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On the Shadowing Property and Shadowable Point of Set-valued Dynamical Systems 被引量:6
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作者 Xiao Fang LUO Xiao Xiao NIE Jian Dong YIN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2020年第12期1384-1394,共11页
In this article,the authors introduce the concept of shadowable points for set-valued dynamical systems,the pointwise version of the shadowing property,and prove that a set-valued dynamical system has the shadowing pr... In this article,the authors introduce the concept of shadowable points for set-valued dynamical systems,the pointwise version of the shadowing property,and prove that a set-valued dynamical system has the shadowing property iff every point in the phase space is shadowable;every chain transitive set-valued dynamical system has either the shadowing property or no shadowable points;and for a set-valued dynamical system there exists a shadowable point iff there exists a minimal shadowable point.In the end,it is proved that a set-valued dynamical system with the shadowing property is totally transitive iff it is mixing and iff it has the specification property. 展开更多
关键词 Shadowing property shadowable point set-valued dynamical system SPECIFICATION
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On the Eventual Shadowing Property and Eventually Shadowable Point of Set-valued Dynamical Systems 被引量:2
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作者 Xue Rong XIE Jian Dong YIN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2022年第6期1105-1115,共11页
The authors introduce the concepts of the eventual shadowing property and eventually shadowable point for set-valued dynamical systems and prove that a set-valued dynamical system has the eventual shadowing property i... The authors introduce the concepts of the eventual shadowing property and eventually shadowable point for set-valued dynamical systems and prove that a set-valued dynamical system has the eventual shadowing property if and only if every point in the phase space is eventually shadowable;every chain transitive set-valued dynamical system has either the eventual shadowing property or no eventually shadowable points;and a set-valued dynamical system admits an eventually shadowable point if and only if it admits a minimal eventually shadowable point.Moreover,it is proved that a set-valued dynamical system with the eventual shadowing property is chain mixing if and only if it is mixing and if and only if it has the specification property. 展开更多
关键词 Eventual shadowing property eventually shadowable point set-valued dynamical system SPECIFICATION
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Vector Fields with Stable Shadowable Property on Closed Surfaces
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作者 Sheng Zhi ZHU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第8期1449-1456,共8页
We prove that the set of vector fields satisfying the C1 stable shadowable property on closed surfaces is characterized as the set of Morse-Smale vector fields. Hence, the vector fields satisfying shadowing property o... We prove that the set of vector fields satisfying the C1 stable shadowable property on closed surfaces is characterized as the set of Morse-Smale vector fields. Hence, the vector fields satisfying shadowing property on closed surfaces are C1 dense. 展开更多
关键词 Pseudo orbit SHADOWING stable shadowable
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Special Artists Find their Calling in Shadow Puppetry
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作者 DENG DI 《China Today》 2026年第1期64-66,共3页
Before joining the Beijing Dragon Shadow Puppetry Art Theatre,this group of young people rarely had the chance to meet people like themselves,lacked friends,faced obstacles at work,and felt alienated from society.Now,... Before joining the Beijing Dragon Shadow Puppetry Art Theatre,this group of young people rarely had the chance to meet people like themselves,lacked friends,faced obstacles at work,and felt alienated from society.Now,they have gained appreciation,recognition,confidence,friendships,and love. 展开更多
关键词 FRIENDSHIPS Beijing Dragon Shadow Puppetry Art Theatre recognition love APPRECIATION confidence young people shadow puppetry
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Geometric,thermodynamic and perturbative properties of Frolov black holes surrounded by a cloud of strings and a global monopole
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作者 Ahmad Al-Badawi Faizuddin Ahmed Izzet Sakallı 《Communications in Theoretical Physics》 2026年第2期53-77,共25页
In this study,we present a comprehensive analysis of a modified Frolov black hole(BH)model that incorporates two types of topological defects,a global monopole(GM)and a cloud of strings(CS).This composite BH solution ... In this study,we present a comprehensive analysis of a modified Frolov black hole(BH)model that incorporates two types of topological defects,a global monopole(GM)and a cloud of strings(CS).This composite BH solution is examined from multiple theoretical perspectives to explore the impact of these modifications on the BH's geometric,thermodynamic and dynamical properties.We begin by studying the geometrical optics of the spacetime,focusing on the motion of null geodesics.Key features,such as the effective potential,photon sphere,the force acting on photons and the stability of circular photon orbits,are analyzed in detail.Our results show that the presence of GM and CS significantly affects the spacetime geometry and photon dynamics.In addition,the thermodynamic behavior of the modified BH is also investigated.We derive essential quantities such as the Hawking temperature and entropy,demonstrating how the inclusion of GM and CS leads to deviations from the standard thermodynamic relations observed in classical BH solutions.These deviations may offer valuable insights into quantum gravity and the role of topological defects in BH physics.Furthermore,we examine the BH shadow as an observational signature of the underlying geometry.Our analysis shows that the Frolov parameter tends to reduce the apparent size of the shadow,while the presence of topological defects,particularly GM and CS,enlarges it.In addition,we investigate the perturbative dynamics of the BH by studying both scalar(spin-0),fermionic(spin-1/2)and electromagnetic(spin-1)fields through the massless Klein-Gordon and Maxwell equations,respectively.Using the Wentzel-Kramers-Brillouin approximation,we compute the quasinormal modes(QNMs)for scalar and electromagnetic field perturbations.The results confirm the stability of the BH under small perturbations and show that the QNM frequencies and damping rates are strongly influenced by the Frolov parameter,electric charge,GM and CS. 展开更多
关键词 black hole Frolov global monopole cosmic string quasinormal modes THERMODYNAMICS SHADOW
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IN-CLASS DEMONSTRATION OF THE ZEEMAN EFFECT:FROM QUALITATIVE OBSERVATION TO QUANTITATIVE EXPERIMENTS
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作者 QIN Shaohan MA Yuhan 《物理与工程》 2026年第1期21-27,共7页
The Zeeman effect,a fundamental quantum phenomenon,demonstrates the interaction between magnetic fields and atomic systems.While precise spectroscopic measurements of this effect have advanced significantly,there rema... The Zeeman effect,a fundamental quantum phenomenon,demonstrates the interaction between magnetic fields and atomic systems.While precise spectroscopic measurements of this effect have advanced significantly,there remains a lack of simple,visually accessible demonstration for educational purposes.Here,we present a low-cost experiment that allows for direct visual observation of the Zeeman effect.Our setup involves a flame containing sodium(from table salt)placed in front of a sodium vapor lamp.When a magnetic field is applied to the flame,the shadow cast by the flame noticeably lightens,providing a clear,naked-eye demonstration of the Zeeman effect.Furthermore,we conduct two quantitative experiments using this setup,examining the effects of varying magnetic field strength and sodium concentration.This innovative approach not only enriches the experimental demonstration for teaching atomic physics at undergraduate and high school levels but also provides an open platform for students to explore the Zeeman effect through hands-on experience. 展开更多
关键词 Zeeman effect demonstration experiment CANDLE sodium vapor SHADOW
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Thermal,topological,and scattering effects of an AdS charged black hole with an antisymmetric tensor background
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作者 H Chen M Y Zhang +2 位作者 A A Araújo Filho F Hosseinifar H Hassanabadi 《Communications in Theoretical Physics》 2026年第2期98-107,共10页
In this study,we explore a spherically symmetric charged black hole(BH)with a negative cosmological constant under the influence of a Kalb-Ramond field background.We compute the photon sphere and shadow radii,validati... In this study,we explore a spherically symmetric charged black hole(BH)with a negative cosmological constant under the influence of a Kalb-Ramond field background.We compute the photon sphere and shadow radii,validating our findings using observational data from the Event Horizon Telescope,with a particular emphasis on the shadow images of Sagittarius A^(*).Furthermore,we investigate the greybody factors,emission rate,and partial absorption cross section.It is shown that the Lorentz-violating parameter l has an important effect on the absorption cross section.Our analysis also includes an examination of the topological charge,temperature-dependent topology,and generalized free energy.In particular,we regard the AdS charged BH with an antisymmetric tensor background as a topological defect in the thermodynamic space,then the system has the same topological classification to the charged Reissner-Nordström-AdS BH. 展开更多
关键词 black hole topological classification SHADOW greybody factors
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Stable Weakly Shadowable Volume-preserving Systems Are Volume-hyperbolic 被引量:1
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作者 Mrio BESSA Manseob LEE Sandra VAZ 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2014年第6期1007-1020,共14页
We prove that any C1-stable weakly shadowable volume-preserving diffeomorphism defined on a compact manifold displays a dominated splitting E ⊕ F. Moreover, both E and F are volume-hyperbolic. Finally, we prove the v... We prove that any C1-stable weakly shadowable volume-preserving diffeomorphism defined on a compact manifold displays a dominated splitting E ⊕ F. Moreover, both E and F are volume-hyperbolic. Finally, we prove the version of this result for divergence-free vector fields. As a consequence, in low dimensions, we obtain global hyperbolicity. 展开更多
关键词 Weak shadowing dominated splitting HYPERBOLICITY
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光纤光栅传感网络恶意攻击篡改信标节点安全定位方法
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作者 王文霞 李智玲 杨文彬 《激光杂志》 北大核心 2025年第4期198-202,共5页
为了防止恶意节点攻击篡改信标节点信息,保护网络正常运行的同时提高信标节点定位精度,提出光纤光栅传感网络恶意攻击篡改信标节点安全定位方法。首先,计算节点信任值,将计算结果作为恶意节点判断依据,识别恶意节点并剔除;其次,采用Boun... 为了防止恶意节点攻击篡改信标节点信息,保护网络正常运行的同时提高信标节点定位精度,提出光纤光栅传感网络恶意攻击篡改信标节点安全定位方法。首先,计算节点信任值,将计算结果作为恶意节点判断依据,识别恶意节点并剔除;其次,采用Bounding-box算法搜索未知信标节点其所在区域,完成节点的初步定位;最后,建立Shadowing模型结合质心算法,计算信标节点的具体位置坐标。实现光纤光栅传感网络恶意攻击篡改信标节点安全定位方法。仿真实验结果表明,所提方法对恶意节点检测率高,信标节点定位精度高,覆盖性强。 展开更多
关键词 传感网络 恶意节点检测 信标节点定位 Shadowing模型
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Parallel Theaters in CPSS:From Shadows of ISDOS to Intelligence of Decision Theaters 被引量:2
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作者 Qinghua Ni Buday Viktória +4 位作者 Fei Lin Jun Huang Levente Kovács Nan Zheng Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 2025年第6期1059-1062,共4页
As Artificial Intelligence(AI)is moving fast from Large Language Models(LLMs)to AI Agents and Agentic Intelligence,the need to incorporate new AI into Decision Intelligence(DI)is becoming more and more urgent for both... As Artificial Intelligence(AI)is moving fast from Large Language Models(LLMs)to AI Agents and Agentic Intelligence,the need to incorporate new AI into Decision Intelligence(DI)is becoming more and more urgent for both practical and theoretic reasons:both decision and process complexities would be significantly increased due to the use of advanced AI tools and agents,and both traditional and recent thinking must be rethought and reconstructed accordingly.Our perspective would like to address this important issue based on some historical milestone developments in Computer-Aided Software Engineering(CASE)and recent efforts in digital theatrical technology[1]. 展开更多
关键词 traditional recent thinking large language models llms agentic intelligencethe parallel theaters ai agents shadows isdos artificial intelligence ai decision intelligence di
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Digital shadow of an electric vehicle-permanent magnet synchronous motor drive for real-time performance monitoring
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作者 Mahmoud Ibrahim Viktor Rjabtšikov Anton Rassõlkin 《Digital Twins and Applications》 2025年第1期1-12,共12页
Digital twin(DT)technology has been utilised in many applications including electric vehicles(EVs).A DT is a virtual representation of a physical object,enabled through real-time data integration,simulation,and optimi... Digital twin(DT)technology has been utilised in many applications including electric vehicles(EVs).A DT is a virtual representation of a physical object,enabled through real-time data integration,simulation,and optimisation tools.Unlike conventional simulations,which are typically offline and lack real-time interaction,a DT continuously synchronises with the physical system,enabling dynamic performance monitoring and predictive an-alytics.Achieving a full DT involves progressive stages,with the digital shadow(DS)being the final step before realising a bidirectional DT.Building a DS provides a scalable real-time performance monitoring and fault detection framework,enabling proactive decision-making in EV operations.This study introduces a DS system specifically designed to monitor the performance of a permanent magnet synchronous motor(PMSM)drive system in EVs,marking a critical phase towards a complete DT.The methodology for creating the DS is detailed,including the establishment of a compre-hensive test bench for the EV powertrain as the physical reference model.The mathe-matical model of the EV-PMSM was formulated,and an advanced estimation model utilising the extended Kalman filter(EKF)was implemented.MATLAB/Simulink was employed to develop the motor’s digital model.Real-time data acquisition from the physical model was facilitated through a data acquisition system(DAS)equipped with a controller area network(CAN)communication interface.The digital model underwent thorough validation against sensory data collected from the test bench.The motor digital model was deployed to a DS framework enabled through real-time data flow from the actual EV during real-world driving conditions.The results demonstrated a high accuracy of 97%between the DS predictions and the corresponding EV data,confirming the DS’s reliability.These findings pave the way for future advancements,including bidirectional interaction and the realisation of a full DT. 展开更多
关键词 digital shadow electrical engineering MODELLING MONITORING
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Confucian Sincerity and Jungian Individuation:A Cross-Cultural Study of Authentic Selfhood
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作者 CHANG Shu-yuan 《Journal of Literature and Art Studies》 2025年第12期936-940,共5页
This study compares Confucian sincerity(cheng)and Jungian individuation as two paths toward authentic selfhood.Confucian sincerity stresses aligning inner intention with outward action,while Jungian individuation emph... This study compares Confucian sincerity(cheng)and Jungian individuation as two paths toward authentic selfhood.Confucian sincerity stresses aligning inner intention with outward action,while Jungian individuation emphasizes integrating persona and shadow.The paper argues that both traditions describe a shared developmental pattern:authenticity emerges when individuals confront inner contradictions,cultivate honest self-awareness,and reduce the gap between internal and external selves. 展开更多
关键词 Confucian sincerity Jungian individuation authenticity SELF-CULTIVATION persona and shadow
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Double Reduction in China:Demand-Supply Mismatch,On-Campus Substitution,and Policy Rebalancing
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作者 Xinghe Fang 《Journal of Contemporary Educational Research》 2025年第10期346-349,共4页
This review takes stock of China’s Double Reduction.In the short run,it lowered visible burden and pushed demand from subject tutoring toward on-campus and non-subject services.But with high-stakes selection unchange... This review takes stock of China’s Double Reduction.In the short run,it lowered visible burden and pushed demand from subject tutoring toward on-campus and non-subject services.But with high-stakes selection unchanged,demand reappears as small-group/one-to-one provision,advantaging families with high socioeconomic status and strong schools.Lasting relief will require tighter oversight and admissions reform with targeted,well-funded in-school support. 展开更多
关键词 Double Reduction Shadow education After-school services Demand rigidity EQUITY Income heterogeneity
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Night Lights
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作者 YASMINE RAMADAN 《China Today》 2025年第2期35-37,共3页
China’s night fairs,combining history with food and adventure,are what you need to unwind after a hard day’s work.I have lived in China for several years,and visiting night fairs has become a part of my life.In Beij... China’s night fairs,combining history with food and adventure,are what you need to unwind after a hard day’s work.I have lived in China for several years,and visiting night fairs has become a part of my life.In Beijing,I often go to Guijie on weekends to discover new things.It’s a historical place with an enticing old name:Ghost Street.I am told this used to be a popular market in the Qing Dynasty(1644-1911)and the oil lamps used in the stalls,giving a dim light and casting long shadows,made it look so eerie that people began to call it the Ghost Street. 展开更多
关键词 GHOST CASTING SHADOW
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Quasinormal modes and shadow of Schwarzschild black holes embedded in a Dehnen-type dark matter halo exhibiting a cloud of strings
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作者 Ahmad Al-Badawi Sanjar Shaymatov 《Communications in Theoretical Physics》 2025年第3期101-111,共11页
In this paper we consider a static spherically symmetric black hole(BH)embedded in a Dehnen-(1,4,0)-type dark matter(DM)halo in the presence of a cloud string.We examine and present data on how the core density of the... In this paper we consider a static spherically symmetric black hole(BH)embedded in a Dehnen-(1,4,0)-type dark matter(DM)halo in the presence of a cloud string.We examine and present data on how the core density of the DM halo parameter and the cloud string parameter affect BH attributes such as quasinormal modes(QNMs)and shadow cast.To do this,we first look into the effective potential of perturbation equations for three types of perturbation fields with different spins:massless scalar field,electromagnetic field and gravitational field.Then,using the sixth-order Wentzel-Kramers-Brillouin approximation,we examine QNMs of the BH disturbed by the three fields and derive quasinormal frequencies.The changes in QNM versus the core density parameter and the cloud string parameter for three disturbances are explored.We also investigate how the core density and the cloud string parameter affect the photon sphere and shadow radius.Interestingly,the study shows that the influence of Dehnen-type DM and cloud strings increases both the photon sphere and the shadow radius.Finally,we employ observational data from Sgr A^(*) and M87^(*) to set limitations on the BH parameters. 展开更多
关键词 SCHWARZSCHILD Dehnen type dark matter halo string cloud quasinormal modes SHADOW
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Space weathering characteristics of lunar permanently shadowed regions soils:Evidence from experimental simulation
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作者 Zixuan Han Yang Li +7 位作者 Chen Li Ronghua Pang Sizhe Zhao Zhuang Guo Kairui Tai Rui Li Zhenhao Hu Li Liu 《Acta Geochimica》 2025年第1期1-10,共10页
Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,i... Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,in particular reduction-oxidation processes that diff er from those in illuminated regions.To determine the characteristics of products formed during space weathering in PSRs,the lunar meteorite NWA 10203 with artifi cially added water was irradiated with a nanosecond laser to simulate a micro-meteorite bombardment of lunar soil containing water ice.The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness,poor stratifi cation,the appearance of bubbles,and a reduced number of npFe^(0).Additionally,EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles(npFe^(0))in the amorphous rim with the involvement of water.The results suggest that water ice is another possible factor contributing to oxidation during micrometeorite bombardment on the lunar surface.In addition,it off ers a reference for a new space weathering model that incorporates water in PSRs,which could be widespread on asteroids with volatiles. 展开更多
关键词 Space weathering Permanently shadowed regions The Moon laser irradiation Water ice
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Dramatic Connection Singaporean theater company Toy Factory seeks closer exchange with Chinese theater
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作者 Huang Jiangqin 《China Report ASEAN》 2025年第10期55-55,共1页
Goh Boon Teck is the chief artistic director of Toy Factory,a Singaporean theater company founded in 1990.According to Goh,a group of young people decided to organize their own theater company due to a love for drama.... Goh Boon Teck is the chief artistic director of Toy Factory,a Singaporean theater company founded in 1990.According to Goh,a group of young people decided to organize their own theater company due to a love for drama.The“Toy”in the name of the theater company comes from a Thai shadow puppet artist who worked with them,and“Factory”highlights the organization’s devotion to training theater practitioners for the art community.Goh said that in addition to staging productions,Toy Factory has also vigorously worked to discover new drama artists including actors,designers,and playwrights. 展开更多
关键词 Singapore chief artistic director theater company thai shadow puppet artist CHINESE EXCHANGE Toy Factory training theater practitioners
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Shadows and intensities of Simpson–Visser black holes in Verlinde's emergent gravity
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作者 Shahid Chaudhary Muhammad Danish Sultan +4 位作者 Asifa Ashraf Ali M Mubaraki Saad Althobaiti Ahmadjon Abdujabbarov Awatef Abidi 《Communications in Theoretical Physics》 2025年第12期119-132,共14页
Verlinde's emergent gravity(VEG)posits that gravity arises as an emergent phenomenon rooted in the entropic properties of spacetime,challenging the traditional view of gravity as a fundamental force.Building on th... Verlinde's emergent gravity(VEG)posits that gravity arises as an emergent phenomenon rooted in the entropic properties of spacetime,challenging the traditional view of gravity as a fundamental force.Building on this paradigm,recent developments have introduced a novel class of black holes within the VEG framework,revealing intriguing connections between apparent dark matter effects and the distribution of baryonic matter.In this study,we delve into the observational signatures of a Simpson–Visser(SV)Minkowski core regular black hole in VEG,focusing on its shadow images and intensity profiles.Our analysis highlights the profound influence of model parameters,including A(governing baryonic matter distribution),B(strength of interaction between apparent dark matter and baryonic matter),and n(characterizing diverse spacetime geometries),on the effective potential and observable properties.Notably,we find that the modifications introduced by these parameters lead to distinct changes in the black hole's shadow size and intensity distribution.Comparing our results to the Reissner–Nordström(RN)black hole,we uncover a striking reduction in the apparent shadow size and an enhancement in intensity for the SV solution in VEG. 展开更多
关键词 Simpson-Visser black holes Verlinde's emergent gravity shadow images observable intensities
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Estimating shadow price of CO_(2) emissions in China’s construction industry under policy regulations
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作者 Xiaoxiao Liu Mingyue Wang 《Chinese Journal of Population,Resources and Environment》 2025年第4期505-519,共15页
The marginal abatement cost(MAC)of CO_(2)emissions is one of the most critical indicators used to assess energy conservation and emission reduction.Although extensively measured,few studies have incorporated the influ... The marginal abatement cost(MAC)of CO_(2)emissions is one of the most critical indicators used to assess energy conservation and emission reduction.Although extensively measured,few studies have incorporated the influence of policy constraints when evaluating MAC.To address this gap,this paper proposes a nonparametric directional distance function approach under policy regulations to estimate the CO_(2)shadow price in the construction industry across 30 Chinese provinces from 2010 to 2017.Based on this enhanced method,four key findings emerge:①the annual CO_(2)shadow price exhibits an overall upward trend during the observation period;②regional shadow prices display marked variation across provinces;③regional heterogeneity in shadow prices has increased steadily over time;and④both urbanization rate and energy consumption per unit of gross domestic product are significantly negatively correlated with the CO_(2)shadow price.Finally,the paper offers several policy recommendations for CO_(2)emissions reduction in the Chinese construction industry at the national,industry,and enterprise levels. 展开更多
关键词 Construction industry Shadow price CO_(2)emission China Nonparametric directional distance function
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《品牌光影》
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作者 Ale Burset(摄影) 《现代广告》 2025年第12期F0002-F0002,1,共2页
案例简介:面对近年来巴拉圭创纪录的酷热夏季,Brahma啤酒以清凉为灵感,推出了极具创意的户外广告活动Branded Shadows。品牌团队在亚松森最炎热的地带精准选点,将带有Brahma标志的广告牌安装于酒吧和建筑物的屋顶。当阳光照射下,这些广... 案例简介:面对近年来巴拉圭创纪录的酷热夏季,Brahma啤酒以清凉为灵感,推出了极具创意的户外广告活动Branded Shadows。品牌团队在亚松森最炎热的地带精准选点,将带有Brahma标志的广告牌安装于酒吧和建筑物的屋顶。当阳光照射下,这些广告牌在地面上投射出清晰的品牌光影,让人们在最炎热的时段,于阴凉处看见Brahma的名字。 展开更多
关键词 Brahma啤酒 户外广告 Branded Shadows
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