Conjugacy relationship between M-convex and L-convex functions in continuous variables

By extracting combinatorial structures in well-solved nonlinear combinatorial optimization problems, Murota (1996,1998) introduced the concepts of M-convexity and L-convexity to functions defined over the integer lattice. Recently, Murota–Shioura (2000, 2001) extended these concepts to polyhedral convex functions and quadratic functions in continuous variables. In this paper, we consider a further extension to more general convex functions defined over the real space, and provide a proof for the conjugacy relationship between general M-convex and L-convex functions.Mathematics Subject Classification (1991): 90C10, 90C25, 90C27, 90C35This work is supported by Grant-in-Aid of the Ministry of Education, Culture, Sports, Science and Technology of Japan     

Synthesis of Bioactive and Porous Organic-Inorganic Hybrids for Biomedical Applications

Bioactivity has been exhibited by a limited range of ceramics since the invention of Bioglass®. Recently, some bioactive polymeric organic-inorganic hybrids were introduced, including not only organically modified silicates (Ormosils) synthesized from polydimethylsiloxane (PDMS) and tetraethoxysilane but also those with gelatin and 3-glycidoxypropyl-tremethoxysilane. Preparation of the bulk and porous hybrids and their polymeric structures analyzed by Si NMR spectroscopy were presented. In vitro bioactivity or apatite deposition in a simulated body fluid of the Kokubo recipe were also described for those hybrids. Freeze-drying techniques introduced porosity (up to 90%) and pores extending in a preferred direction.     

Spurious Shell Closures in the Relativistic Mean Field Model

Following a previous systematic theoretical study of the ground-state properties of over 7000 nuclei from the proton drip line to the neutron drip line in the relativistic mean field model [Prog. Theor. Phys. 113 （2005） 785], which is in fair agreement with existing experimental data, we observe a few spurious shell closures, i.e. proton shell closures at Z = 58 and Z = 92. These spurious shell closures are found to persist in all the effective forces of the relativistic mean field model, e.g. TMA, NL3, PKDD and DD-ME2.     

Flow injection analysis of potassium using an all-solid-state potassium-selective electrode as a detector

The concentration of potassium was determined by a combination of flow injection analysis (FIA) with an all-solid-state potassium sensor detection. The all-solid-state potassium-selective electrode possessing long-term potential stability was fabricated by coating an electroactive polypyrrole/poly(4-styrenesulfonate) film electrode with a plasticized poly(vinyl chloride) membrane containing valinomycin. The simple FIA system developed in this laboratory demonstrated sensitivity identical to that in the batch system and achieved considerably rapid assay (150 samples h⁻¹). Analyses of soy sauce and control serum samples by this FIA system yielded results in good agreement with those obtained by conventional measurements.     

Creation of highly functional thin films using electrochemical nanotechnology

This overview describes the results of our recent study of the application of electrochemical nanotechnology to the fabrication of magnetic recording materials, interconnects in ultra-large-scale integrated (ULSI) devices, energy storage materials, and on-chip biosensors. It is important to note that electrochemical processes play significant roles in developing and fabrication such sophisticated materials and devices. In the field of magnetic recording, electrodeposition methods for preparing CoNiFe and CoFe soft magnetic thin films with a high saturation magnetic flux density were newly developed, and the significant issues for obtaining those films are highlighted. In the area of ULSI interconnects, we developed a technique using a self-assembled monolayer (SAM) for direct bonding of the interconnect layer to SiO2, and proposed a novel electroless deposition method for fabricating a diffusion barrier layer. In the field of batteries, electrodeposited SnNi alloy was proposed as a future anode material for Li batteries, and electrochemical MEMS processes were shown to be useful for fabricating micro-sized direct methanol fuel cells (DMFCs) as portable batteries for electronics applications. In the area of chemical sensors, we developed a new process for fabricating field effect transistors (FETs) modified with SAMs for on-chip biosensing applications.     

Dynamic covalent approach to [2]- and [3]roxtanes by utilizing a reversible thiol-disulfide interchange reaction

A dynamic covalent approach to disulfide-containing [2]- and [3]rotaxanes is described. Symmetrical dumbbell-shaped compounds with two secondary ammonium centers and a central located disulfide bond were synthesized as components of rotaxanes. The rotaxanes were synthesized from the dumbbell-shaped compounds and dibenzo-[24]crown-8 (DB24C8) with catalysis by benzenethiol. The yields of isolated rotaxanes reached about 90 % under optimized conditions. A kinetic study on the reaction forming [2]rotaxane 2 a and [3]rotaxane 3 a suggested a plausible reaction mechanism comprising several steps, including 1) initiation, 2) [2]rotaxane formation, and 3) [3]rotaxane formation. The whole reaction was found to be reversible in the presence of thiols, and thermodynamic control over product distribution was thus possible by varying the temperature, solvent, initial ratio of substrates, and concentration. The steric bulk of the end-capping groups had almost no influence on rotaxane yields, but the structure of the thiol was crucial for reaction rates. Amines and phosphines were also effective as catalysts. The structural characterization of the rotaxanes included an X-ray crystallographic study on [3]rotaxane 3 a.     

1-D cobalt(II) spin transition compound with strong interchain interaction: [Co(pyterpy)Cl(2)].X

Cobalt(II) compounds [Co(pyterpy)Cl(2)].MeOH (1.(MeOH)) and [Co(pyterpy)Cl(2)].2H(2)O (1.(2H(2)O)) were synthesized. The compound 1.(MeOH) forms the quasi 3-D networks by making pi-pi stacking between the 1-D chains. The methanol molecules from 1.(MeOH) can be removed by heating, and substituted by absorption of water molecules. The MeOH molecules in 1.(MeOH) are removed by heating at 410 K, and they are substituted by water molecules to form 1.(2H(2)O). 1.(2H(2)O) exhibits a S = (3)/(2) (HS) left arrow over right arrow S = (1)/(2) (LS) spin transition with a thermal hysteresis. We have succeeded in constructing a guest dependent 1-D spin-crossover cobalt(II) compound.     

Stereoselective synthesis of cis- and trans-2,3-disubstituted eight-membered medium-ring ethers based on Ireland-Claisen rearrangement of 3-alkoxy-2-propenyl glycolate esters and ring-closing olefin metathesis

A simple stereoselective synthesis of cis- and trans-2,3-disubstituted medium-sized cyclic ethers has been developed based on geometry-selective synthesis of 3-alkoxy-2-propenyl glycolate esters, Ireland-Claisen rearrangement of the glycolate esters, and ring-closing olefin metathesis.     

Determination of trace elements in sea water by inductively-coupled plasma emission spectrometry

Pb, Zn, Cd, Ni, Mn, Fe, V and Cu in sea water are determined by extraction of their complexes with sodium diethyldithiocarbamate into chloroform, decomposition of the chelates and inductively-coupled plasma emission spectrometry. When 1-l water samples are used, the lowest determinable concentrations are: 0.063 μg Mn l^-1, 0.13 μg Zn l^-1, 0.25 μg Cd l^-1, 0.25 μg Fe l^-1, 0.38 μg V l^-1, 0.5 μg Ni l^-1, 0.5 μg Cu l^-1, and 2.5 μg Pb l^-1. Above these levels, the relative standard deviations are better than 12% for the complete procedure.