检索结果-南通市图书馆

Random pinhole attenuator for high-power laser beams

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2024年第3期12卷 116-121页

作者： seong Cheol Park Hyeok Yun Jin Woo yoon seong Ku Lee Jae Hee Sung Il Woo Choi Chang Hee Nam Kyung Taec Kim Department of Physics and Photon Science Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea Center for Relativistic Laser Science Institute for Basic ScienceGwangjuRepublic of Korea Advanced Photonics Research Institute Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea

The intensity attenuation of a high-power laser is a frequent task in the measurements of optical *** intensity can be attenuated by inserting an optical element,such as a partial reflector,polarizer or absorption *** devices are,however,not always easily applicable,especially in the case of ultra-high-power lasers,because they can alter the characteristics of a laser beam or become easily *** this study,we demonstrated that the intensity of a laser beam could be effectively attenuated using a random pinhole attenuator(RPA),a device with randomly distributed pinholes,without changing the beam *** this device,a multi-PW laser beam was successfully attenuated and the focused beam profile was measured without any alterations of its *** addition,it was confirmed that the temporal profile of a laser pulse,including the spectral phase,was ***,the RPA possesses significant potential for a wide range of applications.

关键词： high-power laser intensity attenuation laser diagnostics

Confluence of ZnO and PTFE Binder for Enhancing Performance of Thin-Film Lithium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第5期7卷 52-60页

作者： Subhashree Behera Swathi Ippili Venkatraju Jella Na-Yeong Kim seong Cheol Jang Ji-Won Jung Soon-Gil yoon Hyun-Suk Kim Department of Materials Science and Engineering Chungnam National University School of Materials Science and Engineering University of Ulsan Department of Energy and Materials Engineering Dongguk University

Developing anode materials with high specific capacity and cycling stability is vital for improving thin-film lithium-ion batteries. Thin-film zinc oxide （ZnO）holds promise due to its high specific capacity, but it suffers from volume changes and structural stress during cycling, leading to poor battery performance. In this research, we ingeniously combined polytetrafluoroethylene （PTFE） with ZnO using a radio frequency （RF）magnetron co-sputtering method, ensuring a strong bond in the thin-film composite electrode. PTFE effectively reduced stress on the active material and mitigated volume change effects during Li+ion intercalation and deintercalation. The composite thin films are thoroughly characterized using advanced techniques such as X-ray diffraction, scanning electron microscopy,and X-ray photoelectron spectroscopy for investigating correlations between material properties and electrochemical behaviors. Notably, the ZnO/PTFE thin-film electrode demonstrated an impressive specific capacity of1305 mAh g-1(=7116 mAh cm-3) at a 0.5C rate and a remarkable capacity retention of 82%from the 1st to the 100th cycle, surpassing the bare ZnO thin film （50%）. This study provides valuable insights into using binders to stabilize active materials in thin-film batteries, enhancing battery performance.

关键词： li-ion batteries metal oxides anodes polytetrafluoroethylene (PTFE) thin films

SARS-CoV-2 aberrantly elevates mitochondrial bioenergetics to induce robust virus propagation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第6期9卷 2702-2715页

作者： Hye Jin Shin Wooseong Lee Keun Bon Ku Gun Young yoon Hyun-Woo Moon Chonsaeng Kim Mi-Hwa Kim yoon-Sun Yi Sangmi Jun Bum-Tae Kim Jong-Won Oh Aleem Siddiqui seong-Jun Kim Department of Convergent Research of Emerging Virus Infection Korea Research Institute of Chemical TechnologyDaejeon 34114Republic of Korea Gyeongnam Biohealth Research Center Gyeongnam Branch InstituteKorea Institute of ToxicologyJinju 52834Republic of Korea Center for Research Equipment Korea Basic Science InstituteCheongjuChungcheongbuk-do 28119Republic of Korea Department of Biotechnology Yonsei UniversitySeoul 03722Republic of Korea Division of Infectious Diseases School of MedicineUniversity of CaliforniaSan DiegoLa JollaCA 92093USA Present address:Department of Microbiology Chungnam National University School of MedicineDaejeon 35015Republic of Korea

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is a‘highly transmissible respiratory pathogen,leading to severe multiorgan ***,knowledge regarding SARS-CoV-2-induced cellular alterations is *** this study,we report that SARSCoV-2 aberrantly elevates mitochondrial bioenergetics and activates the EGFR-mediated cell survival signal cascade during the early stage of viral ***-CoV-2 causes an increase in mitochondrial transmembrane potential via the SARS-CoV-2 RNAnucleocapsid cluster,thereby abnormally promoting mitochondrial elongation and the OXPHOS process,followed by enhancing ATP ***,SARS-CoV-2 activates the EGFR signal cascade and subsequently induces mitochondrial EGFR trafficking,contributing to abnormal OXPHOS process and viral *** EGFR inhibitors remarkably reduce SARS-CoV-2 propagation,among which vandetanib exhibits the highest antiviral *** of SARS-CoV-2-infected cells with vandetanib decreases SARS-CoV-2-induced EGFR trafficking to the mitochondria and restores SARS-CoV-2-induced aberrant elevation in OXPHOS process and ATP generation,thereby resulting in the reduction of SARS-CoV-2 ***,oral administration of vandetanib to SARS-CoV-2-infected hACE2 transgenic mice reduces SARS-CoV-2 propagation in lung tissue and mitigates SARS-CoV-2-induced lung *** also exhibits potent antiviral activity against various SARS-CoV-2 variants of concern,including alpha,beta,delta and omicron,in in vitro cell culture *** together,our findings provide novel insight into SARS-CoV-2-induced alterations in mitochondrial dynamics and EGFR trafficking during the early stage of viral infection and their roles in robust SARS-CoV-2 propagation,suggesting that EGFR is an attractive host target for combating COVID-19.

关键词： alterations aberrant thereby

A Dynamical System-Based Framework for Dimension Reduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第2期6卷 757-789页

作者： Ryeongkyung yoon Braxton Osting Department of Mathematics University of UtahSalt Lake CityUTUSA

We propose a novel framework for learning a low-dimensional representation of data based on nonlinear dynamical systems,which we call the dynamical dimension reduction(DDR).In the DDR model,each point is evolved via a nonlinear flow towards a lower-dimensional subspace;the projection onto the subspace gives the low-dimensional *** the model involves identifying the nonlinear flow and the *** the equation discovery method,we represent the vector field that defines the flow using a linear combination of dictionary elements,where each element is a pre-specified linear/nonlinear candidate function.A regularization term for the average total kinetic energy is also introduced and motivated by the optimal transport *** prove that the resulting optimization problem is well-posed and establish several properties of the DDR *** also show how the DDR method can be trained using a gradient-based optimization method,where the gradients are computed using the adjoint method from the optimal control *** DDR method is implemented and compared on synthetic and example data sets to other dimension reduction methods,including the PCA,t-SNE,and Umap.

关键词： Dimension reduction Equation discovery Dynamical systems Adjoint method Optimal transportation

Negative Stiffness Mechanism on An Asymmetric Wave Energy Converter by Using A Weakly Nonlinear Potential Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 689-700页

作者： Sunny Kumar POGULURI Dongeun KIM yoon Hyeok BAE Department of Ocean Engineering IIT MadrasChennaiIndia Multidisciplinary Graduate School Program for Wind Energy Jeju National UniversityJejuRepublic of Korea Mechanical and System Design Engineering Hongik UniversitySeoulRepublic of Korea

Salter's duck,an asymmetrical wave energy converter(WEC)device,showed high efficiency in extracting energy from 2D regular waves in the past;yet,challenges remain for fluctuating wave *** can potentially be addressed by adopting a negative stiffness mechanism(NSM)in WEC devices to enhance system efficiency,even in highly nonlinear and steep 3D waves.A weakly nonlinear model was developed which incorporated a nonlinear restoring moment and NSM into the linear formulations and was applied to an asymmetric WEC using a time domain potential flow *** model was initially validated by comparing it with published experimental and numerical computational fluid dynamics *** current results were in good agreement with the published *** was found that the energy extraction increased in the range of 6%to 17%during the evaluation of the effectiveness of the NSM in regular *** irregular wave conditions,specifically at the design wave conditions for the selected test site,the energy extraction increased by 2.4%,with annual energy production increments of approximately *** findings highlight the potential of NSM in enhancing the performance of asymmetric WEC devices,indicating more efficient energy extraction under various wave conditions.

关键词： asymmetric wave energy converter negative stiffness mechanism weakly nonlinear potential flow power

100 W-class green hydrogen production from ammonia at a dual-layer electrode containing a Pt-Ir catalyst for an alkaline electrolytic process

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 352-360,I0009页

作者： Donghyun yoon Sunki Chung Minjun Choi Eunhyeok Yang Jaeyoung Lee School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology(GIST)Gwangju 61005Republic of Korea International Future Research Center of Chemical Energy Storage and Conversion Processes GISTGwangju 61005Republic of Korea Ertl Center for Electrochemistry and Catalysis GISTGwangju 61005Republic of Korea TKG Huchems Co.Ltd 963Sangam-roYeosu-siJeollanam-do 59614Republic of Korea

Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen *** decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO_(2)-free pure ***,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs)with a total geometric area of 200 cm~2 on the anode side,which resulted in a hydrogen production rate of 25 L h~(-1).We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia ***,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER).

关键词： Ammonia oxidation Dual-layer catalyst Green hydrogen Electrolytic process Oxygen evolution reaction

Modification strategies improving the electrochemical and structural stability of high-Ni cathode materials

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第9期96卷 185-205页

作者： yoon Bo Sim Hami Lee Junyoung Mun Ki Jae Kim Department of Energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

With the increasing spotlight in electric vehicles,there is a growing demand for high-energy-density batteries to enhance driving ***,several studies have been conducted on high-energy-density LiNi_(x)Co_(y)Mn_(z)O_(2)***,there is a limit to permanent performance deterioration because of side reactions caused by moisture in the atmosphere and continuous microcracks during cycling as the Ni content to express high energy increases and the content of Mn and Co that maintain structural and electrochemical stabilization *** direct modification of the surface and bulk regions aims to enhance the capacity and long-term performance of high-Ni cathode ***,an efficient modification requires a study based on a thorough understanding of the degradation mechanisms in the surface and bulk *** this review,a comprehensive analysis of various modifications,including doping,coating,concentration gradient,and single crystals,is conducted to solve degradation issues along with an analysis of the overall degradation mechanism occurring in high-Ni cathode *** also summarizes recent research developments related to the following modifications,aims to provide notable points and directions for post-studies,and provides valuable references for the commercialization of stable high-energy-density cathode materials.

关键词： High energy density High-Ni cathode materials Degradation Structural stability Lithium-ion battery

Synaptic a-Si:H/a-Ga_(2)O_(3) phototransistor inspired by the phototaxis behavior of organisms with all-optical and all-electrical stimulation modes

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7631-7642页

作者： Youngbin yoon Youngki Kim Soowon Choi Jungdae Kwon Myunghun Shin School of Electronics and Information Engineering Korea Aerospace UniversityGoyang10540Republic of Korea Nano Materials Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Engineering Pusan National UniversityBusan 46241Republic of Korea

To improve neuromorphic computing performance,neuromorphic system components should mimic the behaviors of organic *** this study,a synaptic a-Si:H/a-Ga_(2)O_(3)phototransistor featuring all-optical and-electrical emulation is fabricated in a manner advantageous for complementary metal-oxide-semiconductor process *** phototransistor exhibits excitatory and inhibitory synaptic behaviors under stimulation by both optical and electrical *** mimics several essential synaptic functions,including excitatory postsynaptic current,inhibitory postsynaptic current,short-term memory,long-term memory,pairedpulse facilitation,and spike-timing-dependent *** optical and electrical modulation mechanisms are confirmed to arise from the a-Si:H/a-Ga_(2)O_(3) heterojunction structure and interface effects,and the device is shown to operate at low power in both optical and electrical *** all-optical weight modulation function is applied to the wavelength-differential behavior response of zebrafish,successfully mimicking the color perception process of the ***,to verify the translation of the optoelectrical-derived synaptic behaviors of the phototransistor into artificial neuromorphic computation,handwritten digit image recognition of the Modified National Institute of Standards and Technology dataset is performed by a convolutional neural network,with a demonstrated average learning accuracy of 98.46%.These findings verify the applicability of the synaptic a-Si:H/a-Ga_(2)O_(3) phototransistor in neuromorphic computing.

关键词： synaptic phototransistor artificial synapse phototaxis neuromorphic computing interface charge state optoelectronic synaptic device

Biochemical consequences of glucocerebrosidase 1 mutations in Parkinson’s disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第4期19卷 725-727页

作者： Jeong Hyun yoon Chiao-Yin Lee Anthony HV Schapira Department of Clinical and Movement Neurosciences University College London Institute of Neurology Faculty of Medicine Imperial College London Aligning Science Across Parkinson's(ASAP)Collaborative Research Network

Parkinson’s disease(PD,OMIM#168600)is a common neurodegenerative disorder with a global prevalence of approximately 8.5 *** is characterized by four cardinal motor symptoms:bradykinesia,rigidity,resting tremor,and subsequently by postural *** usually involves non-motor symptoms such as rapid eye movement sleep disorder,dementia,anosmia,and autonomic *** gene glucocerebrosidase 1(GBA1),which encodes the lysosomal enzyme glucocerebrosidase(GCase)(IUBMB:EC 3.***.1.45),shows strong linkage with PD;variants of GBA1 are the commonest genetic association with PD(Sidransky et al.,2009).Several mechanisms may underlie the relationship between GBA1 mutations/variants and the molecular pathology of PD(Figure 1A and B).

关键词： cerebro consequences