[en] The properties of superfluid turbulence in HeII at elevated pressures were studied at 1.385 and 1.600K. The temporal profiles of the temperature gradient in counterflow channels were observed following an application of heat pulses. Two large-aspect-ratio rectangular channels (10.8cm long 2.54 x 0.102cm² and 0.953 x .0826cm² cross-section), each equipped with two heaters at the closed end and three thin-film superconducting bolometers, equally spaced along the channel length, were used in the present work. The channels were made from filled PMMA (Corian). From the steady-state results, the dimensionless coefficient F₀/v₀³), which appears in the Schwarz theory of superfluid turbulence, was obtained as a function of temperature and pressure dependent quantity α = (B rho/sub n/)/(2 rho). The obtained results are in excellent agreement with the computed results obtained by Schwarz. In effect, this work extends the verification of Schwarz's vortex reconnection model to HeII at pressures of up to 24 bar. The present work also yields new data on the growth and decay of superfluid turbulence in HeII at elevated pressures. The values of Vinen's growth and decay parameters, chi₁ and chi₂, are obtained from the analysis of transient behavior of temperature gradients in the channel. The values of chi₂ derived form transient data show dependence on line density and regime (growth or decay) as well as α

[en] New results are presented on thermally driver counterflow in nonrotating HeII at pressures up to 24 bar in an 11-cm long channel with a relatively large rectangular cross-section area (0.83mmx9.52mm). Values for the Gorter-Mellink coefficient A and Vinen growth and decay parameters chi₁ and chi₂ are obtained from direct measurements of time development of temperature gradient following the application of a heat pulse with and without a steady background heat current. The results are compared with a microscopic vortex model proposed by Schwartz

[en] The thickness dependence of the resistivity for Cu films deposited by ion beam deposition (IBD) was evaluated using Fuchs-Sondheimer (F-S) model for electron surface scattering and Mayadas-Shatzkes (M-S) model for electron grain boundary scattering. For fitting the F-S and M-S models to the experimental data, the approximate equations proposed in both models were discussed and it was confirmed that the experimental resistivity of the Cu films could be described well by a simple form combined of the approximate equations for both models. By means of the simple form in this work, the most reasonable fit to the experimental data could be obtained under the conditions of the surface scattering coefficient p=0 and the reflection coefficient at grain boundary R=0.40

[en] Cu films were deposited on Si (1 0 0) substrates at room temperature by a non-mass separated ion beam deposition method. The effect of the negative substrate bias voltage on the property of the Cu films was investigated by using field emission scanning electron microscopy and secondary ion mass spectroscopy. The Cu film deposited at the negative bias voltage of -50 V showed an extremely fine and homogeneous morphology without a columnar structure. The purity of the Cu film deposited at the bias voltage of -50 V was much improved in comparison with the 6N Cu target, while the Cu film deposited without applying substrate bias voltage contained more impurities than the 6N Cu target

[en] Paramagnetic species produced in a series of linear aliphatic oligoesters [--O--(CH₂)/sub m/--O--CO--(CH₂)/sub n/--CO--]/sub p/ by γ-irradiation at 77⁰K was investigated by an electron spin resonance (ESR) method. A predominant doublet observed immediately after γ-irradiation, which has hyperfine splitting of 20 to 23 gauss, is attributed to a radical anion. Slight decay of this radical anion is observed by illuminating the sample with visible light at 77⁰K. A small amount of the radical anion is converted to double triplet, which is assigned to --(ES)--CH--CH₂-- (where ES denotes the ester group), from the result of heat treatment. The conformational angles for the two β-protons in the (6,2) oligoester are determined to be theta₁ = theta₂ = 30⁰

[en] In this paper, biofouling in condenser tubes and methods of prevention are described. Biofouling has a tendency to occur in tubes under lower velocity of sea water, and fouling organisms, if allowed to build up, cannot be removed by ordinary nylon brush cleaning. As the results of our investigation, it was concluded that sponge ball cleaning should be employed when the condenser is operated under lower velocity of sea water in the bacteria breeding season. (author)

[en] Cu films were deposited on Si(1 0 0) substrates by applying a negative substrate bias voltage using non-mass separated ion beam deposition (IBD) method. By the SIMS results with Cs⁺ ion beam, the Cu film deposited at V_S=0 V was found to contain more impurities than the Cu film deposited at V_S=-50 V. On the other hand, from the SIMS results with O₂⁺ ion beam, it was found that elements which are easy to be positive ions such as B, Mg, Na, Al, K, Ca and Fe seem to be increased slightly as compared to the those of the Cu film deposited at V_S=0 V. As a result, higher-purity Cu film deposited at V_S=-50 V could be obtained in comparison with the film deposited at V_S=0 V. The purification effect of the Cu film deposited at V_S=-50 V was described in details

[en] Mn 3s photoemission spectroscopy has been performed at 300 and 100 K for Pr_0.5Ca_0.5MnO_3-δ which undergoes a charge-ordering transition around 235 K with decreasing temperature. We have observed in the Mn 3s spectrum the change in the Mn valency of Pr_0.5Ca_0.5MnO_3-δ accompanied by the transition. The Mn 3s spectrum at 300 K for Pr_0.5Ca_0.5MnO_3-δ is nearly identical to that of La_1.2Sr_1.8Mn₂O₇ in which the formal valence of the Mn ion is +3.4. This is consistent with the fact that the oxygen deficiency δ is 0.05 for the present sample. On the other hand the Mn 3s spectrum at 100 K is well reproduced by a superposition of those for LiMnO₂ with Mn³⁺ and for SrMnO₃ with Mn⁴⁺, while the mean Mn valency at 100 K remains being +3.4. This indicates that the Mn ions in Pr_0.5Ca_0.5MnO_3-δ are in the two different valence states below the transition temperature

No abstract available

[en] Full text: have performed Ce 4d-4f resonant photoemission measurements (hv 122 eV) at temperatures from 5.6 to 200 K in order to investigate the relation between the Ce 4f electronic structure and the peculiar magnetic structure of CeSi. The photoemission measurements were done at BL-1 of HiSOR. Temperature dependent resonant photoemission spectra of CeSi are shown. The spectral intensity of Ce 4f_5/2¹ final state observed at 25 meV gradually increases as the temperature goes form 200 to 30 K. However, that at 5.6 K decreases in comparison with that at 30 K. This temperature dependence is consistent with that of the electric resistivity data. Furthermore, the photoemission spectra measured with He I (hv= 21.2 eV), in which the electronic structure of conduction electrons like Si 3p is dominantly observed, have also shown a spectral change similar to the result mentioned above. These suggest that the hybridization between the Ce 4f and conduction electrons may play an important role for the formation of magnetic structure