中国古代趣味物理实验拾零

将分布在中国古籍中的一些趣味性浓的物理实验收集拢来予以介绍，扼要地分析了实验原理与方法，指出其在当今物理学中的应用，对了解中国古代物理实验产生、变化、发展的历程具有参考价值。     

结合实际谈焓及容积变化功—《热学》教改点滴

本文介绍了焓在热力学工程中的一种解释，表明它是随物质迁移的能量；并讨论了可压缩气体系统的容积变化功与技术上可利用功的区别。     

对国内外热学教材的评述

本文对国内外现有热学教材进行研究和评述，介绍了英、美、前苏联等国的热学教材，比较了各国教材的风格、特色，并提出一些在我国热学教材改革中值得注意和借鉴的问题。     

牛顿对热学的贡献

针对学术界对牛顿热学成就的研究较为薄弱的状况，详细论述了牛顿在计温术和传热学上所取得的成果，并分析了其发现冷却定律的背景，指出该定律的发现与他长期从事冶金试验密切相关；探讨了牛顿对热的本质与若干热现象的见解及其历史价值。     

中国古代的力学

中国古代的力学研究范围是很广的,其中重要的成果是时空与运动,对力的认识.     

中国古代在声学上的几项发现

中国古代在“声学”方面有许多杰出成就.1987年,河南舞阳县贾湖新石器遗址出土的制作于8000年前的骨笛,已具有和今天相似的音阶结构,能吹奏悠美的乐曲,从这不难看出中国古代声学知识的实际水平[1].本文介绍古籍中记载的中国古代在声学上的几项发现. 一、关于低频声的远距离传播 笔者在《中国古代已知听觉有频率下限》一文中[2],曾说明中国人在春秋时就已知有人耳所听闻不到的“次声”的存在.《老子》所说“听之不闻名日希”,“大音希声”,指的就是“次声”. 次声波的一个重要特性是它易于作远距离传播.在大气中,有的次声在传播数千公里之后,…     

中国古代的电学和磁学

一般来说,18世纪以前的科学家主要是对一些零散的静电和静磁现象进行观察.中国古代较早地开始积累电学和磁学方面的知识,像雷电现象的观察和摩擦起电的经验,磁石吸铁和指向性的研究与应用都是早期研究的重要内容.特别是磁学的研究与应用对中国古代的生产、军事、航海、测量等技术的发展产生了重要作用,同时,在东西方科学与文化的交流上也发挥了巨大的作用.     

Heat pipe research and development in China

A review is given of heat pipe research and development in China. It includes data presented at the 2nd National Heat Pipe Conference in 1988, and covers basic research, heat pipe performance and applications. The applications range from heat exchangers (gas-gas and waste heat boilers), to electric motor cooling, spacecraft and solar collectors.     

NAA and Mössbauer Study on the Colorative Mechanism of Yaozhou Celadon in Ancient China

The contents of 30 colorative elements in the glaze of Yaozhou celadon have been measured by neutron activation analysis (NAA) with the conclusion that iron is the dominant colorative element. It is further detected by Mössbauer spectroscopy that the iron in the glaze exists in the chemical state of structural iron (Fe²⁺, Fe³⁺) and that there is quantitative relation between the dominant wavelength of various colored glazes and the relative content of structural iron. Thus the colorative mechanism of Yaozhou celadon has been revealed entirely.     

利用PIXE和ICP-AES 对蛇纹石原料及中国古代蛇纹石玉器的微量元素分析

以蛇纹石这一中国传统的玉材为对象,旨在通过微量元素含量分析来探索古代蛇纹石玉器原料的可能来源。采用无损的外束质子激发X射线荧光技术(PIXE)对来自中国几个典型矿区的蛇纹石样品主量元素和微量元素进行了分析。同时也采用有损的电感耦合等离子体原子发射光谱技术(ICP-AES)对这些蛇纹石样品的微量元素含量进行了比较分析。结果表明,两种分析方法所获取的蛇纹石微量元素含量趋势具有一致性,说明PIXE无损分析技术可以应用于蛇纹石的微量元素分析研究。讨论了蛇纹石的微量元素含量与地质成因之间的关系,这些蛇纹石的微量元素含量存在明显的差异,这种差异可以用来区分不同地质成因的蛇纹石。Ⅰ型地质成因的蛇纹石中微量元素中Ni含量较低,且几乎不含Cr和Co,而Ⅱ型地质成因的蛇纹石中则含有较高微量元素的Cr,Co和Ni。采用PIXE技术分析了来自浙江、江苏、河南、安徽和湖北等省出土的新石器时代至战国时期(4585 BC—221 BC)14个遗址或墓葬出土的18件蛇纹石玉器的化学成分,通过与两种地质成因类型蛇纹石的微量元素比较分析,初步推测了这些蛇纹石玉器原料的可能来源。以蛇纹石微量元素含量与地质成因类型之间的关系来探索古代蛇纹石玉器玉料可能的来源是一种有益的尝试。     

Heat pumps in industry

An analysis of influences of connection ways on the efficiency of a heat pump in an industrial energy system was made. A new special connection of a heat pump with a heat accumulator system was introduced and is fully discussed with respect to the operating procedure as well as advantages. The dynamics of heat energy consumption influences the economics and efficiency of an industrial heat pump. Simulation of a heat pump in an industrial energy system is established in accordance with the dynamic energy consumption and condition of electrical power consumption with respect to the peak power. As a demonstration example of the simulation, data from a chemical plant were used.     

Heat loss in friction

The heat loss accompanying (external) friction is calculated on the basis of arguments relating the Umov vector to the friction force.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 47–49, July, 1974.This study was carried out in the physics laboratory of the Moscow Machine and Instrument Institute. The author thanks Professor A. S. Akhmatov for much interest in this study and for useful discussion of these results.     

Flow Boiling Heat Transfer in Micro-Channel Heat Sinks under Sub-Atmospheric Pressures

A closed-loop two-phase mini-channel-based heat sink driven by a micro-gear pump was developed in this work. Using water as an example, experiments were performed in two micro-channel heat sinks under the conditions of initial pressure of P_in = 34–113 kPa, mass velocity of G = 19–468 kg/m₂s, outlet quality of x_e,out = ?14–66%, and heat flux of q″ = 0–230 W/cm², which covered single-phase flow, subcooled flow boiling, and saturated flow boiling regions. The results showed distinctive differences between the subcooled and saturated boiling regime and revealed that the influence of the system pressure. The experimental data were also compared to a boiling mechanism demarcation map and assessed against some empirical correlations, which suggests some uniqueness of the current heat sink associated with flow boiling at the mesoscale.     

二维变几何域下的表面热流反演

采用共轭梯度法,给出二维变几何域下的热流反演算法,并对算法的有效性和稳定性进行验证.结果显示:测点数目对反演结果有较大影响,测点数目的选取和热流的空间变化剧烈程度有关;反演初值的选取对反演结果,尤其是末时段,会有较大影响,应尽可能选择传热过程末时刻热流作为反演初值.     

Empirical Study of an Air-to-Air Heat Pipe Heat Exchanger in Tropical Climates

Abstract

This article presents the empirical study of a heat pipe heat exchanger that was directly experiencing the ambient tropical air in its evaporator section. The performance of the heat pipe heat exchanger was monitored during two weeks of operation to determine the performance curves. The temperature of return air was controlled at about 22°C as the representative temperature of inside air, and a face velocity of 2 m/s on the heat pipe heat exchanger coil was established for this purpose. It was found that for the present investigation, the heat pipe heat exchanger can pay for itself in 1.5 years.