is decelerated by the surrounding medium to a comparable Lorentz factor. Such a process will develop a long-lasting weak reverse shock until the whole ejecta are shocked. Meanwhile, the forward shocked materials are gradually supplied with energy from the ejecta that are catching-up, and thus the temporal decay of the forward shock emission will be slower than that without an energy supply. However, the reverse shock may be strong. Here, we extend the standard reverse-forward shock model to the case of radially nonuniform ejecta. We show that this process can be classified into two cases： the thick shell case and the thin shell case. In the thin shell case, the reverse shock is weak and the temporal scaling law of the afterglow is the same as that in Sad ＆ Meszaros （2000）. However, in the thick shell case, the reverse shock is strong and thus its emission dominates the afterglow in the high energy band. Our results also show slower decaying behavior of the afterglow due to the energy supply by low Lorentz factor materials, which may help the understanding of the plateau observed in the early optical and X-ray afterglows.

关键词： gamma-rays bursts -- hydrodynamics -- radiation mechanisms nonther- mal -- shock waves

Modeling the quasi-periodic oscillation of Swift J1644+57

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Research in Astronomy and Astrophysics 2020年第2期20卷 31-36页

作者： Meng-Meng Zheng Shuang-Xi Yi Fa-Yin Wang yuan-chuan zou School of Physics and Physical Engineering Qufu Normal UniversityQufu 273165China School of Astronomy and Space Science Nanjing UniversityNanjing 210093China School of Physics Huazhong University of Science and TechnologyWuhan 430074China

A 200-second X-ray quasi-periodicity in the 2-8 ke V band from Swift J1644+57 was found by Reis et *** the onset time of quasi-periodic oscillation(QPO),we show that Swift J1644+57 is a plunging *** QPO may be related to discrete clumps from the accretion disk falling into a supermassive black hole,then the outflow in the jet may be also *** estimate the lifetime of clumps to be about several hundreds seconds and the fraction of clumpy ejecta to be about 30% from the *** other possible model involves the interface between the inflow and jet magnetosphere in the magnetically choked accretion *** and numerical simulations indicate that a magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface can produce a jet-disk QPO *** event may be the first evidence of jet-disk *** observations,the two models are comparable.

关键词： accretion accretion discs gamma-ray burst:general radiation mechanism:non-thermal

Methane activation by[LnO]^(+):the 4f orbital matters

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Science China Chemistry 2024年第1期67卷 330-335页

作者： Bowei yuan Jingxiang zou Mincheng Yu Shaodong Zhou College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027China Zhejiang Provincial Innovation Center of Advanced Chemicals Technology Institute of Zhejiang University–QuzhouQuzhou 324000China Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

Gas-phase reactions of[LnO]^(+)with methane have been studied by using inductively coupled plasma-mass spectrometer(ICP-MS)combined with quantum chemical *** indicate that the[LnO]^(+)(Ln=Sm-Lu)ions are able to activate methane to generate methyl *** particular,[EuO]^(+)and[YbO]^(+)exhibit the highest ***,ab initio computations reveal a novel HAT process operating in the absence of a terminal oxygen radical,as mediated by[EuO]^(+)and[YbO]^(+).Such a process diverges from previous findings on the methane activation by metal oxide clusters,not only on the electronic pattern during the course of hydrogen transfer,but also on the important role that 4f electrons *** associated electronic origins have been discussed,and the well-designed 4f electron occupation may turn to be a promising approach in constructing lanthanide involved catalysts.

关键词： lanthanide oxides methane activation 4f orbitals quantum chemical calculation ion-molecule reaction

The updated Bulk Lorentz Factors of Gamma-Ray Burst X-Ray Flares

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Research in Astronomy and Astrophysics 2017年第6期17卷 37-46页

作者： Shao-Qiang Xi Shuang-Xi Yi yuan-chuan zou Fa-Yin Wang College of Physics and Engineering Qufu Normal University Qufu 273165 China School of Physics Huazhong University of Science and Technology Wuhan 430074 China School of Astronomy and Space Science Nanjing University Nanjing 210093 China Key Laboratory of Modem Astronomy and Astrophysics (Nanjing University) Nanjing 210093 China

X-ray flares are the most common phenomena in the afterglow phase of gamma-ray bursts （GRBs） in the Swift era, and are known as a canonical component in X-ray afterglows. In this work, we constrain the Lorentz factor of X-ray flares with an updated sample. We extensively search for X-ray light curves showing flare and jet break simultaneously. A smooth broken power law function is used to fit the jet breaks in 11 GRBs. We also use a smooth broken power law function to fit the profile of X-ray flares, and the total number of the flares is 20. We obtain the lower and upper limits of Lorentz factor （Гx） with the timescale, half-opening angle and mean luminosity of the X-ray flares for interstellar medium （ISM） and wind cases. The lower limits on Px range from tens to a few hundred, and the upper limits are mainly about a few hundred. We also apply the limited Lorentz factor to test correlations of Г0 - γ,iso and Г0 - Lγ,iso for GRBs, and find X-ray flares in the ISM case are much more consistent with those of prompt emission than the wind case in a statistical sense for both correlations. X-ray flares are almost consistent with the trend in the correlations of Г0 - Eγ,iso（Lγ,iso） for prompt GRBs, indicating X-ray flares and prompt bursts may have the same physical origin.

关键词： gamma ray bursts -radiation mechanism: non-thermal

Severe liver injury and clinical characteristics of occupational exposure to 2-amino-5-chloro-N,3-dimethylbenzamide: A case series

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Hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 186-194页

作者： Meng-Xiao Feng Hua zou yuan-Qiang Lu Department of Emergency Medicine The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Key Laboratory for Diagnosis and Treatment of Aging and Physic-chemical Injury Diseases of Zhejiang Province Hangzhou 310003China Occupational Health and Radiation Protection Institute Zhejiang Provincial Center for Disease Control and PreventionHangzhou 310051China

Background:The 2-amino-5-chloro-N,3-dimethylbenzamide is a key intermediate in the synthesis of pesticides and ***,no literature currently exists on 2-amino-5-chloro-N,3-dimethylbenzamide poisoning in *** study aimed to reveal the health hazard of this chemical for humans and summarize the clinical characteristics of patients with occupational 2-amino-5-chloro-N,3-dimethylbenzamide ***:This observational study included four patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning from June 2022 to July *** entire course of the incidents was described in *** 2-amino-5-chloro-N,3-dimethylbenzamide concentrations were detected by a mass ***-toxylin and eosin staining was performed to assess liver injury,and immunofluorescence was used to evaluate hepatic ***:The 2-amino-5-chloro-N,3-dimethylbenzamide powder(99%purity)entered the human body mainly via the skin and respiratory tract due to poor personal protective *** typical course of 2-amino-5-chloro-N,3-dimethylbenzamide poisoning was divided into latency,rash,fever,organic dam-age,and recovery phases in accordance with the clinical *** and fever may be the important premonitory symptoms for further organ *** chemical was detected in the blood of all patients and caused multiple organ injuries,predominantly liver injury,including kidney,myocardium,and *** patients recovered smoothly after comprehensive treatments,including artificial liver therapy,continuous renal replacement therapy,glucocorticoids,and other symptomatic and supportive *** patient survived by liver *** postoperative pathological findings of the removed liver showed acute liver failure,and immunofluorescence staining confirmed the abundance of mitophagy in residual ***:This study is the first to elaborate the clinical characteristics of patients with 2-amino-5-chloro-N,

关键词： 2-amino-5-chloro-N,3-dimethylbenzamide Poisoning Clinical characteristics Liver injury