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  • WANG Fangfang, LU Hongbin, WANG Xiuxiu, YANG Yan, XIU Yuxin
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    The study of microstructural changes in loess during the consolidation creep process helps to gain a deeper understanding of the evolution mechanisms of soil mass.This study takes the loess in the Yan'an region as the research object,examines samples at different stages of the consolidation creep test by scanning electron microscopy,and conducts qualitative and quantitative analysis on the microscopic images using IPP (image pro plus)and Matlab software,thereby exploring the microscopic creep mechanism of compacted loess.The results show that during the consolidation creep process,the flocculent structure and aggregate structure of compacted loess increase,and the soil particle morphology gradually changes from granular and blocky to granular-agglomerate.The overall pore structure decreases while the number of small pores increases.The number of elongated soil pores and particles decreases slightly,showing an overall tendency towards oblate shape,and the soil structure tends to be stable.The orientation of soil pores is less obvious,but the soil particles exhibit significant orientation,predominantly in the range of 80° to 90° ,indicating a tendency towards ordered arrangement.
  • WANG Jixin, LI Jiahao, HU Zhangqi
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    The segmentally prestressed cylindrical reticulated mega-structure is a novel hybrid spatial structure proposed to accommodate the development of super-large-span structures.The members in the upper reticulated mega-structure are highly prone to buckling due to their large slenderness ratios and high stress, and neglecting their influence may lead to unsafe results.To accurately reveal the stability performance of this new structure,this study conducted an in-depth investigation on the coupling effect between member buckling and global structural stability under a full-span uniformly distributed load.First,a quantitative analysis was performed by comparing the stable bearing capacity and buckling mode to assess the influence of member buckling.Then,by tracking the stress changes in each member during the global buckling process,the development and propagation law of member buckling as well as the distribution area of buckled members during the global buckling process were revealed.The results indicate that:1)Member buckling reduces the structural stable bearing capacity by over 30% ,diminishes the efficiency of the segmental cable-strut prestressed system,and also alters the global instability mode; 2 )The lower chord members near the supports in the middle section of the structure buckle first,after which member buckling gradually propagates toward the supports along the truss arch and along the longitudinal direction towards both ends of the structure;3)The buckled members are mainly distributed within an arc length of 1/6 of the span near the supports on the left side of the structure,with only a small number distributed near the supports in the central section of the right side.
  • CAO Yaolin, ZENG Zhiwei, YAN Jie, LIU Sijia, LIU Jiaying
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    First,based on the literature from the core databases of CNKI(China National Knowledge Infrastructure)and WOS(Web of Science),this study systematically analyzes the research hotspots and development trends of urban community renewal in China and abroad by using CiteSpace software;then,it provides a review of community renewal from both theoretical and practical perspectives based on existing literature;finally,considering the context of urban renewal and high-quality development,it proposes future research directions for urban community renewal.The analysis shows that:1)Chinese research emphasizes government-led spatial transformation and resident participation in governance,with debates focusing on environmental governance and property rights distribution,whereas international studies primarily focus on multi-stakeholder collaboration and environmental justice;2)Chinese research has gradually shifted from the transformation of material space to the concern of people-oriented needs,while international research has changed from focusing on management methods and economic development to collaborative planning and sustainable development;3)Chinese research on urban community renewal still has shortcomings in interdisciplinary integration,resident participation,social organization and market power activation.
  • XIAO Tieqiao, XU Yunqiang, ZHANG Shaojie, GAN Shenqi
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    The acute man-land conflict in mountainous counties has made optimizing land use and balancing the relationship among farmland conservation,economic development,and ecological restoration a central issue today.Taking Taihu County in Anqing City,Anhui Province as a case study,this research first constructs the Sustainable Development Index(ISDI)based on a multidimensional evaluation system and employs the PLUS model for multi-scenario simulation;it then analyzes the land change characteristics from 2000 to 2020 and the forecast period using a transition matrix;finally,it integrates land use change patterns constrained by topography with multidimensional,multi-scenario evaluations to comprehensively analyze multi-scenario development suitability and reveal the impacts of land use changes on sustainable development. Results indicate that:1)From 2000 to 2020,forest land constituted the primary land use type in Taihu County. The significant expansion of construction land resulted from encroachment on farmland.Under mountainous terrain constraints,ecological land was concentrated in the central and western mountainous areas,while construction land and farmland competed for the gently sloping,high-quality land resources in the southeast. 2)Under multi-scenario simulations,the 2030 land use patterns and multidimensional development suitability varied significantly.Under the natural development scenario,substantial expansion of construction land squeezed the space of farmland and water bodies,resulting in the lowest ISDI ;Under the farmland protection scenario, growth in both farmland and construction land led to issues such as forest land reduction,ecological space fragmentation,and water resource pressure,with ISDI slightly increasing compared to the natural development scenario.Under the ecological protection scenario,expansion of all land categories was effectively controlled, achieving the highest ISDI .3)Land use in Taihu County is significantly influenced by topography.The ecological protection pathway effectively balances food security,economic development,and ecological security,representing a scientific pathway for Taihu County and similar regions to achieve sustainable development.
  • CHEN Wu, LI Guo, HU Wenmin
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    As an important venue for people's daily life and recreational activities,enhancing the vitality of urban park green spaces is of great significance for optimizing the layout of public spaces,improving residents'quality of life,and promoting the urban sustainable development.Currently,it has become a hot topic in urban space research,with increasing research achievements and social attention.This study first systematically analyzes the evolutionary trajectory of research on park green space vitality using the CiteSpace knowledge mapping tool based on the CNKI(China National Knowledge Infrastructure)and WOS (Web of Science)databases.Secondly,according to national policy guidance and mutation nodes of bibliometric analysis,the research is divided into three stages:the preliminary theoretical exploration stage (before 2012),the mid-term empirical stage(2012 to 2019),and the current information deepening stage (2019 to present).Thirdly,this study summarizes the research focus and development directions of each stage, identifies current research gaps,and proposes future research directions.
  • ZHENG Zhun, CHEN Hua, ZHANG Fan
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    Effectively enhancing urban innovation capability is essential for building Hunan into an innovative province and creating a"highland of scientific and technological innovation"in inland China.This study constructs a three-dimensional evaluation index system encompassing innovation input,innovation output,and innovation environment support,employing an improved TOPSIS model,ArcGIS spatial visualization analysis,and coupling coordination model to systematically analyze the spatiotemporal evolution of urban innovation capability in Hunan Province from 2014 to 2022.The findings reveal that:1) Urban innovation capability in Hunan exhibits significant spatiotemporal differentiation,with innovation input showing an"east-high,west-low"gradient distribution,innovation output displaying widening regional gaps while expanding toward central and western areas,and innovation environment support tending toward convergence while maintaining its overall spatial pattern;2)The coupling coordination degree of urban innovation capability among Hunan's cities demonstrates"central agglomeration and peripheral differentiation"characteristics,with most cities remaining in a discoordinated state;3)The lag in the coupling coordination of urban innovation capability in Hunan manifests in three typical modes:the"innovation input-innovation output lag"type represented by Yueyang,the"innovation output-innovation environment support lag"type represented by Xiangtan and Hengyang,and the"comprehensive lag"type represented by Changde,Shaoyang,and others.Based on these findings,the study proposes policy recommendations for constructing differentiated mechanisms for enhancing urban innovation capability,optimizing the allocation of regional innovation resources,and improving the regional innovation governance system.
  • ZHOU Cheng, ZHENG Weimin, LI Sheng
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    Against the backdrop of new urbanization,with urban spatial expansion,population and industrial agglomeration,and diversified travel demands of residents,public transport,as a core urban infrastructure,requires rational layout planning.Traditional evaluations rely on static statistics and manual surveys,suffering from data lag,lack of spatial dimension,and inaccurate depiction of supply-demand matching,making it difficult to support refined decision-making.Taking the urban area of Hengyang as the research scope,this paper proposes a comprehensive evaluation framework for public transportation based on POI(Point of Interest)data,including commercial,residential,office,and other functional locations. Combined with spatial analysis technology,this study constructs an evaluation system covering public transport route density,station coverage,functional mixing degree of POI,and spatial supply-demand matching degree to realize multi-dimensional quantitative evaluation.The results show that POI data can accurately capture urban spatial characteristics and compensate for the deficiencies of traditional methods. Public transport services in Hengyang's core urban areas(Zhengxiang District,Shigu District)are of high quality,while emerging areas face problems such as sparse public transport routes,unreasonable layout,and low supply-demand adaptability.Finally,the study proposes several targeted suggestions to address these deficiencies.
  • LI Yuan, CHEN Lurong, FANG Suyi, LONG Xixuan, TANG Kaien, LIU Zhanjun
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    After honeydew melon is consumed,a large amount of peel waste is produced,which will cause environmental pollution if not handled properly.In this study,a superabsorbent resin was prepared from honeydew melon peel as raw material,acrylic acid as monomer,and modified palygorskite using solution polymerization method.The effects of different factors on its water absorption performance were investigated. The superabsorbent resin under the optimal preparation conditions was also characterized by Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The results showed that when the mass ratio of honeydew melon peel to acrylic acid was 9:100 ,the neutralization degree was 80% , the content of modified palygorskite was 9% ,the content of cross-linking agent was 0.30% ,and the content of initiator was 1.2% ,the superabsorbent resin exhibited the maximum swelling ratio in distilled water,tap water and 0.9%NaCl solution.When the particle size of the superabsorbent resin was 0.425~0.850 mm,its swelling ratios at swelling equilibrium in the above three solutions were 50.4,43.2,and 37.5g/g,respectively.When the temperature was maintained at 25℃,the superabsorbent resin retained a water retention rate of 75.6%. These results indicate that the resin has excellent water absorption capacity and is suitable for various application scenarios.
  • LONG Bing, ZHAO Yulin
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    This paper mainly focuses on the existence of solutions for a class of p-Kirchhoff-Choquard type equations involving the Hardy-Littlewood-Sobolev critical exponent.We first prove that the problem possesses a mountain pass structure.Then,by employing the concentration-compactness principle,we overcome the lack of compactness caused by the critical exponent.Finally,we prove the existence of a nontrivial solution to the problem.