超臨界メタノール中での木質バイオマスの分解挙動

京都大学新制・課程博士博士(エネルギー科学)甲第24922号エネ博第464号京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻(主査)教授 河本 晴雄, 教授 亀田 貴之, 准教授 南 英治学位規則第4条第1項該当Doctor of Energy ScienceKyoto UniversityDFA

Influence of Proteins on the Lignin Decomposition Behavior of Japanese Cedar (Cryptomeria japonica) Wood by Supercritical Methanol Treatment

The effect of adding protein on the decomposition behavior of lignin in Japanese cedar under supercritical methanol conditions (270 °C/27 MPa) was studied. The Klason method was used to detect the lignin content in the insoluble residue following to a 30 min treatment. Adding either an animal (bovine serum albumin) or plant (soy) protein enhanced delignification from 50 to 65% of the lignin-based wt %. This result was attributed to enhanced lignin depolymerization owing to inhibited lignin recondensation and/or the suppressed formation of polysaccharide-derived char via reactions between the protein and polysaccharides. Although the solubilization of lignin was promoted and the yield of lignin-derived low-molecular-weight compounds increased, the selectivity of major monomers such as coniferyl alcohol (CA) and γ-methylated CA decreased. The addition of proteins has a substantial impact on the decomposition behavior of cell wall components under supercritical methanol conditions. This information provides insights into the use of protein-rich lignocelluloses

Single-shot compressed ultrafast photography: a review

Compressed ultrafast photography (CUP) is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred frames. This technique synergizes compressed sensing and the streak camera technique to capture nonrepeatable ultrafast transient events with a single shot. With recent unprecedented technical developments and extensions of this methodology, it has been widely used in ultrafast optical imaging and metrology, ultrafast electron diffraction and microscopy, and information security protection. We review the basic principles of CUP, its recent advances in data acquisition and image reconstruction, its fusions with other modalities, and its unique applications in multiple research fields

Colorimetric/ratio fluorescence determination of glucose using bifunctional carbon dots

Based on biomass (taro leaf). Iron was prepared by hydrothermal method with ammonium ferric sulfate dodecahydrate and urea as raw materials. Nitrogen Co doped carbon dots (Fe, N-CDs) were characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The Fe, N-CDs not only has peroxidase like activity, but also can produce strong fluorescence emission at 450 nm. Using Fe, N-CDs and o-phenylenediamine (OPD) as probes, a dual signal colorimetric/ratio fluorescence method for the determination of hydrogen peroxide (H2O2) was established. In the presence of H2O2, Fe, N-CDs catalyze the oxidation of OPD to yellow 2, 3-diaminophenazine (DAP), which has a characteristic absorption peak at 420 nm. Under the excitation of 360 nm wavelength light, DAP has strong fluorescence emission at 550 nm; DAP can quench the fluorescence of Fe and N-CDs at 450 nm due to the fluorescence internal filtering effect. Based on this, the absorbance of DAP at 420 nm (A420) and the fluorescence intensity ratio of DAP to Fe, N-CDs (I550/I450) can be used for the quantitative analysis of H2O2. Considering that glucose oxidase can catalyze the oxidation of glucose to H2O2, a colorimetric/ratio fluorescence dual signal glucose determination method was further developed. Under the conditions of pH=5.4, temperature 40℃, 1.75 mmol/L OPD and reaction time 25 min, when the glucose concentration is in the range of 1.0~100μmol/L, the values of A420 and I550/I450 have a good linear relationship with the concentration, and the detection limits of the method are respectively 0.8 (colorimetry) and 0.6 μmol/L (ratio fluorescence). The method was successfully applied to the determination of glucose in human serum

Hidden Real Topology and Unusual Magnetoelectric Responses in Monolayer Antiferromagnetic Cr2_2Se2_2O

Recently, the real topology has been attracting widespread interest in two dimensions (2D). Here, based on first-principles calculations and theoretical analysis, we reveal the monolayer Cr$_2$Se$_2$O (ML-CrSeO) as the first material example of a 2D antiferromagnetic (AFM) real Chern insulator (RCI) with topologically protected corner states. Unlike previous RCIs, we find that the real topology of the ML-CrSeO is rooted in one certain mirror subsystem of the two spin channels, and can not be directly obtained from all the valence bands in each spin channel as commonly believed. In particular, due to antiferromagnetism, the corner modes in ML-CrSeO exhibit strong corner-contrasted spin polarization, leading to spin-corner coupling (SCC). This SCC enables a direct connection between spin space and real space. Consequently, large and switchable net magnetization can be induced in the ML-CrSeO nanodisk by electrostatic means, such as potential step and in-plane electric field, and the corresponding magnetoelectric responses behave like a sign function, distinguished from that of the conventional multiferroic materials. Our work considerably broadens the candidate range of RCI materials, and opens up a new direction for topo-spintronics and 2D AFM materials research