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91.
Substituted 1,2-dithiole-3-thiones react with nucleophiles (alkoxides, thiolates) to give various reaction products depending on the nucleophiles and on the substituents on the 1,2-dithiole-3-thione ring. The mechanistic aspects of these reactions are discussed. 相似文献
92.
A. Rougé G. De Rosny P. Fleury B. Eisenstein P. Briandet P. Benkheiri P. Rivet A. Volte B. Bouquet B. DAlmagne A. Ferrer A. Jacholkowski P. Petroff F. Richard P. Roudeau J. Six D. Treille H. Yoshida 《Physics letters. [Part B]》1977,69(1):115-118
In π?p interactions at 9 GeV/c and 12 GeV/c, the forward production of N11680 and N11520 has been observed with features of nucleon exchange. The production of Δ1232 is strongly suppressed. 相似文献
93.
T. Buran A. Eide P. Helgaker P. Lehmann A. Lundby A. Navarro-Savoy L. Staurset O. S?rum C. Baglin P. Briandet P. Fleury G. De Rosny J.M. Thenard P.J. Carlson K.E. Johansson B. DAlmagne F. Richard D. Treille V. Gracco 《Nuclear Physics B》1975,97(1):11-28
Antiproton-proton elastic scattering data at 6.2 GeV/c in the range 0.3 (GeV/c)2 ? ?t ? 10.0 (GeV/c)2 is presented. The experiment, using spark chambers and proportional chambers, was performed at the CERN Proton Synchroton.The dip at about ?t = 0.5 and the structure at about ?t = 2.2 (GeV/c)2 are equally strong at 6.2 GeV/c as they are at 5.0 GeV/c. The differential cross sections around 90° c.m. are not very different at 5.0 GeV/c and at 6.2 GeV/c, whereas in the backward region there is a decrease of the order of one magnitude. 相似文献
94.
Fluorescence detected Lamb dips have been observed in D2CO. The D2CO was placed inside a CO2 waveguide laser cavity and fluorescence detection was performed with a InSb detector. Possible explanations for this observation are discussed. 相似文献
95.
96.
We present a corresponding states analysis of existing data on sound velocity, transport coefficients and intermolecular interaction times of a number of simple fluids. With appropriate choices of parameters for the intermolecular pair potential, such properties as the adiabatic sound velocity, the shear and bulk viscosities, the thermal conductivity and the intermolecular interaction time can be reduced along the liquid-vapor equilibrium curve. Deviations from the simple law of corresponding states are most pronounced for the transport properties, indicating a stronger sensitivity of the dynamical properties to the interaction potential and the molecular structure. 相似文献
97.
Medical imaging is a vital component of high intensity focused ultrasound (HIFU) therapy, which is gaining clinical acceptance for tissue ablation and cancer therapy. Imaging is necessary to plan and guide the application of therapeutic ultrasound, and to monitor the effects it induces in tissue. Because they can transmit high intensity continuous wave ultrasound for treatment and pulsed ultrasound for imaging, dual-mode transducers aim to improve the guidance and monitoring stages. Their primary advantage is implicit registration between the imaging and treatment axes, and so they can help ensure before treatment that the therapeutic beam is correctly aligned with the planned treatment volume. During treatment, imaging signals can be processed in real-time to assess acoustic properties of the tissue that are related to thermal ablation. Piezocomposite materials are favorable for dual-mode transducers because of their improved bandwidth, which in turn improves imaging performance while maintaining high efficiency for treatment. Here we present our experiences with three dual-mode transducers for interstitial applications. The first was an 11-MHz monoelement designed for use in the bile duct. It had a aperture that was cylindrically focused to 10 mm. The applicator motion was step-wise rotational for imaging and therapy over a 360°, or smaller, sector. The second transducer had 5-elements, each measuring for a total aperture of . It operated at 5.6 MHz, was cylindrically focused to 14 mm, and was integrated with a servo-controlled oscillating probe designed for sector imaging and directive therapy in the liver. The last transducer was a 5-MHz, 64-element linear array designed for beam-formed imaging and therapy. The aperture was with a pitch of 0.280 mm. Characterization results included conversion efficiencies above 50%, pulse-echo bandwidths above 50%, surface intensities up to , and axial imaging resolutions to 0.2 mm. The second transducer was evaluated in vivo using porcine liver, where coagulation necrosis was induced up to a depth of 20 mm in 120 s. B-mode and M-mode images displayed a hypoechoic region that agreed well with lesion depth observed by gross histology. These feasibility studies demonstrate that the dual-mode transducers had imaging performance that was sufficient to aid the guidance and monitoring of treatment, and could sustain high intensities to induce coagulation necrosis in vivo. 相似文献
98.
Homotopy Algorithm for Optimal Control Problems with a Second-order State Constraint 总被引:1,自引:0,他引:1
Audrey Hermant 《Applied Mathematics and Optimization》2010,61(1):85-127
This paper deals with optimal control problems with a regular second-order state constraint and a scalar control, satisfying
the strengthened Legendre-Clebsch condition. We study the stability of structure of stationary points. It is shown that under
a uniform strict complementarity assumption, boundary arcs are stable under sufficiently smooth perturbations of the data.
On the contrary, nonreducible touch points are not stable under perturbations. We show that under some reasonable conditions,
either a boundary arc or a second touch point may appear. Those results allow us to design an homotopy algorithm which automatically
detects the structure of the trajectory and initializes the shooting parameters associated with boundary arcs and touch points. 相似文献
99.
Lenize F. Maia Vanessa E. de Oliveira Maria E. R. Oliveira Felipe D. Reis Beatriz G. Fleury Howell G. M. Edwards Luiz F. C. de Oliveira 《Journal of Raman spectroscopy : JRS》2013,44(4):560-566
Polyenic pigments in octocorals have been investigated by Raman spectroscopy using laser excitation at 532, 785 and 1064 nm. The spectral features suggest the structural nature of carotenoids from Phyllogorgia dilatata, Leptogorgia punicea, Muricea atlantica, Carijoa riisei and conjugated polyenals from L. punicea, L. setacea, Muricea flamma and Renilla muelleri. The observed vibrational bands at ca. 1540–1520 ν1(C=C), 1159 ν2(C–C) and 1005 cm−1 ρ3(C–CH3) were assigned to carotenoids, whereas the identification of non‐methylated conjugated polyenals have been proposed due to two major Raman bands at ca. 1500 and 1120 cm‐1, assigned to ν(C=C) and ν(C–C), respectively. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
100.
In this article, we establish a bijection between the set of mutation classes of mutation-cyclic skew-symmetric integral 3 × 3-matrices and the set of triples of integers (a, b, c) such that 2 ≤ a ≤ b ≤ c and ab ≥ c. We also give an algorithm allowing to verify whether a matrix is mutation-cyclic or not. We prove that given a, b, the two cases depend on whether c is large enough or not. 相似文献