Advanced Electronic Materials最新文献_第6页

Layer-By-Layer Approach to Improve the Capacitance of Conducting Polymer Films 提高导电聚合物薄膜电容的逐层方法

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-15 DOI: 10.1002/aelm.202400761

Małgorzata Skorupa, Ethan Cao, Adrian Barylski, Sara Shakibania, Sandra Pluczyk-Małek, Zuzanna Siwy, Katarzyna Krukiewicz

{"title":"Layer-By-Layer Approach to Improve the Capacitance of Conducting Polymer Films","authors":"Małgorzata Skorupa, Ethan Cao, Adrian Barylski, Sara Shakibania, Sandra Pluczyk-Małek, Zuzanna Siwy, Katarzyna Krukiewicz","doi":"10.1002/aelm.202400761","DOIUrl":"https://doi.org/10.1002/aelm.202400761","url":null,"abstract":"In the pursuit of energy storage devices offering high power density, rapid charge and discharge rates, a layer-by-layer deposition approach is shown to improve the capacitive properties of conducting polymer-based devices. This work describes the synthesis and characterization of a composite material based on poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedioxypyrrole) (PEDOP) for supercapacitor applications. PEDOT and PEDOP are sequentially electropolymerized using cyclic voltammetry to form bilayer structures, overcoming challenges associated with copolymerization. The evaluation of electrochemical performance of the PEDOT/PEDOP composite reveals superior areal capacitance (42.2 ± 2.8 mF cm−2 at the scan rate of 5 mV s−1) outperforming both homopolymers by up to 30%. Microscopic and spectroscopic surface analysis confirm the uniform coating of PEDOT/PEDOP and enhanced surface roughness resulting from the formation of 3D nanostructures, contributing to improved electrochemical performance. Further electrochemical impedance spectroscopic analysis demonstrates low charge transfer resistance (25 ± 8 Ω) and high energy density with respect to the area of the electrode (3.53 ± 0.3 µWh cm−2 at 55 µW cm−2), making PEDOT/PEDOP composite a promising material for high-performance supercapacitors.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"5 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Degradation Properties of Organic Light-Emitting Diodes with Modified Interface Charge Density via Dipolar Doping Studied by Displacement Current Measurement 用位移电流测量研究了偶极掺杂改性界面电荷密度有机发光二极管的降解特性

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-15 DOI: 10.1002/aelm.202400788

Mihiro Takeda, Alexander Hofmann, Wolfgang Brütting, Yutaka Noguchi

{"title":"Degradation Properties of Organic Light-Emitting Diodes with Modified Interface Charge Density via Dipolar Doping Studied by Displacement Current Measurement","authors":"Mihiro Takeda, Alexander Hofmann, Wolfgang Brütting, Yutaka Noguchi","doi":"10.1002/aelm.202400788","DOIUrl":"https://doi.org/10.1002/aelm.202400788","url":null,"abstract":"Accumulated charges at the interfaces of organic light-emitting diodes (OLEDs) often induce exciton quenching and lead to device degradation. This work delves into the correlations of the interface charge accumulation and degradation properties of tris(8-quinolinolato)aluminum (Alq3)-based OLEDs. The interface accumulated charge density is modified by spontaneous orientation polarization (SOP) induced in the hole transport layer (HTL) by means of dipolar doping, where N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) or tris(4-carbazoyl-9-ylphenyl) amine (TCTA) is employed as a hole transport material and 2,2′,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-bensimidazole) (TPBi) as a dipolar dopant. It is confirmed that NPB cation acts as an exciton quencher, but TCTA cation does not, depending on the spectral overlap of Alq3 emission and the absorption of the respective cations. On the other hand, the TCTA devices degrade much faster than the NPB devices. Moreover, the device lifetime is similar or even shorter for the doped devices despite less interface charge density. These results suggest that holes accumulated at the interface between the hole transport material and Alq3 due to SOP are not mainly involved in the degradation mechanism. Furthermore, it is found that the charge traps generated due to degradation do not act as exciton quenchers, suggesting that they rather act as nonradiative recombination centers.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"75 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bandgap-Dependent Doping of Semiconducting Carbon Nanotube Networks by Proton-Coupled Electron Transfer for Stable Thermoelectrics 稳定热电体中质子耦合电子转移的半导体碳纳米管网络带隙依赖掺杂

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-14 DOI: 10.1002/aelm.202400817

Angus Hawkey, Xabier Rodríguez-Martínez, Sebastian Lindenthal, Moritz C. F. Jansen, Reverant Crispin, Jana Zaumseil

{"title":"Bandgap-Dependent Doping of Semiconducting Carbon Nanotube Networks by Proton-Coupled Electron Transfer for Stable Thermoelectrics","authors":"Angus Hawkey, Xabier Rodríguez-Martínez, Sebastian Lindenthal, Moritz C. F. Jansen, Reverant Crispin, Jana Zaumseil","doi":"10.1002/aelm.202400817","DOIUrl":"https://doi.org/10.1002/aelm.202400817","url":null,"abstract":"Networks of semiconducting single-walled carbon nanotubes (SWNTs) are a promising material for thermoelectric energy harvesting due to their mechanical flexibility, solution processability, high Seebeck coefficients and high electrical conductivities after chemical p- or n-doping. Here, we demonstrate that proton-coupled electron transfer (PCET) with benzoquinone (BQ) as the oxidant and lithium bis(trifluoromethylsulfonyl)imide (Li[TFSI]) for electrolyte counterions is a highly suitable method for p-doping of polymer-sorted semiconducting SWNT networks. The achieved doping levels, as determined from absorption bleaching, depend directly on both the pH of the aqueous doping solutions and the bandgap (i.e., diameter) of the nanotubes within the network. Fast screening of different nanotube networks under various doping conditions is enabled by a high-throughput setup for thermoelectric measurements of five samples in parallel. For small-bandgap SWNTs, PCET-doping is sufficient to reach the maximum thermoelectric power factors, which are equal to those obtained by conventional methods. In contrast to other doping methods, the electrical conductivity of PCET-doped SWNTs remains stable over at least 5 days in air. These results confirm PCET to be a suitable approach for more environmentally friendly and stable doping of semiconducting SWNTs as promising thermoelectric materials.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"31 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Computational and AI-Driven Design of Hydrogels for Bioelectronic Applications 生物电子应用水凝胶的计算和人工智能驱动设计

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-14 DOI: 10.1002/aelm.202400763

Rebekah Finster, Prashant Sankaran, Eloise Bihar

引用次数: 0

Neuron-Inspired Biomolecular Memcapacitors Formed Using Droplet Interface Bilayer Networks 利用液滴界面双层网络形成神经元启发的生物分子膜电容器

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-13 DOI: 10.1002/aelm.202400644

Braydon Segars, Kyle Rosenberg, Sarita Shrestha, Joshua J. Maraj, Stephen A. Sarles, Eric Freeman

{"title":"Neuron-Inspired Biomolecular Memcapacitors Formed Using Droplet Interface Bilayer Networks","authors":"Braydon Segars, Kyle Rosenberg, Sarita Shrestha, Joshua J. Maraj, Stephen A. Sarles, Eric Freeman","doi":"10.1002/aelm.202400644","DOIUrl":"https://doi.org/10.1002/aelm.202400644","url":null,"abstract":"Brain-inspired (or neuromorphic) computing circumvents costly bottlenecks in conventional Von Neumann architectures by collocating memory and processing. This is accomplished through dynamic material architectures, strengthening or weakening internal conduction pathways similar to synaptic connections within the brain. A new class of neuromorphic materials approximates synaptic interfaces using lipid membranes assembled via the droplet interface bilayer (DIB) technique. These DIB membranes have been studied as novel memristors or memcapacitors owing to the soft, reconfigurable nature of both the lipid membrane geometry and the embedded ion-conducting channels. In this work, a biomolecular approach to neuromorphic materials is expanded from model synapses to a charge-integrating model neuron. In these serial membrane networks, it is possible to create distributions of voltage-sensitive gates capable of trapping ionic charge. This trapped charge creates transmembrane potential differences that drive changes in the system's net capacitance through electrowetting, providing a synaptic weight that changes in response to the history and timing of input signals. This fundamental change from interfacial memory (dimensions of the membrane) to internal memory (charge trapped within the droplets) provides a functional plasticity capable of multiple weights, longer-term retention roughly an order of magnitude greater than memory stored in the membranes alone, and programming-erasure.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"41 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Transient Photoelectric Spiking Neuron Based on a Highly Robust MgO Composite Threshold Switching Memristor for Selective UV Perception 基于高鲁棒MgO复合阈值开关忆阻器的瞬态光电脉冲神经元选择性紫外感知

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-13 DOI: 10.1002/aelm.202400678

Yaxiong Cao, Rui Wang, Saisai Wang, Tonglong Zeng, Wanlin Zhang, Jing Sun, Xiaohua Ma, Hong Wang, Yue Hao

{"title":"A Transient Photoelectric Spiking Neuron Based on a Highly Robust MgO Composite Threshold Switching Memristor for Selective UV Perception","authors":"Yaxiong Cao, Rui Wang, Saisai Wang, Tonglong Zeng, Wanlin Zhang, Jing Sun, Xiaohua Ma, Hong Wang, Yue Hao","doi":"10.1002/aelm.202400678","DOIUrl":"https://doi.org/10.1002/aelm.202400678","url":null,"abstract":"The biological photoreceptors in the retina convert light information into spikes, inspiring the emergence of artificial photoelectric spiking neurons. However, due to the lack of biocompatible and biodegradable characteristics, artificial photoelectric spiking neurons based on threshold switching (TS) devices are not available for bio‐integrated optical medical diagnostics and neuromorphic computing. Here, an artificial photoelectric spiking neuron integrated with a physically transient memristor and photodetector for UV perception is proposed. The transient memristor with a MgO:Mg resistive layer implemented by the co‐sputtering process of MgO and Mg targets shows highly robust TS performance, while the ZnO‐based transient photodetector can selectively detect UV light at power densities below 10 mW cm−2. More interestingly, the frequency of the firing spikes generated by artificial photoelectric spiking neuron increases with the enhancement of UV light intensity. In addition, the recognition accuracy of UV information extracted from the surrounding environment reaches ≈99.8% by spiking neural network consisting of photoelectric spiking neuron when the object that blended into the background are not easily detected. This work demonstrates that the functions of the biological photoreceptors may be truly mimicked by artificial photoelectric spiking neuron with transiency, expanding its application in optical disease diagnosis and implantable visual neuromorphic computing.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"14 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142968278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Organic Photo-Responsive Piezoelectric Materials Based on Pyrene Molecules for Flexible Sensors 基于芘分子的柔性传感器有机光响应压电材料

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-13 DOI: 10.1002/aelm.202400933

Xinyi Song, Xiaohui Wang, Wei Liu, Xiaoxue Chen, Shaoling Li, Md Shariful Islam, Ling Li, Xiaobo Zhao, Carl Redshaw, Yu Zhao, Changyong (Chase) Cao, Xing Feng

{"title":"Organic Photo-Responsive Piezoelectric Materials Based on Pyrene Molecules for Flexible Sensors","authors":"Xinyi Song, Xiaohui Wang, Wei Liu, Xiaoxue Chen, Shaoling Li, Md Shariful Islam, Ling Li, Xiaobo Zhao, Carl Redshaw, Yu Zhao, Changyong (Chase) Cao, Xing Feng","doi":"10.1002/aelm.202400933","DOIUrl":"https://doi.org/10.1002/aelm.202400933","url":null,"abstract":"Due to the advantages of multiplicity, functionality, and flexibility of organic building blocks, organic piezoelectric materials are regarded as next-generation materials for potential applications in flexible sensors and energy harvesting devices. Here, a new pure organic pyrene-based molecule, PyPT is presented, which crystallizes in a non-centrosymmetric structure. PyPT is synthesized and demonstrated to be suitable for developing flexible sensors due to its remarkable piezoelectric properties. The pyrene-based piezoelectric molecule exhibits excitation wavelength-dependent emission behavior and aggregation-caused quenching properties and demonstrated a piezoelectric coefficient (d33) of 8.02 ± 0.26 pm V−1. The output electronic signal of a PyPT-based flexible sensor shows a significant increase from 30 to 721 pA as the strain increases from 0.12% to 0.59% with a low Young's modulus of 1.63 Gpa. This high-performance piezoelectric sensor can serve as a sensitive sound sensor for sound detection and recognition based on the basic characteristics of sound, such as amplitude, frequencies, and timbres. This research offers new insights into advancing pure organic luminescent materials with piezoelectric properties, paving the way for applications in flexible electronics for wearables, human–machine interfaces, and the Internet of Things.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"47 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Highly Robust Double Memristive Device Based on Perovskite/Molybdenum Oxide‐Sulfide Compound Heterojunction System 基于钙钛矿/氧化钼-硫化钼复合异质结体系的高鲁棒双忆阻器件

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-11 DOI: 10.1002/aelm.202400433

Gion Kalemai, Apostolos Verykios, Georgios Chatzigiannakis, Polychronis Tsipas, Athanasios Dimoulas, Vassilis Psycharis, Elias Sakellis, Nikos Boukos, Vlassis Likodimos, Ioannis Karatasios, Michael‐Alexandros Kourtis, Konstantinos Aidinis, Alexander Chroneos, Abd Rashid bin Mohd Yusoff, Panagiotis Argitis, Dimitris Davazoglou, Maria Vasilopoulou, Anastasia Soultati

{"title":"Highly Robust Double Memristive Device Based on Perovskite/Molybdenum Oxide‐Sulfide Compound Heterojunction System","authors":"Gion Kalemai, Apostolos Verykios, Georgios Chatzigiannakis, Polychronis Tsipas, Athanasios Dimoulas, Vassilis Psycharis, Elias Sakellis, Nikos Boukos, Vlassis Likodimos, Ioannis Karatasios, Michael‐Alexandros Kourtis, Konstantinos Aidinis, Alexander Chroneos, Abd Rashid bin Mohd Yusoff, Panagiotis Argitis, Dimitris Davazoglou, Maria Vasilopoulou, Anastasia Soultati","doi":"10.1002/aelm.202400433","DOIUrl":"https://doi.org/10.1002/aelm.202400433","url":null,"abstract":"Halide organic–inorganic perovskites (HOIPs) are a promising class of materials for neuromorphic computing and processing systems demonstrating a variety of resistive switching (RS) mechanisms. HOIPs have been used as active layers in two‐ and three‐terminal synaptic devices reporting high performance in metrics of speed and energy consumption. Nevertheless, halide perovskites suffer from poor ambient stability and reproducibility. In this work, a highly robust double memristor based on two active layers forming a stacking heterojunction is demonstrated. In particular, the functional layer consists of a molybdenum oxide‐molybdenum sulfide compound (MoO3‐MoS2) and a quadruple cation perovskite (RbCsMAFA) deposited on top showing favorable band alignment for the specific application. The double memristor based on the MoO3‐MoS2/RbCsMAFA heterojunction exhibits impressive and stable resistive switching behavior with endurance of 100 cycles, high retention of 2 × 104 s, high environmental stability maintaining its memristive behavior for 1 month, and excellent artificial synaptic functions. The robust device also exhibits good thermal stability maintaining the memristive characteristics at 85 °C, as well as good photonic memristive behavior with an improved ON/OFF ratio under constant illumination. Here it is proven that the proposed double memristor is a promising candidate for artificial synapses and neuromorphic computing systems.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"29 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Extreme Enhancement‐Mode Operation Accumulation Channel Hydrogen‐Terminated Diamond FETs with Vth < −6 V and High on‐Current Vth < - 6 V和高导通电流的极增强模式操作积累通道氢端金刚石场效应管

IF 6.2 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-11 DOI: 10.1002/aelm.202400770

Chunlin Qu, Isha Maini, Qing Guo, Alastair Stacey, David A. J. Moran

{"title":"Extreme Enhancement‐Mode Operation Accumulation Channel Hydrogen‐Terminated Diamond FETs with Vth < −6 V and High on‐Current","authors":"Chunlin Qu, Isha Maini, Qing Guo, Alastair Stacey, David A. J. Moran","doi":"10.1002/aelm.202400770","DOIUrl":"https://doi.org/10.1002/aelm.202400770","url":null,"abstract":"In this work, a new Field Effect Transistor device concept based on hydrogen‐terminated diamond (H‐diamond) is demonstrated that operates in an Accumulation Channel rather than a Transfer Doping regime. The FET devices demonstrate both extreme enhancement‐mode operation and high on‐current with improved channel charge mobility compared to Transfer‐Doped equivalents. Electron‐beam evaporated Al2O3 is used on H‐diamond to suppress the Transfer Doping mechanism and produce an extremely high ungated channel resistance. A high‐quality H‐diamond surface with an unpinned Fermi level is crucially achieved, allowing for the formation of a high‐density hole accumulation layer by gating the entire device channel which is encapsulated in dual‐stacks of Al2O3. Completed devices with gate/channel length of 1 µm demonstrate record threshold voltage < −6 V with on‐current > 80 mA mm−1. Carrier density and mobility figures extracted by CV analysis indicate a high 2D charge density of ≈ 2 × 1012 cm−2 and increased hole mobility of 110 cm2 V−1 s−1 in comparison with more traditional Transfer‐Doped H‐diamond FETs. These results demonstrate the most negative threshold voltage yet reported for H‐diamond FETs and highlight a powerful new strategy to greatly improve carrier mobility and enable enhanced high power and high frequency diamond transistor performance.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"35 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wide-Bandgap Nickel Oxide with Tunable Acceptor Concentration for Multidimensional Power Devices (Adv. Electron. Mater. 1/2025) 具有可调受体浓度的宽禁带氧化镍用于多维功率器件（Adv.电子）。板牙。1/2025)

IF 5.3 2区材料科学

Advanced Electronic Materials Pub Date : 2025-01-10 DOI: 10.1002/aelm.202570001

Yunwei Ma, Yuan Qin, Matthew Porter, Joseph Spencer, Zhonghao Du, Ming Xiao, Boyan Wang, Yifan Wang, Alan G. Jacobs, Han Wang, Marko Tadjer, Yuhao Zhang

引用次数: 0