Measurement of nuclear moments and radii by collinear laser spectroscopy and by β-NMR spectroscopy

Experiments using laser spectroscopy and nuclear magnetic resonance techniques have been performed at ISOLDE on the unstable isotopes of several light elements. The results include nuclear ground state spins, magnetic dipole and electric quadrupole moments, and the behaviour of mean square nuclear charge radii within isotopic strings. These give important information about the nuclear structure at shell closures and close to the drip lines. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparison of TiO2 and ZrO2 Films Deposited by Electron-Beam Evaporation and by Sol-Gel Process

TiO2 and ZrO2 films are deposited by electron-beam （EB） evaporation and by sol-gel process. The film properties are characterized by visible and Fourier-transform infrared spectrometry, x-ray diffraction analysis, surface roughness measure, absorption and laser-induced damage threshold （LIDT） test. It is found that the sol-gel films have lower refractive index, packing density and roughness than EB deposited films due to their amorphous structure and high OH group concentration in the film. The high LIDT of sol-gel films is mainly due to their amorphous and porous structure, and low absorption. LIDT of EB deposited film is considerably affected by defects in the film, and LIDT of sol-gel deposited film is mainly effected by residual organic impurities and solvent trapped in the film.     

Spin and valley half metal induced by staggered potential and magnetization in siliceneSpin and valley half metal induced by staggered potential and magnetization in siliceneSpin and valley half metal induced by staggered potential and magnetization in silicene

We investigate the electron transport in silicene with both staggered electric potential and magnetization; the latter comes from the magnetic proximity effect by depositing silicene on a magnetic insulator. It is shown that the silicene could be a spin and valley half metal under appropriate parameters when the spin-orbit interaction is considered; further, the filtered spin and valley could be controlled by modulating the staggered potential or magnetization. It is also found that in the spin-valve structure of silicene, not only can the antiparallel magnetization configuration significantly reduce the valve-structure conductance, but the reversing staggered electric potential can cause a high-performance magnetoresistance due to the spin and valley blocking effects. Our findings show that the silicene might be an ideal basis for the spin and valley filter analyzer devices.     

Topological insulators induced by disorder and non-Hermiticity

Searching for topological states of matter in real materials or engineered systems has been a fundamental theme in condensed matter physics in the past decade[1].It is known that the topological insulators are robust against certain disorders,but they usually become trivial under strong disorders due to the Anderson localization.In the year 2009,it was theoretically found that a topological insulator can be surprisingly driven from a trivial phase by disorders,which is called the topological Anderson insulator[2].Although the topological Anderson insulator has been studied in various theoretical models[3-5],it was not until 2018 that its experimental observation was reported in two different artificial systems[6,7],i.e.,the one-dimensional cold atomic wires and two-dimensional photonic waveguide arrays.     

Measuring vibration by using fiber Bragg grating and demodulating it by blazed grating

A method of measuring vibration by using fiber Bragg grating (FBG) and demodulating the spectrum by blazed grating is introduced. The sensor system is made of a simple supported beam with a FBG adhered to its upper surface. A blazed grating is used to demodulate the changing spectrum that is got from the sensor system, and a line charge-coupled device (CCD) is used to accept the diffraction spectrum. Through analyzing the number of the CCD's pixels, we can get the amplitude of vibration and the change of the temperature. The experimental results show that the vibration amplitude of the exciter matches the detected signal under the stable frequency. The temperature shift and vibration signal are also successfully separated.     

Hypernuclear production induced by in-flight K and π

The development in treating K- and -induced hypernuclear production reactions is reviewed, including the application of DWIA to the (K^–, K⁺) reaction to produce ^–. After summarizing the conventional DWIA treatment without spin-dependence, we discuss the calculational method of strength functions up to the continuum. Finally the process is reformulated starting from the elementary amplitudes with the spin-flip component as well as the spin-nonflip one. The new treatment is shown to be powerful and the emphasis is put on the production of polarized hypernuclei, which provides a useful spectroscopic tool for the weak-decay mechanism.Dedicated to our distinguished collaborator, Professor Jan ofka (1943–1991), to the memory of his inspiration in hypernuclear physics and his wide, friendly activities in our community.The authors are very grateful to the late Professor Jan ofka who was a distinguished collaborator for a long time. He coordinated many collaborations between e and Japan. We will miss his scientific and organizational activities in hypernuclear physics. The authors express their thanks to O. Richter, M. Sotona, R. Wünsch, H. Ejiri and T. Kishimoto for collaboration and discussion on several parts of the calculated results. This work has been supported by the Grant-in-Aid for Scientific Research (C) and also by A Grant under The Monbusho International Scientific Research program (Joint Research 1990–1991).     

Scattering of protons and antiprotons by hydrogen atoms

The two-,four-,five-and fourteen-state approximations of the inpact parameter method have been applied to the excitation of hydrogen atoms by proton(p)and antiproton(p) impact.The effect of both channel and back couplings on the 2s and 2p excitations are investigated.The total cross sections are calculated for incident energies ranging from 1 to 2500keV.it is found that the effect of both channel and back couplings on the antiproton-induced reactions is greater than on that induced by protons.We compare the results with those of other theoretical and experimental works.     

Crack-free processing of glasses by 1 μm-YAG laser and translucent adhesive tape and its numerical analyses by CIP

We succeeded in drilling a crack-free high-aspect-ratio hole through glass with a YAG laser of 1 m wavelength, 5 ns pulse width and 30–630 mJ energies. The hole is 25.5 mm long with 500 m radius, and no crack is observed even in atmospheric condition. This success is due to the translucent adhesive tape pasted on glass surface in which the temperature is controlled and thermal stress is reduced. Computer simulation revealed the occurring phenomena. PACS 61.43.Fs; 61.80.; 68.08.De     

Imaging by Photonic Crystal Using Reflection and Negative Refraction

Point imaging by a photonic crystal slab due to the negative refraction is studied by the finite-difference timedomain method. With a layer metal coating on one termination of a photonic crystal （PC） slab which intensifies the light reflection, one image occurs in the same side with the point source by negative refraction and reflection at the two sides of the photonic crystal slab, which brings about a new kind of imaging for the PC slab.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A·C mismatches are studied by Raman spectral characterization of PolyA,PolyC,and their equimolar complex in solution of 0.14 mol/L Na~ ,pH7.0.Experimental results show that A·C mismatches occur to be A/B(mainly A)conformers,and unlike Watson-Crick base pairing,this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H_2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger,and conformation of the backbone more ordered,which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.     

Localization and Threshold of Bistable Switching by Gap-Edge Shifting

We numerically investigate the localization behaviour of light propagation in a one-dimensional nonlinear photonic crystal (1D-NPC). It is found that the localization of a high gap-edge mode is better than that of a low one, so that the switching threshold of the 1D-NPC with plus Kerr L-layers is much lower than that with minus Kerr H-layers. For a structure of 16 periods, the threshold of the structure with nonlinear L-layers is about 1/10 of that with nonlinear H-layers in the same level of nonlinear refractive coefficient.     

Strengthen Vanadium Alloy by Aging and Its Thermal Stability

V-4Cr-4Ti is the leading candidate vanadium alloy for fusion applications as structural material of first wall and blanket. Due to the interaction between Ti and interstitial solutes of C, N, and O, precipitation occurs at elevated temperature. The behavior has been studied in the past few years by short time annealing and results showed that it may greatly affect its mechanical properties Ti-CON type precipitates, appearing at- 700℃ in the solid-solution annealed alloy in high number density and small size, strengthen the alloy significantly and reduce its ductility. As the ductility reduction is in an acceptable level, the strengthening might be utilized for a light and strong vanadium alloy structure. Before a conclusion, uncertainty of its thermal stability should be studied during the high temperature serves. Besides, seldom has been studied for the effect of long time aging on precipitation behavior and tensile properties of the alloy.     

Study on vibrational modes by group theory and infrared spectra by DFT for calcite crystal

The factor group symmetry analysis(FSA)method and position symmetry analysis(PSA)method are used to analyze the vibrational modes of calcite(CaCO_3)crystal,respectively.With the activated results of infrared and Raman spectra presented,strong points of each method are concluded.The infrared spectra are studied by using dynamics calculations based on density-functional theory(DFT)with the supercell model of calcite crystal.The frequencies of 27 normal modes are achieved,which are consistent with that by the group symmetry analysis very well,and fit with the experimental results better than the lattice dynamical methods.     

Glass-Forming Ability of an Iron-Based Alloy Enhanced by Co Addition and Evaluated by a New Criterion

A new Fe-based alloy that can be cast into a fully amorphous rod with a diameter of at least 16mm by the conventional copper-mould casting technique is obtained by partially replacing Fe with Co in a previously reported Fe-based bulk metallic glass. The preliminary thermodynamic analysis indicates that the Co-containing alloy has a significantly lower Gibbs free energy difference between the undercooled melt and the corresponding crystalline solid, compared to the Co-free alloy, reflecting the dramatic role of the Co addition in stabilizing the supercooled melt and facilitating glass formation in iron-based alloys. Here, a new criterion, derived from the classical nucleation and growth theory, is introduced to evaluate the glass-forming ability of Fe-based bulk metallic glasses.     

Cellular and tissue effects induced by photogem® and red LED in photodynamic therapy

In order to consider the photodynamic therapy (PDT) as a clinical treatment for candidosis, it is necessary to know its cytotoxic effect on normal cells and tissues. Therefore, this study evaluated the toxicity of PDT with Photogem® associated with red light-emitting diode (LED) on L929 and MDPC-23 cell cultures and healthy rat palatal mucosa. In the in vitro experiment, the cells (30000 cells/cm²) were seeded in 24-well plates for 48 h, incubated with Photogem® (50, 100, or 150 mg/l) and either irradiated or not with a red LED source (630 ± 3 nm; 75 or 100 J/cm²; 22 mW/cm²). Cell metabolism was evaluated by the MTT assay (ANOVA and Dunnet’s post hoc tests; p < 0.05) and cell morphology was examined by scanning electron microscopy. In the in vivo evaluation, Photogem® (500 mg/l) was applied to the palatal mucosa of Wistar rats during 30 min and exposed to red LED (630 nm) during 20 min (306 J/cm²). The palatal mucosa was photographed for macroscopic analysis at 0, 1, 3, and 7 days posttreatment and subjected to histological analysis after sacrifice of the rats. For both cell lines, there was a statistically significant decrease of the mitochondrial activity (90–97%) for all Photogem® concentrations associated with red LED regardless of the energy density. However, in the in vivo evaluation, the PDT-treated groups presented intact mucosa with normal characteristics both macroscopically and histologically. From these results, it may be concluded that the association of Photogem® and red LED caused severe toxic effects on normal cell cultures, characterized by the reduction of mitochondrial activity and morphological alterations, but did not cause damage to the rat palatal mucosa in vivo.     

Investigation of muon states in silicon and germanium by field-quenching and RFμSR

The temperature dependence of the three states of positive muons in the semiconductors with diamond structure ( ⁺ in diamagnetic states ^d and paramagnetic muonium Mu and Mu^*) have been investigated on six Si (pure, B and P doped) and four Ge (ultrapure, CZ-grown undoped, Ga and Sb doped) single crystals by longitudinal field-quenching and radio-frequency ⁺SR. Clear evidence for the transition Mu^{* d} is found. The influence of light-induced charge-carriers is shown to be quite different in p- and n-type material.The work has been supported by the Bundesministerium für Forschung und Technologie in Bonn, Germany, under contract no. 03-SE3STU.     

Anterior cingulate and cerebellar GABA and Glu correlations measured by ¹H J-difference spectroscopy

Gamma-aminobutyric acid (GABA) and glutamate (Glu) levels, normalized to total creatine (tCr), were measured in the anterior cingulate and cerebellar vermis in healthy adults (n=19, age=24.6±6.4 years) using ¹H MRS at 3 T, and metabolite correlations across regions and subjects were determined. Mean anterior cingulate and cerebellar GABA/tCr ratios were 0.31 (0.08) and 0.23 (0.06), respectively, while corresponding Glu levels were 1.16 (0.10) and 0.70 (0.07), respectively. Anterior cingulate and cerebellar glutamate levels were correlated (r=0.6103, P=.0140), although it is noted that when adjusted for multiple comparisons, all correlations reported here cluster to a P value of .0583. It is unlikely that this correlation is driven by correlations in tCr, since interregional correlations were not observed for other metabolites referenced to tCr. Correlations were also observed among metabolites in both the anterior cingulate and cerebellar vermis. In the former, N-acetylasparate was linearly dependent on glutamate (r=0.6577, P=.0063) and, at or below this significance threshold, four metabolites were correlated in the cerebellar vermis (Ins/tCh: r=0.6261, P=.0109. NAA/tCh: r=0.6426, P=.0082. NAA/Glu: r=0.6412, P=.0085. tCh/Glu: r=0.6193, P=0.0122).