Showing papers by "Nanjing University of Science and Technology published in 1998"
TL;DR: In this paper, the multidimensional transient temperature profiles of the arterial and venous blood flows and of the tissue within a limb are simulated with the bioheat equations developed by means of the heat transfer principle in porous media.
109 citations
TL;DR: Experimental results show the proposed perceptually based watermarking technique for an image has excellent performance in the quality of the watermarked images and the robustness of theWatermark.
Abstract: A perceptually based watermarking technique for an image is proposed. Based on the just-noticeable difference model in the wavelet domain, the watermark is inserted in the wavelet coefficients and its amplitudes are controlled by the wavelet coefficients so that watermark noise does not exceed the just-noticeable difference of each wavelet coefficient. Meanwhile, the order of inserting watermark noise in the wavelet coefficients is the same as the order of the visual significance of the wavelet coefficients. Hence, our approach is adapted with the image content and transparency, and the robustness of the digital watermark can be guaranteed. Experimental results show our approach has excellent performance in the quality of the watermarked images and the robustness of the watermark.
108 citations
TL;DR: In this paper, the UHF-SCF-AM1 MO method has been applied to study pyrolysis initiation reactions (homolysis of bond C-NO2 into radicals) of seven nitro derivatives of aminobenzenes.
80 citations
43 citations
TL;DR: In this paper, the authors measured biogenic sulfur gases emitted from Chinese rice paddies with a laboratory incubation and a closed chamber method in the field and found that the diurnal and seasonal variations of total volatile sulfur gases and DMS indicate that their emissions were greatly influenced by air temperature and the activity of the rice plant.
34 citations
TL;DR: An algorithm is derived to find a minimum spanning table which corresponds to a Minimum spanning tree in the directed graph, and how to use the algorithm to find the optimal competence set expansion is discussed.
Abstract: Each directed graph with asymmetric costs defined over its arcs can be represented by a matrix or table, called an expansion table. We explore first the basic properties of cycles and spanning tables of expansion tables, which correspond to the cycles and spanning trees of the directed graph. Then, we derive an algorithm to find a minimum spanning table which corresponds to a minimum spanning tree in the directed graph. Finally, we discuss how to use the algorithm to find the optimal competence set expansion and also discuss related problems.
33 citations
TL;DR: In this article, Al 2 O 3 -TiO 2 composite oxide nanocrystals with different ratios (1/4, 2/3, 3/2, and 4/1) were prepared by the poly(ethylene glycol) (PEG) sol-gel method.
25 citations
TL;DR: In this article, eight novel polyurea-imides were prepared by a three-step reaction procedure, and the results of the interfacial tension of the PUI indicate that not only the choice of diamines and dianhydrides with different structures, but also the introduction of ureylene linkage into polyimides are effective approaches to the modification of polyimide's interface.
22 citations
TL;DR: In this paper, the authors report morphologies of polypyrrole (PPy) films with different thicknesses on the microporous films of TiO2 and the influence of the thickness of PPy films on the characteristics of the TiO 2/PPy diodes.
22 citations
TL;DR: In this paper, the full optimized geometries, electronic structures and thermodynamic properties of 1H-tetrazole, 2H-to-trazole and the transition state of the tautomerization reaction are obtained based on ab initio MO calculations at MP2/6-311G** level.
Abstract: Fully optimized geometries, electronic structures and thermodynamic properties of 1H-tetrazole, 2H-tetrazole and the transition state of the tautomerization reaction are obtained based on ab initio MO calculations at MP2/6-311G** level. In addition the thermodynamic functions and kinetic parameters of the tautomerization reaction are also computed. The influence of temperature on the properties and on the equilibrium of the tautomerization is elucidated. It is found that the calculated thermodynamic properties with the unscaled frequencies at MP2/6-311G** and MP2/6-31G* levels agree quite well with the experiment results.
22 citations
12 Oct 1998
TL;DR: In this article, the authors analyzed a kind of chaotic modulated signal, these phase modulated radar signals are generated by chaotic signals and the ambiguity function of the coded signals is also given.
Abstract: This paper analyzes a kind of chaotic modulated signal, these phase modulated radar signals are generated by chaotic signals. The ambiguity function of the coded signals is also given. Theory and simulation results show that the ambiguity function of the chaotic modulated signals is approximately "thumbtack-shaped" for the ideal result. Thus the signal has high resolution both in the time-delay domain and the Doppler frequency domain. It implies the possibility and advantages for chaos to be used in radar signal processing.
TL;DR: It is shown that synchronization of smooth (hyper)chaotic systems can be attained with any scalar transmitted signal by combining the technique of observer design and phase space reconstruction in nonlinear dynamical systems theory.
Abstract: By combining the technique of observer design in nonlinear control systems theory and the technique of phase space reconstruction in nonlinear dynamical systems theory, we show that synchronization of smooth (hyper)chaotic systems can be attained with any scalar transmitted signal. The proposed method has been illustrated via two examples.
TL;DR: In this article, an explicit representation for the rotation tensor which contains the lower powers of deformation gradient is proposed and used to evaluate the angle and axis of the rotational tensor.
Abstract: An explicit representation for the rotation tensor which contains the lower powers of deformation gradient is proposed and used to evaluate the angle and axis of the rotation tensor. Some related equations about the rotation tensor are established. Through the approximate analysis, the relation between the S-R decomposition and the polar decomposition is examined.
TL;DR: In this paper, the degradation of polysilanes in solution irradiated by ultrasonic waves has been studied by measurements of reduced viscosity and dynamic mechanical behavior in all cases ultrasonic degradation occurs.
TL;DR: In this paper, the currentvoltage characteristics of ITO/TiO2/PPy/Al microporous diodes were measured, revealing that the current density for electropolymerizing polypyrrole (PPy) films affects not only the conductivity of PPy films but also the rectifying ratios for the ITO, TiO2, and PPy/Al Diodes.
TL;DR: A modified iterative conjugate gradient technique is developed and applied to limited-view interferometric tomography for reconstructing flow fields of simple structure and is effective in dealing with significant noise present in the data.
Abstract: A modified iterative conjugate gradient technique is developed and applied to limited-view interferometric tomography for reconstructing flow fields of simple structure. The approach is also effective in dealing with significant noise present in the data. From a computer simulation of experiments, a multipath interferometric system is built, from which multidirectional projection interferograms can be captured in real time for fast transient phenomena. The system is employed to measure an asymmetric temperature field. The three-dimensional field is then reconstructed with the developed experimental and computational techniques. The results are satisfactory when compared with thermocouple measurements.
TL;DR: In this paper, the potential energy curves of internal rotation were calculated for 1,3-butadiene at the MP2/6-311G level, for isoprene and 1, 3-pentadiene and styrene at MP2 /6-31G* level.
Abstract: The potential-energy curves of internal rotation were calculated for 1,3-butadiene at the MP2/6-311G** level, for isoprene and 1,3-pentadiene at the MP2/6-311G* level, and for 2,3-dimethyl-1,3-butadiene and styrene at the MP2/6-31G* level. The geometries of the energy minima (stable conformers) and maxima (transition states) on the curves are completely optimized. For butadiene and its methyl derivatives, two stable rotamers, s-trans and gauche conformers, are obtained. s-trans forms have the lowest energies and gauche conformers twisted by 39.9°–48.3° around the central bond of the butadiene skeleton are, on average, 9.8 kJ/mol above the trans forms. s-cis forms are rotational transition states. The computed gauche–cis barriers range from 4.30 to 11.70 kJ/mol. The regular effects of methyl substitutions at the end and central carbons are found. For styrene, the planar form is calculated to be a saddle point which is only about 1 kJ/mol higher in total energy than a twisted minimum, in which the torsional angle between the phenyl and vinyl planes is 27.4°. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: 659–667, 1998
TL;DR: The use of a segmental flow injection analysis (SFIA) system, a hybrid of segmented continuous flow analysis (SCFA) and Flow Injection Analysis (FIA), can significantly expand the application scope of flow analysis techniques by facilitating determinations with relatively slow reactions.
Abstract: The use of a segmental flow injection analysis (SFIA) system, a hybrid of segmented continuous flow analysis (SCFA) and flow injection analysis (FIA) that integrates the essential favorable merits of FIA and SCFA, can significantly expand the application scope of flow analysis techniques by facilitating determinations with relatively slow reactions and/or requiring reaction at elevated temperatures. The higher dispersion with longer residence times inherent in flow injection systems can be feasibly and efficiently improved by adopting the SFIA technique. The principle behind this technique, some innovative designs of the devices for SFIA sampling and segmentation, and for bubble removing, as well as novel applications to a variety of analytical problems, are reviewed and discussed. Some salient features and unique advantages of this technique are outlined.
TL;DR: In this article, thin films of MgO have been grown on H-terminated Si (100) substrates by pulsed laser deposition and the (110)-oriented and (111)-oriented films were obtained at ambient pressure of 10−3 Pa and at various substrate temperatures from 400 to 750°C.
TL;DR: In this article, the molecular geomitries and electronic structures of four chlorotetrazoles were calculated with an ab initio method at MP2/6-311G* * level.
Abstract: Molecular geomitries and electronic structures of four chlorotetrazoles are calculated withab initio method at MP2/6-311G* * level. The results show that all the titled compounds are planar and aromatic. The skeletal bond lengths of the ring tend to be uniformized. Compared with 1-and 2-substituted chlorotetrazoles, 5-substituted chlorotetrazoles are more acidic and lower in total energy. 5-chloro-2H-tetrazole has the lowest energy and is the most stable.
TL;DR: In this paper, the transition of laser plasma waves into laser plasma acoustic waves has been discussed first, and it is suggested that the weak limitation of laser-induced-plasma shock wave is an acoustic wave.
Abstract: In this paper, the transition of laser plasma waves into laser plasma acoustic waves has been discussed first, and it is suggested that the weak limitation of laser-induced-plasma shock wave is an acoustic wave. Based on this idea, a definition of laser plasma acoustic wave is given, and this kind of acoustic waves for some materials has been obtained experimentally.
18 Aug 1998
TL;DR: In this article, an approximate analysis of microstrip lines with finite metallization thickness and conductivity by method of lines (MOL) combined with the synthetic asymptote method is presented.
Abstract: Using the approximate spectral domain Green's function, which is based on the current and charge distribution at the top and bottom surfaces of the microstrip, an approximate analysis of microstrip lines with finite metallization thickness and conductivity by method of lines (MOL) combined with the synthetic asymptote method is presented. Also the loss of dielectric and ground plane have been taken into account in the analysis. Numerical results show the validity of this method.
TL;DR: In this paper, an anti-condensation ship coating is discussed, and equipment designed for evaluating the performance of the coating quantitatively is described, and an isobutylene-anhydride based copolymer is synthesized and used as a water absorbing resin instead of a starch-based water-absorbing resin currently used in the coatings.
Abstract: A novel anti-condensation ship coating is discussed, and equipment designed for evaluating the performance of the coating quantitatively is described. An isobutylene-anhydride based copolymer was synthesized and used as a water-absorbing resin instead of a starch-based water-absorbing resin currently used in the coatings. Expanded perlite was used as the heat insulation material. The optimum formulation was determined to be titanium dioxide powder 5.1 g (8.26%); perlite 12 g (19.44%); zeolite 13 g (21.06%); water-absorbing resin 3 g (4.86%); tributyl-phosphate 0.3 g (0.49%); emulsifier OP-10 0.3 g (0.49%); and styrene-acrylate copolymer emulsion 28 g (45.38%).
06 Oct 1998
TL;DR: A set of effective algorithms to automatically detect the lung cancer cells in the cytological color image of examines' sputum smears using a hierarchical processing architecture for segmentation and recognition is proposed.
Abstract: In this paper, we propose a set of effective algorithms to automatically detect the lung cancer cells in the cytological color image of examines' sputum smears. To increase the stability and efficiency of the detection of the cancer cells, a hierarchical processing architecture is adopted for the segmentation and recognition. For segmentation, RGB space and Lab space are combined to segment cell. By this method, both the nucleus and cytoplasm of cancer cells can be separated from background. Then, the candidate cancer cells are selected using some morphological features of nuclei, the purpose of this step is to pick out most of non cancer cells and leave a few doubtful cells for further verification, therefore improve the efficiency of the whole recognition process. As the last step, all the candidate cell, some statistic parameters in different color space are calculated, which are used as features for recognition. Experiment results are given.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
01 Oct 1998-Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering
TL;DR: In this article, the quantitative prediction abilities of three competing multivariate calibration methods for concentration analysis of FTIR Spectra are compared and the results showed that PLS is the best calibration method among the three methods examined for a given real spectral data set while CLS and KFM had no obvious difference in the performance.
Abstract: The quantitative prediction abilities of three competing multivariate calibration methods for concentration analysis of FTIR Spectra are compared. The calibration methods compared include classical least squares method (CLS), Kaiman filter method (KFM) and partial least squares method (PLS). The mixtures of seven air toxic organic compounds whose FTIR Spectra are known to seriously overlap were chosen to evaluate the preceding calibration methods. The concentrations of the seven air toxic organic compounds mixtures varied from 1 to 50 or 100 ppm. A relatively simple model involving the mean prediction error (MPE) and mean relative error (MRE) was developed for estimating each calibration method mentioned above. The results showed that PLS is the best calibration method among the three methods examined for a given real spectral data set while CLS and KFM had no obvious difference in the performance. Better predictable results were obtained when the measurement is taken at a series of equispaced wa...
TL;DR: In this paper, the authors proposed a new synchronization theorem for a subclass of chaotic Lur'e systems, where a specific state variable of the drive system was taken as the driving signal.
Abstract: This Letter proposes a new synchronization theorem for a subclass of chaotic Lur'e systems. We take a specific state variable of the drive system as the driving signal. We prove that globally synchronization can be attained via the simple linear error feedback. The approach is illustrated using Chua's chaotic oscillator and a hyperchaotic oscillator.
TL;DR: In this article, the preparation of W-type nanocrystalline hexaferrite powders by a new stearic acid gel method was investigated using X-ray diffraction and transmission electron microscopy (TEM).
TL;DR: In this paper, a method for measuring molar substitution of hydroxypropyi cellulose with concentrated deuteriochloric acid (DC1) and integration of area of the 1H-nmr peaks of the hydrolyzed product was proposed.
Abstract: Proton nuclear magnetic resonance (1H-nmr) techniques have been used for the determination of the molar substitution (MS) of hydroxypropyi cellulose. The method for measuring MS was based on the hydrolysis of hydroxypropyi cellulose with concentrated deuteriochloric acid (DC1) and integration of area of the nmr peaks of the hydrolyzed product. The results obtained by the proposed nmr method agreed well with those provided by the chromic acid oxidation distillation method. Furthermore, according to the established relationship between average MS and the content of hydroxypropyi group (HC), the MS of hydroxypropyi cellulose was also calculated, and therefore further verifying the accuracy of the nmr data.
18 Aug 1998
TL;DR: The recently proposed modified PML absorbing boundary condition (ABC) has been proved to be very efficient in absorbing propagating and evanescent waves in lossless media and is extended to the case of lossy media.
Abstract: The recently proposed modified PML (MPML) absorbing boundary condition (ABC) has been proved to be very efficient in absorbing propagating and evanescent waves in lossless media. In this paper, MPML is extended to the case of lossy media. The numerical experiment shows that MPML is also effective in terminating the loss media.