检索结果-南通市图书馆

Optimal Forward-Scattering Angles of Atmospheric Aerosols in North China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2014年第3期7卷 236-242页

作者： JIA Sheng-Jie Lü Da-Ren Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of Science University of Chinese Academy of Sciences

The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers （PWIs） in addition to the de- tection of forward-scattering optical properties.

关键词： forward-scattering anglesphase function complex refractive index visibility meters

Significant broadband extinction abilities of bioaerosols

在线全文

学校读者我要写书评

暂无评论

Science China Materials 2019年第7期62卷 1033-1045页

作者： Yihua Hu Xinying Zhao Youlin Gu Xi Chen Xinyu Wang Peng Wang Zhiming Zheng Xiao Dong State Key Laboratory of Pulsed Power Laser Technology National University of Defense Technology Hefei 230037 China Anhui Province Key Laboratory of Electronic Restriction National University of Defense Technology Hefei 230037 China Key Laboratory of Ion Beam Bioengineering Hefei Institutes of Physical Science Chinese Academy of Sciences Hefei 230001 China

Bioaerosol, an important constituent of the atmosphere, can directly affect light radiation characteristics due to absorption and scattering effects. Current research lacks a reasonable explanation for the extinction abilities of bioaerosols in a broadband. Herein, we measured the reflectance spectra of 12 com m on biomaterials and calculated their complex refractive indexes. The peaks of the imaginary part of the complex refractive indexes are located at wavelengths of approximately 0.7, 2.7, 6.1 and 9.5μm. Based on photographs of the floating structures of bioaerosols, we constructed a model for calculating the extinction abilities of bioaerosols in the wavelength range of 240 nm to 14 (im. Taking AN02 spores as an example, absorption was found to account for more than 90% of the total extinction. In addition, the theoretical calculations and experimental data of transmittance corresponding to the smoke box show that bioaerosol exhibits significant broadband extinction ability from UV to IR bands, which provides new directions for the development of broadband light attenuation materials.

关键词： bioaerosol complex refractive index UV to IR broadband light attenuation

Understanding angle-resolved polarized Raman scattering from black phosphorus at normal and oblique laser incidences

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2020年第22期65卷 1894-1900,M0004页

作者： Miao-Ling Lin Yu-Chen Leng Xin Cong Da Meng Jiahong Wang Xiao-Li Li Binlu Yu Xue-Lu Liu Xue-Feng Yu Ping-Heng Tan State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering&CAS Center of Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100049China Shenzhen Engineering Center for the Fabrication of Two-Dimensional Atomic Crystals Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China College of Physics Science and Technology Hebei UniversityBaoding 071002China Beijing Academy of Quantum Information Science Beijing 100193China

The selection rule for angle-resolved polarized Raman(ARPR)intensity of phonons from standard grouptheoretical method in isotropic materials would break down in anisotropic layered materials(ALMs)due to birefringence and linear dichroism *** two effects result in depth-dependent polarization and intensity of incident laser and scattered signal inside ALMs and thus make a challenge to predict ARPR intensity at any laser incidence ***,taking in-plane anisotropic black phosphorus as a prototype,we developed a so-called birefringence-linear-dichroism(BLD)model to quantitatively understand its ARPR intensity at both normal and oblique laser incidences by the same set of real Raman tensors for certain laser *** fitting parameter is needed,once the birefringence and linear dichroism effects are considered with the complex refractive *** approach was proposed to experimentally determine real Raman tensor and complex refractive indexes,respectively,from the relative Raman intensity along its principle axes and incident-angle resolved reflectivity by Fresnel’s *** results suggest that the previously reported ARPR intensity of ultrathin ALM flakes deposited on a multilayered substrate at normal laser incidence can be also understood based on the BLD model by considering the depth-dependent polarization and intensity of incident laser and scattered Raman signal induced by both birefringence and linear dichroism effects within ALM flakes and the interference effects in the multilayered structures,which are dependent on the excitation wavelength,thickness of ALM flakes and dielectric layers of the *** work can be generally applicable to any opaque anisotropic crystals,offering a promising route to predict and manipulate the polarized behaviors of related phonons.

关键词： Angle-resolved polarized Raman scattering Anisotropic layered material Birefringence Linear dichroism Real Raman tensor complex refractive index

Regarding the Optical Properties of Porous Layers Prepared on Si Substrates

在线全文

学校读者我要写书评

暂无评论

Journal of Energy and Power Engineering 2017年第11期11卷 687-692页

作者： Emil Pincik Robert Brunner Hikaru Kobayashi Pavel Vojtek Zuzana Zabudla Milan Mikula Jan Gregus Michal Kucera Institute of Physics SAS Dubravska cesta 9 Bratislava 84511 Slovak Republic Institute of Scientific and Industrial Research Osaka University Mihogaoka Ibaraki Osaka 567-0047 Japan FMPI of Comenius University Mlynsk6 dolina F2 Bratislava 84248 Slovak Republic Faculty of Chemical and Food Technology of STU Radlinskeho 9 Bratislava 8123 7 Slovak Republic Institute of Electrical Engineering SAS Dubravska cesta 9 Bratislava 84104 Slovak Republic

The paper deals with the complex refractive index and photoluminescence in the IR-VIS light region of two sample types （i） black p-type silicon （BSi） produced by the surface structure chemical transfer method using Pt catalytic mesh, and （ii） porous p-type silicon prepared by standard electrochemical etching. We present, compare, and discuss the values of the IR-VIS complex refractive index obtained by calculation using the Kramers-Kronig transformation and the photoluminescence properties thereof. The results indicate that differences between the optical properties of the BSi and the porous Si are given by （a） the oxidation procedure of BSi, （b） the thickness of the formed black and porous Si layer, and by （c） the porosity of both layer types. We assume that the photoluminescence signal generated by oxidized BSi structures can be mainly related to the quantum confinement effect, while the photoluminescence of the porous p-type Si is caused by the optical activity of the SiOxHy compounds covering its surface region.

关键词： Black silicon porous silicon complex refractive index photoluminescence.

Research on complex Refraction Indices of Expanded Graphite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2011年第4期7卷 243-247页

作者：豆正伟李晓霞赵纪金 State Key Laboratory of Pulsed Power Laser Technology Key Laboratory of Infrared and Low Temperature Plasma of Anhui Province Electronic Engineering Institute of PLA

The expanded graphite (EG) with a low density and better extinction performance can be used in military as passive jamming material in IR and MMW bands. Its complex refractive index is a significant parameter for the extinction property. This paper presents a method to calculate the complex refractive index of EG. The reflection spectra of EG pellets were measured in the 0.24-2.6μm and 2.5-25μm bands, respectively. Based on the measurement results, the complex refractive index of EG in 5-10μm band was calculated by using Kramers-Kronig(K-K) relation and Bruggeman effective medium theory, and then the errors were analyzed. The results indicate that it is feasible to calculate the complex refractive index of EG based on its IR reflection spectra data.

关键词： non-metallic inorganic material expanded graphite complex refractive index Kramers-Kronig relation effective medium theory