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Effects of selenium-containing compounds on Cu^(2+)/Zn^(2+)-induced neuronal cell death and potential application as therapeutic agents for neurological diseases

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Neural Regeneration Research 2022年第2期17卷 311-312页

作者： ken-ichiro Tanaka Mikako Shimoda Masahiro Kawahara Department of Bio-Analytical Chemistry Faculty of PharmacyMusashino UniversityShinmachiNishitokyoTokyoJapan

In many tissues, trace metals such as iron(Fe), zinc(Zn), and copper(Cu) are important for various physiological functions such as immune function, cell division, and enzyme function. However, it has been shown in humans and experimental animal models that excessive amounts of these trace metals in the body can induce various diseases in the central nervous system, liver.

关键词： metals potential copper

Chitosan and chemically modified chitosan beads for acid dyes sorption

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Journal of Environmental Sciences 2009年第3期21卷 296-302页

作者： AZLAN Kamari WAN SAIME Wan Ngah LAI ken Liew Department of Chemistry Faculty of Science and Technology Universiti Pendidikan Sultan Idris School of Chemical Sciences Universiti Sains Malaysia

The capabilities of chitosan and chitosan-EGDE （ethylene glycol diglycidyl ether） beads for removing Acid Red 37 （AR 37） and Acid Blue 25 （AB 25） from aqueous solution were examined. Chitosan beads were cross-linked with EGDE to enhance its chemical resistance and mechanical strength. Experiments were performed as a function ofpH, agitation period and concentration of AR 37 and AB 25. It was shown that the adsorption capacities of chitosan for both acid dyes were comparatively higher than those of chitosan- EGDE. This is mainly because cross-linking using EGDE reduces the major adsorption sites -NH3＋ on chitosan. Langmuir isotherm model showed the best conformity compared to Freundlich and BET. The kinetic experimental data agreed very well to the pseudo second-order kinetic model. The desorption study revealed that after three cycles of adsorption and desorption by NaOH and HCl, both adsorbents retained their promising adsorption abilities. FT-IR analysis proved that the adsorption of acid dyes onto chitosan-based adsorbents was a physical adsorption. Results also showed that chitosan and chitosan-EGDE beads were favourable adsorbers and could be employed as low-cost alternatives for the removal of acid dyes in wastewater treatment.

关键词： cross-linking acid dyes adsorption capacities adsorption rates adsorption isotherm desorption

A pulse of the Earth: A 27.5-Myr underlying cycle in coordinated geological events over the last 260 Myr

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Geoscience Frontiers 2021年第6期12卷 236-242页

作者： Michael R.Rampino ken Caldeira Yuhong Zhu Departments of Biology and Environmental Studies New York University100 Washington Square EastNew YorkNY 10003USA Department of Global Ecology Carnegie Institution for Science290 Panama StreetStanfordCA 94305USA Center for Data Science New York University60 Fifth AvenueNew YorkNY 10011USA

We performed spectral analyses on the ages of 89 well-dated major geological events of the last 260 Myr from the recent geologic literature. These events include times of marine and non-marine extinctions,major ocean-anoxic events, continental flood-basalt eruptions, sea-level fluctuations, global pulses of intraplate magmatism, and times of changes in seafloor-spreading rates and plate reorganizations. The aggregate of all 89 events shows ten clusters in the last 260 Myr, spaced at an average interval of ~ 26.9 Myr, and Fourier analysis of the data yields a spectral peak at 27.5 Myr at the ≥96% confidence level. A shorter period of ~ 8.9 Myr may also be significant in modulating the timing of geologic *** results suggest that global geologic events are generally correlated, and seem to come in pulses with an underlying ~ 27.5-Myr cycle. These cyclic pulses of tectonics and climate change may be the result of geophysical processes related to the dynamics of plate tectonics and mantle plumes, or might alternatively be paced by astronomical cycles associated with the Earth’s motions in the Solar System and the Galaxy.

关键词： Global geological events Fourier analysis Cyclic pulses Tectonics Correlations

Low-loss wide-bandwidth planar transmission line with a laminated conductor

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Science China(Information Sciences) 2023年第5期66卷 248-256页

作者： ken NING Xiao-Chun LI Yan SHAO Junfa MAO Key Laboratory of Ministry of Education of Design and Electromagnetic Compatibility of High-Speed Electronic Systems Shanghai Jiao Tong University

In this paper, the laminated conductor technology is first introduced to planar-integrated transmission lines. The laminated conductor is composed of multilayers of metal and insulator, which has a lower conductor loss than a solid conductor. Based on the silicon-based micro electromechanical system technology,a laminated coplanar waveguide(CPW) with wide bandwidth and low loss is proposed, which uses a laminated conductor for signal lines and grounds. A laminated CPW and its transition are designed, fabricated,and measured. The simulation results show that the laminated CPW with many insulator layers has a low conductor loss. The measurement results illustrate that the average insertion loss of the laminated CPW is0.65 d B from DC to 40 GHz, which is 44.4% smaller than that of the solid CPW.

关键词： coplanar waveguide (CPW) laminated conductor conductor loss skin effect silicon-based technology wide-bandwidth

In situ formation of an intimate solid-solid interface by reaction between MgH_(2) and Ti to stabilize metal hydride anode with high active material content

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Journal of Magnesium and Alloys 2024年第8期12卷 3193-3203页

作者： Yixin Chen Atsushi Inoishi Shigeto Okada Hikari Sakaebe ken Albrecht Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityKasuga-koen 6-1KasugaFukuoka 816-8580Japan Institute for Materials Chemistry and Engineering Kyushu UniversityKasuga-koen 6-1KasugaFukuoka 816-8580Japan Transdisciplinary Research and Education Centre for Green Technology Kyushu UniversityKasuga-koen 6-1KasugaFukuoka 816-8580Japan

MgH_(2) and TiH_(2) have been extensively studied as potential anode materials due to their high theoretical specific capacities of 2036 and 1024 mAh/g,***,the large volume changes that these compounds undergo during cycling affects their performance and limits practical *** present work demonstrates a novel approach to limiting the volume changes of active *** effect is based on mechanical support from an intimate interface generated in situ via the reaction between MgH_(2) and Ti within the electrode prior to lithiation to form Mg and TiH_(2).The resulting Mg can be transformed back to MgH_(2) by reaction with LiH during *** addition,the TiH_(2) improves the reaction kinetics of MgH_(2) and enhances electrochemical *** intimate interface produced in this manner is found to improve the electrochemical properties of a MgH_(2)-Ti-LiH *** exceptional reversible capacity of 800 mAh/g is observed even after 200 cycles with a high current density of 1 mA/cm^(2) and a high proportion of active material(90 wt.%)at an operation temperature of 120℃.This study therefore showcases a new means of improving the performance of electrodes by limiting the volume changes of active materials.

关键词： All-solid-state battery In situ formation of solid electrolyte In situ formed intimate interface MgH_(2)anode

Examination on the wear process of polyformaldehyde gears under dry and lubricated conditions

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Friction 2021年第3期9卷 538-550页

作者： Guoda YU Huaiju LIU ken MAO Caichao ZHU Zehua LU State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400030China School of Engineering the University of WarwickCoventry CV47ALUK

This study presents the results of detailed wear process examination on polyformaldehyde gears under both dry and lubricated conditions.A multi-purpose durability test rig was employed to study the wear performance of polyformaldehyde gear *** wear behaviors of polyformaldehyde gears under dry and oil-lubricated operating conditions were characterized via measurements of gear tooth surface micro-topography and tooth profile *** the dry running condition,a hump and a gully appear on the tooth surface in the pitch line area of the driving gear and the driven wheel,*** largest amount of wear was observed around the tooth root of the driving ***,the gear tooth wear pattern with lubrication is different from that under the dry running condition.

关键词： polyformaldehyde gear lubrication wear surface damage

Carbon nanosheets derived from reconstructed lignin for potassium and sodium storage with low voltage hysteresis

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Nano Research 2021年第12期14卷 4664-4673页

作者： Keren Jiang Xuehai Tan Shengli Zhai ken Cadien Zhi Li Department of Chemical and Materials Engineering University of AlbertaEdmontonAlbertaT6G 1H9Canada

Lignin is the second most abundant and the only nature polymer rich in aromatic *** aromatic-unit-rich precursors often yield soft carbon after carbonization,the side chains in lignin crosslink with the aromatic units and form a rigid three-dimensional(3D)structure which eventually leads to hard *** a graphene oxide-catalyzed decomposition and repolymerization process,we successfully reconstructed lignin by partially tailoring the side *** to directly carbonized lignin,the carbonized reconstructed lignin possesses significantly fewer defects,86%fewer oxygen-functionalities,82%fewer micropores,and narrower interlayer *** parameters can be tuned by the amount of catalysts(graphene oxide).When tested as anode for K-ion and Na-ion batteries,the carbonized reconstructed lignin delivers notably higher capacity at low-potential range(especially for Na-storage),shows much-improved performance at high current density,and most importantly,reduces voltage hysteresis between discharge and charge process by more than 50%,which is critical to the energy efficiency of the energy storage *** study reveals that the voltage hysteresis in K-storage is much severer than that in Na-storage for all *** practical K-ion battery applications,the voltage hysteresis deserves more attention in future electrode materials design and the reconstruct ion strategy introduced in this work provides potential low-cost solution.

关键词： lignin batteries polarization voltage hysteresis ring-forming defects

Elastic line deformed on a pseudo-hypersurface by an external field in pseudo-Euclidean spaces

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Science China Mathematics 2008年第2期51卷 233-240页

作者： YCESAN Ahmet ken A.Ceylan Department of Mathematics Süleyman Demirel University32260 IspartaTurkey

We derive intrinsic formulation for elastic line deformed on a pseudo-hypersurface by an external field in the pseudo-Euclidean spaces E_v^*** formulation determines elastic line deformed on a pseudo-hypersurface.

关键词： elastic line pseudo-Euclidean spaces intrinsic formulation external field 53A35 53B30 74M30

Numerical and Experimental Studies of an Arc-heated Nonequilibrium Nozzle Flow

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Journal of Thermal Science 2003年第4期12卷 289-293页

作者： Michio Nishida ken-ichi Abe Hisashi Kihara Department of Aeronautics and Astronautics Kyushu University Fukuoka 812-8581 JapanDepartment of Aeronautics and Astronautics Kyushu University Fukuoka 812-8581 JapanDepartment of Aeronautics and Astronautics Kyushu University Fukuoka 812-8581 Japan

The arc-heated high-temperature gas is rotationally and vibrationally excited, and partially dissociated and ionized. When such gas flows inside a nozzle, energy transfers from rotational and vibrational energy modes to translational energy mode, and, in addition, recombination reactions occur. These processes are in thermal and chemical nonequilibrium. The present computations treat arc-heated nonequilibrium nozzle flows using a six temperature model (translational, rotational, N2 vibrational, O2 vibrational, NO vibrational and electron temperatures), and nonequilibrium chemical reactions of air. From the calculated flow properties, emission spectra at the nozzle exit were re-constructed by using the code for computing spectra of high temperature air. On the other hand, measurements of N2+(1-) emission spectra were conducted at the nozzle exit in the 20 kW arc-heated wind tunnel. Vibrational and rotational temperatures of N2 were determined using a curve fitting method on N2+(1-) emission spectra, with the vibrational and rotational temperatures for N2 and N2+ being assumed equal. Comparison of the measured and computed results elucidated that the experimental temperatures were larger than the computed ones. At present, we are trying to reveal the main reason for the discrepancy between the computed and measured N2 vibrational and rotational temperatures.

关键词： nozzle flow high temperature gas nonequilibrium flow arc-heated gas.