studies of fibril structures by x ray diffraction
Báo cáo khoa học: An X-ray diffraction study of model membrane raft structures doc
... parameters of the bilayers Assignment of lamellar structures The next task was to establish the identity of the coexisting lamellar phases in ternary mixtures contain- A C Fig Characterization of egg-PtdCho ... formation of a gel phase by brainSM in this mixture Assignment of peak to a structure of pure brainSM can also be excluded on this evidence The fit of peak to brainSM ⁄ cholesterol mixtures was ... Cartoons of the molecular composition of the different structures proposed for the lipid matrix model of membrane raft structure and their relationship to the Bragg spacings of ternary mixtures of...
Ngày tải lên: 15/03/2014, 23:20
Structure of hibiscus latent singapore virus determined by x ray fiber diffraction
... List of abbreviations viii List of figures x List of tables xii Summary xiii CHAPTER X- RAY FIBER DIFFRACTION TECHNIQUES 1-19 1.1 INTRODUCTION 1.2 THEORY OF FIBER DIFFRACTION 1.2.1 Diffraction by ... and RMV but different from that of TMV and CGMMV xiii By solving the structure of HLSV by X- ray fiber diffraction, we will be able to have a better understanding of the structural differences between ... DEPARTMENT OF BIOLOGICAL SCIENCES NATIONAL UNIVERSITY OF SINGAPROE 2010 ACKNOWLEDGEMENTS At the threshold of completing my doctor of philosophy (PhD) in X- ray fiber diffraction, I feel extremely...
Ngày tải lên: 10/09/2015, 15:53
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 1
... annealed (unpoled) relaxor ferroelectric PZN-(4.5-9)%PT single crystals by means of high-resolution synchrotron x- ray diffraction (HR-XRD) To avoid undesired surface effects produced by mechanical polishing, ... surface For x- ray of low energy as in the present work, the diffraction profile thus depends on the penetration depth in the (see text for details) Fig 8.8 Room temperature HR-XRD (002) RSM of an as-grown ... phenomenological theoretical work of Vanderbilt and Cohen [25] Subsequently, extensive structural studies by means of high-resolution synchrotron x- ray and neutron diffractions have been carried...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 2
... surface X- ray 44.65o ~43.0-44.0o 42 43 44 45 46 47 2θ [010]W [100] L PZN-4.5%PT b) b) Fractured surface Intensity (arb units) X- ray X- ray 44.62 42 43 44 45 o 46 47 2θ Figure 5.1 (002) XRD profiles of ... structure of the thin surface layer The experimental results pertaining to the origin of the broad lower 2θ peak adjacent to the major (002)R peak and the effects of surface layer on x- ray diffraction ... Typical (002) XRD profile of an as-polished sample of PZN-4.5%PT is given in Figure 5.1(a) The XRD result, which relates to the surface layer of the as-polished 54 sample, revealed two (002) diffraction...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 3
... the x- ray diffraction patterns (Figures 5.11a, c, and e) As a result, the polished surface can hardly reveal any useful structural information of the crystals hence unsuitable for x- ray diffraction ... x- ray diffraction study 5.3.2 Electrical resistance 73 The effect of room-temperature poling on the stability of the deformed surface layer was also investigated Figure 5.12 shows the XRD profiles ... treatment 5.4 (a) Summary of main observations The cause for the occurrence of the extremely broad lower 2θ peak adjacent to the main (002)R peak in standard XRD profiles of (001)-orientated PZN-PT...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 4
... in the x- ray profile following any direction of polishing, suggesting that the surface phase is always present regardless of the direction and/or mode of polishing This behavior can be explained ... shows the (002) XRD profiles of the differently annealed PZN-4.5%PT samples and the (002) XRD profile of the as-polished sample After annealing for h at 300 °C, the position of the lower 2θ peak ... was tilted by an angle of 45° and again polished back and forth in the new direction After the second polishing, the earlier set of domains disappeared and was replaced by a new set of elongated...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 5
... HR-XRD measurements The incident x- ray beam, of 8.048 keV in energy, had typical divergence of about 0.01°, with the best divergence being 0.006° A series of rocking (∆ω) scans at a range of ... T nanotwin diffraction here) Subtle changes of the various diffractions with increasing temperature indicate that these diffractions is a mixture of R phase and the coherent effects of (100)T-(001) ... corresponding diffraction patterns on the (002) RSM To explain how domain size may affect the (002) diffraction profiles, we begin with diffractions arising from untilted T microdomains By microscale...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 6
... projection of coexistence of the {100}-type and {110}-type R nanotwins onto the (002) RSM (b) The projection of the coexistence of R micro- and nanotwins onto (002) RSM 112 coexistence of R micro- ... variants of opposite polarization In Figure 7.2(b), each variant diffraction is represented by circles of half-intensity contours Since the R phase of PZN-PT is elastically soft, individual variant diffractions ... result of the large diffraction width associated with the fine domain structure and the extreme compliant nature of the R phase The diffraction pattern indicating possible coexistence of {100}-type...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 7
... configurations of coexistence R* and T* domain structures The arrows represent the directions of the polar axis in T phase The two polar directions are joined by the {110}-type T* as indicated by the ... radiation used (of 8.048 keV in energy and with an estimated penetration depth of only a few µm thick), the underlying (001)T domains could not be detected by the x- ray This would explain the observation ... However, careful examination of the roomtemperature RSMs revealed that only (100)T diffractions were detected but not the (001)T diffractions In this section, we shall examine the nature of the T phase...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 8
... to Tmax ≅ 165 ºC, the scattered areas started to exhibit extinction at most P/A angles, suggesting the occurrence of the C phase (Figure 8.14f) Above Tmax, the sample exhibited a total extinction ... scattered areas started to exhibit extinction at most P/A angles, suggesting the occurrence of the C phase (Figure 8.11f) Above Tmax, the sample exhibited a total extinction, indicating the C ... consistent with the HR-XRD results 147 Figure 8.11 shows the domain structures obtained by the PLM as a function of temperature At 25 ºC, the crystal exhibited complete optical extinction at only...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 9
... (standard + extended) region where (R+T) coexist, the crystal exhibits extremely high piezoelectric properties This suggests that the presence of (R+T) phase mixture in the form of micro/nanotwin ... slight tilting of the R diffraction out of the ω = 0° plane indicates that both crystals existed in a strained state as the result of poling induced stresses This finding is supported by the work ... electromechanical properties of PZN-PT and other relaxor crystals 9.2 Room temperature phase of PZN-PT single crystals of different PT contents Figure 9.2 shows the (002) RSMs of PZN-(4.5-8)%PT single...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 10
... transformation in relaxor single crystals occurs over a temperature range, manifested by the coexistence of R* and T* domains, a string of thermal current signals, and continued degradation of KT and k31 ... corresponding to the first dielectric anomaly of the plot; Tmax is the temperature at which the ε’ is at its maximum Determined by means of the temperature cycling tests of Honoso et al [77, 78] and [b] Rajan ... of dielectric and electromechanical properties begins [c] [d] Determined from the thermal current density data of [001]-poled crystals Determined by means of HR- XRD results 176 9.5 Summary of...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 11
... ferroelectric relaxor (1 -x) Pb(Mg1/3Nb2/3)O3-xPbTiO3, Phys Rev B, 66, p 054104 2002 36 Bai, F., N Wang, J Li, D Viehland, P M Gehring, G Xu and G Shirane X- ray and neutron diffraction investigations of the ... high-synchrotron x- ray as available in SSLS Higher energy x- ray of improved 182 resolution is required to resolve these fine nanotwin diffractions and to decipher the detailed configurations of the R* ... of relaxor materials) are of extreme value to provide fundamental insight into the hierarchy of domain structures and its role in the superior piezoelectricity of relaxor ferroelectric single...
Ngày tải lên: 14/09/2015, 08:40
Báo cáo khoa học: The effect of replacing the axial methionine ligand with a lysine residue in cytochrome c-550 from Paracoccus versutus assessed by X-ray crystallography and unfolding ppt
... R Worrall et al X- ray and unfolding studies of cyt c-550 Fig Close up of the heme binding pocket of (A) wt and (B) the M100K(rt) variant of ferricyt c-550, with the positions of the buried water ... al X- ray and unfolding studies of cyt c-550 mid-point of the unfolding transition (Cm) for the M100K variant monitored by peroxidase activity is again considerably shifted compared to that of ... concentrations of % lm were used Peroxidase activity was assayed using hydrogen peroxide and guaiacol (O-methoxyphenol, Sigma) The synthesis of the fourfold oxidized product of guiacol, 3,3¢-dimethoxy-4,4¢-biphenoquinone...
Ngày tải lên: 07/03/2014, 17:20
Báo cáo Y học: Determinants of the inhibition of a Taiwan habu venom metalloproteinase by its endogenous inhibitors revealed by X-ray crystallography and synthetic inhibitor analogues pdf
... Biochem 269) are grouped in a superfamily of metzincin which exhibits some typical structural features, such as the Met-turn and active-site consensus HExxHxxGxxH sequence [15–17] Some organisms and ... to the carbonyl oxygen of Arg106 (b) The N-terminal nitrogens of these three residues are hydrogen-bonded to the carbonyl oxygen of Asn107 (c) The C-terminal carbonyl oxygens of these residues ... Yu of the Institute of Biological Chemistry at Ó FEBS 2002 Inhibition of a SVMP by its endogenous inhibitors (Eur J Biochem 269) 3055 Fig Comparison of the binding mode of pENW with some of other...
Ngày tải lên: 08/03/2014, 23:20
ELEMENTS OF X-RAY DIFFRACTION ppt
... the exact relation The region between netic X X X bemg lkX= 1.00202A worth while to review briefly some properties of electromagnetic Suppose a monochromatic beam of x- rays, i.e., x- rays of a ... detector of x- rays is a very PROPERTIES OF X- RAYS 24 [CHAP Photographic film is affected by much the same way as by (a) x- rays in visible light, and film is the most widely used means of recording ... precise understanding of the radiation used, because it was not until 1912 that the exact nature of x- rays was established In that year the phenomenon of x- ray diffraction by crystals was discovered,...
Ngày tải lên: 29/03/2014, 11:20
Báo cáo hóa học: "Valence band offset of InN/BaTiO3 heterojunction measured by X-ray photoelectron spectroscopy" pot
... Zhou XL, Yang AL, Zheng GL, Liu XL, Yang SY, Wang ZG: Valence band offset of ZnO/BaTiO3 heterojunction measured by X- ray photoelectron spectroscopy Appl Phys A 2010, 99: 511 16 You JB, Zhang XW, ... Zhang RQ, Zhang PF, Kang TT, Fan HB, Liu XL, Yang SY, Wei HY, Zhu QS, Wang ZG: Determination of the valence band offset of wurtzite InN/ZnO heterojunction by x- ray photoelectron spectroscopy Appl ... carbon) existing in the sample surface, which may prevent the precise determination of the positions of the VBMs To reduce 40 50 (deg.) 60 70 80 Figure X- ray θ-2θ diffraction pattern of the thick...
Ngày tải lên: 21/06/2014, 04:20
Báo cáo hóa học: " Valence band offset of wurtzite InN/SrTiO3 heterojunction measured by x-ray photoelectron spectroscopy" ppt
... Oxidation study of polycrystalline InN film using in situ X- ray scattering and X- ray photoemission spectroscopy Thin Solid Films 2007, 515:4691 Lee IJ, Kim JY, Shin HJ, Kim HK: Near-edge x- ray ... to contamination by oxygen during the growth process The ratio of In-N peak intensity to the oxygen-related peak indicates that only a small quantity of oxygen contamination exists in our samples ... valence band offset: High-resolution x- ray photoemission spectroscopy measurements Phys Rev B 2008, 78:033308 Liu JM, Liu XL, Xu XQ, Wang J, Li CM, Wei HY, Yang SY, Zhu QS, Fan YM, Zhang XW, Wang...
Ngày tải lên: 21/06/2014, 05:20
Báo cáo hóa học: " Determination of InN/Diamond Heterojunction Band Offset by X-ray Photoelectron Spectroscopy" docx
... valence band offset of the InN/diamond heterojunction has been measured by XPS A type-I band alignment with a valence band offset of ΔEv ~ 0.39 ± 0.08 eV and conduction band offset of ΔEc ~ 4.42 ... Determination of InN/Diamond Heterojunction Band Offset by X- ray Photoelectron Spectroscopy Nanoscale Res Lett 2011 6:50 Author details Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, ... Academy of Sciences, P O Box 912, 100083, Beijing, People’s Republic of China 2Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of...
Ngày tải lên: 21/06/2014, 11:20
Báo cáo hóa học: " Measurement of w-InN/h-BN Heterojunction Band Offsets by X-Ray Photoemission Spectroscopy" docx
... deexcitation of the photohole by quantized excitations the conduction-electron system However, the extrinsic plasmons are excited by the outgoing photoelectron traveling from the place of the photoexcitation ... (mixed Lorentz–Gaussian) lineshape and Shirley background The positions of valence band maximum (VBM) in valence band (VB) spectra are determined by linear extrapolation of leading edges of VB ... determined by linear extrapolation of the leading edge to the base line BN InN bulk constants of thick films, respectively, and EVBM , EVBM means the bulk position of the valence band maximum with...
Ngày tải lên: 21/06/2014, 17:20