Conductance asymmetry of a slot gate Si‐MOSFET in a strong parallel magnetic field

We report measurements on a Si‐MOSFET sample with a slot in the upper gate, allowing for different electron densities n_1,2 across the slot. The dynamic longitudinal resistance was measured by the standard lock‐in technique, while maintaining a large DC current through the source‐drain channel. We find that the conductance of the sample in a strong parallel magnetic field is asymmetric with respect to the DC current direction. This asymmetry increases with magnetic field. The results are interpreted in terms of electron spin accumulation or depletion near the slot.     

Kinetics of α-olefin metathesis over the heterogeneous catalytic system (MoOCl<Subscript>4</Subscript>/SiO<Subscript>2</Subscript>)-SnMe<Subscript>4</Subscript>

The kinetics of 1-hexene and 1-octene metathesis over the (MoOC_l4/SiO₂)-SnMe₄ catalytic system at 27 and 50°C has been investigated. The rate constants of the forward and reverse reactions and the catalyst deactivation constants have been measured. The number of active sites has been determined to be 10–13 mol % of the total number of molybdenum atoms.     

Analysis of Metrological Provision Problems of a Test Stand for Testing Radio-Electronic Products for Resistance to Irradiation with High-Energy Heavy Ions

Physics of Particles and Nuclei Letters - The problems of the metrological certification of beams of high-energy heavy charged particles (HCPs) and protons that will be used in the study—as...     

Dipole moments,molar kerr constants,and three-dimensional structure of some 4,5-dihydro-1, 3,5-dithiazines

The three-dimensional structure of some 4,5-dihydro-1,3,5-dithiazine derivatives was investigated by means of dipole moments and the Kerr effect. The presence of equilibrium boat and chair forms in the conformational mixture is proposed for the 2,4,6-trimethyl and 2,4,-5, 6-tetramethyl derivatives. Energy data that confirm the possibility of anomalous conformations are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 321–324, March, 1972.     

Reaction of dibenzylphosphinous acid with formic acid esters

Summary The reaction of dibenzylphosphinous acid with formic acid esters was studied in the presence of sodium. Here we obtained dibenzylmethylolphosphine oxide and the enol form of the phenylalkoxybenzylphosphorylacetaldehyde.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1085–1088, June, 1965     

Neutron activation analysis for determination of trace elements in sediments in the Sea of Galilee,Israel

The feasibility of applying both thermal and epithermal neutron activation analysis for simultaneous determinations of elemental composition in sediments, collected from the Sea of Galilee (Kineret Lake), Israel, during 1988–1993, was experimentally investigated. In the present work, the concentrations of 30 elements (Al, Ba, Br, Ca, Ce, Co, Cs, Cr, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sc, Si, Sr, Ta, Tb, Th, Ti, U, V, Yb and Zn) in sediments were determined. The validity of the method was checked by analyzing the U.S. NBS Standard Reference Material SRM-1633a; the elemental content found agreed well with the published certified data. Aluminium was determined by reactor neutron activation analysis (RNAA) taking into account the contribution of silicon to the total²⁸Al activity by the²⁸Si(n,p)²⁸Al reaction. Measurements of irradiated mixtures of Si and Al showed that the dependence of log SiAl mass ratio vs. log cadmium ratio (R _Cd) of²⁸Al is almost linear. The data can be analyzed more accurately by a parabolic correlation (log Si:Al mass ratio vs logR _Cd). The concentrations of fission radionuclide¹³⁷Cs, an activation radionuclide¹³⁴Cs (derived from Chernobyl accident) and the naturally occuring radionuclides⁴⁰K,²²⁶Ra and²³²Th in sediments were also measured by -ray spectrometry using Marinelli (Reentrant) Beaker-Sample Containers.     

Kinetics of α-olefin metathesis on binary and ternary catalytic systems based on MoCl<Subscript>5</Subscript>/SiO<Subscript>2</Subscript>: Determination of the number of active centers and the mechanisms of their formation,deactivation, and reactivation

The kinetics of α-olefin metathesis in the presence of binary (MoCl₅/SiO₂-Me₄Sn) and ternary catalytic systems (MoCl₅/SiO₂-Me₄Sn-ECl₄, E = Si or Ge) was studied. It was found that reactivation in the course of metathesis occurred on the addition of a third component (silicon tetrachloride or germanium tetrachloride in combination with tetramethyltin) to a partially deactivated catalyst. The number of active centers was determined (5–6% of the amount of Mo), and the mechanisms of formation, deactivation, and reactivation were proposed for the binary and ternary catalytic systems. The roles of the individual components of the catalytic systems were revealed.     

Nonequilibrium state of grain boundaries and spontaneous grain-boundary slippage in bicrystals

Variables (order parameters) that are related to plastic deformation sites and complement the local densities of grain-boundary defects are separated out in a bicrystal being deformed under creep. By solving an evolutionary equation for the order parameters, it is shown that the nonuniformity and periodicity of spontaneous grain-boundary slippage in bicrystals and an increase in the grain-boundary strain rate under the conditions of boundary-lattice dislocation interaction may be attributed to the occurrence of local nonequilibrium regions (autosolitons).