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.
期刊:
Journal of Mathematical Analysis and Applications,2024年534(2):128071 ISSN:0022-247X
通讯作者:
Ponnusamy, S
作者机构:
[Liu, Gang] Hengyang Normal Univ, Coll Math & Stat, Hunan Prov Key Lab Intelligent Informat Proc & App, Hengyang 421002, Hunan, Peoples R China.;[Ponnusamy, S; Ponnusamy, Saminathan] Indian Inst Technol Madras, Dept Math, Chennai 600036, India.;[Ponnusamy, S; Ponnusamy, Saminathan] Lomonosov Moscow State Univ, Moscow Ctr Fundamental & Appl Math, Moscow, Russia.
通讯机构:
[Ponnusamy, S ] I;Indian Inst Technol Madras, Dept Math, Chennai 600036, India.;Lomonosov Moscow State Univ, Moscow Ctr Fundamental & Appl Math, Moscow, Russia.
关键词:
schroder's method;cycle;attracting basin;parabolic basin;siegel disk
摘要:
Let ��,� and ��,� be the functions defined in Schroder's method of the first and second kind for an entire function f with given order n (�>= 2), respectively. Based on unrefined algebra characterizations of ��,� and ��,�, we obtain some sufficient conditions on f such that both ��,� and ��,� possess given finite pairs of extraneous non-repelling cycles. Here, these conditions are a pair of equations, which have infinitely many polynomials or transcendental entire functions as its solutions. For obtaining some solutions f of such equations, we provide a step-by-step method. We start from any solution g in corresponding equations so that the function ��,2 possesses the above finite pairs of extraneous cycles but all are super-attracting, and then f can be obtained by a series of formulas concerning the function g, points and multipliers of those cycles. Note that ��,2=��,2 is identical with Newton's method for f. In a sense, this fact reveals that some extraneous super-attracting cycles of Newton's method imply certain extraneous non-repelling cycles of any method from the two families of methods. More generally, for any given orders n and m, some extraneous non-repelling cycles of ��,� or ��,� imply that of ��,� or ��,� for some entire functions f and F. These give a partial answer for the problem of finding possible link between the two families of methods, which was posed by Steven Smale in 1994.
摘要:
Medical image encryption is essential to protect the privacy and confidentiality of patients' medical records. Deep learning-based encryption, which leverages the nonlinear characteristics of neural networks, has emerged as a promising new method for protecting medical images. In this paper, we present insights into deep learning-based medical image encryption and propose a novel end-to-end medical image encryption scheme based on these insights that leverages feature encoding and decoding for encrypting and decrypting images. Firstly, we explore a method that combines keys generated by the Logistic Map with encoded plaintext image features to improve network diffusion performance. Secondly, we employ a reversible neural network to enhance plaintext image reconstruction while maintaining encryption effectiveness. Finally, we propose a series of novel loss functions to measure the cost with the ideal cryptographic algorithm and continuously optimize our network. Experimental results demonstrate that our scheme improves the performance of image encryption and decryption and resists brute force attacks, statistical attacks, noise and cropping attacks.
通讯机构:
[Tan, YL ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421008, Hunan, Peoples R China.
关键词:
Vertexing algorithms;Analysis and statistical methods;Computing (architecture, farms, GRID for recording, storage, archiving, and distribution of data);Data processing methods
摘要:
Radon and its decay products emit internal radiation in the respiratory system upon inhalation, which is a significant contributor to the development of lung cancer in humans. Accurate measurement of radon concentration is undoubtedly very important. Among the commonly used radon measurement methods, the electrostatic collection method stands out. This method involves counting the energy spectrum peaks of alpha particles, generated by the decay of radon daughters Po-218 and Po-214, which are collected on the surface of a semiconductor detector to determine radon concentration. According to experimental findings, measurements at different ambient temperatures cause Po-218 and Po-214 to peak drift. This drift adversely affects the accuracy of radon measurement using traditional methods. This study focuses on the characteristics of alpha-energy spectra from Po-218 and Po-214. It calculates the peak heights for all alpha-energy spectra and identifies the two peaks with the highest heights. Subsequently, an algorithm is developed to automatically track the peak positions of Po-218 and Po-214, accurately locating their counting intervals. The results demonstrate that the algorithm successfully achieves the desired outcomes through experiments conducted at different temperatures and measurement durations, thus validating its effectiveness. This method holds significant practical value in ensuring the accuracy of radon measurement.
摘要:
Perovskites have great potential for optoelectronic applications due to their high photoluminescence quantum yield, large absorption coefficient, great defect tolerance, and adjustable band gap. Perovskite heterostructures may further enhance the performance of optoelectronic devices. So far, however, most of perovskite heterostructures are fabricated by mechanical stacking or spin coating, which could introduce a large number of defects or impurities at the heterointerface owing to the random stacking process. Herein, we report the epitaxial growth of CsPbBr<INF>3</INF> pyramids/CdS nanobelt heterostructures via a 2-step vapor deposition route. The CsPbBr<INF>3</INF> triangular pyramids are well aligned on the surface of CdS nanobelts with the epitaxial relationships of (0-22)<INF>CsPbBr<INF>3</INF></INF>||(1-20)<INF>CdS</INF> and (-211)<INF>CsPbBr<INF>3</INF></INF>||(002)<INF>CdS</INF>. Time-resolved photoluminescence results reveal that effective charge transfer occurred at the heterointerface, which can be attributed to the type-II band arrangement. Theoretical simulations reveal that the unique CsPbBr<INF>3</INF> pyramids/CdS nanobelt structure facilitates diminishing the reflection losses and enhancing the light absorption. The photodetector based on these CsPbBr<INF>3</INF> pyramids/CdS nanobelt heterostructures exhibited an ultrahigh photoswitching ratio of 2.14 x 10<SUP>5</SUP>, a high responsivity up to 4.07 x 10<SUP>4</SUP> A/W, a high detectivity reaching 1.36 x 10<SUP>13</SUP> Jones, fast photoresponses (tau<INF>rise</INF> = 472 mu s and tau<INF>decay</INF> = 894 mu s), low dark current, and suppressed hysteresis.
摘要:
Exploring new electrode structures and co-doped composite biomass material electrodes is considered to be an effective way of developing cheap, efficient carbon-based supercapacitors. A bamboo-based sandwich-structured matrix was prepared from thin bamboo veneer and bamboo fiber by pretreatment with H(3)PO(4) and Co(2+)-catalyzed graphitization. The pore structure was modulated by hydrothermal activation with NaOH and electrodeposition of carbon nanotubes (CNTs) to obtain CNTs modified, Co/P co-doped sandwich-structured woodceramics electrode (CNT@Co/P). It not only has an obvious sandwich structure, but also retains the natural structural characteristics of bamboo. The specific capacitance of the resulting electrode (CNT@Co/P-20) is as high as 453.72F/g using 1wt% of carboxylated multi-walled carbon nanotubes (CMWCNT) solution as the deposition electrolyte at a current density of 0.2 A/g for 20min at room temperature. When the power density is 500W/kg, the energy density reaches 21.3Wh /kg, showing a good electrochemical performance.
作者机构:
Authors to whom correspondence should be addressed.;School of Geographical Sciences, East China Normal University, Shanghai 200241, China;[Jialu Zhou; Wenlong Zhou] College of Geography and Tourism, Hengyang Normal University, Hengyang 421002, China;Cooperative Innovation Center for Digitalization of Cultural Heritage in Traditional Villages and Towns, Hengyang 421002, China;National-Local Joint Engineering Laboratory on Digital Preservation and Innovative Technologies for the Culture of Traditional Villages and Towns, Hengyang 421002, China
通讯机构:
[Yunyuan Deng; Xiangxiang Fu] A;Authors to whom correspondence should be addressed.<&wdkj&>School of Geographical Sciences, East China Normal University, Shanghai 200241, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>College of Geography and Tourism, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Cooperative Innovation Center for Digitalization of Cultural Heritage in Traditional Villages and Towns, Hengyang 421002, China<&wdkj&>National-Local Joint Engineering Laboratory on Digital Preservation and Innovative Technologies for the Culture of Traditional Villages and Towns, Hengyang 421002, China
关键词:
traditional village;roof feature line;slope segmentation;cloth simulation filter;UAV
摘要:
Traditional Chinese buildings serve as a carrier for the inheritance of traditional culture and national characteristics. In the context of rural revitalization, achieving the 3D reconstruction of traditional village buildings is a crucial technical approach to promoting rural planning, improving living environments, and establishing digital villages. However, traditional algorithms primarily target urban buildings, exhibiting limited adaptability and less ideal feature extraction performance for traditional residential buildings. As a result, guaranteeing the accuracy and reliability of 3D models for different types of traditional buildings remains challenging. In this paper, taking Jingping Village in Western Hunan as an example, we propose a method that combines multiple algorithms based on the slope segmentation of the roof to extract feature lines. Firstly, the VDVI and CSF algorithms are used to extract the building and roof point clouds based on the MVS point cloud. Secondly, according to roof features, village buildings are classified, and a 3D roof point cloud is projected into 2D regular grid data. Finally, the roof slope is segmented via slope direction, and internal and external feature lines are obtained after refinement through Canny edge detection and Hough straight line detection. The results indicate that the CSF algorithm can effectively extract the roofs of I-shaped, L-shaped, and U-shaped traditional buildings. The accuracy of roof surface segmentation based on slope exceeds 99.6%, which is significantly better than the RANSAC algorithm and the region segmentation algorithm. This method is capable of efficiently extracting the characteristic lines of roofs in low-rise buildings within traditional villages. It provides a reference method for achieving the high-precision modeling of traditional village architecture at a low cost and with high efficiency.
期刊:
Complex Variables and Elliptic Equations,2024年:08 ISSN:1747-6933
通讯作者:
Li, LL
作者机构:
[Li, Liulan; Li, LL] Hengyang Normal Univ, Coll Math & Stat, Hengyang, Hunan, Peoples R China.;[Qian, Tao] Macau Univ Sci & Technol, Macao Ctr Math Sci, Macau, Peoples R China.;[Wang, Shilin] Unitedhlth Grp, Med Informat Dept, Cypress, CA USA.
通讯机构:
[Li, LL ] H;Hengyang Normal Univ, Coll Math & Stat, Hengyang, Hunan, Peoples R China.
摘要:
In this paper, we introduce a new member to the universal families, called universal quotient Blaschke product, which is a formal quotient of two formal infinite Blaschke products. A formal infinite Blaschke product is of the form B(z)=Pi(infinity)(k=1) z-z(k)/1-(z) over bar (k)z' where {zk}(k=1)(infinity) is a sequence of points in the unit disk but may not satisfy the Blaschke condition: Sigma(infinity)(k=1)(1 - vertical bar z(k vertical bar)) < infinity. A partial quotient of a universal quotient Blaschke product is the quotient of two finite Blaschke products. We show that the set of partial quotients of a universal quotient Blaschke product is dense in the set of continuous self-mappings on the unit circle in the complex plane. Meanwhile, subsequences of the partial quotients of a universal quotient Blaschke product can be used to approximate any holomorphic functions bounded by one on the unit disk. Moreover, we prove that the set of universal quotient Blaschke products is huge in the sense of Baire category.
期刊:
Chemical Engineering Science,2024年285:119575 ISSN:0009-2509
通讯作者:
Liu, J
作者机构:
[Liu, Jian; Liu, Yuanyuan; Ni, Wenjin; Yi, Zhengji] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Liu, Jian; Yi, Zhengji] Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.;[Liu, Jian; Yi, Zhengji] Hunan Engn Res Ctr Monitoring & Treatment Heavy Me, Hengyang 421008, Peoples R China.;[Ni, Wenjin] Xiangtan Univ, Sch Chem Engn, Xiangtan 411105, Peoples R China.
通讯机构:
[Liu, J ] H;Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.
关键词:
Dandelion-like;Nickel foam;PMS;Fixed bed
摘要:
A novel dandelion-like catalyst, nickel foam supported NiCo2O4 (NiCo2O4/NF), was successfully synthesized and applied to the activation of peroxymonosulfate (PMS) in a fixed bed system for the degradation of Orange II (OII). The physicochemical properties of synthesis catalysts were identified by various characterization methods (SEM, EDS, XRD and XPS), revealing that the dandelion-like NiCo2O4 nanosheets were evenly distributed on the surface of NF. NiCo2O4/NF-250 showed excellent catalytic performance at a hydrothermal reaction time of 8 h, urea/ metal ratio of 10:1, and Co/Ni concentration of 10 mM/5 mM. When PMS concentration was 5 mM, reaction temperature was 50 celcius, pH was 7.5, space velocity was 0.236 min-1, the conversion ratios of OII, PMS and COD were 99.8 %, 71.3 %, and 71.4 % at 240 min, respectively. In particular, NiCo2O4/NF still could reach 99.9 % OII conversion and 64.4 % COD conversion in the third cycle. DFT calculations implied that NiCo2O4/NF had excellent PMS activation performance.
摘要:
A two-step hydrothermal process was used to successfully create Ti3+, N, and B co-doped TiO2 modified with nitrogen doped graphene quantum dots (Ti3+/N/B-TiO2@NGQDs (TNBTN)) composite photocatalyst for photodegradation of bisphenol A (BPA) and methyl orange (MO) under visible-light illumination. The prepared TNBTN composite demonstrated significantly enhanced visible light catalytic performance. Especially, the apparent rate constant of BPA degradation with TNBTN was approximately 56.9 times that of pure TiO2, which was attributed to broader visible light absorbance and faster transmission and separation of photoinduced charge. In addition, the mechanism of BPA and MO degradation with TNBTN was distinct.
摘要:
In recent years, there has been a growing interest in antimicrobial peptides as innovative antimicrobial agents for combating drug-resistant bacterial infections, particularly in the fields of biofilm control and eradication. In the present study, a novel cationic antimicrobial peptide, named LC-AMP-F1, was derived from the cDNA library of the Lycosa coelestis venom gland. The sequence, physicochemical properties and secondary structure of LC-AMP-F1 were predicted and studied. LC-AMP-F1 was tested for stability, cytotoxicity, drug resistance, antibacterial activity, and antibiofilm activity in vitro compared with melittin, a well-studied antimicrobial peptide. The findings indicated that LC-AMP-F1 exhibited inhibitory effects on the growth of various bacteria, including five strains of multidrug-resistant bacteria commonly found in clinical settings. Additionally, LC-AMP-F1 demonstrated effective inhibition of biofilm formation and disruption of mature biofilms. Furthermore, LC-AMP-F1 exhibited favorable stability, minimal hemolytic activity, and low toxicity towards different types of eukaryotic cells. Also, it was found that the combination of LC-AMP-F1 with conventional antibiotics exhibited either synergistic or additive therapeutic benefits. Concerning the antibacterial mechanism, scanning electron microscopy and SYTOX Green staining results showed that LC-AMP-F1 increased cell membrane permeability and swiftly disrupted bacterial cell membranes to exert its antibacterial effects. In summary, the findings and studies facilitated the development and clinical application of novel antimicrobial agents.
作者机构:
[Chenguang Li; Chenbiao Lai] College of Chemistry and Material Science, Hengyang Normal University, Hengyang, 421008, PR China;[Yaoyan Wu; Hanxiang Ouyang] College of Nanyue, Hengyang Normal University, Hengyang, 421008, PR China;Hunan Province Key Laboratory of Functional Metal-Organic Compounds (Hengyang Normal University), Hengyang, 421008, PR China;Key Laboratory of Organometallic New Materials (Hengyang Normal University), College of Hunan Province, Hengyang, 421008, PR China;Hunan Engineering Research Center for Monitoring and Treatment of Heavy Metals Pollution in the Upper Reaches of Xiangjiang River (Hengyang Normal University), Hengyang, 421008, PR China
通讯机构:
[Junbin Sun; Weihong Lu] C;College of Chemistry and Material Science, Hengyang Normal University, Hengyang, 421008, PR China<&wdkj&>Hunan Province Key Laboratory of Functional Metal-Organic Compounds (Hengyang Normal University), Hengyang, 421008, PR China<&wdkj&>Key Laboratory of Organometallic New Materials (Hengyang Normal University), College of Hunan Province, Hengyang, 421008, PR China<&wdkj&>Hunan Engineering Research Center for Monitoring and Treatment of Heavy Metals Pollution in the Upper Reaches of Xiangjiang River (Hengyang Normal University), Hengyang, 421008, PR China
摘要:
Alumina based rare earth oxides ceramic materials, with the good performance against the CMAS corrosion, were widely used as the thermal/environmental barrier coatings. In this work, three Y2O3–Al2O3 binary ceramic bulks, which were the Y3Al5O12, YAlO3 and Y4Al2O9, were prepared by high temperature solid state reaction using the Y2O3 and Al2O3 as the raw materials. The resistances to CMAS corrosion of these materials at 1250 °C and 1350 °C were compared fully. The compositions and structures of the samples before and after corrosion were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that the different chemical compositions of the materials resulted in the different optical basicity (OB) values which can decide the reactivity of the material with the CMAS melts. The Y3Al5O12 ceramic material was inert to the CMAS for its low OB value of 0.75 and damaged seriously by the CMAS through physical penetration. The YAlO3 and Y4Al2O9 with the high OB values of 0.80 and 0.87 reacted with the CMAS to form the Ca4Y6(SiO4)6O. The YAlO3 ceramic bulk exhibited the good performance against the CMAS corrosion benefitting from the formation of the Ca4Y6(SiO4)6O and the CaAl2Si2O8.
期刊:
Chemical Engineering Journal,2024年483 ISSN:1385-8947
通讯作者:
Xia, Xiaohong;Li, R;Xia, XH
作者机构:
[Gao, Yingxv; Chen, Yuxi; Li, R; Hui, Qunbo; Xia, Xiaohong; Li, Run; Xia, XH; Liu, Hongbo; Liu, Qi] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.;[Xia, Xiaohong; Xia, XH] Hunan Univ, Hunan Joint Int Lab Adv Mat & Technol Clean Energy, Changsha 410082, Hunan, Peoples R China.;[Wang, Deping] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构:
[Li, R ; Xia, XH; Xia, XH ] H;Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.;Hunan Univ, Hunan Joint Int Lab Adv Mat & Technol Clean Energy, Changsha 410082, Hunan, Peoples R China.
关键词:
Conjugated microporous polymers;Nitrogen and sulfur coordination;Anode materials;Potassium-ion batteries
摘要:
Conjugated microporous polymers (CMPs) with enhanced electrical conductivity and insolubility against liquid electrolytes are receiving increasing attention as promising organic anode materials for rechargeable batteries. However, the poor electronic conductivity and restricted-access active sites limit the specific capacity and cycling stability of CMPs and the potassium-storage mechanism in hetero-incorporated CMPs not well understood. Herein, a highly conjugated polymer network with hierarchically interconnected porous structure was deliberately constructed by selecting 4,7-dibromo-2,1,3-benzothiadiazole (BT) and 1,3,5-triacetylene benzene as the acceptor and donor, respectively. The good planarity and high pi-electron delocalization of BT units lead to an enhanced conductivity of BT-CMP. Ex-XPS analysis and DFT calculations reveal that the synergistic coupling of S and N enables a prompt complexation and release of K+ ions and improves the coordination activity of the C--N active sites. More importantly, the hierarchically interconnected porous networks make active sites facilely accessible and accommodate the volumetric expansion effectively, enabling highly stable storage of K-ions. Therefore, the as-prepared BT-CMP anode displays a high specific capacity (462 mAh/g- 1 at 30 mA g-1 after 100 cycles) and ultra-long stability (226.2 mAh g-1 at 1000 mA g-1 after 2000 cycles without significant attenuation) in potassium-ion storage.
摘要:
Lactarius hatsudake (LH), a great wild endemic fungus, contains rich nutritional components with medicinal properties. The effects of LH on body weight, liver weight, liver injury, blood lipids, and gut microbiota in C57BL/6 mice fed a high-fat diet (HFD) for 8 weeks was examined in this research. Though there was no clear impact on weight loss, the findings indicate that LH treatment effectively decreased liver damage caused by HFD, as well as lowered serum total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels. Additionally, it positively influenced gut microbiota to resemble that of mice on a normal diet. In HFD-fed mice, LH markedly boosted the levels of Parabacteroides, unclassified Muribaculaceae, Oscillibacter, and unclassified Oscillospiraceae, while reducing the abundance of Lachnospiraceae NK4A136 group and Erysipelatoclostridium, as well as the ratio of Firmicutes to Bacteroidetes. Further analysis of correlation indicate a possible connection between obesity and gut microbiota. Obesity-related indices show a positive association with unclassified Eubacterium coprostanoligenes group, Blautia, and Erysipelatoclostridium, while displaying a negative correlation with unclassified Muribaculaceae, unclassified Clostridia vadinBB60 group, Helicobacter, Oscillibacter, unclassified Ruminococcaceae, Parabacteroides, and unclassified Oscillospiraceae. The results suggest that LH can help combat obesity and may have the potential to be utilized as a functional food.
摘要:
Camouflaged instance segmentation (CIS) focuses on handling instances that attempt to blend into the background. However, existing CIS methods emphasize global interactions but overlook hidden clues at various scales, resulting in inaccurate recognition of camouflaged instances. To address this, we propose a multi-scale pooling network (MSPNet) to mine the hidden cues offered by the camouflaged instances at various scales. The network achieves an enhanced fusion of multi-scale information mainly through multilayer pooling. Specifically, the pyramid pooling transformer (P2T) is utilized as a robust backbone for extracting multi-scale features. Then, we introduce an end-to-end pooling learning transformer (PLT) to obtain instance-aware parameters and high-quality mask features. To further augment the fusion of various mask features, we design a novel multi-scale complementary feature pooling (MCFP) module. Additionally, we also suggest an instance normalization module with fused spatial attention (FSA-IN) to combine instance-aware parameters and mask features, resulting in the final camouflaged instances. Experimental results show the effectiveness of MSPNet, surpassing existing CIS models on the COD10K-Test and NC4K datasets, with respective average precision (AP) scores of 49.6% and 53.4%. This demonstrates the effectiveness of the proposed approach in detecting camouflaged instances. Our code will be published at
https://github.com/another-u/MSPNet-main
.