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Showing papers by "Nanjing University of Science and Technology published in 1994"


Journal ArticleDOI
TL;DR: In this article, the authors presented a unified approach based on frequency matching to form the model of a length of transmission line with skin effect and frequency-dependent dielectric loss, treating the ordinary RLGC line as a special case.
Abstract: We present circuit models of a length of transmission line with skin effect and frequency-dependent dielectric loss, treating the ordinary RLGC line as a special case. The line is modeled as a characteristic two-port in which the characteristic impedance is approximated as the input impedance of a lumped circuit and the propagation function is approximated as the transfer function of a second lumped circuit plus an ideal delay. A unified approach based on frequency matching is presented to form the model. In the approximation, the skin effect is represented as the impedance of an RL ladder, and the complex dielectric parameter as the admittance of an RC ladder. A table of the rms error of the approximation is derived from which the complexity of the model can be found for a desired accuracy. The model is guaranteed to be stable, and since it consists entirely of lumped circuit elements and ideal delay lines and since the model parameters can be easily computed, it can be incorporated as a subcircuit model in a general circuit simulator, and the solution can be obtained by integrating the circuit equations in the usual manner. No FFT or convolution is required. >

32 citations


Journal ArticleDOI
TL;DR: In this paper, a set of series consisting of a combination of free vibrating beam functions and polynomials is used as the admissible functions in the Rayleigh-Ritz method to study the problem of the flexural vibration of thin, uniform thickness, orthotropic rectangular plates which may be continuous over several supports in one or two directions.

23 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of β-cyclodextrin (β-CD) on the spectral properties and electrochemical behaviour of barbitone sodium were studied using electrochemical and optical techniques.

19 citations


Journal ArticleDOI
TL;DR: In this article, an exact solution for the problem of radial vibrations and dynamic stresses in an anisotropic hollow sphere acted on by a dynamic interior and exterior pressure is obtained, and the features of the solution are related to the propagation of the spherical wave.

12 citations


Journal ArticleDOI
TL;DR: In this paper, a general analytical method for free vibration of arbitrarily shaped plates with an arbitrary number of concentric ring supports, elastic and/or rigid, has been presented, and the analytical solution of dynamic response of the plate is given, and unknown integral constants in the solution are obtained by utilizing the Fourier expansion collocation method.

10 citations


Journal ArticleDOI
TL;DR: In this article, a fast converging series consisting of static beam functions under point load is used as admissible functions in the Rayleigh-Ritz method to study the problem of the flexural vibration of thin, isotropic rectangular plates.

10 citations


Journal ArticleDOI
TL;DR: In this paper, the transcendental equations for twin ferrite toroidal grooved waveguide shifters are given, with typical parameters, the differential phase shift, the insertion loss and the sizes of the /spl lambda/sub g/4 impedance transformer are calculated.
Abstract: In this paper, the transcendental equations for twin ferrite toroidal grooved waveguide shifters are given. With typical parameters, the differential phase shift, the insertion loss and the sizes of the /spl lambda//sub g//4 impedance transformer are calculated. The results show that the figure of merit and the differential phase shift of the phase shifter are larger than those of rectangular waveguide phase shifter under the same condition. To prove the equations given in the paper, phase shifts are measured by experiments. The results are basically in agreement with those calculated by given equations. >

9 citations



Journal ArticleDOI
TL;DR: The photogravitational restricted three-body problem in which the mass reduction factors of two primaries q1, q2 e −∞,1] are studied and an analytic method to estimate the number of libration points and to calculate their location is given in this article.
Abstract: The photogravitational restricted three-body problem in which the mass reduction factors of two primaries q1, q2 e −∞,1] are studied and an analytic method to estimate the number of libration points and to calculate their location is given in this paper. The results show that in photogravitational restricted three-body problem, the number of libration points is from one to seven for different q1 and q2. As application, the motion of dust grain like comet tail in the solar system is also discussed.

5 citations


Journal ArticleDOI
TL;DR: In this paper, the spectral characteristics of thiamine hydrochloride in the absence and presence of β-cyclodextrin (β--CD) have been investigated to reveal the nature of the non-covalent interaction of the cyclodesxtrin system.
Abstract: The spectral characteristics of thiamine hydrochloride in the absence and presence of β–-cyclodextrin (β–-CD) have been investigated to reveal the nature of the non covalent interaction of the cyclodextrin system. It is indicated that Fourier transform infrared (FTIR) spectrometry could provide a unique and sensitive technique for the detection of microenvironment changes in solutions of the guest, which is especially important in the cases like the weak interaction between thiamine hydrochloride and β–-CD, where other spectroscopic data lack of distinct changes.

4 citations


Journal ArticleDOI
TL;DR: In this article, the free bending vibration of an annular cylindrical tank partially filled with liquid in the consideration of surface wave was studied. And the exact formulae of the mode shape functions and frequencies were deduced by means of computer.
Abstract: This paper studies the problem of free bending vibration of annular cylindrical tank partially filled with liquid in the consideration of surface wave. The exact formulae of the mode shape functions and frequencies are deduced. Results can be obtained by means of computer. The analysis shows that the effect of liquid on vibration of annular cylindrical tank is equivalent to different generalized distributive masses attached to inner and outer cylinders respectively.

Proceedings ArticleDOI
05 Aug 1994
TL;DR: In this paper, a mode filter was proposed to suppress the LLL image noise in a CCD camera using the analysis of the main noise sources of the low light level (LLL) CCD cameras.
Abstract: In this paper, on the basis of the analysis of the main noise sources of the `Low Light Level (LLL) CCD Camera' which our teaching and research section developed, a new method, mode filter, is put forward and taken to suppress the LLL image noise. At last the detailed analysis and discussion on the processing results are given.

Proceedings ArticleDOI
21 Sep 1994
TL;DR: The nuclei are segmented by thresholding using the adaptive threshold function obtained in the learning phase using the B-Spline technique for RGB and HSI color spaces for the detection of lung cancer cells.
Abstract: This presentation discusses the problem of segmentation of nuclei in cytological color images in different color spaces, namely RGB and HSI color spaces, for the detection of lung cancer cells. For the segmentation in each color space, the background and foreground of the images are first defined, and the chromatic mean values of the background and foreground are then extracted. In the learning phase, based on the chromatic mean values of the background and foreground of training samples, an adaptive threshold function is constructed for each color space using the B-Spline technique. The nuclei are then segmented by thresholding using the adaptive threshold function obtained in the learning phase. Comparisons between the segmentation in RGB color space and in HSI color space are carried out.

Journal ArticleDOI
TL;DR: The conformation of the inclusion complexes between barbitone sodium and β-cyclodextrin (β-CD) has been specifically investigated by nuclear magnetic resonance (NMR) spectrometry as discussed by the authors.
Abstract: The conformation of the inclusion complexes between barbitone sodium and β-cyclodextrin (β-CD) has been specifically investigated by nuclear magnetic resonance (NMR) spectrometry. It appears that the presence of the nitrogen heteroatoms within the barbiturate ring and the space-regulatory role of the side-chains contribute to the relatively weak complexes formed.

Proceedings ArticleDOI
05 Aug 1994
TL;DR: The author conducted the research and manufactured the device which measured automatically the image point homogeneity of the high density matrix LED display, and gave the measuring plan of the integrating sphere-photoelectric multiplex tube.
Abstract: In this paper, the author conducted the research how to measure automatically the image point homogeneity of the high density matrix LED display, gave the measuring plan of the integrating sphere-photoelectric multiplex tube, manufactured the device which measured automatically the image point homogeneity of the matrix LED display. Because the device adopted MCS-51 microcomputer on chip for controlling system, quick and automatical measurement was realized. The device had the function that information was exchanged between user and computer so as to measure all kinds of high density matrix LED display. After correcting the measuring error, the precision of complete set of measurement equipment was up to 1.7%.

Journal ArticleDOI
TL;DR: This work combines the technique of stepped acousto-optic defection with a laser interferometer to construct a new high-speed and multiframe interferometric photography instrument and uses it to record time-sequence interferograms of a transient combustion field.
Abstract: We present the application of a stepped acousto-optic deflection technique to interferometric photography. We combine the technique of stepped acousto-optic defection with a laser interferometer to construct a new high-speed and multiframe interferometric photography instrument and use it to record time-sequence interferograms of a transient combustion field. Furthermore, on the basis of these interferograms, we calculate the temperature variations of the field with time quantitatively.

Proceedings ArticleDOI
01 Jun 1994
TL;DR: An on-line image analysis system for the automatic distribution analysis of holographic particles in 3D space is described, and an entropy based automatic threshold selection method is adopted to segment the candidate particles.
Abstract: This presentation describes an on-line image analysis system for the automatic distribution analysis of holographic particles in 3D space. To obtain the 3D distribution parameters of particles, sequences of 2D cross-sectional retrieved images of the particle hologram are obtained using the in-line retrieval method, and the processing of the 2D retrieved images is discussed in this presentation. To segment the candidate particles, an entropy based automatic threshold selection method is adopted. In the process of out-of-focus particle removal, the radial intensity profile of the candidates in the original image and the clearness of the candidate neighboring areas in the Sobeled image are analyzed. Experimental results are presented to show the efficiency of the approach described in this presentation.

Journal ArticleDOI
TL;DR: Algorithms for extracting shock wave fronts from interferograms of a flow field and for registering time-series shock waves are proposed and results indicate that the propagation velocity of the shock wave can be easily calculated with this method.
Abstract: Algorithms for extracting shock wave fronts from interferograms of a flow field and for registering time-series shock waves are proposed. Based on these, application software is developed on a PC-Vision 100 image-processing system. As application examples, interferograms of a primary high-explosive flow field and a real, solid rocket muzzle flow field are processed. The results indicate that the propagation velocity of the shock wave can be easily calculated with this method.

Journal ArticleDOI
01 Sep 1994-Polymer
TL;DR: In this article, metal-containing polyimides having ionic linkages in the main chain and their parent polyimide, were synthesized and the structures of these materials were investigated by using solid-state n.m.r. spectroscopy.

Proceedings ArticleDOI
23 Sep 1994
TL;DR: In this article, an analytical solution for nonlinearity of the scanning with tetrahedral column rotation mirror is obtained, and a nonlinear curve of the rotating mirror scanning is given.
Abstract: According to optical basic theory, an analytical solution for nonlinearity of the scanning with tetrahedral column rotation mirror is obtained, and a nonlinear curve of the rotating mirror scanning is given. On the basis of the theoretical analysis, a single-chip double-face-mirror two-dimension scanning system is designed, and this system can overcome effectively the nonlinear feature of the polyhedral column rotating-mirror pendulum-mirror system, and also bring a convenience for succedent real-time image treatment by computer.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Journal ArticleDOI
TL;DR: Azatyan et al. as mentioned in this paper calculated the excitation energies for low-lying electronic states X 2 B 1, 2 A 1, 2 B 2 and 2 A 2 of the NCl 2 radical with a double-zeta plus polarization basis set.
Abstract: The equilibrium geometries, excitation energies, force constants and vibrational frequencies for the low-lying electronic states X 2 B 1 , 2 A 1 , 2 B 2 and 2 A 2 of the NCl 2 radical have been calculated at the MRSDCI level with a double-zeta plus polarization basis set. Our calculations indicate that the X 2 B 1 → 2 A 2 transition may correspond to the X → A band system which lies between 275 and 314nm in the absorption spectrum reported in A.G. Briggs and R.G.W. Norrish, Proc. R. Soc. London, A278 (1964) 27; T.C. Clark and M.A.A. Clyne, Trans. Faraday Soc., 65 (1969) 2994; V.V. Azatyan, R.R. Borodulin and N.M. Rubtsov, Dokl. Akad. Nauk SSSR, 249 (1980) 1375; V.V. Azatyan, R.R. Borodulin and N.M. Rubtsov, Dokl. Phys. Chem., 249 (1980) 1056. Our calculated excitation energies for X 2 B 1 → 2 A 1 and X 2 B 1 → 2 A 2 , vibrational frequencies for the X 2 B 1 and 2 A 2 states and the geometry for the X 2 B, state are in agreement with available experimental data. The electronic transition dipole moments, oscillator strengths for the 2 A 2 → X 2 B 1 and 2 A 2 → X 2 B 1 transitions and radiative lifetimes for the 2 A 1 and 2 A 2 states are calculated based on the MRSDCI wavefunctions, predicting value of the radiative lifetime for the 2 A 1 state also in reasonable agreement with experiment.

Proceedings ArticleDOI
01 Feb 1994
TL;DR: In this paper, the state of linear polarization degenerates into an average elliptical polarization for the multi-effect diffuser, and the degeneration increases as the multi effect is stronger.
Abstract: When laser light is incident on biotissue, the multiple reflection and scattering occur, which may cause the polarization state of laser speckles to have some changes. In this paper, we present an experiment study of the state of polarization of speckles generated from a multi- effect simulated biotissue, i.e., diffuse having multi-effects, via transmission, illuminated by a linearly polarized laser beam. It is found that in the case of non-multieffect diffuser the resulting speckles are linearly polarized as that of the illuminating beam. However, the state of linear polarization degenerates into an average elliptical polarization for the multi effect diffuser, and the degeneration increases as the multi-effect is stronger.

Proceedings ArticleDOI
05 Jan 1994
TL;DR: A new method to realize a Pade approximation of the characteristic impedance function at any given set of matching frequencies with any given order is provided and applied to approximate the propagation function.
Abstract: We present a SPICE model for a length of RLGC transmission line. The line is modeled as a characteristic two-port in which the characteristic impedance is approximated as the input impedance of a lumped circuit and the propagation function is approximated as the transfer function of a second lumped circuit plus an ideal delay. We provide a new method to realize a Pade approximation of the characteristic impedance function at any given set of matching frequencies with any given order, and we apply it to approximate the propagation function. The model is stable, exact at s=0 and accurate in the whole frequency region /spl omegaspl isin/(0,/spl infin/). Therefore, for a given accuracy, our model is simpler than the existing models. >

Proceedings ArticleDOI
26 May 1994
TL;DR: In this paper, the authors investigated the polarization properties of reflection laser speckles and the relative correlation between speckle patterns of different polarization, and found that the maximum linear polarization always occurs at the direction of specular reflection of the average diffuser surface.
Abstract: In this paper we present the study on reflection speckles. We have investigated the polarization properties of reflection laser speckles and the relative correlation between speckle patterns of different polarization. If the diffuser is a pure glass it is found that reflection speckles are linear--polarized as that of the incident beam. This state of linear polarization of the speckle field degenerates into a state of average elliptical polarization as the diffuser surface is coated with a layer of flat white paint, as simulated biotissue; the degeneration increases as the thickness of the paint increases. The state of polarization is also a function of the scattering angle, and the maximum linear polarization always occurs at the direction of specular reflection of the average diffuser surface.

Proceedings ArticleDOI
25 Oct 1994
TL;DR: The basis idea is that the front face images of a person are considered as the samples coming from multiple classes, each class corresponding to theFace images of one head orientation based on which an algebraic feature extractor and a classifier can be built for this person.
Abstract: This paper proposes a new technique for the identification of face images. The basis idea is that the front face images of a person are considered as the samples coming from multiple classes, each class corresponding to the face images of one head orientation. Therefore, for each person, we can take his front facial images from a number of head orientations as training data based on which an algebraic feature extractor and a classifier can be built for this person. The problems of feature extraction, classifier design, face verification and recognition are discussed in this paper. Experimental results are also provided.

Proceedings ArticleDOI
18 Mar 1994
TL;DR: In this paper, an iterative direct 3D reconstruction algorithm from the interferometric data of two consecutive times is presented, where the problem of calculating physical fields of fluid is discussed.
Abstract: In practical applications, it is possible to acquire multidirectional interferometric data of different instants. In such cases, refractive-index fileds can be reconstructed based on the multidirectional interferometric data of two consecutive times. The advantages of using the interferometric data of different instants include: more a priori information and knowledge about refractive-index fields can be incorporated in reconstruction and the problem of sovling velociety, temperature and pressure fields will be simplified. In this paper. An iterative direct 3D reconstruction algorithm from the interferometric data of two consecutive times is presented. The problem of calculating physical fields of fluid is discussed. The experimental results are also provided.

Proceedings ArticleDOI
30 May 1994
TL;DR: A new lumped model of /spl radic/s which is scalable, exact at zero frequency and accurate over a wide frequency range is presented, which can be implemented in SPICE using existing circuit elements.
Abstract: A system of coupled transmission lines with frequency-dependent parameters is decoupled into separate, uncoupled lines by a linear transformation, in which each element, being a function of frequency, is modeled as a transfer function of a lumped circuit. Each decoupled line is modeled by its characteristic 2-port. Lumped models of the characteristic impedance and the propagation function are given. For lines with skin effects, we present a new lumped model of /spl radic/s which is scalable, exact at zero frequency and accurate over a wide frequency range. The model of the entire system of coupled lines can be implemented in SPICE using existing circuit elements. >

Proceedings ArticleDOI
10 May 1994
TL;DR: In this paper, a new algorithm is proposed to calculate the Laplace transform of the product of functions, so that the transformation can be used to solve the problem of nonlinear systems.
Abstract: A new algorithm is proposed to calculate the Laplace transform of the product of functions, so that the transformation can be used to solve the problem of nonlinear systems. The nonlinear transfer functions and approximate solutions of pulse response of first and second order systems calculated by this method are the same as by Volterra series method, but can be obtained more conveniently. The frequency responses of first and second order systems with cubical nonlinearities and their stability problem are studied. A judgement is proposed for second order nonlinear systems to prevent some special phenomena of nonlinear systems, such as jump, superharmonic resonance, bifurcation, etc. >

Proceedings ArticleDOI
25 May 1994
TL;DR: In this article, the TEA CO2 laser has many advantages, such as high gain, no gas flow is needed and multi-light pulses output can be obtained in very little time interval.
Abstract: The TEA CO2 laser studied in this paper has many advantages. The multi—dis-charge regions are arranged in its optical cavity. It can produces multi—optical puls- es and the interval time between these pulses may be adjusted. Its structure is sim- ple , and it can be operated without gas flow. However , it is concerned by many sci-entists , that the stable output of multi — optical pulses how to be obtained. In thepresent paper, we have paid special attention to study the measurements and experi-mental technolgies for raising the output stability of multi—optical pulses.1. INTRODUCTION The laser studied in this paper is multi—electrod pairs TEA CO2 laser. Multi—electrod pairs are arranged in its optical oscillating cavity to obtain multi—light puls- es output. This type of laer has many advantages, such as high gain, no gas flow is needed and multi—light pulses output can be obtained in very little time interval.The application of intence laser pulses is wide. It can be used in the study of two—photon effection and holography, and also be used as a puming source of far infra-red laser. However the stability of its light pulses output is always poorer, and it haslimited the application of this type of laser. So, it is concerned by many scientists,that the stable output of multi—light pulses how to be obtained. For this reason, wehave paid more attention to the general design of apparatus and the choicing of opti-mum distance between multielectrod pairs to raising the output stability

Journal ArticleDOI
TL;DR: In this paper, the domain integral of the form of Poisson equation is translated into complete boundary integral by the fundamental solution of higher-order Laplace operator, the dimensions of the problem can be contracted into one.
Abstract: In this paper, the domain integral of the form of Poisson equation is translated into complete boundary integral by the fundamental solution of higher-order Laplace operator, the dimensions of the problem can be contracted into one. The numerical examples for Stokes equations show that this method is efficient.