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101.
102.
Lancaster KM Sproules S Palmer JH Richards JH Gray HB 《Journal of the American Chemical Society》2010,132(41):14590-14595
Redox and spectroscopic (electronic absorption, multifrequency electron paramagnetic resonance (EPR), and X-ray absorption) properties together with X-ray crystal structures are reported for the type 2 Cu(II) C112D/M121E variant of Pseudomonas aeruginosa azurin. The results suggest that Cu(II) is constrained from interaction with the proximal glutamate; this structural frustration implies a "rack" mechanism for the 290 mV (vs NHE) reduction potential measured at neutral pH. At high pH (~9), hydrogen bonding in the outer coordination sphere is perturbed to allow axial glutamate ligation to Cu(II), with a decrease in potential to 119 mV. These results highlight the role played by outer-sphere interactions, and the structural constraints they impose, in determining the redox behavior of transition metal protein cofactors. 相似文献
103.
As much as 3 W of average power at 1064 nm from a diode-pumped Nd:YAG laser, Q switched at 4 kHz, was used to pump an external-resonator, crystalline Ba(NO3)2 Raman laser generating a maximum of 1.3-W output at the first Stokes wavelength of 1197 nm. The slope efficiency was 63% with respect to the fundamental power incident on the Ba(NO3)2 crystal. A reduction in the beam quality of the Stokes output from M2 approximately 1.4 at lower Stokes powers to M2 approximately 3.4 at higher powers is attributed to thermal loading of the Raman-active crystal. 相似文献
104.
The near field of helium-air jets exhausting into an air environment has been experimentally investigated using an aspiration probe and flow visualization. Jets with varying density ratios and Reynolds numbers were studied. Pure helium jets with density ratios of 0.14 were found to display a self-excited behavior characterized by intense mixing. The centerline concentration decay was found to be substantially increased for the self-excited jet. Flow visualization revealed the expulsion of side jets from the potential core region of low density jets. Radial profiles of concentration provide additional evidence that side-jets produce vigorous mixing. 相似文献
105.
Th. W. Richards J. H. Mathews und L. Bigelow 《Fresenius' Journal of Analytical Chemistry》1909,48(1):40-42
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106.
H. Landolt Kreichgauer F. Sandford L. E. Ray A. Lo Surdo und Th. W. Richards 《Fresenius' Journal of Analytical Chemistry》1909,48(3):180-183
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107.
M. Lindroos P. Richards J. Rikovska N. J. Stone I. Oliveira K. Nishimura M. Booth 《Hyperfine Interactions》1992,75(1-4):323-330
A low temperature nuclear orientation experiment has been performed on the 14.8d225Ra activity. Gamma anistotropy [221Fr (4.8m) and213Bi (45.6m)] and alpha anisotropy [225Ac (10.0d),221Fr,217At (32.3ms) and209Po (4.2μs)] measurements has been carried out and values for the hyperfine field of225Ac and221Fr in iron and the magnetic moment of213Bi are reported. 相似文献
108.
Stephen P. Watson Richard D. Wilson Duncan B. Judd Stephen A. Richards 《Tetrahedron letters》1997,38(52):179-9068
The development of a novel solid phase synthesis of some 5-aminopyrazoles and derivatives is described. Reaction of hydrazines with solid supported β-keto-nitrile (1) affords 5-aminopyrazoles (2) the amino group of which is readily acylated or sulphonylated. Generation of the solid supported β-keto-nitrile (1) is non trivial and represents a key step in the overall synthesis. 相似文献
109.
D M Green V M Richards Z A Onsan 《The Journal of the Acoustical Society of America》1990,87(1):323-329
Measurements are reported on the ability of observers to discriminate whether the envelope of two amplitude-modulated sinusoids are in phase or out of phase. Spacing between the two carriers was either 2/3 or 4/3 octave, and the depth of modulation was varied to determine threshold. Discrimination performance improved as the level of the carriers increases up to about 60 dB SPL. The frequency locus of the two carriers (geometric mean of the two frequencies), which varied from 500 to 8000 Hz in different experiments, had little effect on discrimination accuracy. Discrimination performance was relatively constant for modulation rates below 100 Hz and deteriorates for higher modulation rates. These results are compared with data obtained from comodulation masking release experiments. 相似文献
110.
Th. W. Richards Ch. F. Mc. Caffrey H. Bisbee und H. P. Talbot 《Fresenius' Journal of Analytical Chemistry》1902,41(1):50-52
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