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Experimental demonstration of 220-GHz terahertz signals wireless transmission over 4.6 km

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science China(information sciences) 2025年第1期68卷 386-388页

作者： Yi WEI Jianjun YU Mingxu WANG Xiongwei YANG Qiutong ZHANG Jingwen TAN Bing ZHANG Ying WU Yang HAN Peng TIAN Wen ZHOU Kaihui WANG Feng ZHAO State Key laboratory of ASIC and System Key Laboratory for Information Science of Electromagnetic Waves (MoE)School of Information Science and Technology Fudan University School of Electronic Engineering Xi'an University of Posts and Telecommunications

The advancement of terahertz (THz) communication technology drives the evolution of wireless communication systems,offering novel pathways and technical means for the development of future 6G communication *** wireless communication systems are often constrained by bandwidth limitations of electronic devices in high frequency ***,THz communication technology leverages the characteristics of electromagnetic waves to transcend these limitations,enabling communication athigher frequencies and wider bandwidths.

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Ultra-high-Q photonic crystal nanobeam cavity for etchless lithium niobate on insulator(LNOI)platform

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Opto-Electronic Advances 2025年第1期8卷 59-70页

作者： Zhi Jiang Cizhe Fang Xu Ran Yu Gao Ruiqing Wang Jianguo Wang Danyang Yao Xuetao Gan Yan Liu Yue Hao Genquan Han State Key laboratory of Wide-Bandgap Semiconductor Devices and Integrated technology School of MicroelectronicsXidian UniversityXi’an 710071China Key laboratory of Light Field Manipulation and information Acquisition Ministry of Industry and Information Technologyand Shaanxi Key Laboratory of Optical Information TechnologySchool of Physical Science and TechnologyNorthwestern Polytechnical UniversityXi’an 710129China Hangzhou Institute of technology Xidian UniversityHangzhou 311200China

The expansive spectral coverage and superior optical properties of lithium niobate(LN)offer a comprehensive suite of tools for exploring novel *** high-quality(Q)photonic resonator cavities is crucial for enhancing light-matter ***,this task is challenging as the device performance is heavily dependent on the fabrication quality of the *** this paper,we present experimental validation of an etchless approach to fabricating high-Q photonic crystal nanobeam cavities(PCNBCs).We successfully fabricate PCNBCs with Q factors exceeding 105 while maintaining high transmittance by capitalizing on the low waveguide loss and high fabrication tolerance of TE-polarized ***,the Q factor achieved here exceeds previous reports on etchless LN PCNBCs by over an order of *** from this advancement,we further explore a variety of optical functions,including thermo-optic tuning,optically induced bistability,and Fano line shapes *** findings present promising prospects for a versatile platform technique,facilitating the development of high-performance electro-optic or acousto-optic modulators,optical logic devices,and quantum photonics,highlighting its significant impact in the field of photonic integration.

关键词： photonic crystal nanobeam cavity LNOI platform high Q thermo-optic tuning bistability Fano line shapes

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Quantitative impacts of meteorology and emissions on the long-term trend of O3 in the Yangtze River Delta(YRD),China from 2015 to 2022

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Journal of Environmental sciences 2025年第3期149卷 314-329页

作者： Lingxia Wu Junlin An Key laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science and TechnologyNanjing 210044China

Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically *** this study,by using 8-year-long(2015–2022)surface ozone observation data,we attempted to reveal the variation ofmultiple timescale components using the Kolmogorov–Zurbenko filter,and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological *** results showed that the short-term,seasonal,and long-term components accounted for daily maximum 8-hr average O_(3)(O_(3–8)hr)concentration,46.4%,45.9%,and 1.0%,*** meteorological impacts account for an average of 71.8%of O_(3–8)hr,and the YRD’s eastern and northern sections aremeteorology-sensitive *** on statistical analysis technology with empirical orthogonal function,the contribution of meteorology,local emission,and transport in the long-term component of O_(3–8)hr were 0.21%,0.12%,and 0.6%,*** spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest,influenced by the monsoon and synoptic *** central urban agglomeration north and south of the YRD was particularly susceptible to local *** the cities studied,Shanghai,Anqing,and Xuancheng,located at similar latitudes,were significantly impacted by atmospheric transmission—the contribution of Shanghai,the maximum accounting for 3.6%.

关键词： O_(3)Yangtze River Delta(YRD)Kolmogorov-Zurbenko filter Empirical orthogonal function Long-term trend

Processing,microstructure,and mechanical properties of wire arc additively-manufactured AZ91 magnesium alloy using cold arc process

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 91-104页

作者： Bai-hao CAI Ji-kang FAN Jie LI Dong-qing YANG Yong PENG Ke-hong WANG Key laboratory of Controlled Arc Intelligent Additive technology Ministry of Industry and Information TechnologyNanjing University of Science and TechnologyNanjing 210094China School of Materials science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were *** results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer *** microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine *** layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg *** mechanical properties of the CA-WAAM deposited sample showed isotropic *** ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,*** microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.

关键词： AZ91 magnesium alloy droplet transfer microstructure mechanical properties cold arc process

Quantum public-key crypto via EPR pairs

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science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 54-59页

作者： Xiang-Qun Fu Hong-Wei Li Jian-Hong Shi Tan Li Wan-Su Bao Henan Key laboratory of Quantum information and Cryptography Information Engineering UniversityZhengzhou 450004China Synergetic Innovation Center of Quantum information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

With the development of quantum computing technology,quantum public-key cryptography is gradually becoming an alternative to the existing classical public-key *** paper designs a quantum trapdoor one-way function via EPR pairs and quantum *** on this,a new quantum public-key cryptosystem is presented,which offers forward security,and can resist the chosen-plaintext attack and chosen-ciphertext *** with the existing quantum public-key cryptos,eavesdropping can be automatically detected in this new quantum public-key cryptosystem under a necessary condition,which is also detailed in the paper.

关键词： quantum public-key crypto trapdoor one-way function EPR pairs

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Characterization of size-resolved aerosol hygroscopicity and liquid water content in Nanjing of the Yangtze River Delta

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Journal of Environmental sciences 2025年第5期151卷 26-41页

作者： Youling Jiang Yan Ma Jun Zheng Nan Ye Cheng Yuan School of Environmental science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Collaborative Innovation Center of Atmospheric Environment and Equipment technology Nanjing University of Information Science&TechnologyNanjing 210044China School of Emergency Management Nanjing University of Information Science&TechnologyNanjing 210044China

Aerosol hygroscopicity and liquid water content(ALWC)have important influences on the environmental and climate effect of *** this study,we measured the hygroscopic growth factors(GF)of particles with dry diameters of 40,80,150,and 200 nm during the wintertime in *** the GF-derived hygroscopicity parameter(κ_(gf))and ALWC increased with particle size,but displayed differing diurnal variations,withκ_(gf)peaking around the midday,while ALWC peaking in the early ***,ammonium and oxygenated organic aerosols(OOA)were found as the chemical components mostly strongly correlated with ALWC.A closure study suggests that during midday photo-oxidation and nighttime high ALWC periods,theκof organic aerosols(κ_(org))was underestimated when using previous ***,we re-constructed parameterizations forκ_(org)and the oxidation level of organics for these periods,which indicates a higher hygroscopicity of photochemically formed OOA than the aqueous OOA,yet both being much higher than the generally assumed OOA ***,in a typical high ALWC episode,concurrently increased ALWC,nitrate,OOA as well as aerosol surface area and mass concentrations were observed under elevated ambient *** strongly indicates a coupled effect that the hygroscopic secondary aerosols,in particular nitratewith strong hygroscopicity,led to large increase in ALWC,which in turn synergistically boosted nitrate and OOA formation by heterogeneous/aqueous *** interaction may represent an important mechanism contributing to enhanced formation of secondary aerosols and rapid growth of fine particulate matter under relatively high RH conditions.

关键词： Aerosol hygroscopicity Aerosol liquid water content Photo-oxidation Aqueous/heterogeneous reactions

GPS: graph contrastive learning via multi-scale augmented views from adversarial pooling

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science China(information sciences) 2025年第1期68卷 145-158页

作者： Wei JU Yiyang GU Zhengyang MAO Ziyue QIAO Yifang QIN Xiao LUO Hui XIONG Ming ZHANG School of Computer science National Key Laboratory for Multimedia Information ProcessingPeking University Artificial Intelligence Thrust The Hong Kong University of Science and Technology Department of Computer science University of California

Self-supervised graph representation learning has recently shown considerable promise in a range of fields, including bioinformatics and social networks. A large number of graph contrastive learning approaches have shown promising performance for representation learning on graphs, which train models by maximizing agreement between original graphs and their augmented views(i.e., positive views). Unfortunately, these methods usually involve pre-defined augmentation strategies based on the knowledge of human experts. Moreover, these strategies may fail to generate challenging positive views to provide sufficient supervision signals. In this paper, we present a novel approach named graph pooling contrast(GPS) to address these *** by the fact that graph pooling can adaptively coarsen the graph with the removal of redundancy, we rethink graph pooling and leverage it to automatically generate multi-scale positive views with varying emphasis on providing challenging positives and preserving semantics, i.e., strongly-augmented view and weakly-augmented view. Then, we incorporate both views into a joint contrastive learning framework with similarity learning and consistency learning, where our pooling module is adversarially trained with respect to the encoder for adversarial robustness. Experiments on twelve datasets on both graph classification and transfer learning tasks verify the superiority of the proposed method over its counterparts.

关键词： graph representation learning graph neural networks graph contrastive learning graph augmentations graph pooling

Spatial-temporal distribution and emission of urban scale air pollutants in Hefei based on Mobile-DOAS

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Journal of Environmental sciences 2025年第5期151卷 238-251页

作者： Zhidong Zhang Pinhua Xie Ang Li Min Qin Jin Xu Zhaokun Hu Xin Tian Feng Hu Yinsheng Lv Jiangyi Zheng Youtao Li School of Environmental science and Optoelectronic technology University of Science and Technology of ChinaHefei 230026China Key laboratory of Environmental Optics and technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Chinese Academy of sciences Beijing 100049China information Materials and Intelligent Sensing laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China

As a significant city in the Yangtze River Delta regions,Hefei has experienced rapid changes in the sources of air pollution due to its high-speed economic development and urban ***,there has been limited research in recent years on the spatial-temporal distribution and emission of its atmospheric *** address this,this study conducted mobile observations of urban roads using the Mobile-DOAS instrument from June 2021 to May *** monitoring results exhibit a favourable consistent with TROPOMI satellite data and ground monitoring station ***,there were pronounced seasonal variations in air ***,high concentration of HCHO and NO_(2)were closely associated with traffic congestion on roadways,while heightened SO_(2)levels were attributed to winter heating and industrial *** study also revealed that with the implementation of road policies,the average vehicle speed increased by 95.4%,while the NO concentration decreased by 54.4%.In the estimation of urban NO_(x)emission flux,it was observed that in temporal terms,compared with inventory data,the emissions calculated viamobile measurements exhibitedmore distinct seasonal patterns,with the highest emission rate of 349 g/sec in winter and the lowest of 142 g/sec in *** spatial terms,the significant difference in emissions between the inner and outer ring roads also suggests the presence of the city’s primary NO_(x)emission sources in the area between these two *** study offers data support for formulating the next phase of air pollution control measures in urban areas.

关键词： Mobile-DOAS HCHO NO_(2) SO_(2) Spatial-temporal distribution NOx emission

Enhanced dynamics of Al3+/H+ ions in aqueous aluminum ion batteries:Construction of metastable structures in vanadium pentoxide upon oxygen vacancies

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Journal of Energy Chemistry 2025年第2期101卷 562-569页

作者： Zhibao Wang Hanqing Gu Tianci Wu Wenming Zhang Zhanyu Li Hebei Key laboratory of Optic-Electronic information and Materials National & Local Joint Engineering Laboratory of New Energy Photoelectric Devices College of Physics Science and Technology Hebei University

In recent years,aqueous aluminum ion batteries have been widely studied owing to their abundant energy storage and high theo retical *** in-depth study of vanadium oxide materials is necessary to address the precipitation of insoluble products covered cathode surface and the slow reaction ***,a method using a simple one-step hydrothermal preparation and oxalic acid to regulate oxygen vacancies has been reported.A high starting capacity(400 mAh g-1) can be achieved by Ov-V2O5,and it is capable of undergoing 200 cycles at 0.4 A g-1,with a termination discharge capacity of103 mAh *** analysis demonstrated that metastable structures（AlxV2O5and HxV2O5） were constructed through the insertion of Al3+/H+during discharging,which existed in the lattice intercalation with *** incorporation of oxygen vacancies lowers the reaction energy barrier while improving the ion transport *** addition,the metastable structure allows the electrostatic interaction between Al3+and the main backbone to establish protection and optimize the transport *** parallel,this work exploits ex-situ characterization and DFT to obtain a profound insight into the instrumental effect of oxygen vacancies in the construction of metastable structures during in-situ electrochemical activation,with a view to better understanding the mechanism of the synergistic participation of Al3+and H+in the *** work not only reports a method for cathode materials to modulate oxygen vacancies,but also lays the foundation for a deeper understanding of the metastable structure of vanadium oxides.

关键词： Electrochemical activation Metastable structure Oxygen vacancies Vanadium pentoxide