共查询到20条相似文献,搜索用时 31 毫秒
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利用8Li次级束测量了质心系能量7.8 MeV2H(8Li, 9Li)1H反应的角分布,导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数. We have measured the angular distribution of 2H(8Li,9Li)1H at Ecm= 7.8 MeV and deduced the astrophysical S factor of 8Li(d, p)9Li reaction as well as the Asymptotic Normalization Coefficient (ANC) for 9Li → 8Li+n virtual decay. 相似文献
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Z. O. Beslaneeva T. M. Taova Kh. B. Khokonov 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(8):815-819
The dimensional dependence of the angle of solid surface wetting by a small drop on the latter’s size R and radius of the wetting outline r is considered. Numerical values of specific linear energy γ?(r) and line tension σ r (r) of the wetting outline are calculated for a nanometer tin drop-substrate surface-aluminum film system. It is shown that wetting angle θ(R,r) in the drop-substrate surface system increases as the wetting outline’s radius decreases. 相似文献
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《Nuclear Physics A》1998,636(2):240-246
We calculate several “size-like” 8B observables within the microscopic three-cluster model and study their potential constraints on the zero-energy astrophysical S17(0) factor of the 7Be(p,γ)8B reaction. We find within our three-cluster model that a simultaneous reproduction of the experimental data for the 8B radius and quadrupole moment and of the 8B8Li Coulomb displacement energy implies S17(0) = (23–25) eV b. 相似文献
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Duan Yiwu 《中国物理C(英文版)》1995,19(1):59-63
A new effective interaction between a neutron and the 9Li core is introduced, and based on the n+n+9Li model, a variational calculation on the neutron rich nucleus 11Li is completed. The one-body density, formfactor and shapedensity are investigated, The RMS radius and the binding energy are also calculated and are in good agreement with the experimental data. 相似文献
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随着手机市场对高像素手机镜头的需求增大,利用Zemax光学设计软件设计一款大相对孔径800万像素的广角镜头。该镜头由1片非球面玻璃镜片,3片非球面塑料镜片,1片滤光镜片和1片保护玻璃构成。镜头光圈值F为2.45,视场角2ω为68°,焦距为4.25 mm,后工作距离为0.5 mm。采用APTINA公司的MT9E013型号800万像素传感器,最大分辨率为3 264×2 448,最小像素为1.4 μm。设计结果显示:各视场的均方根差(RMS)半径小于1.4 μm,在奈奎斯特频率1/2处大多数视场的MTF值均大于0.5,畸变小于2 %,TV畸变小于0.3 %。 相似文献
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P. Heitjans B. Bader H. -J. Stöckmann K. Dörr G. Kiese H. Ackermann P. Freiländer W. Müller-Warmuth K. Meise-Gresch 《Hyperfine Interactions》1983,16(1-4):597-600
Nuclear spin-lattice relaxation in Li20·2Si02 glass below 200 K has been studied using the asymmetric Β-decay radiation of polarized8Li (T1/2=0.Bs) nuclei produced by capture of polarized neutrons. Transients of the8Li polarization follow an exp(?√E/T1) law. The dependence of the spin-lattice relaxation rate ⊥¯1 1 on temperature T and magnetic field B can roughly be described by T¯1 1~T/B. The interpretation is based on the assumption that for8Li, contrary to7Li in the same glass, spin-diffusion is absent and that each probe nucleus is coupled by quadrupolar interaction to an individual distribution of nearby centres typical of glasses. The fluctuation of these centres causing relaxation may be induced by either a multi-phonon or a thermally activated motional process. 相似文献
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F. Strieder L. Gialanella U. Greife C. Rolfs S. Schmidt W. H. Schulte H. P. Trautvetter D. Zahnow F. Terrasi L. Campajola A. D’Onofrio V. Roca M. Romano M. Romoli 《Zeitschrift für Physik A Hadrons and Nuclei》1974,355(2):209-218
The absolute cross section σ of the d(7Li, p)8Li reaction near the Ecm = 0.61 MeV resonance has been measured using a 7Li ion beam and a windowless gas target system filled with D2 gas. The proton yield of the reaction and the β-delayed α-activity of the residual nuclides 8Li were observed both concurrently with the elastic scattering yield, relating σ to the Rutherford scattering cross section σR. The resulting values, σ (from p) = 143.6 ± 8.9 mb and σ (from 8Li) = 151 ± 20 mb, lead to a weighted mean value of σ = 153 ± 6 mb (χ2 = 2.26) including all available values and σ = 146 ± 5 mb (χ2 = 0.05) removing some values from the data set. The consequences for the expected flux of high-energy solar neutrinos are discussed. 相似文献
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From the analysis of Monte Carlo simulations of a binary Lennard-Jones mixture in the coexistence region, we provide evidence that the curvature dependence of the interfacial tension can be described by a simple theoretical function σ(R)ξ(2)=C(1)/[1+C(2)(ξ/R)(2)], where ξ is the correlation length and R is the droplet radius. The universal constants C(1) and C(2) are estimated. In the model, a Tolman length is strictly absent, but, since its critical behavior is believed to be much weaker than ξ, we argue that it only provides a correction to scaling and does not affect the leading critical behavior, which should be described by the above function for any system in the Ising universality class. The large value of C(2)?32 implies that conventional nucleation theory becomes inaccurate even for a significantly large droplet radius. 相似文献
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Yu. B. Gurov L. Yu. Korotkova S. V. Lapushkin D. S. Markov V. G. Sandukovsky B. A. Chernyshev T. D. Shchurenkova 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(4):366-369
Highly excited states of the 8Li isotope are sought in absorption reactions of π? mesons stopped by 10,11B isotopes. The ground and three excited states of the 8Li isotope are observed in inclusive measurements of reactions 10B(π?, d)X and 11B(π?, t)X. The states with excitation energies E x ≈ 8.7 and 10.1 MeV are observed for the first time in correlation measurements of reactions 10B(π?, dt)X and 11B(π?, tt)X. 相似文献
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Wuosmaa AH Rehm KE Greene JP Henderson DJ Janssens RV Jiang CL Jisonna L Moore EF Pardo RC Paul M Peterson D Pieper SC Savard G Schiffer JP Segel RE Sinha S Tang X Wiringa RB 《Physical review letters》2005,94(8):082502
We have studied the 2H(8Li,p)9Li reaction to obtain information on the spins, parities, and single-neutron spectroscopic factors for states in 9Li, using a radioactive 8Li beam. The deduced properties of the lowest three states are compared to the predictions of a number of calculations for the structure of 9Li. The results of ab initio quantum Monte Carlo calculations are in good agreement with the observed properties. 相似文献
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The angular distribution of recoil 8Li in the reaction 9Be(π-, πN) 8Li at 1.0 GeV/c was measured with a solid state track detector. The experimental results seem consistent with the assumption that the heavy-fragment knockout process is dominant, but other mechanisms are also required. 相似文献
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The ^8Li(p, d)^7 Li reaction plays an important role in the inhomogeneous Big Bang nucleosynthesis and in the seed-nuclide production phase for the r-process. For the first time, its angular distribution at backward angles was measured in inverse kinematics at Ec.m.=4.0 MeV by using an ^8Li secondary beam. The result of measurement includes the contributions of ^8Li(p, d0)^7Li and ^8Li(p, d1)^7Li^*. The ^8Li(p, d0)^7Li component is estimated to be 40%-58% in the mixture angular distribution by analysing the measured result. 相似文献
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We summarize in this article an extensive experimental and theoretical effort carried out to understand the behavior of a single ball when rolling down a bumpy surface. This may appear to be a simple problem but in fact is one that displays a rich variety of different behaviors which allow us to understand better dissipative systems such as granular media. Studies performed previously have shown that the motion of the single ball on the rough surface can be characterized by three different dynamic regimes according to the different values of the two control parameters, the inclination angle theta and the ratio Phi=R/r, where R is the radius of the rolling ball and r the radius of the glass beads which make up the rough surface. The three regimes are a decelerated regime A, a stationary regime B, characterized by a constant average velocity and a jumping regime C. This result was found to be independent of the composition of the rolling ball and the rough surface. It has been demonstrated that regime B is characterized by a viscous-like friction force that appears for specific parameter values. This friction force can be explained by a model whose central ingredient is the geometry of the surface. The trajectory of the ball in regime B can be pictured as a driven random walk motion where the fluctuations of the local velocities are due to collisions of the moving sphere and the surface grains. A detailed analysis of diffusive properties of the motion is discussed. (c) 1999 American Institute of Physics. 相似文献
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We investigate the size distribution of electron-hole drops collected in an illuminated p-n junction. The observed size distribution are of complex nature with several pronounced peaks revealing drop sizes of about 108 electron-hole pairs (drop radius μm). An observed suppression of drop formation at low temperatures indicate that supersaturation effect are present. 相似文献
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B. Bader P. Heitjans H. Ackermann P. Freiländer F. Fujara G. Kiese H. -J. Stöckmann C. van der Marel 《Hyperfine Interactions》1983,16(1-4):593-596
Polarized8Li nuclei were produced in a Li3N single crystal by irradiation with polarized neutrons, Β-ray detected NMR signals and spin-lattice relaxation of8Li were observed between B and 300 K. In Li3N there are two non-equivalent Li sites. The corresponding two quadrupole split NMR spectra could be resolved. From the measured relaxation rates activation enthalpies for two diffusion processes were deduced. 相似文献
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T. Sumikama T. Iwakoshi T. Nagatomo M. Ogura Y. Nakashima H. Fujiwara K. Matsuta T. Minamisono M. Mihara M. Fukuda K. Minamisono T. Yamaguchi 《Hyperfine Interactions》2004,159(1-4):281-284
The pure nuclear spin alignments of 8Li and 8B were produced from the nuclear spin polarization applying the β-NMR method. The alignment correlation terms in the β-ray angular distribution were observed to test the G parity conservation in the nuclear β decay. 相似文献