Lec 22 | MIT 3.091 Introduction to Solid State Chemistry Chemical Kinetics: The Rate Equation, Order of Reaction, Rate Laws for Zeroth, First, and Second Order Reactions Temperature Dependence of Rate of Reaction View the complete course at: ocw.mit.edu License: Creative Commons BY-NC-SA More information at ocw.mit.edu More courses at ocw.mit.edu
Modeling Lecture 18: Introduction to RTDs - Quantum Charge Self-Consistency (Hartree) - Part 1/2 The previous lectures showed that a semi-classical charge distribution results in a vast improvement in the realism of the electrostatic potential over a linear potential drop approximation. In this semi-classical charge and potential model the quantum mechanical simulation is performed once and the quantum mechanical charge is in general not identical to the semi-classical charge. In the high doping contacts that is a reasonable assumption, however close to heterointerfaces the quantum mechanical nature of the carriers reflects itself in the charge profile significantly and a semi-classical charge profile is not necessarily the best approximation. Simple quantum charge-selfconsistent potential (Hartree) calculations feed the quantum charge into the potential calculation and iterate until the two do not change anymore from one iteration step to the next. The quantum mechanical charge calculations predict a charge accumulation inside the central RTD which increases the charge inbalance in the undoped region, which in turn forces the electrostatic potential to resist that charge inbalance. The resonances therefore do not get pulled down in voltage linearly anymore. The charge & potential interactions introduce a non-linear device behavior which stretches out the voltage axis, linearizes the IV curve, and increases the peak current. Learning Objectives: Semi-classical charge and quantum charge differ significantly at the interfaces and inside the RTD. The electrostatic ...
32x RGB LED board with TLC5947 Each LED is individually controlled with 12-bit dimming using four TLC5947's. The MCU (Arduino) has a lookup table that linearizes the dimming ratio for human vision. See my blog for details:
WAVE Toolbar The WAVE Toolbar is an extremely useful Firefox add-on by WebAIM that allows you to test Web pages for a number of accessibility issues. It can be downloaded at: This video tutorial shows the basics of how to use it.