Table of Content

20 September 1999, Volume 34 Issue 5

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A Method to Decide Non-zero Degree of A Map between Seifert Manifolds

HUANG Chengbang

1999, 35(5):  576-588. 

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In a recent paper, A. Reid, Shicheng Wang and Qing Zhou proved the following theorem: Let M₁ and M₂ be two closed aspherical Seifert 3-manifolds, whose fundamental groups have same rank. If the map f: M₁→M₂ is (π₁-surjective, i.e. f*π₁(M₁)=π₁(M₂), then f is of non-zero degree. Using this result, they also constructed a minimal Haken manifold and studied the epimorphism between the fundamental groups of 3-manifolds. In this paper, we prove that if we replace the condition "π₁-surjective" by "π₁-finite index", i.e. [π₁(M₂) : f*π₁(M₁)]<∞, the conclusion degf≠0 remans true.

Multiple-valued Feature Structure Description

YU Jiangsheng,CHENG Minde

1999, 35(5):  589-601. 

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Feature structures are used in represention of linguistic knowledge. Rounds and Kasper proposed the acyclic finite automaton to describe the feature structures (f-structures) on which Rounds-Kasper Logic is defined. Later, several persons proposed various logics that include negation in Rounds-Kasper-like framework. In this article, a description of multiple-valued feature structures based on belief lattice is established, which extends the ability of semantic operations. Then, Minimally Inconsistent Feature Description Logic and its semantics are defined. We also showed some properties of them. Finally, we presented a sound and complete proof system for our logic and a theorem of NP-completeness.

The Relations between the Hermite Interpolant and Jacobi Expansion on Equiconvergenc

LOU Yuanren

1999, 35(5):  602-608. 

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A quantitative estimates in the theory of equiconvergence of differences between the Hermite interpolant and Jacobi polynomials is obtained for functions analylic inside lemniscate. A necessary and sufficient condition that the related difference converges uniformly to zero on the boundary of the equiconvergence area is also showed.

Some Geometrical Properties of Stable Matrix Families

YU Xuegang,HUANG Lin

1999, 35(5):  609-615. 

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In this paper, we have discussed the convex directions of Hurwitz and Schur matices, then the necessary and sufficient conditions are obtained. Using these results, the continuous connection of two D-matices problem is considered, when the D set is convex, it is shown that the set which is consisted of D-matrices is connected. Then we also discuss the analogical questions in the case of polynomials.

On the Solutions of Boussinesq and Love in Elasticity

WANG Wei

1999, 35(5):  616-623. 

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The completeness of the solutions of Boussinesq and Love has been proved by Noll and Gurtin if the four hypotheses about an elastic region are satisfied. In this paper, it is proved that the four hypotheses about the elastic region are unnecessary for the completeness of Boussinesq's solution and that only two hypotheses are sufficient for the completeness of Love's solution.

Diffusional Release of Drug from Polymeric Matrix: An Approximate Analytical Solution

TAN Wenchang,WU Wangyi,YAN Zongyi,WEN Gongbi

1999, 35(5):  624-629. 

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A variable eigenvalue method has been successfully applied to moving boundary problems encountered in the diffusional release of drug from polymeric matrix. An approximate analytical solution was obtained. The computed result showed that the zeroth order solution of drug release from planar polymeric matrix was sufficiently accurate for engineering application. This investigation provided a new theoretical tool to study the diffusional release of drug from polymeric matrix.

Proper Efficiency Conditions for a Class of Multiobjective Fractional Optimal Control Problems

LIANG Zhian,YE Qingkai

1999, 35(5):  630-636. 

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It is discussed that the proper efficiency conditions for a class of constrained multiobjective fractional optimal control problems proposed by Zalmai. One important relationship between proper efficient solutions of such a multiobjective fractional optimization problems and that of a corresponding multiobjective nonfractional optimization problem is explored. By making use of this relationship, necessary and/or sufficient proper efficient proper efficiency conditions are given out.

Duality Models for a Class of Multiobjective Fractional Optimal Control Problems

LIANG Zhian,YE Qingkai

1999, 35(5):  637-645. 

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It is discussed that duality models for a class of constrained multiobjective fractional optimal control problems proposed by Zalmai on the base of the proper efficiency conditions proved by the authors earlier. Parametric type duality models like ones in the scalar case are constructed.

Measurement of Void Fraction Wave in Vertical Gas-liquid Flow

SUN Baojiang,YAN Dachun

1999, 35(5):  646-654. 

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Gas-liquid two phase flow experiments were conducted in a vertical pipe whose diameter is 112.5mm, and length is 12m. Void fraction waves were measured by impedance void fraction meters and analyzed. The results show that the liquid superficial velocity and the pipe diameter are two main factors to affect the evolution of the flow regime and the characteristics of void fraction wave. The critical void fraction of bubbly flow losing its stability becomes lower with the liquid superficial velocity goes high. The propagating velocity value of void fraction wave is higher in big diameter pipe than that of small diameter pipe. Analyzing results show that the turbulivity plays an important role in the process of flow regime evolution. The analysis on void fraction waves shows that the curves of PDF and amplitude spectrum in different regimes are different, and the frequencies of void fraction waves become single with increasing of void fraction.

The Field Distributon of the Ending Space in RFQ Accelerator and the Influence of This Distribution on Particle Motion

WU Yu

1999, 35(5):  659-664. 

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In this paper, RFQ accelerator ending space voltage distribution is calculated by using the RELAX3D software, a program motion which can simulate the influence of RFQ accelerator ending space on the particle motion is made up and this influence is calculated.

Response Time Characteristics of Proton-implanted KNbO₃ Crystals

LI Qi,XIA Zonghuang,WANG Xuemei,ZHAO Qiang,SHEN Dingyu,LU Xiting,WANG Feng,CHEN Zhijian,GONG Qihuang,SHEN Dezhong

1999, 35(5):  655-658. 

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The experimental investigation on the intensity-dependent photorefractive response of the proton-implanted KNbO₃ crystals is presented. The decay time constant was measured. The results revealed that two gratings existed simultaneously, one was caused by the photorefractive effect, and the other was contributed from the proton-implantation. The experimental results also reflect that low dose implantation hardly influence the photorefractive decay time.

Thermal Characters of Molecular Clouds and Evolutionary States of Young Stars in the Taurus and Ophiuchus

WU Jingwen,WU Yuefang

1999, 35(5):  665-671. 

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Gas kinetic temperature T_k and dust temperature T_d were obtained for the clouds in Ophiuchus and Taurus based on CO observation as well as IRAS data. The requested T_d>T_k for dust collision heating mechanism has been tested. The relationship between T_d, T_bol and evolutionary states has been analyzed. Results show that young stars in Ophiuchus core are younger than in those of Taurus, and IRAS colour temperature can be used to estimate the evolutionary states of young stars as a whole.

The Impacts of Tropical Western Pacific Warm Pool on Precipitation and Disasters in Coastal Region of China

LI Wanbiao,ZHOU Chunping

1999, 35(5):  672-679. 

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The impacts of Tropical Western Pacific Warm Pool on precipitation of China and disasters in China's coastal region have been discussed by using Warm Pool Index. The results show that Warm Pool Area Index is meanful in a certain sense for forecasting precipitation of China, Northern Boundary Index can well forecast precipitation of Yangtze River Valley and other regions of China. Area Index has anti-correlation with the interannual change of occurred numbers of typhoon in coastal region of China, significantly relation with the sea ice disaster after 1950, little relation with the occurrence frequency of sea wave disaster, and regular relation with tsunami.

Investigation of the 532nm Single-frequency Nd: YVO₄/KTP Laser and the Observation of I₂ Absorption Lines

XU Chunlin,ZANG Erjun,ZHANG Xuebin,SUN Yimin,LU Haining,ZHAO Kun,CAO Hongjun,SHEN Naicheng

1999, 35(5):  680-684. 

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A diode-pumped single-frequency Nd: YVO₄/KTP intracavity frequency-doublingcw laser has been demonstrated by the precise temperature control of the Nd: YVO₄, KTP and diode Laser. The single-frequency output power of 40.4mW at 532nm was obtained for an incident power of 515mW. The reasons of the single-frequency operation of the intracavity frequency-doubling Nd: YVO₄/KTP laser are analyzed. It is derived in theory and verified in experiment that the frequency drift of free-running laser can be decreased by increasing the cavity length. The new I₂ absorption lines besides which were recommended by CCDM in 1997 have been observed using the single-frequency Nd: YVO₄/KTP laser at 532nm.

A Fire-new Equivalent Sampling Theory

ZHENG Yi,WANG Chu

1999, 35(5):  685-690. 

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A fire-new theory for periodic or quasi-periodic signal sampling is proposed, which is especially for sampling high-frequency wideband periodic or quasi-periodic signal by low sampling rate system. We can get sample of signal using Nyquist sampling theorem, but Nyquist sampling theorem is only a sufficient theorem. After adding the periodic condition, we can obtain less limited requirements. In this paper, a mathematical model of sampling process is presented, based on stochastic processes theorem, then using this model, we establish a fire-new equivalent sampling theory.

Study of the Stark Shift of New Type Rubidium Atomic Optical Filter

ZHANG Liang,SUN Xiuqing,TANG Junxiong

1999, 35(5):  691-696. 

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It is reported in this paper the measurement on Stark shift of the center frequency of Stark tuned rubidium active atomic optical filter, by employing the scheme of acousto-optical frequency shift scaling and two-photon absorption spectroscopy. The measured value complied with the theoretically estimated result roughly. With external electrical field of up to 11kV/cm, the measured frequency shift was about 50MHz.

All Optical Add/Drop Multiplexing (OADM) Technologies in Optical Networks

ZHANG Baicheng,WU Deming,XU Anshi,WANG Chu

1999, 35(5):  697-704. 

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OADM schemes at present are summarized in this paper and all of them are classified to 4 types. Their configurations and main performance are introduced and evaluated. Also two types of configurations of OADM are verified in experiments. Finally a example is given for showing the all-optical WDM networks using OADM.

Plane-wave Scattering from Parallel Circular Dielectric Cylinders Embedded by Arbitrary Conducting Cylinders

ZHANG Yaojiang,GONG Zhonglin,XU Chenghe

1999, 35(5):  705-711. 

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A hybrid method of the equivalent microwave network technique and aggregated T-matrix algorithm is used to analyze the multiple scattering of parallel circular dielectric cylinders embedded by arbitrary conducting cylinders in this paper. A new formula is derived to relate the T-matrix of conducting cylinders with the impedance matrix of the moment method. The coupled utilization of the numerical method and analytical approach simplifies the analysis of interactions between parallel cylinders.

An Equalizer for GSM System Based on Hardware Annealing CNN

ZHAO Jianye,WANG Tingwu,YU Daoheng

1999, 35(5):  712-719. 

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In this paper, we proposed a discrete time cellular neural network (DTCNN) equalizer for GSM system and discussed the annealing method for DTCNN, both unannealed and annealed CNN equalizer's performance are simulated on computer. Compared with traditional GSM equalizer based on Viterbi Algorithm, DTCNN equalizer is easily realized. Through hardware annealing, we can set up high quality equalizer based on CNN for GSM system.

The Model of the Database System Based on Structured Markup Language

WANG Yongqun

1999, 35(5):  720-726. 

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In electronic publishing and electronic delivery, structured markup language is a key to the Single source, many applications solutions. The structured markup language provides structural information for the database and fits into information retrieval and information reuse. This article discusses the advantages of applying structured markup language into the database building and publishing. By analyzing one of the technologies SQml which get structured markup language and database connected, we discuss the defects of applying structured markup language into RDBMS. We define the database system based on the structured markup language and design a model for it.