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Probing the bardeen-Kiselev black hole with the cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds

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Communications in Theoretical Physics 2024年第6期76卷 102-119页

作者： S R Wu b q Wang Z W Long College of Physics Guizhou UniversityGuiyang 550025China College Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this work,we investigate a static and spherically symmetric bardeen-Kiselev black hole(bH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field *** compute the quasinormal frequencies for the bardeen-Kiselev bH with the cosmological constant due to electromagnetic and gravitational *** varying the bH parameters,we discuss the behavior of both real and imaginary parts of the bH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de Sitter bH surrounded by quintessence(RN-dSq).Interestingly,it is shown that the responses of the bardeen-Kiselev bH with the cosmological constant and the RN-dSq under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the bardeen-Kiselev bH with the cosmological constant and the RN-dSq are different only when the charge parameter q is ***,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the bardeen-Kiselev bH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates *** also study the reflection and transmission coefficients along with the absorption cross section in the bardeen-Kiselev bH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors bardeen-Kiselev black hole with cosmological constant

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A Tightly Coupled Dipole Array with Diverse Element Reflection Phases for RCS Reduction

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Chinese Journal of Electronics 2024年第2期33卷 449-455页

作者： Yuewen gou.Yikai CHEN Shiwen YANG University of Electronic Science and Technology of China

This paper proposes a novel low scattering tightly coupled dipole array(TCDA), aiming to reduce the radar cross section(RCS) of phased antenna arrays under a certain oblique incident wave. First, we build three types of antenna elements that exhibit similar radiation characteristics but diverse reflection phase differences based on the proposed theoretical analysis. The required reflection phase difference is achieved by using different dielectric superstrates for each antenna element. Then, by arranging the three types of subarrays next to each other, a low scattering TCDA(8 × 9) is designed. Meanwhile, a reference antenna array with a single type of antenna element is also constructed. To demonstrate the effectiveness of the proposed RCS reduction technique, simulated and measured results of the reference and proposed antenna array are compared. both antenna arrays operate over the 6–18 GHz frequency band and can scan up to ±45° in the E-/H-planes. However, the proposed antenna array achieves a significant monostatic RCS reduction over 8–12 GHz, with a maximum reduction value of 7.55 d b. It indicates that this diverse element reflection phase technique is a good candidate for wideband RCS reduction.

关键词： Antenna measurements Phased arrays Dipole antennas Antenna theory Scattering Reflector antennas Reflection

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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

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In situ TEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10Gd-3Y-1Zn-0.5Zr alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： M.Lv H.L.Ge q.q.Jin X.H.Shao Y.T.Zhou b.Zhang X.L.Ma Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10Gd-3Y-1Zn-0.5Zr(GWZ1031K,wt.%)alloy to improve the *** results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately 64% higher than that of the samples before being *** is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous *** latter plays a key role in precipitation *** result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation Hardening Precipitates In-situ TEM

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Reservoir characteristics and controlling factor of tight sandstone in Shuixigou.Group in Taibei depression,Turpan-Hami basin

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Energy Geoscience 2024年第2期5卷 70-80页

作者： Tong Lin Xuan Chen Fan Yang Hongguang gou.Mingyu Liu Runze Yang PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China Research Institute of Exploration&Development PetroChina Tuha Oilfield Company HamiXinjiang839009China China University of Geosciences(beijing) Beijing100083China

The positive structure belts surrounding the Taibei Sag,Turpan-Hami basin,have been the main targets for oil and gas exploration for years and are now left with remaining resources scattering in reservoirs adjacent to source rocks in the sag,where the Shuixigou.Group with substantial oil and gas potential constitutes the primary focus for near-source ***,characterization of development and key controlling factors of reservoir space becomes a must for future exploration in the *** study investigates the development traits,genesis,and controlling factors of the Xishanyao and Sangonghe formations in the Shengbei and qiudong Sub-sags of the Taibei Sag with techniques such as cast thin-section observation,porosity and permeability tests,high-pressure mercury injection,and saturation fluid NMR analysis of reservoir *** findings reveal that the Shuixigou.Group in the Taibei Sag consists of lithic *** in the group are mostly poor in terms of physical properties,with undeveloped primary pores dominated by intergranular dissolved pores as a result of a strong *** analysis of key controlling factors of the Sangonghe Formation reveals significant distinctions in sandstone particle size,sand body thickness,genesis and distribution,provenance location,and source rock type between the qiudong area and Shengbei ***,the coal seams of the Xishanyao Formation exhibit heightened development with shallower burial depth and lower maturity compared to those of the Sangonghe ***,this environment fosters the formation of organic acids,which have a stronger dissolution effect on minerals to develop secondary dissolution pores,and ultimately resulting in better reservoir physical ***,the reservoirs within the qiudong area of the Taibei Sag demonstrate superior characteristics compared to those in the Shengbei ***,the reservoir physical properties of the Xishanyao For

关键词： Intergranular dissolved pore Organic acid dissolution Secondary dissolution pore Tight sandstone Shuixigou.group Turpan-Hami basin

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Rescattering of stimulated Raman side scattering in nonuniform plasmas

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Matter and Radiation at Extremes 2024年第5期9卷 68-76页

作者： S.Tan q.Wang Y.Chen W.b.Yao C.Z.Xiao J.F.Myatt School of Physics and Electronics Hunan UniversityChangsha 410082China Institute of Applied Physics and Computational Mathematics Beijing 100094China School of Electrical and Information Engineering Anhui University of Science and TechnologyHuainanAnhui 232001China Department of Electrical and Computer Engineering University of Alberta9211116 St.NWEdmontonAlberta T6G 1H9Canada

Rescattering of stimulated Raman side scattering(SRSS)is observed for the first time via two-dimensional(2D)particle-in-cell(PIC)*** construct a theoretical model for the rescattering process,which can predict the region of occurrence of mth-order SRSS and estimate its *** rescattering process is identified by the 2D PIC simulations under typical conditions of a direct-drive inertial confinement fusion *** electrons produced by second-order SRSS propagate nearly perpendicular to the density gradient and gain nearly the same energy as in first-order SRSS,but there is no cascade acceleration to produce superhot *** studies for a wide range of ignition conditions show that SRSS and associated rescatterings are robust and important processes in inertial confinement fusion.

关键词： nonuniform acceleration scattering

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Linking Perceived Risk of Public Health Emergency to Psychological Distress among Chinese College Students: The Chain Mediation Role of balanced Time Perspective and Negative Coping Styles

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International Journal of Mental Health Promotion 2024年第8期26卷 599-610页

作者： Chang b. Zhu S. Xie q. Dai Y. School of Education Science Nanjing Normal University Nanjing 210024 China Center of Clinical Psychology The Third People’s Hospital of Heze City Heze 274031 China School of Education Science Northwest Normal University Lanzhou 730070 China Mental Health Center Hubei Polytechnic University Huangshi 435003 China College of Teacher Education Zhejiang Normal University Jinhua 321004 China

background: With public health emergencies (PHE) worldwide increasing, the perceived risk of PHE has been one of the critical factors influencing college students’ psychological distress. However, the mechanisms by which the perceived risk of PHE affects college students’ psychological distress are not clear. The study’s purpose was to investigate the mediation roles of deviation from a balanced time perspective (DbTP) and negative coping styles between the perceived risk of PHE and psychological distress. Methods: A convenience sampling method was used to survey 1054 Chinese college students with self-reporting. Data was collected using the Public Risk Perception Scale (PRPS), the Zimbardo Time Perspective Inventory (ZTPI), the Simplified Coping Style questionnaire (SCSq), the PHE Anxiety Scale, and the Chinese version of the Patient Health questionnaire (PHq). The associations between the perceived risk of PHE, DbTP, negative coping styles, and psychological distress were clarified using the correlation analysis. Additionally, the mediating roles of DbTP and negative coping styles between the perceived risk of PHE and psychological distress were investigated using a structural equation model. Results: The findings revealed low to moderate correlations between the variables studied. Students’ perceived risk of PHE was a positive predictor of their psychological distress (b = 0.219, p bTP and negative coping styles played chain mediation roles between them with the effect being 0.009 and a 95% boot CI of [0.003, 0.023]. This chain mediation model had an excellent fit index (χ2/df = 4.732, CFI = 0.973, TLI = 0.930, RMSEA = 0.048, SRMR = 0.047). Conclusion: These findings showed how the perceived risk of PHE affected college students’ psychological distress. Specifically, these results suggested that improving students’ mental ability to switch effectively among different time perspectives depending on task features and situational considerations and reducin

关键词： balanced time perspective China college students negative coping styles Perceived risk of public health emergency psychological distress

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bioceramic scaffolds with two-step internal/external modification of copper-containing polydopamine enhance antibacterial and alveolar bone regeneration capability

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Journal of Zhejiang University-Science b(biomedicine & biotechnology) 2024年第1期25卷 65-82页

作者： Xiaojian JIANG Lihong LEI Weilian SUN Yingming WEI Jiayin HAN Shuaiqi ZHONG Xianyan YANG Zhongru gou.Lili CHEN Department of Oral Medicine the Second Affiliated HospitalZhejiang University School of MedicineHangzhou310009China bio-nanomaterials and Regenerative Medicine Research Division Zhejiang–California International Nanosystem InstituteZhejiang UniversityHangzhou310058China

Magnesium-doped calcium silicate(CS)bioceramic scaffolds have unique advantages in mandibular defect repair;however,they lack antibacterial properties to cope with the complex oral ***,for the first time,the CS scaffold was functionally modified with a novel copper-containing polydopamine(PDA(Cu^(2+)))rapid deposition method,to construct internally modified(*P),externally modified(@PDA),and dually modified(*P@PDA)*** morphology,degradation behavior,and mechanical properties of the obtained scaffolds were evaluated in *** results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical *** the prolonged immersion stage,the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained *** in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA,while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis ***,the PDA(Cu^(2+))-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect ***,it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu^(2+))modification,and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.

关键词： Copper-containing polydopamine Modification Antibacterial property bone regeneration Angiogenesis bioceramic scaffold

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Discovery of a potent and selective cell division cycle 7 inhibitor from 6-(3-fluoropyridin4-yl)thieno[3,2-d]pyrimidin-4(3H)-one derivatives as an orally active antitumor agent

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Acta Pharmaceutica Sinica b 2024年第2期14卷 893-896页

作者： Mingwei Fu Min Ge Wanxiang Yang Chunchen Hu Xiaowei Li Yuanjiang Wang Shaohua gou Pharmaceutical Research Center and School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Jiangsu Province Hi-Tech Key Laboratory for biomedical Research Southeast UniversityNanjing 211189China Zenji Research Laboratories Nanjing 211189China

To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA ***7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MCM)family members that bind to *** addition,CDC7 kinase,as a molecular switch regulating DNA replication,can mediate DNA damage signaling pathways to stimulate cell cycle termination as well as DNA *** have shown that CDC7 is overexpressed in many types of cancer cells,and its overexpression was related to poor patient survival,tumor grade,genetic instability,aneuploidy and so ***,CDC7 is a promising target for antitumor therapy.

关键词： Cell division cycle 7 DNA replication CDC7 inhibitor Anti-tumor

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Precipitation of multi-type nano-quasicrystals in a Mg-Zn-Y alloy

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Journal of Magnesium and Alloys 2024年第3期12卷 997-1008页

作者： W.Z.Wang X.Z.Zhou L.F.Zhang H.q.Ye Z.q.Yang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China Ji Hua Laboratory Foshan 528251China Foshan University Foshan 528231China

Mg-6Zn-1Y(at.%)ribbons with strengthening precipitates of multi-type nanoquasicrystals were prepared by melt-spinning followed by aging *** evolution of the rapidly solidified ribbons during isothermal aging was comprehensively studied using various electron microscopy *** new kinds of decagonal quasicrystals were formed in aged ribbons,in addition to precipitation of nanometer icosahedral ***-resolution observations reveal that both decagonal quasicrystals can be modeled by quasiperiodic tiling with decagonal clusters of 2.5 nm in diameter,but overlap of neighboring clusters in both decagonal quasicrystals is different from the Gummelt model observed in other quasicrystals.A shell composed of complex Laves Mg-Zn domains was formed surrounding each decagonal quasicrystal precipitate upon prolonged *** addition,all kinds of nanoprecipitates exhibit excellent structure and size stability at 573 *** findings may have implications for not only fundamental studies about quasicrystals,but also microstructural manipulation of high-performance Mg alloys.

关键词： quasicrystal Mg alloys Rapid solidification Scanning-transmission electron microscopy.

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