Showing papers by "Henan Normal University published in 1999"
TL;DR: In this article, the authors measured the viscosities and densities of aqueous solutions of glycine, DL-alanine and DL-α-amino-n -butyric acid, DL -valine and L -serine.
142 citations
TL;DR: In this paper, the authors derived the infinite dilution apparent molar volumes V02,φ for the amino acids in aqueous sodium acetate solutions and the standard volumes of transfer, ΔtV0, of the amino acid from water to aaqueous sodiumacetate solutions.
70 citations
TL;DR: In this paper, an electroless cobalt plating on spherical nickel hydroxide is tested in order to improve the conductivity of Ni(OH) 2 and the capacity of the electrode.
31 citations
TL;DR: In this paper, three kinds of nickel electrodes with various cobalt levels were made with different methods of cobalt addition and the electrochemical properties, including charge-discharge characteristics of the nickel electrodes were investigated.
26 citations
TL;DR: In this article, the relative viscosities of the alkyl chains of the amino acids in 6 mol kg 1 aqueous guanidine hydrochloride solution have been measured at 278.15, 288.15 and 308.15 K.
Abstract: The relative viscosities of glycine, DL-a-alanine, DL-a-amino-n-butyric acid, DL-valine, DL-leucine and L-serine in 6 mol kg 1 aqueous guanidine hydrochloride solution have been measured at 278.15, 288.15, 298.15 and 308.15 K. The viscosity fi-coefficients for each of the amino acids have been determined and used to probe the changes of water structure when guanidine hydrochloride is added. The corresponding activation free energies ( μ ) for viscous flow have been evaluated with the help of the Feakins equation. It has been observed that both B-coefficient and activation free energy vary linearly with increasing number of carbon atoms in the alkyl chains of the amino acids at given temperatures. These linear correlations were used to estimate the contributions of the charged end group (NHt, COO\") and CH, groups of the amino acids to ñ-coefftcient and μ . Based on the data of μ for the amino acids and their groups, the contributions of (NHÍ, COO\") and CH, groups to activation enthalpy ( ) and entropy (¿JS?'\") were also reported. The activation parameters are discussed in terms of the solutesolvent and solvent-solvent interactions in the ground and transition states.
21 citations
TL;DR: In this article, the effects of metal powders on the thermal degradation of waste polystyrene were studied, and it was shown that the catalytic effects have a relationship with their activities.
Abstract: In the present article, the effects of Al, Zn, Fe, Ni, and Cu powders on the thermal degradation of waste polystyrene were studied. The results show that the catalytic effects of metal powders have a relationship with their activities. The catalytic effects increase with the increasing activities of metals. It is suggested that polystyrene degrades through a transient intermediate in the presence of metal powders, and the degradation of the transient intermediate is the rate-determining step. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1139–1143, 1999
21 citations
TL;DR: CeCO2 Catalyzed selective Oxidation of Alkylbenzene with NaBrO3 affords aldehydes and ketones in good yields as discussed by the authors.
21 citations
TL;DR: In this article, the authors used ammonium chlorochromate adsorbed on alumina under mild conditions for deprotection of p-nitrophenylhydrazones and semicarbazones.
19 citations
TL;DR: In this paper, the authors propose a braided hopf algebra structure over the twisted smash products, which is a variant of the twisted hopf over the spline product structure.
Abstract: (1999). On braided hopf algebra structures over the twisted smash products. Communications in Algebra: Vol. 27, No. 11, pp. 5561-5573.
18 citations
TL;DR: Fe2(S04)3 XH2O has been used for the catalyst in the esterification of aromatic carboxylic acids with alcohols as discussed by the authors, which offers mild reaction condition, easy work-up, and high yields of the products.
18 citations
TL;DR: A rapid and sensitive flow-injection kinetic spectrophotometric method, based on the inhibiting effect of ascorbic acid on the enhancing effect of oxalate on the potassium dichromate-potassium iodide/rhodamine 6G system, has been successfully used to determine ascorBic acid in pharmaceuticals, tomatoes and oranges.
TL;DR: In this article, the enthalpies of solution have been measured for acetamide in LiCl and KCl aqueous solutions at 298.15 K. The enthalpic interaction parameters hxy, hxyy and hxxy of acetamide with these salts have been evaluated.
TL;DR: In this article, the antibacterial properties of PPA complexes were investigated by micro-analyses, IR and 13C NMR spectroscopy, and the complexes were characterized by microanalyses and micro-analysis.
Abstract: Complexes of main group metal with pipemidic acid (PPA), [Ca(PPA)4]Cl2, [Sr(PPA)4]Cl2, [Ba(PPA)4]Cl2, [Sn(PPA)]Cl4, and [Sn(PPA)2]Cl2 have been prepared in anhydrous ethanol and acetic acid. The complexes have been characterized by microanalyses, IR and 13C NMR spectroscopy. The antibacterial activities of the complexes were also investigated.
TL;DR: In this article, the Gibbs free energy of transfer of HCl from water to aqueous solutions of 5, 10, and 15 wt.% of d -arabinose were evaluated.
TL;DR: In this paper, the existence of positive radial solutions of the equation-div(|Du| p−2ドラゴン Du)=f(u) is studied in annular domains in R n, n≥2.
Abstract: The existence of positive radial solutions of the equation-div(|Du|
p−2
Du)=f(u) is studied in annular domains in R
n, n≥2. It is proved that if f(0)≥0, f is somewhere negative in (0, ∞), lim
u→0+f′(u)=0 and lim
u→∞(f(u)/u
p−1)=∞, then there is a large positive radial solution on all annuli. If f(0)<0 and satisfies certain conditions, then the equation has no radial solution if the annuli are too wide.
TL;DR: In this paper, the reaction of Ph2PCl with alanine methyl ester affords the chiral aminophosphine Ph2NHCH(CH3)C(O)OCH3 (dppal) which reacts with M(COD)Cl2 to give Pt(dpla)2Cl2 (1) and Cl(dppa)PdCl2Pd(dpal)Cl (2).
TL;DR: In this paper, the authors used trimethylammonium chlorochromate adsorbed on alumina as a selective oxidant under mild conditions for deprotection of 4-phenylsemicarbazones and semicarazones.
TL;DR: Treatment of various of alcohols with mandelic acid in the presence of a catalytx amount of Fe2(SO4)3 XH2O to give the corresponding esters in good yields as discussed by the authors.
TL;DR: In this paper, a convenient method using FeCl3 as oxidant to dehydrogenate symmetric hydrazo compounds is reported for the first time, which needs only cheap and less toxic reagents, mild conditions and short reaction time.
TL;DR: The concentration dissociation constants of methyl yellow, MY (H(+)In) in mixed aqueous solvents of methanol, ethanol, iso-propanol, tert-butanol have been accurately determined and it has been shown that in thesesolvents, the pK(a) values decrease with increasing composition of the organic co-solvent.
TL;DR: The positron annihilation mechanism and its relation with superconductivity are discussed in this paper, where the local electron density n e and vacancy concentration C v are evaluated as a function of oxygen deficiency δ.
TL;DR: In this paper, a general formalism of one-loop radiative corrections to the spin correlations in the top quark pair production at the Next Linear Collider, and calculate the O(αs) QCD corrections under the soft gluon approximation.
TL;DR: In this paper, the symmetries of the R-transformation of the reflection equation for two-component systems are analyzed. And the classification of solutions to the RE for eight-, six-and seven-vertex-type R-matrices is given.
Abstract: The symmetries, especially those related to the R-transformation, of the reflection equation (RE) for two-component systems are analysed. The classification of solutions to the RE for eight-, six- and seven-vertex-type R-matrices is given. All solutions can be obtained from those corresponding to the standard R-matrices by K-transformation. For the free-fermion models, the boundary matrices have property tr K+ (0) = 0, and the free-fermion-type R-matrix with the same symmetry as that of a Baxter type corresponds to the same form of a K-matrix for the Baxter type. We present the Hamiltonians for the open spin systems connected with our solutions. In particular, the boundary Hamiltonian of seven-vertex models is obtained with a generalization to the Sklyanin formalism.
TL;DR: The synthesis of the new long-chain saturated fatty hydrocarbon substituting group compound, N-undecyl-N'-(sodium p-aminobenzenesulfonate)-thiourea (UPT) is described and it is found that this reagent can be used to identify Cu(2+)(PD 6.3) and determine microamounts of copper in aqueous solution.
TL;DR: In this paper, the existence and nonlinear stability of strong stationary discrete travelling waves for the explicit and implicit relaxing schemes introduced by Jin and Xin was shown. But for the implicit relaxing scheme, we do not need such a restriction.
Abstract: In this paper we show the existence and nonlinear stability of strong stationary discrete travelling waves for the explicit and implicit relaxing schemes introduced by Jin and Xin [3] For the explicit relaxing scheme, we require that the ratio of the size of the time step and the relaxation rate is bounded above for proving the stability But for the implicit relaxing scheme, we do not need such a restriction This is comparable to the numerical results obtained in [3] The proofs involve a detailed study of error equations for perturbations and an elementary but technical energy method
TL;DR: In this paper, a new facile method for the synthesis of diaryl carbazone (ArN=NCONHNHAr) from aryl substituted carbazide is described.
TL;DR: The morphology, structure, and physiology of regenerated plantlets of maize (Zea mays L.) were affected by paclobutrazol, especially during the hardening process, and after transplanting, survival rate of the plantlets treated with paclol was up to 3 times that of the controls.
Abstract: The morphology, structure, and physiology of regenerated plantlets of maize (Zea mays L.) were affected by paclobutrazol, especially during the hardening process. Hardened plantlets developed dark green leaves and an extensive root system. Plantlets treated with paclobutrazol exhibited retarded development of the stem and leaf, but the lateral growth was improved. After transplanting, survival rate of the plantlets treated with paclobutrazol was up to 3 times that of the controls.
TL;DR: In this article, the single top quark production process in various kinds of technicolor models in high energy positron photon collisions at the future electron positron linear colliders was studied.
Abstract: We study the single top quark production process in various kinds of technicolor models in high energy positron photon collisions at the future electron positron linear colliders. It is shown that if there is certain charged pseudo Goldstone boson (PGB) coupling to t(anti-b), the t(anti-b)-channel PGB contribution is dominant, but the situation is quite different from that in the neutral channel, t(anti-t) production in photon photon collisions, due to the destructive nature of different amplitudes. At the DESY limear collider TESLA, the event rates in models with t(anti-b)-channel PGB contributions, such as the top-color-assisted technicolor model, etc. are experimentally measurable. This process provides a feasible test of technicolor models with t(abti-b)-channel PGB contributions.
TL;DR: In this article, the authors calculate the one-loop penguin contributions to the rare K-decays, and find that the contribution from the unit-charged technipions (i.e., penguins) can provide one to two orders enhancements to the branching ratios of the rare k-decay.
Abstract: We calculate the one-loop \(Z^0\)-penguin contributions to the rare K-decays, \(K^+ \to \pi^+
u \bar
u\), \(K_L \to \pi^0
u \bar
u\) and \(K_L \to \mu^+ \mu^-\), from the unit-charged technipions \(\pi_1\) and \(\pi_8\) in the framework of the Multiscale Walking Technicolor Model. We find that: (a) the \(\pi_1\) and \(\pi_8\) can provide one to two orders enhancements to the branching ratios of the rare K-decays; (b) by comparing the experimental data of \(Br(K^+ \to \pi^+
u \bar
u)\) with the theoretical prediction one finds the lower mass bounds, \(m_{p8} \geq 249\) GeV for \(F_Q=40\) GeV and \(m_{p1}=100\) GeV; (c) by comparing the experimental data of \(Br(K_L \to \mu^+ \mu^-)\) with the theoretical predictions one finds the lower bounds on \(m_{p1}\) and \(m_{p8}\), \(m_{p1} \geq 210\) GeV if only the contribution from \(\pi_1\) is taken into account, and \(m_{p8} \geq 580\) GeV for \(m_{p1}=210\) GeV, assuming \(F_Q=40\) GeV; (d) the assumed ranges of the masses \(m_{p1}\) and \(m_{p8}\) in the Multiscale Walking Technicolor Model are excluded by the rare K-decay data.
TL;DR: In this paper, a new and rapid synthetic method of diaryl carbazone (ArN=NCONHNHAr) from aryl substituted carbazide is reported for the first time.