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131.
Free axisymmetric vibrations of a stretched circular membrane are studied using a membrane theory consisting of a pair of non-linear partial differential equations coupled between the transverse and radial displacements of the membrane. A systematic perturbation method, in which the amplitude of the transverse displacement is taken as the perturbation parameter, is used to obtain periodic solutions of the non-linear equations. The initial membrane strain enters the problem as a parameter which is allowed to vary over a range of values. A case of self-resonance is encountered when the initial membrane strain approaches some critical values. This self-resonance case is also treated through an appropriate modification of the perturbation method. 相似文献
132.
Exact solutions in closed-form are presented for the dynamic response of an infinite elastic membrane to a suddenly applied, radially expanding ring load. 相似文献
133.
本工作是在35℃下测定对(艹孟)烷(p-Menthane)(即对位甲基异丙基环已烷)的~(13)C-NMR谱。由取代基参数,经验加和规律计算各碳化学位移数值,归属各谱峰位置。由积分值得知顺式、反式对(艹孟)烷含量之比。并根据权分法计算顺式对(艹孟)烷中构象1与构象2分子数之比。结果表明顺式对(艹孟)烷中异丙基处于平展位置的构象2为主。 相似文献
134.
Stability properties of the solution set of generalized inequality systems with locally Lipschitz functions are obtained under a regularity condition on the generalized Jacobian and the Clarke tangent cone. From these results, we derive sufficient conditions for the optimal value function in a nonsmooth optimization problem to be continuous or locally Lipschitz at a given parameter. 相似文献
135.
稀土添加剂对镍,铜刷镀层质量的影响 总被引:2,自引:0,他引:2
通过在刷镀镀液中加入稀土添加剂,研究稀土对刷镀层质量的影响。实验结果表明,稀土起到平整、光亮、细化镀层晶粒、减少镀层应力的作用,并增强镀层结合力,提高镀层的耐磨性、耐蚀性。 相似文献
136.
Ya-Hew Yen 《Tetrahedron letters》2004,45(44):8137-8140
Because of their negligible vapor pressures and large dipoles, ionic liquids are excellent media for microwave-accelerated organic reactions. Using low-power microwave irradiation in the new [bdmim][PF6] ionic liquid with temperature controlled at 60 °C, a three-step synthesis (Pictet-Spengler, Schotten-Baumann, and intramolecular ester amidation) of tetrahydro-β-carbolinediketopiperazines starting from tryptophan methyl ester was achieved with good isolated yields (49-69%) in only 5 min. 相似文献
137.
Tsu-Chiang Yen Jer-Wei Chang Jenn-Ming Lin Rong-Jyh Chen 《Optics Communications》1998,150(1-6):158-162
This work examines the feasibility of using incoherent optical feedback to generate high-frequency optical signals in a semiconductor laser. At a roundtrip feedback distance of 30 cm, a signal appears at around 1 GHz while the laser output is kept in single longitudinal mode and single polarization. The proposed method does not use any external modulation or saturable absorber. Some of the signal's properties are discussed as well. 相似文献
138.
W. Bartel D. Cords P. Dittman R. Eichler R. Felst D. Haidt S. Kawabata H. Krehbiel B. Naroska L.H. ONeill P. Steffen W.L. Yen E. Elsen M. Helm A. Petersen P. Warming G. Weber H. Drumm C. Yanagisawa 《Physics letters. [Part B]》1981,99(3):281-286
The processes e+e? → e+e? and μ+μ? have been studied at PETRA using the JADE detector. The data, which were collected at s-values of up to 1300 GeV2 have been analysed in terms of an electro-weak extension of QED to obtain values for the weak vector and axial vector couplings in the lepton sector. The values obtained agree with the predictions of the standard Salam-Weinberg model and the data are further analysed in terms of this model to obtain the limits 0.10 < sin2?w < 0.40 (68% CL). The mass of the neutral weak gauge boson is deduced to be greater than 51 GeV/c2. 相似文献
139.
H.W. Yen M. Nakamura E. Garmire S. Somekh A. Yariv H.L. Garvin 《Optics Communications》1973,9(1):35-37
Surface corrugations with a period of 0.115 μ were ion-milled on GaAs dielectric waveguides. Laser action was observed under optical pumping. Single mode as well as multimode oscillation was obtained under different pumping conditions. 相似文献
140.
A shell-model calculation of the N = 51, 39 ≦ Z ≦ 42 nuclei is presented. The 88Sr nucleus is assumed to be an inert closed core. The extra-core protons are restricted to the (, ) configurations, and the active neutron is allowed to occupy the , , and orbits. The proton-proton effective interaction is directly taken from the previous analysis on the energy levels for N = 50 isotones by Ball et al. The proton-neutron effective interaction is assumed to be of the form of the surface δ-interaction. The energy spectra are calculated from a least-squares fit to the experimental data, varying the T = 0 and T = 1 strengths of the surface δ-interaction. Spectroscopic factors, E2 transition rates and two-body matrix elements are also calculated and compared with the observed values and the previous theoretical results. 相似文献