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91.
J. F. Bruandet Tsan Ung Chan M. Agard J. P. Longequeue C. Morand A. Giorni 《Zeitschrift für Physik A Hadrons and Nuclei》1976,279(1):69-77
The decay scheme of62Zn has been investigated by studying the yield functions, angular distributions and coincidence relation-ships of theγ-rays emitted in the63Cu(p, 2nγ) and60Ni(α, 2nγ) reactions. Spins up to7? were assigned to the observed states. Nuclear Reactions 60Ni(α, 2nγ)62Zn,E α=28–35 MeV and63Cu(p, 2nγ)62Zn,E p = 22–31 MeV; measuredE γ,I γ(θ),I γ(E p , andI γ,E α-γ coincidences,62Zn deduced decay scheme. Enriched target, Ge(Li) detectors. 相似文献
92.
The total synthesis of (±)-desepoxy-4,5-didehydromethylenomycin A employing a retrolactonization strategy has been achieved. 相似文献
93.
A hydrophilic interaction liquid chromatographic method with tandem mass spectrometry for the determination of atenolol, a beta-blocking agent, in human plasma has been developed and validated over the curve range of 10--2000 ng/mL. The assay was based on protein precipitation followed by evaporation of the extraction solvent, reconstitution with acetonitrile, and chromatography on an Hypersil silica column (50 x 4.6 mm) using a low aqueous--high organic mobile phase. The mobile phase consists of 85% acetonitrile, 15% water, 0.5% acetic acid and 0.04% trifluoroacetic acid and runs isocratically at a flow rate of 2.0 mL/min. The column ef fluent was split so that 50% of it was transferred into the LC-MS/MS interface operated in positive electrospray ionization mode. The chromatographic run time was 2.0 min per injection. Atenolol and the internal standard, atenolol-d(7), showed a retention time of 1.0 min. The inter-day and intra-day precision and accuracy of the quality control samples were <5.3% relative standard deviation and <8.0% relative error, respectively. To explore the application of the current method for the analysis of other beta-blocking agents, propranolol and metoprolol were tested under the same chromatographic conditions with retention times of 0.68 and 0.75 min, respectively. The present method could be used for therapeutic drug monitoring, pharmacokinetic and drug--drug interaction studies of beta-blocking agents. 相似文献
94.
–Quantitative comparison of the decay rate for absorbance photochanges in chromatophores of R. rubrum at the major wavelengths of peaks and troughs (280, 365, 385, 433, 605, 763, 790, 810, 850, 865, 890 nm) reveal no major differences under a variety of sample conditions. In addition, the decay kinetics of EPR phtochange at the two environmental potentials used in this study are identical with the absorbance ph;otochange decay. Decay curves for fresh chromatophores, aged chromatophores, and fresh chromatophores at high ionic strength display a variety of half times and curve shapes. All of these data however, may be fit (within 10 per cent) by the equation x=αe8.2t+βe0.18t by merely varying the values of α and β. This is interpreted as meaning that any single trapping site may exist in one of two major forms each of which decays following a first order or pseudo-first order reaction. Although the change in decay pattern upon aging is not reversible, that due to high ionic strength is. The time dependencies for two light emission phenomena have been measured as well as their response to the oxidation state of molecules at the trapping site. A major component of long-lived luminescence follows pseudo-second order kinetics with a half time of 38 msec. A very long lived luminescence shows an increse with time which is nearly proportional to the decay of absorbance photochanges. 相似文献
95.
Aryl benzoates are reduced to 1,4-dihydroaromatics with Na/NH3 in the presence of water. 相似文献
96.
Cho DW Fujitsuka M Sugimoto A Yoon UC Mariano PS Majima T 《The journal of physical chemistry. B》2006,110(23):11062-11068
Photoinduced electron transfer (PET) processes of 1,8-naphthalimide-linker-phenothiazine (NI-L-PTZ) dyads have been investigated using the nanosecond- and picosecond-transient absorption measurements. Two kinds of linker were introduced, i.e., polymethylene-linked dyad (NI-C8-PTZ and NI-C11-PTZ) and a poly(ethyl ether)-linked one (NI-O-PTZ). The 355 nm pulsed laser excitation of NI-C8-PTZ, NI-C11-PTZ, and NI-O-PTZ in acetonitrile produced NI radical anion (NI*-) and PTZ radical cation (PTZ*+) with the absorption bands around 420 and 520 nm, respectively, through charge transfer from PTZ to NI in the singlet excited state (NI(S1)) as well as in the triplet excited states (NI(T1)) in acetonitrile. On the other hand, the charge transfer process occurred only from NI(S1) in nonpolar solvents. The rates of charge transfer and charge recombination processes largely depended on the solvent polarity and they are affected by the length of linkers and electronic coupling through polyether linker. The PET mechanism is discussed in terms of the free energy change for the charge transfer. 相似文献
97.
Sang Soo Shin Diane M. Armao Monty Shah Young Hoon Kim Chang Hee Lee Tara Rubinas Lauren M. Brubaker Richard C. Semelka 《Magnetic resonance imaging》2010
Purpose
To evaluate the clinical outcomes of conservative management by observation with MRI of patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs).Materials and Methods
Twenty-three consecutive patients, who were followed up by MRI with magnetic resonance cholangiopancreatography (MRCP) over a period of more than 9 months after initial MRI examinations, were enrolled in this study. On MRI, number of lesions, the maximum diameter of BD-IPMNs, lesion location, the presence of associated dilatation of main pancreatic duct (MPD), the presence of enhancing mural nodules within the lesion and the presence of interval change were retrospectively reviewed on initial and follow-up MR images in consensus by two radiologists. All patients were evaluated to search for evidence of malignant progression of disease.Results
The follow-up period ranged from 10 to 96 months (mean, 37 months). On initial MRI with MRCP, a total of 39 lesions were found in 23 patients. The maximum diameter of BD-IPMNs ranged between 6 and 32 mm, with a mean of 12 mm. Thirty-four lesions (87%) of 19 patients remained unchanged in the maximum diameter. Five lesions (13%) of four patients showed an increase in the maximum diameter. Enhancing mural nodules were not found in any individual, neither on the initial MRI study nor on the follow-up studies. There was no patient who had evidence of local aggressive growth of tumor or evidence of metastases to distant sites.Conclusion
Our study suggests that branch-duct IPMNs without enhancing mural nodules are essentially benign and should be managed nonoperatively through observation by MRI. 相似文献98.
Christian Daveau Diane Manuel Douady Abdessatar Khelifi Anton Sushchenko 《Applicable analysis》2013,92(5):975-996
We consider the numerical solution, in a three-dimensional bounded domain, of the inverse problem for identifying the location of small electromagnetic imperfections in a medium with homogeneous background. Our numerical algorithm is based on the coupling of a discontinuous Galerkin method for the time-dependent Maxwell's equations, on the exact controllability method and on a Fourier inversion. Several numerical results are given with one and two imperfections and the robustness and accuracy of the numerical method used for the dynamic detection problem are shown. 相似文献
99.
100.
Gill Barequet Nadia Benbernou David Charlton Erik D. Demaine Martin L. Demaine Mashhood Ishaque Anna Lubiw André Schulz Diane L. Souvaine Godfried T. Toussaint Andrew Winslow 《Computational Geometry》2013,46(2):148-153
In 1994 Grünbaum showed that, given a point set S in , it is always possible to construct a polyhedron whose vertices are exactly S. Such a polyhedron is called a polyhedronization of S. Agarwal et al. extended this work in 2008 by showing that there always exists a polyhedronization that can be decomposed into a union of tetrahedra (tetrahedralizable). In the same work they introduced the notion of a serpentine polyhedronization for which the dual of its tetrahedralization is a chain. In this work we present a randomized algorithm running in expected time which constructs a serpentine polyhedronization that has vertices with degree at most 7, answering an open question by Agarwal et al. 相似文献