Journal of Jishou University(Natural Sciences Edition)

Liu Estimation in Partially Linear Varying Coefficient Models

AN Bailing, LU Qi, MA Ning

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 1-6.

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This paper considers the biased estimators on the parameter components in partially linear varying coefficient model.Based on the Profile least-square approach and Liu estimation method,we propose Profile-Liu estimator and section least-square general Liu estimator for the parametric components.We prove that the Profile-Liu estimation is better than the Profile least-square estimation,and the section least-square general Liu estimation is better than the Profile-Liu estimation under certain conditions.

New Lower Bound of Wrap-Around L2-Discrepancy for Five-Level U-Type Designs

HU Liuping, PEI Wu, ZHOU Yu, OU Zujun

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 7-10.

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We obtain a new expression of wrap-around L₂-discrepancy for five-level U-type designs.A new lower bound of wrap-around L₂-discrepancy can be derived via the expression and a mathematical inequality.

A Class of Time-Inconsistent Control Problems

JI Wei

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 11-14.

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A class of time-inconsistent control problems is researched.With classical methods of mathematical analysis and calculus of variation,we prove that the optimal control of classical optimal control problems is an equilibrium control of time-inconsistent control problems.

Effect of Higher-Order Interactions on Species Coexistence in Intra-Guild Predation System

ZHANG Rong, ZHOU Shuai, WANG Qiongzhi

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 15-19.

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An ordinary differential equation system model is established to study the effects of intra-specific high-order interaction,inter-specific high-order interaction and density-mediated effect,as well as the integration of the three on population density.MATLAB numerical simulation shows that intra-specific high-order interaction and inter-specific high-order interaction can promote the coexistence between prey and predator,and the influence intensity and density-mediated effect are similar,but the action mechanism is different.

Shape Reconstruction Based on Polarization and Coarse Depth Images

ZHOU Mengyuan, YANG Fenlin

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 20-26.

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Firstly,the coarse depth image is smoothed by bilateral filtering,which can remove noise well while keeping edge details.Then,the depth information is taken as a prior condition to correct the ambiguity of polarization normals by using a self-defined threshold segmentation method.Finally,a penalty function method with depth constraint as the fitting term and polarization normal constraint as the smooth term is constructed,and the least square method is used to calculate the fusion reconstruction.Four polarization images with different polarization angles and a coarse depth map are selected for experiments.The experimental results show that compared with single mode,the fusion of depth and polarization can recover better surface details and achieve better geometric shape effect.

Application of an Optimized NGM (1,1,k) Model in Domestic Energy Consumption

SHI Jiyu, YU Siyao, YI Yeqing

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 27-33.

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In order to explore the future development trend of domestic energy consumption in China,an optimized NGM(1,1,k) model is developed to study domestic energy consumption in China.The proposed model is applied to the case of China's domestic energy consumption with 2 other grey prediction models respectively,and five indicators commonly used to evaluate the performance of prediction models are used to make comparison.The results of the cases show that the optimized NGM(1,1,k) model shows the best performance in the applied cases,thus confirming the feasibility and validity of the model.At the end of the paper,the metabolic idea is introduced into the proposed model to make a reasonable prediction of China's domestic energy consumption in the next 10 years.

Thermal Lens Effect with Low-Power Laser

LIN Yiping, CHEN Kexiong, LI Lingyan, LIU Jingfeng

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 34-41.

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COMSOL Multiphysics 5.5 software was used to build a model to study the relationship between the change of lens focal length and the change of laser power.The experimental scheme was designed through theoretical analysis and the formula for calculating the focal length of the thermal lens was determined.Experiments were conducted to explore the thermal lens effect with low power laser,and the visualization of the thermal lens effect with low-power laser was realized.The soy sauce lens was measured as thermal concave lens.Using knife edge method and software fitting measurement of laser radius,combined with other data to calculate the focal length of the thermal concave lens,the measured relative error was 3.6%.Finally,taking the focal length as the intensity reference of the thermal lens effect,the measured intensity of the thermal lens effect was positively correlated with the optical power.

Doping Regulation of Rectification Characteristics of GeSe Nanoelectronic Devices

CHENG Yangming, LIAO Wenhu

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 42-46.

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The rectification characteristics of GeSe nanoelectronic devices with different channel length of the central semiconductor doped with group V atomic substitution is investigated by using a combination of density general function theory and nonequilibrium Green's function.Results that:under positive bias,the current of armchair germanium selenide nanoribbons with 5.1 nm central semiconductor channel lengths increases with increasing voltage;while under negative bias,the current does not vary with voltage as the central semiconductor channel length increases from 1.7 nm to 3.4 nm;the magnitude is close to zero when the channel length of the central semiconductor continues to increase,and the devices exhibit significant rectification characteristics.

Topological States of Two-Dimensional Honeycomb Elastic Materials

LI Yinming, KONG Peng, BI Rengui, HE Zhaojian, DENG Ke

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 47-50.

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We introduce the concept of valley states to elastic materials and design a two-dimensional honeycomb elastic phonon crystal.When the system is protected by inverse symmetry,three pairs of Dirac points appear at the K and K′ point,distributed in different frequency bands.The spatial symmetry of the system is broken by adjusting its geometrical structure parameters so that the Dirac points open and form valley at the K and K′ point.In this multi-band valley exists edge states connecting the upper and lower body bands,which is used in elastic materials can be used to achieve edge transport and design acoustic devices with good performance.

Safety Impact of Blasting Construction in Xiazhuang Copper Mine on Adjacent Binghanhe Tunnel

CUI Guangyao, TIAN Yuhang, WANG Mingsheng

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 51-57.

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Through FLAC3D calculation software,the displacement,stress and safety factor of adjacent tunnel lining and rail during construction blasting in Xiazhuang copper mine are analyzed.The results show that after the blasting construction,the maximum horizontal displacement of the lining is 4.07 mm,the maximum horizontal convergence is 0.08 mm,the maximum settlement is 4.23 mm,the maximum lateral displacement of the rail is 3.46 mm,and the maximum settlement is 3.48 mm,which all meet the displacement control standard.The maximum principal stress,minimum principal stress and maximum shear stress of lining and rail increase slightly.The minimum safety factor of lining is 4.49,and the safety factor of lining after blasting construction meets the specification requirements.

Mechanical Properties of Stress Corroded Steel Wire with Cracks

WANG Xin, DU Siyu, GAO Yang

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 58-66.

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In order to study the tensile mechanical properties of stress corroded high strength galvanized steel wire with cracks,the mechanical model of high strength steel wire with cracks was established based on the data of stress corrosion test,static tensile test,electron microscope test and finite element simulation.The results show that in the static tensile test,the critical failure factor of the steel wire is the crack,and the stress concentration factor of the notch is much higher than that of the corrosion pit.The mechanical property change is caused by further corrosion of the initial crack.When corrosion is serious,the mechanical properties is mainly determined by the crack and the corrosion pit.

Ultrastructure of Cymbella subhelvetica Krammer

LONG Jiyan, LIU Bing, XU Sanmei, TANG Haipeng

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 67-71.

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To reveal the ultrastructural features of Cymbella subhelvetica Krammer,this study carries out a thorough observation using scanning electron microscope.The observational results demonstrate that C. subhelveticapossesses the following diagnostic features:(1)valves distinctly dorsiventral;(2)distal raphe fissure curved dorsally,proximal raphe ends teardrop not deflected;(3)no apical pore fields;(4)striae uniseriate,slightly radiate except closing to each apex where becoming convergent dorsal striae 9~11/10 μm,ventral striae 9~13/10 μm;(5) Areolae mostly lineate,occasionally Y-shaped,and areolae 30~33/10 μm;(6) 4~7 stigmata.Above characteristics together constitute a unique combination of features that distinguish and identify C. subhelvetica.

Photocatalytic Degradation of Bisphenol a by Sulfur-Modified Cadmium-Rich Biomass Carbon

CAO Jiaji, WANG Ping, LING Dingxun, HUANG Chao

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 72-80.

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Using biomass sorghum after remediation of cadmium-contaminated soil as raw material,sulfur-modified biochar based photocatalyst was prepared by calcination and hydrothermal reaction.The morphology and crystal structure of the photocatalyst were analyzed by scanning electron microscopy and X-ray diffraction.The results showed that cadmium sulfide crystals were successfully loaded on the biochar.The photocatalytic degradation experiment found that the photocatalyst can rapidly degrade bisphenol A (BPA) in water,and its photocatalytic degradation rate is 15.5 times and 2.4 times that of biomass sorghum biochar and cadmium sulfide,respectively.The influencing factor experiment found that the acidic conditions and the increase of the material dosage can significantly improve the photocatalytic degradation rate of BPA.Cycling experiments showed that the material has good photocatalytic stability,and quenching experiments showed that the main active species in the reaction are holes (h⁺),followed by ·OH and ·O^-2.

Research Advances in Diagnosis and Treatment of Metabolic- Associated Fatty Liver Disease

WANG Zijin, LI Xuefeng, XIANG Mingjun, OU Fangbo

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 81-86.

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Metabolic-associated fatty liver disease (MAFLD) is the most common chronic liver disease in the world and also the number one liver disease in China.Its incidence rate shows an upward trend year by year.If the degree of liver steatosis is aggravated,liver fibrosis may occur and eventually lead to liver cirrhosis and even hepatocarcinoma.All these are serious hazards to people's health.In recent years,many new changes have taken place in the diagnosis and treatment of MAFLD,which has become a research hotspot.This article reviews the global harm and health burden of fatty liver disease,the change of fatty liver naming and the diagnosis and treatment of metaboli-associated fatty liver disease.The purpose of this study is to provide reference for the early diagnosis,disease evaluation and new drug development of metabolic-associated fatty liver disease.

Chemical Constituentsfrom the Aerial Partsof Dichrocephala benthamii

ZHANG Yue, WEI Hua, CAO Xinjie, LIU Hongyu

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 87-91.

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The chemical composition of Dai Medicine Dichrocephala benthamii has been studied.The ethanol extract in Dichrocephala benthamii was isolated and purified by silica gel chromatography repeatedly,and the structures were identified by spectral analysis and chemical methods.Results showed that fifteen compounds were isolated from the ethanol extraction of Dichrocephala benthamii and the structures were identified as piperine (1),capsaicin (2),dihydrocapsaicin(3),1H-indole-3-carboxylic acid,ethyl ester(4),1H-indole-3-carboxylic acid,methyl ester (5),3-formylindole (6),pomolic acid (7),floridiolide A (8),16-methoxycleroda-3,13-dien-15,16-olide-18-oic acid (9),16-ethoxycleroda-3,13-dien-15,16-olide-18-oic acid (10),friedelin (11),Kaempferol (12),quercetin (13),syringenin isovalerate (14),gallic acid (15).It can be concluded that compounds 1-12,14 were obtained from the genus of Dichrocephala for the first time.

HPLC Determination of Ursolic Acid and Oleanolic Acid in Paulownia Leaves from Xiangxi

XU Yuhui, ZHOU Jiani, QIN Aitao, HAN Xiangyun, YANG Dequan

Journal of Jishou University(Natural Sciences Edition), 2022, 43(4): 92-96.

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An efficient,accurate and stable method for the determination of ursolic acid and oleanolic acid has been established.Then the contents of ursolic acid and oleanolic acid in Paulownia leaves in Xiangxi were determined.High performance liquid chromatography (HPLC) method was adopted,and the chromatographic conditions were as follows:(1) chromatographic column:TADE-PAK AF-C18 column(250 mm×4.6 mm,5 μm;(2) mobile phase:acetonitrile-methanol-0.5% ammonium acetate solution (Volume ratio 61∶18∶21);(3) flow rate:1 mL/min；(4) detection wavelength:210 nm;(5) column temperature:35 ℃;(6) sample size:10 μL.The results showed that the separation degree of oleanolic acid and ursolic acid was 1.73,which met the requirements.The linear relationship between ursolic acid and oleanolic acid was good in the range of 0.497 6～9.952 μg and 0.126 1～2.523 μg (r=0.999 9),respectively，The average recoveries of ursolic acid and oleanolic acid were 99.93% and 98.97%,respectively.The contents of ursolic acid and oleanolic acid in Paulownia leaves in Xiangxi were 4.54～7.07 mg/g and 2.50～3.20 mg/g,respectively.HPLC method has good separation effect,high sensitivity and high accuracy,and is a scientific and effective method for the determination of ursolic acid and oleanolic acid in Paulownia leaves.

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