منابع مشابه
analyzing patterns of classroom interaction in efl classrooms in iran
با به کار گیری روش گفتما ن شنا سی در تحقیق حا ضر گفتا ر میا ن آموزگا را ن و زبا ن آموزا ن در کلا سهای زبا ن انگلیسی در ایرا ن مورد بررسی قرار گرفت. ا هداف تحقیق عبا رت بودند از: الف) شنا سا ئی سا ختارهای ارتبا ط گفتا ری میا ن معلمین و زبا ن آموزا ن ب) بررسی تا ثیر نقش جنسیت دبیرا ن و زبا ن آموزان بر سا ختا رهای ارتبا ط گفتا ری میا ن آنها پ) مشخص کردن اینکه آ یا آموزگاران غا لب بر این ارتبا ط گف...
Short-range versus long-range electron-hole exchange interactions in semiconductor quantum dots
Using a many-body approach based on atomistic pseudopotential wave functions we show that the electronhole exchange interaction in semiconductor quantum dots is characterized by a large, previously neglected long-range component, originating from monopolar interactions of the transition density between different unit cells. The calculated electron-hole exchange splitting of CdSe and InP nanocry...
متن کاملFine structure of exciton levels in carbon nanotubes: A semianalytical approach
We propose a new approach toward excitons in carbon nanotubes whereby the matrix elements of the electronhole Coulomb interaction are expanded into a series over the nanotube’s one-dimensional reciprocal lattice vectors. We show that only a few terms of this expansion give a nonvanishing contribution to the Coulomb matrix elements. The proposed approach allows one to single out Fourier componen...
متن کاملSubband Tunneling and Coulomb Effects in Coupled Quantum Wells
We have solved in space and time the effective-mass nonlinear Schrödinger equation for an electron-hole gas in a semiconductor superlattice. Considering a Coulomb interaction between both electronhole gases and two subbands, we have obtained a time-varying dipole moment in the heterostructure. In this way, we have shown the possibility of having another kind of terahertz electromagnetic radiati...
متن کاملInteraction Grammars Interaction Grammars
Interaction Grammar (IG) is a grammatical formalism based on the notion of polarity. Polarities express the resource sensitivity of natural languages by modelling the distinction between saturated and unsaturated syntactic structures. Syntactic composition is represented as a chemical reaction guided by the saturation of polarities. It is expressed in a model-theoretic framework where grammars ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature Photonics
سال: 2017
ISSN: 1749-4885,1749-4893
DOI: 10.1038/nphoton.2016.267