Structure Definition and 1000 Threads

Dear forum people, I just learned how to get a tight-binding dispersion for graphene: E = +- \sqrt{1+4\cos((\sqrt{3}a/2) k_x)\cos((a/2) k_y)+4\cos^2((a/2) k_y)} But i can not figure out how can I plot that. I want to plot that in the following path: K \rightarrow \Gamma \rightarrow M...

guys can u help me how ta make a structure in DEV C++ ? the all information i need thanks guys :)

I've been having a very difficult time understanding why band structure is expressed in terms of momentum/crystalline directions. I've included a picture of the band structure of silicon so that you can better understand my question. I think I understand basic crystalline structures and the...

I am not a chemist. I have a molecular structure question. Is it possible to bind two positively charged molecules together by having two electrons bounce up and down in the space between them? M1+ e e M2+ imagine the e, electrons oscillating up and down. Either in sync and 180...

I'm thinking mainly within the context of the useful semiconductors here (Si, GaAs, etc.)... What does it mean for an electron to be in the L or X valley instead of the Gamma valley? If Gamma is the k = 0 point, then momentum p = 0. Does that mean being in L or X means all the electrons...

I have this question: "What micro-structural features of metal alloys can be studied by using equilibrium diagrams and how? Can the equilibrium diagrams be used for some other purposes? What are the limitations?" I think that only the composition of micro-structure can be predicted in a...

I am a mechanical engineering student so don't have experience in specifying magnets and or using them. So its out of my comfort zone. I currently have a U shaped structure holding two large permanent magnets apart at either end. The magnets will need to be 200x200x40 in size and the gap is...

How do crystallographers go from a diffraction pattern to actually determining the structure of the crystal? http://pwatlas.mt.umist.ac.uk/internetmicroscope/micrographs/microscopy/decr5a-a-big.jpg

Hi, thanks for reading my questions. I've been reading and reading and reading and reading and I'm trying to understand the difference between conductors, semiconductors, and insulators at an atomic level. When reading about electricity I often find that metals have a "sea" of "free"...

I know of the theorem that says that in any fiber bundle with structure group G having finitely many connected component, the structure group can be reduced to a maximal compact subgroup of G. But here I am reading a thesis in which the author says: "[Since U(n,n)] is homotopic to its maximal...

Hi I've been searching on the web for this two topics, band structure and fermi surface, both of copper. I can't find any of them from a free source, I am doing just a report of my class of introduction to solid state and I just have found this two things in articles that must be bought. If...

Lets us say we are doing a vibration analysis of a structure with cyclic symmetry In very brief (as pointed out by AlephZero in one of his excellent reply) the whole motion can be represented by complex numbers which describe the motion of one segment. Now, my question is: 1)Is it...

Hi! I need a reference (book, webpage) that explains how the structure of a polymer affects its properties. I've found plenty of material over how structure changes its mechanical properties, but I could not find how it changes other parameters (e.g. electrical conductivity, boiling point...)

Hello all, I'm an amateur interested in nuclear structure. I'm interested in the (by now) age old questions of "Why is alpha radiation so much more prevalent than simple neutron or proton emission?" and "Why aren't nuclear isomers like Tantalum a lot more common or identified?" and especially...

Why does the LED structure "favorizes" p-type semiconductor? Hi all, At first I apologize if my English makes this post harder to understand ;). I am trying to figure out why there is always P-type semiconductor flashing outside in LEDs, both planar and edge ones - P-type region is the active...

Hi, I refer to the second edition (international edition) of Griffiths. He proves that the total fine structure correction (spin orbital plus relativistic) is given by E_{fs}^{1}\propto (3-\frac{4n}{j+1/2}) After that, he writes this. "Fine structure breaks the degeneracy in l (that is, for a...

So I have a structure that I have to test, or more so a "model" structure. It is in the shape of a T, but rotated on its side, so that the stem of the T is a cantilever beam. An actuator will be used to load the structure at the free tip of the stem. My task is to design the supports of the...

Homework Statement Find force between all members. Homework Equations torque=force x distanceThe Attempt at a Solution to use sections as seen in the photo, beyond that no idea how to attempt it. It would helpful if anyone could show me how to get the force out of even 1 member.

I have been reading about http://en.wikipedia.org/wiki/3-sphere" and found it was impossible for me to visualize it. I tried visualizing a 4d structure with 3 space-like and one time-like dimensions by imagining a sphere (with 3 dimensions) growing with time, with successive layers (formed...

I am pondering on what the correct Lewis structure(s) for Nitrogen Dioxide (NO2) may be... I have come up with 7 possible structures, but am unsure which are correct and which are not. I have compiled a small list of notes for your convenience and they are all in this picture. Which...

Homework Statement The level n=3 for atoms with 1 electron have the states 3s_{1/2}, 3p_{1/2}, 3p_{3/2}, 3d_{3/2}, 3d_{5/2}. If we ignore the spin-orbit coupling these states are degenerated. Calculate the degeneration due to the the spin-orbit coupling for the levels 3p and 3d for the...

http://www.swinburne.edu.au/chancellery/mediacentre/media-centre/news/2011/10/natures-laws-may-vary-across-the-universe One of the laws of nature may vary across the Universe, according to a study published today in the journal Physical Review Letters. One of the most cherished principles in...

Hi, Let's say I have a 10 dimensional Lie algebra over some field of functions, something along the lines of at least twice differentiable with twice differentiable inverses. The structure constants have inputs from this field. Is it possible to build a metric from these structure...

Homework Statement Draw the lewis structure for ClNO2 The Attempt at a Solution When I first drew this I had two double bonds in between the N and the Os. However, the answer suggests only one is a double bond in the structure. Why is this correct? Aren't we suppose to balance the...

Hello, suppose I have a set of sentences Ʃ from the language of number theory ( the usual one ). Then, I extend this to a maximally consistent set of sentences Ʃ' and create a henkin term structure for it ( i.e. as in the popular proof of the completeness theorem ). Can it be true that this...

Homework Statement I have to draw Lewis structures and Lewis dot structures of these salts The Attempt at a Solution I attached images of how I tried to traw Fe(ClO4)3 and (NH4)2SO3 but I can't figure anything out about Al2(SO4)3

I got a question : Why is the nucleon of Chlorine 35.5 ? Why is is not a whole number ?

Homework Statement 3) Compare the structure of RNA and DNA with respect to the following characteristics. Length Function Molecular components Homework Equations The Attempt at a Solution I know nothing about the length, Function: RNA reads the info in DNA and transports...

Please I have a problem with natural log for group set as follow:a*b=eln(a)*ln(b) 1- Show that the group law * is associative and commutative 2- Show that the group law * accept an element e (Identity element) Thank you !

So I am given 3-methylheptane I know that it looks like this: CH3-CH2-CH-CH2-CH2-CH2-CH3 And the methyl group is attached to CH It is heptane so I have 7 carbons and a total of 15 Hydrogens but I don't understand why it isn't 16 Hydrogens don't I use the formula CnH2n+2=16Hydrogen If...

I am confused as to what that means? Is that a coordinate system with 3 y-values?

How can one derive the relationship for a cubic crystal: d= \frac{a}{\sqrt{h^2 + k^2 + l^2}} It is shown here. This is probably trivial but I am having trouble proving it as the Miller indices are reciprocals but the reciprocal is not distributive. This isn't for homework by the way - I...

is this this the correct structure for 2-methyl, 3-phenylbutane?

ideas for a lecture in "new technologies in aircraft structure" Hi everybody... One of my doctors wants to give a practical and a little technical lecture about "new technologies in aircraft structure" and he is requisting ideas from us... What practical ideas can be presented ...

As i know, the metallic structure for example a pure copper metal which is made up of all metal atoms that is the copper atoms actually have all its atom of metallic element bonded together by metallic bonding. Metallic bonding is the electrostatic force of attraction between the positively...

Im supposed 2 design a robo like this 1, but here, the mechanical part seems more tought thn the electrical and programming. I couldn’t make out what mechanical structure is being used to have this type of motion. Can anyone please help. Here’s a start: There r 2 motors attached in the...

Homework Statement Homework Equations - The Attempt at a Solution i understand that benzoate is derived from carboxylic acid (COOH) to which isopropyl has replaced the H, forming a benzoate substituent to which we derive the parent name of the structure. I understand that Chloro...

As we know, plastic is non-conductor, iron metal is conductor, does anyone have any suggestions on what kind of property in term of molecule structure allows electricity to get through? Thanks in advance for any suggestions

what is basic principle followed by atoms to arrange in basic structure?

Are all acid have covalent structure in solid state?

Protein structure drawing method I want to know the proper name given to this particular method of drawing proteins, RNA and Genes. I have two examples; If you look at the Wikipedia page for tRNA, they show the Tertiary structure of tRNA like this...

Identifying proteins by structure Can proteins be identified by their structural image alone? What do i mean by that? Well i understand the basics of protein folding and protein structure. I have a basic understanding of primary, secondary and tertiary structure of DNA/RNA. But i want to...

How to prove there is no primitive cell of diamond structure with only one atom? Thanks in advance!

Hi All, Does anyone if it's possibe to use the 'exist' function in Matlab to check whether any data has been entered into a particular field of a structure. I'd like something like the following, where 'identification' is a user-input variable, 'team' is the structure and 'city' is the field...

what is the general structure of ganglioside? and what are the differences between GM1, GM2 and GM3?

how is the relationship between fermi level and band structure of solids can effect electrical conduction properties of a material?

Homework Statement Bond Order of NO- Bond Order of NO Bond Order of NO+ Homework Equations No Equations The Attempt at a Solution I determined the Bond order of NO+ to be 3 due to their triple bond and the Bond order of NO- to be 1 due to their single bond Lewis Structures...

Hi, All: I am reading a paper in which , if I understood well, a spin structure in a manifold M is equivalent to M admitting a trivialization of the tg.bundle over the 1-skeleton of M ( I guess M is assumed to be "nice-enough" so that it is a simplicial complex ) so that...

Metal nanoparticles (Au, Ag, Al or ...) can coat on porous silicon, the particles can be located inside the pores or on the silicon micro/nano structures. By applying this type of coating is there any change in band structure of porous silicon? As I've measured the band gap has changed.

What is a "Space Structure" in relativity? I remember reading an article that said essentially that the point of reference and the number of "space structures" affect the speed of light. Is this a popular theory? What is a space structure in physics anyway, I'm pretty well versed in physics and...