关键词：
Deformation;Windows;Object detection;Education and training;Image processing;Feature extraction;Cameras;Distortion;Head;Data modeling
摘要：
Retail product detection in fisheye camera capture scenes frequently suffers from excessive object occlusion and deformation, as well as difficulty in distinguishing products with small fine-grained differences, so accurately classifying and localizing products in these images presents a challenge for computer vision. We propose an efficient product detection network called EPformer by fusing a visual transformer and convolutional neural network to reliably detect retail products in fisheye images. We employ a shifted window strategy for feature information interaction across windows to more precisely detect products due to the issue of dense occlusion of products. To address the issue of excessive product deformation brought on by fisheye cameras, we develop a deformation image processing module without explicit correction and embed it into the path aggregation network structure. This enables the model to efficiently capture product geometric changes and conduct feature fusion. To address the issue of differentiating fine-grained products, we design an effective coordinate squeeze-excitation (ECSE) attention module that can capture the fine-grained texture and boundary information differences between individuals in terms of spatial and channel relationships. The inability to differentiate fine-grained products can be solved by training the ECSE module in tandem with the decoupled head. The experimental results demonstrate that EPformer is a potent product detection model with a 4.9% higher mean average precision than the state-of-the-art method (YOLOX) on the fisheye product image dataset. In addition, the EPformer model can effectively detect products in fisheye images on the Jeston Xavier NX embedded device to meet the application requirements in realistic scenarios.
作者机构：
[Sun, Junbin; Lu, Weihong; Li, Chenguang; Xu, Zhifeng; Sun, JB; Li, Lizhen] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Sun, Junbin; Lu, Weihong; Xu, Zhifeng; Sun, JB] Hengyang Normal Univ, Hunan Prov Key Lab Funct Met Organ Cpds, Hengyang 421008, Peoples R China.;[Sun, Junbin; Lu, Weihong; Xu, Zhifeng] Hengyang Normal Univ, Coll Hunan Prov, Key Lab Organometall New Mat, Hengyang 421008, Peoples R China.;[Sun, Junbin; Lu, Weihong; Xu, Zhifeng] Hengyang Normal Univ, Hunan Engn Res Ctr Monitoring & Treatment Heavy Me, Hengyang 421008, Peoples R China.
通讯机构：
[Xu, ZF ; Sun, JB] H;Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;Hengyang Normal Univ, Hunan Prov Key Lab Funct Met Organ Cpds, Hengyang 421008, Peoples R China.
摘要：
Calcium-magnesium-alumina-silicate (CMAS) attack is a major challenge for thermal barrier coatings (TBCs) during the application. In this work, four rare earth phosphates materials including (La0.2Nd0.2Sm0.2Eu0.2Gd0.2) PO4, (La0.5Nd0.5)PO4, (La0.5Gd0.5)PO4 and (Nd0.5Gd0.5)PO4 were synthesized by chemical co-precipitation. The resistance behaviors to CMAS of the materials were investigated at 1250 degrees C and 1350 degrees C for 5 h, 10 h and 20 h, respectively. Results show that the main corrosion products are the apatite compounds (Ca2+xRe8-x(PO4)x(SiO4)6-xO2) and the Ca3(PO4)2. Increasing the corrosion temperature from 1250 degrees C to 1350 degrees C will promote the penetration of the melted CMAS. It would not lead to the more serious corrosion by prolonging the corrosion time at 1250 degrees C and 1350 degrees C. The P-Ca layer composed by the Ca3(PO4)2, which relates to the rare earth elements compositions, prevent the CMAS corrosion to the materials effectively. Preparing multi-components rare earth phosphates and optimizing their element compositions will be a new way to improve the resistance to the CMAS for these materials.
期刊：
Chemical Engineering Science,2023年280:119026 ISSN：0009-2509
通讯作者：
Yang, CM;Liu, Jinlong;Qian, D
作者机构：
[Ren, Jun; Yang, Chunming; Liang, Yun; Wang, Qing; Xiang, Qian] Hunan Normal Univ, Natl & Local Joint Engn Lab New Petro Chem Mat & F, Changsha 410081, Peoples R China.;[Ren, Jun; Yang, Chunming; Liang, Yun; Wang, Qing; Xiang, Qian] Hunan Normal Univ, Coll Chem & Chem Engn, Key Lab Chem Biol & Tradit Chinese Med Res, Minist Educ China, Changsha 410081, Peoples R China.;[Liu, Jinlong; Ren, Jun; Qian, Dong; Liu, JL] Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;[Li, Junhua] Hengyang Normal Univ, Coll Chem & Mat Sci, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.
通讯机构：
[Qian, D ; Liu, JL] C;[Yang, CM ] H;Hunan Normal Univ, Natl & Local Joint Engn Lab New Petro Chem Mat & F, Changsha 410081, Peoples R China.;Hunan Normal Univ, Coll Chem & Chem Engn, Key Lab Chem Biol & Tradit Chinese Med Res, Minist Educ China, Changsha 410081, Peoples R China.;Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.
关键词：
Cu;Cu 2 O;NiO@NiCu foam;O-vacancy;Heterostructure;Electrocatalyst;Hydrogen evolution;Density functional theory calculations
摘要：
Defect-engineering and heterojunction-creating on a catalyst have been endorsed as effective approaches to enhance the hydrogen evolution reaction (HER) behavior. By skillfully employing the transformation of Cu2S/ Ni3S2 to NiO/Cu2O and the electroreduction of partial Cu2O to Cu/Cu2O for the O-vacancy (Ov) production and in-situ reactions for the heterostructure construction, we fabricated a self-supported heterostructured hybrid with Ov-rich Cu/Cu2O coupled with few NiO grown in-situ on the NiCu bimetallic foam (named as Cu/NiO/ Cu2O@NCF). Cu/NiO/Cu2O@NCF records a low overpotential of 79 mV at 10 mA cm-2 with a small Tafel slope of 60 mV dec � 1 and sustained the activity without distinct decay for 100 h towards catalyzing HER in 1.0 M KOH. More profoundly, density functional theory computations reveal that Ov-Cu2O holds a much lower energy barrier for the rate-determining step of the H2O dissociation and a more electron density with respect to Ov-NiO, thereby accelerating the alkaline HER kinetics.
摘要：
We present a method for implementing quantum temperature sensing for extremely low temperatures in a quasi-1D dipolar Bose-Einstein condensate reservoir with a magnetic field-driven impurity atom acting as a quantum sensor. By analyzing the quantum signal-to-noise ratio (QSNR) as a metric for temperature sensing performance, we demonstrate that the presence of an attractive dipolar interaction in the reservoir, which includes the effects of non-Markovian dynamics on the sensor, significantly enhances estimation efficiency. We also investigate the steady-state estimation efficiency for long-encoding times through an analytical expression, which shows that the optimal QSNR depends on the driving magnetic field of the impurity atom. Our method can achieve high-efficiency temperature sensing for any low temperature by tuning the magnetic field. These findings suggest that our approach has potential applications in high-resolution quantum thermometry.
作者机构：
[Yuan, Ji-Bing; Zhang, Bo; Song, Ya-Ju; Yuan, JB; Tang, Shi-Qing; Wang, Xin-Wen] Hengyang Normal Univ, Key Lab Optoelect Control & Detect Technol Univ Hu, Hengyang 421002, Peoples R China.;[Yuan, Ji-Bing; Zhang, Bo; Song, Ya-Ju; Yuan, JB; Tang, Shi-Qing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Kuang, Le -Man; Kuang, LM] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contro, Minist Educ, Changsha 410081, Peoples R China.;[Kuang, Le -Man; Kuang, LM] Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China.;[Kuang, Le -Man; Kuang, LM] Zhengzhou Univ Light Ind, Synerget Innovat Acad Quantum Sci & Technol, Zhengzhou 450002, Peoples R China.
通讯机构：
[Kuang, LM ; Yuan, JB ] H;Hengyang Normal Univ, Key Lab Optoelect Control & Detect Technol Univ Hu, Hengyang 421002, Peoples R China.;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contro, Minist Educ, Changsha 410081, Peoples R China.;Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China.
摘要：
We propose a theoretical scheme for quantum sensing of temperature close to absolute zero in a quasi-one-dimensional Bose-Einstein condensate (BEC). In our scheme, a single-atom impurity qubit is used as a temperature sensor. We investigate the sensitivity of the single-atom sensor in estimating the temperature of the BEC. We demonstrate that the sensitivity of the temperature sensor can saturate the quantum Cramér-Rao bound by means of measuring quantum coherence of the probe qubit. We study the temperature sensing performance by using quantum signal-to-noise ratio (QSNR). It is indicated that there is an optimal encoding time at which the QSNR can reach its maximum in the full-temperature regime. In particular, we find that the QSNR reaches a finite upper bound in the weak coupling regime even when the temperature is close to absolute zero, which implies that the sensing-error-divergence problem is avoided in our scheme. Our work opens a way for quantum sensing of temperature close to absolute zero in the BEC.
作者机构：
[Xiao, Zhenxiu] Hengyang Normal Univ, Nanyue Coll, Hengyang 421008, Hunan, Peoples R China.;[Jiang, Wujiu; Fu, Weiwei] Hengyang Normal Univ, Key Lab Met Organ New Mat, Sch Chem & Mat Sci, Key Lab Funct Met Organ Cpds Hunan Prov,Coll Hunan, Hengyang 421008, Hunan, Peoples R China.;[Deng, Xin] Hengyang Normal Univ, Sch Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Wujiu Jiang; Weiwei Fu] S;School of Chemistry and Materials Science, Hengyang Normal University, Hengyang, Hunan 421008, China
摘要：
C22H28N2O2, monoclinic, P21/n (no. 14), a = 6.463(3) Å, b = 14.889(6) Å, c = 10.282(4) Å, β = 95.105(5)°, V = 985.5(7) Å3, Z = 2, Rgt(F) = 0.0425, wRref(F2) = 0.1206, T = 296 (2) K.
作者机构：
[He, Quanguo; Zhou, Chuanqin; Chen, Aiting; Tang, Nana; Shi, Shuting; Wei, Yanping; He, QG] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[Deng, Peihong; Deng, PH] Hengyang Normal Univ, Dept Chem & Mat Sci, Key Lab Organometall New Mat, Hunan Prov Key Lab Funct Met Organ Cpds, Hengyang 421008, Peoples R China.
通讯机构：
[Deng, PH ; He, QG ] H;Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;Hengyang Normal Univ, Dept Chem & Mat Sci, Key Lab Organometall New Mat, Hunan Prov Key Lab Funct Met Organ Cpds, Hengyang 421008, Peoples R China.
关键词：
Dopamine;Electrochemical sensor;Nanomolar level;Reduced graphene oxide;MnS/Co 3 S 4 hybrids
摘要：
An ultrasensitive and selective electrochemical sensor has been constructed for the quantitative assay of dopa-mine (DA) based on hollow tubular manganese-cobalt sulfide (MnS/Co3S4) hybrids embedded on electrochem-ically reduced graphene oxide (ErGO). The MnS/Co3S4 heterostructures were created by two-step ion exchange method, of which Co9S8 with hollow tubular structures was fabricated by solvothermal method using the self-made cobalt chloride carbonate hydroxide (CO(CO3)0.35Cl0.20(OH)1.10) as precursor and sodium disulfide mon-ohydrate as sulfur source and manganese chloride as manganese source. The MnS/Co3S4-ErGO/GCE could exhibit strong catalytic ability for the redox reaction of DA. Under the optimal conditions, the developed sensor exhibits a wide linear response for DA ranging from 6.0 nM to 20.0 & mu;M by second-order derivative linear sweep voltammetry (SDLSV), with a detection limit of 2.0 nM. In addition, the developed method exhibited high sensitivity and selectivity, good reproducibility and low-cost. It is a very promising analytical method for the determination of DA in pharmaceutical and biological samples.
作者机构：
[Zhou, Zhong-Peng; Deng, Xiao-Hui; Zhang, Qian-Kui; Tang, Zhen-Kun] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Zhou, Zhong-Peng; Tong, Chuan-Jia; Hao, Ning-Jing] Cent South Univ, Sch Phys & Elect, Hunan Key Lab Nanophoton & Devices, Hunan Key Lab Super Microstructure & Ultrafast Pro, Changsha 410083, Peoples R China.;[Zhang, Hui] Shenyang Univ, Normal Sch, Shenyang 110044, Peoples R China.
通讯机构：
[Zhen-Kun Tang] C;[Chuan-Jia Tong] H;Hunan Key Laboratory of Nanophotonics and Devices, Hunan Key Laboratory of Super-Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China<&wdkj&>College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China
作者机构：
[Zhu, Xiaoming; Deng, Zheyu; Li, Biao; Ou, Jiaqi; Li, Jiahong] Hengyang Normal Univ, Sch Chem & Mat Sci, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Xiaoming Zhu] S;School of Chemistry and Materials Science , Hengyang Normal University, Hengyang, Hunan 421008, China
摘要：
C22H16O5Pb, orthorhombic, P2(1)2(1)2(1) (no. 19), a = 7.3395(8) angstrom, b = 10.7768(11) angstrom, c = 23.034(3) angstrom, V = 1821.9(3) angstrom(3), Z = 4, R-gt(F) = 0.0327, wR(ref)(F-2) = 0.0735, T = 296(2) K.
作者机构：
[Long, Jiumei; Liu, Zui; Zhang, Guocheng; Zhou, Dongsheng; Wang, Jing; Luo, Yuanlai; Huang, Binyan] Hengyang Normal Univ, Coll Life Sci, Hunan Key Lab Conservat & Utilizat Biol Resources, Hengyang 421008, Peoples R China.;[Lei, Ming] Hunan Agr Univ, Coll Resource & Environm, Hunan Engn Res Ctr Safe & High Efficient Utilizat, Changsha 410128, Peoples R China.
通讯机构：
[Ming Lei] H;Hunan Engineering Research Center for Safe & High-Efficient Utilization of Heavy Metal Pollution Farmland, College of Resource & Environment, Hunan Agricultural University, Changsha, 410128, PR China
通讯机构：
[Tao LAN] U;[Shoubiao ZHANG] I;Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China<&wdkj&>University of Science and Technology of China, Hefei 230026, People's Republic of China
摘要：
Compact torus (CT) injection is a highly promising technique for the central fueling of future reactor-grade fusion devices since it features extremely high injection velocity and relatively high plasma mass. Recently, a CT injector for the EAST tokamak, EAST-CTI, was developed and platform-tested. In the first round of experiments conducted with low parameter settings, the maximum velocity and mass of the CT plasma were 150 km center dot s(-1) and 90 mu g, respectively. However, the parameters obtained by EAST-CTI were still very low and were far from the requirements of a device such as EAST that has a strong magnetic field. In future, we plan to solve the spark problem that EAST-CTI currently encounters (that mainly hinders the further development of experiments) through engineering methods, and use greater power to obtain a more stable and suitable CT plasma for EAST.
通讯机构：
[Tang, ZK ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.
摘要：
Two-dimensional Ruddlesden-Popper (2D RP) perovskites can form layered protective materials using long organic cations as "barrier" caps, which is expected to solve the problem of instability of perovskites in the working environment. In this work, we systematically studied the 2D Ruddlesden-Popper (C(6)H(5)CH(2)NH(3))(2)PbI(4) hybrid perovskites using density functional theory. The results reveal that the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskites are semiconductors with band gaps of 2.22 eV. The optical absorption peak of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure is located at 532 nm in the visible region. Interestingly, the optical absorption spectrum of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure enhanced under suitable strains. The highest optical absorption peak appears in 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) under a -2% strain, and its theoretical photoelectric conversion efficiency is 28.5%. More interestingly, the replacement of surface I atoms with Br is another ways to enhance the optical absorption spectrum of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure. The optical absorption peak blue-shifts to the high energy region, which has higher solar energy flux density than the low energy region. The good stability, tuneable band gap and excellent theoretical photoelectric conversion efficiency of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure make it a promising candidate for novel 2D hybrid perovskite based photoelectronic devices and solar cells.
作者机构：
[Shi, Xiulian] Zhaoqing Univ, Sch Math & Stat, Zhaoqing 526061, Peoples R China.;[Wang, Keyan] Hengyang Normal Univ, Sch Math & Stat, Hengyang 421008, Peoples R China.;[Sun, Hui] Xinyang Normal Univ, Sch Math & Stat, Xinyang 464000, Peoples R China.
通讯机构：
[Shi, XL ] Z;Zhaoqing Univ, Sch Math & Stat, Zhaoqing 526061, Peoples R China.
摘要：
In this paper, we propose and analyze a spectral collocation method for the numerical solutions of fractional multipantograph delay differential equations. The fractional derivatives are described in the Caputo sense. We present that some suitable variable transformations can convert the equations to a Volterra integral equation defined on the standard interval [-1, 1]. Then the Jacobi-Gauss points are used as collocation nodes, and the Jacobi-Gauss quadrature formula is used to approximate the integral equation. Later, the convergence analysis of the proposed method is investigated in the infinity norm and weighted L(2 )norm. To perform the numerical simulations, some test examples are investigated, and numerical results are presented. Further, we provide the comparative study of the proposed method with some existing numerical methods.
期刊：
Obesity Research & Clinical Practice,2023年17(1):16-24 ISSN：1871-403X
通讯作者：
Lu, Tom;He, Jinbo
作者机构：
[Cheng, Yawei; Lu, Tom] Texas Tech Univ, Dept Math & Stat, Lubbock, TX 79409 USA.;[Barnhart, Wesley R.] Bowling Green State Univ, Dept Psychol, Bowling Green, OH USA.;[Liang, Guangsheng] Texas Tech Univ, Dept Psychol Sci, Lubbock, TX 79409 USA.;[Chen, Gui] Hengyang Normal Univ, Coll Educ Sci, Hengyang, Hunan, Peoples R China.;[He, Jinbo] Chinese Univ Hong Kong, Sch Humanities & Social Sci, Shenzhen, Guangdong, Peoples R China.
通讯机构：
[Lu, Tom] D;[He, Jinbo] S;Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, United States of America. Electronic address: t.;School of Humanities and Social Science, The Chinese University of Hong Kong, Shenzhen, Guangdong, China. Electronic address:
摘要：
A longitudinal approach with Latent Growth Curve Modeling (LGCM) was adopted to explore the trajectories of appetitive traits corresponding to BMI in Chinese adolescents. Within a large sample of adolescents (N=2566, 45.9% boys) aged from 11 to 17 years (M = 13.80, SD = 1.56) at the baseline survey, our results indicated that appetitive traits of emotional overeating, food fussiness, and hunger increased significantly over time while enjoyment of food decreased over time. Slowness in eating and satiety responsiveness significantly increased in girls, while emotional undereating significantly decreased in boys. Moreover, the growth parameters of emotional undereating and satiety responsiveness were significantly and negatively related to BMI in girls. Our findings evidence that certain appetitive traits could change over time in adolescence and these changes relate to weight status. Gender differences are suggested in the design of future intervention and treatment of overweight/obesity in Chinese adolescents.
摘要：
Forest aboveground biomass (AGB) retrieval using synthetic aperture radar (SAR) backscatter has received extensive attention. The water cloud model (WCM), because of its simplicity and physical significance, has been one of the most commonly used models for estimating forest AGB using SAR backscatter. Nevertheless, forest AGB estimation using the WCM is usually based on simplified assumptions and empirical fitting, leading to results that tend to overestimate or underestimate. Moreover, the physical connection between the model and the polarimetric synthetic aperture radar (PolSAR) is not established, which leads to the limitation of the inversion scale. In this paper, based on the fully polarimetric SAR data from the Advanced Land Observing Satellite-2 (ALOS-2) Phased Array-type L-band Synthetic Aperture Radar (PALSAR-2), the relative contributions of the three major scattering mechanisms were first analyzed in a hilly area of southern China. On this basis, the traditional WCM was extended by considering the secondary scattering mechanism. Then, to establish the direct relationship between the vegetation scattering mechanism and forest AGB, a new relationship equation between the PolSAR decomposition model and the improved water cloud model (I-WCM) was constructed without the help of external data. Finally, a nonlinear iterative method was used to estimate the forest AGB. The results show that volume scattering is the dominant mechanism, accounting for more than 60%. Double-bounce scattering accounts for the smallest fraction, but still about 10%, which means that the contribution of the double-bounce scattering component is not negligible in forested areas because of the strong penetration capability of the long-wave SAR. The modified method provides a correlation coefficient R2 of 0.665 and a root mean square error (RMSE) of 21.902, which is an improvement of 36.42% compared to the traditional fitting method. Moreover, it enables the extraction of forest parameters at the pix scale using PolSAR data without the need for low-resolution external data and is thus helpful for high-resolution mapping of forest AGB.
通讯机构：
[Huihuang Zhao] C;College of Computer Science and Technology, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Hunan Provincial Key Laboratory of Intelligent Information Processing and Application, Hengyang 421002, China
关键词：
VStyclone;Voice clone;Efficient tone extractor;Style synthesizer;Transformer;Vocoder
作者机构：
[Liu, ZS; Liu, Z. -S] Hengyang Normal Univ, Coll Math & Stat, Hengyang 421002, Hunan, Peoples R China.
通讯机构：
[Liu, ZS ] H;Hengyang Normal Univ, Coll Math & Stat, Hengyang 421002, Hunan, Peoples R China.
关键词：
spectral measure;orthonormal basis;spectrum;Moran measure;Moran set
摘要：
Let
$$\{(R_k,D_k)\}_{k=1}^\infty$$
be a sequence of pairs, where
$$D_k=\{0,1,\ldots,q_k-1\}(1,1)^T$$
is an integer vector set and
$$R_k$$
is an integer diagonal matrix or upper triangular matrix, i.e.,
$$R_k={\begin{pmatrix} s_k & 0\\ 0 & t_k \end{pmatrix}}$$
or
$$R_k={\begin{pmatrix} u_k & 1\\ 0 & v_k \end{pmatrix}}$$
.
Associated with the sequence
$$\{(R_k,D_k)\}_{k=1}^\infty$$
, Moran measure
$$\mu_{\{R_k\},\{D_k\}}$$
is defined by
$$\mu_{\{R_k\},\{D_k\}}=\delta_{R_{1}^{-1}D_{1}}\ast\delta_{R_{1}^{-1}R_{2}^{-1}D_{2}}\ast\cdots\ast \delta_{R_{1}^{-1}R_{2}^{-1}\cdots R_{k}^{-1}D_{k}}\ast \cdots.$$
In this paper, we consider the spectrality of
$$\mu_{\{R_k\},\{D_k\}}$$
. We prove that
$$\mu_{\{R_k\},\{D_k\}}$$
is a spectral measure under certain conditions in terms of
$$(R_k,D_k)$$
, i.e., there exists a Fourier basis for
$$L^2(\mu_{\{R_k\},\{D_k\}})$$
.
期刊：
Results in Physics,2023年54:107047 ISSN：2211-3797
通讯作者：
Lan, Y;Huang, WQ
作者机构：
[Zhang, Jing; Luo, Jia-Cheng; He, Zi-Cheng] Hengyang Normal Univ, Nanyue Coll, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Lan, Yu] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Huang, Wei-Qing; Huang, Gui-Fang] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Peoples R China.;[Hu, Wangyu] Hunan Univ, Sch Mat Sci & Engn, Changsha 410082, Peoples R China.
通讯机构：
[Lan, Y ; Huang, WQ ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Peoples R China.
关键词：
Schottky barrier;Metal-semiconductor contact;van der Waals heterostructure;Electric field;First -principles calculations
摘要：
Two-dimensional (2D) transition metal carbides, nitrides, or carbonitrides (MXenes) have emerged as promising ultrathin materials for nanoelectronics and optoelectronics. However, the contact barrier at metal --semiconductor (MS) junctions still significantly limits the device's performance. Here, we propose a novel strategy-functionalizing accompanied with external electric fields-to tune the MS contact nature in MXene-based van der Waals (vdW) heterostructures, taking 2D Ti2C as an example, by means of first-principles calcu-lations. Different Ti2CO2/Ti2CX2 (X = OH or S) vdW heterostructures are designed via functionalizing Ti2C metals to contact with 2D Ti2CO2. We reveal that OH functionalized vdW MS heterostructure (Ti2CO2/Ti2C (OH)2) can be tuned to the Ohmic contact owing to the strong interlayer interaction inducing a large number of interlayer transferred electrons; while for the sulfurized vdW MS heterostructure (Ti2CO2/Ti2CS2), its Schottky barrier height and contact type can be effectively tuned by external electric field due to the rather weak inter -layer interaction. Our work paves a new way for the construction of 2D MXene-based vdW MS heterostructures and demonstrates the great potential of 2D MXenes in future nanoelectronics and optoelectronics.
摘要：
Image transmission is happening more frequently in this era of technologically sophisticated digital information. Additionally, more individuals are becoming aware of its importance. In order to secure images, many academics are participating in research, which is advantageous for guaranteeing data security. In order to strengthen the security of images during transmission, we have investigated new encryption algorithms to guarantee this. First, a current representing the Lorenz chaotic system is introduced into the neuron model. The neuron model generates sequences after receiving the current signal. The next move is made as the current shifts depending on whether the resulting sequences are chaotic or not. If so, the subsequent operation is carried out; otherwise, the current is altered until chaotic sequences are produced. Second, a global scrambling with de-duplication technique is used to scramble the image using the resulting chaotic sequences. To complete the dislocation effect, the Latin square is used to dislocate the image after the initial dislocation. Fourth, the image that has been scrambled is subjected to two rounds of additive mode diffusion. They are diffusion in the forward additive mode and diffusion in the inverse additive mode. Lastly, to improve the diffusion effect, the image is diffused in the finite domain. Eventually, the encrypted image is obtained. After evaluation tests and comparison with related literature, it can be found that the algorithm of this study has certain advantages. Also, the resistance to attack is good. It can protect the security of the image.
