Journal of Jishou University(Natural Sciences Edition)

Zero Duality Gap Property of Quasiconvex Programming

YANG Fang, WANG Xianyun

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 1-5.

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By using the generator of the quasiconvex functions and the epigraph property of conjugate functions,we introduce some new constraint qualifications.Under those constraint qualifications,the zero duality gap properties between the quasiconvex programming problem and its Lagrange dual problem are established.

Notations to Exponential Diophantine Equations (204m²+1)^x+(237m²－1)^y=(21m)^z

WANG Cheng, YANG Hai, CHENG Yajie

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 6-9.

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Let m be a positive integer.By using the upper bound of solutions to the generalized Ramanujan-Nagell equation,Jacobi symbols,modular arithmetic,and methods of elementary number theory,it is proven that that the equation (204m²+1)^x+(237m²－1)^y=(21m)^z only has the positive integer solution (x,y,z)=(1,1,2) when 2|/m,3|/m and m≡3,4(mod 7).

Hopf Bifurcation of the Leslie-Gower Predator-Prey Model with Fear Effect

FAN Ru, LI Jiemei

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 10-17.

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We investigate the Hopf bifurcation behavior of a Leslie-Gower predator-prey model with Holling-type Ⅱ functional response and fear effect.By applying the Hurwitz criterion,we analyze the existence and stability of the equilibrium points of the model.Taking the fear factor as the bifurcation parameter and combining with bifurcation theory,we rigorously prove that the model undergoes a Hopf bifurcation under certain conditions.On this basis,we further discuss the direction of the Hopf bifurcation,the stability of the periodic solutions,and the existence of limit cycles,and completely characterize the complex dynamical behaviors of the model under the fear effect.

A Solvable Model for Two-Stage Distributionally Robust Optimization with Conditional Value-at-Risk

LIU Yinghui, HAN Youpan

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 18-23.

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This paper presents an equivalent solvable model for a two-stage distributionally robust optimization (DRO) framework with Conditional Value-at-Risk (CVaR).Under the condition of incomplete information regarding the distribution of random variables,an ambiguity set is constructed using the second-order moment information to establish the two-stage DRO-CVaR model.When the coefficients of the second-stage objective function are random variables,the model is transformed into a directly solvable semidefinite programming (SDP) problem by leveraging conic duality theory and the minimax principle.

Fixed Points and Periodic Points in XOR-OR Parallel Hybrid Dynamical Systems over Complete Bipartite Graphs

XUE Yating, ZHENG Jie, LI Qike

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 24-33.

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This paper investigates the dynamical evolution of parallel hybrid dynamical systems on complete bipartite graphs,where the local functions for the two vertex sets are configured as the Boolean XOR and OR functions,respectively.Through mathematical deduction and computer simulation,the results show that when the number of OR-vertices is odd,the system exhibits both fixed points and period-2 points.Conversely,when the number of OR-vertices is even,only fixed points exist.Furthermore,the necessary and sufficient conditions for the existence of these states,along with their specific counting formulas,are derived.

Thyroid Nodule Segmentation Based on Improved SAMUS

LUO Xiang, TAN Zihan, XIE Jianyu, LI Shu

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 34-43.

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To address the issues of noise interference,low contrast,and blurred boundaries in thyroid nodule ultrasound images,an improved SAMUS was constructed based on the SAMUS framework.This model employs a shallow feature extraction module to obtain multi-scale detail information and introduces a shallow feature fusion strategy in the decoding stage to supplement shallow representations and enhance adaptability to morphological changes of nodules.A comparative experiment conducted between the improved SAMUS and four traditional models shows that compared with the U-Net,U-Net v2,DAEFormer and SAMUS,the improved SAMUS can more accurately restore the target shape,effectively reduce mis-segmentation and under-segmentation phenomena;compared with the SAMUS,the IOU of the improved SAMUS increases by 0.89,the Dice increases by 0.73,and the HD95 decreases by 0.30.This indicates that the improved SAMUS can obtain shallow multi-scale detailed features and fuse them during the decoding stage,which can improve the overlap degree of thyroid nodule image segmentation and reduce boundary errors.

A Method for Three-Dimensional Reconstruction of Moving Targets Based on a Dual-Galvanometer System

WANG Ran, QIAN Jiaxin, LI Maoran, GENG Shuqiao, WANG Lichao

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 44-53.

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To address the limitations of traditional three-dimensional reconstruction methods,which have a limited field of view and are difficult to apply to the three-dimensional reconstruction of moving targets,a three-dimensional reconstruction method for moving targets based on a dual-galvanometer system is proposed.The dual-galvanometer system is utilized to construct a stereo vision-like architecture,combined with a high-speed camera to achieve stable acquisition of moving target image sequence.This effectively expands the reconstruction scene range while reducing the motion blur during target movement,ensuring image acquisition quality.By preprocessing the acquired images and extracting point cloud information frame by frame,the point cloud stitching algorithm is used to achieve three-dimensional reconstruction of the moving target.Experimental results show that compared with traditional vision systems,the dual-galvanometer system can expand the measurement field of view by 2.10 times,significantly increase the number of point clouds,and significantly reduce the reconstruction error of each part of the target.

Damping Effect of Different Damping Layer Arrangements for Rectangular Tunnels with Weak Surrounding Rocks in Strong Seismic Areas

LIANG Weijin, CUI Guangyao, NING Maoquan

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 54-61.

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In order to improve the safety of shallow buried rectangular tunnels with weak surrounding rocks when subjected to strong earthquakes,a comparative analysis of the seismic damping effect of rectangular tunnels with different damping layer arrangements is carried out using the finite element software ABAQUS.The results show that compared with the condition without damping layer (condition 1),after adding the segmental structure,the damping effects of condition 2 (cushion damping layer),condition 3 (semi-covered damping layer),and condition 4 (full-covered damping layer) were significantly improved,and condition 3 had the best damping effect.Compared with condition 1,the maximum principal stress peak,minimum principal stress peak,maximum shear stress,maximum lateral displacement,maximum vertical displacement,and minimum safety factor of the damping effect in condition 3 increased by 8.893%,13.433%,5.698%,15.190%,41.860%,and 27.590% respectively.In seismic design,a semi-covered seismic damping layer construction scheme is recommended.

Seismic Response of Offshore Reinforced Concrete Bridges Under Main-Aftershock Sequences

CAO Jing, LI Yue, ZHANG Changyong, LI Chong

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 62-71.

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To investigate the seismic response evolution of offshore bridges under the coupled effects of main-aftershock sequences and chloride-induced erosion,a time-dependent damage finite element model of a three-span,three-column simply supported bridge was established based on energy dissipation theory and static pushover analysis.Seismic time-history analysis was conducted to obtain key response indicators,including the maximum displacement and residual displacement at the pier top,as well as the proportion of cumulative hysteretic energy generated at the pier bottom during aftershocks.The results show that structural durability degradation significantly affected the seismic responses:under the same seismic excitation,the maximum pier-top displacement of long-term service bridges increased by at least 10%,with a maximum increase of up to 43%,compared with newly built bridges.When subjected to high-intensity earthquakes,the residual displacement at the pier top continuously increased with service time,rising by 66%,121%,and 163% after 50,75,and 100 a of service,respectively,compared with new bridges.Aftershocks induced noticeable cumulative damage at critical locations such as the pier bottom,with the cumulative hysteretic energy accounting for an average of 14.08% of the total energy dissipation during the main-aftershock sequence,reaching a maximum of 25.3%.Therefore,it is recommended that both the energy contribution of aftershocks and the effect of durability degradation be considered in the seismic design of offshore bridges.

Extraction and Characterization of Bletilla striata Polysaccharide and Its Potentiating Effect on the Antibacterial Activity of Daptomycin

ZHOU Lanting, YAN Xinping, CHEN Ye, CAI Jianping, CAI Weifan, WANG Jianchao, PENG Huayong

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 72-80.

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Bletilla striata polysaccharide (BSP) was prepared by hot water extraction combined with alcohol precipitation.The molecular characteristics of BSP were analyzed by MCR702,GPC-MALS-RI,and SEM.On this basis,the combined antibacterial effect of BSP and daptomycin (DAP) was further investigated.The results showed that the yield of BSP was 53.3%,the number average molecular weight was 58.635 kDa,the weight average molecular weight was 83.319 kDa,the polydispersity index was 1.421,the average rotational radius was 18.3 nm,and the weight average radius of gyration was 22.5 nm.In salt solution,the BSP molecules presented a compact and quasi-spherical conformation.In water solution,BSP could spontaneously form multi-level aggregation structures with an average particle size of 410.7 nm.BSP (at a mass concentration of 1.0 g/L) could increase the antibacterial activity of DAP against Staphylococcus aureus by 2 times.Compared with DAP alone,the combination of DAP and BSP could enhance the permeability of bacterial cell membranes,leading to the leakage of nucleic acids,proteins,K+,and other contents,causing cell shrinkage and accelerating the decline of membrane potential.It is suggested that BSP can enhance the killing effect of DAP on Staphylococcus aureus by promoting the insertion of DAP into bacterial cell membrane phospholipids and the formation of ion channels in a synergistic manner.

Antitussive and Expectorant Effects of the Volatile Oil of Alpinia japonica Rhizome from Tujia Medicine#br#

CHEN Dongfan, TANG Yuqing, GONG Xuan, FAN Junjie, JIANG Mengyao, YIN Lidan, TANG Yuren, NIE Lu, YANG Xueni, XIANG Juan

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 81-88.

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A cough hypersensitivity mouse model was established by continuous 14-day cigarette smoke exposure.Concurrently,mice were intragastrically administered with medium-dose (0.8 g/kg) and high-dose (1.6 g/kg) of volatile oil from Alpinia japonica rhizome and a positive drug.The body weight changes of the mice were recorded daily.On the 15th day,cough was triggered by citric acid in the mice,and the cough latency and the number of coughs within 3 minutes were recorded.The pathological changes of the mouse lung tissue were evaluated by hematoxylin-eosin staining,and the inflammatory score was determined.The cough-suppressing effect of low,medium,and high doses of volatile oil from Alpinia japonica rhizome (0.4,0.8,1.6 g/kg) was examined through the mouse phenol red tracheal secretion experiment.The results showed that volatile oil from Alpinia japonica rhizome could antagonize the weight loss in mice caused by cigarette smoke modeling to a certain extent;the high-dose of volatile oil from Alpinia japonica rhizome could effectively reduce the number of coughs in mice,prolong the cough latency;the medium and high-dose of volatile oil from Alpinia japonica rhizome could significantly improve the inflammation of mouse lung tissue;the medium and high-dose of volatile oil from Alpinia japonica rhizome could effectively increase the phenol red secretion in the mouse trachea.This suggests that volatile oil from Alpinia japonica rhizome has good anti-cough and expectorant effects.

Corporate Risk Hedging and Asset Pricing Under Irrational Factors

HAN Shuting, ZHANG Yong, CHEN Chaolong, TANG Zhongqun

Journal of Jishou University(Natural Sciences Edition), 2026, 47(2): 89-96.

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From the perspective of behavioral finance,under the assumption that corporate managers exhibit both time-inconsistent preferences and ambiguity aversion,this paper introduces the minimum variance hedge ratio and constructs a model of corporate risk hedging and asset pricing under irrational factors.Furthermore,we examine the impact of risk hedging strategies and managerial irrationality on corporate asset pricing.The results show that:(1) Under the same level of ambiguity aversion,a smaller degree of time-inconsistency significantly enhances firm value through risk hedging strategies.Firms that adopt risk hedging strategies exhibit a weaker incentive to increase leverage compared with those which do not.The difference in bankruptcy thresholds between firms adopting and not adopting risk hedging strategies is substantially influenced by the degree of time-inconsistency.(2) Under the same degree of time-inconsistency,risk hedging reduces firm value fluctuations caused by ambiguity aversion.When the level of ambiguity aversion is low,the bankruptcy threshold for those which do not adopt a risk hedging strategy fluctuates more compared with those which do adopt such strategy.

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