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排序方式: 共有205条查询结果,搜索用时 281 毫秒
1.
Ahmed Waqar Chowdhury Z. Z. Kazi S. N. Johan MR. Akram Naveed Oon C. S. Abdelrazek Ali H. 《Journal of Thermal Analysis and Calorimetry》2021,144(4):1517-1534
Journal of Thermal Analysis and Calorimetry - In recent decades, the growth of heat transfer using nanomaterials in the conventional base fluid has caught the attention of researchers... 相似文献
2.
S.D. Gopal Ram G. Ravi MR. Manikandan T. Mahalingam M. Anbu Kulandainathan 《Superlattices and Microstructures》2011,50(4):296-302
In the present work, a controlled growth of ZnO nanostructures by manipulating Zn metal ion concentration by the chelating action of ethylene diaminetetra acetic acid in hydrothermal method is studied. EDTA produces metal–chelate complex by the formation of bidentate ligand with Zn2+ in the solution and diminishes the reactivity of Zn metal cations. Concentration of EDTA in the mother solution was varied in different ranges like 3, 5 and 10 mM while retaining the zinc metal salt and the NaOH concentration the same. Three different morphologies of wurtzite structured ZnO nanostructures such as nanorods-bunch, separate/discrete uniformly sized hexagonal nanorods and tapered flower petals like shapes are achieved by 3, 5 and 10 mM strengths of EDTA, respectively. The medium concentration 5 mM of EDTA is found to have moderate control over producing ZnO nanostructures of uniform diameter and a high aspect (length to diameter) ratio. An array of vertically aligned free standing ZnO nanorods with uniform spacing is successfully achieved by the addition of 5 mM of EDTA in the mother solution and the same is studied for its fluorescence property at an excitation of 325 nm and it has exhibited a characteristic UV emission of ZnO around 383 nm. 相似文献
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Middleton CT Buchanan LE Dunkelberger EB Zanni MT 《The journal of physical chemistry letters》2011,2(18):2357-2361
We report that the waiting time delay in 2D IR pulse sequences can be used to suppress signals from structurally disordered regions of amyloid fibrils. At a waiting time delay of 1.0 ps, the random coil vibrational modes of amylin fibrils are no longer detectable, leaving only the sharp excitonic vibrational features of the fibril β-sheets. Isotope labeling with (13)C(18)O reveals that structurally disordered residues decay faster than residues protected from solvent. Since structural disorder is usually accompanied by hydration, we conclude that the shorter lifetimes of random-coil residues is due to solvent exposure. These results indicate that 2D IR pulse sequences can utilize the waiting time to better resolve solvent-protected regions of peptides and that local mode lifetimes should be included in simulations of 2D IR spectra. 相似文献
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H. H. Willard J. J. Thompson E. Kasper P. Slawik A. W. Middleton K. Seelkopf H. Taeger P. Schmidt F. Weyrauch A. Necke H. Müller A. J. Lindsey B. Park E. J. Lewis O. B. Winter Helen M. Robinson F. W. Lamb E. J. Miller C. E. Willoughby E. S. Wilkins E. O. Kraemer A. Jílek J. Kota 《Analytical and bioanalytical chemistry》1936,106(4-6):200-207
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M. B. Rane K. Kondaiah A. R. Middleton G. T. Wernimont S. L. Archangelowa M. Stschigol N. Dubinski L. W. N. Godward A. M. Ward A. D. Worobjewa P. Wukolow A. Reich N. A. Tananajew F. P. Dwyer R. H. Bullard J. S. Knapper K. A. Craig G. C. Chandlee W. I. Kosakow L. Szebellédy M. Ajtai M. Uljanitschew M. S. Platonow N. F. Kriwoschlykow A. A. Marakajew M. J. Petrow K. M. Rauner 《Analytical and bioanalytical chemistry》1939,117(3-4):118-132
9.
Richard W. Middleton John Parrick Eric D. Clarke Peter Wardman 《Journal of heterocyclic chemistry》1986,23(3):849-855
A number of novel N-substituted-1,8-naphthalimides have been prepared and their fluorescence yields measured in water at pH 7.4. The type of substitutent and the substitution pattern on the naphthalimide nucleus produce markedly different fluorescence yields, (quantum efficiencies, ø varying from ø = 0-0037 for N-(3-N'-morpholino-1-propyl)-4-amino-3-methoxy-1,8-naphthalirnide (7) to ø = 0–77 for N-(3-bromopropyl)-4-acetamido-1,8-naphthalimide (31). 相似文献
10.
Devon M. Middleton Feroze B. Mohamed Nadia Barakat Louis N. Hunter Sphoorti Shellikeri Jürgen Finsterbusch Scott H. Faro Pallav Shah Amer F. Samdani M.J. Mulcahey 《Magnetic resonance imaging》2014
Patient and physiological motion can cause artifacts in DTI of the spinal cord which can impact image quality and diffusion indices. The purpose of this investigation was to determine a reliable motion correction method for pediatric spinal cord DTI and show effects of motion correction on DTI parameters in healthy subjects and patients with spinal cord injury. Ten healthy subjects and ten subjects with spinal cord injury were scanned using a 3 T scanner. Images were acquired with an inner field-of-view DTI sequence covering cervical spine levels C1 to C7. Images were corrected for motion using two types of transformation (rigid and affine) and three cost functions. Corrected images and transformations were examined qualitatively and quantitatively using in-house developed code. Fractional anisotropy (FA) and mean diffusivity (MD) indices were calculated and tested for statistical significance pre- and post- motion correction. Images corrected using rigid methods showed improvements in image quality, while affine methods frequently showed residual distortions in corrected images. Blinded evaluation of pre and post correction images showed significant improvement in cord homogeneity and edge conspicuity in corrected images (p < 0.0001). The average FA changes were statistically significant (p < 0.0001) in the spinal cord injury group, while healthy subjects showed less FA change and were not significant. In both healthy subjects and subjects with spinal cord injury, quantitative and qualitative analysis showed the rigid scaled-least-squares registration technique to be the most reliable and effective in improving image quality. 相似文献