摘要:

When large numbers of electrons and holes are created by optical pumping in a semiconductor at low temperatures they condense to form a high density metallic liquid. This electron-hole liquid is unique because both charged species are itinerant and form separate Fermi seas. Numerous experiments have established the metallic nature of the liquid and the ground state density and binding energy. The latter are in excellent agreement with theoretical estimates.

ISSN:0010-7514    

DOI:10.1080/00107517908210899

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This article discusses some preliminary studies dealing with the mechanical characteristics of a new type of reinforced composite material. The reinforcing members used differ from conventional reinforcements, and consist of two components, a core and an outer sheath. The sheath is bonded to the composite structure using conventional techniques but the shear strength of the core/sheath interface does not have a fixed value and is reduced as the tensile load carried by the core element is increased. The mechanism of stress transfer is arranged so that the reinforcing members are progressively decoupled from the rest of the structure where and when they are experiencing unacceptably high tensile stresses. This action is reversible and decoupling can be arranged to occur at any desired stress value. Decoupling would normally occur at a stress level rather less than the ultimate tensile strength of the core or alternatively at rather less than its fatigue endurance limit. By this means it can be arranged for the core members not to fracture whatever the tensile loads or displacements applied to the composite structure. Because the core elements do not fracture they bridge any transverse matrix crack which may be generated and inhibit its propagation in various ways. In addition they provide a residual tensile load bearing capability and absorb large amounts of energy under overstrain conditions.

ISSN:0010-7514    

DOI:10.1080/00107517908210900

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In November 1974 a dramatic revolution occurred in high-energy physics when two teams of workers independently discovered a massive subatomic particle named the J or ψmeson (Aubertet al.1974, Augustinet al.1974). Within two years the leaders of these two teams (B. Richter and S. C. C. Ting) had been awarded the Nobel Prize for physics. This alone bears testimony to the significance of the discovery. In this article I hope to be able to explain why this discovery was so significant, how it opened up a new conception of the sub-atomic world and describe some of the related discoveries and developments that have been made in the subsequent four years.

ISSN:0010-7514    

DOI:10.1080/00107517908210901

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Recent advances in the use of physico-mathematical models to forecast the weather over the Northern Hemisphere for up to six days ahead are described. A higher-resolution model is used to predict the evolution of smaller-scale weather systems such as fronts and their associated rainfall over western Europe up to 36 h ahead. An example of a five-day numerical forecast and its verification are presented.

ISSN:0010-7514    

DOI:10.1080/00107517908210902

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107517908210903

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107517908210904

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107517908210905

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Mathematical Methods for Physics.By H. W. Wyld. (W. A. Benjamin, 1977.) [Pp. 629.] Scope: Texbook; Library. Level: Undergraduate.

ISSN:0010-7514    

DOI:10.1080/00107517908210906

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107517908210907

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107517908210908

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor