检索结果-南通市图书馆

Improving ionic conductivity of von-Alpen-type NASICON ceramic electrolytes via magnesium doping

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2023年第5期12卷 1058-1066页

作者： il-seop Jang Wooseok go Bo-Ye Song Hayoung Park Yun Chan Kang Jinyoung Chun Emerging Materials R&D Division Korea Institute of Ceramic Engineering and Technology(KICET)Jinju 52851Republic of Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea Energy Storage and Distribution Resources Division Lawrence Berkeley National LaboratoryBerkeley 94720USA

NASICON (sodium (Na) superionic conductor) compounds have attracted considerable attention as promising solid electrolyte materials for advanced Na-based batteries. In this study, we investigated the improvement in ionic conductivities of von-Alpen-type NASICON (vA-NASICON) ceramic electrolytes by introducing a magnesium ion (Mg^(2+)) as a heterogeneous element. The optimal Mg-doped vA-NASICON exhibited a high ionic conductivity of 3.64×10^(−3) S·cm^(−1), which was almost 80% higher than that of un-doped vA-NASICON. The changes in physicochemical properties of the vA-NASICONs through the Mg introduction were systematically analyzed, and their effects on the ionic conductivities of the vA-NASICON were studied in detail. When the optimal ratio of Mg^(2+) was used in a synthetic process, the relative density (96.6%) and grain boundary ionic conductivity (σgb) were maximized, which improved the total ionic conductivity (σt) of the vA-NASICON. However, when Mg^(2+) was introduced in excess, the ionic conductivity decreased because of the formation of an undesired sodium magnesium phosphate (NaxMgyPO_(4)) secondary phase. The results of this study are expected to be effectively applied in the development of advanced sodium-based solid electrolytes with high ionic conductivities.

关键词： NASICON solid electrolyte von-Alpen-type magnesium(Mg)doping ionic conductivity

Hydrodynamics of air-kerosene bubble column under elevated pressure in homogeneous flow regime

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第5期34卷 190-202页

作者： Bay Van Tran Son Ich Ngo Young-il Lim Keon Bae Dong Hyun Lee Kang-seok go Nam-Sun Nho Center of Sustainable Process Engineering(CoSPE) Department of Chemical EngineeringHankyong National UniversityGyeonggi-doAnseong-siJungang-ro 32717579Republicof Korea School of Chemical Engineering Sungkyunkwan University2066 Seobu-roJanganSuwon 16419Republic of Korea Center for Convergent Chemical Process(CCP) 141 Gajeong-roYuseong-guDaejeon 34114Republic of Korea

A multiphase computational fluid dynamics(CFD)model coupled with the population balance equation(PBE)was developed in a homogeneous air-kerosene bubble column under elevated pressure(P).The specific pressure drop(ΔP/L),gas holdup(α_(G)),and Sauter mean diameter(d_(32))were experimentally measured in the bubble column with 1.8 m height and 0.1 m inner diameter,which was operated at a superficial gas velocity of 12.3 mm·s^(-1),and P=1-35 bar(1 bar=10^(5) Pa).A modified drag coefficient model was proposed to consider the effect of bubble swarm and pressure on hydrodynamics of the bubble *** Luo breakage model was modified to account for liquid density,viscosity,surface tension and gas ***ΔP/L,α_(G),and d_(32) obtained from the CFD model were compared with experimental data,and the gas density-dependent parameters of the CFD model were *** increasing P from 1 to 35 bar,theα_(G) varied from 5.4%to 7.2% and the d32 decreased from 2.3 to 1.5 *** CFD-PBE model is applicable to predict hydrodynamics of pressurized bubble columns for gas-organic liquid in the homogeneous regime.

关键词： Bubble column Air-kerosene High pressure Homogenous regime Computational fluid dynamics (CFD) Population balance equation (PBE)

Electrochemical behavior of Nd in its pyrometallurgical recovery from waste magnet

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第2期34卷 111-117页

作者： Hong-Youl Ryu Jong-Hyeon Lee Wan-gou Kim Hayk H.Nersisyan go-Gi Lee Sung-Koo Jo Huk-Hee Lee il-Soon Hwang Graduate School of Green Energy Technology Chungnam National University Department of Nano Materials Engineering Chungnam National University Rapidly Solidified Materials Research Institute Chungnam National University Research Institute of Industrial Science and Technology Korea Research Institute of Chemical Technology School of Energy Systems Engineering Seoul National University

High-purity Nd metal was recovered from waste Nd–Fe–B magnet by the molten salt electrowinning process with chemical pretreatment. X-ray diffraction（XRD）, scanning electron microscopy（seM）, energy dispersive spectroscopy（EDS）, cyclic voltammetry（CV）,chronopotentiometry（CP）, and inductively coupled plasma-atomic emission spectrometer（ICP/AES） were used to characterize the deposit and electrochemical behaviors. The results show that NdF_3 is effectively synthesized from the Nd–Fe–B magnet using HCl solution and NH4F. During the chemical treatment of the waste magnet,iron impurity is eliminated as a soluble [NH4]3[FeF6]complex. Electrowinning using NdF_3 in LiF molten salt shows that Nd metal is deposited from the electrolyte onthe cathode at the reduction potentials ranging from-1.48to-1.35 V（vs. W） with the concentration change of NdF_*** final purity of Nd metal deposit is higher than99.78 %.

关键词： Electrowinning Neodymium Nd-Fe-Bmagnet Rare earth recycling

A qualitative approach to aberrations of optical elements

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2010年第11期8卷 1022-1023页

作者： Jerry Barretto Clark Kendrick go Department of Physics School of Science and EngineeringAteneo de Manila University Department of Mathematics School of Science and EngineeringAteneo de Manila University

A qualitative method to analyze wavefront aberrations is *** of the primary type,expressed in their matrix forms,are used to write the generalized ray transfer matrix of an optical *** aberrations were treated collectively by examining the pseudospectra of an augmented matrix constructed from the aberration *** show that aberrations can be distinguished and relative strengths pronounced using this qualitative method.

关键词： A qualitative approach to aberrations of optical elements

Key changes across valley floors in mountain areas affected by different levels of human impact: a case study of the Ochotnica river catchment in the Polish Carpathians

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第11期21卷 3567-3583页

作者： Agata goŁĄB Anna MICHNO Doctoral School of Exact and Natural Sciences Jagiellonian UniversityProf.St.Łojasiewicza St 11Cracow 30348Poland Faculty of Geography and Geology Jagiellonian UniveristyGronostajowa St 3Cracow 30387Poland

The goal of this paper was to present knowledge on changes in the morphodynamic structure of the Ochotnica River(Polish Carpathians)and transformations within its active river zone since the end of the 19th *** study used a set of archival and contemporary cartographic materials and the results of three-fold field mapping of the morphodynamic structure of the *** and indirect human interference with the natural environment of the catchment and the fluvial system was taken into account in the *** of changes in the morphodynamic structure of the Ochotnica and its active river zone since the end of the 19th century indicated significant changes in the development trend of the *** contemporary structure of the Ochotnica is more complex than in the *** has been a fragmentation of the riverbed into sections with different morphodynamic *** proportion of erosive sections has increased,which explains the reduced in the width of the active river zone of the *** average width of the active river zone of the river between 1861 and 2022 has changed from 80 m to 18 *** impact has been identified as the main reason for the changes in the morphodynamic structure of the riverbed and its active river ***,only the unregulated sect ion is characterised by free lateral migration of the riverbed and the widest active river zone(~28 m).

关键词： Active river zone Channel changes Mountain river Human impact

Metal chalcogenide-based photoelectrodes for photoelectrochemical water splitting

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第10期31卷 189-213,I0005页

作者： Marwa Mohamed Abouelela go Kawamura Atsunori Matsuda Department of Electrical and Electronic Information Engineering Toyohashi University of TechnologyToyohashi 441-8580AichiJapan Petrochemical Department Egyptian Petroleum Research InstituteCairo 11727Egypt

Photoelectrochemical water splitting(PEC-WS)is a promising technique for transforming solar energy into storable and environmentally friendly chemical *** semiconductor photoelectrodes with high light absorption capability,rapid e-/h+separation and transfer,and sufficient chemical stability is vital for developing an efficient PEC-WS *** chalcogenides(MCs)have emerged as promising candidates for light absorbers because of their unique electrical and optical *** this review,we present recent developments in hydrogen generation via PEC-WS using MC-based ***,we present a simple illustration of PEC-WS ***,the current performance of various metal(mono-,di-,and tri-)chalcogenide/semiconductor photoelectrodes in PEC-WS is ***,the charge transfer mechanism at the MC/semiconductor interface and the PEC-WS mechanism is thoroughly ***,we discuss future research perspectives toward developing efficient and stable MC/semiconductor photoelectrodes.

关键词： Photoelectrochemical water splitting Metal chalcogenides Photoelectrode Energy conversion

"Cap and glycosylate"strategy for direct radical functionalization of native sugars

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第20期69卷 3163-3165页

作者： Hiroaki Matoba go Hirai Graduate School of Pharmaceutical Sciences Kyushu UniversityFukuoka 812-8582Japan

Glycoconjugates are biologically significant molecules,but their precise role in many biological phenomena remains unclear,largely due to their heterogeneity and complexity,as well as the dynamic enzymatic remodeling/hydrolysis of glycan ***,for mechanistic studies,it is desirable to use metabolically stable mimics of *** this context,S-,se-,and notably C-linked glycoconjugates have emerged as attractive targets,leading to the development of numerous synthetic methods[1–3].

关键词： sugar hydrolysis attractive

Characteristics of Nb/Al superconducting tunnel junctions fabricated using ozone gas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第9期24卷 182-186页

作者： Masahiro Ukibe go Fujii Masataka Ohkubo Nanoelectronics Research Institute (nano) National Institute of Advanced Industrial Science and Technology (AIST)

To improve the energy resolution（？E） of Nb/Al superconducting tunnel junctions（STJs）, an ozone（O3） oxidation process has been developed to fabricate a thin defect-free tunnel barrier that simultaneously shows high critical current JC〉 1000 A/cm^2 and high normalized dynamic resistance RDA 〉 100 MΩ·μm^2, where A is the size of the STJ. The 50-μm^2 STJs produced by O3 exposure of 0.26 Pa·min with an indirect spray of O3 gas, which is a much lower level of exposure than the O2 exposure used in a conventional O2 oxidation process, exhibit a maximum JC= 800 A/cm^2 and a high RDA = 372 MΩ ·μm^2. The 100-pixel array of the 100-μm^2STJs produced using the same O3 oxidation conditions exhibits a constant leak current I leak= 14.9 ± 3.2 n A at a bias point around △ /e（where e is half the energy gap of an STJ）,and a high fabrication yield of 87%. Although the I leak values are slightly larger than those of STJs produced using the conventional O2 oxidation process, the STJ produced using O3 oxidation shows a ？E = 10 eV for the C-Kα line, which is the best value of our Nb/Al STJ x-ray detectors.

关键词： Nb/Al superconducting tunnel junctions high critical current density high energy resolution ozone

First quarter century of laparoscopic liver resection

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第20期23卷 3581-3588页

作者： Zenichi Morise go Wakabayashi Department of Surgery Fujita Health University School of Medicine Department of Surgery Center for Advanced Treatment of HBP DiseasesAgeo Central General Hospital

The beginnings of laparoscopic liver resection(LLR)were at the start of the 1990s,with the initial reports being published in 1991 and *** were followed by reports of left lateral sectionectomy in *** the years following,the procedures of LLR were expanded to hemi-hepatectomy,sectionectomy,segmentectomy and partial resection of posterosuperior segments,as well as the parenchymal preserving limited anatomical resection and modified anatomical(extended and/or combining limited)resection *** expanded range of LLR procedures,mimicking the expansion of open liver resection in the past,was related to advances in both technology(instrumentation)and technical skill with conceptual *** this period of remarkable development,two international consensus conferences were held(2008 in Louisville,KY,United States,and 2014 in Morioka,Japan),providing up-to-date summarizations of the status and perspective of *** advantages of LLR have become clear,and include reduced intraoperative bleeding,shorter hospital stay,and-especially for cirrhotic patients-lower incidence of complications(e.g.,postoperative ascites and liver failure).In this paper,we review and discuss the developments of LLR in operative procedures(extent and style of liver resections)during the first quarter century since its inception,from the aspect of relationships with technological/technical developments with conceptual changes.

关键词： Hepatectomy Laparoscopic surgery Liver cancer History Technology Technique Concept Approach Posture Simulation