bluuebunny/crossref_metadata_2025 huggingface dataset:
Bürger in Uniform
Authors: Münch Philipp
Published: December 2020

Anhand der Feldpost von 30 miteinander bekannten Mitgliedern einer Hamburger Turnerriege soll die Frage beantwortet werden, weshalb bürgerliche Soldaten im Ersten Weltkrieg eine relativ positive Einstellung gegenüber ihrem Militärdienst zeigten. Nach einer Analyse ihrer Militär- und Kriegserfahrungen stellt sich heraus, welche Aspekte des Kriegsdienstes mit bürgerlichen Werthaltungen vereinbar waren und dass daraus überwiegend eine gesellschaftliche Pflicht zum treuen Dienen abgeleitet wurde. Gleichzeitig werden jedoch auch die Fälle herausgearbeitet, in denen bürgerliche Soldaten eine Berechtigung zur Verweigerung empfanden.
Book review: Committed employees, effective companies
Authors: Castro-Martinez Andrea
Published: December 2020

Committed employees, effective companies (Berceruelo & Estudio de Comunicación, 2020) is not only an enjoyable and interesting volume, but also a very useful tool for professionals in the field of communication, human resources, business management or public relations, as well as for researchers and academics. This is due to the fact that it tackles internal communication from a strategic perspective to make the organizational culture and values of an entity evolve, with the aim of reflecting internal audiences and promoting their sense of belonging by constituting the link between all of them at an individual level
A Necessary Ethics Definition for Conflicts of Interest
Authors: Ibáñez Franklin ,   Philosophy Documentation Center
Published: December 2020

The paper examines Villarán’s definition of conflicts of interest to improve it. Some clarifications are necessary but also some amendments. The basic difference consists of first distinguishing between interest and moral grounds, and, second, by emphasizing the voluntary nature of the commitment of the person facing a conflict of interest. Such a commitment arises within a work-related or professional context. It must be explicit with regard to individuals, public institutions, private organizations, whether for profit or nonprofit, or professional associations. To support this concept, a method is used that is similar to the recent tradition of the English-speaking world expressed by Rawls, instead of the search for universal or essentialist concepts of the Platonic tradition. The result is not a true definition of conflicts of interest, but a necessary one given our historical-social context.
Análisis de la problemática de las infracciones por falta de ingreso tributario
Authors: Pérez Jordá Iván
Published: December 2020

El presente artículo se analiza detenidamente la problemática que plantean los supuestos infractores consistente en dejar de ingresar la deuda tributaria.The present article analyses in detail the problem posed by the alleged offenders consisting in the failure to pay the tax debt.
Um campo para a criação: o desenvolvimento poético através do diário de pesquisa do pintor em formação
Authors: Werneck Martha , Bossolan Lícius
Published: December 2020

O artigo versa sobre o que tomamos por poética, tratando da importância do entendimento desse conceito para o ensino e metodologia aplicados em disciplinas práticas de ateliê, no Ciclo Básico do Curso de Graduação em Pintura da Escola de Belas Artes da Universidade Federal do Rio de Janeiro. O termo, que abarca tantas possíveis questões no universo das artes, é fundamental para aprofundar o trabalho de um estudante cuja formação é de um artista pesquisador em pintura. O artista é agente que pensa, propõe e transforma sua cultura e sociedade através de uma linguagem e justamente por isso é importante a consciência de seu campo poético, pois é ele que impulsiona a pesquisa, o ato criativo e a expressão. A poética que um estudante de pintura gesta e desenvolve funciona como principal catalisador de sua produção, norteando o processo criativo, a imaginação e a intuição. Além de tratar desse conceito, apresentaremos aqui a metodologia de ensino aplicada às turmas de segundo e terceiro períodos da graduação em Pintura. Esta propõe, através da elaboração de um corpo de imagens e de documentos de artista dos mais variados tipos, a organização do pensamento criativo em diários de pesquisa, também chamados sketchbooks. Esses suportes são como receptáculos que fomentam simultaneamente aprendizado, pesquisa e criação de estudantes iniciados nessa complexa, rica e ancestral linguagem: a pintura.
O Encantado: mediações e diálogos da cultura no processo de criação de Attílio Colnago
Authors: Cirillo Aparecido José
Published: December 2020

Este texto trata de aspectos compartilhados do processo criador de Attilio Colnago, em especial para a mostra “O Encantado” (2014). O foco central está nas mediações entre a mente criadora e a cultura que a envolve e que se materializa como imagem geradora. A partir dos pressupostos dos estudos atuais do processo criativo, buscamos evidenciar alguns aspectos da estrutura rizomática que envolve o gesto criador. O texto procura inferir uma análise de um processo criativo que se constitui como uma linguagem de natureza dialógica que revela a dimensão transcultural e transtemporal do discurso artístico de Colnago.Inferimos que a interlocução estética desse artista, nesta mostra, reopera o vivido a partir de matrizes culturais e conceituais impressas na sua memória e na do público, o que pode ser evidenciado contextos amplos, extra mostra, compartilhados por meio de recursos tecnológicos contemporâneos como o QR Codes. Com isto, busca-se acionar a rede de relações semióticas que nos aproxima das artimanhas dessa mente criadora e dos modos de recepção do público.
Desenhos do desenhar: pesquisa e práticas de Stephen Farthing
Authors: Zimmermann Anelise , Farthing Stephen
Published: December 2020

Este artigo tem como objetivo apresentar um panorama dos estudos em desenho realizados por Stephen Farthing, artista e pesquisador. Esses estudos incluem definições e taxonomias para o desenho, elaborados com o propósito de ampliar a compreensão de sua prática e ensino, estendendo-se para além do território das artes. Farthing utiliza o próprio desenho como meio de investigação. O levantamento desses estudos foi realizado por Zimmermann (2016) durante o doutorado sanduíche na University of the Arts London, período no qual teve a supervisão de Farthing, com acesso a seu acervo de desenhos e publicações e a realização de entrevistas gravadas[1]. Por fim, esses estudos tanto representam o percurso de pesquisa de Farthing, como também demostram a interdisciplinaridade do desenho como um conhecimento que transita entre áreas, um meio de investigação e uma função intelectual com territórios ainda a serem explorados.
CRIAÇÃO: descobrindo um percurso hibrido
Authors: Dias Deni
Published: December 2020

A pesquisa desenvolveu-se a partir do uso do corpo em vivências lúdicas em diálogo com a produção plástica do artista propositor, integrando uma poética pessoal e uma vivência pedagógica em Artes Visuais. Os trabalhos produzidos durante esse processo provocaram uma inquietação que instigaram a pesquisa sobre: criação artística, corpo como suporte, experiência estética, exploração de materiais e produção coletiva. Na linha pedagógica a intenção foi criar estratégias que levassem os participantes a explorarem o universo da arte, ampliando seu conhecimento artístico através do Método P.E.R.A, Yoshiura (1982). Na linha artística havia a busca de uma singularidade poética que de maneira muito sutil já trazia a união de técnicas e suportes, configurando-se como uma Hibridação Interformativa, Valente (2008), desse processo resultaram as séries Desplante e Azuis.
Fora da Capital – Oficina de documentários em vídeo digital
Authors: Gervilla Lucas Rossi
Published: December 2020

Documentários sempre estiveram no centro das discussões cinematográficas, seja pelas suas semelhanças e/ou diferenças com a ficção, liberdade estética ou vanguardismo. Atualmente, a tecnologia digital permite que documentários sejam produzidos e distribuídos em curtíssimos intervalos de tempo. Esses fatores têm gerado um número crescente de interessados na produção documental. A partir desse interesse foi criada, pelo próprio autor, a oficina Documentários em Vídeo Digital, cujo o principal objetivo é compartilhar com os participantes ferramentas para que estes possam contar suas próprias histórias. O artigo trata dos processos de criação, metodologia e desenvolvimento da atividade em mais de 40 cidades do estado de São Paulo; e aborda o processo de realização do documentário longa-metragem Fora da Capital, resultante das oficinas. Também é apresentada uma breve retrospectiva histórica do documentário, o constante processo de evolução da sua linguagem e seus atuais desdobramentos.
O processo criativo de um livro ilustrado: uma experiência em artes visuais
Authors: Pacheco Maria Clara de Oliveira , Petry Arlete dos Santos
Published: December 2020

Livros ilustrados são produções culturais que associam, em um mesmo suporte, a linguagem visual e a linguagem escrita. A ilustração pretende sugerir novas leituras e interpretações a partir daquilo que o leitor está vendo, instigando a imaginação. Visando entender essa relação entre texto e imagem, é apresentado um recorte sobre o que deve fazer uma ilustração, qual o seu papel no livro ilustrado e o que é necessário a ela. A literatura destinada ao público infantil é outro ponto abordado nesta pesquisa em arte, bem como a organização da disposição dos elementos no processo de diagramação. O foco do trabalho está no processo de criação do livro ilustrado A Galinha Branca, levando em consideração como ele foi pensado, executado e registrado. Sendo assim, o estudo teórico acerca dos tópicos abordados vem como resposta às experiências práticas vivenciadas, dissolvendo as fronteiras desses dois aspectos da pesquisa.
Lugar de Memória e Arte: Rastros de uma escola
Authors: Carvalho Francione Oliveira , Penna Ana Beatriz Marques , Sant'Ana Vitor Fernando de Barros
Published: December 2020

Este texto parte das provocações de Fischer, Loponte (2020) a respeito dos modos de habitar a escola, e no convite que fazem para olharmos para a escola pelo que é possível de inventar e criar nela. Dentro deste contexto tece diálogo com autores como Masschelein, Simons;  Helguera; Bosi; Vergara; Irwin, para  refletir sobre Lugar de Memória e Arte, projeto vinculado ao PIBID da UFJF que propôs uma série de proposições de fruição e criação artística com estudantes do segundo ciclo do Ensino Fundamental de uma escola pública da cidade de Juiz de Fora, Minas Gerais, e promoveu trocas de experiências entre esses estudantes e artistas convidados, o que possibilitou habitar um museu com obras criadas na escola pelos participantes dos encontros, revelando com isso, uma escola que inventa e que ocupa espaços.
A viagem como formação
Authors: Giannotti Marco Garaude
Published: December 2020

O texto discorre sobre como o ato de viajar pode despertar e formar um pensamento plástico. Neste sentido, uma série de considerações históricas confere diferentes sentidos a uma atividade que embora extra cotidiana, acaba por propiciar uma dimensão estética ao simples ato de ver o mundo ao redor numa nova perspectiva.
Da leveza como modo de habitar a paisagem: uma experiência
Authors: Araujo Mariana Libero Hauck
Published: December 2020

O relato de experiência faz parte de um processo de pesquisa em curso no contexto do Projeto de pesquisa/Residência artística próxima paisagem: escola de arte provisória, que acontece no Córrego do Bação, em Itabirito/MG, desde 2018. Na origem dessas fotografias encontra-se uma vivência com a paisagem do Bação, mais especificamente o exercício de percorrer com frequência um determinado caminho, por meio do qual procurei responder à proposição do Projeto próxima paisagem, formalizando assim minha maneira pessoal de perceber, representar e habitar a paisagem do Córrego do Bação, que venho visitando desde outubro de 2018.
Anatomical and histochemical study of Sechium edule (Jacq.) Sw.
Authors: Karina de Andrade Silva Francilainy , dos Santos Magalhães Cledson , Damasceno Sá Rafaela , Carolina Lins da Silva Flávia , Perrelli Randau Karina
Published: December 2020

Sechium edule (Jacq.) Sw. tiene un papel importante nutricional y terapéuticamente en la medicina popular, especialmente utilizado como agente hipotensor. Para ampliar la información farmacológica sobre esta especie, este trabajo tiene como objetivo el estudio histoanatómico de sus hojas. Se prepararon muestras con secciones transversales y paradérmicas de la hoja para el estudio microscópico. Para el análisis histoquímico, se utilizaron reactivos específicos para los metabolitos objetivo. A través del análisis realizado se identificaron estructuras anatómicas para la correcta identificación de la especie estudiada. La histoquímica mostró la presencia de alcaloides, triterpenos y esteroides, compuestos lipofílicos y lignina. Esta información sobre la localización de los compuestos no tiene precedentes. Así, el trabajo amplía el conocimiento sobre la especie y la familia Cucurbitaceae.

Sechium edule (Jacq.) Sw. plays an important role as for its nutritional and therapeutical use in folk medicine, being especially used as a hypotensive agent. In order to expand the pharmacobotanical information on this species, this work aims to perform the histoanatomical study of its leaves. Samples containing cross-section and paradermic sections of the leaf were prepared for microscopic study. For the histochemical analysis, specific reagents were used, according to the targeted metabolites. Through the performed analysis, it was possible to identify the anatomical structures that confer the correct identification of the studied species. The histochemistry showed the presence of alkaloids, triterpenes and steroids, lipophilic compounds and lignin. This information on the localisation of the compounds is unprecedented. Thus, the work expands the knowledge about the species and the family Cucurbitaceae.
Constancio II y los cultos tradicionales romanos
Authors: Jiménez Sánchez Juan Antonio
Published: December 2020

En este trabajo, estudiamos la legislación de Constancio II en relación con los cultos tradicionales. En un principio, esta no fue muy diferente de la promulgada por su padre Constantino I y su hermano Constante, caracterizándose por ser ambigua y no muy radical; su intención era probablemente eliminar tan solo los sacrificios realizados para conocer el futuro (como los nocturnos), un tipo de sacrificios vetados también por emperadores anteriores. No obstante, más tarde (en el 356), Constancio II endureció su política y probablemente prohibió por vez primera los cultos tradicionales por completo, aunque esta interdicción seguramente duró poco tiempo, tal vez un año, cuando este soberano decidió derogarla tras su visita a Roma en el 357.

In this work, we study the legislation of Constantius II in relation to traditional cults. At first, it was not very different from his father Constantine I and his brother Constans’ legislation, characterized by being ambiguous and not very radical; its intention was probably to eliminate only the sacrifices made to know the future (like the nocturnal ones), a type of sacrifices forbidden by previous emperors. Nevertheless, later (in 356), Constantius II hardened his policy and probably banned traditional cults for the first time, although this interdiction surely lasted a short time, perhaps a year, when this sovereign decided to abolish it after his visit to Rome in 357
60-90-20: cultura de la nostalgia o la nostalgia en la cultura
Authors: San Cornelio Gemma
Published: December 2020

En este artículo me gustaría continuar con el tema desarrollado por Cristina Pujol en un artículo publicado recientemente en COMeIN y relacionado con la deconstrucción de los años 90. Más concretamente, me centraré en profundizar en la nostalgia cultural que opera en el cine, la música, el diseño o las series de televisión.
Diseñar como acto natural
Authors: Foglia Efraín
Published: December 2020

El especialista en diseño para la sostenibilidad Ezio Manzini publicó en 2015 un libro de referencia bajo el título Cuando todos diseñan. Una introducción al diseño para la innovación social. Hace tiempo que Manzini viene profundizando en la idea de que el diseño se debe volcar en el cambio social en un momento en que los problemas globales se acentúan.
Riflessioni su un frammento di Policleto di Larissa (FGrHist 128 F3 = Strab. XV 3, 21): interpretatio graeca dell’attività economica del Gran Re?
Authors: Biondi Ennio
Published: December 2020

The aim of this article is to propose an historical analysis of the fragment FGrHist 128 F3 (= Strab. XV 3, 21) of the historian Polykleitos of Larissa. Polykleitos reports mostly administrative and economic news on the Persian Great King’s activity and testifies to a new approach to the study of the Persian Empire and its tribute system compared to Herodotus: these are complex evidences clarified in the light of the Aristotelian reflection on the oikonomia and the politics of Macedonians in Asia.
Investigating quantum coherence from discrete Wigner function
Authors: Lin Yin  , Huang Ming-Da  , Yu Ya-Fei  , Zhang Zhi-Ming  ,   Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices (SIPSE), Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
Published: December 2020

Quantum coherence is an essential ingredient in quantum information processing and plays an important role in quantum computation. Therefore, it is a hot issue about how to quantify the coherence of quantum states in theoretical framework. The coherence effect of a state is usually described by the off-diagonal elements of its density matrix with respect to a particular reference basis. Recently, based on the established notions from quantitative theory of entanglement, a resource theory of coherence quantification has been proposed[1,2]. In the theory framework, a proper measure of coherence should satisfy three criteria: the coherence should be zero for all incoherent state; the coherence should not increase under mixing quantum states; the coherence should not increase under incoherent operations. Then, a number of coherence measures have been suggested, such as l1 norm of coherence and the relative entropy of coherence[2]. Wigner function is known as an important tool to study the non-classical property of quantum states for continuous-variable quantum systems. It has been generalized to finite-dimensional Hilbert spaces, and named as discrete Wigner function[9-16]. The magic property of quantum states, which promotes stabilizer computation to universal quantum computation, can be generally measured by the absolute sum of the negative items (negativity sum) in the discrete Wigner function of the observed quantum states. In this paper we investigate quantum coherence from the view of discrete Wigner function. From the definition of the discrete Wigner function of the quantum systems with odd prime dimensions, for a given density matrix we analyze in phase space the performance of its diagonal and off-diagonal items. We find that, the discrete Wigner function of a quantum state contains two aspects: the true quantum coherence and the classical mixture, where the part of classical mixture can be excluded by only considering the discrete Wigner function of the diagonal items of the density matrix. Thus, we propose a possible measure method for quantum coherence from the discrete Wigner function of the off-diagonal items of the density matrix. We show that the proposed measure method satisfies the criteria (C1) and (C2) of coherence measure perfectly. For the criteria (C3), we give a numerical proof in three-dimensional quantum system. Meanwhile, we compare the proposed coherence measure with l1 norm coherence, and get an inequality relationship between them. Finally, an inequality is obtained to discuss the relation between quantum coherence and the negativity sum of discrete Wigner function, which shows that the quantum coherence is only necessary but not sufficient for quantum computation speed-up.
Target reconstruction algorithm for four-beam sheared coherent imaging
Authors: Lu Chang-Ming  , Chen Ming-Lai  , Luo Xiu-Juan  , Zhang Yu  , Liu Hui  , Lan Fu-Yang  , Cao Bei  ,   Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China;,   University of Chinese Academy of Sciences, Beijing 100049, China;,   Beijing Institute of Tracking and Telecommunications Technology, Beijing 100049, China
Published: December 2020

Sheared-beam imaging, which is a nonconventional coherent laser imaging technique, can be used to better solve the problem of taking pictures with high resolution for remote targets through turbulent medium than conventional optical methods. In the previous research on this technique, a target was illuminated by three coherent laser beams that were laterally arranged at the transmitter plane into an L pattern. In order to obtain a high quality image, a series of time-varying scattered signals is collected to reconstruct speckled images of the same object. To overcome atmospheric turbulence, multiple sets of three-beam laser should be emitted, which increases data acquisition time. In this paper, aiming at the quasi real-time problem of conventional sheared beam imaging technique, we use four-beam laser with rectangular distribution instead of the traditional L type sheared three-beam laser to illuminate the target. According to this, we propose a target reconstruction algorithm for four-beam sheared coherent imaging to reconstruct four target images simultaneously in one measurement, which can acquire high quality images by reducing the amount of measurement and the speckle noise. Meanwhile, it can greatly reduce the amount of beam switching in multi-group emission and improve the imaging efficiency. Firstly, the principle of the four-beam sheared coherent imaging technique is deduced. Secondly, in the algorithm, the speckle amplitude and phase difference frames can be extracted accurately by searching for the accurate positions of the beat frequency components. Based on the speckle phase difference frames, four sets of wavefront phases can be demodulated by the least squares method, and wavefront amplitude can be obtained by algebraic operation of speckle amplitude. The reconstructed wavefront is used for inverse Fourier transform to yield a two-dimensional image. A series of speckled images is averaged to form an incoherent image. Finally, the validity of the proposed technique is verified by simulations. From the simulation results, the image quality of the proposed method is better than that of the traditional method in the same amount of measurement. Furthermore, on the premise of the same image quality, the data acquisition amount of the proposed method is 2-3 times as large as that of the traditional method. In other words, compared with that of the traditional method, the data acquisition time of the proposed method is reduced at least by half and the algorithm processing time is less. It can be concluded that the proposed imaging technique can not only improve the efficiency of target reconstruction, but also present a better way of imaging the remote moving targets.
Photonic crystal frequency band selecting and power splitting devices based on the energy coupling effect between waveguides
Authors: Zhao Xuan  , Liu Chen  , Ma Hui-Li  , Feng Shuai  ,   College of Science, Minzu University of China, Beijing 100081, China
Published: December 2020

The photonic crystal power splitter based on the energy coupling effect between waveguides has the advantages of compact structure, wide bandwidth, low bending loss, large angle of separation, and no external electromagnetic interference. In this paper, the power splitting characteristics of two-dimensional triangular-lattice photonic crystal coupled waveguide are theoretically studied by using the finite-difference time-domain method, and a functional device is designed in order to achieve different output power ratios within different frequency ranges.In the two-dimensional photonic crystal structure with triangular lattice, we set two adjacent straight waveguides and the light beam is introduced from one of them. Because of the energy coupling effect between the two line defects, the light energy propagates alternately in them. Based on this principle, structures of different coupling lengths are simulated and the interference effect of each surface is considered. The device with the best coupling length is achieved for three different output energy propagating characteristics at different frequencies, which include three-division, two-division and single output cases. That is to say, the incident light beam within a frequency band travels through a particular waveguide; light in another frequency band only flows through the other two output waveguides; light in the third frequency band is assigned to all the three output waveguides equally. However, the frequency band width for the high-quality light beam splitting area as well as the transmittance contrast of the other two functional band areas are not very ideal.Based on the above numerical results, two transmission modes in the coupling waveguides are achieved by changing the cross section shape of the dielectric column in the coupling region and also by changing the connecting position between the output branch waveguide and the energy-coupling waveguide. Through the above change, the splitting performance is further optimized.By detecting and analyzing the relative intensity of the three output waveguides, we can determine the range of the incident light beam. Furthermore, the frequency ranges of the three different light output characteristics can be adjusted flexibly by changing the cross section shape of the dielectric column in the coupling region or by changing the connecting position of output waveguides. The functional device proposed in this paper has a high transmittance contrast ratio and a compact structure, which will promote the practical application of the all-optical functional devices in the fields of large-scale all-optical complex integration.
Nickel oxide as back surface field buffer layer in CdTe thin film solar cell
Authors: Xiao Di  , Wang Dong-Ming  , Li Xun  , Li Qiang  , Shen Kai  , Wang De-Zhao  , Wu Ling-Ling  , Wang De-Liang  ,   Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
Published: December 2020

In this work, we report that NiO thin film can be used as a back contact buffer layer in CdTe thin film solar cells. The NiO layer is prepared by electron beam evaporation. To optimize the thickness of the NiO thin film, we fabricate some CdTe solar cells with different NiO thickness values. A NiO/Au back contact CdTe solar cell with an efficiency of 12.17% and an open-circuit voltage Voc of 789 mV is obtained, which are comparable to those of a standard Cu/Au back contact solar cell. The X-ray photoelectron spectroscopy (XPS) is used to quantitatively characterize the band alignment at the CdTe/NiO interface. It can be seen from the band alignment that the valence band offset (EVBO) is 0.52 eV and the conduction band offset (ECBO) is 2.68 eV. The EVBO presents no energy barrier for hole to transport from CdTe to NiO. The value of ECBO indicates that NiO can act as a back surface field layer (BSF) to dramatically reduce carrier recombination in the contact region of a CdTe cell, leading to an improved Voc. The band alignment obtained from XPS measurement shows that the band alignments of NiO and CdTe are perfectly matched. However, the conductivity of NiO film is poor. The insertion of a NiO buffer layer in the back contact increases the series resistance and reduces the fill factor (FF). We propose to use Cu/NiO composite structure as a bi-layer contact to improve the conductivity of the NiO buffer layer, which at the same time can be used to dope the CdTe film surface by Cu to obtain a low resistive contact. We fabricate a cell with a contact structure of 3-nm-Cu/20-nm-NiO/Au and the cell has a Voc of 796 mV, a Jsc (short-circuit currrent) of 24.2 mA/cm2, an FF of 70.2% and an efficiency of 13.5%. In order to study the stability of the solar cell with a Cu/NiO/Au back contact, a thermal stressing test is carried out at a temperature of 80 ℃ in the air atmosphere. For the Cu/NiO/Au back contact structure solar cell, the efficiency decreases from 13.1% to 12.9% after the cell is stressed for 80 h, showing that the stability of the Cu/NiO/Au back contact cell is significantly improved compared with that of the standard Cu/Au contact cell. In summary, the experimental results obtained in this study demonstrate that NiO thin film is a promising buffer layer for manufacturing stable and high efficiency CdTe thin film solar cells.
Polarization characteristic and control of the conical diffracted output field under annular beam
Authors: Du Chuang  , Jia Da-Gong  , Zhang Hong-Xia  , Liu Tie-Gen  , Zhang Yi-Mo  ,   Key Laboratory of Opto-electronics Information Technology, Ministry of Education, School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
Published: December 2020

Conical diffraction, a unique optical phenomenon in biaxial crystal, has important applications for the manipulation of particles. In this paper, a new model of annular Gaussian beam is constructed based on the Tovar's flat-topped multi-Gaussian laser beams. The conical diffraction of annular Gaussian beam is calculated using Belsky-Khapalyuk-Berry theory. The polarization characteristics of conical diffracted output beams under the annular Gaussian beam are theoretically calculated and experimentally demonstrated by means of the linearly polarized annular Gaussian beams with different polarization directions. It is found that the same azimuth angles of the inner and outer rings of the conical diffracted output beams have orthogonal polarization characteristics. A combined polarizer (CP) composed of eight polarizing segments with different specific pass axes of polarization is presented to simulate the polarization characteristic of the optical field of conical diffraction. Furthermore the calculations for output-field control of conical diffraction under the annular beam by using the proposed CP are compared with the experimental results. The results show that the intensities of both the inner and outer rings are periodically varied with CP azimuth angle. And when the azimuth angle of CP is 0, only the conical diffracted outer ring is remained, while only the inner ring of conical diffraction is remained for 180. This tunable conical diffracted field has important applications in optical tweezers and wavelength division multiplexing.
Removal of additive noise in adaptive optics system based on adaptive nonconvex sparse regularization
Authors: Zhang Yan-Yan  , Chen Su-Ting  , Ge Jun-Xiang  , Wan Fa-Yu  , Mei Yong  , Zhou Xiao-Yan  ,   Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Technology and Engineering Center of Meteorological Sensor Network, Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information and Science Technology, Nanjing 210044, China
Published: December 2020

Adaptive optics (AO) system which is widely used in astronomical observations can improve the image quality by the real-time measurement and correction of the wave-front. One of the main problems in the AO system is the poor quality of the image because of the system noises. The noises in AO system are additive noises. The main sources of the noises are the background noise, the photon noise, and the readout noise of charge-coupled device. The background noise is distributed evenly and is easy to process. The photon noise is dependent on the characteristics of the spot itself. Readout noise, which is Gaussian distribution with the mean value of 0 and the variance of 2, is the main noise source in AO system. In this paper, we focus on the readout noise and propose a new regularization model to remove additive noises from the AO system. In this model, the regularization parameters can be adaptively changed. A nonconvex regularization term is used to make the homogeneous region of the image smooth efficiently, while the integrity of the spot can be well restored. The properties of the regularization proposed are shown below. 1) The proposed nonconvex regularization term can act as the L0 norm which is sparser than L1 norm. 2) The proposed model can protect the edge of the spot from over smoothing. To prevent the edges from over smoothing, the regularization parameter must be an increasing function. Moreover, it converges to a constant so that it cannot affect the strong gradient of the image. 3) The regularization term proposed is nonconvex which is more sensible to the minor change of the image. Therefore, the edges of the image can be better preserved. Though the proposed model can well preserve the edges of the spot, it is difficult to resolve by traditional methods because of the nonconvexity. Split Bregman algorithm and augmented Lagrangian duality algorithm are used to solve this problem. We can obtain a denoised spot image as well as an edge indicator by using the proposed model. The visual and quantitative evaluations are used to value the restored images. The evaluating indicators are the peak signal-to-noise ratio and centroid detecting error which includes the root mean square and the peak valley value of the centroid deviation. The simulation and experimental results show the efficiency of this model in removing the additive noises from the AO system.
Traveling wave solutions of the cylindrical nonlinear Maxwell's equations
Authors: Hu Liang  , Luo Mao-Kang  ,   Department of Mathematics, Sichuan University, Chengdu 610065, China
Published: December 2020

Study on propagation of cylindrical electromagnetic waves in various inhomogeneous and nonlinear media is of fundamental importance, which can be described by the cylindrical nonlinear Maxwell's equations. In recent years, finding exact solutions for these equations has emerged as a popular research topic. The exact solutions play an irreplaceable role in understanding and predicting physical phenomena, and developing numerical calculation methods, and so on. However, due to the extreme complexity of nonlinear partial differential equations, exact solutions of the cylindrical Maxwell's equations were only able to be obtained in a nonlinear and nondispersive medium whose dielectric function is an exponential function in previous researches. Actually, there is no general method at present which can exactly solve arbitrary cylindrical nonlinear Maxwell's equations. Therefore, finding physically admissible solutions meeting certain particular condition for the cylindrical nonlinear Maxwell's equations might be feasible.
In this paper, we discuss the traveling wave solutions which are very important in electromagnetic theory, especially in solitary wave theory. To our knowledge, research on obtaining traveling wave solutions of the cylindrical nonlinear Maxwell's equations is still lacking. The main conclusions in this paper are listed as follows.
Firstly, we introduce the cylindrical nonlinear Maxwell's equations mentioned in some previous publications, which can describe cylindrical electromagnetic waves propagation in inhomogeneous nonlinear and nondispersive media. In this paper, we focus on the nondispersive media with arbitrary nonlinearity and power-law inhomogeneity.
Secondly, we point out that the electric field component E of the model has no plane traveling wave solutions E=g(r-kt), after theoretical analysis and study. Then generalized traveling wave solutions in form of E=g(lnr-kt) for the electric field component are obtained by finding correct variable substitution and solving second-order nonlinear ordinary differential equation.Finally, we provide two examples to show the physical meanings of our generalized traveling wave solutions. We find that the transmitting speeds of vibrations vary with different points of the electric field. Actually, the transmitting speed of the vibration of a certain point closer to the cylinder center is lower. As a result, we observed a physical phenomenon similar to that of self-steepening.
Our work can be used to analyze the electromagnetic properties of ferroelectric materials and new materials. Theoretically, it can also provide an approach to studying the cylindrical nonlinear Maxwell's equations.
Analytic function for spontaneous emission spectrum of InP/InGaAsP multi-quantum wells
Authors: Liu Zhi-Yong  , Chen Hai-Yan  ,   School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China
Published: December 2020

The analytic function for the amplified spontaneous emission spectrum of InP/InGaAsP multi-quantum wells is studied by spectrum fitting. Three fitting functions, Lorentz, Gaussian and Sech line shape functions are chosen, and the analytical expressions for the above three functions are obtained with Levenberg-Marquardt algorithm, respectively. The center wavelength of Lorentz line shape function spectrum fitting is 1548.707 nm with 66.23 nm of full-width half maximum (FWHM), -0.00036484 mW power compensation, 0.98294 of R-square and 4.7674310-6 of residual sum of squares; the center wavelength of Gaussian line shape function spectrum fitting is 1548.651 nm with 61.42 nm of FWHM, 0.00212 mW power compensation, 0.99191 of R-square and 2.2650510-6 of residual sum of squares; the center wavelength of Sech line shape function spectrum fitting is 1548.787 nm with 36.99 nm of FWHM, 0.00222 mW power compensation, 0.98128 of R-square and 5.2433110-6 of residual sum of squares. It can be seen that Gaussian line shape function spectrum fitting has the highest R-square and smallest residual sum of squares, and the residual squares of data are symmetrically distributed among 0.0001. Gaussian line shape function spectrum fitting has higher fitting degree. It is demonstrated that InP/InGaAsP multi-quantum wells is a kind of active layer quantum well structure semiconductor material, whose amplified spontaneous emission spectrum line shape belongs to inhomogeneous broadening due to the effect of lattice defects, the corresponding line shape function is Gaussian line shape function, and the amplified spontaneous emission spectrum line shape function can be used for designing the optical passive devices.
Modelling of multi-stage nonlinear interaction of micro-crack and ultrasonic based on equivalent elastic modulus
Authors: Yang Bin  , Wei Shuo  , Shi Kai-Yuan  ,   University of Science and Technology Beijing, National Center for Materials Service Safety, Beijing 100083, China
Published: December 2020

A multi-stage model of nonlinear interaction between micro-crack and ultrasound based on equivalent elastic modulus is presented in this paper. In this model, the interface characteristics of micro-cracks at a micro-level and the relative motion at a macro-level are unified into an elastic modulus of the mesoscopic element. The equivalent elastic modulus is used to characterize the stress-strain of the damage region. Then piecewise function is used to describe the nonlinear interaction between ultrasound and micro-crack. Finally, the wave equation is solved by the finite element simulation. In this manner, the nonlinear interaction law between ultrasound and micro-crack is obtained, and the validity of the model is verified. The simulation results also show that compared with bilinear stiffness model and contact surface model, the multi-stage model can well reflect the distortion of the waveform in one period of ultrasonic wave passing through the micro-crack. In addition, the influences of the crack angle, the crack length and the input amplitude on the second harmonics generation and the third harmonics generation are analyzed. In the end, the comparison and analysis of the experimental test and simulation calculations based on the proposed multi-stage model show that the proposed multi-stage model and the experimental test can well reflect the second harmonic signal produced by the nonlinear interaction of micro-crack and ultrasound, and the second harmonic amplitudes of the experimental test are basically the same as the simulation calculations based on the proposed multi-stage model. Thus, the effectiveness of the proposed multi-stage model is verified. The model provides a new simulation method to quantitatively detect the micro-crack by ultrasonic nonlinear effect.
Experimental investigation on dynamic lattice response by in-situ Xray diffraction method
Authors: Li Jun  , Chen Xiao-Hui  , Wu Qiang  , Luo Bin-Qiang  , Li Mu  , Yang Qing-Guo  , Tao Tian-Jiong  , Jin Ke  , Geng Hua-Yun  , Tan Ye  , Xue Tao  ,   National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP, Mianyang 621900, China
Published: December 2020

Structure evolution under dynamic compression condition (high temperature, high pressure and high strain rate) is one of the most important problems in engineering and applied physics, which is vital for understanding the kinetic mechanism of shock-induced phase transition. In this work, an in-situ dynamic X-ray diffraction (DXRD) diagnostic method is established to probe the lattice response driven by shock waves. The geometry is suitable for the study of laser-shocked crystals. In order to eliminate the measurement error arising from the difference in experimental setup, the static and dynamic lattice diffraction signals are measured simultaneously in one shot by using a nanosecond burst of X-ray emitted from a laser-produced plasma. Experimental details in our investigation are as follows. 1) The laser driven shock wave transit time △ tShock and the shock pressure in sample are accurately determined from the shock-wave profile measurement by dual laser heterodyne velocimetry. 2) A laser pump-and-probe technique for adjusting the time-delay of DXRD diagnosis during △ tShock, with a series of repeated shock loadings is then employed to generate and measure the dynamic structure evolution. Using this method, the dynamic lattice response of[111] single-crystal iron is studied on Shenguang-Ⅱ facility. Single-shot diffraction patterns from both unshocked and shocked crystal are successfully obtained. An elastic-plastic transition process –elastic wave followed by a plastic wave– is observed in shocked[111] single-crystal iron on a lattice scale. The lattice compressibility values of the elastic wave and plastic wave are in agreement with those derived from the wave profiles. It is found that the Hugoniot elastic limit is measured to be about 6 GPa under nanosecond-pulsed laser shock compression. Such a high yield strength is consistent with recent laser ramp compression experimental results in polycrystalline Fe[Smith et al. 2011 J. Appl. Phys. 110 123515], suggesting that the peak pressure of elastic wave is dependent on the loading rate and the thickness of sample. Based on the analysis of diffraction patterns, the BCC phase is determined to be stable till 23.9 GPa, the highest pressure explored in this work, which might indicate that the phase transition strongly couples with the crystal orientation and loading rate. Some possible physical mechanisms remain to be further studied:whether the transition time hysteresis occurs or the metastable FCC phase exists in shocked[111] single crystal Fe, or the phase transition onset pressure increases under high strain-rate compression. Our DXRD results provide a primary experimental reference for the follow-up study on the phase kinetics.
Efficient simulation of marine controlled source electromagnetic responses for axisymmetric scatter by using numerical mode matching approach
Authors: Lin Lin  , Jiao Li-Guang  , Chen Bo  , Kang Zhuang-Zhuang  , Ma Yu-Gang  , Wang Hong-Nian  ,   College of Physics, Jilin University, Changchun 130012, China
Published: December 2020

Horizontal disk, sphere, and spherical crown are a very important type of scatter in geophysics research. In the marine environment, a disk-like scatter can be used to describe several resistive targets, e.g., basaltic sills and stratigraphic hydrocarbon reservoirs while spherical crown can be used to approximately depict the topography of interface for basement rock. This type of scatter has characteristics of axisymmetrical distribution of the conductivity. If some approaches can be established to efficiently simulate the marine controlled source electromagnetic (MCSEM) response to this scatter, it will be meaningful to investigate the nature of MCSEM responses in complex formation and to build appropriate method of processing and explaining MCSEM data. In this paper, the resistive scatters are approximated by one or several horizontal concentric disks with different radii and thickness values, based on the axially symmetrical spatial distribution of conductivity. Then, a combination of these concentric disks with air, sea water and surrounding beds will construct a horizontally stratified inhomogeneous formation with common axis-center, whose spatial distribution of conductivity is layered in the vertical direction and axisymmetric in the horizontal direction. Based on the approximations mentioned above, the computation of MCSEM response excited by horizontal electrical dipole (HED) located at the z-axis is entirely transformed into two axially symmetrical problems for the Fourier harmonic components of the electromagnetic (EM) fields. The differential operators about the horizontal magnetic components and transformation of horizontal electrical components and other EM components from horizontal magnetic components are derived. Then, the numerical mode matching approach is extended to the simulation of the EM field and three-dimensional (3D) MCSEM responses excited by the HED in the formation. The procedure for solving the EM field is presented. The semi-analytic solution of EM field in the whole space is obtained to efficiently and numerically model MCSEM response in the complex formation. Finally, the efficiency and accuracy of the present method are demonstrated numerically. The characteristics of 3D MCSEM responses in three different cases are further investigated.
Flexural vibration band gaps for a phononic crystal beam with X-shaped local resonance metadamping structure
Authors: Du Chun-Yang  , Yu Dian-Long  , Liu Jiang-Wei  , Wen Ji-Hong  ,   Laboratory of Science and Technology on Integrated Logistics Support, National University of Defense Technology, Changsha 410073, China
Published: December 2020

Structural vibration is commonly seen in engineering, which can cause resonance and fatigue damage in structure. Therefore, it is very desirable in vibration control techniques to achieve structure with low-frequency and broadband damping feature. In this paper, we design a phononic crystal (PC) beam with X-shaped locally resonant metadamping (X-LRMD) structures. Based on the PC theory, the flexural wave propagation in X-LRMD beam is studied. The equivalent dynamic properties of the X LRMD structure are analyzed by Lagrange equation. It is shown that due to its geometric nonlinearity, the X LRMD can effectively increase the damping of the system, which is validated by the transfer matrix method. The influence of structural parameters of X LRMD on band gap characteristics of the PC beam is then discussed in detail by using the finite element method with COMSOL multiphysics software in conjunction with Matlab, where the PC beam with X LRMD is modeled with the multi-body dynamic module within COMSOL and the band gap characteristics are calculated. The damping properties of the system are studied also using the finite element method. It is shown that compared with the equivalent structures, the PC beam with X LRMD can magnify the damping of the structure system, demonstrating a meta-damping phenomenon. The X LRMD in the PC beam can not only generate lower frequency and wider range band gaps but also suppress the vibration in passband ranges. This can bring a new design for reducing the vibration of structural systems.