Parameters for the 3W1 source at BSRF were determined in both the dedicated and parasitic mode and their suitability for protein crystallography beamline at BSRF were realized.It is discussed that the physics motivati...Parameters for the 3W1 source at BSRF were determined in both the dedicated and parasitic mode and their suitability for protein crystallography beamline at BSRF were realized.It is discussed that the physics motivation and the design of the 3W1 is compared with similar experimental stations at the Brazilian Light Sourec(1.37Gev) and Max-II in Sweden(1.5GeV).The photon flux from the 3W1 sourcd is about 2×10^11 photon/smA in the wavelength range of 2.0-0.9A in parasitic mode and 50-80 times higher in the dedicated mode.Both the dedicated and parasitic modes are suitable for macromolecular structure experiments.2001 Elsevier Science B.V.All rights reserved.展开更多
The effects of growth time on the structure and morphology of cubic GaN nucleation layers on GaAs(001)substrates by metalorganic chemical vapor deposition (MOCVD) have been investigated using a synchrotron X-ray diffr...The effects of growth time on the structure and morphology of cubic GaN nucleation layers on GaAs(001)substrates by metalorganic chemical vapor deposition (MOCVD) have been investigated using a synchrotron X-ray diffraction(XRD).The XRD results show that the GaN 111 reflections at 54.75° inχ are a measurable component,however the 002 reflections parallel to GaAs(001) surface are not detected.The XRD Φ scans and pole figures give a convincing proof that the GaN nucleation latyers show exactly the cubic symmetrical structure.The coherence lengths along the close-packed<111> direction estuimated from the 111 peak are nanometer order of magnitude,The optimal photoluminescence (PL) spectrum was obtained from the cubic GaN epilayer deposited on the nucleation layer for 60sec.展开更多
文摘Parameters for the 3W1 source at BSRF were determined in both the dedicated and parasitic mode and their suitability for protein crystallography beamline at BSRF were realized.It is discussed that the physics motivation and the design of the 3W1 is compared with similar experimental stations at the Brazilian Light Sourec(1.37Gev) and Max-II in Sweden(1.5GeV).The photon flux from the 3W1 sourcd is about 2×10^11 photon/smA in the wavelength range of 2.0-0.9A in parasitic mode and 50-80 times higher in the dedicated mode.Both the dedicated and parasitic modes are suitable for macromolecular structure experiments.2001 Elsevier Science B.V.All rights reserved.
文摘The effects of growth time on the structure and morphology of cubic GaN nucleation layers on GaAs(001)substrates by metalorganic chemical vapor deposition (MOCVD) have been investigated using a synchrotron X-ray diffraction(XRD).The XRD results show that the GaN 111 reflections at 54.75° inχ are a measurable component,however the 002 reflections parallel to GaAs(001) surface are not detected.The XRD Φ scans and pole figures give a convincing proof that the GaN nucleation latyers show exactly the cubic symmetrical structure.The coherence lengths along the close-packed<111> direction estuimated from the 111 peak are nanometer order of magnitude,The optimal photoluminescence (PL) spectrum was obtained from the cubic GaN epilayer deposited on the nucleation layer for 60sec.
