bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing students' language skills through project-based teaching of the languages for specific purposes: A case study
Authors: Prodanović Marijana , Gavranović Valentina
Published: December 2020

Starting from the analysis of the legislation regulating the education system in the Republic of Serbia, and through the prism of the theoretical review of the project-based teaching as a model of interactive and innovative teaching, as well as the fundamental principles set out in the Common European Framework of Reference for Languages, this paper aims to explore what opportunities the project-based teaching provides for the purpose of strengthening students' language skills in the context of learning English for Specific Purposes, particularly English for Medical Profession at secondary level. Theoretical assumptions were tested empirically using a case study. The qualitative analysis showed that project-based teaching, a model placing students and their needs in the centre of the teaching process, is an effective didactic system that teachers can use in organising and implementing instruction that encourages the development of all language skills.
Vita mixta u učenju Svetog Grigorija Dvojeslova
Authors: Kisić Rade
Published: December 2020

Kao polaznu tačnu za svoja antropološka razmišljanja Sv. Grigorije Dvojeslov često koristi posledice prvorodnog greha. Nakon što je čovek isteran iz raja, on je izgubio ingenita standi soliditas i time mogućnost stalne kontemplacije. Ipak, čak i u ovom svetu čovek može da iskusi doživljaj kratkotrajne kontemplacije. Polazeći od ovih principa Sv. Dvojeslov razvija svoj koncept vita contemplativa, koji je u ovom svetu ipak teško ostvariv jer je, između ostalog, svaki čovek opterećen mnogobrojnim svetovnim obavezama (vita activa). Proživljavajući i sam razapetost između želje za kontemplativnim, monaškim životom i brojnih svakodnevnih obaveza Sv. Grigorije povezuje ova dva načina života u koncept vita mixta.
Učenje Didima Slepog o jednosušnosti Svetoga Duha sa Ocem i Sinom
Authors: Bundalo Sava
Published: December 2020

Didima Slepog, profesora i upravitelja aleksandrijske bogoslovske škole, možemo svrstati u red prvih bogoslova drevne Crkve koji bogoslovstvuju o Duhu Svetom. Kada govori o Svetom Duhu Didim usvaja kapadokijsku terminologiju. Na njegovu pnevmatologiju veliki uticaj imaju Atanasijeva Pisama Serapionu. Oslanjajući se na 146. i 147. paragraf Didimovog dela O Duhu Svetom autor pokušava da prikaže na koji način Didim Slepi uči o jednosušnosti Svetoga Duha sa prva dva lica Svete Trojice. Jedan od načina je i učenje o dejstvu Božijem, odnosno dejstvu Svete Trojice u kojoj učestvuju jednako Otac, Sin i Sveti Duh, zatim o milosrđu, o ljubavi, o zajedništvu u svetosti i mudrosti. Kao aleksandrijski bogoslov on svoje učenje zasniva na Svetom Pismu i svoje stavove potkrepljuje redovnim navođenjima svetopisamskih stihova. Srž Didimove pnevmatologije je izražena u 166. paragrafu njegovog dela: "Priroda Svetoga Duha je ista kao priroda Oca i Sina". Na osnovu ovoga vidimo da je Didimova pnevmatologija sledovala učenju nikejsko-carigradskog simvola vere koji kaže: "I u Duha Svetoga, Gospoda, Životvornog, Koji od Oca ishodi, Koji sa sa Ocem i Sinom zajedno poštuje i zajedno slavi".
Arijanstvo i Goti - uloga gotskog faktora u prenosu Arijanstva na tradicionalne prostore Starog Rima i Italije
Authors: Radić Radovan
Published: December 2020

Arijanstvo jeste jeres koja doživljava svoj ogroman uspon u IV vijeku. Tokom navedenog vijeka, arijanstvo se od učenja jednog sveštenika sa aleksandrijske parohije Vavkale razvija u arijansko ispovijedanje, koje sredinom IV vijeka stvara jaku krizu unutar granica Imperije. Arijevo učenje postaje razlog sazivanja Prvog i velikog vaseljenskog sabora na kome se isto učenje kao jeres osuđuje. Predmet ovog istraživanja predstavlja period arijanske krize kada narod Goti primaju hrišćanstvo od strane arijanaca propovjednika ali i epoha neposredno nakon ove, kraj V i prva polovina VI vijeka, kada arijanstvo postaje religija vladajuće garniture vlasti Ostrogotskog kraljevstva Italije.
Thermodynamic investigation of disperse dyes sorption on polyester fibers
Authors: Kodrić Marija , Reka Arianit , Dimić Čedomir , Tarbuk Anita , Đorđević Dragan
Published: December 2020

The thermodynamics of sorption during the dyeing process of raw polyester fibers with disperse dye was studied in this article. Dyeing of fibers is carried out by a discontinuous batch process, according to standard procedures with varying of the initial dye concentration and the dyeing temperature. Several of the accepted models for calculation of thermodynamic parameters were used which define and clarify the sorption of disperse dyes on polyester fibers. High functionality of variables for the calculation of basic thermodynamic parameters was determined, which confirmed the validity of the results. Depending on the method of calculation , the change of free energy during the dyeing of the polyester was negative (-10-40 kJ·mol-1), which corresponds to the spontaneous and mainly the physical process of sorption. A positive value for the change in enthalpy during dyeing (1.1×10-2-2.9×10 1 kJ·mol-1) reflects the endothermic nature of the interactions, and a relatively lower value characterizes the physisorption phenomenon. A positive value for the change in entropy (1.1×10-4-1.5×10-1 kJ·mol-1 ·K-1) confirms that it is a physical sorption.
Hydrolates: By-products of essential oil distillation: Chemical composition, biological activity and potential uses
Authors: Aćimović Milica , Tešević Vele , Smiljanić Katarina , Cvetković Mirjana , Stanković Jovana , Kiprovski Biljana , Sikora Vladimir
Published: December 2020

Hydrolates, also referred to as hydrosols, floral or distillate waters, as well as aromatic waters, are produced in the same isolation process with essential oils by steam distillation. A small amount of essential oil constituents is dissolved in hydrolates providing specific organoleptic properties and flavor, as well as biological activity which makes them useful as raw material in many industries. Their popularity is still on the rise, especially in aromatherapy. The objective in this review is to analyze the chemical compositions of hydrolates and their corresponding essential oils, as well as biological activity of hydrolates (antimicrobial, antioxidant and antiinflamatory) and potential uses, not only in food industry for flavoring, and preservation of fresh-cut fruits and vegetables, but also as functional (soft) drinks. However, hydrolates can be used in aromatherapy and cosmetics, as well as in organic agriculture and aquaculture.
School and learning from the perspective of elementary school students
Authors: Rajović Ranko , Budić Spomenka , Radulović Branka
Published: December 2020

The paper deals with examining the opinions of the seventh and eighth-grade students on school, learning and of their rapport towards doing homework. The research included 286 students of seventh and eighth grade in four elementary schools in Serbia. The data were collected via survey method and processed using the SPSS software package. The questionnaire was the instrument used in the research, and descriptive-analytical method was used for data interpretation. The research results demonstrate that students with excellent academic performance show a high level of responsibility concerning regular studying, whilst students with good and satisfactory academic performance do not. Likewise, the students with excellent academic performance to a greater extent perceive studying as a positive activity, in comparison to the students with poorer academic performance. A positive correlation of medium intensity was recorded between the variables of regular studying and doing homework regularly. However, the percentage of students who stated they did not do their homework regularly due to the lack of motivation, homework overload or insufficiently clear expectations is not negligible. They describe school as a well-equipped, safe and stimulating environment with strict teachers. This research contributes to the understanding of the role of school from the perspective of the students atswhom the goals of school studying are directed.
Family circumstances and relationships as a factor of children crime behavior
Authors: Marković Mirjana , Lakićević Miloš
Published: December 2020

Statistics show that crime rates are rising globally. Not a single period of the development of human society was spared from the pathological phenomena and deviant behavior, nor even the modern era, where an explosion of various forms of deviant behavior can actually be noticed. What are the conditions and causes that have led to such global trends? In this paper, family circumstances and relationships will be analyzed as a crime factor. We will see what the universal and unchanged characteristics of the family are, how it affects the socialization, cultivation and individualization of children. In one systematic way, we will try to respond to the universal issues of family influence on its members. What are the interactive relationships between family members? How the functional and dysfunctional families affect their members? If and how can a family create a favorable climate for deviant behavior and how to avoid the multiplication of pathological phenomena in dysfunctional families? How youth and juvenile delinquency can be connected? All these are questions that we will try to give an answer to, although this answer is unlikely to be one-dimensional, since the family is a complex social group, with a complex mechanism of action.
The influence of project teaching on creativity and achievements of students in studying social contents within the subject Nature and Society
Authors: Janković Aleksandar
Published: December 2020

Creativity represents the point in which all contradictions of contemporary social development are summed up, refracted and reflected. Therefore, the question arises: "Is school a place that does (not) encourage creativity?" Creativity, as a psychological, social and pedagogical phenomenon, has a markedly positive impact on the overall development of a child or, in case of school, a student. The project teaching method calls for the school to be open and to be more closely connected with its environment, in order to enhance the students' independence and creativity, self-initiative, responsibility, cooperativeness, ability to apply information and communication technologies as well as digital teaching tools as sources of knowledge. This article presents the project method as an element of stimulating students' creativity in teaching the subject Nature and Society, planned for the third grade of elementary school. By reviewing the relevant literature as well as by experimental research on a convenience sample of students, we have identified acceptable options and some effects of applying this method. At the same time, we have also raised a number of issues that should be addressed later in order to further stimulate the development of creativity through teaching.
Media as an instrument of strategic communication in armed conflicts: The CNN effect
Authors: Mitrović Miroslav
Published: December 2020

Media, politics and public opinion are mutually conditioned social categories. Their interdependence is particularly pronounced in armed conflicts, especially in the context of armed interventions. The forum of the interaction of these phenomena is framed by the paradigm of strategic communication, which is transmitted to the public through the actions of entities identified as strategic communicators to achieve a motivating effect for reactions that are in line with communicators' interests. One of the emerging forms of strategic communication in all its forms and contents is the CNN effect. The paper contributes to the definition of the CNN effect as a broader concept than the television station, after which it was named. Furthermore, the paper analyzes the relationship between politics, the media and the public to gain public support for military intervention. The paper also provides an analysis of the CNN effect in the function of strategic communication on the example of the media use of bloodshed in the Markale market during the war in Bosnia and Herzegovina in 1995, with an analysis of the US actions and effects to support the idea of military intervention.
Career development of Geodetic Service Officers
Authors: Đorđević Dejan , Lojić Ranko , Banković Radoje
Published: December 2020

The relevance of this topic reflects the fact that individuals should understand the necessity of career change and the creation of individual portfolios. There is a universal understanding that the main characteristic of officers' career is vertical promotion. Officers' career is insufficiently investigated or researched, which includes a frequent change of jobs and assignments that are not related only to vertical career promotion. Both transfers and deployments of the Serbian Armed Forces Geodetic Service Officers (GSO), which are in scope of this paper, in regard to career accomplishment, represent the career matrix. The importance of research refers not only to officers' career, but it can be implemented for understanding and getting an insight into career development, in general, through the career matrix.
Haderen, elskeren og læseren: Holdning, underholdning og pædagogisk potentiale i essayistisk skrivelitteratur
Authors: Isager Christine
Published: December 2020

I en sammenlignende læsning af to markante eksempler på essayistisk skrivning om skrivning, Ole Meisners ”Haderen” (2008) og Stanley Fishs How To Write a Sentence and How to Read One (2011), udpeges styrker og svagheder ved underholdende og holdningspræget håndbogsretorik. Formen kan engagere urutinerede skribenter, heriblandt journaliststuderende, og styrke deres sprogfaglige selvforståelse. Den ironiske humor hos Meisner synes imidlertid at undergrave dette ærinde ved at fokusere på fejltrin og ufrivilligt komisk sprogbrug. Fishs fokus på bevidst efterligning af gode eksempler synes i højere grad at bemyndige læserne og anvise et videre skrivepædagogisk potentiale.
Phase field modelling of grain growth in polycrystalline material
Authors: Chen Yun  , Kang Xiu-Hong  , Xiao Na-Min  , Zheng Cheng-Wu  , Li Dian-Zhong  ,   中国科学院金属研究所，沈阳材料科学国家（联合）实验室，沈阳  110016
Published: December 2020

Based on the two-parameter phase field model of polycrystalline, the grain growth in polycrystalline material during isothermal holding is simulated by using the adaptive finite element method. The calculated results demonstrates that the cusp grain boundaries are inclined to planar and some small grains coarsen into larger ones through grain boundary migration due to the curvature effect. When the grain boundary misorientations are small enough and meet certain energy and geometric conditions, two grains can rotate to reduce external energy of grain boundaries and coarsen into a single grain. All the modelling results are in good agreement with some experimental observations, and the phase-field model can be successfully employed to simulate polycrystalline grain growth.
Study on the relation among grain edge length, grain size and topology with Monte Carlo simulation
Authors: Wang Hao  , Liu Guo-Quan  , Luan Jun-Hua  , Yue Jing-Chao  , Qin Xiang-Ge  ,   (1)北京科技大学材料科学与工程学院，北京  100083; (2)北京科技大学材料科学与工程学院，北京  100083；北京科技大学新金属材料国家重点实验室，北京  100083; (3)佳木斯大学材料科学与工程学院，佳木斯  154007
Published: December 2020

The relation among grain edge length, grain size and topology is studied by large-scale Potts model-Monte Carlo simulation. The results show that the grain edge length is related to the number of grain faces by a linear relation, which is also observed to hold in Poisson-Voronoi structure and average N-hedra. The distribution of the grain edge lengths maintains self-similarity in the period of quasi-stationary grain growth. The average length of an edge segment in individual grains varies with grain size （or the number of grain faces）,thereby indicating that assuming the lengths of edge segments in all individual grains to be equal averagely as does in some models is subject to some limitations. The data of Monte Carlo simulated grains and pure iron show that the grain size is related to the face number by a curve convex upward.
Numerical investigation of deformation-induced dynamic transformation in Fe-C alloy by using a Q-state potts Monte Carlo model
Authors: Xiao Na-Min  , Li Dian-Zhong  , Li Yi-Yi  ,   中国科学院金属研究所，沈阳材料科学国家（联合）实验室，沈阳  110016
Published: December 2020

The deformation induced dynamic transformation （DIDT） of a Fe-C alloy above austenite transformation equilibrium temperature is simulated by using a Q-state potts Monte Carlo （MC） model. The austenite-to-ferrite transformation, dynamic recrystallization （DRX） of austenite and ferrite, and the ferrite-to-austenite reverse transformation can be simulated simultaneously in the same MC model by building suitable MC transition rules. Meanwhile, an affine transformation model based on vector operation is also coupled with the MC model for the first time for tracking the changes in grain shape during dynamic transformation. The formation of ferrite during DIDT and the influence of austenite DRX on DIDT are simulated based on this MC model. The simulation results show that the competition between the DRX of austenite and the austenite-to-ferrite transformation causes the oscillation behaviour of ferrite kinetics.
Approximate analytic and numerical study on indentation of cellular/foam film with glass substrate
Authors: Fan Tian-You  , Fan Lei  , Mai Y. W.  ,   (1)Centre for Advanced Materials Technology，University of Sydney，Sydney  2006，Australia; (2)北京理工大学理学院，北京  100081; (3)北京理工大学生命科学学院，北京  100081
Published: December 2020

Approximate analytic and numerical studies on depth-sensing indentation response of ordered cellular/foam materials with glass substrate are carried out based on the elasticity theory and the theory of cellular solids. The observation focuses on the pressure distribution and critical value of indentation depth in the contact zone，which are approximately determined. The theoretical results are compared with the experimental measurements. The comparison shows that they are in good agreement with each other. In order to give a reasonable estimation on the integrality of the film system, the deformation and the failure mechanism are analyzed. And further we observe the indentation energy and derive its analytic expression， whose form is very simple and we suggest that it can be used as a parameter characterizing the indentation response.
Electronic structure and doping effect of kink in edge dislocation of body-centred cubic iron
Authors: Chen Li-Qun  , Yu Tao  , Xia Can-Fang  , Qiu Zheng-Chen  ,   (1)钢铁研究总院功能材料研究所，北京  100081; (2)中南林业科技大学理学院，长沙  410004
Published: December 2020

The self-consistent discrete variational method and the DMol method， based on the density functional theory， are employed to study the electronic structure and the doping effect （N，O） of the kink in the 1/2［111］（110） edge dislocation of body-centred cubic Fe. Our calculations of energies （impurity segregation energy and structural energy） show that N and O each have a strong segregation tendency to enter a kink region， which is related to the lattice distortion introduced by the kink. Furthermore， we find that there exist some charge accumulations between impurity and its neighbouring Fe atoms， resulting in unhomogeneous charge distribution in the kink. N and O atoms obtain electrons while the neighbouring Fe atoms lose electrons. It is found that the interactions between impurity N atom and neighbouring Fe atoms are strengthened due to the strong hybridizations between N-p and Fe-3d4s4p states. The migrations of kink and dislocation motion are impeded by N， which may be beneficial to an increase in strength of material. While the interaction between O and its neighbouring Fe atoms is weaker. The localized effect of impurity-kink complex distinctly affects the electronic structure and properties of the system.
First principles study of electron field emission from the system of BN nano tuber capped and doped with carbon atom
Authors: Chen Guo-Dong  , Wang Liu-Ding  , An Bo  , Yang Min  ,   西北工业大学应用物理系，西安  710072
Published: December 2020

The electron field emission performances of BN nano tube （BNNT） capped and doped with one carbon atom are investigated through the first principles calculations. The results show that the electronic structures of the systems change obviously. The shift of margin of the density of states （DOS） towards low energy position increases as the applied electric field and the highest occupied molecular orbital （HOMO）-lowest unoccupied molecular orbital （LUMO） gap decrease. The analyses of DOS, local DOS，HOMO, LUMO and their gap consistently indicate that CeqBNNT system is more propitious to the electron field emission than other systems.
Modelling of dendritic growth in forced and natural convections
Authors: Sun Dong-Ke  , Zhu Ming-Fang  , Yang Chao-Rong  , Pan Shi-Yan  , Dai Ting  ,   东南大学江苏省先进金属材料高技术研究重点实验室，南京  211189
Published: December 2020

A two-dimensional lattice Boltzmann method （LBM） based model is developed for the modelling of dendritic growth during alloy solidification in the presence of forced and natural convections. Instead of conventional continuum-based Navier-Stokes solvers，the present model adopts a kinetic-based LBM for the numerical computations of transport phenomena during solidification. Three sets of distribution functions are employed to constitute the LBM evolution equations for numerically calculating fluid flow as well as solutal and thermal transports which are controlled by both diffusion and convection. By solving the LBM evolution equations， the local temperature and the composition at the solid/liquid interface can be obtained. The kinetics of dendritic growth is then investigated based on a solutal equilibrium approach proposed by Zhu and Stefanescu. The model is verified by the comparison between the simulations and theoretical predictions. The simulated upstream tip velocities and radii of the dendrite growing in a melt with natural convections are found to be in reasonabl agreement with the predictions from the modified Lipton-Glicksman-Kurz model that takes into account the effects of convection. For the convective dendritic growth in a forced flow， the simulated growth Pclet number of the upstream tip as a function of the flow Pclet number is very close to the Oseen-Ivantsov solution. It is also found that convection transports heat and solute from the upstream region to the downstream region， producing asymmetrical dendrite that grows faster in the upstream direction， whereas slower in the downstream direction.
Effects of oxygen plasma treatment on tensile deformation of nano-SiO2 sol-gel coating ultra-high molecular weight polyethylene filaments
Authors: Zhang Ying-Chen  , Zhu Hai-Yan  , Huang Jing-Nan  , Zou Jing  , Wu Hong-Yan  , Qiu Yi-Ping  ,   (1)东华大学纺织面料技术教育部重点实验室，上海  201620; (2)东华大学纤维材料改性国家重点实验室，上海  201620；东华大学纺织面料技术教育部重点实验室，上海  201620; (3)东华大学纤维材料改性国家重点实验室，上海  201620；东华大学纺织面料技术教育部重点实验室，上海  201620；中原工学院河南省功能性纺织材料重点实验室，郑州  450007；中原工学院纺织学院，郑州  450007; (4)中原工学院纺织学院，郑州  450007
Published: December 2020

The effects of oxygen plasma treatment on tensile deformation of nano-SiO2 sol-gel coating ultra-high molecular weight polyethylene（UHMWPE） filaments are investigated and a new concept for the nano-structural interface between fiber surface and nano-coating is provided. The tensile test results show that the activation volumes of UHMWPE filaments untreated and treated with oxygen plasma ranging from 1718.448 to 16603.070 nm3 by using Eyrings equation are an important description of the properties of the nano-structural interface between fiber surface and nano-coating, in addition to the enhanced ductility of UHMWPE filaments after nano-SiO2 sol-gel coating UHMWPE filaments treated by oxygen plasma. From the results of scanning electron microscope and Fourier transform infrared spectroscopy, it is observed that the uniform dispersion of the nano-SiO2 coating on the UHMWPE filaments treated by oxygen-plasma not only fills in the micro-flaws, but also introduces the activated functional groups into the fiber surfaces.
Numerical relationship between hardness and microstructure of JLF-1 steel after cyclic deformation
Authors: Li Huai-Lin  , Yang Wen  , Yang Qi-Fa  ,   中国原子能科学研究院，北京  102413
Published: December 2020

The cyclic softening of a reduced-activation ferritic/martensitic steel, JLF-1, is one of main problems for application. The microstructure of JLF-1 steel after cyclic deformation is analysed by transmission electron microscope and the Vickers hardness is tested. Based on the dislocation theory, the numerical relationship between change in hardness and microstructure of JLF-1 （dislocation density, lath width and dislocation cell size） is given.
Molecular dynamics simulations of a molten Cu55 cluster embedded in face-centred cubic bulk during
Authors: Xu Song-Ning  , Zhang Lin  , Zhang Cai-Bei  , Qi Yang  ,   (1)东北大学理学院，沈阳  110004; (2)沈阳理工大学理学院，沈阳  110168；东北大学理学院，沈阳  110004
Published: December 2020

The structural evolution of a molten Cu55 cluster embedded in face-centred cubic （FCC） bulk is simulated by molecular dynamics method based on the embedded-atom method potential through mean square displacement, pair analysis indices, and the average energy of atoms. The simulated results show that final structure of the embedded Cu55 cluster mainly presents local FCC structure at the quenching temperatures. During solidification, the atoms continuously interchange their positions, and the rearrangement of atom positions is sensitive to the temperature change. As the quenching temperature increases, diffusion abilities of the atoms increase. At 100—500 K, the formed FCC structures are stable, whereas at 700—1100 K, the local structures of the clusters fluctuate with time step increasing.
Molecular dynamics study of structures of a Cu13 cluster supported on a Cu(001) surface at low temperatures
Authors: Zhao Qian  , Zhang Lin  , Qi Yang  , Zhang Zong-Ning  ,   (1)东北大学理学院，沈阳  110004; (2)沈阳工业大学理学院，沈阳  110178；东北大学理学院，沈阳  110004
Published: December 2020

Structural changes of a Cu13 cluster supported on a Cu（001） surface at low temperatures of 10 and 50 K are investigated through molecular dynamics simulations with using interatomic potentials from embedded atom method presented by Johnson. The calculations of atom density profiles show that the cohesive energy is affected mainly by the number and the configuration of the atoms which are directly contacted with the Cu（001） surface, as well as some different configurations of the atoms at higher positions. At 10 K, the initial position of the supported cluster has a larger effect on the atomic packing and the binding energy of cluster.
New application of (G′/G)-expansion method to high-dimensional nonlinear physical equations
Authors: Ma Yu-Lan  , Li Bang-Qing  , Sun Jian-Zhi  ,   北京工商大学计算机与信息工程学院,北京  100048
Published: December 2020

The （G′/G)-expansion method is firstly extended to construct exact non-traveling wave general solutions of high-dimensional nonlinear equations, explore special soliton-structure excitation and evolution, and investigate the chaotic patterns and evolution of these solutions. Taking as an example, new non-traveling solutions are calculated for （3+1)-dimensional nonlinear Burgers system by using the （G′/G)-expansion method. By setting properly the arbitrary function in the solutions, special soliton-structure excitation and evolution are observed, and the chaotic patterns and evolution are studied for the solutions.
Analysis on theory of selective model
Authors: Wei Wei-Feng  ,   北京交通大学电子信息工程学院，北京  100044
Published: December 2020

Selective model provided a way to explain the generation of index law and power law on the basis of preferential probability analysis. A transformation formula between the selective scope rule and selective distribution was deduced through the research on preferential trials. It was named as preferential transformation, which offered a mean to study the rule of monotone distributions. A corresponding continuous transformation can be deduced by the preferential transformation for analyzing probability density function. Compared with the discrete distribution, we defined a comparison function for continuous distribution, and pointed out the relationship between the discrete distribution and continuous distribution. Through selective model, we simulated and analyzed the power law phenomena. Selective theory was important to the research on huge complex system and social behavior. It could also expand the foundation of statistical physics and probability theory.
Noether symmetry and Mei symmetry of discrete holonomic system in phase space
Authors: Lu Kai  , Fang Jian-Hui  , Zhang Ming-Jiang  , Wang Peng  ,   (1)新疆师范大学数学物理和信息科学学院，乌鲁木齐  830054; (2)中国石油大学（华东)物理科学与技术学院，东营  257061
Published: December 2020

The Noether symmetry, the Mei symmetry and the conserved quantities of discrete holonomic system in phase space are studied in this paper. Using the difference discrete variational approach, the difference discrete variational principle of discrete holonomic system in phase space is derived. The discrete canonical equations and energy evolution equation are established. The criterion of Noether symmetry and Mei symmetry of the system are given. The discrete Noether and Mei conserved quantities and the conditions for their existence are obtained. An example is discussed to show the applications of the results.
A new type of Mei adiabatic invariant induced by perturbation to Mei symmetry for nonholonomic mechanical systems
Authors: Ding Ning  , Fang Jian-Hui  ,   (1)滨州学院物理与电子科学系，理论物理研究所,滨州  256603; (2)中国石油大学物理科学与技术学院，东营  257061
Published: December 2020

A novel type of Mei adiabatic invariant induced by perturbation to Mei symmetry for nonholonomic mechanical system is reported. The form of criteria and restriction equations for Mei symmetry after being disturbed are given. The new form and conditions of the Mei adiabatic invariant are obtained.
Near classical states of oscillator in square potential well with infinitely high walls
Authors: Li Xing-Hua  , Yang Ya-Tian  , Xu Gong-Ou  ,   (1)福建师范大学物理与光电信息科技学院,福州  350007; (2)南京大学物理系,南京  210093；兰州重离子加速器国家实验室理论核物理中心，兰州  730000
Published: December 2020

We define such quantum state as near classical state （NCS), in which the mean values of coordinates equal to the classical solution in macroscopic scale. We obtained the NCS for oscillator in square potential well with infinitely high walls as example.
Pairwise entanglement in three-qubit Heisenberg model with Dzyaloshinskii-Moriya interaction
Authors: Wang Yan-Hui  , Xia Yun-Jie  ,   山东省激光偏光与信息技术重点实验室，曲阜师范大学物理系，曲阜  273165
Published: December 2020

In this paper, we study the improvement and manipulation of pairwise thermal entanglement in one-dimentional three-qubit Heisenberg model, where Dzyaloshinskii-Moriya （DM） interaction is considered and concurrence is calculated to research this entanglements property. The results show that for XXX model, DM interaction can induce entanglement in the antiferromagnetic and ferromagnetic spin chains although the required critical values are different for these cases. For XXZ model, by introducing DM interaction D, antiferromagnetic spin chain has entanglement which is absent when D=0, and in addition, for antiferromagnetic and ferromagnetic cases, DM interaction D and the anisotropy parameter Δ have different effects on entanglement. As a result, the entanglement can be controlled and enhanced by choosing appropriate DM interaction and anisotropy parameter. Furthermore, we find that at the same temperature, no matter for antiferromagnetic or ferromagnetic spin chains, the critical DM interaction inducing entanglement should be greater in a three-qubit XXZ model than that in a two-qubit XXZ model.
Charged particle tunneling in a static dilaton black hole
Authors: Liu Cheng-Zhou  , Zhang Chang-Ping  , Wang Zhong-Lin  ,   (1)滨州学院理论物理研究所，滨州  256600; (2)绍兴文理学院物理系，绍兴  312000；滨州学院理论物理研究所，滨州  256600
Published: December 2020

In the Parikh and Wilczek’s tunneling framework，Hawking radiation of charged particle in the Gibbons-Maeda dilaton black hole is investigated. When a particle with electromagnetic charge tunnels across the event horizon，energy conservation and electromagnetic charge conservation of the spacetimes are emphasized and the back-reaction effects of the charged particle are considered.The present results show that the tunneling probability is related to the difference of the Benkenstin-Hawking entropy of the black hole.This implies that black hole radiation is consistent with information conservation and the underlying unitary theory.
Resonance response of a single-degree-of-freedom nonlinear dry system to a randomly disordered periodic excitation
Authors: Rong Hai-Wu  , Wang Xiang-Dong  , Xu Wei  , Fang Tong  ,   (1)佛山大学数学系，佛山  528000; (2)西北工业大学应用数学系，西安  710072
Published: December 2020

The resonance response of a single-degree-of-freedom nonlinear dry oscillator of Coulomb type to narrow-band random parameter excitation is investigated. The analysis is based on the Krylov-Bogoliubov averaging method. The averaged equations are solved exactly and the algebraic equation of the amplitude of the response is obtained in the case without random disorder. Linearization method and moment method are used to obtain the mean square response amplitude for the case with random disorder. The effects of damping, nonlinear intensity, detuning, bandwidth, dry intensity, and magnitudes of random excitations are analyzed. The theoretical analyses are verified by numerical results. Theoretical analyses and numerical simulations show that the peak amplitudes may be strongly reduced and the bifurcation of the system will be delayed when intensity of the nonlinearity increases. The peak amplitudes will also be reduced and the bifurcation of the system will be delayed when damping and dry intensity of the system increases.
Terahertz and Raman spectra of L-threonine
Authors: Wang Wei-Ning  ,   首都师范大学物理系，北京市太赫兹波谱与成像重点实验室，教育部太赫兹光电子重点实验室，北京  100048
Published: December 2020

The THz absorption within the range of 0.2—2.8 THz（6.7—93.2 cm－1）and Raman scattering spectra within the range of 10—4000 cm－1 of polycrystalline L-threonine have been examined with terahertz time-domain spectroscopy （THz-TDS） and Raman spectroscopy. Infrared spectrum between 400 and 4000 cm－1 were also recorded. We assigned the polar and the non-polar vibrational modes of the polycrystalline molecule in the range of both 6.7—93.2 cm-1 and 400—4000 cm-1 based on the theory of space group and the comparison of Raman and absorption spectra. Normal frequency vibrational modes were calculated for the single crystal form using the B3LYP method of density functional theory （DFT） and 6-311+G** basis set. All the experimental THz absorption peaks and low frequency Raman scattering peaks of polycrystalline L-threonine were assigned.
Generation of 100-J sub-picosecond laser pulse in high energy Nd:glass chirped pulse amplification system
Authors: Xie Xu-Dong  , Zhu Qi-Hua  , Zeng Xiao-Ming  , Wang Xiao  , Huang Xiao-Jun  , Zuo Yan-Lei  , Zhang Ying  , Zhou Kai-Nan  , Huang Zheng  ,   中国工程物理研究院激光聚变研究中心,等离子体物理国家级重点实验室，绵阳  621900
Published: December 2020

Generation of high energy sub-picosecond laser pulse was demonstrated in the Nd:glass chirped pulse amplification system. Seeded with pulse originating from OPA front end, the laser system output chirped pulse with maximum energy up to 168 J, and the spectral width was 5.5 nm （FWHM）， centering at 1054 nm. Systematic investigation showed the spectral width of pulses was about 4—6 nm with energy higher than 100 J, which supports high energy laser pulse with pulse duration less than 300 fs. The final pulse was compressed to as short as 710 fs by a mosaic grating compressor.
Femtosecond pump-probe technique assisted by surface plasmon resonance
Authors: Long Yong-Bing  , Zhang Jian  , Wang Guo-Ping  ,   (1)五邑大学数学物理系，薄膜与纳米材料研究所,江门  529020; (2)武汉大学物理科学与技术学院，教育部声光材料与器件重点实验室，武汉  430072
Published: December 2020

Femtosecond pump-probe technique assisted by surface plasmon resonance （SPR） is investigated numerically in this paper. Our calculations show that the signal ratio ΔR/R is increased by 2—3 orders of magnitude higher than the standard pump-probe technique， where ΔR　and　R are the intensity change and total intensity of the probe beam， respectively. It should also be pointed out that ΔR/R is sensitive to the incident angle of the pump beam and the thickness of the metal film. In particular for the metal-absorbing material system， ΔR induced by the hot electrons in the metal is only 2 percent of that induced by excited absorbing material， so ΔR/R is mainly related to the dynamics of the absorbing material. This technique will be interesting in investigating the ultrafast surface dynamics of thin films.
An extraction method of seabed reflection loss based on towed tilted line array
Authors: Li Xue-Gang  , Yang Kun-De  , Zhang Tong-Wei  , Qiu Hai-Bin  ,   西北工业大学航海学院,西安  710072
Published: December 2020

Seabed acoustic parameters are very important to underwater acoustic field prediction in shallow water. The existing inversion methods generally uses a vertical line array to receive the signal and its platform is stationary, which can not be operated for a large area with high resolution. The methods for extracting seabed reflection losses based on three kinds of line arrays were studied. A fast inversion scheme for the seabed acoustic parameters was presented, which uses a towed tilted line array and three acoustic sources to cover a large scope of grazing angles. The error analysis was made for this method. The simulation results show that different arrays require different experimental configurations to cover the same scope of grazing angles. The vertical line array must operate with several acoustic sources and require a stationary platform of the array. The towed horizontal line array needs only one acoustic source but requires a large-aperture line array. The towed tilted line array combines the merits of the vertical line array and the horizontal line array, which can inverse the seabed acoustic parameters in a moving and high resolution way and requires only a line array of smaller aperture.
Effect of the transverse electric field on the pitch and reflective characteristics of the planar texture cholesteric liquid crystals
Authors: Deng Luo-Gen  , Zhao Zhao-Li  ,   北京理工大学理学院物理系,北京  100081
Published: December 2020

The reflective spectrums of the cholesteric liquid crystals under the condition of normal incident light are computed by using Jones matrix method. A theoretical model for discussing the influence of the transverse electric field on the twist angle and the pitch of the planar texture cholesteric liquid crystals under the in-plane switching mode is established. Based on the model, the relation between the electric field and the reflective peak for the cholesteric liquid crystals, and the relation between the electric field and the reflective spectral width for the cholesteric liquid crystals are calculated. The effects of the transverse electric field on the pitch and the reflective characteristics of the planar texture cholesteric liquid crystals are studied under different anchoring conditions. The results show that, under the in-plane switching mode, the color of the light reflected from the cholesteric liquid crystals can be changed by the applied transverse electric field, which supplies a theoretical support for the planar texture cholesteric LC color display based on the electrically-controlled pitch.
Thermal conductivity of carbon nanotube: From ballistic to diffusive transport
Authors: Hou Quan-Wen  , Cao Bing-Yang  , Guo Zeng-Yuan  ,   清华大学航天航空学院,热科学与动力工程教育部重点实验室,北京  100084
Published: December 2020

Length dependence of the thermal conductivity of （5, 5） carbon nanotube at 300 K and 1000 K is studied by nonequilibrium molecular dynamics simulations. At room temperature the thermal conductivity shows linear length dependence for the tube length less than 40 nm, which shows completely ballistic transport. The calculated ballistic thermal conductance per unit area is 5.88×109 Wm-2K-1. The thermal conductivity increases with the increase of the nanotube length, but the increase rate decreases as the length increases. It shows that the phonon transport is in the ballistic-diffusive regime, and transits from ballistic to diffusive with increase of the tube length. The thermal conduction is close to completely diffusive transport and the ballistic transport can be ignored when the nanotube is longer than 10 μm. In the simulations, the power exponent of the thermal conductivity of carbon nanotube to the tube length decreases by decaying exponential function as the tube length increases. Different from one-dimensional material, in the thermodynamic limit, a completely diffusive transport will dominate the thermal transport in carbon nanotubes, and the thermal conductivity will converge to a finite value.
Long-range Finnis-Sinclair potential for molecular dynamics simulation of α-Al2O3
Authors: Hu Zhi-Gang  , Liu Yi-Hu  , Wu Yong-Quan  , Shen Tong  , Wang Zhao-Ke  ,   上海大学上海市现代冶金及材料制备重点实验室，上海  200072
Published: December 2020

The molecular dynamics （MD） simulation of metal-metal oxide interface requires a uniform potential to simultaneously describe metal and metal oxide. Accordingly, we obtained a set of long-range Finnis-Sinclair （F-S） potential parameters of α-Al2O3. All of the parameters were fitted to the targets, i.e. the experimental lattice energy, lattice constants, and elastic constants of α-Al2O3. Meanwhile, we compared our results with those reported by EAM, Glue and modified Matsui （m-Matsui） potentials and found that our rcsults are equivalent or better. After that, MD simulation of α-Al2O3 at 300 K with our long-range F-S potential was performed and the pair correlation functions, coordination numbers were calculated. The good agreement between calculation results and experiments validated the feasibility of this set of F-S potential parameters to the description of α-Al2O3 system.
Microparticles manipulation based on dielectrophoresis in microsystem
Authors: Ren Yu-Kun  , Ao Hong-Rui  , Gu Jian-Zhong  , Jiang Hong-Yuan  , Antonio Ramos  ,   (1)哈尔滨工业大学机电工程学院，哈尔滨  150001; (2)西班牙塞维利亚大学电子与电磁系，塞维利亚  41012 西班牙
Published: December 2020

Dielectrophoresis （DEP） has a high potential in the manipulation of low concentration microparticles in microsystem, which is an urgent project. The complex DEP expression was induced based on the basic DEP theory. The main factor of the conventional DEP force and the traveling wave DEP force was analyzed and 2D analytical model with star electrodes as well as parallel electrodes were founded in order to act as the manipulation construction of them. Boundary conditions were set and the real part and imaginary part were coupled to compute the DEP force. The DEP distribution of the two electrodes was simulated numerically in order to obtain the parameters for the experiment. Based on the conventional DEP force, the star electrodes were used to collect microparticles and based on the travelling wave DEP force, the parallel electrodes were used for microparticles lift and directional driving, respectively. Comparing the experimental results with theoretical and simulation analysis, they had a good agreement. The results show that DEP force can be used to manipulate microparticles effectively in microsystem.
Properties of electric transport in crystallized silicon films under different annealing temperatures
Authors: Song Chao  , Chen Gu-Ran  , Xu Jun  , Wang Tao  , Sun Hong-Cheng  , Liu Yu  , Li Wei  , Chen Kun-Ji  ,   南京大学物理系,固体微结构物理国家重点实验室，南京  210093
Published: December 2020

Hydrogenated amorphous Si thin films were prepared by plasma-enhanced chemical vapor deposition. As-deposited samples were annealed at different temperatures to obtain nano-crystalline Si. During the transition process from amorphous to nano-crystalline structure, Raman scattering spectroscopy was used to characterize the changes of microstructures. The temperature-dependent conductivity was measured in order to understand the electric transport processes in the films. It was found that the crystallization occurs at around 700 °C. The crystal volume fraction （Xc） increases with the increase of annealing temperature, and in the case of the Si film annealed at 1000 ℃, the Xc is beyond 90%. The carrier transport characteristics in the films annealed at the different temperatures are different from the as-deposited film. For the sample annealed at 700 ℃, the carrier transport is strongly influenced by the defect states resulting from the effusion of hydrogen, and it is controlled by the hopping conduction of the localized states in the difference measurement temperature regions causing the dual activation energies. For the highly crystallized Si film annealed at 1000 °C, the transport process is strongly influenced by the transport of the extended states in the crystalline silicon, while in the high temperature region, the quantum tunneling process plays an important role in the carrier transport property.
Determination of electron diffusion length in HgCdTe photodiodes using laser beam induced current
Authors: Yin Fei  , Hu Wei-Da  , Quan Zhi-Jue  , Zhang Bo  , Hu Xiao-Ning  , Li Zhi-Feng  , Chen Xiao-Shuang  , Lu Wei  ,   中国科学院上海技术物理研究所，红外物理国家重点实验室，上海  200083
Published: December 2020

The standard diffusion length （Lp） test procedure is apt to damage the p-n junction, so we often use characteristic decay length （L） obtained by laser beam induced current　（LBIC） instead of Lp. Two dimensional modeling is used to get the relations of L and Lp. Calculated L/Lp ratio is about 1.1, and it is not affected by doping concentration, Shockley-Read-Hall （SRH） lifetime and mobility. For HgCdTe photodiodes, we get characteristic decay length from the LBIC experiment, and get the true diffusion length by division by the ratio 1.1.
The theory of physical doping in organic semiconductor
Authors: Wang Run-Sheng  , Meng Wei-Min  , Peng Ying-Quan  , Ma Chao-Zhu  , Li Rong-Hua  , Xie Hong-Wei  , Wang Ying  , Zhao Ming  , Yuan Jian-Ting  ,   (1)兰州大学磁学与磁性材料教育部重点实验室，兰州  730000; (2)兰州大学物理科学与技术学院微电子研究所，兰州  730000; (3)兰州大学物理科学与技术学院微电子研究所，兰州  730000；兰州大学磁学与磁性材料教育部重点实验室，兰州  730000
Published: December 2020

A theory for carrier concentration in physically doped organic semiconductors has been presented based on Gaussian energy distribution of the lowest unoccupied molecular orbitals （LUMOs） and the highest occupied molecular orbitals （HOMOs） as well as the Fermi - Dirac distribution of carriers in allowed quantum states. The dependence of carrier concentration on doping concentration, ambient temperature and energy gap of organic semiconductors were numerically investigated. It is shown that carrier concentration will increase with the ambient temperature in doped or undoped organic semiconductors, and the carrier concentration decreases exponentially with the reciprocal of temperature. For intrinsic organic semiconductor, carrier concentration will decrease exponentially with the energy gap （the difference between the average energy levels of HOMO and LUMO ）and increase exponentially with the square of the width of Gaussian distribution. We then discussed the effect of doping concentration on carrier concentration for different HOMO and LUMO positions of the dopant relative to that of the host.