Coupling coordination analysis of Mazu culture,socio-economy and ecological environment of Meizhou Island

Taking the pilgrimage,tourism and cultural island of Meizhou Island as an example,the evaluation index system of the coupling and coordinated development of“Mazu culture,socio-economy,eco-environment”(MSE)compound system was constructed.The index weights were determined by AHP-entropy method,and the coupling degree,coordinated degree,comprehensive evaluation index and grey correlation degree of MSE system of Mazu Island from 2012 to 2022 were measure.The results showed that:(1)the comprehensive evaluation indexes of the three subsystems was on the rise in general,but the evaluation index of the ecological subsystems increased relatively slowly.(2)The coupling degree was only in the running-in stage in 2012,and the other years were in the coordinated coupling stage.(3)The coupling coordination degree increased from 0.35 in 2012 to 0.82 in 2022,the coupling coordination level was changed from mild imbalance to good coordination.(4)Through the comparison of grey correlation degree,the 24 indexes in the evaluation index system had great influence on the coupling coordination degree of MSE system.The coupling coordination degree was closely related to the development of socio-economy and the spread of Mazu culture.With the rapid development of tourism brought about by the spread of Mazu culture,the pressure on the ecological environment will be increasing.Compared with the rapid growth of tourism and economy,it is equally important to strengthen environmental protection and pay attention to the quality of ecological environment development.

Development of a Meteorological and Hydrological Coupling Index for Droughts and Floods along the Yangtze River Valley of China

To comprehensively investigate characteristics of summer droughts and floods in the Yangtze River valley, a meteorological and hydrological coupling index （MHCI） was developed using meteorological and hydro- logical data. The results indicate that： （1） in representing drought/flood information for the Yangtze River valley, the MHCI can reflect composite features of precipitation and hydrological observations; （2） compre- hensive analysis of the interannual phase difference of the precipitation and hydrological indices is important to recognize and predict annual drought/flood events along the valley; the hydrological index contributes more strongly to nonlinear and continuity features that indicate transition from long-term drought to flood conditions; （3） time series of the MHCI from 1960-2009 are very effective and sensitive in reflecting annual drought/flood characteristics, i.e. there is more rainfall or typical flooding in the valley when the MHCI is positive, and vice versa; and （4） verification of the MHCI indicates that there is significant correlation between precipitation and hydrologic responses in the valley during summer; the correlation coefficient was found to reach 0.82, exceeding the 0.001 significance level.

Coupled effects of climate change and human activities on vegetation dynamics in the Southwestern Alpine Canyon Region of China

The driving effects of climate change and human activities on vegetation change have always been a focal point of research.However,the coupling mechanisms of these driving factors across different temporal and spatial scales remain controversial.The Southwestern Alpine Canyon Region of China(SACR),as an ecologically fragile area,is highly sensitive to the impacts of climate change and human activities.This study constructed a vegetation cover dataset for the SACR based on the Enhanced Vegetation Index(EVI)from 2000 to 2020.Spatial autocorrelation,Theil-Sen trend,and Mann-Kendall tests were used to analyze the spatiotemporal characteristics of vegetation cover changes.The main drivers of spatial heterogeneity in vegetation cover were identified using the optimal parameter geographic detector,and an improved residual analysis model was employed to quantify the relative contributions of climate change and human activities to interannual vegetation cover changes.The main findings are as follows:Spatially,vegetation cover exceeds 60%in most areas,especially in the southern part of the study area.However,the border area between Linzhi and Changdu exhibits lower vegetation cover.Climate factors are the primary drivers of spatial heterogeneity in vegetation cover,with temperature having the most significant influence,as indicated by its q-value,which far exceeds that of other factors.Additionally,the interaction q-value between the two factors significantly increases,showing a relationship of bivariate enhancement and nonlinear enhancement.In terms of temporal changes,vegetation cover shows an overall improving trend from 2000 to 2020,with significant increases observed in 68.93%of the study area.Among these,human activities are the main factors driving vegetation cover change,with a relative contribution rate of 41.31%,while climate change and residual factors contribute 35.66%and 23.53%,respectively.By thoroughly exploring the coupled mechanisms of vegetation change,this study provides important references for the sustainable management and conservation of the vegetation ecosystem in the SACR.

Strip Waveguide Directional Coupling Modulator with Equivalent Refractive Index

The equivalent refractive index（ERI） method is employed to analyze the function of the strip waveguide directional coupling modulator（SWM）. Through deducing the diagnostic equation of the Exmn mode of the four-layer media film waveguide equivalent to the SWM,the transmission constant of the symmetrical mode of the positive phase and negative one and the coupling length of powerful transference are obtained. The veracity of ERI is validated with the example of Ex11 basal mode under conditions of comparing the three results of ERI,EIM and Marcatili.

Derivation of General Formula for Coupling Loss of Single-mode Fiber Collimators with Gradient-index Rod Lenses

Gradient-index rod lens (GRIN-lens) whose pitch is ordinary value with bevel ferrule coupling system is analyzed, an equivalent method which can be used to analyze this system is put forward, and a general formula for determining the coupling loss with axes mismatch, radial mismatch, and angular mismatch is derived by use of the Gaussian field approximation and mode-field coupling theory. The experimental results are in good agreement with the theory prediction. It indicates that these formulas are suitable to analyze the gradient-index rod lens coupling system with pigtail fiber.

Durability of Reinforced Concrete Structures under Coupling Action of Load and Chlorine Erosion

Diffusion behavior of chloride ion in reinforced concrete under bendingmoment was studied by taking the ratio of bending moment to ultimate flexural capacity asload level indicator. The function relationship between load level and chloride iondiffusion coefficient was established, based on that the limit state equation of the chlorideion critical concentration and chloride ion concentration on surface of the steel bar wasestablished. Then by applying Monte-Carlo method the corrosion probability ofreinforcement under different load levels in splash zone was calculated. Calculation resultsdemonstrated that compared with the durability reliability index considering loading effect,the reliability index without considering loading effect could be 100% higher. Inconsideration of requirement for concrete durability, some revision suggestion was putforward. It was recommended that for beam members with different design life in splashzone, the corresponding minimum cover thickness should be adjusted properly as well aswater-cement ratio limit.

Spatial-temporal characteristics of the coupling coordination of social security and economic development in China during 2002–2018

Clarifying the relationship between social security and economic development is helpful to realize the sustainable social security system and the stable function of sustainable economic development.In this paper,the entropy method,coupling coordination degree,standard deviation ellipse model,and spatial autocorrelation were used to study the spatial-temporal characteristics of coupling coordination of social security and economic development in China from 2002 to 2018.The results indicate that the relationship between social security and economic development in China has been gradually strengthened in the process of mutual adaptation and common development.The benign interaction between the two was unstable,though the coupling coordination degree gradually transitioned to the primary coupling coordination type.Besides,from a spatial perspective,first,the coupling coordination degree of social security and economic development in China contracted in the east-west and north-south directions,and the coupling coordination clustered in the central region in this period;second,the coupling coordination degree generally presented a positive spatial autocorrelation,and regions with similar coupling coordination degrees were in a state of agglomeration;finally,the hot spots clumped together to form a continuous area in the eastern coastal area while the cold spots expanded toward the northwest and northeast.Furthermore,the random distribution areas exhibited a trend of contraction.

An exact inflationary solution in the chaotic model with non-minimal coupling

This paper presents a new exact inflationary solution to the non-minimMly coupled scalar field. The inflation is driven by the evolution of a scalar field with inflation potential V（φ） = （λ/4）φ4 ＋ b1φ2 ＋ b2 ＋ b3φ-2 ＋ b4φ-4. The spectral index of the scalar density fluctuations ns is consistent with the result of WMAP3 （Wilkinson Microwave Anisotropy Probe 3） for ACDM （Lambda-Cold Dark Matter）. This model relaxes the constraint to the quartic coupling constant. And it can enter smoothly into a radiation-dominated stage when inflation ends.

Study of Mode Coupling on Coaxial Resonators

A study of mode coupling phenomenon of coaxial resonators has been conducted with theories. Through establishing the source-free transmission line equation, boundary conditions of the coaxial resonators with a corrugated inner conductor are analyzed. In the end, calculations are performed in a wide range of corrugation parameters for the resonator of the Karlsruhe Institute of Technology （KIT） relevant coaxial gyrotron.

Coupling analysis of the major impact on sustainable development of the typical arid region of Turpan in Northwest China

Analyzing the sustainable development of a given region can provide an important reference and guide for future orientation.The study selects Turpan(including Gaochang District,Shanshan County,and Toksun County)in Xinjiang Uygur Autonomous Region of Northwest China as the study area and first investigates the essence of regional sustainable development.Based on the relevant data of the population,economy,and environment of Turpan from 2002 to 2018,we constructed an evaluation index system for three dimensions,namely,the population,economy,and environment,and analyzed them systematically.Specifically,we quantitatively calculated the comprehensive evaluation index,coupling degree,and coupling coordination degree of the sustainable development system of the study area.The study finds that Turpan has become increasingly sustainable and orderly;the development level has continually improved from near imbalance to positive coordination.During the study period,the government has adopted appropriate models and paths to promote positive interactions among the population,economy,and environment based on engineering techniques and ecological means.The results show that the coupling coordination degree has increased from 0.3692 to 0.8894 during the period 2002–2018,which reflects the actual situation of Turpan and indicates that the proposed analysis method can effectively measure and evaluate the level of sustainable development in this region.Moreover,the study also puts forward main functional zoning of Turpan(i.e.,Gaochang District as an optimized development zone,Shanshan County as a major agricultural production zone,and Toksun County as a key ecological function zone)and regional planning principles based on the population,economic,and environmental coupling analysis for the three jurisdictions in Turpan.

Compact and high-efficient wavelength demultiplexing coupler based on high-index dielectric nanoantennas

Wavelength demultiplexing waveguide couplers have important applications in integrated nanophotonic devices. Two of the most important indicators of the quality of a wavelength demultiplexing coupler are coupling efficiency and splitting ratio. In this study, we utilize two asymmetric high-index dielectric nanoantennas directly positioned on top of a silicon-on insulator waveguide to realize a compact wavelength demultiplexing coupler in a communication band, which is based on the interference of the waveguide modes coupled by the two nanoantennas. We add a Au substrate for further increasing the coupling efficiency. This has constructive and destructive influences on the antenna＇s in-coupling efficiency owing to the Fabry-Perot（FP） resonance in the SiO2 layer. Therefore, we can realize a wavelength demultiplexing coupler with compact size and high coupling efficiency. This coupler has widespread applications in the areas of wavelength filters,on-chip signal processing, and integrated nanophotonic circuits.

河北省休闲农业与旅游业耦合协调关系研究

休闲农业是一项旅游性较强的新兴产业,深入探索休闲农业与旅游业的耦合协调关系是促进两者可持续发展的重要基础。基于此,本研究以河北省为例,构建休闲农业与旅游业评价指标体系,采用熵权法确定指标权重,利用线性加权法测算两系统的综合发展指数,最后利用耦合协调度模型测算2013—2022年河北省休闲农业与旅游业的耦合协调度。实证结果表明:河北省休闲农业与旅游业综合发展指数变动趋势大体保持一致,整体呈现先升后降的趋势,呈现倒“V”型态势,2013—2019年指数上升,2019年后受疫情影响逐渐下降;两系统耦合度较低,目前处于拮抗阶段,耦合协调度发展经历了中度失调、轻度失调、濒临失调、勉强协调、初级协调、勉强协调、濒临失调7个阶段,后期疫情对于两系统的发展影响较大;在划分类型上,以休闲农业主导性为主,两大系统相互支撑、相互促进作用显著。基于此,促进河北省休闲农业与旅游业耦合协调关系进一步健康发展,应建立耦合协调发展管理机制、加强政府扶持及完善基础设施等。

基于功率诊断的微波辅助点火能量沉积研究

基于功率诊断方法,研究了不同微波参数(脉冲波形和馈入延迟时间)下对微波辅助点火的增强效果,精确测量了点火过程中与火核耦合的微波能量,并分析了能量耦合的内在机制.结果表明:入射的部分微波能量以产生等离子体的形式耦合到点火火核中,耦合能量随微波脉冲功率的增大而提高,随延迟时间的增大而减小,最高耦合能量达到6.16 mJ;火核的增强效果与耦合能量的变化趋势一致,表明耦合的微波能量是点火增强的内在原因;能量耦合效率(耦合能量/入射能量)一般随脉宽和延迟时间增大而减小,最高耦合效率达到7.23%;并发现了微波能量耦合过程中存在从较低的效率转变到较高的稳定耦合效率的现象,将后者定义为饱和耦合模式;脉冲持续时间内到达饱和耦合模式的转变过程越短,能量耦合效率越高;饱和耦合模式下的能量耦合效率不受微波参数的影响,但高功率短脉宽的脉冲波形和低延迟时间能够更快达到饱和耦合模式,明显提高点火增强效果.

北京市滨水空间环境品质提升的潜力分析探索

城市滨水空间的综合治理工作越来越表现出持续性、系统性、复杂性的特点,行业对滨水空间治理提升的重点以及建设时序的把握仍存在偏差。本文以北京市中心城重要河道为例,首先甄别滨水空间环境品质核心评价指标,运用时空大数据并结合GIS空间分析方法,对滨水空间现状情况进行定量化的全要素评价。短板指标统计发现,新时期河道及滨水空间品质提升的主要关注焦点为交通可达性的提升、人文及配套服务设施的完善、绿地开放空间的营造等。其次调研剖析滨水空间环境品质优劣的内驱动力,提出了多维度、多层次、全要素的城市滨水空间潜力分析指标体系,构建了“供给-需求”耦合互动模型,建立了城市滨水空间潜力分析研究方法。通过供需匹配分析发现并非高需求河道都得到了相应的治理,另外也存在治理超前或者过度治理的情况。最后,基于滨水空间潜力分析评价结果和两岸土地资源,制定了“三级-两类”治理行动方案,突出规划引领作用,注重滨水空间提升改造与城市片区整体的发展建设和需求的匹配,形成良性互动的机制。

黄河流域城市群水资源利用与城市发展协调水平评价

黄河流域城市群水资源利用与城市发展交互状态是影响流域城市群高质量发展的关键,亟须在可持续发展目标下探讨二者之间的耦合协调关系,为探索黄河流域城市群生态保护与高质量发展协同机制提供新思路。以黄河流域5个城市群为例,依据联合国提出的可持续发展目标,建立2010—2019年水足迹与城市发展指数的耦合协调度及水资源利用差异分析框架,采用Theil变异指数方法,对耦合协调结果的空间差异进行评价。结果表明:2010—2019年黄河流域城市群水足迹年均减少0.43%,城市发展指数年均增长0.73%,二者耦合协调等级呈升—降—升的不稳定状态;城市群水资源利用水平差异是造成城市发展水平差异的主要原因,且在不同城市群发展阶段中水资源利用与城市发展协调关系差异显著。建议构建跨域水资源共治体系、发挥城市群水资源公共政策的调节作用、系统规划城市群水环境保护与水资源开发利用安全格局。

干旱区农业农村现代化发展水平测度及阻碍因素研究——以张掖市为例

干旱区农业农村现代化实现对促进国家粮食安全、水安全、生态安全,推进乡村振兴意义重大。以位于西北干旱区张掖市为研究区域,基于农业农村现代化内涵,从8个维度出发构建一个包含22个具体指标的农业农村现代化评价指标体系,运用熵权综合评价法对2001-2019年该区域农业农村现代化发展水平及障碍因素进行分析。结果表明,(1)农业农村现代化发展水平总体呈现波动下降再上升趋势,发展阶段已从尚未实现过渡到初步实现。(2)各子系统发展水平和速度存在明显差异,农村公共服务、农业生产体系和农业经营体系贡献最大,农村公共服务、农业生态环境和农业生产体系是农业农村现代化发展水平提升的三大“短板”子系统。(3)万人拥有文化站数、森林覆盖率、有效灌溉率和单位面积农药施用量是制约张掖市农业农村现代化水平提升的主要因素。最后,从农业现代化,农村现代化以及两者协调发展三个方面提出相关的政策建议。

新质生产力与数字经济高质量发展的耦合协调度研究——基于我国30个省(区、市)的面板数据

利用2012—2022年我国30个省(区、市)的面板数据,采用熵值法和线性加权法对新质生产力和数字经济高质量发展的综合评价指数进行测算。在此基础上,利用耦合协调度模型研究新质生产力与数字经济高质量发展的耦合协调水平。研究结果显示:我国新质生产力与数字经济高质量发展的耦合协调度大致呈逐年递增的趋势;两者的耦合协调度从高到低依次为东部地区、中部地区、西部地区、东北地区;按耦合协调类型划分,东部地区已处于初级协调水平,中部地区处于勉强协调水平且基本上代表全国平均水平,西部地区和东北地区仍处于轻度失调水平;共有6个省份的耦合协调水平较高,11个省份的耦合协调水平较低,13个省份的耦合协调水平处于中间位置。基于研究结论,提出如下对策:坚持创新驱动发展战略,完善科技创新体系;深入实施区域协调发展战略,积极发挥政府职能;加大新型基础设施建设投入力度,健全创新人才培养机制。

绿色转型与经济发展的耦合协调度分析——基于我国31个省(自治区、直辖市)面板数据的实证分析

中国式现代化是人与自然和谐共生的现代化,协同推进绿色转型与经济发展是实现高质量发展的必然要求。选取2011—2021年全国及31个省(自治区、直辖市)的面板数据,构建综合评价指标体系和耦合协调度模型,并测算各地区耦合协调度的莫兰指数。研究发现:全国绿色转型与经济发展指数总体呈大幅上升趋势,2021年分别达到0.840、0.809,较2011年分别上涨715.5%、235.7%。耦合协调度仅在2011年表现为轻度协调,2021年达到优质协调,说明绿色转型与经济发展之间不是“零和博弈”,必须协同推进、坚定不移地走绿色经济发展道路。各地区绿色转型与经济发展存在异质性,失调成因存在显著差异,广东省等7个省(自治区、直辖市)绿色转型与经济发展水平均高于全国平均水平,在绿色转型与经济发展的道路上起到带头作用,黑龙江省等8个省份绿色转型与经济发展水平均低于全国平均水平,原因在于这些地区对传统化石能源依赖程度较高,产业转型压力较大。地区间耦合协调度存在空间溢出效应,15个省(自治区、直辖市)与周边地区存在显著正向相关关系,表现出“辐射”效应,北京等3个省(自治区、直辖市)与周边地区存在负相关,出现“虹吸”效应,这导致京津冀区域耦合协调度差距拉大。为进一步提升我国及各省(自治区、直辖市)绿色转型与经济发展的耦合协调度,提出坚定绿色发展道路,强化绿色转型与经济发展协同推进顶层设计、建立科学合理的绿色高质量发展体制机制、抢抓机会,转化“虹吸”效应为“辐射”效应、攻关能源技术,助力重化工业地区加速能源体系转型的政策建议。

社会保障质量与经济高质量发展协调性研究:脱钩与耦合视角

社会保障与经济高质量发展是实现共同富裕的重要行动途径。从系统论视角分析社会保障与经济两大系统的学理关系,并基于中国省级面板数据对社会保障质量与经济高质量发展指数分别进行综合测度,利用脱钩理论与耦合协调度分析两者之间的动态关系。研究发现:(1)社会保障质量与经济高质量发展指数均呈现逐年递增趋势,但两者在整体上呈现脱钩、负脱钩与连结波动特征,主流脱钩状态呈现“递进恶化”,各省份经济高质量发展主要表现出低效扩张型趋势;(2)两系统的耦合度与耦合协调度虽均呈逐年上升趋势,但仍处于较低的协调状态;(3)异质性分析中,社会保障与经济高质量发展的系统耦合协调度在东部地区从勉强协调转向初级协调,中部地区从濒临失调向勉强协调演进,西部地区从轻度失调转向濒临失调。总之,做大蛋糕是社会保障稳定运行的物质基础,分好蛋糕是社会保障有效运行的保证。

长江流域旱涝急转演变特征及其社会经济暴露度

旱涝急转是指干旱和洪水之间的快速转变,对农业生产和人类安全造成巨大威胁。本研究基于月尺度的旱涝急转量级指数,分析了长江流域历史和未来四种旱涝急转事件,并通过滑窗法构建了旱涝急转量级的时变函数,揭示了未来旱涝急转风险变化。同时,结合共享社会经济路径量化了人口和经济受旱涝急转风险变化影响的程度。结果显示,历史时期长江流域中下游旱涝急转事件频发,旱–涝和涝–旱事件每10年发生10~12次,而旱–涝–旱和涝–旱–涝事件每10年发生3~4次。未来旱–涝–旱和涝–旱–涝事件预计大幅增加,其中长江上游部分地区增长了约7倍。对于历史基准期50年一遇的旱涝急转事件,未来发生概率将增加5~10倍,给长江流域的人口和经济带来重大影响。