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101.
Topoglidis E Campbell CJ Palomares E Durrant JR 《Chemical communications (Cambridge, England)》2002,(14):1518-1519
Transient optical spectroscopies and photocurrent action spectra are used to demonstrate photoinduced charge separation between zinc-substituted cytochrome c and a nanocrystalline TiO2 electrode. 相似文献
102.
Borghesi M Bulanov S Campbell DH Clarke RJ Esirkepov TZh Galimberti M Gizzi LA MacKinnon AJ Naumova NM Pegoraro F Ruhl H Schiavi A Willi O 《Physical review letters》2002,88(13):135002
A novel physical phenomenon has been observed following the interaction of an intense (10(19) W/cm(2)) laser pulse with an underdense plasma. Long-lived, macroscopic bubblelike structures have been detected through the deflection that the associated electric charge separation causes in a proton probe beam. These structures are interpreted as the remnants of a cloud of relativistic solitons generated in the plasma by the ultraintense laser pulse. This interpretation is supported by an analytical study of the soliton cloud evolution, by particle-in-cell simulations, and by a reconstruction of the proton-beam deflection. 相似文献
103.
Campbell S. J. Klingelhöfer G. Kaczmarek W. A. Hofmann M. Nagel R. Wang G. 《Hyperfine Interactions》2002,139(1-4):407-416
Integral conversion electron Mössbauer spectroscopy has been used to investigate the phases and transformations which occur when -Fe2O3 is wet-milled in vacuum for up to 144 h. In addition to the transformation to off-stoichiometric Fe3–x
O4 observed previously by transmission Mössbauer spectroscopy, the room temperature ICEMS spectra reveal the presence of 10–15% -Fe2O3 on the surfaces of particles milled for more than 24 h. Time-of-flight neutron diffraction of an -Fe2O3 sample wet-milled for 200 h also provides evidence of the occurrence of a small fraction (4%) of -Fe2O3 in the milled product. The -Fe2O3 is likely to occur as a surface oxide layer and does not appear to play a significant role in the mechanochemical transformation of -Fe2O3 to Fe3–x
O4. 相似文献
104.
A. V. Bulgakov O. F. Bobrenok V. I. Kosyakov I. Ozerov W. Marine M. Hedén F. Rohmund E. E. B. Campbell 《Physics of the Solid State》2002,44(4):617-622
Experimental results on the gas-phase formation of neutral and cationic phosphorus clusters are presented. The clusters were synthesized by visible (532 nm) or UV (193 nm) laser ablation of crystalline red phosphorus under high vacuum conditions and were analyzed using TOF mass spectrometry. Neutral Pn clusters produced by 532-nm ablation are found to be even-numbered while P n + cations are mainly odd-numbered, with P 7 + and P 21 + being the most abundant ions. For UV laser ablation, stable compound clusters, neutral P7H3 and P23H5, and cations P23H 6 + were synthesized for the first time. The formation of Pn clusters by thermal vaporization of red phosphorus into a cold He gas was also investigated and only small clusters (n<6) were found. Possible structures of the observed phosphorus clusters, as well as their formation mechanisms under different conditions, are discussed. 相似文献
105.
G. A. Stewart G. L. Whittle S. J. Campbell J. Zukrowski 《Hyperfine Interactions》1983,16(1-4):681-684
The intermetallic compound, YMn12, doped with 0.5at.%57Fe has been investigated using the57Fe Mössbauer resonance. The data show that the Fe impurities occupy preferentially the f-site at the expense of the i- and j-sites. Whereas the i- and j-sites are expected to carry identical local magnetic moments in the ordered state, low temperature hyperfine fields of 50.08(±0.05)T and 2.90(±0.03)T are measured for the i- and j-sites respectively. It is proposed that large transferred hyperfine fields are responsible for this disparity. 相似文献
106.
The short-term (up to 24 h) stability of estuarine water with high (22%?) and low (<21%?) salinity, stored unacidified in polythene containers prior to filtration, preservation and determination of dissolved trace metals, was assessed. For the-salinity sample a massive (140%) increase in copper concentration was observed, indicating desorption from the particulate phase; a similar, although less pronounced (11%) effect was found for the high-salinity sample, Evidence was also obtained for a significant loss (30%) of lead from a pre-filtered low-salinity sample, suggesting appreciable adsorption to the container walls. For cadmium and nickel, no substantial changes in concentration were observed. 相似文献
107.
Douglas J. Raber Milton D. Johnston Catherine M. Campbell Christopher M. Janks Pamela Sutton 《Magnetic resonance in chemistry : MRC》1978,11(7):323-328
The use of lanthanide shift reagents (LSR's) to obtain additional structural information from nuclear magnetic resonance studies has gained widespread acceptance. However, there has not been general agreement with regard to the most appropriate methodology for analysis of the shifted NMR spectra. We present arguments that only the bound shifts (Δ1) corresponding to the LS complex should be used for correlation of lanthanide-induced shifts with molecular structure by means of the pseudocontact equation. Several examples are discussed of compounds for which the relative induced shifts are dependent on the concentration of LSR. For such cases it is not possible for both Δ1 and Δ2 (the bound shift corresponding to the LS2 complex) to correlate successfully with the correct structure. Alternative methods of obtaining bound shifts are critically evaluated. 相似文献
108.
The paper reports the results of work on the construction of LISP programs for various symbolic operations in complex analysis, including the evaluation of integrals around closed contours by the use of Cauchy's Theorem. It is concluded that the only difficulty in the way of the preparation of programs for all of the important and useful textbook calculations in complex analysis is that large amounts of fast storage in the computer are needed. 相似文献
109.
110.
This article describes the life, career, and research of the American mathematician Anna Johnson Pell Wheeler (1883–1966). 相似文献