207Pb chemical shift thermometer at high temperature for magic angle spinning experiments

The temperature dependence of 207Pb chemical shift in magic angle spinning (MAS) NMR spectrum of Pb(NO3)2 provides a sensitive method to calibrate sample temperatures in MAS NMR. The temperature dependence is uniform in the temperature range between 30 degrees C and 400 degrees C. The NMR sensitivity and the line width are also favorable.     

Measurements ofg-factor in94Mo

Then _th,α)-reaction spectroscopical data are reported on⁹⁵Mo,¹²³Te and¹⁴⁵Nd (target nuclei). The⁹⁵Mo(n, α)⁹²Zr and¹²³Te(n, α)¹²⁰Sn reactions showed up two lines each corresponding to the ground state and the 1st excited state with a total cross section of 32 ub and 52 μb respectively. In the case of¹⁴⁵Nd(n, α)¹⁴²Ce, a transition only to the 1st excited state of¹⁴²Ce is present. It is shown that in the case of⁹⁵Mo,¹⁴⁵Nd and probably¹²³Te, most of the cross-section comes respectively from the 2⁺ possibly 4^?, and 0 bound levels whose widths are determined to beΓ ^α=0.5 × 10^?6 eV,Γ ^α=1.6×10^?8 eV andΓ ^α=1.6 × 10^?6 eV. The present results on these three nuclei, when combined with the existing data, are consistent with the calculated statistical model values.     

The reaction of iodine with vinyltrialkylborates derived from trialkylboranes and trisylhydrazones of methyl ketones. A new method for synthesis of 1,1-dialkylethenes

1,1-Dialkylethenes are readily prepared in good yields from vinyltrialkylborates derived from trialkylboranes and trisylhydrazones of methyl ketones by treatment with iodine.     

Interpretation of electronic spectra by configuration analysis: Absorption spectra of monosubstituted naphthalenes

The electronic absorption spectra of four monosubstituted naphthalenes, α-, β-naphthols, and α-, β-naphthylamines have been investigated by means of configuration analysis with particular attention to the dependence of spectra on the position of substitution and on the electron-donating power of the substituent. The results of molecular orbital calculations based on the Pariser-Parr-Pople method are analyzed in terms of locally excited states and intramolecular charge-transfer configurations. The characteristic changes in location and polarization of the L_b, L_a, and B_b bands caused by substitution at the α- or β-position are adequately explained by the analysis. Two strong absorption bands of α-substituted naphthalenes, which appear in place of the B_b band of naphthalene, are shown to result from a mixing of the $\text{B}{}_{\mathrm{3u}}{}^{\mathrm{+}}\text{(B}{}_{\mathrm{b}}\text{)}$ and $\text{A}{}_{\mathrm{g}}{}^{\mathrm{?}}$ states. The amino group exerts a great influence on the electronic structure of the parent molecule, so that the B_b band cannot be identified in the spectrum of β-naphthylamine.     

Observation of Ramsey resonance absorption in three separated laser fields produced by a corner reflector

Experimental observation of optical Ramsey interference in saturated absorption of methane in a low-pressure gas cell with three spacially separated laser beams at 3.39 μm is reported.     

Bio-sensing on a chip with compact discs and nanofibers

This paper describes a novel, sensitive detection system for biomolecules (DNA and proteins etc.) that is integrated in a lab-on-a-chip utilizing optical compact discs (CDs) and bio-nanofibers. The new method comprises a microchannel containing CD grating that confines fragments of unique bacterial cellulose fibrils (BC), which have nanometre scale fibers and holes. A maximum of six times higher sensitivity to detect DNA was obtained with this CD and BC system compared to a conventional method. We also demonstrate an effective light-confining effect for biological application with the new method.     

High-order harmonic generation from boron plasma in the extreme-ultraviolet range

We demonstrate the generation of up to the 63rd harmonic (lambda = 12.6 nm) of a Ti:sapphire laser pulse (150 fs, 10 mJ), using a prepulse- (210-ps,24-mJ) produced boron plasma as the nonlinear medium. The influence of various parameters on the harmonic conversion efficiency was analyzed. The steep decrease in intensity for low-order harmonics (up to 19th order) was followed by a plateau. Typical conversion efficiencies were evaluated to be 10(-4) (for a 3rd harmonic) to 10(-7) (within the plateau region). Harmonic generation appeared to be efficient for the plasma that comprised neutral atoms and singly ionized boron.