共查询到20条相似文献,搜索用时 85 毫秒
1.
2.
3.
高分子科学已在各个学科广泛渗透,鉴于此,《高分子物理》被设置为天津大学理学院应用化学专业的专业基础课。但相对于高分子专业,应用化学专业《高分子物理》课程存在着课时少、无实验环节的不足。本文介绍了作者在应用化学专业《高分子物理》教学中采取的一些措施,如依据专业特点精选教学内容,弱化次要内容和公式推导;演示实验、实物教学、多媒体教学和问题驱动教学相结合;加强理论与应用的联系;将高分子学科史知识和人文精神融合到课堂中等。 相似文献
4.
5.
高分子化学是高分子材料专业学生接触到的第一门专业基础课程,本文从多个方面对高分子化学课程教学进行探讨,包括注重专业教育及兴趣培养、注重与基础化学的衔接和对比、注重科研素质培养、板书与多媒体教学相结合、注重专业前沿知识的讲授、充分利用实物教学等几方面,并通过在教学实践中加以运用,有效提高了课程教学质量。 相似文献
6.
《高分子化学》是研究高分子化合物合成和化学反应的一门科学,是高分子材料专业的一门重要专业基础课,是应用化学和化学工程与工艺专业等非高分子专业的选修课。本文针对应用化学和化学工程与工艺专业等非高分子专业在高分子化学教学中存在的问题与对策进行了积极的探索与实践。结合多年的教学体会,从如何上第一节课、教学内容的取舍、课外活动的开展以及教学方法和手段的改进等方面总结出了一些行之有效的提高非高分子专业高分子化学教学效果的具体措施。 相似文献
7.
8.
9.
10.
白绘宇罗静倪才华东为富刘晓亚陈明清 《高分子通报》2015,(7):89-94
高分子流变学是一门研究聚合物材料的流动与变形的科学。在高分子专业本科教学过程中高分子流变学课程是一门承上启下的关键课程,地位与作用明显。高分子流变学课程又不同于一般流变学课程,有着自身的特点,在课程的教学过程中,既要突出其科学研究的前沿性也要强调其实用性。本文借鉴美国大学高分子流变学课程教学经验,针对我校高分子材料与工程专业高分子流变学教学中存在的问题,提出了一系列改革思路,希望为高校高分子流变学教学改革提供借鉴。 相似文献
11.
将NaOH与NH+4离子作用产生氨气 ,然后通入盐酸溶液中被吸收 ,当吸收完全后 ,以 0 .1 %甲基红为指示剂 ,用标准氢氧化钠滴定过剩的盐酸 ,从而计算出氮的含量 ,这是测定氮的经典方法[1 ,2 ] 。用上述方法测定氮含量有两点不太理想 :第一点是氨溶于盐酸中生成氯化铵 ,其溶液是无色的 ,不能直观地看到氨气是否溶于盐酸中的现象 ;第二点是采用甲基红为指示剂 ,其pH变色范围较宽 (pH =4.4~ 6.2 )。判断终点不太灵敏 ,容易带来误差。本文采用微型实验方法以硼酸为氨的吸收液 ,0 .1 %的亚甲基蓝和 0 .1 %的甲基红的混合液为指示剂 ,用标… 相似文献
12.
Nd比值测定中的Sm、Nd分离——HDEHP分离法 总被引:3,自引:0,他引:3
利用一种涂结型阳离子分离交换树脂分离测定Sm-Nd年龄中的Sm、Nd二元素。本文详细介绍了这种方法的基本原理和树脂制备、装柱条件及化学分离过程。并且与测定Sm-Nd同位素年龄中的另一种Sm、Nd元素分离方法(α-羟基异丁酸HBAR分离法)进行了比较。 相似文献
13.
氢的电负性值是氢元素性质的重要参数,1932年Pauling犤1~3犦定量确定氢的相对电负性值等于2.1,1961年Allred犤4,5犦用更准确的实验数据对Paul-ing电负性标度进行了修正,氢的电负性值被确定为2.2,目前这两个数值都在采用。元素的电负性值是与元素的性质紧密相关的,一个合适的电负性标度应该至少反映所有重要元素的电负性值,氢的化合物比任何其它元素都多,理应有一个基本的准确电负性值,然而一些电负性标度中却缺乏这样的数据。在Murphy等四人犤6犦最近发表的论文中,对Pauling电负性标度又进行了深入考查与… 相似文献
14.
Two methods are proposed, one for the location of saddle points and one for the calculation of steepest-descent paths on multidimensional surfaces. Both methods are based on a constrained simplex optimization technique that avoids the evaluation of gradients or second derivative matrices. Three chemical reactions of increasing structural complexity are studied within the PRDDO SCF approximation. Predicted properties of reaction hypersurfaces are in good overall agreement with those determined by gradient minimization and gradient following algorithms in connection with various ab initio SCF methods. Computational efforts required by the new procedures are discussed. 相似文献
15.
Giacomo Fonte 《Theoretical chemistry accounts》1981,59(5):533-549
We investigate the analytical convergence of SCF and MCSCF calculations, when the dimension of the subspaces to which the orbitals are restricted tends to infinity. We show that the completeness only inL
2(R
3;C
2) of the orbital bases does not ensure the convergence of the Ritz-energy, neither in SCF nor in MCSCF calculations, but that this convergence — as well as the convergence of the Ritz-orbitals in SCF calculations — is on the contrary guaranteed if the orbital bases are complete in the Sobolev spaceW
1,2(R
3;C
2). Some consequences on the choice of the orbital exponents of Slater and Gauss functions are also discussed. 相似文献
16.
由完全非线性函数经变换得到自函数递推方程.根据回归分析理论,建立了一种化学反应动力学研究法──自函数回归法.应用该法在25℃水溶液中研究了乙酸乙酯和了酸乙酯的皂化反应的动力学常数. 相似文献
17.
Previously, J. B. Krieger, Y. Li, and G. J. Iafrate suggested a new form of exchange correlation potential for electronic structure calculations (KLI form). This paper deals with some problems of adaptation of the KLI formalism to the scattered wave method in the cluster model. The basic approximations of the model (frozen core, muffin tin, and the form of the exchange correlation functional) are examined from the viewpoint of their effect on the results of calculations, considering the given form of the exchange correlation potential. The results of test calculations are given for isolated H, He, Mg, and Xe atoms and H2O, CH4, and CO molecules. 相似文献
18.
In physicochemical studies on the sea-surface microlayer (SML) in seawater, the main researches conducted were as follows:
(1) It was found that there is an objective layer of sudden change in physical and chemical properties between the SML and
the subsurface layer in seawater. (2) The SML thickness was determined and should be about 50±10 μm. (3) The Gibbs model of
the SML was extended, and the multilayer model of the SML was advanced. (4) The original-location method, which corresponds
with the traditional removal-location method, was founded and used to determine the SML thickness. The results obtained from
the two methods were almost identical. (5) An abnormal phenomenon was found when the Gibbs solution adsorption was applied
to the seawater system, the reason for which was discussed preliminarily. 相似文献
19.
对中学化学的主要任务和教材改革的看法 总被引:17,自引:7,他引:10
本文介绍了作者对中学化学教学和教材改革的一些看法。涉及到中学化学教学的主要目标、任务,以及编写教材时应当突出的基本理论、化学基本概念和观念等问题。本文对于中学化学教学各学段的主要着重点提出了看法。对于分类法的意义、元素论、物质的静态和动态、化学计量关系和浓度概念等在中学化学教学和教材中的地位和作用,也简要地进行了讨论。 相似文献
20.
W. Zielenkiewicz 《Journal of Thermal Analysis and Calorimetry》2007,88(1):59-63
The paper describes the fundamentals and applications of the thermal-dynamic
analogy method to analyze the course of heat effects occurring in calorimeters.
The method is based on introduction to the heat effect analysis of the terms,
notions and mathematical procedures used in the steering theory. It was pointed
out that this method can well be applied for elaboration of mathematical models
of various types of calorimeters. These models determine both the heat properties
of calorimeters as well as the dynamic ones. 相似文献