检索结果-内蒙古大学图书馆

Electron injection and acceleration in a twisted laser driven by the light fan

High Power Laser Science and engineering 2024年第6期12卷 156-167页

作者： Xiang Tang Juexuan Hao Yin Shi Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefeiChina

The longitudinal fields of a tightly focused Laguerre–Gaussian(LG) laser can be used to accelerate electron pulse trains when it is reflected from a solid plasma. However, the normal transverse mode of laser beams in high-power laser systems is approximately Gaussian. A routine and reliable way to obtain high-intensity LG lasers in experiments remains a major challenge. One approach involves utilizing a solid plasma with a ‘light fan' structure to reflect the Gaussian laser and obtain a relativistic intense LG laser. In this work, we propose a way to combine the mode transformation of a relativistic laser and the process of electron injection and acceleration. It demonstrates that by integrating a nanowire structure at the center of the ‘light fan', electrons can be efficiently injected and accelerated during the twisted laser generation *** three-dimensional particle-in-cell simulations, it is shown that a circularly polarized Gaussian beam with a_(0) = 20can efficiently inject electrons into the laser beam in interaction with the solid plasma. The electrons injected close to the laser axis are driven by a longitudinal electric field to gain longitudinal momentum, forming bunches with a low energy spread and a small divergence angle. The most energetic bunch exhibits an energy of 310 MeV, with a spread of 6%. The bunch charge is 57 pC, the duration is 400 as and the divergence angle is less than 50 mrad. By employing Gaussian beams, our proposed approach has the potential to reduce experimental complexity in the demonstrations of twisted laser-driven electron acceleration.

关键词： laser-driven electron acceleration laser-plasma interactions light fan Laguerre-Gaussian laser

来源：评论

学校读者我要写书评

暂无评论

Improved optical, mechanical, and electrochemical performances of MWCNT/MnS-incorporated bioderived gel ternary nanocomposite

引用

Nanomaterials and Energy 2025年第1期14卷 33-41页

作者： Noboni, Sanzida Roy, Probal Islam, Muhammad Rakibul Department of Physics University of Dhaka Dhaka Bangladesh Department of Physics Bangladesh University of Engineering and Technology Dhaka Bangladesh

Nanocomposite film-based biodegradable gelatin (gel) polymer incorporated with multi-walled carbon nanotube (MWCNT) and manganese sulfide (MnS) nanoparticles has been fabricated by the solution casting technique. The diversity of different chemical groups in the gel/MWCNT/MnS ternary nanocomposite polymer has been investigated by Fourier transform infrared spectra. The DC resistivity of the gel/MWCNT/MnS reduces in comparison with the pure gel polymer. The inclusion of MWCNT and MnS remarkably enhances the tensile strength with an estimated value of 2.11 MPa. Due to the enhanced charge transfer phenomenon between layers and defect states, the optical bandgap of gel has been observed to be reduced from 4.91 to 4.37 eV while incorporating MWCNT and MnS nanofillers. The electrochemical energy storage performances of gel/MWCNT/MnS have been studied in the three-electrode configuration. The gel/MWCNT/MnS sample exhibits a maximum specific capacitance of 64.46 Fg-1 at 10 mV/s. In addition, the ternary nanocomposite exhibits the highest energy density of 38 Wh/g at specific power of 210 W/g and maximum specific power of 210 W/g at specific energy of 6.475 Wh/g. This work promotes possible strategies for improving the electrochemical performances of gel/MWCNT/MnS as an electrode material. © 2025 Emerald Publishing Limited: All rights reserved.

关键词： Tensile strength

来源：评论

学校读者我要写书评

暂无评论

High-flux angularly uniform proton beams from multiple laser interaction with wire-hemisphere targets

引用

High Power Laser Science and engineering 2024年第6期12卷 97-105页

作者： Xiangrui Jiang Debin Zou Mingyang Yu Na Zhao Lixiang Hu Jianming Ouyang Fuqiu Shao Wenhui Tang Tongpu Yu Department of Physics National University of Defense TechnologyChangshaChina Department of Nuclear Science and Technology National University of Defense TechnologyChangshaChina College of Engineering Physics Shenzhen Technology UniversityShenzhenChina School of Microelectronics and Physics Hunan University of Technology and BusinessChangshaChina

A scheme for generating high-flux angularly uniform proton beams with high laser-to-proton energy conversion efficiency is proposed. Three laser beams are focused on a microwire array attached to a solid-density hemispheric target. The laser-driven hot electrons from the front of the microwire hemisphere generate a hot-electron sheath in the hollow behind it, so that the protons on its back are accelerated by target normal sheath acceleration. The accelerated protons are of high flux, as well as angularly and energetically uniform. The scheme should be useful for applications involving warm dense matter, such as isochoric heating and modification of materials, as well as for proton therapy and inertial confinement fusion.

关键词： angular uniformity high-flux proton beams multiple lasers

来源：评论

学校读者我要写书评

暂无评论

Investigation of decay mechanisms and associated aspects of exotic nobelium isotopes using the Skyrme energy density formalism

引用

Chinese physics C 2025年第3期49卷 132-142页

作者： Shubhpreet Kaur Raj Kumar Manoj K.Sharma Department of Physics and Materials Science Thapar Institute of Engineering and TechnologyPatiala 147004India

The search for heavy elements has yielded many surprises and enhanced our knowledge of nuclear synthesis and associated dynamical *** new elements and their associated isotopes have been synthesized,information concerning elements with Z≥102,remains ***,concerning the transfermium elements,the nuclear shell structure is key to ensuring nuclear ***,the shell effects have key implications on such *** experimental and theoretical investigations have been conducted to examine the reactions induced by heavy ions and the subsequent decay mechanisms in the superheavy mass *** addition,the region of transfermium elements is of great interest because of the neutron/proton shell ***,our objective is to analyze the decay mechanisms of nuclides having Z=102 nuclei,i.e.,^(248)No*and^(250)No*.An extensive study was conducted using the dynamical cluster-decay model(DCM)based on Quantum Mechanical Fragmentation Theory(QMFT).The focus was to investigate compound nucleus(CN)and non-compound nucleus(nCN)mechanisms,including fusion-fission(ff),quasi-fission(QF),and fast fission(FF).The specific isotopes of interest are^(248)No*and^(250)No*,with attention given to the role of the center-of-mass energy(E_(c.m))and angular momentum(l).The nuclear interaction potential was derived using the Skyrme energy density formalism(SEDF)with the GSkI force *** capture cross-sections were calculated using the-summed Wong *** determination of the probability of compound nucleus formation(PCN)involved a function that is dependent upon the center-of-mass *** lifetimes of the ff and QF channels were also ***,CN and nCN decay mechanisms for two isotopes of Z=102 nobelium were analyzed over the range of center-of-mass values(E_(c.m))considering the quadrupole deformationβ_(2)and optimum orientations(θ_(opt))of the decaying *** fragmentation potential,preformation probability,neck length parameter,and

关键词： super heavy nuclei Z=102 cross-sections lifetimes

来源：评论

学校读者我要写书评

暂无评论

Exploring the effects of Mn substitution on structural, morphological and electrical properties of Co0.7Zn0.3Fe2O4 ceramics

引用

Ceramics International 2025年第15期51卷 19845-19859页

作者： Shah, Tuntun Dalai, Biswajit Mohanty, Hari Sankar Bhoi, Krishnamayee Sutar, Bijuni C. Pradhan, Dillip K. Department of Physics School of Sciences Gandhi Institute of Engineering and Technology University Odisha Gunupur765022 India Department of Physics KMBB College of Engineering & Technology Odisha Bhubaneswar752056 India Department of Physics and Astronomy National Institute of Technology Odisha Rourkela769008 India

This report examines the effects of manganese (Mn) substitution on structural, morphological and electrical properties of the sol-gel-fabricated zinc modified cobalt ferrite (Co0.7Zn0.3Fe2O4) ceramics. Co0.7Zn0.3Fe(2-y)MnyO4 (0.05 ≤ y ≤ 0.30) were synthesized employing sol-gel auto-combustion technique. X-ray diffraction (XRD) pattern shows formation of single-phase Co0.7Zn0.3Fe(2-y)MnyO4 (CZFMO) without emergence of any impurity phases. XRD patterns were refined by considering Fd-3m space group in a cubic spinel crystal structure which further confirms formation of single phase Co0.7Zn0.3Fe(2-y)MnyO4. The average particle size of Co0.7Zn0.3Fe(2-y)MnyO4 estimated using Williamson-Hall method, was found to increase from 31.52 nm to 96.55 nm with increasing Mn concentration. Field emission scanning electron microscopy (FESEM) micrographs reveal an even distribution of grain sizes along with existence of minimal amounts of pores across the sample microstructure. The elemental accuracy of these samples was confirmed by EDX characterization. The temperature dependent dielectric properties are studied over wide frequency ranges. Among the prepared compounds, maximum value of dielectric constant is obtained for Co0.7Zn0.3Fe1.75Mn0.25O4 composition. The dielectric relaxation behaviour of the non-Debye type was found using complex impedance and complex modulus spectroscopy methods. Nyquist plot is used to investigate the existence of grain and grain boundary involvement to impedance spectra in modified cobalt ferrite samples. Temperature-dependent of AC conductivity (σac) study also suggests the presence of negative temperature coefficient of resistance (NTCR) behaviour in Co0.7Zn0.3Fe(2-y)MnyO4 ceramics and follows overlapping large polaron tunnelling (OLPT) conduction mechanism. The Jonscher's power law provides a good fit for AC conductivity spectra of all the compounds. The total resistivity of the synthesized compounds is increased by increasing Mn content. The chosen s

关键词： Rietveld refinement

来源：评论

学校读者我要写书评

暂无评论

On the topological surface states of the intrinsic magnetic topological insulator Mn-Bi-Te family

引用

National Science Review 2024年第2期11卷 50-64页

作者： Yuan Wang Xiao-Ming Ma Zhanyang Hao Yongqing Cai Hongtao Rong Fayuan Zhang Weizhao Chen Chengcheng Zhang Junhao Lin Yue Zhao Chang Liu Qihang Liu Chaoyu Chen Shenzhen Institute for Quantum Science and Engineering(SIQSE)and Department of Physics Southern University of Science and Technology(SUSTech)

We review recent progress in the electronic structure study of intrinsic magnetic topological insulators（MnBi2Te4）·（Bi2Te3）n（n = 0, 1, 2, 3） family. Specifically, we focus on the ubiquitously（nearly）gapless behavior of the topological Dirac surface state observed by photoemission spectroscopy, even though a large Dirac gap is expected because of surface ferromagnetic order. The dichotomy between experiment and theory concerning this gap behavior is perhaps the most critical and puzzling question in this frontier. We discuss various proposals accounting for the lack of magnetic effect on the topological Dirac surface state, which are mainly categorized into two pictures, magnetic reconfiguration and topological surface state redistribution. Band engineering towards opening a magnetic gap of topological surface states provides great opportunities to realize quantized topological transport and axion electrodynamics at higher temperatures.

关键词： intrinsic magnetic topological insulator topological surface states magnetic gap magnetic reconfiguration topological surface state redistribution van der Waals spacing expansion

来源：评论

学校读者我要写书评

暂无评论

Density of excess modes below the first phonon mode in four-dimensional glasses

引用

Chinese physics B 2024年第7期33卷 483-489页

作者：王利近胥鼎张世允 School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230601China Department of Physics University of Science and Technology of ChinaHefei 230026China

Glasses are known to possess low-frequency excess modes beyond the Debye *** decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law scaling:D(ω)~ω~γ.However,it remains debated on the value of γ at low frequencies below the first phonon-like mode in finitesize *** simulation studies reported γ=4 at low frequencies in two-(2D),three-(3D),and four-dimensional(4D)glasses,whereas recent observations in 2D and 3D glasses suggested γ=3.5 in a lower-frequency *** is uncertain whether the low-frequency scaling of D(ω)~ω^(3.5) could be generalized to 4D ***,we conduct numerical simulation studies of excess modes at frequencies below the first phonon-like mode in 4D model *** is found that the system size dependence of D(ω) below the first phonon-like mode varies with spatial dimensions:D(ω) increases in2D glasses but decreases in 3D and 4D glasses as the system size ***,we demonstrate that the ω^(3.5)scaling,rather than the ω~4 scaling,works in the lowest-frequency regime accessed in 4D glasses,regardless of interaction potentials and system sizes ***,our findings in 4D glasses,combined with previous results in 2D and 3D glasses,suggest a common low-frequency scaling of D(ω)~ ω^3.5) below the first phonon-like mode across different spatial dimensions,which would inspire further theoretical studies.

关键词： vibrational density of states excess modes four-dimensional glasses scaling computer simulation

来源：评论

学校读者我要写书评

暂无评论

Bessel vortices in spin-1 Bose-Einstein condensates with Zeeman splitting and spin-orbit coupling

引用

Chinese physics B 2024年第10期33卷 159-165页

作者： Huan-Bo Luo Xin-Feng Zhang Runhua Li Yongyao Li Bin Liu Department of Physics South China University of TechnologyGuangzhou 510640China School of Physics and Optoelectronic Engineering Foshan UniversityFoshan 528000China

We investigate the ground states of spin-orbit coupled spin-1 Bose-Einstein condensates in the presence of Zeeman *** introducing the generalized momentum operator,the linear version of the system is solved exactly,yielding a set of Bessel ***,based on linear solution and using variational approximation,the solutions for the full nonlinear system and their ground state phase diagrams are derived,including the vortex states with quantum numbers m=0,1,as well as mixed *** this work,mixed states in spin-1 spin-orbit coupling(SOC)BEC are interpreted for the first time as weighted superpositions of three vortex ***,the results also indicate that under strong Zeeman splitting,the system cannot form localized *** variational solutions align well with numerical simulations,showing stable evolution and meeting the criteria for long-term observation in experiments.

关键词： spin-orbit coupling Bessel vortices variational method

来源：评论

学校读者我要写书评

暂无评论

Clinical Accuracy Analysis and Error Modeling in the CyberKnife System;A Comparative Study

引用

Iranian Journal of Medical physics 2025年第1期22卷 36-43页

作者： Miandoab, Payam Samadi Setayeshi, Saeed Saramad, Shahyar Department of Energy Engineering and Physics Medical Radiation Engineering Group Amirkabir University of Technology Tehran Iran

Introduction: This study conducted a clinical accuracy analysis of Synchrony Respiratory Tracking System across different CyberKnife generations (G3, G4, VSI, and M6) to provide comprehensive comparing across different generations. Additionally, appropriate regression models were developed to explain the behavior of standard deviation (SD) of the errors (correlation and prediction) and tumor motion in each region. Material and Methods: The clinical log data was analyzed to assess the correlation and prediction errors. A retrospective analysis was conducted on 46 patients with thoracic or abdominal cancers treated using the CyberKnife G3. Furthermore, the F-test, P-value, and R2 analysis were applied to model the SD of correlation and prediction errors as a function of tumor displacements across five lung regions and two abdomen regions. Results: Using a systematic approach, linear, quadratic, cubic, or piecewise regression models were proposed for SD of the errors across tumor displacement. The estimated radial Synchrony error (mean±SD) for the CyberKnife G3, G4, VSI, and M6 was 2.60±0.93 mm, 2.00±0.60 mm, 1.79±1.16 mm, and 0.66±0.23 mm, respectively. Conclusion: The results indicate that correlation error remains predominant in both lung and abdominal regions across all CyberKnife generations. However, prediction error has been significantly reduced in the G4, VSI, and M6 systems. This improvement is attributed to the newer generations incorporating a combination of historical pattern-matching filters and least-mean-square filters. Error modeling based on tumor motion in different regions reveals a linear relationship between errors and target amplitude in the lung region, while the liver and pancreas regions exhibit non-linear relationships. © (2025), (Mashhad University of Medical Sciences). All rights reserved.

关键词： Radiotherapy

来源：评论

学校读者我要写书评

暂无评论

Design and construction of two biased electrodes and preliminary experiments on the Keda Torus eXperiment

引用

Plasma Science and technology 2025年第4期27卷 42-49页

作者： Jiaren WU Tao LAN Ge ZHUANG Jie WU Wenzhe MAO Chen CHEN Xingkang WANG Peng DENG Qilong DONG Yongkang ZHOU Tianxiong WANG Pengcheng LU Zeqi BAI Yuhua HUANG Zhengwei WU Zian WEI Xiaohui WEN Hai WANG Chu ZHOU Ahdi LIU Jinlin XIE Hong LI Weixing DING Wandong LIU Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026People’s Republic of China

The electromagnetic turbulence in reversed field pinch(RFP)plasmas exhibits three-dimensional *** of this turbulence is crucial for enhancing plasma confinement,necessitating control over the electric field or the current *** this end,two sets of electrodes have been designed and installed on the Keda Torus eXperiment(KTX)RFP device to manipulate the edge electric field and the edge parallel current ***,the edge radial electric field and edge parallel current profile control experiments are *** the edge radial electric field control experiments,the edge radial electric field is altered under bias,accompanied with an increase in the electron density and plasma ***,under bias,both electrostatic and magnetic fluctuations are *** the edge parallel current profile control experiments,the results indicate that bias modifies the edge parallel current profile locally,leading to a localized increase in the field reversal depth and electron ***,a reduction in magnetic fluctuations is observed within the reversed field enhanced region under bias,suggesting that the bias suppresses magnetic perturbations.

关键词： KTX biased electrode radial electric field parallel current profile(Some figures may appear in colour only in the online journal)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：