bluuebunny/crossref_metadata_2025 huggingface dataset:
Museos memoriales, museos diferentes: buscando claves para su conservación
Authors: Galán-Pérez Ana , Vieira Eduarda
Published: December 2020

El presente ensayo parte de la reflexión sobre los museos memoriales como museos diferentes que custodian un tipo de objetos sensibles por su origen y heterogéneos en cuanto a sus valores (tangibles e intangibles), materialidad y significancia, que requieren una nueva perspectiva por parte de los profesionales de la conservación del patrimonio. A lo largo del artículo abordaremos varias cuestiones para identificar y comprender mejor los fines y las fórmulas que adoptan estos museos: cómo es la institución, cuál es el peso del lugar patrimonial donde se ubican y cómo se construye la significancia de las colecciones. Para ello nuestro punto de partida será el marco de construcción de la nueva definición de museos del ICOM, International Council of Museums, y la carta de Museos memoriales de ICMEMO, el Comité Internacional para Museos en Memoria de las Víctimas de Crímenes Públicos.
El Instante Fundación. Un proyecto artístico conceptual y multidisciplinar
Authors: Arroyo Fernández María Dolores
Published: December 2020

El Instante Fundación nació hace cuatro años en el barrio de Palos de Moguer de Madrid con el objetivo de añadir un nuevo espacio de encuentro cultural, expositivo y multidisciplinar. El proyecto está en consonancia con una línea de actuaciones urbano-arquitectónicas y propuestas integrales, que tiene como prioridad dar nuevo sentido a obsoletos edificios y aprovechar así su potencial como espacios expositivos para los nuevos contenidos. Este hecho contribuye a la regeneración urbana y redunda en beneficio de los entes sociales al dotarles de puntos de encuentro que integran diversas disciplinas desde el arte, música, ciencia y conferencias, talleres, estancias. Una programación cultural múltiple, ofrecida en sus contenidos como imagen de lo breve, el presente, de ahí su nombre de marca, y en un espacio diáfano que se distancia de las recargadas salas de exposición más convencionales.
Missing the (Data) Point? Analysis, Advocacy and Accountability in the Monitoring of Attacks on Healthcare in Syria
Authors: Roborgh Sophie
Published: December 2020

Monitoring of attacks on healthcare has made great strides in the past decade,
even if improvement in information has not necessarily resulted in changes on
the ground. However, important questions on the knowledge production process
continue to be under-explored, including those pertaining to the objectives of
monitoring efforts. What does our data actually tell us? Are we missing the
(data) point? This paper explores several monitoring mechanisms, and analyses
the limitations of the data-gathering exercise, affecting the ability of
healthcare workers to share their experiences. By drawing on the experiences of
those involved in the medical-humanitarian response in non-government controlled
areas in Syria, these dynamics are further brought to the fore, advocating for a
more discerning approach in the use of data for such disparate goals as analysis
on patterns of attacks (and their implications), advocacy, and
accountability.
Heavy quarkonium mass spectra in a relativistic quark model
Authors: Chen Hong  , Mei Hua  , Shen Peng-Nian  , Jiang Huan-Qing  ,   (1)西南师范大学物理学院，重庆400715; (2)中国科学院高能物理研究所,北京100039
Published: December 2020

The mass spectra of heavy quarkonia are calculated with the relativistic quark model.The effective interaction between a quark and an antiquark of the same flavor is assumed to be the sum of the one_gluon exchange with the inclusion of annihilation terms and the mixture of scalar and vector linear confining potentials with the relativisic corrections.The effects of the annihilation and the relativistic correction terms on the hyperfine splittings of quarkonium states are discussed in detail,and a good fit to the observed experimental data is obtained on the mass spectra.
Theoretical and experimental studies on large-ratio stretching of femtosecond pulse with ?ffner triplet stretcher
Authors: Tian Jin-Rong  , Sun Jing-Hua  , Wei Zhi-Yi  , Wang Zhao-Hua  , Ling Wei-Jun  , Huang Xiao-Jun  , Liu Lan-Ting  , Wei Xiao-Feng  , Zhang Jie  ,   (1)中国工程物理研究院激光聚变中心，绵阳  621900; (2)中国科学院物理研究所光物理开放实验室，北京  100080
Published: December 2020

The dispersive character of ?ffner stretcher was studied, and a concise expression of output pulse duration was presented. An ?ffner stretcher was setup experimentally, which could stretch a 19fs seed pulse to 605 ps after 4 passes in it free of aberration.
Theoretical study of polarization mode dispersion emulators
Authors: Zeng Li  , Lou Cai-Yun  , Zhang En-Yao  ,   (1)清华大学电子工程系,北京100084; (2)清华大学精密仪器与机械学系，精密测试技术与仪器国家重点实验室，北京100084
Published: December 2020

The performances of the three polarization mode dispersion (PMD) emulators commonly used today are analyzed and compared among them through numerical simulation of their differential group delay (DGD) statistical characteristics and PMD vector autocorrelation function. The results demonstrate that to produce DGD that can match theoretical distribution, one DGD generator is adequate, while at least 15 sections are necessary in the emulator built by polarization maintaining fibers and rotatable connectors. And the autocorrelation function of the emulator based on polarization maintaining fibers depends on DGD of every section, while that of the emulator based on DGD generators is smooth and can be regarded as constant outside the central frequency range.
Acoustic diagnostics of plasma channels in air induced by intense femtosecond laser pulses
Authors: Hao Zuo-Qiang  , Yu Jin  , Zhang Jie  , Yuan Xiao-Hui  , Zheng Zhi-Yuan  , Yang Hui  , Wang Zhao-Hua  , Ling Wei-Jun  , Wei Zhi-Yi  ,   (1)Laboratoire de Spectrométrie Ionique et Moléculaire，UMR CNRS 5579，Université Claude Bernard_Lyon 1,43,Bd. du 11 Novembre 1918，F_69622 Villeurbanne Cedex，France; (2)中国科学院物理研究所光物理开放实验室，北京  100080; (3)中国科学院物理研究所光物理开放实验室，北京  100080;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
Published: December 2020

Long plasma channels can be formed when intense femtosecond laser pulses propagate in air. In contrast to other conventional diagnostic techniques, the acoustic method to probe the plasma channel has its advantages. By measuring the sound signals along the channel, the channel length and the distribution of electron density along it can be retrieved easily.
Study on the microstructure and properties of (Ti, Al)N film deposited by pulsed high energy density plasma
Authors: Liu Yuan-Fu  , Han Jian-Min  , Zhang Gu-Ling  , Wang Jiu-Li  , Chen Guang-Liang  , Li Xue-Ming  , Feng Wen-Ran  , Fan Song-Hua  , Liu Chi-Zi  , Yang Si-Ze  ,   (1)北京交通大学机械与电子控制工程学院，北京  100044; (2)北京交通大学机械与电子控制工程学院，北京  100044;中国科学院物理研究所，北京  100080; (3)北京科技大学材料科学与工程学院，北京  100083; (4)中国科学院物理研究所，北京  100080
Published: December 2020

Hard and corrosion resistance (Ti, Al)N film was deposited by pulsed high energy density plasma on the substrate of 045% C carbon steel at ambient temperature. The microstructure of the film has been investigated by SEM,XRD,XPS and AES. The nanohardness of the film was tested by nanoindentation tester. The corrosion resistance of the film was tested by potentiodynamic polarization in 05 mol /L H2SO4 aqueous solution. The results indicate that the film mainly composed of (Ti, Al)N and a small amount of AlN. The nanohardness of the film approaches 26 GPa. The corrosion resistance of the film is improved by about one order of magnitude, compared with 1Cr18Ni9Ti austenitic stainless steel.
Pairing symmetry with interband interaction
Authors: Cao Tian-De  , Xu Li-Na  ,   (1)复旦大学物理系，上海200433; (2)南京信息工程大学物理系，南京210044
Published: December 2020

We investigate the superconductivity of highTc oxides with the dp model. It is shown that the dp pairing can dominate the superconductivity. The pairing symmetry depends on the anisotropic dp interaction in CuO2 plane. The anisotropic dp interaction can lead to dwave or swave symmetry, but the repulsive interaction in the CuO2 plane cannot lead holes to being paired. The ‘preliminary pairing' may appear in a lightly doped regime. The critical temperature cannot be found for the pairing order parameter when the pairs are localized. The delocalization of holes and evolution of pairing symmetry with increasing doping are explained.
The effect of nitrogen-implantation on the field-emission properties of CVD diamond films
Authors: Li Jun-Jie  , Wu Han-Hua  , Long Bei-Yu  , Lü Xian-Yi  , Hu Chao-Quan  , Jin Zeng-Sun  ,   吉林大学超硬材料国家重点实验室，物理学院，长春130023
Published: December 2020

Nitrogen was implanted into the chemical vapor deposition(CVD) diamond films, and the electron fieldemission properties of the nitrogenated diamond films were investigated. Raman and xray photoelectron spectroscopy(XPS) measurement revealed that nitrogenimplantation damaged the structure of diamond film and promoted the formations of sp2 C—C and sp2 C—N bonding. By increasing the implantation dose， the threshold field of the emission of the diamond film could be lowered from 18V/μm to 4V/μm. The enhancement of field emission for nitrogenimplanted CVD diamond films was attributed to the increase of the fraction of sp2 C bonds and the formation of defect bands within the bulk diamond band gap induced by nitrogenimplantation, which could alter the work function and elevate the Feimi level. Consequently, the energy barrier on diamond surface for electron tunneling was reduced.
Circuit implementation for generating three-dimensional multi-scroll chaotic att ractors via triangular wave series
Authors: Yu Si-Min  ,   广东工业大学自动化学院，广州  510090
Published: December 2020

This paper proposes a new approach for generating three_dimensional (3_D) multi_scroll chaotic attractors via triangular wave series. The chaotic dynamic char acteristic of multi_scroll system constructed by triangular wave series is furth er investigated. The hardware experimental circuit is designed and the interrela ted circuit implementation is realized. A blocking circuit diagram, including in tegrator N11, triangular wave series generators N22, N33 and N44, switch linkage K, is designed for the hardware imp lementations. The triangular wave series developed here can adjust the swings, w idths, equilibrium points, breakpoints, and slopes so as to generate a large num ber of scrolls with adjustable sizes and shapes. Moreover, the number of scrolls can be controlled via switching of the switch linkage K. The experimental resul t demonstrates that this method can be a new approach for generating 3_D multi_s croll chaotic attractors with up to 21_scrolls in practical circuit by construct ing a family of triangular wave series with adjustable parameters.
Effect of nonuniform-defect split ring resonators on the left-handed metamater ials
Authors: Luo Chun-Rong  , Kang Lei  , Zhao Qian  , Fu Quan-Hong  , Song Juan  , Zhao Xiao-Peng  ,   西北工业大学电流变技术研究所,西安  710072
Published: December 2020

We have investigated the defect effect in three_dimensional (3_D) left_handed metamaterials, consisting of an array of repeated unit cells of copper wires and hexagon split ring resonators (SRRs) on strips of standard circuit board materi al. By measuring the X_band transmission through this metamaterial with differen t point_ and linear_defected SRRs, we find that the resonance frequency, its val ue and passband of transmission peaks, changes markedly. It is suggested that su ch tunable left_handed properties may arise from the symmetry breaking of SRRs i n the metamaterials.
Theoretical study of the Ti:sapphire laser with low pump threshold
Authors: Ling Wei-Jun  , Zheng Jia-An  , Jia Yu-Lei  , Wei Zhi-Yi  ,   中国科学院物理研究所,北京  100080
Published: December 2020

In this paper, a theoretical and numerical analysis of the factors that affect mode_locked pump threshold was made. The key effect of cavity mode in Kerr_lens mode_locking was illustrated. At the same time, a soliton model showed the rela tion between the pump threshold and dispersion in the cavity. Based on the gene ral analysis, a self_starting femtosecond Ti:sapphire laser with mode_locking th reshold as low as 390 mW was demonstrated.
Hydrothermal synthesis of iron pyrite (FeS22) crystalpowder and the rmal-kinetic study on crystal growth
Authors: Duan He  , Zheng Yu-Feng  , Zhang Xiao-Gang  , Sun Yan-Fei  , Dong You-Zhong  ,   (1)新疆大学化学化工学院,乌鲁木齐  830046; (2)新疆大学物理系,乌鲁木齐  830046
Published: December 2020

Single_phase iron pyrite (FeS22) crystalpowder was prepared by so l_gel hydrothermal method, which was characterized via x_ray diffraction, Fourier transform infrared and scanning electron microscope. A simplified mathematic model was established to analyze the crystal growth process. Results indicate that phase transformation and diffusion mechanism control the process, which fits the secon d_order kinetic equation with an exponent 3215 for time t. This is a decel erated process that can be divided into three steps: during the first period, ma rcasite and pyrite phases are produced, and then with inducting of sulfur into t he reaction, the process is dominated by the merging of marcasite into pyrite. U ltimately, with the fuse of small grains and the growing of larger ones, single_ phase iron pyrite crystals grow up through diffusion mechanism.
Investigation of the acceptor and donor in fast neutron irradiated Czochralski s ilicon
Authors: Li Yang-Xian  , Yang Shuai  , Chen Gui-Feng  , Ma Qiao-Yun  , Niu Ping-Ｊuan  , Chen Dong-Feng  , Li Hong-Tao  , Wang Bao-Yi  ,   (1)河北工业大学材料学院,天津  300130; (2)天津工业大学信息与通信学院，天津  300160; (3)中国科学院高能物理研究所，北京  100049; (4)中国原子能科学研究院，北京  102413
Published: December 2020

Variations of the irradiated defects, resistivity, carrier mobility ratio and ca rrier concentration in high-dose neutron-irradiated n-type Czochralski silico n have been investigated by means of Fourier transform infrared spectrometer, po sitron annihilation spectroscopy and Hall effect. After irradiated with fast neu tron, the sample transformed from n to p-type. Two types of acceptor centers th at contribute to the V22O22, V22O, VO22, V-O-V and V 44-type defects will appear after annealing at temperature of 450 a nd 600 ℃, respectively. After annealing at temperatures above 650℃, with the elimin ation of acceptors, the carrier mobility ratio and the carrier-type began to re cover and a type of donor related to the irradiated defects will appear. The eff ective annealing temperature is 750℃ at which the donor is formed, and anneal ing above 900℃ for 1h will eliminate the donor.
The study of static and stable gravitational fields by using the gravitational field theory including the energy-momentum tensor of the pure gravitational field part of matter
Authors: Lou Tai-Ping  ,   东北大学材料与冶金学院,沈阳  110004
Published: December 2020

In this paper, a general gravitational field theory containing the effect of cosmic constant and the energy_momentum tensor of the pure gravitational field part of matter is proposed. The equation of the grovitational field is Rμν -gμνR/2+λgμν=8πG(T(Ⅰ)μν+T(Ⅱ)μν )/c4， where λ is Einstein’s cosmic constant， Ｔ（Ⅰ） μν and Ｔ（Ⅱ）μν are energy_ momentum tensor of the p ure matter part and pure gravitational field part, respectively. Ｔ（Ⅱ） μν can be expressed by T(Ⅱ)μν=(DμρＤρ ν-gμνＤαβＤαβ/4)/4πG， where Ｄμν＝ωμ／xν-ων／xμ， and the vector is defined as: ωμ≡-c2gμ0/g00. The several static and stable gravit ational fields, such as the external static metric tensor of an isolated globula r symmetric pure matter which contain Einstein's cosmic constant or that with charge, the external stable metric tensor of a rotation isolated globular symm etric pure matter or that with charge, and the internal static gravitational equ ilibrium in a globular symmetric pure ideal fluid star matter are studied and di scussed respectively by the general gravitational field theory which contains the energy-momentum tensor of pure gravitational field part of matter.
Studies on the electronic structures, exchange coupling and magnetic moments of spin and orbital in the compound SmCo55
Authors: Zhang Chang-Wen  , Li Hua  , Dong Jian-Min  , Wang Yong-Juan  , Pan Feng-Chun  , Gu Yong-Quan  , Li  Wei  ,   (1)钢铁研究总院功能材料研究所,北京  100081; (2)山东大学物理与微电子学院,济南  250100
Published: December 2020

The electronic density of states, spin-splittings and atomic magnetic moment of RE-TM compound SmCo55 have been studied by spin-polarized MS-Xα method. The results show that a few of electrons are transferred to Sm(5d00) o rbital because of orbital hybridization between Sm and Co atoms in the compound. The exchange interactions between 3d and 5d electrons lead to the magnetic coupling betwee n Sm and Co, and therefore, result in the long-range ferromagnetic order inside the compound SmCo55 There are some negative exchange couplings occ urring at six levels, which make the Curie temperature of SmCo55 decrease disti nctly, com pared with pure Co. The spin moment and orbital moment of 2c and 3g site s have been also studied in this paper. We found that the spin moment, orbital m oment and its quenched part of Co(2c) are greater than that of Co(3g).Th erefore, the strength of L-S coupling of the former is a little greater tha n that of the latter, which implies the contribution to magneto-anisotropy of 2c site is greater than that of 3g site. But the unquenched orbital mome nt in 2c site is slightly smaller than that in 3g site. So, the differen ce of contribution to the anisotropy between the two Co-sites is not very disti nct. Considering the localization of 4f electrons and the few 5d electrons, the magnetic moment of Sm atom will be 129μBB in SmCo55, wh ich is in agreem ent with the experiments of Sm3+3+ ion-moment (132—163μBB) and the Sm atom-moment (174μBB) in metal.
The micromechanism of alloying element Zr affecting the ductility of Ni33Al alloy with different Al contents
Authors: Guo Jian-Ting  , Li Yu-Fang  , Xiong Liang-Yue  , Ye Heng-Qiang  ,   中国科学院金属研究所，沈阳  110016
Published: December 2020

Positron lifetime parameters have been measured by position annihilation technique in binary Ni7777Al2323 and Ni7474 Al2626 alloys with different Al contents and Ni33Al alloy doped with different amounts of Zr. The density o f free electrons in bulk materials and grain boundaries was calculated in this p aper. The results show that the density of free electrons in bulk materials and grain boundaries in Ni7474Al2626 alloy is lower t han that in Ni7777Al2323 alloy. The open volume in grain boundary is larger in Ni7474Al2626 alloy, and the cohesion of grain boundaries is weaker. When an amount of Zr atoms is added into the Ni33Al alloy, they increase the density of f ree electr ons in the bulk and thus increase the bonding cohesion in the bulk. The other Z r atoms will segregate at grain boundaries and increase their free electron dens ity; this will strengthen the bonding cohesion in grain boundaries. Alloying ele ment Zr is found to be beneficial to reduce the brittleness of Ni33Al alloy with different Al contents.
Preparation and properties of polycrystalline CdSxxTe1-x1-x thin films for solar cells
Authors: Li Wei  , Feng Liang-Huan  , Wu Li-Li  , Cai Ya-Ping  , Zhang Jing-Quan  , Zheng Jia-Gui  , Cai Wei  , Li Bing  , Lei Zhi  , Zhang Dong-Min  ,   四川大学材料科学与工程学院，成都  610064
Published: December 2020

The structural, optical and electrical properties of CdSxxTe1-x1-x thin films prepared by co_evaporation of powders of CdS and CdTe ha ve been studie d by x_ray diffraction, atomic force microscopy and optical transmittance spectr a measurements. Results show that the as_deposited CdSxxTe1-x1 -x thi n films are homogeneous, adherent and compact on the glass slides substrates wit hout pinhole and that their conductivity is n_type for x≥05 and p_type fo r xxTe1-x1-x thin f ilms are pol ycrystalline and show highly preferential orientation. The predominant direct op tical transitions were observed and the variation of the optical energy gap E gg is nonlinear with x. Given the values of lattice parameter and opt ical energy gap, the exact composition of the phase change at x=025 has been determined. The films are of a cubic phase for x025. After annealing there is no change in the structure of the films with a slight decrease in optical energy gap. Finally, a new structure of CdS/CdTe/Z nTe/ZnTe:Cu/Au solar cells with a CdSxxTe1-x1-x buffer l ayer has been proposed.
Effect of RF power on the structure and properties of diamond-like carbon films
Authors: Li Hong-Xuan  , Xu Tao  , Chen Jian-Min  , Zhou Hui-Di  , Liu Hui-Wen  ,   中国科学院兰州化学物理研究所固体润滑国家重点实验室,兰州  730000
Published: December 2020

Diamond-like carbon (DLC) films were deposited on Si substrates by a dual direct current and radio frequency plasma-enhanced chemical vapor deposition (DC-RF-PECVD) technique. The effect of RF power on the surface morphology, micros tructure, hardness and Young's modulus of DLC films was investigated by atomic f orce microscopy, Raman spectroscopy, x-ray photoelectron spectrometry, infrared spectroscopy and nano-indentation. The films produced by DC-RF-PECVD have typical hydrogenated diamond-like characteristics, and the surface of the film s was smooth and compact.With the increase of RF power the bonded hydrogen conte nt in the films decreased while the sp33 content, hardness and Youn g's modulus of the DLC films reached the maxima at an RF power of 100W and then they decr eased with further increase of the RF power.
Beating patterns in the oscillatory magnetoresistance of a Si modulation-doped AlGaN/GaN heterostructure
Authors: Yao Wei  , Qiu Zhi-Jun  , Gui Yong-Sheng  , Zheng Ze-Wei  , Lü Jie  , Tang Ning  , Shen Bo  , Chu Jun-Hao  ,   (1)南京大学物理系，南京  210093; (2)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

Magneto-transport measurements have been carried out on a Si modulation-doped Al 022Ga078N/GaN heterostructure in a temperature range between 1 5 and 25 K under magnetic field up to 10T. Striking beating patterns in magnetor esistance vs magnetic field are observed in the vicinity of a specific temperatu re. Theoretical simulation is performed and the comparison between numerical sim ulations and the experimental data reveals that the beating patterns are due to the interference of the magneto-intersubband scattering and the SdH oscillator o f first subband.
Investigations on the structural and optical properties of silicon nanoporous pillar array
Authors: Xu Hai-Jun  , Fu Xiao-Nan  , Sun Xin-Rui  , Li Xin-Jian  ,   郑州大学物理系，材料物理教育部重点实验室，郑州  450052
Published: December 2020

A novel silicon-based micron/nanometer structural composite system, silicon nanoporous pillar array(Si-NPA), was prepared on the substrate of single-crystal si licon (sc-Si) wafers by a hydrothermal etching method; and the studies on its mo rphological structural and optical properties were carried out. Structural exper iments disclose that Si-NPA could be well described by triple hierarchical struc tures: the array composed of micron-sized silicon pillars, the nanopores densely distributing on each pillar, and the silicon nanocrystallites constructing the walls of nanopores. Optical measurements prove that Si-NPA has good performances on light absorption and photoluminescence(PL). Based on the experimental data o f the integral reflectance spectrum, the structural and optical parameters such as complex refractive index, complex dielectric constant and absorption coeffici ent of Si-NPA are calculated by adopting Kramers-Kronig transformation; based on which, the origin of the notable difference between the optical properties of S i-NPA and sc-Si is discussed. Through analyzing the function relation between th e absorption coefficient of Si-NPA and the photon energy of incident light, the characteristic of the electronic structure of Si-NPA is proved to be that of a d irect-band-gap semiconductor, and the calculated bandgaps agree well with the PL peak energies given by experiments.
Temperature in an arbitrary rectilinearly accelerating spacetime
Authors: Zhang Jing-Yi  ,   北京师范大学物理系,北京  100875
Published: December 2020

The event horizon equation is given.Using Damour_Ruffini method improved by Zhao Zheng, the formula of temperature is obtained, which supports the result by Zhao Z (Acta Phys. Sin. 1990 39 1845) (in Chinese).
Solution of the Kirchhoff equation for thin elastic rod under bending by constraint violation correction method
Authors: Huang Lei  , Bao Guang-Wei  , Liu Yan-Zhu  ,   上海交通大学工程力学系，上海  200240
Published: December 2020

To further study the mechanical property of a thin elastic rod, this paper will employ the Kichhoff equation which takes the form of Euler quaternion and study the topological configuration of the rod under compression. Adding the constraint condition to the differential equation, we can get a differential-algebraic equation(DAE).In order to be solved easily, DAE will be transformed into a c riterion form. To satisfy the boundary condition, we apply the shooting techniq ue to get the solution satisfying the boundary condition, and imitate the proced ure of pulling and pressing of thin elastic rod suffering a force. Simultaneousl y,to deal with the constraint stabilization phenomenon which is caused by errors , and according to the Euler quaternion character, we select a proper correction coefficient to keep the stability of the differential equation.
An asymptotic analysis for the stochastic dynamics model on ENSO event
Authors: Han Xiang-Lin  ,   湖州师范学院理学院，湖州  313000
Published: December 2020

Using the boundary layer function, we study the stochastic dynamics model on ENS O event. The n-order asymptotic expansion of solution for the original probl em is obtained. By appling the result to a special ENSO event, the zero-order a symptotic expansion is obtained. A theoretical basis for analyzing the behavior of ENSO event is presented.
Computation of Gaussian beam scattering for larger particle
Authors: Wu Peng  , Han Yi-Ping  , Liu De-Fang  ,   (1)西安电子科技大学理学院 应用物理系, 西安  710071; (2)西北大学物理系,西安  710069
Published: December 2020

By using a generalized Lorenz_Mie theory, the scattering field of spheres under Gaussian beams and plane_wave illumination is computed. The code is written with Matlab, and computational methods are improved. Computations for scattered fiel d in our code are extended to fairly large size parameters, up to 80000 The l ight scattering properties of absorbing and nonabsorbing homogeneous spherical p articles, coated spheres are investigated.
Comparison of Lorentz pulsed beams obtained by using complex amplitude envelope representation and complex analytic signal representation
Authors: Peng Run-Wu  , Fan Dian-Yuan  ,   中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

By using complex amplitude envelope representation and complex analytic signal r epresentation, propagation expressions of Lorentz pulsed beams are derived. Prop agation properties of them with different bandwidths are illustrated by numerica l calculations. It is found that they are the same in the neighbourhood of z _axis for narrowband pulses, but in the case of broadband pulses, singularities emerge near z_axis for pulsed beams obtained by using complex amplitude enve lope representation and only complex analytic signal representation is applicabl e. The conditions to decide what representation should be chosen to study pulsed beams are given. And the origin that results in the emergence of singularity is given.
Compensation of gain narrowing by using AOPDF in high-power ultra-short pulse laser systems
Authors: Liu Lan-Qin  , Peng Han-Sheng  , Wei Xiao-Feng  , Zhu Qi-Hua  , Huang Xiao-Jun  , Wang Xiao-Dong  , Zhou Kai-Nan  , Zeng Xiao-Ming  , Wang Xiao  , Guo Yi  , Yuan Xiao-Dong  , Peng Zhi-Tao  , Tang Xiao-Dong  ,   (1)中国工程物理研究院 激光聚变研究中心,绵阳  621900; (2)中国工程物理研究院 激光聚变研究中心,绵阳  621900;中国工程物理研究院研究生部,绵阳  621900
Published: December 2020

Laser pulse durations are dominated by the spectral bandwidths in chirped pulse amplification systems.Therefore,gain narrowing during amplification is one of the most important factors that limits the minimal pulse durations of compressed pulses in high_power ultrashort_pulse laser systems.The gain narrowing can be compensated by applying an acousto_optic programmable dispersive filter(AOPDF) to the laser system.Here we present the experiments and results with an AOPDF for the 200_TW Ti:sapphire laser.The spectral bandwidth is increased from the original 27?nm to 44?nm.The pulse duration correspondingly is decreased from 60?fs to 30?fs and thus the output pulse power is doubled.
Experimental study of fullerene-PVP polymers by small-angle neutron scattering
Authors: Chen Bo  , Xia Qing-Zhong  , Lebedev V. T.  ,   (1)俄罗斯科学院圣彼得堡核物理研究所，卡特金娜  188300，俄罗斯; (2)中国工程物理研究院核物理与化学研究所，绵阳  621900,中国
Published: December 2020

Small_angle neutron scattering technique is employed to investigate the structure of fullerene-PVP polymers and the variation of their size with fullerene content. The results indicate that the relative lengths of both mono-molecule and mac romolecule chains in solution with fullerene are shorter than those in pure PVP solution, and the volumes of fullerene-PVP polymers in solution with high fullerene content become much smaller.
Effects of oxygen adsorption on the electronic structure and optical properties of single-wall carbon nanotubes
Authors: Liang Jun-Wu  , Hu Hui-Fang  , Wei Jian-Wei  , Peng Ping  ,   (1)湖南大学材料科学与工程学院，长沙  410082; (2)湖南大学应用物理系，长沙  410082
Published: December 2020

The binding energy,energy band structure and optical properties of the oxygen physical adsorption on semiconducting single_wall carbon nanotube are studied by the density functional theory. The most stable adsorption site is the one in which the oxygen molecule lies above the center of the carbon ring. It is showed th at the oxygen physical adsorption strongly affects the transport properties and the optical absorption spectra of carbon nanotubes. And the phenomenon of oxygen photoinduced desorption has been explained theoretically.
Method for fabricating Fe3O4 nanoparticles using H2O2 and its comparison with coprecipitation method
Authors: Li Fa-Shen  , Wang Tao  , Wang Ying  ,   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

Fe3Ｏ4 nanoparticles were successfully synthesized from an aqueous Fe (OH)2 colloid under nearly neutral condition by oxidizing it with H2Ｏ2. The m orphology, structure, and magnetic properties were characterized and measured by transmission electron microscopy (TEM), x-ray diffraction (XRD), vibrating sam ple magnetometer, and superconducting quantum interference devices (SQUID). The TEM image shows that the sample consists of well-dispersed spherical particles with diameter about 18nm, and has a cubic spinel structure according to XRD. The mssbauer spectrum at room temperature is fitted using two sextet spectrum cor responding to Fe ions at A site and B site, and the results show that th e hyperfine field of the sample is a little smaller than that of bulk value, and crystalline defects exist in the sample. The saturation magnetization of the sa mple fabricated by using H2Ｏ2 is 67×10-3A·m 2/g, and the Ver wey transition was observed at 20K, but the magnetization of the sample fabricat ed by coprecipitation is only 46×10-3A·m2/g when the app lied field is 1 Tesla, and the Verwey transition was not observed in our temperature range of measurement. In addition, the superparamagnetic blocking temperature of the s ample fabricated by coprecipitation was observed at 178K.
Zr-N films prepared by MW-ECR PE-UNB alanced magnetron sputtering: plasma diagnostics and structure evolution
Authors: Zhang Zhi-Guo  , Liu Tian-Wei  , Xu Jun  , Deng Xin-Lu  , Dong Chuang  ,   大连理工大学三束材料改性国家重点实验室，大连  116024
Published: December 2020

ZrN films were prepared using microwave electron cyclotron resonance (MW-ECR) plasma enhanced unbalanced magnetron sputtering (PE-UMS) technique. The plasma characteristics near the holder were diagnosed by Langmuir probe for various depo sition conditions and the films obtained were characterized by electron probe mi croanalysis x-ray diffraction and micro-hardness. As the N2 flow rate increas es from 2 to 20sccm, the ion density initially increases from 807×109 to 8 31×109cm-3 and then decreases to 752×109c m-3, while the N +2 ion density increases monotonically from 312×10 -8 to 335×109cm-3 and the electron temperature does not va ry much. The N concentration in t he films increases and the grain size decreases as the N+2 ion density increases. And the films become more and more amorphous as the N/Zr ratio is above 1 4 The corresponding microhardness of the deposited films increases from 22 5GPa to the maximum of 2678GPa, and then decreases linearly to 1982GPa as th e N2 flow rate increases from 8 to 14sccm. The mechanism of the influ ence of t he plasma characteristics on the microstructure and mechanical properties of the deposited films were discussed.
Study on the electrical characteristic of different modes of dielectric barrier discharge in argon
Authors: Dong Li-Fang  , Mao Zhi-Guo  , Ran Jun-Xia  ,   河北大学物理科学与技术学院，保定  071002
Published: December 2020

Three modes of discharges, including diffuse, streamer, and patterned discharges , are achieved in dielectric barrier discharge in argon at 40 kPa gas pressure b y using a dielectric barrier discharge device with water electrodes. The electri cal and optical characteristics of the discharges are investigated. The voltage drop across discharge gap is obtained by measuring the voltage drop across the t est capacitor. Results show that the moment of discharge initiation is shifted e arlier and duty ratio of the discharge increases as the applied voltage increase s. At the moment of discharge initiation, the voltage drop across the discharge gap decreases and the transported charges abruptly increase. So the waveforms of the voltage drop across the discharge gap and the transported charges deviate from sinusoidal. The relationship between the voltage drops across the discharg e gap and the transported charges is nonlinear. Also the relationship between th e voltage drops across the discharge gap corresponding to zero applied voltage a nd the applied voltage is given. The function of wall charges and the influence of them on the voltage drops across the discharge gap and the transported charge s are discussed.
Vertically aligned carbon nanotubes grown on Au/Ni films and the role of Au in the grown process
Authors: Chen Shu-Xia  , Gu Chang-Zhi  , Wang Bi-Ben  , Li Hai-Jun  , Li Jun-Jie  , Lü Xian-Yi  , Jin Zeng-Sun  ,   (1)北京工业大学应用数理学院，北京  100022; (2)吉林大学超硬材料国家重点实验室，长春  130012; (3)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
Published: December 2020

The vertically aligned carbon nanotubes( CNTs) were synthesized on Au/Ni catalyst films by plasma enhanced hot filament chemical vapor deposition( PE-HFCVD) me thod at 96% concentration of hydrogen. The growing process of CNTs on Au/Ni film was discussed. The realization of the vertically aligned CNTs grown at high hyd rogen concentration can be attributed to the adoption of the Au/Ni catalyst film s. The element Au promoted the diffusion of the carbon and improved the activity of carbon in catalyst. By comparing with the use of only Ni as catalyst, the Au in Au/Ni catalyst film can increase the carbon absorption, so carbon could be e asily saturated in the catalyst and the vertically aligned CNTs were achieved at a high hydrogen concentration.
Computer simulation of a-Si:H/μc-Si:H diphasic silicon solar cells
Authors: Hao Hui-Ying  , Kong Guang-Lin  , Zeng Xiang-Bo  , Xu Ying  , Diao Hong-Wei  , Liao Xian-Bo  ,   (1)中国科学院半导体研究所凝聚态物理中心，表面物理国家重点实验室，北京  10008 3; (2)中国科学院半导体研究所凝聚态物理中心，表面物理国家重点实验室，北京  10008 3;中国地质大学（北京）材料科学与工程学院，北京  100083
Published: December 2020

Based on our experimental research on diphasic silicon films, the parameters suc h as absorption coefficient, mobility life- time product and bandgap were estima ted by means of effective-medium theory. And then computer simulation of a-Si:H/ μc-Si:H diphasic thin film solar cells was performed. It was shown that the mor e crystalline fraction in the diphasic silicon films, the higher short circuit d ensity, the lower open-circuit voltage and the lower efficiency. From the spectr al response, we can see that the response in long wave region was improved signi ficantly with increasing crystalline fraction in the silicon films. Taking Lamb ertian back refraction into account, the diphasic silicon films with 40%—50% cr ystalline fraction was considered to be the best intrinsic layer for the bottom solar cell in micromorph tandem.
The oxygen in- and out-diffusion behavior in melt-textured YBCO measured by thermogravimetry
Authors: Zhang Yu-Long  , Yao Xin  , Zhang Hong  , Jin Yan-Ping  ,   (1)上海交通大学金属基复合材料国家重点实验室，上海  200030; (2)上海交通大学物理系，上海  200030; (3)上海交通大学物理系，上海  200030;上海交通大学金属基复合材料国家重点实验室，上海  200030; (4)中国科学院上海微系统与信息技术研究所，上海  200050
Published: December 2020

The chemical oxygen in- and out-diffusion in melt-textured YBa2Cu 3O7-δ（YBCO）is investigated by thermogravimetry. The weight relaxations resulting from the sudden change of temperature at a fixed oxygen partial pressure of 033×１０5Pa are recorded. By fitting the isothermal curves, the chemical diffusion coefficients at 375—600℃ are determined. It is found that the resultant numerical values for melt-textured YBCO are larger than that of crushed single crystal YBCO obtained in our previous study by about 50%, whereas all of them are of the order of 10-10cm2s-1 . The activation energies for both samples are estimated as ～1eV. It is believed that those values represent the nature of the lattice diffusion. The oxygen diffusion in me lt-textured-grown-YBCO is attributed to the YBCO matrix and the micro-cracks are responsible for the huge diffusion coefficients. Moreover, the same kinetics o f in- and out-diffusion is confirmed to be intrinsic, and it suggests that the d ifferent in- and out-diffusion coefficients measured in other works are controll ed by the large concentration gradient and the shell effect.
Influence of concentration of Er3+ ions on luminescence and fluorescence lifetime in TeO2-ZnO-Na2O-K2O glasses
Authors: Chen Bing-Yan  , Liu Yue-Hui  , Chen Dong-Dan  , Jiang Zhong-Hong  ,   (1)华南理工大学光通信材料研究所，广州  510640;特种功能材料及其制备新技术教育部重点实验室(华南理工大学)，广州  510640; (2)华南理工大学光通信材料研究所，广州  510640;特种功能材料及其制备新技术教育部重点实验室(华南理工大学)，广州  510640;中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

Absorption spectra, emission spectra and fluorescence lifetime of Er3+ions were measured for TeO2-ZnO-Na2O-K2O glasses w ith different doping concentrations of Er3+ and the emission cross section σe of Er3+ was calculated. Dependence of luminescence intensity and fluorescence lifetime on concentration of Er3+ were analyzed. The influence of concentratio n of Er3+ ions on luminescence intensity and fluorescence lifetime was unc onspi cuous in the case of low doping level of Er3+. However, high concentr ation of Er3+ ions resulted in the concentration quenching, which reduced the l uminescence intensity and fluorescence lifetime. The optimum concentration of Er3+ ions was determined for TeO2-ZnO-Na2O-K 2O glasses, and the mechanism of concentration quenching was also discussed and explained in detail.
Photon absorption of conduction band electronsand impact ionization under irradiation of few-cycle ultrashort laser pulses
Authors: Wang Xiao-Feng  , Jia Tian-Qing  , Xu Zhi-Zhan  ,   中国科学院上海光学精密机械研究所，强场激光物理国家重点实验室，上海  201800;中国科学院研究生院，北京  100039
Published: December 2020

We discuss the limitation of classical Drude Model, solve the kinematics equation for electrons in the few-cycle laser field, and calculate the photon absorpti on of conduction-band electrons(CBE) and impact ionization under irradiation of few-cycle ultrashort laser pulses. The effects of laser intensity, carrier-en velope-phase on impact ionization are discussed.
Control of the preferred orientation in electrodeposited single-crystal Fe nanowires
Authors: Hu Hai-Ning  , Chen Jing-Lan  , Wu Guang-Heng  ,   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
Published: December 2020

Three different_structured Fe nanowires, including preferred orientations of [110],[200] and morphology nanowires,were electrodeposited by a method of changing the pH value of the aqueous bath.And the [200]_preferred Fe nanowire was reported for the first time so far as we know.Magnetic properties of the three kinds of nanowires were measured by superconducting quantum interference devics(SQ UID) magnetometer.Compared with the [110] preferred nanowire array,the [200] preferred one has a high aspect ratio with improved anisotropy and coercivity.It is first time that the magnetization of Fe nanowire arrays with the crystal anis otropy and shape anisotropy in the same direction has been reported.
The piezoelectricity of heat-expanded PP cellular electret
Authors: Qiu Xun-Lin  , Xia Zhong-Fu  , An Zhen-Lian  , Wu Xian-Yong  ,   同济大学波耳固体物理研究所，上海  200092
Published: December 2020

The piezoelectricity of commercially available PP cellular (EUH75 and SHD50) has been studied. Their piezoelectric d33 coefficients up to 219 pC/N and 196 pC/N were achieved after heat expansion, which are about two orders of magn itude larger than the corresponding coefficients of the samples without heat exp ansion and over one order of magnitude larger than that of the well_known ferroe lectric polymer PVDF. Definitely different influence of corona charging with high voltage up to 60kV in dielectric gas SF6 on the piezoelectric d33 coefficient for EUH75 and SHD50 samples was observed. The structural origin o f this phenomenon was discussed.
Eavesdropping on practical QKD system based on six-state protocol
Authors: Liu Jing-Feng  , Tang Zhi-Lie  , Liang Rui-Sheng  , Li Ling-Yan  , Wei Zheng-Jun  , Chen Zhi-Xin  , Liao Chang-Jun  , Liu Song-Hao  ,   (1)华南师范大学物理与电信工程学院，广州  510631; (2)华南师范大学信息光电子科技学院，广州  510631
Published: December 2020

Based on practical implementations of quantum cryptography with the attenuated laser pulses as the signal source rather than single photon, as well as lossy channels, detection efficiency, dark count of singlephoton counter, and technological possibilities of a realistic eavesdropping, we discuss a combining eavesdropping strategy of Breidbart basis and beamsplitting, and give a bound on maximum disturbance for a given mean photon number and transmission length for which a secret key can be distilled.
Effect of interchain coupling on the inversed polarization of a biexciton in conjugated polymers
Authors: Gao Kun  , Fu Ji-Yong  , Liu De-Sheng  , Xie Shi-Jie  ,   山东大学物理与微电子学院晶体材料国家重点实验室,济南  250100
Published: December 2020

Effect of interchain coupling on the inversed polarization of a biexciton has been studied in the framework of a tightbinding approximation. It was found that a biexciton state is mainly confined in one chain even the interchain coupling is included. The inversed polarization will be enhanced remarkably with the interchain coupling in the case of a weak nondegenerate confinement. However, the inversed polarization will keep nearly unchanged for a strong nondegenerate confinement.
Study on Brillouin amplification in different liquid media
Authors: Hasi Wu-Li-Ji  , Lü Zhi-Wei  , He Wei-Ming  , Wang Shuang-Yi  ,   (1)哈尔滨工业大学光电子技术研究所,哈尔滨  150001; (2)哈尔滨工业大学光电子技术研究所,哈尔滨  150001;内蒙古民族大学化学学院,通辽  028043
Published: December 2020

The two_cell stimulated Brillouin scattering (SBS) system that uses different media in generator and amplifier cells is investigated. It is demonstrated that th e seed light still has enough amplification when the Brillouin frequency shifts of this two media are near and their Brillouin line_widths are crossed. In exper iment, when CCl4 is used as an amplifying medium and liquid mixture of CCl4/ CS2 as generating medium, and the two_cell SBS system is pumped by Nd:YAG Qs witched laser, the influence of the deviation of Brillouin frequency shift on seed light Brillouin amplification is studied. The result shows that amplification efficiency and pulse compression ratio are still large enough when Brillouin frequency deviation is small. Moreover, under the condition of CS2 as the amplifying medium and benzene as the generating medium, seed light amplification efficiency of 44, pulse compression ratio of 72, phase_conjugation fidelity of 98%, and stability of seed light amplification efficiency of <3% are obtaine d.
Local potential energy surface and vibration analysis for the S2O molecule
Authors: Han Hui-Xian  , Peng Qian  , Wen Zhen-Yi  , Wang Yu-Bin  ,   (1)西北大学化学系, 西安  710069; (2)西北大学现代物理研究所, 西安  710069; (3)西北大学现代物理研究所, 西安  710069;西北大学化学系, 西安  710069
Published: December 2020

Analytic local potential energy surfaces for S2O in the ground state and the excited states were calculated at MRCISD and MRPT2 levels. Further, the data points selected were fitted to a polynomial force field and the calculations for the interaction of vibration configuration were carried out. Then, the analyses of normal vibration modes and vibration energy levels were performed. The local potential energy surfaces were improved by adjusting a few force constants. The mean-square roots of the deviation between computed and available experimental vibration spectra for the ground state and the excited state are 3852cm-1 and 644cm-1, respectively.
The non-Newtonian fluid mathematical model for strata static temperature forecast
Authors: Guo Yong-Cun  , Zeng Yi-Shan  , Lu De-Tang  ,   (1)合肥工业大学机械与汽车工程学院，合肥  230009; (2)中国科学技术大学力学和机械系，合肥  230026; (3)中国科学技术大学力学和机械系，合肥  230026;安徽理工大学机械系，淮南  232001
Published: December 2020

Firstly,we choose a strata temperature gradient and start to compute.According to thermodynamic parameters,mud fluid parameters and well casing structure parameters etc.,the exit temperature of mud fluid can be obtained.By comparing the calculated value with the measured value of the exit temperature,we correct the chosen strata temperature gradient.Sequentially,we do above_mentioned works repeatedly until a proper strata temperature gradient is gained.Based on this,derived from the equations of thermodynamics and fluid mechanics,we can obtain the temperature variation along the depth of sidewall,and the mathematical model of distribution of strata temperature.Since mud fluid,rock and the temperature field are interactive and interfering during the process of drilling wells,the above technique provides a new method for investigating the theory and applications of the coupled thermal_hydrological_mechanical processes.
Effects of ponderomotive forces and space-charge field on laser plasma hydrodynamics
Authors: Cang Yu  , Lu Xin  , Wu Hui-Chun  , Zhang Jie  ,   中国科学院物理研究所光物理重点实验室，北京  100080
Published: December 2020

Using a two_fluid two_temperature hydrodynamic code, we studied the hydrodynamic s in the interaction of intense (1015W/cm2) ultrashort (150fs) laser pulses and linear density plasmas. The simulation results show the ponderomotiv e force effect on the formation of the electron density ripples in underdense re gion, such ripples increase the reflection of the laser pulse, and on the separa tion of the plasma in critical surface. Quasi_electroneutrality is not suitable in this case because of the different ponderomotive force and the gradient of th ermal_pressure for ions and electrons. Ions are moved by the electrostatic force . Comparing with the simulation results from one_fluid two_temperature code, we find that under strong ponderomotive force and gradient of thermo_pressure, two_ fluid code is more suitable to simulate the hydrodynamics of plasmas.
Intersubband and intraband transitions of self-assembled quantum wires for the infrared detectors
Authors: Li Liang-Xin  , Hu Yong-Hua  ,   湖南大学应用物理系，长沙  410082
Published: December 2020

This paper have studied the structures、microstrain distributions、and optical properties of self-assembled quantum wires Ga1-xInxAs made of sho rt-period superlattices with strain induced lateral ordering. The research has t aken into account of valence-band anisotropy, band mixing and effects due to mic rostrain distributions at the atomistic level. The results show that the selfa ssembled QWRs have favorable optical properties for application in infrared dete ction with normal incidence. The wavelength for subband transitions ranges from 10 to 20μm with the length of QWR period varying from 15 to 30nm. The wavelengt h for inter-band absorption is in the midIR range.