低掺量胶粉对EPS系统粘接砂浆拉伸粘结强度的影响

选取了市场中常见的几种可再分散乳胶粉,采用低掺量配比拌制粘接砂浆,列出试验资料,分析了在较低的可再分散乳胶粉掺量下,胶粉对EPS薄抹灰系统中胶粘剂拉伸粘结强度的影响效果。     

Improvement of enamel bond strengths for conventional and resin-modified glass ionomers: acid-etching vs. conditioning

Objective:This study deals with the effect of phosphoric acid etching and conditioning on enamel micro-tensile bond strengths(μTBSs)of conventional and resin-modified glass ionomer cements(GICs/RMGICs).Methods:Forty-eight bovine incisors were prepared into rectangular blocks.Highly-polished labial enamel surfaces were either acid-etched,conditioned with liquids of cements,or not further treated(control).Subsequently,two matching pre-treated enamel surfaces were cemented together with one of four cements[two GICs:Fuji I(GC),Ketac Cem Easymix(3M ESPE);two RMGICs:Fuji Plus(GC),RelyX Luting(3M ESPE)]in preparation forμTBS tests.Pre-treated enamel surfaces and cement-enamel interfaces were analyzed by scanning electron microscopy(SEM).Results:Phosphoric acid etching significantly increased the enamelμTBS of GICs/RMGICs.Conditioning with the liquids of the cements produced significantly weaker or equivalent enamelμTBS compared to the control.Regardless of etching,RMGICs yielded stronger enamelμTBS than GICs.A visible hybrid layer was found at certain enamelcement interfaces of the etched enamels.Conclusions:Phosphoric acid etching significantly increased the enamelμTBSs of GICs/RMGICs.Phosphoric acid etching should be recommended to etch the enamel margins before the cementation of the prostheses such as inlays and onlays,using GICs/RMGICs to improve the bond strengths.RMGICs provided stronger enamel bond strength than GICs and conditioning did not increase enamel bond strength.     

Politicking for the Public Library

ABSTRACT

In today's current political environment raising support for millage renewals, bond campaigns or even millage continuations for public libraries is affected by national politics, and a tendency towards tax aversion on principle across the country. The lessons we can learn from the governing boards of small and rural public libraries are worth raising up to a greater national consciousness. Board governance, community consciousness, and facilities management are clear and logical tools that elected boards of public libraries can use to politick for support of libraries.     

东亚新兴债券市场的发展及其启示

东亚新兴市场国家的国内债券市场发展水平存在着很大差异,根据相关指标大体可以将其划分为四个层次：中国香港、新加坡为第一层次,韩国、马来西亚、中国台湾为第二个层次,中国、菲律宾和泰国为第三层次,印尼为第四层次。通过对其发展状况的考察,可以得出几点启示,即保持一个稳定的宏观经济环境、发展政府公债市场、完善银行部门的体制改造、扩大机构投资者基础、合理调整税率待遇和加强法制建设等,是发展债券市场所需要的基本条件。     

从电负性概念看化学键

“化学键”在无机化学教学中既是重点,又是难点。本文从电负性这一概念出发对化学键的成键类型与电负性大小的关系进行了阐述。     

可转换债券的初始基准转换价格的确定

可转换债券是近年发展很快的金融创新品种。国内对于可转换债券的投资价值的研兜已经比较全面了。从每股收益的角度来考察可转换债券的初始转换价格的确定，从而为可转换债券的发行公司选择最佳的发行时机提供参考。     

氢键效应及对有机反应活性的影响

在有机化合物中广泛存在着分子内氢键或分子间氢键,多种因素影响着氢键效应,氢键效应对有机物的理化性质和反应活性产生较大的影响。     

论契约交往方式的现代意义

在社会主义市场经济建设过程中 ,以市场为中心的公共生活正在逐步形成和发展 ,对社会交往方式提出了新的要求。契约交往方式最适合于公共生活领域 ,它具有三个方面的优势 :即 :有利于权利与义务的平衡 ;有利于效率与公平的统一 ;有利于自由与秩序的结合。总之 ,契约交往关系能够为解决社会交往中的冲突提供更合理的途径 ,能够为公共生活的繁荣和稳定提供更可靠的保障。因此 ,在公共生活领域需要以契约关系解构人情交往方式 ,建构适合现代社会要求的契约交往方式     

一类信息不对称时的公司债券定价模型

在Merton的结构化方法框架下,运用偏微分方程（PDE）的方法,给出了随机利率基于Hull-White模型且信息不对称时的可违约公司债券的定价公式和信用利差公式,并进行了实证检验.     

本质不连通六角系统图的结构特征

本质不连通六角系统图定义为含有固定键且含有完美匹配的六角系统图.给出关于本质不连通六角系统图的本质不连通结构特征：删除本质不连通六角系统图的固定键后所得的子图是不连通的,即至少含有两个正规分支,且每个分支是正规的六角系统图或者正规的广义六角系统图.