The different arrangements of atoms caused by rotation about a single bond are called conformations (构象)of the molecule, and a specific conformation is called a conformer (构象异构体, conformation isomer). An analysis of the energy changes that a molecule undergoes as groups rotate about single bonds is called a conformational analysis (构象分析)
Functional groups The structural features that make it possible to classify compounds by reactivity are called functional groups. A functional group is a part of a larger molecule and is composed of an atom or a group of atoms that have a characteristic chemical behavior. The Chemistry of every organic molecules
A ring that contains at least one heteroatom (an atom other than carbon) is called a heterocycle, and a substance based on a heterocyclic ring is a heterocyclic compound. Heterocyclic compounds containing N, O or S are by far the most common
Definition. A flow network is a directed graph G = (V, E) with two distinguished vertices: a source s and a sink t. Each edge (u, v) ∈ E has a nonnegative capacity c(u, v). If (u, v) ∉ E, then c(u, v) = 0
Medical Genetics What is a population from a genetic perspective? A population in the genetic sense, is not just a group of individuals, but a breeding group
We are going to consider the forces exerted on a material. These can be external or internal. External forces come in two flavors: body forces(given per unit mass or volume) and surface forces(given per unit area). If we cut a body of material in equilibrium under a set of external forces along a plane as shown in fig. 1. and consider one side of it we draw two conclusions: 1 the equilibrium provided by the loads from the side taken out is provided by a set of forces that are distributed among the material particles adjacent to
