溴化银中氯离子含量对增感染料吸附及增感作用的影响

本文研究了在氯溴化银上不同类型染料的吸附和不同氯离子含量的溴化银乳剂中染料的增感作用。证明在溴化银乳剂中加入氯离子以后,光谱增感的倍率增加了。不同类型的染料呈现出不同的增感规律。份菁染料在氯溴化银乳剂上具有最好的吸附能力和光谱增感作用。实验结果还表明,染料的吸附与乳剂光谱增感效果,有着良好的对应关系。证实了染料和卤化银所形成的吸附络合物是具有照相活性的。对不同类型染料的增感现象进行了讨论。     

类比思想在高中数学教学中的应用

在教学中恰当地应用类比方法,不仅能突出问题的本质,提高教学效率,而且有助于培养学生的创造力、想象力等各项思维品质,从而提     

高三“数学概念复习课”的几种新尝试

“数学概念”既是数学基础知识,又是数学核心知识,而一些重要概念又成为基础的基础,对学生理解数学,掌握数学具有至关重要的意义．数学基本概念与基本方法又是互相联系、互相渗透的,学好数学概念,是学生学好数学、提高数学技能的前提．因此,“概念教学”,尤其是“高三数学概念”的复习教学,就成为高三数学复习课的核心教学．     

以思想方法为纽带,促进学生提高学力

作为一名数学教师,我在教学中越来越强烈地感觉到要使教学改革有所突破,数学教学必须跳出知识传授的框框,有实质性地提高教学效率和效果,更多体现数学的价值.理解数学思想方法十分重要,而知识教学仅仅是为了达到实施一般方法的目的而借助的载体.让学生在主动学习一般规律的过程中,学会方法、抓住实质、渗透思想、提高效率、增强学力.一、围绕学科本质的教学数学的本质是一个动态的概念体系,不同的历史时期,赋予了数学逐步发展、变化和越来越深刻的意义,因此我们对数学本质的认识,也应该是辩证发展的.在中学数学学习中,运用数学思想,实际上就…     

EFFECT OF CONTENT OF CHLORIDE IONS IN SILVER BROMIDE ON THE ADSORPTION AND SENSITIZATION OF DYES

The adsorption and spectral sensitization of different types of dyes (cationic, anionic cyanine andmerocyanine) on silver chlorobromide were investigated by clectrochemical method, FT-IR and modelPhotographic emulsion. It has been found that addition of chloride ions can enhance the adsorption ofdyes and improve the ability of spectral sensitization. Different behaviors in adsorption and spectralsensitization appeared in different types of dyes depending on the structures and electric charges ofdyes. Merocyanine dye has the best adsorption and remarkable spectral sensitization ability on silverchlorobromide in comparison with other cyanine dyes. Experimental results also showed that there wasa good correlativity between adsorption behavior of dyes obtained by electrochemical method and spec-tral sensitization in model photographic emulsion, and the adsorption complex composed of dye andsilver halide was electro-inert but photo-active. The mechanism of spectral sensitization with variousdyes has been dis