Singlet-triplet Crossover in the Two-dimensional Dimer Spin System YbAl3C3

Low-temperature magnetization (M) measurements down to 0.1 K have been performed in magnetic fields up to 14.5 T for a single piece of a tiny single-crystalline sample (0.2 mg weight) of the spin-gap system YbAl3C3. At the base temperature of 0.1 K, several metamagnetic transitions were clearly observed for H // c in the range 6 T < H < 9 T whereas only two transitions were observed, one at 4.8 T and the other at 6.6 T, for H // a. At fields above 9 T, the magnetization becomes almost saturated for both H // a and H // c. The present results indicate that a singlet-triplet crossover occurs in a relatively narrow field range, suggesting a rather weak interdimer interaction in spite of the nearly triangular lattice of Yb ions.Comment: 5 pages, 6 figures, proceedings of ICM 201

THE RELATIONSHIP BETWEEN FOOT MOVEMENT AND THE COM VELOCITY IN ELITE FEMALE BRESTSTROKE SWIMMERS

The purpose of this study was to investigate the effect of foot movement on the instantaneous COM velocity changing during kick movement for elite female breaststroke swimmers. Nine elite swimmers swam at their maximal effort in a 25-m pool. The swimming motions were recorded with the motion capture system. The COM velocity generated by kick movement was not related the foot velocity. In contrast, the COM velocity was correlated with the sweepback angle of foot. The swimmers who showed high kick velocity were moved their foot outward during early kick movement. In contrast the swimmer who showed low kick velocity moved their foot backward. These results suggest that the higher increased COM velocity obtained by kick movement would not be related to foot velocity, but foot angle for elite female swimmers

原子核の中性子共鳴反応におけるパリティの破れの研究

京都大学0048新制・課程博士博士(理学)甲第7132号理博第1906号新制||理||1031(附属図書館)UT51-98-G61京都大学大学院理学研究科物理学第二専攻(主査)教授 政池 明, 教授 小山 勝二, 教授 今井 憲一学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDFA

On the Radio Noises and Oscillations Caused by Fluorescent Lamps

The radio noises caused by fluorescent lamps were investigated in connection with high frequency oscillations in fluorescent lamps, and the mechanisms of oscillations were considered with some experimental results. Reignition oscillation, the wave form of which is irregular and consists of train of fine pulses, is sensitive to external heating of the filament and magnetic field near the cathode. Its frequency spectrum is nearly flat in broadcast band, and its noise level is 62 db (20W lamp) and 50 db (40W lamp) respectively in mean value of symetric quasi-peak voltage at 1MC, and is reduced by 30 db with 0.005 µPF capacitor conncted between lamp terminals. The twin oscillation, the waveform of which is regular and nearly sinusoidal, has the frequency spectrum which is similar to the resonance curve, and in many cases the peak of its spectrum is found in broadcast band. The high frequency oscillation is observed also in DC discharge, and its characteristics are just the same with those of the twin oscillation. The frequencies of these oscillations vary nearly in proportion to the square root of the lamp current, and are affected by interterminal capacitor. The cause of reignition oscillation is the fluctuation of ionization in increasing and decreasing period of space charge during transient time on reversing of the lamp current. The origin of twin oscillation is the oscillatory behavior of ionized medium with suitable accelerating field at the cathode surface, and for generation of the oscillation it is necessary that some conditions of the feedback from the boundary of the medium to the cathode are satisfied

On the Role of Technical Cooperation in International Technology Transfers

We investigate whether and how technical cooperation aid (TC) facilitates technological diffusion from developed to developing countries, comparing it with foreign direct investment (FDI) and external openness. Extending the model of Benhabib and Spiegel (2005), we estimate the degree to which these three channels contribute to countries total factor productivity (TFP) growth rates. Our econometric model also allows us to identify whether a country will catch up to or diverge from the technological leader nation over time. Two sets of robust findings emerge. First, TC, FDI and openness all contribute to facilitate international technology transfers. Yet, among these three channels, openness seems to contribute the most, followed by TC. Also, TC seems to compensate for the lack of sufficient human capital in developing countries. Second, around 6 to 17 countries out of 85 in our sample fail to catch up to the technological leader over the 36 years. These results suggest that TC can play an important role in facilitating the technological catch up of developing countries.

A reservoir trap for antiprotons

We have developed techniques to extract arbitrary fractions of antiprotons from an accumulated reservoir, and to inject them into a Penning-trap system for high-precision measurements. In our trap-system antiproton storage times > 1.08 years are estimated. The device is fail-safe against power-cuts of up to 10 hours. This makes our planned comparisons of the fundamental properties of protons and antiprotons independent from accelerator cycles, and will enable us to perform experiments during long accelerator shutdown periods when background magnetic noise is low. The demonstrated scheme has the potential to be applied in many other precision Penning trap experiments dealing with exotic particles.Comment: Article by the BASE-collaboration at CERN. Results from the Antiproton physics run 2014. Submitted to International Journal of Mass Spectrometry, 8th of April 201