试论《化学教学论》教材的修订——从六大类中学化学教材内容的编排顺序谈起

现行《化学教学论》教材将典型教学示例放在化学教学原则之后，致使整本教材缺乏逻辑性，不符合当前创新能力培养的要求，不利于坚定师范生从事教育事业的信心，笔者认为应先讲教学示例、后授教学原则。     

The application of spectral distribution of product of two random matrices in the factor analysis

In the factor analysis model with large cross-section and time-series dimensions,we pro- pose a new method to estimate the number of factors.Specially if the idiosyncratic terms satisfy a linear time series model,the estimators of the parameters can be obtained in the time series model. The theoretical properties of the estimators are also explored.A simulation study and an empirical analysis are conducted.     

脉冲时滞抛物型偏微分方程组解的振动性

研究一类脉冲时滞抛物型偏微分方程组解的振动性,利用一阶脉冲时滞微分不等式获得了该类方程组在两类不同边值条件下所有解振动的若干充分条件.所得结果充分反映了脉冲和时滞在振动中的影响作用.     

Monotonic solutions of a quadratic integral equation of fractional order

In the paper we indicate an error made in the proof of the main result of the paper [M.A. Darwish, On quadratic integral equation of fractional orders, J. Math. Anal. Appl. 311 (2005) 112-119]. Moreover, we provide correct proof of a slightly modified version of the mentioned result. The main tool used in our proof is the technique associated with the Hausdorff measure of noncompactness.     

Path properties of l_p-valued Gaussian random fields

General limit theorems are established for l~p-valued Gaussian random fields indexed by a multidimensional parameter,which contain both almost sure moduli of continuity and limits of large increments for the l~p-valued Gaussian random fields under(?)explicit conditions.     

A new formula for the saddle-to-scission time

We propose a new formula for the saddle-to-scission time that is more general that the one based on Kramers' approach. Its validity and applicability is then studied in detail. Such a formula is useful for the evaluation of the fission time of very heavy nuclei.     

Arenesulfonylimines of methyl trifluoropyruvate in the cyclocondensation reactions with 1,3-C,N-and-N,N-binucleophiles

Reaction of arenesulfonylimines of methyl trifluoropyruvate with 1,3-C,N-and-N,N-binucleophiles led to a variety of N-sulfonylated fluorine-containing heterocycles, including the fused ones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2171–2175, November, 2007.     

Mechanism of the reaction of neutral and anionic N-nucleophiles with α-halocarbonyl compounds

N-Acylalkylation of neutral and anionic N-nucleophiles with α-halocarbonyl compounds was investigated by quantum chemical methods in terms of the density functional theory and by experimental methods for 2,3-dihydroimidazo[2,1-b]quinazolin-1(10)H-5-one, its N-anion, and simpler model structures. High reactivity of these reagents is determined primarily by stabilization of transition states (TS) by bridge bonds involving halogen or nitrogen atoms rather than by conjugation, as has been commonly accepted. Bridged TS are formed by both the substitution mechanism S _N 2 and the addition-elimination mechanism. α-Haloalkyl-substituted zwitterions, which are potential intermediates of stepwise N-acylalkylation of neutral N-nucleophiles, do not exist in the isolated state, but they are rather efficiently stabilized upon solvation. These zwitterions, as well as analogous O-anions generated from anionic N-nucleophiles, can serve as intermediates of N-acylalkylation, as was demonstrated by localization of the corresponding TS. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1150–1164, June, 2007.     

Heat of adsorption and density distribution in slit pores with defective walls: GCMC simulation studies and comparison with experimental data

The adsorption behavior (capacity, density distribution and packing density) and the isosteric heat versus loading in a slit pore whose walls contain defective graphene layers are investigated in this paper. The defective wall is characterized by the extent and size of the defect. Simulation results obtained with the Grand Canonical Monte Carlo method reveal complex patterns of isosteric heat, and this complex behavior is a result of the interplay between three factors: (i) the surface heterogeneity (solid-fluid interaction, sites with varying degree of affinity), (ii) fluid-fluid interaction and (iii) the overlapping of potentials exerted by the two defective walls. We illustrate this with argon adsorption in pores of various sizes, and results obtained from the simulation agree qualitatively with the experimental data at 77 K on Saran microporous S600H and micro-mesoporous S84 charcoals of Beebe et al. [R.A. Beebe, B. Millard, J. Cynarski, J. Am. Chem. Soc. 75 (1953) 839]. The S600H was found to contain pores predominantly in the neighborhood of 7 Å with 30% of defect and a defective size of 2.84 Å. This is consistent with the argument made by Beebe et al. that this sample is a microporous solid and most pores can accommodate only one layer. The other sample, S84, has larger pores than S600H, and it is found that it has a wider pore size distribution and the pore width is centered at about 12 Å.     

Global smooth solutions to the multi-dimensional hydrodynamic model for two-carrier plasmas

The existence of global smooth solutions to the multi-dimensional hydrodynamic model for plasmas of electrons and positively charged ions is shown under the assumption that the initial densities are close to a constant. The model consists of the conservation laws for the particle densities and the current densities, coupled to the Poisson equation for the electrostatic potential. Furthermore, it is proved that the particle densities converge exponentially fast to the (constant) steady state. The proof uses a higher-order energy method inspired from extended thermodynamics.