Showing papers by "National Tsing Hua University published in 1986"
TL;DR: In this paper, a new route for producing hydrogen from methanol was proposed and studied, which is an exothermic reaction of partial oxidation of methanols and its steam reforming.
95 citations
TL;DR: In this article, a tetrapropylammonium (TPA) ZSM-5 zeolite was studied by X-ray diffraction techniques in the orthorhombic space group Pnma.
73 citations
TL;DR: In this paper, a 2-phase solution method is presented for solving a class of reliability optimization problems with multiple-choice constraints, where at least one design alternative can be chosen as redundancy for each subsystem.
Abstract: This paper presents a class of reliability optimization problems with multiple-choice constraints. We assume that at least one design alternative can be chosen as redundancy for each subsystem. A 2-phase solution method is presented for solving these problems. In phase I, we decompose a problem into n subproblems. These subproblems can be solved by dynamic programming, independently. That is, these subproblems can be solved by parallelism. In phase II, we solve a 0-1 multiple-choice knapsack problem which is generated from phase I. We use a combinatorial tree which always satisfies the multiple-choice constraints. The 2-phase solution method is illustrated with a numerical example.
59 citations
TL;DR: An algorithm for solving three-level programming problem is developed and the hybrid algorithm is coded and used to test a group of problems.
50 citations
TL;DR: In this paper, the electrostatic cyclotron instability driven by a relativistic mechanism is analyzed with a small-signal theory and is shown to be a significant noise amplification mechanism in gyrotrons.
Abstract: The electrostatic cyclotron instability driven by a relativistic mechanism is analyzed with a small-signal theory and is shown to be a significant noise amplification mechanism in gyrotrons. The mode is localized in the electrotron beam, with a growth rate strongly dependent on the wavelength and electron density but insensitive to the velocity spread.
39 citations
TL;DR: A parallel algorithm to generate the permutations of at mostk out ofn objects which achieves the best possible speedup for any givenk and can be modified to generate combinations.
Abstract: In this paper we will present a parallel algorithm to generate the permutations of at mostk out ofn objects. The architecture consists of a linear processor array and a selector. When one single processor array is available, a parallel algorithm to generate permutations is presented which achieves the best possible speedup for any givenk. Also, this algorithm can easily be modified to generate combinations. When multiple processor arrays are available, a parallel scheme is proposed to speed up the generation by fully utilizing these processor arrays. The degree of parallelism is related to the number of available processor arrays.
36 citations
TL;DR: In this article, Lagrangian multipliers are introduced to evaluate the contact pressures due to friction and determine the adhesion or release of contact surfaces, based on these, the sliding process between two contact surfaces is accurately modelled.
35 citations
01 Feb 1986-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: A Compton suppression spectrometer used for gamma-ray spectroscopy in high level radio-environmental studies is described in this paper, where a 113 cm 3 intrinsic germanium detector is inserted into a 22.9×25.4 cm annular NaI(Tl) detector and coupled to an anticoincidence gating system.
Abstract: A Compton suppression spectrometer used for gamma-ray spectroscopy in high level radioenvironmental studies is described. A 113 cm 3 intrinsic germanium detector is inserted into a 22.9×25.4 cm annular NaI(Tl) detector and coupled to an anticoincidence gating system. The performance of suppression of the Compton continuum is studied as a function of various source-to-detector distances, incident gamma-ray energies, as well as the intensity of activities. The optimum suppression factor is 5.2 at a photon energy of 662 keV. Examples are given for use at medium and high level radioenvironmental measurements on the nuclear reactor experimental floor before and during reactor operation. Characteristics of this spectrometer are compared with other representative systems and special features are discussed.
32 citations
TL;DR: Measurements on the fluorescence induction of Triton X-100 extracted Photosystem II (PSII) particles confirmed the existence of the two sites of inhibition in PSII for the herbicide DCMU and suggested that the inhibitions of DCMU at these two sites were mutually exclusive, i.e., the binding on one site prevented thebinding on the other site.
30 citations
TL;DR: The results strengthen the earlier conclusion that some pharmacological effects of phospholipase A2 are not due to enzymatic hydrolysis, and that there are separate but perhaps partly overlapping sites for enzymatics and pharmacological activities.
29 citations
TL;DR: In this article, the effects of such reaction variables as initiator, cross-linking agent, crosslinking accelerator, and blowing agent on the gel fraction, density, and expansion ratio of polypropylene foam were studied.
Abstract: Polypropylene containing the blowing agent azodicarbonate was first grafted with vinyl trimethoxy silane, then crosslinked using the hot water treatment. Two heating stages initiated the blowing agent and formed polypropylene structural foam. The effects of such reaction variables as initiator, cross-linking agent, cross-linking accelerator, and blowing agent on the gel fraction, density, and expansion ratio of polypropylene foam were studied. Furthermore, cell dimension, compression strength, and volume resistivity were also measured and analyzed.
TL;DR: In this article, the tensile properties of an Al-3.6Li-1.1Mg-0.3Zr alloy with different cold rolling before peak aging were studied.
TL;DR: In this article, the electrostatic cyclotron instability was simulated in slab geometry with dc space charge effects neglected, and the noise was characterized by a broad spectrum, low saturation levels, and a strong disturbing effect on the electron energy distribution.
Abstract: Electrostatic noise generated by the electrostatic cyclotron instability is simulated in slab geometry with dc space charge effects neglected, The noise is found to be characterized by a broad spectrum, low saturation levels, and a strong disturbing effect on the electron energy distribution.
TL;DR: In this article, necessary and sufficient conditions of Fritz John type for Pareto optimality of nonlinear, non-differentiable, convex multiobjective minimization problems are derived.
Abstract: Necessary and sufficient conditions of Fritz John type for Pareto optimality of multiobjective programming problems are derived. This article suggests to establish a Wolfe-type duality theorem for nonlinear, nondifferentiable, convex multiobjective minimization problems. The vector Lagrangian and the generalized saddle point for Pareto optimality are studied. Some previously known results are shown to be special cases of the results described in this paper.
TL;DR: It is concluded that lethal toxicity is not necessarily associated with enzymatic, antigenic, and Ca2+-binding activities in β1-Bgt.
Abstract: β1-Bungarotoxin (β1-Bgt) fromBungarus multicinctus (Taiwan banded krait) snake venom was subjected to tyrosine modification withp-nitrobenzenesulfonyl fluoride (NBSF) atpH 8.0 and the NBS derivatives were separated by high-performance liquid chromatography. The results of amino acid analysis revealed that only one Tyr residue out of 14 was modified, and the modified residue was identified to be Tyr-68 in the A chain of β1-Bgt. Spectrophotometric titration indicated that the phenolic group of Tyr-68 has apK of 10.1. Modification of Tyr-68 in the A chain caused a selective loss in lethal toxicity, but had no effect on either enzymatic or antigenic activities. The Ca2+-induced difference spectra and fluorescence study indicated that β1-Bgt possesses at least two different types of Ca2+-binding sites. However, modification of Tyr-68 in β1-Bgt did not cause any change of the Ca2+-induced difference spectra and fluorescence spectra in native toxin and the two types of Ca2+-binding sites were retained. Moreover, the affinity of Tyr-68-modified β1-Bgt for 8-anilinonaphthalene sulfonate was also unaffected in both the presence and absence of Ca2+. All of the results indicated that Tyr-68 is not involved in the Ca2+ and substrate bindings in the A chain of β1-Bgt. It is concluded that lethal toxicity is not necessarily associated with enzymatic, antigenic, and Ca2+-binding activities in β1-Bgt.
TL;DR: In this paper, the precuring reaction between nBA/AA copolymer and DGEBA, the curing cycle of the DICY and aluminum powder, and the effects of aluminum powder upon the adhesive strength of modified DGEBa were studied.
Abstract: n-Butylacrylate/acrylic acid (nBA/AA) copolymers were synthesized and used to modify epoxy resin (DGEBA) cured with dicyandiamide (DICY). The precuring reaction between nBA/AA copolymer and DGEBA, the curing cycle of DGEBA, and the effects of DICY and aluminum powder upon the adhesive strengths of modified DGEBA were studied. It was found that the optimum DICY/DGEBA ratio was 6 g/100 g, and lap shear strength and T-peel strength increased with increasing amount of aluminum powder. The curing cycle for modified DGEBA was determined to be 1 h at 177°C.
TL;DR: In this article, discharge flow-resonance fluorescence technique was used to determine the rate constant of the reaction between OH and OCS in helium over the temperature range 255-483 K.
Abstract: The rate constant of the reaction between OH and OCS in helium over the temperature range 255–483 K has been determined using the discharge flow-resonance fluorescence technique. The OCS has been carefully purified to avoid interference from H2S and CO impurities. An FTIR with a multireflection cell was used to determine the impurity concentrations and the purified sample was found to contain less than 0.005% of H2S. At 300 K, the rate constant was determined to be (2.0 ±0.40.8) × 10−15 cm3 molecule−1 s−1. Although the rate constants showed slight positive deviation at lower temperatures, thev can be satisfactorily fitted by the Arrhenius equation, k = 1.13 × 10−13 exp(−1200/T) cm3 molecule−1 s−1. No pressure dependence was observed at all temperatures, nor was O2 enhancement observed under our experimental conditions.
TL;DR: In this article, five different epitaxial modes, referring to sets of definite orientation relationships between silicides and the substrate Si, were identified for t • MoSi2, whereas three distinct modes were found for h • Mo Si2.
Abstract: Epitaxial tetragonal and hexagonal MoSi2 (t‐MoSi2 and h‐MoSi2) were grown locally in (001), (111), and (011)Si. Five different epitaxial modes, referring to sets of definite orientation relationships between silicides and the substrate Si, were identified for t‐MoSi2, whereas three distinct modes were found for h‐MoSi2. Variants of epitaxy, required by the symmetry consideration, were also observed. It is conceived that ample thermal energy was supplied during high‐temperature annealings to cause various modes of epitaxy which presumably correspond to low‐energy states that occur. The reactive nature of the silicide formation is suggested to facilitate the growth of epitaxial silicides on silicon.
TL;DR: In this article, the anion effect on surface-enhanced Raman scattering (SERS) of interfacial water molecules on Ag electrodes has been studied by adding concentrated KCl, KBr, KI or KF solution to dilute solutions.
TL;DR: Human platelets in three physiological states were prepared and the existence of these three hydrolytic phases may signify that the phospholipase A2 sequentially hydrolyzed its substrates in the membrane outer leaflet, in the inner one, and in the cytosol.
TL;DR: In this paper, the main object of this paper is to answer in the affirmative a conjecture in [4] that for an integral operator generated by a p times continuously differentiable positive definite kernel, the eigenvalues are $o(1 / {n^{p + 1} }})$
Abstract: The main object of this note is to answer in the affirmative a conjecture in [4] that for an integral operator generated by a p times continuously differentiable positive definite kernel, the eigenvalues are $o({1 / {n^{p + 1} }})$
TL;DR: In this article, the authors used different normalization schemes in studying the excitation profile of the surface-enhanced resonance Raman scattering (SERRS) from crystal violet (CV) on silver films demonstrated the importance of surface roughness and chemical effects.
Abstract: The observed thickness dependence and excitation profiles of the surface-enhanced resonance Raman scattering (SERRS) from crystal violet (CV) on silver films demonstrated the importance of surface roughness and chemical effects. Using different normalization schemes in studying the excitation profile of SERRS we were able to identify that there are three multiplicative contributions to the observed overall enhancement, viz. the electromagnetic effect, the molecular resonance effect and the charge-transfer effect originating from the strong electronic interactions between CV and the metal islands.
TL;DR: In this article, the authors performed interrupted hot torsion tests at 450 °C on homogenized as-cast specimens of Al-Mg alloys and found that minor Si impurity, as little as 0.05 pct, is very harmful to the hot ductility.
Abstract: Interrupted hot torsion tests at 450 °C have been performed on homogenized as-cast specimens of Al-Mg alloys. The chemical compositions are approximately Al-4.85 pct Mg-0.74 pct Mn-0.22 pct Cr. The testpieces have been homogenized by three different heating schedules, and the number of revolutions to fracture in hot torsion tests has been measured. The tests lead to the finding that minor Si impurity, as little as 0.05 pct, is very harmful to the hot ductility. On the other hand, Fe impurity up to 0.34 pct has no influence. It is also found that homogenization schedule is very important to hot ductility. A two-stage heating consisting of a preheating at 430 °C for one and a half hours plus a soaking at 530 °C for eight hours results in the best hot ductility. Three different kinds of interdendritic precipitates of the compositions (Fe, Mn)Alx, (Cr, Mn, Fe, Ti)Al7, and Mg2Si have been identified by electron microscopy. After homogenization submicron dispersoids of the composition MnAl6, containing Fe and Cr as alloying elements, precipitate within the dendrites. These dispersoids are shown to exert major influences on hot ductility.
TL;DR: It is proposed that differences in the extent of high-affinity noncatalytic binding to membrane phospholipids may be at least partly responsible for the marked difference in central toxicities of these two phospholIPases A2.
TL;DR: In this paper, generalized orthogonal polynomials that represent all types of orthogonality functions are introduced and the operational matrix for integration of a generalized polynomial is derived and then applied to solve the equations of linear dynamic systems.
Abstract: Generalized orthogonal polynomials that represent all types of orthogonal polynomial are introduced in this paper. Using the idea of orthogonal polynomial functions that can be expressed by power series, and vice versa, the operational matrix for integration of a generalized orthogonal polynomial is first derived and then applied to solve the equations of linear dynamic systems. The characteristics of each kind of orthogonal polynomial in relation to solving linear dynamic systems is demonstrated. The computational strategy for finding the expansion coefficients of the state variables is very simple, straightforward and easy. The operational matrix is simpler than those of conventional orthogonal polynomials. Hence the expansion coefficients are more easily calculated from the proposed recursive formula when compared with those obtained from conventional orthogonal polynomial approximations.
TL;DR: In this paper, the 17O chemical shifts of some aromatic carbonyl compounds were measured, and it was shown that the dominant factor influencing the variation of 17 O chemical shift is the charge density bond order matrix.
DOI•
01 Jan 1986TL;DR: In this article, a mixed method of discrete system model reduction retaining the advantages of the power decomposition method and the system identification method is proposed, which is fully computer-oriented.
Abstract: A mixed method of discrete system model reduction retaining the advantages of the power decomposition method and the system identification method is proposed. From the viewpoint of energy contributions to the system output, the dynamic modes with dominant energy contributions, instead of those with dominant eigenvalues, will be preserved by power decomposition method. Having determined the denominator of the reduced model, the parameters of the numerator are found by system identification technique. The reduction procedure is fully computer-oriented. The reduced model is always stable if the original one is stable. Moreover, the reduced model gives good approximation in both the transient and the steady-state responses of the original system.
TL;DR: In this article, the defect levels existing in the interface of the heterojunction, and four levels E c −0.25, 0.34,0.44 and 0.76 eV are investigated.
TL;DR: In this paper, an efficient numerical method that can treat both the propagation constants and cutoff frequencies of optical fibers with arbitrary permittivity profiles is developed in the rigorous vector form, and the associated boundary conditions including those at cntoff are derived in a novel way.
Abstract: Based on the finite-difference technique, an efficient numerical method that can treat both the propagation constants and cutoff frequencies of optical fibers with arbitrary permittivity profiles is developed in the rigorous vector form. Such a propagation problem is formulated in transverse fields so that the proposed method does not suffer from spurious modes. The associated boundary conditions including those at cntoff are derived in a novel way. Thereafter, numerical results of the cutoff frequency and propagation constant of a fiber with the parabolic profile are presented.