Ground state of the spin-1/2 chain of green dioptase at high fields

The gem-stone dioptase Cu6Si6O18.6H2O has a chiral crystal structure of equilateral triangular helices consisting of Cu-3d spins. It shows an antiferromagnetic order with an easy axis along c at TN = 15.5 K under zero field, and a magnetization jump at HC = 13.5 T when the field is applied along c-axis. By 29Si-NMR measurements, we have revealed that the high-field state is essentially the two sub-lattice structure, and that the component within ab-plane is collinear. The result indicates no apparent match with the geometrical pattern of helical spin chain.Comment: SCES2013, Hongo, Toky

Removal of accidentally ingested large foreign object via the anus after watchful waiting

One of the commonest complaints, for which a patient arrives in hospitals, is the presence of foreign body. It could be due to accidental ingestion or any other cause which leads to presences of a foreign body in the gastrointestinal tract. It is believed that foreign objects larger than 5–6 cm in size are unlikely to pass through the duodenum. Here, we describe a case wherein the patient accidentally swallowed a 7-cm-sized mouthguard that could not be removed by emergency upper gastrointestinal endoscopy but was subsequently removed via the anus after a period of watchful waiting

Carbonization of Wood-Silica Composites and Formation of Silicon Carbide in the Cell Wall

Wood-mineral composites (WMCs) impregnated with silica (SiO2) were carbonized at high temperature to form silicon carbide (SiC) directly using carbon from the wood with the impregnated silica. Carbonized composites were investigated using X-ray diffraction and EPMA (electron probe X-ray microanalysis). Water-saturated sapwood specimens of sugi, Japanese cedar (Cryptomeria japonica), were diffuse-penetrated with a colloidal silica solution or a water glass solution followed by drying to fix silica gel for preparing wood-SiO2 composites. The composites were burned at 600°C, 1000°C, and 1300°C for 30-120 minutes in a furnace in nitrogen gas. X-ray diffraction showed that the peak of SiO2 was recognized at 20 = 22°, and the peak became greater with an increase in burning temperature. The peak at 1300°C became very sharp, revealing the change of crystalline structure of SiO2 (cristobalite). In addition, the occurrence of the peak around 20 = 35° at 1300°C appeared, which confirmed the formation of silicon carbide (β-SiC) in the carbonized composites. EPMA observation showed the distribution of silicon in the cell walls that were carbonized at 1300°C. In conclusion, we showed that SiC was produced in the cell walls and the crystalline structure-changed SiO2 (cristobalite) existed in the cell lumina

モクシツ タンソ オ モチイタ シンキ タンカ ケイソ ネツデン ヘンカン ザイリョウ ノ カイハツ

京都大学0048新制・課程博士博士(農学)甲第13138号農博第1643号新制||農||943(附属図書館)学位論文||H19||N4264(農学部図書室)UT51-2007-H411京都大学大学院農学研究科森林科学専攻(主査)教授 今村 祐嗣, 教授 中野 隆人, 教授 橋本 弘藏学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA

Effect of graphene on plasmonic metasurfaces at infrared wavelengths

Significant enhancement of infrared transmittance by the presence of a graphene layer on a plasmonic metasurface (PLM) has been demonstrated. PLMs with different configurations were fabricated, and their transmittance with and without graphene was compared. Selective enhancement by graphene occurred at the plasmon resonance wavelength. The degree of enhancement was found to depend on the width of the gap between the periodic metal regions in the PLM. A maximum enhancement of ∼210% was achieved at a wavelength of 10 μm. The ability to achieve such a drastic increase in transmittance at the plasmon resonant wavelength is expected to lead to improvements in the performance of energy collecting devices and optical sensors