讨论光的干涉和衍射问题时引入光程差概念的物理意义

本文主要论述结合光的干涉,衍射现象的本质,讨论引入光程差概念的物理意义,从波动性概念解释光的干涉和衍射现象的本质,最后得到光程差概念的物理意义。     

四元体系RbCl-ErCl_3-HCl(约22.6%)-H_2O(298.15K)的相平衡

用等温溶度方法测定了四元体系RbCl-ErCl3-HCl-H2O沿22.6%HCl截面,在298.15 K时的溶度数据,绘制了相应的溶度图.该四元体系由1个双饱点,2个固相区RbCl和ErCl3·6H2O组成,是一简单共饱型体系.     

＂相＂及＂组织＂概念的定义

“相”与“组织”是材料类课程中非常重要的概念,在目前的材料科学基础和工程材料教材中,相关概念的定义各有千秋。根据目前一些教材中的定义及教学过程中的体会,阐述了这两个重要概念应有的内涵,并提出“相’’与“组织”的定义。     

在社会经济发展背景下对高等教育功能的再认识--马丁·特罗高等教育发展阶段论批判

马丁·特罗在30年前首次描述了高等教育存在着三个以数量为标准的发展阶段.这一理论是基于当时部分发达国家高等教育完成"大众化"或"普及化"之现实,围绕着高等教育内部革新问题而建构的,在方法论上,具有十分明显的归纳取向,对高等教育发展与社会经济发展之间互为因果的关系,缺乏足够的认识.这一理论存在着内在的缺陷.当代高等教育的发展极大地丰富了我们对高等教育大众化、普及化之功能及其重要性的认识.高等教育更多地体现着一国社会经济的巨大利益,高等教育的发展更多地是国家意志的产物,对发展中国家来说,尤其如此.     

Application of colour metallography in the examination of ancient metals

The use of colour in the metallographic examination of ancient metals is useful both for research and teaching purposes. Application of different optical methods of examination include: polarized light, with or without a first-order red compensator, and differential interference contrast microscopy (DIC). The use of DIC can be combined with the other techniques mentioned in the text for the examination of etched or unetched metal surfaces, which are best observed microscopically using a metallograph. Colour techniques are now used routinely in industrial metallography, and are available for a variety of metals and alloys. Colour tint etching can be used to enhance grain structure or different phases present in the metallic artefact which may not be visible in conventional etched samples, or which lack optical contrast. Many more applications of these techniques in the examination of ancient metals will be published in the literature as they become better known and second-hand equipment with DIC lenses enter the market at a price suitable for conservation laboratories to purchase them.     

A(副相)/Nd_2Fe_(14)B(主相)系列双相纳米晶复合永磁体的研究

介绍了双相纳米晶ＮｄＦｅＢ复合永磁材料的设计与制备工艺，以及它的最新研究进展和研究方向．     

从历史的角度看中国成人教育发展的阶段和特点

在新中国建立50余年的发展历程中,我国成人教育既有迅猛发展的“凯歌行进”时期,亦有迅速下滑的低谷阶段,其发展过程的高低起伏及阶段性特征与我国特定时期的历史环境有着密不可分的关系。从历史的角度分析我国成人教育发展的阶段和特点,可以使我们高屋建瓴,站在历史的高度审视成人教育的发展历程,从高峰中汲取经验,从低谷中汲取教训,为未来成人教育的持续发展提供借鉴。     

再生制动能量的储能方式分析

再生制动是汽车节能的一项重要举措.目前汽车上常采用的4种再生制动能量储能方式是蓄电池储能、超级电容储能、超高速飞轮储能和液压储能.文章在介绍以上4种储能方式特点的基础上,对比分析了它们的技术参数,总结了当前储能方式的各种方案,并对未来发展趋势进行了预测.     

Preparation and adsorption behaviors of Cu(II) ion-imprinted polymers

Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.