基于康奈尔笔记法的Nyquist判据教学方法研究

针对“自动控制原理”Nyquist稳定判据教学中存在的应用条件复杂、奈氏图环绕判断抽象等问题,给出一种基于康奈尔笔记法的Nyquist稳定判据教学方法。依据康奈尔笔记法对Nyquist稳定判据的使用条件及准则进行5R归纳,总结为与系统开环频率特性相关的Nyquist曲线起点、终点及奈氏图与(-1,j0)点的影响关系,给出应用旋转矢量代替回环以及正负穿越判定的特定应用准则,突出判据的数学机理分析。实际教学效果验证了所提方法的有效性与可行性。     

亨普尔关于意义标准的批判与修正

意义标准是逻辑经验主义关心的一个重要问题。亨普尔批判了可检验标准和可翻译性原则,并且在此基础上修正了逻辑经验主义的意义标准,认为在确有认知意义和确无此种意义的句子之间没有明确的界限,而只有程度之别。     

教师资格认证制度存在的问题及其完善策略

我国的教师资格认证制度无论在理论上还是在实践上都存在许多漏洞,建立更加完善的教师资格认证制度已经势在必行,本文整理了目前我国教师资格认证制度存在的主要问题,并有针对性地提出了若干完善策略。     

识别理论在中国区际民商事审判中的运用

识别是国际私法学中极其重要的理论.在案件的审理中,无论是国际(或区际)民商事案件还是国内民商事案件,法官首先都要面临一个识别问题.香港与澳门回归祖国近十年,在中国区际民商事审判实践中,由于各法域法律制度和法律概念存在差异,不可避免地存在识别冲突,规制识别依据应当结合中国区际法律冲突的特点,确立以法院地法识别为主、辅之以特殊识别的法律制度.     

Efficient volume preserving approach for skeleton-based implicit surfaces

This paper presents an efficient way to preserve the volume of implicit surfaces generated by skeletons. Recursive subdivision is used to efficiently calculate the volume. The criterion for subdivision is obtained by using the property of density functions and treating different types of skeletons respectively to get accurate minimum and maximum distances from a cube to a skeleton. Compared with the criterion generated by other ways such as using traditional Interval Analysis, Affine Arithmetic, or Lipschitz condition, our approach is much better both in speed and accuracy.     

男女言语及行为差异研究

本文对男女言语及行为的差异进行实例分析，并从夸赞、恭雄、道歉及社会衡量标准等不同侧面加以概括和说，进一步探讨了产生差异的心理因素和社会因素，并着力以科学为依据，从心理语言学、语用学的角度进行分析和归纳，希望对解决性别歧视及社会对男女的双重判断标准等问题能提供一定的帮助。     

新时期生物课堂教学的再思考

《课程标准》在课程体系构建上有重大突破,至使当前生物课堂教学存在诸如探究活动课安排,教材把握,进度安排,教师素质提高等问题．结合教学实践,在探讨了相应对策的同时,阐述重建新型的师生关系和调整课堂教学策略．     

浅谈高校科技档案的规范化管理

文章从科技档案管理的内涵着手,指出了高校科技档案管理中存在的问题,阐述了实现高校科技档案规范化管理的有效途径。     

建立大学物理实验教学质量保证与监控体系

分别从学生实验流程、能力培养、成绩考核以及教师工作流程和教学监控体系等几个方面介绍了太原理工大学物理实验中心在建立教学质量保证与监控体系中的实践经验。在物理实验教学的各环节中建立了相应的操作规范,说明了旨在培养学生素质及能力的几个方面的探索。     

Evaluation of Energy Saving Operational Modes for Industrial Fracture Connected Processes on the Basis of Incubation Time Fracture Criterion

A problem for a central crack in a plate subjected to plane strain conditions is investi-gated. Mode Ⅰ crack loading is created by a dynamic pressure pulse applied at a large distance from the crack. It was found that for a certain combination of amplitude and duration of the pulse applied, the energy transmitted to the sample has a strongly marked minimum, meaning that with the pulse amplitude or duration moving away from the optimal values, minimum energy required for initiation of crack growth increases rapidly. The results obtained indicate a possibility to optimise energy consumption of different industrial processes connected with fracture. Much could be gained in, for example, drilling or rock pounding where energy input accounts for the largest part of the process cost. Presumably further investigation of the effect observed can make it possible to predict optimal energy saving parameters, i.e. frequency and amplitude of impacts, for industrial devices, e.g. bores, grinding machines, and hence significantly reduce the process cost. The pre-diction can be given based on the parameters of the media fractured (material parameters, preva-lent crack length and orientation, etc.).