兰州市幼儿体质现状调查的必要性及意义

幼儿体质的好坏直接影响着他们今后的生活、学习、工作质量以及心理反应。论文结合实际,深入分析了兰州市开展幼儿体质状况调查的必要性和意义。     

基于CELTS元数据标准的多媒体课件制作的应用和推广

发展现代网络教育的关键在于教育资源的建设,而改进资源的重用性和通用性是教育改革的重要环节.本文介绍了教育资源元数据及目前流行的几种网络教育资源元数据标准,重点从基于CELTS（教育部教育信息化技术标准委员会制定的技术规范）的网络多媒体课件制作基本原理着手,介绍一种基于CELTS元数据标准的多媒体课件制作方法及过程,旨在通过推广和应用,实现多媒体教育资源的共享和重用.     

网络经济时代传统企业管理理念的变革

随着计算机技术的发展，特别是Internet技术的应用和普及，人类已步入网络经济时代。作为网络经济时代主流的商业模式——电子商务，对传统企业的经营管理造成巨大的冲击和影响。传统企业的管理理念发生了巨大的变革：从“传统商务”向“电子商务”的转变。     

网络教学质量评价指标探析

目前，我国网络教师教学质量评价的研究，虽然作出了一些有益的尝试，但不完善，尚未形成独立的、系统的评价指标体系。通过国内外比较分析和实践调研，从网络教学准备、实施、学习支持服务、教学改革和研究四个方面构建一套科学有效、切实可行的网络教育教师教学质量评价指标体系。为今后的高等教育实施基于Internet的网络教学教师教学质量评价提供一个理论依据，促进我国网络教育教学质量的提高。     

张衡与托勒密天文学思想的哲学基础之比较

张衡是中国古代博学的天学家，托勒密是西方古代学的集大成,他们的天学理论受中西古代哲学思想的影响很深，比较他们哲学思想的异同对于中西化的比较与交流都是十分有意义的事。具体来讲，张衡的天学思想的哲学基础是中国古代的天人合一理论、气一元论和阴阳五行论以及群体本位主义；而托勒密的天学思想的哲学基础是毕达哥拉斯的天体运动正圆说、柏拉图的世界二分法和源于古希腊的人类中心论和个体本位主义。张衡与托勒密天学思想的差异深深地植根于中西早期化的差异之中。     

Measurement of conversion efficiency of soft X-ray from 0.35μm laser-irradiated aluminum planar targets

Conversion efficiency of soft X-ray from 0.35 μm pulse laser-irradiated aluminium planar target at laser intensities 10¹³–10¹⁵ W/cm² on the Xingguang-II facility (laser energy 5–90 J, focal spot ⊃ Ф 200 μm full width of half maximun (FWHM) 400–800 ps) was measured. A simple model was given to explain soft X-ray conversion efficiency. In this model, because of the heat conduction from the laser-heated spot, the conversion was very small at lower irradiance limit, while at higher limit it was bounded by the energy lost in blow off plasma. Consequently, at the laser intensity around 2×10¹⁴ W/cm², the X-ray conversion efficiency reaches a maximum. Project suppoted by Shanghai Leading Academic Discipline Foundation (Grant No. T0104), and Science Foundation of Shanghai Municipal Commission of Education (Grant No. 214680)     

Word-learning skills of deaf preschoolers: the development of novel mapping and rapid word-learning strategies

Word-learning skills of 19 deaf/hard-of-hearing preschoolers were assessed by observing their ability to learn new words in two contexts. The first context required the use of a novel mapping strategy (i.e., making the inference that a novel word refers to a novel object) to learn the new words. The second context assessed the ability to learn new words after minimal exposure when reference was explicitly established. The children displayed three levels of word-learning skills. Eleven children learned words in both contexts. Five were able to learn new words rapidly only when reference was explicitly established. Two children did not learn new words rapidly in either context. The latter seven children were followed longitudinally. All children eventually acquired the ability to learn new words in both contexts. The deaf children's word-learning abilities were related to the size of their vocabularies. The present study suggests that word-learning strategies are acquired even when children are severely delayed in their language development and they learn language in an atypical environment.     

用直接代数法研究一些特殊非线性系统的行波激发模式

运用直接代数法研究一些特殊非线性系统:sine-Gordon系统和Bullough-Mikhailov系统的行波激发模式,得到了上述系统的孤波解、周期波解和双周期波解。     

Random vibration analysis of switching apparatus based on Monte Carlo method

The performance in vibration environment of switching apparatus containing mechanical contact is an important element when judging the apparatus’s reliability. A piecewise linear two-degrees-of-freedom mathematical model considering contact loss was built in this work, and the vibration performance of the model under random external Gaussian white noise excitation was investigated by using Monte Carlo simulation in Matlab/Simulink. Simulation showed that the spectral content and statistical characters of the contact force coincided strongly with reality. The random vibration character of the contact system was solved using time (numerical) domain simulation in this paper. Conclusions reached here are of great importance for reliability design of switching apparatus.