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Wenliang Zhu

Bio: Wenliang Zhu is an academic researcher from Kyoto Institute of Technology. The author has contributed to research in topics: Raman spectroscopy & Cathodoluminescence. The author has an hindex of 22, co-authored 204 publications receiving 2208 citations. Previous affiliations of Wenliang Zhu include Chinese Academy of Sciences & Fraunhofer Society.


Papers
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TL;DR: In this paper, kelp-like structured NiCo2S4-C-MoS2 composite electrode materials for supercapacitors were successfully synthesized by a facile hydrothermal and solvothermal method.

80 citations

Journal ArticleDOI
TL;DR: In this paper, vanadium pentoxide and reduced graphene oxide (rGO) nanocomposites were synthesized by a simple solvothermal process with subsequent annealing treatment.

65 citations

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TL;DR: New insights are obtained into the biological interactions between Si3N4 and living cells, as a consequence of the off-stoichiometric chemical nature of its surface at the nanometer scale and it is suggested that Si3n4 might provide unique new medicinal therapies and effective remedies for various bone or joint maladies and diseases.
Abstract: While the reciprocity between bioceramics and living cells is complex, it is principally governed by the implant’s surface chemistry. Consequently, a deeper understanding of the chemical interactions of bioceramics with living tissue could ultimately lead to new therapeutic strategies. However, the physical and chemical principles that govern these interactions remain unclear. The intricacies of this biological synergy are explored within this paper by examining the peculiar surface chemistry of a relatively new bioceramic, silicon nitride (Si3N4). Building upon prior research, this paper aims at obtaining new insights into the biological interactions between Si3N4 and living cells, as a consequence of the off-stoichiometric chemical nature of its surface at the nanometer scale. We show here yet unveiled details of surface chemistry and, based on these new data, formulate a model on how, ultimately, Si3N4 influences cellular signal transduction functions and differentiation mechanisms. In other words, we interpret its reciprocity with living cells in chemical terms. These new findings suggest that Si3N4 might provide unique new medicinal therapies and effective remedies for various bone or joint maladies and diseases.

61 citations

Journal ArticleDOI
16 Mar 2016-Langmuir
TL;DR: Exploiting the peculiar surface chemistry of Si3N4 bioceramics could be helpful in counteracting Porphyromonas gingivalis in an alkaline pH environment.
Abstract: Organisms of Gram-negative phylum bacteroidetes, Porphyromonas gingivalis, underwent lysis on polished surfaces of silicon nitride (Si3N4) bioceramics. The antibacterial activity of Si3N4 was mainly the result of chemically driven principles. The lytic activity, although not osmotic in nature, was related to the peculiar pH-dependent surface chemistry of Si3N4. A buffering effect via the formation of ammonium ions (NH4(+)) (and their modifications) was experimentally observed by pH microscopy. Lysis was confirmed by conventional fluorescence spectroscopy, and the bacteria's metabolism was traced with the aid of in situ Raman microprobe spectroscopy. This latter technique revealed the formation of peroxynitrite within the bacterium itself. Degradation of the bacteria's nucleic acid, drastic reduction in phenilalanine, and reduction of lipid concentration were observed due to short-term exposure (6 days) to Si3N4. Altering the surface chemistry of Si3N4 by either chemical etching or thermal oxidation influenced peroxynitrite formation and affected bacteria metabolism in different ways. Exploiting the peculiar surface chemistry of Si3N4 bioceramics could be helpful in counteracting Porphyromonas gingivalis in an alkaline pH environment.

61 citations

Journal ArticleDOI
TL;DR: In this paper, the full set of Raman tensor elements was experimentally determined for the corundum structure of a sapphire single-crystal, and a tensorial algorithm was proposed for the practical determination of unknown crystallographic textures in polycrystalline alumina materials.
Abstract: Raman selection rules were theoretically put forward and, according to the obtained relationships, the full set of Raman tensor elements was experimentally determined for the corundum structure of a sapphire single-crystal. The knowledge of the Raman selection rules allowed us to represent the change in polarizability of the aluminium oxide molecule with respect to each of the available vibrational modes. Restrictions related to the symmetry of the scattering system are also discussed together with directional properties, thus leading to unambiguous assignment of the fundamental modes available in sapphire single-crystal. From the experimental side, scattering intensities of Raman bands located at 378 cm–1 and 417 cm–1, which correspond to the Eg and the A1g phonon modes of the corundum structure, respectively, were collected in selected polarization configurations as a function of in-plane rotation angle on different crystallographic planes. Fitting to theoretical equations (i.e., worked out for different crystallographic orientations) enabled us to unequivocally define the elements of the Raman tensor. Finally, a tensorial algorithm was proposed for the practical determination of unknown crystallographic textures in polycrystalline alumina materials, an issue of significant importance in materials science. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

55 citations


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TL;DR: This Review presents a comprehensive review of the use of ferroelectric polymers, especially PVDF and PVDF-based copolymers/blends as potential components in dielectric nanocomposite materials for high energy density capacitor applications.
Abstract: Dielectric polymer nanocomposites are rapidly emerging as novel materials for a number of advanced engineering applications. In this Review, we present a comprehensive review of the use of ferroelectric polymers, especially PVDF and PVDF-based copolymers/blends as potential components in dielectric nanocomposite materials for high energy density capacitor applications. Various parameters like dielectric constant, dielectric loss, breakdown strength, energy density, and flexibility of the polymer nanocomposites have been thoroughly investigated. Fillers with different shapes have been found to cause significant variation in the physical and electrical properties. Generally, one-dimensional and two-dimensional nanofillers with large aspect ratios provide enhanced flexibility versus zero-dimensional fillers. Surface modification of nanomaterials as well as polymers adds flavor to the dielectric properties of the resulting nanocomposites. Nowadays, three-phase nanocomposites with either combination of fillers...

1,143 citations

Journal ArticleDOI
TL;DR: In this article, a review of recent advances in supercapacitor (SC) technology with respect to charge storage mechanisms, electrode materials, electrolytes (e.g., particularly paper/fiber-like 3D porous structures), and their practical applications is presented.

1,058 citations

Journal Article
TL;DR: In this article, a theory of the band strength based on the point-charge model and p-d mixing has been developed and applied to the data with results in fair agreement with experiment.
Abstract: The polarized optical spectra of the ions Ti3+, V3+, Cr3+, Mn3+, Co3+, and Ni3+ in corundum single crystals have been studied at temperatures from 4.2° to 1200°K. A theory of the band strength based on the point‐charge model and p‐d mixing has been developed and applied to the data with results in fair agreement with experiment. The effects of temperature show that the vibrational‐electronic contribution to band strength is quite small at low temperature but may be appreciable at high temperatures. The crystal‐field parameters have been calculated as convergent lattice sums. The observed trigonal‐field parameter has the opposite sign from that calculated by the point‐charge model if the impurity ion is assumed to occupy an Al3+ ion position in the lattice, but has the same sign as calculated for an ion 0.1 A displaced along the c3 axis toward the empty octahedral site. Details of the spectra have been interpreted as showing that the surroundings of an ion are distorted in some electronic states.

543 citations

Journal ArticleDOI
K. Syassen1
TL;DR: In this article, the ground-state physical properties of corundum (α-Al2O3) with some emphasis on its behavior under high pressure were reviewed, and the effects of temperature and stress on the R-line luminescence of ruby were surveyed.
Abstract: The ruby luminescence method is widely used for pressure measurement in the diamond anvil cell and other optically transparent pressure cells. With this application in mind, we briefly review the ground-state physical properties of corundum (α-Al2O3) with some emphasis on its behavior under high pressure, survey the effects of temperature and stress on the R-line luminescence of ruby (Cr-doped corundum), and address the recent efforts towards an improved calibration of the R-line shift under hydrostatic pressures beyond the 50 GPa mark.

351 citations