摘要:
A structure including a substrate, an intermediate layer provided and formed directly onto the substrate, a transition region, and a group II-VI bulk crystal material provided and formed as an extension of the transition region. The transition region acts to change the structure from the underlying substrate to that of the bulk crystal. In a method of manufacture, a similar technique can be used for growing the transition region and the bulk crystal layer.
摘要:
A method and system for facilitating the identification and/ or authentication of objects, and to a method and system for the marking of objects with an identity and/ or as of authentic origin, anda set of objects marked to facilitate subsequent identification and/ or authentication are described. The marking comprises incorporating into an object or part thereof or onto a tag mechanically engaged therewith a marker material exhibiting a characteristic radiation interaction response to incident high- energy ionizing radiation from a test source that is known to vary spectroscopically across the spectrum of the source. The presence or otherwise of the marker material may be determined by subsequent interrogation of an object with a suitable radiation source and detector to infer whether an object is of marked identity or origin.
摘要:
An apparatus for vapour phase crystal growth comprising an envelope assembly with a one source module defining at least one source volume, a growth module defining at least one growth volume, and a manifold module defining at least one manifold volume. The source module, manifold module and growth module are configured co-operably to define a fluidly continuous envelope volume including a flow restrictor between the source volume and the growth volume. A vacuum vessel containing one or more of the envelope assemblies. An evacuator to evacuate the vacuum vessel. A fluid communication path between the envelope volume and the vacuum vessel associated with each source volume at a location on the source volume side of its associated flow restrictor. A closure mechanism is configured to restrict the fluid communication path between each source volume and the vacuum vessel. A method of employing such an apparatus is also disclosed.
摘要:
A method and apparatus are described for the collection and interpretation of radiographic data from an object scanned by a suitable radiation source. A radiation detector system is provided that is detecting and collecting spectroscopically resolved information. An object is scanned from a plurality of perspectives, and the resultant data from each perspective resolved into at least three spectroscopic energy bands. For each such resolved spectroscopic energy band an image analysis is performed to derive depth slicing to produce a series of output datasets each comprising a 2-D dataset of intensity information resolved to a single energy band and depth slice.