对与连通器相关的功能问题的续貂

文献[1]于连通器中开拓出一些有关功能问题的新视角，颇具启发性和教学参考意义．笔者不禁不揣浅陋，略续狗尾些许，以就教于作者及诸同仁．     

在物理课程教学设计中引入中国元素——以倒注壶与连通器为例

物理核心素养是物理学科课程设计的依据.在物理课程教学设计中引入中国元素,既提升了物理课的趣味,提高教学质量,又能在学习过程中感受中国文化,提升学生的文化素养.论文在连通器的教学设计中引入"倒注壶",将理论知识与实践操作结合起来,使物理真正源于生活,助于生活.教师在教学中通过实验、设问等手段,引导学生自主深入剖析倒注壶的原理,使学生在学习物理知识的同时,感受到先人的智慧和中华民族文明成果的独特魅力.     

功和能的系统性

功和能是两个密切相关的概念，它们又与系统这一概念有密切的联系。在功和能的教学中，常常忽视功和能的系统性，使学生在解决功和能的问题时不习惯于先确定系统，影响了对有关问题的正确理解。     

功和能的基本知识

功和能是十分重要的物理概念.关于功和能的定义,本通报曾有专论.本文仅谈谈功和能的一些基本知识,不妥之处,请同志们指正. 一、运动的量度之争——动量和动能的概念物质的运动存在量的规定性.我们看到一片树叶落下,敢于披襟当之;若兄一个石头飞     

经典力学中功与能的相对性问题讨论

功和能是两个截然不同的重要概念，又是物理学中两个关系最密切的重要物理量．功与能量转化的关系不仅为解决力学问题开辟了一条新的重要途径，同时也是分析电磁学、热学等领域中问题的重要依据，搞清功与能的相对性，有利于更好地应用动能定理、机械能守恒定律和功能关系．下面就从三个方面进行初步探讨．     

离子液体[Emim]Br水溶液的密度和超额体积

离子液体作为一种新的环境友好的溶剂,拥有作为吸收式工质对的优良特性.本文对离子液体[Emim]Br及其水溶液的热力学性质进行了研究,使用DMA-55型精密数字密度计测定了[Emim]Br-水二元混合物在298.15 K,308.15K和318.15 K三个温度下全浓度范围内的密度数据,关联得出密度与组成和温度的关系式.计算了三个温度下混合物的超额体积,并用六参数Redlich-Kister方程进行关联.     

功和能教学中两个被忽略的问题

在物理教学中,功和能的教学是力学中的重点,而用功和能解决力学问题也是学生学习的难点.要使学生掌握这部分内容,以下两问题值得引起注意.1 机械能的相对性 重力势能、弹性势能属于系统所有,其大小与零势能点(面)的选择有关;即系统的势能是相对于零势能点而言.具有相对性.然而,系统的动能也具有相对性,相对于参考系.     

与电象有关的互作用力及其所作功和互能

通过实例说明,用电场强度和功的定义可以直接计算与电象有关的互作用力、通过平移无限分离二体系的准静态过程中电场力所作的功,并根据功能关系定义了电象情形与真实情形的互能,指出两种情形下在无限分离二体系的过程中电场力所作的功及二体系的互能均不一定是半值关系．     

非平衡功与自由能差的关系

以一个受迫谐振子为对象证明了Jarzynski等式,即两平衡态的自由能差可以用它们之间非平衡功的指数平均来表示,这里两个态的转换是在有限时间完成的.当外部驱动力是一个周期信号时,发现外界对系统所做的广义功存在一个共振现象.     

基于labview与容栅传感器的液位测控系统

根据容栅传感器的检测原理,设计了一套基于LabVIEW和容栅传感器的液位精密测控系统,精度达0.05ml。利用容栅传感器输出的电容信号经信号调理模块输入msp430单片机处理并精密控制液位,采用LabVIEW设计系统监控界面程序,实现系统数据的显示、存储、绘图以及人机控制测定仪工作等功能。可配装为数显测定仪和物体密度测量仪,人机界面良好,成本低,易推广。     

以核能为中心的中子工作

本文简要地介绍并评述了中国原子能科学研究院现在正在进行的和将要进行的与核能相关的、特别是与聚变能相关的中子实验工作． Neutron expertrients related to the development of nuclear energy, especially fusion energy,in CIAE at Ptesent and in the near future are briefly introduced and reviewed.     

Communicating with noise: How chaos and noise combine to generate secure encryption keys

An approach for the secure transmission of encrypted messages using chaos and noise is presented in this paper. The method is based on the synchronization of certain types of chaotic oscillators in response to a common noise input. This allows two distant oscillators to generate identical output which can be used as a key for encryption and decryption of a message signal. The noiselike synchronizing input-which contains no message information-is communicated to identical oscillators in the transmitter and the receiver over a public channel. The encrypted message is also sent over a public channel, while the key is never transmitted at all. The chaotic nature of the oscillators which generate the key and the randomness of the signal driving the process combine to make the recovery of the key by an eavesdropper extremely difficult. We evaluate system performance with respect to security and robustness and show that a robust and secure system can be obtained. (c) 1998 American Institute of Physics.     

Ground State Energy of Unitary Fermion Gas with the Thomson Problem Approach

The dimensionless universal coefficient ε defines the ratio of the unitary fermions energy density to that for the ideal non-interacting ones in the non-relativistic limit with T = 0. The classical Thomson problem is taken as a nonperturbative quantum many-body arm to address the ground state energy including the low energy nonlinear quantum fluctuation/correlation effects. With the relativistic Dirac continuum field theory formalism, the concise expression for the energy density functional of the strongly interacting limit fermions at both finite temperature and density is obtained. Analytically, the universal factor is calculated to be ε= 4/9. The energy gap is△= 5/8k^2f/（2m）.     

Relating the approaches to quantised algebras and quantum groups

This paper constructs two representations of the quantum groupU _q g' by exploiting its quotient structure and the quantum double construction. Here the quantum group is taken as the dual to the quantised algebraU _q g, a one parameter deformation of the universal enveloping algebra of the Lie algebra g, as in Drinfel'd [6] and Jimbo [10]. From the two representations, the Hopf structure of the quantised algebraU _q g is reexpressed in a matrix format. This is the very structure given by Faddeev et al. [7], in their approach to defining quantum groups and quantised algebras via the quantisation of the function space of the associated Lie group to g.Supported by a SERC studentship     

做功与内能变化的关系

1 几种误解 物质是由分子组成的,分子在不停地运动,所以分子有动能.分子之间有分子力.所以,分子有势能.温度是物体内大量分子平均动能的标志.分子势能的变化,可由物体的体积及形状变化表现出来.物体的内能的绝对值无法测定,也没有意义.物体内能的变化则是可以量度的.     

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