关键词:
Photonic spin Hall effect;Transverse beam shift;Tuning range;Insulating-metallic phase transition
摘要:
The photonic spin Hall effect (PSHE) can manifest as the spin-dependent splitting (perpendicular to the plane of incidence) of a light beam, i.e., transverse beam shift. Introducing dynamically tunable PSHE into post-fabricated systems has great potential for the new type of photonic devices and its tuning range can be manipulated with different reconfigurable methods. Most of these methods are based on modifying the refractive index of bulk or interface materials. However, the perturbation on the refractive index is usually small, leading to difficulty in enhancing PSHE. Fortunately, the changes in the refractive index of Vanadium Dioxide (VO2) with insulating-metallic phase transition can be larger in several orders than that of other materials, making it possible for enhancing PSHE to have greater tuning range. Here, to explore the dynamically tunable PSHE based on the insulating-metallic phase transition of VO2, the transverse beam shift (as an indicator of PSHE) was calculated with a full wave theory at a wavelength of 1550 nm in a layered structure. Without a gold layer, only the PSHE of the H-polarized beam shows significant tunability in the insulating-metallic phase transition of VO2. With the Au layer, the PSHE of the H- and V-polarized beam is enhanced around the Brewster and Brewster-like (originating from the destructive interference between the nanosized layers) angle, respectively. For H- and V-polarized beams, the tuning range of PSHE is mainly determined by the insulating phase of VO2 and can be enhanced with the Au layer. Finally, as an example, the enhanced tuning range makes the output of a two-digit binary code conversion based on PSHE easier to recognize. These results offer us possible ways to control the tuning range of PSHE in post-fabricated systems and provide more potential for new applications.
摘要:
Metal single-atom catalysts offer the dual advantages of high electrochemical activity and near 100 % metal atom utilization, leading to their potential use in low-cost electrochemical sensor development. Herein, a novel electrocatalyst comprising atomically-dispersed Mn on B,N co-doped bamboo-derived carbon (MnSAs-BN-BC) was synthesized via a facile pyrolysis procedure. A high dispersion of Mn single atoms in MnSAs-BN-BC was confirmed by aberration-corrected transmission electron microscopy and elemental mapping. The Mn loading in the MnSAs-BN-BC determined by inductively coupled plasma mass spectrometry was 255 mg kg-1. MnSAs-BNBC displayed outstanding electrocatalytic performance for levodopa (LD) oxidation, allowing a robust electrochemical sensing platform for LD detection to be established. The MnSAs-BN-BC/GCE sensing platform offered a wide LD detection range (concentrations from 2 to 683 mu M) and a very low limit of detection (LOD) of 0.45 mu M, outperforming almost all electrochemical sensors reported to date for LD sensing. The MnSAs-BN-BC/GCE platform also featured outstanding repeatability, reproducibility, selectivity, and stability. The as-developed sensing platform was successfully applied to LD quantification in commercial tablets with satisfactory recoveries (85.2-102.4 %), with the analytical precision of method validated against a traditional UV-vis spectrophotometry method. Density functional theory (DFT) calculations showed that Mn single atom sites lowered the reaction energy barrier for LD oxidation, with the favorable d-band center position of Mn single atom sites in MnSAs-BN-BC contributing to the enhanced LD sensing performance. This work encourages the use of singleatom metal catalysts in design of high-performance electrochemical sensors for the rapid detection of LD.
通讯机构:
[Feng, C ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词:
Event-based extreme precipitation;Time distribution pattern;Contribution rate of urbanization;Xiangjiang River Basin
摘要:
An in-depth understanding of event-based extreme precipitation (EEP), emphasizing precipitation process, can help to prevent the risk posed by regional high-intensity and persistent precipitation. The concept of time distribution pattern (TDP) is used to distinguish EEPs, which classifies EEPs according to the occurrence time of extreme precipitation. Furthermore, TDP1,2,3 is that the distribution of daily precipitation above the threshold is in the first half, in the second half, and both the first half and second half of EEP, respectively. We analyze temporal characteristics, spatial distribution, future trends of EEP, and the contribution rate of urbanization to EEP in this study. EEP thresholds exhibit a latitudinal gradient from central to northern and southern regions except for Nanyue Station (NY). TDP1 and TDP2 account for more than 60% among the total of EEPs. However, TDP3 is the dominant precipitation type observed at each station from the perspective of precipitation, intensity, duration, especially, in summer. EEP is less and TDP is unstable in autumn and winter. In general, there is an increasing trend in EEP and it is predicted that the trend of EEP will continue to rise. Moreover, the contribution rate of urbanization to EEP varies significantly, with a more pronounced inhibitory effect observed. The inhibitory effect of urbanization on the frequency and duration of TDP3 reached 60.83% and 72.77%, respectively. However, it is more significant on the extreme nature of TDP1 under urbanization, with a positive contribution rate of 9.63% and 21.83% to precipitation and intensity of TDP1, respectively. The results conclude that the higher the level of urbanization, the more pronounced the extreme trend of TDP1 becomes.
摘要:
Uranium mining operations produce large volumes of acidic uranium mining wastewater, necessitating the development of environmentally friendly and recyclable materials for efficient uranium removal and recovery. The current study successfully produced hydroxyapatite (HAP-L) and magnetic phosphate composites (CaFeP-1, CaFeP-2, and FePO4) through a combination of mixing, ultrasonication, hydrothermal precipitation, and calcination methods. The research explores the influence of various parameters such as pH, solid-liquid ratio, contact time, initial uranium concentration, co-existing ions, and recyclability on the uranium removal efficiency of these materials. The findings indicate exceptional uranium adsorption capacities, with CaFeP-1 exhibiting the highest capacity among the materials, especially in acidic environments. Moreover, CaFeP-1 displays strong resistance to interference from other ions and can be recycled multiple times while maintaining high removal rates. Treatment of acidic uranium mining wastewater by CaFeP-1 results in pH adjustment and the reduction of uranium and other ion concentrations, making it a promising solution for comprehensive remediation of acidic uranium mining wastewater. The U(VI) removal mechanism by CaFeP-1 was validated through XRD, FT-IR, and XPS results. The U(VI) removal was attributed to processes such as dissolution-precipitation, surface complexation, and ion exchange. The formation of sodium uranyl phosphate hydrate was identified as a new product following U(VI) abatement by CaFeP-1. In summary, CaFeP-1 shows great potential for the effective treatment of acidic uranium mining wastewater.
摘要:
The massive collection and transmission of various crop and livestock data in smart agriculture leads to serious security concerns. Furthermore, many Internet of Things (IoT) devices in smart agriculture are battery-powered, with limited energy resources. Therefore, a low energy lightweight block cipher (LELBC) is proposed to overcome the data leakage problem during sensor data transmission in smart agriculture. Firstly, a new permutation substitution permuta-tion (PSP) structure is proposed, taking into account the energy resource constraints of unified encryption and decryption (ED) circuits. It has highly consistent encryption and decryption and a good diffusion effect. Secondly, a 4-bit low energy involutive S-box is obtained based on a genetic algorithm. The proposed S-box has lower area and latency compared to the existing S-boxes. The experimental data show that LELBC consumes 1864 gate equivalents (GE) in area and 6.99 mu J/bit in energy (encryption + decryption) under the UMC 0.18 mu m 1P6M process library. LELBC decreases energy and area consumption by 24.02% and 24.04%, respectively, compared to Midori. Finally, a temperature collection and encryption transmission platform is established. LELBC is deployed on the platform to encrypt the collected data, establishing the first line of defense for the secure transmission of smart agriculture sensor data.
通讯机构:
[Tang, LW ] H;Hengyang Normal Univ, Sch Comp Sci & Technol, Hengyang, Peoples R China.;Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang, Peoples R China.
摘要:
The energy epsilon(G) of a graph G is the sum of the absolute values of all eigenvalues of G. Two graphs of the same order are said to be equienergetic if their energies are equal. As pointed out by Gutman, it is not known how to systematically construct any pair of equienergetic, non-cospectral trees until now. Inspired by the research of integral trees, we proposed a construction of infinite pairs of equienergetic trees of diameter 4.
期刊:
Journal of Hydrology: Regional Studies,2024年52:101690 ISSN:2214-5818
通讯作者:
Zhang, XP
作者机构:
[Xiao, Xiong; Rao, Zhiguo; Li, Jiajie; Zhang, Xinping; Dai, Junjie; He, Xinguang; Zhang, Cicheng] Hunan Normal Univ, Coll Geog Sci, Changsha, Peoples R China.;[Xiao, Xiong; He, Xinguang; Zhang, Xinping] Hunan Normal Univ, Key Lab Geospatial Big Data Min & Applicat Hunan P, Changsha, Peoples R China.;[Liu, Na] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang, Hunan, Peoples R China.
通讯机构:
[Zhang, XP ] H;Hunan Normal Univ, Coll Geog Sci, Changsha, Peoples R China.
关键词:
Stable isotopes;Seasonal origin index;Xylem water;Leaf water;Soil water
摘要:
Study region: From 2017 to 2019, xylem and leaf samples of Cinnamomum camphora were sampled and soil water samples at 0-100 cm depth were sampled 65 times simultaneously in a typical East Asian monsoon region. Study focus: The seasonal origin of plant and soil water from precipitation was inferred based on the stable isotope techniques, including the evaporation line slope (SEL) estimations and the seasonal origin index (SOI) calculation. New hydrological insights for the region: The regression SEL of leaf water was close to the theoretical SELs estimated based on the Craig-Gordon model, but xylem water and soil water showed higher regression SELs than the theoretical SELs, this may be due to the seasonality of the precipitation isotopes and evaporative fractionation. The fractionation-compensated isotopic values calculated based on the theoretical SELs of different water types were close, with the differences within 2.4%o for 618O and 20.0%o for 62H of each other, and the uncertainty of the fractionationcompensated isotopic values was low enough in the calculation of SOI. The SOI results showed that summer precipitation was more prevalent in plant and soil water, and more winter precipitation may recharge runoff when evapotranspiration demand is weak. Overall, the leaf sampling and the theoretical method have the potential to infer the seasonal water origin over a relatively long period.
通讯机构:
[Tang, ZK ] U;Univ Hunan Prov, Key Lab Micronano Energy Mat & Applicat Technol, Hengyang 421002, Peoples R China.
摘要:
Two-dimensional material-supported single metal atom catalysts have been extensively studied and proved effective in electrocatalytic reactions in recent years. In this work, we systematically investigate the OER catalytic properties of single metal atoms supported by the NiN(2) monolayer. Several typical transition metals with high single atom catalytic activity, such as Fe, Co, Ru, Rh, Pd, Ir, and Pt, were selected as catalytic active sites. The energy calculations show that transition metal atoms (Fe, Co, Ru, Rh, Pd, Ir, and Pt) are easily embedded in the NiN(2) monolayer with Ni vacancies due to the negative binding energy. The calculated OER overpotentials of Fe, Co, Ru, Rh, Pd, Ir and Pt embedded NiN(2) monolayers are 0.92 V, 0.47 V, 1.13 V, 0.66 V, 1.25 V, 0.28 V, and 0.94 V, respectively. Compared to the 0.57 V OER overpotential of typical OER noble metal catalysts IrO(2), Co@NiN(2) and Ir@NiN(2) exhibit high OER catalytic activity due to lower overpotential, especially for Ir@NiN(2). The high catalytic activity of the Ir embedded NiN(2) monolayer can be explained well by the d-band center model. It is found that the adsorption strength of the embedded TM atoms with intermediates follows a linear relationship with their d-band centers. Besides, the overpotential of the Ir embedded NiN(2) monolayer can be further reduced to 0.24 V under -2% biaxial strain. Such findings are expected to be employed in more two-dimensional material-supported single metal atom catalyzed reactions.
作者机构:
[Liu, Qin; He, Yingjian; Liu, Jinlong; Qian, Dong; Chen, Xiangxiong; Wang, Bowen; Luo, Ziyu; Liu, JL; Zhang, Xinxin] Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;[Chen, Xiangxiong] Yoening Tianci Min Changsha Technol Ctr, Changsha 410083, Peoples R China.;[V. Kennedy, John] GNS Sci, Natl Isotope Ctr, POB 30368, Lower Hutt 5010, New Zealand.;[Li, Junhua] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Waterhouse, Geoffrey I. N.; Waterhouse, GIN] Univ Auckland, Sch Chem Sci, Auckland 1142, New Zealand.
通讯机构:
[Qian, D; Liu, JL ] C;[Waterhouse, GIN ] U;Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;Univ Auckland, Sch Chem Sci, Auckland 1142, New Zealand.
关键词:
Electrochemical reconstruction;CoMoO4-based catalyst;Phosphorization;Heterojunction;Overall water splitting
摘要:
Phosphorization of molybdates has been shown to promote hydrogen evolution reaction (HER) activity but is usually detrimental to oxygen evolution reaction (OER) activity, frustrating efforts to create bifunctional HER/OER electrocatalysts. Herein, we show that Fe2O3-modulated P-doped CoMoO4 on nickel foam (Fe-P-CMO) is an excellent bifunctional HER/OER electrocatalyst in alkaline media, with the adverse effect of phosphorization on the OER activity of CoMoO4 being countered via Fe2O3 introduction. An alkaline splitting electrolyser assembled directly using the self-supporting Fe-P-CMO electrode possessed outstanding long-term durability with ultralow cell voltages of 1.48 and 1.59 V required to achieve current densities of 10 and 100 mA cm−2, respectively. Detailed experimental investigations showed that during HER, P-doped CoMoO4 in Fe-P-CMO underwent surface reconstruction with the in-situ formation of Co(OH)2 on the P-CoMoO4 (Co(OH)2/P-CoMoO4). During OER, P-doped CoMoO4 was deeply reconstructed to CoOOH with the complete dissolution of Mo, leading to the in-situ formation of Fe2O3/CoOOH heterojunctions.
作者机构:
[Yao, Yong-Sheng; Wei, Xiao-Lin; Gong, Ze-Ting; Tang, Zhen-Kun; Li, Jun-Yao; Liu, Yao-Zhong; Liang, Zheng; Tang, ZK] Hengyang Normal Univ, Univ Hunan Prov, Key Lab Micronano Energy Mat & Applicat Technol, Hengyang 421002, Peoples R China.;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang, Peoples R China.
通讯机构:
[Wei, XL ; Tang, ZK] H;Hengyang Normal Univ, Univ Hunan Prov, Key Lab Micronano Energy Mat & Applicat Technol, Hengyang 421002, Peoples R China.
摘要:
The need for low-carbon solar electricity production has become increasingly urgent for energy security and climate change mitigation. However, the bandgap and carrier separation critical requirements of high-efficiency solar cells are difficult to satisfy simultaneously in a single material. In this work, several van der Waals ZnIn(2)X(4) (X = S, Se, and Te) heterostructures were designed based on density functional theory. Our results suggest that both ZnIn(2)S(4)/ZnIn(2)Se(4) and ZnIn(2)Se(4)/ZnIn(2)Te(4) heterostructures are direct bandgap semiconductors at the Γ point. Besides, obvious carrier spatial separations were observed in the ZnIn(2)S(4)/ZnIn(2)Se(4) and ZnIn(2)Se(4)/ZnIn(2)Te(4) heterostructures. Interestingly, the ZnIn(2)S(4)/ZnIn(2)Se(4) heterostructure has a suitable bandgap of 1.43 eV with good optical absorption in the visible light range. The calculated maximum theoretical photoelectric conversion efficiency of ZnIn(2)S(4)/ZnIn(2)Se(4) heterostructure was 32.1%, and it can be further enhanced to 32.9% under 2% tensile strain. Compared to single-layer ZnIn(2)X(4) materials, the electron effective mass of the ZnIn(2)S(4)/ZnIn(2)Se(4) heterostructure is relatively low, which results in high electron mobility in the heterostructure. The suitable bandgap, obvious carrier separation, high electron mobility, and excellent theoretical photoelectric conversion efficiency of the ZnIn(2)S(4)/ZnIn(2)Se(4) heterostructure make it a promising candidate for novel 2D-based photoelectronic devices and solar cells.
摘要:
Direct Synthesis of Phosphoryltriacetates from White Phosphorus via Visible Light Catalysis: The reaction of P4 with α‐bromo esters using fac‐Ir(ppy)3 as the photocatalyst and blue LEDs (456 nm) as the light source was developed for the first time to afford a series of phosphoryltriacetates. This approach features mild reaction conditions and simple operational process without chlorination. Abstract Organophosphorus compounds (OPCs) are widely used in many fields. However, traditional synthetic routes in the industry usually involve multistep and hazardous procedures. Therefore, it's of great significance to construct such compounds in an environmentally‐friendly and facile way. Herein, a photoredox catalytic method has been developed to construct novel phosphoryltriacetates. Using fac‐Ir(ppy)3 (ppy=2‐phenylpyridine) as the photocatalyst and blue LEDs (456 nm) as the light source, white phosphorus can react with α‐bromo esters smoothly to generate phosphoryltriacetates in moderate to good yields. This one‐step approach features mild reaction conditions and simple operational process without chlorination.
摘要:
Carbon nitride quantum dots (CNQDs) modified cobalt phosphate (CoPi) composites CNQDs/CoPi‐x were applied in photocatalytic H2 evolution. It shown enhanced activity and stability compared to pure CoPi using Eosin Y (EY) as a sensitizer. The employment of CNQDs boosted electron transfer from radical EY·− to CNQDs/CoPi‐x. Abstract In the present work, carbon nitride quantum dots (CNQDs)‐modified cobalt phosphate (CoPi) composites CNQDs/CoPi‐x (x = 1, 2, 3) were prepared at room temperature and characterized by FTIR, XRD, UV–Vis DRS, EIS, SEM, TEM/HR‐TEM, XPS, and N2 gas adsorption. The morphologies and surface areas of CNQDs/CoPi‐x have no remarkable change after modification of CNQDs, compared with pure CoPi. The obtained CNQDs/CoPi‐x shows enhanced activity and stability of photocatalytic H2 evolution compared to pure CoPi using Eosin Y (EY) as a sensitizer and triethanolamine as an electron donor. The CNQDs/CoPi‐2 possesses the highest hydrogen evolution rate, 234.5 μmol h−1 g−1, upon visible light, which outshines that of CoPi by 2.4 times. It was believed that the enhanced photocatalytic performances of the CNQDs/CoPi‐2 could result from the boosted electron transfer from radical EY·− to CNQDs/CoPi‐2 by the employment of CNQDs; in addition, the visible‐light activity of CNQDs contributes to hydrogen evolution. The mechanism of photocatalytic hydrogen production was discussed. This study may contribute toward the development of production of “green hydrogen” using solar.
期刊:
Environmental Geochemistry and Health,2024年46(1):1-15 ISSN:0269-4042
通讯作者:
Zhou, DS
作者机构:
[Huang, Zhigang; Xiao, Ye; Long, Jiumei; Zhou, Dongsheng; Xiao, Hanxi] Zunyi Normal Univ, Coll Resources & Environm, Zunyi 563006, Peoples R China.;[Long, Jiumei; Huang, Binyan] Hengyang Normal Univ, Coll Life Sci, Hengyang 421008, Peoples R China.;[Tan, Di] Changde Ecol Environm Bur, Changde 415000, Peoples R China.
通讯机构:
[Zhou, DS ] Z;Zunyi Normal Univ, Coll Resources & Environm, Zunyi 563006, Peoples R China.
关键词:
Antimony and arsenic contamination;Soil washing;Agricultural soil;Bioavailability
摘要:
Antimony (Sb) and arsenic (As) contamination in agricultural soil poses human health risks through agricultural products. Soil washing with degradable low molecular weight organic acids (LMWOAs) is an eco-friendly strategy to remediate agricultural soils. In this study, three eco-friendly LMWOAs, oxalic acid (OA), tartaric acid (TA), and citric acid (CA), were used to treat Sb and As co-contaminated agricultural soil from Xikuangshan mine area. The OA, TA, and CA washed out 18.4, 16.8, and 26.6% of Sb and 15.3, 19.9, and 23.8% of As from the agricultural soil, with CA being the most efficient reagent for the soil washing. These organic acids also led to pH decline and macronutrients losses. Fraction analysis using a sequential extraction procedure showed that the three organic acids targeted and decreased the specifically sorbed (F2) (by 19.3-37.6% and 2.41-23.5%), amorphous iron oxide associated (F3) (by 49.1-61.2% and 51.2-70.2%), and crystallized iron oxide associated (F4) (by 12.3-26.0% and 26.1-29.1%) Sb and As. The leachability of Sb and As, as well as their concentrations and bioconcentration factor (BCF) in vegetables reduced due to the soil washing. It demonstrated that the bioavailability of both the elements was decreased by the organic acids washing. The concentrations of Sb and As in typical vegetable species cultivated in CA washed soil were less than the threshold value for consumption safety, while those in OA and TA washed soils were still higher than the value, suggesting that only CA is a potential washing reagent in soil washing for Sb- and As-contaminated agricultural soil.
摘要:
Developing high-efficiency electrocatalysts for the oxygen evolution reaction (OER) remains a crucial bottleneck on the way to the water splitting for producing clean fuel (H2). Compared with single atom catalysis (SACs), dualatom catalysts (DACs) have attracted great interest due to higher OER catalytic efficiency. In this work, the OER properties of dual-metal-N4 embedding armchair single-walled carbon nanotubes (D-MN4/CNTs) were systematic studied by density functional theory (DFT) simulations. Our results indicate that CoN4 embedding armchair CNTs exhibit higher OER activity than the corresponding planar structure, especially for CoN4 embedding in armchair CNT (4, 4) (CNT4). For MN4-CoN4 co-embedding CNTs, the TiN4-CoN4/CNTs have good OER synergistic effect with the lowest overpotential. Besides, the diameter of CNTs have a significant impact on the OER efficiency. The lowest reaction overpotential 0.47 V were obtained in TiN4-CoN4/CNT4 with a 5.69 angstrom tube diameter. Interestingly, compressive stress will further enhance the synergistic effect between two metal atoms in the OER reaction. The OER overpotential of CoN4-TiN4 embedding armchair CNT4 can reduce to 0.40 V under the -4 % uniaxial compression strain. These works were expected to better understand the synergistic mechanisms and design high-efficiency dual-atom OER electrocatalysts.
作者机构:
[Wu, Yi-jin; Wang, Si-ping; Liu, Wan-xin; Zhou, Xiao; Wu, YJ; Li, Yi; Tan, Liang] Hengyang Normal Univ, Coll Chem & Mat Sci, Hunan Engn Res Ctr Monitoring & Treatment Heavy Me, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421001, Peoples R China.;[Zhou, Yao; Zhou, Y] Xiamen Univ, Coll Energy, Xiamen 361005, Peoples R China.;[Tu, Teng-xiu] Chinese Acad Sci, Inst Solid State Phys, Hefei Inst Phys Sci, Hefei 230031, Peoples R China.;[Zhang, Peng-fang] Liaocheng Univ, Sch Chem & Chem Engn, Shandong Prov Key Lab Chem Energy Storage & Novel, Liaocheng 252000, Peoples R China.
通讯机构:
[Wu, YJ ] H;[Zhou, Y ] X;Hengyang Normal Univ, Coll Chem & Mat Sci, Hunan Engn Res Ctr Monitoring & Treatment Heavy Me, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421001, Peoples R China.;Xiamen Univ, Coll Energy, Xiamen 361005, Peoples R China.
摘要:
Different from the conventional Zinc-Air batteries which only involves oxygen reduction and evolution (ORR/ OER) in the cathode, the cathode of rechargeable zinc-air/iodide hybrid batteries (ZAIHBs), with the addition of I- species, involves I- electrooxidation (IOR) during charging and oxygen/iodate reduction (ORR and IDR) during discharging. This work reports the synthesis of a hierarchically porous tungsten-based nitrogen-doped carbon framework (W/N/C) with abundant WNx active sites and numerous ultrafine WN nanoclusters and explores their application as a trifunctional IOR/ORR/IDR electrocatalyst for ZAIHBs. The formation mechanism of ZIF-8-derived W/N/C framework as well as its structural and compositional features were investigated. The catalyst demonstrates high trifunctional catalytic activity and robust durability towards IOR/ORR/IDR in alkaline condition, owing to the uniform copresence of the numerous sub-nanometer-sized WN nanoclusters and the abundant single atom WNx sites in the hierarchically structured carbon framework. When applied in homemade ZAIHBs, it revealed a high peak energy density (141.9 mW cm-2) and remarkable cycling stability (65 h), outperforming the commercial Pt/C catalysts. This work demonstrates the multi-functional electrocatalytic activity of tungsten-based non-noble metal electrocatalyst for high-performance ZAIHBs.
期刊:
Results in Mathematics,2024年79(2) ISSN:1422-6383
通讯作者:
Chen, SL
作者机构:
[Chen, Shaolin; Chen, SL] Hengyang Normal Univ, Coll Math & Stat, Hengyang 421002, Hunan, Peoples R China.;[Chen, Shaolin; Chen, SL] Hunan Prov Key Lab Intelligent Informat Proc & App, Hengyang 421002, Peoples R China.;[Hamada, Hidetaka] Kyushu Sangyo Univ, Fac Sci & Engn, 3-1 Matsukadai 2 Chome,Higashi Ku, Fukuoka 8138503, Japan.
通讯机构:
[Chen, SL ] H;Hengyang Normal Univ, Coll Math & Stat, Hengyang 421002, Hunan, Peoples R China.;Hunan Prov Key Lab Intelligent Informat Proc & App, Hengyang 421002, Peoples R China.
关键词:
Bloch type space;complex-valued harmonic function;composition operator;hardy space;pluriharmonic functions
摘要:
The main purpose of this paper is to investigate characterizations of composition operators on Bloch and Hardy type spaces. Initially, we use general doubling weights to study the composition operators from harmonic Bloch type spaces on the unit disc D\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb {D}}$$\end{document} to pluriharmonic Hardy spaces on the Euclidean unit ball Bn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb {B}}<^>n$$\end{document}. Furthermore, we develop some new methods to study the composition operators from harmonic Bloch type spaces on D\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb {D}}$$\end{document} to pluriharmonic Bloch type spaces on D\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb {D}}$$\end{document}. Additionally, some application to new characterizations of the composition operators between pluriharmonic Lipschitz type spaces to be bounded or compact will be presented. The obtained results of this paper provide the improvements and extensions of the corresponding known results.
摘要:
Hair editing is challenging due to the complexity and variety of hair materials and shapes. Existing methods employ reference images or user-painted masks to edit hair and have achieved promising results. However, discrepancies in color and shape between the source and target hair can occasionally result in unrealistic results. Therefore, we propose a new hair editing method named HairManip, which decouples the hair information from the input source image into shape and color components. We then train hairstyle and hair color editing sub-networks to handle this complex information independently. To further enhance editing efficiency and accuracy, we introduce a latent code preprocessing module that effectively extracts meaningful features from hair regions, thereby improving the model’s editing capabilities. The experimental results demonstrate that our method achieves significant results in editing accuracy and authenticity, thanks to the carefully designed network structure and loss functions. Code can be found at https://github.com/Zlin0530/HairManip .
通讯机构:
[Zhao, HH ] H;Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang 421002, Hunan, Peoples R China.
关键词:
Talking face generation;Lip sync;Face motion;Virtual reality;Multimodality
摘要:
In this paper, we present TellMeTalk, an innovative approach for generating expressive talking face videos based on multimodal inputs. Our approach demonstrates robustness across various identities, languages, expressions, and head movements. It overcomes four key limitations of existing talking face video generation methods: (1) reliance on single -modal learning from audio or text, lacking the complementary nature of multimodal inputs; (2) deployment of traditional convolutional neural network generation, leading to restricted capture of spatial features; (3) the absence of natural head movements and expressions; and (4) limitations of artifacts, prominent boundaries caused by image overlapping, and unclear mouth regions. To address these challenges, we propose a face motion network to imbue character images with facial expressions and head movements. We also take text and reference audio as input to generate personalized audio. Furthermore, we introduce a generator equipped with a crossattention module and Fast Fourier Convolutional blocks to model spatial dependencies. Finally, a face restoration module is designed to reduce artifacts and prominent boundaries. Extensive experiments demonstrate our method produces high -quality expressive talking face videos. Compared to state-of-the-art approaches, our method exhibits superior performance in terms of video quality and precise synchronization of lip movements. The source code is available at https://github.com/lifemo/TellMeTalk.
通讯机构:
[Chen, Z ] H;Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang 421002, Peoples R China.;Hunan Prov Key Lab Intelligent Informat Proc & App, Hengyang 421002, Peoples R China.
关键词:
color image encryption;hyperchaotic system;region of interest;security analysis
摘要:
The significance of safeguarding the security of image information has escalated significantly, owing to the exponential proliferation of digital images containing sensitive information being disseminated on the Internet. In this paper, we first propose a novel 4D hyperchaotic system and design a new image encryption algorithm in conjunction with the hyperchaotic system. The algorithm uses a split random swap permutation method to permute the image and combines the S-box to diffuse the image. To improve the diffusivity of this encryption algorithm, a cross-random diffusion method is designed to diffuse the image again. Then, we propose a region of interest (ROI) encryption scheme for images. This scheme can automatically identify irregular privacy targets in images and encrypt them. To ensure the security of the region of interest location information during transmission, the scheme compresses the location information of the privacy target using a run-length encoding technique and then embeds the compressed data into the ciphertext image using reversible steganography based on histogram shift. The experimental results and security analysis unequivocally demonstrate that the image encryption algorithm proposed in this paper exhibits robust resistance against a wide array of attacks, thereby ensuring a high level of security. Additionally, the devised image ROI encryption scheme effectively safeguards diverse privacy targets.