指向思考力课堂的学习单设计

学习单是教师从教学目标、教学内容和具体学情出发设计的适合学生自主学习和合作探索的方案,更是构建思考力课堂的“线路图”.教师想要用学习单串联课堂,应主张“对比”“分层”“出错”和“留白”,以打开学生的思维通道,构建精彩的思考力课堂.     

新课标下的小学数学“大单元”教学探析

为加强小学数学的教学质量和水平,小学数学教学出现“大单元”的模式,对小学数学教学的发展有着积极意义.“大单元”的教学模式具有整体性,以一种规范化、结构化的方式,助力小学生更深层次的学习,最终促进学生核心素养的形成.     

Mass Fraction of 13C-Pocket in Metal-Poor AGB Stars and the Primary Nature of Neutron Source

Chemical abundances of very metal-poor s-rich stars contain excellent information to set new constraints on models of neutron-capture processes at low metallicity. Using the parametric approach based on the radiative s-process nucleosynthesis model, we obtain the mass fraction q of 13 C-pocket, the overlap factor r, the neutron exposure per interpulse △τ, and the component coefficients of the s-process and the r-process for 25 s-rich stars, respectively. We find that q deduced for the lead stars is comparable to the overlap factor r, which is larger than the standard case （hereafter ST case） of the AGB model （q - 0.05） about 10 times, and AT are about 10 times smaller than the ST case （AT = 7.0 mbarn^-1）. Although the two parameters obtained for the lead stars are very different from the ST case of the AGB stellar model, it is worth noting that the total amounts of 13 C in metal-poor condition are close to the ST case. The above relation is a significant evidence for the primary nature of the neutron source and the lead stars could be polluted by low-mass AGB stars. Because interpulse period declines with increasing stellar mass, for high-mass AGB star, the neutron irradiation may be terminated due to their shorter interpulse period. Thus the neutron exposure per interpulse of the larger AGB stars should be about 10 times smaller than the ST case. In this ease, the primary nature of the neutron source also exists.     

Ce（SO4）2-mediated Oxidative Coupling of Primary Aromatic Amines in Water

The oxidative coupling of primary aromatic amines was investigated. Ce(SO4)2 can mediate the oxidative coupling of primary aromatic amines in water to dimers, trimers and/or tetramers, which depended on the substituents of primary aromatic amines. When 2,6-dimethylaniline or 2,6-diethylaniline was used as substrate, dimer, and tetramer were formed as major products. When 2,6-diisopropylaniline or 2,6-dihaloanilines was used as substrate, dimer, and trimer were formed. The mechanistic aspect was also investi...     

讲故事

中奖送的 庄库的小表弟只有5岁,但是他经常一有钱就自己去买东西,家里人都拿他没办法。一天,庄库看见他手里又拿着气球,故意生气地说：“你怎么又买东西了？”     

蚂蚁懂数学

这天,我正在一条小路上散步。突然,一只死蝗虫吸引了我的注意。这只蝗虫显然被摆弄过,它的身体被分为3段,第二段几乎是第一段大小的2倍,而第三段又大约在第二段的基础上增加了1倍。一群小蚂蚁正抬着那被分开的第一段,吃力地向洞穴里面爬。     

克隆时代

1．机器人大赛 “杀手”眼看“长江”号要从自己身旁超过去,便抽出一把长刀,猛地向“长江”号的头部砍去。观众席上一阵惊呼!只见“长江”号一跃而起,长刀恰好从他的下面刮过。“杀手”趁对方腾空之际,“呼”的一下又占了第一位。     

“比和比例”大观园一日游

Q岛中心小学校园的东头有一所带围墙的大观园。据说是学校的重难点知识教学基地．这次园里安排了“比和比例”的知识点,还在各个教学景点安排了专门的解说员。     

魔法幻方

亲爱的同学们,很高兴又和大家见面了！欢迎你们也来这做客哦!只要将你的靓照寄来就可以喽!     

巧算塔中灯

一天,唐僧师徒四人来到一座高大的宝塔前。抬头一看,只见那宝塔红墙绿瓦,雕梁画栋,香烟缭绕,十分惹人喜爱。师徒四人商议当晚就在塔旁小庙住宿。夜幕降临,七层宝塔层层灯火通明,而且一层比一层明亮。四人非常惊奇,唐僧命八戒去数一数塔内各层灯的数目。