Conservation science and technology identity instrument: Empirically measuring STEM identities in informal science learning programs

Our research centered on developing the Conservation Science and Technology Identity (CSTI) instruments as an empirical way to measure STEM identities and the intersection of identity constructs such as competence, performance, recognition, and ways of seeing and being. The surveys were used in a large funded multi-year project for teens and adults learning geospatial technologies and conservation science to use in intergenerational community conservation projects. We investigated whether an informal STEM learning program was developing new STEM identities or advancing well-developed identities. The instruments’ content validity was determined through a vetting process from national STEM identity research experts. Reliability was estimated with Cronbach coefficient alpha. Mann-Whitney and Wilcoxon Signed Rank tests were used to determine participants’ STEM identities and the workshop’s effect on specific identity constructs. We found teens and adults had historically similar STEM identities, with stronger conservation science than technology. Both science and technology competences, as well as technology ways of seeing and being, significantly increased, suggesting CSTI can be a valuable instrument in empirically assessing STEM identities.     

基于大理科模式的化学拔尖学生培养的课程体系与教学实践

介绍南京大学大理科模式化学拔尖学生培养的课程体系和教学实践的初步成果,指出该课程体系的特点是系统地传授数、理、化、生等学科的基础知识,强化化学专业核心课程,尤其注重国际化教学与交流,学生适应化学及其相关交叉学科研究。     

Vocal Problems Among Teachers: Evaluation of a Preventive Voice Program

Vocal education programs for teachers may prevent the emergence of vocal disorders; however, only a few studies have tried to evaluate the effectiveness of these preventive programs, particularly in the long term. Two hundred and sixty-four subjects, mostly kindergarten and primary school female teachers, participated in a course on voice care, including a theoretical seminar (120 minutes) and a short voice group therapy (180 minutes, small groups of 20 subjects). For 3 months, they had to either attend the vocal ergonomics norms and, as psychological reinforcement, they had to make out a daily report of vocal abuse, or to follow the given exercises for a more efficient vocal technique, reporting on whether the time scheduled was respected or not. The effectiveness of the course was assessed in a group of 21 female teachers through a randomized controlled study. Evaluation comprehended stroboscopy, perceptual and electro-acoustical voice analysis, Voice Handicap Index, and a course benefit questionnaire. A group of 20 teachers matched for age, working years, hoarseness grade, and vocal demand served as a control group. At 3 months evaluation, participants demonstrated amelioration in the global dysphonia rates (P=0.0003), jitter (P=0.0001), shimmer (P=0.0001), MPT (P=0.0001), and VHI (P=0.0001). Twelve months after the course, the positive effects remained, although they were slightly reduced. In conclusion, a course inclusive of two lectures, a short group voice therapy, home-controlled voice exercises, and hygiene, represents a feasible and cost-effective primary prevention of voice disorders in a homogeneous and well-motivated population of teachers.     

Quality assurance in daily practice

 A report based on the workshop on "Quality Assurance in Daily Practice", organised by the study group "Quality Assurance and Accreditation" from the Division of Analytical Chemistry of the Federation of European Chemical Societies (SGQAA/DAC/FECS) held at the EUROANALYSIS-10 conference in Basle, 6–11 September 1998.     

基于教育基金保险的期权定价

本文基于文献[1]引入一种基于教育年金保险的欧式看涨期权,它赋予合约持有人在约定时间以约定价格购买一份连续支付一定年限的教育年金的权利,本文运用保险精算和期权定价的二叉树方法对其进行的定价,并说明这种合约方便于一些低收入家庭进行教育投资.     

Vibrational spectroscopy at very high pressures: Part 21. Raman and infrared study of mercury(II) iodide [1]

The solid phase behaviour of HgI₂ is reviewed, together with IR and Raman data for the red and the high-temperature yellow forms. New IR transmission, single-crystal reflectance, and Raman data were obtained at temperatures down to 80 K for red HgI₂ but no evidence of a temperature-induced transition to HgI₂ IV was found.The high pressure results showed a possible break in the slope of the pressure versus frequency plot for the 29 cm^?1 Raman mode of red Hgl, at 6 ± 0.5 kbar, close to the reported III/IV phase boundary. Both Raman and far-IR spectra of the high pressure form of yellow HgI₂ differ significantly from those of high temperature yellow HgI₂ : the two forms are regarded as having different structures. These, and other data, reveal a much closer similarity between the phase diagrams of HgBr₂ and HgI₂ than has been suspected hitherto.     

Inter-comparison exercises as a tool for teaching quality assessment: an experience in Spanish universities

Since the academic year 2001–2002, inter-laboratory trials for students of Analytical Chemistry in Spanish Universities have been organised by the Department of Analytical Chemistry at the University of Barcelona in collaboration with the Complutense University of Madrid, the University of Cordoba and the University of Huelva. The aim of these exercises is to train students in the use of tools for the assessment and improvement of quality in analytical laboratories.Representative samples of environmental and food analysis, agricultural soils and a type of beer were selected. The ethanol content of the beer and the pH, conductivity, and extractable phosphorus and potassium content in the soil were the chosen analytical parameters.Sample preparation, homogeneity and stability studies, as well as the statistical treatment of data from participants, were carried out by the laboratory Mat Control of the Department of Analytical Chemistry of the University of Barcelona.The paper presented heregives the results obtained after two years of experience.Presented at BERM-9—Ninth International Symposium on Biological and Environmental Reference Materials, June 15–19, 2003, Berlin, Germany.     

The Teaching/Learning Process in Analytical Chemistry

Before teaching a course, the instructor must identify what she or he intends for the students to learn. For most analytical chemistry instructors, this usually involves an assessment of what methods and techniques to include and at what depth to cover them. There are many other skills, though, that will be important to students for their future success. Most college classes in analytical chemistry are taught in a lecture format. Techniques that can be used to improve the learning that can occur during a lecture are described. An alternative to lecturing is the use of cooperative learning. Cooperative learning offers the potential to develop skills such as teamwork, communication, and problem-solving that are more difficult to impart in a lecture format. The laboratory component of analytical chemistry courses is often an underutilized learning resource. More often than not, the lab is used to demonstrate fundamental wet and instrumental analysis techniques and develop rudimentary laboratory skills. The analytical lab should also be used to develop meaningful problem-solving skills and to demonstrate and have students participate in the entire analytical process. Ways of enhancing the analytical laboratory to include more global skills that are important to career success are described.Received January 12, 2003; accepted March 7, 2003 Published online July 16, 2003     

二维可积系统的求迹公式和周期轨道的量子化

从Berry–Tabor求迹公式出发,导出了二维可积系统周期轨道作用量的半经典量子化条件.利用此量子化条件,考虑周期轨道满足的周期条件,得到了二维无关联四次振子系统周期轨道作用量的半经典量子化条件,并给出了半经典能级公式.对能级与周期轨道的对应关系做了分析.     

Ab initio Study on Structures and Isomerization of Magnesium Fluorosilylenoid H2SiFMgF

The structures and isomerization of magnesium fluorosilylenoid H2SiFMgF were investigated by ab initio molecular orbital theory. Four equilibrium structures and three isomeric transition states were located and fully optimized at the B3LYP/6-31G(d,p) and G3MP2B3 levels, respectively. Based on the B3LYP/6-31G(d,p) optimized geometries, harmonic frequencies of various structures were obtained and 29Si chemical shifts were calculated. The solvent effects were investigated by means of the polarizable continuum model using THF as a solvent at B3LYP/6-31G(d,p) level. Isomerization paths for isomers were confirmed by intrinsic reaction coordinate calculations. The calculated results show that tetrahedral structure has the lowest energy and is the most stable; tetrahedral, three-membered ring, and p-complex structures are suggested to be the experimentally detectable ones; and σ-complex structure has the highest energy and will not exist.