bluuebunny/crossref_metadata_2025 huggingface dataset:
La escuela de hijos de obreros de minas de Almadén. Un ejemplo de enseñanza manjoniana
Authors: Almansa Rodriguez Emiliano , Hernández Sobrino Angel Manuel
Published: December 2020

Ave Maria Schools were founded in Granada in 1889 by the priest and educator Andrés Manjón. Unlike the traditional method of infant education in those years, Father Manjón centered pedagogy in the Catholic religion, considering nature as God’s work. In his concept, play, manual labor andoutdoor teaching were good Christians in a happy environment so that they would later join the working world. They quickly spread throughout Spain and other countries, Ave Maria Schools are considered a pioneering experience of teaching in their time and enjoyed great social prestige.In the subsoil of Almadén, the largest mercury deposit in the world was exploited from the Arab domination, with 2,500 workers working in the first half of the 20th century. The School of Children of Workers had been founded in 1908, but in 1926, coinciding with the proclamation of the dictatorship of Primo de Rivera, it was transformed into a Manjonian school. Become a secular school during the Second Republic and the subsequent civil war, he returned to act as a school of Ave Maria from 1939 until the 1960s. Minas de Almadén, like other large mining and industrial companies in northern Spain, exercised a paternalistic strategy with its operators and chose religious education as the most appropriate for the formation of their children.
Manual de Campamentos del Frente de Juventudes (ediciones de 1943 y 1948): variaciones en torno a la cultura política y la disciplina de los cuerpos en la España franquista
Authors: Castillejo Cambra Emilio
Published: December 2020

This article analyzes and compares the 1943 and 1948 editions of the Camp Manual, which provides instructions for the camp commanders of the Youth Front, the Francoist equivalent of Mussolini’s Balilla and the Nazi Hitler-Jugend. In these manuals, the camp appears as a microcosm that reflects the organic structure and government practice of the Francoist State, including its biopolitical aspects: health, food storage, calorie consumption... The political culture that they transmit and its variants maintain an affinity with the normalization of the bodies of the campers: while the Phalangist subculture imposes strength, martiality and rectitude upon the bodies, the Catholic subculture imposes meekness and sinuous forms. The two editions of the manual also reflect the evolution of Franco’s regime. In the 1943 edition, the leaflet of the camp leader reflects the Fascistization of the State. The 1948 edition, on the other hand, stresses the legitimization of the encyclical Divini Illius Magistri or the imposition of a Christian pedagogy (principle of self-direction), and it speaks of the establishment of a Catholic State. This includes the concept of the culture of the participative subject, linked in turn to a new normalization of the bodies (greater distention, oblique lines), without this implying the disappearance of the traditional forms of control or the automatic movements (parades, formations), characteristic of the culture of the subject that gives unity to Francoism.
Raul Lino e o programa decorativo da Escola Primária de Alcântara - Lisboa (1917)
Authors: Manique da Silva Carlos Miguel
Published: December 2020

Using as a reference the Primary School of Alcântara (Lisbon) – designed in 1815 by the architect Raul Lino and inaugurated one year later –, my analysis will focus on the decorative program (set of paintings, dated from 1917) on the walls of the classrooms of this building. My main goal is to examine the impact that the paintings, from the perspective of their author - Raul Lino, whose Anglo German education was strongly influenced by the Arts & Crafts movement – would have on the children. For the architect, images was not just decorative. In fact, they were meant to help the children appreciate nature and art, to educate their sense of taste, and even to develop in them a patriotic sense (an agenda involving the formation of the republican citizen). In this sense, we see the emergence the of an aesthetic education as part of a more general social and political program. In line with the same idea, we can conceive of the curriculum in a wider sense, i. e., as including knowledge and skills obtained in formal lessons, but also values and attitudes received from the impact of school decoration on the students individual and collective memory. Methodologically, itis worth emphasizing that the sources I value are not just visual. In fact, some written texts by Raul Lino, namely, active correspondence and articles, are also used; the triangulation of several sources of evidence is very important. The analysis of the visual sources goes from the description of the elements present in the paintings (mostly, Nature and animals) to close observation of the sources that inspired the author. In relation to this last aspect, I should underline that Raul Lino was an illustrator of children’s books, an experience that he integrated into the school buildings that he planned.
Modesto Bargalló en España (1894-1939): Una biografía entre la historia de la educación y la historia de la ciencia
Authors: Moreno Martínez Luis
Published: December 2020

This paper deals with the professional career of Modesto Bargalló Ardévol (1894-1981) in Spain, who has been singled out as a one of the outstanding renovators of Spanish science teaching in the first third of the 20th century. After undertaking a review of the biographical studies of this training- school professor and an analysis of his wide range of publications and other historical sources, the paper focuses on several neglected questions regarding his work in Spain. I will argue that Modesto Bargalló’s biography can contribute to a reflection on the use of teacher biographies for exploring the history of science education and its role as a field of scholarship shared by historians of education and science historians.
Xosé María Álvarez Blázquez, mestre republicano. Diario escolar e desterró
Authors: Malheiro Gutiérrez Xosé M.
Published: December 2020

Review of the book by Narciso de Gabriel,  Xosé María Álvarez Blázquez, mestre republicano. Diario escolar e desterró (Vigo. Editorial Galaxia, 2019)
Yo aconsejaría a los maestros, que sueñan con grandes ideales, que comiencen por estas cosas, pequeñas si se quiere, pero que no son más que estos ideales que tanto apreciamos… A propósito de una comunicación inédita (1909) de Juan Bardina
Authors: Ortega González Eric , Garcia Farrero Jordi , Margalef Ferran Sánchez
Published: December 2020

The present paper is an exercise in pedagogical archeology that rescues a relevant document for the history of Catalan pedagogy, and by extension, Chilean pedagogy, given the fact that Bardina resided in Chile for many years. We begin by presenting a paper, unpublished until now, that Juan Bardina presented in the Primary Teaching Conference of Barcelona (1909) and in which he summarizes what he considered to be the new education (the “stimulating pedagogy”, in his own words). We provide a brief biography of the author and some notes about his thought and pedagogical work, in order to contextualize, analyze and, where necessary, clarify the paper’s content. In it Bardina leaves traces of his filo-Americanism and his agreement with the postulates of Spencer about the philosophy of evolutionism. Finally, the reader will find the transcription of the paper, published for the first time.
Argentina y España: representaciones de la juventud y la cultura física argentinas en imágenes del NO-DO español
Authors: Galak Eduardo
Published: December 2020

The aim of this article is to analyze the uses of documentary informative cinema as a cultural artifact which was employed as a pedagogical device. To do so, we studied motion pictures filmed in Argentina and shown in Spain in the second quarter of the 20th century, in an attempt to understand how a symmetrical aesthetic is shaped to narrate the bodily practices of youth. Informative documentary cinema, especially newsreels, constituted a resource for mass communications. A familiarity can be observed between the Argentinean images analyzed between 1938-1955 in Sucesos Argentinos, with others made in the second quarter of the 20th century in Spain, through No-Do. In addition to economic, political and cultural influences, Argentina imported into Spain ways of narrating state-organized physical culture. Sheltered in a nationalist rhetoric characteristic of the interwar period and the Second World War, it can be affirmed that there was a transnational aesthetic of how to narrate correct corporal and cultural comportment. Through images that were projected in theaters in these countries, newsreel broadcasts simultaneously and homogeneously transmitted the same discourse –everything, to everyone, at the same time–, resulting in a true transnational pedagogy. In short, a pedagogy outside the school walls is studied through informative documentary film images from the second quarter of the 20th century that aimed to form bodies and sensibilities.
Mensuração da percepção estética de aparelhos auditivos por meio do rastreamento ocular
Authors: Cunha Julia Marina , Merino Giselle Schmidt Alves Díaz
Published: December 2020

As características estéticas dos produtos influenciam nas interações que se tem com os mesmos, assim como podem alterar os significados atribuídos a eles. Em se tratando de tecnologias assistivas essas associações podem levar ao reforço do estigma de incapacidade com relação aos seus usuários. Assim, essa pesquisa teve como objetivo mensurar a experiência estética visual com 3 diferentes modelos de aparelhos auditivos, por meio do rastreamento ocular. Dessa forma, possibilitando identificar como os princípios de estética considerados (contraste, proporção, pureza, familiaridade e novidade) se comportam em aparelhos auditivos de acordo com os padrões visuais identificados (número e duração de fixações, dilatação da pupila).
Sistematização de diretrizes para a reabilitação virtual de idosos por meio do card sorting
Authors: Pillon Carolina Bravo , Silva Régio Pierre da
Published: December 2020

O objetivo desse artigo foi sistematizar um conjunto de diretrizes, recomendações e princípios de design para a reabilitação virtual de idosos por meio da atividade de card sorting. A metodologia incluiu quatro etapas. Na primeira etapa, foi feito um levantamento bibliográfico para a reabilitação virtual de idosos. Na segunda etapa, foi realizada a atividade de card sorting para classificar um conjunto de diretrizes conforme os grupos já definidos. Na terceira etapa, foi feita a análise estatística dos dados coletados. Na etapa final, as diretrizes foram reagrupadas conforme os resultados encontrados na pesquisa. A aplicação do card sorting possibilitou sistematizar um conjunto de 60 diretrizes para a reabilitação virtual de idosos em quatro grupos, sendo eles: terapia, motivação, interação e segurança.
Creencias y actitudes de adolescentes españoles hacia el consumo de tabaco en pipa de agua
Authors: Jorge-Araujo Pedro , Torres-García Milagros , Marrero-Montelongo Magdalena , Navarro Rodríguez Carmen
Published: December 2020

Objetivo: Identificar las creencias y actitudes de los estudiantes de educación secundaria obligatoria y bachillerato de la provincia de Las Palmas respecto al consumo de tabaco en pipa de agua. Dicho objetivo responde a la reciente y rápida expansión del consumo de tabaco en pipa de agua entre los adolescentes europeos, la relativa escasez de datos acerca de sus determinantes y la falta de estudios al respecto en los adolescentes de nuestro país.Método: La muestra, constituida por 1770 alumnos de la provincia de Las Palmas, se obtuvo estratificando cada bloque académico por áreas geográficas, agrupando a los alumnos en tantos clusters como grupos había en el centro por cada uno de los cursos. Se utilizó un cuestionario ad hoc para la recogida de datos, realizándose un análisis descriptivo de los mismos. Las proporciones se compararon utilizando el test de la χ2.Resultados: El 70,7% de los adolescentes consideró que fumar en pipa de agua es menos perjudicial que fumar cigarrillos y el 71,3%, menos adictivo. Los estudiantes manifestaron que es una práctica muy aceptada por sus amigos (63,7%) y por la sociedad (78,9%). El 27,8% declaró percibir que sus padres le permitirían fumarla en casa. Todas estas creencias y actitudes fueron más frecuentes entre los fumadores (p<0,001).Conclusiones: La mayoría de los estudiantes considera menos peligroso y adictivo este consumo que el de cigarrillos. Estas creencias, la percepción de la aceptación social y de la tolerancia familiar han aumentado su popularidad entre los adolescentes.

Objective: To identify beliefs and attitudes of high school students in Las Palmas regarding waterpipe smoking. This objective responds to the recent and increasing waterpipe smoking among European adolescents, the lack of data on its determinants and the absence of research on this issue among adolescents in Spain.Method: The sample, which comprised 1770 students of the province of Las Palmas (Canary Islands, Spain), was obtained by stratifying each academic block by geographic areas, grouping the students in as many clusters as existing groups in the school for each year group. An ad hoc questionnaire was used to collect data and a descriptive analysis of the data carried out. Proportions were compared using the χ2 test.Results: 70.7% of adolescents considered that waterpipe smoking is less harmful than smoking cigarettes and 71.3% believed it to be less addictive. Students asserted that it is a generally accepted practice among their friends (63.7%) and in society (78.9%). 27.8% of the interviewees perceived that their parents would allow them to smoke waterpipe at home. All of these beliefs and attitudes were more common among smokers (p<0.001).Conclusions: Most students consider waterpipe smoking to be less dangerous and less addictive than cigarette consumption. This belief, the perception of its social acceptance and family tolerance towards it have increased its popularity among adolescents.
Matrimonio, consanguinidad y la aristocracia nueva castellana: consolidación de la Casa de Alba (1440-1531)
Authors: HERNÁNDEZ FRANCO Juan
Published: December 2020

Historia Social, Historia de la Familia e Historia Política convergen en el presente artículo para intentar analizar cómo se forma la casa de Alba, y avanzar en su trayectoria de ascenso social desde el siglo XIII, cuando son miembros de la oligarquía toledana, hasta 1531, inicios del periodo del ducado de Fernando Álvarez de Toledo, el Grande. En ese proceso desempeña un destacado papel las alianzas matrimoniales con casas aristocráticas de más lustre (Enríquez y Benavente) y con posterioridad, especialmente en el siglo XVI, la recurrencia a matrimonios entre parientes muy cercanos en grado de consanguinidad.

Social History, Family History and Political History converge on this article, in which we try to analyse how the house of Alba was formed, and progress in the trajectory of social ascent the house of Alba experienced from the 13th century —when they were members of the oligarchy of Toledo— until 1531, when the Duchy was created for Fernando Álvarez de Toledo, the Great. In this process, marital alliances with more prestigious aristocratic families, such as the Enríquez and the Benavente, played a prominent role, and subsequently, in the sixteenth century, marriages between close relatives with some degree of consanguinity became recurrent.
"No hay que tolerar a aquellos que con boca de perro intentan hablar mal de las mujeres": Alonso de Cartagena, la cuarta cuestión del "Duodenarium" y la Querella de las mujeres
Authors: RÍOS DE LA LLAVE Rita
Published: December 2020

El objetivo del presente trabajo es demostrar, a través del análisis de la cuarta cuestión del Duodenarium de Alonso de Cartagena, la participación de este último en la Querella de las mujeres. Para ello se analizan los temas abordados por el autor, que pretende rebatir a los autores que critican a las mujeres, y se compara su pensamiento con el de otros autores que participaron en el debate, como Giovanni Boccaccio, Juan Rodríguez del Padrón, Diego de Valera, Álvaro de Luna y Teresa de Cartagena. Finalmente, se lleva a cabo una valoración del pensamiento de Alonso de Cartagena a través de las diversas formas de entender el concepto de mujer enunciadas por Prudence Allen.

The objective of this paper is to demonstrate, through the analysis of the fourth issue of the Duodenarium written by Alonso de Cartagena, his participation in the Woman Question. In order to do so, I analyse the themes addressed by the author, who pretends to refute those who criticize women, and I compare his ideas to those of other authors participating in the debate, such as Giovanni Boccaccio, Juan Rodríguez del Padrón, Diego de Valera, Álvaro de Luna, and Teresa de Cartagena. I finally carry out an assessment of Alonso de Cartagena’s thought through the various ways of understanding the concept of woman enunciated by Prudence Allen.
Literatura de caballerías: entidad receptora y difusora de un pensamiento moderno
Authors: García Álvarez Juan Pablo Mauricio
Published: December 2020

Justificación de los presupuestos teóricos sobre la temática de este monográfico. Además, se presentan y reseñan losacercamientos críticos en los trabajos aquí reunidos. La línea directriz de todos ellos sería el análisis de las trazas de pensamiento moderno en los libros de caballerías, ya sea por las estrategias utilizadas por sus autores para la configuración del texto, ya por los significados que articulan estas obras, permeadas de las principales problemáticas culturales, sociales, políticas y económicas de la época. Los libros de caballerías se convirtieron en verdaderos receptáculos y difusores de las distintas posibilidades de interpretar la realidad, y ver y representar el mundo.
Política de la riqueza en el «Libro del cavallero Zifar»
Authors: Rodríguez Victoria Rafael
Published: December 2020

En este artículo se analizan los juicios y valoraciones expresados en torno a la obtención y el uso de la riqueza en elLibro del cavallero Zifar, así como las representaciones de la fortuna material dentro de las historias, las sentencias y los exempla del texto; asimismo, se intenta destacar la influencia que estos elementos tendrían en las prácticas, hábitos ndividuales y sociales de los escuchantes o lectores. Tanto juicios como representaciones pueden considerarse una política de la riqueza. El enfoque de este análisis pretende resaltar la relevancia de la riqueza material en esta obra, ya que el devenir de la historia principal está impulsado por el deseo de Zifar de recuperar el esplendor perdido de su linaje. El encumbramiento del personaje y su familia dependen directamente de la posesión de fortuna material, como ocurre normalmente en una sociedad estamental como la que se representa en el libro.
Lletres i rajoles: «Tirant lo Blanc» i els emblemes cavallerescos
Authors: Serra Vives Neus
Published: December 2020

El present article analitza les divises representades sobre dues rajoles valencianes datades del segle XV. Els taulellss’haurien inspirat en la poètica i la literatura del moment, i en particular podrien haver-se apropiat de determinatspassatges de Tirant lo Blanc. D’altra banda, els motius representats podrien beure de diverses fonts visuals, tot mostrantles ambigüitats pròpies de la lectura d’aquestes construccions emblemàtiques produïdes en una època de transiciócultural.
Las adaptaciones de «Tirant lo Blanc» al cómic
Authors: Tena Medialdea Santiago
Published: December 2020

El presente artículo recoge información sobre las diferentes adaptaciones de Tirant lo Blanc al cómic que se han publicadohasta la fecha, aportando un análisis de las mismas enfocado principalmente a establecer el modo en cada unade ellas se relaciona con la fuente original: la novela. Al mismo tiempo se realiza una aproximación a las diferentespoéticas visuales y a las características de edición que ofrecen dichas reescrituras. El estudio no pretende entrar envaloraciones sobre la pertinencia o no pertinencia de las adaptaciones de los clásicos literarios al cómic, ni tampococalibrar o establecer cuáles serían sus posibles intereses didácticos, sino indagar hasta qué punto el recorrido intermedialtebeístico de Tirant lo Blanc ha podido contribuir al lugar que ocupa la obra de Martorell dentro del imaginariocolectivo de la actual sociedad globalizada.
Relationship Between Interpersonal Depressive Symptoms and Reduced Amygdala Volume in People with Multiple Sclerosis
Authors: Haines Sarah , Butler Ernest , Stuckey Stephen , Hester Robert , Grech Lisa B.
Published: December 2020

Background:

The lifetime prevalence of depression in people with multiple sclerosis (MS) is approximately 50% compared with around 15% in the general population. There is a relationship between depression and quality of life in people with MS and evidence that depression may contribute to disease progression.

Methods:

This cross-sectional pilot study assessed the association between depression and regional brain atrophy, including amygdala and hippocampal volume. Forty-nine participants with MS recruited through a hospital MS clinic were administered the Center for Epidemiological Studies Depression Scale Revised (CESD-R) to investigate whether higher endorsements on the items depressive affect and interpersonal symptoms were associated with volumetric magnetic resonance imaging measurements of hippocampal and amygdala atrophy.

Results:

Regression analysis revealed an association between depression-related interpersonal symptoms and right amygdala volume. No association was found between depression and hippocampal volume.

Conclusions:

These results provide preliminary support for a unilateral, biologically based relationship between the right amygdala and characteristic interpersonal depressive symptoms expressed by people with MS and add to the growing body of literature implicating regional brain atrophy in MS-associated depression. Given that the interpersonal subcomponent of the CESD-R measures social functioning, and the neural networks in the amygdala are known to be implicated in processing social stimuli, this research suggests that targeted diagnosis and treatments for depression in people with MS may be particularly beneficial. Further confirmatory research of this relationship is required.
Current and Future Contributing Factors and Trends in the Usage of IT Cloud Computing in Manufacturing and Service Sectors
Authors: Agrawal Vipin K , Agrawal Vijay K , Chau Ngan N. , Miller Matthew , Harms Sherri
Published: December 2020

Cloud computing provides organisations with the ability to quickly change infrastructure, provider and service levels. The study looks at factors affecting the usage of cloud computing by organisations in the manufacturing and service sectors in the United States. Extrinsic motivation was found to be a significant factor for change in cloud computing budget allocation in manufacturing, whereas intrinsic motivation was a significant factor in the service sector. The study also shows that organisations’ future budgets include internal and external sources to fulfil their IT needs.
Fast Probabilistic Neuro-Fuzzy System for Pattern Classification Task
Authors: Bodyanskiy Yevgeniy , Deineko Anastasiia , Pliss Irina , Chala Olha
Published: December 2020

The probabilistic neuro-fuzzy system to solve the image classification-recognition task is proposed. The considered system is a “hybrid” of Specht’s probabilistic neural network and the neuro-fuzzy system of Takagi-Sugeno-Kang. It is designed to solve tasks in case of overlapping classes. Also, it is supposed that the initial data that are fed on the input of the system can be represented in numerical, rank, and nominal (binary) scales. The tuning of the network is implemented with the modified procedure of lazy learning based on the concept “neurons at data points”. Such a learning approach allows substantially reducing the consumption of time and does not require large amounts of training dataset. The proposed system is easy in computational implementation and characterised by a high classification speed, as well as allows processing information both in batch and online mode.
Parameter tuning of a local search heuristic for a vehicle routing problem with loading constraints
Authors: Pollaris Hanne , Janssens Gerrit Karel , Braekers Kris , Caris An
Published: December 2020

A vehicle routing problem (VRP) with sequence-based pallet loading and axle weight constraints is introduced in the study. An Iterated Local Search (ILS) metaheuristic algorithm is used to solve the problem. Like any metaheuristic, a number of parameters need to be set before running the experiments. Parameter tuning is important because the value of the parameters may have a substantial impact on the efficacy of a heuristic algorithm. While traditionally, parameter values have been set manually using expertise and experimentation, recently several automated tuning methods have been proposed. The performance of the routing algorithm is mostly improved by using parameter tuning, but no single best tuning method for routing algorithms exists. The tuning method, Iterated F-race, is chosen because it seems to be a very robust method and it has been shown to perform well on the ILS metaheuristic and other metaheuristics. The research aims at developing an algorithm, which performs well over a wide range of network sizes.
Visual-spatial Working Memory Span of Indonesian Children with Deafness in Oral, Total, and Sign Language Communication Methods
Authors: Aprilia Johana , Mangunsong Frieda Maryam
Published: December 2020

Children with hearing impairment or deafness experience cognitive function delays but not limited visual-spatial working memory, which is commonly used to solve mathematical problems. Previous studies have discovered that visual or spatial working memory in such children is different because of the communication methods that rely on vision. This study explores the visual-spatial working memory in children with deafness by measuring the memory of 70 elementary school children with deafness and identifying their communication methods through questionnaires. The questionnaires were completed by the children’s parents. The visual-spatial working memory measurement utilized the Lion Game through Zoom meetings. Consequently, it was found that there was no significant difference in visual-spatial working memory capacity in children with hearing impairment using oral, total communication, and sign language. It can be argued that in children with deafness, their visual-spatial working memory span with oral, total, and sign language communication methods have still not reached the maximum point. The use of hearing aids, popular among such children also did not significantly enhance visual-spatial working memory capacity. This research recommends parents be more attentive not only toward the communication methods of children with deafness but also to their cognitive function development.
Symmetry reductions, exact equations and the conservation laws of the generalized (3+1) dimensional Zakharov-Kuznetsov equation
Authors: Zhang Li-Xiang  , Liu Han-Ze  , Xin Xiang-Peng  ,   School of Mathematical Sciences, Liaocheng University, Liaocheng 252059, China
Published: December 2020

Because the nonlinear evolution equations can describe the complex phenomena of physical, chemical and biological field, many methods have been proposed for investigating such types of equations, and the Lie symmetry analysis method is one of the powerful tools for studying the nonlinear evolution equations. By using the Lie symmetry analysis method, we can obtain the symmetries, reduced equations, group invariant solutions, conservation laws, etc. In the reduction process, we can reduce the order and dimension of the equations, and a complex partial differential equations (PDE) can be reduced to ordinary differential equations directly, which simplifies the solving process. Meanwhile, the symmetries, conservation laws and exact solutions to the nonlinear partial differential equations play a significant role in nonlinear science and mathematical physics. For example, we can obtain a lot of new exact solutions by the known symmetries of the original equation; through the analysis of the special form of solution we can better explain some physical phenomena. In addition, the studying of conservation laws and symmetry groups is also the central topic of physical sciencein both classical mechanics and quantum mechanics. Lie symmetry analysis method is suitable for not only constant coefficient equations, but also variable coefficient equations and PDE systems. By using Lie symmetry analysis method, the symmetries and corresponding symmetry reductions of the (3+1) dimensional generalized Zakharov-Kuzetsov (ZK) equation are obtained. Combining the homogeneous balance principle, the trial function method and exponential function method, the group invariant solutions and some new exact explicit solutions are obtained, including the shock wave solutions, solitary wave solutions, etc. Then, we give the conservation laws of the generalized (3+1) dimensional ZK equation in terms of the Lagrangian and adjoint equation method.
Extracting the driving force signal from hierarchy system based on slow feature analysis
Authors: Pan Xin-Nong  , Wang Ge-Li  , Yang Pei-Cai  ,   Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;,   University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

Extracting the signals from non-stationary time series is a difficult task in many fields such as physics, economics, and atmospheric sciences. The theory of hierarchy suggests that varying driving force leads to the non-stationary behavior, so extracting and analyzing the slowly varying features can help to study non-stationary dynamical system, which has become a compelling question recently. Slow feature analysis (SFA) is an effective technique for extracting slowly varying driving forces from quickly varying non-stationary time series. The basic idea of SFA is to nonlinearly extend the reconstructive signal into a combination form with one or higher order polynomials, and to apply the principal component analysis to this extended signal and its time derivatives. The algorithm is guaranteed to seek an optimal solution from a group of functions directly and can extract a lot of uncorrelated features that are ordered by slowness. A series of studies has shown its superiority in extracting the driving force of non-stationary time series. The extracted signal is found to be highly correlated with the real driving force. Results based on ideal models show that either the slow driving force itself or a slower subcomponent can be detected by SFA. Yet despite all that, the further investigating of SFA is still needed to reduce its uncertainty. In this study, we create two types of non-stationary models by the logistic map with time-varying parameters: one includes two varying driving forces with different time periods constraining the evolution of time series in a non-stationary way; and the other is a three-layer structure encompassing two superimposed signals in which the slower signal of driving force is modulated by the lowest one. According to the ideal model and SFA, we conduct the numerical experiments to develop corresponding analysis method and discuss its application prospect in extracting driving force signals. We find that for the system of first kind, either the slowest signal or the combination of two driving forces constructed by SFA contains some uncertain information. However, we can detect the two independent driving forces from the constructed signal by wavelet analysis. For the three-hierarchy system that includes two superimposed signals of driving force, successive applications through SFA on the original time series and the constructed SFA signal will in turn detect the slower varying driving force signal and the slowest varying driving forces signal. The successful application of SFA shows its promising prospect in analyzing the external driving forces in non-stationary system and understanding relevant dynamic mechanism.
Analysis of the influence of diattenuation on optical imaging system by using the theory of vector plane wave spectrum
Authors: Zhang Min-Rui  , He Zheng-Quan  , Wang Tao  , Tian Jin-Shou  ,   Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences, Xi'an 710119, China;,   University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

In most of the researches of polarization aberration, the influence of diattenuation is not large enough to affect imaging quality evidently. However, the modulation transfer function decreases when optical elements with complex planar dielectric structures and low transmittance, such as beam-splitter and optical modulator, are introduced into an imaging system. In this paper, a vector optical model in Descartes coordinate system is proposed based on the concept of vector plane wave spectrum (VPWS). The results of calculation show that the VPWS model is consistent with Debye model. Compared with Debye vector diffraction integral, the VPWS method is more suitable to the description of the PA introduced by planar optical device with opaque mask, such as larger surface quantum-confined-stark-effect electro-absorption modulator, which is used to modulate the light collected by optical antenna of time-of-flight (TOF) depth system or modulating-retroreflector free-space-optical communication system. In order to simplify the calculation and obtain the conclusion of the change in imaging quality directly, the formula of optical transfer function is decomposed into three parts (TE component, TM component and the correlation of them) instead of polynomial expansion of pupil function. The influences of diattenuation on MTF is studied globally and locally in a range of cut-off frequency of optical imaging system (2NA/ ). Allowance of diattenuation is analysed by numerical calculation, and a mathematical expression is derived. The result shows that the change of diattenuation can be neglected when the spatial frequency v is less than 0.2NA/, and the range of allowance decreases with the increase of spatial frequency. According to numerical calculation shown in Fig.7 and the derived formulas (15) and (16), the ratios of reflection/transmission coefficient of s-light and p-light D should range respectively from 0.63 to 1.6(0.2NA/ v 0.8NA/) and from 0.9 to 1.11(v0.8NA/ ) when the MTF is required to be not less than 90% of the value in ideal diffraction-limited system. The range of allowance becomes larger gradually with the increase of angle n between the normal of optical interface n and the optical axis of imaging system z. If a polarization beam splitter is considered, D,n sin-1 NA should be greater than 1-3.
Moving object detection based on optical flow field analysis in dynamic scenes
Authors: Cui Zhi-Gao  , Wang Hua  , Li Ai-Hua  , Wang Tao  , Li Hui  ,   The Rocket Force of Engineering University, Xi'an 710025, China;,   Department of Automation, Tsinghua University, Beijing 100084, China
Published: December 2020

To overcome the limitation of existing algorithms for detecting moving objects from the dynamic scenes, a foreground detection algorithm based on optical flow field analysis is proposed. Firstly, the object boundary information is determined by detecting the differences in optical flow gradient magnitude and optical flow vector direction between foreground and background. Then, the pixels inside the objects are obtained based on the point-in-polygon problem from computational geometry. Finally, the superpixels per frame are acquired by over-segmenting method. And taking the superpixels as nodes, the Markov Random field model is built, in which the appearance information fitted by Gaussian Mixture Model is combined with spatiotemporal constraints of each superpixel. The final foreground detection result is obtained by finding the minimum value of the energy function. The proposed algorithm does not need any priori assumptions, and can effectively realize the moving object detection in dynamic and stationary background. The experimental results show that the proposed algorithm is superior to the existing state-of-the-art algorithms in the detection accuracy, robustness and time consuming.
Precise control of branch-length of light irradiated gold nanostars and associated thermal performance
Authors: Shi Na-Na  , Zhao Yan  , Feng Chao  , Huang Jie  , Xu Jia-Yu  ,   Institute of Laser Engineering, Beijing University of Technology, Beijing 100124, China
Published: December 2020

Gold nanostars are multi-branched nanoparticles with tip structures. Nanostars have excellent photoelectric properties, which make them able to be used in a variety of optoelectronics devices. Moreover, these stars have good biocompatibility and low toxicity, which opens broad application prospect in the biomedical field. Gold nanostars with admirable optical as well as thermal properties, are thought as a good candidate in cancer treatment that is a hot research topic in recent years. Gold nanostars with different branch-lengths were prepared by the photo-assisted method, and the effect of light was well studied in relation with gold nanostar branch-length. In the solution system, HEPES was used as the reducing agent, stable agent and shape-inducing agent. Under light irradiation, a certain amount of chloroauric acid solution (HAuCl4) was added to the HEPES solution. After a period of time, gold nanostars were prepared. Different wavelengths of irradiating light were selected in this experiment. The wavelength has different effects on the growth of branches associated with gold nanostars. The transmission electron microscope and the ultraviolet-visible-near infrared spectrophotometer were used to analyze the morphology and absorption spectra of gold nanostars. Meanwhile, a nano-measurer software was used to determine branch-lengths of gold nanostars under light irradiation of different wavelengths. The results indicate that the branches of the nanostars under irradiation were shorter than those of nanostars without irradiation. Different branch lengths correspond to different irradiation wavelengths. Based on these results, the physical process of shortening nanostars branches was analyzed, and a theoretical model of changing branch-length in the process of light-induced nanostars growth was proposed. The model indicates that there are two steps when the branch-length is changing. Firstly, the branch-length grows longer with the overall growth of the nanostar. Secondly, the nanostar becomes shorter because of the insatiability of HEPES molecules that are adsorbed on the nanostar surface with the increasing solution temperature. Through a photothermal measurement, a xenon lamp (wavelength 670 nm) was used as a light source to measure the temperature change within 30 min, and then the photothermal conversion efficiency of the gold nanostars was calculated. The results show that the branch-length of gold nanostars can be precisely controlled by light irradiation with slight variation in wavelength. The photothermal conversion efficiency of gold nanostars can also be regulated.
The twins structure and electric properties of Cl doped CdTe film by magnetron sputtering
Authors: Zhu Zi-Yao  , Liu Xiang-Xin  , Jiang Fu-Guo  , Zhang Yue  ,   School of Materials Science and Engineering, Beihang University, Beijing 100191, China;,   National Institute of Clean and Low-Carbon Energy, Beijing 102211, China;,   The Key Laboratory of Solar Thermal Energy and Photovoltaic System, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China;,   University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

CdTe is a promising material for fabricating high-efficient and low-cost thin film solar cell. To achieve high energy conversion efficiency, polycrystalline CdTe films must go through an annealing process in an atmosphere containing chlorine. Numerous researches of the mechanisms of chlorine treatment have been conducted. It is generally believed that chlorine treatment can increase the quantum efficiency of CdTe, cause CdTe grain to recrystallize, and reduce the defect density. In 2014 a research discovered that after chlorine treatment, Cl atoms are segregated at grain boundaries of CdTe and form p-n-p junction, which can separate electrons and holes, thus inhibiting the carrier recombination at grain boundaries. Another first-principle calculation research claimed that Cl atoms form VCd-ClTe complex, which is also named A-center, and provide extra shallow p-energy level to improve shallow p-doping of CdTe. It seems that both segregation and doping of Cl atoms can enhance cell performance.To test whether chlorine doping can contribute to the enhancement of cell performance, in this work we study chlorine doping in CdTe absorption layer by experiment. We deposit chlorine doped CdTe (CdTe:Cl) film by well controlling the chlorine concentration ((1005) ppm) to investigate the effects of Cl doping on device performance. In this work, we also compare the lattice structure and electrical properties of CdTe:Cl films with those of conventional Cl treated CdTe films.The CdTe:Cl film deposited at low temperatures consists of both cubic and hexagonal phases. CdTe:Cl film deposited at high temperature consists of only cubic phase with (111) orientation. Phase structure remains stable after annealing. Serried twins can be observed in all CdTe:Cl rods and the twins each contain only several atom layers. The ultra-thin twins can be found in both as-deposited CdTe:Cl and post-annealing CdTe:Cl. There is neither separate conduction channel of electrons nor that of holes in CdTe:Cl. But for chlorine treated CdTe, grain boundaries are the conduction channels of electrons and holes traveling within grains. The resistivity of the CdTe:Cl film is found to increase drastically, and carrier density reduces to intrinsic state after annealing. The efficiency of CdTe:Cl cell is lower than that of chlorine treated CdTe cell. It seems that non-balanced heavy chlorine doping by magnetron sputtering is bad to CdTe absorption layer.
Electromagnetically induced transparency of a cesium Rydberg atom in weak radio-frequency field
Authors: Yang Zhi-Wei  , Jiao Yue-Chun  , Han Xiao-Xuan  , Zhao Jian-Ming  , Jia Suo-Tang  ,   State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
Published: December 2020

Rydberg atoms are highly excited atoms with large principal quantum number n, big sizes (~n2) and long lifetimes (~n3). Rydberg atoms are very sensitive to an external field due to the large polarizabilities of Rydberg atoms (~n7). Electromagnetically induced transparency (EIT) of Rydberg atom provides an ideal method to detect Rydberg atoms without destroying atoms, and can be used to measure the external direct current and radio frequency (RF) field. In this paper, we study the EIT effect of a cesium ladder-type three-level atom involving Rydberg state exposed to a weak RF field. The ground state (6S1/2), the excited state (6P3/2) and Rydberg state (48D5/2) constitute the Rydberg three-level system, in which the probe laser couples 6S1/2(F=4)6P3/2(F'=5) transition, whereas the coupling laser scans across the 6P3/248D5/2 Rydberg transition. The coupling laser (510 nm laser, propagating in the z-axis direction and linear polarization in the y-axis direction) and the probe laser (852 nm laser, linear polarization in the y-axis direction) counter-propagate through a 50-mm-long cesium vapor cell at room temperature, yielding Rydberg EIT spectra. Rydberg EIT signal is detected as a function of the detuning of the coupling laser. When a weak RF (80 MHz) electric field polarized in the x-axis direction is applied to a pair of electrode plates located on both sides of the cesium cell, the EIT spectrum of Rydberg 48D5/2 shows the Stark splitting and the even order harmonic sidebands. The experimental results are analyzed by using the Floquet theory. The simulation results accord well with the experimentally measured results. Furthermore, we also investigate the influence of the self-ionization effect of Rydberg atom on the Stark spectrum by changing the RF frequency. We put forward a proposal to avoid the effect of ionization by placing electrode plates in the cesium cell. In the weak RF-field domain, mj=5/2 Stark line crosses mj=1/2, 3/2 sidebands, these cross points provide an antenna-free method of accurately calibrating the RF electric field based on Rydberg atoms.
Structural derivative and electronic properties of zigzag carbon nanotubes
Authors: Liu Ya-Nan  , Lu Jun-Zhe  , Zhu Heng-Jiang  , Tang Yu-Chao  , Lin Xiang  , Liu Jing  , Wang Ting  ,   College of Physics and Electronic Engineering, Xinjiang Normal University, Urumuchi 830054, China
Published: December 2020

It is well known that carbon nanotubes (CNTs) have received much attention since they were discovered. With the rapid development of carbon-based electronics and quantum computers, CNTs are required to have their unique physical and chemical properties in many fields. However, due to their uncertain mechanism of growth, it is difficult to achieve high production of CNTs with certain controlled structures. In this paper, we construct the nuclei of specific single- and double-walled zigzag CNTs and study their structural derivatives and electronic properties by using the density functional theory. According to the study of carbon clusters, we find some stable cage-like clusters containing zigzag structure which can be used as the nucleus of the corresponding single-walled CNTs. The nucleus of the double-walled CNTs is composed of the corresponding nucleus of single-walled CNTs.
It is possible to obtain a tubular cluster by optimizing the structure of the nucleus with accumulating carbon atoms at one end. The results show that the pentagonal structure plays a key role in the growing of tubular clusters. We find that the tubular clusters are grown in the form of global reconstruction when the clusters are short, but grown by local reconstruction when the clusters are longer. It can provide a theoretical reference to realize numerous CNTs with certain structures. Furthermore, the average binding energy (Eb) of tubular clusters is studied, and we find that their Eb is more and more stable and then close to the corresponding CNTs. At the same time, the study of the thermodynamic quantities of tubular clusters shows that their structures are thermodynamically stable.
In addition, the infinite zigzag CNTs can be obtained by using the periodic boundary conditions. Furthermore, the energy bands and density of states are calculated to study their electronic properties. The results show that the energy band structures of zigzag CNTs are closely related to the chiral index n. For zigzag CNTs (n, 0) and (n, 0)@(2n, 0), they show a metal property or narrow band gap semiconductor when n=3q (q is an integer); when n3q, they show a wide band gap semiconductor, and the band gap decreases with the diameter increasing. It is interesting that the two metallic single-walled CNTs (SWCNTs) are nested to obtain metallic double-walled (CNTs) DWCNTs, while the two semiconducting SWCNTs are nested to obtain semiconducting DWCNTs. However, due to the obvious curvature effect, small-diameter CNTs (4, 0), (4, 0)@(8, 0) and (5, 0)@(10, 0) show the metal properties but CNT (6, 0)@(12, 0) shows the obvious semiconductor property.