Coupled multiphysical model for investigation of influence factors in the application of microbially induced calcite precipitation

The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios.

Interaction and coordinated development between desertification control and social economy in Xizang,China

Based on the general requirements of the coordinated development of"ecological livable"and"affluent life"in the rural revitalization strategy,the evaluation index system of desertification control was constructed,the interaction between desertification control and regional social economy and the internal space-time coordination mechanism were explored,and the quality of desertification control and its coordination degree with regional economic development were quantitatively analyzed.The decoupling mechanism of desertification governance society economy system were analyzed,and the high level for the government to promote desertification governance,constructing ecological economy coordinated development pattern to provide decision basis to Xizang desertification governance-social economic system interaction and coupling coordination development as the research object,introducing the coupling decoupling model to measure the coupling coordination model and system coordination and decoupling decoupling.Desertification control in Xizang shows a trend of gradual improvement,but the overall level is still not high and there is a lot of room for optimization.The coupling coordination degree of desertification control-social and economic system is in a steady fluctuation trend,rising from D value less than 0.55 in 2004 to 0.87 in 2018,in a state of coordinated development(good),and grey prediction analysis shows that D value is in a continuous rise.The coupling coordination degree of the six prefecture-level cities in Xizang and Ngari region is different in time and space,but the overall development trend is coordinated.The development index of desertification control and the socio-economic development index show the interaction of strong decoupling,strong negative decoupling and weak decoupling,and there are interaction effects of desertification control,economic development and social development at different scales.

Measurement for coordinated development of＂four modernizations＂ and its efficiency ofprefecture level cities or above in China

The efficient and coordinated development of industrialization, urbanization, informatization and agricultural modernization(so called 'Sihua Tongbu' in China, and hereinafter referred to as 'four modernizations') is not only a practical need but also an important strategic direction of integrating urban-rural development and regional development in recent China. This paper evaluated the comprehensive, coupling and coordinated developmental indices of 'four modernizations' of China's 343 prefecture-level administrative units, and calculated their efficiency of 'four modernizations' in 2001 and 2011. The efficiency evaluation index system was established. The efficiencies and their changing trend during the period 2001–2011 were investigated using the data envelopment analysis(DEA) model. Spatial-temporal pattern of the efficiency of China's prefecture-level units was explored by using exploratory spatial data analysis(ESDA). Finally, the main influencing factors were revealed with the aid of geographically weighted regression(GWR) model. Results indicate that the comprehensive, coupling and coordinated developmental indices and efficiency of 'four modernizations' of China's prefecture-level administrative units have obvious spatial differences and show diverse regional patterns. Overall, the efficiency is relatively low, and only few units with small urban populations and economic scale are in DEA efficiencies. The efficiency changing trends were decreasing during 2001–2011, with a transfer of high efficiency areas from inland to eastern coastal areas. The difference between urban and rural per capita investment in fixed assets boasts the greatest influence on the efficiency.

Modelling the response of larch growth to age,density,and elevation and the implications for multifunctional management in northwest China

Plantations of Rupprecht's larch(Larix principis-rupprechtii)have been widely established in the drylands of northwest and north China under traditional fastgrowing plantation management strategies.These strategies and the long-term logging ban have led to over-populated stands with lower structural and functional stability,less economic benefit and higher water consumption.To guide the sustainable management of larch plantations,field surveys and historical data compilation were undertaken in the Liupan Mountains of northwest China.The main influencing factors(stand structure and site condition)and their effects on mean tree height,mean DBH and timber volumes were determined based on up-boundary line analysis.Tree growth models coupling the effects of tree age,stand density,and elevation were established.Both height and DBH markedly increased initially and then slowly with tree age,decreased with stand density,and showed unimodal change with elevation.The coupled growth models accounted for72-78%of the variations in tree height,DBH and timber growth.Recommendations for future plantation management are:(1)prolong the rotation to at least 60 years to produce large-diameter,high-quality timber and maintain greater carbon stocks;(2)zone the target functions of stands by elevation;and,(3)reduce stand density for balanced supply of multiple ecosystem services.The growth models developed can predict growth response of larch plantations to density alteration under given ages and elevations,and assist the transformation from traditional management for maximum timber production to site-specific and multifunctional management with longer rotations and moderate tree density.

Coupling and Coordination Characteristics and Influencing Factors of the Livable Environment System for the Elderly in China

The construction of a livable environment for the elderly is an important measure to address the challenges of aging and improve their livelihood and well-being.Based on China’s national conditions and combined with the actual development needs of the cities,it is of great significance to explore the coupling and coordination characteristics and influencing factors within the livable environment system for the elderly for the coordination and stable development.This article was based on the three subsystems of’living service environment,socioeconomic environment and ecological livable environment’,following the research framework of’process-pattern-trend-impact’,constructs an evaluation index system for the livable environment for the elderly.Entropy weight-TOPSIS evaluation model,coupling coordination degree model,center of gravity and standard deviation ellipse model and the geographic detector model were used starting from the evolution of coupling coordination types to study the spatial and temporal pattern and dynamic trend characteristics and influencing factors of internal coupling coordination types in the livable environment system for the elderly from2010 to 2019.The results showed that:1)The coordinated development of life service environment system and ecological livable environment system(LE)and socioeconomic environment system and ecological livable environment system(SE)in the livable environment for the elderly decreased from the intermediate coordination level coordination areas to the low-level quality improvement and optimization areas:coordinated transition type.The overall development level of life service environment system and socioeconomic environment system(LS)was low,and it was always at a low level.2)The coupling degree of livable environment system for the elderly was high,the coupling coordination type shown a gradually decreasing layer structure with Zhejiang,Beijing and Guangdong high-level leading demonstration areas as the axis belt.3)The coupling coordination center of the elderly livable environment system was located in Henan,and the standard deviation ellipse was distributed in the northeast-southwest direction.The development center and the ellipse of the high-level leading demonstration areas and the intermediate coordination level areas were concentrated in the central and eastern regions,while the low-level coordination areas for improving quality and efficiency are mainly located in the western region.4)Urban development,green facilities,infrastructure,government macroscopic regulation and control,economic stimulus,and housing construction were all important factors affecting the coordinated development of the livable environment system for the elderly,exerting a varying degree of effect on the level of coordinated development of various types of systems.

Spatial Heterogeneity and Influencing Factors of HFRS Epidemics in Rural and Urban Areas:A Study in Guanzhong Plain of Shaanxi Province,China

Objective The Guanzhong Plain of Shaanxi Province is a severely afflicted hemorrhagic fever with renal syndrome(HFRS)epidemic area,while HFRS prevalence has decreased in most epidemic areas in China.Little information is available regarding the leading fine-scale influencing factors in this highly HFRSconcentrated area and the roles of natural environmental and socioeconomic factors.To investigate this,two regions in the Guanzhong Plain,that is,the Chang’an District and Hu County,with similar geographical environments,different levels of economic development,and high epidemic prevalence,were chosen as representative areas of the HFRS epidemic.Methods Maximum entropy models were constructed based on HFRS cases and fine-scale influencing factors,including meteorological,natural environmental,and socioeconomic factors,from 2014 to 2016.Results More than 95% of the HFRS cases in the study area were located in the northern plains,which has an altitude of less than 800 m,with topography contributed 84.1% of the impact on the spatial differentiation of the HFRS epidemic.In the northern plains,precipitation and population density jointly affected the spatial differentiation of the HFRS epidemic,with contribution rates of 60.7% and 28.0%,respectively.By comparing the influencing factors of the northern plains of Chang’an District and Hu County,we found that precipitation and the normalized difference vegetation index(NDVI)dominated the HFRS epidemic in the relatively developed Chang’an District,while land-use type,temperature,precipitation and population density dominated the HFRS epidemic in the relatively undeveloped Hu County.Conclusion Topography was the primary key factor for HFRS prevalence in the Chang’an District and Hu County,and the spatial differentiation of HFRS was dominated by precipitation and population density in the northern plains.Compared with the influencing factors of the relatively developed Chang’an District,the developing Hu County was more affected by socioeconomic factors.When formulating targeted HFRS epidemic prevention and control strategies in the targeted areas,it is crucial to consider the local economic development state and combine natural environmental factors,including the meteorological environment and vegetation coverage.

Theoretical and Empirical Analysis on Influence Factors of Modern Agricultural Equipment Level in the Processof Agricultural Sustainable Development

To promote modem agricultural equipment level is one characteristic of constructing and developing modem agriculture in China. This paper makes up stepwise linear regression analysis model of influence factors of modem agricultural equipment level, and chooses rural labor, per capita income of rural residents, rural investment, proportion of people at secondary education level and at higher level in per hundred rural labor force and arable land area as independent variables, and total power of machine as induced variable. The major results show that the relativity of modem ag- ricultural equipment level, rural investment and education level of peasants is remarkable, and they are the major influence factors of modem agricultural equipment level. Raising investment level of rural infrastructure construction as well as and research and devel- opment and promotion of advanced and applicable modem agricultural equipment, improving quality and education level of peasants can accelerate the development of China＇s modern agricultural equipment effectively in the process of agricultural sustainable development.

能源资源开发区域大气CO_(2)时空变化及影响因素分析

分析能源资源开发区域大气碳浓度的时空变化和影响因素,对于探索“碳达峰”“碳中和”背景下能源资源开发高质量发展路径至关重要。新疆维吾尔自治区是我国重要的能源和战略资源基地,本文面向新疆维吾尔自治区的能源资源开发现状,采集并预处理了2015—2021年轨道碳观测卫星-2(Orbiting Carbon Observatory-2,OCO-2)二氧化碳L3数据产品,分析研究区大气碳浓度的时间变化趋势和空间分布格局,构建深度森林回归模型,并分析各影响因素对碳浓度时空变化的驱动作用。结果表明:(1)新疆维吾尔自治区、准噶尔盆地、吐哈盆地和塔里木盆地XCO_(2)浓度在2015—2021年均呈周期性上升趋势,增长率呈“先减后增”,且季节变化趋势呈现明显的“春季高冬季低”;(2)在春、秋和冬季,新疆XCO_(2)浓度空间格局呈现“北高南低”的趋势,在盆地区域及能源资源开发区域出现XCO_(2)高浓度积聚现象,夏季则呈现“北低南高”趋势;(3)地形起伏、风场流速、NDVI、地表温度、降水量、10 mV风、10 mU风和能源开发强度对区域XCO_(2)浓度时空分布有显著影响,各因素呈现明显的空间异质性和显著差异。研究结果有助于理解能源资源开采区域的大气碳浓度时空演变机制,在国家碳减排目标的实现、指导碳中和策略、追踪碳减排效果等方面具有深远意义。

数字经济与海洋经济高质量发展耦合协调分析

数字经济作为经济发展的新动能,为我国海洋经济实现高质量发展提供了新方向。构建数字经济与海洋经济高质量发展的评价指标体系,运用耦合协调模型和障碍因子模型,探究中国11个沿海省区市数字经济与海洋经济高质量发展耦合协调发展现状及其障碍因子。结果发现:①2011—2020年沿海地区数字经济和海洋经济高质量发展的综合发展水平及耦合协调度均呈现上升趋势,其中数字经济发展迅猛,海洋经济发展稳中向好,耦合系统从整体失调状态发展到整体良好耦合协调状态;②沿海各省区市耦合协调度均有不同程度的提升,耦合协调状态空间差异逐渐减小,2020年9个省区市均发展到基本协调状态以上,其中广东处于高度耦合协调状态;③通过障碍度诊断发现,数字经济障碍度具有“数字基础设施>数字产业化>产业数字化”的特征,海洋经济高质量发展层面具有“海洋科技创新>海洋社会效益>海洋经济效益>海洋资源环境”的特征。

我国农村碳排放强度与乡村振兴协同发展分析

基于对2010—2020年中国农村碳排放强度与乡村振兴发展水平的测算,探究两者耦合协调度并进行空间自相关分析,借助面板向量自回归(VAR)模型佐证农村碳排放强度与乡村振兴互动效应。研究结果表明:我国农村碳排放强度波动下降,乡村振兴发展水平持续上升,但区域间发展差异性较大;两者耦合协调度稳步提升,从期初的中等协调转为优质协调状态,空间上存在正相关性,主要表现为高-高集聚和低-低集聚两种分布类型,且集聚程度均逐年减弱;农村碳排放强度与乡村振兴存在长期稳定的协整关系,农村碳排放强度与乡村振兴对自身冲击效应较大,而农村碳排放强度对乡村振兴发展的抑制作用强于乡村振兴对农村碳排放强度的促进作用。基于实证分析,建议加强政策制度建设和碳排放监管、实施补贴政策,并促进农业技术创新,以推动农业生产方式向低碳转型,以实现农村碳排放与乡村振兴的协同发展。

高质量发展目标下脱贫县农业产业化与农地利用生态效率耦合协调分析:以江西省为例

探究脱贫县农业产业化与农地利用生态效率耦合协调关系,对促进农业高质量发展具有重要意义。基于新发展理念,以江西省25个脱贫县为研究对象,构建农业产业化与农地利用生态效率耦合评价体系,借助耦合协调模型和泰尔指数模型测度两者的耦合协调水平及其区域差异。结果表明:(1)2011—2020年,江西省脱贫县农地利用生态效率总体水平较高,年均值为0.738,赣南地区高于赣中和赣北地区;(2)2011—2020年,江西省脱贫县农业产业化发展指数总体水平较低,年均值为0.414,赣北地区最高,其次为赣中,赣南最低;(3)2011—2020年,脱贫县农业产业化与农地利用生态效率耦合协调指数由期初的0.321升至期末的0.342,总体处于中度失调和轻度失调阶段;(4)脱贫县地区内差异对泰尔指数总体贡献最大,县域农业发展协调性较弱。进一步分析可以发现,市场与政府的作用差异是导致农业产业化水平与农地利用生态效率存在差异的主要原因,综合运用行政和市场手段推动农业产业化发展是提高两者耦合协调水平的关键。

浙江省数字经济与绿色发展耦合协调关系测度及政策启示

绿色发展与数字经济的有机融合是实现区域高质量发展的重要途径。本文以浙江省11个地级市为典型案例区,构建了包含7个子系统、37个指标的绿色发展与数字经济评价指标体系,采用改进的耦合协调度模型对2014—2020年数字经济和绿色发展系统的耦合协调关系进行关系测度,以期为区域可持续发展决策提供参考。结果发现:(1)绿色发展系统与数字经济系统综合发展水平总体都呈现上升趋势,除了杭州外,其他城市均表现数字经济发展水平滞后于绿色发展水平。(2)杭州是浙江省的绿色发展和数字经济“领头羊”,并在2019年率先进入高级协调阶段,其余10个城市仍处于初级协调阶段。未来,需注重城市间的差异性发展和重点扶持数字基础设施的投入建设。

黄河流域生态保护与高质量发展耦合协调性及障碍度研究

为给黄河流域生态保护和高质量发展的政策研究提供参考,以2006—2020年黄河流域九省(区)为研究对象,分别构建生态保护与高质量发展评价指标体系,采用熵值法进行测度,并借助耦合协调模型和障碍度模型,探究生态保护与高质量发展2个系统之间的耦合协调关系及其障碍因子。结果表明:1)黄河流域九省(区)生态保护与高质量发展时序上发展态势良好,但各省(区)异质性明显;2)黄河流域生态保护与高质量发展耦合协调度整体处于上升阶段,但水平仍较低,在时序上经历了濒临失调—勉强协调—基本协调的演变历程,在空间上呈现下游>中游>上游的分布格局;3)黄河流域生态保护与高质量发展耦合协调关系主要受污染治理、生态建设和创新发展三重制约,且各省(区)的主要障碍因子存在差异。

光纤耦合光学系统的单模耦合效率研究

单模耦合是光纤耦合光学系统中的关键技术,当前单模耦合过程中还存在一些难题,直接影响单模耦合结果,为了获得更优的单模耦合结果,对光纤耦合光学系统的单模耦合效率进行分析和研究。首先根据单模耦合原理设计了光纤耦合光学系统,并设计了发射端与接收端,然后构建光纤耦合光学系统的单模耦合模型。测试结果表明,设计系统的单模耦合模型优越性十分明显,耦合效率得到了明显提升,为相关光纤耦合光学系统提供了有价值的参考意见。

物流业和制造业融合发展对全要素生产率的影响

基于2006—2020年的省际面板数据,使用耦合协调度模型测算我国物流业和制造业的融合发展水平。研究发现:我国各省份物流业和制造业融合发展度逐步上升,总体上处于低水平向高水平过渡的协调阶段。(1)省际之间物流业与制造业融合水平存在差异,其中浙江、江苏、山东和广东的融合发展水平最高,中部和西部省份融合发展水平提高较快,吉林、黑龙江和辽宁三省则有退步。(2)使用固定效应模型检验两业融合发展对全要素生产率的影响,发现两业融合发展度的提高能够促进区域全要素生产率的提升,该结论在利用IV-GMM和IV-LIML等模型估计下依旧显著。(3)两业融合发展度的提高一方面可以推动全要素生产率边界的扩大,另一方面有利于实际效率趋近最优效率。

移民安置区农地流转意愿影响因素及耦合协调关系研究——以贵州PQ水库为例

移民问题是水利水电项目中的关键问题,关系到社会稳定与乡村振兴。运用地理探测器,因子分析法和耦合协调度模型对水库移民农地转入意愿与安置区农户农地转出意愿影响因素及其耦合协调关系进行研究。研究结果表明:(1)安置点社区融入状况,转入农地的距离,种植业等技能培训,农地价值,家庭农业劳动力人数,非农就业机会对移民农地转入意愿起着主要影响作用;非农就业水平,对土地权益受损的担忧程度,是否有闲置土地,非农就业机会,对土地流转政策了解程度,土地流转收益预期对安置区农户农地转出意愿起着主要的影响作用。(2)各影响因子之间存在两两交互关系,其中任意两因子交互作用后因子解释力均明显增强。转入农地的距离与安置区融入情况的交互作用对移民农地转入意愿的影响力最大;农地细碎化程度,是否有闲置土地,非农就业机会这3个因子与对土地权益受损担忧程度的交互作用对安置区居民农地转出意愿的影响力最大,家庭人均耕地面积安置区居民农地转出意愿具有隐形作用。(3)移民农地转入意愿与安置区农户农地转出意愿存在强关联性,二者相互影响,相互促进,并处于农地转入意愿超前的基本协调阶段。

基层医疗资源配置与经济高质量发展的耦合协调及其预测分析

背景精准识别制约基层医疗资源配置与经济高质量耦合协调发展的因素,对于有针对性地推动两系统耦合协调共进至关重要。然而,当前鲜有研究深入探讨阻碍两者耦合协调发展的关键因素。目的 对比分析“十二五”和“十三五”时期我国基层医疗资源配置与经济高质量发展的耦合协调水平,识别障碍因子,并预测“十四五”时期两系统的耦合协调趋势。方法 于2022年7月—2023年5月,从基层医疗资源配置系统选取卫生设施、卫生人员数、卫生经费3个维度,从经济高质量发展系统选取创新、协调、开放、共享、绿色5个维度,最终选取17项指标建立评价指标体系,指标数据源于2012—2021年的《中国统计年鉴》和相应卫生健康统计年鉴。借助熵值法与综合评价函数测算“十二五”与“十三五”时期基层医疗资源配置与经济高质量发展的综合评价值,通过构建耦合协调度模型测算其耦合协调水平,建立障碍函数诊断与识别影响耦合协调发展的障碍因子,引用灰色模型预测“十四五”期间两系统的耦合协调趋势。结果 “十二五”和“十三五”期间我国基层医疗资源配置与经济高质量发展耦合协调度由0.15上升到0.68,整体呈逐年上升的态势,虽增速较快但层次较低。卫生设施、卫生人员数、经济共享与绿色发展是制约“十二五”与“十三五”时期基层医疗资源配置与经济高质量发展二元复合系统耦合协调水平的主要障碍因子。借助修正GM(1,1)预测模型预测可知,“十四五”时期基层医疗系统与经济发展水平系统的耦合度在1.00左右微浮动,整体处于高耦合阶段,耦合协调度由0.73上升至1.12,总体呈上升态势,相对发展度>1.20,处于过度供给状态。结论为赋能基层医疗卫生体系的可持续发展,建议秉承绿色、共享的发展理念,从促进系统协调发展、完善基层医疗设施条件和打通基层医疗人才输送路径等方面着手,推动两系统和谐发展。

数字经济、环境规制与可持续发展耦合协调度时空分异及影响因素研究

数字经济和环境规制是可持续发展的重要驱动因素,探讨三者的耦合关系对促进区域经济、社会和环境协调发展具有重要意义。通过对2011—2020年我国30个省份的数字经济、环境规制与可持续发展水平进行测算,构建耦合协调度模型识别三者耦合协调发展的时空分异特征,并引入时空地理加权回归模型(GTWR)探究耦合协调度的影响因素。研究结果表明:(1)数字经济、环境规制与可持续发展水平呈现波动增长趋势,其中环境规制综合水平最高;(2)三者耦合协调度存在时空差异,时间层面上全国耦合协调度位于中等和良好协调之间,总体呈现“W”型上升态势,空间层面上“链条式”和“组团式”特征明显,呈现“马太效应”;(3)耦合协调度存在显著的空间自相关性,局部上表现为“高—高”“低—低”集聚模式;(4)产业结构、政府能力和国际贸易是耦合协调度提升的主要因素,研发资金、人口压力成为抑制因素。

茶文旅耦合协调发展分异及其影响因素——以云南省30个茶叶重点县为例

茶文旅协调发展是促进农文旅融合与乡村全面振兴的重要途径。基于云南30个茶叶重点县的茶文旅产业数据,对其发展水平、耦合协调度及影响因素进行实证研究,构建协调发展机制。研究表明:云南30个茶叶重点县的茶产业、文化产业、旅游产业发展水平存在显著差异,茶文旅产业综合发展排前6位的依次是景洪市、腾冲市、思茅区、澜沧县、勐海县、勐腊县;茶文旅三系统和三类双系统呈现不同耦合协调发展态势,其中,茶-文化-旅游三系统耦合协调度以濒临失调情况居多,但景洪市、腾冲市、思茅区、澜沧县达到了中级协调;旅客周转量、茶产业政策、茶叶专业合作社、规模以上文化产业企业等市场、政策、技术方面的因素对耦合协调发展有极大影响。据此,各县需因地制宜,实行差异化的茶文旅融合发展战略。

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。