现有的端到端方法和基于预训练模型的方法在训练过程中未有效利用表格单元格的结构信息，从而影响了表格文本在模型中的向量表示和最终的语义信息抽取精确率；因此提出了进一步利用单元格结构信息来改进光学字符识别效果的端到端方法和增加单元格序列预测任务的预训练方法。实验结果显示改进后的2种方法在表格语义信息抽取任务中取得了更好的效果，F1值分别提升了0.204 6和0.017 6。改进后的方法加强了单元格结构信息在表格中的重要性，提高了表格语义信息抽取的精确率。
[Purposes]The initial-boundary value problem of Rosenau-Kawahara equation is numerically studied. The Sinc collocation method for solving Rosenau-Kawahara equation is proposed. [Methods]The equation is fully-discretized by using Sinc collocation method for spatial discretization and the forward finite difference for time discretization. A hybrid difference scheme is obtained by means of parameter θ. [Findings]The stability of difference scheme is analyzed and the stability condition is given. [Conclusions]A numerical experiment is performed to illustrate the validity of the constructed method. The numerical results of the Crank-Nicholson scheme are better than those of the conservative finite difference schemes and the quintic B-spline collocation finite element method.
[Purposes]To identify transferrin of Apis mellifera ligustica（AmTsf） by bioinformatics, and to analyze the role of AmTsf in tolerance to toxicity of insecticide imidacloprid. [Methods]The amino acid sequence characteristics and domain composition of AmTsf were analyzed by multiple sequences alignment.Online tools predict the structure, cellular localization, interacting protein networks and biological functions of the protein. Phylogenetic tree was constructed to analyze the phyloclassification and evolutionary relationship of the protein.The response characteristics and functions of AmTsf to insecticide imidacloprid toxicity in bees were analyzed by real-time quantitative PCR combined with iron homeostasis. [Findings]Bioinformatics analysis predicted that AmTsf protein was hydrophobic, consisting of 712 amino acid residues, with a molecular weight of 78.7 kDa and pI of 6.77. A conserved amino acid residue of the signal peptide and transferrin family, primarily located in the nucleus and mitochondria. Experimental analysis found that exposure to environmental concentrations of imidacloprid caused mass bee deaths. Compared with the control group, 24 h exposure to imidacloprid resulted in excess iron ions in the head, thorax and midgut of bees. Importantly, the transferrin encoding gene AmTsf, which is closely related to the regulation of iron homeostasis, was synchronously up-regulated in all tissues with the increase of iron（p＜0.05）. [Conclusions]The results suggest that AmTsf may actively respond to imidacloprid toxicity tolerance in honeybees by regulating iron homeostasis.
[Purposes]The Cahn-Hilliard-Navier-Stokes equations, which are coupled by incompressible Navier-Stokes equations and higher-order anisotropic Cahn-Hilliard equations, are widely used and play an important role. [Methods]Bounded absorbing sets and uniform compactness of solution semigroup to the equations are obtained by using energy estimates. [Findings]Then the existence of attractors are proved according to the existence theorem of attractor. [Conclusions]The large time behavior of the equations under Neumann boundary condition for relative concentrations is studied.
[Purposes]Bioinformatics was used to identify glutathione specific γ-glutamyl cyclotransferase 2（AmCHAC2） in Apis mellifera ligustica, and quantitative PCR was used to analyze the temporal and spatial expression characteristics of AmCHAC2 in A. mellifera ligustica. To explore the role of this gene in bee resistance to Nosema infection. [Methods]The amino acid sequence characteristics and domain composition of AmCHAC2 were analyzed by multiple sequence alignment. Online prediction of the protein structure, interacting protein network, cell localization characteristics and function. The phylogenetic tree was constructed to analyze the phylogenetic classification and evolutionary relationship of the protein. Temporal and spatial expression characteristics of AmCHAC2 in honeybee tissues were analyzed by real-time quantitative PCR. The expression characteristics of glutathione content in honeybee tissues were analyzed by kit. The content of reactive oxygen species in honeybee midgut was determined by ELISA. [Findings]AmCHAC2 was composed of 245 amino acid residues with a relative molecular weight of 28.3 kDa and a pI of 6.71. AmCHAC2 is a hydrophobic protein with no signal peptide and is localized in the cytoplasm. A large number of honeybees died after 14 days of infection with Noseama ceranae, and the survival rate was only 23%. Compared with the control group, the expression of AmCHAC2 was significantly up-regulated in the breast and midgut tissues of the bees infected with nosema, the content of GSH was significantly decreased, and the content of reactive oxygen species was significantly increased in the midgut, which triggered oxidative stress. [Conclusions]The upregulation of AmCHAC2 after infection with Nosema may play an important role in the resistance of A. mellifera ligustica to Nosema infection.
[Purposes]In order to promote the development of new urbanization and the adjustment of economic structure in Chongqing, to reveal the coupling coordination law between economy, urbanization and carbon emissions. [Methods]Taking 38 districts and counties in Chongqing as a unit, the evaluation index system of economy-urbanization-carbon emission subsystem was established, and the coupling coordination model was constructed to analyze the spatial variation and evolution characteristics of subsystem coupling coordination in 2015, 2017 and 2019. [Findings]The results showed that: 1) The spatial distribution of coupling coordination was greatly affected by the comprehensive development level of districts and counties. Among the counties with high level coupling coordination, 60% were in metropolitan areas, and only 16% were in southeast Chongqing. 2) The coupling coordination changes have convergent correspondence characteristics. In the metropolitan area, double high level coupling coordination is 93%, while in northeast and southeast Chongqing, double low level coupling coordination is 52% and 33%, respectively. 3) There are significant differences in coupling coordination degree. Spatially, the coupling coordination degree presents a “point + line” structure, with the urban functional core area, Wanzhou in northeast Chongqing and Qianjiang in southeast Chongqing as the central radiating points, forming a gradient line with high east and low west. In time, the coupling degree is an “inverse L-shaped” rising curve, and the coordination degree is an “M-shaped” wave curve. [Conclusions]Due to the differences in economic and urbanization development levels between regions and counties, carbon emission reduction policies should be tailored to local conditions, and different policies should be implemented in the aspects of industrial coordination, urban and rural overall planning, and increasing income and reducing expenditure.
[Purposes]In order to realize the high-speed and high-resolution imaging of the biological tissue tomography, a set of optical coherence tomography imaging system is developed based on the swept. [Methods]The hardware of the system is based on the 1 310 nm center wavelength frequency Scanning laser source, and the software system compiled by LabVIEW is used as the processing tool to carry out experiments on the animal and plant epidermis. [Findings]The results show that the system can realize the high-speed acquisition and processing of 1 million data points within 5 s, achieve the high-resolution optical imaging of 10 μm, and the imaging depth can reach 2.3 mm, which can fully meet the imaging needs of biological tissue tomography. [Conclusions]In addition, the system also has the characteristics of small volume, simple operation and strong portability, which is enough to meet the optical imaging requirements of clinical biomedical scenes.
[Purposes]It studied the integral weight kernel estimators of nonparametric regression functions which is proposed by Gassor and Müller under AANA errors.[Methods]By using truncation method and exponential inequality of AANA sequence, it obtained the complete consistency of integral weight kernel estimators of nonparametric regression functions.[Findings]The results extended the existing related conclusions.[Conclusions]Some simulations are illustrated to verify the validity of our results.
[Purposes]The trend and sudden change identification of precipitation series in the source region of the Yangtze River are carried out, which provides a theoretical basis for the ecological protection of wetlands and water resources development and utilization in the source region of the Yangtze River. [Methods]Taking 8 representative meteorological stations in the source region of the Yangtze River as the research object, namely Qumalai, Qingshuihe, Yushu, Nangqian, Zhiduo, Zaduo, Tuotuohe and Wudaoliang, based on the meteorological data from 1961 to 2020, using linear tendency estimation, sliding average, Mann-Kendall test, sliding T test and other methods to identify and analyze the change characteristics of precipitation series in the source region of the Yangtze River. [Findings]1) From 1961 to 2020, the precipitation series in the source region of the Yangtze River shows an upward trend, with an increase rate of 0.809 mm·a -1 . 2) The precipitation in spring and winter shows a significant increasing trend, while the increasing trend in summer and autumn is not obvious. 3) When the subsequence was 5, the precipitation sequence in the source region of the Yangtze River was abruptly changed in 1970. When the subsequence was 7, it abruptly mutated in 1997 and 1998, changing from a downward to an upward trend. 4) When the subsequence was 5, the precipitation sequences of the eight research meteorological stations in the source region of the Yangtze River all had mutation points from 1961 to 2020. When the subsequence was 7, only the precipitation sequences of Qumalai, Qingshuihe, Zhiduo, Tuotuohe and Wudaoliang have mutation points during the above 60 years. [Conclusions]From 1961 to 2020, the total amount of precipitation in the source region of the Yangtze River increased, and the climate change prevention work about the source region of the Yangtze River urgently needs to be strengthened.
[Purposes]To investigate the effect of mowing on the species diversity and biomass of Cynodon dactylon communities growing at different elevations in the riparian zone of the Three Gorges Reservoir Area（TGRA）. [Methods]C. dactylon communities in the riparian zones of 160 m and 170 m in the Ruxi River were selected. The effects of elevation and mowing on community biomass and species diversity were studied by using no mowing control, stubble 30 cm, stubble 20 cm, and stubble 10 cm mowing treatments. [Findings]Mowing significantly reduced the coverage, density, important value, and aboveground biomass of C. dactylon, and the biomass of C. dactylon decreased more at 170 m elevation. There was an insignificant difference in C. dactylon community biomass under different mowing intensities（except for C. dactylon communities grown at 170 m elevation treated with stubble 30 cm）, and the C. dactylon community biomass at 160 m elevation was significantly higher than that at 170 m elevation. The proportion of C. dactylon biomass at 170 m elevation decreased more than that at 160 m elevation, mowing significantly increased the biomass of other species in the community. The mowing treatment significantly increased the Species richness, the Simpson index, the Shannon-Wiener index, and the Pielou evenness index. There was no significant correlation between community biomass and species diversity, but there was a significantly negative correlation between C. dactylon community biomass and species diversity. [Conclusions]C. dactylon grown at 160 m elevation were more tolerant of mowing stress than at 170 m elevation in the TGRA, a certain degree of mowing can significantly increase the species diversity of the C. dactylon community.
[目的]研究爱因斯坦积下L?wner偏序A≥B和A＞B与它们的Moore-Penrose逆的关系.[方法]通过张量特征值、值域及Moore-Penrose逆来研究张量L?wner偏序A≥B和A＞B.[结果]得到了 一些关于偏序A≥B和A＞B的基本性质和充要条件.[结论]L?wner偏序A≥B和A＞B成立的充要条件表明,矩阵L?wner偏序的性质能够推广到张量上.
[目的]考虑将光滑线性化结果延伸至环面,并考察扰动下系统对参数的依赖性.[方法]采用经典方法构造完备度量空间,定义了特殊范数来实现压缩性.[结果]在一维圆周上实现扩张映射的H?lder线性化,并且给出了共轭映射H?lder依赖于参数的条件.[结论]一般而言,能将线性化结果提升至H?lder,且圆周动力系统的线性化与一维线性动力系统保持一致.
[Purposes]In order to study the disjoint path cover（DPC for short） problem, the structures of 1-disjoint path coverable, 2-disjoint path coverable and k-disjoint path coverable that still maintain the DPC property after deleting vertices and passing through specified edges are discussed on the unit interval graph.[Methods]Using the structural characteristics of unit interval graphs and the structural properties of path cover, the paired many to many k-DPC fault tolerance problem of unit interval graphs is studied by mathematical induction and counter proof method. [Findings]Arbitrarily delete p vertices and pass through q edges, the unit interval graph G is still paired k-DPC, if and only if G is（2k+r-1）-connected, where（p+q）≤r.[Conclusions]The fault tolerance path cover problem of unit interval graphs is closely related to Hamiltonian properties and connectivity. The research results and methods provide a theoretical basis for the research of paired k-DPC fault tolerance of interval graphs, and help to design an effective algorithm to find paired k-DPC fault tolerance on unit interval graphs.
[Purposes]It aims to investigate the plankton community structure, biodiversity, and fish resources in the Puli River Basin of the Three Gorges Reservoir Area, and provide data support for the monitoring and management of the ecological environment in the Puli River Basin. [Methods]From March to April 2019, eight sampling sections were set up in the Puli River to conduct investigations and analyses on the plankton community structure and fish resources. The Shannon-Wiener diversity index（H′）, Pielou index（J）, and Marglef index（D） were used to evaluate the biodiversity of plankton and comprehensively assess the degree of water pollution. [Findings]A total of 92 species belonging to 44 genera and six phyla of phytoplanktons were collected in the Puli River, dominated by the Bacillariophyta phylum, which accounted for 60.87% of the total species. The average density and biomass of phytoplanktons were 4.0×10~4 individuals·L -1 and 0.061 9 mg·L -1 , respectively. The average values of H′, J, and D for phytoplanktons were 2.244 0, 0.896 8, and 2.961 7, respectively. A total of 28 species belonging to 21 genera and four phyla of zooplanktons were collected, dominated by the Rotifera phylum, which accounted for 53.57% of the total species. The average density and biomass of zooplanktons were 246 individuals·L -1 and 3.684 7 mg·L -1 , respectively. The average values of H′, J, and D for zooplanktons were 1.370 4, 0.889 5, and 1.326 7, respectively. A total of 24 species belonging to five families and three orders of fish were identified in the Puli River, dominated by the Cyprinidae family, which accounted for 62.5% of the total species. [Conclusions]The overall water quality of the Puli River Basin ranged from clean to moderately polluted, and the fish resources were significantly reduced compared to historical survey records. Therefore, it is necessary to strengthen the water ecological management and fishery resource protection in the Puli River Basin.
[Purposes]A special kind of multi-objective optimization problem with norm structure is studied, which can be applied to the processing of many practical problems.[Methods]Based on the idea of scalarization, an approximate method is proposed to solve this kind of multi-objective optimization problem under some suitable assumptions.[Findings]It can obtain Pareto solutions of multi-objective optimization problems by adjusting the ranges of several parameters. [Conclusions]The multi-objective optimization model with norm structure and the approximate solution method are used in the setting of basic workload and the assignment of power plant generators in performance management.
[Purposes]It is difficult to express the real degree of topographic uplift, gully cutting or basin collapse by absolute elevation, and defining and quantifying the height and depth of topographic uplift and cutting are useful for the portrayal and study of various geological phenomena such as mountainous landforms. [Methods]Based on the digital elevation model data and Yunnan Province as the research area, a method is proposed to construct an index for the degree of topographic uplift and cut. The method uses the geographic raster map algebra as the part, divides the mountainous area by small watersheds and selects the average elevation of each watershed as the sample point to construct the average trend surface, and uses this trend surface as the starting point.[Findings]1) Topographic uplift height and depth of cut can well express the uplift and cut changes of large landforms, better characterize mountain features, and reflect the differences of mountain structure between large regions. 2) The values of topographic uplift height and depth of cutting in Yunnan Province are mainly concentrated in the range of-500 to 500 m, and its spatial distribution characteristics are similar to that of the average elevation changing pattern with inverted “U” type distribution. 3)The uplift height and cutting depth of low altitude terrain in Yunnan Province are-157～599 m. In the middle elevation area, the eastern uplift height is mostly less than 252 m and the absolute value of the cutting depth is mostly less than 439 m, while the western topographic uplift height is 252～＜579 m and the cutting depth is-439～＜-157 m; The elevation of topographic uplift in high altitude area is 579～＜1 807 m and the cutting depth is-1 332～＜-439 m. The elevation of topographic uplift in extremely high-altitude area is 1 807 m. 4) The topographic uplift height and cutting depth of Yunnan Province are analyzed by latitude and longitude profiles. In the latitudinal direction, the overall trend is gradually decreasing from west to east. From north to south, the cutting of topographic uplift is decreasing. [Conclusions]The construction of the topographic uplift and cutting depth index compensates for the shortcomings of the existing geological indexes that cannot characterize the upward uplift of mountains and the downward cutting of valleys, which can better reflect the mountain tectonic conditions of large inclined surfaces, for example, large inter-regional areas, and provide data support for various geological studies.
[Purposes]Aiming at the irregular shape, blurred boundaries and hair artifacts of skin lesions in skin lesion images, it proposes a skin lesion segmentation algorithm combining CNN and Transformer. [Methods]Firstly, the skin lesion image was pre-treated for hair removal to reduce the influence of hair noise on the result, and then a segmentation model combining CNN and Transformer was constructed, using Resnet as the backbone feature extraction network to extract features, and the extracted feature map sequence was used as the input of Transformer, and a new structural boundary attention gate was added to the Transformer to extract enough local details to process the blurry boundary. Finally, The DeanseASPP enhanced feature is used to represent and process multi-scale information, and an improved loss function is proposed, the purpose of which is to make the model focus on the boundary region part when calculating the loss function. [Findings]The experimental results show that the dice value and JI value are 0.854 534 and 0.767 901 on the ISIC2017 dataset, and 0.908 548 and 0.843 689 on the ISIC2018 dataset, respectively, which achieves good results compared with other advanced models. [Conclusions]Its effectiveness is proved by comparing with different models and showing the effect.
[Purposes]As for the valuation of American options under regime-switching Kou’s jump-diffusion processes. [Methods]Based on the linear complementarity problem discretized by Crank Nicolson fitted finite volume method, an efficient modulus matrix splitting iterative method is introduced to solve it. [Findings]The convergence theorem of the algorithms are given under the H+-matrix property of the discrete matrix. [Conclusions]Numerical experiments verify the effectiveness, robustness and convergence of the new method, and the computational efficiency of themodulus-based matrix splitting iteration methods is superior to the projected successive overrelaxation iteration method.
[Purposes]Consider a class of quasilinear biharmonic equations in the plane. [Methods]This problem can be transformed into an ordinary differential equation boundary value problem via the method of radial symmetry, and obtained its equivalent Hammerstein-type integral equation. Then, an operator equation is established in an appropriate work space, and using an inequality from the Green and the fixed point theorem of increasing operators, the main results are obtained. [Findings]The uniqueness and existence of positive radial solutions are obtained, and an iterative sequence for the positive solution is also offered. [Conclusions]Two examples are given to illustrate that the conclusion has a wide application, and the result extends and generalizes the existing study in the literature.
[Purposes]A response surface method is proposed for the optimization of expensive black box functions, which can better balance local search and global search. [Methods]The CORS method is improved, introducing the mechanism of judging the local optimum solution to CORS, then jump out of it using filled function method. [Findings]Numerical experiments on 37 open global optimization algorithm test problems show that the adaptive response surface algorithm based on the local jump out local optimal mechanism of filled functions can converge to a better approximate global optimal solution. [Conclusions]The local optimal solution jumping mechanism based on the filled function method can improve the global search ability of the algorithm.
