Determination of Tiny Scatterer#x0027;s Shape by Light Scattering Tomography

We have developed a new method of recognizing the shape of tiny light scatterers by matrix calculation (conjugate gradient method) using the wave field on the objective lens. We describe simulation results for scatterers of about 100 nm and show that they accurately produce the scatterer shape.     

(S)‐4‐Benzyl‐3‐[(R)‐4,4,4‐tri­fluoro‐3‐(4‐methoxy­phenyl)­butanoyl]‐1,3‐oxazolidin‐2‐one

The C atom at the chiral centre of the title compound, C₂₁H₂₀F₃NO₄, takes an R configuration. From this assignment, useful information on the intermediate process of the reaction was deduced.     

GaN外延层中的缺陷对光学性质的影响

用金属有机化合物气相外延（ＭＯＶＥＰ）方法生长具有不同表面形貌的非掺杂ＧａＮ，并对部分样品的外延层表面进行镜面加工．用阴极射线发光、光散射和拉曼散射方法观察ＧａＮ中深能级发光、缺陷散射光分布和拉曼散射光频移．结果表明，缺陷不但影响ＧａＮ的发光和光散射，而且影响拉曼频移     

Observation of 1,6-anhydro-beta-maltose and 1,6-anhydro-beta-D-glucopyranose complexed with rubidium by NMR spectroscopy and electrospray ionization mass spectrometry.

A complex of 1,6-anhydro-beta-maltose with rubidium and that of 1,6-anhydro-beta-D-glucopyranose with rubidium were characterized using 87Rb NMR spectroscopy, diffusion-ordered NMR spectroscopy (DOSY) and electrospray ionization mass spectrometry (ESI-MS). Although subtle differences were observed in the 1H chemical shifts of 1,6-anhydro-beta-maltose in between the presence and absence of rubidium in deuterium oxide, measurements of the spin-lattice relaxation time (T1) of the 87Rb nucleus, the diffusion coefficients of 1,6-anhydro-beta-maltose using 1H DOSY and ESI-MS indicated the complex formation of 1,6-anhydro-beta-maltose with rubidium. The complex formation with rubidium was also identified for 1,6-anhydro-beta-D-glucopyranose using NMR and ESI-MS techniques.     

Search for B+-->D*+pi0 decay

We report on a search for the doubly Cabibbo suppressed decay B+-->D*+pi0, based on a data sample of 657x10(6) BB pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find no significant signal and set an upper limit of B(B+-->D*+pi0)<3.6x10(-6) at the 90% confidence level. This limit can be used to constrain the ratio between suppressed and favored B-->D*pi decay amplitudes, r<0.051, at the 90% confidence level.     

Precision measurement of neutrino oscillation parameters with KamLAND

The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.     

Theoretical studies on magnetic atom imaging by use of photoelectron diffraction

We theoretically study possible methods how to obtain imaging of magnetic atoms by use of photoelectron diffraction (PD). We propose a novel method to apply Daimon effect where PD peaks are rotated around forward focusing peaks. In usual circular dichroism, we simply use the difference of the PD intensities for different X-ray circular polarization. In contrast to this dichroism, we rather use the difference of the PD intensities for different circular polarizations but - is used for the – circular polarization only in the data handling. This technique allows us to obtain clear atomic image only of spin polarized atoms, and to distinguish magnetic atoms with up-spins from those with down spins. Some illustrative calculations demonstrate the potential use and also the limitation of this technique.     

Temperature and species measurement in a quenching boundary layer on a flat-flame burner

A detailed understanding of transport phenomena and reactions in near-wall boundary layers of combustion chambers is essential for further reducing pollutant emissions and improving thermal efficiencies of internal combustion engines. In a model experiment, the potential of laser-induced fluorescence (LIF) was investigated for measurements inside the boundary layer connected to flame-wall interaction at atmospheric pressure. Temperature and species distributions were measured in the quenching boundary layer formed close to a cooled metal surface located parallel to the flow of a premixed methane/air flat flame. Multi-line NO-LIF thermometry provided gas-phase temperature distributions. In addition, flame species OH, CH₂O and CO were monitored by single-photon (OH, CH₂O) and two-photon (CO) excitation LIF, respectively. The temperature dependence of the OH-LIF signal intensities was corrected for using the measured gas-phase temperature distributions. The spatial line-pair resolution of the imaging system was 22 μm determined by imaging microscopic line pairs printed on a resolution target. The experimental results show the expected flame quenching behavior in the boundary layer and they reveal the potential and limitations of the applied diagnostics techniques. Limitations in spatial resolution are attributed to refraction of fluorescence radiation propagating through steep temperature gradients in the boundary layer. For the present experimental arrangements, the applied diagnostics techniques are applicable as close to the wall as 200 μm with measurement precision then exceeding the 15–25% limit for species detection, with estimates of double this value for the case of H₂CO due to the unknown effect of the Boltzmann fraction corrections not included in the data evaluation process. Temperature measurements are believed to be accurate within 50 K in the near-wall zone, which amounts to roughly 10% at the lower temperatures encountered in this region of the flames.     

Synthesis of γ‐Boryl‐Substituted Homoallylic Alcohols with anti Stereochemistry Based on a Double‐Bond Transposition

The stereoselective synthesis of anti isomers of γ‐boryl‐substituted homoallylic alcohols is disclosed. (E)‐1,2‐Di(boryl)alk‐1‐enes undergo Ru‐catalyzed double‐bond transposition with control of the geometry. The in situ generated (E)‐1,2‐di(boryl)alk‐2‐enes add to aldehydes in a stereospecific manner. The alkenylboron group within the product is amenable to a variety of synthetic derivatizations.     

A Polyaromatic Gemini Amphiphile That Assembles into a Well‐Defined Aromatic Micelle with Higher Stability and Host Functions

A gemini‐type amphiphilic molecule, constituted of two V‐shaped polyaromatic amphiphiles linked by a linear acetylene spacer, was synthesized. The gemini amphiphile assembles into a well‐defined aromatic micelle (ca. 2 nm in core diameter), providing higher stability in water even at low concentration (0.09 mm ) and high temperature (>130 °C). Unlike common gemini amphiphiles with aliphatic chains, the present amphiphile and its micellar assembly emit green and orange fluorescence (Φ_F=33 and 9 %), respectively. Despite strong and multiple π‐stacks of the polyaromatic panels of the amphiphiles, the water‐soluble gemini aromatic micelle incorporates medium‐size to large hydrophobic compounds into the frameworks. Interestingly, the guest binding capability toward large planar molecules was enhanced by more than two times through the pre‐encapsulation of spherical molecules in the cavity.