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排序方式: 共有106条查询结果,搜索用时 15 毫秒
71.
Urszula Salaj-Kosla Micheál D. Scanlon Tobias Baumeister Kawah Zahma Roland Ludwig Peter Ó Conghaile Domhnall MacAodha Dónal Leech Edmond Magner 《Analytical and bioanalytical chemistry》2013,405(11):3823-3830
Nanoporous and planar gold electrodes were utilised as supports for the redox enzymes Aspergillus niger glucose oxidase (GOx) and Corynascus thermophilus cellobiose dehydrogenase (CtCDH). Electrodes modified with hydrogels containing enzyme, Os-redox polymers and the cross-linking agent poly(ethylene glycol)diglycidyl ether were used as biosensors for the determination of glucose and lactose. Limits of detection of 6.0 (±0.4), 16.0 (±0.1) and 2.0 (±0.1) μM were obtained for CtCDH-modified lactose and glucose biosensors and GOx-modified glucose biosensors, respectively, at nanoporous gold electrodes. Biofuel cells composed of GOx- and CtCDH-modified gold electrodes were utilised as anodes, together with Myrothecium verrucaria bilirubin oxidase (MvBOD) or Melanocarpus albomyces laccase as cathodes, in biofuel cells. A maximum power density of 41 μW/cm2 was obtained for a CtCDH/MvBOD biofuel cell in 5 mM lactose and O2-saturated buffer (pH 7.4, 0.1 M phosphate, 150 mM NaCl). 相似文献
72.
A three-dimensional computer simulation of the motion of a water jet is described which includes the effects of wind from any direction. The simulation is useful in the design of fire-fighting systems, particularly those used in offshore situations. The equations of motion are presented in vector form and the problem of the fluid dynamic drag variation is discussed. Semi-empirical approximations for the drag components along and across the jet are presented which involve four unknown constants. These are reduced to three by using previous data on the efficiency of vertical jets. To fix the remaining constants, information was available from a series of large jets tests carried out to prove an offshore fire fighting system. In these tests different nozzle shapes were tried and, using the best of these shapes, a large number of trajectories were measured photographically. These were used to fix the simulation drag constants and good agreement is shown between measurements and predictions. The simulation enables the effects of flow-rate, pressure, nozzle size, elevation and wind strength to be evaluated in the system design 相似文献
73.
Three sharp absorption features in the energy range 2.36–2.55 eV have been detected in the transmission spectrum of Co-diffused ZnSe, and a number of luminescence transitions originating from the lowest of these states at 2.361 eV have been observed. Photoluminescence excitation spectra prove that these are high energy excited states of the Co2+Zn impurity, a conclusion confirmed by comparison of measured and predicted luminescence energies. This represents the first identification of luminescence branching from a higher excited state of a transition metal ion in any semiconductor. The sharp, weakly phonon-coupled transitions involve either intra-impurity excitation or transitions from the impurity to localised states split off from a minimum in the conduction band. The implications of these observations for the mechanism of host-impurity energy transfer and for the nature of the excited state wavefunctions are discussed. 相似文献
74.
P.W. Leech A.S. Holland S. Sriram M. Bhaskaran 《Applied Physics A: Materials Science & Processing》2008,91(4):679-684
The patterning of lanthanum-doped lead zirconate titanate (PLZT) and strontium-doped lead zirconate titanate (PSZT) thin films
has been examined using a 5-ns pulsed excimer laser. Both types of film were deposited by rf magnetron sputtering with in
situ heating and a controlled cooling rate in order to obtain the perovskite-structured films. The depth of laser ablation
in both PSZT and PLZT films showed a logarithmic dependence on fluence. The ablation rate of PLZT films was slightly higher
than that of PSZT films over the range of fluence (10–150 J/cm2) and increased linearly with number of pulses. The threshold fluence required to initiate ablation was ∼ 1.25 J/cm2 for PLZT and ∼ 1.87 J/cm2 for PSZT films. Individual squares were patterned with areas ranging from 10×10 μm2 up to 30×30 μm2 using single and multiple pulses. The morphology of the etched surfaces comprised globules which had diameters of 200–250 nm
in PLZT and 1400 nm in PSZT films. The diameter of the globules has been shown to increase with fluence until reaching an
approximately constant size at ≤ 20 J/cm2 in both types of film. The composition of the films following ablation has been compared using X-ray photoelectron spectroscopy
and energy-dispersive X-ray spectroscopy.
PACS 79.20.Ds; 82.80.Pv; 82.80.Ej 相似文献
75.
Every skew Boolean algebra S has a maximal generalized Boolean algebra image given by S/ where is the Green’s relation defined initially on semigroups. In this paper we study skew Boolean algebras constructed from generalized Boolean algebras B by a twisted product construction for which . In particular we study the congruence lattice of with an eye to viewing as a minimal skew Boolean cover of B. This construction is the object part of a functor from the category GB of generalized Boolean algebras to the category LSB of left-handed skew Boolean algebras. Thus we also look at its left adjoint functor .
This paper was written while the second author was a Visiting Professor in the Department of Education at the University of
Cagliari. The facilities and assistance provided by the University and by the Department are gratefully acknowledged. 相似文献
76.
S. Withington J. Leech G. Yassin K. G. Isaak B. D. Jackson J. R. Gao T. M. Klapwijk 《International Journal of Infrared and Millimeter Waves》2001,22(9):1305-1312
We have developed a 330-370GHz SIS mixer for small-format, heterodyne, astronomical imaging arrays. Fixed-tuned broadband operation is achieved by means of a superconducting radial waveguide probe. A horn-reflector antenna provides high-efficiency optical coupling. Using a variable-temperature cryogenic noise source, we measured a DSB system noise temperature of 32±1K. The mixer contributes 3±3K, supporting the theoretically-predicted result that the noise temperature of a DSB mixer can be less than h/2 (8.6K) 相似文献
77.
Zhou SZ Sey M De Clercq PJ Milanesio M Viterbo D 《Angewandte Chemie (International ed. in English)》2000,39(16):2861-2863
78.
Gunter S Wolf RC Leuterer F Gruber O Kaufmann M Lackner K Maraschek M Mc Carthy PJ Meister H Peeters A Pereverzev G Salzmann H Schade S Schweinzer J Suttrop W 《Physical review letters》2000,84(14):3097-3100
Internal transport barriers have been demonstrated to exist also under conditions with T(e) approximately T(i) approximately 10 keV and predominant electron heating of the tokamak core region. Central electron cyclotron heating was added to neutral beam injection-heated ASDEX Upgrade discharges with a preexisting internal transport barrier, established through programmed current ramping leading to shear reversal. Compared to a reference internal transport barrier discharge without electron cyclotron resonance heating, the electron heat conductivity in the barrier region was found not to increase, in spite of a fivefold increase in electron heat flux, and also angular momentum and ion energy transport did not deteriorate. 相似文献
79.
80.
Jonathan Leech 《Algebra Universalis》1989,26(1):48-72
Presented by Boris M. Schein. 相似文献