Organic room-temperature phosphorescence(RTP)materials are promising for bioimaging applications due to their tunable structures,excellent biocompatibility,and long-lived luminescence.However,the development of highly...Organic room-temperature phosphorescence(RTP)materials are promising for bioimaging applications due to their tunable structures,excellent biocompatibility,and long-lived luminescence.However,the development of highly efficient organic RTP materials for aqueous systems remains challenging,as the organic phosphorescence is prone to being quenched by the dissolved oxygen in water.Herein,heteroaromatic carboxylic acids serve as ligand vips to construct a series of host-vip composites with nontoxic,dense EDTA-M(M=Ca,Mg,and Al)coordination polymer in water.These composites exhibit ultra-long pure RTP of vip molecules with phosphorescence quantum yield up to 53%,and lifetime up to 589.7 ms,due to the synergistic effect of dual-network structure:a coordinatively cross-linked network of EDTA-M,and a non-covalent bonded network formed by ligands and water molecules.The phosphorescence intensity is more than three times that of the composite with a single coordination network.Notably,the dual-network configuration can form a rigid and dense structure and block the intrusion of external H_(2)O and O_(2) molecules to avoid phosphorescence quenching in water.As a result,the RTP of the composites remains unchanged after 1 month in water.Furthermore,the nanoparticles fabricated from composites and anionic surfactants can be successfully applied in in vivo imaging of mice for the stable RTP in water.This work provides a novel strategy for the development of high-performance RTP materials in aqueous systems.展开更多
The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various...The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various applications.Herein,a dual-network(DN)gel was successfully prepared using acrylamide and sodium lignosulphonate as the basic units by simple chemical cross-linking and physical cross-linking methods.Specifically,the hydrogel forms two types of cross-linking networks through metal coordination and hydrogen bonding.Benefiting from the combined effects of dipole polarization and conductivity loss,the gel achieves an effective absorption bandwidth(EAB)of 6.74 GHz at a thickness of only 1.89 mm,demonstrating excellent EMW absorption performance.In addition,this unique structural configuration endows the EMW absorber with multifunctional features,such as remarkable tensile strength,good environmental compatibility,ultraviolet(UV)resistance,and excellent adhesion.Integrating multiple functional features into the EMW gels displays a broad application prospect in a variety of application scenarios.This research reveals the significance of DN structure design in the electromagnetic wave absorption(EWA)performance of gel-based materials,providing a substantial foundation for the multifunctional design of gel-based absorbers.展开更多
Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with...Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.展开更多
针对柑橘病虫害领域文本数据中存在重叠三元组、嵌套实体和复杂实体抽取困难的问题,提出一种基于DPNA-CASREL(Dual-pointer network annotation-cascade binary tagging framework for relational triple extraction)的柑橘病虫害实体...针对柑橘病虫害领域文本数据中存在重叠三元组、嵌套实体和复杂实体抽取困难的问题,提出一种基于DPNA-CASREL(Dual-pointer network annotation-cascade binary tagging framework for relational triple extraction)的柑橘病虫害实体关系联合抽取方法。通过结合预训练模型RoBERTa-wwm-ext (Robustly optimized BERT pre-training approach with whole word masking and extended training data)与双向长短期记忆网络(Bi-directional long short-term memory,BiLSTM)构建编码器获取文本的多维向量编码,并根据柑橘病虫害语料特点设计双重指针网络标注的解码网络,在头实体解码中引入多级指针网络标注方法,在尾实体解码网络中采用复杂实体标注策略以增强模型对复杂实体的抽取性能,实现对实体关系三元组的同步抽取,解决三元组重叠、嵌套实体等问题。在自建柑橘病虫害数据集上的实验结果表明,DPNA-CASREL模型的精确率、召回率和F1值分别为82.12%、81.97%、82.05%,优于其他模型,对嵌套、复杂实体抽取的F1值比CASREL分别提升8.16、6.58个百分点,有效解决了实体嵌套和实体边界不清晰问题。本文方法可为柑橘病虫害知识图谱构建提供基础。展开更多
In high-intensity electromagnetic warfare,radar systems are persistently subjected to multi-jammer attacks,including potentially novel unknown jamming types that may emerge exclusively under wartime conditions.These j...In high-intensity electromagnetic warfare,radar systems are persistently subjected to multi-jammer attacks,including potentially novel unknown jamming types that may emerge exclusively under wartime conditions.These jamming signals severely degrade radar detection performance.Precise recognition of these unknown and compound jamming signals is critical to enhancing the anti-jamming capabilities and overall reliability of radar systems.To address this challenge,this article proposes a novel open-set compound jamming cognition(OSCJC)method.The proposed method employs a detection-classification dual-network architecture,which not only overcomes the false alarm and misdetection issues of traditional closed-set recognition methods when dealing with unknown jamming but also effectively addresses the performance bottleneck of existing open-set recognition techniques focusing on single jamming scenarios in compound jamming environments.To achieve unknown jamming detection,we first employ a consistency labeling strategy to train the detection network using diverse known jamming samples.This strategy enables the network to acquire highly generalizable jamming features,thereby accurately localizing candidate regions for individual jamming components within compound jamming.Subsequently,we introduce contrastive learning to optimize the classification network,significantly enhancing both intra-class clustering and inter-class separability in the jamming feature space.This method not only improves the recognition accuracy of the classification network for known jamming types but also enhances its sensitivity to unknown jamming types.Simulations and experimental data are used to verify the effectiveness of the proposed OSCJC method.Compared with the state-of-the-art open-set recognition methods,the proposed method demonstrates superior recognition accuracy and enhanced environmental adaptability.展开更多
基金supported by the Startup Funds for Introduced Talents of Wuyi University(YJ202304)the National Natural Science Foundation of China(22375044).
文摘Organic room-temperature phosphorescence(RTP)materials are promising for bioimaging applications due to their tunable structures,excellent biocompatibility,and long-lived luminescence.However,the development of highly efficient organic RTP materials for aqueous systems remains challenging,as the organic phosphorescence is prone to being quenched by the dissolved oxygen in water.Herein,heteroaromatic carboxylic acids serve as ligand vips to construct a series of host-vip composites with nontoxic,dense EDTA-M(M=Ca,Mg,and Al)coordination polymer in water.These composites exhibit ultra-long pure RTP of vip molecules with phosphorescence quantum yield up to 53%,and lifetime up to 589.7 ms,due to the synergistic effect of dual-network structure:a coordinatively cross-linked network of EDTA-M,and a non-covalent bonded network formed by ligands and water molecules.The phosphorescence intensity is more than three times that of the composite with a single coordination network.Notably,the dual-network configuration can form a rigid and dense structure and block the intrusion of external H_(2)O and O_(2) molecules to avoid phosphorescence quenching in water.As a result,the RTP of the composites remains unchanged after 1 month in water.Furthermore,the nanoparticles fabricated from composites and anionic surfactants can be successfully applied in in vivo imaging of mice for the stable RTP in water.This work provides a novel strategy for the development of high-performance RTP materials in aqueous systems.
基金supported by the National Natural Science Foundation of China(Nos.52231007,51872238,52074227,and 21806129)the Fundamental Research Funds for the Central Universities(Nos.3102018zy045,3102019AX11,and 5000220455)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2017JQ5116 and 2020JM-118).
文摘The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various applications.Herein,a dual-network(DN)gel was successfully prepared using acrylamide and sodium lignosulphonate as the basic units by simple chemical cross-linking and physical cross-linking methods.Specifically,the hydrogel forms two types of cross-linking networks through metal coordination and hydrogen bonding.Benefiting from the combined effects of dipole polarization and conductivity loss,the gel achieves an effective absorption bandwidth(EAB)of 6.74 GHz at a thickness of only 1.89 mm,demonstrating excellent EMW absorption performance.In addition,this unique structural configuration endows the EMW absorber with multifunctional features,such as remarkable tensile strength,good environmental compatibility,ultraviolet(UV)resistance,and excellent adhesion.Integrating multiple functional features into the EMW gels displays a broad application prospect in a variety of application scenarios.This research reveals the significance of DN structure design in the electromagnetic wave absorption(EWA)performance of gel-based materials,providing a substantial foundation for the multifunctional design of gel-based absorbers.
基金Funded by National Natural Science Foundation of China(No.51472166)。
文摘Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.
文摘针对柑橘病虫害领域文本数据中存在重叠三元组、嵌套实体和复杂实体抽取困难的问题,提出一种基于DPNA-CASREL(Dual-pointer network annotation-cascade binary tagging framework for relational triple extraction)的柑橘病虫害实体关系联合抽取方法。通过结合预训练模型RoBERTa-wwm-ext (Robustly optimized BERT pre-training approach with whole word masking and extended training data)与双向长短期记忆网络(Bi-directional long short-term memory,BiLSTM)构建编码器获取文本的多维向量编码,并根据柑橘病虫害语料特点设计双重指针网络标注的解码网络,在头实体解码中引入多级指针网络标注方法,在尾实体解码网络中采用复杂实体标注策略以增强模型对复杂实体的抽取性能,实现对实体关系三元组的同步抽取,解决三元组重叠、嵌套实体等问题。在自建柑橘病虫害数据集上的实验结果表明,DPNA-CASREL模型的精确率、召回率和F1值分别为82.12%、81.97%、82.05%,优于其他模型,对嵌套、复杂实体抽取的F1值比CASREL分别提升8.16、6.58个百分点,有效解决了实体嵌套和实体边界不清晰问题。本文方法可为柑橘病虫害知识图谱构建提供基础。
文摘In high-intensity electromagnetic warfare,radar systems are persistently subjected to multi-jammer attacks,including potentially novel unknown jamming types that may emerge exclusively under wartime conditions.These jamming signals severely degrade radar detection performance.Precise recognition of these unknown and compound jamming signals is critical to enhancing the anti-jamming capabilities and overall reliability of radar systems.To address this challenge,this article proposes a novel open-set compound jamming cognition(OSCJC)method.The proposed method employs a detection-classification dual-network architecture,which not only overcomes the false alarm and misdetection issues of traditional closed-set recognition methods when dealing with unknown jamming but also effectively addresses the performance bottleneck of existing open-set recognition techniques focusing on single jamming scenarios in compound jamming environments.To achieve unknown jamming detection,we first employ a consistency labeling strategy to train the detection network using diverse known jamming samples.This strategy enables the network to acquire highly generalizable jamming features,thereby accurately localizing candidate regions for individual jamming components within compound jamming.Subsequently,we introduce contrastive learning to optimize the classification network,significantly enhancing both intra-class clustering and inter-class separability in the jamming feature space.This method not only improves the recognition accuracy of the classification network for known jamming types but also enhances its sensitivity to unknown jamming types.Simulations and experimental data are used to verify the effectiveness of the proposed OSCJC method.Compared with the state-of-the-art open-set recognition methods,the proposed method demonstrates superior recognition accuracy and enhanced environmental adaptability.
