•Hydrogenation reaction processes of Fe–Mo at 6 GPa and 750 °C were investigated.•Two kinds of novel hydrides were synthesized.•The hydrogenation reaction process was classified into three types.
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Conventional hydrides obtained thus far contain at least one type of metal with high hydrogen affinity, which can form metal hydrides near ambient pressure. In contrast, we synthesized metal hydrides comprising only metals with low hydrogenation affinity which are metals that do not form metal hydrides MHx (M stands for metal element, x > 0.5) below 1 GPa. This is because such hydrides are rare and would demonstrate novel properties and functionalities. To provide a guideline for synthesizing such hydrides, we clarified the hydrogenation reaction processes of FexMo1−x alloys at 6 GPa and 750 °C over a wide composition range of 0.41 ≤ x ≤ 0.88, where both Fe and Mo demonstrate low hydrogen affinities. Depending on the alloy composition, the hydrogenation reaction process can be classified into three types. Two kinds of novel hydrides were synthesized herein. First, FexMo1−xH (0.50 ≤ x ≤ 0.74) with metal elements at the vertices of hexagonal close-packed (hcp) lattices, and second, Fe0.88Mo0.12H with a complex crystal structure, which is likely to be a long-period close-packed structure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Over the past five decades, transitions from kelp beds (or forests) to barrens have occurred as a result of sea urchin overgrazing along the temperate coastlines. The deterioration of mature kelp ...beds has been mainly observed for
Laminaria
,
Saccharina
, and
Macrocystis
in the order Laminariales. In northern Miyagi Prefecture, Japan, the destruction of adult
Ecklonia bicyclis
kelp beds by the overgrazing of
Mesocentrotus nudus
was observed since 2013. In this study, we analyzed the process of deterioration of an
E
.
bicyclis
bed, from the changes in morphology of the thallus, with or without urchin grazing marks and urchin attachment, from video and photographic records. The processes of deterioration followed one of two strategies. In the first strategy, sea urchins climb from the stipes to the branches under calm conditions in winter. Subsequently, the fronds and branches are grazed by these urchins, as shown by large numbers of bare stipes and holdfasts. After the disappearance of the fronds and the branches, sea urchins mainly graze above the stipe bases, as illustrated by the high percentage of stipes with grazing marks. Finally, rigid holdfasts are left on the seafloor. The kelp bed is most likely to be destroyed by this grazing strategy. In the second strategy, urchins aggregate on the holdfasts of the entire plants and graze the stipe bases, particularly in February. The stipes are severely grazed by sea urchins, and the thalli above the stipe bases fall to the seafloor. Urchins aggregated firstly graze the fronds of the detached thalli followed by the branches and the stipes. The results of this study suggest that protection of the stipes from the grazing and climbing of
M
.
nudus
would be desirable for the conservation and restoration of
E
.
bicyclis
kelp beds.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The existence of large stationary gravity waves was discovered during Akatsuki's first observation sequence in 2015. In this study, the further detection of large stationary gravity waves in ...brightness temperature images over a 1.5 year period is reported. The waves periodically appeared mostly above four specific highland regions in the low latitudes when these regions were in the local afternoon. The wave amplitudes attenuated after the wave locations passed beyond the evening terminator, and the locations of the waves tended to slowly drift eastward over their lifetimes. The appearances of stationary waves depend not only on surface topography but also on latitude and local time, suggesting that solar heating during the daytime and atmospheric structure affected by solar heating may control the excitation and propagation of stationary waves.
Plain Language Summary
The Japanese Venus satellite “Akatsuki” has repeatedly found large atmospheric waves with north‐south lengths, which sometimes reach more than 10,000 km at the cloud top level on Venus (altitude ~70 km). These waves have repeatedly appeared above the Venusian highlands in low latitudes, such as Aphrodite Terra. Interestingly, the waves appeared and became clearer each time the highlands passed from noon to evening; therefore, they can be regarded as “daily” Venusian phenomena. Despite westward wind speeds reaching 100 m s−1 at the cloud top level (known as atmospheric superrotation), the east‐west propagation speeds of the large waves were nearly zero, and the waves stayed above their initial locations (stationary). This means that the origin of the waves could be the highland terrains below. Because waves can transport energy via propagation, stationary waves may transport atmospheric energy from the lower atmosphere to the cloud top level and may affect the speed of the superrotation. The existence and regular appearance of the large stationary waves indicate a continuous interaction between the lower and upper atmospheres on Venus via wave propagation, which provides a novel perspective of the Venusian atmosphere.
Key Points
Stationary gravity waves with large horizontal extent at the cloud top level of Venus have been repeatedly identified
The locations of these waves show a clear connection to Venusian highlands, and wave amplitude depends on the local time at the highlands
Monitoring of the stationary waves would bring information of the Venusian atmosphere along the wave propagation paths
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We have demonstrated an ultra-power-efficient 2 × 2 Si Mach-Zehnder interferometer optical switch with III-V/Si hybrid metal-oxide-semiconductor (MOS) phase shifters. The efficient low-loss phase ...modulation enables low-crosstalk and broadband switching in conjunction with multimode interference couplers consisting of tapered input and output ports. Owing to the negligible gate leakage current in the hybrid MOS capacitor, the power consumption required for switching is 0.18 nW, approximately 10
times smaller than that of a Si thermo-optic phase shifter. We also demonstrated a switching time of less than 20 ns. The III-V/Si hybrid MOS phase shifter is promising for fabricating large-scale Si photonic integrated circuits that require efficient, low-loss, and high-speed optical phase control.
Four types of meso -phenyl or pyridyl-substituted monocationic antimony( v ) porphyrin derivatives (Sb V Pors)—5,10,15,20-tetraphenyl; 5,10,15-triphenyl-20-mono(4-pyridyl); ...5,15-diphenyl-10,20-di(4-pyridyl); and 5,10,15,20-tetra(4-pyridyl)porphyrinato dihydroxo antimony( v ) chloride—with different hydrophobicities were synthesised, and their photochemical properties on anionic clay were investigated. The absorption and fluorescence behaviour of the Sb V Pors were strongly affected by complex formation with clay. Interestingly, the absorption transition probabilities and fluorescence quantum yields of the Sb V Pors prominently increased on the clay surface. The more hydrophobic Sb V Por showed greater absorption transition probability increase and fluorescence quantum yield enhancement. These unique effects of the highly flat clay surface on the photochemical behaviour of Sb V Por were discussed mainly from the viewpoint of transition probability, by using the potential energy curves of Sb V Por with and without clay. For the more hydrophobic Sb V Por, the molecular structure of the ground and excited states on the clay surface tended to become similar because of the strong hydrophobic interaction between porphyrin and the clay surface, i.e. the ‘structure resembling effect’. This effect induces a change in the transition probabilities.
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IJS, KILJ, NUK, UL, UM, UPUK
Abstract Left ventricular–arterial (VA) coupling has been recognized to be of great significance in understanding both the global and local mechanical performance of the circulatory system. In this ...study, a closed-loop multi-scale model of the human cardiovascular system is established for the purpose of studying the coupled VA hemodynamic changes during aging. Obtained results show that age-associated changes in arterial properties have some negative but relatively small influences on left ventricular (LV) mechanical performance, whereas they progressively increase LV and aortic systolic pressures, and aortic pulse pressure during aging. Wave analysis reveals that increased aortic characteristic impedance and premature wave reflection induced by arterial stiffening are two coexistent factors responsible for aortic systolic hypertension and increased aortic pulse pressure at old age. In contrast, aortic dilatation can partly counteract the negative influences of arterial stiffening. Coupled LV-systolic and arterial stiffening (a constant VA coupling index) well preserves LV mechanical performance given normal LV diastolic function during aging, but with a concomitant further elevation of LV and aortic systolic pressures. Furthermore, it is found that the states of arterial, LV-systolic and diastolic stiffness can be distinguished by investigating the sensitivity of LV-systolic pressure to various cardiac indices.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We describe a surgical technique to re‐establish urine flow in a 3‐year‐old Scottish Fold cat. A ureteral stent and subcutaneous urinary bypass failed after their placement due to rapid ...mineralisation of the lumen. Direct pelvicocystostomy anastomosis using a modified tube cystoplasty technique was performed. A wide rectangular apex‐based full‐thickness flap was created from the ventral aspect of the urinary bladder, which was sutured longitudinally to form a large‐diameter tube. The resulting tube‐shaped portion of the bladder was then directly anastomosed to the renal pelvis. No major postoperative complications were observed and no further recurrence of obstruction of the upper urinary tract was noted during follow‐up. The cat died at home 481 days postoperatively from an undetermined cause. A pelvicocystostomy technique can be considered as an alternative salvage surgical technique for obstructive ureteral disease in cats.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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