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BDMFuse:Multi-scale network fusion for infrared and visible images based on base and detail features
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作者 SI Hai-Ping ZHAO Wen-Rui +4 位作者 LI Ting-Ting LI Fei-Tao Fernando Bacao SUN Chang-Xia LI Yan-Ling 《红外与毫米波学报》 北大核心 2025年第2期289-298,共10页
The fusion of infrared and visible images should emphasize the salient targets in the infrared image while preserving the textural details of the visible images.To meet these requirements,an autoencoder-based method f... The fusion of infrared and visible images should emphasize the salient targets in the infrared image while preserving the textural details of the visible images.To meet these requirements,an autoencoder-based method for infrared and visible image fusion is proposed.The encoder designed according to the optimization objective consists of a base encoder and a detail encoder,which is used to extract low-frequency and high-frequency information from the image.This extraction may lead to some information not being captured,so a compensation encoder is proposed to supplement the missing information.Multi-scale decomposition is also employed to extract image features more comprehensively.The decoder combines low-frequency,high-frequency and supplementary information to obtain multi-scale features.Subsequently,the attention strategy and fusion module are introduced to perform multi-scale fusion for image reconstruction.Experimental results on three datasets show that the fused images generated by this network effectively retain salient targets while being more consistent with human visual perception. 展开更多
关键词 infrared image visible image image fusion encoder-decoder multi-scale features
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Phase distortion correction of fringe patterns in spaceborne Doppler asymmetric spatial heterodyne interferometry
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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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Effects of silica fume on the multi-scale material properties of composite Portland cement-based cutoff wall backfill
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作者 ZHOU Tan HU Jian-hua +2 位作者 ZHAO Feng-wen GUO Meng-meng XUE Sheng-guo 《Journal of Central South University》 2025年第1期205-219,共15页
Soil cement bentonite(SCB)is a common material for constructing vertical cutoff walls to prevent groundwater migration at contaminated industrial sites.However,site contaminants can degrade the durability of the cutof... Soil cement bentonite(SCB)is a common material for constructing vertical cutoff walls to prevent groundwater migration at contaminated industrial sites.However,site contaminants can degrade the durability of the cutoff wall.To enhance its performance,this study developed a silica fume-SCB(SSCB).The macroscopic and microscopic properties of SSCB were assessed by unconfined compressive strength test,variable head permeability test,X-ray diffraction(XRD),scanning electron microscopy(SEM)and nuclear magnetic resonance(NMR)spectroscopy.The correlation between its multi-scale properties was analyzed based on pore characteristics.The results indicate that increasing the silica fume substitution ratio improved SSCB strength,especially in the middle and late curing stages.Moreover,increasing the substitution ratio decreased SSCB permeability coefficient,with a more pronounced effect in earlier curing stages.Silica fume addition also refined SSCB pore structure and reduced its porosity.The fractal dimension was used to quantify SSCB pore structure complexity.Increasing silica fume content reduced small pore fractal dimension in SSCB.Concurrently,SSCB strength increased and SSCB permeability coefficient decreased.The findings of this research will demonstrate the great potential of SSCB backfill for practical applications. 展开更多
关键词 silica fume SSCB cutoff wall multi-scale material properties engineering properties microscopic mechanism
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Femtosecond laser modulated into Bessel beam by spatial light modulator for Fresnel zone plate processing
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作者 DUAN Lian ZHOU Fang +3 位作者 KONG De-jian ZHANG Fan SUN Xiao-yan DUAN Ji-an 《Journal of Central South University》 2025年第2期469-482,共14页
Femtosecond laser processing is an important machining method for micro-optical components such as Fresnel zone plate(FZP).However,the low processing efficiency of the femtosecond laser restricts its application.Here,... Femtosecond laser processing is an important machining method for micro-optical components such as Fresnel zone plate(FZP).However,the low processing efficiency of the femtosecond laser restricts its application.Here,a femtosecond laser Bessel beam is proposed to process micro-FZP,which is modulated from a Gaussian beam to a Bessel annular beam.The processing time for FZP with an outer diameter of 60μm is reduced from 30 min to 1.5 min on an important semiconductor material gallium arsenide(GaAs),which significantly improves the processing efficiency.In the modulation process,a central ablation hole that has an adverse effect on the diffraction performance is produced,and the adverse effect is eliminated by superimposing the blazed grating hologram.Meanwhile,the FZP machined by spatial light modulator(SLM)has good morphology and higher diffraction efficiency,which provides a strong guarantee for the application of micro-FZP in computed tomography and solar photovoltaic cells. 展开更多
关键词 femtosend laser Fresnel zone plate spatial light modulator Bessel beam GAAS
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Agricultural Carbon Emissions in Henan Province:Influence Mechanism,Regional Differences and Spatial Effects
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作者 Hu Jingna He Puming Cui Weiwei 《Journal of Northeast Agricultural University(English Edition)》 2025年第1期45-58,共14页
Exploring the effective and efficient path of agricultural carbon emission reduction in Henan Province is of great significance to optimizing the strategic layout of China's agricultural emission reduction and car... Exploring the effective and efficient path of agricultural carbon emission reduction in Henan Province is of great significance to optimizing the strategic layout of China's agricultural emission reduction and carbon sequestration.Accordingly,the agricultural carbon emissions of each county were measured scientifically and then the spatial measurement model was utilized to clarify the spatial and temporal evolution trend and spatial effect mechanism of agricultural carbon emissions based on the county data of Henan Province from 2010 to 2020.The results showed that:(1)in 2020,the total agricultural carbon emissions were 134.7274 million tons,with the high distribution in the southeast and low distribution in the northwest;(2)the spatial dependence of agricultural carbon emissions showed a four-stage trend of fluctuating down-continuing up-plummeting-fluctuating up again,and the spatial heterogeneity was dominated by low-low agglomeration,followed by high-low agglomeration;(3)there was an inverted U curve relationship between the level of agricultural economic development and agricultural carbon emissions.The increase in the level of agricultural mechanization and urbanization rate significantly reduced agricultural carbon emissions.The opposite was true for the financial support for agriculture,the income level of rural residents and the structure of the agricultural industry;(4)in terms of spatial spillover effects,the increase in the level of agricultural development in neighbor counties first increased and then decreased agricultural carbon emissions in Henan Province.The mechanization level and urbanization rate of neighbor counties reduced agricultural carbon emissions in Henan Province,and the opposite was true for the income level of rural residents and the scale utilization of agricultural land. 展开更多
关键词 Henan Province agricultural carbon emission spatiotemporal evolution spatial spillover effect
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Disparity estimation for multi-scale multi-sensor fusion
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作者 SUN Guoliang PEI Shanshan +2 位作者 LONG Qian ZHENG Sifa YANG Rui 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期259-274,共16页
The perception module of advanced driver assistance systems plays a vital role.Perception schemes often use a single sensor for data processing and environmental perception or adopt the information processing results ... The perception module of advanced driver assistance systems plays a vital role.Perception schemes often use a single sensor for data processing and environmental perception or adopt the information processing results of various sensors for the fusion of the detection layer.This paper proposes a multi-scale and multi-sensor data fusion strategy in the front end of perception and accomplishes a multi-sensor function disparity map generation scheme.A binocular stereo vision sensor composed of two cameras and a light deterction and ranging(LiDAR)sensor is used to jointly perceive the environment,and a multi-scale fusion scheme is employed to improve the accuracy of the disparity map.This solution not only has the advantages of dense perception of binocular stereo vision sensors but also considers the perception accuracy of LiDAR sensors.Experiments demonstrate that the multi-scale multi-sensor scheme proposed in this paper significantly improves disparity map estimation. 展开更多
关键词 stereo vision light deterction and ranging(LiDAR) multi-sensor fusion multi-scale fusion disparity map
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Underwater Image Enhancement Based on Multi-scale Adversarial Network
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作者 ZENG Jun-yang SI Zhan-jun 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第5期70-77,共8页
In this study,an underwater image enhancement method based on multi-scale adversarial network was proposed to solve the problem of detail blur and color distortion in underwater images.Firstly,the local features of ea... In this study,an underwater image enhancement method based on multi-scale adversarial network was proposed to solve the problem of detail blur and color distortion in underwater images.Firstly,the local features of each layer were enhanced into the global features by the proposed residual dense block,which ensured that the generated images retain more details.Secondly,a multi-scale structure was adopted to extract multi-scale semantic features of the original images.Finally,the features obtained from the dual channels were fused by an adaptive fusion module to further optimize the features.The discriminant network adopted the structure of the Markov discriminator.In addition,by constructing mean square error,structural similarity,and perceived color loss function,the generated image is consistent with the reference image in structure,color,and content.The experimental results showed that the enhanced underwater image deblurring effect of the proposed algorithm was good and the problem of underwater image color bias was effectively improved.In both subjective and objective evaluation indexes,the experimental results of the proposed algorithm are better than those of the comparison algorithm. 展开更多
关键词 Underwater image enhancement Generative adversarial network multi-scale feature extraction Residual dense block
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Ship recognition based on HRRP via multi-scale sparse preserving method
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作者 YANG Xueling ZHANG Gong SONG Hu 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期599-608,共10页
In order to extract the richer feature information of ship targets from sea clutter, and address the high dimensional data problem, a method termed as multi-scale fusion kernel sparse preserving projection(MSFKSPP) ba... In order to extract the richer feature information of ship targets from sea clutter, and address the high dimensional data problem, a method termed as multi-scale fusion kernel sparse preserving projection(MSFKSPP) based on the maximum margin criterion(MMC) is proposed for recognizing the class of ship targets utilizing the high-resolution range profile(HRRP). Multi-scale fusion is introduced to capture the local and detailed information in small-scale features, and the global and contour information in large-scale features, offering help to extract the edge information from sea clutter and further improving the target recognition accuracy. The proposed method can maximally preserve the multi-scale fusion sparse of data and maximize the class separability in the reduced dimensionality by reproducing kernel Hilbert space. Experimental results on the measured radar data show that the proposed method can effectively extract the features of ship target from sea clutter, further reduce the feature dimensionality, and improve target recognition performance. 展开更多
关键词 ship target recognition high-resolution range profile(HRRP) multi-scale fusion kernel sparse preserving projection(MSFKSPP) feature extraction dimensionality reduction
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Unconditionally stable Crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma
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作者 WEN Yi WANG Junxiang XU Hongbing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期65-73,共9页
Large calculation error can be formed by directly employing the conventional Yee’s grid to curve surfaces.In order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is ... Large calculation error can be formed by directly employing the conventional Yee’s grid to curve surfaces.In order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized plasma.Within the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution domains.Convolutional perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region problems.Numerical example is carried out for the illustration of effectiveness including the efficiency,resources,and absorption.Through the results,it can be concluded that the proposed scheme shows considerable performance during the simulation. 展开更多
关键词 anisotropic magnetized plasma body-of-revolution(BOR) Crank-Nicolson Douglas-Gunn(CNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems
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Opto-mechanical-thermal integration analysis of Doppler asymmetric spatial heterodyne interferometer
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作者 WANG Jin-jiang JIANG Lun +3 位作者 TONG Shou-feng PEI Hui-yi CUI Yong GUO Ming-hang 《中国光学(中英文)》 EI CAS CSCD 北大核心 2024年第6期1489-1511,共23页
In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation betw... In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation between the interference phase and temperature is established according to the working principle and the phase algorithm of the interferometer.Secondly,the optical mechanical thermal analysis model and thermal deformation data acquisition model are designed.The deformation data of the interference module and the imaging optical system at different temperatures are given by temperature load simulation analysis,and the phase error caused by thermal deformation is obtained by fitting.Finally,based on the wind speed error caused by thermal deformation of each component,a reasonable temperature control scheme is proposed.The results show that the interference module occupies the main cause,the temperature must be controlled within(20±0.05)℃,and the temperature control should be carried out for the temperature sensitive parts,and the wind speed error caused by the part is 3.8 m/s.The thermal drift between the magnification of the imaging optical system and the thermal drift of the relative position between the imaging optical system and the detector should occupy the secondary cause,which should be controlled within(20±2)℃,and the wind speed error caused by the part is 3.05 m/s.In summary,the wind measurement error caused by interference module,imaging optical system,and the relative position between the imaging optical system and the detector can be controlled within 6.85 m/s.The analysis and temperature control schemes presented in this paper can provide theoretical basis for DASH interferometer engineering applications. 展开更多
关键词 Doppler asymmetric spatial heterodyne interferometer interference module imaging optical system opto-mechanical thermal integration analysis phase error temperature control
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Quantitative method for calculating spatial release region for laser-guided bomb
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作者 YANG Ping XIAO Bing +1 位作者 CHEN Xin HAO Yuntao 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期1053-1062,共10页
The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheri... The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their accuracy.The spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of view.This can result in a lower real hit probability.To increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been pro-posed.This method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser seeker.Then,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release region.This method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric visibility.By more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%. 展开更多
关键词 laser-guided bombs(LGBs) hit probability atmo-spheric transmittance spatial release region(SRR)boundary ballistic
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基于多分支HRNet的图像篡改检测与定位模型 被引量:1
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作者 曾桢 谭平 《现代电子技术》 北大核心 2025年第3期35-42,共8页
传统的篡改方法如拷贝粘贴和拼接已演变为利用深度学习生成的高质量伪造图像,这些篡改技术在图像纹理和细节上留下难以察觉的痕迹,如高频噪声模式的异常、颜色分布的微妙变化,以及边缘区域的不自然过渡。这些痕迹分布在不同分辨率层次... 传统的篡改方法如拷贝粘贴和拼接已演变为利用深度学习生成的高质量伪造图像,这些篡改技术在图像纹理和细节上留下难以察觉的痕迹,如高频噪声模式的异常、颜色分布的微妙变化,以及边缘区域的不自然过渡。这些痕迹分布在不同分辨率层次和空间位置,增加了检测的难度。现有模型在整合多尺度和多位置特征时存在不足,难以有效捕捉局部细微纹理变化。针对这一问题,文中提出一种基于多分支HRNet的图像篡改检测与定位模型。该模型通过集成纹理增强模块,增强对图像篡改细节特征的捕获能力。同时,结合Spatial Weighting与Cross Resolution Weighting策略优化特征融合,并使用新的损失函数W_Arcloss,显著提升了模型在复杂篡改检测任务中的性能。在CASIA、Columbia、COVERAGE和NIST16等数据集上,该模型的检测准确度相较于PSCC⁃Net、HIFI⁃Net模型分别平均提升了6.5%与0.8%,并且泛化能力得到提升。这些结果证明了模型在处理多种篡改类型时的有效性和鲁棒性,为图像篡改检测与定位领域提供了新的研究视角和技术手段。 展开更多
关键词 图像篡改检测 深度学习 多分支HRNet 纹理增强模块 spatial Weighting Cross Resolution Weighting W_Arcloss
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我国省际碳排放脱钩的动态演变及收敛性分析 被引量:1
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作者 郭文强 于忠萍 +2 位作者 雷明 史瑞雪 韦星羽 《地域研究与开发》 北大核心 2025年第1期166-172,180,共8页
运用Tapio脱钩指数、空间自相关与空间马尔科夫链模型,探讨2001—2022年我国省际碳排放脱钩的时空动态演化特征,并根据收敛模型进行俱乐部划分分析从而揭示我国省际脱钩关系的演变以寻求低碳发展路径。结果表明:(1) 2001—2022年我国各... 运用Tapio脱钩指数、空间自相关与空间马尔科夫链模型,探讨2001—2022年我国省际碳排放脱钩的时空动态演化特征,并根据收敛模型进行俱乐部划分分析从而揭示我国省际脱钩关系的演变以寻求低碳发展路径。结果表明:(1) 2001—2022年我国各省份的脱钩类型由多样化共存逐步发展到以弱脱钩为主导,整体发展形势向好。(2)碳排放脱钩的全局空间正自相关性显著,局部空间发展以L-L聚集为主,东西空间分异愈发显著,出现极化效应。(3)较少出现跨越性的脱钩转移,且转移概率受邻域脱钩状态影响存在差异。理想脱钩省份可产生正向空间溢出效应,有助于发挥低碳锁定作用,而脱钩不理想省份则会发挥负向溢出效应。(4)我国整体脱钩水平尚未达到同一稳态,局部检验共得到6个收敛俱乐部,内部表现出较显著的趋同效应。 展开更多
关键词 脱钩 Tapio 空间自相关 空间马尔科夫链 俱乐部
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城乡融合发展:中国城市化进程中空间治理的新议题及其推进理路 被引量:4
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作者 任维德 张乐 《内蒙古社会科学》 北大核心 2025年第1期40-47,共8页
改革开放以来,中国政府通过撤地设市、地市合并、撤县设市、撤县(市)设区、市辖区调整、乡镇撤并以及地级市代管县(市)等行政区划调整,运用城市与区域空间治理的多种政策工具,以城市空间的增量与重构激发城市化发展动力,推动经济、社会... 改革开放以来,中国政府通过撤地设市、地市合并、撤县设市、撤县(市)设区、市辖区调整、乡镇撤并以及地级市代管县(市)等行政区划调整,运用城市与区域空间治理的多种政策工具,以城市空间的增量与重构激发城市化发展动力,推动经济、社会的发展与现代化。城乡融合发展是中国式现代化的必然要求,是统筹推进新型城镇化的重要途径,已成为中国城市化进程中空间治理的新议题。基于此,有必要对城乡融合发展的多重逻辑、推进理路展开深入探讨,这对于破解城乡发展差距、实现共同富裕的意义十分重大。 展开更多
关键词 城乡融合发展 城市化进程 空间治理 空间增量
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我国农产品流通效率时空演变、地区差异与收敛性 被引量:4
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作者 高国生 叶林祥 支海兵 《经济问题》 北大核心 2025年第1期100-112,共13页
农产品流通效率事关我国粮食安全和全国统一大市场的建成。运用熵值法测度了2011—2022年我国31个省级行政区的农产品流通效率,并使用Moran’s I、Kernel核密度估计、Markov链、Dagum基尼系数和β收敛模型分别分析了我国农产品流通效率... 农产品流通效率事关我国粮食安全和全国统一大市场的建成。运用熵值法测度了2011—2022年我国31个省级行政区的农产品流通效率,并使用Moran’s I、Kernel核密度估计、Markov链、Dagum基尼系数和β收敛模型分别分析了我国农产品流通效率的时空演变、地区差异与收敛性情况。结果显示:研究期内我国农产品流通效率存在显著正向空间相关性,“高—高”集聚和“低—低”集聚特征明显;核密度曲线宽度变大呈现右拖尾和高度差明显的双峰形态,表明农产品流通效率逐渐提升,地区内部存在极化趋势;相邻省区市空间滞后水平对本省区市农产品流通效率维持原有状态或向更高水平发展均有较大影响;地区间差异是造成农产品流通效率总体差异显著的主要原因;农产品流通效率存在显著绝对β收敛和条件β收敛。据此,对如何提高农产品流通效率和缩小地区间差距提出了相关政策建议。 展开更多
关键词 农产品流通效率 时空演变 空间分布 地区差异
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社会空间实践与空间表象和表征——列斐伏尔《空间的生产》解读 被引量:2
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作者 张一兵 《武汉大学学报(哲学社会科学版)》 北大核心 2025年第3期64-76,共13页
社会空间是作为一定生产方式的社会关系的生产,生产社会关系的空间实践是当下发生和随时消失的,于是,就一定会出现保证空间实践日常重构的空间表象和表征性空间的引导,这就造成了空间存在认知上的巨大复杂性。空间关系表象在社会空间中... 社会空间是作为一定生产方式的社会关系的生产,生产社会关系的空间实践是当下发生和随时消失的,于是,就一定会出现保证空间实践日常重构的空间表象和表征性空间的引导,这就造成了空间存在认知上的巨大复杂性。空间关系表象在社会空间中锚定和展示关系的场境存在的同时,往往会悄悄地转换真实关系的存在。 展开更多
关键词 列斐伏尔 《空间的生产》 空间实践 空间表象 表征性空间
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三维空间土壤推测与土壤模型构建研究进展 被引量:1
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作者 解宪丽 夏成业 +3 位作者 殷彪 李安波 李开丽 潘贤章 《土壤学报》 北大核心 2025年第1期14-28,共15页
土壤是具有高度异质性的复合体。早期的数字土壤制图研究主要关注水平方向的土壤空间变异和制图,对垂直方向空间变异和土壤三维制图考虑较少。近年来,三维地理信息技术和对地观测与探测技术的快速发展,极大地促进了土壤三维空间数据获... 土壤是具有高度异质性的复合体。早期的数字土壤制图研究主要关注水平方向的土壤空间变异和制图,对垂直方向空间变异和土壤三维制图考虑较少。近年来,三维地理信息技术和对地观测与探测技术的快速发展,极大地促进了土壤三维空间数据获取、三维空间推测、三维数据模型、三维模型构建和可视化方法等方面的研究。本文对三维空间土壤推测与土壤模型构建的已有方法进行梳理和评述,以期为三维数字土壤制图的应用和发展提供建议。以三维土壤制图、三维GIS、三维数据模型、三维地质建模、三维可视化、土壤空间变异、空间推测、克里格插值、土壤-景观分析、深度函数、机器学习、地统计学、随机模拟等为关键词检索Web of Science数据库,基于相关度、引用率和文献来源等因素进一步筛选出重点文献进行分析。归纳整理了土壤空间变异性、三维空间土壤推测、三维空间数据模型和三维模型构建等关键技术的现有研究体系,对各种三维推测和建模方法的优缺点和适用场景作出评价。针对目前研究中存在的垂直方向土壤数据稀少、土壤三维推测精度低、三维模型质量待提高等问题,提出一些可行的研究思路。 展开更多
关键词 三维空间 土壤空间变异性 土壤空间推测 三维数据模型 三维模型构建 数字土壤制图
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数字时代基层协商民主的空间运行及活化路径 被引量:2
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作者 袁芳 《中州学刊》 北大核心 2025年第2期21-29,共9页
党的二十届三中全会将健全协商民主机制和基层民主制度作为进一步全面深化改革的着力点,体现了党对聚焦发展全过程人民民主的深刻把握。当前基层协商民主呈现为物理空间、制度空间、网络空间以及精神文化空间等多元空间形态的良性运行,... 党的二十届三中全会将健全协商民主机制和基层民主制度作为进一步全面深化改革的着力点,体现了党对聚焦发展全过程人民民主的深刻把握。当前基层协商民主呈现为物理空间、制度空间、网络空间以及精神文化空间等多元空间形态的良性运行,数字技术为基层协商民主提供全新的空间融合、平等的空间互动和共享的空间秩序,有助于激活政治参与过程,增强民主实践的多样性和包容性,但在数字技术价值、空间权益保障、协商意见表达、协商回应落实等方面还存在一些现实问题。秉持创新思维、开放思维和协同思维,亟待整合空间形态、优化空间关系、创新协商模式、凝聚空间合力,充分释放数字时代基层协商民主的活力和效能。 展开更多
关键词 数字时代 基层协商民主 空间运行 空间活化
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新型城镇化建设对我国农业经济韧性的影响研究——基于空间双重差分模型的实证分析 被引量:2
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作者 周利平 辛婷 《中国生态农业学报(中英文)》 北大核心 2025年第4期807-819,共13页
厘清中国新型城镇化与农业经济发展间的关系,对实现城乡共荣、赋能农业高质量发展具有重要意义。本文基于2006—2020年中国31个省(自治区、直辖市,不包括中国香港地区、澳门地区和台湾地区)的面板数据,运用空间双重差分模型(SDID),实证... 厘清中国新型城镇化与农业经济发展间的关系,对实现城乡共荣、赋能农业高质量发展具有重要意义。本文基于2006—2020年中国31个省(自治区、直辖市,不包括中国香港地区、澳门地区和台湾地区)的面板数据,运用空间双重差分模型(SDID),实证分析了新型城镇化战略对农业经济韧性的影响效应及其空间溢出效应。研究发现:1)空间相关性分析显示,中国农业经济韧性具有显著为正的空间相关性,呈现出“高-高”型和“低-低”型聚集模式;2)基准回归结果显示,新型城镇化战略显著提高了试点省份的农业经济韧性;3)空间双重差分结果表明,新型城镇化战略对农业经济韧性产生空间溢出效应,该结论在更换空间权重矩阵、安慰剂等一系列检验下仍具有稳健性;4)进一步的机制分析表明,新型城镇化战略主要通过技术进步、优化产业结构和提升农村人力资本水平来提高农业经济韧性。研究结论不仅从农业经济韧性的视角丰富了新型城镇化实施效果的研究成果,同时也为农业经济韧性水平的提升提供了来自新型城镇化战略的解释。 展开更多
关键词 新型城镇化 农业经济韧性 空间溢出 空间双重差分
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黄土高原退耕刺槐中龄林密度和空间结构对灌草多样性的影响 被引量:3
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作者 王宇 王冬梅 +3 位作者 王彦辉 云慧雅 张梦棋 张莹莹 《生态学报》 北大核心 2025年第2期822-836,共15页
为了在理解林分密度和空间结构参数对林下灌草多样性的影响基础上科学指导黄土高原退耕还林工程早期栽植的刺槐(Robinia pseudoacacia)中龄林经营,于甘肃省泾川县官山林场选择了生长在残塬顶部退耕梯田相似立地上的林龄18—25 a的4个密... 为了在理解林分密度和空间结构参数对林下灌草多样性的影响基础上科学指导黄土高原退耕还林工程早期栽植的刺槐(Robinia pseudoacacia)中龄林经营,于甘肃省泾川县官山林场选择了生长在残塬顶部退耕梯田相似立地上的林龄18—25 a的4个密度梯度的刺槐中龄人工林,建立了样地共12个,调查角尺度、混交度、密集度、开敞度和大小比数等林分空间结构参数,同时调查计算林下灌木、草本层的Simpson指数、Gini多样性指数、Shannon-Wiener指数、Pielou均匀度指数及Patrick指数等林下植物多样性指标,运用Person相关性分析和灰色关联度分析探究刺槐中龄人工林密度和空间结构参数与林下灌木层和草本层植物多样性的关系,并确定主要影响因子。结果表明:(1)林下植物物种总数随林分密度增加呈先增后减的变化,在密度1300—1700株/hm^(2)时,林下植物物种总数和草本层多样性指数均达到最大。(2)林分密度主要影响刺槐林的透光性、分布格局和混交程度,密度<1300株/hm^(2)时林分透光性最好;密度1300—1700株/hm^(2)时,57%的刺槐林木呈随机分布,此时分布格局最接近天然状态;密度>2100株/hm^(2)时,林分的混交程度最高。(3)Person相关性分析表明,开敞度和灌木层Simpson指数、物种丰富度指数呈极显著正相关(P<0.01),混交度和草本层物种丰富度指数、Gini指数呈显著正相关(P<0.05)。灰色关联度分析表明,当林分密度<1300、1300—1700、>1700株/hm^(2)时,影响林下灌草多样性的主要因子分别是混交度、开敞度、胸径大小比数。(4)对在研究立地条件上退耕栽植的刺槐中龄林,可将1300—1700株/hm^(2)作为考虑林下植物多样性的合理经营密度范围。可以基于研究结果,针对性地优化刺槐人工中龄林的林分密度和空间结构,促进林下灌草层发育,提高林下植物多样性和森林的多功能性。 展开更多
关键词 黄土高原 林分空间结构 林下植被多样性 林分密度
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