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61.
Padhee S Hu Y Niu Y Bai G Wu H Costanza F West L Harrington L Shaw LN Cao C Cai J 《Chemical communications (Cambridge, England)》2011,47(34):9729-9731
We report a new class of peptide mimetics, α-AApeptides, that display broad-spectrum activity against both Gram-negative and Gram-positive bacteria and fungi. With non-hemolytic activity, resistance to protease hydrolysis, and easy sequence programmability, α-AApeptides may emerge as a novel class of antibiotics. 相似文献
62.
Watling KM Parr JF Rintoul L Brown CL Sullivan LA 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):106-111
Many phosphate containing minerals are found in the Jenolan Caves. Such minerals are formed by the reaction of bat guano and clays from the caves. Among these cave minerals is the mineral taranakite (K,NH(4))Al(3)(PO(4))(3)(OH)·9(H(2)O) which has been identified by X-ray diffraction. Jenolan Caves taranakite has been characterised by Raman spectroscopy. Raman and infrared bands are assigned to H(2)PO(4), OH and NH stretching vibrations. By using a combination of XRD and Raman spectroscopy, the existence of taranakite in the caves has been proven. 相似文献
63.
64.
Simon N. Davey Lee W. Tetler David A. Leigh Andrew E. Moody 《Journal of mass spectrometry : JMS》1993,28(5):559-563
The products of the reaction between fullerenes (C60/C70) and dimethylamine were investigated by fast atom bombardment (FAB) mass spectrometry and tandem mass spectrometry (MS/MS). The FAB mass spectrum shows peaks corresponding to the addition of up to eight dimethylamine species, exclusively to C70. MS/MS reveals an unusual fragmentation pattern. The mass spectrum of the reaction products, together with a number of tandem mass spectra, are shown. 相似文献
65.
66.
G.J. Leigh 《Journal of organometallic chemistry》1984,266(3):c51-c54
Photolysis of cis-HMn(CO)4PPh3 in the presence of H2 and 1-alkene results in catalytic hydrogenation and isomerization of the alkene. The isomerization leads to cis- and trans-2-alkene in the presence or absence of H2. Catalytic hydrogenation also occurs when cis-CH3Mn(CO)4PPh3 is irradiated in the presence of H2; use of D2 leads exclusively to CH3D. The possible mechanism of the hydrogenation is discussed. 相似文献
67.
Five rotational bands in 172Hf have been observed to high spin following the 160Gd(16O, 4n)172Hf reaction, using γ-γ coincidence techniques. The ground-state band is extended to spin 20+ without backbending, in contrast to the neighbouring even-even isotones. The most strongly populated side-band, consisting of separated odd-spin and even-spin sequences, appears to result from the partial decoupling of an i neutron. Three other bands are identified with the following band-heads: an 8? state at 2006 keV with 163 ns half-life; a 6+ state at 1685 keV with a half-life < 16 ns; and a level at 1857 keV with spin 4, 5, 6 or 7 and a half-life < 16 ns. The differences between the bands are discussed in terms of the influence of Coriolis forces and the two-quasiparticle level structure. 相似文献
68.
Leigh B. Clark 《Chemical physics》1974,6(3):484-487
Polarized reflection spectra of the (001) face of diphenylacetylene single cyrstals have been measured. Analysis of the corresponding absorption spectra obtained by Krames-Krönig analysis yields the excited state symmetries of five strong bands in the wavelength rage 3000 Å to 1300 Å. 相似文献
69.
D. Ward G.D. Dracoulis J.R. Leigh R.J. Charity D.J. Hinde J.O. Newton 《Nuclear Physics A》1983,406(3):591-612
Levels to spin 16+ in the ground band and 17? in the octupole band in 222Th have been identified using the reaction 208Pb(18O, 4n)222Th at 93 MeV. To suppress intense γ-ray background from fission a residue detector was built and operated in coincidence with the Ge(Li) and NaI(Tl) detectors. The apparent moment of inertia in the ground-state rotational band rises very rapidly with increasing spin, however, no indications of backbending were observed. The octupole band at low spin has an aligned angular momentum relative to the ground-state band. Strong cross-band E1 transitions competed with collective E2 transitions within each band. Analysis showed that the ratios were within experimental uncertainty independent of both the spin and parity of the parent state.The average γ-ray multiplicity per cascade was measured for 222Th. The results were in reasonable agreement with the computer code ORNL-ALICE. 相似文献
70.
Leigh Tesfatsion 《Applied mathematics and computation》1978,4(1):27-44
A new approach to adaptive control is proposed. The principal distinguishing feature is the direct estimation and updating of the criterion function by means of a filtering operation on a vector of transitional pseudo-return functions. The data storage and computational problems often associated with explicit probability distribution updating via Bayes' rule are thus avoided. Convergence properties are established for a simple linear criterion function filter designed for a class of adaptive control problems typified by a well-known two-armed bandit problem. Optimality properties are established for the filter in a companion paper. 相似文献