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Study on the characteristics of precipitation particle size distribution during freezing weather in the southwest mountainous areas of China

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science China Earth sciences 2025年第5期68卷 1429-1447页

作者： Haopeng WU Shengjie NIU Seong Soo YUM Jingjing Lü Chunsong LU Yue ZHOU Jing SUN Yixiao HE Tianshu WANG Xinyi WANG School of Atmospheric Physics Nanjing University of Information Science and Technology Department of Atmospheric Science Yonsei University College of Safety Science and Engineering Nanjing Tech University Institute of Heavy Rain China Meteorological Administration Reading Academy Nanjing University of Information Science and Technology China Meteorological Administration Training Center Key Laboratory for Meteorological Disaster Monitoring and Early Warning and Risk Management of Characteristic Agriculture in Arid Regions China Meteorological Administration

This study utilized continuous observational data from a PARSIVEL2 disdrometer collected during winter from 2019 to 2021 in the southwest mountainous areas of China. Based on the diameter and terminal fall velocity of the precipitation particles, combined with the discrete Fréchet distance method, the precipitation particles were classified into five categories:freezing raindrops, freezing raindrops-graupel mixed(F-G Mixed), graupel, graupel-snow mixed(G-S Mixed), and snow. The characteristics of their particle size distributions(PSDs) were analyzed, and the results indicated that during freezing weather, the dominant precipitation type was G-S Mixed, accounting for 44.80% of total precipitation. The total number concentration(Nt),mass-weighted mean diameter(Dm), and spectrum dispersion(σ) of all precipitation particles exhibit a positive correlation with precipitation intensity(PI), while the normalized intercept parameter in logarithmic form(log10Nw) shows minimal correlation with PI. Particles with diameters smaller than 2 mm contributed significantly to Nt, with freezing raindrops, F-G Mixed, and graupel particles between 1 mm and 2 mm, and G-S Mixed and snow particles larger than 4 mm contributing the most to PI. The mean PSD width followed the order of snow > G-S Mixed> graupel > freezing raindrops > F-G Mixed. Furthermore, this study derives the shape(μ) and slope(Λ) parameters of the Gamma distribution for different precipitation types, as well as the relationships between radar reflectivity(Z) and PI, and between kinetic energy(KE) and PI. These findings are expected to enhance the accuracy of PSD retrieval and the quantitative estimation of winter precipitation in this area.

关键词： Freezing weather Precipitation particles Discrete Fréchet distance Microphysical characteristics Southwest mountainous areas

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Enhanced piezoelectric properties and thermal stability of BiFeO3-BaTiO3-based ceramics with local structural heterogeneity

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Ceramics International 2025年第14期51卷 18587-18596页

作者： Fang, Juan Mao, Suwen Jiang, Minhong Zhou, Changrong Yu, Hongbao Rao, Guanghui Zhao, Jingtai Han, Jin Hou, Long Sun, Kang Cheng, Shuai Guangxi Key Laboratory of Information Materials and Property for New Energy Materials Guilin University of Electronic Technology Guangxi Guilin541004 China School of Material Science and Engineering Guilin University of Electronic Technology Guangxi Guilin541004 China College of Material Science and Engineering Kunming University of Science and Technology Kunming650093 China School of Materials Science and Engineering Shanghai University Shanghai200444 China

Pb-free piezoceramics have been extensively studied as alternatives to commercial Pb-based ceramics because of environmental concerns. However, their intrinsic thermal degradation of piezoelectric properties limits their industrial applications. Herein, by designing a sandwich-structured BaTi0.93Sn0.07O3/0.75BiFeO3-0.25BaTiO3-0.1 wt%MnO2/BaTi0.93Sn0.07O3 (SWS-BFBT), we achieve significant improvements in piezoelectric properties and depolarization temperature (Td) by forming a heterogeneity on the surface of BFBT ceramics. The wide temperature range of phase boundaries and enhanced relaxor behavior resulting from the reduced domain size and the increased number of polar nanoregions (PNRs) are attained in the diffusion layer of the SWS-BFBT ceramic, thereby enhancing piezoelectricity and thermal stability with the synergistic effect of polar pinning by more defects collectively. Compared to the Td of BFBT ceramic below 300 °C, we have designed SWS-BFBT ceramics with a heterogeneity, which improves Td to 423 °C and piezoelectric constant (d33) to 137 pC/N. Furthermore, their d33 can still maintain above a value of 111 pC/N at temperatures below 423 °C. We believe our finding will contribute significantly to the design of high-temperature lead-free piezoelectric materials. © 2025

关键词： Piezoelectricity

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CBWF+: Collaboratively Enhanced Lightweight Circular-Boundary-Based WiFi Fingerprinting

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IEEE Internet of Things Journal 2025年第1期12卷 650-662页

作者： Tao, Ye Tan, Shaolin Yan, Rongen Liu, Nian Wang, Wei Lü, Jinhu Zhongguancun Laboratory Beijing100094 China The School of Information Science and Technology The Engineering Research Center for Forestry-Oriented Intelligent Information Processing of National Forestry and Grassland Administration Beijing Forestry University Beijing100083 China The School of Automation Science and Electrical Engineering Beihang University Beijing100191 China The Zhongguancun Laboratory Beijing100094 China

—Users upload their own WiFi localization request signals to match against the received signal strengths (RSSs) in an offline constructed fingerprint database, thereby obtaining their own geographic location estimates. However, the relationships between the measured signals of users are seldom explored for enhancing the localization accuracy. Furthermore, the tedious site surveys required for building an offline fingerprint database hinder the wider application of this technology. To address the above issues, this article proposes a collaboratively enhanced lightweight WiFi localization algorithm named CBWF+, capable of providing an accurate indoor position with low-overhead fingerprints and collaborative localization. Specifically, we first discretize the area of interest to produce virtual points (VPs), and leverage the concept of circular-boundary-based localization to select a few VPs that share similar signal characteristics with the request signals. Then, important users for collaborative localization are chosen by two new proposed indicators. Next, based on the selection results and the RSS relationships among users, the spatiotemporal characteristics of WiFi signals are used to further filter out VPs that contradict the relationship between RSS and physical location. Finally, the credible VPs are used to obtain a high-accuracy estimate, by a proposed weighting method. The results of the real-world experiments validate the effectiveness of our proposed CBWF+ algorithm, compared to other state-of-the-art approaches (e.g., NN, OCLoc, CBWF, etc.). Specifically, in a 40-m × 17-m real scenario with only 20 reference points (RPs) and 11 access point (APs), our algorithm achieves an average localization accuracy of 2.49 m. Our codes are available at: https://***/dadadaray/CBWF2.0. © 2024 IEEE.

关键词： Wi-Fi

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Density waves of vortex fluids on a sphere

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Communications in Theoretical Physics 2025年第4期77卷 159-166页

作者： Yanqi Xiong Zhijun Zou Liang Luo Key Laboratory of Hunan Province on Information Photonics and Freespace Optical Communications School of Physics and Electronic ScienceHunan Institute of Science and TechnologyYueyang 414006China Graduate School of China Academy of Engineering Physics Beijing 100193China

We aim to find one highly nontrivial example of the solutions to the vortex fluid dynamical equation on the unit sphere(S^(2))and compare it with the numerical *** the rigid rotating steady solution for vortex fluids on S^(2)is already known to us,we consider the perturbations above *** decomposing the perturbation of the vortex number density and vortex charge density into spherical harmonics,we find that the perturbations are propagating *** be precise,the velocities for different single-mode vortex number density waves are all the same,while the velocities for single-mode vortex charge density waves depend on the degree of the spherical harmonics l,which is a signal of the existence of ***,we find that there is a beat phenomenon for the positive(or negative)vortex density *** simulation based on the canonical equations for the point vortex model agrees perfectly with our theoretical calculations.

关键词： quantum vortex 2D sphere superfluid density wave dispersion ome

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Enhanced MADM Strategy with Heptapartitioned Neutrosophic Distance Metrics

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Neutrosophic Sets and systems 2025年 78卷 74-96页

作者： Eassa, Mohamed Myvizhi, M. Elkholy, Mohamed Abdelhafeez, Ahmed Elbehiery, Hussam Computer Science Department Faculty of Information System and Computer Science October 6 University Giza12585 Egypt Applied Science Research Center Applied Science Private University Amman Jordan Department of Mathematics KPR Institute of Engineering and Technology Tamilnadu Coimbatore India Faculty of Computer Science& Engineering Alamein International University Egypt

In this work, a novel methodological approach to multi-attribute decision-making problems is developed and the notion of Heptapartitioned Neutrosophic Set Distance Measures (HNSDM) is introduced. By averaging the Penta-Partitioned Neutrosophic Distance Measures under particular conditional criteria, the suggested technique ranks the options. Additionally, we explore the fundamental characteristics of HNSDM and provide several illustrative theorems. The Heptapartitioned Neutrosophic Set Distance Measures are formulated based on the Hepta Neutrosophic Set. Lastly, a practical numerical example is provided to illustrate the efficacy of the suggested methodology. © 2025, University of New Mexico. All rights reserved.

关键词： Heptapartitioned Neutrosophic set Heptapartitioned Neutrosophic set and MADM strategy Heptapartitioned set Neutrosophic sine distance measure

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Fiber wireless seamless integrated encryption transmission scheme based on ciphertext-key double collaborative DNA reconstruction

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Optics Letters 2025年第9期50卷 2876-2879页

作者： Guo, Zhiruo Liu, Bo Ren, Jianxin Zhong, Qing Mao, Yaya Song, Xiumin Chen, Shuaidong Chen, Qingqing Wang, Feng Ullah, Rahat Institute of Optics and Electronics Nanjing University of Information Science & Technology Nanjing210044 China State Key Laboratory Cultivation Base of Atmospheric Optoelectronic Detection and Information Fusion Nanjing University of Information Science & Technology Nanjing210044 China Jiangsu International Joint Laboratory for Meteorological Photonics and Optoelectronic Detection Nanjing University of Information Science & Technology Nanjing210044 China Jiangsu Engineering Research Center for Intelligent Optoelectronic Sensing Technology of Atmosphere Nanjing University of Information Science & Technology Nanjing210044 China Beijing University of Posts and Telecommunications Beijing100876 China Department of Electronic Engineering Tsinghua University Beijing100084 China National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Nanjing University of Posts and Telecommunications Nanjing210003 China

In this paper, a double reconstructive DNA encryption transmission scheme based on ciphertext-key coordination is proposed for a fiber wireless seamless integrated communication system. The scheme uses a 5D memristor ring chaotic system and 1D chaotic system to realize the double collaborative reconstruction encryption transmission of ciphertext-key information through DNA coding mapping rules. The key space of the chaotic system reaches 10221. This paper successfully demonstrated the transmission of 48 Gb/s encrypted 16QAM signals with 25 km standard single-mode fiber (SSMF) and 10 m wireless distance. The bit error rate (BER) of the signal can meet the hard decision forward error correction (HD-FEC) threshold @3.8 × 10−3. When the offsets of DNA masking factors are more than 1, the BER is greater than 0.4. The results show that this scheme can guarantee the security of the optical fiber wireless seamless integrated transmission system. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Single mode fibers

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Photonics-assisted intensity-modulation and direct-detection MIMO millimeter-wave system in the D-band

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Chinese Optics Letters 2025年第1期23卷 7-12页

作者： Jingwen Tan Peng Tian Jianjun Yu Xianming Zhao Xinglin Dou Long Zhang Xiongwei Yang YangHan Yi Wei Bing Zhang Qinyi Zhang Luhan Jiang Weiping Li Rahim Uddin Kaihui Wang Wen Zhou State Key Laboratory of ASIC and System Key Laboratory for Information Science of Electromagnetic Waves(MoE)School of Information Science and TechnologyFudan UniversityShanghai 200433China Beijing Hongshan Information Technology Research Institute Co. Ltd.Beijing 100176China

We experimentally demonstrate the transmission of discrete multi-tone(DMT)millimeter-wave(mm-wave)signals over a 1.2-km distance at the D-band(110–170 GHz)in a cost-effective intensity-modulation and direct-detection(IM/DD)communication *** the experiment,we successfully achieve the transmission of DMT-QPSK and DMT-16QAM mm-wave signals over multiple-input multiple-output(MIMO)*** the 1.2-km free-space transmission,the bit error rate(BER)of the DMT-16QAM is below the 25%soft decision forward error correction(25%SD-FEC)threshold of 4×10-2,with a maximum net bit rate of 24.62 Gbit/s achieved in this system.

关键词： D-band discrete multi-tone intensity modulation and direct detection long-distance wireless transmission photonics-assisted technique

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Flexible, Super-stable, and Multifunctional Capacitive Pressure Sensors with Tilted Micropillar Array by Inclined Laser Ablation and Demolding

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IEEE Sensors Journal 2025年第6期25卷 9367-9374页

作者： Xu, Tianlong Li, Kaixin Zhou, Yihao Zhang, Dawei Sheng, Bin College of Optical Electrical and Computer Engineering Unversity of Shanghai for Science and Technology Shanghai 200093 China. Shanghai Key Laboratory of Modern Optical Systems Engineering Research Center of Optical Instruments and System Shanghai 200093 China

Flexible capacitive pressure sensors have garnered considerable interest across diverse applications, including medical monitoring, electronic skin, and robotic tactile systems, owing to their straightforward fabrication process, low energy consumption, and robust stability. In this paper, we introduce a new inclined laser ablation (ILA) combined with demolding technique for the fabrication of flexible capacitive sensors featuring a microstructured dielectric layer composed of a tilted micropillar array (TMA). The design parameters of TMA were systematically optimized, including the tilt angle of the micropillars, array gap, aspect ratio, and bottom film thickness. The resulting capacitive pressure sensor, equipped with 75° tilted micropillar arrays (aspect ratio of 5:1), demonstrates exceptional sensitivity (1.12 kPa-1) within the low-pressure range (0-2 kPa), rapid response and recovery times, a low pressure detection limit of 0.25 Pa, and transient response stability factor as high as 243.9. The proposed capacitive pressure sensor was validated for the detection and recognition of human motions when attached to various body parts. Additionally, the sensors also demonstrated significant potential for diverse applications, including tactile sensing, and Morse code communication. © 2025 IEEE.

关键词： Aspect ratio

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Buried interface bridging for inverted cesium-formamidinium triiodide perovskite solar cells with long operational stability

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science China Chemistry 2025年第1期68卷 163-173页

作者： Chenhui Zhang Chunjun Liang Fulin Sun Ting Zhu Xinghai Huang Yuzhu Guo Xinyu Guo Kunyang Ge Dan Li Fangtian You Zhiqun He Key Laboratory of Luminescence and Optical Information Ministry of EducationInstitute of Optoelectronic TechnologyBeijing Jiaotong UniversityBeijing 100044China Department of Physics School of Physical Science and EngineeringBeijing Jiaotong UniversityBeijing 100044China

In the field of perovskite solar cells(PSCs),the research on defects in the buried interface has been relatively limited due to its non-exposure;however,this interface significantly impacts the performance enhancement of inverted *** study employs phenylethylammonium chloride(PEACl)molecules as a buffer layer to modify the buried interface of p-i-n structured PSCs,aiming to enhance the uniformity of self-assembled monolayers(SAMs)and facilitate the uniform nucleation and growth of perovskite films on the ***,the introduction of the PEACl buffer layer effectively passivates defects at the bottom of the perovskite layer and notably enhances the crystal quality of the perovskite film by mitigating residual stress,thereby reducing nonradiative recombination *** these optimizations,the MA-free PSCs treated with PEACl achieve a power conversion efficiency(PCE)of 24.11%,with significant improvements in storage,thermal stability,and operational *** noteworthy is the device's performance in an unencapsulated state,whereas after 1,500 hours of continuous light operation stability testing,it retains 97%of its original *** study not only enriches the systematic understanding of the characteristics of the buried interface in PSCs but also contributes significantly to advancing the commercial production of perovskite photovoltaic technology.

关键词： defect-induced recombination buried interfaces inverted perovskite solar cells crystallization lattice mismatch

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Unintentional emissions of polychlorinated naphthalenes in China:Sources,composition,and historical trends

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Journal of Environmental sciences 2025年第2期148卷 221-229页

作者： Ye Huang Lin Huang Ying Li Nazupar Sidikjan Yunshan Zhang Yan Chen Yangmin Chen Ye Li Wei Du Long Chen YanWu Shanshan Zhang Jing Yang Wenjun Meng Guofeng Shen Min Liu Shu Tao Key Laboratory of Geographic Information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control Faculty of Environmental Science&EngineeringKunming University of Science&TechnologyKunming 650500China Laboratory of Earth Surface Processes College of Urban and Environmental SciencePeking UniversityBeijing 100871China

Polychlorinated naphthalenes(PCNs)are detrimental to human health and the *** the commercial production of PCNs banned,unintentional releases have emerged as a significant environmental ***,relevant information is still *** this study,provincial emissions for eight PCNs homologues from 37 sources in the Chinese mainland during the period of 1960-2019 were estimated based on a source-specific and time-varying emission factor *** results showed that the total PCNs emissions in 2019 reached 757.0 kg with Hebei ranked at the top among all the provinces and iron&steel industry as the biggest ***-chlorinated PCNs comprised 90%of emissions by mass,while highly chlorinated PCNs dominated in terms of toxicity,highlighting divergent priorities for mitigating emissions and safeguarding human *** emissions showed an overall upward trend from 1960 to 2019 driven by emission increase from iron&steel industry in terms of source,and from North China and East China in terms of geographic ***-capita emissions followed an inverted U-shaped environmental Kuznets curvewhile emission intensities decreased with increasing per-capita Gross Domestic Product(GDP)following a nearly linear pattern when log-transformed.

关键词： PCNs Emission inventory Emission factor Composition profile Emission intensity Chinese mainland

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