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气候与人类活动对丹江口上下游植被覆盖变化的影响

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Journal of Plant Ecology 2022年第1期15卷 180-195页

作者： Hai LIU Feng liu Hongmeng Yuan Liang Zheng Yuan Zhang Faculty of Resources and Environmental Science Hubei UniversityWuhan 430062China Key Laboratory of Regional Development and Environmental Response Hubei UniversityWuhan 430062China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China Ecological Research Laboratory Environmental Monitoring Center Station of Hubei ProvinceWuhan 430071China

丹江口水库是南水北调中线工程的水源地,研究丹江口水库植被覆盖动态变化及其影响因素,对于了解南水北调中线工程的生态环境及制定保护措施具有重要意义。本研究采用归一化植被指数(NDVI)分析了1982-2018年丹江口大坝上下游植被的动态... 详细信息

丹江口水库是南水北调中线工程的水源地,研究丹江口水库植被覆盖动态变化及其影响因素,对于了解南水北调中线工程的生态环境及制定保护措施具有重要意义。本研究采用归一化植被指数(NDVI)分析了1982-2018年丹江口大坝上下游植被的动态变化及其影响因素。研究结果表明,研究时段内NDVI呈0.017year-1的增加趋势(P<0.05),显著增加的区域位于大坝上游河谷附近,显著减少的区域主要分布在大坝下游流域和中心城区周围。气候变化和人类活动对NDVI变化的综合贡献率分别为92.03%和7.97%。大坝上游的人类活动主要体现在退耕还林等生态措施的实施,大坝下游的人类活动主要表现为城市扩张、建设用地占用耕地和林地等。

关键词：遥感监测 NDVI 气候变化城市扩张退耕还林

The role of circadian clocks in cancer:Mechanisms and clinical implications

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Genes & Diseases 2023年第4期10卷 1279-1290页

作者： Huiwen liu Ying liu Rihan hai Weihua Liao Xiangjian Luo Key Laboratory of Carcinogenesis and Invasion Chinese Ministry of EducationDepartment of RadiologyXiangya HospitalCentral South UniversityChangshaHunan 410078China Cancer Research Institute School of Basic MedicineCentral South UniversityChangshaHunan 410078China Department of Medicine Hunan Traditional Chinese Medical CollegeZhuzhouHunan 412000China Molecular Imaging Research Center of Central South University ChangshaHunan 410078China Hunan Key Laboratory of Oncotarget Gene Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangshaHunan 410078China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan 410078China

Circadian rhythm refers to the inherent 24-h cycle oscillation of biochemical,phys-iological and behavioral functions,which is almost universal in eukaryotes.At least 14 core clock genes have been reported to form multiple chain feedback loops that confer intrinsic circadian rhythmicity onto the molecular clock.Accumulating evidence has shown that the circadian gene dysfunction resulted from single nucleotide polymorphisms(SNPs),deletions,epigenetic modification,and deregulation is strongly associated with cancer risk.In the pre-sent review,we describe the composition of circadian rhythm system.We highlight the func-tion and mechanism of clock genes in cancer pathogenesis and progression.Moreover,their potential clinical implications as prognostic biomarkers and therapeutic targets have been ad-dressed.

关键词： Cancer Cancer metabolism Circadian clock Circadian rhythm Chronotherapy Tumor microenvironment

D-Shaped Tellurite Photonic Crystal Fiber Hydrogen and Methane Sensor Based on Four-Wave Mixing With SPR Effect

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Photonic Sensors 2023年第1期13卷 25-39页

作者： Hai LIU Bo WU Cong CHEN Benlei ZHAO Xu ZHANG Hancheng ZHANG School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China Engineering Research Center of Intelligent Control for Underground Space(Ministry of Education) China University of Mining and TechnologyXuzhou 221116China

A new D-shaped tellurite photonic crystal fiber sensor based on the four-wave mixing(FWM)effect with the surface plasmon resonance(SPR)effect is designed and optimized.The substrate of the D-shaped photonic crystal fiber(D-PCF)is tellurite glass,and the polished surface is plated with the gold film and hydrogen gas-sensitive film.An air hole of the inner cladding,which is plated with the gold film and methane gas-sensitive film,is selected as the second sensing channel to simultaneously measure the concentration of hydrogen and methane.Based on the four-wave mixing,the wavelength shifts of the Stokes and anti-Stokes spectra resulting from the variation of the gas concentration can be used to accurately detect the concentrations of methane and hydrogen.Meanwhile,it is found that the SPR effect can increase the wavelength shifts,which means the sensitivity of methane and hydrogen augment.After parameter optimization,the maximum sensitivities of methane and hydrogen are 4.03 nm/%and-14.19 nm/%,respectively.Both the linearities are up to 99.9%.The resolution of methane is 1.25×10^(-2)%and hydrogen is 7.14×10^(-3)%.Moreover,the fiber length of this sensor is only 20mm,which is conducive to the construction of a compact or ultra-compact embedded FWM fiber sensor.

关键词： Four-wave mixing surface plasmon resonance D-shaped photonic crystal fiber gas sensing

“社会经济形势分析”课程教学模式创新研究——以北京航空航天大学经管学院教学改革为例

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教育教学论坛 2023年第10期 117-120页

作者：刘宁郑海涛北京航空航天大学经济管理学院北京100191

“社会经济形势分析”是北航经管学院配合“形势与政策”课开设的学生综合素质课程,也是学院开展意识形态教育的重要阵地之一。为适应学生成长需求,提高课程教学质量,更好地发挥思想引领作用,“社会经济形势分析”课程教学改革组围绕加... 详细信息

“社会经济形势分析”是北航经管学院配合“形势与政策”课开设的学生综合素质课程,也是学院开展意识形态教育的重要阵地之一。为适应学生成长需求,提高课程教学质量,更好地发挥思想引领作用,“社会经济形势分析”课程教学改革组围绕加强高校思想政治教育这一目标,提出课程教学改革的“123”模式,即一个中心:以全面提升学生科学精神、人文素养、专业技能、积极心理、管理者禀赋等五方面综合素质为中心;两个基本点:以改革创新教学内容、建立健全课程保障体系为基本点;三个支撑点:以建立复合式教学团队、改进互动式教学方法、创新探究式学习方法为支撑点。

关键词：社会经济形势分析形势与政策课程改革探究式学习教学模式

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Geometric Probability on a Lattice with the 15th Type of Convex Pentagon as a Fundamental Region

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Acta Mathematica Sinica,English Series 2024年

作者： Jiang Fu ZHAO Jun JIANG Hai LIU National Engineering Research Center for E-learning Central China Normal University College of Science Wuhan University of Science and TechnologyHubei Province Key Laboratory of Systems Science in Metallurgical Process Department of Mathematics and Physics Fujian Jiangxia University

In 2015, a group of mathematicians at the University of Washington, Bothell, discovered the15th pentagon that can cover a plane, with no gaps and overlaps. However, research on its containment measure theory or geometric probability is limited. In this study, the Laplace extension of Buffon’s problem is generalized to the case of the 15th pentagon. In the solving process, the explicit expressions for the generalized support function and containment function of this irregular pentagon are derived.In addition, the chord length distribution function and density function of random distance of this pentagon are obtained in terms of the containment function.

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Resonant-Superlinear Nonhomogeneous Dirichlet Problems

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Acta Mathematica Sinica,English Series 2023年第11期39卷 2091-2116页

作者： Zhen Hai LIU Nikolaos S.PAPAGEORGIOU Center for Applied Mathematics of Guangxi Yulin Normal UniversityYulin 537000P.R.China Guangxi Key Laboratory of Universities Optimization Control and Engineering Calculation College of Mathematics and PhysicsGuangxi Minzu UniversityNanning 530006P.R.China Department of Mathematics National Technical UniversityZografou Campus15780 AthensGreece

We consider a Dirichlet nonlinear equation driven by the(p,2)-Laplacian and with a reaction having the competing effects of a parametric asymmetric superlinear term and a resonant perturbation.We show that for all sma... 详细信息

关键词： Asymmetric reaction resonance superlinear term nonlinear regularity comparison principle critical groups solutions with sign information

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Parametric Anisotropic(p,q)-Neumann Problems

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应用数学学报:英文版 2023年第4期39卷 926-942页

作者： Zhen-Hai LIU Nikolaos S.PAPAGEORGIOU Center for Applied Mathematics of Guangxi Yulin Normal UniversityYulin 537000China Guangxi Key Laboratory of Universities Optimization Control and Engineering Calculation Guangxi Minzu UniversityNanning 530006China Department of Mathematics National Technical UniversityZografou Campus15780 AthensGreece

We consider a Neumann problem driven by a(p(z), q(z))-Laplacian(anisotropic problem) plus a parametric potential term with λ > 0 being the parameter. The reaction is superlinear but need not satisfy the Ambrosetti-Rabinowitz condition. We prove a bifurcation-type theorem describing the changes in the set of positive solutions as the parameter λ moves on R_(+)=(0,+∞).

关键词： variable exponent spaces superlinear reaction bifurcation-type theorem anisotropic regularity strong comparison positive solutions

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UCat: heterogeneous memory management for unikernels

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Frontiers of Computer Science 2023年第1期17卷 51-61页

作者： Chong TIAN haikun liu Xiaofei LIAO hai JIN National Engineering Research Center for Big Data Technology and System Services Computing Technology and System Lab/Cluster and Grid Computing LabSchool of Computing Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Unikernels provide an efficient and lightweight way to deploy cloud computing services in application-specialized and single-address-space virtual machines (VMs). They can efficiently deploy hundreds of unikernel-based VMs in a single physical server. In such a cloud computing platform, main memory is the primary bottleneck resource for high-density application deployment. Recently, non-volatile memory (NVM) technologies has become increasingly popular in cloud data centers because they can offer extremely large memory capacity at a low expense. However, there still remain many challenges to utilize NVMs for unikernel-based VMs, such as the difficulty of heterogeneous memory allocation and high performance overhead of address translations.In this paper, we present UCat, a heterogeneous memory management mechanism that support multi-grained memory allocation for unikernels. We propose front-end/back-end cooperative address space mapping to expose the host memory heterogeneity to unikernels. UCat exploits large pages to reduce the cost of two-layer address translation in virtualization environments, and leverages slab allocation to reduce memory waste due to internal memory fragmentation. We implement UCat based on a popular unikernel--OSv and conduct extensive experiments to evaluate its efficiency. Experimental results show that UCat can reduce the memory consumption of unikernels by 50% and TLB miss rate by 41%, and improve the throughput of real-world benchmarks such as memslap and YCSB by up to 18.5% and 14.8%, respectively.

关键词： unikernel virtualization non-volatile memory heterogeneous memory large page slab allocation

Advances in magnetic nanoparticle-based magnetic resonance imaging contrast agents

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Nano Research 2023年第11期16卷 12531-12542页

作者： Huan Zhang Xiao Li liu hai Ming Fan Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China Department of Radiology Zhuhai People’s Hospital(Zhuhai Hospital Affiliated with Jinan University)Zhuhai 519000China Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationProvincial Key Laboratory of Biotechnology of Shaanxi ProvinceNorthwest UniversityXi’an 710069China Institute of Regenerative and Reconstructive Medicine Med-X InstituteFirst Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710049China National Local Joint Engineering Research Center for Precision Surgery&Regenerative Medicine Shaanxi Provincial Center for Regenerative Medicine and Surgical EngineeringFirst Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061China

Magnetic resonance imaging(MRI)has revolutionized medical imaging diagnostics with the advantages of non-invasive nature,absence of ionizing radiation,unrestricted penetration depth,high-resolution imaging of soft tissues,organs and blood vessels,and multi-parameter and multi-sequence imaging.Contrast agents(CAs)are crucial for enhancing image quality,detecting molecular-level changes,and providing comprehensive diagnostic information in contrast enhanced MRI.However,the performance of clinical Gd-based CAs represents a limitation to the improvement of MRI sensitivity,specificity,and versatility,thereby impeding the achievement of satisfactory imaging outcomes.In recent years,the development of magnetic nanoparticle-based CAs has emerged as a promising avenue to enhance the capabilities of MRI.Here,we review the advances in magnetic nanoparticle-based MRI CAs,including blood pool CAs,biochemically-targeted CAs,stimulus-responsive CAs,and ultra-high field MRI CAs,as well as the use of CAs for cell labeling and tracking.Additionally,we offer insights into the future prospects and challenges associated with the integration of these nanoparticles into clinical practice.

关键词： magnetic resonance imaging magnetic nanoparticle blood pool contrast agents biochemically-targeted contrast agents stimulus-responsive contrast agents