职前化学教师实践性知识探析

探讨了教师实践性知识和化学教师实践性知识的内涵。从教师教学实践、专业发展以及职前教育3个角度探索了化学教师实践性知识的价值以及化学师范生实践性知识养成的必要性。最后,基于化学师范生的实践性知识养成现状,从创建实践共同体、践行实践主体性和深化个体性反思3个维度出发探析了职前化学教师实践性知识的有效生成途径。     

中学化学教师实践性知识调查研究

实践性知识作为教师知识的重要构成部分,是反映教师教学实践水平的重要标准,对其重视和研究能更好地促进教师自身学习和专业成长。在查阅国内外有关实践性知识研究成果的基础上,结合教育学、心理学相关理论和前期化学教师访谈内容,编制了“中学化学教师实践性知识现状调查问卷”,对河北省内201位中学化学教师进行了调查。研究表明,河北省内2/3以上的中学化学教师的实践性知识处于中等水平以上。教师培训、教研活动、自我学习与反思对教师的实践性知识有不同程度的影响,教师的性别、工作环境、教龄、职称、教研方式等不同的化学教师,其实践性知识水平也存在着显著性差异。     

中学化学教师实践性知识发展状况的调查及启示

提升教师的实践性知识并促成教师专业成长,是新课程背景下教研部门工作的重点和难点。采用问卷调查、课堂听课及听课后的访谈等研究方法,对中学化学教师教学实践性知识发展状况进行了调查和梳理分析,并以此为基础提出了基层区域教研工作的重点内容和一般思路。     

稀土羧酸配合物的结构

本文系统地对200 多个稀土羧酸配合物的结构进行了归纳和总结, 重点对配合物的结构骨架、羧基的配位方式及稀土离子的配位数进行了讨论。     

碘酸盐的晶体结构与热力学性质——(Ⅰ)碘酸盐的晶体结构特点

本文根据作者等人的实验结果并结合文献报导的数据,综述了碘酸盐及其复盐的晶体结构特点和分类。对α-LiIO_3,Li_2H(IO_3)3,Mg(IO_3)_2,Mg(IO_3)_2-LiIO_3固溶体,Zn(IO_3)_2等晶体结构变迁的情况进行了分析。阐述了由于空位数量和分布的不同,以及阳离子性质(电价、离子极化能力和离子半径等)的不同,晶格场发生变化,引起了IO_3~-在不同方向和不同程度的移动或转动,因而有可能在不同方向上形成不同程度的各种畸变型结构和超结构。     

The Stabilization of Bridged Structures of Ethanes

The source of the instability of D_2h, bridged, diborane type geometries of ethanes is traced to a single molecular orbital, b_2g or π* in symmetry. The energy of this orbital can be lowered, and the barrier to bridging accordingly decreased, by appropriately placed acceptor substituents. Low bridging barriers, relative to ethane, are predicted for cyclopentenyl cation, and cyano or nitro substituted ethanes.     

化学专业师范生实践性知识水平及影响因素调查研究*

基于自主建构的化学师范生实践性知识水平研究模型,采用自编调查问卷,对河北某高校化学专业271名师范生进行问卷调查,运用SPSS 13.0数据统计分析软件进行数据处理,研究结论如下:(1)化学专业师范生在经过系统的理论学习之后,在实习之前,其实践性知识整体和各维度均处于本研究的中等水平;(2)化学专业师范生实践性知识的5个维度之间具有较强的相关性,各维度在一定程度上相互影响、相互制约;(3)教学经验的积累、大学之前的学习经历、自己敬重和喜欢的老师、优质课的观摩、教学案例分析、微格教学技能训练是影响化学专业师范生实践性知识的主要因素。     

HPOS体系异构体结构与稳定性

在MP2／6－311＋＋G(d,p)和QCISD（T）／6－311＋＋G（3df,2p)（单点）水 平下计算得到了HPOS体系势能面上18个异构体和25个过渡态及解离碎片等驻点，并 分析了这些异构体的结构及异构化过程，讨论了可能的解离方式。在得到的异构体 中，有8个异构体是动力学较稳定的，它们是dis-HOPS,trans-HOPS,trans-HSPO, cis-HSPO,HP(O)S(Cs),trans-HPSO,cis-HPSO和HP（O）S（C1）。这些异构体在实 验中应该可以观测到。理论研究表明，P与S原子较强的超价能力在降低异构体能量 ，提高异构体动力学稳定性方面起到了关键的作用。得到的计算结果与HPO2， HPS2，HNOS等价电子相同的体系进行了比较。     

The Structures and Stability of HNOS Isomers

Potential energy surface of HNOS system is investigated by means of MP2 method with 6-311 G(d,p) basis set.The energy for each minimum and saddle point on the potential energy surface is corrected at the QCISD(T)/6-311 G(3df,2p) level of theory with zero-point vibrational energy included.As a result ,eighteen isomers are theoretically predicted and cis-HNSO is found to be global minimum on the potential energy surface,Wherein,fourteen isomers are considered as kinetically stable species,and should be experimentally observed.Comparisons are made for HNOS system with its analogues,HNO2 and NHS2.The nature of bonding and isomers‘ stability of HNOS system are similar to HNS2.The obvious similarities and discrepancies among HNOS,HNO2 and HNS2 are attributed to the hypervalent capacity of sulfur,oxygen and nitrogen atoms.     

关注职前化学教师实践性知识的主题教学研修——以师范生“化学肥料”课堂教学为例

为了探索职前化学教师实践性知识生成的指导和培养,由化学师范生、化学教学论教师和初高中化学教师组成的教师学习共同体开展主题教学研修。在关注师范生试教“化学肥料”的基础上,从不同角度开展评析和指导。基于共同体的研修活动指出化学师范生应回归学科知识,职前指导需要多元化补充,来自不同层面的师生组成学习共同体利于共同成长。该活动从实践层面开拓教师教育课程改革的新方向。     

The EuOnCoordination Polyhedra in Crystal Structures

The Voronoi–Dirichlet polyhedra (VDP) and the method of intersecting spheres were used to perform crystal-chemical analysis of the compounds studied to date containing EuO _n polyhedra. The Eu(III) and Eu(II) atoms were found to have coordination numbers (C.N.s) from 6 to 12 with respect to oxygen. The Eu(III) Eu(II) transition entails an increase in the VDP volume by, on average, 4 ų. For a constant valence state of europium, the VDP volume barely depends on the C.N., although the Eu–O interatomic distances change by 0.72 Å for Eu(III)-containing structures and by 0.59 Å for Eu(II)-containing structures.     

微量元素应用须知

提出了微量元素食品必须适量的问题，即微量元素在人体内含量应平衡，不宜过多，也不宜过少，并以碘、锌、锗为例加以说明，提倡杂食。不断变换食谱以调节体内微量元素的平衡，有利于保障人体健康。     

Current Knowledge on Mammalian Phospholipase A1, Brief History,Structures, Biochemical and Pathophysiological Roles

Phospholipase A₁ (PLA₁) is an enzyme that cleaves an ester bond at the sn-1 position of glycerophospholipids, producing a free fatty acid and a lysophospholipid. PLA₁ activities have been detected both extracellularly and intracellularly, which are well conserved in higher eukaryotes, including fish and mammals. All extracellular PLA₁s belong to the lipase family. In addition to PLA₁ activity, most mammalian extracellular PLA₁s exhibit lipase activity to hydrolyze triacylglycerol, cleaving the fatty acid and contributing to its absorption into the intestinal tract and tissues. Some extracellular PLA₁s exhibit PLA₁ activities specific to phosphatidic acid (PA) or phosphatidylserine (PS) and serve to produce lysophospholipid mediators such as lysophosphatidic acid (LPA) and lysophosphatidylserine (LysoPS). A high level of PLA₁ activity has been detected in the cytosol fractions, where PA-PLA₁/DDHD1/iPLA₁ was responsible for the activity. Many homologs of PA-PLA₁ and PLA₂ have been shown to exhibit PLA₁ activity. Although much has been learned about the pathophysiological roles of PLA₁ molecules through studies of knockout mice and human genetic diseases, many questions regarding their biochemical properties, including their genuine in vivo substrate, remain elusive.     

情境引领深度学习 实践应用促旧知新识——溶液单元复习教学

基于走向真实情境的化学教学研究的基础,对初中化学溶液的复习进行了整体单元设计,以“自贡井盐的制作过程”为情境,采用任务驱动、问题驱动的教学方法,渗透不同的评价方式,引导学生应用所学的溶液知识解读自贡井盐的制作工艺,加强对溶液知识的理解与应用,提升知识迁移运用的能力。     

The Observation of Plasma Structures in Electrolyte Solution

The passage of the electrical current (the voltage 1–2 kV) through dielectric tubes filled with electrolyte solutions causes the formation of luminous plasma zones moving along the tube. The visual observations and camera control (24 frames/s) show the possibility of the simultaneous existence up to three luminous zones. They may be as cylinder with the length up to four diameters of the tube, disc or ring. The estimations result in the lifetime of these luminous objects ≤ 0.2 s. The discharge current oscillography demonstrates the sequences of the attenuated pulses modulated with the frequency of 50 Hz. This type of plasma-solution system demonstrates high efficiency modification of the polymer materials.     

The Electronic Structures of Dimeric Diboroxane and Aldiminoborane

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Dawson结构硫钼杂多阴离子的电子结构

使用第一原理密度泛函理论中的离散变分方法（DFT-DVM）对（S2Mo18O62）4-的电子结构进行了理论计算,并与Keggin结构（SMo12O40）2-的电子结构作了比较分析,结果表明,（S2Mo18O62）中的电子离域地分布在整个阴离子骨架中,但极位和赤道位原子的电荷分布有明显差异。端氧与Mo之间的键均较强,中心氧与Mo之间形成的键最弱。（S2Mo18O62）4-的化学行为的活性中心是赤道位钼Moe、极位端氧Opt、极位共顶桥氧Opea、赤道位端氧Oet和赤道位共边桥氧Oeb。与（SMo12O40）2-相比,（S2Mo18O62）4-的稳定性和氧化性均较弱。但在两种类型的硫钼杂多阴离子中,Mo对其氧化性的产生起了重要的作用。