We have studied the electronic structure of Ba1−xSrxV13O18 (x=0,0.2,1) at different temperatures across the trimerization and charge-order transitions using hard x-ray photoemission spectroscopy ...(HAXPES). The V 2p HAXPES indicates V2+/V3+ charge order and fluctuation in the high-temperature tetramer phase, low-temperature trimer phase, and intermediate-temperature charge-order phase in the series of x=0,0.2,1. In the valence-band HAXPES, although the spectral weight at the Fermi level tends to be suppressed in all the phases due to strong charge order or fluctuation, it increases in the trimer phase at x=0.2, in agreement with the decrease of resistivity and the increase of itinerant electrons in the trimer phase. Interestingly, in the most conducting x=1 without the charge-order phase, the spectral weight at the Fermi level is strongly suppressed even in the trimer phase, indicating that charge fluctuation in the trimer phase is different between x=0.2 and 1.
We have performed scanning photoemission spectromicroscopy of BaV10O15 across the metal-insulator transition at 123 K, which is accompanied by V 3d charge/orbital order and V trimerization. ...Nucleation of metallic domains is observed at the cleaved surface of BaV10O15 single crystals, similar to Cr-doped V2O3 in which electronic configurations of Cr3+ and V3+ are the same as those of V2+ and V3+ in BaV10O15. Typical domain size is ∼5–10μm at 150 K, just above the transition temperature. The metallic domains continuously grow up to 240 K, well above the transition temperature. The temperature evolution of the metallic phase in BaV10O15 is different from that of Cr-doped V2O3, probably due to the charge degrees of freedom in BaV10O15.
In this talk I will be presenting the results of breaking strength, Young's modulus and thermal conductivity of the materials which are under study for the development of cryogenic suspensions of the ...KAGRA gravitational wave detector in Japan.
We synthesized highly amorphous GeO x powders by a solution synthesis method, in which NaGe was oxidized by alcohol and placed in distilled water. Further, we investigated the effect of the alcohol ...used during the solution synthesis method on the electrochemical Na- and Li-ion insertion/extraction performances of the powder sample. We compared the oxidation process as performed using various alcohols. The amorphous GeO x powder sample synthesized by oxidation in 2-propanol (secondary alcohol) exhibited good electrochemical performance with respect to Na- and Li-ion insertion/extraction, while the amorphous GeO x powders synthesized using methanol, ethanol, and 1-propanol (primary alcohol) showed poor performances. These powders consisted of large particles, which was the reason for their poor electrochemical performance. In particular, their cycling performance in a Na-ion cell was significantly lowered by the large particle size. Hence, during the solution synthesis process, the use of a secondary alcohol is the key to synthesizing highly amorphous GeO x powders with small particle sizes. Finally, electrolyte decomposition was also found to be one of the main causes for the deterioration of the cycling performance in a Na-ion cell, because the change in the volume of the GeO x particles during charging/discharging was smaller in the Na-ion cell than in a Li-ion cell.
Present understanding of neutrino mass and mixing are discussed based on recent neutrino experiments, including solar, atmospheric, reactor and long baseline accelerator neutrino experiments. ...Especially, the results from the Super-Kamiokande experiment are discussed in detail.PUBLICATION ABSTRACT
A total of 137 upward stopping muons of minimum energy 1.6 GeV are observed by Super-Kamiokande during 516 detector live days. The measured muon flux is
0.39±0.04
(stat.)±0.02
(syst.)×10
−13
cm
−2s
...−1sr
−1
compared to an expected flux of
0.73±0.16
(theo.)×10
−13
cm
−2s
−1sr
−1
. Using our previously-published measurement of the upward through-going muon flux, we calculate the stopping/through-going flux ratio
R
, which has less theoretical uncertainty. The measured value of
R=0.22±0.02
(stat.)±0.01
(syst.)
is significantly smaller than the value 0.37
+0.05
−0.04(theo.) expected using the best theoretical information (the probability that the measured
R
is a statistical fluctuation below the expected value is 0.39%). A simultaneous fitting to zenith angle distributions of upward stopping and through-going muons gives a result which is consistent with the hypothesis of neutrino oscillations with the parameters sin
22
θ>0.7 and 1.5×10
−3<
Δm
2<1.5×10
−2 eV
2 at 90% confidence level, providing a confirmation of the observation of neutrino oscillations by Super-Kamiokande using the contained atmospheric neutrino events.
The charge-conjugation and parity-reversal (CP) symmetry of fundamental particles is a symmetry between matter and antimatter. Violation of this CP symmetry was first observed in 1964
, and CP ...violation in the weak interactions of quarks was soon established
. Sakharov proposed
that CP violation is necessary to explain the observed imbalance of matter and antimatter abundance in the Universe. However, CP violation in quarks is too small to support this explanation. So far, CP violation has not been observed in non-quark elementary particle systems. It has been shown that CP violation in leptons could generate the matter-antimatter disparity through a process called leptogenesis
. Leptonic mixing, which appears in the standard model's charged current interactions
, provides a potential source of CP violation through a complex phase δ
, which is required by some theoretical models of leptogenesis
. This CP violation can be measured in muon neutrino to electron neutrino oscillations and the corresponding antineutrino oscillations, which are experimentally accessible using accelerator-produced beams as established by the Tokai-to-Kamioka (T2K) and NOvA experiments
. Until now, the value of δ
has not been substantially constrained by neutrino oscillation experiments. Here we report a measurement using long-baseline neutrino and antineutrino oscillations observed by the T2K experiment that shows a large increase in the neutrino oscillation probability, excluding values of δ
that result in a large increase in the observed antineutrino oscillation probability at three standard deviations (3σ). The 3σ confidence interval for δ
, which is cyclic and repeats every 2π, is -3.41, -0.03 for the so-called normal mass ordering and -2.54, -0.32 for the inverted mass ordering. Our results indicate CP violation in leptons and our method enables sensitive searches for matter-antimatter asymmetry in neutrino oscillations using accelerator-produced neutrino beams. Future measurements with larger datasets will test whether leptonic CP violation is larger than the CP violation in quarks.
Synthesis and superconductivity of new Li-intercalated layered perovskites, LixSr2CuO2X2 (X=Cl, Br, I) and LixAB2M3O10 (A=K, Rb, Cs; B=Ca, Sr, Ba; M=Nb, Ta), are reviewed. Li-intercalation has been ...carried out by the electrochemical technique. First, layered cuprates LixSr2CuO2X2 show superconductivity with Tc=8.0K and 4.5K for X=Br and I, respectively. However, no superconductivity appears for X=Cl. Next, we have succeeded in preparing new superconductors, LixCsSr2Nb3O10 with Tc=5.5K and LixRbSr2Nb3O10 with Tc=6K. In the layered tantalates of LixCsSr2Ta3O10, however, no superconductivity has been observed.
Microsatellite markers were developed for three major mangrove species Avicennia alba, Sonneratia alba and Rhizophora mucronata to investigate the genetic diversity and spatial genetic structure of ...these species. The numbers of polymorphic compound microsatellite markers isolated were four, four and three for A. alba, S. alba and R mucronata respectively. Genetic parameters of these markers were evaluated with three populations from the Malay peninsula. The numbers of alíeles per locus within each population ranged from 1-13 for A. alba, 1-6 for 5. alba and 1-3 for R mucronata. Expected heterozygosity per population ranged from 0.000-0.877 for A. alba, 0.000-0.647 for S. alba and 0.000-0.558 for R mucronata. All 11 microsatellite markers displayed polymorphism within and between populations. Most markers were also amplified in closely-related species: Avicennia rumphiana, Sonneratia caseolaris, S. ovata, Rhizophora stylosa and R apiculata. This demonstrates the usefulness and robustness of the described markers in population genetic studies and potential forestry research in mangroves. Penanda mikrosatelit dibangunkan untuk tiga spesies pokok bakau utama iaitu Avicennia alba, Sonneratia alba dan Rhizophora mucronata untuk menyiasat kepelbagaian genetik dan Struktur genetik ruang spesiesspesies tersebut. Bilangan penanda mikrosatelit majmuk polimorfik yang diasingkan ialah empat untuk A. alba, empat untuk S. alba dan tiga untuk R mucronata. Tiga populasi dari Semenanjung Tanah Melayu digunakan dalam penilaian parameter genetik penanda-penanda ini. Bilangan alel setiap lokus dalam setiap populasi berjulat an tara 1-13 untuk A. alba, 1-6 untuk S. alba dan 1-3 untuk R. mucronata. Keheterozigotan yang dijangkakan bagi setiap populasi adalah dalam lingkungan 0.000-0.877 untuk A. alba, 0.000-0.647 untuk S. alba dan 0.000-0.558 untuk R mucronata. Kesemua 11 penanda mikrosatelit adalah polimorfik dalam dan di antara populasi. Kebanyakan penanda ini boleh digunakan untuk spesies bakau yang berkait rapat: Avicennia rumphiana, Sonneratia caseolans, S. ovata, Rhizophora stylosa dan R apiculata. Ini menunjukkan kegunaan penanda-penanda ini dalam kajian genetik populasi dan penyelidikan ten tang hutan bakau.
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Dostopno za:
BFBNIB, DOBA, FFLJ, IZUM, KILJ, NMLJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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