Heating and quenching of metastable superconducting compounds with a plasma jet

Superconducting compounds, such as cubic -MoC_1–x, cubic -WC_1–x, hexagonal MoB₂, and cubic -TaN, which are metastable at room temperature, have been formed by heating and quenching of their respective equilibrium phases, such as hexagonal -MoC_1–x, hexagonal WC, rhombohedral Mo₂B₅, and hexagonal -TaN in a plasma jet. From calculations based on a simple model, the quenching rate of particles has been estimated to be 10⁵ deg s^–1.     

A structure analysis of Ag-adsorbed Si(111) surface by LEED/CMTA

The Ag induced superstructures on the Si(111) surface have been studied by low energy electron diffraction constant momentum transfer averaging (LEED/CMTA) technique. The vertical displacements of the atoms are determined from the analysis of the specularly reflected (00) beam intensities. Unexpected behavior of the Ag atoms is clarified: For the √3 × √3-Ag surface it is verified that the Ag atoms are embedded in the first double layer of Si, leading to a considerable rearrangement of the substrate. In contrast, for the 3 × 1-Ag surface, the Ag atoms are riding on the Si surface and the reconstruction of the substrate is small.     

Dendrimer N-heterocyclic carbene complexes with rhodium(I) at the core

Novel dendrimer N-heterocyclic carbene complexes with rhodium(I) located at the core were synthesized, and a positive dendrimer effect was found in the hydrosilylation of ketones catalyzed by them.     

On first passage time structure of random walks

For continuous time birth-death processes on {0,1,2,…}, the first passage time T⁺_n from n to n + 1 is always a mixture of (n + 1) independent exponential random variables. Furthermore, the first passage time T_0,n+1 from 0 to (n + 1) is always a sum of (n + 1) independent exponential random variables. The discrete time analogue, however, does not necessarily hold in spite of structural similarities. In this paper, some necessary and sufficient conditions are established under which T⁺_n and T_0,n+1 for discrete time birth-death chains become a mixture and a sum, respectively, of (n + 1) independent geometric random variables on {1,2,…};. The results are further extended to conditional first passage times.     

A glycine receptor is involved in the organization of swimming movements in an invertebrate chordate

Background  

Rhythmic motor patterns for locomotion in vertebrates are generated in spinal cord neural networks known as spinal Central Pattern Generators (CPGs). A key element in pattern generation is the role of glycinergic synaptic transmission by interneurons that cross the cord midline and inhibit contralaterally-located excitatory neurons. The glycinergic inhibitory drive permits alternating and precisely timed motor output during locomotion such as walking or swimming. To understand better the evolution of this system we examined the physiology of the neural network controlling swimming in an invertebrate chordate relative of vertebrates, the ascidian larva Ciona intestinalis.