初中化学解题推理思维的案例分析

在初中化学教学阶段,由于受年龄和身心发展的影响,学生思维的运作形式主要是具体形象的推理思维,包括演绎推理和归纳推理,本文结合具体的案例,从定性推理思维和定量推理思维两个方面加以分析。1 定性推理思维及其案例分析定性推理是确定研究对象具有某种属性的推理     

The effect of 14 weeks of vitamin D3 supplementation on antimicrobial peptides and proteins in athletes

Heavy training is associated with increased respiratory infection risk and antimicrobial proteins are important in defence against oral and respiratory tract infections. We examined the effect of 14 weeks of vitamin D₃ supplementation (5000 IU/day) on the resting plasma cathelicidin concentration and the salivary secretion rates of secretory immunoglobulin A (SIgA), cathelicidin, lactoferrin and lysozyme in athletes during a winter training period. Blood and saliva were obtained at the start of the study from 39 healthy men who were randomly allocated to vitamin D₃ supplement or placebo. Blood samples were also collected at the end of the study; saliva samples were collected after 7 and 14 weeks. Plasma total 25(OH)D concentration increased by 130% in the vitamin D₃ group and decreased by 43% in the placebo group (both P = 0.001). The percentage change of plasma cathelicidin concentration in the vitamin D₃ group was higher than in the placebo group (P = 0.025). Only in the vitamin D₃ group, the saliva SIgA and cathelicidin secretion rates increased over time (both P = 0.03). A daily 5000 IU vitamin D₃ supplement has a beneficial effect in up-regulating the expression of SIgA and cathelicidin in athletes during a winter training period, which could improve resistance to respiratory infections.     

硝酸法处理废硬质合金回收金属钴和碳化钨

介绍了用硝酸法处理废硬质合金，回收金属钴和碳化钨的方法，并且设计了对废气氛氧化物的处理方法，消除了对环境的污染。是一种工艺简单，投资省，成本低，能耗少，污染小的回收工艺。     

应用MATLAB求线性方程组的Cramer法则方法探讨

本文分析了几种用MATLAB求解线性方程组的Cramer法则的方法,并指出这些方法的改进过程及其教学价值.     

中职教师在职攻读硕士学位问题探讨

近年来,中职教师在职攻读硕士学位的过程中,出现了许多不尽人意之处,如学员学前背景、学前动机、学中态度、学中效果、学后质量等差异较大,影响了培养质量。为此,有必要加强与学员所在单位的联系与合作;加强对学员的管理与规范;以人为本,全面提高学员综合素质和学术价值观;优化导师的整体指导资源,提升导师小组的指导能力。     

Visualization of structured packing with laser induced fluorescence technique: Two-dimensional measurement of liquid concentration distribution

A method of using laser induced fluorescence(LIF)technique was applied to two-dimensional measurement of the liquid concentration distribution in the 250Y structured packing sheet. The experimental structured packing sheet was made of perspex so that the laser could pass through it. The visualization of the distribution of the liquid concentration in the structured packing sheet was realized. The calibration of the thickness and liquid concentration was carried out firstly and the regression formula I=kcd was acquired, in which concentration c and the liquid film thickness d were both considered. Then the liquid feed of uniform tracer(rhodamine)concentration entered the perspex structured packing from the top under different spraying densities. The corresponding thickness of liquid film on the packing was calculated. Finally, tracer(rhodamine)with a high concentration was injected only at one fixed point of the structured packing under different spraying densities of the liquid. With the known liquid film thickness, the concentration distribution of the tracer can be calculated inside the structured packing sheet.     

英汉词汇的民族文化特征和语用差异

词汇是语言的主要构素;词汇不仅有其字面意义,还有其内涵意义。在语言中,词汇和语义最能充分、生动地反映出生活的不同侧面。在跨文化交际中,词汇在不同的语境和不同的历史条件下会表现出不同的内涵和语用差异,这既反映出不同的民族文化,也反映出词汇在不同民族文化中特有的文化内涵。     

多元智能与幼儿英语教学

近几年来,幼儿英语教学在我国获得蓬勃发展,但是由于缺少先进的科学理论指导,目前很多幼儿园的英语教学定位不准,目标不明确,给人感觉英语教学好像游离于学前教育体系之外。如何真正把英语教学纳入学前教育体系之中,已成为摆在我们面前的新课题。本文认为,加德纳的多元智能理论符合我国学前教育的培养目标和要求,用它来指导英语教学,能激发幼儿学习英语的兴趣,促进多种智能开发,提高整体素质,从而推进我国幼儿教育事业的发展。     

陆费逵论职业教育

陆费逵是中国现代著名教育家、出版家，他的职业教育思想主要涉及三个方面，即民国教育方针、职业教育与国民教育及人才教育的关系，职业道德教育等。     

中国古代的习惯法及其当代意义

中国古代的习惯法主要存在于“礼”中,且具有宗族性和民族性的特点。习惯法的形成有其客观的经济基础和社会基础,同时能够有效弥补制定法的不足。古代习惯法对当代中国在法源理论以及法的实现等方面具有深刻的借鉴意义。