In the primary somatosensory cortex (SI), the body surface is mapped in a relatively continuous fashion, with adjacent body regions represented in adjacent cortical domains. In contrast, somatosensory maps found in regions of the cerebellar hemispheres, which are influenced by the SI through a monosynaptic link in the pontine nuclei, are discontinuous ("fractured") in organization. To elucidate...

Vibrational spectra of neutral silicon clusters Si(n), in the size range of n = 6-10 and for n = 15, have been measured in the gas phase by two fundamentally different IR spectroscopic methods. Silicon clusters composed of 8, 9, and 15 atoms have been studied by IR multiple photon dissociation spectroscopy of a cluster-xenon complex, while clusters containing 6, 7, 9, and 10 atoms have been stu...

Recent work in high-performance computing has shifted attention to PC clusters. For PC-clusters, member nodes are independent computers connected by generalpurpose networks. The latency of data communications is long and load balancing among the nodes becomes a critical issue. We introduce a new model for program development on PC clusters, namely the SuperProgramming Model (SPM) to address thi...

A transferable tight-binding parametrization of the Ni–Si interactions, from small binary Ni Si clusters to bulk NiSi , m n 2 Ž . is presented within a minimal parameter basis. The data base for fitting the parameters is obtained from i ab initio results for the NiSi dimer obtained using the density functional method and the single, double and triple coupled clusters method, Ž . and ii band str...

Polymorphous Si is a nanostructured form of hydrogenated amorphous Si that contains a small fraction of Si nanocrystals or clusters. Its thermally induced transformations such as relaxation, dehydrogenation, and crystallization have been studied by calorimetry and evolved gas analysis as a complementary technique. The observed behavior has been compared to that of conventional hydrogenated amor...

Solute clustering and partitioning behavior in the early crystallization stage of an Fe73.5Si13.5B9Nb3Cu1 amorphous alloy have been studied by employing a three dimensional atom probe (3DAP) and a high resolution electron microscope (HREM). 3DAP results have clearly shown that Cu atom clusters are present in the amorphous state after annealing below the crystallization temperature. The density ...

The Cp*Si(+) cation acts as a stoichiometric source of silicon in the reaction with the disilenide Tip(2)Si=Si(Tip)Li (Tip = 2,4,6-(i)Pr(3)C(6)H(2)) affording known neutral unsaturated silicon clusters. It thereby provides a conceptually different approach to this novel class of compounds. The proposed mechanism involves a Cp*-substituted cyclotrisilene in which Cp*(-) acts as a leaving group u...

The adsorption of atomic hydrogen on the reconstructed Si ( lOO)-2 x I surface is studied using embedded Si clusters as models of an extended Si surface. Analytic gradients of generalized valence bond (GVB) wavefunctions are used to predict equilibrium structures and harmonic vibrational frequencies; the correlation-consistent configuration interaction (CCCI) method is used to calculate heats o...

Theoretical assessment of the protonation reaction in the activation of propene on hydroxylated Mo(VI) and W(VI) metathesis catalysts is presented in this paper using the density functional theory calculations and five support clusters varying from simple SiO4H3 clusters to a large Si4O13H9 cluster. The bond distances and thermochemical...