真实而有意义的学习情景:内涵、特征及创设

《义务教育化学课程标准(2011版)》在教学建议中提倡"努力创设真实而有意义的学习情景"。真实而有意义的学习情景应具备真实性、目的性、问题性、可理解性以及过程性等特征。创设真实而有意义的学习情景需要教师善于积累学习情景素材,并能依据教学需要适当加工并合理组织。     

“支点驱动-科研探索-逻辑拓展”模式下高校双语有机化学教学设计与实践**

建设高效课堂是教育主体回归育人主旨的一种教学重构。基于双语有机化学的课堂教学,系统阐述了以“支点驱动-科研探索-逻辑拓展”为模式,从“点”到“线”再到“面(体)”的高校双语有机化学金课课堂的设计与实践,以期为普通高校开拓双语有机化学的课堂教学提供方法分享、观点讨论以及有价值的思路借鉴。     

STUDY OF MESOPOROUS SILICA MATERIALS BY SMALL ANGLE X—RAY SCATTERING

Small angle X-ray scattering experiments have been performed to study the microstructure of messoporous silica meterials prepared by condensation of tetraethylorthosilicate using nonionic alkylpolyethyleneoxide(AEO9) and ionic cetyltrimethylammonium bromide (CTAB) surfactant as templates.It is the pores within the nanometre range that produce the main cattering.The scattering of the pure silica systems obey Porod’s law.This may be because the templates produce some additional scattering background and then make the scattering of pores distorted.The results show that the full removal of templates from the pores of the materials by Soxhlet extraction is very easy for AEO9,but it is difficult for CTAB.The positive deviation correction is also perfromed.     

Monte Carlo Study of Griffiths Phase in Randomly Site Diluted Ising Magnetic System

We study the dynamics of spin autocorrelation function and the non-equilibrium decay of magnetization in the Criffiths phase of randomly site diluted Ising magnetic systems by Monte Carlo simulation. The results show that the relaxations are non-exponential for both two- and three-dimenslonal diluted Ising magnetic systems. At a long timescale, the asymptotic dynamics of the spin autocorrelation function C（t） behaves in the form of C（t） ～ exp{-A（lnt）^d/d-1}, expected by the theoretical prediction based on clustering arguments. Furthermore we show that the evolution of the spin autocorrelation function satisfies rather well a stretched exponential form of C（t） ～ exp{-（t/t）^β} even at quite small timescales.     

计算器按千遍过 不及珠算万木春

当珠心算教育正在我国小学蓬勃发展之时,我却从新华通讯社主办的《参考消息》(1997年10月5日)上看到了刊载的《数学课该怎么上?》,该文系转自美国《时代》周刊8月25日一期文章,题:数学课就是这样的么?(作者罗梅什·拉特纳萨尔)。 加利福尼亚州森瓦利市费南格勒斯小学     

Abundance gradients in the galactic disk

The relationship between abundances and orbital parameters for 235 F- and G-type intermediate- and low- mass stars in the Galaxy is analyzed. We foundthat there are abundance gradients in the thin disk in both radial and verticaldirections (-0.116 dex kpc-1 and -0.309 dex kpc-1 respectively). The gradients appear to be flatter as the Galaxy evolves. No gradient is found in the thick disk based on 18 thick disk stars. These results indicate that the ELS model is mainly suitable for the evolution of the thin disk, while the SZ model is more suitable for the evolution of the thick disk. Additionally, these results indicate that in-fall and out-flow processes play important roles in the chemical evolution of the Galaxy.     

辐射法——一种独特多效的复习方法

复习课的目的不仅是温故知新 ,而且应该培养各项能力 ,尤其是整理知识的能力 .我们对复习课教学进行了不懈的探究 ,通过观察和分析 ,我们把突破口定位在如何使学生学会寻找整理知识的线索上 ,构建了一种新的复习方法———辐射法 .1　辐射法概要辐射法是指以主干知识为中心作为     

ZnCrDyK和ZnCrTbK合成低碳醇催化剂的XPS表征

ＺｎＣｒＤｙＫ和ＺｎＣｒＴｂＫ合成低碳醇催化剂的ＸＰＳ表征安炜，牛玉琴，陈正华（中国科学院山西煤炭化学研究所，太原０３０００１）关键词稀土元素，Ｚｎ－Ｃｒ氧化物催化剂，低碳醇，Ｘ射线光电子能谱近年来，稀土氧化物（ＲＥＯ，ＲＥ表示稀土元素）作为助剂或载...     

浅谈珠算在会计实务及其它经济计算中的作用

随着我国经济的不断发展,电子计算机的普及和会计电算化的进一步实施,越来越多的企、事业单位使用电脑计算、记账(即实施会计电算化),相对而言,珠算这一传统的手工计算工具就位于其次。一些人认为有了能够高速运转自动进行计算的电脑,珠算应该消声匿迹了。一些学校取消了珠算课。笔者认为即使在计算机计算相对发达的今天,珠算也仍有其存在的价值     

线状锗等离子体空间分布特性实验研究

在电子碰撞激发类Ne锗X光激光实验的基础上,对线状等离子体空间分布特性进行定量测量和分析。首次给出了线状等离子体分布尺度,同时也研究了不同的激光参数和靶结构对等离子体状态的影响。