In the domain of perovskite solar cells(PSCs),the imperative to reconcile impressive photovoltaic performance with lead-related issue and environmental stability has driven innovative solutions.This study pioneers an ...In the domain of perovskite solar cells(PSCs),the imperative to reconcile impressive photovoltaic performance with lead-related issue and environmental stability has driven innovative solutions.This study pioneers an approach that not only rectifies lead leakage but also places paramount importance on the attainment of rigorous interfacial passivation.Crown ethers,notably benzo-18-crown-6-ether(B18C6),were strategically integrated at the perovskite-hole transport material interface.Crown ethers exhibit a dual role:efficiently sequestering and immobilizing Pb^(2+)ions through host-guest complexation and simultaneously establishing a robust interfacial passivation layer.Selected crown ether candidates,guided by density functional theory(DFT)calculations,demonstrated proficiency in binding Pb2+ions and optimizing interfacial energetics.Photovoltaic devices incorporating these materials achieved exceptional power conversion efficiency(PCE),notably 21.7%for B18C6,underscoring their efficacy in lead binding and interfacial passivation.Analytical techniques,including time-of-flight secondary ion mass spectrometry(ToF-SIMS),ultraviolet photoelectron spectroscopy(UPS),time-resolved photoluminescence(TRPL),and transient absorption spectroscopy(TAS),unequivocally affirmed Pb^(2+)ion capture and suppression of non-radiative recombination.Notably,these PSCs maintained efficiency even after enduring 300 h of exposure to 85%relative humidity.This research underscores the transformative potential of crown ethers,simultaneously addressing lead binding and stringent interfacial passivation for sustainable PSCs poised to commercialize and advance renewable energy applications.展开更多
Perovskite materials have triggered a renewed interest in photovoltaic research in the recent years.They display crystal forms with 0D,1D and 2D,3D motifs,and several chemical forms,namely inorganic(titanates,rubidiat...Perovskite materials have triggered a renewed interest in photovoltaic research in the recent years.They display crystal forms with 0D,1D and 2D,3D motifs,and several chemical forms,namely inorganic(titanates,rubidiates,nobiates,tantalates etc.),organic/inorganic metal halides with single to multiple cations,and even organic polymer or quantum dot-infused hybrids.Each crystal type and chemical form are endowed with specific physicochemical,optical,electronic,and morphological properties.These unique properties render them suitable for targeted applications,namely photovoltaics,LEDs,photocatalysis/electrolysis/solar fuels/solar and Li-ion batteries,gas-sensors,ferroelectrics,capacitors,transistors and memristors,photodetectors,and lasers,for advanced quantum cryptography and outer space applications.At first,the crystal and material types,and physicochemical,morphological,and optoelectronic properties of perovskite materials are discussed.Particularly,we focus on those properties which cumulatively contribute to their application in the abovementioned fields.Simultaneously,a comprehensive discussion about the advances in each field is presented.Structure/property/application relationships with key advances demonstrate the versatility of perovskites in modern optoelectronic technologies.展开更多
Due to the importance of Critical Infrastructure(Cl)in a nation's economy,they have been lucrative targets for cyber attackers.These critical infrastructures are usually Cyber-Physical Systems such as power grids,...Due to the importance of Critical Infrastructure(Cl)in a nation's economy,they have been lucrative targets for cyber attackers.These critical infrastructures are usually Cyber-Physical Systems such as power grids,water,and sewage treatment facilities,oil and gas pipelines,etc.In recent times,these systems have suffered from cyber attacks numer-ous times.Researchers have been developing cyber security solutions for Cls to avoid lasting damages.According to standard frameworks,cyber security based on identification,protection,detection,response,and recovery are at the core of these research.Detection of an ongoing attack that escapes standard protection such as firewall,anti-virus,and host/network intrusion detection has gained importance as such attacks eventually affect the physical dynamics of the system.Therefore,anomaly detection in physical dynamics proves an effective means to implement defense-in-depth.PASAD is one example of anomaly detection in the sensor/actuator data,representing such systems physical dynamics.We present EPASAD,which improves the detection technique used in PASAD to detect these micro-stealthy attacks,as our experiments show that PASAD's spherical boundary-based detection fails to detect.Our method EPASAD overcomes this by using Ellipsoid boundaries,thereby tightening the boundaries in various dimen-sions,whereas a spherical boundary treats all dimensions equally.We validate EPASAD using the dataset produced by the TE-process simulator and the C-town datasets.The results show that EPASAD improves PASAD's average recall by 5.8%and 9.5%for the two datasets,respectively.展开更多
Photonic bound states in the continuum(BICs)are spatially localized modes with infinitely long lifetimes,which exist within a radiation continuum at discrete energy levels.These states have been explored in various sy...Photonic bound states in the continuum(BICs)are spatially localized modes with infinitely long lifetimes,which exist within a radiation continuum at discrete energy levels.These states have been explored in various systems,including photonic and phononic crystal slabs,metasurfaces,waveguides,and integrated circuits.Robustness and availability of the BICs are important aspects for fully taming the BICs toward practical applications.Here,we propose a generic mechanism to realize BICs that exist by first principles free of fine parameter tuning based on non-Maxwellian double-net metamaterials(DNMs).An ideal warm hydrodynamic double plasma(HDP)fluid model provides a homogenized description of DNMs and explains the robustness of the BICs found herein.In the HDP model,these are standing wave formations made of electron acoustic waves(EAWs),which are pure charge oscillations with vanishing electromagnetic fields.EAW BICs have various advantages,such as(i)frequency-comb-like collection of BICs free from normal resonances;(ii)robustness to symmetry-breaking perturbations and formation of quasi-BICs with an ultrahigh Q-factor even if subject to disorder;and(iii)giving rise to subwavelength microcavity resonators hosting quasi-BIC modes with an ultrahigh Q-factor.展开更多
The rise in the adoption of blockchain technology has led to increased illegal activities by cybercriminals costing billions of dollars.Many machine learning algorithms are applied to detect such illegal behavior.Thes...The rise in the adoption of blockchain technology has led to increased illegal activities by cybercriminals costing billions of dollars.Many machine learning algorithms are applied to detect such illegal behavior.These algorithms are often trained on the transaction behavior and,in some cases,trained on the vulnerabilities that exist in the system.In our approach,we study the feasibility of using the Domain Name(DN)associated with the account in the blockchain and identify whether an account should be tagged malicious or not.Here,we leverage the temporal aspects attached to the DN.Our approach achieves 89.53%balanced-accuracy in detecting malicious blockchain DNs.While our results identify 73769 blockchain DNs that show malicious behavior at least once,out of these,34171 blockchain DNs show persistent malicious behavior,resulting in 2479 malicious blockchain DNs over time.Nonetheless,none of these identified malicious DNs were reported in new officially tagged malicious blockchain DNs.展开更多
Male Lawes’s Parotia,a bird of paradise,use the highly directional reflection of the structurally colored,brilliant-silvery occipital feathers in their courtship display.As in other birds,the structural coloration is...Male Lawes’s Parotia,a bird of paradise,use the highly directional reflection of the structurally colored,brilliant-silvery occipital feathers in their courtship display.As in other birds,the structural coloration is produced by ordered melanin pigmentation.The barbules of the Parotia’s occipital feathers,with thickness,3 μm,contain 6–7 layers of densely packed melanin rodlets(diameter,0.25 μm,length,2 μm).The effectively,0.2 μm thick melanin layers separated by,0.2 μm thick keratin layers create a multilayer interference reflector.Reflectance measurements yielded peak wavelengths in the near-infrared at,1.3 μm,i.e.,far outside the visible wavelength range.With the Jamin-Lebedeff interference microscopy method recently developed for pigmented media,we here determined the refractive index of the intact barbules.We thus derived the wavelength dependence of the refractive index of the barbules’melanin to be 1.7–1.8 in the visible wavelength range.Implementing the anatomical and refractive index data in an optical multilayer model,we calculated the barbules’reflectance,transmittance and absorptance spectra,thereby confirming measured spectra.展开更多
Dear Editor,Colorectal cancer(CRC)is the second leading cause of cancer death according to the World Health Organization.Patients with inflammatory bowel disease(IBD),ulcerative colitis(UC)or Crohn’s disease(CD)are a...Dear Editor,Colorectal cancer(CRC)is the second leading cause of cancer death according to the World Health Organization.Patients with inflammatory bowel disease(IBD),ulcerative colitis(UC)or Crohn’s disease(CD)are at increased risk of developing colitis-associated CRC(CAC)[1];however,our understanding of the inflammationcancer interplay at the molecular level is still limited.展开更多
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1F1A1047203)financially supported by the Ministry of Trade,Industry and Energy(MOTIE)and Korea Institute for Advancement of Technology(KIAT)through the International Cooperative R&D program(P0026100)+1 种基金the NRF grant funded by the Korea government(MSIT)(2021R1I1A1A01061036)financial support from the NRF grant funded by the Korea government(MSIT)(RS-2023-00213920)。
文摘In the domain of perovskite solar cells(PSCs),the imperative to reconcile impressive photovoltaic performance with lead-related issue and environmental stability has driven innovative solutions.This study pioneers an approach that not only rectifies lead leakage but also places paramount importance on the attainment of rigorous interfacial passivation.Crown ethers,notably benzo-18-crown-6-ether(B18C6),were strategically integrated at the perovskite-hole transport material interface.Crown ethers exhibit a dual role:efficiently sequestering and immobilizing Pb^(2+)ions through host-guest complexation and simultaneously establishing a robust interfacial passivation layer.Selected crown ether candidates,guided by density functional theory(DFT)calculations,demonstrated proficiency in binding Pb2+ions and optimizing interfacial energetics.Photovoltaic devices incorporating these materials achieved exceptional power conversion efficiency(PCE),notably 21.7%for B18C6,underscoring their efficacy in lead binding and interfacial passivation.Analytical techniques,including time-of-flight secondary ion mass spectrometry(ToF-SIMS),ultraviolet photoelectron spectroscopy(UPS),time-resolved photoluminescence(TRPL),and transient absorption spectroscopy(TAS),unequivocally affirmed Pb^(2+)ion capture and suppression of non-radiative recombination.Notably,these PSCs maintained efficiency even after enduring 300 h of exposure to 85%relative humidity.This research underscores the transformative potential of crown ethers,simultaneously addressing lead binding and stringent interfacial passivation for sustainable PSCs poised to commercialize and advance renewable energy applications.
文摘Perovskite materials have triggered a renewed interest in photovoltaic research in the recent years.They display crystal forms with 0D,1D and 2D,3D motifs,and several chemical forms,namely inorganic(titanates,rubidiates,nobiates,tantalates etc.),organic/inorganic metal halides with single to multiple cations,and even organic polymer or quantum dot-infused hybrids.Each crystal type and chemical form are endowed with specific physicochemical,optical,electronic,and morphological properties.These unique properties render them suitable for targeted applications,namely photovoltaics,LEDs,photocatalysis/electrolysis/solar fuels/solar and Li-ion batteries,gas-sensors,ferroelectrics,capacitors,transistors and memristors,photodetectors,and lasers,for advanced quantum cryptography and outer space applications.At first,the crystal and material types,and physicochemical,morphological,and optoelectronic properties of perovskite materials are discussed.Particularly,we focus on those properties which cumulatively contribute to their application in the abovementioned fields.Simultaneously,a comprehensive discussion about the advances in each field is presented.Structure/property/application relationships with key advances demonstrate the versatility of perovskites in modern optoelectronic technologies.
文摘Due to the importance of Critical Infrastructure(Cl)in a nation's economy,they have been lucrative targets for cyber attackers.These critical infrastructures are usually Cyber-Physical Systems such as power grids,water,and sewage treatment facilities,oil and gas pipelines,etc.In recent times,these systems have suffered from cyber attacks numer-ous times.Researchers have been developing cyber security solutions for Cls to avoid lasting damages.According to standard frameworks,cyber security based on identification,protection,detection,response,and recovery are at the core of these research.Detection of an ongoing attack that escapes standard protection such as firewall,anti-virus,and host/network intrusion detection has gained importance as such attacks eventually affect the physical dynamics of the system.Therefore,anomaly detection in physical dynamics proves an effective means to implement defense-in-depth.PASAD is one example of anomaly detection in the sensor/actuator data,representing such systems physical dynamics.We present EPASAD,which improves the detection technique used in PASAD to detect these micro-stealthy attacks,as our experiments show that PASAD's spherical boundary-based detection fails to detect.Our method EPASAD overcomes this by using Ellipsoid boundaries,thereby tightening the boundaries in various dimen-sions,whereas a spherical boundary treats all dimensions equally.We validate EPASAD using the dataset produced by the TE-process simulator and the C-town datasets.The results show that EPASAD improves PASAD's average recall by 5.8%and 9.5%for the two datasets,respectively.
基金funding from the Swiss National Science Foundation (Grant No. 188647)from the Adolphe Merkle Foundation
文摘Photonic bound states in the continuum(BICs)are spatially localized modes with infinitely long lifetimes,which exist within a radiation continuum at discrete energy levels.These states have been explored in various systems,including photonic and phononic crystal slabs,metasurfaces,waveguides,and integrated circuits.Robustness and availability of the BICs are important aspects for fully taming the BICs toward practical applications.Here,we propose a generic mechanism to realize BICs that exist by first principles free of fine parameter tuning based on non-Maxwellian double-net metamaterials(DNMs).An ideal warm hydrodynamic double plasma(HDP)fluid model provides a homogenized description of DNMs and explains the robustness of the BICs found herein.In the HDP model,these are standing wave formations made of electron acoustic waves(EAWs),which are pure charge oscillations with vanishing electromagnetic fields.EAW BICs have various advantages,such as(i)frequency-comb-like collection of BICs free from normal resonances;(ii)robustness to symmetry-breaking perturbations and formation of quasi-BICs with an ultrahigh Q-factor even if subject to disorder;and(iii)giving rise to subwavelength microcavity resonators hosting quasi-BIC modes with an ultrahigh Q-factor.
基金partially funded by the National Blockchain Project(grant number NCSC/CS/2017518)at Indian Institute of Technology KanpurIndia sponsored by the National Cyber Security Coordinator's office of the Government of India and partially by the C3i Center funding from the Science and Engineering Research Board of the Government of India(grant number SERB/CS/2016466).
文摘The rise in the adoption of blockchain technology has led to increased illegal activities by cybercriminals costing billions of dollars.Many machine learning algorithms are applied to detect such illegal behavior.These algorithms are often trained on the transaction behavior and,in some cases,trained on the vulnerabilities that exist in the system.In our approach,we study the feasibility of using the Domain Name(DN)associated with the account in the blockchain and identify whether an account should be tagged malicious or not.Here,we leverage the temporal aspects attached to the DN.Our approach achieves 89.53%balanced-accuracy in detecting malicious blockchain DNs.While our results identify 73769 blockchain DNs that show malicious behavior at least once,out of these,34171 blockchain DNs show persistent malicious behavior,resulting in 2479 malicious blockchain DNs over time.Nonetheless,none of these identified malicious DNs were reported in new officially tagged malicious blockchain DNs.
基金This study was financially supported by AFOSR/EOARD (grant FA8655-08-1-3012).
文摘Male Lawes’s Parotia,a bird of paradise,use the highly directional reflection of the structurally colored,brilliant-silvery occipital feathers in their courtship display.As in other birds,the structural coloration is produced by ordered melanin pigmentation.The barbules of the Parotia’s occipital feathers,with thickness,3 μm,contain 6–7 layers of densely packed melanin rodlets(diameter,0.25 μm,length,2 μm).The effectively,0.2 μm thick melanin layers separated by,0.2 μm thick keratin layers create a multilayer interference reflector.Reflectance measurements yielded peak wavelengths in the near-infrared at,1.3 μm,i.e.,far outside the visible wavelength range.With the Jamin-Lebedeff interference microscopy method recently developed for pigmented media,we here determined the refractive index of the intact barbules.We thus derived the wavelength dependence of the refractive index of the barbules’melanin to be 1.7–1.8 in the visible wavelength range.Implementing the anatomical and refractive index data in an optical multilayer model,we calculated the barbules’reflectance,transmittance and absorptance spectra,thereby confirming measured spectra.
基金the MCIN/AEI/10.13039/501100011033(PID2019-108349RB-100 and SAF2016-79792R)to AC and JJSEVillum Foundation,grant no.13152 to KAby Agencia Estatal de Investigación(PID2019-104867RBI00/AEI/10.13039/501100011033)and the Instituto de Salud Carlos III-Fondo Europeo de Desarrollo Regional(CIBERONC/CB16/12/00273 and ICI20/00057)to AM and AB.PF received MCIN FPI fellowship(BES-2017-080139).
文摘Dear Editor,Colorectal cancer(CRC)is the second leading cause of cancer death according to the World Health Organization.Patients with inflammatory bowel disease(IBD),ulcerative colitis(UC)or Crohn’s disease(CD)are at increased risk of developing colitis-associated CRC(CAC)[1];however,our understanding of the inflammationcancer interplay at the molecular level is still limited.