bluuebunny/crossref_metadata_2025 huggingface dataset:
The Structure of Forest Management and the Role of the Soviet Union in the World Wood Industry During the Modernization Era at the End of the 1920s - 1930s
Authors: Zykin Ivan
Published: December 2020

In the late 1920s - 1930s, according to official figures, the Soviet Union significantly increased its volume of timber industry production. However, the statistics did not include the private harvesting and procurement of wood by the population, that is, for household consumption, which until about the mid-1930s and its almost complete cutback, reached impressive quantities. Historiography formed an incomplete picture of timber management in the Soviet Union during the modernization period, and part of the official indexes are still today used by researchers to prove a significant increase in the volume of timber production in the country during the late 1920s - 1930s. This has made currently very relevant the task of studying changes in the structure of forest management and of determining the country's place in the global timber industry using estimates of the total volume of forestry resources and the value of the gross output of the wood industry. The author reveals that in the first decades of the 20th century the most actively developed areas of forestry were logging and mechanical processing of wood, while the proportion of deep wood processing in the value structure of forest management has changed little and remained at a low level. The author identifies the principal systemic problems in the forest industry of the Soviet Union in the late 1920s - 1930s, which became the causes of imbalances in its structure. Additionally, the author conducted a comparative analysis of the indexes of the Soviet state and of other countries and regions - leaders in the global wood industry. The study's conclusions include the highlighting of the persistence of imbalances in the timber industry in the late 1920s - 1930s and the lagging of the Soviet Union from other countries - industry leaders in the most important areas of timber production.
Manuscript tradition of the “Chosen Chronicler”
Authors: Bogdanov Andrey Petrovich
Published: December 2020

This article examines over twenty lists of a popular chronicle of the XVII century, discovered only in the middle of the XX century. Historiography mentions approximately ten of them, and even fewer were described. Although the “Chosen Chronicler” enjoyed wide popularity and has a rich history. Such compositions that were revised by virtually every scribes and continued in their chronicles, represent a remarkable source on the history of culture. However, present considerable difficulties for research. The first one consists in detection, examination, and comparison of the greatest possible amount of list. This is the only accurate method to elucidate the evolution of the literary monument and the novelty introduced by each editor and continuator. The attribution of each list allows determining in which social circles and regions of Russia were created the lists and revisions of the literary monument, as well as their correlation in time. Preliminary comparison of the texts indicates the time, place, and composition of protographs of the chronicle tradition under review. Studying the lists also demonstrates the evolution of the “Chosen Chronicler”, who was born and became popular in the XVII century, evolved into the new monuments of historical thought of the next century.
Organization of salt extraction on Lake Baskunchak of Astrakhan Governorate in f the XIX century
Authors: Khairlapova Marina Marksovna
Published: December 2020

The object of this research is the Baskunchak industry. The subject of this research is organization of salt extraction on Lake Baskunchak in the late XIX century. The chronological framework covers the period from the second half of the XIX century, i.e. from the beginning of regular state-ran salt extraction in the Baskunchak deposit until the abolishment of excise tax on salt, transfer of salt extraction to private Industrialists. The article provides detailed description of the methods of salt extraction on the lake, social composition of personnel engaged in the industry, transportation of salt on trucks and railways, statistical data on salt prices, salaries, and rent of salt plots by salt producers on Lake Baskunchak is given. The novelty of the research consist in comprehensive examination of the previously researched direction – development of salt industry on Lake Baskunchak in the late XIX century. As one of major salt deposits of Russia, Lake Baskunchak is of special value for the salt trade. In the second half of the XIX century Baskunchak was the large supplier of salt in Russia. The acquires materials can be used in educational process of the universities of Astrakhan Region in teaching general and specialized courses on the History of Russia.
The initial stage of the Muslim Brotherhood's activity: from political self-isolation to the demand to create an "Islamic party" (1928-1936)
Authors: Fedorov Nikolay
Published: December 2020

The subject of the research in the article is the development of the political doctrine of the Egyptian organization "Muslim Brotherhood" in the period from 1928 to 1936. The author examines in detail the historical context in which the Brotherhood arose and developed at the initial stage of its existence. The political situation that developed in Egypt by the end of the 1920s - early 1930s, as well as the peculiarities of the socioвЂ”economic development of the country in the interwar period (1919-1939) are analyzed. The author examines in detail the evolution of the views and rhetoric of the founder of the organization Hassan al-Banna. Special attention is paid in the article to the formation of the structure of society, its apparatus, as well as the political doctrine and the question of the positioning of the "Brotherhood". В  The main conclusions of the study are the existence of a visible connection between the nature of al-Banna's statements and the political situation prevailing in Egypt at a particular time, as well as the conscious desire of the founder of the organization to isolate himself from participating in the struggle for power for the sake of further strengthening the Muslim Brotherhood. A special contribution of the author is the deconstruction of the events of 1936, which led to a sharp politicization of the Brotherhood, reflected in the demand to create an "Islamic party". The novelty of the research lies in the involvement of a large array of materials in Arabic, as well as in an attempt to compare the development of nationalist and Islamist movements in Egypt.
“Digital legitimation” of scientific knowledge: to articulation of the problem
Authors: Yanik Andrey Aleksandrovich
Published: December 2020

Manifestation of the new methods of scientific research based on computational processing of high volumes of data (experimental, statistical, secondary information, etc.) led to broadening of the methods of scientific cognition, as well as to changes in the processes of legitimation of new knowledge. The article examines separate aspects of the indicated changes, and raises a question on the need for more accurate and systematic monitoring and analysis over the processes of changing the mechanisms of legitimation of scientific knowledge, obtained within the framework of “science based on big data”. The conclusion is made that in the context of the Fourth Paradigm (Data-Intensive Science) is being formed the fourth strategy for legitimation of scientific knowledge – “digital legitimation”. The knowledge generated by data-intensive science is legitimized virtually by complexity and scale of technologies used for its acquisition. The author underlines the need for thorough analysis of the “digital” type of legitimation due to the fact that the expansion of digital method for production of scientific results bears a number of risks. Particularly, alongside with accumulation of inaccuracies and deterioration in the quality of scientific examination, most severe risks consist in possibility of science being caught into the institutional development traps, as well as in exacerbation of the existing systemic crisis.
Pregnant Women’s Experience during Antenatal Care in Private Clinic Maternity Nursing
Authors: Fujiana Fitri , Setyowati Setyowati , Rachmawati Imami Nur
Published: December 2020

Maternity nurses are authorized health workers that provide antenatal care, but their roles and function in antenatal care services are not recognized by the public. This research aims to reveal the experience of pregnant women during antenatal visits in private clinic maternity nursing. Six pregnant women selected using purposive sampling underwent an in-depth interview in this descriptive phenomenological study. Data were analyzed through thematic content analysis with Moustakas approach. Three themes were identified in this study: 1) women experience good communication with maternity nurses; 2) women receive family-centered nursing care; 3) the schedule, cost, facility, and types of service meet the participants’ needs. This study suggests for nurses to improve their competencies in delivering antenatal care according to clients’ needs.Abstrak Pengalaman Kehamilan Wanita Selama Masa Perawatan Antenatal di Klinik Mandiri Keperawatan Maternitas. Perawat spesialis maternitas adalah petugas kesehatan berwenang yang menyediakan perawatan antenatal, tetapi peran dan fungsinya dalam layanan perawatan antenatal belum dikenal oleh masyarkat. Penelitian ini bertujuan untuk mengungkapkan pengalaman ibu hamil selama kunjungan antenatal di klinik mandiri keperawatan maternitas. Enam ibu hamil yang dipilih menggunakan purposive sampling menjalani wawancara mendalam dalam studi fenomenologis deskriptif ini. Data dianalisis melalui tematik konten analisis dengan pendekatan Moustakas. Tiga tema diidentifikasi dalam penelitian ini: 1) ibu hamil mengalami komunikasi yang baik dengan perawat maternitas; 2) wanita menerima asuhan keperawatan yang berpusat pada keluarga; 3) jadwal, biaya, fasilitas, dan jenis pelayanan sesuai keinginan ibu hamil. Studi ini menyarankan bagi perawat untuk meningkatkan kompetensi mereka dalam memberikan pelayanan antenatal sesuai dengan kebutuhan klien. Kata Kunci: antenatal care, ibu hamil, perawat maternitas
The Professional Identity of EFL Teachers: The Complexity of Nativeness
Authors: Mannes Adina , Katz Yaacov J
Published: December 2020

The current study quantitatively examines the professional identity of 150 EFL teachers in the Israeli educational system. Findings indicate that native English-speaking teachers (“NESTs”) rate themselves higher than non-native English-speaking teachers. Still, fewer differences
between the groups were found than predicted. While the results of this study support the idea of considering native English proficiency to be advantageous, the global situation of English use suggests that a different direction should be adopted. Taking advantage of the strengths of each
group by embracing cooperation between teachers from different linguistic backgrounds could contribute to a stronger professional identity for language teachers, thus reducing the dichotomy between native English speakers and those who do not speak English natively.
A Comparative Study of Higher-Order Thinking and Teaching in the United States and United Kingdom
Authors: Solanki Vibhakumari , Evans Brian R.
Published: December 2020

The United States and the United Kingdom have used standardized high-stakes testing as a measurement of students’ cognitive level to determine success in the 21st century. Standardized tests have given teachers guidance to help them determine what to teach students and how to teach to the test. With such increased emphasis on high-stakes standardized tests, students are being taught based on tested content. This study evaluates the frequency of higher-and lower-order items in the respective country’s standardized test, and analyzes the teaching of higher-order thinking within classroom instruction.
Parameters that influenece the nonlinear Thomson scattering of single electrons in high-intensity laser fields
Authors: Zheng Jun  , Sheng Zheng-Ming  , Zhang Jie  , Wei Zhi-Yi  , Yu Wei  ,   (1)中国科学院物理研究所光物理开放实验室,北京100080;(2)中国科学院上海光学精密机械研究所,上海201800
Published: December 2020

The scattering of ultrashort and ultraintensie laser pulses by single electrons has been investigated theoretically and numerically by use of the classical theory of Thomson scattering by free electrons. The results indicate that attosecond pulse trains are emitted during the interaction. The temporal and spatial characteristics of the radiation are presented for different laser parameters(including intensity, pulse duration, initial phases and polarizations) and initial states of the electron(including different initial velocities and positions). Usually, with the increase of the incident laser intensity, the radiation becomes more powerful, its central frequency becomes higher, its duration becomes shorter, and its angular distribution becomes smaller. The radiation produced by the electron under a linearly polarized laser has a higher amplitude than under a circularly polarized laser pulse with the same intensity. In both cases, the polarization state of the radiation is very complicated, which depends n the observation direction. In spite of its initial energy and moving direction, the radiation produced by relativistic energetic electrons tends to be predominantly along the moving direction of the electron.
Hopf bifurcation from synchronous chaos and its circuit simulation in a coupled nonlinear oscillator system
Authors: Ma Wen-Qi  , Yang Cheng-Hui  ,   北华大学理学院物理系,吉林132013
Published: December 2020

For a coupled nonlinear oscillator system with diffusion and gradient couplings, spatial Fourier transformation is performed and the dynamic equations of various space modes are derived. By calculating the Lyapunov exponents of the transverse modes, one can determine the stable region of the synchronous chaos on the plane of coupling parameters. On the boundary of the stable region, a couple of conjugate transverse modes destabilize, and a Hopf bifurcation takes place. Numerical simulations are carried out for the coupled Lorenz oscillator system. An electronic circuit is designed for simulating the bifurcation in the system. Results from the simulations show that the frequency created by the Hopf bifurcation is equal to the oscillation frequency of the destabilized transverse modes.
Preparation and properties of nano-structure Cu33N thin films
Authors: Wu Zhi-Guo  , Zhang Wei-Wei  , Bai Li-Feng  , Wang Jun  , Yan Peng-Xun  ,   兰州大学等离子体与金属材料研究所,兰州  730000
Published: December 2020

Copper nitride(Cu33N) thin films with nano-crystalline were deposite d on glass substrates at a temperature of 100℃ by DC magnetron sputtering with a columnar target. The structure of the Cu33N thin films was characterized by x-ray diffraction, x-ray photoelectron spectroscopy and atomic force microsco py. The results indicate that Cu33N thin films are composed of nanome ter grains with a cu bic crystal structure of anti-ReO33 type. The films have a uniform s mooth surf ace with only a roughness(Raa) of 17nm. The binding energy peaks of Cu2 p3/23/2, Cu2p1/21/2 and N1s were at 9327, 9527 and 3999eV respecti vely, and spin-orbit coupling energy gap of Cu2p was 20eV. The film thickness was determined by a profile step scanner, and its resistivity was measured usin g the four-probe method. The deposition rate and resistivity were found to chan ge with the nitrogen content.
The property of transformation strain in the texturedNi50550.5Mn 2424Ga25525.5 alloy
Authors: Liang Ting  , Jiang Cheng-Bao  , Xu Hui-Bin  ,   (1)北京航空航天大学材料科学与工程学院,北京  100083; (2)北京航空航天大学材料科学与工程学院,北京  100083;中国人民解放军防化指挥工程学院装备系,北京  102205
Published: December 2020

A large strain of 14% during the martensitic transformation has been observed in the textured Ni50550.5Mn2424Ga25525 .5 polycrystal prepared by vertical zone melting unidirectional solidification. This martensitic transformation strain decreases to 08% at the ninth and tenth thermal cycles. Expansion and shrinkage phenomenon during the martensitic transformation has been obtained, indicating the existence of a preferential orientation of martensitic variants.
CaCu33Ti44O1212 films prepared by magnetron s puttering
Authors: Zhou Xiao-Li  , Du Pi-Yi  ,   (1)台州学院物理系,临海  317000;浙江大学硅材料国家重点实验室,杭州  310027; (2)浙江大学硅材料国家重点实验室,杭州  310027
Published: December 2020

Thin CaCu33Ti44O1212 ceramic films have been successfully fabricated by a magnetron sputtering method and the surface morphology, microstructure and dielectric property of the samples have been measured by using atom force microscope, x-ray diffractometer (XRD) and LCR meter. XRD patterns show that the lattice constant of the films is less than that of the bulk materials, while the distort ion of the lattice in the films is comparatively larger. LCR results show that t he relative dielectric constant of the films is lower than that of the bulck mat erials at fixed temperature, and the temperature at which the dielectric constan t transits abruptly is higher and the activation energy of the films is larger. Further analysis shows that the lower crystallinity and more defects in the samp les result in the rapid decrease of the barrier layer capacity and film density, which should be responsible for the lower relative dielectric constant. The inc rease of the activation energy in the samples depends mainly on the factors such as internal stress, microstructure, defect and domain etc. The rapid increase o f the dielectric constant in lower frequency range implies that there exists int erface polarized phenomenon in the samples, which is related to the defects and dangling bonds on the interface.
Experimental study on energy distribution of the hot electrons generated by femtosecond laser interacting with solid targets
Authors: Gu Yu-Qiu  , Cai Da-Feng  , Zheng Zhi-Jian  , Yang Xiang-Dong  , Zhou Wei-Min  , Jiao Chun-Ye  , Chen Hao  , Wen Tian-Shu  , Chunyu Shu-Tai  ,   (1)四川大学原子分子物理研究所，成都  610065; (2)中国工程物理研究院激光聚变研究中心，绵阳  621900; (3)中国工程物理研究院激光聚变研究中心，绵阳  621900;四川大学原子分子物理研究所，成都  610065; (4)中国工程物理研究院激光聚变研究中心，绵阳  621900;四川大学原子分子物理研究所，成都  610065;内江师范学院物理系，内江  641112
Published: December 2020

This paper reports the results of the experiment of hot electron energy distribution during the femtosecond laser-solid target interaction. The hot electrons formed an anisotropic energy distribution. In the direction of the target normal, the energy spectrum of the hot electron was a Maxwellian-like distribution with an effective temperature of 206keV, which was due to the resonance absorption. In the direction of the specular reflection of laser, there appeared a local plateau of hot electron energy spectrum at the beginning and then it was decreased gradually, which maybe produced by several acceleration mechanisms. The effective temperature and the yield of hot electrons in the direction of the target normal is larger than those in the direction of the specular reflection of laser, which proves that the resonance absorption mechanism is more effective than others.
Polarization effects of coherent control photocurrent in semiconductors
Authors: Liu Lu-Ning  , Shou Qian  , Lei Liang  , Lin Chun-Mei  , Lai Tian-Shu  , Wen Jin-Hui  , Lin Wei-Zhu  ,   中山大学理工学院光电材料与技术国家重点实验室，广州  510275
Published: December 2020

Quantum interference control photocurrent in bulk semiconductors is analyzed using the Fermi golden rule and Kane six-band model. The initial momentum distributions of photoexcited carriers in different polarized light fields are calculat ed. The polarization dependence of the coherent currents is shown explicitly in a microscopic level. For the case of parallel linear polarizations, the current direction is along the direction of the light polarization; while for the case of perpendicular polarizations the current direction is along the polarization o f the harmonic frequency light. It is also shown that when the one-photon trans ition and the two-photon transition is balanced, the maximum current injection efficiency is achieved.
Study of microcrystalline silicon solar cells fabricated by very high frequency plasma-enhanced chemical vapor deposition
Authors: Zhang Xiao-Dan  , Zhao Ying  , Gao Yan-Tao  , Zhu Feng  , Wei Chang-Chun  , Sun Jian  , Wang Yan  , Geng Xin-Hua  , Xiong Shao-Zhen  ,   南开大学光电子薄膜器件与技术研究所，天津  300071;光电子薄膜器件与技术天津市重点实验室，天津  300071;南开大学光电信息技术科学教育部重点实验室，天津  300071
Published: December 2020

Microcrystalline silicon solar cells with the variation of silane concentration (SC) and discharge power were fabricated by very high frequency plasma_enhanced chemical vapor deposition. The results of J_V measurements showed that open circuit voltage (Vococ) of solar cells decreases with the decr ease of silane concentration and the increase of power in the range of experiments. I nfluence of SC on short_circuit current density (Jscsc) is more evi dent than power. As for microcrystalline silicon solar cells, the optimum choice for N layer is amorphous, because it can decrease the lateral collection effect of current on the one hand and increase the fill factor on the other hand.
Micro-distribution of carbon in semi-insulating gallium arsenide
Authors: Xu Yue-Sheng  , Yang Xin-Rong  , Wang Hai-Yun  , Tang Lei  , Liu Cai-Chi  , Wei Xin  , Qin Dao-Zhi  ,   (1)河北工业大学信息功能材料研究所,天津  300130; (2)空军天津航空装备技术训练基地，天津  300131
Published: December 2020

Micro-distribution of C acceptor defect in semi-insulating gallium arsenide (SI-GaAs) wafer has been investigated by means of chemical etching, microscopic observation, transmission electron microscope, eelectron probe x-ray microanalyz er.Experimental results show that there is a corresponding relationship between the distribution of C impurity and dislocation density in a wafer. In relatively high dislocation density areas, dislocations form relatively small cells with few isolated dislocation within each cell. Here the profile of C distribution in the area of a cell is “U”-shaped. The cell diameter increases as the dislocation density decreases, and the dislocations form relatively large cells with a few isolated dislocations within each cell. The profiles of C distributio n in the area of a cell is “W”-shaped.
Theoretical studies on optical fiber secure communication using chaotic phase encoding
Authors: Yan Sen-Lin  ,   南京晓庄学院物理系，南京  210017
Published: December 2020

In this paper, we present the synchronization of chaotic injected semiconductor lasers in an optical fiber system via phase-controllers controlling its lasing p hase shift, and a theoretical model for optical fiber chaotic secure communicati on system via chaos phase shift modulation by coupling a chaotic laser phase con trolled synchronization system and an optical fiber channel. Chaotic synchroniza tion is realized numerically under phase-controllers controlling in a long-haul optical fiber system. Optical fiber chaos propagation formula is demonstrated by analyzing theoretically the effect of optical fiber self-phase modulation on ch aotic signal and synchronization. Chaotic laser phase shift is controlled and it s signal is transmitted via continuous chaos shift keying modulation on end for optical fiber communication encoding. Chaotic laser demodulation is achieved via setting a phase shift of the receiver phase-controllers for optical fiber commu nication decoding. Application of chaotic digital encoding of 50Mbit/s rate is simulated numerically for long-haul optical fiber secure communication. The system parameter mismatch and robustness of anti-noise are analyzed numerically in long-haul optical fiber propagation, in particular.
Spontaneous emission properties of a two-level atom with an intense low-frequency field in a three-dimensional photonic crystal
Authors: Tan Rong  , Li Gao-Xiang  ,   华中师范大学物理科学与技术学院，武汉  430079
Published: December 2020

We have investigated spontaneous emissions from a two-level atom embedded in a p hotonic crystal with three-dimensional dispersion relation as well as interacted with a coherent intense low-frequency field .Due to this field, additional deca y channels with exchange of one low-frequency photon during an atomic transition are created, resulting in the spontaneously induced quantum interference. The s pontaneous emission can be suppressed significantly because of the combinational influences of the quantum interference effect and the band edge effect. The pop ulation in the upper levels depends on the relative position of the upper level from the band edge. The frequency of the low-frequency field and the relative in tensity of the coupling strength for the transitions can affect spontaneous emis sion from the atom.
Experimental and theoretical investigation on novel all-optical logic AND gates
Authors: Zhang Xin-Liang  , Dong Jian-Ji  , Wang Ying  , Huang De-Xiu  ,   华中科技大学光电子工程系,武汉  430074
Published: December 2020

A novel scheme based on cross-gain modulation in cascaded single-port-coupled se miconductor optical amplifier(SOA) is studied theoretically and experimentally. Theoretical model for the single-port-coupled SOA is established for theoretical simulation and performance evaluation.The 10Gb/s all-optical logic AND operatio n has been demonstrated theoretically and experimentally. A parameter is exploit ed to evaluate the output performance. Results show that the output performance is tightly related to input power and input extinction ratio. Theoretical calcul ation results are in agreement with the experimental results.
Coherent collisions of multi photovoltaic bright spatial solitons
Authors: Jiang De-Sheng  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室，广州  510275
Published: December 2020

We present a numerical study of coherent collisions of multi photovoltaic bright spatial solitons. The result shows that when the colliding solitons are in-phas e, they will attract each other and the inner ones will fuse together gradually. When the relative initial phase between any two adjacent solitons is π2, they will experience a power transfer which includes three basic interaction modes. When the colliding solitons are out of phase, they will propagate stably, which may be useful for the formation of soliton arrays and waveguide arrays.
Influence of cerium metal as catalyst on the growth and structure of single-walled carbon nanotubes
Authors: Li Zhen-Hua  , Wang Qin-Mei  , Wang Miao  ,   (1)浙江大学力学系，杭州  310027; (2)浙江大学物理系，杭州  310027
Published: December 2020

A method to prepare single-walled carbon nanotubes (SWNTs) by using a new type o f catalyst is presented. With a certain proportion, cerium oxide (CeO2) and gr aphite powders were mixed. The mixture was then filled into the longitudinal hol es of graphite sticks used as composite graphite electrode. With it as the anode , arc discharge was carried out in He atmosphere. The resultant collected was ob served and analyzed by using HRTEM and Raman spectroscopic analysis, indicating that a large amount of SWNTs with a uniform diameter were close-packed in bundl es and the average diameter of SWNTs was about 120nm—132nm.
Temporal evolution of electron excited temperature in micro-discharge in argon at atmospheric pressure
Authors: Dong Li-Fang  , Ran Jun-Xia  , Mao Zhi-Guo  ,   河北大学物理科学与技术学院，河北保定  071002
Published: December 2020

The temporal evolution of electron excited temperature of micro-discharge in die lectric barrier discharge (DBD) in argon at atmospheric pressure is studied by s pectroscopy method. The time-resolved spectra of 69654nm (2P2→1S5), 763 51nm (2P6→1S5) and 77242nm (2P2→1S3) Ar are measured. It is found th at the voltage decreases during the discharge, and increases after the discharge quenched. The transition of lower level 2P6 (76351nm) is some doze ns of ns ahead of the transitions of higher level 2P2 (77242nm and 69654nm ). Accord ing to the time-resolved spectrum, the electron excited temperature is estimated during the discharges. It is shown that the temperature is not a constant.It is variable with the time.The peak value of temperature exists about two hundred n s time_delay after the peak value of the discharge current.It is shown that the electron excited temperature does not reach its peak value when the electron den sity is at the peak value.And the electron excited temperature reaches the peak value 200ns late.
The improvement of thermal stability in NiSi film by adding Mo
Authors: Huang Wei  , Zhang Li-Chun  , Gao Yu-Zhi  , Jin Hai-Yan  ,   北京大学微电子研究院，北京  100871
Published: December 2020

A novel silicide technology to improve the thermal stability of the conventional Ni silicide is studied by adding a small quantity of Mo element in Ni flim.The results show that during rapid thermal annealing (RTA) temperature from 650 to 800℃,sheet resistance of Ni(Mo)Si silicide formed is low,whose value is about 2.4(Ω/□).X_ray diffraction(XRD) analysis identifies the existance of NiSi phase and no peak of NiSi2 phase for the above samples.Furthermore,accordin g to the theory on Gibbs free enery,the results show that adding 5.9 atomic% of Mo element can enhance thermal stability of nickel monosilicide.Finally,after annealed at temperatures ranging from 650 to 800℃,Ni(Mo)Si/Si Schottky barrier diodes(SBDs ) are fabricated.Good I_V characteristics of SBD that the range of Schotty b arrier height is from 0.64 to 0.66eV and the ideal factor is close to unity are shown.This further proves that the addition of a little amount of Mo in Ni film can improve the thermal stability of the NiSi film.
Properties of solitons stimulated by electric field in collagen molecule
Authors: Deng Chuang  , Weng Yu-Min  , Xu Zhi-Zhong  , Fei Lun  ,   (1)复旦大学材料科学系,上海  200433; (2)复旦大学物理系,上海  200433
Published: December 2020

A new model of collagen molecule is constructed, thus obtaining the Hamiltonian that can characterize its 3-dimensional structure properties better. The 4th Run ge-Kutta algorithm is used to numerically solve the obtained kinetic equations o f excited energy transport in the collagen molecules under an applied electric f ield. The results indicate that soliton waves of amide-I will be stimulated by t he electric field in collagen molecules with phonon emission.
Sliding mode control for the synchronization of master-slave chaotic systems with sector nonlinear input
Authors: Wang Xing-Yuan  , Liu Ming  ,   大连理工大学电子与信息工程学院，大连  116024
Published: December 2020

This paper analyses the synchronization control for a class of master_slave chaotic systems with parameter uncertainties,external noise disturbances and sector nonlinear input.It designs a class of sliding mode controllers for chaos synchro nization,testifying theoretically that the effectiveness of the controller is be yond the impact from the parameter uncertainties and external noise disturbances of the system under control and thus it is of strong robust nature.Finally,the effectiveness of this kind of controller is also proved by numerical simulations for the master_slave Duffing_Holmes systems.
Variational calculations and relativistic corrections to the nonrelativistic ground energies of the helium atom and the helium-like ions
Authors: Liu Yu-Xiao  , Zhao Zhen-Hua  , Wang Yong-Qiang  , Chen Yu-Hong  ,   (1)兰州大学理论物理研究所,兰州  730000; (2)兰州理工大学理学院,兰州  730050
Published: December 2020

Mathematica language is used to make a program that can solve the three_body pro blem with variational method. Considering the nuclear motion, the nonrelativisti c ground energies and the analytic wave functions of the helium atom and the hel ium_like ions (H+, He, Li+, Be++, B3+, C4+, N5+, O6+) are presented by using a simp le effective variational wave funct ion with a flexible parameter k. Based on these results, the influence of a finite nucleus charge radius, the relativistic and radiative corrections on the nonrelativistic Hamiltonian are discussed. The high precision values of the heli um atom and the helium_like ions ground energies are evaluated.
Experimental study on polarization holographic high density optical data storage with bacteriorhodopsin film
Authors: Ren Zhi-Wei  , Yao Bao-Li  , Menke Neimule  , Wang Ying-Li  , Zheng Yuan  , Lei Ming  , Chen Guo-Fu  ,   (1)中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室，西安  710068; (2)中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室，西安  710068 ;中国科学院研究生院，北京  100039
Published: December 2020

Genetic mutant bacteriorhodopsin BR_D96N film was experimentally studied on its holographic storage properties with different polarization recording waves. The influences of the different polarization states of the recording and readout wav es on the retrieval diffractive image's intensity and signal_to_noise_ratio were compared with each other. The experimental results showed that compared with ot her polarization holographic recording, orthogonal circular polarization recordi ng can realize the separation of the polarization state of the diffractive wave from the scattering noise, and thus has high signal_to_noise_ratio as well as hi gh diffraction efficiency. Using He_Ne laser (633nm, 3mW) as recording and reado ut beam, spatial light modulator as data input element and CCD as data capture e lement, orthogonal circular polarization holographic optical data storage was ma de on 60μm×42μm area of the BR_D96N film by Fourier transform holographic met hod. The area density of 2×108bit/cm2 was obtained, and t he encoded data was retrieved without errors.
The solution of phase-mismatched Fokker-Planck equation and its application in the QPM device
Authors: Zhao Chao-Ying  , Tan Wei-Han  ,   上海大学物理系,上海  200444
Published: December 2020

A new analytical solution for the phase_mismatched Fokker_Planck equation of deg enerate parametric amplification, and its application in evaluation of the ampli tude quantum fluctuation after passing through the quasi_phase_matching(QPM) dev ice is presented. The calculated results for QPM device, agree with that of the Langevin equation in the case of no loss k=0, and give a general solution fo r k≠0, from which we can derive the influence of squeezing on the loss coef ficient k.
The lasing time of soft x-ray laser pumped by capillary discharge
Authors: Zhao Yong-Peng  , Cheng Yuan-Li  , Wang Qi  , Hayashi Yasushi  , Hotta Eiki  ,   (1)哈尔滨工业大学可调谐激光技术国家重点实验室，哈尔滨  150001，中国; (2)日本东京工业大学能源科学系，东京  226_8502，日本
Published: December 2020

The laser spike of Ne_like argon at 469nm pumped by capillary discharge is mea sured with x_ray diode. Changing the pressure of Ar gas filled in the ceramic ca pillary and the peak value of the main discharge current, we study the effects o f experimental parameters on lasing time, which is the time of spike after the o nset of the main discharge current. The experimental results show that the soft x_ray laser is produced at the rise_time of the main discharge current which is 65%—75% of the peak at the lasing time. The lasing time can be delayed several ns when the pressure increases from 28Pa to 55Pa or the peak of main discharge c urrent decreases. In addition, there is maximum amplitude of the laser spike abo ut 42Pa.
Surface plasmon polaritons and its coupling with cavity mode in the system of dielectric spherical shells periodically mounted in a metal substrate
Authors: Zheng Jun-Juan  , Sun Gang  ,   中国科学院物理研究所,北京  100080
Published: December 2020

We investigate the surface plasmon polaritons and its coupling with other electromagnetic modes by observing the absorption spectrum on a system of dielectric spherical shells periodically mounted in a metal substrate. We found that there exist two resonance frequencies in the system corresponding to surface plasmon polaritons mode and cavity mode. At these frequencies, we can find related peaks i n absorbance. Since the surface plasmon polaritons cannot couple with the incide nt plane wave directly and both couplings of the cavity mode with the incident w ave and the surface plasmon polaritons are also weak, so the strength of absorpt ion peaks are generally very limited. However, we can adjust some parameters in the system to make the surface plasmon polaritons and the cavity mode with almos t the same frequency. In this case, the coupling can be dramatically enhanced, a nd we can observe very strong peaks in absorbance. The relationships of resonanc e absorption with some physical and geometrical parameters are discussed in deta il.
Temperature and strain sensing property of grapefruit microstructure fiber Bragg grating
Authors: Zhang Chun-Shu  , Kai Gui-Yun  , Wang Zhi  , Wang Chao  , Sun Ting-Ting  , Zhang Wei-Gang  , Liu Yan-Ge  , Liu Jian-Fei  , Yuan Shu-Zhong  , Dong Xiao-Yi  ,   南开大学现代光学研究所  天津  300071
Published: December 2020

The temperature and strain sensing property of a grapefruit microstructure fiber (MF) Bragg grating with multi-reflection peaks have been studied. Analysis indicates that the wavelength shift of this grating changes quadratically with the environmental temperature. Experimental results show that different reflection p eaks have their individual temperature sensitivities. Furthermore, the relations hip between the wavelength shifts and temperature variation has been fitted, whi ch confirms the above analysis. However, theoretical analysis indicates that the wavelength shift have a good linear relationship with the strain change. The re lationship between the wavelength shift and strain changes has been fitted throu gh experiment. The inconsistent sensitivity of different reflection peaks for th is grating ensures its practical applications in the field of multi-parameter se nsing measurement.
Molecular dynamics simulation of void growth in single crystal copper under uniaxial impacting
Authors: Luo Jin  , Zhu Wen-Jun  , Lin Li-Bin  , He Hong-Liang  , Jing Fu-Qian  ,   (1)四川大学物理科学与技术学院,成都  610064; (2)四川大学物理科学与技术学院,成都  610064;中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室,绵阳   621900; (3)中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室,绵阳   621900; (4)中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室,绵阳   621900;四川师范大学高压物理研究中心,成都  610068
Published: December 2020

The evolution of micro-voids under dynamic loading mainly contributes to the dynamic damage of ductile materials. In this work, the evolution of a preexisting nano-void in single crystal copper is investigated by means of molecular dynamics(MD) simulation. The relation between the time evolution of complicated stress distribution and the void growth is obtained. The precompression process before the tension process has strong influence to the void growth. That high threshold makes the void grow coincides with the trend that a shorter tension duration wi ll lead to a higher spallation strength, which was found in latest single crysta l spallation experiment.
Pr-based bulk nanocrystalline alloy and its properties
Authors: Wang Yong-Tian  , Zhao Zuo-Feng  , Pang Zhi-Yong  , Liu Ran  , Pan Ming-Xiang  , Zhao De-Qian  , Wang Wan-Lu  , Han Bao-Shan  , Wang Wei-Hua  ,   (1)山东大学物理电子系，济南  250100; (2)中国科学技术大学物理系，合肥  230026; (3)中国科学院物理研究所，北京  100080; (4)重庆大学数理学院，重庆  400044; (5)重庆大学数理学院，重庆  400044;中国科学院物理研究所，北京  100080
Published: December 2020

The formation of bulk nanocrystalline alloys based on the Pr60Al 10Ni 10Cu20 bulk metallic glass forming alloy by doping Fe is r eported. B y varying the content of Fe, the microstructure of the Pr-based alloy changes pr ogressively from full glassy state to composite with nanocrystalline particles e mbedded in the glassy matrix, and finally into nano-structured state accompanied by the gradual magnetic property changes. A simple approach to obtain the bulk nanocrystalline material with controllable microstructure is presented, and the relation between microstructure and property is discussed.
Ordered nanostructures on La-Sr-Cu-O thin films deposited by pulsed electron beam technique
Authors: Chen Lei-Ming  , Li Pei-Gang  , Fu Xiu-Li  , Zhang Hai-Ying  , Li Ling-Hong  , Tang Wei-Hua  ,   (1)Department of Physics,University of Rhode Island,Kingston RI02881,USA; (2)浙江理工大学物理系，杭州  310018，中国; (3)浙江理工大学物理系，杭州  310018，中国;中国科学院物理研究所，北京凝聚态物理国家实验室，北京  100080，中国; (4)中国科学院物理研究所，北京凝聚态物理国家实验室，北京  100080，中国
Published: December 2020

La_Sr_Cu_O thin films on Si(100) substrates have been grown by pulsed electron beam deposition technique.The thin films obtained have been characterized by x_ray diffraction (XRD),scanning electron microscope(SEM),energy dispersive x_ray analysis (EDX) and focusing ion beam (FIB) technology.Highly ordered surface nanostructure has been found.FIB technology has been used to characterize those nanostructures.The nanostructure was cut by FIB,and its cross section can be seen clearly also.The nanostructure was etched by FIB step by step,and the depth_resolved morphology was shown.It is suggested that those nanostructures could come from the thermal expansion and lattice mismatching between Si substrate and La_Sr_Cu_O thin film.If the growth of the nanostructure can be controlled,it could be used to form high_Tc junctions by directly growing.
Improving the efficiency of time-delayed feedback control of chaos through linear invertible transform
Authors: Zhang Xiao-Ming  , Peng Jian-Hua  , Zhang Ru-Yuan  ,   (1)东北师范大学数学系，长春  130024; (2)深圳大学理学院，深圳  518060;东北师范大学物理系，长春  130024
Published: December 2020

A scheme,which can be used to effectively improve the quality of time-delayed feedback control of chaos,was proposed based on linear invertible transform.Through transforming parts of state variables of the system in the corresponding sub-space,we can successfully control chaos by a single time-delayed feedback signal instead of multi-signals in the original system before the transformation.Therefore,the conditions for stabilizing the system can be found theoretically.The numerical simulation results show that this chaos control method is commendably effective and feasible.
Theoretical study of graded-index coatings prepared by glancing angle deposition
Authors: Shen Zi-Cai  , Shao Jian-Da  , Wang Ying-Jian  , Fan Zheng-Xiu  ,   (1)中国科学院上海光学精密机械研究所,上海  201800; (2)中国科学院上海光学精密机械研究所,上海  201800;中国科学院研究生院,北京  100039
Published: December 2020

Relationship between refractive index and packing density of coatings prepared by glancing angle deposition is analyzed and three expressions are given firstly. And then optical characteristics of the graded-index coating, which is deposi ted as the linear changing of packing density, are discussed from some aspects a s positive or negative change,integral periods or have hale period,different per iods etc, and more over, the influences of different refractive-index theories on the optical characteristics are compared. Finelly, the preparation method,ap plications and some problem in preparation of the graded coating are discussed s eparately.
The geometrical structure of B2H6 molecule
Authors: Yan Shi-Ying  , Ma Mei-Zhong  , Zhu Zheng-He  ,   (1)四川大学原子分子物理所,成都  610065; (2)四川大学原子分子物理所,成都  610065;青岛大学理工学院物理系,青岛  266071; (3)四川大学原子分子物理所,成都  610065;烟台师范学院物理系,烟台  264025
Published: December 2020

The possible geometrical configuration of B2H6 molecule of D3d,D3h，D2d and planar or stereo D2h have long been argued about.In this work different methods of B3P86,BP86,B3LYP,BLYP,UHF,HF and LSDA in Gaussian 98 program have been used to optimize the structure of B2H 6.Our result shwos that the ground state geometrical configuration for B2H6 molecules is stereo D2h,i.e.,the three-center two bridge hydrogen structure,in wh ich two boron and four hydrogen atoms lie in a plane while the other two bridge hydrogen atoms lie in a plane perpendicular to it.This three-center two bridge hydrogen structure is more stable than two-center two-electron bond structure.
Spectral time evolution of quasistate modes in two-dimensional random media
Authors: Liu Jin-Song  , Liu Hai  , Wang Chun  ,   华中科技大学激光技术国家重点实验室,武汉  430074
Published: December 2020

The spectral time evolution of optical modes in planar random media is analyzed by using the finite difference time domain method to numerically solve Maxwell equations. The character of random media can be described by some factors, including the random constitution of scattering particles, medium parameters (such as the surface-filling fraction and the size of particle), and the shape of me dium. Such factors determine the frequency property and number of optical modes in random medium under quasi-stable state. However, the media with different f actors have approximately the same character and rate for the generation, sele ction and evolution of optical modes. Such cold cavity properties of planar rand om media are similar to that in conventional optical cavities.
Investigation of the precision of curved surface fitting in the measurement of near-cylindrical surfaces’ mid-wavelength deformations
Authors: Xie Ben-Chao  , Lu Zhen-Wu  , Li Feng-You  ,   (1)中国科学院长春光学精密机械与物理研究所，应用光学国家重点实验室，长春  130 033; (2)中国科学院长春光学精密机械与物理研究所，应用光学国家重点实验室，长春  130 033;中国科学院研究生院，北京  100039
Published: December 2020

The application of curved surface fitting for the disposal of the wavefront aberrations got in the measurement of certain paraboloid and hyperboloid is studied. It is found that,for mid-wavelength deformations with an amplitude of 01λ, results can be obtained with RMS error smaller than 0015λ and 0013λ separately. The existence of a special fitting order which leads to the smallest RMS e rror is affirmed. To find out the special fitting order,we work out two methods which help us get the order's value successfully.
The propagation properties of the elliptic Gaussian beam in strongly nonlocal nonlinear media
Authors: Wang Xing-Hua  , Guo Qi  ,   (1)华南师范大学传输光学实验室,广州  510631; (2)华南师范大学传输光学实验室,广州  510631;赣南师范学院物理与电子信息科学系,赣州  341000
Published: December 2020

In this paper,the propagation properties of a paraxial elliptic Gaussian beam in strongly nonlocal nonlinear media are discussed.We obtain a set of evolution equations for the param eters of the elliptic Gaussian beam,and also their exact analytical solutions.When the beam propagates in the media,the beam widths in the two trasverse directions oscillate generally along a propagation direction.What ever an intial power is,the elliptic Gaussian beam will evolve into the circular ly symmetrical Gaussian beam,then evolve back to the elliptic Gaussian beam agai n,but with the change of its major axis into the minor axis.This process is peri odic.For a certern initial power,the beam width in one trasverse direction can k eep constant,which is an optical soliton state,while the width in the other tran sverse direction vibrates.
Low-frequency electromagnetic instabilities in a collisionless current sheet:magnetohydrodynamic model
Authors: Wei Xin-Hua  , Zhou Guo-Cheng  , Cao Jin-Bin  , Li Liu-Yuan  ,   (1)中国科学院空间科学与应用研究中心，北京  100080; (2)中国科学院空间科学与应用研究中心，北京  100080;中国科学院研究生院，北京  100039
Published: December 2020

Low-frequency electromagnetic instabilities in a collisionless current sheet are discussed by using the 3-dimensional,collisionless and compressible magnetohydrodynamic model with the isotropic pressure.The linear dispersion relations are numerically solved at the middle plane (z=0) and edges (z=1) of the current sheet for modes of 2-and 3-dimensional propagation.The main results are as follows.(1) For 2-dimensional disturbed propagation (kz=0),at the middl e plane (z=0),the growth rate of Alfven waves is maximum,and the frequency and the wavenumber region of unstable waves are widest.The farther the distance from the middle plane,the smaller the growth rate and the wavenumber region.As the ion-inertial length becomes longer,the growth rate of Alfven waves becomes larger.(2)For 3-dimensional disturbed propagation (kz≠0),whistler waves are unstable.At the current sheet middle plane,whistler waves have an obvious growth rate.Outside the ion-inertial region,the growth rate of whistler waves becomes larger.(3)At the middle plane (z=0),low-frequency waves are mainly excited by the current-driven instabilities.At places far from the middle plane,the gradient instabilities of the current,density and pressure become more important.