πNN Dynamics in pp → pp,pp →πd and πd →πd Processes Below 1 GeV

pp and πd scattering and pp →πd reaction processes at incident proton laboratory energies T _L ≤ 1 GeV are studied in the framework of πNN dynamics. For this purpose three-body calculations are performed with the πN interaction in the P ₁₁, P ₃₃, S ₁₁ and S ₃₁ states and NN forces in the ³ S ₁ -³ D ₁, ¹ S ₀, and ³ P ₂ states. In addition, the backward-going pion contribution at the πNΔ vertex, the πN-ρN coupling, the heavy-meson exchanges in the NN → NN driving term, and the effect of the off-shell structure in the πN-ρN P ₃₃ interaction are taken into account. Received March 28, 1994; revised July 29, 1994; accepted for publication August 31, 1994     

Microscopic measurements in La-NQR of the ternary carbide superconductor LaNiC2

¹³⁹La-NQR measurements have been carried out in the ternary carbide superconductor LaNiC₂. The nuclear quadrupole frequency and the asymmetry parameter of ¹³⁹La in LaNiC₂ were estimated to be about 1.9 MHz and 0, respectively. In the normal state, the nuclear spin relaxation rate (1/T₁) in the ¹³⁹La NQR signal was proportional to temperature (T) in zero external field above the superconducting transition temperature (T_c) or in an external field larger than the superconducting critical field, which means the system is in the Fermi-liquid state. In the superconducting state, on the other hand, 1/T₁ decreases no more linearly with T, but decreases rapidly exponentially as exp (−Δ/k_BT) at low T with an appreciable enhancement just below T_c. The value of the superconducting energy gap, 2Δ, was estimated to be 3.34k_BT_c, compared with 3.52k_BT_c of the BCS-value. This result strongly suggests that the superconductivity in LaNiC₂ is of a conventional BCS type.     

μ− SR studies of oxide-superconductorsSR studies of oxide-superconductors

The negative muon spin rotation method (μ⁻ SR) has been applied to studies of electronic states at oxygen sites of oxide superconductors YBa₂Cu₃O₇, Nd_2−x Ce _x CuO_4−δ (x=0.15, oxygen reduced), LiTi₂O₄ and related oxide-insulators La₂CuO_4−δ, CuO, Cu₂O. The paramagnetic shifts of μ⁻ trapped at oxygen nuclei in these polycrystalline powder samples have been measured at 300 K. All the measured shifts are positive. In copper-oxides the paramagnetic shifts are of the order 10⁻³, while in LiTi₂O₄ is very small (8.4±3.34×10⁻⁵). In YBa₂Cu₃O₇, a fast μ⁻ spin relaxation timeT ₂ ^* (∼ 200 ns) has been observed; the reason for this is unknown and further studies are now in progress.     

A novel method for the direct derivatization of straight-chain aliphatic carboxylates after trapping on anion-exchange resin

A novel procedure for the characterization of traces of lipophilic straight-chain aliphatic carboxylate ions in aqueous samples is described. The carboxylates are adsorbed on an Amberlyst A26 [Cl^-] resin column. The resin is then dried and suspended in methyl iodide at room temperature. A gas Chromatographic analysis of the methyl iodide solution allows the determination of the carboxylates as their methyl esters. Full characterization of each carboxylate with an overall recovery over 84% from 1 ppm aqueous sample solutions is attained.     

Physicochemical Properties of Large-Ring Cyclodextrins (CD 18 ∼CD 21

Cyclomaltooctadecaose(CD₁₈),cyclomaltononadecaose(CD₁₉),cyclomaltoeicosaose(CD₂₀) andcyclomaltoheneicosaose(CD₂₁) are cyclic oligosaccharides composed of 18, 19, 20 and 21 D-glucose units, respectively. This report describes the physicochemical properties of CD₁₈, CD₁₉, CD₂₀ and CD₂₁ in terms of aqueous solubility, surface tension, optical rotation and acid-catalyzed hydrolysis.     

Novel High Precision Optoelectronic Device Fabrication Technique Using Guided Fluidic Assembly

High precision assembly of laser diodes (LDs) on silicon wafer substrates for use in advanced optoelectronic devices is an important issue from a mass production point of view. An acceptable alternative to replace an obsolete pick and place flip chip bonding robotic technology with a simple, low cost and high speed technique is desired for industrial applications. We have investigated a novel assembling technique with micrometer order accuracy for LDs and other microchips. Its feasibility for rapidly assembling a large number of high power edge emitting LDs is practically demonstrated. A 150 $mUm thick nickel metal mask is used to confine as well as guide the unassembled LDs into the recesses by its restricted displacements. This technique is based on guiding the LDs within a suitable fluidic medium and the assembling process is performed in two steps: (i) coarse precision with a confinement mask to bring LDs near the recesses to achieve high assembling efficiency and (ii) fine precision due to the electrode patterns on the base surface of LDs, under fluidic as well as gravitational force. The assembly of 80 red LDs of the same size and of 40 pairs of red and infrared LDs of two different sizes is successfully demonstrated within less than ±2 $mUm precision and 100% efficiency in a few seconds after transferring them into a confinement mask region.     

Gamma and sine functions for Lie groups and period integrals

We study gamma and sine functions attached to a finite dimensional linear representation of a Lie group including their multiple versions via zeta regularizations. These definitions allow us to understand several multiple gamma and sine functions known so far, such as Barnes' gamma functions, Shintani's sine functions, and their q-analogues, in a unified way. Further, we discuss period integrals for such gamma functions.