Showing papers by "Donghua University published in 2001"
25 Jun 2001
TL;DR: The robust fault detection problems for time-delay LTI systems with unknown inputs are studied and, using the H/sub /spl infin// optimization technique, an LMI approach to the solution of the optimization problem.
Abstract: The robust fault detection problems for time-delay LTI systems with unknown inputs are studied. The basic idea of our study is to express the robustness as well as the sensitivity of residual signals to the unknown inputs as well as to the faults in terms of L/sub 2-/gain and, based on it, to formulate the design of fault detection filters as an optimization problem. Applying the H/sub /spl infin// optimization technique, an LMI approach to the solution of the optimization problem is then proposed. The main results consist of the derivation of the existence conditions of the fault detection filter for time-delay LTI systems and further the solution of the optimal design problem.
115 citations
TL;DR: In this paper, the conductivity of PANI/polyamide-11 fibers was analyzed using scanning electron microscope (SEM) and transmission electron microscopy (TEM) images and micrographs of the cross-section, axial section and the surface of the monofilament.
60 citations
TL;DR: Zinc oxide whisker with a tetrapod shape was treated with a coupling agent using an orthogonal design and was mixed into the substrate of natural rubber to obtain the composites as mentioned in this paper.
Abstract: Zinc oxide whisker with a tetrapod shape was treated with a coupling agent using an orthogonal design and was mixed into the substrate of natural rubber to obtain the composites. The results of the experimental tests show that the tensile strength of the composites progressively increases with an increased amount of the related whisker. The experiments also indicate that the rubber reinforced by the tetrapod-shaped ZnO whisker is distinct isotropy. The wear tests demonstrate that the composites containing ZnO whisker appear to have good wear-resistance behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1520–1525, 2001
59 citations
TL;DR: A series of copolymers were synthesized by chemically oxidative polymerization of pyrrole (PY) and o -anisidine (AS) in acidic aqueous medium as mentioned in this paper.
44 citations
TL;DR: A series of copolymers were synthesized by chemically oxidative polymerization of pyrrole (PY) and m -toluidine (MT) in hydrochloride aqueous medium at ambient temperature.
43 citations
TL;DR: The trifluoromethylation of 2-aryl-1,1-dibromo-1-alkenes with CF3Cu under palladium catalysis has been shown to yield bistrifluorsylated compounds.
29 citations
TL;DR: In this paper, a phosphonate anion derived in situ from ethyl bis(2, 2,2,2-trifluoroethyl)phosphonoacetate was used to produce (E)-α-bromo-α, β-unsaturated esters.
28 citations
TL;DR: In this article, the optimum technique of finishing silk fabric with EPSIA (a silicone-containing epoxy crosslinking agent) has been investigated through single factor experiments and orthogonal design.
Abstract: The optimum technique of finishing silk fabric with EPSIA (a silicone-containing epoxy crosslinking agent) has been investigated through single factor experiments and orthogonal design. Treatment parameters such as finishing agent concentration, catalyst concentration, steaming temperature and time have been investigated. Changes of physical properties, durability to laundering and dyeing properties of the finished silk are also discussed.
26 citations
04 Dec 2001
TL;DR: In this article, the authors propose an approach to the fault detection problem, which consists of two steps: selection of a stable weighting function matrix, optimized in the sense of the maximum sensitivity from the faults to residual signal; and formulation of the design of fault detection filters as a model-matching problem and solving the optimization problem using the LMI technique.
Abstract: Deals with the design of a fault detection filter for discrete-time systems with both model uncertainty and disturbances. We propose an approach to the solution, which consists of two steps: (a) selection of a stable weighting function matrix, optimized in the sense of the maximum sensitivity from the faults to residual signal; (b) formulation of the design of fault detection filters as a model-matching problem and solving the optimization problem using the LMI technique. The achieved results are illustrated by a numerical example.
25 citations
TL;DR: In this paper, the authors studied the transesterification reaction between poly(ethylene terephthalate) (PET) and poly(methylene 2,6-naphthalate (PEN) with and without the addition of a chain extender were studied with 1H NMR.
Abstract: The kinetics of the transesterification reaction between poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalate) (PEN) with and without the addition of a chain extender were studied with 1H NMR. Different kinetic approaches were considered, and a second-order, reversible reaction was accepted for the PET/PEN reactive blend system. The addition of 2,2′-bis(1,3-oxazoline) (BOZ) promoted the transesterification reaction between PET and PEN in the molten state. The activation energy of the transesterification reaction for the PET/PEN reactive blend with BOZ (94.0 kJ/mol) was lower than that without BOZ (168.9KJ/mol). The rate constant k took an almost constant value for blend samples with different compositions mixed at 275 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2607–2614, 2001
20 citations
TL;DR: In this paper, an unsaturated linear structure of octafluorotoluene was used to obtain a high deposition rate for precursors with cyclic and unsaturated structures.
TL;DR: In this article, the effects of conditions such as the reaction time and concentration of trimesinic acid on the polymerization were investigated, and it was shown that the conversion of caprolactam was almost insensitive to the initial concentrations of the regulators.
Abstract: With trimesinic acid as a molecular weight regulator, the hydrolytic polymerization of e-caprolactam was carried out, and nylon-6 or polyamide-6 with three-branched chains was obtained. Through a systematic study of the effects of conditions such as the reaction time and concentration of trimesinic acid on the polymerization, we found that the conversion of caprolactam was almost insensitive to the initial concentrations of the regulators, but the relative viscosity of the polymer decreased with increasing trimesinic acid. Characterization investigations showed that differential scanning calorimetry curves changed from a single peak for normal nylon-6 to one main peak and one shoulder or one small peak for the branched polymer; the melting point of the star-shaped nylon-6 decreased with an increasing amount of trimesinic acid, whereas its crystallization temperature was higher than that of linear-chain nylon-6. A wide-angle X-ray diffraction study indicated that the crystal structure of the star-shaped nylon-6 still belonged to the a form, and the crystallizability of the branched polymer with an elevated amount of trimesinic acid during polymerization did not seem to be weakened; the characteristic absorption of infrared spectra provided indirect evidence for the existence of branched chains in the polymer. Moreover, the mechanical properties of star-shaped nylon-6 and linear-chain nylon-6 were compared.
TL;DR: In this paper, the development of diameter and surface temperature of lyocell fibers was measured online and the diameter and tensile force on the spin line in the coagulation bath were traced.
Abstract: In this paper, the development of diameter and surface temperature of lyocell fibers was measured online. The diameter and tensile force on the spin line in the coagulation bath were traced. The velocity, velocity gradient and the tensile stress profiles development of the fibers in the air grap were studied. The apparent elongantional viscosity of cellulose N-methylmorpholine-N-oxide monohydrate (NMMO-MH) solutions was studied by steady-state melt spinning theory. The decrease of the fiber diameter was mainly taking place near the spinneret, and the decrease of the diameter became more dramatic with increasing taking-up speed. The surface temperature of the fibers was also dropping faster with increasing takin-up speed for the heat transfert coefficient increased. The diameter of the Lyocell fibers almost did not change before and after it entered the coagualtion bath. The tensile force on the spin line increase with increasing taking-up speed and coagulation bath length. The velocity and the tensile strees increase slowly near the spinneret, and then accelerate. The apparent elongational viscosity of cellulose NMMO-MH solutions decreases with increasing temperature at the same elongation rate and decreases with increasing elongation rate at the same temperature. The fiber of the Lyocell process was not really solidified in the air gap and a gel or ribbery state was formed.
TL;DR: The reaction of (Z )-3-iodo-3trifluoromethyl allylic alcohols 2 and CO in the presence of catalytic Pd(PPh 3 ) 4 afforded 3-triflormethyl-2(5 H )-furanones (γ-lactones).
TL;DR: The fuzzy-valued mapping with finite variation, the distribution function of a fuzzy- valued measure and the fuzzy-value Lebesgue–Stieltjes integral are defined and the correlative properties with them are established.
TL;DR: The reaction of trifluoromethyl propargylic alcohols 1, CO and H 2 in the presence of catalytic Pd(OAc) 2 and PPh 3 afforded 3-trifluorsmethyl-2(5 H )-furanones 2 in high yields as discussed by the authors.
TL;DR: In this article, four bi-functional monomers, two dichloride monomers and two diamine monomers were deposited alternately onto the substrate with layer-by-layer polycondensation.
Abstract: Quadruple nylon systems, nylon-6688, nylon-661010 and nylon-6668, were prepared by layer-by-layer alternating vapour deposition polymerization (AVDP). In the AVDP process, four bi-functional monomers, two dichloride monomers and two diamine monomers were deposited alternately onto the substrate with layer-by-layer polycondensation. The films showed a highly ordered structure with the molecular orientation tilting to the substrate. The film thickness could be effectively controlled by the number of deposition reaction cycles. The intensities for characteristic IR band peaks and for x-ray diffraction peaks associated with the layer structure showed good linear relationship to the film thickness.
TL;DR: The question when sums of independent fuzzy random variables converge almost surely is discussed in detail and the Kolmogorov three-series theorem is established.
Journal Article•
TL;DR: A prototype of fault diagnosis based on Petri net, which is developed for a satellite tele-control subsystem, is introduced in this paper and can store the knowledge in mathematical matrix and make inference more quickly and effectively.
01 Jan 2001
TL;DR: In the process of automatic selecting mechanisms, the solutions meeting requirements of motion function were captured by accurate reasoning that were completed by a computer.
Abstract: ion:Task requirements of automatic selecting mechanisms were compartmentalized into motion function and function qualities. We described the motion function in standardization methods and represented function qualities in human language. In the process of automatic selecting mechanisms, the solutions meeting requirements of motion function were captured by accurate reasoning that were completed by a computer. These mechanisms and the appraisals about their function qualities were stored in knowledge base. Designer can select them according to function qualities of each mechanism and complete fuzzy reasoning.The reasoning method for automatic selecting mechanisms is so predigested, and automatic selecting mechanisms become reality. The difficulty of CAD for mechanical kinematic scheme is solved and then CAD for mechanical kinematic scheme has a good base.
TL;DR: Author explored principles and methods for automated connection of mechanisms, which can be identified by computer, and applied these research results to software development for automated synthesis of mechanisms.
TL;DR: In this paper, the phase separation kinetics of liquid-crystalline polymer/flexible polymer blends were studied by the coupled time-dependent Ginzberg-Landau equations for compositional order parameter o and orientational order parameter S ij.
Abstract: The phase-separation kinetics of liquid-crystalline polymer/flexible polymer blends was studied by the coupled time-dependent Ginzberg-Landau equations for compositional order parameter o and orientational order parameter S ij . The computer simulations of phase-separated structures of the blends were performed by means of the cell dynamical system in two dimensions. The compositional ordering processes of phase separation are demonstrated by the time evolution of o. The influence of orientational ordering on compositional ordering is discussed. The small-angle light scattering patterns are numerically reproduced by means of the optical Fourier transformation of spatial variation of the polarizability tensor α ij , and the azimuthal dependence of the scattering intensity distribution is interpreted.
TL;DR: In this paper, the authors obtained sufficient conditions for the zero solution of the one-dimensional nonautonomous neutral differential equation with unbounded delay to be uniformly stable as well as asymptotically stable.
TL;DR: In this article, a new way of applying on-line experimental data and basic theory to study the mechanism of orientation of a high-speed melt spinning process is described, and the relationship of birefringence and stress for Nylon-66 was developed to understand the phenomena in the spinning line.
Abstract: A new way of applying on-line experimental data and basic theory to study the mechanism of orientation of a high-speed melt spinning process is described. The relationship of birefringence and stress for Nylon-66 was developed to understand the phenomena in the spinning line. The value of birefringence along the spinning line was calculated by various models to predict the orientation change. By comparison of the model prediction and on-line experimental birefringence, a suitable mechanical model to simulate the change of the profiles along the spinning line was chosen, and the structural development mechanism is discussed. The results show that the orientation mechanism of high-speed melt spinning of Nylon-66 is determined by deformation and deformation rate along the spinning line. For Nylon-66, molecular and crystal orientations develop independently and are controlled by the rotation of crystals and chain segments in the deformation field. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3157–3163, 2001
Journal Article•
TL;DR: In this paper, a non-formaldehyde dye fixative agent AE was synthesized and the optimal synthesis conditions for AE were obtained through studying its synthesis conditions, and applied experiments from laboratory-to-factory hand sample to bulk proved its colour fixing effect on the cotton fabric dyed with reactive dyes.
Abstract: Non-formaldehyde dye fixative agent AE was synthesized. The optimal synthesis conditions for non-formaldehyde dye fixative agent AE were obtained through studying its synthesis conditions. Applied experiments from laboratory-to-factory hand sample-to-bulk proved its colour fixing effect on the cotton fabric dyed with reactive dyes. The result shows that this non-formaldehyde dye fixative agent AE can replace agent Y in colour fixing on cotton fabric dyed with reactive dyes.
Journal Article•
TL;DR: The linguistic expression is a signal of pragmatic distance between participants and pragmatic distance is the determinant of politeness at the utterance level as mentioned in this paper, which is characterized by fluidity, and by negotiability.
Abstract: The linguistic expression is a signal of pragmatic distance between participants and pragmatic distance between participants is the determinant of politeness at the utterance level. Utterance politeness is the appropriateness of linguistic politeness to pragmatic distance between participants, which is calculated and determined in the process of communication. Participants can maintain or alter their pragmatic distance between them by employing certain linguistic means. Therefore, utterance politeness is characterized by fluidity, and by negotiability.
12 Jul 2001
TL;DR: This paper is interested in detecting circular-like structure in semi-structure data, so that infinitude circulating can be avoided for the query on OEM model-based.
Abstract: There is no obvious schema information for the characteristic of self-describing semi-structure data, since the data structure is dynamic but not regular nor complete The data mode often adopted is a directed graph with its root, in which it often appears a circular-like structure In this paper we address the issue of querying semi-structure data Particularly, we are interested in detecting circular-like structure, so that infinitude circulating can be avoided for the query on OEM model-based As an application, the approach (the Processing Cycle Query's Strategy) proposed in this paper has been successfully implemented in the design of www Ego365com E-business network station (built by authors' team)
TL;DR: The reaction of (Z )-3-iodo-3trifluoromethyl allylic alcohols 2 and CO in the presence of catalytic Pd(PPh 3 ) 4 afforded 3-triflormethyl-2(5 H )-furanones (γ-lactones) as discussed by the authors.
Abstract: The reaction of ( Z )-3-iodo-3-trifluoromethyl allylic alcohols 2 and CO in the presence of catalytic Pd(PPh 3 ) 4 afforded 3-trifluoromethyl-2(5 H )-furanones (γ-lactones) 3 .