高考改革背景下CAP课程的建设与实践

介绍了中国大学先修课程(CAP)的概念、缘由和价值。以简明有机化学为例,阐述了一门CAP课程具体的建设过程与运行情况。CAP课程改善了高中和大学部分课程的衔接,CAP制度的建设与有效实施有助于传播先进的教学理念和优质教学资源的共享,同时多角度的学习能力考评便于新高考模式下辅助高校进行人才选拔。CAP课程体系建设是新时期教学改革发展的必然趋势,但目前还存在CAP课程成绩的权威性、成绩和学分互认困难、高中师资不足、学生学业负担增加等问题。教育部门进行顶层设计,由专业领域具有权威的第三方机构来提供课程运行管理、考试评价服务和师资培训服务是可行做法。     

Hidden correlation between absorption peaks in achiral carbon nanotubes and nanoribbons

In this paper we study the effect of absorption peak correlation in finite length carbon nanotubes and graphene nanoribbons. It is shown, in the orthogonal π-orbital tight-binding model with the nearest neighbor approximation, that if the ribbon width is a half of the tube circumference the effect takes place for all achiral ribbons (zigzag, armchair and bearded), and corresponding tubes, starting from lengths of about 30?nm. This correlation should be useful in designing nanoribbon-based optoelectronics devices fully integrated into a single layer of graphene.     

Fluorescence Reduction by a Triplet-State Population

The range of applications for fluorescent dyes in medicine and biology is increasing greatly. At the same time, the demands on the dyes are getting bigger. The dye molecules are often expected to emit maximum-intensity fluorescence. The primary requirement for this is naturally a high fluorescence quantum yield. Beyond this, it must be considered that fluorescent molecules located in a meta-stable triplet state are not able to emit fluorescent radiation. This represents a reduction of the intensity of the fluorescence, which is generally underestimated in its importance. The size of this perturbation can be grasped by knowledge of the quantum yield for occupation of the triplet state and its lifetime. Unfortunately these parameters are completely unknown, even for frequently used dyes. On investigating some medically and biologically relevant dyes, it is shown that the attainable fluorescence intensity could be reduced strongly by occupation of the triplet state.     

具连续变量和最大值项的二阶差分方程的振动性

研究了一类具有最大值项和连续变量的非线性二阶中立型时滞差分方程的振动性,利用Banach空间的不动点原理和一些不等式技巧,得到了这类方程存在最终正解的充分条件,并得到了该方程振动的一些判别准则.     

Spatial decay estimates for heat-conducting fluids

Received August 29, 2001 / Published online November 15, 2001     

浅谈高等数学教学中的概念引入模式

本文介绍了几何图示等五种概念引入模式．提出高等数学教学中应高度重视概念引入模式的观点,试图以此作为提高教学水平与学生数学素质的一个新的突破口.     

Existence results for problems with deviating arguments

This paper deals with some problems of calculus of variation for functionals with deviating arguments. We use the direct method to establish some existence results and extend the corresponding results obtained in literature.     

Studies of the oxidation of palladium complexes by the advanced oxidation process Pretreatment of model catalysts for precious metal analysis

The advanced oxidation process (AOP) for the pretreatment of model palladium catalysts has been studied. Most standard metal analysis techniques are for metal ions free of organic ligands. Spent palladium catalysts contain organic ligands that need to be removed prior to analysis. AOP uses a combination of hydrogen peroxide and UV light to generate radicals that decompose such ligands, freeing up metals for further analysis. Palladium acetate Pd(OAc)₂, palladium acetylacetonate Pd(acac)₂, and tris(dibenzylideneacetone)dipalladium (Pd₂(dba)₃) were chosen as model precious metal catalysts for investigation. AOP was found to decompose ligands in Pd(OAc)₂, Pd(acac)₂ and give accurate Pd(II) quantification, while ligand decomposition and oxidation of Pd(0) to Pd(II) were demonstrated in treatments involving Pd₂(dba)₃. The effects of solubility of the palladium complexes, continuous addition of H₂O₂ during AOP treatments, sample pH, concentration of H₂O₂, and length of UV irradiation are reported.     

Existence and global attractivity of solutions of a nonlinear functional integral equation

In this paper we prove a result on the existence and global attractivity of solutions of a nonlinear functional integral equations with deviating arguments. The investigations are placed in the Banach space of real functions defined, continuous and bounded on the real half-axis. The main tool used in consideration is a fixed point theorem of Krasnosel’skii type. A few examples illustrating the obtained results are also included.     

The improved linear multistep methods for differential equations with piecewise continuous arguments

This paper deals with the convergence of the linear multistep methods for the equation x′(t) = ax(t) + a₀x([t]). Numerical experiments demonstrate that the 2-step Adams-Bashforth method is only of order p = 0 when applied to the given equation. An improved linear multistep methods is constructed. It is proved that these methods preserve their original convergence order for ordinary differential equations (ODEs) and some numerical experiments are given.