检索结果-南通市图书馆

TiO2 nanotube branched tree on a carbon nanofiber nanostructure as an anode for high energy and power lithium ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2014年第4期7卷 491-501页

作者： Taeseup Song Hyungkyu Han Heechae Choi Jung Woo Lee Hyunjung park Sangkyu Lee won ii park Seungchul Kim Li Liu Ungyu Paik Department of Materials Science Engineering Hanyang University Seou113 3-791 Korea Center for ComputationalScience Korea Institute of Science and Technology Seou1136-791 Korea School of Chemistry Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education Xiangtan University Xiangtan 411105 China

The inherently low electrical conductivity of TiO2-based electrodes as well as the high electrical resistance between an electrode and a current collector represents a major obstacle to their use as an anode for lithium ion batteries. In this study, we report on high-density TiO2 nanotubes (NTs) branched onto a carbon nanofiber (CNF) “tree” that provide a low resistance current path between the current collector and the TiO2 NTs. Compared to a TiO2 NT array grown directly on the current collector, the branched TiO2 NTs tree, coupled with the CNF electrode, exhibited ∼10 times higher areal energy density and excellent rate capability (discharge capacity of ∼150 mA·h·g−1 at a current density of 1,000 mA·g−1). Based on the detailed experimental results and associated theoretical analysis, we demonstrate that the introduction of CNFs with direct electric contact with the current collector enables a significant increase in areal capacity (mA·h·cm−2) as well as excellent rate capability.

关键词： TiO2纳米管碳纳米纤维锂离子电池阳极高能量二氧化钛构作放电容量

Paleozoic tectonic evolution of the proto-Korean Peninsula along the East Asian continental margin from detrital zircon U-Pb geochronology and Hf isotope geochemistry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第1期15卷 97-117页

作者： Yirang Jang Sung won Kim Vinod O.Samuel Sanghoon Kwon Seung-Ik park M.Santosh Keewook Yi Department of Earth and Environmental Sciences Chonnam National UniversityGwangju 61186Republic of Korea Geology Division Korea Institute of Geoscience and Mineral ResourcesDaejeon 34132Republic of Korea Department of Earth System Sciences Yonsei UniversitySeoul 03722Republic of Korea Department of Geology Kyungpook National UniversityDaegu 41566Republic of Korea School of Earth Sciences and Resources China University of Geosciences BeijingBeijing 100083China Department of Earth Science University of AdelaideAdelaide SA 5005Australia Yonsei Frontiers Lab Yonsei UniversitySeoul 03722Republic of Korea Division of Earth and Environmental Sciences Korea Basic Science InstituteChungbuk 28119Republic of Korea

Detrital zircon geochronology and Hf isotope analysis can be used for inferring provenance characteristics,and to evaluate the tectonic evolution of sedimentary basins and their link with regional *** Paleozoic sequences of the Okcheon Belt consist of the Lower Paleozoic Joseon and the Upper Paleozoic Pyeongan supergroups with Middle Paleozoic hiatus locally on top of the Neoproterozoic bimodal volcanic rocks,reflecting an intracontinental rift setting between the two basements(*** and Yeongnam massifs)at southern part of the Korean *** detrital zircon U-Pb ages and Lu-Hf isotope results show that all these Paleozoic strata commonly have Paleoproterozoic and Paleozoic zircon ages with rare Meso-to Neoproterozoic *** individual zircon populations display following features,allowing estimation of their sedimentary provenances:(i)The Paleoproterozoic zircons(ca.1.85 Ga and 2.50 Ga)with similar ranges ofεHf(t)values are most common in the basement rocks of the Korean Peninsula,and were sourced from both the Gyeonggi and Yeongnam massifs.(ii)The Meso-to Neoproterozoic zircons,preserved only in the Middle to Late Cambrian clastic sedimentary rocks within the carbonate sequences probably reflect proximal provenance.(iii)The youngest Paleozoic zircons of each formation,almost coincident with their deposition ages,suggest presence of syndepositional magmatism,indicating proximal magmatic sources during their deposition.(iv)The Cambrian-Ordovician zircons,from the Lower Paleozoic sequences,but rare in the successive Upper Paleozoic sequences,suggest a provenance change after the hiatus between the two sedimentary successions.(v)The Permian zircons showing differentεHf(t)values indicate that detrital sources were varied at that *** integrated results in our study suggest provenance variability linked to diverse tectonic environments,reflecting prolonged subduction-related crustal evolution of the proto-Korean Peninsula during the Paleozo

关键词： Detrital zircon U-Pb and Hf isotopes Paleozoic metasedimentary rocks Okcheon Belt Taebaeksan zone Korean Peninsula

Depolarization mitigated in ferroelectric Hf_(0.5)Zr_(0.5)O_(2)ultrathin films(<5 nm)on Si substrate by interface engineering

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 2024年第3期13卷 282-292页

作者： Se Hyun Kim Younghwan Lee Dong Hyun Lee Geun Hyeong park Hyun Woo Jeong Kun Yang Yong Hyeon Cho Young Yong Kim Min Hyuk park Department of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Research Institute of Advanced Materials College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Inter-university Semiconductor Research Center College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Pohang Accelerator Laboratory Pohang University of Science&TechnologyPohang 790784Republic of Korea

(Hf,Zr)O_(2)offers considerable potential for next-generation semiconductor devices owing to its nonvolatile spontaneous polarization at the ***,scaling this material to sub-5 nm thickness poses several challenges,including the formation of an interfacial layer and high trap *** particular,a low-k SiO_(2)interfacial layer is naturally formed when(Hf,Zr)O_(2)films are directly grown on a Si substrate,leading to high depolarization fields and rapid reduction of the remanent *** address these issues,we conducted a study to significantly improve ferroelectricity and switching endurance of(Hf,Zr)O_(2)films with sub-5 nm thicknesses by inserting a TiO_(2)interfacial *** deposition of a Ti film prior to Hf_(0.5)Zr_(0.5)O_(2)film deposition resulted in a high-k TiO_(2)interfacial layer and prevented the direct contact of Hf_(0.5)Zr_(0.5)O_(2)with *** findings show that the high-k TiO_(2)interfacial layer can reduce the SiO_(2)/Si interface trap density and the depolarization field,resulting in a switchable polarization of 60.2μC/cm^(2)for a 5 nm thick Hf_(0.5)Zr_(0.5)O_(2)***,we propose that inserting a high-k TiO_(2)interfacial layer between the Hf_(0.5)Zr_(0.5)O_(2)film and the Si substrate may offer a promising solution to enhancing the ferroelectricity and reliability of(Hf,Zr)O_(2)grown on the Si substrate and can pave the way for next-generation semiconductor devices with improved performance.

关键词： ferroelectric charge trapping hafnia depolarization

Dispersal patterns of exotic forest pests in South Korea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2012年第5期19卷 535-548页

作者： won ii Choi Young-Seuk park Division of Forest Disease and Insect Pests Korea Forest Research Institute Dongdaemun Seoul Department of Biology and The Korea Institute of Ornithology Kyung Hee University Dongdaemun Seoul Republic of Korea

Invasive species have potentially devastating effects on ecological communi- ties and ecosystems. To understand the invasion process of exotic forest pests in South Korea, we reviewed four major species of exotic forest pests： the pine needle gall midge （Thecodiplosis japonensis）, pine wilt disease caused by the pine wood nematode （Bur- saphelenchus xylophilus）, the fall webworm （Hyphantria cunea） and the black pine bast scale （Matsucoccus thunbergianae）. We consider their biology, ecology, invasion history, dispersal patterns and related traits, and management as exotic species. Among these species, the dispersal process of fall webworm was linear, showing a constant range expan- sion as a function of time, whereas the other three species showed biphasic patterns, rapidly increasing dispersal speed after slow dispersal at the early invasion stage. Moreover, human activities accelerated their expansion, suggesting that prevention of the artificial movement of damaged trees would be useful to slow expansion of exotic species. We believe that this information would be useful to establish management strategies for invasion species.

关键词： Bursaphelenchusxylophilus dispersal pattern exotic species fall webworm,forest management Hyphantria cunea Matsucoccus thunbergianae pine wilt disease,Thecodiplosis japonensis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

黄海大海洋生态系滨海湿地保护:进展与建议

国家公园（中英文） 2024年第4期2卷 272-280页

作者：曲方圆 Jae-won Yoo 王守强自然资源部第一海洋研究所渤海海峡生态通道野外科学观测研究站青岛266061 Korea Institute of Coastal Ecology Inc. Bucheon 14449

黄海大海洋生态系(YSLME)滨海湿地是东亚—澳大利西亚候鸟的中转站和越冬栖息地,对东亚-澳大利西亚迁徙路线的候鸟至关重要。由于过去几十年的经济发展,中国和韩国都开垦了大量的滨海湿地,因此生境丧失被确定为是对YSLME的一个重大跨界... 详细信息

黄海大海洋生态系(YSLME)滨海湿地是东亚—澳大利西亚候鸟的中转站和越冬栖息地,对东亚-澳大利西亚迁徙路线的候鸟至关重要。由于过去几十年的经济发展,中国和韩国都开垦了大量的滨海湿地,因此生境丧失被确定为是对YSLME的一个重大跨界威胁。为缓解这一跨界威胁,YSLME二期项目在其战略行动计划中提出数项管理行动计划,同时,旨在2030年前保护30%海洋的全球生物多样性保护目标(3030目标)也得到了通过。因此,重点介绍了中国和韩国在湿地保护法律法规、滨海湿地保护地建设、公众意识以及国际合作等方面的进展,并简要介绍了朝鲜的滨海湿地保护情况,为更好地解决滨海湿地丧失这一跨界威胁和实现3030目标提供了建议。YSLME滨海湿地保护主要进展为:中韩两国逐渐完善其湿地保护法律法规体系、早期滨海湿地面积急剧丧失的趋势在近年来得到缓解、两国都建立了越来越多的滨海湿地保护地、提升公众意识已经体现在各级法律法规中、中韩之间有持续的滨海湿地国际合作交流活动。对于未来的保护工作,提出了四点建议:扩大滨海湿地保护地面积、保护迁徙动物的生态廊道、加强YSLME滨海湿地保护地网络建设以及增强保护地信息的可获得性。

关键词：黄海大海洋生态系滨海湿地保护进展建议

维普期刊数据库博看期刊

Electrocatalytic Reduction of CO_(2)to CO with Almost 100%Faradaic Efficiency Using Oxygen-Vacancy Enriched Two-Dimensional MgO

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第6期6卷 1477-1486页

作者： Yu Han Sunggi An Xinyu Zhan Leiduan Hao Liang Xu Song Hong Dongmin park Yuxin Chen Yiwen Xu Jiwen Zhao Xinyi Tan Alex W.Robertson Yousung Jung Zhenyu Sun State Key Laboratory of Organic-Inorganic Composites College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029 Department of Chemical and Biomolecular Engineering(BK21four) Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141 Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081 Department of Physics University of WarwickCoventry

The design and development of cheap,abundant,and efficient electrocatalysts for selective CO_(2)electroreduction is highly desirable yet remains an ongoing ***,we report on our discovery of the use of two-dimensional MgO rich in oxygen vacancies(VO)as an electrocatalyst for the efficient reduction of CO_(2)to yield CO in 1-butyl-3-methylimidazolium hexafluorophosphate dissolved in *** faradaic efficiency toward CO reaches as high as 99.6±0.24%with a current density of up to 40.8 mA cm−*** functional theory calculations illustrate that the introduction of VO in MgO substantially lowers the reaction-free energy for the transformation of ^(*)COO^(−) to ^(*)COOH,the potential determining step,which greatly boosts CO_(2)conversion *** work opens the way to realizing economic and efficient CO_(2)electrolysis of group ii metals.

关键词： CO_(2)reduction electrocatalysis CO MgO ionic liquid oxygen-vacancy

海南热带雨林国家公园尖峰岭片区山铜材种群空间分布格局

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

林草资源研究 2024年第2期 17-25页

作者：张顺卫李婧涵杨小波李东海黄耀杜春雁商乃演海南大学生态与环境学院海口570228

山铜材(Chunia bucklandioides)为国家二级重点保护野生植物,数量稀少、分布范围狭窄,研究山铜材的种群现状及分布格局对其种群的保护和可持续发展具有重要意义。以海南热带雨林国家公园尖峰岭片区内的山铜材种群为研究对象,采用径级结... 详细信息

山铜材(Chunia bucklandioides)为国家二级重点保护野生植物,数量稀少、分布范围狭窄,研究山铜材的种群现状及分布格局对其种群的保护和可持续发展具有重要意义。以海南热带雨林国家公园尖峰岭片区内的山铜材种群为研究对象,采用径级结构代替年龄结构的方法,将山铜材划分为4个龄级(Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级),运用成对相关函数g(r)对山铜材种群及其各龄级的空间分布格局及关联性进行分析。研究表明:1)山铜材种群存在假性稳定增长的现象,只能在该生境中繁衍,很难扩大其种群规模;2)山铜材种群在小尺度下呈聚集分布,随着尺度的增加,大部分种群向均匀分布发展,少部分种群呈随机分布和聚集分布趋势;3)不同龄级的个体皆在小尺度下为聚集分布,其中Ⅰ级和Ⅱ级个体聚集程度较大,随着尺度的增加,部分龄级存在均匀分布,最终皆演变为随机分布;4)不同龄级间的空间关联性表明了山铜材主要靠Ⅲ级和Ⅳ级个体扩萌更新,其萌生个体对母树的依赖性强弱为Ⅱ级>Ⅰ级>Ⅲ级>Ⅳ级。因此,未来在山铜材种群的保护中,应以保护母树为主,适当间伐母树周边的萌生苗和清除倒伏枝条萌生苗附近的小型植物,将实生苗进行迁地保护,以此来扩大和保护山铜材野生种群。

关键词：山铜材萌生种群结构空间分布格局空间关联性

维普期刊数据库

同方期刊数据库

Delivery of nitric oxide-releasing silica nanoparticles for in vivo revascularization and functional recovery after acute peripheral nerve crush injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第9期17卷 2043-2049页

作者： Jung Il Lee Ji Hun park Yeong-Rim Kim Kihak Gwon Hae won Hwang Gayoung Jung Joo-Yup Lee Jeong-Yun Sun Jong Woong park Jae Ho Shin Myoung-Ryul Ok Department of Orthopedic Surgery College of MedicineKorea UniversitySeoulRepublic of Korea Medical Sensor Biomaterial Research Institute Kwangwoon UniversitySeoulRepublic of Korea Center for Biomaterials Korea Institute of Science&TechnologySeoulRepublic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoulRepublic of Korea Department of Orthopedic Surgery College of MedicineCatholic UniversitySeoulRepublic of Korea Department of Chemistry Kwangwoon UniversitySeoulRepublic of Korea

Nitric oxide(NO)has been shown to promote revascularization and nerve regeneration after peripheral nerve ***,in vivo application of NO remains challenging due to the lack of stable carrier materials capable of storing large amounts of NO molecules and releasing them on a clinically meaningful time ***,a silica nanoparticle system capable of reversible NO storage and release at a controlled and sustained rate was *** this study,NO-releasing silica nanoparticles(NO-SNs)were delivered to the peripheral nerves in rats after acute crush injury,mixed with natural hydrogel,to ensure the effective application of NO to the *** using a polymer dye and immunohistochemical staining for the detection of CD34(a marker for revascularization)results showed that NO-releasing silica nanoparticles increased revascularization at the crush site of the sciatic *** sciatic functional index revealed that there was a significant improvement in sciatic nerve function in NO-treated *** and anatomical analyses showed that the number of myelinated axons in the crushed sciatic nerve and wet muscle weight excised from NO-treated rats were ***,muscle function recovery was improved in rats treated with *** together,our results suggest that NO delivered to the injured sciatic nerve triggers enhanced revascularization at the lesion in the early phase after crushing injury,thereby promoting axonal regeneration and improving functional recovery.

关键词： crush injury nerve injury,nerve regeneration nitric oxide peripheral nerve revascularization silica nanoparticles

维普期刊数据库

Crystal Facet Engineering of TiO_(2) Nanostructures for Enhancing Photoelectrochemical Water Splitting with BiVO_(4) Nanodots

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第3期14卷 201-215页

作者： Mi Gyoung Lee Jin Wook Yang Hoonkee park Cheon Woo Moon Dinsefa M.Andoshe Jongseong park Chang‑Ki Moon Tae Hyung Lee Kyoung Soon Choi Woo Seok Cheon Jang‑Joo Kim Ho won Jang Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoul 08826Republic of Korea Department of Chemistry and Nanoscience Ewha Womans UniversitySeoul 03693Republic of Korea National Research Facilities and Equipment Center Korea Basic Science InstituteDaejeon 34133Republic of Korea Advanced Institute of Convergence Technology Seoul National UniversitySuwon 16229Republic of Korea

Although bismuth vanadate(BiVO4)has been promising as photoanode material for photoelectrochemical water splitting,its charge recombination issue by short charge diffusion length has led to various studies about heterostructure *** a hole blocking layer of BiVO4,titanium dioxide(TiO_(2)) has been considered unsuitable because of its relatively positive valence band edge and low electrical ***,a crystal facet engineering of TiO_(2) nanostructures is proposed to control band structures for the hole blocking layer of BiVO4 *** design two types of TiO_(2) nanostructures,which are nanorods(NRs)and nanoflowers(NFs)with different(001)and(110)crystal facets,respectively,and fabricate BiVO4/TiO_(2) heterostructure *** BiVO4/TiO_(2) NFs showed 4.8 times higher photocurrent density than the BiVO4/TiO_(2) *** decay time analysis and time-resolved photoluminescence reveal the enhancement is attributed to the reduced charge recombination,which is originated from the formation of type ii band alignment between BiVO4 nanodots and TiO_(2) *** work provides not only new insights into the interplay between crystal facets and band structures but also important steps for the design of highly efficient photoelectrodes.

关键词： Crystal facet control Bismuth vanadate Titanium dioxide Heterojunction Water splitting

维普期刊数据库