Showing papers by "Wuhan University published in 1996"
TL;DR: A simple analytical embedded-atom method EAM model is developed that resolves the problems of Johnson’s model for predicting the properties of the alloys involving metal Pd and finds that the stability energy is dominated by both the embedding energy and the pair potential for fcc-bcc stability.
Abstract: Centre of Instrumental Analysis, Wuhan University, Wuhan 430072, China~Received 19 October 1995; revised manuscript received 4 March 1996!A simple analytical embedded-atom method~EAM! model is developed. The model includes a long-rangeforce. In this model, the electron-density function is taken as a decreasing exponential function, the two-bodypotential is defined as a function like a form given by Roseet al. @Phys. Rev. B 33, 7983 ~1986!#, and theembedding energy is assumed to be an universal form recently suggested by Banerjea and Smith. The embed-ding energy has a positive curvature. The model is applied to seven fcc metals ~Al, Ag, Au, Cu, Ni, Pd, and Pt!and their binary alloys. All the considered properties, whether for pure metal systems or for alloy systems, arepredicted to be satisfactory at least qualitatively. The model resolves the problems of Johnson’s model forpredicting the properties of the alloys involving metal Pd. However, more importantly, ~i! by investigating thestructure stability of seven fcc metals using the present model, we found that the stability energy is dominatedby both the embedding energy and the pair potential for fcc-bcc stability while the pair potential dominates andis underestimated for fcc-hcp stability; and~ii! we find that the predicted total energy as a function of latticeparameter is in good agreement with the equation of state of Rose et al. for all seven fcc metals, and that thisagreement is closely related to the electron density, i.e., the lower the contribution from atoms of the second-nearest neighbor to host density, the better the agreement becomes. We conclude the following: ~i! for anEAM, where angle force is not considered, the long-range force is necessary for a prediction of the structurestability; or ~ii! the dependence of the electron density on angle should be considered so as to improve thestructure-stability energy. The conclusions are valid for all EAM models where an angle force is not consid-ered. @S0163-1829~96!07727-2#I. INTRODUCTION
342 citations
TL;DR: In this paper, the modification of glassy carbon and gold electrodes with DNA by adsorption or covalent immobilization in a mono- or submonolayer has been investigated using the couple Co(bpy)3+2+3 as an indicator.
114 citations
TL;DR: In this article, the authors used the chemiluminescence reagent luminol as a component of the separation electrolyte, thus preventing loss of the light signal where luminol and H2O2 are mixed in advance in conventional flow injection analysis or ion chromatography chemilumininescence detection.
Abstract: Highly sensitive chemiluminescence detection for capillary ion analysis has been developed. The new idea lies in using the chemiluminescence reagent luminol as a component of the separation electrolyte, thus preventing loss of the light signal where luminol and H2O2 are mixed in advance in conventional flow injection analysis or ion chromatography chemiluminescence detection. Signal enhancement is achieved by sample stacking injection in the electrophoresis process. The detection limit (S/N = 3) of 20 zmol (5 × 10-13 mol/L) for cobalt(II) is ∼2 orders of magnitude better than the most sensitive results (1.7 × 10-11 mol/L) reported so far. Detection limits are 2 amol, 80 amol, 740 amol, and 100 fmol for copper(II), nickel(II), iron(III), and manganese(II), respectively. The sensitivity is significantly better than that in the electrochemical detection and the commonly used UV detection in capillary ion analysis. The capillary electrophoresis−chemiluminescence detector has been used to separate five metal i...
81 citations
TL;DR: In this paper, the structure and substructure in a Ti36.5Ni48.5Hf15 high temperature shape memory alloy were investigated by X-ray diffraction, transmission electron microscopy (TEM) and high resolution electrom microscopy, and it was determined as being CsCl (B2) type structure with a = 0.309 nm.
72 citations
TL;DR: In this article, a pH sensor was constructed with a polyaniline-coated piezoelectric crystal, which has a good selectivity, a long life and a wide linear resoponse range.
61 citations
TL;DR: The potential analytical applicability of the CFCNEs was tested by differential pulse voltammetric measurements of two well-known neurotransmitters, dopamine and 5-hydroxytryptamine, and the results achieved were highly satisfactory.
Abstract: A novel method has been developed for the fabrication of carbon fiber cone nanometer-size ultramicroelectrodes (nanoelectrodes) with overall tip dimensions as small as 50 nm in diameter. In this method, carbon fibers were initially etched by an argon ion beam thinner. Afterward, a single etched carbon fiber was inserted into a glass capillary, which was then sealed by heating the glass/fiber interface in a vacuum; thus, no epoxy resin is involved. The success rate of our fabrication route for the electrodes with overall tip diameters of up to 500 nm was about 80%; for those with tip diameters of up to 100 nm, it was about 50%. The fabricated carbon fiber cone nanoelectrodes (CFCNEs) were inspected by optical and scanning electron microscopy. Their electrochemical behavior was examined by cyclic and linear sweep voltammetric measurements of ferricyanide and ferrocene ions in aqueous and nonaqueous media. The potential analytical applicability of the CFCNEs was tested by differential pulse voltammetric meas...
52 citations
TL;DR: In this article, a regenerated cellulose microporous membrane was satisfactorily prepared by mixing cellulose cuoxam with polyethylene glycol (PEG) and gelatin as pore former.
41 citations
30 Nov 1996-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the structures of coherent and semi-coherent interphase interfaces between Ti3Ni4 precipitates and parent phase in different aged Ti 51.5Ni (at.%) shape memory alloy have been studied by means of diffraction contrast analyses in transmission electron microscopy (TEM) and HREM.
Abstract: The structures of coherent and semi-coherent interphase interfaces between Ti3Ni4 precipitates and parent phase in different aged Ti 51.5Ni (at.%) shape memory alloy have been studied by means of diffraction contrast analyses in transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). When the alloy was aged at 723 K for 3 h, very small Ti3Ni4 precipitates formed in the matrix with a coherent interface to the parent phase. Very strong strain field was observed in this kind of coherent interface using TEM and HREM. When the alloy was aged at 873 K for 20 h, large Ti3Ni4 precipitates formed in the parent phase matrix possessing a semi-coherent interface. The dislocation networks were observed in the semi-coherent interface. The Burgers vectors of these sets of dislocations are determined to be 〈111〉B2 and 〈200〉B2 types. Very weak strain field was observed in this kind of interface.
37 citations
TL;DR: In this paper, the mechanism of the electrochemical formation of silver(I) oxide on a polycrystalline silver electrode in 0.1 M NaOH was investigated, and the mass change was monitored in a series of potentiodynamic experiments.
37 citations
TL;DR: In this paper, a method was developed to determine refractory elements by inductively coupled plasma-atomic emission spectrometry (ICP-AES) with sample introduction by electrothermal vaporization (ETV).
35 citations
TL;DR: In this paper, the authors examined how federal and local income taxes, local consumption tax, and federal matching grants for local public consumption and local public investment affect the long-run equilibrium (equilibria) of private consumption, private capital accumulation, local public Consumption, and local capital stock.
TL;DR: In this paper, the authors investigated the changes in matrix plate thickness occurring during creep at elevated temperatures and found that the changes were controlled by the local resolved shear stress and the thickness of matrix plates.
TL;DR: In this article, the principle and methods of computerizing irrigation scheduling of paddy fields under intermittent submerged conditions were presented, and models for forecasting daily evapotranspiration of rice were discussed.
TL;DR: In this article, a new method for direct ICP-AES determination of refractory elements in solid biological materials with slurry sampling electrothermal vaporization (ETV) for sample introduction is described.
TL;DR: A new intercalation compound Mn0.86PS3(bipy)0.56 has been synthesized by a direct reaction of MnPS3 with 2,2-bipyridine as discussed by the authors.
TL;DR: It is found that the thermogenesis curves of mitochondria are similar to those obtained from prokaryotic cells, but not similar to Those obtained from eukaryotic Cells.
TL;DR: In this article, a luminous oxidation with acidic permanganate was used for chemiluminescence determination of hydrazine and its derivatives, and the linear range is 3.0 × 10 −5 − 1.0 g/ml.
TL;DR: Chelating resins have some good adsorption properties for some metal ions, especially for several noble metal ions and Hg(II), and as discussed by the authors showed that the resins had remarkable adsorbing capacities and adaption rates for four noble metal ion and Zn(II).
Abstract: Chelating resins have some good adsorption properties for some metal ions, especially for several noble metal ions. Thus to retrieve rare metals using chelating resins is always an interesting project for chemistry researchers. In this study we synthesized a series of chelating resins based on chitosan and investigated adsorbing capacities, adsorption rates, and adsorption selectivities for Ag(I), Au(III), Pd(II), Pt(IV), Cu(II), Hg(II), and Zn(II). The results indicate that the resins have remarkable adsorbing capacities and adsorption rates for four noble metal ions and Hg(II). For instance, one of the resins adsorbs Au(III) and the adsorbing capacity is up to 7.11 mmol/g. However, the adsorbing capacities of the resins for Cu(II) and Zn(II) are much less than for the noble metal ions. Finally, x-ray photoelectron spectroscopy studies of a chelating resin and its metal chelates were made. The result reveals that the basis of the chelations is a chemical process. © 1996 John Wiley & Sons, Inc.
TL;DR: In this paper, a simple ion chromatographic (IC) method for the direct determination of bromide (Br−) in sea water was developed, where zwitterionic surfactants immobilized on octadecylsilica (ODS) surfaces were used as the stationary phase and water as the mobile phase.
09 Nov 1996
TL;DR: A normalized floating point representation has been used for making it be possible to design biotechnical genetic operators as well as to apply some genetic operators like inversion and the experimental results show that the adaptive evolutionary algorithm has a better performance than the BGA and GAFOC.
Abstract: In this paper, a normalized floating point representation has been used for making it be possible to design biotechnical genetic operators as well as to apply some genetic operators like inversion. To improve the adaptation of evolutionary algorithms and avoid the biases which may exist in some genetic operators, we have designed and applied several kinds of genetic operators with some probability. The experimental results show that our adaptive evolutionary algorithm has a better performance than the BGA (Breeder genetic Algorithm) and GAFOC (Genetic Algorithm For Optimal Control problems) for the test problems.
TL;DR: In this article, the electrochemical redox of hemoglobin at a bare silver electrode promoted by cetyl pyridinium chloride with the cyclic voltammetric technique has been studied.
Abstract: The electrochemical redox of hemoglobin at a bare silver electrode promoted by cetyl pyridinium chloride with the cyclic voltammetric technique has been studied. The electrode reaction exhibits such good stability that the peak currents change less than 8.5% (oxidation) and 10.2%(reduction) for a continuing scan of 30 min in a solution containing 1 × 10−7mol/L hemoglobin. The electrode reaction rate constant Ks is 0.0865s−1 with a single electron transfer. Moreover, both the oxidation currents and the reduction currents are linear with the concentration of hemoglobin over the range of 1 × 10 −8−5 × 10−7mol/L. So, it can be used as an analytical method of determining hemoglobin.
TL;DR: In this article, a numerical Laplace inversion technique (i.e., CONTIN algorithm) was employed to obtain the probability distribution functions (PDF) of free-volume radius, which indicates the interaction of two phases, and the impact strength of PP/EPDM blends.
Abstract: Positron annihilation lifetime measurements were performed on pure polypropylene (PP), ethylene-propylene-diene monomer (EPDM) rubber, and their blends PP/EPDM with a series of EPDM volume fraction ϕ (= 10–40%). A numerical Laplace inversion technique (i.e., CONTIN algorithm), was employed to obtain the probability distribution functions (PDF) of free-volume radius. We observed that, first, the average free-volume radius in PP/EPDM blends is generally same as that in PP and is much smaller than that in EPDM. Second, the standard deviation σR or the width of the free-volume radius PDF in the blend decreases with ϕ in the region of ϕ = 10ndash;30%, and it increases when ϕ increases from 30% to 40%. The difference in the σR of the blend and the calculated value σcR according to the simple-mixing rule of PP and EPDM is interpreted by the existence of the two-phase interaction (i.e., the residual thermal pressure and shear stress between PP and EPDM phases in the PP/EPDM blends). The correlation between σR, which indicates the interaction of two phases, and the impact strength of PP/EPDM blends was found and discussed. © 1996 John Wiley & Sons, Inc.
TL;DR: In this article, the first example of the preparation of enantiomerically pure 1,1′-bi-2-naphthol via cyclic borate ester was described.
Abstract: The first example of the preparation of enantiomerically pure 1,1′-bi-2-naphthol via cyclic borate ester was described. Both enantiomers were obtained with about 80% yield and 100% ee.
TL;DR: In this article, two chiral stationary phases, named Chirasil-man-18C6-25 and Chirrasil-aza-15C-25, were prepared by hydrosilylating two allyl-crown ethers onto polyhydromethylsiloxane containing 25% SiH units.
TL;DR: In this article, a carbon powder electrode was chemically modified with two phenols and its oxidized products, quinones, were studied by voltammetry and in-situ ESR techniques.
TL;DR: A flow injection analysis (FIA) method for on-line monitoring of trace amounts of copper(II) in steam condensate and boiler feed-water is described in this article.
TL;DR: In this paper, the possibility of using a sidechain crown ether polysiloxane (PDB-14-C4) and a side-chain liquid-crystalline PSC-3 as matrices for peralkylated β-CD employed as stationary phases was investigated.
Abstract: This paper investigates the possibility of using a sidechain crown ether polysiloxane (PDB-14-C4) and a side-chain liquid-crystalline polysiloxane-containing crown ether (PSC-3) as matrices for peralkylated β-CD employed as stationary phases Three columns, coated with PSC-3 + permethylated β-CD, PDB-14-C4 + permethylated β-CD and PDB-14-C4 + perethylated β-CD were characterized by gas chromatography The column efficiencies, phase transitions, and selectivities were measured and compared
TL;DR: In this paper, the authors investigated the effect of the number of excited states on the third-order nonlinear optical susceptibility of a square planar complex, (2,2′-bipyridine)Pt(1,2-dicyano-1, 2-ethylene-dithiolate), when the sample was optically pumped by either a picosecond or a nanosecond pump beam of 355 nm wavelength.
TL;DR: In this paper, the authors used microcalorimetry to study the kinetics of action of five kinds of Schiff base on a strain of Aerobacter aerogenes.
TL;DR: In this article, the influence of oxygen-containing groups of the carbon surface on the properties of metal + carbon catalysts was studied by using pre-oxidized carbon as a support for an Ag + C catalyst.