bluuebunny/crossref_metadata_2025 huggingface dataset:
A MICROMECHANISM FOR B IMPROVING THE MECHANICAL PROPERTIES OF MONO- AND POLYCRYSTALLINE Ni3Al ALLOYS
Authors: DENG WEN  , XIONG LIANG-YUE  , LONG QI-WEI  , WANG SHU-HE  , GUO JIAN-TING  ,   (1)中国科学院国际材料物理中心,中国科学院金属研究所; (2)中国科学院金属研究所
Published: November 2020

The microdefects and electronic structure have been studied by measuring the positron lifetime spectra of mono- and polycrystalline Ni3Al alloys with B content ranging from 0.00 to 2.22at%，The experimental results show that the opening space of the defect on grain boundary is larger than that of a monovacancy in polycry-stalline Ni3Al alloy. More valence electrons participate in Ni-Ni and Ni-Al bondings in bulk corresponding to stronger cohesion, while less valence electrons parti-cipate in those on grain boundaries corresponding to weaker cohesion. When B atoms segregate to defects, they form strong covalent bondings with Ni and A1 atoms and strengthen the bonding cohesion in those locations. The interaction of B atoms which occupy interstitial sites，with Ni and Al atoms in bulk leads to the increase of the density of valence electrons, thus increases the bonding cohesion in the bulk.
NEW PHOTOEMISSIVE THIN FILM FOR ULTRASHORT DURATION LASER PULSE DETECTION
Authors: WU JIN-LEI  , LIU WEI-MIN  , DONG YIN-WU  , WU QUAN-DE  ,   北京大学无线电电子学系
Published: November 2020

A kind of photoemissive thin films which can be exposed to or stored in the atmosphere and can be used again in a vacuum system without any activation process for laser pulse detection is presented. They are different from usual photoemissive materials, since they do not contain alkali elements. They consist of metallic oxide thin film or other material thin film embedded with metallic ultrafine particles. A main interesting material is barium oxide thin film embedded with Ag ultrafine particles. The phenomenon that photoemissive sensitivity of this kind of ultrafine particle thin film rose up under the action of laser pulses was discovered.
A CLASSICAL COMPLETELY INTEGRABLE EXTENDED SINH-CORDON SYSTEM ARISING FROM NON CONFORMALLY CONSTRAINED SL(2,R) WZNW MODEL (I)
Authors: WANG YAN-SHEN  , YANG WEN-LI  , YANG HUAN-XIONG  , HOU BO-YU  ,   西北大学现代物理研究所
Published: November 2020

By imposing conformally broken constraints on SL(2,R) WZNW model, we obtain a new classical completely integrable system which contains the famous sinh-Gordon system as a special case. The integrability of this extended sink-Gordon system is exhibited by the existence of the Lax pair with spectral parameters. And its funda-mental .Poisson-Lie brackets can be ultralocalized, corresponding classical r-matrix depends on two spetral parameters and satisfies the classical Yang-Baxter equation. After a suitable automorphic transformation of the loop algebra on which the above Lax pair takes value, such an ultralocalized r-matrix can be classified to the so-cal-led trigonometric type of r-matrices depending essentially on one spectral parameter.
A CLASSICAL COMPLETELY INTEGRABLE EXTENDED SINH-CORDON SYSTEM ARISING FROM NON CONFORMALLY CONSTRAINED SL(2,R) WZNW MODEL (II)
Authors: WANG YAN-SHEN  , YANG WEN-LI  , YANG HUAN-XIONG  , HOU BO-YU  ,   西北大学现代物理研究所
Published: November 2020

On the basis of the study in Ref [4],we construct the dressing transformations of the fundamental variables and show the dressing symmetry of the constrained system (extended sinh -Gordon equations). Finally, we discuss the ultralocalizable-criterion of an arbitrary 2D integrable model.
COOLING OF A STRANGE STAR
Authors: DAI ZI-GAO  , LU TAN  ,   南京大学天文系
Published: November 2020

Since the equilibrium composition of strange matter is crucial to the accurate calculation of its neutrino energy loss rates, we determine the composition by using the thermodynamic potentials (per unit volume) of the strange matter, and find that the electron abundance decreases with the strong interaction coupling constant or ba-ryon density. After deriving the formula of neutrino energy loss rates of the strange matter, we study the cooling of a homogeneous strange star with a thin crust in detail, and compare it with that of a neutron star. We conclude that the surface temperature of a young strange star is much less than that of a young neutron star of the same age, so one can distinguish between a strange star and a neutron star.
A NEW TYPE OF DYE LASER USED FOR A FEMTOSECOND SQUEEZED STATE──Stability analysis and experimental study
Authors: DAI JIAN-MING  , ZHANG RUO-BING  , WANG QING-YUE  ,   天津大学精密仪器工程系
Published: November 2020

A theoretical model for the laser which can produce femtosecond squeezed state has been developed. The stability of the cavity has been analyzed in detail by numerical computation. A stable mode-locked pulse train with pulse width of 160 fs and repetition rate of 67MHz has been obtained, which afforded a new important means for the realization of femtosecond squeezed state.
EFFECT OF CONFIGURATION INTERACTION ON THE AUTOIONIZATION RATES AND BRANCH RATIOS OF Na LIKE Cu ION
Authors: TENG HUA-GUO  , SHEN BAI-FEI  , ZHANG WEN-QI  , XU ZHI-ZHAN  ,   中国科学院上海光学精密机械研究所
Published: November 2020

By using the theory of configuration-interaction, we ireade a analysis of the effect of configuration interaction on the autoionization rates and branch ratios of the configurations 2p53s3l(l=0，1，2) for the Nalike Cu ion. It is shown that the autoionization rates in all the three configurations are changed substantially when the configuration-interaction are included in comparing with the calculations in single-configuration approxmation, and the branch ratios increase both in the configuration 2p53s3d and in 2p53s3p but decrease in the configuration 2p53s2.
COUPLING BETWEEN ATMOSPHERIC GRAVITY WAVES AND PLASMA INTERCHANGE INSTABILITY IN THE IONOSPHERE
Authors: HUANG CHAO-SONG  , LI JUN  , M. C. KELLEY  ,   (1)School of Electrical Engineering,Cornell University,Ithaca,N Y 14853. U.S.A.; (2)中国科学院武汉物理研究所
Published: November 2020

Coupling between atmospheric gravity waves and plasma interchange instability in the equatorial ionosphere is studied. The interchange instability is saturated at a small amplitude by nonlinear effects if there are not any external geophysical distu-rbances to influence it. It is shown that the gravity waves can initiate the interchange instability under some conditions. The initiated instability grows to an amplitude of 50% even larger and forms plasma bubbles if the amplitude of the seed ,gravity waves is large enough. The present theory shows physical mechanism for producing large scale equatorial spread F and explains a lot of ionospheric observations.
DEMONSTRATION AND APPLICATION OF HAM'S THEORY
Authors: LUAN HONG-FA  , XIAO ZHI-GANG  , KE JUN  ,   (1)北京科技大学材料物理系; (2)清华大学微电子学研究所
Published: November 2020

Hanis theory of precipitate growth controlled by diffusion is demonstrated by studying the growth of the oxygen precipitates at high temperature with two-step heat treatment. And the nucleation of the oxygen precipitates is disussed according to Ham's theory tantatively.
A STUDY ON THE LOCAL ELECTRONIC STRUCTURE OF GRAPHITE SURFACE WITH SCANNING TUNNELING SPECTROSCOPY (STS)
Authors: LI NAN  , QIAN SHEND-FA  , FU CHUN-SHENG  , XIE SI-SHEN  ,   中国科学院物理研究所
Published: November 2020

By using STS, combined with STM imaging, the STS spectra d(lnI)/d(lnV) -eV were measured point by point along a line on the surface of a single crystal graphite. The local density of states (LDOS) around the Fermi level EF obtained from the spectra showed basically an agreement with that of theoretical calculation. By plotting the energy positions of the LDOS peaks around EF with respect to the measurement positions, the spatial variations of the energy band of graphite close to EF were shown. With a discussion of the local electronic structure around the ine-quivalent A, B type atoms on the surface, a simple model calculation for the spatial variations of the energy band was conducted and that showed an agreement with the experimental results. By comparison of the results, the site of A type atoms on the graphite surface, which did not appear in the STM image, was determined.
STUDY OF SdH OSCILLATIONS OF 2-D ELECTRON GAS IN Si δ-DOPED AlxGa1-xAs/GaAs HETEROJUNCTION
Authors: WEI YA-YI  , SHEN JIN-XI  , ZHENG GUO-ZHEN  , GUO SHAO-LING  , TANG DING-YUAN  , PENG ZHENG-FU  , ZHANG YUN-QIANG  ,   (1)南京电子器件研究所; (2)中国科学院上海技术物理研究所
Published: November 2020

A new type of AlxGa1-xAs/GaAs beterojunction based on Si δ-doping has been fabricated by MBE method. We measured the magnetoresistances, mobility and Hall resistance of the 2-D electron gas at the junction in a transvers magnetic field from 0.3 to 30K. Using Fourier-transform analysis, the distribution of electrons and their effective masses for each subband are determined. which
are ｍ0*／ｍ0＝０．０７３，ｍ1*／ｍ0＝０．０６８. With the decreasing of temperature，the electrons in each subband increase continuously. We observed abnormal peaks in magnetoresistance wben magnetic field was scanned from 0 to 7T at 0.3K.
EFFECT OF GRAIN SIZE ON TEMPERATURE COEFFICIENT OF RESISTIVITY OF Pd THIN FILMS
Authors: WANG XIAO-PING  , ZHAO TE-XIU  , JI HANG  , LIANG QI  , DONG YI  ,   中国科学技术大学物理系
Published: November 2020

The temperature coefficient of resistivity (TCR) of Pd thin film with different thicknesses and annealled at different tempertures has been investigated. The experi-mental results indicated that the TCR value of thin films is much smaller than that of bulk material and it also depcnds on grain size of the thin films. It was found that the TCR is higher for larger grain size. The result is explained readily by using the two-fluid model.
M?SSBAUER STUDY OF MECHANICALLY ALLOYED Cu1-xSnx SERIES
Authors: LIU FANG-XIN  , ZHANG DAO-YUAN  , WANG GEN-MIA0  , LI YU-ZHI  , YANG YUAN-ZHENG  , DONG YUAN-DA  ,   (1)中国科学技术大学基础物理中心; (2)中国科学技术大学结构分析开放研究实验室; (3)中国科学技术大学物理系; (4)中国科学院固体物理研究所
Published: November 2020

Several samples of Cu1-xSnx series were obtained by mechanical alloying, including η-Cu6Sn5 alloy which are difficult to prepare by melting method. XRD results show that the solid solution with nanometer size is formed which including definite alloy phase in each ball milling sample. M?ssbauer spectra indicate that the Sn-rich-phase and the Cu-rich phase exist besides the alloy phase. We suggest that in the process of the ball milling, the crystallites of Cu and Sn are nanometerized, at first, and then the interdiffusion of the two kinds of atoms takes place and finally the solid solution is formed including the alloy phase, the α-Sn-rich phase and the fcc-Cu-rich phase.
STOCHASTIC CHARACTRISTICS OF MAGNETIC FIELD LINE IN TOKAMAK
Authors: ZHU XIONG-WEI  ,   中国科学院物理研究所
Published: November 2020

Under the cylindrical approximation, we apply nonlinear Hamiltonian oscilation theory to investigate the process of transition of perturbed equilibrium magnetic field to randomness. The results show that perturbed magnetic hamiltonian is only rela-ted to the radial perturbation of magnetic field, the magnetic field line takes the form of regular magnetic island under a single mode perturbation. The overla-pping criterion for magnetic field to enter the random state is given for the case of existence of two mode action, and the relation of points on the poincare section is reduced to a kind of standard mapping under special multimode perturbation.
NUMERICAL SIMULATION STUDIES ON FILAMENTATION IN COHERENCE AND INCOHERENCE LASER
Authors: ZHANG JIA-TAI  , NIE XIAO-BO  , SU XIU-MIN  ,   北京应用物理与计算数学研究所
Published: November 2020

The filamentation instabilities in coherence and induced spatial incoherence laser beam have been investigated by computer simulation using a two-dimensional three temp-erature MHD laser target code. A numerical analysis is employed based on the random phase plate smoothing techniques and resolving of laser beam propagarion equations for the coupled simplified hydrodynamic model to derive the effects on the filamentation;nstability. These results show that the filarnentaion instabilities may be suppressed or eliminated under some conditions.
THE NONLINEAR THEORY OF INTERACTION BETWEEN LIGHT AND MATTER DESCRIBED BY q-DEFOR- MED OSCILLATOR MODEL
Authors: YANG GUANG-CAN  ,   广西师范学院物理系,南宁530001
Published: November 2020

The nonlinear theory of interaction between light and matter has been established by using q-oscillator as a model for the light field. The formal solution of Schr?di-ngar equation is obtained, and the first crder approximation of emission and absorption probability are acquired by perturbation theory. We also discussed the Rabi problem for resonance condition. When q→1, the theory reduces to the common linear theory.
MEASUREMENT OF SHEET RESISTANCE FOR MICROA- REAS BY USING A MODIFIED VAN DER PAUW'S METHOD
Authors: SUN YI-CAI  , ZHANG LIN-ZAI  ,   河北工学院电子工程系,天津300130
Published: November 2020

The sheet resistance of square microareas with an area of 100 × 100μm2 can be determined by using a modified Van der Pauw's method. In this method, the tip positions of the four probes are controlled respectivly at the four corners out side the inner tangential circle of square microareas by direct inspection using a microscope with a magnification of 8 × 10. The measurement results are independent of wanderings of probes and it is not necessary to determine the precise positions of probes in order to make corrections for the boundary effect. These conclusions are proved in this paper by using FEM and have been confirmed by the determination of sheet resistance of gold microbumps.
EXPERIMENTS ON INSTABILITY AND POTENTIAL CON- FINEMENT CONFIGURATION IN MM-4U TANDEM MIRROR
Authors: MING LIN-ZHOU  , YE RU-BIN  , WU GUANG-JUN  , LI ZHI-CAI  , ZHCU XIAO-BING  , SHI QIANG  , ZHAO GUO-PING  , XU LI-YUN  ,   核工业西南物理研究院,成都610041
Published: November 2020

Experimental results on plasma instability and potential confinement configuration in MM-4U tandem mirror are presented. The measured axial potential profile shows that the axisymmetric negative plasma potential tandem mirror confinement configuration has been established; the obtained plasma density profile is similar to the potential profile. The relationships between the plasma parameters and the eng-neering parameters have also been studied prelimilarily. The low frequency instability was observed at low plasma density in the central cell. By means of the linear spectral analysis techniques, the instability mode has been determined. It is suggested that the instability is excited in the low density plasma when the electron beam drift velocities exceed the ion acoustic speed.
LOW FREQUENCY VOLTAGE NOISE IN IMPURITY- DOPED BLUE BRONZES
Authors: TIAN MING-LIANG  , MAO ZHI-QIANG  , ZHANG YU-HENG  , SHI JING  , MEI XUE-FEI  , TIAN DE-CHENG  ,   (1)武汉大学物理系,武汉430072; (2)中国科学技术大学结构分析开放研究实验室,合肥230026
Published: November 2020

In this paper, low frequency voltage noise property in impurity-doped blue bronzes is investigated. It is found that these low frequency voltage noise can be strongly enhanced by impurities or defects, for which the amplitude and shape of the oscillations are closely related to the initial conducting current of sample during cooling. The results indicate that the origin of the broad-band noise in charge-density-wave system may result from the macroscopic defects or impurities.
AN INVESTIGATION FOR THE EPR PARAMETERS AND THE CRYSTAL LATTICE DEFECTS OF THE TETRAGONAL SYMMETRY IN KZnF3:Cr3+ AND KMgF3:Cr3+
Authors: ZHANG XIN-MING  , ZENG BAO-QING  , YU WAN-LUN  ,   (1)曲靖师范专科学校物理系,曲靖655000; (2)四川师范大学物理系,成都610066
Published: November 2020

In this work, the ground state zero-field spitting of the tetragonal symmetry in KZnF3:Cr3+ has been studied using the Newman superposition model. The existence of Zn2+ -vacancy and the crystal lattice distortion has been verified. It is found that the contribution from the Zn2+-vacancy are non-negligible. Meanwhile, we obtain that the F- ion along [001] axis moves towards the central Cr3+ ion by Δ = 0.0029-0.0043nm. It has been verified also that the tetragonal center with D = - 0.2167cm-1 in KMgF3:Cr3+ is a CrOF5 cluster. To get agreement with the EPR experiment data it is necessary to introduce a contraction of the four fluorine ions in the plane perpendicular to the Cr3+-O2- axies pair, at the same time, the Cr3+ moves towards the O2- and the O2- moves towards the Cr3+ ion, but the displacement of the Cr3+ is larger than that O2- in CrOF5 cluster.
A NEW METHOD FOR DETECTION OF THE ELECTRON TEMPERATURE IN LASER-PLASMA SHORT WAVE CUT OFF OF STIMULATED RAMAN SCATTERING SPECTRUM
Authors: ZHANG JIA-TAI  ,   北京应用物理与计算数学研究所
Published: November 2020

From the theory of stimulated Raman scattering (SRS) three wave interaction, a new method of detecting the electron temperature in laser-plasma is obtained. SRS spectrum obtained from Shenguang 12# Nd-laser experiments are analysed. Using the wave length of short wave cut off of SRS, the electron temperature in corona plasma region is calculated consistently. These results agree reasonably with X-ray spectrum experiments.
ANALYTICAL DEVELOPMENT OF AN APPROXIMATE EXPRESSION OF THE DIFFUSE REFLECTANCE JUST BENEATH THE SEA SURFACE
Authors: YOU MING-CHANG  , ZHANG SHU-AN  ,   (1)华东师范大学物理系,上海200062; (2)上海教育学院物理系,上海200050
Published: November 2020

An approximate expression of the diffuse reflectance just beneath the sea surface is developed theoretically by analytical way which is essentially consistent with the results of numerical methods
THE DYNAMICAL BEHAVIOR OF A DISCRETE MODEL OF OPTICAL BISTABLE SYSTEM
Authors: YANG YUAN  , DAI JIAN-HUA  , ZHANG HONG-JUN  ,   中国科学院物理研究所
Published: November 2020

The differential equation with delayed feedback of the optical bistable system is discretized into a two-dimensional mapping. It is shown that the four-fold oscil-lation mode presents instead of single-mode oscillation upon the loss of stability of the system and that the four modes enter chaos with period-doubling cascade independently with the change of parameter A. In addition, a coexisting attractor is found in the window of period-three. The basin of the coexisting attractor is a fractal structure similar to the two-dimensional Mandeblort set.
MEAN FIELD THEORY OF CRITICAL PHENOMENA IN INCREASING ABSORPTION OPTICAL BISTABILITY
Authors: OU FA  , WEI BAO-HUA  , LIU CUI-HONG  ,   (1)广州师范学院; (2)华南理工大学
Published: November 2020

It is demonstrated that the mean field (Landau) theory of critical phenomena (including the two kinds of critical point) and transitions can also be applied to the increasing absorption optical bistubility (IAOB), far from equilibrium. On the basis of analysing the dynamical fea Lures of the IAOB model proposed recently[９］, the socalled quasi-thermodynamic potential is introduced. This potential, near the critical point (of the second kind), reflects not only the general properties of phase transitions in bistable systems, but also the specific characteristics of the IAOB.
KUSTANNHEIMO -STIEFEI TRANSFORMATION OF BARY-ON STRUCTURE MODEL WITH A FOUR-DIMENSI-ONAL COVARIANT HARMONIC OSCILLATOR
Authors: LONG JUN-YAN  ,   长沙水电师院物理系
Published: November 2020

In this paper, we assume there exist no three-body forces in a baryon. So that the constraint equations for two particles Pi2+U(x2)+mi2=0 (i=1，2 )can be applied to the SU3 model of the baryon. Next, we take U(x2) as a+bx2. By use of a proper coordinate transformation, the internal motion of the baryon can be reduced to double covariant harmonic oscillators. From the Kustannheimo-Stiefel transformation, the problem of a covariant harmonic oscillator can be transformed to that of a threedimensional hydrogen atom with constranits. On that basis, the difficulty of the excitation of the time degree of freedom can be avoided naturally and the mass-squared formula for baryons can be obtained.
ON THE SATURATION PROPERTIES AND THE LIQUID-GAS PHASE TRANSITION OF FINITE NUCLEAR MATTER WITH GOGNY INTERACTION
Authors: CAO FU-GUANG  , YANG SHAN-DE  ,   (1)吉林大学理论物理中心; (2)吉林大学物理系
Published: November 2020

The Hill-Wheeler formula is applied to deriving the equation of state for finite nuclei with the Gogny effective interaction in the framework of the Hartree-Fock theory. The reasonable zero-temperature saturation properties is obtained, and the critical temperature for liquid-gas phase transition of finite nuclei is found to be around 12MeV. It is found that the phenomenological formula for surface energy which is used widely is not available when the density is far away from the normal nuclear density, and a new formula is proposed.
CHARACTERIZATION OF MICRO-DEFECTS IN SILICON SINGLE CRYSTALS BY ANALYZING THE PENDELL?SUNG FRINGES
Authors: LI MING  , MAI ZHEN-HONG  , CUI SHU-PAN  ,   中国科学院物理研究所
Published: November 2020

Based on the statistical theory of X-ray dynamical diffraction, a method to obtain the static Debye-Waller facter from section topographs is described. By analyzing the intensity distribution of the Pendelldsung fringes in the X-ray diffraction topograghs for heat treated CZ and MCZ silicon single crystals, the number density and the size of the oxygen precipitates which are smaller than X-ray topographic resolution are estimated. This quantitative analysis method provides a new means of studying the micro-defects.
THERMAL EXPANSION PROPERTIES OF Fe-BASED NANOCRYSTALLINE ALLOYS
Authors: LU ZHI-CHAO  , XIAN YU-ZE  , SHEN BAO-GEN  ,   (1)东北大学物理系; (2)中国科学院物理研究所
Published: November 2020

Thermal expansion properties of Fe-based nanocrystalline Fe１３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９ and Ｆｅ９１Ｚｒ７Ｂ２ alloys are studied, and are compared with that of the amorphous alloys with the same composition. The experimental results indicated that, below Curie temperature, the thermal expansion coefficients of the nanocrystalline alloys are much greater than that of the amorphous alloys, and above Curie temperature, the thermal expansion coefficients of the nanocrystalline alloys exceed that of the amorphous alloys a little. We believe that the difference of the thermal expansion between Fe-based nanocrystalline and amorphous alloys is related to the Invar effect.
ELECTRICAL PROPERTIES OF WSix/Si(111)FILMS BY MULTILAYER SPUTTERING
Authors: WANG XIAO-PING  , ZHAO TE-XIU  , LIU HONG-TU  , SHI YI-SHENG  , WENG HUI-MIN  , GUO XUE-ZHE  ,   (1)江苏盐城师范专科学校物理系; (2)中国科学技术大学近代物理系; (3)中国科学技术大学物理系
Published: November 2020

Tungsten silicide films have been sputtered onto silicon substrate and annealed at temperature ranging from 400 to 1000℃ in vacuum. The structure and defect of each film is detected by X-ray diffraction (XRD) and positron annihilation technology (PAT), respectively. The sheet resistance has been measured and the result in-dicates that the sheet resistance of films decrease steeply as a result of annealing in the range of 600-700℃. This phenomenon corresponds to the crystallization of W5Ｓｉ3 tetragonal phase in films which has been certified by XRD. Electrical properties of films are sensitive to structure and defects in films and electrical measurement can be used as a good probe for the study on the characteristics of films.
INFLUENCE OF INTERACTION BETWEEN ELECTRONS AND PHONONS ON THE MAGNETIC EXCITATION OF ITINERANT ELECTRONS SYSTEM
Authors: YU CHAO-FAN  , CHEN BIN  , HE GUO-ZHU  ,   (1)南开大学数学研究所; (2)南开大学物理系
Published: November 2020

Based on the Peierls-Hubbard Hamiltonian, the influence of electron-phonon inte-raction on the spin excitation of itinerant electron system has been analysed. It is shown that the interaction not only changes the dynamic property of －＋（ｑ，ω），but also causes the gap between two spin subbands to become narrow, which makes the electron-hole pairs easy to be excited singly. It should be emphasized that the spin excitation spectrum has an energy gap duo to the presence of above-mentioned electron-phonon interaction.
PHOTOLUMINESCENCE PROPERTIES OF TUNABLE LASER CRYSTAL Cr3+:ZnWO4
Authors: CHEN WEI  , XIA SHANG-DA  , TANG HONG-GAO  , LIU JING-QING  , ZANG JING-CUN  , WAN SHOU KE  ,   (1)北京工业大学; (2)中国科学技术大学材料科学与工程系; (3)中国科学技术大学材料科学与工程系,中国科学技术大学结构分析开放研究实验室; (4)中国科学技术大学物理系; (5)中国科学院半导; (6)中国科学院物理研究所
Published: November 2020

We investigate the photoluminescence properties of Cr3+:ZnWO4 single crystals which channels all the fluorescence into the broadband 4T2(t22e) to 4A2(t32) transition at about 990nm wavelength. Experiment results of the absorption spectra and the excitation spectrum, temperature dependence of the emission spectra, decay curves of Cr3+ ions are presented and discussed. The most efficient excitation wavelength is in the red region. Radiative decay from the luminescence level to the ground level is characterized by broad emission bands as a consequence of a strong electron-phonon interaction ——Hua-Rhys factor S(300K)=4.22, S(12.7K) = 7.09, the average pho-non energy hv(300K)=405cm-1, hv(12.7K)=213cm-1. The zero-phonon transition line probably is at wavelength of 856.7nm. If there are two kinds of Cr3+ center, one is compensated by the adjacent vacancy(1.8μs), and the other is compersated nonl-ocally (5.45μs).
ELECTRON TRANSPORT PROCESS IN CATHODE SHEATH OF HELIUM dc HOLLOW CATHODE GLOW DISCHARGE PLASMA
Authors: WEI HE-LIN  , LIU ZU-LI  ,   华中理工大学物理系,中国科学院武汉物理研究所波谱与原子分子物理国家重点实验室
Published: November 2020

In this paper, the electron transport process in cathode sheath of helium dc hollow cathode glow discharge is studied by using Monte Carlo simulation. The electron is accelerated between collisions by the non-uniform electric field of the hollow cathode sheath. The electron free flying time between collisions is determined by collision frequency of electron with neutral particle. The experimental data of collision cross section are fitted to semi-experience expressions. The electron mean energy and spatial energy distribution, and other parameters distribution are studied. The results are in good agreement with experimental ones.
PHOTOLUMINESCENCE FROM NANO-CRYSTALLITES OF SILICON FILMS PREPARED BY PECVD
Authors: LIU XIANG-NA  , WU XIAO-WEI  , BAO XI-MAO  , HE YU-LIANG  ,   南京大学物理系
Published: November 2020

We report in this paper the observation of visible photoluminescence (PL) at room temperature from nano-crystallites of silicon films, which are prepared in a PE CVD system by using strong hydrogen diluted silane as the reactant gas source, without any post-processings. We attribute the PL to the photons above the band gap of bulk crystal silicon created by the carriers in the nano-crystallites under the function of quantm size effect. The effective deposition parameters are concerned.
PHONON DENSITIES OF STATES IN Fe-BASED AMORPHOUS INVAR ALLOYS
Authors: XIAN YU-ZE  , LU ZHI-CHAO  , LI JI ZHOU  , YE CHUN-TANG  , LI ZHU-QI  , KANG JIAN  , SHEN BAO-GEN  ,   (1)东北工学院物理系; (2)中国科学院物理研究所; (3)中国原子能科学研究院
Published: November 2020

Generalized phonon densities of states (PDOS) for amorphous Ｆｅ９０－ｘＣｏｘＺｒ１０（ｘ＝１０，４０） and Ｆｅ８０－ｙＣｒｙＰ１３Ｃ７（ｙ＝４，８） alloys have been deduced from inelastic neutron scattering experiments. And the softening phenomena of the PDOS in the energy region below 17 meV have been observed for the amorphous Invar alloys. The anomalies in the dynamics of Invar alloys were discussed, and preliminary results show that the phonon softening of the amorphous Invar alloys may closely connected with the enhanced electron—phonon interaction in lnvar alloys.
Multi-parameter measurement sensor based on no-core fiber
Authors: Sun Jia-Cheng , Wang Ting-Ting , Dai Yang , Chang Jian-Hua , Ke Wei ,   School of Electronics and Information Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China,   Key Laboratory of Optoelectronics Technology of Jiangsu Province, Nanjing Normal University, Nanjing 210023, China,   Center for Collaborative Innovation in Geographical Information Resource Development and Application of Jiangsu Province, Nanjing 210023, China
Published: November 2020

Aiming at the phenomenon of single measurement parameters and low sensitivity of most Mach-Zehnder sensors based on fiber core mismatch, in this paper we design and build a Mach-Zehnder sensor based on single-mode-no-core-single-mode-no-core-single-mode fiber structure, which can be used to measure refractive index and temperature simultaneously. In this sensor, two no-core optical fiber serve as input and output couplers, the intermediate single-mode is used as a sensing arm. Using finite element simulation and theoretical analysis, the optimal length of the coupler and the sensing arm are determined to be 15 mm. High-order modes excited by no-core optical fiber propagate through the cladding of single-mode fiber, which is affected by the ambient refractive index and temperature because of the influence of the evanescent filed. Trough of different interference orders of transmission spectrum is selected as a research object to realize the simultaneous measurement of refractive index and temperature by using sensitivity coefficient matrix. After the further Fourier transform of the transmission spectrum, the frequency of the main mode that interferes with the fundamental mode is analyzed from the spectrogram to be 0.00098 nm–1. Because of the influence of temperature on the refractive index of water during temperature sensitivity measurement, temperature sensitivity formula and water temperature coefficient are introduced to perform temperature compensation to eliminate the cross sensitivity. In this paper, the 10 mm and 15 mm sensing arms are selected for refractive index comparison experiment, and the temperature experiment is focused on the sensing arm with an optimal length of 15 mm. The experimental results show that the transmission spectrum is blue-shifted with the increase of refractive index in a refractive index range of 1.333–1.397, and the transmission spectrum is red-shifted with the increase of temperature in a temperature range from 30 ℃ to 70 ℃. The refractive index and temperature sensitivity of the interference valley near 1545 nm are –153.89 nm/RIU and 0.166 nm/℃, respectively; the refractive index and temperature sensitivity of the interference valley near 1570 nm are –202.74 nm/RIU and 0.183 nm/℃, respectively. The experimental results are consistent with the theoretical analyses. Compared with the sensor of the same type, this sensor can still maintain high sensitivity while achieving simultaneous measurement of refractive index and temperature, and has a simple structure, which has a good application prospect in biomedical and other aspects.
Tunable electronic structure and optical properties of BlueP/X Te2 (X = Mo, W) van der Waals heterostructures by strain
Authors: Xing Hai-Ying , Zheng Zhi-Jian , Zhang Zi-Han , Wu Wen-Jing , Guo Zhi-Ying ,   School of Electronics and Information Engineering, Tiangong University, Tianjin 300387, China,   Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, China Academy of Sciences, Beijing 100049, China,   Engineering Research Center of High Power Solid State Lighting Application System, Tianjin 300387, China
Published: November 2020

First principles calculations are performed to explore the electronic structure and optical properties of BlueP/X Te2 (X = Mo, W) van der Waals heterostructures after biaxial strain has been applied. The type-II band alignments with indirect band gap are obtained in the most stable BlueP/X Te2 heterostructures, in which the photon-generated carriers can be effectively separated spatially. The BlueP/MoTe2 and BlueP/WTe2 heterostructures both have appreciable absorption of infrared light, while the shielding property is enhanced. The increase of biaxial compressive strain induces indirect-direct band gap transition and semiconductor-metal transition when a certain compressive strain is imposed on the heterostructures, moreover, the band gap of the heterostructures shows approximately linear decrease with the compressive strain increasing, and they undergo a transition from indirect band gap type-II to indirect band gap type-I with the increase of biaxial tensile strain. These characteristics provide an attractive possibility of obtaining novel multifunctional devices. We also find that the optical properties of BlueP/X Te2 heterostructures can be effectively modulated by biaxial strain. With the increase of compression strain, the absorption edge is red-shifted, the response of light absorption extends to the mid-infrared light and the absorption coefficient increases to 10–5 cm–1 for the two heterostructures. The BlueP/MoTe2 shows stronger light absorption response than the BlueP/WTe2 in the mid-infrared to infrared region and the ε1(0) increases significantly. The BlueP/X Te2 heterostructures exhibit modulation of their band alignment and optical properties by applied biaxial strain. The calculation results not only pave the way for experimental research but also indicate the great potential applications of BlueP/XTe2 van der Waals heterostructures in narrow band gap mid-infrared semiconductor materials and photoelectric devices.
Properties of hyperbolic generalized Pell numbers
Authors:   Department of Mathematics, Zonguldak Bülent Ecevit University, Soykan Yüksel , Göcen Melih ,   Department of Mathematics, Zonguldak Bülent Ecevit University
Published: November 2020

In this paper, we introduce the generalized hyperbolic Pell numbers over the bidimensional Clifford algebra of hyperbolic numbers. As special cases, we deal with hyperbolic Pell and hyperbolic Pell–Lucas numbers. We present Binet’s formulas, generating functions and the summation formulas for these numbers. Moreover, we give Catalan’s, Cassini’s, d’Ocagne’s, Gelin–Cesàro’s, Melham’s identities and present matrices related to these sequences.
Padovan sequence generalization – a study of matrix and generating function
Authors:   Department of Mathematics, Institute Federal of Tecnology of State of Ceara (IFCE), Vieira Renata Passos Machado , Alves Francisco Regis Vieira ,   Department of Mathematics, Institute Federal of Tecnology of State of Ceara (IFCE), Catarino Paula Maria Machado Cruz ,   Department of Mathematics, University of Trás-os-Montes and Alto Douro
Published: November 2020

The Padovan sequence is a sequence similar to the Fibonacci sequence, the former being third order and the latter second. Having several applications in architecture, these numbers are directly related to plastic numbers. In this paper, the Padovan sequence is studied and investigated from the standpoint of linear algebra. With this, we will study the matrix and the generating function of the extensions of this sequence (Tridovan and Tetradovan), thus determining the generalization of this sequence.
Dual bicomplex Horadam quaternions
Authors:   Department of Computer Engineering, University of Kafkas, Gül Kübra
Published: November 2020

The aim of this work is to introduce a generalization of dual quaternions called dual bicomplex Horadam quaternions and to present some properties, the Binet’s formula, Catalan’s identity, Cassini’s identity and the summation formula for this type of bicomplex quaternions. Furthermore, several identities for dual bicomplex Fibonacci quaternions are given.
Congruences involving alternating sums related to harmonic numbers and binomial coefficients
Authors:   Ibn Khaldoun University, EDPNLHM Laboratory of ENS, Elkhiri Laid , Mihoubi Miloud ,   USTHB, Faculty of Mathematics, RECITS Laboratory, Derbal Abdellah ,   ENS, Department of Mathematics, EDPNLHM Laboratory
Published: November 2020

In 2017, Bing He investigated arithmetic properties to obtain various basic congruences modulo a prime for several alternating sums involving harmonic numbers and binomial coefficients. In this paper we study how we can obtain more congruences modulo a power of a prime number p (super congruences) in the ring of p-integer \mathbb{Z}_{p} involving binomial coefficients and generalized harmonic numbers.
On a translated sum over primitive sequences related to a conjecture of Erdős
Authors:   Faculty of Exact Sciences, Djillali Liabes University, Rezzoug Nadir , Laib Ilias ,   Laboratory of Equations with Partial Non-Linear Derivatives, ENS Vieux Kouba, Kenza Guenda ,   Faculty of Mathematics, University of Sciences and Technology Houari Boumédiène
Published: November 2020

For x large enough, there exists a primitive sequence \mathcal{A}, such that \begin{equation*} \sum\limits_{a\in \mathcal{A}}\frac{1}{a(\log a+x)}\gg \sum\limits_{p\in \mathcal{P}}\frac{1}{p(\log p+x)}\text{,} \end{equation*} where \mathcal{P} denotes the set of prime numbers.
The translated Whitney–Lah numbers: generalizations and q-analogues
Authors:   Department of Mathematics, Mindanao State University–Main Campus, Mangontarum Mahid M.
Published: November 2020

In this paper, we derive some combinatorial formulas for the translated Whitney–Lah numbers which are found to be generalizations of already-existing identities of the classical Lah numbers, including the well-known Qi’s formula. Moreover, we obtain q-analogues of the said formulas and identities by establishing similar properties for the translated q-Whitney numbers.
Earthquake Performance Analysis of Existing Reinforced Concrete Structure in the Istanbul Metropolitan Area Using Non-Linear Method
Authors: Çavdar Özlem
Published: December 2020

Many people suffer loss of life and property due to the earthquake disaster in Turkey. In order to minimize this disaster, the resistance of the structures to earthquake should be determined under the light of studies done before. Turkey is in one of the most dangerous seismic regions in the World. As a sub plate between the large Eurasian, Arabian and African plates, Turkey rests on the Anatolian tectonic plate. Arabian plate in the direction of pushing Turkey to the North, the Anatolian plate moves in the opposite clockwise. However, it is prevented to move in the North direction due to the Eurasian plate. In this case, it contains many active faults and Turkey’s most populous city of Istanbul is in danger. In this study, it is aimed to perform a performance analysis according to the Turkey Building Earthquake Code 2018 in a six-story reinforced concrete shear wall-framed structure in Istanbul where active fault lines are located. This existing complex designed reinforced concrete building investigated in this study is in the city of ?stanbul, Turkey. This city is under danger of approaching and inevitable Great Istanbul Earthquake likely greater than Mw 7. The nonlinear seismic behavior of a complex reinforced concrete (RC) residential building is investigated by and linear and the static pushover. The selected reinforced concrete structure was designed according to 1998 version of Turkish Earthquake Code (TEC-1998). In the earthquake engineering, performance-based design method is used to determine the level of expected performance of the structures under the earthquake effect. According to the code, the reinforced concrete shear wall building is not expected to satisfy controlled damage (life safety) performance levels under design earthquake
Parametric Strategy for Composite Cement Concrete Blended with Fly Ash & Glass Fiber
Authors: Das Madhurima , Mishra Siba Prasad
Published: November 2020

Coping with population growth, houses are built to meet the hike. The prerequisites for concrete and steel reinforcements have surged up globally since last 3 to 4decades. Shortage of natural building materials, increased wastes from coal based industries to augment carbon foot print has worried the engineers to reuse their wastes (such as fibres, powders, granules, etc.) as building materials ingredient. Glass fibre has improved flexural capabilities with fly ash dosages in cement concrete and alternately helps in restricting environmental degradation. Present research aims at investigating the impact of glass fiber (at 1%, 2% and 3% addition) and fly ash (dosages of 10% and 20% over the existing fly ash in PPC). The ingredients and microstructure of composites are found by either X-ray fluorescent spectroscopy or scanning electron microscope. Experimental evaluation results of the blended composite concrete parameters of RCC are experimentally evaluated and compared have shown that concrete with 10% cement substitution with fly ash and 3% fibre showed optimum compressive strength performance than the concrete without fibre and fly ash and also chemically resistant against commonly used M-20 grade of Concrete.
Delineating Efficient Cropping Zones of Potato and Chilli in Tamilnadu
Authors: Sankar T. , Kowshika N.
Published: November 2020

Potato and Chilli are the most significant horticultural vegetable crops commercially cultivated in both field level and homestead gardening. India is leading producer of chilli and 2nd leading of potato in the world, but inadequate storage and huge unpredictable weather  conditions leads to loses. This study was done to analyse trend changes in area, production and productivity over 30 years study period (1985-2015) and also identify Efficient Cropping zones of potato and chillies, at district level for Tamil Nadu during 2000-2015, in order to venture the hotspots of 21st century. Results of trend analysis revealed   that potato production was decreasing till early 21st century and thereafter increasing gradually   with respect to cropping area and chilli showed reduction in production over the years. Relative Yield Index (RYI) and Relative Spread Index (RSI) were used to figured out potential cropping districts for both crops over Tamil Nadu. Dindigul, Erode and Krishnagiri    districts were found to be efficient cropping zone, while Nilgiris is sole district of Most Efficient Cropping Zone (MECZ) for potato. Virudhunagar district has been the Most Efficient  Cropping Zone for chilli crop, while Ramanathapuram, Sivagangai, Tirunelveli, and Thoothukkudi districts were identified as potential efficient zone (ECZs) in Tamil Nadu. Hence, this paper attempts to identify the hotspot area and to study the deviation in cultivable land, production and productivity of the crops where farmers are facing most of the problems. The climate change scenarios could influence crop cultivation, and this paper is evident on the changes in efficient cropping zones.
Modelling and Forecasting of Monthly Rainfall and Temperature Time Series Using SARIMA for Trend Detection- A Case Study of Umiam, Meghalaya (India)
Authors: Dabral P. P. , Tabing Issac
Published: November 2020

Seasonal Auto Regressive Integrative Moving Average Models (SARIMA) were developed for monthly rainfall, mean monthly maximum and minimum temperature time series for Umiam (Barapani), Meghalaya (India). The best model was selected based on the minimum values of AIC and BIC criteria as well as based on observing the ACF and PACF plot of residuals. SARIMA (5,1,2) x (1,1,1)12, SARIMA (2,1,2) x (2,1,1)12, SARIMA (6,1,4) x (2,1,3)12 models were found to be the best fit model for the monthly rainfall, mean monthly maximum  and minimum temperatures time series respectively. The adequacy of the SARIMA models was also verified using the Ljung-Box (Q) statistic test. McLeod-Li test and Engle’s ARCH LM test were carried out for residuals. The results indicated that there was no Arch effect in the established SARIMA models and models can be used for forecasting the future values for the year 2013 to 2028. The determination of trend in monthly rainfall, mean maximum and minimum temperatures in the forecasted series were done using different trend analysis techniques. For monthly rainfall and mean monthly minimum temperature time series, all the selected methods supported no significant trend. However, in the case of mean monthly maximum temperature time series, three selected methods supported falling trend.
Integrated Waste Management System as a Sustainable Option for Managing Plastic Waste in Ghana: The Case of Madina-La Nkantanan Municipality
Authors: Richard Ampadu-Ameyaw , Richard Nkum , Ahwireng Anderson Kwasi
Published: November 2020

This study elucidates the current state of plastic waste management in urban areas of Ghana, with a particular focus on Madina-La Nkwntanan municipality. As a result of the current uncontrollable plastic waste challenge, the Government of Ghana, is seeking sustainable approaches to reduce th effect of plastic waste in the country. A number of arrangements, including various forms of privatization, tax regimes and public-private partnership have already been initiated as first step solutions to the challenge, yet management of plastic waste, has not been encouraging. Using a case study from one municipality in Ghana, this paper shows that domestic plastic wastes forms the second most generated wastes in the study area. The results show that the practice of separation at source, which is the first step toward dealing with plastic waste, was uncommon in the study area, although pockets of houses in the municipality and other places in the country practiced it. This article proposes the integrated waste management (IWM) concept, as one of the possible sustainable options that could help tackle the plastic waste issue in municipality. This is in view of the sustainable nature of the concept as well as its integrative way of dealing with waste. This reality has been confirmed by other authors in several countries.
Application of Statistical Quality Control in Monitoring the Production, Packaging and Marketing Process of Sachet Water
Authors: Ieren Terna Godfrey , Kuje Samson , Asongo Abraham Iorkaa , Eraikhuemen Innocent Boyle
Published: November 2020

Statistical process control is a technique employed to enhance the quality and productivity of processes and the distribution or marketing of its products. Sachet water is a product that has become popular and is being used as a replacement for lack of potable water. It is an alternative that is readily available, affordable but with questions about its purity, production and marketing processes. The objective of this study is to apply statistical control charts in monitoring the production, packaging and distribution or marketing processes of sachet water in Nigeria. This paper employed statistical quality control approach to monitor process stability in a Table Water manufacturing company. Quality control tools such as p-chart, u-chart, X-bar and R charts as well as process capability chart were use to observed field data obtained from the sachet water manufacturing company on important processes of sachet water production and marketing for 30 working days. This was done to check if the processes were in control or out of control and to verify the capability of the marketing process of the product meeting preset specifications. With this, the statistical control charts suitable for the processes were constructed using package “qcc” in R software version 3.6.1. The results from p-chart and u-chart showed that the production and packaging process of the product is not in control and hence the need for further investigations and corrective measures to prevent variability in the process and thus allowing improvement in the quality of the product. Also, the results from X-bar and R charts showed that the marking process was in statistical process control in respects of the product sales recorded by the four independent marketers, with no assignable cause of variation. It also revealed that, the product marketing process has low capability of successfully attending the preset specification limits in respect of the product sales and hence generating low profit for the company.
Sensitive fluorometric determination of plasminogen activator in cell lysates and supernatants
Authors: Obrénovitch A. , Maintier C. , Maillet T. , Mayer R. , Kieda C. , Monsigny M.
Published: July 2002

A fluorogenic substrate for plasmin, CBZ‐Gly—Pro—Arg‐AEC, has been synthesized and used to develop a new sensitive photometric and fluorometric assay of plasminogen activator activity. The fluorescence intensity of free AEC at 460 nm is about 3 orders of magnitude higher than that of acyl‐AEC. The release of AEC from the peptidyl derivative was monitored fluorometrically after extraction of free AEC in ethylacetate. Under such conditions, theKmwas 0.16 mM. This method was used to monitor the activity of plasminogen activator synthetized by fibroblastic cells (BHK 21 C 13) either released in the supernantants or cell‐associated.