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低碳城市试点政策对企业创新效率的影响及作用机制——基于空间DID模型的实证研究 被引量:1
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作者 王胜今 庞志有 《吉林大学社会科学学报》 北大核心 2025年第2期113-130,237,共19页
低碳城市试点政策是国家为实现城市可持续发展和创新发展而采取的一项重大举措。探究该政策对企业创新效率的影响及其作用机制,有助于评估政策实施效果,进一步完善“双碳”政策框架。文章基于2008—2022年中国上市A股528家上市公司的面... 低碳城市试点政策是国家为实现城市可持续发展和创新发展而采取的一项重大举措。探究该政策对企业创新效率的影响及其作用机制,有助于评估政策实施效果,进一步完善“双碳”政策框架。文章基于2008—2022年中国上市A股528家上市公司的面板数据,利用空间DID模型、PSM-空间DID模型、面板Tobit模型等方法,从实证角度分析了低碳城市试点政策对企业创新效率的影响。研究结果显示,该政策显著提升了本地企业的创新效率,但对邻近地区企业的创新效率产生了抑制作用,这一结论得到了多项稳健性检验的支持。机制路径检验表明,低碳城市试点政策通过增强城市政府对环境重视程度、推动产业结构升级以及促进企业人才聚集来发挥作用。 展开更多
关键词 低碳城市试点政策 企业创新效率 空间did方法 PSM-空间did模型 面板Tobit模型
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智慧城市试点与知识创新发展——基于空间DID的实证研究 被引量:2
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作者 杨浩东 王高峰 《科学学与科学技术管理》 北大核心 2025年第1期137-153,共17页
作为数字化与城市化协同发展的崭新模式,智慧城市影响逐渐渗透至科学领域,不仅冲击了研究范式,而且革新了治理方式。从理论上概述了智慧城市建设对知识创新发展的影响机理,基于资源基础观,提出基础效应、网络效应和配置效应三大作用机... 作为数字化与城市化协同发展的崭新模式,智慧城市影响逐渐渗透至科学领域,不仅冲击了研究范式,而且革新了治理方式。从理论上概述了智慧城市建设对知识创新发展的影响机理,基于资源基础观,提出基础效应、网络效应和配置效应三大作用机制。实证层面,手工整理了各城市科技论文发表、合作情况,依托于2000—2020年中国283个地级市构成的面板数据,采用空间双重差分估计模型(空间DID)检验智慧城市试点政策对地区知识创新产生的影响。具体研究发现:(1)智慧城市试点建设不仅促进了本地知识创新,而且提升了地理邻近地区的创新水平;(2)智慧城市建设通过增加地区财政科技投入、提升科技从业人数和完善数字基础设施等基础效应机制,以及提升网络效应机制中的城市中心性和配置效应中的研发全要素生产率,从而促进地区知识创新发展;(3)虽然与地理邻近相比,合作邻近表现出更为显著的创新溢出现象,但智慧城市建设的政策溢出效应主要体现在地理空间邻近这一知识扩散渠道上;(4)智慧城市试点政策促进了区域整体知识创新收敛,且相比未试点地区,试点城市具有更快的收敛速度。 展开更多
关键词 智慧城市 知识创新 知识扩散 空间did
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Phase distortion correction of fringe patterns in spaceborne Doppler asymmetric spatial heterodyne interferometry 被引量:1
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作者 PEI Hui-yi JIANG Lun +4 位作者 WANG Jin-jiang CUI Yong FANG Yuan-xiang ZHANG Jia-ming CHEN Ci 《中国光学(中英文)》 北大核心 2025年第2期382-392,共11页
As an advanced device for observing atmospheric winds,the spaceborne Doppler Asymmetric Spatial Heterodyne(DASH)interferometer also encounters challenges associated with phase distortion,par-ticularly in limb sounding... As an advanced device for observing atmospheric winds,the spaceborne Doppler Asymmetric Spatial Heterodyne(DASH)interferometer also encounters challenges associated with phase distortion,par-ticularly in limb sounding scenarios.This paper discusses interferogram modeling and phase distortion cor-rection techniques for spaceborne DASH interferometers.The modeling of phase distortion interferograms with and without Doppler shift for limb observation was conducted,and the effectiveness of the analytical expression was verified through numerical simulation.The simulation results indicate that errors propagate layer by layer while using the onion-peeling inversion algorithm to handle phase-distorted interferograms.In contrast,the phase distortion correction algorithm can achieve effective correction.This phase correction method can be successfully applied to correct phase distortions in the interferograms of the spaceborne DASH interferometer,providing a feasible solution to enhance its measurement accuracy. 展开更多
关键词 Doppler asymmetric spatial heterodyne spectroscopy phase distortion phase inversion atmospheric wind measurement
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A Framework for Analyzing Spatial Heterogeneity and Influencing Factors of Campus Green Space in Xi’an,China 被引量:2
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作者 ZANG Zexuan ZHANG Liwei +5 位作者 LIU Yu YANG Xiping WANG Zhuangzhuang JIAO Lei WANG Hao LUO Ying 《Chinese Geographical Science》 2025年第4期786-801,共16页
Increased exposure to campus green spaces can make a positive contribution to the healthy development of students.However,understanding of the current supply of campus green space(CGS)and its drivers at different educ... Increased exposure to campus green spaces can make a positive contribution to the healthy development of students.However,understanding of the current supply of campus green space(CGS)and its drivers at different education stages is still limited.A new framework was established to evaluate the spatial heterogeneity and its influencing factors across all education stages(kindergarten,primary school,middle school,college)in 1100 schools at the urban scale of Xi’an,China.The research results show that:1)CGS is lower in the Baqiao district and higher in the Yanta and Xincheng districts of Xi’an City.‘Green wealthy schools are mainly concentrated in the Weiyang,Chang’an and Yanta districts.2)CGS of these schools in descending order is college(31.40%)>kindergarten(18.32%)>middle school(13.56%)>primary school(10.70%).3)Colleges have the most recreation sites(n(number)=2),the best education levels(11.93 yr),and the lowest housing prices(1.18×10^(4) yuan(RMB)/m^(2));middle schools have the highest public expenditures(3.97×10^(9) yuan/yr);primary schools have the highest CGS accessibility(travel time gap(TTG)=31.33).4)Multiscale Geographically Weighted Regression model and Spearman’s test prove that recreation sites have a significant positive impact on college green spaces(0.28–0.35),and education level has a significant positive impact on kindergarten green spaces(0.16–0.24).This research framework provides important insights for the assessment of school greening initiatives aimed at fostering healthier learning environments for future generations. 展开更多
关键词 campus green space(CGS) spatial heterogeneity multiscale geographically weighted regression Xi’an China
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Customizing solid electrolyte interphase with bilayer spatial structure to mitigate swelling towards long-term life lithium battery 被引量:1
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作者 Dongni Zhao Hongcheng Liang +6 位作者 Shumin Wu Yin Quan Xinyi Hu Jingni Li Peng Wang Xiaoling Cui Shiyou Li 《Journal of Energy Chemistry》 2025年第6期702-712,I0015,共12页
The swelling behavior and stability in solid electrolyte interphase(SEI)have been proved to determine the battery cycle life.A high swollen,unstable SEI shows a high permeability to electrolyte,which results in the ra... The swelling behavior and stability in solid electrolyte interphase(SEI)have been proved to determine the battery cycle life.A high swollen,unstable SEI shows a high permeability to electrolyte,which results in the rapid battery performance degradation.Here,we customize two SEIs with different spatial structures(bilayer and mosaic)by simply regulating the proportion of additive fluoroethylene carbonate.Surprisingly,due to the uniform distribution of dense inorganic nano-crystals in the inner,the bilayer SEI exhibits low-swelling and excellent mechanical properties,so the undesirable side reactions of the electrolyte are effectively suppressed.In addition,we put forward the growth rate of swelling ratio(GSR)as a key indicator to reveal the swelling change in SEI.The GSR of bilayer SEI merely increases from1.73 to 3.16 after the 300th cycle,which enables the corresponding graphite‖Li battery to achieve longer cycle stability.The capacity retention is improved by 47.5% after 300 cycles at 0.5 C.The correlation among SEI spatial structure,swelling behavior,and battery performance provides a new direction for electrolyte optimization and interphase structure design of high energy density batteries. 展开更多
关键词 Lithium battery SEI film spatial structure Swelling behavior Cycle-stable
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Impact of coking plant to heavy metal characteristics in groundwater of surrounding areas:Spatial distribution,source apportionment and risk assessments 被引量:1
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作者 Congqing Wang Wanjun Wang +5 位作者 ChaoWang Shixing Ren Yingjun Wu Meicheng Wen Guiying Li Taicheng An 《Journal of Environmental Sciences》 2025年第3期688-698,共11页
Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution character... Coking industry is a potential source of heavy metals(HMs)pollution.However,its impacts to the groundwater of surrounding residential areas have not been well understood.This study investigated the pollution characteristics and health risks of HMs in groundwater nearby a typical coking plant.Nine HMs including Fe,Zn,Mo,As,Cu,Ni,Cr,Pb and Cd were analyzed.The average concentration of total HMswas higher in the nearby area(244.27μg/L)than that of remote area away the coking plant(89.15μg/L).The spatial distribution of pollution indices including heavy metal pollution index(HPI),Nemerow index(NI)and contamination degree(CD),all demonstrated higher values at the nearby residential areas,suggesting coking activity could significantly impact the HMs distribution characteristics.Four sources of HMs were identified by Positive Matrix Factorization(PMF)model,which indicated coal washing and coking emission were the dominant sources,accounted for 40.4%,and 31.0%,respectively.Oral ingestionwas found to be the dominant exposure pathway with higher exposure dose to children than adults.Hazard quotient(HQ)values were below 1.0,suggesting negligible non-carcinogenic health risks,while potential carcinogenic risks were from Pb and Ni with cancer risk(CR)values>10−6.Monte Carlo simulation matched well with the calculated results with HMs concentrations to be the most sensitive parameters.This study provides insights into understanding how the industrial coking activities can impact the HMs pollution characteristics in groundwater,thus facilitating the implement of HMs regulation in coking industries. 展开更多
关键词 Coking industry Heavy metal GROUNDWATER spatial distribution Source apportionment Monte Carlo simulation
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Spatial differentiation of carbon emissions from energy consumption based on machine learning algorithm:A case study during 2015–2020 in Shaanxi,China 被引量:1
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作者 Hongye Cao Ling Han +1 位作者 Ming Liu Liangzhi Li 《Journal of Environmental Sciences》 2025年第3期358-373,共16页
Carbon emissions resulting from energy consumption have become a pressing issue for governments worldwide.Accurate estimation of carbon emissions using satellite remote sensing data has become a crucial research probl... Carbon emissions resulting from energy consumption have become a pressing issue for governments worldwide.Accurate estimation of carbon emissions using satellite remote sensing data has become a crucial research problem.Previous studies relied on statistical regression models that failed to capture the complex nonlinear relationships between carbon emissions and characteristic variables.In this study,we propose a machine learning algorithm for carbon emissions,a Bayesian optimized XGboost regression model,using multi-year energy carbon emission data and nighttime lights(NTL)remote sensing data from Shaanxi Province,China.Our results demonstrate that the XGboost algorithm outperforms linear regression and four other machine learning models,with an R^(2)of 0.906 and RMSE of 5.687.We observe an annual increase in carbon emissions,with high-emission counties primarily concentrated in northern and central Shaanxi Province,displaying a shift from discrete,sporadic points to contiguous,extended spatial distribution.Spatial autocorrelation clustering reveals predominantly high-high and low-low clustering patterns,with economically developed counties showing high-emission clustering and economically relatively backward counties displaying low-emission clustering.Our findings show that the use of NTL data and the XGboost algorithm can estimate and predict carbon emissionsmore accurately and provide a complementary reference for satellite remote sensing image data to serve carbon emission monitoring and assessment.This research provides an important theoretical basis for formulating practical carbon emission reduction policies and contributes to the development of techniques for accurate carbon emission estimation using remote sensing data. 展开更多
关键词 Machine learning Energy carbon emissions Nighttime light spatial distribution
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Spatial and Temporal Evolution of Lithospheric Mantle beneath the Eastern North China Craton:Constraints from Mineral Chemistry of Peridotite Xenoliths from the Miocene Qingyuan Basalts and a Regional Synthesis 被引量:1
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作者 Jian-Fang Guo Qiang Ma +1 位作者 Jian-Ping Zheng Yu-Ping Su 《Journal of Earth Science》 2025年第2期474-484,共11页
Mineralogical data are presented for the peridotite xenoliths from Miocene(~19 Ma)Qingyuan basalts in the eastern North China Craton(NCC),with the aim of constraining on property of the sub-continental lithospheric ma... Mineralogical data are presented for the peridotite xenoliths from Miocene(~19 Ma)Qingyuan basalts in the eastern North China Craton(NCC),with the aim of constraining on property of the sub-continental lithospheric mantle(SCLM)beneath the northern Tan-Lu fault zone(TLFZ)during the Cenozoic.The Qingyuan peridotites are dominated by spinel lherzolites with moderate-Mg^(#)olivines(89.4 to 91.2),suggesting that the regional SCLM is mainly transitional and fertile.Light rare earth element(LREE)-depleted,slightly depleted and enriched clinopyroxenes(Cpx)are identified in different peridotites.Chemical compositions of the LREE-enriched Cpx and the presence of phlogopite suggest that the Qingyuan SCLM has experienced silicate-related metasomatism.The synthesis of available mineral chemical data of the mantle xenoliths across the NCC confirms the SCLM beneath the NCC is highly heterogeneous in time and space.The Mesozoic–Cenozoic SCLM beneath the TLFZ and neighboring regions are more fertile and thinner than that beneath the region away from the fault zone.The fertile and refractory peridotite xenoliths experienced varying degrees of silicate and carbonatite metasomatism,respectively.The spatial-temporal lithospheric mantle heterogeneity in composition,age and thickness suggest that the trans-lithosphere fault zone played an important role in heterogeneous replacement of refractory cratonic lithospheric mantle. 展开更多
关键词 lithospheric mantle peridotite xenoliths temporal and spatial variations Tan-Lu fault zone North China craton PETROLOGY GEOCHEMISTRY
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Single-cell and spatial omics:exploring hypothalamic heterogeneity
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作者 Muhammad Junaid Eun Jeong Lee Su Bin Lim 《Neural Regeneration Research》 SCIE CAS 2025年第6期1525-1540,共16页
Elucidating the complex dynamic cellular organization in the hypothalamus is critical for understanding its role in coordinating fundamental body functions. Over the past decade, single-cell and spatial omics technolo... Elucidating the complex dynamic cellular organization in the hypothalamus is critical for understanding its role in coordinating fundamental body functions. Over the past decade, single-cell and spatial omics technologies have significantly evolved, overcoming initial technical challenges in capturing and analyzing individual cells. These high-throughput omics technologies now offer a remarkable opportunity to comprehend the complex spatiotemporal patterns of transcriptional diversity and cell-type characteristics across the entire hypothalamus. Current single-cell and single-nucleus RNA sequencing methods comprehensively quantify gene expression by exploring distinct phenotypes across various subregions of the hypothalamus. However, single-cell/single-nucleus RNA sequencing requires isolating the cell/nuclei from the tissue, potentially resulting in the loss of spatial information concerning neuronal networks. Spatial transcriptomics methods, by bypassing the cell dissociation, can elucidate the intricate spatial organization of neural networks through their imaging and sequencing technologies. In this review, we highlight the applicative value of single-cell and spatial transcriptomics in exploring the complex molecular-genetic diversity of hypothalamic cell types, driven by recent high-throughput achievements. 展开更多
关键词 cellular diversity HYPOTHALAMUS multi-omics single-cell transcriptomics spatial transcriptomics
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Spatial transcriptomics combined with single-nucleus RNA sequencing reveals glial cell heterogeneity in the human spinal cord
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作者 Yali Chen Yiyong Wei +3 位作者 Jin Liu Tao Zhu Cheng Zhou Donghang Zhang 《Neural Regeneration Research》 SCIE CAS 2025年第11期3302-3316,共15页
Glial cells play crucial roles in regulating physiological and pathological functions,including sensation,the response to infection and acute injury,and chronic neurodegenerative disorders.Glial cells include astrocyt... Glial cells play crucial roles in regulating physiological and pathological functions,including sensation,the response to infection and acute injury,and chronic neurodegenerative disorders.Glial cells include astrocytes,microglia,and oligodendrocytes in the central nervous system,and satellite glial cells and Schwann cells in the peripheral nervous system.Despite the greater understanding of glial cell types and functional heterogeneity achieved through single-cell and single-nucleus RNA sequencing in animal models,few studies have investigated the transcriptomic profiles of glial cells in the human spinal cord.Here,we used high-throughput single-nucleus RNA sequencing and spatial transcriptomics to map the cellular and molecular heterogeneity of astrocytes,microglia,and oligodendrocytes in the human spinal cord.To explore the conservation and divergence across species,we compared these findings with those from mice.In the human spinal cord,astrocytes,microglia,and oligodendrocytes were each divided into six distinct transcriptomic subclusters.In the mouse spinal cord,astrocytes,microglia,and oligodendrocytes were divided into five,four,and five distinct transcriptomic subclusters,respectively.The comparative results revealed substantial heterogeneity in all glial cell types between humans and mice.Additionally,we detected sex differences in gene expression in human spinal cord glial cells.Specifically,in all astrocyte subtypes,the levels of NEAT1 and CHI3L1 were higher in males than in females,whereas the levels of CST3 were lower in males than in females.In all microglial subtypes,all differentially expressed genes were located on the sex chromosomes.In addition to sex-specific gene differences,the levels of MT-ND4,MT2A,MT-ATP6,MT-CO3,MT-ND2,MT-ND3,and MT-CO_(2) in all spinal cord oligodendrocyte subtypes were higher in females than in males.Collectively,the present dataset extensively characterizes glial cell heterogeneity and offers a valuable resource for exploring the cellular basis of spinal cordrelated illnesses,including chronic pain,amyotrophic lateral sclerosis,and multiple sclerosis. 展开更多
关键词 astrocyte glial cell HUMAN microglia oligodendrocyte sex differentiation single-nucleus RNA sequencing spatial transcriptomics species variation spinal cord
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Territorial Ecological Restoration with a High-carbon Storage Focus in the Beibu Gulf Urban Agglomeration of China:Insights from Carbon Metabolism Spatial Security Patterns 被引量:1
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作者 QIN Menglin LIU Yuting +5 位作者 TAN Qianxi ZHU Ziming WU Xinyu JIANG Hongbo LI Hang SHI Qianqian 《Chinese Geographical Science》 2025年第1期73-91,共19页
This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking an... This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region. 展开更多
关键词 carbon metabolism spatial security pattern(CMSSP) territorial ecological restoration carbon sink carbon storage capacity Beibu Gulf Urban Agglomeration China
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Bombing Inequality:Graffiti Writing and Spatial Justice
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作者 Andrea L.Baldini 《文艺理论研究》 北大核心 2025年第4期165-178,共14页
This study contests the prevalent perception of graffiti writing,especially tagging and bombing,as meaningless vandalism.It contends that graffiti is a form of expression with intrinsic political implications.Leveragi... This study contests the prevalent perception of graffiti writing,especially tagging and bombing,as meaningless vandalism.It contends that graffiti is a form of expression with intrinsic political implications.Leveraging the notion of spatial justice and Jacques Ranciere's philosophy,I demonstrate how graffiti reclaims urban visibility against the commercial monopoly of visibility in public spaces and challenges the inequitable allocation of opportunities for self-expression in modern cities.Despite writers'common denial of political motives,their actions may be interpreted as manifestations of resistance within wider sociospatial conflicts.This study situates grffti within discussions of political art,spatial commodification,and everyday resistance,proposing a normative framework for viewing the art of the urban signature as an activity that redefines"the community that speaks." 展开更多
关键词 Graffiti writing spatial justice public space resistance Ranciere political art
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“制造强国”政策能否提升产业基础能力?——基于连续型空间DID模型的实证分析
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作者 季凯文 罗璐薏 +1 位作者 汤文颖 袁子晨 《管理评论》 北大核心 2025年第9期42-55,共14页
产业基础能力薄弱已成为制约中国产业链供应链现代化水平提升的关键因素。本文基于2013—2019年中国省域数据,构建了产业基础能力评价指标体系,采用变异系数模型分析了中国省域产业基础能力的σ收敛特征,并运用连续型DID模型和连续型空... 产业基础能力薄弱已成为制约中国产业链供应链现代化水平提升的关键因素。本文基于2013—2019年中国省域数据,构建了产业基础能力评价指标体系,采用变异系数模型分析了中国省域产业基础能力的σ收敛特征,并运用连续型DID模型和连续型空间DID模型实证分析了“制造强国”政策对中国产业基础能力的影响效应。主要结论如下:(1)中国省域产业基础能力总体呈现上升趋势,特别是2015年“制造强国”政策实施后,中国省域产业基础能力打破了新古典经济增长理论的收敛现象,不存在σ收敛,仍具增长潜力;(2)“制造强国”政策提升了产业基础能力,且政策的正向促进效应持续;(3)考虑政策的空间影响后发现,“制造强国”政策对产业基础能力存在本地、邻地和整体地区的正向空间效应,且空间溢出效应大于对本地的直接效应;(4)进一步分析发现,“制造强国”政策主要通过提高产业创新基础能力和产业基础设施服务能力来提升产业基础能力,对于产业基础供给能力的影响仅存在空间总效应,对于产业竞争基础能力和产业链管控能力尚无明确影响;(5)机制分析表明,数字经济和金融科技是“制造强国”政策影响产业基础能力的两个机制,且这两个机制的传导路径皆对本地和整体地区存在正向影响,对于邻地存在负向影响。 展开更多
关键词 “制造强国”政策 产业基础能力 变异系数法 Σ收敛 连续型空间did模型
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Spatial correlation singularities and orbital angular momentum spectra of partially coherent beams with noncanonical vortex pairs
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作者 MEI Chao CHENG Ke +2 位作者 YI Xiao-wen FU Cai-ying ZENG Ti-xian 《中国光学(中英文)》 北大核心 2025年第5期1243-1254,共12页
By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integra... By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integral. The effect of noncanonical strength, off-axis distance and vortex sign on spatial correlation singularities in far field is stressed. Furthermore, far-field OAM spectra and densities are also investigated, and the OAM detection and crosstalk probabilities are discussed. The results show that the number of dislocations of SCS always equals the sum of absolute values of topological charges for canonical or noncanonical vortex pairs. Although the sum of the product of each OAM mode and its power weight equals the algebraic sum of topological charges for canonical vortex pairs, the relationship no longer holds in the noncanonical case except for opposite-charge vortex pairs. The changes of off-axis distance, noncanonical strength or coherence length can lead to a more dominant power in adjacent mode than that in center detection mode, which also indicates that crosstalk probabilities of adjacent modes exceed the center detection probability. This work may provide potential applications in OAM-based optical communication, imaging, sensing and computing. 展开更多
关键词 spatial correlation singularity orbital angular momentum noncanonical vortex partially coherent beam
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Spatial Grasp Model for Distributed Management and Its Comparison With Traditional Algorithms
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作者 Peter Simon Sapaty 《International Relations and Diplomacy》 2025年第3期164-179,共16页
The word“spatial”fundamentally relates to human existence,evolution,and activity in terrestrial and even celestial spaces.After reviewing the spatial features of many areas,the paper describes basics of high level m... The word“spatial”fundamentally relates to human existence,evolution,and activity in terrestrial and even celestial spaces.After reviewing the spatial features of many areas,the paper describes basics of high level model and technology called Spatial Grasp for dealing with large distributed systems,which can provide spatial vision,awareness,management,control,and even consciousness.The technology description includes its key Spatial Grasp Language(SGL),self-evolution of recursive SGL scenarios,and implementation of SGL interpreter converting distributed networked systems into powerful spatial engines.Examples of typical spatial scenarios in SGL include finding shortest path tree and shortest path between network nodes,collecting proper information throughout the whole world,elimination of multiple targets by intelligent teams of chasers,and withstanding cyber attacks in distributed networked systems.Also this paper compares Spatial Grasp model with traditional algorithms,confirming universality of the former for any spatial systems,while the latter just tools for concrete applications. 展开更多
关键词 spatial awareness spatial control spatial consciousness spatial Grasp Technology spatial Grasp Language spatial scenarios cyber attacks distributed algorithms mobile agents
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Spatial optimisation based on ecosystem service spillover effect and cross-scale knowledge integration:A case study of the Yellow River Basin
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作者 ZHANG Kaili FANG Bin +3 位作者 ZHANG Zhicheng XIA Chunhua LIU Qiqi LIU Kang 《Journal of Geographical Sciences》 2025年第5期1080-1114,共35页
The exploration of the variability of spatial spillovers of ecosystem services(ESs)across scales is essential for sustainable regional development.Using advanced models such as In VEST,Geodetector,MGWR,and SLM/SEM/SDB... The exploration of the variability of spatial spillovers of ecosystem services(ESs)across scales is essential for sustainable regional development.Using advanced models such as In VEST,Geodetector,MGWR,and SLM/SEM/SDB,this study investigates spatial heterogeneity and cross-regional effects on ESs at the raster and county scales.Key findings from 2000 to 2020 include an upward trend in ESs,with pronounced regional variations.The southern Yellow River Basin(YRB)shows higher levels of water yield,carbon sequestration,soil retention,and habitat quality,while the northern areas score lower,except for food provisioning in central and lower regions.The overall ES index has risen,particularly in the southern part,aligning with China's ecological patterns and showing significant cross-regional benefits.At various scales,natural elements,landscape configurations,and human influences significantly impact ESI,with different cross-regional effects.While natural and landscape indices demonstrate substantial cross-regional impacts at the raster scale,human influence is more apparent at the county scale.The identified cross-regional impacts underscore the interconnectedness of regional ES and sustainability,extending to nearby areas.Spatial management and planning may be limited by zoning and regulations.This study underscores regional ecosystem spatial spillovers and cross-scale knowledge differences and linkages,introducing new perspectives and methods for spatial planning in watersheds to support sustainable ecosystem optimisation. 展开更多
关键词 ecosystem services driving mechanisms spatial spillovers spatial non-stationarity spatial planning
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A Spatial Autoregressive Model on the Effect of E-Money,Fintech Lending,and ATM Usage on Economic Performance across Provinces in Sumatra
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作者 Zahra Assyfa Frisky Anistya +1 位作者 Iskandar Muda Erlina 《Journal of Modern Accounting and Auditing》 2025年第3期170-182,共13页
This study investigates the spatial courting between digital economic signs and local monetary overall performance throughout ten provinces in Sumatra,Indonesia,from 2019 to 2022.As digitalization hastens economic and... This study investigates the spatial courting between digital economic signs and local monetary overall performance throughout ten provinces in Sumatra,Indonesia,from 2019 to 2022.As digitalization hastens economic and business sports,devices together with fintech lending,e-cash,debit card usage,and e-commerce are increasingly more diagnosed as capability drivers of regional increase.But,the unequal distribution of digital infrastructure and monetary literacy across regions raises issues approximately the inclusivity of these benefits.constructing upon current findings by using Miranti et al.(2024),this research employs spatial econometric fashions-particularly the Spatial Lag model(SLM)and Spatial mistakes model(SEM)-to evaluate how digital variables influence provincial financial overall performance while accounting for spatial spillover consequences.The results reveal that fintech lending and debit card usage exert a positive and significant impact on economic growth,whereas the effect of e-money is negative,suggesting potential substitution effects or access constraints.Spatial dependency is also evident,as demonstrated by the significant lambda coefficient in the SEM model.These findings highlight the importance of spatially coordinated digital policies,particularly in addressing disparities and enhancing digital financial inclusion.The study concludes with policy recommendations aimed at fostering inclusive and spatially balanced digital economic development in Sumatra. 展开更多
关键词 digital finance spatial econometrics regional economic performance fintech SUMATRA e-money spatial spillover
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Advances in spatial transcriptomics and its application in the musculoskeletal system
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作者 Haoyu Wang Peng Cheng +5 位作者 Juan Wang Hongzhi Lv Jie Han Zhiyong Hou Ren Xu Wei Chen 《Bone Research》 2025年第3期534-554,共21页
While bulk RNA sequencing and single-cell RNA sequencing have shed light on cellular heterogeneity and potential molecular mechanisms in the musculoskeletal system in both physiological and various pathological states... While bulk RNA sequencing and single-cell RNA sequencing have shed light on cellular heterogeneity and potential molecular mechanisms in the musculoskeletal system in both physiological and various pathological states,the spatial localization of cells and molecules and intercellular interactions within the tissue context require further elucidation.Spatial transcriptomics has revolutionized biological research by simultaneously capturing gene expression profiles and in situ spatial information of tissues,gradually finding applications in musculoskeletal research.This review provides a summary of recent advances in spatial transcriptomics and its application to the musculoskeletal system.The classification and characteristics of data acquisition techniques in spatial transcriptomics are briefly outlined,with an emphasis on widely-adopted representative technologies and the latest technological breakthroughs,accompanied by a concise workflow for incorporating spatial transcriptomics into musculoskeletal system research.The role of spatial transcriptomics in revealing physiological mechanisms of the musculoskeletal system,particularly during developmental processes,is thoroughly summarized.Furthermore,recent discoveries and achievements of this emerging omics tool in addressing inflammatory,traumatic,degenerative,and tumorous diseases of the musculoskeletal system are compiled.Finally,challenges and potential future directions for spatial transcriptomics,both as a field and in its applications in the musculoskeletal system,are discussed. 展开更多
关键词 cells molecules spatial transcriptomics gene expression profiles musculoskeletal system cellular heterogeneity bulk rna sequencing biological research situ spatial information
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Spatially random polarization-smoothing optics by residual stress birefringence of fused silica for laser-driven inertial confinement fusion
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作者 Chuanchao Zhang Wei Liao +6 位作者 Xiaolong Jiang Haijun Wang Fa Zeng Wei Ni Ping Li Xiaodong Jiang Qihua Zhu 《Matter and Radiation at Extremes》 2025年第5期54-63,共10页
We demonstrate a new polarization smoothing(PS)approach utilizing residual stress birefringence in fused silica to create a spatially random polarization control plate(SRPCP),thereby improving target illumination unif... We demonstrate a new polarization smoothing(PS)approach utilizing residual stress birefringence in fused silica to create a spatially random polarization control plate(SRPCP),thereby improving target illumination uniformity in inertial confinement fusion(ICF)laser systems.The fundamental operating mechanism and key fabrication techniques for the SRPCP are systematically developed and experimentally validated.The SRPCP converts a linearly polarized 3ω incident laser beam into an output beam with a spatially randomized polarization distribution.When combined with a continuous phase plate,the SRPCP effectively suppresses high-intensity speckles at all spatial frequencies in the focal spot.The proposed PS technique is specifically designed for high-fluence large-aperture laser systems,enabling novel polarization control regimes in laser-driven ICF. 展开更多
关键词 spatially ra fused silica spatially random polarization control plate srpcp thereby linearly polarized incident laser beam residual stress birefringence fabrication techniques improving target illumination uniformity spatially random polarization smoothing
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Spatial distribution and pollution assessment of nitrogen,phosphorus,and heavy metals in the surface sediments of Xiaonanhai Lake,Hubei Province
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作者 Wei Liang Yang Ding +4 位作者 Jinyong Zhao Qiwen Wang Wenqi Peng Zhenghe Xu Muyun Yan 《River》 2025年第2期223-236,共14页
Located in Nanhai Town,Songzi City,Hubei Province,Xiaonanhai Lake is the largest natural lake in Songzi.It was once severely polluted due to the discharge of urban and rural domestic sewage,disorderly development of a... Located in Nanhai Town,Songzi City,Hubei Province,Xiaonanhai Lake is the largest natural lake in Songzi.It was once severely polluted due to the discharge of urban and rural domestic sewage,disorderly development of agricultural planting,unregulated aquaculture,and poultry farming.However,relevant esti-mations of the pollutant content in its sediment have not been carried out.This study analyzed the spatial patterns of heavy metal pollution and eutrophication at 36 water sampling sites in the Xiaonanhai Lake area,focusing on eight heavy metals:Cd,Cr,Cu,Ni,As,Pb,Hg,and Zn.The nutrient status of the lake area was evaluated using the nitrogen-phosphorus comprehensive pollution index,and heavy metal pollution status of the lake area was evaluated using geo-accumulation and the potential ecological risk index.Spatial autocorrelation analysis revealed the spatial correlation and aggregation of eutrophication levels in Xiaonanhai Lake.The results showed that the overall trophic state of the Xiaonanhai Lake area was moderate eutrophication,with a gradually decreasing eutrophication level from north to south.The Chengnan Wastewater Treatment Plant in the northern part of the lake area and surface source pollution from aquaculture were the main nitrogen and phosphorus sources.The overall eco-logical risk index of heavy metal pollution was medium and gradually weakened from north to south,consistent with the thickness of the bottom mud.The heavy metal pollution load was mainly precipitated from the bottom mud in the lake area.The eutrophication and heavy metal pollution levels in the lake area showed significant positive spatial autocorrelation,the influence range of the regional eutrophication level was small,and the spatial heterogeneity of the eutrophication and heavy metal pollution levels in Xiaonanhai Lake was relatively high.The northern part of the lake was a hotspot(high/high aggregation)of eutrophication(p<0.01)while the southern part was a cold spot(low/low concentration;p<0.05).The middle and northern part of the lake area was the hot spot(high/high concentration)of heavy metal pollution level(p<0.1)while the southern part was the cold spot(low/low concentration;p<0.1).Therefore,when carrying out water environment management in Xiaonanhai Lake,the northern area and the middle area should be prioritized for eutrophication prevention and control and dredging. 展开更多
关键词 eutrophication level heavy metal pollution spatial autocorrelation spatial characteristics Xiaonanhai Lake
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