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91.
A one-pot method for the preparation of 1,3-dihydro-1-(trifluoromethyl)isobenzofuran-1-ol derivatives 5 from 1,2-dibromobenzene is described. 相似文献
92.
W. E. Wallace K. M. Flynn C. M. Guttman D. L. VanderHart V. M. Prabhu A. De Silva N. M. Felix C. K. Ober 《Rapid communications in mass spectrometry : RCM》2009,23(13):1957-1962
The polydispersity in the degree of functionalization for two calix[4]resorcinarenes was determined by measuring quantitatively their molecular mass distribution with matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. A mathematical method for polydisperse materials is described that creates a calibration curve to correct the ion signal intensities in the mass spectrum to give a more reliable molecular mass distribution. Correction is required due to various sample preparation and instrumental effects that may produce a systematic mass bias in the number of oligomers measured. This method employs gravimetric mixtures of analytes with different degrees of functionalization. One calix[4]resorcinarene was found to give accurate molecular mass distributions with little correction, while another, having a very similar molecular structure, was found to exhibit strong over‐counting of the oligomers having a high degree of functionalization. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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94.
Paul D. Flynn 《Experimental Mechanics》1975,15(5):192-200
This paper deals with a feasibility study on the use of electrical-resistance strain gages for quality-assurance testing of ammunition. A special combination of strain gages was selected to measure the quantity ( \( \in _\theta + v \in _z \) ) on the outer surface of a test barrel. This combination of strain gages was essentially a stress gage which has several advantages over commercially available types. The combined strain signal was proportional to \(\sigma _\theta \) which was related to the internal ballistic pressure. The results of ballistic firings and hydraulic tests are reported which demonstrate the feasibility of this method for acceptance testing of ammunition. 相似文献
95.
96.
C.R. Hirning D.G. Burke E.R. Flynn J.W. Sunier P.A. Schmelzbach R.F. Haglund 《Nuclear Physics A》1977,287(1):24-47
Proton hole states in 187Re, 189Re and 191Re have been studied using the () reaction. Beams of 17 MeV tritons with a polarization of 0.75 were obtained from the tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. The α-particles were detected in a Q3D magnetic spectrometer with a helical-cathode position-sensitive proportional counter. Spectra were recorded up to > 2 MeV excitation energy with a resolution (FWHM) of ≈ 20 keV. These measurements exhibit large analyzing powers for transitions to well-known states in the deformed nuclide 187Re. This is of interest because the only other single-nucleon transfer results on heavy deformed nuclei (in a () study of tungsten isotopes) showed “disappointingly small” analyzing powers. The () analyzing powers were reproduced by DWBA calculations very well. Thus other levels in 187Re and many states in 189Re and 191Re could be assigned spins and parities on the basis of angular distributions for the cross sections and analyzing powers. In particular, the present results have made it possible to determine which of the three possible interpretations suggested previously for the structure of 191Re is correct. The results have been interpreted within the framework of the Nilsson model, with pairing and Coriolis mixing corrections included. The energy systematics of single-quasiparticle states are well reproduced by the Nilsson model if a hexadecapole deformation is included in the nuclear potential. Finally, it has been demonstrated that the () reaction is an extremely useful spectroscopic tool for studies of heavy deformed nuclei. 相似文献
97.
Experimental Mechanics - A two-dimensional photoelastic study was made of stress-concentration factors and stress distributions in a statically loaded tension bar with symmetrical U-shaped grooves.... 相似文献
98.
99.
100.
E.R. Flynn Gorden L. Struble Robert G. Lanier Lloyd G. Mann 《Physics letters. [Part B]》1977,67(2):158-160
Previous reports of two-neutron stripping reactions in the actinide nuclei have not indicated any excited 0+ strength below an excitation energy of 1.5 MeV. In contrast, the 246 Cm(t,p) 248Cm reaction shows a relatively strong 0+ state at 1.084 MeV. We believe that this result, coupled with a marked change in ground-state transition strenghts between 246 Cm and 248 Cm targets, indicates a gap in the single-particle orbitals that is larger than the pairing gap. 相似文献