Journal of Non-crystalline Solids最新文献_第3页

Effect of La2O3 on structure and chemical strengthening properties of Li2O–Al2O3–SiO2 glass: experiment and simulation La2O3对Li2O-Al2O3-SiO2玻璃结构及化学强化性能的影响：实验与模拟

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-11 DOI: 10.1016/j.jnoncrysol.2025.123675

Yingliang Tian , Hongshi Zhao , Dayi Yang , Xuejie Tian , Feng He , Peihao Li , Zhiyong Zhao

{"title":"Effect of La2O3 on structure and chemical strengthening properties of Li2O–Al2O3–SiO2 glass: experiment and simulation","authors":"Yingliang Tian , Hongshi Zhao , Dayi Yang , Xuejie Tian , Feng He , Peihao Li , Zhiyong Zhao","doi":"10.1016/j.jnoncrysol.2025.123675","DOIUrl":"10.1016/j.jnoncrysol.2025.123675","url":null,"abstract":"<div><div>This study systematically investigates the regulatory effect of La2O3 on the structure, mechanical and chemical strengthening properties of lithium aluminosilicate (LAS) glass through experiment and molecular dynamics (MD) simulation. MD simulations demonstrate that La2O3 incorporation enhances network densification through the high field strength of La³⁺ (Z/r²=2.82). The main coordination number (CN) of La atoms is 6, which dynamically changes to 5∼8 with the increase of content, and the bond length of La-O is shortened from 2.24 Å to 2.21 Å and then increased to 2.31 Å. When adding 1.0 mol % La2O3, the Vickers hardness and bending strength of glass are as high as 7.15 GPa and 205 MPa, respectively. However, the excessive La2O3 (>1.0 mol %) destroys the connectivity of [SiO4] network and reduces the proportion of Q⁴. With the increase of La2O3 content, the chemical strengthening results show that the surface compressive stress decreases linearly. In contrast, the depth of the stress layer (DOL) decreased first and then increased, attributed to the “densification-depolymerization” competition mechanism of La2O3 in LAS glass. Results provide the theoretical guidance for development of LAS glass containing rare earth oxides that have highly effective chemical strengthening properties.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123675"},"PeriodicalIF":3.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Effect of pre-deformation on structure and dynamic relaxation behavior of a Zr-based bulk metallic glass 预变形对zr基大块金属玻璃结构和动态弛豫行为的影响

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-09 DOI: 10.1016/j.jnoncrysol.2025.123672

Aasma Tabassum , Wei Xiong , Baoan Sun , Ying Liu , Jing Tao Wang

引用次数: 0

Photo-induced surface metal-semiconductor transition driven by silver diffusion into amorphous chalcogenide 银扩散成非晶硫化物驱动的光致表面金属半导体跃迁

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-09 DOI: 10.1016/j.jnoncrysol.2025.123646

Yoshifumi Sakaguchi , Yuji Baba , Yoshihiro Okamoto

{"title":"Photo-induced surface metal-semiconductor transition driven by silver diffusion into amorphous chalcogenide","authors":"Yoshifumi Sakaguchi , Yuji Baba , Yoshihiro Okamoto","doi":"10.1016/j.jnoncrysol.2025.123646","DOIUrl":"10.1016/j.jnoncrysol.2025.123646","url":null,"abstract":"<div><div>The bandgap light illumination of a Ag/ amorphous chalcogenide bilayer film causes Ag diffusion into the chalcogenide layer. Investigating how the electronic states and the bond configurations change is important to gain an understanding of Ag photo-diffusion on a microscopic scale. In this study, we perform the optical reflectivity, X-ray photoelectron spectroscopy, and extended X-ray absorption fine-structure spectroscopy measurements on Ag/ amorphous Ge20S80 films and examine the changes in measurements with bandgap illumination. The results showed that metallic reflectivity, which was caused by Ag 5s delocalized electrons, was lost and the electronic density of states at the Fermi energy disappeared upon light illumination, indicating a surface metal-semiconductor transition. Changes in the chemical bonds were clearly observed. The Ag ions were captured by the S atoms, but not by the Ge atoms. With increasing light-exposure time, both the S-S and Ge-S bonds break, and Ag-S bonds are formed. A model of the Ag photo-diffusion at the microscopic scale is proposed based on these experimental results.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123646"},"PeriodicalIF":3.2,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Mixed alkali effect on chemical durability and mechanical properties of a borosilicate glass series 混合碱对硼硅玻璃系列化学耐久性和力学性能的影响

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-07 DOI: 10.1016/j.jnoncrysol.2025.123669

Pengcheng You , Yang Shen , Rui Yang , Hong Jiang , Yanfei Zhang , Qiuju Zheng , Yuanzheng Yue

{"title":"Mixed alkali effect on chemical durability and mechanical properties of a borosilicate glass series","authors":"Pengcheng You , Yang Shen , Rui Yang , Hong Jiang , Yanfei Zhang , Qiuju Zheng , Yuanzheng Yue","doi":"10.1016/j.jnoncrysol.2025.123669","DOIUrl":"10.1016/j.jnoncrysol.2025.123669","url":null,"abstract":"<div><div>Understanding the mixed alkali effect (MAE) on the chemical durability of glass is crucial for optimizing the composition of nuclear waste immobilization glasses. In this work, we investigated the impact of the substitution of K2O for Na2O on structure, chemical durability, and some physical properties of a borosilicate glass series. We found that the fraction of four-coordinated boron (N4) exhibited a drastic decrease when the molar ratio of potassium ions surpassed a certain threshold. Beyond this threshold, the N4 fraction remained constant. The structure analyses showed that the additional potassium ions were inclined to break the ring structure, leading to the formation of chain structure. Furthermore, the leaching of the different cations took place through synergistic mechanisms involving {Na&B}, {K&B} and {Al&Ca} pairs. Both the coefficient of thermal expansion (α) and the hardness (H) manifested a pronounced mixed alkali effect. This work provides insights into the correlation between the mixed alkali effect and the physical and chemical properties.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123669"},"PeriodicalIF":3.2,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144229820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

First principles calculations of electronic structure and optical properties for radiation-induced oxygen related defects in silica glass 二氧化硅玻璃辐射诱导氧相关缺陷的电子结构和光学性质的第一性原理计算

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-04 DOI: 10.1016/j.jnoncrysol.2025.123665

Cai Donglin, Dong Shangli, Liu Hai, Zhang Xudong

{"title":"First principles calculations of electronic structure and optical properties for radiation-induced oxygen related defects in silica glass","authors":"Cai Donglin, Dong Shangli, Liu Hai, Zhang Xudong","doi":"10.1016/j.jnoncrysol.2025.123665","DOIUrl":"10.1016/j.jnoncrysol.2025.123665","url":null,"abstract":"<div><div>Prolonged exposure of silica glass to radiation environments leads to the degradation of optical properties, significantly compromising the performance of optical systems. This study systematically investigates oxygen-related radiation-induced defects through first-principles calculations. Two primary defect types are characterized: non-bridging oxygen defects comprising a radical oxygen atom and a triple-coordinated silicon atom formed by Si-O bond rupture under irradiation, and oxygen vacancy defects featuring two adjacent triple-coordinated silicon atoms created through oxygen displacement by high-energy particles, which may subsequently transform into E' color centers. The electronic structure and optical properties of both the pristine 90-atom silica glass model and the defect models that may arise during irradiation have been systematically investigated. Calculations show an improved band gap value of 9.4 eV for pristine silica glass. Several new occupied and unoccupied defect states are found near the valence band maximum and in the band gap from the defect models. As the distance between the defect-related atoms increases, the valence band maximum moves away from the highest occupied state energy level, while the lowest unoccupied state shifts to lower energies, leading to a red-shift in the absorption spectrum. The calculated absorption peak positions are found to closely match the published experimental measurements.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123665"},"PeriodicalIF":3.2,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Environmentally safe high density lanthanum doped glasses for radiation shielding windows 环境安全的高密度掺杂镧辐射屏蔽窗玻璃

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-04 DOI: 10.1016/j.jnoncrysol.2025.123649

Anchal Pathania , Neetu Verma , Rohit Mehra , P. Nandi , Gopi Sharma , Sandeep Kaur , Richa Mishra , B. Sanyal

{"title":"Environmentally safe high density lanthanum doped glasses for radiation shielding windows","authors":"Anchal Pathania , Neetu Verma , Rohit Mehra , P. Nandi , Gopi Sharma , Sandeep Kaur , Richa Mishra , B. Sanyal","doi":"10.1016/j.jnoncrysol.2025.123649","DOIUrl":"10.1016/j.jnoncrysol.2025.123649","url":null,"abstract":"<div><div>In this present work, a series of lead-free xLa2O3–30xBi2O3-(100-x)B2O3, where x = 0, 3, 6, and 9 mol % glass systems have been studied for Radiation Shielding Windows (RSWs) applications. The prepared glass shows high densities from 5.05 to 5.46 g/cc which is an important aspect for RSW. The Vicker's hardness and UV–Vis spectroscopy performed before and after irradiation shows that 6 mol % of lanthanum is most stable composition for radiation shielding after exposure to gamma radiation of 1 kGy. The radiation-induced absorption coefficients at different visible wavelengths are determined using transmission data after the irradiation dose. The glass with 6 mol % doping of La2O3 has the least radiation-induced absorption coefficient among all prepared glass samples. The structural modifications have been confirmed with the help of Raman spectroscopy. The obtained results suggest that La2O3 doping enhances the radiation stability of glass samples. Therefore, the developed lanthanum-doped bismuth-borate glass could find its application as lead-free RSW glass as an alternative to high lead-containing glass.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123649"},"PeriodicalIF":3.2,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144211974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Universal correlation between boson peak and quasi-localized modes in solids 固体中玻色子峰与准局域模式的普遍关联

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-03 DOI: 10.1016/j.jnoncrysol.2025.123668

G. Ding , J. Duan , S.L. Cai , L.H. Dai , M.Q. Jiang

{"title":"Universal correlation between boson peak and quasi-localized modes in solids","authors":"G. Ding , J. Duan , S.L. Cai , L.H. Dai , M.Q. Jiang","doi":"10.1016/j.jnoncrysol.2025.123668","DOIUrl":"10.1016/j.jnoncrysol.2025.123668","url":null,"abstract":"<div><div>The low-temperature specific heat capacity Cph of ideal crystals can be effectively described by the classical Debye T3 law. However, in amorphous solids and defective crystals, the reduced phonon heat capacity, Cph/T3, consistently deviates from the Debye model, exhibiting the well-known non-Debye excess anomaly, namely the boson peak (BP). In this work, we systematically study the low-temperature heat capacity Cp across a wide range of solids, finding that Cp can be accurately described by the soft potential model. The Cph/T3 of these solids begins to deviate from the Debye prediction near the characteristic temperature TC and displays a pronounced excess hump at TBP, which is the characteristic temperature of BP. We find that the reduced BP in both glasses and crystals exhibits a universal behavior, which can be described by an empirical function Δ*. Furthermore, a linear correlation between TC and TBP is observed among solids regardless of their topology, which reveals a universal connection between the BP and quasilocalized modes in solids. The result provides experimental support for the soft potential model, which may underpin the explanation of low-temperature anomalies and the formation of the BP in solids.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123668"},"PeriodicalIF":3.2,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144194907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Improvement of the formation ability and soft magnetic properties of Fe-Co-B-Si amorphous alloys with ultrahigh saturation magnetization of 2.0 T by P and C additions P和C对2.0 T超高饱和磁化Fe-Co-B-Si非晶合金形成能力和软磁性能的改善

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-03 DOI: 10.1016/j.jnoncrysol.2025.123648

A.I. Bazlov , D.A. Milkova , E.N. Zanaeva , E.V. Ubyivovk , I.V. Strochko , A. Inoue

{"title":"Improvement of the formation ability and soft magnetic properties of Fe-Co-B-Si amorphous alloys with ultrahigh saturation magnetization of 2.0 T by P and C additions","authors":"A.I. Bazlov , D.A. Milkova , E.N. Zanaeva , E.V. Ubyivovk , I.V. Strochko , A. Inoue","doi":"10.1016/j.jnoncrysol.2025.123648","DOIUrl":"10.1016/j.jnoncrysol.2025.123648","url":null,"abstract":"<div><div>The improvement effect of replacing B with C or P on the formation ability, thermal stability and magnetic properties for melt-spun (Fe0.8Co0.2)85B14-xSi1Mx and (Fe0.8Co0.2)84B15-xSi1Mx amorphous alloy ribbons was examined because the base amorphous alloy exhibits ultrahigh saturation magnetization (MS) reaching 2.0 T The minor alloying by C or P causes an enhancement of its formation ability, a decrease in the onset temperature of the first-stage crystallization (Tx1) due to the precipitation of bcc FeCo phase and a slight increase in the second-stage crystallization temperature (Tx2) due to the decomposition of the residual amorphous phase, resulting in an extension of the temperature interval between Tx1 and Tx2. The annealing of their amorphous alloys causes a reduction of coercive force (HC) and an increase of effective permeability (µe) at 1 kHz, though the MS decreases slightly. The excellent soft magnetic properties of 1.98 T for MS, 8.0 A/m for HC and 5800 for µe were attained for (Fe0.8Co0.2)85B13Si1P1 amorphous ribbon with a thickness of 20 µm annealed for 500 s at 570 K. Their soft magnetic properties are promising for future application of the present amorphous alloys as a new high MS soft magnetic material for electric motors.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123648"},"PeriodicalIF":3.2,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Enabling extrapolation of Young’s modulus of CaO-Al2O3-SiO2 ternary glasses by topology-informed machine learning 通过拓扑信息机器学习实现CaO-Al2O3-SiO2三元玻璃杨氏模量的外推

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-06-02 DOI: 10.1016/j.jnoncrysol.2025.123610

Kai Yang , Yu Song , Yuhai Li , Morten M. Smedskjaer , Mathieu Bauchy , Fabian Rosner

{"title":"Enabling extrapolation of Young’s modulus of CaO-Al2O3-SiO2 ternary glasses by topology-informed machine learning","authors":"Kai Yang , Yu Song , Yuhai Li , Morten M. Smedskjaer , Mathieu Bauchy , Fabian Rosner","doi":"10.1016/j.jnoncrysol.2025.123610","DOIUrl":"10.1016/j.jnoncrysol.2025.123610","url":null,"abstract":"<div><div>The application of machine learning (ML) in material discovery, particularly in the design of novel materials like glasses, has shown considerable promise. However, the efficacy of data-driven ML approaches is often hindered by the limited volume and representativeness of material datasets. While these approaches demonstrate notable success in interpolating data, they tend to perform inadequately in extrapolation tasks, which are crucial in the context of material discovery. In this study, we address this challenge by incorporating topological knowledge, derived from the atomic structures of glasses, to inform ML models with physics-based insights. To showcase this approach, we focus on predicting Young's modulus of CaO-Al2O3-SiO2 glasses. By leveraging the topological information, i.e., the fractions of bond-stretching and bond-bending constraints, we transform a non-linear composition-property mapping to a higher-linearity topology-property mapping to improve the extrapolation abilities of ML models. Our results demonstrate that the topology-informed ML approach maintains comparable prediction accuracy within the training domain while significantly improving performance in extrapolating the Young’s modulus of glasses beyond the training domain. Therefore, our topology-informed approach can offer a more efficient and expedited pathway towards the discovery of new glass materials in unexplored domains.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123610"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144189378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Factors influencing slag viscosity measurements using the Concentric Cylinder Measuring System at high temperatures 高温同心圆筒测量系统测量炉渣粘度的影响因素

IF 3.2 3区材料科学

Journal of Non-crystalline Solids Pub Date : 2025-05-31 DOI: 10.1016/j.jnoncrysol.2025.123647

Mykyta Levchenko , Nataliia Tinkova , Anton Yehorov , Rie Endo , Olena Vokova

{"title":"Factors influencing slag viscosity measurements using the Concentric Cylinder Measuring System at high temperatures","authors":"Mykyta Levchenko , Nataliia Tinkova , Anton Yehorov , Rie Endo , Olena Vokova","doi":"10.1016/j.jnoncrysol.2025.123647","DOIUrl":"10.1016/j.jnoncrysol.2025.123647","url":null,"abstract":"<div><div>This paper examines the factors that influence viscosity measurements of oxide melts at high temperatures and may lead to inaccurate results. These include the chemical instability of iron oxide in FeO-bearing slags under low oxygen partial pressures and its reaction with crucible materials, particularly molybdenum, leading to contamination and the formation of molybdenum oxides and iron–molybdenum alloys. These reactions increased viscosity values in the liquid-dominated region by up to 50 %, with molybdenum contents reaching up to 45 at % in alloys and 11.8 at % in oxides after 4 h at high temperature. The use of platinum crucibles also proved unsuitable under these conditions due to crucible breakage. In fluorine-containing mold powders, the evaporation of volatile components such as fluorine and sodium significantly affected viscosity, with the loss of fluorine and sodium causing a 19 % increase in viscosity within one hour. For CaO–SiO₂ melts, measurements at a constant cooling rate of 10 K/min showed viscosity reductions of up to 25 mPa·s compared to equilibrium conditions, alongside transient viscosity fluctuations. A reduced homogenization time caused a shift in the break point temperature by up to 50 °C, though liquid-phase viscosity remained stable. Experimental findings were supported by thermochemical simulations using FactSage 8.1 and validated via scanning electron microscopy of quenched slag samples to confirm the presence of metallic phases. Based on the results, recommendations are proposed to minimize the influence of these factors and improve the reliability of high-temperature viscosity measurements.</div></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":"666 ","pages":"Article 123647"},"PeriodicalIF":3.2,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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