SENSORS
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2021
·Vol. 21
·期 8
·2824
·
IF 3.576
Angelo Coluccia,Alessio Fascista,Arne Schumann,Lars Sommer,Anastasios Dimou,Dimitrios Zarpalas,Miguel Méndez,David de la Iglesia,Iago González,Jean-Philippe Mercier,Guillaume Gagné,Arka Mitra,Shobha Rajashekar
Adopting effective techniques to automatically detect and identify small drones is a very compelling need for a number of different stakeholders in both the public and private sectors. This work presents three different original approaches that competed in a grand challenge on the “Drone vs. Bird” detection problem. The goal is to detect one or more drones appearing at some time point in video sequences where birds and other distractor objects may be also present, together with motion in background or foreground. Algorithms should raise an alarm and provide a position estimate only when a drone is present, while not issuing alarms on birds, nor being confused by the rest of the scene. In particular, three original approaches based on different deep learning strategies are proposed and compared on a real-world dataset provided by a consortium of universities and research centers, under the 2020 edition of the Drone vs. Bird Detection Challenge. Results show that there is a range in difficulty among different test sequences, depending on the size and the shape visibility of the drone in the sequence, while sequences recorded by a moving camera and very distant drones are the most challenging ones. The performance comparison reveals that the different approaches perform somewhat complementary, in terms of correct detection rate, false alarm rate, and average precision.
研究领域:
计算机视觉
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深度学习
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监控系统
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模式识别
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高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 41
·26513-26521
·
IF 3.906
Chaojun Li,Xiaofeng Liu,Jianrong Qiu
Organic semiconductors, such as polycyclic aromatic hydrocarbons, are typically not responsive to near infrared (NIR) light due to their relatively large bandgaps. Here, we show that the NIR light at 980 nm can be efficiently converted to broadband visible upconversion (UC) emission by rubrene molecules in a solution dispersed with upconversion nanoparticles (UCNPs). Spectroscopic characterizations indicate that the sensitization of emission by rubrene molecules strongly depends on the location of the 4f levels of Er3+ ions and the interplay between reabsorption and Förster-type energy transfer. Even for the solution with the highest rubrene concentration (>1 mg mL−1), energy transfer by reabsorption of UC emission from the UCNPs is the dominant process, and the radiationless resonant energy transfer process is weak, as the separation between most rubrene molecules and NCs is far larger than the Förster distance. The results of this work could be of particular interest for the development of organic–inorganic hybrid systems for NIR light harvesting and detection.
研究领域:
材料科学
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光学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Changyin Zhu,Chenyan Xue,Mingquan Huang,Fengxiao Zhu,Guodong Fang,Dixiang Wang,Shaochong Liu,Ning Chen,Song Wu,Dongmei Zhou
Activated carbon (AC) is widely used in pollutant removal , due to its adsorption capacity, conductivity and catalytic performance. However, few studies focus on the redox activity of AC and its role in pollutant transformation. In this study, we found that AC could efficiently mediate the oxidation of As(III) and the process of As(III) oxidation was pH and oxygen concentration dependent. In general, the presence of O 2 promoted As(III) oxidation at pH 3.0–9.5. Acidic and alkaline conditions favored As(III) oxidation regardless of whether there was oxygen, but the mechanisms involved were quite different when there was oxygen. At pH 3.0, reactive species (H 2 O 2 and ·OH) were generated and accounted for As(III) oxidation; at pH 9.5, As(III) was directly oxidized by O 2 (electron transfer from As(III) to O 2 mediated by carbon matrix) under aerobic conditions . Pre-oxidation and cyclic experiments results indicated the ability of AC to oxidize As(III) at pH 9.5 was sustainable and recyclable. This study provided a new insight in pollutant oxidation by AC in the environment.
研究领域:
环境科学
·
化学
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DOI
PubMed
高影响因子
JOURNAL OF CONTROLLED RELEASE
·
2022
·
IF 11.467
Xiaoshu Gao,Yin Xiong,Hening Chen,Xuheng Gao,Jiaxin Dai,Yutong Zhang,Wanhang Zou,Yang Gao,Zhenyan Jiang,Bing Han
Nanocarrier-aided drug delivery techniques have improved the absorption and permeability of drugs in nose-to-brain delivery. However, the molecular properties of nanocarriers during the delivery process are of great interest; in particular, the characteristics when penetrating barriers in vivo are crucial for the screening and optimization of materials for nasal inhalation. In this study, we have focused on two types of delivery systems: mucoadhesive nanoparticles (MAPs) and mucopenetrating nanoparticles (MPPs); both have been widely used for mucosal delivery, although a method for selecting the more effective type of drug carriers for mucosal delivery has not been established. Molecular dynamics (MD) simulations were used to reveal the all-atom dynamic characteristics of the interaction between different delivery systems and the nasal mucus protein MUC5AC . Among the systems tested, hydroxypropyltrimethyl ammonium chloride chitosan (HTCC) had the strongest interaction with mucin, suggesting it had better mucoadhesive performance, and that it interacted with MUC5AC more strongly than unmodified chitosan. In contrast, the mucus-penetrating material polyethylene gly co l-poly lactic acid-co-glycolic acid (PEG-PLGA), had almost no interaction with MUC5AC. The results of the MD simulations were verified by in vitro experiments on nanoparticles (NPs) and mucin binding. The drug delivery performance of the four types of NPs, analyzed by in vitro and ex vivo mucosal penetration, were all generally consistent with the properties of the material predicted from the MD simulation. These clues to the molecular mechanism of MAPs and MPPs may provide useful insight into the screening and optimization of nanomaterials suitable for nasal inhalation.
研究领域:
药剂学
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生物医学工程
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计算生物学
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产品关联
DOI
PubMed
高影响因子
CRYSTAL GROWTH & DESIGN
·
2021
·
IF 4.076
Yunqiao Guo,Die Zhang,Ting Zheng,Ling Huang,Daojiang Gao,Jian Bi,Guohong Zou
Two new alkali metal formic-borates named Rb3(COOH)3(H3BO3)2 and Cs3(COOH)3(H3BO3)2 have been successfully synthesized under mild conditions. Influenced by the different cation sizes, these two stoichiometrically equivalent compounds reveal discrepant symmetries: Rb3(COOH)3(H3BO3)2 is noncentrosymmetric (NCS) while Cs3(COOH)3(H3BO3)2 is centrosymmetric (CS). Especially, these two title compounds exhibit unique planar [(COOH)3(H3BO3)2]3– layers constructed from two kinds of planar π-conjugated asymmetric BO3 and COOH units, which induce the large birefringence, 0.09@1064 nm for Rb3(COOH)3(H3BO3)2 and 0.10@1064 nm for Cs3(COOH)3(H3BO3)2, respectively. Optical property measurements indicate that these two compounds display short UV absorption edges, suggesting that they are promising short-wave UV birefringent materials. A detailed theoretical analysis confirmed that the excellent linear optical property was derived from the synergistic effect of the two kinds of π-conjugated planar groups.
研究领域:
材料科学
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光学
·
晶体学
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产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2024
·
IF 8.1
Hang Jia,Cheng Liu,Yu Zhang,Yue Qiao,Wenqi Zhao,Xi Chen,Xigao Jian
Electrophoretic deposition (EDP) is a novel and promising technique for surface modification, however, the adsorption of Ti 3 C 2 T x MXene or graphene oxide (GO) onto the basalt fiber (BF) surface by EPD and its effects on the mechanical performance of basalt fiber reinforced high-performance thermoplastic (BFRHPTP) composite have yet to be investigated. Here, the mechanical and interfacial properties of the modified BF/PPENK were explored. The influence of the brittle/tough nanostructures in interphase on the mechanical performance of BF reinforced poly(phthalazinone ether nitrile ketone) (BF/PPENK) was elucidated. The results indicated that the thermal reduction of GO contributed even more to enhancing the tensile, flexural, interlaminar shear, and interfacial shear strength of BF/PPENK compared to the heat oxidation of MXene. Particularly, these properties of BF-NH 2 @GO3/PPENK were improved by approximately 84%, 43%, 60%, and 118% in comparison to BF-Desized/PPENK. This work may provide some guidance on the interfacial modification of the BFRHPTP composites.
研究领域:
材料科学
·
机械工程
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产品关联
DOI
高影响因子
POLYMER
·
2017
·
IF 3.684
Xiaobin Shen,Jinyue Dai,Yuan Liu,Xiaoqing Liu,Jin Zhu
A high performance polybenzoxazine derived from bio-based furfurylamine was synthesized in an efficient and straightforward way. For comparison, its petroleum-based analogue was also prepared from 4, 4-diaminodiphenylmethane (DDM). The chemical structures of the precursors were confirmed by Nuclear Magnetic Resonance Spectroscopy ( 1 H-NMR and 13 C-NMR) and Fourier Transform Infrared Spectroscopy (FT-IR). After the curing reaction was investigated by Differential Scanning Calorimetry (DSC) and FT-IR in detail, the thermal and mechanical properties of the cured resins were studied by Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). Results demonstrated that the polybenzoxazine based on furfurylamine (BZ-F) possessed higher glass transition temperature (270 °C) and better thermal stability associated with higher charring ability when compared with the one (BZ-DDM) derived from DDM, which might be attributed to the stronger hydrogen bonding interaction in the BZ-F system and the post-curing reaction on furan ring above 280 °C. In this paper, the hydrogen bonding effect on the properties of polybenzoxazine has been especially studied, which might give us a guidance to design and synthesize the polybenzoxazine with high performance.
研究领域:
材料科学
·
有机化学
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DOI
高影响因子
FOOD CHEMISTRY
·
2026
·
IF 10.4
Ziqi Chen,Fang Huang,Weitong Shu,Zihang Yan,Songyu Wang,Zhiyuan Huang,Qingqing Cao,Qiang Zhao
Glutinous rice protein acts as “network cooperator” via hydrophobic interactions. • Glutinous rice protein with 3% addition yielding optimal anti-digestive effects. • Reveals homologous advantage mechanism in protein-glutinous rice starch systems. • New design principle: leveraging hydrophobic integration for functional foods. Research on glutinous rice starch (GRS) in combination with proteins remains limited, particularly regarding comparisons between homologous and heterologous proteins. This study aimed to elucidate the functional advantages of homologous glutinous rice protein (GRP) over heterologous rice protein isolate (RPI) in the GRS system and the underlying mechanisms. We compared the GRP-GRS and RPI-GRS systems across multiple scales. GRP, by virtue of its conformational advantages, integrated into the starch network via hydrophobic interactions, enhancing gel strength, hardness, and shear resistance. GRP maintained network integrity at 24% addition level and achieved optimal anti-digestive performance at 3% addition. In contrast, RPI, with its rigid, disulfide-locked conformation, relied on weaker hydrogen bonds, causing network collapse at 24% addition. This study elucidates the homologous advantage mechanism in glutinous rice starch and proposes a formulation design strategy based on conformational flexibility, hydrophobic compatibility, and varietal homology. Download: Download high-res image (190KB) Download: Download full-size image
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高影响因子
POWDER TECHNOLOGY
·
2026
·
IF 5.5
Daolun Liang,Shikai Huang,Lixiang Li,Shan Wang,Lijian Wang,Ji Li,Qili Qiu,Dekui Shen
The print sample exhibits superior combustion performance over the casted sample. • A linear correlation is observed between combustion temperature and burning rate. • The impulse exhibits a linear correlation with pressure for the printed sample. • Secondary merging mechanism of agglomerates is elucidated. Additive manufacturing (AM) provides a superior alternative to casting for solid propellants, enabling complex geometries alongside safer and more efficient manufacturing. This study compares the thermal decomposition behavior of binder systems for these two different processing methods, as well as combustion properties and aluminum agglomeration of the two different solid propellants. The results indicate significant distinctions between casted and printed samples in terms of combustion and aluminum agglomeration characteristics. Although the combustion temperature, burning rate, and impulse of both samples increase with rising pressure, the values for the printed sample are consistently higher than those of the casted sample. Furthermore, strong linear correlations are observed between the combustion temperature and burning rate of both samples, as well as between the impulse of the printed sample and pressure. Despite differences in the degree of aluminum agglomeration between the two samples, the evolutionary trends of their agglomeration behaviors exhibit high consistency. Under identical pressure, the number of agglomerates detaching from the burning surface is significantly greater for casted sample compared to printed sample. At lower pressures, larger or even irregular agglomerates are prone to form during combustion. The secondary merging location of agglomerates is determined by the competition between aerodynamic force and adhesive force. When aerodynamic force dominates, secondary merging tends to occur in the gas-phase flame zone. However, when adhesive force prevails, secondary merging is more likely to happen on the burning surface. The findings provide scientific support for the application of AM technology in the field of solid propellants. This study compares the combustion characteristics and aluminum agglomeration behavior of solid propellants prepared by additive manufacturing and casting, utilizing a visual online monitoring system. Download: Download high-res image (177KB) Download: Download full-size image
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高影响因子
Polymer Chemistry
·
2025
·
IF 3.9
Chunman Li,Mingzhe Zhao,Zenian Gou,Tengda Zhao,Huimin Han,Kongying Zhu,Xiaoyan Yuan,Li-Xia Ren
Magnetic polymers show great potential in biomedical, electronic devices and magnetic responsive materials. The structure and property relationship are very important in design of organic magnetic polymers. In this work, core-shell magnetic bottlebrush polymers (PS-b-QPDMA[FeCl4]) with polystyrene as core block and magnetic poly(ionic liquid)s (QPDMA[FeCl4]) as shell block is prepared by ring-opening metathesis polymerization and post-modification. The self-assembly of core-shell PS-b-QPDMA[FeCl4] is studied in core and shell selecting solvent, respectively. It self-assembles into single macromolecular core-shell nanorod in shell selecting solvent while it self-assembles into core-shell nanoparticles in core selecting solvent. The magnetic property of PS-b-QPDMA[FeCl4] are studied in different morphologies via magnetic field and temperature dependent magnetization, respectively. Compared with the paramagnetic linear block copolymer, the bottlebrush polymer without self-assembly shows ferromagnetic interaction at low temperature with the bifurcation temperature (Tb) of the zero field cooling and field cooling curves of 3.2 K. The nanoparticle self-assemblies show the similar Tb at 3.8 K, while the single macromolecular nanorod self-assemblies show a high Tb of 9.8 K, demonstrating the much stronger ferromagnetic interaction for the nanorod self-assemblies. The increasing of Tb is probably due to the confinement of glassy PS core in the nanorod self-assemblies, which decreases the Fe(III)-Fe(III) distance to enhanced the ferromagnetic interaction of FeCl4- units.
研究领域:
材料科学
·
高分子化学
·
磁性材料
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.3
Xin Li,Qing Xu,Xiaoguang Yang,Mengmeng Ji,Ying Li,Rushan Lin,Lijian Rong,Xue Zhang
Pyrochemical reprocessing of spent fuel via molten chloride electrolysis is a fundamental approach to achieving a closed nuclear fuel cycle. However, the rapid corrosion of apparatus materials poses significant challenges to the safe implementation of this technology. A key unresolved question is whether the Cr-alloying approach is viable for enhancing high-temperature corrosion resistance under molten chloride conditions. Herein, we conduct a systematic examination of the impact of Cr content on the corrosion behavior of structure steels in molten LiCl-KCl eutectic. Our results reveal that Cr exerts a dual role in corrosion resistance by modulating both chemical oxidation and active dissolution processes. Specifically, when the Cr level is insufficient to form a continuous Cr-rich oxide layer via chemical oxidation, increasing Cr concentration markedly accelerates electrochemical corrosion in molten chloride. Our research elucidates the fundamental mechanism by which Cr functions in molten salt corrosion and furnishes essential direction for the compositional design of corrosion-resistant alloys in pyrochemical reprocessing settings.
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2016
·Vol. 4
·期 12
·2295-2301
·
IF 5.066
Yang Zhou,Dan-Dan Zhou,Bo-Mei Liu,Li-Na Li,Zi-Jun Yong,Hao Xing,Yong-Zheng Fang,Jing-Shan Hou,Hong-Tao Sun
Bismuth doped materials with near infrared (NIR) photoluminescence (PL) have recently attracted tremendous attention because of their great potential for photonic and optoelectronic devices that could find broad applications in modern optical telecommunications. However, the mechanistic studies of the NIR PL from these materials still significantly lag behind, which imposes substantial limitations in rationally discovering and designing new materials. In this contribution, we investigated the optical and structural properties of Bi doped CsPbI3 using a diverse range of experimental techniques. We proved that the observed ultrabroad NIR PL with lifetimes of tens of microseconds is not connected with a single-ion Bi active center. For the first time, we proposed a polaron model to rationally explain the observed PL from Bi doped CsPbI3. Finally, we demonstrate the first observation of NIR PL from nanowires among the Bi doped luminescent materials. The experimental results reported here not only deepen the understanding of NIR PL mechanisms in Bi doped materials, but also introduce a new family of solution-processed nanostructures operating in the NIR, which may stimulate further research in exploiting this technique to design a broad range of photonic and optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
光物理
·
纳米材料
·
固体物理
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DOI
高影响因子
危险品化学品经营许可证（带存储）