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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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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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A novel detection method for warhead fragment targets in optical images under dynamic strong interference environments
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作者 Guoyi Zhang Hongxiang Zhang +4 位作者 Zhihua Shen Deren Kong Chenhao Ning Fei Shang Xiaohu Zhang 《Defence Technology(防务技术)》 2025年第1期252-270,共19页
A measurement system for the scattering characteristics of warhead fragments based on high-speed imaging systems offers advantages such as simple deployment,flexible maneuverability,and high spatiotemporal resolution,... A measurement system for the scattering characteristics of warhead fragments based on high-speed imaging systems offers advantages such as simple deployment,flexible maneuverability,and high spatiotemporal resolution,enabling the acquisition of full-process data of the fragment scattering process.However,mismatches between camera frame rates and target velocities can lead to long motion blur tails of high-speed fragment targets,resulting in low signal-to-noise ratios and rendering conventional detection algorithms ineffective in dynamic strong interference testing environments.In this study,we propose a detection framework centered on dynamic strong interference disturbance signal separation and suppression.We introduce a mixture Gaussian model constrained under a joint spatialtemporal-transform domain Dirichlet process,combined with total variation regularization to achieve disturbance signal suppression.Experimental results demonstrate that the proposed disturbance suppression method can be integrated with certain conventional motion target detection tasks,enabling adaptation to real-world data to a certain extent.Moreover,we provide a specific implementation of this process,which achieves a detection rate close to 100%with an approximate 0%false alarm rate in multiple sets of real target field test data.This research effectively advances the development of the field of damage parameter testing. 展开更多
关键词 Damage parameter testing Warhead fragment target detection High-speed imaging systems Dynamic strong interference disturbance suppression Variational bayesian inference Motion target detection Faint streak-like target detection
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Spectrum spatial structure characteristic analysis of remote sensing alteration information and interference factors 被引量:1
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作者 杨自安 彭省临 +3 位作者 朱谷昌 石菲菲 邹林 张远飞 《Journal of Central South University》 SCIE EI CAS 2009年第4期647-652,共6页
Based on the statistical characteristics of remote sensing data, the spatial geometric structure characteristics of spectral data and distribution of background, interference and alteration information in characterist... Based on the statistical characteristics of remote sensing data, the spatial geometric structure characteristics of spectral data and distribution of background, interference and alteration information in characteristic space were researched through the analysis of two-dimensional and three-dimensional scatter diagrams. The results indicate that the hyper-space of remote sensing multi-data aggregation belongs to low-dimensional geometric structure, i.e. hyperplane form, and anomalous point groups including alteration information usually dissociate out of hyperplane. Scatter diagrams of remote sensing data band are mainly presented as two distribution forms of single-ellipse and dual-ellipse. Clarifying the relations of three objects of background, disturbance and alteration information in remote sensing images provides an important technical thought and guidance for accurately detecting and extracting remote sensing alteration information. 展开更多
关键词 remote sensing data alteration information BACKGROUND interference factor spectrum spatial structure scatter diagram
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Cognitive interference decision method for air defense missile fuze based on reinforcement learning 被引量:1
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作者 Dingkun Huang Xiaopeng Yan +2 位作者 Jian Dai Xinwei Wang Yangtian Liu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期393-404,共12页
To solve the problem of the low interference success rate of air defense missile radio fuzes due to the unified interference form of the traditional fuze interference system,an interference decision method based Q-lea... To solve the problem of the low interference success rate of air defense missile radio fuzes due to the unified interference form of the traditional fuze interference system,an interference decision method based Q-learning algorithm is proposed.First,dividing the distance between the missile and the target into multiple states to increase the quantity of state spaces.Second,a multidimensional motion space is utilized,and the search range of which changes with the distance of the projectile,to select parameters and minimize the amount of ineffective interference parameters.The interference effect is determined by detecting whether the fuze signal disappears.Finally,a weighted reward function is used to determine the reward value based on the range state,output power,and parameter quantity information of the interference form.The effectiveness of the proposed method in selecting the range of motion space parameters and designing the discrimination degree of the reward function has been verified through offline experiments involving full-range missile rendezvous.The optimal interference form for each distance state has been obtained.Compared with the single-interference decision method,the proposed decision method can effectively improve the success rate of interference. 展开更多
关键词 Cognitive radio interference decision Radio fuze Reinforcement learning interference strategy optimization
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Color-polarization synergistic target detection method considering shadow interference 被引量:1
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作者 Bin Feng Jinpei Xiao +3 位作者 Junchao Zhang Lin Li Yunlong Wu Qing Ye 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第7期50-61,共12页
Aiming at the problem of shadow interference in UAV's ground reconnaissance,a color and polarization synergistic target detection method is proposed for anti-shadow interference,based on the influence of two physi... Aiming at the problem of shadow interference in UAV's ground reconnaissance,a color and polarization synergistic target detection method is proposed for anti-shadow interference,based on the influence of two physical characteristics(wavelength and polarization)under different illuminations.A valid fusion strategy is proposed via integrating two separate detection results on color and polarization images.Moreover,a local enhancement and recognition module(LER)is introduced to boost the performance.Based on our built dataset,experimental results show that our method achieves mAPof 87.76%,and12.37%higher than that of color image and 14.68%higher than that of polarization image. 展开更多
关键词 Electro-optical countermeasure Ground reconnaissance Color-polarization Shadow interference Target recognition
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Adaptive detection of range-spread targets in homogeneous and partially homogeneous clutter plus subspace interference 被引量:1
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作者 JIAN Tao HE Jia +3 位作者 WANG Bencai LIU Yu XU Congan XIE Zikeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期43-54,共12页
Adaptive detection of range-spread targets is considered in the presence of subspace interference plus Gaussian clutter with unknown covariance matrix.The target signal and interference are supposed to lie in two line... Adaptive detection of range-spread targets is considered in the presence of subspace interference plus Gaussian clutter with unknown covariance matrix.The target signal and interference are supposed to lie in two linearly independent subspaces with deterministic but unknown coordinates.Relying on the two-step criteria,two adaptive detectors based on Gradient tests are proposed,in homogeneous and partially homogeneous clutter plus subspace interference,respectively.Both of the proposed detectors exhibit theoretically constant false alarm rate property against unknown clutter covariance matrix as well as the power level.Numerical results show that,the proposed detectors have better performance than their existing counterparts,especially for mismatches in the signal steering vectors. 展开更多
关键词 adaptive detection subspace interference constant false alarm rate Gradient test partially homogeneous environment
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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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Full-domain collaborative deployment method of multiple interference sources and evaluation of its deployment effect
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作者 Yue Wang Fuping Sun +2 位作者 Xian Wang Jinming Hao Kai Xiao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期572-595,共24页
This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the at... This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation countermeasures.Key evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment principles.The principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively deploying.Accordingly,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to space.Varied evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality. 展开更多
关键词 Jamming effect Multiple interference sources Collaborative deployment Effect evaluation Defense capability
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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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多目标联合优化的车联网动态资源分配算法 被引量:3
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作者 宋晓勤 张文静 +2 位作者 雷磊 宋铁成 赵丽屏 《东南大学学报(自然科学版)》 北大核心 2025年第1期266-274,共9页
为了解决车联网(IoV)信道高动态不确定性及多用户干扰所导致的通信传输性能下降问题,提出了一种基于多智能体增强型双深度Q网络(EDDQN)的多目标联合优化资源分配算法。首先,考虑车辆运动和信道时变特性,建立多用户干扰下频谱共享和功率... 为了解决车联网(IoV)信道高动态不确定性及多用户干扰所导致的通信传输性能下降问题,提出了一种基于多智能体增强型双深度Q网络(EDDQN)的多目标联合优化资源分配算法。首先,考虑车辆运动和信道时变特性,建立多用户干扰下频谱共享和功率控制联合优化的资源分配决策模型,在满足时延和可靠性等约束下,最小化网络时延和能耗加权和(成本);然后,将模型转换为马尔可夫决策过程(MDP),利用双深度Q网络(DDQN),并引入优先经验回放和多步学习,通过集中式训练和分布式执行,优化车间(V2V)链路的频谱共享和功率分配策略。结果表明,所提算法具有良好的收敛性,在不同负载下相较对比算法成本减少8%以上,负载传输成功率提升19%以上,有效提高了通信传输性能。 展开更多
关键词 车联网 多用户干扰 多目标联合优化 深度强化学习
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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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