bluuebunny/crossref_metadata_2025 huggingface dataset:
CRYSTAL STRUCTURE OF THE LOW TEMPERATURE FORM OF BARIUM BARATE Ba3(B3O6)2
Authors: LU SHAO-FANG  , HE MEI-YUN  , HUANG JIN-LING  ,   中国科学院福建物质结构研究所
Published: November 2020

In this paper, we report the crystal structure of the low temperature form of barium borate-a new type of SHG material. Ba3(B3O6)2 crystal belongs to trigonal system with space group C34-R3. There are 6 formula units in one hexagonal cell. The unit cell dimensions referring to hexagonal axes are a = b = 12.532?, c = 12.717?. Diffraction data were collected on Philips PW-1100 four-circle diffractometer. The number of independent reflections amounts to 693. The structure was determined by conventional three-dimensional Patterson and Fourier syntheses and refined by "block diagonal" matrix least-squres procedures to R = 0.046. This structure can be considered as a layer step type of lattice built up by Ba2+ and (B3O6)3- rings atterna-tively. The anion (B3O6)3- group is nearly planar with its plane perpendicular to the threefold axis which passes through the center of the ring. Each barium atom has seven oxygen neighbors. In comparison with the high temperature form of barium borate, it is shown that the acentric symmetry of the barium cations in this structure changes the electron density distribution of the inorganic conjugated boron-oxygen rings, thereby making principal contributions to the SHG effect.
DETERMINATION OF CRYSTAL STRUCTURE OF NORSESQUILERPENOID LACTONE
Authors: GU YUAN-XIN  ,   中国科学院物理研究所
Published: November 2020

The molecular formula of Norsesquilerpenoid Lactone is C14H20O3. The crystal belongs to the orthogonal system, with space group D24-P21 21 21. The cell dimensions are α=7.526(3)?, b=24.642(10)?, c=6.887(2)?. Four molecules are contained in a cell (z = 4). Intensity data were collected on a RASA-IIS four circle diffractometer.The original MULTAN-80 was proved to be not successful in solving the structure. The correct structure solution was obtained by improving distribution of reflexion indexes.Finally, we analyse the cause of failure that original start set created and give reason for selecting new one.
AN EFFECTIVE METHOD FOR INDEXING KIKUCHI LINES FROM UHVEM
Authors: YANG QI-BING  ,   中国科学院金属研究所
Published: November 2020

The difficulty of automatic indexing of Kikuchi lines by computer lies in exper-mental errors in the mesurements of Kikuchi line positions and the camera constant. These errors were minimized by adopting a least square method to fit Kikuchi lines and correcting camera constant automatically. In addition, the geometry of lattice planes was used to aid the indexing of Kikuchi lines. Consquently, the reliability of correct indexing has been greatly improved. This method is universally applicable, however, it is, in particular, suitable to the case of Kikuchi lines from UHVEM.
A MATRIX THEORY FOR OPTICAL PASSIVE RESONATORS (IN CYLINDRICAL COORDINATES) (II)——CALCULATION FOR AXIAL SYMMETRIC STABLE RESONATORS
Authors: LI XIAN-SHU  , GAO YAN-QIU  , CHEN ZHI-TIAN  , FENG ZENG-YE  ,   (1)中山大学电子系; (2)中山大学计算机科学系; (3)中山大学物理系
Published: November 2020

Attempts are made to explore the way of solving the problem of calculating modes in optical passive resonators on the basis of the matrix equation in the previous papers, and to determine the superior limits of calculation errors resulting from truncating the matrix equation. For convenience of comparison between the results of ours and those obtained previously by other methods in literatures, we have calculated the characteristics of the modes in various stable resonators with two symmetric reflectors for Fresnel numbers N ≤ 1, and have determined the superior limits of the calculation errors using both the trial method of mathematics (the matrix has been truncated into various order to solve the matrix equation) and the rigorous formulae derived in the previous paper in general. It is shown that the superior limits followed from these formulae are resonable for all modes, including high order modes, but they are far larger than real errors. So that a new formula, which is more suitable for determining the superior limits of errors in our calculation than the previous one, has been adopted.Some new characteristics of the modes are obtained.It is obvious that, by means of the matrix equation, all modes in a resonator, whose losses are not very close to unity, with various radial mode numbers p and an arbitrary given angular mode number l can be caculated at a time, It has been found that a satisfactory accuracy can be achieved for the modes in resonators 0 ≤g≤0.95 in our calculation,provided the matrix equation is truncated into (N + 1) order, where N≥ 8N(1+g)1/2-l/2.
THEORY OF “CLUMPS” IN DRIFT-WAVE TURBULENCE
Authors: QIU XIAO-MING  ,   中国西南物理研究所
Published: November 2020

In this paper, a theory of "clumps" in drift-wave turbulence is developed, based on the stochastic treatment of trajectories developed by Misguich and Balescu. It is shown that there exists a clump effect in a magnetized turbulent plasma as well as in an un-magnetized one. The existence of this effect makes the actual diffusion across the magnetic field much smaller than the diffusion predicted by Dupree's theory. Ah explicit expression for the clump life-time is derived this life-time is proportional to the diffusion (across magnetic field) characteristic time and depends logarithmically on the initial relative position of particles.
INVESTIGATION OF RAMAN SPECTRA OF LiNbO3: MgO CRYSTALS
Authors: LIU SI-MIN  , ZHANG GUANG-YIN  ,   南开大学物理系
Published: November 2020

Raman spectra of LiNbO3: MgO crystals has been obtained for the first time and compared with Raman spectra of pure LiNbO3 crystals. No change of the number, frequency, and relative intensity of Raman spectral lines of A1(TO) and E(TO) mode is found. There are only a very little increase in the line width. It is shown from this result that the more, intensive Raman spectral lines o,f A1(TO) and E(TO) vibrational mode are contributed by (NbO6) oxygen octahedra characteristic group of LiNbO3 crystals.
STUDY OF THE RESOLUTION IN IMAGING PROCESS OF DIELECTRIC TARGETS
Authors: TONG LIN-SU  , YIN HAN-CHUNG  ,   南京工学院电子学研究所
Published: November 2020

The influences of various factors of dielectric target in certain pick-up tubes, storage devices and electro-optic display devices on the resolution are studied in this paper. By considering the general case of anisotropic dielectric target, the optical transfer function (OTF) from surface charge raster pattern to potential or optical pattern of dielectric target is deduced. The resolution limit of the dielectric target is analyzed quantitatively. The leakage of electricity on surface and the influence of the other medium film layer introduced on target surface on the resolution are discussed in detail. For example, the MTF curves of silicon target in pick-up tubes, polystyrene target in video tape and anisotropic medium target of DKDP crystal in large screen projection TV are calculated by TQ-16 type computer, then the resolutions of these targets are found accordingly. The results obtained well coincide with the experimental curves and data in literatures. Finally, the calculation results are further confirmed by experiments on DKDP crvstal.
A NOTE ON THE NEGATIVE TEMPERATURE COEFFICIENT OF RESISTIVITY OF A Fe-25Mn-5Al-0.2C ALLOY IN LOW TEMPERATURE
Authors: YAN SHOU-SHENG  , WANG XIAO-QIAN  , LI XIAO-YU  , CHAI SHOU-SHEN  , LI YI-YI  ,   (1)北京大学物理系; (2)中国科学院金属研究所
Published: November 2020

An anomalous behaviour of the negative temperature coefficient of resistivity of a crystalline bulk Fe-25Mn-5Al-0.2C alloy was observed at low temperatures. Below 50 K the resistivity is roughly proportional to InT. It seems that the anomaly is due to some land of magnetical mechanism.
FINITE-AMPLITUDE REFLECTION WAVE OF CIRCULAR PISTON SOUND SOURCES
Authors: QIAN ZU-WEN  , SHI XIU-XIANG  , ZHAO CHUN-SHENG  , LU FENG-LING  , WANG XIAO-XIA  ,   中国科学院声学研究所
Published: November 2020

In this paper, an experimental and theoretical investigation on finite-amplitude reflection sound wave of circular piston sources is presented. The reflected field of harmonic waves from the boundary surface have been calculated. Thinking of them as the waves which radiate from the image of the piston source and treating them as the waves that seem to be generated by a new source on the vibrating boundary surface, by means of weak-shock theory, the reflection of the finite-amplitude waves can be predicated.By making use of the boundary wall of a pool, some experiments on second harmonic reflection have been done. It is shown that the average attenuation of the harmonic pressure with distance is consistent with the theory. However, along the longitudinal distance and in the cross sections perpendicular to it there are obvious interference of the harmonic waves, and longitudinal interference lengths have an order of magnitude greater than the traverse ones. According to the theoretical evaluation, it seems to be that the reflection results from the pool wall that has a thickness, a small angle between its two boundary surfaces and a fixed beam width of the primary wave. The theoretical evaluation and the experiments are in agreement with each other.
INTERMITTENT CHAOS IN THE FORCED BRUSSELATOR
Authors: WANG GUANG-RUI  , CHEN SHI-GANG  , HAO BAI-LIN  ,   (1)北京8009信箱; (2)中国科学院物理研究所
Published: November 2020

We show numerically that in the model of trimolecular reaction under external periodic force (the forced Brusselator) there exists the intermittent route to chaos. The time development of intermittent chaos and the method to distinquish intermittency from transients are studied. The large region of period 3 in the parameter space, discovered previously in the forced Brusselator, as well as smaller regions of periods 4, 5, 6 … etc., correspond to tangent bifurcations in one-dimensional mappings. Intermittency appears just before the start of every tangent bifurcation. Therefore, the period-doubling and the intermittent routes to chase are "twin" phenomena and they should be observable in many other systems described by nonlinear differential equations.
IONIC CONDUCTION DURING PRE-CRYSTALLIZATION PROCESS IN AMORPHOUS IONIC CONDUCTOR Li2B2O4
Authors: CHEN LI-QUAN  , WANG LIAN-ZHONG  , CHE GUANG-CAN  , WANG GANG  ,   中国科学院物理研究所
Published: November 2020

The temperature dependence of ionic conductivity, especially the ion transport property during pre-crystallization process in amorphous ionic conductor Li2B2O4 has been studied. When the temperature is lower than Tk(≈310℃), the ionic conduction obeys Arrhenius relation. Above the crystallization temperature Tc(≈411℃), the ion transport behaviour is dominated by the process in crystalline state. In the range Tkc, the ionic conductivity deviates from thermal excitation mechanism and is enhanced anomalously. This process is now called pre-crystallization process. It is found that the free volume model could be used to describe the ion transport properties. In pre-crystallization process there are two distinguishable steps. Below Tp(≈380℃) the ionic conductivity increase is due to the redistribution of free volume. While above Tp considerable enhancement of the ionic conductivity is caused by the in-terfacial effect between the crystallites and amorphous matrix because small amount of crystallites (less than 5%) were emerged. The pre-crystallization status of the amorphous could be remained at ambient condition by quenching the specimen to room temperature. Therefore it is possible to prepare material with higher ionic conductivity than that of pure amorphous.
THE P-T PHASE DIAGRAM OF LITHIUM IODATE (LiIO3) UP TO 40 KBARS
Authors: SHEN ZHONG-YI  , LIU JUN  , ZHANG YUN  , YIN XIU-JUN  , HE SHOU-AN  ,   (1)北京航空学院,研究生; (2)中国科学院物理研究所
Published: November 2020

The possible high pressure modifications of Lithium Iodate (LiIO3) were surveyed in the high pressure and high temperature ranges up to 40 kbar and 750℃. Two high pressure modifications have been observed. The first is found in the range of 1.5-4.9 kbars and 310-450℃, while another appears in the pressure range above 15 kbars. The phase boundries were determined by DTA and quenching method. The diagram published abroad in 1969 have been corrected and the stability of each phase at high pressures and high temperatures has been discussed.
DETERMINING THE POSITION OF LITHIUM ATOM IN LITHIUM POTASSIUM SULPHATE (C66)
Authors: GU YUAN-XIN  ,   中国科学院物理研究所
Published: November 2020

The structure of KLiSO4 at room temp erature was determined (C66) in 1925 by Bradley. The position of Li atom at the void on a triad was inferred but not measured. This result is in contradiction with the general theory of chemical bonding, so, recently, Meng and Cao presented a view disagreeing with it.We have redetermined the structure of KLiSO4, in particular the position of Li atom. New result shows that Li atom is located at x=1/3, y=2/3, z=0.1797(16) instead of x=1/3, y=2/3, z=0.3488 as described by Bradley. The former is roughly the same as that predicted by steric considerations in ref. [8]. Four nearest O atoms around Li atom form a tetrahedroid.
THE RAMAN SPECTRUM OF SINGLE CRYSTAL Gd3Ga5O12
Authors: ZHANG PENG-XIANG  , LIU YU-LONG  , MO YU-JUN  ,   中国科学院物理研究所
Published: November 2020

The Raman spectrum of Gd3Ga5O12 single crystals grown by both flux and pulling methods are measured. The different Raman phonons, are identified. Comparing with ref. [6], we get more complete results. The Raman spectrum of the two kinds of crystals grown by different methods are also compared, the phonon modes are in agreement with each other. The observed different lines are interpreted as fluorescence of contaminating rare earth ions introduced possibly during the sample preparation.
CALCULATION OF PHONON SPECTRUM USING THE RECURSION METHOD
Authors: S. Y. WU  , ZHENG ZHAO-BO  ,   (1)美国路易维尔大学物理系; (2)中国科学技术大学物理系
Published: November 2020

The phonon spectra of crystalline solids with bcc, fcc and diamond structures were calculated using the recursion method. The result of the calculation demonstrated the feasibility of this method in treating complicated systems. This work also provided a base for applying the method to study the dynamics and electronic structure of amorphous systems.
EFFECT OF H+ ON THE β→α TRANSITION IN β-LiIO3 AFTER HIGH PRESSURE TREATMENT
Authors: He Shou-an  , Zhao You-xiang  , Liu Jia-rui  , Li Yin-yuan  ,   中国科学院物理研究所
Published: November 2020

Using the X-ray diffraction method, we have investigated the effects of high pressure and H+ impregnation on β→α transition in β-LiIO3 crystals. The samples had been subjected to high pressure treatment (up to 80kb)at room temperature and then preserved in ordinary environmental condition for different periods of time. The experimental results show that in β→α transition in the samples treated as above the pressure can be understood to play a role of promoting the nucleation of a -phase in β-matrix, and the pressure dependence of the rate of nucleation N can be expressed in the form of N ∝ekp (k= 26.8/bar). The significant increase of quantity of α-phase in such samples may be attributed to the rapid growth of α-LiIO3 nucleus under the influenle of H+ formed through the dissociation of adsorped water molecules on the surface of a nucleus. This conclusion is supported by the similar effects in the experiment of H+ impregnation of pressurized β-LiIO3 samples.
DETERMINATION OF THE DISPERSION AND THE MEASURE-MENT OF THE THICKNESS OF EPITAXIAL GARNET FILMS
Authors: Wang Li-xuan  ,   中国科学院上海冶金研究所
Published: November 2020

A technique is proposed for determining the dispersion and measureing the thickness of epitaxial garnet films. Use is made fully of the transmission spectrum obtained by spe-ctrophotometer. When the wave length is greater than 2μm so that the absorption and dispersion become negligible, the refractive index at the corresponding wave length may be calculated from the extrema of the transmittance. According to the condition of in-terferrence, the order of interferrence is calculated and deduced for all interferrence extrema. The refractive indices of the film at the wave lengths corresponding to the interferrence extrema may be calculated. Finally the coefficience of Cauchy's dispersion formula are evaluated by the method of least squares, thus the dispersion relation is obtained for this film. Then, in making use of the dispersion relation, the thickness of the film may be calculated.
MEASUREMENT OF DISCHARGE CIRCUIT DISTRIBUTIVE INDUCTANCE FOR BLUMLEIN EXCIMER LASER
Authors: Chen Jian-wen  , Xia Kang-min  , Liu Miao-hong  , Zhong Fan  ,   中国科学院上海光学精密机械研究所
Published: November 2020

Technique on measuring discharge current of Blumlein circuit using magnet-light method is described briefly in this paper. The more exact method estimating distributive inductance of discharge circuit is presented. The circuit equations are solved and the analytic expression of distributive inductance is derived. Finally, the calculated result is discussed.
CRYSTAL-FIELD ENERGY LEVELS OF BeAl2O4:Cr3+
Authors: WU GUANG-ZHAO  , ZHANG XIU-RONG  ,   中国科学院上海光学精密机械研究所
Published: November 2020

The 4T2,4T1, and 2E levels of Cr3+ ion on the mirror-site in an alexandrite crystal are in relation to the laser operation of that material. The 4T2 (or 4T1) level splits into three sublevels. In order to determine the energy levele diagram of Cr3+ ions in chrysoberyl, the splitting of the 4T2 and 4T1 are calculated. We have discussed the anisotropic transition intensities of corresponding absorption bands and have found a method to fit the spectra. Furthermore, the values of the parameters K1 and K2 that represent the magnitude of the splitting are obtained, and the crystal field energy level diagram of BeAl2O4:Cr3+(II), labelled by the irreducal representations of point group C3, is given.
THE CALCULATION OF CRITICAL TEMPERATURE FOR Nb-Cu MULTILAYER FILM SUPERCONDUCTOR
Authors: CAI XUE-YU  , YIN DAO-LE  ,   北京大学物理系
Published: November 2020

The calculation of critical temperature for Nb-Cu multilayer film superconductor without any adjustable parameter shows that as the periodic character of multilayer film is considered, the theory of proximity effect agrees reasonably with experiment within the range of layer thickness d>30?.It is also shown that there exists damped oscillation in the dependence of critical temperature Tcns on d, the electronic structure of interface between Nb and Cu has obvious influence upon Tcns only when d<30? and the strong heterogeneous interface probably increases the (NV) of Nb.
OBSERVATION ON “AS GROWN” MICRODEFECTS IN CZ SILICON SINGLE CRYSTAL
Authors: MAI ZHEN-HONG  , CUI SHU-FAN  , FU QUAN-GUI  , LIN RU-GAN  , ZHANG JIN-FU  ,   (1)中国科学院半导体研究所; (2)中国科学院物理研究所
Published: November 2020

Two different type of microdefects have been observed by means of Cu-decorating X-ray topography and etching method in p-type silicon single crystal grown along and/or n-type ones grown along direction. A kind of defects with special configuration has also been found in n-type silicon single crystal. The distribution and configuration of these defects are discussed preliminarily.It was the first time to investigate the "as grown" microdefects in silicon single crystal grown by Czochraski method directly by means of X-ray transmission projection and/or section topography. X-ray topographs of microdefects in CZ silicon crystal were obtained. The configuration, size and distribution of the microdefects observed were in agreement with that obtained by Cu-decorating X-ray topography quite well.
DETERMINATION OF THE ATOMIC CONCENTRATION RATIO ON InP (100) CLEAN SURFACES BY X-RAY PHOTOELECTRON SPECTROSCOPY
Authors: Yu Ming-ren  , Yang Guang  , Wang Xun  ,   复旦大学物理系
Published: November 2020

The atomic concentration ratio of In to P on InP(100) surfaces has been determined to an accuracy of 20% by measuring the In 3d5/2 and P 2p XPS intensities and using the corresponding atomic sensitivity factor values previously derived by the authors. The experimental results show that there exists a preferential sputtering effect for the argon ion bombardment. The In to P concentration ratio reaches a value of 2.2 at 1 keV ion beam energy and increases monotonically with the ion energy. After annealing the sample at approximate 300℃ in ultra high vacuum for 30 minutes, the In to P ratio at the surface decreases to 1.2 which is quite closed to the value of bulk stoichiometric ratio. It can be deduced from the angular dependence of the XPS intensities and the chemical shift of In 3d5/2 binding energy that after the heat treatment, the In-P chemical bonds which were broken by the ion bombarding could reconnect, and the surface atomic arrangement was thus led to become an ordered structure with an outmost atomic layer rich in In.
MOSSBAUER STUDY OF Fe-Ni INVAR ALLOY
Authors: JIN MING-ZHI  , YU EN-HUA  , SUN SHAO-ZHOU  ,   (1)东北工学院; (2)吉林大学
Published: November 2020

In this paper, the magnetic behaviour of Fe-Ni invar alloy is analysed on the basis of Mossbauer spectrum. The coexistence of two magnetic states of iron atom is revealed and invar mechanism of Fe-Ni invar alloys is interpreted according to the above view point. The equations with which one can determine experimentally the magnetic moments of the iron atom in two magnetic states are presented. Anomalous phenomena of Fe-Ni alloy at about 32 wt% Ni are observed.
A STATISTICAL THEORY OF THE COLLINS' MODEL IN THE PHASE TRANSITION OF TWO-DIMENSIONAL SYSTEM
Authors: DU YI-JING  , CHEN LI-RONG  , YAN ZU-TONG  ,   安徽师范大学物理系
Published: November 2020

By using the Collins' model, Kawamura had studied the phase transition of a two dimensional system. In this work, taking into account the molecular fraction and the presence of the 4-atom, we calculated the Gibbs free energy and studied, the influence of the percent of 4-atom on the parameters of the triple point and the critical point. We obtain a phase diagram showing three phases with a triple point and a critical point. The relation between the extent of each phase and the temperature is calculated along each transition line. The obtained results are quite analogous to the behavior of the three-dimensional substances.
SOLVING THE EQUATION OF X-RAY DIFFRACTION BY GREEN'S FUNCTION
Authors: SUN ZhANG-DE  ,   北京大学物理系
Published: November 2020

Green's function of the wave equation for a perfect crystal is obtained by means of Fourier integration. Using Green's formulae, the expression of X-ray transmission wave field, D0 Dh, have been derived. With incident spherical and plane wave, Dh,D0 value are found and compared with previous results of other authors. Relationship between thickness of the sample and D0, Dh is discussed.
MEASUREMENT OF THE PITCH OF A MBBA-CC MIXTURE AND AN EMPIRICAL FORMULA FOR THE TEMPERA-TURE DEPENDENCE OF THE PITCH OF CHOLESTERICS
Authors: XIE YU-ZHANG  , RUAN LI-ZHEN  ,   (1)清华大学物理系; (2)清华大学物理系,现在上海交通大学应用物理系
Published: November 2020

The pitch of the mixture MBBA:CC=22.7 :77.3 (by weight) at different tempera-lures ranging from 37℃ to 55℃ is determined by method of Bragg scattering using 6328? He-Ne laser beam. From the present measurement and the published data on other materials, we propose an empirical formula for the temperature dependence of the pitch of cholesterics, namely p=p0-b/(T-T0), with the pitch p0 for dextrorotatory materials. This formula is well suited not only for pure materials but also for mixtures as long as the temperature is not very close to the point of transition or the point of inversion of the helicity of the materials. The constants p0 ,b and T0 for different cholesteric liquid crystals are determined from their related data.
AN INVESTIGATION ON COAGULATION EFFECT OF Fe3+ TO OXYGEN IONS IN GLASSES
Authors: XIA YUAN-FU  , LIU RONG-CHUAN  , WANG SHU-XIN  , XU CHAO  , PAN SHU-YING  , CHENG YI-BING  ,   (1)南京大学物理系; (2)武汉建材学院硅酸盐材料与工程系
Published: November 2020

Three Fe2O3 containing alkali-silicate glass systems in which the connection of glass uetwork are different each other are studied by means of M?ssbauer spectro-scopy. It is observed that Fe3+ ions in the glasses have a stronger coagulation effect in comparison with oxygen ions. There are two manifestations of the effect, i.e., the inter-polarization of Fet3+ in tetrahedra and the outer-polarization of Fe03+ in octahedra to the glass hetwork.
THE SUPERCONDUCTING TRANSITION TEMPERATURE AND THE DENSITY OF ELECTRON STATES OF TERNARY COMPOUNDS SnMo6S8
Authors: LI HONG-CHENG  , D. G. HINKS  ,   (1)Argonne National Laboratory,U. S. A.; (2)中国科学院物理研究所
Published: November 2020

It is shown in this paper that the Pauli susceptibility of the ternary compound SnMo6S8 decreases as the oxygen content increases. The change of Tc deduced from susceptibility using BCS theory is consistent with experiments.
SOUND-LIKE COLLECTIVE MODE EXCITATION WITH PION ABSORPTION IN NUCLEAR MATTER
Authors: QIU XI-JUN  , SHEN JIAN-GUO  , HUANG LING-FANG  ,   (1)中国科学院上海原子核研究所; (2)中国科学院上海原子核研究所,中国科学院上海药物研究所
Published: November 2020

The relativistic mean field theory consistent with bulk properties of nuclear matter is extended to study the excitations of the sound-like collective modes in nuclear matter. Corresponding relativistic mean field equations are solved numerically and self-consis-tently. The effective mass of nucleon the speed of the sound and the amplitude of the sound-like solution are calculated. When the nuclear density is near or greater than the saturation density, the sound-like non-trivial solution could be found.
THE CALCULATION AND OBSERVATION OF OPTICAL ROTARY ECHOS
Authors: SUN TAO-HENG  , J. A. KASH  , E. L. HAHN  ,   (1)Department of Physics,University of California,Berkeley; (2)北京大学物理系
Published: November 2020

The observation of optical rotary echos by Stark switching in infra-red region is reported. Optical rotary echo is a nutation echo and has a long relaxation time which makes it particularly useful in the study of relaxation process. An improvment of experimental condition has been made and a theoretical calculation of rotary echo is presented.
NONLINEAR OPTICAL EFFECTS OF POLYCRYSTALLINE WAVEGUIDE THIN FILM BY HIGH POWER LASER EXCITATION
Authors: XU DE-WEI  , WANG XIAN-XIU  , ZHAO JI-RAN  , JIANG MIN-HUA  ,   (1)中国科学院长春物理研究所; (2)中国科学院上海光学精密机械研究所
Published: November 2020

In ZnS waveguide thin film, using the possitively mode-looked ps (aser beam and light wave coupler, phase matching between foundamental mode TE3(ω) and second harmonic mode TE3(2ω) has been obtained and third harmonic spectra was also observed. The width of the spectral curve were 1.3 and 1.4? respectively. The conversion efficiency of second harmonic is 1.8×10-3 while the incident foundamental power is 20 MW.
THE IRVERSE SOURCE PROBLEM IN PARTIALLY COH-ERENT OPTICAL INFORMATION PROCESSING
Authors: ZHUANG SONG-LIN  , ZHENG QUAN  ,   (1)上海光学仪器研究所; (2)上海科学技术大学
Published: November 2020

In this paper, we established a mathematical model for describing a partially coherent optical processing, and the error transfer formulas are also derived. The mathematical model could be used not only for estimating the error of a restoration image, but also for predicting the optimum source distribution. The necessary and sufficient condition for achieving non-error restoration image is obtained. And we also proved that for a truncation signal, the restoration image could be obtained with arbitrary precision by using an appropriate light source.
STUDIES OF FOURIER-TRANSFORM ANALYSIS METHOD FOR ENERGY-DEPENDENT PHOTOELEC-TRON-DIFFRACTION (Ⅰ)——THE SYSTEMS OF Se-Ni(001) AND S-Ni(001)
Authors: TANG JING-CHANG  , HUANG YI  ,   (1)浙江大学物理系; (2)中国科学院物理研究所
Published: November 2020

Direct Fourier-transform analysis method for energy-dependent photoelectron-dif-fraction curves of Se-Ni(001) and S-Ni(001) systems has been studied. The effect of different energy range in which Fourier-transformation was performed on △a (layer-spacing modification) was considered. The possibility that surface structure could be determined by using these △a value and FT of experimental EDPD data has been discussed.
THEORY OF N-COMPONENT DISORDER MATERIALS WITH SHORT-RANGE ORDER
Authors: FU ZHUO-WU  ,   上海机械学院基础教学部
Published: November 2020

A theory for studying the properties of N-component disorder materials is developed. It takes into account the short-range correlation effect of nearest-neighbor atoms and includes various disorder arrangements of atoms from segregation to forming N-component compound within the same framework. The method to calculate the density of electronic states of disorder materials using extended Cluster-Bethe-Lattice Green function with a tight-binding Hamiltonian is present in detail. As an application, we calculated the densities of states of ternary disorder alloys AxByCz(x + y + z) =1 under various concentrations and different correlation parameters. The results show strikingly the effects of correlation among the atoms and of disorder on the densities of states.
BIFURCATION AND CHAOS IN FORCED VIBRATION SYSTEMS CONTAINING A SQUARE NONLINEAR TERM
Authors: NI WAN-SUN  , WEI RONG-JUE  ,   南京大学物理系及声学研究所
Published: November 2020

The phenomena of bifurcation and chaos in forced vibration systems containing a square nonlinear term x+kx+ω02x-ax2 =μcosωt have been investigated by using a 2-D iterated map and by integrating the differential equation. The critical values of control parameter μ are inversely proportional to a.
STUDIES ON PHASE EQUILIBRIUM RELATION IN PSEUDO-BINARY SYSTEMS BaB2O4-K2O AND BaB2O4-K2B2O4
Authors: WANG GUO-FU  , HUANG QING-ZHEN  ,   中国科学院福建物质结构研究所
Published: November 2020

The pseudo-binary systems BaB2O4-K2O and BaB2O4-K2B2O4 have been studies by means of X-ray diffraction and thermal analysis. The system BaB2O4-K3B2O4 is a eutectic one with eutectic temperature at 850±3℃ and the eutectic composition of 45 mol% K2B2O4. In BaB2-K2O system there exist two new compounds. A new compound 5BaB2O4·3K2O melts congruently at 903±3℃. The BaB2O4-5BaB2O4 ·3K2O forms a eutetic system. Its eutetic reaction occurs at 813±3℃ and 25 mol% K2O. Another new compound Ba4K6B8O19 melts incongruently at 860±3℃. The Ba4K6B8O19-K2O also forms a eutectic system. Its eutectic reaction occurs at about 788±3℃ and 67.5 mol% K2O.
THE FIELD EQUATION OF HALF-INTEGER SPIN IN CURVED SPACE-TIME
Authors: WU ZHI-YU  , WANG KE-LIN  ,   中国科学技术大学基础物理中心
Published: November 2020

In curved space-time the γ-algebra is proved and the Barita-Schwinger equation is written out explicitly in the tangent space, On the bases of equivalent principle, the Rarita-Schwinger equation in curved space-time is obtained.
LOW TEMPERATURE THERMOELECTRIC POWER OF AMORPHOUS (Fe1-xCrx)84B16 ALLOYS
Authors: TONG LI-TAI  , ZHOU ZENG-JUN  , WANG GUI-ZHI  ,   北京大学物理系
Published: November 2020

The absolute thermoelectric power S of amorphous metallic alloys (Fe1-xCrx)84B16 has been measured as a function of temperature in the range of 80 to 380 K for 0.01≤x≤0.46. It is found that the behavior of S(T) for the magnetic alloys does not always follow a nonlinear variation law with a shallow minimum. The. addition of a small amount of Cr (x≤0.05) is shown to lower the absolute value of S and wash out the minimum. With a larger Cr content, the alloys are weakly magnetic and the behavior of S(T) changes from nonlinear, typical of magnetic amorphous alloys, to nearly linear, similar to that for nonmagnetic alloys. A value of x of 0.15 and 0.25 is not found to have any effect on the value of 8 at the Curie temperature Tc, which happened to he in our working temperature region.
MONTE CARLO STUDY OF SU(2) LATTICE GAUGE THEORY FOR SOME ALTERNATIVE FORMS OF ACTION
Authors: LI WEN-ZHU  , DONG SHAO-JING  ,   浙江大学物理系
Published: November 2020

For SU(2) lattice gauge theory, three alternative forms of action proposed by us are studied by means of Monte Carlo method, their internal energy per plaquette and specific heat are calculated. The curves of their internal energy approach to the same weak-coupling approximation when β is large. There are peaks on their specific heat curves which indicate the critical points of transition from strong-coupling to weak-coupling. We find clear evidence showing that the deviation of critical point is only due to the difference of higher order terms of lattice spacing a.
THE SELF-FIELD EFFECT OF JOSEPHSON JUNCTION WITH SMALL DIMENSION
Authors: ZHANG YU-HENG  , SHEN XIU-LING  ,   中国科学技术大学物理系
Published: November 2020

It is pointed out in this paper that there is obviously a self-field effect in small dimension Josephson junction consisting of crossed thin films when the current in the junction is asymmetrically supplied. The symmetries of I(H)-H curves would be changed by the asymmetrical self-field.
ANNEALING PROPERTIES OF GOLD-DOPED AND UNDOPED Si-SiO2 INTERFACES IN DRY OXYGEN
Authors: LI SI-YUAN  , ZHANG TONG-JUN  , WANG IU-ZHEN  , LI SHOU-SONG  , YIN ZHI-PING  ,   兰州大学物理系
Published: November 2020

After annealing treatment in dry oxygen, the variations of the surface charges, the interface state densities and the state density distributions in the band gap, of both Au-doped and undoped Si-SiO2 interfaces were studied experimently. The annealing behavior of the negative electric effects of gold was also investigated. Furthermore, this paper presents the compared results of the electric properties of the Si-SiO2 interfaces (including both Au-doped and undoped interfaces) formed by thermo-oxidizing silicon in dry oxygen at various temperatures and gone through annealing in dry oxygen at the same temperatures.
THE EFFECT OF THE STOCHASTIC PROPERTY OF LASER ON THE DEGENERATE FOUR-WAVE MIXING
Authors: FU PAN-MING  , YE PEI-XIAN  ,   中国科学院物理研究所
Published: November 2020

The effect of the stochastic field on the degenerate four-wave mixing signal intensity hag been studied basing on the phase-diffusion model. It is shown that the ratio of the correlation time of the laser source to the relaxation time of the induced grating plays an important role. The effect of the stochastic property of laser source on the linewidth of mixing signal has also been discussed.
PARAMETRIC AND NONPARAMETRIC PROCESSES IN HIGH PRESSURE HYDROGEN SRS
Authors: GUO YI-LI  , YAO MIN-YAN  , LI GANG  , DING HAI-SHU  , LOU CAI-YUN  ,   清华大学无线电电子学系
Published: November 2020

Three orders of Stokes and six orders of anti-Stokes in several tenth atm H2 SRS are obtained simultaneously. The stimulated Raman process (SRP) and four-wave parametric process in SRS energy transfer are investigated in this pper. The off-axis Stokes ring and on-axis anti-Stokes spot are studied experimentally in more detail here, and the experimental results are discussed by means of parametric and nonparametric-theory of nonlinear optics.
THEORETICAL ANALYSIS AND EXPERIMENTAL DEMON-STRATION OF THE RADIALLY POLARIZED LASER FIELD
Authors: ZHUANG JIE-JIA  , ZHAO RUN-QIAO  , YE GUI-MU  , DAI LI-SHENG  ,   (1)中国科学院电子学研究所; (2)中国科学院高能物理研究所
Published: November 2020

The phase-adjusted focusing laser accelerator requires a laser field with special polarized distribution—a radial polarization. The theoretical work shows, by properlytransforming the TEM00 mode, such a laser field can be obtained and propagate stably in the free space. The experimental result agrees with the theoretical analysis.
THE INFLUENCE OF DISORDER ON THE ELECTRONIC STRUCTURES OF THE METALLIC SUPERL-ATT1CES——CPA METHOD
Authors: XIONG SHI-JIE  ,   南京大学固体物理研究所
Published: November 2020

The changes of electronic structures in the metallic superlattices due to disorder have been calculated self-consistently by CPA method for a simple model hamiltonian, using tight-binding approximation and only the random distributions of diagonal matrix elements being taken into account. The local densities of electronic states and the curves of self-energy have been obtained for some values of the parameters.
MEASUREMENTS OF NONLINEAR RESONANT CURVES OF A RECTANGULAR SURFACE WATER WAVE RESONATOR
Authors: WU JUN-RU  , A. LARRAZA  , I. RUDNICK  ,   (1)Department of Physics,University of California Los Augeles,U. S. A.; (2)南京大学物理系
Published: November 2020

The resonant curve of a rectangular surface water wave resonator can bend to lower frequency or to higher frequency, depending upon the depth of equilibrium water level. Besonant curves of finite amplitude water surface wave for various water level are measured. The crossover height at which the bending doesn't occur is determined.
MAGNETIC PROPERTIES OF THE RANDOM MIXTURE OF THE ONE-DIMENSIONAL SYSTEM WITH ANISO-TROPIC HEISENBERG EXCHANGE
Authors: LI ZHEN-YA  , YANG CHUAN-ZHANG  ,   苏州大学物理系
Published: November 2020

In this paper, we extend the method proposed in ref. [1] for the calculation of the partition function of the anisotropic Heisenberg spin system, and calculate the specific heat and magnetic susceptibility for random binary mixture of the one-dimensional system with anisotropic Heisenberg exchange.
THE THEORETICAL CALCULATION OF SHG COEFFICIENTS OF β-BaB2O4 CRYSTAL
Authors: LI RU-KANG  , CHEN CHUANG-TIAN  ,   (1)中国科学技术大学应用化学系; (2)中国科学院福建物质结构研究所
Published: November 2020

β-BaB2O4 crystal is a new-type ultraviolet SHG crystal as found in our Institute for the first time. In this paper, on the basis of our theoretical work of "An anionic group theory of non-linear optical effects of the crystals" and the theory of odd-ordered crystal field produced by A-site cation, we have calculated SHG coefficients of β-BaB2O4 crystal by using CNDO/S approximations. The calculated values agree satisfactorily with the experimental data, for both absolute values and relative sign of the above coefficients. The result shows that the conjugate π orbitals of anionic group (B3O6)3-give major contribution to the SHG coefficients. Moreover, it also shows that the CNDO/S-approximation is a suitable method for calculating molecular orbitals of cova-lent-bonded (B3O6)3- group in crystals.
INFRARED ABSORPTION OF NEUTRON-IRRADIATED FZ-Si GROWN IN HYDROGEN ATMOSPHERE
Authors: ZHANG YU-FENG  , DU YONG-CHANG  , WENG SHI-FU  , MENG XIANG-TI  , ZHANG BING-ZHONG  ,   (1)北京大学化学系; (2)北京大学物理系; (3)清华大学核能技术研究所
Published: November 2020

Infrared absorption spectra of neutron irradiated FZ-Si grown in hydrogen atmosphere have been measured in wavenumber ranges 1800—300 em-1 and 400—200cm-1 by FTIR. The annealing behaviour of stronger absorption bands has been shown. By comparing with spectral results of proton implanted silicon measured by IR and neutron irradiated FZ-Si grown in hydrogen atmosphere measured by DLTS, the possible constructions of H-related centers are discussed.
LATTICE DEFECTS IN α-Si3N4 STUDIED BY HREM
Authors: WEN SHU-LIN  , FENG JING-WEI  ,   中国科学院上海硅酸盐研究所
Published: November 2020

The structure defects were observed by HREM in α-Si3N4, which was made by hot-pressing method with MgO and LiF as the additives. The observations indicate that the phenomenon of phase seperation occured in the grain boundaries of three grains junction, showing inhomogeneous chemical composition in glassy phase of grain boundaries. In the grains, the stress areas caused by lattice distortion and displacement of (100) planes were found. The distortions of the lattices are so serious in some regions that the hexagonal symmetry in the unit-cell gets lost. The distortion of the lattices could be measured by the deviation of the spacings of (100) planes from the normal value, 6.771?. With HREM we have found electron radiation damage of α-Si3N4 grains at lattice level caused probably by the distortion of the unit-cells of α-Si3N4. As compared with β-Si3N4, α-Si3N4 is less stable thermodynamically. According to our observations of both α-Si3N4 and β-Si3N4 made by hot-pressing method, the defects of the structure in α-Si3N4 are much more than that in β-Si3N4. This indicates that the phenomenon probably arises from easier distortion of the α-Si3N4 lattices than that in β-Si3N4.
THE THEOREM OF MINIMUM ENTROPY PRODUCTION AND STABILITY OF STATIONARY STATES
Authors: LI RU-SHENG  ,   清华大学化学与化学工程系
Published: November 2020

The theorem of minimum entropy production and its implication to stability of no-nequilibrium stationary states are examined. It is found that, apart from the assumption of linear phenomenological relations and weak amplitudes, the validity of this theorem depends on the degree of deviation of states discussed from critical stability of local equilibrium. The possibility of oceurence of ordered structures in linear nonequ-ilibrium region is also discussed.
SUPERSTRUCTURES FORMED BY Ga ATOMS ON Ni (111) SURFACE
Authors: TU LI-XUN  , SUN YU-ZHEN  ,   中国科学院金属研究所
Published: November 2020

The structures of Ga atoms deposited on Ni(lll) surface was studied. When the coverage is less than one monolayer, two superstructures. (3(1/2)×3(1/2)) R30°and (2×2), have been observed, by means of LEED and AES.A quasi-equilibrium phase diagram has been drafted, and thus the rangs of coverage and temperature while these superstructures appear can be estimated.
EFFECT OF COMBINED ACOUSTIC AND OPTICAL PHONON SCATTERING IN NONLINEAR ELECTRONIC TRANSPORT
Authors: LEI XIAO-LIN  , TING CHIN-SEN  ,   (1)Department of Physics,University of Houston,U. S. A.; (2)中国科学院上海冶金研究所
Published: November 2020

A new approach to nonlinear electronic transport in solids is described briefly and is applied to the discussion of combined acoustic and optical phonon. scattering. It is found that although a relatively flat region may exist in the currenit-versus-field curve if the scattering by optical phonon is strong, the saturation of the current density, which occurs in the case of pure optical scattering, disappears and the acoustic phon-ons are always important at high current density.
STABLE REGION OF TOKAMAK DEVICE FEEDBACK CONTROL (Ⅱ)——EXPBEIMENTAL
Authors: Shen Zhong-qing  , Zheng Shao-bai  , WANG LONG  ,   中国科学院物理研究所
Published: November 2020

A stable region experiment of feedback control in CT-6B Tokamak has been can-ducted. Two feedback systems have been used simultaneously to control the heating field and the vertical magnetic field in the Tokamak. The experimental results were compared with the linear theory described in the part (I) of our paper. We found that the experimental stable regions is somewhat small than that predicted by the linear feedback theory.
ANALYSIS ON CRYSTAL FIELD PARAMETER OF RARE EARTH IONS IN RX COMPOUNDS
Authors: Yang Gui-ling  , Xu You  , Lu De-ling  , Zhai Hong-ru  ,   南京大学物理系
Published: November 2020

The experimental data of CFP B40 of rare earth ions in RX compounds is analyzed. On this basis, we propose a new relation, through which the CPP B40 values in RX compounds can be calculated by the simple point charge model, namely, B40=k3(B40)p + c3 The CFP B40 values in a lot of RX compouuds were determinded by this relation. Results are in good agreement with experimental values. Finally, the meaning of the relation are discussed.
THE CALCULATION OF HEAVY QUARK FORCE AND POTENTIAL IN SU(2) LATTICE GAUGE THEORY
Authors: Dong Shao-jing  ,   浙江大学物理系
Published: November 2020

The heavy quark-antiquark force and potential are calculated by means of Monte Carlo method in 4 dimensional symmetry lattice gauge theory for a single plaquette EXP action which has a good scaling behaviour. The renormalization group treatment and the icosahedral subgroup approximation to SU(2) are used. The resultes agreet with Coulomb plus linear form obtained from phenomenological string theories.
THE LOW FREQUENCY EFFECTS OF TRANSVERSE CONDUCTIVITY OF ELECTRON IN LOCALIZED STATE OF THE TWO DIMENSIONAL ELECTRON GAS IN MOS INVERSION LAYER UNDER THE CONDITION OF QUANTIZED LIMIT
Authors: Zhao Leng-zhu  ,   上海科学技术大学物理系
Published: November 2020

In this article, we analyze the frequency characteristics of electron conductivity in localized states of the 2 dimensional electron gas (2DEG) in MOS inversion layer under the condition of quantized limit. Based on the frequency dependence of Fermi distribution function, we derived the frequency characteristics of the two dominant conduction processes, i.e., the conductivity due to the process of thermally exciting to the mobility edge, σME (ω),and that due to variable range hopping process, σVRH(ω). We found that σME(ω) and σVRH (ω) are both complex functions. The time constant of σME(ω), τn, is longer, corresponding to a low frequency process. And that of σVRH(ω) is much shorter, corresponding to high frequency process. The theoretical curve is compared with experimental data. It is found that in order to fit the theoretical curve to the experimental one, the time constant τn should be approximately 3.6 ×10-6 s.
DETERMINATION OF REAL IONIZATION AND ATTACHMENT COEFFICIENTS IN OXYGEN
Authors: Li Zhen-ying  ,   华中工学院电力系
Published: November 2020

A new method for determining the real ionization and attachment coefficients in oxygen is presented. Add a small amount of CO(H2) or CO2 into O2 measure the variation of the apparent ionization and attachment coefficients with the compositions of the gaseous mixtures, and then the real ionization and attachment coefficients in O2 can be found respectively.
ELECTRONIC SPECTRA AND MOBILITY EDGES IN ONE-DIMENSIONAL INCOMMENSURATE SYSTEM
Authors: ZHENG ZHAO-BO  , ZHU KAI  ,   中国科学技术大学物理系
Published: November 2020

Fine structures of electronic spectra of one-dimensional lattice with incommensurate potential Hn,n= 1.9*(cos(0.7n) + l/3*cos(1.4n))Hn,n-1=Hn,n+1= 1 are obtained. The precise positions of mobility edges are found by means of self-energy convergence criterion. Self-similarity in spectra and mobility edges are discussed.
Impaired speed encoding and grid cell periodicity in a mouse model of tauopathy
Authors: Ridler Thomas , Witton Jonathan , Phillips Keith G , Randall Andrew D , Brown Jonathan T
Published: November 2020

Dementia is associated with severe spatial memory deficits which arise from dysfunction in hippocampal and parahippocampal circuits. For spatially sensitive neurons, such as grid cells, to faithfully represent the environment these circuits require precise encoding of direction and velocity information. Here, we have probed the firing rate coding properties of neurons in medial entorhinal cortex (MEC) in a mouse model of tauopathy. We find that grid cell firing patterns are largely absent in rTg4510 mice, while head-direction tuning remains largely intact. Conversely, neural representation of running speed information was significantly disturbed, with smaller proportions of MEC cells having firing rates correlated with locomotion in rTg4510 mice. Additionally, the power of local field potential oscillations in the theta and gamma frequency bands, which in wild-type mice are tightly linked to running speed, was invariant in rTg4510 mice during locomotion. These deficits in locomotor speed encoding likely severely impact path integration systems in dementia.
Modelling how antimicrobial resistance spreads between wards
Authors: Donker Tjibbe
Published: November 2020

Moving patients between wards and prescribing high levels of antibiotics increases the spread of bacterial infections that are resistant to treatment in hospitals.
Dansk Folkekalender for 1841
Authors: Selskabet for Trykkefrihedens rette Brug
Published: November 2020

This is the entire issue of Dansk Folkekalender 1841, as published by Selskabet for Trykkefrihedens rette Brug [Society for the Proper Use of the Freedom of the Press] in 1840.