Symmetries and conservation laws in classical and quantum mechanics 2. Quantum mechanics

In Part 1 of this two-part article we have spelt out, in some detail, the link between symmetries and conservation principles in the Lagrangian and Hamiltonian formulations of classical mechanics (CM). In this second part, we turn our attention to the corresponding question in quantum mechanics (QM). The generalization we embark upon will proceed in two directions: from the classical formulation to the quantum mechanical one, and from a single (infinitesimal) symmetry to a multi-dimensional Lie group of symmetries. Of course, we always have some definite physical system in mind. We also assume that the reader is familiar with the elements of quantum mechanics at the level of a standard first course on the subject. Operators will be denoted with an overhead caret, e.g., $ \hat A,\hat G,\hat U $ \hat A,\hat G,\hat U , etc., while $ [\hat A,\hat B] = \hat A\hat B - \hat B\hat A $ [\hat A,\hat B] = \hat A\hat B - \hat B\hat A is the commutator of $ \hat A $ \hat A and $ \hat B $ \hat B .     

浅析我国高职陶瓷艺术设计专业的人才培养模式

陶瓷艺术设计教育,是以陶瓷为媒介和一定的学术侧重而展开的教育活动。对高职陶瓷艺术设计教育而言,在继承陶瓷艺术悠久的历史文化传统的基础上,运用"3+3"人才培养模式,为社会培养出应用型高素质技能人才,是我国当前高职教育发展的必然趋势。     

Nonword repetition with spectrally reduced speech: some developmental and clinical findings from pediatric cochlear implantation

Nonword repetition skills were examined in 24 pediatric cochlear implant (CI) users and 18 normal-hearing (NH) adult listeners listening through a CI simulator. Two separate groups of NH adult listeners assigned accuracy ratings to the nonword responses of the pediatric CI users and the NH adult speakers. Overall, the nonword repetitions of children using CIs were rated as more accurate than the nonword repetitions of the adults. The nonword repetition accuracy ratings from both groups of subjects were correlated with open- and closed-set word recognition scores and forward digit spans. Only the perceptual accuracy scores from pediatric CI users were correlated with measures of speech production accuracy. These results suggest that although the pediatric CI users had more experience and success in perceiving speech under degraded auditory conditions, developmental differences in their memory skills prevent them from performing as well on working memory tasks as mature listeners.     

Peer group socialization of homophobic attitudes and behavior during adolescence

A social developmental framework was applied to test for the socialization of homophobic attitudes and behavior within adolescent peer groups (Grades 7-11; aged 12-17 years). Substantial similarity within and differences across groups were documented. Multilevel models identified a group socializing contextual effect, predicting homophobic attitudes and behavior of individuals within the group 8 months later, even after controlling for the predictive effect of individuals' own previously reported attitudes and behavior. Several group characteristics moderated the extent to which individuals' previously reported attitudes predicted later attitudes. Findings indicate the need to integrate the concurrent assessment of individual and social factors to inform the construction of more comprehensive models of how prejudiced attitudes and behaviors develop and are perpetuated.     

中小学教师信息技术能力培养模式实践研究——以江西省吉安市中小学教师信息技术能力培养为例

随着国家加大对教育信息化的投入力度,中小学信息化教学设备普及率不断提升,信息技术应用能力已经成为教师迫切需要掌握的技能。该文首先简单解读了国家《中小学教师信息技术应用能力标准(试行)》,结合作者在基层电教部门的工作经历,总结该市中小学信息技术现状;然后解剖中小学教师信息技术应用能力培训考核案例,详细阐述信息技术应用能力培养的七种模式的实践过程;最后通过对考核结果的分析,反思培养模式的效果及存在的问题,并据此制定出下一步有针对性的教师培养措施。     

Reviewing patent policy: an exercise in futility?

In 1984, Don Lamberton wrote a two-page disclaimer to a review of the Australian patent system, pointing out that there was nothing economic about the review and that it simply pandered to special interest groups. Some 30 years later, the Productivity Commission has been given a shorter time frame (one year) and a broader remit (all intellectual property). This paper reviews the issues addressed in the Industrial Property Advisory Committee (IPAC) review of 1984. Since it was completed, substantially more empirical evidence has become available, while room for policy improvement has been curtailed by international trade treaties. While the Productivity Commission will take a sound economic approach, the breadth of its remit may prevent full appreciation of the critical issues in patent policy. This paper considers the options remaining to the Commission to recommend improvements in the national interest. Whether these will be taken up depends on the priority given to the interests of small but powerful lobby groups.     

陶渊明诗文平淡自然之风构成因素探析

陶渊明的诗文风格以“平淡自然”为主,其平淡而不枯淡,其中充满了丰润的生机。这种平淡之风,是很多因素共同形成的,题材的选取、语言的朴质自然、意境的浑然天成等皆为陶渊明诗歌平淡之风形成的主要原因。