以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用...以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用。结果表明,将1.6 g PA66、1.1 g IP6加入20 mL乙酸中,于260℃下反应36h,制备的66CDs具有最大荧光强度。66CDs为球形结构,平均粒径4.00nm,表面含有羧基、羟基、氨基等官能团;66CDs的荧光为非激发波长依赖型,最佳激发波长和发射波长分别为360和490 nm,荧光量子产率可达11.69%,其荧光强度不受常见金属阳离子影响,30 d内具有稳定性。由66CDs与水溶性淀粉制备的荧光粉末可用于指纹识别,不仅可将66CDs制成油墨用于荧光防伪,还可将其制成防蓝光膜,用于蓝光防护。展开更多
Phone number recycling(PNR)refers to the event wherein a mobile operator collects a disconnected number and reassigns it to a new owner.It has posed a threat to the reliability of the existing authentication solution ...Phone number recycling(PNR)refers to the event wherein a mobile operator collects a disconnected number and reassigns it to a new owner.It has posed a threat to the reliability of the existing authentication solution for e-commerce platforms.Specifically,a new owner of a reassigned number can access the application account with which the number is associated,and may perform fraudulent activities.Existing solutions that employ a reassigned number database from mobile operators are costly for e-commerce platforms with large-scale users.Thus,alternative solutions that depend on only the information of the applications are imperative.In this work,we study the problem of detecting accounts that have been compromised owing to the reassignment of phone numbers.Our analysis on Meituan's real-world dataset shows that compromised accounts have unique statistical features and temporal patterns.Based on the observations,we propose a novel model called temporal pattern and statistical feature fusion model(TSF)to tackle the problem,which integrates a temporal pattern encoder and a statistical feature encoder to capture behavioral evolutionary interaction and significant operation features.Extensive experiments on the Meituan and IEEE-CIS datasets show that TSF significantly outperforms the baselines,demonstrating its effectiveness in detecting compromised accounts due to reassigned numbers.展开更多
文摘以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用。结果表明,将1.6 g PA66、1.1 g IP6加入20 mL乙酸中,于260℃下反应36h,制备的66CDs具有最大荧光强度。66CDs为球形结构,平均粒径4.00nm,表面含有羧基、羟基、氨基等官能团;66CDs的荧光为非激发波长依赖型,最佳激发波长和发射波长分别为360和490 nm,荧光量子产率可达11.69%,其荧光强度不受常见金属阳离子影响,30 d内具有稳定性。由66CDs与水溶性淀粉制备的荧光粉末可用于指纹识别,不仅可将66CDs制成油墨用于荧光防伪,还可将其制成防蓝光膜,用于蓝光防护。
基金supported by the National Natural Science Foundation of China(Nos.62072115,62202402,61971145,and 61602122)the Shanghai Science and Technology Innovation Action Plan Project(No.22510713600)+2 种基金the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2022A1515011583 and 2023A1515011562)the One-off Tier 2 Start-up Grant(2020/2021)of Hong Kong Baptist University(Ref.RCOFSGT2/20-21/COMM/002)Startup Grant(Tier 1)for New Academics AY2020/21 of Hong Kong Baptist University and Germany/Hong Kong Joint Research Scheme sponsored by the Research Grants Council of Hong Kong,China,the German Academic Exchange Service of Germany(No.G-HKBU203/22),and Meituan。
文摘Phone number recycling(PNR)refers to the event wherein a mobile operator collects a disconnected number and reassigns it to a new owner.It has posed a threat to the reliability of the existing authentication solution for e-commerce platforms.Specifically,a new owner of a reassigned number can access the application account with which the number is associated,and may perform fraudulent activities.Existing solutions that employ a reassigned number database from mobile operators are costly for e-commerce platforms with large-scale users.Thus,alternative solutions that depend on only the information of the applications are imperative.In this work,we study the problem of detecting accounts that have been compromised owing to the reassignment of phone numbers.Our analysis on Meituan's real-world dataset shows that compromised accounts have unique statistical features and temporal patterns.Based on the observations,we propose a novel model called temporal pattern and statistical feature fusion model(TSF)to tackle the problem,which integrates a temporal pattern encoder and a statistical feature encoder to capture behavioral evolutionary interaction and significant operation features.Extensive experiments on the Meituan and IEEE-CIS datasets show that TSF significantly outperforms the baselines,demonstrating its effectiveness in detecting compromised accounts due to reassigned numbers.
