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Evidence for particle acceleration approaching PeV energies in the W51 complex

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Science Bulletin 2024年第18期69卷 2833-2841页

作者： Cao, Zhen Aharonian, F. Axikegu Bai, Y.X. Bao, Y.W. Bastieri, D. Bi, X.J. Bi, Y.J. Bian, W. Bukevich, A.V. Cao, Q. Cao, W.Y. Cao, Zhe Chang, J. Chang, J.F. Chen, 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. Cheng, N. Cheng, Y.D. Cui, M.Y. Cui, S.W. Cui, X.h. Cui, Y.D. Dai, B.Z. Dai, h.l. Dai, Z.G. Danzengluobu Dong, X.Q. Duan, K.K. Fan, J.h. Fan, Y.Z. Fang, J. Fang, J.h. Fang, K. Feng, C.F. Feng, h. Feng, l. Feng, S.h. Feng, X.T. Feng, Y. Feng, Y.l. Gabici, S. Gao, B. Gao, C.D. Gao, Q. Gao, W. Gao, W.K. Ge, M.M. Geng, l.S. Giacinti, G. Gong, G.h. Gou, Q.B. Gu, M.h. Guo, F.l. Guo, X.l. Guo, Y.Q. Guo, Y.Y. han, Y.A. hasan, M. he, h.h. he, h.N. he, J.Y. he, Y. hor, Y.K. hou, B.W. hou, C. hou, X. hu, h.B. hu, Q. hu, S.C. huang, D.h. huang, T.Q. huang, W.J. huang, X.T. huang, X.Y. huang, Y. Ji, X.l. Jia, h.Y. Jia, K. Jiang, K. Jiang, X.W. Jiang, Z.J. Jin, M. Kang, M.M. Karpikov, I. Kuleshov, D. Kurinov, K. li, 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 liang, E.W. liang, Y.F. lin, S.J. liu, 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. luo, Q. luo, Y. lv, h.K. Ma, B.Q. Ma, l.l. Ma, X.h. Mao, J.R. Min, Z. Mitthumsiri, W. Mu, h.J. Nan, Y.C. Neronov, A. Ou, l.J. Pattarakijwanich, P. Pei, Z.Y. Qi, J.C. Qi, M.Y. Qiao, B.Q. Qin, J.J. Raza, A. ruffolo, D. Sáiz, A. Saeed, M. Semikoz, D. Shao, l. Shchegolev, O. Sheng, X.D. Shu, F.W. Song, h.C. Stenkin, Yu.V. Stepanov, V. Su, Y. Sun, D.X. Sun, Q.N. Sun, X.N. Sun, Z.B. Takata, J. Tam, P.h.T. Key laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China University of Chinese Academy of Sciences Beijing 100049 China TIANFU Cosmic Ray Research Center Chengdu China Dublin Institute for Advanced Studies 31 Fitzwilliam Place 2 Dublin Ireland Max-Planck-Institut for Nuclear Physics P.O. Box 103980 Heidelberg 69029 Germany School of Physical Science and Technology & School of Information Science and Technology Southwest Jiaotong University Chengdu 610031 China School of Astronomy and Space Science Nanjing University Nanjing 210023 China Center for Astrophysics Guangzhou University Guangzhou 510006 China Tsung-Dao lee Institute & School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China Institute for Nuclear Research of russian Academy of Sciences Moscow 117312 Russia hebei Normal University Shijiazhuang 050024 China University of Science and Technology of China Hefei 230026 China State Key laboratory of Particle Detection and Electronics China Key laboratory of Dark Matter and Space Astronomy & Key laboratory of Radio Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210023 China Research Center for Astronomical Computing Zhejiang Laboratory Hangzhou 311121 China Key laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China School of Physics and Astronomy Yunnan University Kunming 650091 China Key laboratory of Cosmic Rays (Tibet University) Ministry of Education Lhasa 850000 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China School of Physics and Astronomy (Zhuhai) & School of Physics (Guangzhou) & Sino-French Institute of Nuclear Engineering and Technology (Zhuhai) Sun Yat-sen University Zhuhai 519000 & Guangzhou 510275 Guangdong China Institute of Frontier and

The γ-ray emission from the W51 complex is widely acknowledged to be attributed to the interaction between the cosmic rays (CRs) accelerated by the shock of supernova remnant (SNR) W51C and the dense molecular clouds in the adjacent star-forming region, W51B. however, the maximum acceleration capability of W51C for CRs remains elusive. Based on observations conducted with the large high Altitude Air Shower Observatory (lhAASO), we report a significant detection of γ rays emanating from the W51 complex, with energies from 2 to 200 TeV. The lhAASO measurements, for the first time, extend the γ-ray emission from the W51 complex beyond 100 TeV and reveal a significant spectrum bending at tens of TeV. By combining the "π0-decay bump" featured data from Fermi-lAT, the broadband γ-ray spectrum of the W51 region can be well-characterized by a simple pp-collision model. The observed spectral bending feature suggests an exponential cutoff at ∼400 TeV or a power-law break at ∼200 TeV in the CR proton spectrum, most likely providing the first evidence of SNRs serving as CR accelerators approaching the PeV regime. Additionally, two young star clusters within W51B could also be theoretically viable to produce the most energetic γ rays observed by lhAASO. Our findings strongly support the presence of extreme CR accelerators within the W51 complex and provide new insights into the origin of Galactic CRs. © 2024 Science China Press

关键词： Cosmic rays

A Machine learning Made Catalog of FR-Ⅱ Radio Galaxies from the FIRST Survey

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Research in Astronomy and Astrophysics 2024年第3期24卷 266-282页

作者： Bao-Qiang lao Xiao-long Yang Sumit Jaiswal Prashanth Mohan Xiao-hui Sun Sheng-li Qin ru-Shuang Zhao School of Physics and Astronomy Yunnan UniversityKunming 650091.China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030.China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China

We present an independent catalog(FRIIRGcat)of 45,241 Fanaroff–Riley TypeⅡ(FR-Ⅱ)radio galaxies compiled from the Very large Array Faint Images of the Radio Sky at Twenty-centimeters(FIRST)survey and employed the deep learning *** them,optical and/or infrared counterparts are identified for 41,425 FR-Ⅱ*** catalog spans luminosities 2.63×10^(22)≤l_(rad)≤6.76×10^(29)W hz^(-1)and redshifts up to z=*** spectroscopic classification indicates that there are 1431 low-excitation radio galaxies and 260 high-excitation radio *** the spectroscopically identified sources,black hole masses are estimated for 4837 FR-Is,which are in 10^(7.5)■M_(Bh)■10^(9.5)M_(⊙).Interestingly,this catalog reveals a couple of giant radio galaxies(GRGs),which are already in the existing GRG catalog,confirming the efficiency of this FR-I ***,284new GRGs are unveiled in this new FR-I sample;they have the largest projected sizes ranging from 701 to1209 kpc and are located at redshifts 0.31lore the distribution of the jet position angle and it shows that the faint Images of the FIRST images are significantly affected by the systematic effect(the observing beams).The method presented in this work is expected to be applicable to the radio sky surveys that are currently being conducted because they have finely refined telescope *** the other hand,we are expecting that further new methods will be dedicated to solving this problem.

关键词： radio continuum galaxies-galaxies active-galaxies jets-galaxies statistics

Electron kinetic effects in back-stimulated Raman scattering bursts driven by broadband laser pulses

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Matter and Radiation at Extremes 2024年第4期9卷 54-67页

作者： Q.K.liu l.Deng Q.Wang X.Zhang F.Q.Meng Y.P.Wang Y.Q.Gao h.B.Cai S.P.Zhu Graduate School China Academy of Engineering PhysicsBeijing 100088China Institute of Applied Physics and Computational Mathematics Beijing 100094China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China Shanghai Institute of laser Plasma Shanghai 201800China hEDPS Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China School of Physics Zhejiang UniversityHangzhou 310027China

We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BSRS)bursts using particle-in-cell *** bursts occur during the nonlinear stage,causing reflectivity spikes and generating large numbers of hot ***-duration simulations are performed to observe burst events,and a simplified model is developed to eliminate the interference of the broadband laser’s random intensity *** the simplified model,we isolate and characterize the spectrum of electron plasma *** spectrum changes from a sideband structure to a turbulence-like structure during the burst.A significant asymmetry in the spectrum is *** asymmetry is amplified and transferred to electron phase space by high-intensity broadband laser pulses,leading to violent vortex-merging and generation of hot *** proportion of hot electrons increases from 6.76%to 14.7%during a single violent burst *** demonstrate that kinetic effects profoundly influence the BSRS evolution driven by broadband lasers.

关键词： scattering kinetic simplified

Well-Posedness of Stochastic Continuity Equations on Riemannian Manifolds

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 81-122页

作者： luca GAlIMBERTI Kenneth h.KARlSEN Department of Mathematical Sciences NTNU Norwegian University of Science and TechnologyN-7491 TrondheimNorway Department of mathematics University of OsloP.O.Box 1053BlindernN-0316 OsloNorway

The authors analyze continuity equations with Stratonovich stochasticity,■ρ+divh[ρo(u(t,x)+∑_(i=1)^(N)a_(i)(x)w_(i)(t))]=0defined on a smooth closed Riemannian manifold M with metric *** velocity field u is perturbed by Gaussian noise terms Wi(t),:WN(t)driven by smooth spatially dependent vector fields a1(x),...,aN(x)on *** velocity u belongs to l_(t)^(1)W_(x)^(1,2)with divh u bounded in lf,for p>d+2,where d is the dimension of M(they do not assume div_(h) u∈l_(t,x)^(∞)).For carefully chosen noise vector fields ai(and the number N of them),they show that the initial-value problem is well-posed in the class of weak l^(2) solutions,although the problem can be ill-posed in the deterministic case because of concentration *** proof of this“regularization by noise”result is based on a l^(2) estimate,which is obtained by a duality method,and a weak compactness argument.

关键词： Stochastic continuity equation Riemannian manifold hyperbolic equa-tion Non-smooth velocity field Weak solution Existence Uniqueness

A Comprehensive Review on Charging Topologies and Power Electronic Converter Solutions for Electric Vehicles

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 675-694页

作者： Abdelfatah Ali hossam h.h.Mousa Mostafa F.Shaaban Maher A.Azzouz Ahmed S.A.Awad the Department of Electrical Engineering American University of Sharjah26666 SharjahUnited Arab Emirates the Department of Electrical Engineering South Valley University83523 QenaEgypt the Department of Electrical and Computer Engineering University of WindsorWindsorON N9B 3P4 Canada Electrical Engineering Department Qatar UniversityDoha 2713Qatar Department of Electrical and Computer Engineering Sultan Qaboos UniversityMuscat123Oman

Electric vehicles(EVs)are becoming more popular worldwide due to environmental concerns,fuel security,and price *** performance of EVs relies on the energy stored in their batteries,which can be charged using either AC(slow)or DC(fast)***,EVs can also be used as mobile power storage devices using vehicle-to-grid(V2G)*** electronic converters(PECs)have a constructive role in EV applications,both in charging EVs and in ***,this paper comprehensively investigates the state of the art of EV charging topologies and PEC solutions for EV *** examines PECs from the point of view of their classifications,configurations,control approaches,and future research prospects and their impacts on power *** can be classified into various topologies:DC-DC converters,AC-DC converters,DC-AC converters,and AC-AC *** address the limitations of traditional DC-DC converters such as switching losses,size,and high-electromagnetic interference(EMI),resonant converters and multiport converters are being used in high-voltage EV ***,power-train converters have been modified for high-efficiency and reliability in EV *** paper offers an overview of charging topologies,PECs,challenges with solutions,and future trends in the field of the EV charging station applications.

关键词： Charging station charging topology electric vehicle power electronic converter vehicle-to-grid

Corrosion testing of X52 and X80 steels immersed in stimulated emulsions using a real petroleum sample

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Petroleum Research 2024年第2期9卷 304-316页

作者： l.M.Quej-Ake J.l.Alamilla A.Contreras Instituto Mexicano del Petróleo Eje Central Lázaro CárdenasNorte 152San Bartolo AtepehuacanGustavo A.MaderoCiudad de MéxicoC.P.07730México

The aim of this study is to evaluate the internal corrosion process on X52 and X80 steels/real petroleum interfaces containing condensed hydrocarbon plus oilfield-produced water,which were subjected to stimulated emulsions using 50/50 vol ratio mixtures at 45℃,different hydrodynamic conditions,1 h,and 24 h.A washing process by using deionized water was proposed to simulate and identify the corrosiveness of the hydrocarbon phase after 24 h of exposure *** characterization by electrochemical impedance spectroscopy and the monitoring of the polarization curves indicated that X80 steel/oilfield-produced water interfaces were more susceptible to corrosion than X52 steel exposed to oilfield-produced *** combined speed rotation of 600 rpm using a magnetic stirrer+600 rpm using a rotating disk electrode decreased the corrosion rate on X52 *** stimulated emulsions made of hydrocarbon+oilfield-produced water and hydrocarbon+deionized water at 24 h increased the corrosion rate on X80 steel(0.34 mm/year and 0.43 mm/year,respectively),promoting the formation of erosion and pitting *** types of corrosion depended mainly on the physicochemical properties of the hydrocarbon,oilfield-produced water,exposure times,and hydrodynamic systems in which the hydrocarbon was studied.

关键词： Corrosion Emulsions X52 steel X80 steel

八核铁簇化合物的制备、表征及其对高氯酸铵的热分解催化

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含能材料 2024年第5期32卷 484-491页

作者：黄琪刘丽金波彭汝芳西南科技大学环境友好能源材料国家重点实验室四川绵阳621010 西南科技大学材料与化学学院四川绵阳621010

以5,5′-{[3,3′-双(1,2,4-噁二唑)]-5,5′-基}-双(1-羟基四唑)为配体,通过溶剂热法制备了一种新型含能铁簇化合物[Fe_(2)Ⅲ(μ2-Ch_(3)O)(μ_(3)-Oh)(μ_(2)-O)(BODTO^(2-))(h_(2)O)]4(1),并对其进行了单晶X-射线衍射、差示扫描量热和热重分析等表征,分析了其结构和热稳定性,同时通过差热分析仪研究了化合物1对高氯酸铵(AP)热分解的催化性能。测试结果表明,化合物1为立方晶系I-43d空间群,密度为1.506 g·cm^(-3);晶体结构中Fe^(3+)与Fe^(3+)通过氧原子桥联,形成笼状结构;热分解峰值温度为513.9,617.6 K和669.4 K;爆速为6.94 km·s^(-1),爆压为19.09 GPa;撞击感度为15 J,摩擦感度为360 N。当添加质量分数为10%的化合物1时,AP的高温分解温度降低65 K,活化能降低82.2 kJ·mol^(-1),证实该铁簇化合物对AP的热分解具有较好的催化活性,具有应用于含能燃烧催化剂的潜质。

关键词：含能配合物铁簇高氯酸铵热分解热催化

Optimizing Average Electric Power During the Charging of lithium-Ion Batteries Through the Taguchi Method

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Transactions of Tianjin University 2024年第2期30卷 152-166页

作者： Mohd h.S.Alrashdan Department of Electrical Engineering Al-Hussein Bin Talal UniversityMaan 71110Jordan

In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. This challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the Taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. The Taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. The proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. Three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the Taguchi analysis. The results revealed that the Taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. This indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. The identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17

关键词： lithium-ion batteries Average electric power during charging Taguchi method COMSOl Multiphysics software C rate l27 orthogonal array

Phase structure evolution and its effect on magnetic and mechanical properties of B-doped Sm2Co17-type magnets with high Fe content

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ChINESE PhYSICS B 2024年第9期33卷 582-588页

作者： li, Yao-Wen liu, Zhuang Wu, hai-Chen Wang, Fang Zhu, Chao-Qun Tan, Dong-liang liu, Yu Yang, Yang Zhang, Ming-Xiao Chen, Ren-Jie Yan, A-ru Shanxi Normal Univ Key Lab Magnet Mol & Magnet Informat Mat Minist Educ Taiyuan 030032 Peoples R China Shanxi Normal Univ Sch Chem & Mat Sci Taiyuan 030032 Peoples R China Chinese Acad Sci Ningbo Inst Mat Technol & Engn CISRI & NIMTE Joint Innovat Ctr Rare Earth Permane Ningbo 315201 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

The unique cellular microstructure of Fe-rich Sm2Co17-type permanent magnets is closely associated with the structure of the solid solution precursor. We investigate the phase structure, magnetic properties, and mechanical behavior of B-doped Sm2Co17-type magnets with high Fe content. The doped B atoms can diffuse into the interstitial vacancy, resulting in lattice expansion and promote the homogenization of the phase organizational structure during the solid solution treatment in theory. however, the resulting second phase plays a dominant role to result in more microtwin structures and highly ordered 2 : 17R phases in the solid solution stage, which inhibits the ordering transformation of 1 : 7h phase during aging and affects the generation of the cellular structure, and to result in a decrease in magnetic properties, yet the interface formed between it and the matrix phase hinders the movement of dislocations and enhances the mechanical properties. hence, the precipitation of high flexural strain grain boundary phase induced by B element doping is also a new and effective way to improve the flexural strain of Sm2Co17-type magnets. Our study provides a new understanding of the phase structure evolution and its effect on the magnetic and mechanical properties of Sm2Co17-type magnets with high Fe content.

关键词： Sm2Co17-type magnets magnetic and mechanical properties MICROSTruCTURE