享受物理教学——首届全国高等学校物理基础课程青年教师讲课比赛旁听有感

首届＂高等教育杯＂全国高等学校物理基础课程青年教师讲课比赛已经举行.许多高校的物理教师专程赴会旁听比赛.笔者跟踪旁听了在上海复旦大学举行的上海市的初赛、在青岛市青岛大学举行的华东地区的复赛以及在成都四川大学举行的全国决赛的全过程,本文为旁听的感想和体会.     

Electron neutral collision frequency from breakdown measurements in crossed electric and magnetic fields

A simplified method of determining the electron-neutral collision frequency at unit pressurev ₀ is presented in a number of gases (hydrogen, argon and air) in crossed electric and magnetic fields utilising the sparking voltage data and equivalent pressure concept. The values ofv ₀ for lowH/p are found to agree with those reported by other authors. But at highH/p, the estimated values ofv ₀ are appreciably higher for all the three gases. The increase in the values ofv ₀ possibly occurs due to the change of the electron energy distribution at higherH/p.     

亚里士多德的时间观念研究

在物理认识史上，亚里士多德对时间和空间的基本属性作了前所未有的系统研究，建立了人类历史上第一个比较完整的时间空间理论体系，亚里士多德的时空学说对古代及近代物理学和哲学的发展都产生了重要而深远的影响。文章系统探讨了亚里士多德关于时间的学说，从中归纳出一系列结论性的认识，由此集中展示了他关于时间认识的基本成果，并简单讨论了这些成果对现代物理学认识的启发意义。     

Solar thermal power generation

The technologies and systems developed thus far for solar-thermal power generation and their approximate costs are described along with discussions for future prospects.     

Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound

We report herein the synthesis of a novel modified steroid with two rigidly positioned amino acids in C- and N-protected forms (Gly-O^tBu and N-Fmoc-l-Phe) at the angular positions (C-18 methylamino group and C-19 carboxylic function) of the steroid nucleus via amide bonds, starting from 18-cyanopregnenolone acetate over 10 steps. In an attempt to gain more insight into the structural and conformational features of this novel 18-Phe,19-Gly-containing steroidal compound, we describe the detailed 2D NMR spectral analysis. Despite the large size and the conformational flexibility of the amino acid units in this molecule, conformational analysis by NOESY connectivities showed the existence of mainly one conformation (∼95%) in CDCl₃ solution with approximately parallel orientation of the phenylalanine and glycine moieties.     

Ionic interactions in solutions. II. The theoretical basis of the equilibrium between free and pairwise associated ions

It is shown from recent results based on the statistical mechanics treatment of ionic solutions that the notion of an equilibrium between free ions and paired ions which wasa priori introduced in the chemical model of Bjerrum is essentially correct. The mass-action law which is deduced from such a model is indeed derivable from the more exact treatments of Mayer, Rasaiah, and Friedman starting directly from Hamiltonian models and without any assumptions as to the chemical structure of the ionic solute in the solution. The transformation relation from a primitive-model result to any short-range Hamiltonian model equation is given. It allows a simple mathematical treatment of experimental data for dilute solutions, the derivation of useful information on the Gurney solvation effects, and an interpretation of the multistep association concept.     

检测实验室如何开展质量体系内部审核工作

详细论述了审核的基本概念、开展质量体系内部审核工作的必要性、如何开展质量体系内部审核工作以及中国实验室国家认可委员会的有关政策。     

Mathematics education graduate students’ understanding of trigonometric ratios

This study describes mathematics education graduate students’ understanding of relationships between sine and cosine of two base angles in a right triangle. To explore students’ understanding of these relationships, an elaboration of Skemp's views of instrumental and relational understanding using Tall and Vinner's concept image and concept definition was developed. Nine students volunteered to complete three paper and pencil tasks designed to elicit evidence of understanding and three students among these nine students volunteered for semi-structured interviews. As a result of fine-grained analysis of the students’ responses to the tasks, the evidence of concept image and concept definition as well as instrumental and relational understanding of trigonometric ratios was found. The unit circle and a right triangle were identified as students’ concept images, and the mnemonic was determined as their concept definition for trigonometry, specifically for trigonometric ratios. It is also suggested that students had instrumental understanding of trigonometric ratios while they were less flexible to act on trigonometric ratio tasks and had limited relational understanding. Additionally, the results indicate that graduate students’ understanding of the concept of angle mediated their understanding of trigonometry, specifically trigonometric ratios.     

OBE理念下化学教育硕士教育实习评价体系的构建

为解决化学教育硕士教育实习评价存在的问题,基于OBE(成果导向)理念,聚焦化学教育硕士毕业时“学到了什么”“能做什么”以及毕业后5年应具备的职业能力,从“实习表现、教学工作、班主任工作、教学研究工作”等4个维度出发,开发出包含14个二级指标、65个三级指标的实习评价量表,并建立起与“实习准备阶段、实习实施阶段、实习总结阶段”相对应的“监控—调节—改进”环节以保障实习质量,最终形成了“四维三阶”的闭环式教育实习评价体系,规范了化学教育硕士教育实习评价方式,提高了教育实习质量。