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First‑principles study on electronic structure,optical and magnetic properties of rare earth elements X(X=Sc,Y,La,Ce,Eu)doped with two‑dimensional GaSe
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作者 QIU Shenhao XIAO Qingquan +1 位作者 TANG Huazhu XIE Quan 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第11期2250-2258,共9页
The electronic structure,magnetic,and optical properties of two-dimensional(2D)GaSe doped with rare earth elements X(X=Sc,Y,La,Ce,Eu)were calculated using the first-principles plane wave method based on den-sity funct... The electronic structure,magnetic,and optical properties of two-dimensional(2D)GaSe doped with rare earth elements X(X=Sc,Y,La,Ce,Eu)were calculated using the first-principles plane wave method based on den-sity functional theory.The results show that intrinsic 2D GaSe is a p-type nonmagnetic semiconductor with an indi-rect bandgap of 2.6611 eV.The spin-up and spin-down channels of Sc-,Y-,and La-doped 2D GaSe are symmetric,they are non-magnetic semiconductors.The magnetic moments of Ce-and Eu-doped 2D GaSe are 0.908μ_(B)and 7.163μ_(B),which are magnetic semiconductors.Impurity energy levels appear in both spin-up and spin-down chan-nels of Eu-doped 2D GaSe,which enhances the probability of electron transition.Compared with intrinsic 2D GaSe,the static dielectric constant of the doped 2D GaSe increases,and the polarization ability is strengthened.The ab-sorption spectrum of the doped 2D GaSe shifts in the low-energy direction,and the red-shift phenomenon occurs,which extends the absorption spectral range.The optical reflection coefficient of the doped 2D GaSe is improved in the low energy region,and the improvement of Eu-doped 2D GaSe is the most obvious. 展开更多
关键词 first principle two-dimensional GaSe electronic structure magnetic property optical property
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A study of pulsed high voltage driven hollow-cathode electron beam sources through synchronous optical trigger
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作者 霍卫杰 贺伟国 +2 位作者 韩罗峰 朱康武 王锋 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期82-90,共9页
In this study,a pulsed,high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure,low cost,and easy triggering.To validate the new design,t... In this study,a pulsed,high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure,low cost,and easy triggering.To validate the new design,the characteristics of hollow-cathode discharge and electron beam characterization under pulsed high voltage drive are studied experimentally and discussed by discharge characteristics and analyses of waveform details,respectively.The validation experiments indicate that the pulsed high voltage supply significantly improves the frequency and stability of the discharge,which provides a new solution for the realization of a high-frequency,high-energy electron beam source.The peak current amplitude in the high-energy electron beam increases from 6.2 A to 79.6 A,which indicates the pulsed power mode significantly improves the electron beam performance.Besides,increasing the capacitance significantly affects the highcurrent,lower-energy electron beam more than the high-energy electron beam. 展开更多
关键词 hollow-cathode nanosecond pulsed electron beam sources optical trigger pulsed high voltage supply beam current distribution
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ELECTRON OPTICS OF VARIABLE RECTANGULAR SHAPED BEAM LITHOGRAPHY SYSTEM D J-2
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作者 康念坎 《Journal of Electronics(China)》 1993年第2期170-180,共11页
The electron optical column for the variable rectangular-shaped beam lithographysystem DJ-2 is described,with emphasis on the analysis of the optical configuration and theshaping deflection compensation.In this column... The electron optical column for the variable rectangular-shaped beam lithographysystem DJ-2 is described,with emphasis on the analysis of the optical configuration and theshaping deflection compensation.In this column the variable spot shaping is performed with aminimum number of lenses by a more reasonable optical scheme.A high-sensitivity electrostaticshaping deflector with sequential parallel-plates is implemented for high-speed spot shaping.With a precise linear and rotational approach,the spot current density,the edge resolution aswell as the position of spot origin remain unchanged when the spot size varies.Experiments showthat the spot current density of over 0.4 A/cm^2 is obtained with a tungsten hairpin cathode,andthe edge resolution is better than 0.2μm within a 2×2 mm^2 field size. 展开更多
关键词 electron optics electron BEAM LITHOGRAPHY VARIABLE rectangular-shaped BEAM
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Structure,electronic,and nonlinear optical properties of superalkaline M_(3)O(M=Li,Na)doped cyclo[18]carbon
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作者 刘晓东 卢其亮 罗其全 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期311-317,共7页
Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an ef... Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm. 展开更多
关键词 superalkaline doped carbon structure and electronic properties nonlinear optical properties density functional theory(DFT)
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Structural, Electronic and Optical Properties of ScxAl1-xN alloys within DFT Calculations
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作者 Asma Said Yasmina Oussaifi Moncef Said 《Journal of Applied Mathematics and Physics》 2024年第2期569-584,共16页
Structural, electronic and optical properties of Sc-based aluminum-nitride alloy have been carried out with first-principles methods using both local density approximation (LDA) and Heyd-Scuseria-Ernzerhof (HSE) hybri... Structural, electronic and optical properties of Sc-based aluminum-nitride alloy have been carried out with first-principles methods using both local density approximation (LDA) and Heyd-Scuseria-Ernzerhof (HSE) hybrid functional. This latter provides a more accurate description of the lattice parameters, enthalpy of formation, electronic and optical properties of our alloy than standard DFT. We found the transition from wurtzite to rocksalt structures at 61% of Sc concentration. By increasing the scandium concentration, the lattice parameters and the band gap decrease. The HSE band gap is in good agreement with available experimental data. The existence of the strong hybridization between Sc 3d and N 2p indicates the transport of electrons from Sc to N atoms. Besides, it is shown that the insertion of the Sc atom leads to the redshift of the optical absorption edge. The optical absorption of Sc<sub>x</sub>Al<sub>1-x</sub>N is found to decrease with increasing Sc concentrations in the low energy range. Because of this, Sc<sub>x</sub>Al<sub>1-x</sub>N have a great potential for applications in photovoltaics and photocatalysis. 展开更多
关键词 DFT electronic and Optical Properties ScAlN Hybrid Functional HSE
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First-Principle Study on the Electronic Structure and Optical Property of New Diluted Magnetic Semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO
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作者 Zhou Wenjie 《材料科学与工程(中英文B版)》 2024年第1期14-20,共7页
The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first... The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first-principles calculation.The calculation results indicate that(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO is a direct bandgap semiconductor with a bandgap of 1.1 eV.The Fermi surface is asymmetric and exhibits spin splitting phenomenon.The new type of dilute magnetic semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO exhibits significant light loss around 70 eV,with light reflection gradually increasing after 30 eV,and light absorption mainly occurring around 8-30 eV.These results also provide a basis for the discovery of more types of 1111 phase new dilute magnetic semiconductors in the future. 展开更多
关键词 First-principles calculation electronic structure optical property new diluted magnetic semiconductor
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Optical fiber-based power and data delivery system for high voltage electronic current transformer
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作者 邱红辉 段雄英 邹积岩 《Journal of Shanghai University(English Edition)》 CAS 2008年第3期268-273,共6页
This paper describes a prototype power delivery system developed for high voltage electronic current transformer (ECT) that uses laser light to transfer power to and communicates with the primary converter. The desi... This paper describes a prototype power delivery system developed for high voltage electronic current transformer (ECT) that uses laser light to transfer power to and communicates with the primary converter. The design is based on optical-to-electrical power converters, solid-state diode lasers and optical fibers. Command signals are transmitted via the same up-fiber used to send power from secondary power supply to primary converter. The upward data transmission is completed during the brief interruption of power delivery without affecting steady power-supply. A simple comparator added to the primary converter can take the command data. Experimental results show that the fibers can provide reliable up-link for data transmission at 200 kb/s from the secondary to the primary converter. Based on the delivery system, the secondary converter can control three auxiliary channels to provide additional information. These monitoring channels are used in a time-multiplexing mode to provide information about the operation temperature, voltage and current at the remote unit for monitoring the ECT. This preventive maintenance or built-in test can increase reliability by giving early warning for necessary maintenance request. 展开更多
关键词 high voltage electronic current transformer (ECT) optical power supply delivery system photovoltaic powerconverters supervisory functions
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Simulations of electron energy distribution of Pd-like Xe system based on OFI
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作者 夏元钦 卢发铭 +3 位作者 陈德应 张盛 赵卫疆 王骐 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第1期138-140,共3页
X-ray laser based on OFI is a promising way to realize the table-top X-ray laser.A simple model to describe the electron energy distribution in plasma produced by circularly polarized optical-field-induced ionization ... X-ray laser based on OFI is a promising way to realize the table-top X-ray laser.A simple model to describe the electron energy distribution in plasma produced by circularly polarized optical-field-induced ionization is constructed on the basis of ADK tunneling ionization theory.The ionization rate,threshold intensity,residual energy and electron energy distribution of Pd-like Xe system based on optical-field-induced ionization are calculated.The results are useful to further experments on X-ray laser of Pa-like Xe system. 展开更多
关键词 optical filed-induced ionization femtosecond laser pulses electron energy distribution Pd-like Xe
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Comparative Analysis for Different Mathematical Models in Electron Optics
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作者 Valentin Ivanov 《Journal of Chemistry and Chemical Engineering》 2014年第10期990-995,共6页
The comparative analysis of modem mathematical models for 3D problems in electron optics is presented. The new approach to solve the electron optics problems in three dimensions is presented. It is based on the princi... The comparative analysis of modem mathematical models for 3D problems in electron optics is presented. The new approach to solve the electron optics problems in three dimensions is presented. It is based on the principal ray method suggested by G. Grinberg in 1948. That perspective approach was not realized before for full three-dimensional electron optic systems, probably because of the complexity of its mathematical apparatus. We describe the analytical technique of the BEM (boundary element method) for the field evaluation, and 3rd order aberration expansion for the trajectory analysis. The first version of such computer code "OPTICS-3" and some results of numerical simulations with this code were presented. 展开更多
关键词 electron optics aberration theory analytical technique boundary element method.
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Decomposition Method for Complex 3D Problems in Electron Optics
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作者 Valentin Ivanov 《Journal of Physical Science and Application》 2015年第2期96-100,共5页
The decomposition method was successfully used in solving of 3D problems with complex geometry shape in electron optics for the FDM (Finite Difference Method) and FEM (Finite Element Method) mostly to implement fa... The decomposition method was successfully used in solving of 3D problems with complex geometry shape in electron optics for the FDM (Finite Difference Method) and FEM (Finite Element Method) mostly to implement fast and robust parallel algorithms and computer codes. We suggest a new version of similar approach for the BEM (Boundary Element Method) based on the alternating method by Schwartz. This approach substantially reduce the dimension of dense global matrix of algebraic system produced by BEM algorithm to solve a complex problem on as single CPU (Central Processor Unit) desktop computer. New algorithm is iterative one, but exponential convergence for the Schwatlz's algorithm creates the fast numerical procedures. We describe the results of numerical simulation for a multi electrode ion transport system. The algorithms were implemented in the computer code "POISSON-3". 展开更多
关键词 electron optics decomposition method numerical-analytical technique boundary element method.
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The Advent of Wide Bandgap Green-Synthesized Copper Zinc Tin Sulfide Nanoparticles for Applications in Optical and Electronic Devices
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作者 Opeyemi S. Akanbi Haruna A. Usman +8 位作者 Gbemi F. Abass Kehinde E. Oni Akinsanmi S. Ige Bola P. Odunaro Idowu J. Ojo Julius A. Oladejo Halimat O. Ajani Adnan Musa Joshua Ajao 《Journal of Materials Science and Chemical Engineering》 CAS 2023年第3期22-33,共12页
Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a ... Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a need to reduce their losses and improve their performance to reduce electric power consumption. Current power semiconductor devices, such as inverters, are made of silicon (Si), but the performance of these Si power devices is reaching its limit due to physical properties and energy bandgap. To address this issue, recent developments in wide bandgap (WBG) semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN), offer the potential for a new generation of power semiconductor devices that can perform significantly better than silicon-based devices. In this research, a green synthesized copper-zinc-tin-sulfide (CZTS) nanoparticle is proposed as a new WBG semiconductor material that could be used for optical and electronic devices. Its synthesis, consisting of the production methods and materials used, is discussed. The characterization is also discussed, and further research is recommended in the later sections to enable the continual advancement of this technology. 展开更多
关键词 Wide Bandgap Semiconductor SEMICONDUCTOR electronic Device Power Device Optical Device CZTS
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Study of the Electronic Structure and Optical Properties of Rare Earth Luminescent Materials
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作者 Chengxi Zhang 《Journal of Materials Science and Chemical Engineering》 2023年第10期8-18,共11页
Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properti... Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging. 展开更多
关键词 Rare Earth Luminescent Materials electronic Structure Optical Properties Luminescence Mechanism Prospects for Applications
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A Loop Diagram Approach to the Nonlinear Optical Conductivity for an Electron-Phonon System
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作者 Nam Lyong Kang Sang Don Choi 《Journal of Modern Physics》 2011年第11期1410-1414,共5页
A loop diagram approach to the nonlinear optical conductivity of an electron-phonon system is introduced. This approach can be categorized as another Feynman-like scheme because all contributions to the self-energy te... A loop diagram approach to the nonlinear optical conductivity of an electron-phonon system is introduced. This approach can be categorized as another Feynman-like scheme because all contributions to the self-energy terms can be grouped into topologically-distinct loop diagrams. The results for up to the first order nonlinear conductivity are identical to those derived using the KC reduction identity (KCRI) and the state- dependent projection operator (SDPO) introduced by the present authors. The result satisfies the “population criterion” in that the population of electrons and phonons appear independently or the Fermi distributions are multiplied by the Planck distributions in the formalism. Therefore it is possible, in an organized manner, to present the phonon emissions and absorptions as well as photon absorptions in all electron transition processes. In additions, the calculation needed to obtain the line shape function appearing in the energy denominator of the conductivity can be reduced using this diagram method. This method shall be called the “KC loop diagram method”, since it originates from proper application of KCRI’s and SDPO’s. 展开更多
关键词 Optical CONDUCTIVITY PROJECTION Operator KC Reduction IDENTITY electron-Phononinteraction
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钾掺杂对纤锌矿型氧化锌电子结构和光学性质的影响
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作者 马战红 于仁红 任凤章 《河南科技大学学报(自然科学版)》 北大核心 2024年第2期15-20,M0003,共7页
针对纯纤锌矿型ZnO禁带宽度较高,不能吸收大部分可见光的问题,采用基于密度泛函理论的第一性原理,构建了钾掺杂ZnO的4种超胞模型,并对4种模型进行几何优化,计算了KXZn1-XO的能带结构、态密度和光吸收性能。结果表明:采用广义梯度近似法(... 针对纯纤锌矿型ZnO禁带宽度较高,不能吸收大部分可见光的问题,采用基于密度泛函理论的第一性原理,构建了钾掺杂ZnO的4种超胞模型,并对4种模型进行几何优化,计算了KXZn1-XO的能带结构、态密度和光吸收性能。结果表明:采用广义梯度近似法(GGA)+U方法计算得到纯氧化锌带隙为3.373 eV,与实验值一致;随着钾掺杂量X的增大,ZnO的禁带宽度Eg出现先增大后减小再增加的现象,KXZn1-XO吸收带发生先蓝移后红移的现象。 展开更多
关键词 钾掺杂 纤锌矿型氧化锌 第一性原理 电子结构 光学性质
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B、Cu共掺杂单层g-C_(3)N_(4)电子结构及光学性质的第一性原理研究
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作者 谭秀娟 张旭阳 +2 位作者 杨烁 王勇 张旭昀 《功能材料》 CAS CSCD 北大核心 2024年第7期7111-7115,7131,共6页
g-C_(3)N_(4)是一种极具潜力的绿色半导体光催化剂,但其带隙较宽,对可见光利用率有限。通过元素掺杂可以有效提高g-C_(3)N_(4)的光催化性能,采用第一性原理方法研究了非金属元素B和金属元素Cu共掺杂对g-C_(3)N_(4)电子结构于光学性质的... g-C_(3)N_(4)是一种极具潜力的绿色半导体光催化剂,但其带隙较宽,对可见光利用率有限。通过元素掺杂可以有效提高g-C_(3)N_(4)的光催化性能,采用第一性原理方法研究了非金属元素B和金属元素Cu共掺杂对g-C_(3)N_(4)电子结构于光学性质的影响机理,结果表明,B、Cu共掺杂g-C_(3)N_(4)(001)表面的最稳定位点为B占据H位点,而Cu占据N2位点。B、Cu共掺杂相比单一B元素掺杂可以使g-C_(3)N_(4)(001)表面的能隙和功函数进一步下降,Cu元素的加入主要改善了B掺杂的g-C_(3)N_(4)(001)表面的电子导通能力以及对光的捕捉能力,从而提高了光催化活性。 展开更多
关键词 g-C_(3)N_(4) 光催化 第一性原理 电子结构 光学性质
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DEMATEL-ANP在光电对抗系统作战效能评估中的应用
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作者 吴俊 童忠诚 +1 位作者 叶巨翼 徐磊 《火力与指挥控制》 CSCD 北大核心 2024年第8期26-33,共8页
对光电对抗系统作战效能评估指标体系进行完善和改进,将指挥决策和作战对象等影响因素纳入指标体系。将决策实验室分析法-网络分析法(DEMATEL-ANP)引入光电对抗系统作战效能评估中,研究使用DEMATEL法厘清光电对抗系统作战效能指标体系... 对光电对抗系统作战效能评估指标体系进行完善和改进,将指挥决策和作战对象等影响因素纳入指标体系。将决策实验室分析法-网络分析法(DEMATEL-ANP)引入光电对抗系统作战效能评估中,研究使用DEMATEL法厘清光电对抗系统作战效能指标体系中各指标之间的影响关系,和利用ANP计算得出各指标权重的方法。通过对评估数据进行分析,针对性地提出改进措施来提高光电对抗系统的作战能力。 展开更多
关键词 光电对抗 作战效能评估 DEMATEL-ANP
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SnO_(2)(110)/FAPbBrI_(2)(001)界面电子结构与光学性质的第一性原理研究
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作者 李丽华 周龙杰 +2 位作者 刘硕 王航 黄金亮 《人工晶体学报》 CAS 北大核心 2024年第7期1239-1248,共10页
通过基于密度泛函理论的第一性原理对SnO_(2)(110)/FAPbBrI_(2)(001)界面的电子结构及光学性质进行了研究。FAPbBrI_(2)是带隙值为1.58 eV的直接带隙半导体材料,通过构建SnO_(2)(110)和FAPbBrI_(2)(001)的界面模型,发现其晶格失配率为4.... 通过基于密度泛函理论的第一性原理对SnO_(2)(110)/FAPbBrI_(2)(001)界面的电子结构及光学性质进行了研究。FAPbBrI_(2)是带隙值为1.58 eV的直接带隙半导体材料,通过构建SnO_(2)(110)和FAPbBrI_(2)(001)的界面模型,发现其晶格失配率为4.28%,界面结合能为-0.116 eV/A^(2),说明此界面结构可以稳定存在。通过态密度(DOS)分析SnO_(2)(110)/FAPbBrI_(2)(001)界面的电子结构,发现了主要由界面处O_(2)p、I 5p、Br 4p、Pb 6p轨道电子杂化形成的界面态。差分电荷密度及Bader电荷分析结果说明在界面处存在明显的电荷转移,这促进了界面处原子之间的成键,提高了界面稳定性。同时,有效的电荷分离也使SnO_(2)(110)/FAPbBrI_(2)(001)界面的光吸收系数相比于SnO_(2)(110)表面和FAPbBrI_(2)(001)表面有了明显提升。 展开更多
关键词 第一性原理 钙钛矿材料 SnO_(2)(110)/FAPbBrI_(2)(001)界面 电子结构 光学性质 界面态
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基于密度泛函理论研究Ag-Co团簇的结构、电子和光学性能
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作者 李维银 尚瑞咏 +1 位作者 王春勇 张永莉 《原子与分子物理学报》 CAS 北大核心 2025年第2期63-69,共7页
基于密度泛函理论研究了7个原子Ag-Co团簇结构的稳定性、电子和光学性能.研究结果表明,7个原子Ag-Co团簇的最稳定结构都是十面体结构,Co原子数量较少时,Co原子主要占据十面体的轴向位,Ag原子主要占据赤道位,随着Co原子数的增加,Co原子... 基于密度泛函理论研究了7个原子Ag-Co团簇结构的稳定性、电子和光学性能.研究结果表明,7个原子Ag-Co团簇的最稳定结构都是十面体结构,Co原子数量较少时,Co原子主要占据十面体的轴向位,Ag原子主要占据赤道位,随着Co原子数的增加,Co原子逐渐替换了赤道位上的Ag原子.当Co原子数增加时,Ag-Co团簇的垂直电离势、垂直电子亲能和最高占据轨道与最低未占据轨道之间的能隙整体上都呈现出下降趋势,表明电子稳定性降低;Ag-Co团簇的吸收光谱整体出现了红移,吸收峰的强度逐渐减弱,吸收谱的宽度变窄. 展开更多
关键词 银钴团簇 几何结构 电子性能 光学性能
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磁控溅射制备碳化硼薄膜的结构与成分分析
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作者 朱京涛 刘扬 +3 位作者 周健荣 周晓娟 孙志嘉 崔明启 《光学仪器》 2024年第2期63-68,共6页
近年来国际上^(3)He资源的短缺造成了基于^(3)He的中子探测器高昂的成本,而以碳化硼薄膜作为中子转换层的硼基中子探测器逐渐成为了最有前景的替代方案。通过直流磁控溅射制备了Ti/B_(4)C多层膜,并使用透射电子显微镜(TEM)、飞行时间二... 近年来国际上^(3)He资源的短缺造成了基于^(3)He的中子探测器高昂的成本,而以碳化硼薄膜作为中子转换层的硼基中子探测器逐渐成为了最有前景的替代方案。通过直流磁控溅射制备了Ti/B_(4)C多层膜,并使用透射电子显微镜(TEM)、飞行时间二次离子质谱(ToF-SIMS)、X射线光电子能谱(XPS)等手段对薄膜的结构与成分进行表征。结果表明:Ti层存在结晶情况;H、O、N元素为薄膜内部的主要杂质,且多分布于Ti层与B_(4)C-on-Ti过渡层中;更高的本底真空度能够降低碳化硼薄膜内的杂质含量,提高B含量占比;中子探测效率测试结果证明本底真空度的提高能够有效提高碳化硼中子转换层的效率。 展开更多
关键词 中子光学 碳化硼薄膜 直流磁控溅射 透射电子显微镜(TEM) X射线光电子能谱(XPS) 中子探测
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基于发射光谱的绝缘油中放电参数时间演化特性 被引量:1
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作者 郭凯航 章程 +3 位作者 孙建涛 陈根永 李金忠 邵涛 《高电压技术》 EI CAS CSCD 北大核心 2024年第7期3191-3198,共8页
为了研究绝缘油中击穿放电通道参数演化过程,搭建了绝缘油中放电发射光谱诊断平台,通过实验得到绝缘油中微秒级击穿放电过程的典型发射光谱和时间演化发射光谱,分别使用Stark展宽法和Boltzmann点法对绝缘油中放电等离子体通道的电子数... 为了研究绝缘油中击穿放电通道参数演化过程,搭建了绝缘油中放电发射光谱诊断平台,通过实验得到绝缘油中微秒级击穿放电过程的典型发射光谱和时间演化发射光谱,分别使用Stark展宽法和Boltzmann点法对绝缘油中放电等离子体通道的电子数密度和电子温度时间演化特性进行诊断。从绝缘油中放电击穿的典型发射光谱中可观察到H_(α)谱线、C_(2)斯旺带和电极金属原子发射谱线。对比放电电流波形与时间演化发射光谱可发现电流强度与光谱强度呈正相关。放电等离子体通道参数诊断结果表明:电子数密度在放电1~2μs时达到峰值1.12×10^(18)cm^(-3),18μs后稳定在10^(17)cm^(-3)量级;整个放电过程电子温度在7000~8200K范围内波动,总体呈上升趋势;根据参数诊断结果可判断绝缘油中放电等离子体通道处于局部热力学平衡状态。 展开更多
关键词 绝缘油 发射光谱 放电等离子体 电子数密度 电子温度
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