作者机构:
[Ketel, T.; Tuning, N.; Mauri, A.; Usachov, A.; Lukashenko, V.; Galati, M. D.; Heijhoff, K.; Veronesi, M.; Akiba, K.; Aaij, R.; Snoch, A.; van Beuzekom, M.; Biolchini, A.; Jans, E.; Greeven, L. M.; Geertsema, R. E.; Pellegrino, A.; Gabriel, E.; Merk, M.; Butter, J. S.; Koppenburg, P.; Soares, M. Senghi; Klaver, S.; Gras, C. Sanchez; Raven, G.; Sole, S. Ferreres; Kostiuk, I.; Schubiger, M.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Baptista de Souza Leite, J.; De Freitas Carneiro Da Graca, U.; Massafferri, A.; Cruz Torres, M.; De Miranda, J. M.; Falcao, L. N.; Bediaga, I. B.; Leite, JBD; Gomes, A.; Torres Machado, D.; dos Reis, A. C.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.;[Lopes, J. H.; Polycarpo, E.; Souza De Paula, B.; Souza De Almeida, F. L.; Gandelman, M.; Rangel, M. S.; Ferreira Rodrigues, F.; Hicheur, A.; Otalora Goicochea, J. M.; De Paula, L.; Nasteva, I.; Amato, S.; Meyer Garcia, L.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Wang, Z.; Qu, S.; Qin, N.; Ren, Z.; Xu, L.; Tou, D. Y.; Wang, J.; Li, A.; Hu, X.; Tan, Y.; Gu, C.; Gong, G.; Kang, Y.; Qi, H. R.; Chen, C.; Zhu, X.; Luo, Y.; Yang, D.; Mu, H.; Zeng, M.; Dong, C.; Zhang, L.; Gan, Y.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Lu, Y.; Li, Y.; Ma, L.; Sheng, S.; Li, T.; Wang, J.; Chen, S.; Tobin, M.; Miao, D.; Grieser, N. A.; Jiang, X.; Batsukh, B.; Zou, Q.; Liu, S.] Inst High Energy Phys, Beijing, Peoples R China.
通讯机构:
[Leite, JBD ] C;Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.
摘要:
Searches for the rare hadronic decays B-0 -> p (p) over barp (p) over bar and B-s(0) -> p (p) over barp (p) over bar are performed using proton-proton collision data recorded by the LHCb experiment and corresponding to an integrated luminosity of 9 fb-1. Significances of 9.3 sigma and 4.0 sigma, including statistical and systematic uncertainties, are obtained for the B-0 -> p (p) over barp (p) over bar and B-s(0) -> p (p) over barp (p) over bar signals, respectively. The branching fractions are measured relative to the topologically similar normalization decays B-0 -> J/psi(-> p (p) over bar )K*(0)(-> K+ pi(-) ) and B-s(0) -> J/psi(-> p (p) over bar )X phi(-> K+ K- ). The branching fractions are measured to be B(B-0 -> p (p) over barp (p) over bar) = (2.2 +/- 0.4 +/- 0.1 +/- 0.1) x 10(-8) and B(B-s(0) -> p (p) over barp (p) over bar) = (2.3 +/- 1.0 +/- 0.2 +/- 0.1) x 10(-8). In these measurements, the first uncertainty is statistical, the second is systematic, and the third one is due to the external branching fraction of the normalization channel.
摘要:
Based on the framework of Filippov solution, a non-chattering controller is presented to realize the fixed-time (FXT) stability for a nonlinear system with the discontinuous activation function. First, a novel FXT stability criterion is established through the reduction to absurdity, and the settling time is estimated. Then, by building two controllers without chattering, sufficient conditions are obtained to ensure the FXT synchronization of the drive-response system. Moreover, compared with the existing results, the FXT obtained here is less conservative and more accurate. Finally, the validity of the proposed methods is provided by two numerical examples.
作者机构:
[Xu, Hongbo; Zhu, Li; Li, Ruijie; Chen, Yun; Zhang, Guoping] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.;[Zhu, Li] Hubei Minzu Univ, Coll Intelligent Syst Sci & Engn, Enshi 445000, Peoples R China.
通讯机构:
[Zhang, GP ] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
摘要:
Intelligent reflective surface (IRS) and unmanned aerial vehicle (UAV) communication are two key technologies in the sixth generation of mobile communication (6G). In this paper, IRS is equipped on UAV to form aerial IRS, which can achieve 360° panoramic full-angle reflection and flexible deployment of IRS. In order to achieve high-quality and ubiquitous network coverage under data privacy and low latency requirements, we propose an Federated learning (FL) network via Over-the-Air computation (AirComp) in IRS-assisted UAV communications. Our goal is to minimize the worst-case mean square error (MSE) by jointly optimizing the IRS phase shift, denoising factor for noise suppression, the user's transmission power, and UAV trajectory. Optimizing and quickly adjusting the UAV position and IRS phase shift, it flexibly assists the signal transmission between users and base stations (BS). In order to solve this complex non-convex problem, we propose a low-complexity iterative algorithm, which divides the original problem into four sub-problems, respectively using the semi-definite programming (SDP) method, slack variable introduction method, successive convex approximation (SCA) method to solve each sub-problem. Through the analysis of simulation results, our proposed design scheme is obviously better than other benchmark schemes.
摘要:
Hipposideros pratti called at higher intensities while keeping the constant frequencies of their echolocation pulses consistent under spectrally non-overlapping background noise conditions. The noise could decrease auditory sensitivity and sharp intensity tuning, suggesting an acoustic masking effect. These results provide further evidence of negative consequences of anthropogenic noise. The environment noise may disturb animal behavior and echolocation via three potential mechanisms: acoustic masking, reduced attention and noise avoidance. Compared with the mechanisms of reduced attention and noise avoidance, acoustic masking is thought to occur only when the signal and background noise overlap spectrally and temporally. In this study, we investigated the effects of spectrally non-overlapping noise on echolocation pulses and electrophysiological responses of a constant frequency-frequency modulation (CF-FM) bat, Hipposideros pratti. We found that H. pratti called at higher intensities while keeping the CFs of their echolocation pulses consistent. Electrophysiological tests indicated that the noise could decrease auditory sensitivity and sharp intensity tuning, suggesting that spectrally non-overlapping noise imparts an acoustic masking effect. Because anthropogenic noises are usually concentrated at low frequencies and are spectrally non-overlapping with the bat's echolocation pulses, our results provide further evidence of negative consequences of anthropogenic noise. On this basis, we sound a warning against noise in the foraging habitats of echolocating bats.
作者:
Aaij, R.;Abdelmotteleb, A. S. W.;Beteta, C. Abellan;Abudinen, F.;Ackernley, T.;...
期刊:
Journal of High Energy Physics,2023年2023(9):1-29 ISSN:1029-8479
通讯作者:
Aaij, R
作者机构:
[Ketel, T.; Tuning, N.; Mauri, A.; Usachov, A.; Lukashenko, V.; Galati, M. D.; Heijhoff, K.; Veronesi, M.; Akiba, K.; Aaij, R.; Aaij, R; Snoch, A.; Biolchini, A.; Jans, E.; Greeven, L. M.; Geertsema, R. E.; Pellegrino, A.; Gabriel, E.; Merk, M.; Butter, J. S.; Koppenburg, P.; Soares, M. Senghi; Klaver, S.; Gras, C. Sanchez; Raven, G.; Sole, S. Ferreres; Kostiuk, I.; Schubiger, M.; Hulsbergen, W.] Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.;[Da Graca, U. De Freitas Carneiro; Massafferri, A.; De Miranda, J. M.; Falcao, L. N.; Bediaga, I. B.; Torres, M. Cruz; Machado, D. Torres; Gomes, A.; dos Reis, A. C.; Leite, J. Baptista de Souza] CBPF, Rio De Janeiro, Brazil.;[De Paula, B. Souza; Lopes, J. H.; Goicochea, J. M. Otalora; Polycarpo, E.; Gandelman, M.; Rangel, M. S.; Hicheur, A.; Gomes, A.; Garcia, L. Meyer; Rodrigues, F. Ferreira; De Paula, L.; Nasteva, I.; Amato, S.; De Almeida, F. L. Souza] Univ Fed Rio de Janeiro, Rio de Janeiro, Brazil.;[Wang, Z.; Qu, S.; Qin, N.; Ren, Z.; Xu, L.; Tou, D. Y.; Wang, J.; Li, A.; Hu, X.; Tan, Y.; Gu, C.; Gong, G.; Kang, Y.; Qi, H. R.; Chen, C.; Zhu, X.; Luo, Y.; Yang, D.; Mu, H.; Zeng, M.; Dong, C.; Zhang, L.; Gan, Y.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Lu, Y.; Li, Y.; Sheng, S.; Li, T.; Wang, J.; Chen, S.; Tobin, M.; Miao, D.; Jiang, X.; Batsukh, B.; Zou, Q.; Liu, S.] Inst High Energy Phys, Beijing, Peoples R China.
关键词:
Hadron-Hadron Scattering;Particle Correlations and Fluctuations;QCD
摘要:
Correlations of same-sign charged pions are analysed using proton-lead collision data collected by the LHCb experiment at a nucleon-nucleon centre-of-mass energy of 5.02TeV, corresponding to an integrated luminosity of 1.06 nb(-1). Bose-Einstein correlations are observed in the form of an enhancement of pair production for same-sign charged pions with a small four-momentum difference. The dependence of the correlation radius and the intercept parameter on the reconstructed charged-particle multiplicity is investigated. The measured correlation radii scale linearly with the cube root of the reconstructed charged-particle multiplicity, being compatible with predictions of hydrodynamic models on the collision system evolution.
期刊:
IET Optoelectronics,2023年17(6):249-256 ISSN:1751-8768
通讯作者:
Liu, Y;Lin, H
作者机构:
[Zhou, Bin; Tian, Y.; Liu, Y.; Liu, Zheng-Rong] Hubei Univ, Sch Phys, Wuhan, Hubei, Peoples R China.;[Tian, Y.; Liu, Y.] Hubei Univ, Sch Microelect, Wuhan, Hubei, Peoples R China.;[Zhou, Rui; Lin, Hai; Lin, H] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan, Hubei, Peoples R China.;[Liu, Y.] Lanzhou Univ, Lanzhou Ctr Theoret Phys, Key Lab Theoret Phys Gansu Prov, Lanzhou, Peoples R China.;[Liu, Y.] Lanzhou Univ, Key Lab Quantum Theory & Applicat MoE, Lanzhou, Peoples R China.
通讯机构:
[Lin, H ] C;[Liu, Y ] H;Hubei Univ, Sch Phys, Wuhan, Hubei, Peoples R China.;Hubei Univ, Sch Microelect, Wuhan, Hubei, Peoples R China.;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan, Hubei, Peoples R China.
关键词:
photonic crystals;topological insulators
摘要:
In our paper, the authors take the simple case of periodic randomisation by disrupting two parameters in unit cells. The authors characterise the topological breakdown via directly calculating variances to Chern numbers under their defined perturbation. Their calculation demonstrates that such a periodic perturbation easily annihilates topological invariants, providing benchmark for future design of these topological devices. Abstract In the known field of topological photonics, what remains less so is the breakdown effect of topological phases deteriorated by perturbation. In this study, the authors investigate the variance on topological invariants for a periodic Kekulé medium perturbed in unit cells, which was a gyromagnetic photonic crystal holding topological phases induced by synchronised rotation of unit cells. Two parameters for geometric and material perturbation are respectively benchmarked to characterise the topological degradation. Our calculation demonstrates that such a periodic perturbation easily destructs the topological phase and thus calls for further checkups on robustness under such unit‐cell‐perturbation in realisation.
摘要:
In this work, we investigate the semileptonic decays of
$$B_{c}$$
meson to
$$\eta _{c}(1S,2S,3S)$$
,
$$\psi (1S,2S,3S)$$
and X(3872) within the framework of covariant light-front quark model (CLFQM). We combine the helicity amplitudes via the corresponding form factors to obtain the branching ratios of the semileptonic decays
$$B_{c}\rightarrow \eta _{c}(1S, 2S, 3S)\ell \nu _{\ell }$$
,
$$B_{c}\rightarrow \psi (1S, 2S, 3S))\ell \nu _{\ell }$$
and
$$B_{c}\rightarrow X(3872)\ell \nu _{\ell }$$
, with
$$\ell =e,\mu ,\tau $$
. In view of the
$$R_{J/\Psi }$$
anomaly released by the LHCb collaboration, it is necessary to systematically calculate the ratios
$$R_X$$
with
$$X=\psi (1S,2S,3S),\eta _c(1S,2S,3S),X(3872)$$
, which are helpful for checking the lepton flavor universality (LFU). We also take into account another two physical observables, the longitudinal polarization fraction
$$f_{L}$$
and the forward–backward asymmetry
$$A_{FB}$$
, which can provide new clues for understanding the
$$R_{J /\Psi }$$
anomaly. Such theoretical predictions are necessary and interesting, and can be tested in future LHCb experiments.
作者机构:
[Wu, Yuanfang; Xu, Mingmei] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Wu, Yuanfang; Xu, Mingmei] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构:
[Yuanfang Wu] K;Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079, China
摘要:
Abstract: In the QCD, a transition restoring the chiral symmetry occurs at a high temperature and density. Searching for the signals of the QCD phase transition is one of the goals of the current relativistic heavy-ion physics programs. The metastable state is a unique feature of the first-order phase transition. Using the van der Waals equation of state, the role of the metastable state in finite-size effects is analyzed. It is found that the finite-size effects of the first-order phase transition are closely related to the metastable state. Metastability can be observed in the distribution of the order parameters and the probability of its occurrence depends on the system scale. A sizable probability of the metastability requires a small enough system size. The possibility of observing the metastability in the RHIC/BES is discussed. Keywords: relativistic heavy-ion collision; phase transition; finite-size effect
期刊:
Sensors and Actuators B-Chemical,2023年381:133429 ISSN:0925-4005
作者机构:
[Ma, Weijia; Wang, Yan] Hubei Minzu Univ, Sch Chem & Environm Engn, Enshi 445000, Peoples R China.;[Fu, Yuheng] Wuhan Univ Technol, Sch Mat Sci & Engn, Wuhan 430070, Peoples R China.;[Tan, Jianfeng; Meng, Gaoxiang] Hubei Minzu Univ, Key Lab Green Mfg Superlight Elastomer Mat State E, Enshi 445000, Peoples R China.;[Tan, Jianfeng; Meng, Gaoxiang] Hubei Minzu Univ, Coll Intelligent Syst Sci & Engn, Enshi 445000, Peoples R China.;[Tan, Wenhu] Cent China Normal Univ, Dept Phys Sci & Technol, Wuhan 430079, Peoples R China.
关键词:
Nature-inspired;Branch-leaf structure;Electronic structure regulation;Flexibility;Room-temperature;NO2 gas sensor
摘要:
Flexible room-temperature (RT) gas sensors are highly desirable due to their low power consumption and wearability. However, it is very challenging to integrate excellent mechanical flexibility and superior gas sensing properties. Here, polyacrylonitrile (PAN) nanofiber/cobalt-doping SnS2 nanosheets with nature-inspired "branch-leaf" structure was well tailored by directly grown Co-SnS2 ultrathin nanosheets on PAN nanofiber for the first time. With the interfacial bonding interaction between PAN substrate and SnS2 nanosheets, the geometrical deformability of composite structure, the interfacial bonding force, stress distribution, transfer and dissipation will be enhanced. Moreover, the electronic structure and S vacancy are regulated by Co-doping, then improve the gas transmission/diffusion, gas sensitive reactivity and carrier transfer/transport properties. The integrated RT NO2 gas sensor exhibits excellent flexibility (minimum radius of curvature is 3.9 mu m), high response, fast response/recovery speed (6.2 and 27.5/60 s). Meanwhile, it possesses a low detection limit and long-term sta-bility. This comprehensive strategy for the integration of mechanical and gas sensitive properties unlocks the inherent bottlenecks of conventional film-based gas sensors and open a new design avenue for the development of flexible electronics.
期刊:
Monthly Notices of the Royal Astronomical Society,2023年518(2):2005-2014 ISSN:0035-8711
通讯作者:
Shao-Lin Xiong
作者机构:
[Cai, Ce] Hebei Normal Univ, Coll Phys, Shijiazhuang 050024, Hebei, Peoples R China.;[Cai, Ce] Hebei Normal Univ, Hebei Key Lab Photophys Res & Applicat, Shijiazhuang 050024, Hebei, Peoples R China.;[Zheng, Chao; Cai, Ce; Li, Xin-Qiao; Guo, Zhi-Wei; Liu, Jia-Cong; Zhang, Yan-Qiu; Zhao, Yi; Du, Yan-Qi; Peng, Wen-Xi; Xiong, Shao-Lin; Xue, Wang-Chen; Wang, Ping; Wen, Xiang-Yang; Zhang, Fan; Zhao, Xiao-Yun; Li, Cheng-Kui; Xiao, Shuo; Zheng, Shi-Jie; Xie, Sheng-Lun; Yi, Qi-Bin; Song, Li-Ming] Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing 100049, Peoples R China.;[Zheng, Chao; Cai, Ce; Liu, Jia-Cong; Zhang, Yan-Qiu; Xue, Wang-Chen; Xiao, Shuo; Zheng, Shi-Jie; Song, Li-Ming] Chinese Acad Sci, Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Zhao, Yi] Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China.
通讯机构:
[Shao-Lin Xiong] K;Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China
关键词:
methods: data analysis;gamma-ray burst
摘要:
Searching for X-ray and gamma-ray bursts, including Gamma-ray bursts (GRBs), Soft Gamma-ray Repeaters (SGRs), and high energy transients associated with Gravitational wave (GW) events or Fast radio bursts (FRBs), is of great importance in the multimessenger and multiwavelength era. Although a coherent search based on the likelihood ratio and Gaussian statistics has been established and utilized in many studies, this Gaussian-based method could be problematic for weak and short bursts which usually have very few counts. To deal with all bursts including weak ones, here we propose the coherent search in Poisson statistics. We studied the difference between Poisson-based and Gaussian-based search methods by Monte Carlo simulations, and find that the Poisson-based search method has advantages compared to the Gaussian case, especially for weak bursts. Our results show that, for very weak bursts with very low number of counts, the Poisson-based search can provide higher significance than the Gaussian-based search, and its likelihood ratio (for background fluctuation) still generally follows the chi(2) distribution, making the significance estimation of searched bursts very convenient. Thus, we suggest that the coherent search based on Poisson-likelihood ratio is more appropriate in the search for generic transients including very weak ones.
摘要:
针对当前遥感卫星电荷耦合器件(CCD)相机幅宽越来越大, 速率越来越高, 现有相机模拟源设备数据输出带宽不足的问题, 提出并实现了一种基于非易失性存储器 Express(NVMe)的超高速多通道遥感相机模拟源设备。该设备利用现场可编程逻辑门阵列 (FPGA)实现 4组 NVMe SSD主机控制器, 完成对固态硬盘 (SSD)的读写操作; 同时利用 DMA控制器读取 DDR4中缓存数据, 数据经封装处理后通过光纤接口输出。实验结果表明: NVMe主机控制器的写平均速率可以达到 1.7 GBps, 读平均速率达到 3.2 GBps。模拟源系统整体存储容量 8 TB, 对外输出带宽高达 80 Gbps, 支持 8路光纤接口输出。该模拟源具有较强的稳定性及良好的可扩展性, 已成功应用在某遥感卫星 CCD相机模拟源系统中, 为数传等设备的测试以及调试提供了充分保障。 Aiming at the problem that the current remote sensing satellite Charge Couple Device (CCD) camera has an increasing width and speed, and the output bandwidth of existing camera simulator is insufficient, an Non-Volatile Memory express(NVMe) based ultrahigh-speed multi-channel remote sensing camera simulator is proposed and implemented. This simulator employs a Field Programmable Gate Array(FPGA) to implement four groups of NVMe SSD host controllers and complete the read and write operations on the Solid State Drive(SSD). The Direct Memory Access(DMA) controller is utilized to read the cache data in DDR4, and the data is output through the optical fiber interface after being encapsulated. Experimental results show that the average write rate of the NVMe host controller can reach 1.7 GBps, and the average read rate can reach 3.2 GBps. The overall storage capacity of the simulator is 8 TB, the external output bandwidth is up to 80 Gbps, and it supports eight-way optical fiber interface outputs. This simulator with strong stability and good scalability, has been successfully applied in a remote sensing satellite CCD camera simulator system, which provides sufficient guarantee for the testing and debugging of device such as data transmission.
摘要:
As an novel paradigm, computation offloading in the mobile edge computing (MEC) system can effectively support the resource-intensive applications for the mobile devices (MD) equipped with limited computing capability. However, the hostile radio transmission and data leakage during the offloading process may erode the MEC system's potential. To tackle these hindrances, we investigate an IRS-assisted secure MEC system with eavesdroppers, where the intelligent reflecting surface (IRS) is deployed to enhance the communication between the MD and the AP equipped with edge servers and the malicious eavesdroppers may attack the wireless data offloaded by MD. The MD opt for offloading part of the tasks to the edge server for execution to support the computation-intensive applications. Moreover, the relevant latency minimization problem is formulated by optimizing the offloading ratio, the allocation of edge server computing capability, the multiple-user-detection (MUD) matrix and the IRS phase shift parameters, subject to the constraints of edge computation resource and practical IRS phase shifts. Then, the original problem is decouple into two subproblem, and the computing and communication subproblems are alternatively optimized by block coordinate descent (BCD) method with low complexity. Finally, simulation results demonstrate that the proposed scheme can significantly enhance the performance of secure offloading in the MEC system.(c) 2023 Elsevier B.V. All rights reserved.
作者机构:
[Chen, Wei; Chen, W] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.;[Pang, Longgang; Wang, Xin-Nian; Yang, Zhong] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Peoples R China.;[Pang, Longgang; Wang, Xin-Nian; Yang, Zhong] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[He, Yayun] South China Normal Univ, Guangdong Prov Key Lab Nucl Sci, Inst Quantum Matter, Guangzhou 510006, Peoples R China.;[Luo, Tan] Univ Santiago Compostela, Inst Galego Fis Altas Enerxias IGFAE, Galicia, Spain.
会议名称:
29th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions Quark Matter
会议时间:
APR 04-10, 2022
会议地点:
Krakow, POLAND
会议主办单位:
[Chen, Wei] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.^[Yang, Zhong;Pang, Longgang;Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys, MOE, Wuhan 430079, Peoples R China.^[Yang, Zhong;Pang, Longgang;Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.^[He, Yayun] South China Normal Univ, Guangdong Prov Key Lab Nucl Sci, Inst Quantum Matter, Guangzhou 510006, Peoples R China.^[Luo, Tan] Univ Santiago Compostela, Inst Galego Fis Altas Enerxias IGFAE, Galicia, Spain.^[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, MS 70R0319, Berkeley, CA 94720 USA.
摘要:
Diffusion wake is an unambiguous part of the jet-induced medium response in high-energy heavy-ion collisions that leads to a depletion of soft hadrons in the opposite direction of the jet propagation. Using a coupled linear Boltzmann transport and hydro model, we identify a valley structure caused by the diffusion wake on top of a ridge from the initial multiple parton interaction (MPI) in the jet-hadron correlation as a function of azimuthal angle and rapidity. This gives rise to the unambiguous signals of the diffusion wake on soft hadrons in the opposite direction of the jets, which are reflected in the depletion in azimuthal angle distribution after subtraction of the contributions from MPI with a mixed-event procedure, and the double-peak structure in the rapidity distribution. We further employ the longitudinal and transverse gradient jet tomography for the first time to localize the initial jet production positions in Z/gamma-jet events in which the effect of the diffusion wake is apparent in Z/gamma-hadron correlation even without the subtraction of MPI.
作者机构:
[Xia, Qiaoqiao; Wang, Ji; Wang, J; Ma, Xinxin] Cent China Normal Univ, Dept Elect & Informat Engn, Wuhan, Peoples R China.;[Zheng, Le] Beijing Inst Technol, Sch Informat & Elect, Beijing, Peoples R China.;[Yang, Kai] Tongji Univ, Dept Comp Sci, Shanghai, Peoples R China.;[Chen, Zhao] Tsinghua Univ, Beijing Natl Res Ctr Informat Sci & Technol, Beijing, Peoples R China.
会议名称:
IEEE Wireless Communications and Networking Conference (WCNC)
会议时间:
MAR 26-29, 2023
会议地点:
Glasgow, SCOTLAND
会议主办单位:
[Wang, Ji;Ma, Xinxin;Xia, Qiaoqiao] Cent China Normal Univ, Dept Elect & Informat Engn, Wuhan, Peoples R China.^[Zheng, Le] Beijing Inst Technol, Sch Informat & Elect, Beijing, Peoples R China.^[Yang, Kai] Tongji Univ, Dept Comp Sci, Shanghai, Peoples R China.^[Chen, Zhao] Tsinghua Univ, Beijing Natl Res Ctr Informat Sci & Technol, Beijing, Peoples R China.
会议论文集名称:
IEEE Wireless Communications and Networking Conference
关键词:
Internet of Things;ultra-dense cloud radio access network;energy harvesting;successive convex approximation
摘要:
This paper studies the secrecy wireless information and power transfer problem in ultra-dense cloud radio access network (UD-CRAN) with wireless fronthaul, which is a promising framework for future Internet of Things (IoT). The transmission schemes of wireless fronthaul and access links are jointly designed, while addressing the characteristics of ultra-dense network such as base station diversity and high probability of line-of-sight transmission. Specifically, we employ the idea of block diagonalization to deal with the fronthaul interference, which support multi-stream fronthaul transmission for each remote radio head (RRH). We then jointly optimize the power allocation in the fronthaul and the resource allocation in the access link which includes beamforming for information and energy transmission, on/off of RRHs, and user-RRH association. In order to solve the formulated mixed integer non-convex optimization problem, we leverage the sparsity of beamforming vectors brought by the ultra-dense RRHs. We then solve the reformulated problem by employing the successive convex approximation approach. Finally, numerical results are presented to demonstrate the effectiveness of the proposed scheme.
作者机构:
[Hu, Kun; Katsuragawa, Taishi; Katsuragawa, T] Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.;[Narori, Shin'ichi; Yamakoshi, Makishi] Nagoya Univ, Dept Phys, Nagoya 4648602, Japan.;[Narori, Shin'ichi] Nagoya Univ, Kobayashi Maskawa Inst Origin Particles & Universe, Nagoya 4648602, Japan.;[Qiu, Taotao] Huazhong Univ Sci & Technol, Sch Phys, Wuhan 430074, Peoples R China.
通讯机构:
[Katsuragawa, T ] C;Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.
摘要:
f(Q) gravity is an extension of the symmetric teleparallel equivalent to general relativity (STEGR). This work shows that based on the scalar-nonmetricity formulation, a scalar mode in f(Q) gravity has a negative kinetic energy. This conclusion holds regardless of the coincident gauge frequently used in STEGR and f(Q) gravity. To study the scalar mode, we further consider the covariant f(Q) gravity as a special class in higher-order scalar tensor (HOST) theory and rewrite the four scalar fields, which play a role of the Stueckelberg fields associated with the diffeomorphism, by vector fields. Applying the standard Arnowitt-Deser-Misner (ADM) formulation to the new formulation of the f(Q) gravity, we demonstrate that the ghost scalar mode can be eliminated by the second-class constraints, thus ensuring that f(Q) gravity is a healthy theory.
摘要:
A compact 4-port coplanar waveguide (CPW) fed ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna with enhanced isolation is proposed to operate from 3.66 GHz to 16.61 GHz with 127.78% impedance bandwidth. The proposed antenna system consists of 4 orthogonal arrays of monopole antennas improved by four iterations. The UWB characteristic of the antenna is obtained from an improved monopole antenna fed by CPW. The final MIMO antenna is machined on a Rogers 4003C substrate with dimensions of 60 x 60 x 0.3 mm(3). The orthogonal arrangement of antennas brings about the polarization diversity and certain isolation of MIMO antennas. Four rows of orthogonal metasurface elements with via holes and the ring of the backplane further improve the isolation between antenna elements in the MIMO system. The MIMO antenna has an impedance bandwidth of 12.95 GHz with S-11 < -10 dB and good isolation (S-21 =S-41 < -30 dB and S-31 < -20 dB). In particular, S31 is always less than -25 dB at frequencies greater than 6 GHz. The measured results of MIMO antenna agree with the simulated results. The optimized MIMO antenna has excellent performance in many aspects, such as UWB, compact size, omnidirectional radiation, enhanced isolation and high efficiency, which means that it has application potential in UWB wireless communication systems.