bluuebunny/crossref_metadata_2025 huggingface dataset:
Avaliando o Custo de Contratos Inteligentes em Aplicações Blockchain por meio de Ambientes de Simulação
Authors: Coutinho Emanuel Ferreira , Maia Delano José Holanda , Bezerra Wagner L. Braga , Abreu Antonio Wellington dos Santos
Published: November 2020

Blockchain é uma sequência de blocos contendo um registro completo de transações como um livro público, informando a ordem na qual transações ocorreram, e que vem se tornando uma opção para desenvolvimento de aplicações. Os contratos inteligentes são um fluxo de valor baseado em termos e condições, semelhantes a contratos no mundo real, porém digitais e em código. O objetivo deste trabalho é apresentar uma simulação do uso de contratos inteligentes em blockchain para se ter uma visão do consumo dos recursos na execução das operações, especificamente custos financeiros. Para isso, projetou-se um contrato inteligente para simular um ambiente de doações financeiras. Como resultado foi possível se avaliar os custos dos métodos do contrato inteligente e seu impacto na quantidade de chamadas da aplicação, reforçando a importância de simular ambientes.
Soybean (Glycine max(L.)Merr.) Production in the Cameroonian Cotton Basin between the Dynamics of Structuring an Agricultural Value Chain and Sustainability Issues
Authors: Joël Fofiri Nzossié Eric , Bring Christophe
Published: December 2020

Over the past ten years, the Cameroonian cotton front, in the Sudano-Sahelian region, has experienced dynamics in soybean production, resulting in significant changes in agro-systems. From a simple hut culture not referenced in regional agricultural statistics, since 2010, soybean ranks 2nd in legumes cultivated after peanuts, followed by cowpea and voandzou, yet culturally and economically more adopted by the populations. The rapid development of cultivated areas from 6,705 ha in 2008 to 15,020 ha in 2018 is indicative of the enthusiasm shown by farmers for this speculation which, despite the almost lack of supervision on the part of public authorities, now structures a real value chain with challenges for improving farmers’ incomes, in a space where more than 80% of working people live from agricultural activities. The objective of this research is therefore to analyse the sustainability challenges of a productive and market dynamics built around speculation subject to strong demands of international competitiveness. The results show that the viability of this dynamics remains precarious through a set of constraints inherent in the proven inability of farmers to empower themselves to optimise production and control marketing, as well as the poor technical supervision of cultivation.
Do All Resistance Exercise Protocols Improve the Functional Parameters of the Elderly? A Review Study
Authors: Almeida Fabiano de Jesus , Melo Maycon Henrique , Nogueira Raquel , Prazeres Jozimar , Costa Cyrene , Bavaresco Gambassi Bruno
Published: November 2020

Context: Aging has been associated with negative changes in the neuromuscular system, significantly impairing the performance of daily life activities. A number of studies have validated functional tests (e.g. timed-up-and-go, gait speed) for the assessment of daily activity performance in the elderly. Thus, it is critical to understand the role of exercise training in this context. The practice of resistance training (RT) has been found to promote muscle strength in the elderly; however, we cannot safely state that any of these resistance exercise protocols would lead to improved performance of functional parameters (e.g. timed-up-and-go, gait speed, getting out of a chair) of this population. To assess the effects of RT on functional parameters of the elderly and to undertake a detailed assessment of the exercise protocols surveyed. Methods: PubMed, Cochrane CENTRAL, and PEDro databases were used to search the literature. A total of 917 articles were initially selected, of which 10 peer-reviewed articles met the search criteria. Results: In the included studies, the positive effects of RT on the functional parameters of the elderly were observed. The training protocols presented the following characteristics: duration of 12 – 16 - 24 - 36 - 60 - 72 sec and 96 sessions; frequency of 1 - 3 sessions per week; training volume of 2 - 5 sets of 4 - 15 repetitions; 40 - 60 - 90 - 120 - 180 sec rest interval between sets; 40 - 60 - 90 - 120 - 180 sec rest interval between exercises; 24 - 48 - 72 hour rest interval between sessions; 40 - 85% intensity of one maximum repetition; isotonic contractions, contraction velocity (as fast as possible-1 - 2 - 3 seconds to concentric and 2 - 3 seconds to eccentric phases). Conclusions: Although the benefits of RT were observed, it was not possible to determine that any of these resistance exercise protocols would lead to improved performance of functional parameters (e.g. timed-up-and-go, gait speed, getting out of a chair) of this population, given the limitations we found in the research papers reviewed.
Adhesin HpaA of Helicobacter pylori Promoted Migration of AGS Cells via IL-21 Secretion from HpaA-induced CD4+T Cells
Authors: Xia Xianru , Hua Ying , Hu Pei , Li Jie , Hu Guolin , Tang Xiaolei
Published: November 2020

Background: As known, there is a high correlation between Helicobacter pylori infection and gastric carcinoma. Objectives: Concerning the important role of adhesin HpaA of H. pylori in the infection process, we aimed to explore whether HpaA promotes gastric cancer metastasis. Methods: In this study, the levels of IL-21, MMP-2, and MMP-9 in patients’ biopsies with H. pylori infection were compared with post-treatment condition. The levels of IL-21 from CD4+ T cells and culture supernatants with the recombinant HpaA treatment were detected, and then the levels of MMP-2, MMP-9, and metastasis were detected and verified via AGS cells co-cultured with aforesaid CD4+ T cells. Results: Our results showed that higher levels of IL-21, MMP-2, and MMP-9 in patients’ biopsies with H. pylori infection than without H. pylori infection. Adhesin HpaA induced more IL-21 via CD4+ T cells, and IL-21 induced high MMP-2 and MMP-9 via AGS cells. In particular, HpaA caused this serial reaction to improve the migration of AGS cells, and aptamer HA6 (our previous report) and anti-IL-21 mcAb reduced the above phenomenon remarkably. Conclusions: In summary, our research suggested that adhesin HpaA plays a significant role in the process of gastric carcinoma cell metastasis via IL-21 from HpaA-induced T cells, and aptamer HA6 may be a potential therapeutic agent for H. pylori treatment.
Los ingresos no fiscales de la hacienda castellana en las dos últimas décadas del siglo XVII: la vía de Indias = The Non-Fiscal Income of the Castilian Treasury in the Last Two Decades of the 17th Century: The Road to the Indies
Authors: Andujar Castillo Francisco
Published: December 2020

Durante las dos últimas décadas del siglo XVII diversas reducciones fiscales hicieron disminuir los ingresos de la monarquía, pero entre 1689 y 1697, con motivo de la Guerra de Cataluña, las necesidades de la hacienda se incrementaron de forma exponencial, acentuándose así el déficit. Por tanto, fue necesario recurrir a ingresos extraordinarios, no fiscales, que compensaran esa bajada de los ingresos. Entre esos ingresos parafiscales tuvo un protagonismo de primera magnitud la «vía de Indias», es decir, la obtención en Madrid de recursos procedentes de la venta de cargos de Indias, de los préstamos de los mandos de las armadas y flotas de América y de los servicios e indultos demandados al Consulado de Sevilla, así como la búsqueda de otros medios en España, tales como la venta de títulos nobiliarios o algunos empleos de alta cotización.AbstractDuring the last two decades of the seventeenth century, various fiscal reductions decreased the monarchy’s income, but between 1689 and 1697, due to the War of Catalonia, the treasury needs increased exponentially, thus raising the deficit. Therefore, it was necessary to resort to extraordinary, non-tax income that compensated for this drop in income. Among these kind of revenues, the «Indias route» played a leading role, that is, obtaining in Madrid resources from the sale of Indias posts, loans from commanders of the navies and fleets of America and the services and pardons demanded from the Consulate of Seville, as well as the search for other means in Spain, such as the sale of noble titles or some high-priced jobs.
La insoportable carga de Leviathan. Deuda pública y alivio fiscal de los vasallos en el reinado de Carlos II = Leviathan’s Unbearable Burden. Public Debt and Fiscal Relief of the Vassals in the Reign of Carlos II
Authors: Torres Sánchez Rafael
Published: December 2020

La decadencia del imperio español durante el siglo XVII ha estado vinculada a un creciente descontrol fiscal y financiero de la hacienda estatal. No obstante, venimos asistiendo a una profunda renovación de esta imagen pesimista y finalista. Nuestro objetivo es valorar esta renovación a partir de dos elementos claves: la gestión de la deuda pública y la política fiscal. Concluimos que la hacienda de los últimos Austrias, y en especial del reinado de Carlos II, no sólo ofrecieron soluciones para un problema coyuntural, sino que con ellas se sentaron las bases de una particular política fiscal, que se podría resumir como de «alivio de vasallos» y cuya vigencia se prolongó en el tiempo y estuvo presente en el siglo XVIII.  Abstract The decadence of Spain’s empire during the seventeenth century has always been put down to an unbridled financial system. This pessimistic and doctrinaire view has recently been thoroughly rethought, however. Our objective here is to look at this new view from two key variables: the management of public debt and fiscal policy. We conclude that the financial system of the last Habsburgs, especially in Charles II’s reign, not only came up with solutions to the problems of the time but also laid down the bases for a particular fiscal policy, which could be summed up as «alivio de vasallos» (easing of the tax burden), lingering on throughout the whole eighteenth century.  Finanzas estatales; Fiscalidad; Préstamos para la guerra; Formación del Estado; Siglo XVII; España; Carlos II = State finances; tax system, war loans; state formation; seventeenth century; historiography; Spain
THE CORRELATION FUNCTION OF TWO DIMENSIONAL ELECTRON GAS
Authors: XIONG XIAO-MING  ,   上海工业大学物理教研室,中国高等科学技术中心(世界实验室)理论物理分中心
Published: November 2020

The correlation function of two dimensional electron gas with the presence of a strong perpendicular magnetic field has been studied on the basis of the wave function in small system. A formula of the correlation function of a finite cluster has been obtained for numerical calculation.
THE RELATIONSHIP BETWEEN INTERNAL AND EXTERNAL MAGNETIC FIELD IN YBa2Cu3O7 TUBE
Authors: XU FENG-ZHI  , YANG PEI-RAN  , CHEN LIB  , CHEN XIAO-LAN  , CHAI ZHANG  , LI BI-QING  ,   (1)中国科学技术大学研究生院; (2)中国科学院物理研究所
Published: November 2020

In this paper, we report the time dependence of the magnetic field inside a YBa2Cu3O7 tube, when switching on a field He outside the tube after a zero field cooling the tube into a superconducting state. In our experiment He is smaller than 4Hrm, where Hrm is the trapped field of the tube. The dependence can be expressed as Hi(t)=H0 + B0(Int + 1-exp(-t/τ)), where H0, B0 and 1/τ are functions of He, and they keep rising when He>Hrm. We suggest that the term of Int is caused by flux lines creeping, while (1-exp(-t/τ)) results from flux lines fluctuating, which is a short time effect. The shielding effect of YBa2Cu3O7 tubes is perfect for low dc field (rm/2), and better than the best normal metal for ac magnetic noise.
OPTICAL SPECTRA AND MACHENISM OF PHOTOREFRACT1 VE DAMAGE RESISTANCE OF A PROTON-EXCHANGE LiNbO3 CRYSTAL
Authors: ZHANG CHUN-PING  , SHANG MEI-RU  , ZHANG GUANG-YIN  , WU ZHONG-KANG  , WEN JIN-KE  , WEI JIANG-NAN  ,   南开大学物理系
Published: November 2020

The far IR spectra and the photoconductivity of the proton-exchange LiNbO3 waveguide were measured. Experimental results show that the machanism of good photorefractive damage resistance of protonexchange LiNbO3 waveguide is related to the fact that its photoconductivity is 5-10 times higher than that of pure LiNbO3 crystal.
STUDY OF SURFACE MAGNETISM IN A SEMI-INFINITE ISING FERROMAGNETIC SYSTEM
Authors: JIANG QIN  , LI ZHEN-YA  ,   苏州大学物理系
Published: November 2020

We use the mean field renormalization group method to treat the semi-infinite Ising ferromagnetic system with the amorphization of the surface. The critical behavior of the surface with a surface random field, including critical temperature, the possibility of tricritical and reentrant phenomena, are investigated in detail.
A NEW ATOMIC STRUCTURE MODEL OF Si {001} 2×1 SURFACE
Authors: LAN TIAN  , XU FEI-YUE  ,   成都电讯工程学院微电子技术与电子材料系
Published: November 2020

In this papar,a new atomic structure model of the Si{001}2×1 surface determined from band theory calcution of low-energy-electron diffraction are prensented.The new structure model involves a dimer band length ld = 2.387? and thee atomic layer distances d1 = 0.50±0.01?, d2= 0.96±0.01?, d3 = 1.17±0.01? and two asymmetric displacements of dimer atoms.
SURFACE ATOMIC STRUCTURE OF THE Si (111) 7×7 SURFACE STUDIED BY LOW-ENERGY ELECTRON DIFFRACTION
Authors: LAN TIAN  , XU FEI-YUE  ,   成都电讯工程学院微电子技术与电子材料系
Published: November 2020

In this paper, a scalene triangle-dimer-adatom model of the Si(lll)7×7 surface determined from band theory calculation of Low-Energ electron diffraction is prensented. We found the first-layer spacing distance d1 = 0.95±0.02?(expanded 21.3%±0.02?), the second-layer spacing distance d2=0.83±0.02?(expanded 5.9%±0.02?), the third-layer spacing distance d3 = 0.69±0.05?(contracted 10.9%±0.05?) and the fourth-layer spacing distance d4 = 2.38±0.08? (expanded 3.8%±0.08?).
THE APPLICATION OF DISLOCATION GAUGE FIELD FOR THE DISLOCATION CORE
Authors: GAO FEI  , ZHANG HONG-TU  ,   兰州大学材料科学系
Published: November 2020

In this paper, the strain and stress fields produced by the dislocation are analysed by means of continuous dislocation distribution. The dislocation distribution inside the core is expressed by the dislocation gauge fields which are calculated under certain gauge condition. The stresses inside and outside the core of a screw dislocation are obtained. Outside the core, the stresses are the same as that of Volterra dislocation, but inside the core, the stresses of the screw dislocation approach zero when ρ goes to zero. Finally, the energy of the screw dislocation is calculated.
SELF-AVOIDING TRAILS ON FINITELY RAMIFIED FRACTALS
Authors: ZHENG DA-FANG  , LIN ZHI-FANG  , TAO RUI-BAO  ,   复旦大学物理系
Published: November 2020

Using an exact real-space renormalization-group technique, we show that self-avoiding trails (SAT) and self-avoiding walks (SAW) on the Sierpinski gasket enjoy the same critical exponent ν for the ‘correlation length' and therefore belong to the same universcllily class. On the other hand, it is shown that SAT on branching Koch curves with maximum ramification number Rmax>3 belongs to another universality class different from that of SAW.
THEORY OF VELOCITY OF ULTRASOUND WITH I NFRARED DIVERGENCE IN GIASSES AT LOW TEMPERATURES
Authors: WANG GUO-LIANG  , DAI PEI-YING  ,   郑州大学物理系
Published: November 2020

The behavior of velocity of ultrasound in glasses below 3 K is analysed by combining the tunneling model and the infrared divergence theory. The variation of sound velocity is regarded as consisting of two parts, i.e., non-relaxation process and relaxation process. The former is analysed by the Bose elementary excitation theory and the latter by the theory of tun neling relaxation with infrared divergence. The theoretical curve of sound velocity vs temperature is consistent with the experimental data. The observed In T rule of sound velocity for normal frequency (107Hz) at 0.3-1K, and the phenomenon of appearance of sound velocity minimum for ultrahigh frequency (2GHz) belowe 0.1 K are also explained.
FREQUENCY MATCHING IN BEAT WAVE LASER ACCELERATOR
Authors: ZHU SHI-TONG  ,   中国科学院上海光学精密机械研究所,中国高等科学技术中心(世界实验室)理论物理分中心
Published: November 2020

Arccording the general covariant equation of motion and Maxwell equations, we derive the analytical expressions for various quantities of electron plasma wave. It is pointed out that the plasma wave with △ω = 2ωp is completely harmonic. The condition of complete resonance is given by △ω= 2ω(p0) [1+(e2(A2((1)2)+(A2((2)2))/(2m2c4)+(3e2A2(1)A2(2))/(m2c4)]-1/2.
MAGNETO-EXCHANGE MODES IN ANISOTROPIC MEDIA
Authors: LI YI-BING  , LI SHAO-PING  ,   (1)华中理工大学固体电子学系; (2)华中理工大学固体电子学系,Pennsylvania州立大学材料实验室
Published: November 2020

This paper presents an investigation of dipole spin modes in an anisotropic medium with uniaxial anisotropy and a weak exchange effect. The critical angle between surface wave and volume wave is given according to the new circumstance and the real ω vs k figure in space is analysed. The experimental results of single crystal YIG FMR spectra agree well with our calculation.
THE FREE-FERMION APPROXIMATE SOLUTION FOR KAGOME-LATTICE MIXED-SPIN MODEL
Authors: TANG KUN-FA  ,   上海交通大学应用物理系凝聚态物理研究所
Published: November 2020

In this paper, we consider a Kagome-lattise mixed-spin model and show that it is equivalent to an eight-vertex model via decimation and duality transformation. According to the free-fermion approximate solution of the eight-vertex model, the approximate expressions are given for the free energy and critical condition of the model.
CRITICAL BEHAVIOUR OF ISING MODEL WITH THREE-SPIN INTERACTIONS ON THREE-NODE HIERARCHICAL LATTICES
Authors: WANG FU-GAO  , TANG KUN-FA  , HU JIA-ZHEN  ,   上海交通大学应用物理系凝聚态物理研究所
Published: November 2020

The critical behavior of Ising model with three-spin interactions on three-node hierarchical lattices is investigated by using an exact renormalization group transformation. As in the case of Bravais lattices, the model with two-spin interactions and the one with three-spin interactions belong to different universality classes.
QUASI-TWO DIMENSIONAL BOSE CONDENSATION AND HIGH-Tc SUPERCONDUCTIVITY
Authors: LI WEN-ZU  , WU JIAN-BIN  , CHEN FENG  , CHENG KAI-JIA  ,   (1)西北核技术研究所; (2)浙江大学物理系
Published: November 2020

Starting from the quasi-two dimensional Bose condensation, we studied the influence of layer-thickness and ox gen-vacancy on the critical temperature Tc in real high-Tc, superconductors. The results are consistent with known experiments qualitatively.
THE PROPERTITIES OF GIANT RESONANCED ON HOT NUC-LEI STUDIED BY FINITE TEMPERATURE SELFCO-NSISTENT SEMICLASSICAL APPROACH
Authors: LI GUO-QIANG  , XU GONG-OU  ,   (1)南京大学物理系; (2)南京大学物理系,兰州大学现代物理系
Published: November 2020

The selfconsistent semiclassical approach is extended from the case of zero temperature to finite temperature to determine the nucleon densities of hot nuclei. The properties of giant resonances on hot nuclei, espencially the temperature dependence of the centroids, are evaluated and analysed with help of the densities above determined. Some of the present results are compared with those of HF and RPA.
A SEMICLASSICAL THEORY OF NEGATIVE FEEDBACK SEMICONDUCTOR LASER
Authors: ZHANG JIAN-PING  , LI LING  , YE PEI-DA  ,   北京邮电学院无线电工程系
Published: November 2020

In this paper, a semiclassical rate equation model has been established and the FM noise power spectrum calculated. We show that the spectral line width can be narrowed by the negative electrical feedback technique. Within the feedback loop bandwidth, the chirp-power-ratio (CPR) is reduced by a factor of 1+H, it shows that this kind of laser can be used as the light source in FSK coherent transmission system. Because of the direct modulation phase delay of the semiconductor laser, l/f-type FM noise is one of the important origin of the limitation, for linewidth reduction.
A THEORY OF SWELLING DUE TO VOID GROWTH IN IRRADIATED MATERIALS (Ⅱ)——BIAS FACTOR AND SWELLING FORMULA
Authors: ZHU HUI-LONG  ,   北京师范大学低能核物理研究所
Published: November 2020

Approximate concentration distributions of point defects around a dislocation in irradiated material are obtained by dividing the region near the dislocation into two parts in which some definite approximations are used. Then dislocation biasfactor for interstitials is determined, the value of the factor is less than the previous one by 20-50%. As a result, a formula of swelling due to void growth in irradiated materials is obtained, it agrees with experimental data reasonably.
THE ELASTIC PROPERTIES OF A DISLOCATION IN TWO PHASE MEDIUM
Authors: YANG SHUN-HUA  , HU XIAO-FENG  , MA RU-ZHANG  ,   北京科技大学材料物理系
Published: November 2020

We propose an ideal configuration of a dislocation obliquely intersecting the phase boundary in a two phase medium. By employing the general integral method of anisotropic elas-tic theory of dislocations and the Gibbia-Eshelby theorem for boundaries, we obtain the numerical solutions for elastic field of this dislocation as well as the "image" force acting on it. Our model and computing method are shown to be applicable in general. The results can be used to further calculate the interaction between this dialocation and other defects. This work is also a meaningful starting point for considering the effect of such oblique dislocations in diffusionless phase transformations.
SUPERCONDUCTIVITY RESULTING FROM ANTIFERROMAGNETIC STATES
Authors: FENG SHI-PING  ,   北京师范大学物理系
Published: November 2020

When the dopping is low enough, the holes obey Bose statistics[14], Bose-Einstein condensation of these holes may lead to occurance of superconductivity. In this framework, we have calculated some physical quantities, the results are in qualitative agreement with experiments.
LOCALIZATION-DISLOCALIZATION TRANSITION IN DISSIP-ATIVE QUANTUM TUNNELING SYSTEMS
Authors: CHEN HONG  , ZHANG YU-MEI  , WU XIANG  ,   上海同济大学物理系
Published: November 2020

Based on the renormalization effect of the phonon ground state on the tunneling parameters, a new method is proposed to investigate the localization-dislocalization transition of a tunneling system with bosonic bath. Our study shows the previous theories are in principle built on the displaced phonon state approximation, while our method may be used to examine the effects of other type of phonon ground states (such as squeezed phonon state) on the localization-dislocalization transition.
DETERMINATION OF THE TOPOLOGICAL ENTROPY OF ONE-DIMENSIONAL MAPS BY THE INVERSE ORBITS ANALYSIS
Authors: CHEN RUI-XIONG  ,   广西师范大学物理系
Published: November 2020

We generalize the resuits of ref. [1] , expplain the proof of the formulae shown in this paper by the method of the inverse orbits analysis. According to this, we can calculate the value of the topological entropy on any point in the whole parameter interval. On the basis of discussing the effect of "*" product on the topological entropy, we obtain the overview of the topological entropy of one-dimensional maps.
GROUND STATE AND POLARON AND BIPOLARON EXCITATIONS IN POLY (P-PHENYLENE)
Authors: XIE SHI-JIE  , MEI LIANG-MO  , SUN XIN  ,   (1)复旦大学物理系; (2)山东大学物理系
Published: November 2020

We have proposed a simple Hamiltonian for poly(p-phenylene) in the framework of SSH tight binding model. The calculations presented to the ground state, polaron and bipolaron show that the formation of doubly charged bipolaron is energetically more favorable than the-formation of two polarons with single, charge. Because the period of the chain is 4a, the CB and VB band will split in two, and when there is a polaron (or bipolaron) in the chain, shallow energe levels will emerge near each band edge besides the polaron (or bipolaron) energe levels, all the corresponding electronic states are localized.
HRTEM STUDY OF THE SUPERLATTICE ORTHOCLASE
Authors: XU HUI-FANG  , LUO GU-FENG  , HU MEI-SHENG  , CHEN JUN  ,   (1)南京大学地球科学系; (2)南京大学地球科学系、固体微结构物理实验室; (3)南京大学固体微结构物理实验室; (4)南京大学现代分析中心
Published: November 2020

An HRTEM study was carried out for the orthoclase (Or65 Ab21 An11) taken from the augite-mozonite deposit in Wuliang, Shandong Province. The results showed that this material consists of superlattice with long period. The relationship between extended cell parameter and triclinic subcell parameter is as follows: a=atc, b = 8d010≈8btc c= ctc, β= βtc (tc represents the triclinic subcell).The orthoclase consists of a series of triclinic domains. It is the intermediate modulated structure formed in the process of phase transformation of potassic feldspar horn C2/m symmetry to C1 Symmetry through the ordering of Si and Al in the te-terahedra.
SELF-TRANSMISSION OF PICOSECOND LIGHT PULSES IN GaAs
Authors: MA HAI-MING  , LI FU-MING  ,   复旦大学物理系
Published: November 2020

In this paper, we report the experimental and theorical results of self-transmission of pi-cosecond light pulses of 1 μm in undoped semi-insulating GaAs at Brewster angle incidence. The best fitting density of the deep level EL2 is 1.2×l016cm-3, the two-photon absorption coefficient is 29 cm/GW and the free-carrier cross section is 2.7×10-17 cm2.
SPECTRUM DISTRIBUTION OF RESONANCE FLUORESCENCE FOR ATOMS IN STRONG MAGNETIC FIELD
Authors: PENG JIN-SHENG  , HUANG XIANG-YOU  , LIU WU  ,   (1)北京大学物理系; (2)华中师范大学物理系
Published: November 2020

A theory describing the resonance fluorescance of atoms in strong magnetic field is proposed. A general expression of spectrum distribution for this resonance fluorescence is given and the relation between the spectrum and the magnitude of the magnetic field is examined.
THE INFLUENCE OF THE ATOMIC SIZE RATIO ON THE STRUCTURE OF THE AMORPHOUS ALLOY TM100-xMx
Authors: WANG XU-WEI  , SHI SHUANG-HE  , CHEN JIN-CHANG  , WANG JING-HAN  ,   (1)北京航空航天大学应用数理系; (2)北京师范学院物理系; (3)云南大学物理系
Published: November 2020

In this paper, by the computer simulation of the structure of amorphous alloy, the influence of the size ratio of M atoms to TM atoms on the structure of amorphous alloy TM100-xMx is studied with almost the same composition. For this purpose, the structures of amorphous alloy Fe80P20, Co81P19 and Fe80B20 are simulated, and the influence of the change of the atomic size ratio on the structures of amorphous alloy is analyzed based on the partial reduced distribution function, topologic short-range order, stabilization of structurc and the change of atomic size by the electron transfer etc.
INFLUENCE OF SIZE EFFECT ON CRITICAL BEHAVIORS AT FILM SURFACE
Authors: ZOU NAN-ZHI  , GONG CHANG-DE  ,   (1)南京大学物理系; (2)中山大学物理系,材料科学研究所
Published: November 2020

By using mean field theory, we discuss the influence of size effect on surface exponenu and scaling laws of a film. We indicate that a crossover phenomenon would appear.
THE CORRECTION FOR HFM HOLOGRAPHIC IMAGE FORMULAS WITH WAVELENGTH MAGNIFYIN
Authors: WANG YONG-ZHAO  , C. S. IH  ,   天津大学精密仪器工程系
Published: November 2020

The corrected coefficients for high frequence modulating (HFM) imaging formulas in holographic system are given. The exact results of the diffractive angle and coordinate value for imaging point can be obtained if corrected coefficient is used in these formulas to correct. The checking of results proved that the error in diffractive angle can be kept within 0.4 percent. The formulas of x3ν and y3ν which can be also computed simply from corrected coefficient as μ≤1 are given.
A STUDY OF Co EVAPOURATING ON γ-Fe-2O3 SURFACE BY PHOTOEMISSION SPECTROSCOPY
Authors: WU NIAN-JUAN  , QI SHANG-XUE  , CAO JIAN-MING  , XIE KAN  ,   中国科学院物理研究所
Published: November 2020

The γ-Fe2O3 surface evapourated with Co has been studied by photoemission spectros-copy. The results show that at low coverage, Co is very active and combined with the oxygen in γ-Fe2O3, while Fe in γ-Fe2O3 was reduced; at the coverage of 0.2-0.8 monolayer, some kind of CoFe2O4-like oxide was formed on the surface; with further Co coverage increasing, the Fe in the bulk began to segregate to the surface and the second monolayer of Co began to form on the surface, which destroyed the condition favourable to the formation of the oxide. We can conclude from these results that the magnetism improvement of magnetic powder coated with one- or sub- monolayer Co may have strong relation to the presence of this CoFe2O4-like oxide.
NONLINEAR THEORY OF DISTORTION OF BOUNDED ULTRA- SONIC BEAM IN RELAXATING MEDIA
Authors: DU GONG-HUAN  ,   南京大学声学研究所
Published: November 2020

In this article, a nonlinear wave equation of bounded acoustic beam in relaxating media is presented and a general solution of higher harmonics resulting from the nonlinear distortion of propagation is found by using the pertubation approach. Investigation shows that for the Gaussian ultrasonic field, the solution of higher harmonics can be given analytically, moreover their corresponding radical distributions of amplitude always maintain the Gaussian profiles. Although the dispersion may affect the amplitude of various harmonics, the variation of phase velocity of those keep the same law as the small amplitude waves of corresponding frequencies do.We also show that by means of Blackstock' operator the obtained results can be applied te the case of media with arbitrary dissipation and dispersion, including some biomedia in which the relationship between the absorption and frequency may be obtained only empirically.
IMPROVEMENTS ON THE PERTURBED HARMONIC OSCILLATOR LADDER OPERATORS METHOD IN THE NON LINEAR QUANTUM FIELD THEORY AND THE LASER THEORY
Authors: LI FU-BIN  ,   淮北煤炭师范学院物理系,安徽
Published: November 2020

The interaction potential with the form as V(x)= x2+λx2/(1+gx2) where g >0, appears in several areas of laser theory, quantum field theory, atom and nuclear physics. One could consider that the solution of the eigenequation either by the classical Rayleigh-Schr?dinger perturbation scheme or by the perturbed ladder operators scheme. Nevertheless, the perturbation series does not converge for any values of λ and g. In the present paper, it is shown that this difficulty can be overcome as long as the potential function can be expanded in a convergent series on the basis ofthe Hermite polynomials. Therefore, the eigenequation ((d2)/(dx2)-V(x)+ξ)φ(x)=0,∞2)/(dX2)-b2X2-Σkc2kH2k(b1/2X)+ξ)φ(X)=0.
THEORETICAL CALCULATIONS FOR HYPERFINE INTERACTIONS OF THE JAHN-TELLER DISTORTED DIVACANCY IN SILICON
Authors: FAN XI-QING  , SHEN SAN-GUO  , ZHANG DE-XUAN  ,   郑州大学物理系
Published: November 2020

For two main Jahn-Teller distortion modes of the divacancy in Si, hyperfine interactions of the unpaired electron of both negative and positive charged states (V2-,V2+) are calculated by using extended Koster-Slater model. The calculated results in agreement with the experiments are obtained., From these, we determe that the unpaired electron of V2+ is located at the symmetric state Ag of the energy level at 0.3eV and the V2- is located at the symmetric state Bu of the energy level at 0.63eV. We infer that the EG1 mode is the preferential mode of distortion for both V2- and V2+.
THE MAGNETIC FIELD DEPENDENCE OF THE QUASI-FLU- XON OF EXCITATION IN THE CIRCULAR SYMMETRIC ANNULAR JOSEPHSON JUNCTION
Authors: XU KUN-MING  , SHEN YA-FEI  , YAO XI-XIAN  ,   (1)东南大学计算科学与工程系; (2)南京大学物理系; (3)浙江大学物理系
Published: November 2020

In the case of existence of an applied magnetic field, the movement of the ring-shape quasi-fluxons in the circular symmetric annular Josephson junctions is investigated numerically. The behavoir of the quasi-fluxons in an applied field depends upon the geometric size of the junctions. If the width of the annular junctions is 5λJ in the radial direction, the life time of the quasi-fluxon is increased by applied field. If the width of the annular junction is 10λJ, the life dme of the quasi-fluxon is increased as well, and in addition, some evident changes of the behavior of the quasi-fluxons occur in the process of propagation and in the reflection at the boundary, due to the applied field. The size of the first zero-field step increases with applied field in the lower current direction. These changes are caused by an inhomo-geous distribution of the applied field in the junctions. A tunable resonator in the gigahertz-range using quasi-fluxons on a lossy large-area annular Josephson junction is also proposed in this paper.
THE SPONTANEOUS MAGNETIC MOMENT AND SPECIFIC HEAT ANOMALY IN HEAVY FERMION SYSTEM
Authors: MAO XIANG-LEI  , ZHANG YU-HENG  ,   中国科学技术大学物理系
Published: November 2020

We point out in this paper that the heavy Fermion system is a kind of Kondo system whose localized f-electrons can change with temperature. The theory suggests the existence of spontaneous magnetic moment in particular temperature range. According to the different distance between the f-electron band and Fermi level, there are different types of spontaneous magnetic moment effect. We also point out that the anomaly in specific heat versus temperature-curve is caused by the change of number of f-electron in heavy Fermion system. The theoretical values of specific heat coincide well with six experimental data.
XPS STUDIES OF A SERIES OF Ce(Ⅳ) AND Ce(Ⅲ) COMPOUNDS
Authors: ZHAO LIANG-ZHONG  ,   中国科学院化学研究所
Published: November 2020

XPS from Ce3d level of eerie ammonium sulfate, eerie sulfate, ceric-benzilic acid complex, eeric iodate, cerie peroxide and cerie dioxide were recorded. All of the spectra exhibit two distinct sets of structure corresponding to trivalent and tetravalent cerium ions. The Ce3d XPS of cerous oxalate, cerous sulfate, cerousbenzilic acid complex, cerous iodate and cerous chlorite were also recorded. All of them only show one set of spin-orbit splitting structure with shake-down satellites at lower binding energy side of the main peaks. The Ols spectrum of CeO2 after heating in vacuum shows two peaks with an energy separation of 2.5eV, which reflects that the valence fluctuation Ce(4f0)O(2pπ)←→Ce(4f1)O(2pn+1) may be responsible for the mixed valency in these nominal tetravalent cerium compounds.
AN ANALYSIS OF THE CRITICAL PHASE TRANSITION PHENOMENA OF ONE-DIMENSION PROBABILITY CELLULAR AUTOMATA EVOLUTION
Authors: Lü XIAO-YANG  , KONG LING-JIANG  , CHEN GUANG-ZHI  ,   广西师范大学物理系,桂林,541001
Published: November 2020

The dynamic equation of one-dimension probability cellular automata evolution is studied by means of real space renormalization group method. The phase transition phenomena in the cellular automata evolution are observed. The probability parameters at the critical point take values P0= 0, and P1 = P2 = 0.5. The critical index z = 2. A large number of data are obtained with computer.
A SIMPLE APPROACH TO STATIC PROPERTIES OF HOT NUCLEI
Authors: LI GUO-QIANG  ,   杭州大学物理系,杭州,310028
Published: November 2020

The energy density of nuclear system is derived based on the Skyrme forces and semi-empirical surface correption and Coulomb contribution. For the case of finite temperature, the analytical energy density, entropy density and free energy density are acquired with help of Sommerfield expansion to the Fermi-Dirac integrals. The energy, entropy, free energy per nucleon and the equation of state for hot nuclear matter and hot finite nuclei are calculated, compared and analysed. The possibility of studying dynamical evolution of hot nuclei is predicted.
THE ELECTRONIC PROPERTIES OF THE VERTEX MODEL FOR 2-DIMENSION QUASICRYSTALS
Authors: MA PENG-HUI  , LIU YOU-YAN  , ZOU NAN-ZHI  , ZHOU YI-CHANG  ,   (1)华南理工大学物理系,广州,510641; (2)暨南大学物理系,广州,510632; (3)中山大学物理系,广州,510275
Published: November 2020

This paper is devoted to the study on electronic properties of the vertex model of the Penrose lattice with five-fold rotational symmetric axis in the framework of tight-binding Hamiltonian. A similarity transformation is introduced to reduce the Hamiltonian, which helps to determine analytically the degeneracies of the eigenstates and to simplify the numerical calculation for the eigenenergies and the eigenvectors. It is found that two thirds of the states are doubly degenerate and the remains are non-degenerate. This conclusion is confirmed by group theory. The Hoursehold and improved Dean motheds are used to obtain the energy spectra and examine the localication of the electronic states. By several methods and criteria, three kinds of wavefunction behaviors are definitely found. The highly degenerate states are also investgated.
AMORPHOUS PHASE FORMATION OF Ni/Ti BILAYER SYSTEM BY SOLID STATE REACTION AND ION BEAM MIXING
Authors: LIU WEN-HONG  , ZHU DE-ZHANG  , WANG ZHEN-XIA  , LIU XIANG-HUAI  ,   (1)中国科学院上海冶金研究所; (2)中国科学院上海原子核研究所,上海,201800
Published: November 2020

An amorphous phase of Ni/Ti bilayer system is formed by solid state reaction and inn beam mixing. The results of TEM cross sectional photograph show that the diffusion results in the amorphous phase formation, Ni is the dominate diffusion species, and the ion beam bombardment enhances Ni diffusion.
TEMPERATURE DEPENDENCE OF CONDENSED METHANE STUDIED BY POSITRON LIFETIME MEASUREMENTS
Authors: WANG SHAO-JIE  , Y. C. JEAN  ,   武汉大学物理系,武汉,430071
Published: November 2020

Positron lifetime spectra have been measured as a function of temperature from 30 K to 150 K in condensed methane. In solid phase, the positronium (Ps) formation in free volume and the Ps yield of 27% were observed. The sigmoidal variation of o-Ps lifetime with temperature was interpreted by Ps trapping in the thermally activated defects. The activated energy Ea = 0.10±0.02 eV was derived in terms of Ps trapping model. In liquid methane with saturated vapor pressure, the results that o-Ps lifetime is 5-7ns and Ps formation probability is 36% indicate the Ps bubble formation. The temperature dependence of the bubble size and surface tension were estimated.
GaP BAND STRUCTURE STUDIED BY ARUPS
Authors: LU XUE-KUN  , HOU XIAO-YUAN  , CING XUN-MIN  , CHEN PING  ,   复旦大学表面物理实验室,上海,200433
Published: November 2020

Hel ultraviolet light has been used to take angle resolved ultraviolet photoelectron spectra (ARUPS) of GaP(Ⅲ) surfaces. The observed photoelectron peaks have been explained based on detailed analysis of the data The measured characteristics of the bulk band structure agrees well with the theoretical prediction.
ANALYSIS OF GaII SPECTRUM BY MULTICHANNEL QUANTUM DEFECT THEORY
Authors: LIANG LIANG  , WANG YONG-CHANG  , LIU XUE-WEN  ,   (1)西北师范大学,89届研究生西安冶金建筑学院710055; (2)西北师范大学物理系,兰州,730070; (3)西北师范大学物理系,兰州,730070,西安交通大学物理系710049
Published: November 2020

In this paper we have analysed the spectrum of Gall by means of multichannel quantum-defect theory (MQDT). Here the MQDT parameters for even-parity J = 0,1,2,3 and odd-parity J=1,2 bound levels involving three limits are determined through a fit of the calculated results to experimental data. The unknown energy levels of eleven Rydberg series are predicted by using these optinum parameters. The interaction between these series are discussed. The predicted energy values are in good agreement with the experimental data from ref. [1] .
SUBSTITUTION EFFECTS AND NEUTRON DIFFRACTION STUDY OF YBa2(Cu0.95M0.05)3O7-δ
Authors: YANG YING-CHANG  , ZHA YUAN-BO  , YUAN WEI-CHUN  , YANG JI-LIAN  , ZHANG BAI-SHENG  , ZHOU HUI-MING  , DING YONG-FAN  , JIN LAN  , YE CHUN-TANG  ,   (1)北京大学物理系,北京,100871; (2)中国原子能科学研究院,北东,102413
Published: November 2020

YBa2(Cu0.95M0.05)3O7-δ were identified as single phase with M = Ti, V, Cr, Mn, Fe, Co, N1, Cu and Zn. Substitution of Fe, Co, Ni and Zn for Cu makes Tc, decrease significantly, while at the same content, no distructuve effect on Tc was observed in the replacement of Cu with Ti, V, Cr and Mn. The site occupation of Ti, Mn, Fe and Co ions has been investigated by using neutron diffraction technique, and strong site preference for these ions were observed. Based on these results, the two diffrent Cu sites and their relationship to the superconductivity in YBa2Cu3O7-δ are discussed. The substitution effect for copper on magnetic properties in YBa2(Cu0.95M0.05)3O7-δ and the correlation between magnetic and superconduc-tiviting properties are reported.
TIME RESOLVED REFLECTIVITY MEASUREMENTS OF SOLID PHASE EPITAXY IN P2+ AND P+ IMPLANTED SILICON
Authors: FANG ZI-WEI  , LIN CHENG-LU  , YANG GEN-QING  , LI XIAO-QIN  , ZOU SHI-CHAN  , R. G. ELLIMAN  ,   中国科学院上海冶金研究所离子束开放研究实验室,上海,200050
Published: November 2020

The solid phase epitaxy processes of (100) Si implanted at 77K by 180 keV, 1×1014/cm2 P2+ and 90keV, 2×1014/cm2 P+ have been investigated by using time resolved reflectivity (TRB), Rutherford back scattering and channeling (RBS/C), and cross sectional transmission electron microscopy (XTEM). The difference of TRR spectra between P2+ and P2+ implanted samples annealed at 550℃ is due to the difference in implantation damage of the two different implants. Anomalous TRR spactra for P+ implanted sample can be explained by a model of two direction epitaxial growth from surface layer to amorphous layer and from substrate to amorphous layer.
EXPERIMENTAL STUDIES ON O2- IN KCl:OH-
Authors: YANG BAI-RUI  , ZHANG LIN  , CHEN LUAN  ,   (1)北京师范大学分析测试中心,北京,100875; (2)北京师范大学物理系,北京,100875
Published: November 2020

It is identified by the modulated optical absorption spectra and ESR spectra that the main form of the oxygen components in KC1:OH- is O2-. The density of O2- in the sample increases with the increasing of the irradiation time until the(OH)- ions are completely destroyed by irradiation. O2- is a very stable radical,but no direct effects on the stability of F2+ centers are detected. The energy configuration of O2- is also discussed according to the ESR data.
STRUCTURE CONSTANTS OF QUANTUM ALGEBRA AND YANG-BAXTER RELATION FOR THE Zn-SYMMETRIC STATISTICAL MODEL
Authors: WEI HUA  ,   西北大学现代物理研究所,西安710069
Published: November 2020

The Zn-symmetric solution of Yang-Baxter equation in statistical mechanics is analyzed with care, the structure constants of the corresponding quantum algebra are obtained naturally, and a direct proof for this solution is presented.
A SURVEY ON THE LIMITING BREAKDOWN STRENGTH AND ELECTRON ATTACHMENT RATE CONSTANTS IN ELECTRONEGATIVE GAS MIXTURES
Authors: LI ZHENG-YING  ,   华中理工大学电力系,武汉430074
Published: November 2020

The relationship between the limiting breakdown strength and the pressure-dependent electron attachment rate constants is discussed. Also discussed are the various types of synergistic behavior in the limiting breakdown strengths including linear, synergism, positive synergism and negative synergism which have been observed in binary dielectric gas mixtures as well as the conditions under which different types of synergistic effects would occur.
A NEW METHOD FOR SIMULATING HIGH RESOLUTION ELECTRON MICROSCOPE IMAGES FROM NON-PERIODIC OBJECTS
Authors: WANG YUAN-MING  , HU TIAN-BAO  , CHEN JIANG-HUA  , ZENG XIAO-BIAO  ,   中国科学院金属研究所固体原子象开放研究实验室,沈阳110015
Published: November 2020

It is shown that the dynamical diffraction calculation using periodic extension of the sampling boundary points leads to serious and artificial errors in the High Resolution Electron Microscope (HREM) image simulation for a non-periodic object in FFT Multi-Slice (FFTMS) method which is now routinely used for the simulation of HREM images from periodic objects.In a systematic study of the problem of induced numerical artifacts, a new method has been proposed for the HREM image simulation of non-periodic objects. It is based on some improvements in the calculation of the phase grating and the propagation operator to the Real Space Multi-Slice (RSMS) method, which are compatible with a non-periodic object.It can be seen from the comparison with the experimental HREM images that much more better agreement can be obtained by using Real Space Multi-Slice method for Non-periodic objects (RSMSN).
TRANSFERRED ELECTRON EFFECT BETWEEN DIFFERENT ENERGY VALLEYS IN SEMICONDUCTOR HETEROSTRUCTURE
Authors: XUE FANG-SHI  ,   南京电子器件研究所,南京210016
Published: November 2020

The transferred electron effect between different valleys in AlGaAs/GaAs/AlGaAs heterost-ructure is studied using the one band two valleys model in this paper. Taking the contributions from various electric field and the band offset and current are derived. The tunnelling probabilities and currents for various hetorostructures, alloy components and electric fields have been calculated. The dependence of transferred electron effect on the heterojunction interface, the band structures of the well and barrier materials, and the electric field is discussed. The computed tunnelling current agrees with the experimental results, and so the effectiveness of this model in the research of many valleys system is demonstrated. Furthermore, the difference between this transferred electron effect and the well known Gunn effect is pointed out and its application in the developing 9f semiconductor devices is discussed.
X-RAY TOPOGRAPHIC CONTRAST OF INCLUSIONS IN THE CRYSTAL OF LOW TEMPERATURE FORM BARIUM BORIC OXIDE
Authors: ZHAO QING-LAN  , HUANG YI-SEN  ,   中国科学院福建物质结构研究所,福州350002
Published: November 2020

The inclusion contrast in the crystal of low temperature form barium boric oxide (BBO) has been studied by use of X-ray topography. Two types of contrasts arranged in equi-triangular cones have been observed experimentally, and believed to be due to the atomic displacemens of Ba.
ELIMINATION OF P SEGREGATION DURING MOLECULAR BEAM EPITAXIAL GROWTH OF Si ON GaP (111) SUBSTRATE
Authors: JIANG WEI-DONG  , FAN YONG-LIANG  , SHENG CHI  , YU MING-REN  ,   复旦大学表面物理实验室,上海200433
Published: November 2020

The segregation of P from substrate to the surface of Si epilayer has been observed during MBE preparation of Si/GaP (111) heterostructure. In this paper, the mechanism of P segregation and relationship between the surface reconstruction and segregation are discussed, according to the results of AES and RHEED under different experimental conditions. The conclusion is that the segregation of P was caused by substituting P atom with Si deposited atom during growth. From this, a new method for eliminating the segregation of P efficiently is proposed.
INVESTIGATION OF THE VALENCE-BAND STRUCTURE OF GRAPHITE AND THE INTERACTION OF GRAPHITE WITH NICKEL
Authors: LUO CHUN-PING  , QI SHANG-XUE  , LI NAN  , LIN ZHANG-DA  ,   中国科学院物理研究所,北京100080
Published: November 2020

The valence-band structure of graphite was investigated by UPS and XPS, and the result was compared with theoretical result of Painter et al. Due to the interaction of C-atom with Ni-atom, Ni3C was observed after vapor deposition of Ni on graphite surface. The C 2px,y orbital is raised up to 5eV below the Fermi lever, while the C 2px orbital is approaching the Fermi lever closely after formation of Ni3C.
A NEW GENERAL FORM OF THE KRONIG-PENNEY MODEL SUITABLE FOR SUPERLATTICE STUDIES
Authors: PAN SHAO-HUA  , FENG SI-MIN  , YANC GUO-ZHEN  ,   (1)中国高等科学技术中心(世界实验室); (2)中国科学院物理研究所,北京100080
Published: November 2020

A new form of the Kronig-Penney model has been developed which is more general and practical than the new form in Ref. [1] . It gives not only odd and even index subbands separately but also wave functions for all k values. Moreover, a thorough analysis of the parity of tin-wave functions can also be given. Hence it affords a more suitable theoretical form for the analysis of superlattices and application to device designs.
DISCUSSION ON NORMAL STATE RESISTIVITY IN A RVB SYSTEM
Authors: LIU MEI  , XING DING-YU  ,   (1)东南大学物理系,南京210018; (2)南京大学理论物理中心和物理系,南京210008,中国高等科学技术中心(世界实验室)理论物理分中心
Published: November 2020

In terms of the theory of linear response, we have studied the normal state resistivity due to holon-spinon scattering or holon-phonon scattering in a RVB system. The calculated results show that the resistivity due to holon-spinon scattering may be fitted by a formula ρ- Tα with α depending weakly on temperature and varying between 1.4 and 1.5, while the resistivity due to scattering by phonons exhabits linear temperature behavior in a wide temperature range.
SUBBAND STRUCTURE OF GaAs/AlGaAs SUPERLAT-TICES UNDER CROSSED ELECTRIC AND MAGNETIC FIELDS
Authors: FAN WEI-JUN  , XIA JIAN-BAI  ,   中国科学院半导体研究所,北京100083
Published: November 2020

The subband structure and optical transition of GaAs/AlGaAs superlattices are investigated in the presence of an electric field applied along the growth direction and a magnetic field parallel to the GaAs/AlGaAs interface by using the effective mass theory. In the presence of the parallel magnetic field, the twofold degeneracy is removed and heavy and light holes are mixed. The presence of the electric field introduces the Stark shift. The magnetic-optical transition probability is also discussed.