Estimation of secondary electron effect in the J-PARC rapid cycling synchrotron after first study

The J-PARC 3 GeV rapid-cycling synchrotron (RCS) is required to provide 1 MW pulsed protons to the spallation neutron target and the 50 GeV main ring. Since the RCS finally accelerates very high intensity beam such as 8.3 × 10¹³ ppp, the secondary electron cloud may affect the accelerator performance. We measured the secondary electron emission from the TiN coating surface and the ferrite sample. By using these measurement results, we estimated the effect of the electron cloud made by the emitted secondary electron at present beam parameters.     

Hydrogen absorption and Li inclusion in a Pd cathode in LiOH solution

The amount of electrochemically absorbed hydrogen and lithium in a Pd cathode during electrolysis was measured quantitatively in LiOH solution. The electrode potential was also measured by the current interruption method. Inclusion of Li in Pd was found even at the potential of −0.22 V vs. RHE. This potential is far more positive than the reported UPD potential. Since Li was detected up to a depth of 200 nm, this phenomenon is not a simple UPD. The deposition of Li onto Pd and the formation of Pd---Li alloy are likely to occur at a much more positive potential than expected. The [H]/[Pd] ratio decreased gradually after 50 h electrolysis at a current density greater than 5 mA cm⁻².     

Precise analysis of linear and non-linear chirp parameters of gain-switched distributed feedback laser pulses for the fibre optic compression scheme

Not only linear but also non-linear chirp parameters of a gain-switched distributed feedback (DFB) laser diode (LD) were analysed precisely. For this purpose a method has been developed to determine chirp characteristics from spectrally resolved streak camera images using the short time Fourier transform (STFT) scheme. Using this method a systematic study was carried out also on the dependence of the chirp parameters on the LD driving conditions, through which the importance and preliminary principles of chirp control for the fibre optic compression scheme were clarified.     

C60 molecular bearings

An ultralubricated system is reported which confines a C60 monolayer between graphite plates. C60 molecules act as molecular bearings, assisted by the nanogears of six-membered carbon rings between C60 molecules and graphite, in which the mean dynamical frictional forces are zero up to a high load of 100 nanonewtons. A stick-slip rolling model with a step rotation of a C60 molecule is proposed. This ultralubricated system, very promising for the realization of nano- and micromachines, is expected to open a new field of molecular bearings.     

An integral equation approach to finite deflection of elastic plates

The present paper concerns an approximate integral equation approach to finite deflection of elastic plates with aribitrary plan form. With the combined help of the Berger equation governing non-linear bending and a weighted residual technique for boundary-value problem, a boundary integral equation is formulated for immovable edge conditions. We here clarify the formulation and show that the calculation can be performed, with a slight modification, through a procedure similar to that conventionally employed in the linear bending analysis. Availability of the derived integral equation and the solution scheme is shown by way of simple numerical examples.     

Studies on phosphonic acid antibiotics. I. Structure and synthesis of 3-(n-acetyl-n-hydroxyamino)propylphosphonic acid (FR-900098) and its n-formyl analogue (FR-31564)

The structure elucidation of FR-900098 ($\text{1}$) isolated from a microorganism source and the syntheses of FR-900098 and its N-formyl analogue, FR-31564 ($\text{2}$), are described. The latter possesses a superior antimicrobial activity.     

Novel betaines from a micronesian sponge Dysidea herbacea

Three new betaines, dysibetaine PP (1), dysibetaine CPa (2), and dysibetaine CPb (3), were isolated from an aqueous extract of the marine sponge Dysidea herbacea collected in Yap state, Micronesia. The structure of 1 was determined by spectral methods as well as chemical degradation to be a novel dipeptide betaine, and those for 2 and 3 were determined to be unprecedented cyclopropane betaines. Compounds 2 and 3 showed weak affinity toward the N-methyl-D-aspartic acid-type and the kainic acid-type glutamate receptors, respectively, in a radioligand binding assay.     

Confined organization of Au nanocrystals in glycolipid nanotube hollow cylinders

Mild fabrication of anisotropic metal-lipid nanotube (LNT) nanocomposites, in which Au nanoparticles of 3-10 nm wide are organized in a glycolipid nanotube hollow cylinder, has been achieved by filling the internal channel of the LNT with HAuCl(4) aqueous solution by capillary force and subsequent photochemical reduction of [AuCl(4)](-).