排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Kacher Y. G. Karlova M. G. Glukhov G. S. Zhang H. Zaklyazminskaya E. V. Loussouarn G. Sokolova O. S. 《Crystallography Reports》2021,66(5):711-725
Crystallography Reports - Membrane proteins, including ion channels, became the focus of structural proteomics midway through the 20th century. Methods for studying ion channels are diverse and... 相似文献
2.
Gas phase chromatography of halides of elements 104 and 105 总被引:1,自引:0,他引:1
A. Türler H. W. Gäggeler K. E. Gregorich H. Barth W. Brüchle K. R. Czerwinski M. K. Gober N. J. Hannink R. A. Henderson D. C. Hoffman D. T. Jost C. D. Kacher B. Kadkhodayan J. Kovacs J. V. Kratz S. A. Kreek D. M. Lee J. D. Leyba M. J. Nurmia M. Schädel U. W. Scherer Schimpf D. Vermeulen A. Weber H. P. Zimmermann I. Zvara 《Journal of Radioanalytical and Nuclear Chemistry》1992,160(2):327-339
On-line isothermal gas phase chromatography was used to study halides of261104 (T1/2=65 s) and262,263105 (T1/2=34 s and 27 s) produced an atom-at-a time via the reactions248Cm(18O, 5n) and249Bk(18O, 5n, 4n), respectively. Using HBr and HCl gas as halogenating agents, we were able to produce volatile bromides and chlorides of the above mentioned elements and study their behavior compared to their lighter homologs in Groups 4 or 5 of the periodic table. Element 104 formed more volatile bromide than its homolog Hf. In contrast, element 105 bromides were found to be less volatile than the bromides of the group 5 elements Nb and Ta. Both 104 and Hf chlorides were observed to be more volatile than their respective bromides. 相似文献
3.
In situ straining in the transmission electron microscope and diffraction-contrast electron tomography has been applied to investigate dislocation interactions in α-Ti. Dislocation debris, in the form of small loops, was seen to form from sequential cross-slip events. Electron tomography provided direct three-dimensional visualisation of the dislocation structures, allowing accurate identification of slip planes, dislocation line directions and spatial relations between dislocations. 相似文献
4.
5.
6.
B. Wierczinski K. E. Gregorich B. Kadkhodayan D. M. Lee L. G. Beauvais M. B. Hendricks C. D. Kacher M. R. Lane D. A. Keeney-Shaughnessy N. J. Stoyer D. A. Strellis E. R. Sylwester P. A. Wilk D. C. Hoffman R. Malmbeck G. Skarnemark J. Alstad J. P. Omtvedt K. Eberhardt M. Mendel A. Nähler N. Trautmann 《Journal of Radioanalytical and Nuclear Chemistry》2001,247(1):57-60
Subsecond 224 Pa (T
1/2 = 0.85 s) was produced via the 209 Bi(18 O,3n)224 Pa reaction at the 88 inch cyclotron at the Lawrence Berkeley National Laboratory. After production it was transported via a gas-jet system to the centrifuge system SISAK 3. Following on-line extraction with trioctylamine/scintillation solutions from 1M lactic acid, 224 Pa was detected applying on-line -liquid scintillation counting. Unambiguous identification was achieved using time-correlated --decay chain analysis. This constitutes the first chemical on-line separation and detection of a subsecond -decaying nuclide, 0.85-s 224 Pa with the fast extraction system SISAK 3. 相似文献
7.
Mulkern RV Hung YP Ababneh Z Maier SE Packard AB Uluer MC Kacher DF Gambarota G Voss S 《Magnetic resonance imaging》2005,23(6):757-764
Dairy cream, as a suspension of lipid droplets in water, is a potentially useful magnetic resonance imaging (MRI) phantom material and an interesting material for studying fundamental relaxation mechanisms. Here we report a strong increase in the transverse relaxation rates with field strength for both the water and lipid protons in dairy cream. Also, studies at 4.7 T reveal a nonlinear response of transverse relaxation rates with increasing concentration of a common gadolinium (Gd)-based contrast agent, including an initial decrease of water relaxation rates as measured with Hahn spin echoes at the lower Gd concentrations. The results are treated within the framework of a model in which the magnetic susceptibility difference between the lipid droplets and the aqueous phase plays the prominent role for transverse relaxation. Second-order polynomial fits of the water proton transverse relaxation rate dependence on field strength and on Gd concentration at 4.7 T provided experimental parameters from which model parameters are extracted and compared with expectations available from the literature. 相似文献
8.
The effects of heavy-ion irradiation on dislocation processes in stainless steels were investigated using in situ irradiation and deformation in the transmission electron microscope as well as post mortem electron tomography to retrieve information on the three-dimensional dislocation state. Irradiation-induced defects were found to pose a strong collective barrier to dislocation motion, leading to dislocation pileups forming in grain interiors and at grain boundaries. The passage of multiple dislocations along the same slip plane removes the irradiation defects and leads to the eventual formation of a defect-free channel. These channels are composed of densely tangled dislocation networks which line the channel-matrix walls as well as residual dislocation debris in the channel interiors. The structures of the dislocation tangles were found to be similar to those encountered in later stages of deformation in unirradiated materials, with the exception that they developed earlier in the deformation process and were confined to the defect free channels. Also, defect free channels were found to widen through both source widening as well as complex cross-slip mechanisms. 相似文献
9.
Multiscale characterization was performed on an Al–Mg alloy, Al 5754 O-temper, including in situ mechanical deformation in both the scanning electron microscope and the transmission electron microscope. Scanning electron microscopy characterization showed corresponding inhomogeneity in the dislocation and Mg distribution, with higher levels of Mg correlating with elevated levels of dislocation density. At the nanoscale, in situ transmission electron microscopy straining experiments showed that dislocation propagation through the Al matrix is characterized by frequent interactions with obstacles smaller than the imaging resolution that resulted in the formation of dislocation debris in the form of dislocation loops. Post-mortem chemical characterization and comparison to dislocation loop behaviour in an Al–Cr alloy suggests that these obstacles are small Mg clusters. Previous theoretical work and indirect experimental evidence have suggested that these Mg nanoclusters are important factors contributing to strain instabilities in Al–Mg alloys. This study provides direct experimental characterization of the interaction of glissile dislocations with these nanoclusters and the stress needed for dislocations to overcome them. 相似文献
10.
C.J. Gardner J. Kacher J. Basinger B.L. Adams M.S. Oztop J.W. Kysar 《Experimental Mechanics》2011,51(8):1379-1393
Electron Backscatter Diffraction (EBSD) based Orientation Imaging Microscopy (OIM) is used routinely at ~500 materials laboratories
worldwide for the characterization and development of diverse crystalline materials. Statistically significant data sets (~107 individual EBSD measurements) can be collected and analyzed within time periods of acceptable beam stability (~105s). However, limitations in angular and spatial resolution have motivated a continued search for more robust EBSD-based methods.
Herein is a gathered presentation of advanced techniques in use, intended as a guide to researchers in selecting the most
appropriate method for their work. Wilkinson’s method has been shown to increase angular resolution nearly two orders of magnitude
to ±0.006°, facilitating measurement of elastic strain, lattice curvature, and dislocation density. A simulated pattern adaptation
of Wilkinson’s method extends these measurement capabilities to polycrystalline materials, by avoiding the need for an experimental
strain free reference pattern. The angular resolution limit obtained is ~0.04°. Accurate pattern center calibration, essential
to the high resolution methods, is accomplished by parallelization of band edges projected onto a sphere centered at the interaction
volume. FFT powered cross-correlation functions improve the spatial resolution near grain boundaries and correct for measurement
inaccuracies induced by overlapping patterns. To corroborate these claims, exemplary results taken from a wedge-indented nickel
single crystal, cold-worked copper polycrystal, and rolled nickel polycrystal are shown. 相似文献