BOUNDEDNESS OF FRACTIONAL INTEGRALS IN HARDY SPACES WITH NON-DOUBLING MEASURE - In Memory of Professor Sun Yongsheng

Let μ be a Borel measure on Rd which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)n for any cube Q () Rd with sides parallel to the coordinate axes and for some fixed n with 0 ＜ n ≤ d. The purpose of this paper is to obtain a boundedness property of fractional integrals in Hardy spaces H1 (μ).     

A fast parallel clustering algorithm for molecular simulation trajectories

We implemented a GPU‐powered parallel k‐centers algorithm to perform clustering on the conformations of molecular dynamics (MD) simulations. The algorithm is up to two orders of magnitude faster than the CPU implementation. We tested our algorithm on four protein MD simulation datasets ranging from the small Alanine Dipeptide to a 370‐residue Maltose Binding Protein (MBP). It is capable of grouping 250,000 conformations of the MBP into 4000 clusters within 40 seconds. To achieve this, we effectively parallelized the code on the GPU and utilize the triangle inequality of metric spaces. Furthermore, the algorithm's running time is linear with respect to the number of cluster centers. In addition, we found the triangle inequality to be less effective in higher dimensions and provide a mathematical rationale. Finally, using Alanine Dipeptide as an example, we show a strong correlation between cluster populations resulting from the k‐centers algorithm and the underlying density. © 2012 Wiley Periodicals, Inc.     

Uncertainty functions, a compact way of summarising or specifying the behaviour of analytical systems

Analytical chemists can advantageously use an uncertainty function to describe the performance of an analytical system in terms of the standard uncertainty or standard deviation as a function of the concentration of the analyte. This “characteristic function” is useful for estimating uncertainty at a new concentration. A similar function can be used to prescribe the uncertainty that is regarded as fit for purpose for a particular application. This “fitness function” is useful in setting standards of accuracy in proficiency tests and similar exercises without revealing the concentration of the analyte. In combination, these two functions provide a rational basis for method selection.     

微机结构分析的现状与前景

本文回顾了16位微机上的通用结构分析系统近十年来国际、国内的发展概况,对未来十年微机结构分析的发展与前景提出了一些看法。在未来十年中,微机上的非线性结构分析将不仅成为可能,而且会成为计算力学主要的开发对象。非线性分析的求解器、分叉问题等非常棘手的问题,可望在未来十年中得到解决。多窗口图形系统等现代计算机技术将会使微机结构分析的用户界面增辉生色。     

基于出行目的链的出行生成—分布组合模型分析

目前,我国城市轨道交通客流预测大多采用交通产生、吸引、出行分布、出行方式划分四阶段模型,其中出行生成与分布是方式划分和交通分配的前提,是模型重要的组成部分.在对传统的四阶段模型的分析基础上,结合非集计模型的优点,论文提出了基于出行目的链的出行生成—分布组合模型.模型充分考虑了居民出行链、出行目的等对客流预测的影响,在完善我国轨道交通客流预测理论和方法,提高预测精度等方面具有一定的理论价值和实际意义.     

基于新课程观下的高中物理实验教学目标分类研究

依据现代课程与教学目标取向以及《普通高中物理课程标准(实验)》精神，对高中物理实验教学目标从水平层次、概念内涵、具体内容和设计案例等方面进行了探究，以促使高中物理教学更具实效性，使课堂教学目标更富有物理学科特征．     

New approach based on solid-phase extraction for the assessment of organic compound pollutions in so-called pharmaceutically pure water

The application of a new kind of technique involving solid-phase extraction coupled with thermal desorption (SPE-TD) to the qualitative analysis of water used in pharmaceutical products was evaluated. Comparative analyses performed by the purge and trap (PT) technique were also conducted. The application of this SPE-TD technique resulted in the isolation of a large number of compounds from the water sample. The SPE-TD technique is applied to less volatile compounds, whereas the PT technique is used for more volatile and nonpolar ones. These two techniques should be applied in order to achieve complete identification and quantitative determination. Additionally, an attempt to identify organic compounds in pharmaceutical products was also conducted. The compounds present in such products include aldehydes, ketones, hydrocarbons, alcohols, esters. The influence of storage on the quality of water was also investigated. For samples characterized by a longer storage time, qualitatively richer chromatograms were obtained, which confirmed that components were released from the packaging (especially polyethylene) which entered the stored product.     

Automatic code generation for quantum chemistry applications

A unified, computer algebra system‐based scheme of code‐generation for computational quantum‐chemistry programs is presented. Generation of electron‐repulsion integrals and their derivatives as well as exchange‐correlation potential and its derivatives is discussed. Application to general‐purpose computing on graphics processing units is considered.     

谈数学实验

谈对数学实验的认识 ,开设数学实验课的目的意义、作用及其要完成的任务 .