期刊文献+
共找到1,408篇文章
< 1 2 71 >
每页显示 20 50 100
A visibly transparent radiative cooling film with self-cleaning function produced by solution processing 被引量:1
1
作者 Guoliang Chen Yaming Wang +6 位作者 Jun Qiu Jianyun Cao Yongchun Zou Shuqi Wang Jiahu Ouyang Dechang Jia Yu Zhou 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第31期76-84,共9页
Daylighting structures,including solar cells and building windows,utilize sunlight whilst suffering from undesired solar heat and outdoor dust contamination.A radiative cooling system that is transparent to sunlight a... Daylighting structures,including solar cells and building windows,utilize sunlight whilst suffering from undesired solar heat and outdoor dust contamination.A radiative cooling system that is transparent to sunlight and has a superhydrophobic surface would cool and clean the daylighting structures in a sustainable manner.However,the majority of the current daytime radiative cooling systems were designed to fully reflect the incident sunlight to maximize the cooling power.In this work,we optimized both the sunlight transmission and infrared thermal irradiation by modeling the size-dependent scattering and absorption of light by SiO_(2)spheres embedded in a polymer matrix,we found that the use of nanospheres(20 nm)enabled both high sunlight transmittance(>90%)and infrared emissivity(-0.85).This theoretical prediction was confirmed by experimental measurements of a solution-processed nanocomposite film.When coated on a solar cell,the as-prepared film not only preserved the power conversion efficiency of the cell(14.71%,uncoated cell has an efficiency of 14.79%)but also radiatively cooled the cell by up to 5℃under direct sunlight.This reduction of the operating temperature of the solar cell further enhanced its electrical power output,evidenced by an increase in the equilibrium temperature of the LED load by about 14℃.The nanoscale textured surface formed by the nanospheres further led to superhydrophobicity and thus excellent self-cleaning performance(efficient removal of dust by wind and/or water droplets). 展开更多
关键词 Nanocomposite film Radiative cooling visibly transparent SELF-CLEANING
原文传递
Visible light photocatalytic enhanced heterogeneous cobalt catalyzed peroxymonosulfate synergistic process to degradation atrazine:Efficiency,influencing factors,by-products removal and mechanism
2
作者 Qingkong Chen Jieyu Xia +3 位作者 Fengjun Liu Jianping Fan Peng Yan Mika Sillanpää 《Journal of Environmental Sciences》 2026年第1期166-177,共12页
This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degra... This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degradation.The synergistic process achieved complete ATZ removal within 60 min under near-neutral pH(6.9),outperform-ing individual Fenton-like(39%)and photocatalytic(24%)processes.Key factors influencing the degradation efficiency included light sources(UV>visible),pH(optimal at 6.9),catalyst dosage(0.01 g Co_(3)O_(4)/TiO_(2)),and PMS:ATZ molar ratio(1:2).The system exhibited a synergistic coefficient of 5.03(degradation)and 1.97(miner-alization),attributed to enhanced radical generation and accelerated Co^(3+)/Co^(2+)redox cycling through photoin-duced electron transfer.Intermediate analysis revealed dealkylation,dechlorination,and oxidation pathways,with reduced toxicity of by-products(e.g.,CEAT,CIAT)confirmed by ecotoxicity assessments.The mineralization efficiency(Vis-Photo+Fenton-like)reached 83.1%,significantly higher than that of standalone processes(Fenton-like:43.2%;photocatalysis:30.5%).The catalyst demonstrated excellent stability(nearly 90%recov-ery,<1μg/L Co leaching)and practical applicability.This study provides an efficient,sludge-free,and solar-compatible strategy for eliminating persistent herbicides in water treatment. 展开更多
关键词 Synergistic effect Sulfate radical FENTON-LIKE PHOTOCATALYSIS Visible light Atrazine(ATZ)
原文传递
Efficient chlorination reaction of Pt/RuO_(2)/g-C_(3)N_(4)under visible light irradiation for simultaneous removal of ammonia and bacteria from mariculture wastewater 被引量:1
3
作者 Yizhan Zhang Min Zhao +2 位作者 Yida Huang Yan-Ling Hu Lei Wang 《Journal of Environmental Sciences》 2025年第4期490-502,共13页
The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by deposit... The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight. 展开更多
关键词 PHOTOCATALYSIS Mariculture wastewater Ammonia nitrogen Visible light irradiation Microbial inactivation
原文传递
Development of Palygorskite-CaIn_(2)S_(4) composite for rapid Cr(Ⅵ) reduction under visible light 被引量:1
4
作者 Yuanyuan Wang Shijun Jia +3 位作者 Shiqiang Ding Wenyan Zhang Rui Shu Yingfei Hu 《Journal of Environmental Sciences》 2025年第10期562-575,共14页
Using natural minerals to eliminate harmful Cr(Ⅵ)under sustainable sunshine has significant potential.Herein,Palygorskite nanorods were utilized as carriers for the in-situ synthesis of CaIn_(2)S_(4) photocatalysts t... Using natural minerals to eliminate harmful Cr(Ⅵ)under sustainable sunshine has significant potential.Herein,Palygorskite nanorods were utilized as carriers for the in-situ synthesis of CaIn_(2)S_(4) photocatalysts through a simple one-pot thermal process,enabling the efficient reduction of Cr(Ⅵ).With a Palygorskite to CaIn_(2)S_(4) mass ratio of 5%,the conversion rate of Cr(Ⅵ)reached 98%after 60min of visible-light exposure,with a remarkable reaction rate of 0.0633 min^(-1).The effective integration of CaIn_(2)S_(4) with Palygorskite led to a more uniform dispersion of CaIn_(2)S_(4),exposing more reactive sites.Moreover,the establishment of a heterojunction between CaIn_(2)S_(4) and Palygorskite facilitated the transport of photogenerated electrons from CaIn_(2)S_(4),enhancing the efficiency of charge separation.These factors contribute to the improved photocatalytic performance.Additionally,the developed composite photocatalysts demonstrated excellent stability under light exposure and could be reused efficiently.Trapping tests on active substances revealed that e-played key roles in the Cr(Ⅵ)reduction.This research suggests the potential of using natural minerals to fabricate composite photocatalysts capable of effectively removing pollutants from the environment using solar energy. 展开更多
关键词 Cr(Ⅵ)reduction Visible light PALYGORSKITE CaIn_(2)S_(4)
原文传递
BDMFuse:Multi-scale network fusion for infrared and visible images based on base and detail features
5
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
在线阅读 下载PDF
Photoinduced Nickel-Catalyzed Reductive Heck Reaction
6
作者 Liu Junjie Zhao Hongping +2 位作者 Hu Yuanyuan Wang Hengxin Yuan Weiming 《有机化学》 北大核心 2025年第5期1691-1697,共7页
An efficient visible-light induced nickel-catalyzed reductive Heck reaction of alkenes by using mild organic reductant Hantzsch ester(HEH)instead of traditional metal reductants or hydride reagents was developed.The r... An efficient visible-light induced nickel-catalyzed reductive Heck reaction of alkenes by using mild organic reductant Hantzsch ester(HEH)instead of traditional metal reductants or hydride reagents was developed.The reductive hydroarylation of acrylates with aryl halides was successfully achieved without requiring exogenous photoredox catalysts.This reaction is highlighted by the simple and mild conditions,good functional group tolerance,thus providing a complementary approach for alkenes reductive Heck reaction. 展开更多
关键词 NICKEL reductive Heck reaction visible light organic reductant alken
原文传递
Visible Light-Promoted Aerobic Oxo-azidation of Alkenyl Silanes
7
作者 Tan Yan Ying Jiale +1 位作者 Yu Bing Lu Zhan 《有机化学》 北大核心 2025年第5期1684-1690,共7页
A visible-light-enabled method for the synthesis ofα-azidoketones has been developed via oxo-azidation of alkenyl silanes with trimethylsilylazide and molecular oxygen under mild conditions.The reaction could be carr... A visible-light-enabled method for the synthesis ofα-azidoketones has been developed via oxo-azidation of alkenyl silanes with trimethylsilylazide and molecular oxygen under mild conditions.The reaction could be carried out in gram scale.Various radical sources,including trifluoromethyl radical,thiocyanate radical,bromide radical,chlorine radical could partici-pate effectively instead of azide radical in the reaction. 展开更多
关键词 visible light catalysis aerobic oxidation alkenyl silanes organic azides
原文传递
Na and O Co-doped Carbon Nitride for Efficient Photocatalytic Hydrogen Evolution
8
作者 CHEN Libo SHENG Ying +3 位作者 WU Ming SONG Jiling JIAN Jian SONG Erhong 《无机材料学报》 北大核心 2025年第5期552-560,I0011,I0012,共11页
Elemental doping is an effective strategy for tuning the band structure of graphite carbon nitride(CN)to enhance its photocatalytic performance.In this study,sodium(Na)and oxygen(O)co-doped carbon nitride(Na/O-CN_(x),... Elemental doping is an effective strategy for tuning the band structure of graphite carbon nitride(CN)to enhance its photocatalytic performance.In this study,sodium(Na)and oxygen(O)co-doped carbon nitride(Na/O-CN_(x),x=1.0,2.0,3.0,4.0)was synthesized via solid-phase reaction of sodium citrate(NaCA)and pure CN powder in the Teflon-sealed autoclave under air conditions at 180℃.Surface area of Na/O-CN_(3.0) is measured to be 18.8 m^(2)/g,increasing by 60.7%compared to that of pure CN(11.7 m^(2)/g).Bandgap energy of Na/O-CN_(3.0) is determined to be 2.68 eV,marginally lower than that of pure CN(2.70 eV),thereby enhancing its capacity for sunlight absorption.Meanwhile,the incorporation of Na and O atoms into Na/O-CN_(x) is found to effectively reduce recombination rates of photogenerated electron-hole pairs.As a result,Na/O-CN_(x) samples exhibit markedly enhanced photocatalytic hydrogen evolution activity under visible light irradiation.Notably,the optimal Na/O-CN_(3.0) sample achieves a photocatalytic hydrogen production rate of 103.2μmol·g^(–1)·h^(–1),which is 8.2 times greater than that of pure CN(11.2μmol·g^(–1)·h^(–1)).Furthermore,a series of Na/O-CN_(x)-yO_(2)(y=0,20%,40%,60%,80%,100%)samples were prepared by modulating the oxygen content within reaction atmosphere.The catalytic performance evaluations reveal that the incorporation of both Na and O atoms in Na/O-CN_(3.0) enhances photocatalytic activity.This study also introduces novel methodologies for synthesis of metal atom-doped CN materials at lower temperature,highlighting the synergistic effect of Na and O atoms in photocatalytic hydrogen production of Na/O-CN_(x) samples. 展开更多
关键词 Na and O co-doped carbon nitride synergistic effect visible light photocatalytic hydrogen evolution
在线阅读 下载PDF
Band gap regulation of MIL-101(Fe)via pyrazine-based ligands substitution for enhanced visible-light adsorption and its photo-Fenton-like application
9
作者 Zongchen Li Jian Lu +3 位作者 Renjie Pan Qi Fu Tian-Yang Zhang Bin Xu 《Journal of Environmental Sciences》 2025年第9期762-772,共11页
Regulating the photo-response region of iron metal-organic frameworks(Fe-MOFs)is a viable strategy for enhancing their practical application in the visible-light driven photo-Fenton-like process.This study developed a... Regulating the photo-response region of iron metal-organic frameworks(Fe-MOFs)is a viable strategy for enhancing their practical application in the visible-light driven photo-Fenton-like process.This study developed a novel pyrazine-based Fe-MOFs(MIL-101(Fe)-Pz)by substituting the 1,4-dicarboxybenzene acid ligands in typical MIL-101(Fe)with 2,5-pyrazinedicarboxylic acid(PzDC),in which sodium acetate was used as coordinative modulator to control the crystal size(2–3μm).The incorporation of Fe-pyridine N coordination structures originated from PzDC ligands gave MIL-101(Fe)-Pz narrowed band gap(1.45 eV)than MIL-101(Fe)(2.54 eV)resulting in improved visible-light adsorption capacity(λ>420 nm),and also increased the proportion of Fe(Ⅱ)in the Fe-clusters.Thus MIL-101(Fe)-Pz exhibited a synergistic enhanced photo-Fenton-like catalytic performance under visible-light irradiation.The MIL-101(Fe)-Pz/H_(2)O_(2)/Vis system could degrade 99%of sulfamethoxazolewithin 30min,whichwas 10-fold faster than that of the pristine MIL-101(Fe),it also effectively removed other organic micropollutants with high durability and stability.Mechanistic analysis revealed that the PzDC ligands substitution decreased the band gap of MIL-101(Fe),giving MIL-101(Fe)-Pz appropriate band structure(-0.40∼1.05 V vs.NHE)which can cover several light-driven process for the generation of reactive oxygen species,including Fe(Ⅲ)reduction and H_(2)O_(2) activation for accelerating•OH generation,as well as oxygen reduction reaction for generating H_(2)O_(2),O_(2)^(•−) and ^(1)O_(2).This study highlights the role of pyridine-N containing ligands in regulating the band structure of Fe-MOFs,providing valuable guidance for the design of Fe-MOFs photocatalysts. 展开更多
关键词 Fe-MOFs Pyrazine ligands Photocatalysis Visible light Fenton-like process
原文传递
Critical processes controlling the formation of visible gold in the giant Jiaodong gold province:Constraints from microtextural and geochemical analyses by SEM,TOF-SIMS,and LA-(MC)-ICP-MS
10
作者 Hong Wang Ting-Guang Lan +6 位作者 Lang-Ye Zhao Hong-Rui Fan Zhan-Ping Li Huan-Long Hu Zi-Qi Xu Hong-Wei Peng Lei Shu 《Acta Geochimica》 2025年第6期1167-1185,共19页
The world-class Jiaodong gold province in the North China Craton hosts over 5000 t of Au resource and is characterized by abundant visible gold mineralization.However,the critical processes controlling the formation o... The world-class Jiaodong gold province in the North China Craton hosts over 5000 t of Au resource and is characterized by abundant visible gold mineralization.However,the critical processes controlling the formation of visible gold in this province remain poorly understood.To solve this problem,integrated microtextural,trace elemental,and sulfur isotopic analyses of pyrite from the high-grade Linglong gold deposit in the Jiaodong gold province were conducted in this study.Two distinct pyrite types were identified within auriferous quartz-sulfide veins:(1)Py1 aggregates in quartz-pyrite veins(hydrothermal stageⅡ),and(2)euhedral to subhedral,coarse-grained Py2 crystals in quartz-polymetallic sulfide veins(hydrothermal stageⅢ).Microtextural and elemental analyses revealed that visible gold predominantly occurs as intergranular particles between primary pyrite crystals within Py1 aggregates.The Py1 exhibits complex microtextures with abundant mineral inclusions of polymetallic sulfides and has low concentrations of Au(median:0.032 ppm)with a narrowδ^(34)S range(4.86‰-6.75‰),indicative of rapid crystallization under unstable,disequilibrium conditions.By contrast,the Py2 is texturally homogeneous and contains higher Au concentrations(median:0.304 ppm)with progressively increasingδ^(34)S values(5.25‰-10.14‰)over time,suggesting slow crystal growth under more stable,near-equilibrium conditions.Based on the microtextural and geochemical information,it is proposed that fluid boiling occurred only during the hydrothermal stage Ⅱ,which resulted in the unstable physicochemical environment and rapid deposition of gold.During the boiling processes,gold colloids likely occurred and promoted the formation of visible gold. 展开更多
关键词 Visible gold deposition PYRITE GEOCHEMISTRY Jiaodong gold province Microtextural analyses
在线阅读 下载PDF
HaIVFusion: Haze-Free Infrared and Visible Image Fusion
11
作者 Xiang Gao Yongbiao Gao +2 位作者 Aimei Dong Jinyong Cheng Guohua Lv 《IEEE/CAA Journal of Automatica Sinica》 2025年第10期2040-2055,共16页
The purpose of infrared and visible image fusion is to create a single image containing the texture details and significant object information of the source images,particularly in challenging environments.However,exis... The purpose of infrared and visible image fusion is to create a single image containing the texture details and significant object information of the source images,particularly in challenging environments.However,existing image fusion algorithms are generally suitable for normal scenes.In the hazy scene,a lot of texture information in the visible image is hidden,the results of existing methods are filled with infrared information,resulting in the lack of texture details and poor visual effect.To address the aforementioned difficulties,we propose a haze-free infrared and visible fusion method,termed HaIVFusion,which can eliminate the influence of haze and obtain richer texture information in the fused image.Specifically,we first design a scene information restoration network(SIRNet)to mine the masked texture information in visible images.Then,a denoising fusion network(DFNet)is designed to integrate the features extracted from infrared and visible images and remove the influence of residual noise as much as possible.In addition,we use color consistency loss to reduce the color distortion resulting from haze.Furthermore,we publish a dataset of hazy scenes for infrared and visible image fusion to promote research in extreme scenes.Extensive experiments show that HaIVFusion produces fused images with increased texture details and higher contrast in hazy scenes,and achieves better quantitative results,when compared to state-ofthe-art image fusion methods,even combined with state-of-the-art dehazing methods. 展开更多
关键词 Deep learning dehazing image fusion infrared image visible image
在线阅读 下载PDF
Experimental study on egress capacity of key facilities in pressurized oxygen-supplement compartments
12
作者 Kai-Qiang Wang Xue-Hua Song +5 位作者 Wei-Jun Liu Kang Wen Zhi-Gang Shi Jun Zhang Bin Yao Wei-Guo Song 《Chinese Physics B》 2025年第1期536-546,共11页
Pressurized buildings have emerged as a novel architectural solution to alleviate altitude illness in high-altitude regions.Unlike conventional buildings,evacuation from this kind of building has to experience a depre... Pressurized buildings have emerged as a novel architectural solution to alleviate altitude illness in high-altitude regions.Unlike conventional buildings,evacuation from this kind of building has to experience a depressurization time,which results in air expansion and heat absorption,creating a dense fog and impairing sight within the buildings.Evacuation experiments were performed in a pressurized oxygen-supplement compartment to investigate the pedestrian motion properties.Based on the questionnaires,participants reported varying degrees of symptoms such as ear blockage,reduced environmental noise,and dizziness,which had a measurable impact on their mobility.We focus on the evacuation parameters through three basic building components:staircases,pressure transition cabins,and escape windows.As the visibility in the compartment decreases from high to low,the movement patterns of pedestrian shift from triangular to single-file with a significant decline in evacuation efficiency.It is found that there is a linear relationship between evacuation time and the number of evacuees through escape windows.The pressure transition cabin is a crucial evacuation route in emergencies,and evacuation time is recommended as the key metric for assessing its effectiveness.These findings offer valuable insights for emergency evacuation strategies in pressurized buildings. 展开更多
关键词 ALTITUDE VISIBILITY ARCHITECTURAL
原文传递
Tales That Travel
13
作者 LI XIAOYU 《ChinAfrica》 2025年第2期54-56,共3页
The International Astronomical Union named a small crater on the Moon after the Moroccan explorer Ibn Battouta in 1976.The crater,located on the Moon’s visible side,is called the Ibn Battouta crater.Ibn Battouta is r... The International Astronomical Union named a small crater on the Moon after the Moroccan explorer Ibn Battouta in 1976.The crater,located on the Moon’s visible side,is called the Ibn Battouta crater.Ibn Battouta is regarded as one of the four great medieval travellers.Born in Tangier,he spent nearly 30 years exploring over 30 countries across Africa,Europe,and Asia,including China,covering approximately 120,000 km.In 1355,he documented his travels in a work known as The Rihla.This account has attracted significant academic interest due to its rich details about diverse cultures. 展开更多
关键词 DETAILS TRAVEL VISIBLE
原文传递
Integrating Image Processing Technology and Deep Learning to Identify Crops in UAV Orthoimages
14
作者 Ching-Lung Fan Yu-Jen Chung 《Computers, Materials & Continua》 2025年第2期1925-1945,共21页
This study aims to enhance automated crop detection using high-resolution Unmanned Aerial Vehicle(UAV)imagery by integrating the Visible Atmospherically Resistant Index(VARI)with deep learning models.The primary chall... This study aims to enhance automated crop detection using high-resolution Unmanned Aerial Vehicle(UAV)imagery by integrating the Visible Atmospherically Resistant Index(VARI)with deep learning models.The primary challenge addressed is the detection of bananas interplanted with betel nuts,a scenario where traditional image processing techniques struggle due to color similarities and canopy overlap.The research explores the effectiveness of three deep learning models—Single Shot MultiBox Detector(SSD),You Only Look Once version 3(YOLOv3),and Faster Region-Based Convolutional Neural Network(Faster RCNN)—using Red,Green,Blue(RGB)and VARI images for banana detection.Results show that VARI significantly improves detection accuracy,with YOLOv3 achieving the best performance,achieving a precision of 73.77%,recall of 100%,and reduced training time by 95 seconds.Additionally,the average Intersection over Union(IoU)increased by 4%–25%across models with VARI-enhanced images.This study confirms that incorporating VARI improves the performance of deep learning models,offering a promising solution for precise crop detection in complex agricultural environments. 展开更多
关键词 UAV RGB image deep learning visible atmospherically resistant index CROP
在线阅读 下载PDF
Elastic Spherical Cloak Driven by Bayesian Optimization
15
作者 Zhiwei Yang Xiaofan Wang +3 位作者 Hongbo Xu Xiaochao Li Shan Zhu Huanyang Chen 《Chinese Physics Letters》 2025年第1期83-93,共11页
The introduction of machine learning algorithms has revolutionized the design of invisible devices,particularly in the intricate domain of elasto-dynamics.In this study,we proposed a core-shell configuration to realiz... The introduction of machine learning algorithms has revolutionized the design of invisible devices,particularly in the intricate domain of elasto-dynamics.In this study,we proposed a core-shell configuration to realize elastic sphere cloaks driven by a Bayesian optimization algorithm to pinpoint the optimal configuration with high precision.Numerical simulations in solid and aqueous environments were performed to validate the cloaking efficacy of our design and the parameters identified by the algorithm.The results closely agreed with the theoretical predictions,underscoring the robustness of the proposed method.This approach provides new insights into the design of elastic wave invisibility devices and has potential applications in underwater communication and sonar detection. 展开更多
关键词 configuration VISIBILITY UNDERWATER
原文传递
Effect of assembly pre-stress on the scratch behavior of polycarbonate
16
作者 Qian Cheng Chengkai Jiang +6 位作者 Dadi Zhao Zhuoran Yang Zhijiang Chen Jun Ma Feodor M.Borodich Xiaoqing Jin Han Jiang 《Nanotechnology and Precision Engineering》 2025年第4期78-87,共10页
Scratch damage can reduce both the aesthetic appearance and structural integrity of polymer surfaces.To optimize and enhance the scratch resistance of polycarbonate,this study investigates the influence of assembly pr... Scratch damage can reduce both the aesthetic appearance and structural integrity of polymer surfaces.To optimize and enhance the scratch resistance of polycarbonate,this study investigates the influence of assembly pre-tensile and pre-compressive stresses,with scratch experiments being conducted under both linearly increasing and constant normal load modes.Experimental results and finite element simulations are used to analyze scratch resistance and visibility.The results indicate that the application of 20%pre-compressive stress increases the critical normal load for onset of scratch visibility by 42%compared with the case in which no assembly pre-stress is applied,and it effectively decreases residual scratch depth,shoulder height,shoulder width,and tangential load.This is because assembly pre-compressive stress can effectively counteract the extrusion of material at the front and sides caused by the sliding scratch tip.Pre-compressive stress hinders scratch groove formation,improving the scratch resistance of polycarbonate.By contrast,pre-tensile stress weakens these characteristics.This study provides valuable insights for enhancing the surface damage resistance of polycarbonate materials. 展开更多
关键词 POLYCARBONATE Assembly stress Scratch resistance Scratch visibility
在线阅读 下载PDF
Organocatalyzed iodine-mediated reversible-deactivation radical polymerization via photoinduced charge transfer complex catalysis
17
作者 Xiang Li Beibei Zhang +1 位作者 Zhixiang Wang Xiangyu Chen 《Chinese Chemical Letters》 2025年第6期449-454,共6页
Photoredox-mediated reversible-deactivation radical polymerization(RDRP)is an effective approach to synthesize polymers with defined composition and architecture.Current photoinduced RDRP primarily depends on outer-sp... Photoredox-mediated reversible-deactivation radical polymerization(RDRP)is an effective approach to synthesize polymers with defined composition and architecture.Current photoinduced RDRP primarily depends on outer-sphere electron transfer or homolysis mechanisms.Herein,we describe an example of iodine-mediated RDRP facilitated by photoinduced charge transfer complex(CTC)catalysis.The approach uses cheap and easily accessible N^(-)heterocyclic nitrenium salt(NHN^(+)...I^(-))as the photoactive CTC.Upon the irradiation of visible light,NHN^(+)...I^(-)undergoes single electron transfer to generate NHN·and I·radicals.The NHN·radical activates dormant Pn-I polymers via inner-sphere single electron transfer,leading to the propagating Pn·radical for chain growth and the I^(-)anion for recovering the CTC,and the I·radical deactivates the polymerization via coupling with Pn·. 展开更多
关键词 N-Heterocyclic nitrenium salt RDRP Charge transfer complex Visible light Polymerization
原文传递
A multi-parametric path planning framework utilizing airspace visibility graphs for urban battlefield environments
18
作者 Sidao Chen Xuejun Zhang +1 位作者 Zuyao Zhang Jianxiang Ma 《Defence Technology(防务技术)》 2025年第9期112-126,共15页
Urban combat environments pose complex and variable challenges for UAV path planning due to multidimensional factors,such as static and dynamic obstructions as well as risks of exposure to enemy detection,which threat... Urban combat environments pose complex and variable challenges for UAV path planning due to multidimensional factors,such as static and dynamic obstructions as well as risks of exposure to enemy detection,which threaten flight safety and mission success.Traditional path planning methods typically depend solely on the distribution of static obstacles to generate collision-free paths,without accounting for constraints imposed by enemy detection and strike capabilities.Such a simplified approach can yield safety-compromising routes in highly complex urban airspace.To address these limitations,this study proposes a multi-parameter path planning method based on reachable airspace visibility graphs,which integrates UAV performance constraints,environmental limitations,and exposure risks.An innovative heuristic algorithm is developed to balance operational safety and efficiency by both exposure risks and path length.In the case study set in a typical mixed-use urban area,analysis of airspace visibility graphs reveals significant variations in exposure risk at different regions and altitudes due to building encroachments.Path optimization results indicate that the method can effectively generate covert and efficient flight paths by dynamically adjusting the exposure index,which represents the likelihood of enemy detection,and the path length,which corresponds to mission execution time. 展开更多
关键词 UAV Path planning Urban battlefield environment Airspace visibility graph ISOVIST
在线阅读 下载PDF
Visible light-induced deuteration of arenes via thianthrenation
19
作者 Jia Peng Guo-Ping Luo +1 位作者 Chao Wu Congyang Wang 《Chinese Chemical Letters》 2025年第8期3-4,共2页
Deuterium(D),a stable and non-radioactive isotope of hydro-gen,is naturally present in the environment and is distinguishedfrom hydrogen by its greater mass.This mass difference resultsin a reduced stretching frequenc... Deuterium(D),a stable and non-radioactive isotope of hydro-gen,is naturally present in the environment and is distinguishedfrom hydrogen by its greater mass.This mass difference resultsin a reduced stretching frequency of the carbon-deuterium(C-D)bond,leading to lower ground state energy and higher bond dis-sociation energy compared to the carbon-hydrogen(C–H)bond. 展开更多
关键词 carbon deuterium bond DEUTERIUM thianthrenation DEUTERATION bond dissociation energy ground state energy visible light ARENES
原文传递
A Trifluoromethyl-containing Pyrrolo[3,2-b]pyrrole Photoinitiator with Long Wavelength in Radical Photopolymerization under LED Irradiation
20
作者 Congcong Liu Yuanyuan Xu +6 位作者 Yukun Liu Yu Chen Xiaoyuan Zhang Jinghan Li Ying Ma Yaolong Li Song Xue 《Chinese Journal of Chemical Physics》 2025年第3期300-310,I0020-I0024,I0108,I0109,共18页
Pyrrolo[3,2-b]pyrrole is a good building block for radical photoini-tiators.In this study,free-radical photoinitiator 1,4-bis(4-bro-mophenyl)-2,5-bis(4-(trifluo-romethyl)phenyl)-1,4-dihydropy-rrolo[3,2-b]pyrrole(PyBF)... Pyrrolo[3,2-b]pyrrole is a good building block for radical photoini-tiators.In this study,free-radical photoinitiator 1,4-bis(4-bro-mophenyl)-2,5-bis(4-(trifluo-romethyl)phenyl)-1,4-dihydropy-rrolo[3,2-b]pyrrole(PyBF),con-taining a symmetric trifluo-romethyl(-CF3)end group,is syn-thesized via a one-step aldehyde-ketone condensation re-action for light-emitting diode(LED)photopolymerization.The-CF3 groups are incorporated into the 2,5-phenyl on the pyrrolo[3,2-b]pyrrole core.PyBF rapidly initiates the photopolymerization of acrylate pre-polymers and monomers under LED illumination at 365 and 405 nm.A possible photolysis mechanism is provided.In the presence of amines,PyBF increases the gel fraction rate of polyethylene glycol diacrylate(PEGDA)from 63.4%to 80.0%,indicating good potential as a two-component photoinitiator.PyBF exhibits a thermal decomposition temperature in an ex-cess of 300℃,comparable to that of a commercial photoinitiator(diphenyl(2,4,6-trimethyl-benzoyl)phosphine oxide,TPO),indicating its thermal stability.PyBF shows low migration in light-curing materials.Scanning electron microscopy images indicate that the materials of the PyBF/TPO/PEGDA mixture cured using the PyBF/TPO two-component photoinitia-tor system exhibit a smooth surface,in contrast to those cured with PyBF/PEGDA and TPO/PEGDA systems.The cured materials also display low curing shrinkage.Therefore,the pyrrolo[3,2-b]pyrrole radical photoinitiator exhibits high photoactivity in visible-light pho-topolymerization reactions. 展开更多
关键词 PHOTOPOLYMERIZATION PHOTOINITIATOR Pyrrolo[3 2-b]pyrrole AMINES Trifluo-romethyl groups Visible light
在线阅读 下载PDF
上一页 1 2 71 下一页 到第
使用帮助 返回顶部