美国中学化学教材中情境创设的分析与启示

美国主流理科教材《化学:概念与应用》以化学核心概念为主题,创设了丰富的学习情境。以该教材中"水和溶液"这一章创设的情境为例,讨论该教材中情境的类型、功能及呈现方式,为国内化学教材情境的创设提供建议。     

美国化学教材《化学与社会》习题的特点及启示

教材习题的设计对实施有效教学起着重要的作用。美国化学教材《化学与社会》中习题的设计反映了当代美国化学教材习题的编写理念,分析研究教材在习题数量、习题分布、习题内容与信息技术的关联等方面的特点对我国化学教材习题的设计具有重要的借鉴价值。     

人教版高中化学必修教科书的内容呈现方式及特点分析*

高中化学教科书是发展学生化学学科核心素养的重要载体和资源平台。依据《普通高中化学课程标准(2017年版)》编写的人教版普通高中化学必修教科书作为分析文本,着重从栏目系统、图像系统、习题系统角度对其呈现方式进行分析,具体特点表现为:栏目系统强化功能性,图像系统凸显直观性,习题系统体现针对性、情境性、开放性,以期为高中化学教师有效使用教科书、落实化学学科核心素养的培养发挥积极作用。     

英国《化学故事情节(AS)》配套复习指导书编写特点及启示

介绍了英国索尔特高级化学教材《化学故事情节》AS部分配套复习指导书中课程学习评估要求、编写结构以及复习指导书所涉及知识点内容,据此总结归纳出以下3个编写特点:(1)体现教材编制中收放自如的"收"的重要性;(2)体现与其他相应教材的交叉联系性;(3)体现习题多类型、多层次性。最后,阐释从中获得的几点启示。     

实验对化学概念学习的促进作用——以“胶体”教学为例

以苏教版《化学1》“胶体”的教学为例,分析化学概念的教学中怎样创设实验情境,将微观世界的变化以宏观的现象展现出来,促进学生对化学概念的理解。     

德国初中化学教材单元习题设计特点分析

有效的习题设计是教材编制不可或缺的组成部分。分析德国莱茵兰·普法尔茨州的初中化学启蒙教材《今日化学Ⅰ》中单元习题结构、功能和题型设计特点,其单元习题的设计情境之真实、素材之丰富、视野之开阔及思路之精巧值得学习和借鉴。     

真实情境与化学学科核心素养的发展——基于《普通高中化学课程标准(2017年版)》的解读

《普通高中化学课程标准（2017年版）》构建了化学学科核心素养的内容体系及其发展水平框架,重视开展“素养为本”的教学,重视真实情境的创设。在分析教学情境的内涵与功能的基础上,解读了新课标中课程内容、实施建议和命题原则中对真实情境创设与应用的要求,讨论了真实情境在发展学生化学学科核心素养中的教育价值。通过对具体教学案例的分析,探讨了基于学生化学学科核心素养发展的教学情境设计的策略。     

谈提高化学习题教学的效益

化学习题教学是化学教学内容的重要构成之一,是贯穿整个教学过程、落实学生能力培养的一条重要脉络,也是师生双向交流最广泛的教学活动之一。新颁布的《全日制中学化学教学大纲》,明确提出了“加强化学习题教学”的课题。当前,化学习题教学耗时多,效益不高。落实大纲的要求,加强化学习题教学,减轻负担,提高效益,是十分紧迫的任务。1. 应当重新认识化学习题教学的作用,扭转以题海应付考试的不良倾向。     

人教版《化学1（必修）》教材习题的开发与利用

为了解决教材习题被长期忽视的问题,提出了对习题进行开发与利用,并以《化学1（必修）》中的实例从正文、习题、高考3者关系的角度重新认识习题的重要性,并以发展的眼光看待习题,探讨整合之道。     

人教版高中化学新教材习题系统的分析及教学建议

新课标教材习题系统应包括课文习题与课后习题。高中化学新教材（人教版）习题系统与课文内容相互融合,体现科学探究,题型多样化,问题情境化,语言人性化。在化学教学中应转变观念,重视教材习题系统的教学功能;注重习题的情境性;加强习题的联系,重视变式训练。     

"Alpha"-, "beta"- and "delta"-anhydrodigitoxigenin

The syntheses of 3β-hydroxy-5β-carda-14, 20:22-dienolide (= «β»-anhydro-), 3β-hydroxy-5β-carda-8:14, 20:22-dienolide (= «α»-anhydro-) and «δ»-anhydro-digitoxigenin (= probably 3β-hydroxy-5β, 14β-carda-8, 20:22-dienolide) by the best ways known to date, have been described. «δ»-Anhydro-digitoxigenin represents the thermodynamically most stable isomer. In this isomer the double bond in position 8 is unaffected by hydrogenation with Pt in acetic acid; with perbenzoic acid an epoxide results from which, on hydrogenation, the double bond can be regenerated in its original position. Analogous reactions are known to occur in the 8:14-epoxides.     

Making "wheels" and "cubes" from triangles

[Mn(IV)Mn(II)3] triangular units directed by the presence of tripodal alcohols self-assemble in the presence of azide and acetate ligands to form either a [Mn24] "wheel" or a [Mn32] "cube".     

营养化学课程翻转课堂的探索与实践

With its tailored learning content, flexible learning environment and directed teacher guidance, the flipped classroom in "nutrition chemistry" has effectively solved the problems of students' specialty, large number and limited time in the course of elective course. The teaching mode based on the cultivation of students' ability and the core of improving scientific literacy was constructed.     

Size evolution study of "molecular" and "atom-in-cluster" polarizabilities of medium-size gold clusters

A study on static polarizabilities for a family of gold clusters (Au(n), n = 6, 12, 20, 34, 54) is presented. For each cluster, a density functional theory perturbation theory calculation was performed to compute the cluster polarizability and the polarizability of each atom in the cluster using Bader's "quantum theory of atoms in molecules" formalism. The cluster polarizability tensor, α(cluster), is expressed as a sum of the atom-in-molecule tensors, α(cluster)=∑(Ω)α(Ω). A strong quadratic correlation (R(2) = 0.98) in the isotropic polarizability of atoms in the cluster and their distance to the cluster center of mass was observed. The cluster polarizabilities are in agreement with previous calculations.     

Fabrication of "roll-off" and "sticky" superhydrophobic cellulose surfaces via plasma processing

Most of the artificial superhydrophobic surfaces that have been fabricated to date are not biodegradable, renewable, or mechanically flexible and are often expensive, which limits their potential applications. In contrast, cellulose, a biodegradable, renewable, flexible, inexpensive, biopolymer which is abundantly present in nature, satisfies all the above requirements, but it is not superhydrophobic. Superhydrophobicity on cellulose paper was obtained by domain-selective etching of amorphous portions of the cellulose in an oxygen plasma and subsequently coating the etched surface with a thin fluorocarbon film deposited via plasma-enhanced chemical vapor deposition using pentafluoroethane as a precursor. Variation of plasma treatment yielded two types of superhydrophobicity : "roll-off" (contact angle (CA), 166.7 degrees +/- 0.9 degrees ; CA hysteresis, 3.4 degrees +/- 0.1 degrees ) and "sticky" (CA, 144.8 degrees +/- 5.7 degrees ; CA hysteresis, 79.1 degrees +/- 15.8 degrees ) near superhydrophobicity. The nanometer scale roughness obtained by delineating the internal roughness of each fiber and the micrometer scale roughness which is inherent to a cellulose paper surface are robust when compared to roughened structures created by traditional polymer grafting, nanoparticle deposition, or other artificial means.     

Switching "on" and "off" the expression of chirality in peptide rotaxanes

The hydrogen-bond-directed synthesis, X-ray crystal structures, and optical properties of the first chiral peptide rotaxanes are reported. Collectively these systems provide the first examples of single molecular species where the expression of chirality in the form of a circular dichroism (CD) response can selectively be switched "on" or "off", and its magnitude altered, through controlling the interactions between mechanically interlocked submolecular components. The switching is achievable both thermally and through changes in the nature of the environment. Peptido[2]rotaxanes consisting of an intrinsically achiral benzylic amide macrocycle locked onto various chiral dipeptide (Gly-L-Ala, Gly-L-Leu, Gly-L-Met, Gly-L-Phe, and Gly-L-Pro) threads exhibit strong (10-20k deg cm(2) dmol(-1)) negative induced CD (theta;) values in nonpolar solvents (e.g. CHCl(3)), where the intramolecular hydrogen bonding between thread and macrocycle is maximized. In polar solvents (e.g., MeOH), where the intercomponent hydrogen bonding is weakened, or switched off completely, the elliptical polarization falls close to zero in some cases and can even be switched to large positive values in others. Importantly, the mechanism of generating the switchable CD response in the chiral peptide rotaxanes is also determined: a combination of semiempirical calculations and geometrical modeling using the continuous chirality measure (CCM) shows that the chirality is transmitted from the amino acid asymmetric center on the thread via the macrocycle to the C-terminal stopper of the rotaxane. This understanding could have important implications for other areas where chiral transmission from one chemical entity to another underpins a physical or chemical response, such as the seeding of supertwisted nematic liquid crystalline phases or asymmetric synthesis.     

信息技术与“教学评”一体化深度融合的教学实践*——以“有机合成”为例

以建构有机合成中的顺推法和逆合成分析法思维模型为载体,通过设置驱动任务,将信息技术和“教学评”一体化深度融合,促进学生结构观、发展观和转化观的形成,理解有机化学的社会价值,培养学生的宏微结合、变化观念、科学态度和社会责任等化学学科核心素养。