摘要:

In 1979 astronomers discovered the first gravitational lens, which produced two identical images of a distant quasar. In the intervening period a rich variety of gravitational lensing phenomena have been identified, with new examples emerging serendipitously and increasingly as a result of targetted searches. The detection and study of gravitational lenses is technically demanding but progress has been impressive and astronomers have reached a stage where studies of the frequency and properties of the different classes of gravitational lens should provide crucial information concerning the nature of the elusive dark matter and the evolution of galaxies early in the history of the universe.

ISSN:0010-7514    

DOI:10.1080/00107519208219533

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Gamma-rays are located in the hard electromagnetic wave band. The range of measured energies is restricted to the interval between about 105eV and 1016eV (the latter is the highest energy of detected particles which are supposed to be gamma-ray photons). Gamma-ray astronomy is relatively young—approximately 25 years old. So only a few space experiments have been performed in this energy range. New perspectives opened since the launch of the Gamma-Ray Observatory will provide the basis for experiments over the coming years. In this paper the problems and achievements of gamma-ray astronomy are described.

ISSN:0010-7514    

DOI:10.1080/00107519208219534

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An introduction is given to the methods of production and the properties of one-, two-, and three-dimensional electron gases. In two dimensions this includes the formation of electron solids (Wigner crystallization) and the quantum Hall effects and in one-dimension, the quantization of ballistic transport. The article ends with a short discussion of the applications of low-dimensional structures in electronic and optoelectronic systems.

ISSN:0010-7514    

DOI:10.1080/00107519208219535

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A review ofMechanics: From Newton's Law to Deterministic Chaos. By Florian Scheck (Springer-Verlag, 1990.) [Pp. vii + 431.] DM 68.00 (pbk). ISBN 3 540 52715 X. Scope: Textbook. Level: Third-year undergraduate/postgraduate.

ISSN:0010-7514    

DOI:10.1080/00107519208219536

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A review ofThe Quantum Physics of Atomic Frequency Standards. Volumes 1 and 2. By J. Vanier and C. Audoin. (Adam Hilger, 1989.) [Pp. Vol. 1. viii + 601, Vol. 2. viii + 965.] £250.00. ISBN 0 85274 434 2 (set). Scope: Monograph. Level: Postgraduate.

ISSN:0010-7514    

DOI:10.1080/00107519208219537

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A review ofBasics of Modern Cosmology. By A. D. Dolgov, M. V. Sazhin, and Ya. B. Zeldovich. (Edition Frontières, 1990.) [Pp. 247.] Price unknown. ISBN 2 86332 073 4. Scope: Textbook. Level: Postgraduate.

ISSN:0010-7514    

DOI:10.1080/00107519208219538

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The Sky: A User's Guide. D. H. Levy 1991, £16.95 (hbk), US$24.95 (hbk), pp. xviii + 295. Cambridge University Press, ISBN 0 521 39112 1. Scope: Text. Level: General reader.

ISSN:0010-7514    

DOI:10.1080/00107519208219539

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107519208219540

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor