巧用一般化方法解数学题

1一般化的基本思想一般化是数学中带有普遍性的一种思想方法.它是指从考虑一个对象或较少对象的集合过渡到考虑包含已给对象的更大集合的一种思想方法.例如,人们从锐角三角函数的考虑过渡到任意三角函数的考虑,从正三角形到正多边形,从一元函数到多元函数,等等,均属于一般化.例     

图书馆馆员的继续教育

文章论述了图书馆开展继续教育的必要性,提出了图书馆继续教育的原则、措施、内容和形式。     

数学教育研究中几个理论的简介

2001年以来,云南师范大学数学学院在云南省部分中学开展数学情境与提出问题教改实验,在该项教改实验中,结合数学教育几个理论开展了一些探索,感受到这些理论的深入学习和研究将有助于进一步理解数学新课程的理念,有助于云南省正在进行课程标准实验教材教学的实施。因此在一些初     

一道浮力问题的衍变

【基本题】如图1所示，水面上浮着一块冰，冰在熔化过程中．杯中的水面会[]．     

Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein

Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmicgrowth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF andcultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ inthe four groups were 0 μmol/L, 1.25 μ mol/L, 2.5 μ mol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted toexamine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations wasadded. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μ mol/L, respectively. After the cellswere incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC 12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h timepoints. 3) Aβ (0-5.00 μ mol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of thePC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of thePC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study -05 provide basis for futureresearch on the molecular cure of AD and interdiction of AD evolution.     

记忆与印象:史铁生的写作之源

我是我的印象的一部分,而我的全部印象才是我,记忆与印象作为史铁生的写作之源,经历了极限体验、反思生存、通过写作寻找生存的意义以及把记忆与印象作为写作之源的几个阶段。     

记忆与印象:史铁生的写作之源

"我是我的印象的一部分,而我的全部印象才是我","记忆与印象"作为史铁生的写作之源,经历了极限体验、反思生存、通过写作寻找生存的意义以及把"记忆与印象"作为写作之源的几个阶段.     

任务型教学法下的计算机辅助外语教与学

任务型语言教学法旨在通过任务的形式向学习者提供一种应用语言的自然环境。多媒体辅助英语教与学正是利用现代化教学手段,营造浓厚的英语学习氛围,帮助学生扩大视野,激发学习兴趣,达到自主学习的目的。     

小习惯成就大课堂

陶行知先生说:"播种行为,就收获习惯;播种习惯,就收获性格;播种性格,就收获命运."巴金也说:"孩子成功教育从好习惯培养开始."由此可见,培养好习惯的重要性.我在教学中特别注意培养了孩子下面五种数学好习惯. 一、培养孩子认真倾听的好习惯. 课堂是孩子学习的主阵地,要让教学有效,就必须规范孩子的倾听习惯.首先要学会听老师讲,在低段教学中要注意培养孩子认真倾听的好习惯,我们常用这样一句话提醒孩子:"请听我说."孩子会回答:"我听你说."让孩子听了会复述,会把每天听到的内容讲给同学和家长听.另外,要学会听同学讲,当孩子回答问题时会用"请关注我的发言"这句话来提醒孩子认真倾听,其他同学就会把目光投向发言者,认真倾听同学的发言.如果有孩子没听清楚,课后还可以当小记者去采访发言的同学.老师在教学中多关注多提醒多总结,并用评选"神耳朵"的方法,促使孩子养成认真倾听的好习惯.