Recent content by lionelwang

Thanks for your time on this! I actually prepared the liquid bridge between two substrates, and its shape is much like the catenoid shape, but I can feel that there is Laplace pressure inside the liquid bridge, For a real catenoid liquid ,there should be no Laplace pressure. So this bother me a lot.

Yes, I did not reveal the problem in a perfect way. Thanks for your valuable advice.

Hi all, I am thinking that, A surface is a minimal surface if and only if the mean curvature is zero. then, for a liquid bridge with a catenoid shape, there should be no Laplace pressure due to the zero mean curvature. But it is a capillary bridge with concave meniscus, how can it have no...

After I did some google work, I found that, approximately, that equation works, but yes, as you said, the change of the solid states, nonuniform density, or phase separation, etc. which will make the equation not valid for caculation of the mixture refrective index. Thank you very much for...

Hi all, I am thinking about the refractive index, if I have two components with refractive index n1 and n2, respectively, then I mix them up (chemical reactions might happen after the mixing), and should I expect a mixture with refractive index:n=a*n1 + b*n2, where a+b=1. In other words...

Hi all, Typically, we know that the surface tension for water is about 72mN/m at RT. so do this mean that the surface tension over the whole droplet is exactly the same? Moreover, we know that the Laplace pressure may be different over the whole droplet as the curvature in different parts...

You are of great help, thank you very much!

Thank you very much, guys.

Hi all, Does anyone know the specific names of the high-curvature arc and the low-curvature arc on an ellipse? Or, do they have special names after all? Anyone help me figure this out, thank you very much! Regards.

Thanks!

Hi, guys, Is the ellipse equation "x=acost; y=bcost" a Cartesian coordinates equation or a polar coordinates equation? Someone said that it's a transfer from a polar one to a Cartesian one. Need more help on this, thank you very much!

Just ask your friends nearby

For conductors, the resistance will increase with T, while for some semiconductors, the resistance may decrease with T, which results from the agitation of the electrons in the valence band

You are right, finally I found the reason from a textbook: some of the electrons the ground state in lead will absorb x-ray photons and then excited to a higher energy level. Thanks!

From The Second Law of Thermodynamics，there is no contradiction for a spontaneous process in which energy drops while entropy decreases.