Experimental investigation of highly excited states of the 5,6He and 5,6Li nuclei in the (6Li, 7Be) and (6Li, 7Li) one-nucleon pickup reactions

The (⁶Li, ⁷Be) and (⁶Li, ⁷Li) reactions on ⁶Li and ⁷Li nuclei were investigated in the angular interval 0°–20° in the laboratory system at a ⁶Li energy of 93 MeV. In addition to low-lying states of the ^5,6He and ^5,6Li nuclei, broad structures were observed near the t(³He)+d and t(³He)+t thresholds at the excitation energies of 16.75 (3/2⁺) and ～20 MeV (for ⁵He), 16.66 (3/2⁺) and ～20 MeV (⁵Li), 14.0 and 25 MeV (⁶He), and ～20 MeV (⁶Li). The angular distributions measured in the ⁷Li(⁶Li, ⁷Be)⁶He reaction for transitions to the ground state (0⁺) and excited states at E _x=1.8 MeV (2⁺) and 14.0 MeV of the ⁶He nucleus were analyzed by the finite-range distorted-wave method assuming the 1p-and 1s-proton pickup mechanism. The (⁶Li, ⁷Be) and (⁶Li, ⁷Li) reactions were shown to proceed predominantly through the one-step pickup mechanism, and the broad structures observed at high excitation energies are considered as quasimolecular states of the t(³He)+d and t(³He)+t types.     

卡尔曼滤波紫外光度法同时测定酱油、食醋中的山梨酸和苯甲酸

在酸性条件下，采用乙酸乙酯萃取、Na2HPO4溶液反萃取分离酱汪、食醋中的山梨酸、苯甲酸，卡尔曼滤波法计算结果，并与比值导数波谱法进行比较。结果表明，卡尔曼滤波法较地数波谱法有较高准确度和精密度，并能监测干扰物质存在与否。用于实际样品分析有更高的可靠性。     

Investigation of metal-containing carbon nanostructures prepared from functional polymers

Metal-containing carbon nanostructures are prepared by heating poly(vinyl alcohol) in mineral media with a lamellar structure at a temperature below 300°C. It is demonstrated that three possible types of nanostructures can be formed, namely, multilayer carbon nanotubes, spherical carbon nanoparticles, and finely crystalline carbon structures. According to the data of transmission electron microscopy, the nanotube size falls in the range from 50 to 300 nm and the nanotubes themselves have a stranded structure.     

Reaction Mechanism Investigation Using Vibrational Mode Analysis for the Multichannel Reaction of CH_3O+CO

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｍｅｔｈｏｘｙｒａｄｉｃａｌ (ＣＨ3Ｏ)ｉｓａｎｉｍｐｏｒｔａｎｔｉｎｔｅｒ ｍｅｄｉａｔｅｉｎｔｈｅｐｈｏｔｏｃｈｅｍｉｃａｌｏｘｉｄａｔｉｏｎｏｆｈｙｄｒｏｃａｒｂｏｎｓｉｎｔｈｅａｔｍｏｓｐｈｅｒｅ ,1 3ａｎｄｐｌａｙｓａｓｉｇｎｉｆｉｃａｎｔｒｏｌｅｉｎｔｒａｎｓ ｆｏｒｍｉｎｇｎｉｔｒｉｃｏｘｉｄｅｔｏｎｉｔｒｏｇｅｎｄｉｏｘｉｄｅ .4 Ｓｉｍｉｌａｒｌｙ ,ｔｈｅｒｅａｃｔｉｏｎｍｅｃｈａｎｉｓｍｓｏｆｈｙｄｒｏｘｙｌａｎｄｃａｒｂｏｎｍｏｎｏｘｉｄｅ5,6ａｎｄｏ…     

Vertical variability of sound fields in a coastal wedge

The results of measuring the vertical variability of sound fields are presented for a coastal wedge off the Pacific shelf of the Kamchatka peninsula. It is shown that the vertical radius of sound field correlation can reach ～30 m for frequencies within 600–800 Hz. The scatter of the specific parameters of the variability is in rather wide limits depending on the location of a vertical chain of receiving hydrophones, the hydrological conditions, the azimuth angle of the sound source, and the relief and bottom structure of the coastal wedge.     

Spontaneous polarization and nonlinear susceptibility in various protonated HxLi1−x NbO3 phases

A change in the spontaneous polarization and the nonlinear susceptibility in H: LiNbO₃ waveguides is calculated from experimental data for the shift of the fundamental absorption for variously polarized rays and from IR reflection data in the range of NbO₆ octahedron vibrations. It is shown that taking into account the lattice disorder provides good agreement between the theory and experiment.     

Conductivity and field and current distributions in a two-component system composed of regular triangles

The problem of the effective conductivity and the distributions of a field and currents is analyzed in a regular two-component system composed of regular triangles. An efficient solution method is developed that admits a generalization to multicomponent systems.     

On the contribution of three-body forces to Nd interaction at intermediate energies

Available data on large-angle nucleon-deuteron elastic scattering Nd→dN below the pion threshold give a signal for three-body forces. The problem exists of the separation of possible subtle aspects of these forces from off-shell effects in two-nucleon potentials. By considering the main mechanisms of the process Nd→dN, we show qualitatively that in the quasi-binary reaction N+d→(NN)+N with the final spin singlet nucleon-nucleon pair in the S-state, the relative contribution of the three-nucleon forces differs substantially from the elastic channel. It gives a new testing basis for the problem in question.     

Stability of the Lipschitz extension property under metric transforms

We show that the linear and nonlinear Lipschitz extension properties of a metric space are not changed when the original metric is replaced by a new metric obtained by composition with an arbitrary concave function. Submitted: January 2001, Revised: February 2001.