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Journal of Rare Earths 2024年第1期42卷 36-45,I0002页

作者： Xiaoli Luo Qichen Chen Hongbo Guo Heng Zhang Xiaowei He Wu Zhao School of Mathematics and Computer Science Ningxia Normal UniversityGuyuan756099China School of Information Science and Technology Northwest UniversityXi'an710127China

Fluorescence imaging techniques represent essential tools in in vitro,preclinical,and clinical *** this study,an improved one-step hydrothermal method to synthesize citric acid(CA)modifiedα-NaYbF_(4):2%Er^(3+)nanocrystals was *** introduction of various doping ions into NaYbF_(4):2%Er^(3+)and the different valence states of the same ions affect both the crystal size and upconversion luminesce *** fore,we investigated the upconversion luminesce nce enha ncement of NaYbF_(4):2%Er^(3+)by ion doping and find that the upconversion luminescence intensity of the upconversion nanoparticles(UCNPs)co-doped with 5 mol%Fe^(2+)ions shows the greatest enhancement,especially for red emission at654 ***,HeLa cells incubated with UCNPs allow for imaging with strong red upconversion emission detectio *** laser scanning microscope(CLSM)fluorescent images of HeLa cells indicate that NaYbF_(4):2%Er/5%Fe^(2+)leads to a clear outline and improves visualization of the cell *** addition,the CA coated NaYbF_(4):2%Er^(3+)/5%Fe^(2+)nanoparticles and NaYbF_(4):2%Er^(3+)/5%Fe^(2+)show low cytotoxicity in HeLa *** imaging reveals the efficiency of these UCNPs to analyze the lungs,liver,and ***,these results indicate that the Cit-NaYbF_(4):2%Er^(3+)/5%Fe^(2+)UCNPs are efficient nanoprobes for fluorescence molecular to mography.

关键词： Hydrothermal method Fe^(2+)ion doping Tuning size Nanoprobes Fluorescence imaging Rare earths

THE LIMIT CYCLE BIFURCATIONS OF A WHIRLING PENDULUM WITH PIECEWISE SMOOTH PERTURBATIONS

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Acta Mathematica Scientia 2024年第3期44卷 1115-1144页

作者：杨纪华 School of Mathematics and Computer Science Ningxia Normal UniversityGuyuan756000China Ningxia Basic Science Research Center of Mathematics Yinchuan750000China

This paper deals with the problem of limit cycles for the whirling pendulum equation x=y,y=sin x(cosx-r)under piecewise smooth perturbations of polynomials of cos x,sin x and y of degree n with the switching line x=*** upper bounds of the number of limit cycles in both the oscillatory and the rotary regions are obtained using the Picard-Fuchs equations,which the generating functions of the associated first order Melnikov functions ***,the exact bound of a special case is given using the Chebyshev *** the end,some numerical simulations are given to illustrate the existence of limit cycles.

关键词： whirling pendulum limit cycle Melnikov function Picard-Fuchs equation Chebyshev system

A Stable FE-FD Method for Anisotropic Parabolic PDEs with Moving Interfaces

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Communications on Applied Mathematics and Computation 2024年第2期6卷 992-1012页

作者： Baiying Dong Zhilin Li Juan Ruiz-Alvarez School of Civil and Hydraulic Engineering NingXia UniversityYinchuan 750021NingxiaChina School of Mathematics and Computer Science NingXia Normal UniversityGuyuan 756000NingxiaChina Department of Mathematics North Carolina State UniversityRaleighNC 27695-8205USA Departamento de Matematica Aplicada y Estadistica Universidad Politecnica de CartagenaCartagenaSpain

In this paper,a new finite element and finite difference(FE-FD)method has been developed for anisotropic parabolic interface problems with a known moving interface using Cartesian *** the spatial discretization,the standard P,FE discretization is applied so that the part of the coefficient matrix is symmetric positive definite,while near the interface,the maximum principle preserving immersed interface discretization is *** the time discretization,a modified Crank-Nicolson discretization is employed so that the hybrid FE-FD is stable and second order *** terms are needed when the interface crosses grid *** moving interface is represented by the zero level set of a Lipschitz continuous *** experiments presented in this paper confirm second orderconvergence.

关键词： Anisotropic parabolic interface problem Hybrid finite element and finite difference(FE-FD)discretization Modified Crank Nicolson scheme

Privacy-Preserving Multi-Keyword Fuzzy Adjacency Search Strategy for Encrypted Graph in Cloud Environment

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Computers, Materials & Continua 2024年第3期78卷 3177-3194页

作者： Bin Wu Xianyi Chen Jinzhou Huang Caicai Zhang Jing Wang Jing Yu Zhiqiang Zhao Zhuolin Mei School of Computer and Big Data Science Jiujiang UniversityJiujiang332005China Jiujiang Key Laboratory of Network and Information Security Jiujiang332005China School of Computer and Software Nanjing University of Information Science&TechnologyNanjing210044China School of Computer Engineering Hubei University of Arts and ScienceXiangyang441053China School of Modern Information Technology Zhejiang Institute of Mechanical and Electrical EngineeringHangzhou310053China Information Center Jiangxi Changjiang Chemical Co.Ltd.Jiujiang332005China School of Mathematics and Computer Science Ningxia Normal UniversityGuyuan756099China

In a cloud environment,outsourced graph data is widely used in companies,enterprises,medical institutions,and so *** owners and users can save costs and improve efficiency by storing large amounts of graph data on cloud *** on cloud platforms usually have some subjective or objective attacks,which make the outsourced graph data in an insecure *** issue of privacy data protection has become an important obstacle to data sharing and *** to query outsourcing graph data safely and effectively has become the focus of *** query is a basic and frequently used operation in graph,and it will effectively promote the query range and query ability if multi-keyword fuzzy search can be supported at the same *** work proposes to protect the privacy information of outsourcing graph data by encryption,mainly studies the problem of multi-keyword fuzzy adjacency query,and puts forward a *** our scheme,we use the Bloom filter and encryption mechanism to build a secure index and query token,and adjacency queries are implemented through indexes and query tokens on the cloud *** proposed scheme is proved by formal analysis,and the performance and effectiveness of the scheme are illustrated by experimental *** research results of this work will provide solid theoretical and technical support for the further popularization and application of encrypted graph data processing technology.

关键词： Privacy-preserving adjacency query multi-keyword fuzzy search encrypted graph

Effects of Long-term Site-specific Fertilization on Soil Physical and Chemical Properties and Nutrients in Dry Farmland

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Agricultural Science & Technology 2017年第11期18卷 2118-2122页

作者： Xiaojun WANG Yuqing SUN Yong WANG Xiaojuan ZHANG Shangpei ZHANG Junxue YANG Shiwu LUO Jihong SHANG Bingwen CHENG guyuan branch of Ningxia Academy of Agriculture and Forestry Sciences Guyuan 756000China

In order to investigate the variation in soil physical and chemical properties and nutrients in the mountainous areas in southern Ningxia, and to provide a theoretical basis for fertilization management in local farmland, the soil p H, total salt content,crop root length, root weight, soil organic matter, available nitrogen, total nitrogen, total phosphorous and total potassium in different fertilization treatments were measured from 2010 to 2016. Multiple comparisons of the data were performed using Duncan's new multiple range test. The results indicated that in the 0-20 cm soil layer, soil p H value and total salt content changed in different patterns, and varied greatly from 2010 to 2016(P<0.05). The changes of both root length and root weight of millet over time fitted S-shaped curves. The root length and root weight in the four fertilization treatments(Treatment 2 to Treatment5) increased faster than those in the control(Treatment 1). The soil organic matter content in all the five treatments gradually increased from 2010 to 2016. The content of alkaline hydrolyzable nitrogen in soil rapidly increased in the first two to three years of the experiment, followed by a slow increase or decrease in 2013, and then raised rapidly again from 2014 to *** soil total nitrogen content varied significantly from 2010 to 2016. The total phosphorus content in soil changed in a different pattern from that of total nitrogen content. The seven-year field trails revealed that soil p H, total salt content, root length, root weight and soil nutrient all changed with the increase of fertilizer level, and that long-term fertilization is of significance for maintaining soil fertility, improving soil quality and reducing soil salinization.

关键词： Site-specific fertilization Physical and chemical properties Nutrient Soil quality

Bifurcation of limit cycles of the nongeneric quadratic reversible system with discontinuous perturbations

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Science China Mathematics 2020年第5期63卷 873-886页

作者： Jihua Yang School of Mathematics and Computer Science Ningxia Normal UniversityGuyuan 756000China

By using the Picard-Fuchs equation and the property of the Chebyshev space to the discontinuous differential system, we obtain an upper bound of the number of limit cycles for the nongeneric quadratic reversible syste... 详细信息

关键词： quadratic reversible system Melnikov function Picard-Fuchs equation Chebyshev space

Effects of Irrigation Amount on Soil Water Content of Gentiana macrophylla

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Agricultural Biotechnology 2022年第4期11卷 83-87页

作者： Xiaojun WANG Xinxue ZHANG Hua LIU guyuan branch of Ningxia Academy of Agriculture and Forestry Guyuan 756000China

[Objectives]This study was conducted to investigate the effects of different irrigation quotas and irrigation times on soil physical and chemical properties and water content in the planting areas of Gentiana macrophylla in dry farming areas of southern Ningxia.[Methods]*** planted for three years was selected as the experimental material,and the water content,nutrients,bulk density and total porosity of the soil at different depths(0-20 and 20-40 cm)were measured under different irrigation quotas and irrigation times.[Results]Compared with the CK,different irrigation quotas and irrigation times could significantly improve the water contents of the 0-20 and 20-40 cm layers in the planting areas of *** change trend of water content at the 0-20 cm soil depth was 3 times of irrigation>2 times of irrigation>1 time of irrigation>CK,and that at the 20-40 cm soil depth was 2 times of irrigation>3 times of irrigation>1 time of irrigation>*** the increase of irrigation times,soil urease in the 0-20 cm soil showed a trend of decreasing at first and then increasing,reaching a maximum value of 0.415 mg/g·24 h with 1 time of irrigation,which increased by 84.44%compared with the CK,and the value with two times of irrigation was basically the same as that of the CK,but 3 times of irrigation resulted in a value 57.33%higher than the ***,the changes of 20-40 cm were the *** change trends of alkali-hydrolyzable nitrogen in the 0-20 and 20-40 cm soil layers with irrigation times was smaller,and the contents of soil organic carbon,available phosphorus and available potassium increased first and then decreased with the increase of irrigation times,and were generally higher than those in the CK.[Conclusions]This study provides a theoretical and technical basis for the artificial cultivation of *** in dry farming areas of Ningxia.

关键词： Irrigation quota Irrigation times Water content Effect

Ultrathin atomic vapor film transmission spectroscopy: analysis of Dicke narrowing structure

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Chinese Optics Letters 2005年第11期3卷 672-675页

作者：李院院张彦鹏甘琛利 Department of Physics Ningxia guyuan Teachers College guyuan 756000 Department of Electronic Science and Technology Xi'an Jiaotong University Xi'an 710049 Department of Electronic Science and Technology Xi'an Jiaotong University Xi'an 710049

Transmission sub-Doppler spectroscopy with confined atomic vapor film between two dielectric walls is theoretically studied. Because of atoms flying from wall to wall, where they get de-excited, the atomfield interaction time is anisotropic so that the contribution of slow atoms is enhanced, a sub-Doppler transmission spectroscopy （Dicke narrowing effect） can be obtained when the thickness of the film is much small or comparable with the wavelength even at small angle oblique incidence. It is feasible to get a sub-Doppler structure in a new region （L 〈 λ/4） in experiments.

关键词： Atoms Dielectric materials Films Light refraction Spectroscopy Transmissions Vapors

Diversity Evaluation of Proso Millet Germplasm Resources in Dryland

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Agricultural Biotechnology 2018年第5期7卷 71-75页

作者： Xiaojuan ZHANG Bingwen CHENG Yong WANG Junxue YANG Shangpei ZHANG Shiwu LUO Xiaojun WANG guyuan branch Ningxia Academy of Agriculture and Forestry

[Objective] This study was to provide a theoretical basis for the selection of the parents of proso millet breeding in dry land of south Ningxia, with the aim to improve the production of hilly proso millet in Ningxia hilly area. [Method] The genetic diversity of 46 accessions of dryland proso millet germplasm at 11 agronomic traits were analyzed by using principal component analysis, Shannon-weaver diversity index and non-weighted matching arithmetic average clustering method （UPGMA）. Cluster analysis was also performed. [Result] The proso millet resources mainly had green inflorescence color, panicle spikes, and yellow grain color. The maximum diversity index of proso millet was 2.03. The variation coefficient of grain weight per plant was 19.23. In all the principal components, the main information concentrated on the first 4 principal components with the cumulative contribution rate reaching 83.34%. The tested materials were clustered into 3 categories at euclidean distance of 0.984 4. The first category contained 41 germplasm resources, the second contained 2, and the third category contained 3. [Conclusion] This study could provide references for the targeted use of drought-resistant parents to select hybrid combinations of proso millet in Ningxia.

关键词： Dryland proso millet Germplasm resource Diversity

Analysis on the Climatic Characteristics of Hail in the South Mountain Area of Ningxia

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Meteorological and Environmental Research 2011年第2期2卷 33-35,39页

作者： RAO Tong-hua CHEN Hai-bo ZHANG Cheng-jun guyuan Meteorological Bureau in Ningxia Guyuan 756000China

[Objective] The research aimed to study the climatic characteristics of hail in the southern mountain area of Ningxia in recent 50 years. [Method] Based on the hail observation data of 5 surface meteorological stations (guyuan, Xiji, Jingyuan, Longde, Liupanshan) in the south of Ningxia during 1960-2009, the spatial distribution rule, the interannual and monthly climatic characteristics and variation trends of hail in the south mountain area of Ningxia were analyzed by using the statistical method. Moreover, the hail disaster prevention and reduction measures in guyuan were put forward. [Result] The hail in the south mountain area of Ningxia in recent 50 years had the obvious annual, seasonal, monthly and daily variation characteristics. The hail might occur from March to October and mainly concentrated during May-August which occupied 72% in the whole year. The occurrence probability of hail in June was the biggest and occupied 21.7% in the whole year. It was the typical multi-hail zone in summer. The interannual variation of hail occurrence in guyuan was big and had 3-year periodicity. The secondary-order time trend of hail in guyuan was the anti-parabolic type, and the hail occurrence times during the 1960s-1980s presented the increase trend. It was the hail multi-occurrence period in the 1970s and 1980s. After the 1990s, the hail presented the decrease trend. In recent 20 years, the hail significantly decreased. The hail in guyuan mainly concentrated during 12:00-21:00, and the hail occurrence times occupied 85% of total times. The hail distribution in guyuan area had the obvious regional characteristics. The hail in the mountain area, hilly area was more and in the stream valley, north Pingchuan area was less. The hail cloud mainly derived from the mountain areas, such as Liupanshan, Nanhua Mountain, Yueliang Mountain, Xifeng Mountain and Yunwu Mountain, etc. The move direction of hail cloud was mainly from northwest to southeast or from north to south. Part of

关键词： Hail Climatic characteristics Variation trend South mountain area of Ningxia China