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Tailoring organic bulk-heterojunction for charge extraction and spectral absorption in CsPbBr perovskite solar cells 被引量:1
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作者 Jian Du Jialong Duan +1 位作者 Yanyan Duan Qunwei Tang 《Science China Materials》 SCIE EI CAS CSCD 2021年第4期798-807,共10页
All-inorganic CsPbBr_(3)perovskite solar cells(PSCs)are promising candidates to balance the stability and efficiency issues of organic-inorganic hybrid devices.However,the large energy barrier for charge transfer and ... All-inorganic CsPbBr_(3)perovskite solar cells(PSCs)are promising candidates to balance the stability and efficiency issues of organic-inorganic hybrid devices.However,the large energy barrier for charge transfer and narrow spectral response are still two challenging problems for performance improvement.We present here an organic bulkheterojunction{poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl C61 butyric acid methyl ester(P3HT:PCBM)}photoactive layer to boost the charge extraction and to widen the spectral absorption,achieving an enhanced power conversion efficiency up to 8.94%by optimizing the thickness of P3HT:PCBM photoactive layer,which is much higher than 6.28%for the pristine CsPbBr_(3)device.The interaction between the carbonyl group in PCBM and unsaturated Pb atom in the perovskite surface can effectively passivate the defects and reduce charge recombination.Furthermore,the coupling effect between PCBM and P3HT widens the spectral response from 540 to 650 nm for an increased short-circuit current density.More importantly,the devices are relatively stable over 75 days upon persistent attack by 70%relative humidity in air condition.These advantages of high efficiency,excellent long-term stability,cost-effectiveness and scalability may promote the commercialization of inorganic PSCs. 展开更多
关键词 inorganic CsPbBr3 perovskite solar cells BULK-HETEROJUNCTION charge extraction spectral absorption stability
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A Spectral Index for Estimating Soil Salinity in the Yellow River Delta Region of China Using EO-1 Hyperion Data 被引量:50
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作者 WENG Yong-Ling GONG Peng ZHU Zhi-Liang 《Pedosphere》 SCIE CAS CSCD 2010年第3期378-388,共11页
Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory an... Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory and hyperspectral data were acquired from an EO-1 Hyperion sensor to quantitatively map soil salinity in the region. A soil salinity spectral index (SSI) was constructed from continuum-removed reflectance (CR-reflectance) at 2052 and 2203 nm, to analyze the spectral absorption features of the salt-affected soils. There existed a strong correlation (r = 0.91) between the SSI and soil salt content (SSC). Then, a model for estimation of SSC with SSI was established using univariate regression and validation of the model yielded a root mean square error (RMSE) of 0.986 and an R2 of 0.873. The model was applied to a Hyperion reflectance image on a pixel-by-pixel basis and the resulting quantitative salinity map was validated successfully with RMSE = 1.921 and R2 = 0.627. These suggested that the satellite hyperspectral data had the potential for predicting SSC in a large area. 展开更多
关键词 hyperspectral reflectance soil salt content spectral absorption features
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Research on the sensitivity for the coal mine gas concentration detection by laser spectrum absorption 被引量:1
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作者 周孟然 李振壁 《Journal of Coal Science & Engineering(China)》 2007年第3期370-372,共3页
Because of the former gas chemistry examination method defects, tunable diode laser absorption spectrum technology (TDLAS) was used. It used an isolated absorption spectrum of the gas molecule to measure the gas abs... Because of the former gas chemistry examination method defects, tunable diode laser absorption spectrum technology (TDLAS) was used. It used an isolated absorption spectrum of the gas molecule to measure the gas absorption spectrum in order to distinguish the gas conveniently. The second harmonic (20 was measured in this system. Due to the fact which the harmonious signal is proportional to the concentration of the absorption gas, the gas concentration may be obtained through examining harmonious signal. The theoretical analysis and the experimental result indicate that under the same level of pressure, survey with the signal-to-noise ratio(SNR) of 2fsignal increases the accuracy by one order of magnitude and may reach 10 ^-3 and the sensitivity may reach the 10^-6 level compared to that of direct absorption. 5% methane density and a 30 cm absorption cell were used in the experiment. It has several advantages including high sensitivity, best resolution, and faster response and so on. The gas concentration monitoring of coal mine may be accomplished. 展开更多
关键词 coal mine gas spectral absorption second harmonic (2f) signal-to-noise ratio
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Absorption linewidth inversion with wavelength modulation spectroscopy 被引量:3
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作者 颜悦 杜振辉 +1 位作者 李金义 王瑞雪 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期368-373,共6页
For absorption linewidth inversion with wavelength modulation spectroscopy(WMS), an optimized WMS spectral line fitting method was demonstrated to infer absorption linewidth effectively, and the analytical expressio... For absorption linewidth inversion with wavelength modulation spectroscopy(WMS), an optimized WMS spectral line fitting method was demonstrated to infer absorption linewidth effectively, and the analytical expressions for relationships between Lorentzian linewidth and the separations of first harmonic peak-to-valley and second harmonic zero-crossing were deduced. The transition of CO_2 centered at 4991.25 cm^(-1) was used to verify the optimized spectral fitting method and the analytical expressions. Results showed that the optimized spectra fitting method was able to infer absorption accurately and compute more than 10 times faster than the commonly used numerical fitting procedure. The second harmonic zero-crossing separation method calculated an even 6 orders faster than the spectra fitting without losing any accuracy for Lorentzian dominated cases. Additionally, linewidth calculated through second harmonic zero-crossing was preferred for much smaller error than the first harmonic peak-to-valley separation method. The presented analytical expressions can also be used in on-line optical sensing applications, electron paramagnetic resonance, and further theoretical characterization of absorption lineshape. 展开更多
关键词 absorption linewidth wavelength modulation spectroscopy absorption spectroscopy spectral line fitting separation of harmonics
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Anti-ultraviolet aging tests of asphalts adapting to environment in Tibetan Plateau of China 被引量:15
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作者 廖公云 黄晓明 巴桑顿珠 《Journal of Southeast University(English Edition)》 EI CAS 2008年第4期503-507,共5页
Ultraviolet (UV) aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene r... Ultraviolet (UV) aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene rubber (SBR) asphalts with different contents of three anti-UV-aging agents including nano-TiO2, CeO2 and carbon black are performed. Common indices, which include retained penetration after thin film oven tests (TFOT) and softening point, and strategic highway research program (SHRP) indices of aged asphalts are evaluated. Infrared absorption spectral analysis is performed on asphalt specimens with 0. 8% carbon black which have been aged for different aging times (500, 1000 and 1 500 h). By grey incidence analysis, the optimal contents of anti-UV-aging agents are determined. The results show that TiO2 and CeO2 are not only good UV absorbing or shielding agents, but also strong oxidants. Carbon black is a good anti-UV-aging agent, and its optimal content is about 0. 8% of asphalt weight. UV aging of asphalt mainly occurs in the early stages of aging. The longer the aging time, the more severe the aging of asphalt. 展开更多
关键词 ultraviolet (UV) aging agent carbon black infrared absorption spectral analysis grey incidence analysis
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Promising thermal photonic management materials for sustainable human habitat
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作者 Houze Yao Qihua Liao +1 位作者 Huhu Cheng Liangti Qu 《Nano Research》 SCIE EI CSCD 2024年第1期112-131,共20页
The spectral characteristics of outdoor structures,such as automobiles,buildings,and clothing,determine their energy interaction with the environment,from broad-spectrum absorption of light energy to high-efficiency t... The spectral characteristics of outdoor structures,such as automobiles,buildings,and clothing,determine their energy interaction with the environment,from broad-spectrum absorption of light energy to high-efficiency thermal emission.Recently developed spectrally selective absorption(SSA)materials permit the reduction of energy loss from human habitat eco-system in the sustainable way and further reduce the utilization of fossil energy to achieve carbon neutrality.Here we review recent advances in SSA materials that enable rational and efficient management of thermal energy and provide new solutions for the resource base that supports human life like comfortable heat management,electricity production,and water supply.The basic principles of thermal photonic management,the regulation of SSA materials,and functional properties are summarized.An outlook discussing challenges and opportunities in SSA material energy management for comfortable living environments is finally presented,which expects the enormous potential of this interdisciplinary research in solving growing resource-shortage of human society. 展开更多
关键词 spectrally selective absorption passive cooling solar power eco-system
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A comparative study on the illite crystallinity and the clay mineral reflectance spectral index for subdividing the very low-grade metamorphic belt along the Lizhou-Hekou geological section in the Youjiang sedimentary basin, Guangxi, China
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作者 YAN Shouxun 《Science China Earth Sciences》 SCIE EI CAS 2004年第9期834-845,共12页
To examine the application potential of hyperspectral remote sensing techniques in classifying very low-grade metamorphic belts, the composition of clay minerals and the cyrstallinity of illite from mudstones were mea... To examine the application potential of hyperspectral remote sensing techniques in classifying very low-grade metamorphic belts, the composition of clay minerals and the cyrstallinity of illite from mudstones were measured using XRD and VIS-SWIR (400—2500 nm) reflectance spectroscopy. Based on the illite cyrstallinity, Kbler Index (KI), the Early Triassic LuoLou Group and the Middle Triassic lower Baifeng Formation were classified as the lower Epizone with KID2q° ranging from 0.22 to 0.25, the upper Baifeng Formation as upper anchizone with KID2q° ranging from 0.26 to 0.33, and the Hekou Formation as lower anchizone with KID2q° ranging from 0.38 to 0.40. According to a KID2q° value of 0.43, it is possible that there may exist a local diagenetic zone in the upper strata. The illite cyrstallinity Kbler index and the metamorphic grade increase from the bottom to the top of the stratigraphic sequence. The metamorphic grade boundaries nearly match the stratigraphic boundaries, indicating a burial metamorphism nature for the stratigraphic sequence. From the bottom to the top of the sequence, the spectral absorption band center of clay minerals from fresh rocks is around 2200 nm. The absorption band centers change towards shorter wavelengths: the Luolou Group being at 2220 nm, the Baifeng Formation at 2217—2213 nm, the lower member of the Hekou Formation at 2214—2206 nm, and the upper member of the Hekou Formation at 2205—2197 nm. The spectral absorption band center of illite shows the same change pattern. These results indicate that very low-grade metamorphic belts can be subdivided using spectral indices of clay minerals, which are measured by using field portable spectroradiometers. However, it may not work well with satellite and airborne sensors. 展开更多
关键词 illite crystallinity Kübler index XRD measurement Lizhou-Hekou geological section very low-grade metamorphic belt VIS-SWIR reflectance spectrum change of spectral absorption center.
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Research on Multi-Component Gas Optical Detection System Based on Conjugated Interferometer
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作者 Xin GUI Yuheng TONG +2 位作者 Honghai WANG Haihu YU Zhengying LI 《Photonic Sensors》 SCIE EI CAS CSCD 2017年第3期261-269,共9页
An optical multi-component gas detection system based on the conjugated interferometer (CI) is proposed and experimentally demonstrated. It can realize the concentration detection of mixture gas in the environment. ... An optical multi-component gas detection system based on the conjugated interferometer (CI) is proposed and experimentally demonstrated. It can realize the concentration detection of mixture gas in the environment. The CI can transform the absorption spectrum of the target gases to a conjugated emission spectrum, when combining the CI with the broadband light source, the spectrum of output light matches well with the absorption spectrum of target gases. The CI design for different target gases can be achieved by replacing the kind of target absorbing gas in the CI filter. The traditional fiber gas sensor system requires multiple light sources for detection when there are several kinds of gases, and this problem has been solved by using the CI filter combined with the broadband light source. The experimental results show that the system can detect the concentration of multi-component gases, which are mixed with C2H2 and NH3. Experimental results also show a good concentration sensing linearity. 展开更多
关键词 Gas conjugated interference filter gas sensing spectral absorption
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