How to classify strictly upper triangular matrices by similarity?

Let F be a field. Consider U, the set of n times n strictly upper triangular matrices in F. For X, Y in U, we call them similar if there exists some S, which is non-degenerate and upper...

01 March 2021 2,957 8 View

Can I ask did any good platform or journals for learning the calcluation on the reference governors and command governor?

Recently I face some problems with the mathematical ( calculation) on the reference governor and command governor, so I need some help from you all to get which platform or journal can let me...

23 February 2021 7,746 2 View

What is the difference between the supplementary cementitious materials and alkali-activated concrete?

18 February 2021 9,188 3 View

For displacement control test, what is the relation between stress intensity factor and crack length?

There are two plates with horizontal center crack, one with crack length of a with the other with a+da. The bottoms are fixed while the tops are under the same displacement load. For intuition,...

11 February 2021 9,543 2 View

Difference between Second-harmonic generation and Two-photon absorption?

Hello Dear Researchers, I am confused about the Difference between Second-harmonic generation and Two-photon absorption? Can anyone describe the two phenomena briefly in the physical picture? What...

24 January 2021 9,912 5 View

Which kind of GPC solvent can be used to dissolve both lipid and salt?

I want to find a GPC available solvent to dissolve both lipid (DPPC, 2 mM) and salt (NaCl, 100 mM).

14 January 2021 3,805 2 View

Is it possible to publish a paper contradicting Einstein's special relativity in any Journal?

I just developed a new theory on electromagnetic and plan to publish in a Journal. The findings are purely through strict mathematical derivation without any disputable assumptions and also...

13 January 2021 1,558 5 View

How is linear form of plasmid circularized?

Hi all, I'm working on transforming E. coli with plasmid in a mixture of linear and circular form. What happened to the linear form once uptake? Do cells ligate them directly? Or cell DNase...

13 January 2021 8,336 4 View

Why dose plasma AngII concentration decrease in AngII infusion mice detected by AngII ELISA kit?

I detect the plasma AngII concentration by AngII ELISA kit (ENZO), the results show that plasma AngII decrease in AngII infusion mice. I check with the kit and find that the kit could recognize...

31 December 2020 8,838 3 View

FoldX YASARA plugin keep showing error message. Please help?

Hi, I use YASARA (version 17.8.15) on windows 10 and recently I am trying to install FoldX plugin on YASARA. Here is what I did: 1. Download YASARA plugin for windows (and the executable and...

24 December 2020 536 3 View

Could you recommend any books about Number Theory?

Beginner level books. High level books. Analytical Number Theory. Algebraic Number Theory. Combinatorical Number Theory. Books about partitions. Books about primes.

03 March 2021 7,174 5 View

How to combine two geometries in LAMMPS ?

I am trying to simulate contact angle of water on a quartz slab using LAMMPS. I have created and equilibriated the quartz slab and the water cluster separately. Now I want to create a composite...

17 February 2021 5,884 2 View

Applications of General Multiple Sums?

Does anyone know of applications of multiple sums of a sequence? I know of the Multiple Zeta values (which is a multiple sum of 1/N^s). This has multiple applications in quantum physics, QED,...

08 February 2021 8,047 12 View

How to mesh complex geometry?

I have been trying to mesh some complex geometry and have been having issues. I have attached images of the geometry in question. This structure is very large in size but has some comparatively...

05 February 2021 6,379 5 View

Please recommend me the proper steps (blocking method) to generate Hexahedral mesh of the following geometry inside ICEM-CFD?

I am facing an issue while blocking for the geometry mentioned in the image. After blocking it ends with a triangular block due to its shape. How to create a hexahedral mesh for this geometry in...

02 February 2021 888 1 View

How to find nature of extremum of a functional? what are the mathematical prerequisites to understand it?

For a function, usually sign of second derivative (and if it is zero, even/odd index of higher order derivative whose numerical value is zero) is enough to detect whether the extreme point is...

25 January 2021 7,703 3 View

Frequency calculation with TDDFT???

Hi, I have been trying to calculate the frequency vibrations of the excited state S1 of an organic molecule (24 atoms). The geometry optimisation of the excited state converged smoothly howerver...

22 January 2021 1,463 3 View

Do you have an example of an algebraic Hamiltonian vector field which possess a finite number of periodic orbits?

Is there a polynomial Hamiltonian vector field with a finite number of periodic orbits? Please see this MO question:...

21 January 2021 1,673 4 View

Doubt in DFT geometry preparation?

Hi all, I am trying to perform some ab inito DFT calculations using cp2k code. I have a unit cell of 120 atoms and would like to know how to refine or reduce the number of atoms in the unit cell...

20 January 2021 6,024 3 View

In Ansys APDL the stiffened plate girder is not getting meshed after gluing! What to do?

This is a model of a stiffened plate girder. The APDL code is provided below for its geometry generation. It is not getting meshed after gluing all the volumes. If the volume is subdivided in the...

18 January 2021 4,839 4 View