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Showing papers by "Shanghai Jiao Tong University published in 2004"


Journal ArticleDOI
TL;DR: In this article, a couple-monomer methodology (CMM) is proposed for hyperbranched polymers, which is based on the in situ formation of ABn intermediates from specific monomer pairs.

1,896 citations


Journal ArticleDOI
TL;DR: A powerful, easy-to-use analytic tool for nonlinear problems in general, namely the homotopy analysis method, is further improved and systematically described through a typical nonlinear problem, i.e. the algebraically decaying viscous boundary layer flow due to a moving sheet.

1,589 citations


Journal ArticleDOI
TL;DR: This work explains the main reason why significantly less local controllers are required by specifically pinning the most highly connected nodes in a scale-free network than those required by the randomly pining scheme, and why there is no significant difference between specifically and randomly pinning schemes for controlling random dynamical networks.
Abstract: It is now known that the complexity of network topology has a great impact on the stabilization of complex dynamical networks. In this work, we study the control of random networks and scale-free networks. Conditions are investigated for globally or locally stabilizing such networks. Our strategy is to apply local feedback control to a small fraction of network nodes. We propose the concept of virtual control for microscopic dynamics throughout the process with different pinning schemes for both random networks and scale-free networks. We explain the main reason why significantly less local controllers are required by specifically pinning the most highly connected nodes in a scale-free network than those required by the randomly pinning scheme, and why there is no significant difference between specifically and randomly pinning schemes for controlling random dynamical networks. We also study the synchronization phenomenon of controlled dynamical networks in the stabilization process, both analytically and numerically.

878 citations


Journal ArticleDOI
20 May 2004-Nature
TL;DR: These findings could lead to new uses for mesoporous silica and other chiral pore materials in, for example, catalysis and separation media, where both shape selectivity and enantioselectivity can be applied to the manufacturing of enantiomerically pure chemicals and pharmaceuticals.
Abstract: Chirality is widely expressed in organic materials, perhaps most notably in biological molecules such as DNA, and in proteins, owing to the homochirality of their components (d-sugars and l-amino acids). But the occurrence of large-scale chiral pores in inorganic materials is rare1. Although some progress has been made in strategies to synthesize helical and chiral zeolite-like materials1,2,3, the synthesis of enantiomerically pure mesoporous materials is a challenge that remains unsolved4. Here we report the surfactant-templated synthesis of ordered chiral mesoporous silica, together with a general approach for the structural analysis of chiral mesoporous crystals by electron microscopy. The material that we have synthesized has a twisted hexagonal rod-like morphology, with diameter 130–180 nm and length 1–6 µm. Transmission electron microscopy combined with computer simulations confirm the presence of hexagonally ordered chiral channels of 2.2 nm diameter winding around the central axis of the rods. Our findings could lead to new uses for mesoporous silica and other chiral pore materials in, for example, catalysis and separation media, where both shape selectivity and enantioselectivity5 can be applied to the manufacturing of enantiomerically pure chemicals and pharmaceuticals.

694 citations


Journal ArticleDOI
12 Mar 2004-Science
TL;DR: The spike protein showed the strongest initial responses to positive selection pressures, followed by subsequent purifying selection and eventual stabilization, and major deletions were observed in the Orf8 region of the genome at the start and the end of the epidemic.
Abstract: Sixty-one SARS coronavirus genomic sequences derived from the early, middle, and late phases of the severe acute respiratory syndrome (SARS) epidemic were analyzed together with two viral sequences from palm civets. Genotypes characteristic of each phase were discovered, and the earliest genotypes were similar to the animal SARS-like coronaviruses. Major deletions were observed in the Orf8 region of the genome, both at the start and the end of the epidemic. The neutral mutation rate of the viral genome was constant but the amino acid substitution rate of the coding sequences slowed during the course of the epidemic. The spike protein showed the strongest initial responses to positive selection pressures, followed by subsequent purifying selection and eventual stabilization.

658 citations


Journal ArticleDOI
TL;DR: The in situ ATRP (atom transfer radical polymerization) "grafting from" approach was successfully applied to graft poly(methyl methacrylate) (PMMA) onto the convex surfaces of multiwalled carbon nanotubes (MWNT).
Abstract: The in situ ATRP (atom transfer radical polymerization) “grafting from” approach was successfully applied to graft poly(methyl methacrylate) (PMMA) onto the convex surfaces of multiwalled carbon nanotubes (MWNT). The thickness of the coated polymer layers can be conveniently controlled by the feed ratio of MMA to preliminarily functionalized MWNT (MWNT-Br). The resulting MWNT-based polymer brushes were characterized and confirmed with FTIR, 1H NMR, SEM, TEM, and TGA. Moreover, the approach has been extended to the copolymerization system, affording novel hybrid core−shell nanoobjects with MWNT as the core and amphiphilic poly(methyl methacrylate)-block-poly(hydroxyethyl methacrylate) (PMMA-b-PHEMA) as the shell. The approach presented here may open an avenue for exploring and preparing novel carbon nanotubes-based nanomaterials and molecular devices with tailor-made structure, architecture, and properties.

641 citations


Journal ArticleDOI
TL;DR: In this paper, three main strategies developed in structural bioinformatics, i.e., pure energetic approach, heuristic approach, and homology modeling approach, as well as their underlying principles, are briefly introduced.
Abstract: During the last two decades, the number of sequence-known proteins has increased rapidly. In contrast, the corresponding increment for structure-known proteins is much slower. The unbalanced situation has critically limited our ability to understand the molecular mechanism of proteins and conduct structure-based drug design by timely using the updated information of newly found sequences. Therefore, it is highly desired to develop an automated method for fast deriving the 3D (3-dimensional) structure of a protein from its sequence. Under such a circumstance, the structural bioinformatics was emerging naturally as the time required. In this review, three main strategies developed in structural bioinformatics, i.e., pure energetic approach, heuristic approach, and homology modeling approach, as well as their underlying principles, are briefly introduced. Meanwhile, a series of demonstrations are presented to show how the structural bioinformatics has been applied to timely derive the 3D structures of some functionally important proteins, helping to understand their action mechanisms and stimulating the course of drug discovery. Also, the limitation of these approaches and the future challenges of structural bioinformatics are briefly addressed.

564 citations


Journal ArticleDOI
TL;DR: Wang et al. as mentioned in this paper examined the status of safety management in Chinese construction industry, explore the risk-prone activities on construction sites, and identify factors affecting construction site safety.

522 citations


Journal ArticleDOI
06 Mar 2004-Langmuir
TL;DR: The growth mechanism of the tower-like and tube-like ZnO crystals was investigated by FESEM, and Ultrasonic pretreatment is proved to be effective in promoting the formation of active nuclei, which have important effects on the formation.
Abstract: Large-scale arrayed ZnO crystals with a series of novel morphologies, including tower-like, flower-like, and tube-like samples, have been successfully fabricated by a simple aqueous solution route. The morphology and orientation of the obtained ZnO crystal arrays can be conveniently tailored by changing the reactants and experimental conditions. For example, the tower-like ZnO crystal arrays were obtained in a reaction solution system including zinc salt, ammonia, ammonium salt, and thiourea, and the orientation of these tower-like crystals could be controlled by the contents of these reactants. Flower-like ZnO arrays were obtained at lower temperatures, and tube-like ZnO arrays were obtained by ultrasonic pretreatment of the reaction system. The growth mechanism of the tower-like and tube-like ZnO crystals was investigated by FESEM. The results show that tower-like crystals grow layer by layer, while tube-like crystals grow from active nanowires. Ultrasonic pretreatment is proved to be effective in promoting the formation of active nuclei, which have important effects on the formation of the tube-like ZnO crystals. In addition, large-scale arrays of these ZnO crystals can be successfully synthesized onto various substrates such as amorphous glass, crystalline quartz, and PET. This implies this chemical method has a wide application in the fabrication of nano-/microscale devices.

471 citations


Journal ArticleDOI
TL;DR: This work used human plasma to find the most efficient method for sample preparation and compared four widely applied precipitation methods, using trichloroacetic acid, acetone, chloroform/methanol and ammonium sulfate, as well as ultrafiltration.

467 citations


Journal ArticleDOI
TL;DR: In this article, pullout tests were carried out to evaluate the effects of corrosion on bond and bond-slip behavior, for a series of specimens with varying reinforcement corrosion levels between 0% and 9%, and for specimens with and without stirrups that provide confinement.

Journal ArticleDOI
02 Jan 2004-Science
TL;DR: The macroscopic molecular self-assembly of an amphiphilic hyperbranched copolymer in acetone generated multiwalled tubes millimeters in diameter and centimeters in length that alternates between ordered hydrophobic domains and amorphous, partly irregular hydrophilic domains.
Abstract: The macroscopic molecular self-assembly of an amphiphilic hyperbranched copolymer in acetone generated multiwalled tubes millimeters in diameter and centimeters in length. The thickness of the tube walls approaches 400 nanometers, and the walls have an inhomogeneous lamella structure that alternates between ordered hydrophilic domains and amorphous, partly irregular hydrophilic domains.

Journal ArticleDOI
01 Dec 2004
TL;DR: A modified average method to combine belief function based on distance measures of evidence is proposed, where the weight of each body of evidence (BOE) is taken into account.
Abstract: A modified average method to combine belief function based on distance measures of evidence is proposed. The weight of each body of evidence (BOE) is taken into account. A numerical example is shown to illustrate the use of the proposed method to combine conflicting evidence. Some open issues are discussed in the final section.

Journal ArticleDOI
TL;DR: In this paper, the nonlinear vibration and dynamic response of functional graded material plates in thermal environments were investigated, where heat conduction and temperature-dependent material properties were both taken into account.

Journal ArticleDOI
01 Oct 2004-Fuel
TL;DR: In this paper, the influence of cetane number improver on heat release rate and emissions of a high-speed diesel engine fueled with ethanol-diesel blend fuel was investigated, and the results showed that: the brake specific fuel consumption (BSFC) increased, the diesel equivalent BSFC decreased, the thermal efficiency improved remarkably, and NOx and smoke emissions decreased simultaneously.

Journal ArticleDOI
TL;DR: In this article, the authors presented the conductive behavior of carbon fiber cement-based composites and the relationship between conductivity and volume fraction of carbon fibre indicated that the statistical percolation theory is suitable and applicable for the change rule of conductivity of system with the volume of the carbon fiber.
Abstract: The conductive behavior of carbon fiber cement-based composites is presented. The influence of carbon fiber volume, size, cement-based matrix, relative humidity and curing age on the characteristic of system were studied. The relationship between conductivity and volume fraction of carbon fiber indicated that the statistical percolation theory is suitable and applicable for the change rule of conductivity of system with the volume of carbon fiber. Based on the classic percolation theory, the percolation threshold of carbon fiber cement-based composites was determined as φ=φc2 and the conductive mechanism changes from electron tunneling conduction to ohmic contacting conduction. The studies have offered basic theory for smart cement-based composites.

Journal ArticleDOI
TL;DR: In this article, the residual strength of HSC and hybrid-fiber-reinforced high-strength concrete (HFRHSC) after exposure to high temperatures was investigated.

Proceedings ArticleDOI
13 Nov 2004
TL;DR: A novel iterative reinforced algorithm to utilize the user click-through data to improve search performance and effectively finds "virtual queries" for web pages and overcomes the challenges discussed above.
Abstract: The performance of web search engines may often deteriorate due to the diversity and noisy information contained within web pages. User click-through data can be used to introduce more accurate description (metadata) for web pages, and to improve the search performance. However, noise and incompleteness, sparseness, and the volatility of web pages and queries are three major challenges for research work on user click-through log mining. In this paper, we propose a novel iterative reinforced algorithm to utilize the user click-through data to improve search performance. The algorithm fully explores the interrelations between queries and web pages, and effectively finds "virtual queries" for web pages and overcomes the challenges discussed above. Experiment results on a large set of MSN click-through log data show a significant improvement on search performance over the naive query log mining algorithm as well as the baseline search engine.

Journal ArticleDOI
TL;DR: Support vector machine (SVM), a new powerful machine learning method based on statistical learning theory (SLT), is introduced into soft sensor modeling and a model selection method within the Bayesian evidence framework is proposed to select an optimal model for a soft sensor based on SVM.

Journal ArticleDOI
21 Jul 2004-Polymer
TL;DR: In this article, an organic-inorganic hybrid involving epoxy resin and polyhedral oligomeric silsesquioxanes (POSS) was prepared via in situ polymerization of diglycidyl ether of bisphenol A (DGEBA) and 4,4′-diaminodiphenylmethane (DDM) in the presence of two structurally similar POSS monomers.

Journal ArticleDOI
TL;DR: In this paper, a core−shell hybrid nanostructure, possessing a hard backbone of multiwalled carbon nanotube (MWNT) and a soft shell of brush-like polystyrene (PS), was successfully prepared by in situ atom transfer radical polymerization (ATRP), using Cu(I)Br/N,N, N',N'',N''N'N', N'', N 'N' N' N',N 'N', O pentmethyldiethylenetriamine (PMDETA) as the catalyst,
Abstract: A core−shell hybrid nanostructure, possessing a hard backbone of multiwalled carbon nanotube (MWNT) and a soft shell of brushlike polystyrene (PS), was successfully prepared by in situ atom transfer radical polymerization (ATRP), using Cu(I)Br/N,N,N‘,N‘‘,N‘‘-pentmethyldiethylenetriamine (PMDETA) as the catalyst, at 100 °C in diphenyl ether solution. The molecular weight of PS was well controlled, as was the thickness of the shell layer. TEM images of the samples provided direct evidence for the formation of a core−shell structure, i.e., the MWNT coated with polymer layer. FTIR, 1H NMR, SEM, and TGA were used to determine the chemical structure, morphology, and the grafted PS quantities of the resulting products. To further establish the covalent linkage between PS and MWNT moieties, the resulting PS-functionalized MWNTs were defunctionalized by hydrolysis or by thermal decomposition. Comparative studies, based on TEM and SEM images between the PS-functionalized and chemically defunctionalized MWNT samples...

Journal ArticleDOI
TL;DR: In this paper, the effect of the interface wettability on the pressure driven flow of a LJ fluid in a nanochannel was studied and the results showed that the hydrodynamic boundary condition at the solid-liquid interface depends on both the interface Wettability and the magnitude of the driving force.

Journal ArticleDOI
TL;DR: In this paper, a detailed numerical simulation of forced convection heat transfer occurring in silicon-based microchannel heat sinks has been conducted using a simplified three-dimensional conjugate heat transfer model (2D fluid flow and 3D heat transfer).

Journal ArticleDOI
TL;DR: In this article, conductive sulfur-containing cathode materials for high capacity lithium secondary batteries have been synthesized by heating a mixture of polyacrylonitrile and elemental sulfur.

Journal ArticleDOI
TL;DR: It is demonstrated that zein is a promising biomaterial with good biocompatibility for the development of tissue engineering and attachment, extensibility and proliferation of cells on them.


Journal ArticleDOI
TL;DR: In this article, the homotopy analysis method for strongly non-linear problems is employed to give two kinds of explicit analytic solutions of similarity boundary-layer equations, explicitly expressed by recurrence formulas for constant coefficients and can give accurate results in the whole regions of physical parameters.

Journal ArticleDOI
TL;DR: This paper examined the effects of guanxi on multiple social groups from the perspective of Chinese business people, and found that guanexi may result in positive as well as negative outcomes for focal actors and the aggregate.
Abstract: We present two studies that examine the effects of guanxi on multiple social groups from the perspective of Chinese business people. Study 1 (N = 203) tests the difference in perceived effects of six guanxi contextualizations. Study 2 (N = 195) examines the duality of guanxi as either helpful or harmful to social groups, depending on the contextualization. Findings suggest guanxi may result in positive as well as negative outcomes for focal actors and the aggregate.

Journal ArticleDOI
TL;DR: In this paper, a series of experiments have been carried out to study different boiling instability modes of water flowing in microchannels at various heat flux and mass flux with the outlet of the channels at atmospheric pressure.

Journal ArticleDOI
TL;DR: In this paper, a premix method similar to the sand-wrapping technique was utilized to make expanded polystyrene (EPS) concrete, which achieved a compressive strength of 10-25 MPa.