The lattice and electronic response in the course of concomitant charge and orbital-ordering transition has been investigated for single crystals of layered manganites, single-layered La 0.5 Sr 1.5 MnO 4 , and bilayered LaSr 2 Mn 2 O 7 , by Raman-scattering spectroscopy. In the charge-orbital-ordered state (TϽ217 K for La 0.5 Sr 1.5 MnO 4 and ϳ100 KϽTϽ210 K for LaSr 2 Mn 2 O 7 ), four phonon modes are activated in the MnO 2 plane, indicating the existence of both Jahn-Teller type and breathing mode type lattice distortions. The diffuse scattering response with B 1g symmetry is suppressed in the charge-orbital-ordered state, both for La 0.5 Sr 1.5 MnO 4 and LaSr 2 Mn 2 O 7 , signaling that the fluctuation caused by the dynamical charge-orbital correlation is suppressed in the charge-orbital-ordered state. These features reveal the unique nature of the chargeorbital-ordering transition realized by the complex interplay of charge and orbital degrees of freedom.

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Conventionally organic carbon is assumed to be the limiting nutrient of regrowth. Inorganic phosphorus in comparison to carbon should be a good candidate for regrowth control because it can be measured and controlled. It may be able to limit regrowth in drinking water distribution systems. In order to clarify whether inorganic phosphorus can really control or limit regrowth, three kinds of bioassays were performed: 1. for different combinations of acetate, phosphorus, and other inorganic nutrients added to different test tubes containing pure water, 2. for different tap water dilutions with pure water, and 3. for different phosphorus addition to test tubes containing all nutrients but phosphorus. The inoculum used was taken from a drinking water distribution system carrying chlorinated groundwater. Results indicated the following: 1. tap water bacteria cannot grow on simple organic carbon source (acetate) alone, 2. not organic carbon but inorganic nutrients limited the growth in tap water, and 3. tap water bacterial growth was suppressed when phosphorus was not present and it was not affected by over-presence of phosphorus when carbon or other nutrients became limiting. This gave a clue that phosphorus might play a major role in controlling regrowth in drinking water distribution system.

Aerobic oxidation of native soft wood lignin in an aqueous solution of Bu4NOH facilitates efficient production of vanillin (4-hydroxy-3-methoxybenzaldehyde), which is one of the platform chemicals in industry.

We examined the photo-induced dynamics of ferromagnetic Co/Pt thin films exhibiting perpendicular magnetic anisotropy by means of the resonant polar magneto-optical Kerr effect with element specificity. The investigation was conducted at Pt N6,7 and Co M2,3 edges using an x-ray free electron laser. The obtained results showed a clear element dependence of photo-induced demagnetization time scales: τdemag.Co=80±60 fs and τdemag.Pt=640±140 fs. This dependence is explained by the induced moment of the Pt atom by current flow from the Co layer through the interfaces. The observed magnetization dynamics can be attributed to the characteristics of photo-induced Co/Pt thin film phenomena including all-optical switching.

In periodic systems, electronic wave functions of the eigenstates exhibit the periodically modulated Bloch phases and are characterized by their wave numbers k. We theoretically address the effects of the Bloch phase in general layered materials with stacking shift. When the interlayer shift and the Bloch wave vector k satisfy certain conditions, interlayer transitions of electrons are prohibited by the interference of the Bloch phase. We specify the manifolds in the k space where the hybridization of the Bloch states between the layers is suppressed in accord with the stacking shift. These manifolds, named stacking-adapted interference manifolds (SAIM), are obviously applicable to general layered materials regardless of detailed atomic configuration within the unit cell. We demonstrate the robustness and usefulness of the SAIM with first-principles calculations for layered boron nitride, transition-metal dichalcogenide, graphite, and black phosphorus. We also apply the SAIM to general three-dimensional crystals to derive special k-point paths for the respective Bravais lattices, along which the Bloch-phase interference strongly suppresses the band dispersion. Our theory provides a general and novel view on the anisotropic electronic kinetics intrinsic to the periodic-lattice structure.

The efficient conversion of lignin, a major component of lignocellulosics, to monomeric aromatics is a hot topic in biorefining. In this study, we developed a method for selective degradation of several types of lignin [milled wood lignin, sodium lignosulfonate, soda lignin, and Japanese cedar (Cryptomeria japonica) wood flour] in Bu 4 NOH•30H 2 O (mp 27−30 °C). Degradation at 120 °C for 43−70 h gave low-molecular-weight (MW) compounds such as vanillin, vanillic acid, acetoguiacone, and p-hydroxybenzaldehyde in considerable yields. The total yields were 16.3, 6.5, 6.7, and 22.5 wt % from milled wood lignin, sodium lignosulfonate, soda lignin, and wood flour, respectively. Similar degradation in aqueous NaOH solution with the same OH − concentration (1.25 mol/L) as that in molten Bu 4 NOH•30H 2 O gave much lower yields of these products. This suggests that in addition to the effect of Bu 4 NOH•30H 2 O as a strong alkali, the Bu 4 N + cation increased the selectivity of lignin degradation for low-MW products. Degradation under N 2 gave significantly lower yields of the low-MW products, even in Bu 4 NOH•30H 2 O, suggesting that aerobic oxidation is involved in the formation of low-MW compounds and oxidation is affected by the presence of the Bu 4 N + cation.

Experiments of time-resolved x-ray magnetic circular dichroism (Tr-XMCD) and resonant x-ray scattering at a beamline BL07LSU in SPring-8 with a time-resolution of under 50 ps are presented. A micro-channel plate is utilized for the Tr-XMCD measurements at nearly normal incidence both in the partial electron and total fluorescence yield (PEY and TFY) modes at the L 2,3 absorption edges of the 3d transition-metals in the soft x-ray region. The ultrafast photo-induced demagnetization within 50 ps is observed on the dynamics of a magnetic material of FePt thin film, having a distinct threshold of the photon density. The spectrum in the PEY mode is less-distorted both at the L 2,3 edges compared with that in the TFY mode and has the potential to apply the sum rule analysis for XMCD spectra in pump-probed experiments.Control of electron, magnetic, and lattice states by optical excitations in magnetically ordered materials has attracted considerable attention due to their potential applications in electronic and magnetic recording media functioning on an ultrafast time scale below nanosecond (ns, 10 −9 second, GHz range), since the observation of the ultrafast demagnetization in Ni within 1 picosecond (ps). 1 The ultrafast photo-induced changes of magnetic states are non-equilibrium phenomena and several mechanisms have been proposed to understand them. 2-4 These phenomena generally involve fast structural changes near surface region 5,6 and therefore require cooperative effects, inevitably having a threshold of the photon density.To capture their non-equilibrium dynamics, ultrafast time-resolved experiments have been carried out using ultra-short laser pulses. 3 Recently, the development of a bunched synchrotron light source, 7-11 and x-ray free electron lasers 12-14 have enabled investigation of the dynamic phenomena with element selectivity by tuning the photon energy of the x-ray to the absorption edges of the constituent elements. Especially, time-resolved soft x-ray spectroscopy has many unique characteristics, such as element specificity, chemical specificity and surface sensitivity, which make them versatile for application in a wide range of scientific fields including spintronics and environmental science. Owing to its importance, various time-resolved soft x-ray spectroscopy studies have been carried out. [15][16][17][18][19][20][21] The time-resolved x-ray magnetic circular dichroism (Tr-XMCD) and resonant soft x-ray scattering (Tr-RSXS) measurements for magnetic and electronic materials have been conducted in LCLS, 13,14 ALS, 9 and BESSY II slicing facilities. 10,11,[15][16][17][18][19] The timeresolved x-ray magneto optical Kerr effect (XMOKE) measurements have also been conducted in FERMI. 12 Tr-XMCD measurements at the M absorption below hv <100 eV have also been performed by using high harmonics generation from tabletop lasers in recent years. 22 XMCD at the L 2,3 absorption of 3d transition-metals a) Electronic mail: ktakubo@issp.u-tokyo.ac.jp in the soft x-ray region (hv > 400 eV) is a powerful tool ...