检索结果-南通市图书馆

Superinsulating BNNS/PVA Composite Aerogels with High Solar Reflectance for Energy-Efficient Buildings

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-Micro Letters 2022年第3期14卷 292-307页

作者： Jie Yang Kit‑Ying Chan Harun Venkatesan Eunyoung kim Miracle Hope Adegun Jeng‑Hun Lee Xi Shen jang‐kyo kim Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongPeople’s Republic of China Department of Aeronautical and Aviation Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China

With the mandate of worldwide carbon neutralization,pursuing comfortable living environment while consuming less energy is an enticing and unavoidable *** composite aerogels with super thermal insulation and high sunlight reflection are developed for energy-efficient buildings.A solvent-assisted freeze-casting strategy is used to produce boron nitride nanosheet/polyvinyl alcohol(BNNS/PVA)composite aerogels with a tailored alignment channel *** effects of acetone and BNNS fillers on microstructures and multifunctional properties of aerogels are *** acetone in the PVA suspension enlarges the cell walls to suppress the shrinkage,giving rise to a lower density and a higher porosity,accompanied with much diminished heat conduction throughout the whole *** addition of BNNS fillers creates whiskers in place of disconnected transverse ligaments between adjacent cell walls,further ameliorating the thermal insulation transverse to the cell wall *** resultant BNNS/PVA aerogel delivers an ultralow thermal conductivity of 23.5 mW m^(−1) K^(−1) in the transverse *** superinsulating aerogel presents both an infrared stealthy capability and a high solar reflectance of 93.8%over the whole sunlight wave-length,far outperforming commercial expanded polystyrene foams with reflective *** anisotropic BNNS/PVA composite aerogel presents great potential for application in energy-saving buildings.

关键词： Boron nitride nanosheets Solvent-assisted freeze-casting Thermally insulating aerogel Solar reflectance Energy-saving buildings

Graphene/RuO2 nanocrystal composites as sulfur host for lithium-sulfur batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2019年第8期28卷 204-211,I0007页

作者： Jian-Qiu Huang Jiaqiang Huang Woon Gie Chong Jiang Cui Shanshan Yao Baoling Huang jang-kyo kim Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and Technology

An optimized graphene/RuO2/S composite is prepared by hydrothermal growth of RuO2 particles on graphene oxide sheets as the positive electrode for rechargeable lithium-sulfur batteries. The electrode with 6.1 wt% RuO2 nanocrystals and a high sulfur content of 79.0 wt% delivers an optimal electrochemical performance with high residual capacities of 508 mAh g-1 after 200 cycles and 389 m Ah g-1 after800 cycles at 1 C with a low capacity decay of 0.054%. The RuO2 nanocrystals promote the redox reaction kinetics and facilitate the transformation of sulfur chemistry, leading to large improvements in reversibility and rate capability of the composite electrode. The density functional theory calculations signify the formation of Li–O and Ru–S bonds through chemical interactions between RuO2 and Li polysulfides while the adsorption energies between graphene and polysulfide species are much higher in the presence of RuO2 than that of the neat graphene acting alone. These discoveries support the efficient entrapment of polysulfides by the composite electrode to the benefit of enhanced cyclic stability of the battery.

关键词： Enhanced redox reaction kinetics Polysulfide adsorption Density functional theory Lithium sulfur batteries High sulfur content

Anisotropic,Wrinkled,and Crack-Bridging Structure for Ultrasensitive,Highly Selective Multidirectional Strain Sensors

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2021年第8期13卷 121-135页

作者： Heng Zhang Dan Liu Jeng-Hun Lee Haomin Chen Eunyoung kim Xi Shen Qingbin Zheng Jinglei Yang jang-kyo kim Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongPeople’s Republic of China School of Science and Engineering The Chinese University of Hong KongShenzhen 518172GuangdongPeople’s Republic of China

Flexible multidirectional strain sensors are crucial to accurately determining the complex strain states involved in emerging sensing *** considerable efforts have been made to construct anisotropic structures for improved selective sensing capabilities,existing anisotropic sensors suffer from a trade-off between high sensitivity and high stretchability with acceptable ***,an ultrasensitive,highly selective multidirectional sensor is developed by rational design of functionally different anisotropic *** bilayer sensor consists of an aligned carbon nanotube(CNT)array assembled on top of a periodically wrinkled and cracked CNT-graphene oxide *** transversely aligned CNT layer bridge the underlying longitudinal microcracks to effectively discourage their propagation even when highly stretched,leading to superior sensitivity with a gauge factor of 287.6 across a broad linear working range of up to 100%*** wrinkles generated through a pre-straining/releasing routine in the direction transverse to CNT alignment is responsible for exceptional selectivity of 6.3,to the benefit of accurate detection of loading directions by the multidirectional *** work proposes a unique approach to leveraging the inherent merits of two cross-influential anisotropic structures to resolve the trade-off among sensitivity,selectivity,and stretchability,demonstrating promising applications in full-range,multi-axis human motion detection for wearable electronics and smart robotics.

关键词： Anisotropic strain sensor Wrinkle Aligned carbon nanotube Stretchability Complex motion detection

Ultrathin ZnS nanosheet/carbon nanotube hybrid electrode for high-performance flexible all-solid-state supercapacitor

在线全文

学校读者我要写书评

暂无评论

Nano Research 2017年第8期10卷 2570-2583页

作者： Xiaoyi Hou Tao Peng Jinbing Cheng Qiuhong Yu Rongjie Luo Yang Lu Xianming Liu jang-kyo kim Jun He Yongsong Luo School of Physics and Electronic Engineering Xinyang Normal University Xinyang 464000 China Key Laboratory of Advanced Micro/Nano Functional Materials Xinyang Normal University Xinyang 464000 China College of Chemistry and Chemical Engineering Luoyang Normal University Luoyang 471022 China Department of Mechanical and Aerospace Engineering Hang Kong University of Science and Technology Clear Water Bay Kowloon Hang Kong China National Center for Nanoscience and Technology Beijing 100190 China

Flexible and easily reconfigurable supercapacitors show great promise for application in wearable electronics. In this study, multiwall C nanotubes （CNTs） decorated with hierarchical ultrathin zinc sulfide （ZnS） nanosheets （ZnS@CNT） are synthesized via a facile method. The resulting ZnS@CNT electrode, which delivers a high specific capacitance of 347.3 F·g^-1 and an excellent cycling stability, can function as a high-performance electrode for a flexible all-solid-state supercapacitor using a polymer gel electrolyte. Our device exhibits a remarkable specific capacitance of 159.6 F·g^-1, a high energy density of 22.3 W·h·kg^-1, and a power density of 5 kW·kg^-1 It also has high electrochemical performance even under bending or twisting. The all-solid-state supercapacitors can be easily integrated in series to power different commercial light-emitting diodes without an external bias voltage.

关键词： multiwall C nanotubes decorated with hierarchical ultrathin zinc sulfide nanosheets(ZnS@CNT) ultrathin nanosheet flexible synergistic supercapacitor

Enhancing BiVO_(4)photoanode performance by insertion of an epitaxial BiFeO_(3)ferroelectric layer

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 Energy Chemistry 2024年第2期89卷 71-78,I0003页

作者： Haejin jang Yejoon kim Hojoong Choi Jiwoong Yang Yoonsung Jung Sungkyun Choi Donghyeon Lee Ho Won jang Sanghan Lee School of Materials Science and Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea

BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical ***,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical *** address this,various modifications have been attempted,including the use of ferroelectric *** materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole *** this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of *** self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge *** a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)*** results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.

关键词： Photoelectrochemical Photoanode BiVO_(4) Ferroelectric materials BiFeO_(3)

Programmable directional color dynamics using plasmonics

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第1期10卷 325-334页

作者： Gyurin kim Doeun kim Soeun Ko jang-Hwan Han Juhwan kim Joo Hwan Ko Young Min Song Hyeon-Ho Jeong School of Electrical Engineering and Computer Science Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Semiconductor Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Artificial Intelligence(AI)Graduate School Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea

Adaptive multicolor filters have emerged as key components for ensuring color accuracy and resolution in outdoor visual ***,the current state of this technology is still in its infancy and largely reliant on liquid crystal devices that require high voltage and bulky structural ***,we present a multicolor nanofilter consisting of multilayered‘active’plasmonic nanocomposites,wherein metallic nanoparticles are embedded within a conductive polymer *** nanocomposites are fabricated with a total thickness below 100 nm using a‘lithography-free’method at the wafer level,and they inherently exhibit three prominent optical modes,accompanying scattering phenomena that produce distinct dichroic reflection and transmission ***,a pivotal achievement is that all these colors are electrically manipulated with an applied external voltage of less than 1 V with 3.5 s of switching speed,encompassing the entire visible ***,this electrically programmable multicolor function enables the effective and dynamic modulation of the color temperature of white light across the warm-to-cool spectrum(3250 K-6250 K).This transformative capability is exceptionally valuable for enhancing the performance of outdoor optical devices that are independent of factors such as the sun’s elevation and prevailing weather conditions.

关键词： directional prevailing exceptional

Reconstruction of cervical necrotizing fasciitis defect with the modified keystone flap technique:Two case reports

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第7期12卷 1305-1312页

作者： Wonseok Cho Eun A jang Kyu Nam kim Department of Plastic and Reconstructive Surgery Kangbuk Samsung HospitalSungkyunkwan University School of MedicineSeoul 03181South Korea

BACKGROUND Cervical necrotizing fasciitis(CNF)is a rare,aggressive form of deep neck space infection with significant morbidity and mortality *** surgical debridement acts as the cornerstone of CNF treatment;however,it often results in defects requiring complex *** SUMMARY We report two cases in which the keystone flap(KF)was used for CNF defect coverage:Case 1,an 85-year-old patient with CNF in the anterior neck,and Case 2,a 54-year-old patient with CNF in the posterior *** patients received empirical intravenous antibiotic therapy and underwent serial debridement,enabling adequate wound preparation and *** final defect size measured 5.5 cm×12 cm in Case 1 and 6 cm×11 cm in Case *** defect coverage,we employed an 8 cm×19 cm type II KF based on perforators from the superior thyroid artery in Case 1 and a 9 cm×18 cm type II KF based on perforators from the transverse cervical artery in Case *** flaps showed complete *** postoperative complications occurred in both cases,and favorable outcomes were observed at 7-and 6-month follow-ups in case 1 and 2,*** We effectively treated CNF-associated defects using the KF technique;KF is viable for covering CNF defects in carefully selected cases.

关键词： Fasciitis Necrotizing Debridement Plastic surgery Dermatologic surgical procedures Case report

Enhancement of MoTe2 near-infrared absorption with gold hollow nanorods for photodetection

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 2020年第6期13卷 1636-1643页

作者： Jiawen You Ye Yu Kai Cai Dongming Zhou Haiming Zhu Renyan Wang Qingfu Zhang Hongwei Liu Yuting Cai Dong Lu jang-kyo kim Lin Gan Tianyou Zhai Zhengtang Luo Department of Chemical and Biological Engineering William Mong Institute of Nano Science and Technology and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Leibniz-Institut für Polymerforschung Dresden e.V. Hohe Straße 6Dresden01069Germany State Key Laboratory of Material Processing and Die and Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China Department of Chemistry Zhejiang UniversityHangzhou310027China Shenzhen R&D Center of Huazhong University of Science and Technology Shenzhen518000China Guangzhou HKUST Fok Ying Tung Research Institute Guangzhou511458China Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

Infrared(IR)light photodetection based on two dimensional(2D)materials of proper bandgap has attracted increasing ***,the weak IR absorption in 2D materials,due to their ultrathin attribute and indirect bandgap in multilayer structures,degrades their performance when used as IR *** this work,we utilize the fact that few-layer MoTe2 flake has a near-IR(NIR)bandgap and demonstrate a^60-fold enhancement of NIR response by introducing a gold hollow nanorods on the *** gold hollow nanorods have distinct absorption peak located also at the NIR regime,therefore induces strong resonance,benefitting NIR absorption in MoTe2,resulting in strong near-field *** the evidence from steady and transient state optical spectra,we confirm that the enhancement of NIR response originates only photon absorption,rather than electron transport at interfaces as observed in other heterostructures,therefore,precluding the requirement of high-quality interfaces for commercial applications.

关键词： NIR photodetection LSPR MoTe2 gold hollow nanorods

Ionizing terahertz waves with 260 MV/cm from scalable optical rectification

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第6期13卷 1075-1087页

作者： Hyeongmun kim Chul Kang Dogeun jang Yulan Roh Sang Hwa Lee Joong Wook Lee Jae Hee Sung Seong Ku Lee Ki-Yong kim Advanced Photonics Research Institute GISTGwangju61005Korea Department of Physics and Optoelectronics Convergence Research Center Chonnam National UniversityGwangju61186Korea Pohang Accelerator Laboratory POSTECHPohang37673Korea Center for Relativistic Laser Science Institute for Basic ScienceGwangju61005Korea Institute for Research in Electronics and Applied Physics Department of PhysicsUniversity of MarylandCollege ParkMaryland20742USA

Terahertz(THz)waves,known as non-ionizing radiation owing to their low photon energies,can actually ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and ***,we demonstrate the generation of ionizing,multicycle,15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses.A complete characterization of the generated THz waves in energy,pulse duration,and focal spot size shows that the field strength can reach up to 260 megavolts per *** particular,a single-shot THz interferometer is employed to measure the THz pulse duration and spectrum with complementary numerical *** intense THz pulses are irradiated onto various solid targets to demonstrate THz-induced tunneling ionization and plasma *** study also discusses the potential of nonperturbative THz-driven ionization in gases,which will open up new opportunities,including nonlinear and relativistic THz physics in plasma.

关键词： optical interferometer matched