高中化学课程中实验探究水平和探究技能的分析

运用内容分析法,分析高中化学教科书、山东省高中化学实验报告册和山东省高考化学实验试题中实验探究水平和探究技能。高中化学教科书中的实验以证实性和结构性水平为主,高中化学实验报告册中的实验为结构性水平,山东省高考化学实验试题具有指导性探究水平。3者在设计实验方案探究技能方面,出现不均衡性,较少出现提出问题、实验目的、实验假设等技能,但是,都重视分析证据得出结论和科学解释的探究技能。     

电动汽车的希望:锂空气电池

以高中化学电化学知识为基础,介绍一种学界预期将对电动汽车储能领域产生革命性影响的可逆电池-锂-空气电池的基础知识,涉及这种电池的基本结构、工作原理、电极反应、研究现状、发展前景等内容。     

化学史融入初中化学教学现状的调查与对策研究

为了准确掌握内蒙古地区化学史融入初中化学实际教学的现状与不足。研究选取内蒙古地区10所初中的603名学生和38所初中的113名初中化学教师进行了问卷调查。结果表明内蒙古初三学生对化学史有较浓厚的兴趣,渴望通过化学史知识的学习激发学习化学的兴趣、理清知识脉络、提高创新探究能力、学会科学研究方法,而当前化学教学中存在化学史教学方法单一、化学史融入教学的程度较低、应试教育严重限制化学史教学的开展等诸多问题。针对存在的问题,研究提出化学史融入中学化学教学的"四线式"教学模式,以期改观内蒙古地区化学史融入初中化学实际教学的现状。     

父母教养方式与高中生自我监控学习的关系——核心自我评价的中介作用

考察了父母教养方式与高中生自我监控学习的关系,及核心自我评价在其中的中介作用.选取424名高中生,采用简式父母教养方式问卷、核心自我评价量表和中学生自我调节学习策略问卷,分别测量其父母教养方式、核心自我评价及自我监控学习.父亲情感温暖直接预测自我监控学习(B=0.22,p0.001),又通过核心自我评价间接预测自我监控学习(B=0.09,p0.05);母亲情感温暖直接预测自我监控学习(B=0.27,p0.001),又通过核心自我评价间接预测自我监控学习(B=0.07,p0.05).自我监控学习与父母教养方式、核心自我评价密切相关,核心自我评价在父母教养方式与自我监控学习及其各维度之间起部分中介作用.     

Exact ground-state for the periodic Anderson model in dimensions at finite value of the interaction and absence of the direct hopping in the correlated f-band

We report for the first time exact ground-states deduced for the D = 2 dimensional generic periodic Anderson model at finite U, the Hamiltonian of the model not containing direct hopping terms for f-electrons ( t ^f = 0). The deduced itinerant phase presents non-Fermi liquid properties in the normal phase, emerges for real hybridization matrix elements, and not requires anisotropic unit cell. In order to deduce these results, the plaquette operator procedure has been generalised to a block operator technique which uses blocks higher than an unit cell and contains f-operator contributions acting only on a single central site of the block. Received 1st July 2002 / Received in final form 16 September 2002 Published online 19 December 2002 RID="a" ID="a"e-mail: gulacsi@heavy-ion.atomki.hu     

Students’ use of technological features while solving a mathematics problem

The design of technology tools has the potential to dramatically influence how students interact with tools, and these interactions, in turn, may influence students’ mathematical problem solving. To better understand these interactions, we analyzed eighth grade students’ problem solving as they used a java applet designed to specifically accompany a well-structured problem. Within a problem solving session, students’ goal-directed activity was used to achieve different types of goals: analysis, planning, implementation, assessment, verification, and organization. As we examined students’ goals, we coded instances where their use of a technology feature was supportive or not supportive in helping them meet their goal. We categorized features of this applet into four subcategories: (1) features over which a user does not have any control and remain static, (2) dynamic features that allow users to directly manipulate objects, (3) dynamic features that update to provide feedback to users during problem solving, and (4) features that activate parts of the applet. Overall, most features were found to be supportive of students’ problem solving, and patterns in the type of features used to support various problem solving goals were identified.     

大基数与Chang氏模型C

本文研究了一些基数在Ｃｈａｎｇ氏模型Ｃ中的存在性，证明发如下结果：（１）如果Ｋ是弱紧基数，则Ｋ在Ｃ中也是弱紧基数，（２）如果Ｋ是ｉｎｅｆｆａｂｌｅ基数，则Ｋ在Ｃ中也是ｉｎｅｆｆａｂｌｅ基数。（３）如果Ｋ是完全ｉｎｅｆｆａｂｌｅ基数，则Ｋ在Ｃ中也是完全ｉｎｅｆｆａｂｌｅ基数。（４）设Ｊ：Ｃ→Ｃ为初等嵌入，Ｋ为最小变动的基数，则Ｋ在Ｃ中完全ｉｎｅｆｆａｂｌｅ基数，且是完全Ｒａｍｓｅｙ基数。     

A universal continuum of weight

We prove that every continuum of weight  is a continuous image of the Cech-Stone-remainder  of the real line. It follows that under  the remainder of the half line is universal among the continua of weight  -- universal in the `mapping onto' sense.

We complement this result by showing that 1) under  every continuum of weight less than  is a continuous image of , 2) in the Cohen model the long segment of length  is not a continuous image of , and 3)  implies that is not a continuous image of , whenever  is a -saturated ultrafilter.

We also show that a universal continuum can be gotten from a -saturated ultrafilter on , and that it is consistent that there is no universal continuum of weight  .

     

线性规划中一个避免人工变元的方法

文章讨论了线性规划中人工变元问题，且给出一种避免人工变元有效的并且有可能较简便的方法。     

TOPOS BASED SEMANTIC FOR CONSTRUCTIVE LOGIC WITH STRONG NEGATION

The aim of the paper is to show that topoi are useful in the categorial analysis of the constructive logic with strong negation. In any topos ? we can distinguish an object Λ and its truth-arrows such that sets ?(A, Λ) (for any object A) have a Nelson algebra structure. The object Λ is defined by the categorial counterpart of the algebraic FIDEL-VAKARELOV construction. Then it is possible to define the universal quantifier morphism which permits us to make the first order predicate calculus. The completeness theorem is proved using the Kripke-type semantic defined by THOMASON .