ISSN:1044-8632    

DOI:10.1080/10448639208218745

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

About 270 neutron users of the ILL gathered for a I-day Users' meeting in Uriage, some I5 km from Grenoble, on 17 October. The first, and most important order of the day, was the report by the new French Director J. Charvolin (see separate report on the ILL directorate) on the status of the reactor. He described the results of the investigations so far, as well as possible ‘fixes’ that are being proposed by the ILL in

ISSN:1044-8632    

DOI:10.1080/10448639208218747

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Twenty-five years ago Dubna hosted the first meeting for experts on pulsed neutron sources (PNS). At that time the primary question was which type of intense neutron source should be built at the Laboratory of Neutron Physics (LNP) ofthe Joint Institute ForNuclearResearch (JINR). Preference was given to a repetitively pulsed reactor, IBR-2, which was constructed and put into operation in the early eighties. In the last 10 years effective spallation neutron sources (SNS) have been constructed throughout the world. Both typesof PNS (pulsed reactors and SNS) are complimentary to each other as instruments for physics research, but rnodern physics and technology need more effective neutron sources.

ISSN:1044-8632    

DOI:10.1080/10448639208218748

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Forty-two fledging neutron scatterers from fifteen different countries as far afield as China and New Zealand attended the Second Oxford Summer School on Neutron Scattering, which was held at Somerville College during two pleasantly sunny weeks in September 1991.

ISSN:1044-8632    

DOI:10.1080/10448639208218749

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The reactor Orphee (I) is the third modern reactor built after those of Brookhaven (HFBR, 196.5) and Grenoble (HFR, 197 1), especially dedicated to provide neutron beams for fundamental research. The reactor design is similar to the HFR of ILL. A core of very small size, which provides a high neutron density, surrounded by a heavy water tank to give a good thermal flux, is cooled by a downward circulation of light water. The biological shielding is achieved by a light water pool and a heavy concrete wall. Twenty neutron beams are issued from the reflector tank by nine horizontal beam ports in tangential position. The therma1 power is 14 MW and the maximum thermal neutron flux is 3 × 1014n/cm2/s. The reactor operates for ∼250 days/year in 2½ cycles of ∼100 days each.

ISSN:1044-8632    

DOI:10.1080/10448639208218750

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The Advanced Neutron Source (ANS) is a new user experimental facility planned to be operational at Oak Ridge at the end of this decade. The centerpiece ofthe ANS will beasteady-stateresearch reactor of unprecedented thermal neutron flux (Φth∼9 × 10l9m−2ss1) accompanied by extensive and comprehensive equipment and facilities for neutron-based research.

ISSN:1044-8632    

DOI:10.1080/10448639208218751

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The great majority of technologically applied materials have a polycrystalline structure. In such materials the texture describes statistically the orientation distribution of the crystallographic axes of the grains (crystallites) with respect to a set macroscopic sample axes-i.e. the texturegives information about how large a volume fraction of the material having a specific crystallographic orientation but no information about where in the material thesedifferentgrains are positioned. When the texture is strong, most of the grains have almost identical orientations; whereas, when the texture is weak, the grain orientations are almost random.

ISSN:1044-8632    

DOI:10.1080/10448639208218752

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Ceramic materials in general offer inany unique properties to the materials engineer, including low density, extreme hardness and wear resistance, and excellent resistance to corrosion and chemical attack. Often these properties are retained to much higher temperatures than in other materials. However, traditional engineering ceramics such as AI2O3MgO and mullite, are more brittle than other engineering materials. This is of particular concern in applications in which they are subject to shock loading of either mechanical or thermal origin. The fracture behaviour of materials is commonly discussed in terms of the fracture toughness (I), and several mechanisms for improving it have been discovered. Pioneering work by Garvie, Hannink and Pascoe (2) identified ‘transformation toughening’ as a means to improve fracture toughness of ceramics, and their work has led to an entirely new class of engineering ceramic, based on zirconia, and termed ‘ceramic steel’.

ISSN:1044-8632    

DOI:10.1080/10448639208218753

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1044-8632    

DOI:10.1080/10448639208218754

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor