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Showing papers by "Southeast University published in 1997"


Journal ArticleDOI
TL;DR: In this article, the effect of fiber volume fraction (Vf) and aspect ratio (lfdf) on flexural strength and fracture toughness is investigated, and it is observed that the flexural deflection corresponded to ultimate load increased with the increase of Vf and lfdf, and due to fiber arresting cracking, the shape of the descending branch of load-deflection tends towards gently.
Abstract: This paper presents basic information on the mechanical properties of steel fiber-reinforced, high-strength, lightweight concrete with compressive and flexural strengths up to 85.4 MPa and 11.8 MPa, respectively. The influence of steel fiber on modulus of elasticity and Poisson's ratio of concrete are investigated, and flexural fracture toughness is calculated. Test results show that the effect of fiber volume fraction (Vf) and aspect ratio (lfdf) on flexural strength and fracture toughness is extremely prominent, compressive strength is only slightly improved, and tensile/compressive strength ratio is obviously enhanced. It is observed that the flexural deflection corresponded to ultimate load increased with the increase of Vf and lfdf, and due to fiber arresting cracking, the shape of the descending branch of load-deflection tends towards gently.

335 citations


Journal ArticleDOI
TL;DR: A family of approaches exploiting the derivatives with respect to the LR and MF is presented, which does not need to explicitly compute the first two order derivatives in weight space, but rather makes use of the information gathered from the forward and backward procedures.

130 citations


Journal ArticleDOI
TL;DR: A new prediction search algorithm (PSA) for block motion estimation that can significantly reduce the search times by utilizing the linear weighting of the motion vectors of the three adjacent blocks to obtain a prediction motion vector.
Abstract: motion estimation plays an important role for the compression of video signals. This paper presents a new prediction search algorithm (PSA) for block motion estimation. The proposed method utilizes the linear weighting of the motion vectors of the three adjacent blocks to obtain a prediction motion vector, namely, the initial search point. Using a 3/spl times/3 movable search window, it then searches from the prediction point with a fixed search step size of one until it reaches the boundary of search area or its local minimum point lies in the center of search window. Based on the spatial characteristics of the center-biased distance between a motion vector and the corresponding prediction vector and the temporal correlation of motion vectors, this method can significantly reduce the search times. Simulation results show that the proposed PSA is better than the three-step search algorithm and the four-step search algorithm in terms of MSE with smaller computational requirement.

98 citations


Journal ArticleDOI
TL;DR: In this article, the rotating bending fatigue of a TiNi shape-memory alloy wire was investigated and the influence of air and water atmospheres, temperature, strain amplitude and rotational speed on the fatigue life was discussed.

97 citations


Journal ArticleDOI
Dan Huang1, Zhongdang Xiao1, Jianhua Gu1, Ning Ping Huang1, Cuan-Wei Yuan1 
TL;DR: By exploiting the chemisorption properties of the SO3H group, titanium dioxide (TiO2) thin films were prepared by deposition in aqueous HCI solution of TiCl4 at 80°C as discussed by the authors.

88 citations


Journal ArticleDOI
TL;DR: In this article, the killing effect of photoexcited ultrafine TiO2 particles on U937 cells has been studied and the mechanism concerned has been further investigated by DNA agarose gel electrophoresis.
Abstract: The killing effect of photoexcited ultrafine TiO2 particles (UFP TiO2) on U937 cells has been studied. The mechanism concerned has been further investigated by DNA agarose gel electrophoresis. The electrophorogram shows that reactive oxygen species produced by photoexcited UFP TiO2 can damage DNA, which results in cell death. Finally, a new assumption of the way to kill cancer cells is proposed.

84 citations


Journal Article
TL;DR: In this article, the effect of photoexcited TiO 2 particles on U937 cells has been studied and a new assumption of the way to kill cancer cells is proposed.
Abstract: The killing effect of photoexcited TiO 2 particles on U937 cells has been studied. DNA agarose gel electrophoresis shows that photoexcited TiO 2 particles can damage DNA, leading to the death of cells. So a new assumption of the way to kill cancer cells is proposed.

80 citations


Journal ArticleDOI
Jinghuai Fang1, Jingwen Wu1, Xiaomei Lu1, Yaochun Shen1, Zuhong Lu1 
TL;DR: In this article, a transparent titanium dioxide (TiO 2 ) electrode with large surface roughness factor was prepared on a conducting glass support, and a combination of Q-sized particles and phthalocyanine dye molecules was used to co-sensitize the TiO 2 electrode.

76 citations


Journal ArticleDOI
TL;DR: The crystal structures of two CN-bridged bimetallic copper(II)−chromiun(III) complexes, [{(Cu(dien))2Cr(CN)6}n]n·4nH2O (1), where dien and edma are diethylenetriamine and ethylenediaminemonoacetate respectively, have been determined.
Abstract: The crystal structures of two CN- bridged bimetallic copper(II)−chromiun(III) complexes, [{(Cu(dien))2Cr(CN)6}n][Cu(dien)(H2O)Cr(CN)6]n·4nH2O (1) and [(Cu(edma))3Cr(CN)6] (2) (where dien and edma are diethylenetriamine and ethylenediaminemonoacetate respectively), have been determined. Complex 1 (C24H49N21O5Cr2Cu3) crystallizes in the monoclinic system, space group P21/c, with a = 20.509(2) A, b = 14.376(3) A, c = 15.040(4) A, β = 96.03(2),° and Z = 4. In the crystal structure, complex 1 has two distinct ionic units: one is a cationic polymeric chain formed by [(Cu(dien))2Cr(CN)6]+ and the other is a CN--bridged binuclear anion [(Cu(dien)(H2O)Cr(CN)6]-. Complex 2 crystallizes in the trigonal system, space group R3C, with a = 24.446(2) A, b = 14.446(2) A, c = 22.685(1) A, and Z = 6. Complex 2 consists of discrete tetranuclear molecule [(Cu(edma))3Cr(CN)6]-. In both complexes, the Cr atoms all have an octahedral configuration with six coordinated CN- ions and connect to the copper atoms via the CN- ions. A...

72 citations


Proceedings ArticleDOI
28 Oct 1997
TL;DR: A secure communication system based on CNN is presented and numerical simulation shows the synchronization behavior by only using a transmitted driving signal, which is more secure and robust.
Abstract: In this paper, cellular neural network (CNN) circuits are introduced and the dynamic characters of third order and higher order networks are discussed. Then, a secure communication system based on CNN is presented. Numerical simulation shows the synchronization behavior by only using a transmitted driving signal. Because of the advantages of CNN, this system is more secure and robust.

71 citations


Journal ArticleDOI
01 Jan 1997
TL;DR: The application of fuzzy set theory, expert systems and artificial neural networks to fault diagnosis of power transformers is introduced, and uncertain reasoning and the combination between ES and ANN are studied.
Abstract: The application of fuzzy set theory, expert systems and artificial neural networks to fault diagnosis of power transformers is introduced, and uncertain reasoning and the combination between ES and ANN are studied. Uncertain reasoning is the main diagnostic method. The ES/ANN combination, called the consultative mechanism, can help to improve the correctness of the diagnosis and ensure the accuracy of the knowledge base. Experimental results are given which verify the proposed method.

Journal ArticleDOI
TL;DR: In this article, the microstructure and electrochromic properties of NiO films were investigated using X-ray diffraction and transmission electron microscopy and it was shown that the sputtered nickel oxide films consist of cubic polycrystalline NiO.

Proceedings ArticleDOI
03 Nov 1997
TL;DR: The results show that some 8/spl times/8 S-boxes randomly produced by the method approximately satisfy the strict avalanche criterion and output bits independence criterion, and have an almost equiprobable input/output XOR distribution.
Abstract: A method for obtaining cryptographically strong 8/spl times/8 S-boxes is presented. The method is based on the "mini version" of a new block cipher with block size of 8 bits and can be easily and efficiently performed on a computer. The cryptographic strength of some 8/spl times/8 S-boxes randomly produced by the method is analyzed. The results show (1) all of them are bijective; (2) the nonlinearity of each output bit of is usually about 100; (3) all of them approximately satisfy the strict avalanche criterion and output bits independence criterion; (4) they all have an almost equiprobable input/output XOR distribution; and (5) their inverse S-boxes also possess the former four properties.

Journal ArticleDOI
TL;DR: In this article, a high calcium fly ash with high SO3 content was used to produce high performance concrete and the 3d and 28d compressive strength of mortars reached 25.2 and 42.2MPa respectively with the water binder ratio varying from 0.30 to 0.24.

Journal ArticleDOI
Ping-Qi Pan1
TL;DR: The most-obtuse-angle rule, a two-phase dual simplex algorithm, in which the rule is used as a row selection rule for Phase-1, has been implemented in FORTRAN 77 modules, and was tested on a set of standard linear programming problems from NETLIB.

Journal ArticleDOI
TL;DR: The domain-decomposition method has been used to extract the capacitance matrices of multilayered three-dimensional interconnects in very-large-scale integration (VLSI) circuits and shows that the computing time and memory size used are more than ten times less than those used by Ansoft's Maxwell SpiceLink.
Abstract: In this paper, the domain-decomposition method (DDM) has been used to extract the capacitance matrices of multilayered three-dimensional (3-D) interconnects in very-large-scale integration (VLSI) circuits. Different subdomains are analyzed separately, so the most efficient method can be chosen for every subdomain. Therefore, the DDM can greatly reduce the algorithm complexity and provide a good platform for the development of combining methods. Numerical results show that the computing time and memory size used by the DDM are more than ten times less than those used by Ansoft's Maxwell SpiceLink-and more importantly, they are unrelated to the thickness of the pure dielectric layers.

Journal ArticleDOI
TL;DR: In this article, the influence of the particle size distribution in binary system on the packing density and the rate of hydration is analyzed. And the relationship between the porosity and the Particle Size Distribution is calculated and discussed.

Journal ArticleDOI
01 Jun 1997
TL;DR: A method of liposome preparation that involves two experimental steps is demonstrated and may be useful in the encapsulation of drugs, enzymes, and other macromolecules as well as in the study of membrane properties.
Abstract: A method of liposome preparation that involves two experimental steps is demonstrated. First, water in oil (W/O) emulsions are prepared by sonication. Then, due to centrifugal force, water droplets in the emulsion contact the monolayer at the oil/water interface and transform into liposomes after the monolayer has enwrapped the droplets. This procedure results in liposomes with diameters in the range 50–200 nm. Advantages of this procedure include relatively high (60%) encapsulation efficiency, direct preparation of liposomes in an aqueous medium different from the entrapped phase, and no leakage of the encapsulated chemicals during preparation. This relatively simple and rapid method may be useful in the encapsulation of drugs, enzymes, and other macromolecules as well as in the study of membrane properties.


Journal ArticleDOI
TL;DR: Analysis and experimental results show that, thresholding an image based on the local average histogram, one can obtain segmentation better than that of those simply using criteria based on 2D histograms, while the spent computation time is as much as that costed by the ones using criterion based on 1D histogram.

Journal ArticleDOI
TL;DR: In this article, two kinds of cadmium sulfide (CdS) particulate films have been generated in situ by exposing stearic acid (SA) Langmuir monolayer at the air−aqueous CdCl2 interface to hydrogen sulfide gas.
Abstract: Two kinds of cadmium sulfide (CdS) particulate films have been generated in situ by exposing stearic acid (SA) Langmuir monolayer at the air−aqueous CdCl2 interface to hydrogen sulfide (H2S) gas: particulate films composed of oriented rodlike nanocrystals (A-type particulate films), and those of dotlike nanocrystals which formed a stripelike domain with straight edges aligned with 6-fold symmetry (B-type particulate films). The SA- coated CdS particulate films were transferred to a solid substrate and examined by transmission electron microscopy (TEM) and photoacoustic spectroscopy (PAS). The dark field image and the transmission electron diffraction of the TEM were used to study the morphology and growth mechanisms of the CdS particulate films in detail. The PAS of the CdS particulate films composed of the oriented rodlike nanocrystals shows a new peak at 417.5 nm. This peak implies some new physical phenomena corresponding to the ordered alignment of the semiconductor nanocrystals, which exists in the ...

Proceedings ArticleDOI
04 May 1997
TL;DR: A new OFDM transmission version for multirate integrated service based on wavelet packet transform (WPT), named orthogonal wavelet division multiplexing (OWDM), is proposed and the principle of WPT and the transceiver structure using WPT are presented.
Abstract: A new OFDM transmission version for multirate integrated service based on wavelet packet transform (WPT), named orthogonal wavelet division multiplexing (OWDM), is proposed. Carrying multirate services and restraining non-stationary noise are the two novel aspects of this system. The principle of WPT and the transceiver structure using WPT are presented. The performance of the system under impulse noise and single tone interference is analyzed.

Journal ArticleDOI
TL;DR: In this paper, a novel chemical method for controlled assembly of regular composite nanowire arrays at the molecular level is described, based on the polycationic poly(N-vinylcarbazole) (PNVK) template.
Abstract: This paper describes a novel chemical method for controlled assembly of regular composite nanowire arrays at the molecular level. The polycationic poly(N-vinylcarbazole) (PNVK) template is prepared...

Journal ArticleDOI
TL;DR: In this paper, a new all-solid-state electrochromic display device employing prussian blue and WO 3 particulate film with a PMMA gel electrolyte has been fabricated.

Journal ArticleDOI
TL;DR: In this article, the existence and nonexistence of global positive solutions of reaction diffusion systems with nonlinear boundary conditions is investigated. Necessary and sufficient conditions on the global existence of all positive solutions are obtained.
Abstract: This paper deals with the existence and nonexistence of global positive solutions of reaction diffusion systems with nonlinear boundary conditions. Necessary and sufficient conditions on the global existence of all positive solutions are obtained.

Journal ArticleDOI
TL;DR: In this paper, a TiO2 microporous electrode is modified simultaneously with porphyrin dye molecules and phthalocyanine dye molecules by chemical adsorption, and a significant improvement of photoresponse compared to the of a single dye modified electrode.

Journal ArticleDOI
TL;DR: In this article, an extended high level evaluation Petri nets (EHLEP-N) is proposed for modeling and control of flexible manufacturing systems (FMSs), which can model real-time decisions with which dynamic scheduling rules can be investigated and evaluated.
Abstract: This paper proposes an extended high level evaluation Petri nets (EHLEP-N) for modeling and control of flexible manufacturing systems (FMSs). This new class of models is simple, perceivable and descriptive, having the capability of inference and making decisions. When applied to FMSs, the EHLEP-N can model real-time decisions with which dynamic scheduling rules can be investigated and evaluated. Experimental results show that the throughput for such systems with the new scheduling strategies can increase on an average of 7% by decreasing no-inputs and blockings compared with that of the traditional strategies.

Journal ArticleDOI
Yulong Yan1, Huazhong Shu1, Xudong Bao1, Limin Luo1, Yi Bai1 
TL;DR: A new optimization method for stereotactic radiosurgery treatment planning for gamma unit treatment system that converges quickly and is not sensitive to the initial parameters is presented.
Abstract: Purpose: This article presents a new optimization method for stereotactic radiosurgery treatment planning for gamma unit treatment system. Methods and Materials: The gamma unit has been utilized in stereotactic radiosurgery for about 30 years, but the usual procedure or a physician-physicist team to design a treatment plan is a trial-and-error approach. Isodose curves are viewed on two-dimensional computed tomography (CT) or magnetic resonance (MR) image planes, which is not only time consuming but also seldom achieves the optimal treatment plan, especially when the isocenter weights are regarded. We developed a treatment-planning system on a computer workstation in which Powell's optimization method is realized. The optimization process starts with the initial parameters (the number of isocenters as well as corresponding 3D isocenters' coordinates, collimator sizes, and weight factors) roughly determined by the physician-physicist team. The objective function can be changed to consider protection of sensitive tissues. Results: We use the plan parameters given by a well-trained physician-physicist team, or ones that the author give roughly as the initial parameters for the optimization procedure. Dosimetric results of optimization show a better high dose-volume conformation to the target volume compared to the doctor's plan. Conclusion: This method converges quickly and is not sensitive to the initial parameters. It achieves an excellent conformation of the estimated isodose curves with the contours of the target volume. If the initial parameters are varied, there will be a little difference in parameters' configuration, but the dosimetric results proved almost to be the same.

Journal ArticleDOI
TL;DR: Simulation results indicate that this new algorithm on MPEG-2 target bit-number allocation provides a promising coding quality at scene changes and an approach to improve the coding performance at sceneChanges is presented to avoid a sharp quality decrease of scene-change frames.
Abstract: The bit-number allocation strategy of Test Model 5 (TM5) may cause the coding quality to decrease and the buffer to overflow at scene changes, therefore a new algorithm on MPEG-2 target bit-number allocation is proposed in this letter. Here the influence of scene changes on coding quality is analyzed and an approach to improve the coding performance at scene changes is presented to avoid a sharp quality decrease of scene-change frames. Simulation results indicate that this algorithm provides a promising coding quality at scene changes.

Journal ArticleDOI
TL;DR: In this paper, the effect of fly ash content, the initial curing time, and accelerated ageing on the flexural strength of glass fiber reinforced cementitious composites (GFRCC) was investigated.