PDF HTML?? XML?? ???? ???? ????????????????????????? DOI: 10.5846/stxb202202110335 ??: ????: ????: ????: ?????: ????: ???????????41991233?U21A2011?41971129?????????????? Relationship between plant diversity, productivity and environmental factors at a transect scale in the dryland of China Author: Affiliation: Fund Project: ?? | ?/? ???? ???? ???? ???? ???? ???? ??:?????????????????????????????...

Shannon–Vizing–type problems concerning the upper bound for a distance chromatic index of multigraphs G in terms of the maximum degree ∆(G) are studied. Conjectures generalizing those related to the strong chromatic index are presented. The chromatic d–index and chromatic d–number of paths, cycles, trees and some hypercubes are determined. Among hypercubes, however, the exact order of their gro...

The three most common variations of Fitts’ index of difficulty are the Fitts formulation, the Welford formulation, and the Shannon formulation. A recent paper by Hoffmann [1] critiqued the three and concluded that the Fitts and Welford formulations are valid and that the Shannon formulation is invalid. In this paper, we challenge Hoffmann’s position regarding the Shannon formulation. It is argu...

Based on the local Shannon entropy concept in information theory, a new measure of aromaticity is introduced. This index, which describes the probability of electronic charge distribution between atoms in a given ring, is called Shannon aromaticity (SA). Using B3LYP method and different basis sets (6-31G**, 6-31+G** and 6-311++G**), the SA values of some five-membered heterocycles, C(4)H(4)X, a...

We studied the arboreal composition of the tropical mountain rainforest's upper canopy in the San Martín Pajapán volcano, Tatahuicapan, Veracruz, México (18 degrees 26' N; 94 degrees 17' W). Two forest stands were studied, one in an exposed position and one protected. The Shannon index of diversity and the Jaccard index of affinity were calculated to calculate affinities between plots and betwe...