Colorless‐to‐black switching has attracted widespread attention for smart windows and multifunctional displays because they are more useful to control solar energy.However,it still remains a challenge owing to the t...Colorless‐to‐black switching has attracted widespread attention for smart windows and multifunctional displays because they are more useful to control solar energy.However,it still remains a challenge owing to the tremendous difficulties in the design of completely reverse absorptions in transmissive and colored states.Herein,we report on an electrochemical device that can switch between colorless and black by using the electrochemical process of hybrid organic–inorganic perovskite MAPbBr_(3),which shows a high integrated contrast ratio of up to 73%from 400 to 800 nm.The perovskite solution can be used as the active layer to assemble the device,showing superior transmittance over the entire visible region in neutral states.By applying an appropriate voltage,the device undergoes reversible switching between colorless and black,which is attributed to the formation of lead and Br_(2)in the redox reaction induced by the electron transfer process in MAPbBr_(3).In addition,the contrast ratio can be modulated over the entire visible region by changing the concentration and the applied voltage.These results contribute toward gaining an insightful understanding of the electrochemical process of perovskites and greatly promoting the development of switchable devices.展开更多
We demonstrate a high-quality cross-polarized-wave filter based on spectral phase modulation. Driven by Well- eompressed spectral-phase fully-compensated fundamental laser lmlses, the filter stretches the pulse bandwi...We demonstrate a high-quality cross-polarized-wave filter based on spectral phase modulation. Driven by Well- eompressed spectral-phase fully-compensated fundamental laser lmlses, the filter stretches the pulse bandwidth from 35 nm to 7Ohm with a conversion efficeiency of 20%.展开更多
目的:探讨超高分辨率计算机断层扫描(CT)对小于3 cm肺孤立性磨玻璃密度结节(fGGN)的诊断价值。方法:选取龙岩市第一医院2020年1月至2022年6月收治的96例小于3 cm fGGN患者为研究对象,所有患者均进行高分辨率与超高分辨率CT检查。结果:96...目的:探讨超高分辨率计算机断层扫描(CT)对小于3 cm肺孤立性磨玻璃密度结节(fGGN)的诊断价值。方法:选取龙岩市第一医院2020年1月至2022年6月收治的96例小于3 cm fGGN患者为研究对象,所有患者均进行高分辨率与超高分辨率CT检查。结果:96例fGGN患者中,3例为不典型腺瘤样增生(3.13%),49例为浸润性腺瘤(51.04%),25例为原位癌(26.04%),19例为微浸润性腺瘤(19.79%)。相较于高分辨率CT,超高分辨率CT检查的分叶检出率更高,瘤肺界面清楚光整占比更高,差异均具有统计学意义(P <0.05)。相较于高分辨率CT检查,超高分辨率CT检查明确诊断率更高,差异具有统计学意义(χ^(2)=27.148,P <0.001)。超高分辨率CT的对比度噪声比(CNR)、信噪比(SNR)、图像噪声评分低于高分辨率CT,差异均具有统计学意义(P <0.05)。结论:在小于3 cm fGGN诊断中超高分辨率CT检查能够更加有效的诊断分叶征及瘤肺界面,且明确诊断率明显高于高分辨率CT检查。超高分辨率CT检查具有更为明显的本底噪声,且CNR、SNR评分较高分辨率CT检查均较低。检查过程中心跳、呼吸等造成的伪影虽然会在一定程度上影响超高分辨率CT检查效果,但对其临床诊断效能并无明显影响。展开更多
The theoretical model of spatial noise passing through a spatial filter is established in high power laser system under the small signal approximation. The transmission characteristic for a noise signal passing throug...The theoretical model of spatial noise passing through a spatial filter is established in high power laser system under the small signal approximation. The transmission characteristic for a noise signal passing through spatial filters with different magnifications is analyzed by numerical simulation, according to the actual structure of the high power laser system. The results show that the spatial modulation period of low-frequency noise getting through the pinhole will be proportional to the magnification of the spatial filter. When the magnification is less than 1, the safe low-frequency noise will be extruded into the high-frequency region, which is the fast increasing part, and finally develops into the most dangerous part which can damage the optical devices. The conclusion of this research improves the relay imaging theory of a spatial filter and provides an important theoretical basis for a general design of high power laser systems.展开更多
Electrochromic(EC)materials that change color with voltage have been widely studied for use in dynamic windows.However,colorless-to-colorful switching with high contrast ratio is generically unattainable,especially fo...Electrochromic(EC)materials that change color with voltage have been widely studied for use in dynamic windows.However,colorless-to-colorful switching with high contrast ratio is generically unattainable,especially for colorless-to-black electrochromic materials with an ultrahigh contrast ratio over the entire visible region.In this work,we developed Nb_(1.33)C MXene-based dynamic windows with colorless-to-black switching of up to 75%reversible change in transmittance from 300 to 1,500 nm.By exploring the electrochromic effects of different electrolytes through in situ optical changes and electrochemical quartz crystal microbalance(EQCM),it is found that electrochromic behavior is greatly influenced by the extent of reversible Li^(+)insertion/deinsertion between the two-dimensional Nb_(1.33)C MXene nanosheets.In addition,a colorless-to-black EC device based on Nb_(1.33)C with an overall integrated contrast ratio over 80%was successfully constructed by a solution-processable spin coating method.This work enables a simple route to fabricate MXene-based high-performance electrochromic smart windows,which is important for further expanding the application of MXenes to optoelectronic and photonic applications.展开更多
基金Natural Science Foundation of Hebei Province(China),Grant/Award Numbers:B2020203013,B2021203016Science and Technology Project of Hebei Education Department(China),Grant/Award Number:QN2020137+3 种基金Cultivation Project for Basic Research Innovation of Yanshan University(China),Grant/Award Number:2021LGZD015Subsidy for Hebei Key Laboratory of Applied Chemistry after Operation Performance(China),Grant/Award Number:22567616HNatural Science Foundation of Heilongjiang Province(China),Grant/Award Number:LH2022B025Fundamental Research Funds for the Provincial Universities of Heilongjiang Province(China),Grant/Award Number:KYYWF10236190104。
文摘Colorless‐to‐black switching has attracted widespread attention for smart windows and multifunctional displays because they are more useful to control solar energy.However,it still remains a challenge owing to the tremendous difficulties in the design of completely reverse absorptions in transmissive and colored states.Herein,we report on an electrochemical device that can switch between colorless and black by using the electrochemical process of hybrid organic–inorganic perovskite MAPbBr_(3),which shows a high integrated contrast ratio of up to 73%from 400 to 800 nm.The perovskite solution can be used as the active layer to assemble the device,showing superior transmittance over the entire visible region in neutral states.By applying an appropriate voltage,the device undergoes reversible switching between colorless and black,which is attributed to the formation of lead and Br_(2)in the redox reaction induced by the electron transfer process in MAPbBr_(3).In addition,the contrast ratio can be modulated over the entire visible region by changing the concentration and the applied voltage.These results contribute toward gaining an insightful understanding of the electrochemical process of perovskites and greatly promoting the development of switchable devices.
基金Supported by the National Key Basic Research Program of China under Grant No 2013CB922402the National Natural Science Foundation of China under Grant Nos 61575217 and 11434016+1 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences under Grant Nos KJZD-EW-L11-03 and QYZDJ-SSW-JSC006the Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDB16030200
文摘We demonstrate a high-quality cross-polarized-wave filter based on spectral phase modulation. Driven by Well- eompressed spectral-phase fully-compensated fundamental laser lmlses, the filter stretches the pulse bandwidth from 35 nm to 7Ohm with a conversion efficeiency of 20%.
文摘目的:探讨超高分辨率计算机断层扫描(CT)对小于3 cm肺孤立性磨玻璃密度结节(fGGN)的诊断价值。方法:选取龙岩市第一医院2020年1月至2022年6月收治的96例小于3 cm fGGN患者为研究对象,所有患者均进行高分辨率与超高分辨率CT检查。结果:96例fGGN患者中,3例为不典型腺瘤样增生(3.13%),49例为浸润性腺瘤(51.04%),25例为原位癌(26.04%),19例为微浸润性腺瘤(19.79%)。相较于高分辨率CT,超高分辨率CT检查的分叶检出率更高,瘤肺界面清楚光整占比更高,差异均具有统计学意义(P <0.05)。相较于高分辨率CT检查,超高分辨率CT检查明确诊断率更高,差异具有统计学意义(χ^(2)=27.148,P <0.001)。超高分辨率CT的对比度噪声比(CNR)、信噪比(SNR)、图像噪声评分低于高分辨率CT,差异均具有统计学意义(P <0.05)。结论:在小于3 cm fGGN诊断中超高分辨率CT检查能够更加有效的诊断分叶征及瘤肺界面,且明确诊断率明显高于高分辨率CT检查。超高分辨率CT检查具有更为明显的本底噪声,且CNR、SNR评分较高分辨率CT检查均较低。检查过程中心跳、呼吸等造成的伪影虽然会在一定程度上影响超高分辨率CT检查效果,但对其临床诊断效能并无明显影响。
文摘The theoretical model of spatial noise passing through a spatial filter is established in high power laser system under the small signal approximation. The transmission characteristic for a noise signal passing through spatial filters with different magnifications is analyzed by numerical simulation, according to the actual structure of the high power laser system. The results show that the spatial modulation period of low-frequency noise getting through the pinhole will be proportional to the magnification of the spatial filter. When the magnification is less than 1, the safe low-frequency noise will be extruded into the high-frequency region, which is the fast increasing part, and finally develops into the most dangerous part which can damage the optical devices. The conclusion of this research improves the relay imaging theory of a spatial filter and provides an important theoretical basis for a general design of high power laser systems.
基金This work was financed by the SSF Research Infrastructure Fellow Program(No.RIF 14–0074)the SSF Synergy Program EM16–0004,and by the Knut and Alice Wallenberg(KAW)Foundation through a Fellowship Grant,a Project Grant(No.KAW2020.0033)+4 种基金for support of the electron microscopy laboratory in Linköping University.Support from the National Natural Science Foundation of China(No.61774077)the Guangdong Joint Research Fund(No.2020A1515110738)the Postdoctoral Research Foundation of China(No.2020M683187)the Key Projects of Joint Fund of Basic and Applied Basic Research Fund of Guangdong Province(No.2019B1515120073)the Guangzhou Key laboratory of Vacuum Coating Technologies and New Energy Materials Open Projects Fund(No.KFVE20200006)are also acknowledged.
文摘Electrochromic(EC)materials that change color with voltage have been widely studied for use in dynamic windows.However,colorless-to-colorful switching with high contrast ratio is generically unattainable,especially for colorless-to-black electrochromic materials with an ultrahigh contrast ratio over the entire visible region.In this work,we developed Nb_(1.33)C MXene-based dynamic windows with colorless-to-black switching of up to 75%reversible change in transmittance from 300 to 1,500 nm.By exploring the electrochromic effects of different electrolytes through in situ optical changes and electrochemical quartz crystal microbalance(EQCM),it is found that electrochromic behavior is greatly influenced by the extent of reversible Li^(+)insertion/deinsertion between the two-dimensional Nb_(1.33)C MXene nanosheets.In addition,a colorless-to-black EC device based on Nb_(1.33)C with an overall integrated contrast ratio over 80%was successfully constructed by a solution-processable spin coating method.This work enables a simple route to fabricate MXene-based high-performance electrochromic smart windows,which is important for further expanding the application of MXenes to optoelectronic and photonic applications.
