Nickel Nanoparticles Formation from Solution Plasma Using Edge-Shielded Electrode

Because of the easy massproduction, synthesis of metallic nanoparticles from a solution plasma is an attractive method. However, a solution plasma produces a highly inhomogeneous electric field via transition to full-plasma, and the products are partially oxidized and agglomerated, with a wide size-distribution. Here, we show a simple method of suppressing oxidation of products. An electrode tip was shield by a glass tube and a voltage of up to 180 V was applied with the electrolyte of 0.1 M NaOH solution. Significantly, the edge-shield was quite effective for maintaining partially glow discharge. The results were (1) surface temperature of the electrode less than 100°C, (2) main phase of metallic nickel evaluated by XRD, and (3) nanoparticles of an average size of 220 nm. These results showed the potential for an application to the production of nanoparticles.     

One-pot approach to 2,3-disubstituted-2,3-dihydro-4-quinolones from 2-alkynylbenzamides

Concise and efficient syntheses of various trans-2,3-disubstituted-2,3-dihydro-4-quinolones have been achieved via tandem Hofmann-type rearrangement of 2-alkynylbenzamides, nucleophilic addition of alcohols to the isocyanate intermediates, intermolecular [2+2]-cycloaddition with carbon-carbon triple bonds and aldehydes, and intramolecular aminocyclization of nitrogen of carbamates to the α,β-unsaturated ketones.     

Structures and photovoltaic properties of copper oxides/fullerene solar cells

Copper oxide (CuO_x) thin films were produced by spin-coating and electrodeposition methods, and their microstructures and photovoltaic properties were investigated. Thin film solar cells based on the Cu₂O/C₆₀ and CuO/C₆₀ heterojunction or bulk heterojunction structures were fabricated on F-doped or In-doped SnO₂, which showed photovoltaic activity under air mass 1.5 simulated sunlight conditions. Microstructures of the CuO_x thin films were examined by X-ray diffraction and transmission electron microscopy, which indicated the presence of Cu₂O and CuO nanoparticles. The energy levels of the present solar cells were also discussed.     

Sufficient conditions for open manifolds to be diffeomorphic to Euclidean spaces

Let M be a complete non-compact connected Riemannian n-dimensional manifold. We first prove that, for any fixed point p∈M, the radial Ricci curvature of M at p is bounded from below by the radial curvature function of some non-compact n-dimensional model. Moreover, we then prove, without the pointed Gromov-Hausdorff convergence theory, that, if model volume growth is sufficiently close to 1, then M is diffeomorphic to Euclidean n-dimensional space. Hence, our main theorem has various advantages of the Cheeger-Colding diffeomorphism theorem via the Euclidean volume growth. Our main theorem also contains a result of do Carmo and Changyu as a special case.     

Measurement of the W+ W- cross section in sqrt(s) = 7 TeV pp collisions with ATLAS

This Letter presents a measurement of the W+ W- production cross section in sqrt(s) = 7 TeV pp collisions by the ATLAS experiment, using 34 pb(-1) of integrated luminosity produced by the Large Hadron Collider at CERN. Selecting events with two isolated leptons, each either an electron or a muon, 8 candidate events are observed with an expected background of 1.7 ± 0.6 events. The measured cross section is 41(-16)(+20)(stat) ± 5(syst)±1(lumi) pb, which is consistent with the standard model prediction of 44 ± 3 pb calculated at next-to-leading order in QCD.     

Ultrabroad near-infrared photoluminescence from ionic liquids containing subvalent bismuth

We have shown that Lewis-acidic halogenoaluminate ionic liquid (IL) containing subvalent bismuth can be used as a near-IR (NIR) luminescent material. Raman and absorption spectra evidence the coexistence of Bi(5)(3+) and Bi(+) in the liquid. The Bi(5)(3+) and Bi(+) emitters, stabilized by this Lewis-acidic liquid, demonstrate ultrabroad NIR photoluminescence with a lifetime of around 1 μs. We envisage that the bismuth activated ILs would not only enrich the well-established spectrum of soft luminescent materials but also might promote the design of novel photonic materials activated by other p-block elements.     

Reflection-type wavelength-selective infrared emitter using surface plasmon polaritons

A reflection-type wavelength selective IR emitter is proposed. Surface plasmon polaritons (SPPs), which occur on metallic grating at a wavelength near the pitch of the structure, are used for controlling thermal emissions. An emission peak at a wavelength nearly equal to the period of the grating is observed. As for the other wavelength, which cannot couple with the SPPs, the IR power is confined by the reflectors including the grating. The emitter temperature increases, consuming lower input power with higher power efficiency.     

Surfactant-free solution-dispersible Si nanocrystals surface modification by impurity control

Si nanocrystals (Si-NCs) dispersible in polar liquid without surface functionalization by organic molecules have been realized by simultaneously doping n and p type impurities. We show that the codoped Si-NCs are stable in methanol for more than five months, while intrinsic Si-NCs prepared by the same procedure form large agglomerates. The different behavior of the intrinsic and codoped Si-NCs in solutions suggests that doped impurities exist on the surface of Si-NCs and the surface potential is large enough to prevent the agglomeration. The colloidal solution of codoped Si-NCs exhibits broad photoluminescence with the maximum in the near infrared range (1.1-1.3?eV).     

Optical fiber-based photomechanical gene transfer system for in vivo application

We developed an optical-fiber-based photomechanical gene transfer system for endoscopic or catheter-based application. A fiber tip with a laser-absorbing film covered with a transparent plastic disk for plasma confinement was attached to a quartz fiber; the film was irradiated with nanosecond laser pulses transmitted through the fiber to generate photomechanical waves (PMWs). Characteristics of PMWs emitted from the fiber tip were examined to confirm the necessary conditions for gene transfer. We then attempted to transfer reporter genes to the rat skin as a test tissue in vivo with the fiber system, and the results showed significantly high protein levels and spatially selective pinpoint gene expressions in the tissue.     

Constant-load delayed fracture test of atmospherically corroded high strength steels

Constant load tests of circumferentially notched round bar specimens of high strength steels after cyclic corrosion test and outdoor exposure have been performed to demonstrate that delayed fracture occurs when the hydrogen content from the environment, H_E, exceeds the critical hydrogen content for delayed fracture, H_C. During the constant load tests the humidity around the specimen was increased in stepwise manner to increase hydrogen entry. After fracture the specimen was kept at the humidity long enough to homogenize hydrogen in the specimen and to obtain more quantitative hydrogen content by thermal desorption analysis. H_E of the fractured specimens was higher than H_C, and H_E of the specimens not fractured was lower than H_C. This result confirms that the balance between H_C and H_E determines the occurrence of delayed fracture and that hydrogen-content-based evaluation of susceptibility to delayed fracture is reasonable. To certify the increase of H_E with increase in humidity, electrochemical hydrogen permeation test was carried out. The hydrogen permeation current density was increased especially at 98%RH. Enhancement of hydrogen entry with increase in CCT number was also shown by the test.