摘要:

AbstractIn addition to chromosomal DNA carrying the genetic information of the cell, many bacterial cells contain smaller circular DNA factors known as plasmids or episomes. These genetic elements endow the cell with additional biochemical capabilities. The fertility factors (F and F′), the antibiotic resistance factors (R), the colicinogenic factors (Col), the hemolytic factors (Hly), and other extrachromosomal DNA systems are described. These small DNA molecules can be isolated, and are therefore particularly suitable for the investigation of DNA replication and the stable establishment of genetic material in the bacterial cel

ISSN:0570-0833    

DOI:10.1002/anie.197305171

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe question whether information about the internal structure of crystals can be deduced from their external form,i.e.from their habit, has often been discussed. A rule formulated byDonnayandHarkerattempts to establish the relationship on the basis of structural geometry. Deviations from this rule make it clear that purely geometric correspondence criteria are only of limited applilcation. Physical factors are also taken into account in the PBC vector method. A combination of the two methods can be of practical use in some cases for the determination of the crystal structures of organic compounds.

ISSN:0570-0833    

DOI:10.1002/anie.197305281

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe theory and applications of the very low‐pressure pyrolysis technique to the study of the rates and mechanisms of unimolecular reactions, radical‐radical, and radical‐molecule bimolecular reactions, surface recombination of atoms, heterogeneous reactions, and vibrational energy transfer are rev

ISSN:0570-0833    

DOI:10.1002/anie.197305341

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractFirst the interplay of kinetic and potential energyviathe uncertainty relation is described with the aid of a variational function for the ground state of the H atom. The H 2+ion is used to illustrate the physical mechanism of the occurrence of the chemical bond. The formation of the chemical bond can be divided into three steps: 1. the quasi‐classical (electrostatic) interaction of the unchanged electronic charges of the separate atoms; 2. the interference of the atomic orbitals, which (in the case of positive interference) leads to a displacement of charge into the bonding region and to a decrease in the kinetic energy; 3. deformation of the molecular orbitals to restore the correct balance of kinetic and potential energy. In simple models, it is often sufficient to consider just the second step. A two‐electron bond is not fundamentally different from a one‐electron bond. In larger molecules it is possible to distinguish between long‐range and short‐range interatomic contributions to the chemical bond. If the former are small,i. e.in molecules with non‐polar bonds, a one‐electron molecular orbital theory can be justified. Finally, the possibility of describing molecules by localized bon

ISSN:0570-0833    

DOI:10.1002/anie.197305461

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197305631

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197305641

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197305651

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197305661

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197305671

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197305681

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY