First of all, briefly introduce life.

Claperon (1799 ~ 1864) is a French physicist. 1799 was born in Paris, France on February 26th.

18 18, clapper Long worked in the Mining Institute after graduating from the French Institute of Advanced Technology. 1820 went to Petersburg Institute of Civil Engineering in Russia for further study. 1830 The July Revolution broke out in Russia, and he was forced to leave Petersburg for home because of his obvious liberal tendency. After returning to China, clapper Long engaged in railway engineering, especially the design and structural research of steam locomotives. 1848, he succeeded the great mathematician Colsy (1789-1857) as an academician of the French academy of sciences. 1844 Professor, School of Bridge and Road Engineering, teaching courses related to steam engines.

Clapper Long died in Paris on 18641October 28th at the age of 65.

Second, scientific contribution.

Clapper Long's contribution to physics is mainly in thermodynamic theory.

1. Establish the indicator diagram of Carnot cycle, and calculate the heat engine efficiency from the indicator diagram.

1824, French military engineer sadi carnot (1796-1832) studied the general method of "obtaining motion from heat" in his book "firepower research". Kano believes that any heat engine must work between high-temperature heat source and low-temperature heat source, pointing out that "any place with temperature difference can generate electricity; On the contrary, where the force can be consumed, a temperature difference will be formed, which may destroy the balance between heat and mass. "This constitutes an ideal cycle, consisting of two isothermal processes and two adiabatic processes. In the cycle, the work consumed by compression is less than that obtained by expansion, so there is extra net work that can be used to do work to the outside world. However, the value of Kano's works was not recognized at that time. 1834, Claperon realized the importance of this problem and wrote a paper on the power of heat. Firstly, Carnot's text analysis of ideal heat engine is expressed by calculus, and secondly, Watt's power meter-pressure-volume diagram is used to illustrate it. Claperon explained two isothermal processes and two adiabatic processes in Carnot cycle with four pressure-volume curves on the pressure-volume diagram, and pointed out that the work done by Carnot's ideal heat engine in a cycle is exactly equal to the area surrounded by these four pressure-volume curves. In this way, we can not only estimate the work done in the process of a cycle change, but also put forward that the efficiency of a heat engine can be measured by the ratio of the work done to the heat supplied by this cycle. This kind of diagram is widely used and still appears in thermal textbooks. With the development of Claperon, the significance of Kano's contribution is gradually understood by people.

Clapper Long's work was later re-studied by Kelvin and Clausius (1822- 1888) as the basis of the second law of thermodynamics. Only then did people realize the true meaning of clapper Long's work.

2. The Claperon equation of ideal gas is established.

Clapper Long also put forward the equation of state of the ideal gas named after him.

It is better than the equation of state of an ideal gas with a certain mass:

The application scope is wider. The former can be deduced from the latter. But in history, Claperon equation was induced by the experimental law of gas.

3. Rich railway engineering experience and knowledge.

He designed the first railway line in France, and provided calculation methods and data for the construction of the first railway bridge in France, so he invented the clapper Long calculation method of supporting moment.

From: China Foundation Network >> Encyclopedia of Physics