Journal of Jishou University(Natural Sciences Edition)

Periodic Solutions for a Class of Second-Order Difference Systems with Variable Exponent

ZHANG Shengui

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 1-5.

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This paper investigates the existence of solutions for periodic boundary value of discrete p(k)-Laplacian systems.Under the generalized subquadratic conditions,some results for the existence of periodic solutions are obtained by using the saddle point theorem,and the validity of the solvability conditions is proved.

Error Estimation of the Extended Vertical Linear Complementarity Problems of CKV-Type Matrix and CKV-Type-B Matrix

JIANG Jianxin

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 6-12.

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The error bounds of the solutions to the extended vertical linear complementarity problem are studied for the CKV-type matrix and the CKV-type-B matrix.Under the premise that "any sub-block of the block matrix satisfies the definition of the two types of matrices",it is proved that after row rearrangement of the original block matrix,each sub-block of the new matrix still maintains the same type as the original matrix sub-block,and the rearranged matrix has the row W-property.On this basis,the error bound expressions of the solutions to the problems corresponding to the two types of matrices are derived.

Properties of Ellipsoids and Rotational Ellipsoids

GAO Wen, CAI Xuepeng, LIU Xue'er, PANG Yue

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 13-16.

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In this paper,the trajectory equations of ellipsoid and rotational ellipsoid are described by analyzing the characteristics of the trajectories of the points on these two ellipsoid surfaces.

Several New Criteria for Block H-Matrices

HE Yongfang, MO Hongmin, YI Hong

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 17-24.

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A new class of block H-matrices—block strictly α-locally double diagonally dominant matrices is defined,and three new criteria for the block H-matrices are given.

Strong Continuity of Topological Space

XUE Jie, LIU Gang

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 25-28.

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Based on the convergence of directed sets,the concepts of strongly continuous top ological spaces and strong topology are introduced.It is proved that all strongly continuous spaces are continuous spaces,and counter-examples are provided to demonstrate that continuous spaces are not necessarily strongly continuous spaces.Furthermore,the insertion property of approximation relations on strongly continuous spaces is explained,and the conditions for the equivalence between strongly continuous spaces and approximation spaces are established.

Bayesian Analysis of Kumaraswamy Distribution Parameters Under a Kind of Symmetric Loss

ZHANG Xuecheng, XU Bao

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 29-40.

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Under the weighted p,q symmetric entropy loss function,the Bayesian estimation method is used to estimate the Kumaraswamy distribution parameters,and the general and exact forms of the Bayesian estimation of the parameters are obtained,which proves the acceptability and minimum maximum of the obtained Bayesian estimation.The multi-level Bayesian estimation,E-Bayes estimation and knife-cut Bayesian estimation of the parameters are given.The numerical simulation of Bayes,E-Bayes and knife-cut Bayes estimation of Kumaraswamy distribution parameters is carried out by using R software combined with Metropolis algorithm.The results show that the Bayes estimation under the Jeffreys priors is more accurate than that under the conjugate prior distribution;the estimation properties under the same prior distribution can be better by using the knife cutting method;and the application of E-Bayes estimation can reduce the influence of hyperparameters on the simulation by selecting appropriate constants.

Short-Term Photovoltaic Power Prediction Based on VMD-CNN-BiLSTM-RF

LI Li

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 41-48.

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In response to the non-stationary nature and noise interference caused by weather affected photovoltaic power generation,as well as the spatiotemporal coupling effect,a short-term power prediction composite model VMD-CNN-BiLSTM-RF based on Variational Mode Decomposition (VMD),Convolutional Neural Network (CNN),Bi-directional Long Short-Term Memory(BiLSTM),and Random Forest (RF) is proposed.This model uses VMD to decompose the original power sequence into multiple stationary sub-modes,reducing the impact of noise and non-stationarity.It combines CNN with BiLSTM to simultaneously capture spatial features and temporal dependencies of time series data,improving the accuracy of predictions.RF is integrated with sub-model prediction results to enhance the model's generalization ability.An experimental environment was set up on the Matlab platform to conduct comparative experiments and error analysis for the VMD-CNN-BiLSTM-RF combined model.The results show that this model has significantly improved the accuracy and robustness of short-term photovoltaic power generation prediction.

Design of an Extended State Observer Based on the Improved Fal Function Filter

DING Meiling, CHEN Huirong, ZHANG Zhengzheng

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 49-54.

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A filter based on an improved Fal function was designed,and its filtering performance was analyzed.Simulation results demonstrate that this filter achieves favorable filtering effects.Building upon this,an improved Extended State Observer (ESO) was developed by integrating the improved Fal function filter with the ESO framework.The performance of the traditional ESO and the improved ESO in handling measurement noise in sinusoidal and step signals was compared and analyzed.Simulation results indicate that,compared with the traditional ESO,the improved ESO exhibits superior performance in both noise suppression and target signal tracking.

Effect of the Number of Working Wells on the Seasonal Operation of the Compressed CO₂ Energy Storage System in Aquifers〖STBZ〗

LAI Yangzhi, LI Yi, HUANG Leqing

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 55-66.

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To clarify the influence of the number of working wells on the operational performance of seasonal aquifer compressed CO₂ energy storage systems,three three-dimensional numerical models of well groups - gas storage reservoirs with different numbers of working wells (9,5,and 3) were established.The T2WELL numerical simulation software was used to investigate the seasonal cyclic operation process of the energy storage system under different numbers of working wells.The results showed that when the number of working wells decreased from 9 to 3,the maximum pressure at the wellhead of the central well increased from 17.42 MPa to 18.23 MPa,and the maximum temperature at the wellhead of the central well rose from 59.21 ℃ to 60.18 ℃.The maximum energy efficiency of the energy storage system droped from 1.028 55 to 1.027 74.This indicates that the number of working wells significantly affects the CO₂ migration pattern and pressure/temperature transfer process within the wellbore - formation system.Therefore,in practical engineering,the number of working wells can be increased to reduce the pressure/temperature during the injection stage of the energy storage system's cyclic operation,thereby enhancing the energy efficiency of the energy storage system.

Characteristics of the Nesting Sites and Breeding Behaviors of Myophonus caeruleus in Western Hunan

LIU Yi, WU Tao, XIONG Yixin, CHEN Tianyu, XUE Fengling, NING Luoyang, LIU Zhixiao

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 67-77.

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Myophonus caeruleus is a medium-sized passerine bird of important ecological,scientific and social value,with unique cave-dwelling habits in Xiangxi Prefecture,Hunan Province.A combination of field investigation and portable automatic infrared video recording was employed to explore the main factors influencing the nest-site selection and characteristics of breeding behavior of this species.The major results are as follows:The main factors influencing the choice of nest sites of Myophonus caeruleus are spatial location and microclimatic environment.The nests are bowl-shaped,composed of four layers,and the dominant nest materials included mosses (50%),rhizomes (30%) and leaves (10%) of herbage and lianas.Both female and male birds participate in nesting,and the nesting behaviors primarily include nest-building (68.5%),nest-tidying (13.9%),warning (8.4%) and inspecting (5.7%).Incubation is mainly carried out by the female bird,and the behaviors during the incubation mainly include preening (38.5%),egg-turning (29.3%),nest-sitting (13.2%),inspecting (9.2%) and warning (5.4%).Both the male and female birds raise the chicks together,and the behaviors during the breeding chiefly covere nestling-feeding (38.9%),feces removal (15.8%),nestling-turning (11.6%),brooding (10.9%),preening (9.3%),inspecting (5.3%),and warning (4.6%).

Research Progress on Halophilic Bacteria Based on Bibliometric Evaluation

ZOU Wenhai, DA Chunyao, DENG Liying, CHEN Jinhua, LIU Zhuxiang, CHEN Yiguang

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 78-89.

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With the Web of Science Core Collection as the data source,the "Bibliometrix" R package together with CiteSpace software was applied to perform bibliometric analysis and visualization of research on halophilic bacteria from 2015 to 2024.The results show that publication output in this field has remained relatively stable over the past decade,reaching a peak in 2021.China and the United States are the leading contributors,with the Chinese Academy of Sciences identified as a major institution in this area.Current research hotspots focus on the diversity and polyphasic taxonomy of halophiles,community ecological structure and metagenomic functional analysis,and the resource utilization of metabolites.Research trends have gradually shifted from traditional taxonomy to phylogenomics,functional multi-omics,and applied biotechnology.

Spatial-Temporal Characteristics of Urban Expansion and Evolutionary Features of Spatial Form in the Built-up Areas of Wulingyuan

LONG Tengzhe, LUO Bincheng, HU Yuewen, YANG Jing, WANG Yunzhe

Journal of Jishou University(Natural Sciences Edition), 2026, 47(1): 90-96.

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Taking the built-up areas of Wulingyuan District,Zhangjiajie as the research subject,this study employs fractal theory and equal-sector analysis based on Landsat remote sensing image data in 2000,2005,2010,2015,and 2022 to quantitatively analyze the spatiotemporal characteristics of urban spatial expansion and the evolution of spatial form of the built-up areas in Wulingyuan.Results indicate that from 2000 to 2022,the built-up area expansion exhibited distinct phased characteristics,progressing through four stages:"moderate speed,low intensity","low speed,low intensity","moderate speed,moderate intensity",and "high speed,high intensity".The period from 2015 to 2022 represented the peak phase of expansion.The expansion exhibited pronounced anisotropy,unfolding as an east-west ribbon pattern.The expansion progressed through four phases:slow wing-fan expansion,slow dendritic expansion,rapid wing expansion,and rapid axial expansion.The compactness index of the urban spatial form exhibited a V-shaped pattern,reaching its lowest point in 2015;while the fractal dimension continued to decline.The urban spatial expansion pattern shifted from outward expansion to internal infill,with the strip-like spatial form tending to be stable.Based on these findings,several recommendations are proposed for the urbanization development of Wulingyuan District.

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