Materials Today Electronics最新文献

Metal oxide semiconductor-based negative capacitance field-effect transistors with a sub-threshold swing of below 30 mV/dec 亚阈值摆幅低于30mv /dec的金属氧化物半导体负电容场效应晶体管

IF 7.4

Materials Today Electronics Pub Date : 2025-09-25 DOI: 10.1016/j.mtelec.2025.100178

Ji Hyeon Min , Seong Cheol Jang , Kyong Jae Kim , You Seung Rim , Hyun-Suk Kim

引用次数: 0

Development of an analytical tool to design photovoltaic solar cells: Analysis in outer space conditions 一种设计光伏太阳能电池的分析工具的发展：外太空条件下的分析

IF 7.4

Materials Today Electronics Pub Date : 2025-09-25 DOI: 10.1016/j.mtelec.2025.100176

Miguel Eduardo Pereira Gonçalves , P. Mendonça dos Santos , António Baptista , Marcelino dos Santos , João Paulo N. Torres , Ricardo A. Marques Lameirinhas

{"title":"Development of an analytical tool to design photovoltaic solar cells: Analysis in outer space conditions","authors":"Miguel Eduardo Pereira Gonçalves , P. Mendonça dos Santos , António Baptista , Marcelino dos Santos , João Paulo N. Torres , Ricardo A. Marques Lameirinhas","doi":"10.1016/j.mtelec.2025.100176","DOIUrl":"10.1016/j.mtelec.2025.100176","url":null,"abstract":"<div><div>Various well established solar cell simulation software are presently available; however, they are often closed source, requiring costly licenses, or general-purpose simulation software. The main objective of this work is the development of an analytical tool to model and simulate solar cells, with particular emphasis in space applications. The software was constructed in Python using object-oriented programming by applying the equivalent two-diode electrical model, semiconductor physics, and optical modeling. It was designed to simulate both single- and multi-junction solar cells with additional non-textured anti-reflective coatings and protective layers. A method was also implemented to simulate the effects of ionizing radiation. The program was validated by data comparison with established software and commercially available space solar cells. In both cases, the tool developed was found to have obtained similar results, which seem to indicate that the program is reasonably accurate. Furthermore, three studies were carried out on: Anti-reflection coatings and protective layers, Ionizing-radiation effects and Multi-junction solar cells. In the anti-reflection coatings and protective layers study, it was possible to verify how differences in the type and number of layers affect performance. With the ionizing radiation effects study, the accuracy of the model was tested against research article data. The multi-junction study has shown how important the appropriate selection of semiconductor material, doping, and thickness is to mitigate losses and improve cell performance.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"14 ","pages":"Article 100176"},"PeriodicalIF":7.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Angle-insensitive multilayer metacoating with dual-band selective emission for infrared camouflage and radiative cooling 用于红外伪装和辐射冷却的双波段选择性发射的角度不敏感多层稳镀膜

IF 7.4

Materials Today Electronics Pub Date : 2025-09-22 DOI: 10.1016/j.mtelec.2025.100177

Liyan Li , Dongjie Zhou , Jinguo Zhang , Lei Zhou , Junhao Chu , Qiong He , Jiaming Hao

{"title":"Angle-insensitive multilayer metacoating with dual-band selective emission for infrared camouflage and radiative cooling","authors":"Liyan Li , Dongjie Zhou , Jinguo Zhang , Lei Zhou , Junhao Chu , Qiong He , Jiaming Hao","doi":"10.1016/j.mtelec.2025.100177","DOIUrl":"10.1016/j.mtelec.2025.100177","url":null,"abstract":"<div><div>The mid-infrared (MIR) spectral region, covering the atmospheric transmission windows (ATWs) of 3–5 μm (mid-wavelength infrared, MWIR) and 8–13 μm (long-wavelength infrared, LWIR), is critical for applications such as infrared camouflage and radiative cooling due to its low atmospheric absorption. Here, we present a high-efficiency, deep-subwavelength multilayer metacoating (MMC) designed for dual-band emission in the MWIR and LWIR ATWs. Through selective impedance matching, the quad-layer MMC achieves average emissivities of 0.79 in the MWIR and 0.83 in the LWIR ATWs, while suppressing emissivity to 0.33 in the non-ATW range of 5–8 μm. Experimental results confirm these findings, which arise from electromagnetic localization within the multilayer architecture and dissipation in lossy materials (Ti and Cr). Notably, the emitter exhibits angle-insensitive performance, maintaining emissivities of 0.65 (MWIR) and 0.72 (LWIR) at incidence angles up to 70°, and demonstrates effective LWIR camouflage against high-emissivity backgrounds. Theoretical analysis further reveals its potential for nighttime radiative cooling. This work advances scalable, low-cost metacoatings for dual-functional infrared technologies, addressing key challenges in military signature management, thermal regulation, and energy-efficient aerospace systems.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"14 ","pages":"Article 100177"},"PeriodicalIF":7.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxygen-pressure driven balancing of interface and bulk scattering in amorphous oxide semiconductor thin-film transistors 氧压驱动的非晶氧化物半导体薄膜晶体管界面与体散射平衡

IF 7.4

Materials Today Electronics Pub Date : 2025-09-05 DOI: 10.1016/j.mtelec.2025.100171

Che-Yi Lin , Yu-Ching Kuo , I-Chen Liu , Feng-Shou Yang , Yuan-Ming Chang , Po-Wen Chiu , Toshihide Nabatame , Mengjiao Li , Kazuhito Tsukagoshi , Yen-Fu Lin

{"title":"Oxygen-pressure driven balancing of interface and bulk scattering in amorphous oxide semiconductor thin-film transistors","authors":"Che-Yi Lin , Yu-Ching Kuo , I-Chen Liu , Feng-Shou Yang , Yuan-Ming Chang , Po-Wen Chiu , Toshihide Nabatame , Mengjiao Li , Kazuhito Tsukagoshi , Yen-Fu Lin","doi":"10.1016/j.mtelec.2025.100171","DOIUrl":"10.1016/j.mtelec.2025.100171","url":null,"abstract":"<div><div>Oxygen vacancies (<em>V</em><sub>O</sub>) critically influence the electronic properties and stability of amorphous oxide semiconductor (AOS) thin-film transistors (TFTs). Here, we investigate the impact of oxygen partial pressure during film deposition on charge transport mechanisms in 10-nm-thick silicon-doped indium oxide (ISO) TFTs. By adjusting the Ar:O<sub>2</sub> ratio (11:1, 8:4, and 6:6), we observe a shift from interface-limited to bulk-scattering-dominated transport. Higher O<sub>2</sub> pressure leads to increased subthreshold swing (SS), positive threshold voltage (<em>V</em><sub>th</sub>) shifts, and larger current fluctuations, suggesting greater charge trapping and mobility degradation. Low-frequency noise (LFN) analysis further reveals a shift in the dominant noise mechanism: interface charge trapping dominates at low O<sub>2</sub> pressure, while bulk carrier scattering prevails at high O<sub>2</sub> pressure. The extracted trap density (<em>N</em><sub>it</sub>) increases by nearly two orders of magnitude, confirming the role of fully oxidized indium atoms in the conducting channel as charge-scattering centers. These findings establish oxygen pressure as a key parameter for balancing interface and bulk effects in AOS TFTs and provide a pathway for optimizing device performance and stability in next-generation oxide electronics.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"14 ","pages":"Article 100171"},"PeriodicalIF":7.4,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Artificial intelligence for post-moore field-effect transistors: a review and perspective 后摩尔场效应晶体管的人工智能研究进展与展望

IF 7.4

Materials Today Electronics Pub Date : 2025-09-05 DOI: 10.1016/j.mtelec.2025.100172

Xiang Li, Nan Jiang, Wenhan Zhou, Xiaoyi Zhang, Yang Hu, Shuo Wang, Huipu Wang, Hengze Qu, Haibo Zeng, Shengli Zhang

{"title":"Artificial intelligence for post-moore field-effect transistors: a review and perspective","authors":"Xiang Li, Nan Jiang, Wenhan Zhou, Xiaoyi Zhang, Yang Hu, Shuo Wang, Huipu Wang, Hengze Qu, Haibo Zeng, Shengli Zhang","doi":"10.1016/j.mtelec.2025.100172","DOIUrl":"10.1016/j.mtelec.2025.100172","url":null,"abstract":"<div><div>As Moore’s Law approaches its fundamental physical limits, the development of post-Moore field-effect transistors (FETs) has emerged as a critical pathway to sustain the advancement of semiconductor technology. Artificial intelligence (AI), with its unparalleled capabilities in data-driven modeling, optimization, and predictive analytics, is revolutionizing the design, simulation, and fabrication of next-generation FETs. This review systematically examines the methodological frameworks, algorithmic strategies, and multidimensional applications of AI in FETs research, with particular emphasis on high-throughput screening and performance prediction of channel materials, gate dielectrics, and electrode materials, alongside device architecture optimization. Furthermore, we highlight future opportunities at the intersection of AI to redefine the frontiers of post-Moore electronics. This review aims to inspire multidisciplinary efforts toward AI-empowered FET innovation, bridging the gap between computational intelligence and semiconductor engineering for sustainable technological progress.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"14 ","pages":"Article 100172"},"PeriodicalIF":7.4,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploration and analysis of high-K wrapped underlap based GaN SOI FinFET for enriched performance towards RF applications 探索和分析基于高k包覆的GaN SOI FinFET，以提高射频应用的性能

IF 7.4

Materials Today Electronics Pub Date : 2025-09-04 DOI: 10.1016/j.mtelec.2025.100170

Sneha Singh , Rudra Sankar Dhar , Harith Ahmad , Mousa I. Hussein

{"title":"Exploration and analysis of high-K wrapped underlap based GaN SOI FinFET for enriched performance towards RF applications","authors":"Sneha Singh , Rudra Sankar Dhar , Harith Ahmad , Mousa I. Hussein","doi":"10.1016/j.mtelec.2025.100170","DOIUrl":"10.1016/j.mtelec.2025.100170","url":null,"abstract":"<div><div>GaN Semiconductor on Insulator (SOI) FinFET with high-k wrapped underlaps and TiO<sub>2</sub> gate oxide is initially developed, explored and analysed for enhanced performances suitable for RF applications. The impact of employing SOI substrate layer and high-k wrapped underlaps on various electrical parameters, such as I<sub>on</sub>, I<sub>off</sub>, electric field, potential, I<sub>on</sub>/I<sub>off</sub> (switching ratio), SS, energy band in conduction and valence band regions are extensively investigated and compared with existing devices. An analytical threshold voltage (V<sub>th</sub>) model for the GaN SOI FinFET is derived that delivers a good match with the acquired value, while an excellent experimental calibration is also presented. The device demonstrates significant improvement in electrical and RF/analog performances on incorporation of SOI substrate and high-k wrapped underlaps that minimize parasitic capacitance and fringing field effects resulting in ∼14 % increase in cut-off frequency and 167 % enhancement in transconductance leading to enhanced AC performances. The proposed device also observed to exhibit superior switching characteristics with ∼11 % reduction in subthreshold swing and an increase in I<sub>on</sub>/I<sub>off</sub> ratio of 154 % compared to existing FinFETs, while other SCEs (Short Channel Effects) are well controlled making it suitable for low-power and high-performance CMOS circuits. Additionally, linearity metrics such as VIP2, VIP3, and IIP3 show enrichment with the device achieving lower harmonic distortions (IMD3 and THD) thereby ensuing suitability for RF and analog circuit designs. These results underscore the potential of GaN SOI FinFETs with high-k underlap designs for high-speed, low-power applications in IOT and 5G/6 G technologies, contributing to the development of green and sustainable electronics.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"14 ","pages":"Article 100170"},"PeriodicalIF":7.4,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Glass-like thermal conductivity in higher manganese silicides with grain boundary nanostructures 具有晶界纳米结构的高硅化锰的类玻璃导热性

IF 7.4

Materials Today Electronics Pub Date : 2025-08-12 DOI: 10.1016/j.mtelec.2025.100169

Youming Xu , Shuchen Li , Shucheng Guo , Jianshi Zhou , Li Shi , Xi Chen

{"title":"Glass-like thermal conductivity in higher manganese silicides with grain boundary nanostructures","authors":"Youming Xu , Shuchen Li , Shucheng Guo , Jianshi Zhou , Li Shi , Xi Chen","doi":"10.1016/j.mtelec.2025.100169","DOIUrl":"10.1016/j.mtelec.2025.100169","url":null,"abstract":"<div><div>Higher manganese silicides (HMSs) have emerged as promising candidates for environmentally friendly thermoelectric (TE) materials due to their earth-abundant and non-toxic composition. We report grain boundary engineering in ruthenium-doped HMSs via a melt-quenching followed by annealing method. This approach promotes the formation of MnSi nanoprecipitates and nanopores, preferentially near grain boundaries. The presence of these nanostructures results in a weak temperature-dependent thermal conductivity, resembling glass-like thermal transport behavior. A two-channel model incorporating propagons and diffusons describes this glass-like thermal conductivity, with diffusons contributing about 60 % of the lattice thermal conductivity at 300 K. Furthermore, the quench-annealing process enhances electrical conductivity while preserving a large Seebeck coefficient, which is attributed to a high density-of-states effective mass. As a result of improved power factor and reduced thermal conductivity, the figure of merit <em>zT</em> value increases by 33 % at 300 K compared to undoped HMS synthesized via solid-state reaction. These findings present a promising strategy for manipulating phonon dynamics in functional materials and designing efficient TE systems.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"13 ","pages":"Article 100169"},"PeriodicalIF":7.4,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Micro-nano additive manufacturing for advanced electronic packaging of singulated chips 单芯片先进电子封装的微纳增材制造

Materials Today Electronics Pub Date : 2025-07-22 DOI: 10.1016/j.mtelec.2025.100168

Zhiwen Zhou , Zihan Li , Wenrui Zhang , Yijie Bian , Xing Qiu , Lujun Huang , Mojun Chen

{"title":"Micro-nano additive manufacturing for advanced electronic packaging of singulated chips","authors":"Zhiwen Zhou , Zihan Li , Wenrui Zhang , Yijie Bian , Xing Qiu , Lujun Huang , Mojun Chen","doi":"10.1016/j.mtelec.2025.100168","DOIUrl":"10.1016/j.mtelec.2025.100168","url":null,"abstract":"<div><div>The high costs associated with frontend packaging services, coupled with the incompatibility of wafer-level backend technologies with singulated chips, present significant challenges to the development of high-performance semiconductor devices. Micro-nano additive manufacturing (AM) has emerged as a transformative solution for the packaging of singulated chip, offering customizable designs, rapid prototyping capabilities, and the fabrication of complex three-dimensional (3D) structures. This review highlights the pivotal role of micro-nano AM in the fabrication of 3D antennas, copper pillar micro-bumps, and redistribution layers (RDLs), while also addressing the challenges associated with heterogeneous integration and thermal management. By synergizing AM with conventional packaging techniques, this technology accelerates chip validation, reduces production costs, and enables multifunctional integration. Nevertheless, to realize its full potential at scale, AM still faces critical challenges such as limited scalability and structural consistency. This article provides a comprehensive overview of the integration of AM technologies into advanced electronic packaging, highlighting their potential to revolutionize next-generation semiconductor manufacturing and electronic integration.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"13 ","pages":"Article 100168"},"PeriodicalIF":0.0,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stabilized biskyrmion states in annealed CoFeB bilayer with different interfaces 具有不同界面的退火CoFeB双分子层中铋态的稳定

Materials Today Electronics Pub Date : 2025-07-19 DOI: 10.1016/j.mtelec.2025.100166

Warda Al Saidi , Selma Amara , Myo T. Zar Myint , Salim Al Harthi , Gianluca Setti , Rachid Sbiaa

{"title":"Stabilized biskyrmion states in annealed CoFeB bilayer with different interfaces","authors":"Warda Al Saidi , Selma Amara , Myo T. Zar Myint , Salim Al Harthi , Gianluca Setti , Rachid Sbiaa","doi":"10.1016/j.mtelec.2025.100166","DOIUrl":"10.1016/j.mtelec.2025.100166","url":null,"abstract":"<div><div>This study investigates the stability of skyrmions and biskyrmions in perpendicular magnetic tunneling junctions with a thick CoFeB/Ta/CoFeB free layer. The samples showed a magnetoresistance of ∼ 41 % when annealed at 230 °C. Magnetic force microscopy revealed the existence of skyrmions and biskyrmions at room temperature in the as-deposited state and under an external magnetic field. Annealing at 330 °C enhanced interfacial Dzyaloshinskii-Moriya interaction (DMI) and crystallinity, enabling the spontaneous coexistence of these topological structures. Micromagnetic simulations explored the interplay between DMI strength, sign, and skyrmion chirality. Skyrmions exhibited repulsive interactions while biskyrmions displayed attractive interactions due to the difference in helicities. The study highlights the influence of multilayer structure and varying Ta layer thicknesses on the DMI chirality, which modulates the formation of complex spin textures. These results provide an understanding of skyrmion and biskyrmion dynamics and their potential for spintronic applications, including racetrack memory and data storage technologies.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"13 ","pages":"Article 100166"},"PeriodicalIF":0.0,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144666048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Humidity sensors for wearable health monitoring and human-machine interaction 用于穿戴式健康监测和人机交互的湿度传感器

Materials Today Electronics Pub Date : 2025-07-16 DOI: 10.1016/j.mtelec.2025.100167

Xin Liu , Cong Xiao , Huabin Yang , Qirui Zhang , Na Zhou , Haiyang Mao

{"title":"Humidity sensors for wearable health monitoring and human-machine interaction","authors":"Xin Liu , Cong Xiao , Huabin Yang , Qirui Zhang , Na Zhou , Haiyang Mao","doi":"10.1016/j.mtelec.2025.100167","DOIUrl":"10.1016/j.mtelec.2025.100167","url":null,"abstract":"<div><div>With the rapid development of wearable technology, humidity sensors have become increasingly important in the fields of health monitoring and human-machine interaction. This paper reviews the latest advancements in humidity sensors for wearable health applications, highlighting their applications in key areas such as breath monitoring, emotion recognition, diaper monitoring, and skin moisture detection. Due to their simple structure, high sensitivity, and non-contact detection capabilities, humidity sensors are gradually becoming a core technology for achieving real-time health monitoring and intelligent interaction. We provide an overview of the material innovations and development directions in current humidity sensor technology. Additionally, we systematically discuss the significance of humidity sensors in dynamic physiological signal monitoring and their potential applications in smart healthcare, sports training, emotion recognition, and non-contact interaction. Despite the broad prospects of humidity sensors in various applications, they still face several specific challenges. Finally, this paper proposes future research directions, calling for in-depth exploration of material innovations, system integration, and intelligent applications of humidity sensors to promote the development of personalized healthcare and smart health management.</div></div>","PeriodicalId":100893,"journal":{"name":"Materials Today Electronics","volume":"13 ","pages":"Article 100167"},"PeriodicalIF":0.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0