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High efficiency and high transmission asymmetric polarization converter with chiral metasurface in visible and near-infrared region
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作者 高雨航 田宇 +6 位作者 杜庆国 王原丽 付琴 卞强 李政颖 冯帅 任芳芳 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期368-374,共7页
Polarization manipulation of light is of great importance because it could promote development of wireless communications,biosensing,and polarization imaging.In order to use natural light more efficiently,it is highly... Polarization manipulation of light is of great importance because it could promote development of wireless communications,biosensing,and polarization imaging.In order to use natural light more efficiently,it is highly demanded to design and fabricate high performance asymmetric polarization converters which could covert the natural light to one particular linearly polarized light with high efficiency.Traditionally,polarizers could be achieved by controllers with crystals and polymers exhibiting birefringence.However,the polarizers are bulky in size and the theoretical conversion efficiency of the polarizers is limited to 0.5 with unpolarized light incidence.In this paper,we propose a polarization converter which could preserve high transmission for one linearly polarized light and convert the orthogonal linearly polarized light to its cross-polarized with high transmittance based on a multi-layer chiral metasurface.Theoretical results show that normally incident y-polarized light preserves high transmittance for the wavelength range from 685 nm to 800 nm while the orthogonal normally incident x-polarized light is efficiently converted to the y-polarized light with high transmittance from 725 nm to 748 nm.Accordingly,for unpolarized light incidence,transmittance larger than 0.5 has been successfully achieved in a broadband wavelength range from 712 nm to 773 nm with a maximum transmittance of 0.58 at 732 nm. 展开更多
关键词 asymmetric polarization converter visible and near-infrared light chiral metasurface Fabry-Perot like resonance
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Photoprotective Ability of Sunscreens against Ultraviolet, Visible Light and Near-Infrared Radiation
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作者 Yohei Tanaka 《Optics and Photonics Journal》 2023年第6期140-146,共7页
Despite the widespread prevalence of daily sunscreen usage, solar-induced skin damage continues to occur. We have previously reported that solar visible light and near-infrared, in addition to ultraviolet radiation, p... Despite the widespread prevalence of daily sunscreen usage, solar-induced skin damage continues to occur. We have previously reported that solar visible light and near-infrared, in addition to ultraviolet radiation, perform as aging factors and induce deleterious effects such as photoaging, vasodilation, muscle thinning, skin ptosis, photoimmunosupression and photocarcinogenesis. Despite this, most commonly used sunscreens only block ultraviolet radiation. To evaluate the complete solar-spectrum blocking ability of sunscreens produced by internationally well-known companies, a double-beam spectrophotometer was used to optically measure the transmission spectra. The spectrophotometer utilizes a unique, single monochromatic design covering a wavelength range of 240 to 2600 nm. Sunscreens (thickness, 0.1 mm, SPF50+, PA+++ or ++++) from internationally well-known companies blocked 78.8% - 99.9% of ultraviolet, 33.4% - 99.6% of visible light, and 27.0% - 76.4% of near-infrared. It can be concluded that while most commercially available sunscreens filter ultraviolet radiation, they are not effective at blocking visible light and near-infrared radiation. The results of this study imply that sunscreens that provide comprehensive photoprotection from ultraviolet through to near-infrared should be considered to prevent skin photodamage. 展开更多
关键词 Anti-Photoageing PHOTOPROTECTION SUNSCREEN ULTRAVIOLET visible Light near-infrared
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Novel Low Viscosity Zinc Oxide, Iron Oxides and Erioglaucine Sunscreen Potential to Protect from Ultraviolet, Visible Light and Near-Infrared Radiation
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作者 Yohei Tanaka Richard Parker +1 位作者 Amaryllis Aganahi Ailen Pedroso 《Optics and Photonics Journal》 2023年第9期217-226,共10页
Despite the widespread recommendation and use of sunscreens and ultraviolet blocking materials, solar-induced skin damage and photoageing continues to pose a problem to human health worldwide. We have previously repor... Despite the widespread recommendation and use of sunscreens and ultraviolet blocking materials, solar-induced skin damage and photoageing continues to pose a problem to human health worldwide. We have previously reported that solar visible light and near-infrared also contribute to skin damage and photo ageing. Most commonly recommended sunscreens are only effective throughout the UV spectrum, offering no protection from visible light and near-infrared. A possible solution could be to augment sunscreens with metal oxides which block visible light and near-infrared radiation. To evaluate the enhanced solar-spectrum blocking ability of novel low viscosity sunscreen containing zinc and iron oxides, a double-beam spectrophotometer was used to optically measure the transmission spectra. The spectrophotometer deploys a unique, single monochromatic design to detect wavelength penetration in the range of 240 to 2600 nm. The Sunscreen base without zinc oxide and iron oxides (control) blocked over 80% of ultraviolet-C and ultraviolet-B but did not block ultraviolet-A, visible light, or near-infrared. The novel low viscosity zinc oxide sample blocked almost over 90% ultraviolet, but did not block visible light and near-infrared sufficiently. However, the samples with the novel low viscosity zinc oxide, iron oxides and erioglaucine blocked almost over 90% of ultraviolet, visible light and near-infrared. It can be concluded that this novel combination of low viscosity zinc oxide, iron oxides and erioglaucine is effective at blocking ultraviolet, visible light and near-infrared radiation. The results of this study imply that sunscreens that provide comprehensive photoprotection from ultraviolet through to near-infrared should be adopted to prevent skin photodamage. 展开更多
关键词 Anti-Photoageing Photoimmunosuppression PHOTOPROTECTION SUNSCREEN ULTRAVIOLET visible Light near-infrared
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Photoprotective Ability of Colored Iron Oxides in Tinted Sunscreens against Ultraviolet, Visible Light and Near-Infrared Radiation
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作者 Yohei Tanaka Richard Parker Amaryllis Aganahi 《Optics and Photonics Journal》 2023年第8期199-208,共10页
Solar-induced skin damage continues to pose a problem to human health worldwide, despite the widespread recommendation and use of sunscreens. We have previously reported that solar visible light and near-infrared also... Solar-induced skin damage continues to pose a problem to human health worldwide, despite the widespread recommendation and use of sunscreens. We have previously reported that solar visible light and near-infrared also contribute to skin damage and photoageing. Most commonly recommended sunscreens are only effective throughout the UV spectrum, offering no protection from visible light and near-infrared. To evaluate the enhanced solar-spectrum blocking ability of iron oxides, a double-beam spectrophotometer was used to optically measure the transmission spectra. The spectrophotometer deploys a unique, single monochromatic design to detect wavelength penetration in the range of 240 to 2600 nm. The sample without iron oxide (control) blocked over 80% of ultraviolet-C and ultraviolet-B but did not block ultraviolet-A, visible light, or near-infrared wavelengths. The samples with yellow, and red iron oxide blocked over 90% ultraviolet, but did not block visible light and near-infrared effectively. The sample with black iron oxide blocked visible light, and near-infrared effectively compared with other samples with yellow, blue, and red iron oxide. The sample with red and black iron oxides, and the sample with yellow, blue, red, and black iron oxides blocked ultraviolet through to near-infrared. It can be concluded that dark colored iron oxide combinations are effective at blocking from ultraviolet through to visible light and near-infrared radiation. The results of this study may also suggest that biological colour of human skin and subcutaneous tissues are conserved for comprehensive photoprotection. 展开更多
关键词 Anti-Photoageing Photoimmunosuppression PHOTOPROTECTION SUNSCREEN ULTRAVIOLET visible Light near-infrared
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Rapid Determination of Hemicellulose Content in Corn Stalks by Near-infrared Spectroscopy Based on Dung Beetle Optimizer
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作者 Baihong TONG Jinming LIU Jianfei SHI 《Agricultural Biotechnology》 2024年第5期83-85,92,共4页
Corn stalks are a kind of common organic fertilizer and feed material in agriculture in China,as well as an important source of modern biomass energy and new materials.Hemicellulose is an important component in corn s... Corn stalks are a kind of common organic fertilizer and feed material in agriculture in China,as well as an important source of modern biomass energy and new materials.Hemicellulose is an important component in corn stalks,and it is very important to determine its content in corn stalks.In this paper,the feasibility of near-infrared spectroscopy(NIRS)combined with chemometrics for rapid detection of hemicellulose content in corn stalks was studied.In order to improve the accuracy of NIRS detection,a new intelligent optimization algorithm,dung beetle optimizer(DBO),was applied to select characteristic wavelengths of NIRS.Its modeling performance was compared with that based on characteristic wavelength selection using genetic algorithm(GA)and binary particle swarm optimization(BPSO),and it was found that the characteristic wavelength selection performance of DBO was excellent,and the regression accuracy of hemicellulose quantitative detection model established by its preferred characteristic wavelengths was better than the above two intelligent optimization algorithms. 展开更多
关键词 HEMICELLULOSE near-infrared spectrum Characteristic wavelength selection Intelligent optimization algorithm Dung beetle algorithm
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Visible and Near-Infrared Spectroscopy with Multi-Parameters Optimization of Savitzky-Golay Smoothing Applied to Rapid Analysis of Soil Cr Content of Pearl River Delta 被引量:3
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作者 Xiaowen Shi Lijun Yao Tao Pan 《Journal of Geoscience and Environment Protection》 2021年第3期75-83,共9页
Using visible and near-infrared (Vis-NIR) spectroscopy combined with partial least squares (PLS) regression, the rapid reagent-free analysis model for chromium (Cr) content in tideland reclamation soil in the Pearl Ri... Using visible and near-infrared (Vis-NIR) spectroscopy combined with partial least squares (PLS) regression, the rapid reagent-free analysis model for chromium (Cr) content in tideland reclamation soil in the Pearl River Delta, China was established. Based on Savitzky-Golay (SG) smoothing and PLS regression, a multi-parameters optimization platform (SG-PLS) covering 264 modes was constructed to select the appropriately spectral preprocessing mode. The optimal SG-PLS model was determined according to the prediction effect. The selected optimal parameters <em>d, p, m</em> and LV were 2, 6, 23 and 8, respectively. Using the validation samples that were not involved in modeling, the root mean square error (SEP<sub>V</sub>), relative root mean square error (R-SEP<sub>V</sub>) and correlation coefficients (R<sub>P, V</sub>) of prediction were 11.66 mg<span style="white-space:nowrap;">&middot;</span>kg<sup>-1</sup>, 10.7% and 0.722, respectively. The results indicated that the feasibility of using Vis-NIR spectroscopy combined with SG-PLS method to analyze soil Cr content. The constructed multi-parameters optimization platform with SG-PLS is expected to be applied to a wider field of analysis. The rapid detection method has important application values to large-scale agricultural production. 展开更多
关键词 Soil Heavy Metal CHROMIUM visible and near-infrared Spectroscopy Rapid Reagent-Free Analysis Savitzky-Golay Smoothing
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Visible and Near-Infrared Spectroscopic Discriminant Analysis Applied to Identification of Soy Sauce Adulteration 被引量:1
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作者 Chunli Fu Jiemei Chen +1 位作者 Lifang Fang Tao Pan 《American Journal of Analytical Chemistry》 2022年第2期51-62,共12页
The identification of soy sauce adulteration can avoid fraud, and protect the rights and interests of producers and consumers. Based on two measurement models (1 mm, 10 mm), the visible and near-infrared (Vis-NIR) spe... The identification of soy sauce adulteration can avoid fraud, and protect the rights and interests of producers and consumers. Based on two measurement models (1 mm, 10 mm), the visible and near-infrared (Vis-NIR) spectroscopy combined with standard normal variate-partial least squares-discriminant analysis (SNV-PLS-DA) was used to establish the discriminant analysis models for adulterated and brewed soy sauces. Chubang soy sauce was selected as an identification brand (negative, 70). The adulteration samples (positive, 72) were prepared by mixing Chubang soy sauce and blended soy sauce with different adulteration rates. Among them, the “blended soy sauce” sample was concocted of salt water (NaCl), monosodium glutamate (C<sub>5</sub>H<sub>10</sub>NNaO<sub>5</sub>) and caramel color (C<sub>6</sub>H<sub>8</sub>O<sub>3</sub>). The rigorous calibration-prediction-validation sample design was adopted. For the case of 1 mm, five waveband models (visible, short-NIR, long-NIR, whole NIR and whole scanning regions) were established respectively;in the case of 10 mm, three waveband models (visible, short-NIR and visible-short-NIR regions) for unsaturated absorption were also established respectively. In independent validation, the models of all wavebands in the cases of 1 mm and 10 mm have achieved good discrimination effects. For the case of 1 mm, the visible model achieved the optimal validation effect, the validation recognition-accuracy rate (RAR<sub>V</sub>) was 99.6%;while in the case of 10 mm, both the visible and visible-short-NIR models achieved the optimal validation effect (RAR<sub>V</sub> = 100%). The detection method does not require reagents and is fast and simple, which is easy to promote the application. The results can provide valuable reference for designing small dedicated spectrometers with different measurement modals and different spectral regions. 展开更多
关键词 visible and near-infrared Spectroscopy Soy Sauce Adulteration Identification Partial Least Squares-Discriminant Analysis Standard Normal Variate
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Biological Defenses against Ultra-Violet, Visible Light, and Near-Infrared Exposure
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作者 Yohei Tanaka Hideki Motomura Masafumi Jinno 《Optics and Photonics Journal》 2016年第1期8-14,共7页
Objective: Humans are increasingly exposed to artificial light and electromagnetic wave radiation, in addition to solar radiation. Many studies have shown the biological effects of ultra-violet and near-infrared expos... Objective: Humans are increasingly exposed to artificial light and electromagnetic wave radiation, in addition to solar radiation. Many studies have shown the biological effects of ultra-violet and near-infrared exposure, but few have extensively investigated the innate biological defenses within human tissues against visible light and near-infrared exposure. Herein, we investigated spectral properties of endogenous human biological defenses against ultra-violet to near-infrared. Methods: A double-beam spectrophotometer (190 - 2700 nm) was used to measure the transmission spectra of a saline solution used to imitate perspiration, and oil to imitate sebum, as well as human skin, blood, adipose tissue, and muscle. Results: Saline (thickness, 0.5 mm) blocked 27.5% - 98.6% of ultra-violet, 13.2% - 34.3% of visible light, and 10.7% - 99.8% of near-infrared. Oil (thickness, 0.5 mm) blocked 50.5% - 100% of ultra-violet, 28.7% - 54.8% of visible light, and 19.0% - 98.3% of near-infrared. Blood thicknesses of 0.05 and 0.5 mm blocked over 97.8%, 100% of ultra-violet, over 94.6%, 99.7% of visible light, and over 75.8%, 99.4% of near-infrared, respectively. Skin thicknesses of 0.25 and 0.5 mm blocked over 99.4%, 100% of ultra-violet and over 94.3%, 99.7% of visible light, and over 74.7%, 93.5% of near-infrared, respectively. Adipose tissue thickness of 0.25 and0.5 mm blocked over 98.3%, 100% of ultra-violet, over 94.7%, 99.7% of visible light, and over 88.1%, 98.6% of near-infrared, respectively. Muscle thickness of 0.25 and0.5 mm blocked over 95.4%, 99.8% of ultra-violet, over 93.1%, 99.5% of visible light, and over 86.9%, 98.3% of near-infrared, respectively. Conclusions: Humans possess endogenous biological protection against ultra-violet, visible light and near-infrared exposure on multiple levels, including through perspiration, sebum, blood, skin, adipose tissue, and muscle. Since solar and artificial radiation affects human tissues, biological defenses made of biological materials may be induced to protect subcutaneous tissues against these wavelengths. 展开更多
关键词 Biological Defenses near-infrared Ultra-Violet visible Light
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Evaluation of Expression Recognition Function in Autism Spectrum Disorder Using Near-Infrared Spectroscopy 被引量:1
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作者 Kaoru Furukawa Kenji Mori +4 位作者 Keiko Mori Saori Nakano Kumi Takahashi Hiroko Hashimoto Tetsuya Tanioka 《Open Journal of Psychiatry》 2018年第1期35-49,共15页
One of the characteristics of Autism Spectrum Disorder (ASD) is social disorder. The specificity of facial and expression recognition for people with ASD is gathering attention as a factor of this social disorder. The... One of the characteristics of Autism Spectrum Disorder (ASD) is social disorder. The specificity of facial and expression recognition for people with ASD is gathering attention as a factor of this social disorder. The study examined the hemodynamic activities in the prefrontal cortex using near-infrared spectroscopy (NIRS) when a person with ASD performed an expression recognition task. The subjects were twenty males (18 - 22 years old) with ASD and without intellectual disabilities. Forty-five healthy males matched for age and sex were included as a control group. In both groups, the degree of autistic tendencies was evaluated using the Autism-Spectrum Quotient (AQ). Using eight standard emotional expressions of Japanese people, two expression recognition tasks were set. An NIRS was used to measure the prefrontal cortex blood mobilization during the expression-processing process. The AQ was significantly higher in the ASD group, while the rate of overall correct expression response was significantly lower (p &rho;= &minus;0.40 p < 0.001). In the automatic expression-processing task, no activation in the prefrontal cortex was found in either the ASD or the control group. In the conscious expression-processing task, the activation of the left and right lateral prefrontal cortex was weaker in the ASD group compared to the control group. Unlike in the control group, a mild activation of posterior prefrontal cortex was found in the ASD group. The expression-processing process of the ASD group was found to be different from that of the control group. NIRS was effective in detecting a brain function disorder in people with ASD during an expression-processing process. 展开更多
关键词 AUTISM spectrum Disorder near-infrared Spectroscopy Autism-spectrum QUOTIENT FACIAL Expression Recognition PREFRONTAL CORTEX
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Measurement of the Plasma Rotation Velocity by Using Visible Spectrum on HL-1M Mokamak 被引量:1
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作者 罗俊林 李伟 +3 位作者 王恩耀 董贾福 唐年益 刘泽田 《Plasma Science and Technology》 SCIE EI CAS CSCD 2001年第2期683-690,共8页
The plasma rotation velocity were measured in HL-1M with Doppler shifts of CⅢ、 C Ⅱ、 O Ⅱ and H. line by a SKD high resolution spectrometer. The effects .of density' hydrogen pellet injection and carbon impuri... The plasma rotation velocity were measured in HL-1M with Doppler shifts of CⅢ、 C Ⅱ、 O Ⅱ and H. line by a SKD high resolution spectrometer. The effects .of density' hydrogen pellet injection and carbon impurities injected by laser-blow-off on toroidal(V) and poloidal (Vθ)rotation velocity have been observed. The Vθ measured from H. line is only half of that from C Ⅱ impurity line. 展开更多
关键词 Measurement of the Plasma Rotation Velocity by Using visible spectrum on HL-1M Mokamak HL
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High efficient Al: ZnO based bifocus metalens in visible spectrum
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作者 Pengdi Wang Xianghua Zeng 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第10期300-307,共8页
The optical components of the visible light band are widely used in daily life and industrial development. However due to the serious loss of light and the high cost, the application is limited. The broadband gap meta... The optical components of the visible light band are widely used in daily life and industrial development. However due to the serious loss of light and the high cost, the application is limited. The broadband gap metasurface will change this situation due to its low absorption and high efficiency. Herein, we simulate a size-adjustable metasurface of the Al doped ZnO (AZO) nanorod arrays based on finite difference time domain method (FDTD) which can realize the conversion of amplitude polarization and phase in the full visible band. The corresponding theoretical polarization conversion efficiency can reach as high as 91.48% (450 nm), 95.27% (530 nm), and 91.01% (65 nm). The modulation of focusing wavelength can be realized by directly adjusting the height of the AZO nanorod. The designed half-wave plate and metalens can be applied in the imaging power modulation halfwave conversion and enriching the spectroscopy. 展开更多
关键词 visible spectrum Al doped ZnO half-wave plate metalens
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Determination of Rice Amylose Content by Near-infrared Spectroscopy 被引量:3
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作者 彭玉梅 刘华强 +4 位作者 朱学栋 杨霞 何晓容 蒋欢 况小锁 《Agricultural Science & Technology》 CAS 2017年第4期729-732,共4页
Amylose contents in 298 rice samples were determined by conventional method, and a near-infrared spectral model of rice amylose content was established by partial least squares. The calibration determination coefficie... Amylose contents in 298 rice samples were determined by conventional method, and a near-infrared spectral model of rice amylose content was established by partial least squares. The calibration determination coefficient (RC) was 0.95; the standard error of calibration (SEC) was 1.58; and the determination coefficient of cross validation (RP) was 0.91, and the standard error of prediction SEP was 1.92. External validation was performed with 20 samples, the predicted values and the determined values were not significantly different, and the correlation coefficient between them was over 95%. The calibration model has good prediction perfor- mance, and could rapidly determine rice amylose content instead of chemical ana- lytical method. 展开更多
关键词 RICE Amylose content near-infrared spectrum Partial least squares
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Application of Short-wave Near-infrared Reflectance Spectroscopy in Controlling Extract of Fructus Cnidii Using Supercritical Carbon Dioxide 被引量:1
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作者 MI Hong GUO Ye +4 位作者 LI Wen-liang Qu Nan DOU Ying REN Yu-qiu REN Yu-lin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第1期116-119,共4页
Fructus cnidii (Chinese name shechuangzi) is the fruit produced by Cnidium monnieri (L.) Cusson (Umbelliferae). It is a perennial herb that is used to treat skin-related diseases and gynecopathyell. Recent pharm... Fructus cnidii (Chinese name shechuangzi) is the fruit produced by Cnidium monnieri (L.) Cusson (Umbelliferae). It is a perennial herb that is used to treat skin-related diseases and gynecopathyell. Recent pharmacological studies have revealed crude extracts or components isolated from fructus cnidii possess antiallergic, antipruritic, antidermatophytic, antibacterial, antifungal, and antiosteoporotic activities. Osthole and imperatorin are the major compounds present in shechuangzi. They are often used as standards for the evaluation of the quality of shechuangzi products. 展开更多
关键词 Fructus cnidii Supercfitical carbon dioxide Short-wave near-infrared diffuse reflectance spectrum Artificial neural network Degree of approximation
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Effect of head model on Monte Carlo modeling of spatial sensitivity distribution for functional near-infrared spectroscopy
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作者 Ting Li Yan Li +2 位作者 Yunlong Sun Meixue Duan Liyuan Peng 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2015年第5期77-85,共9页
Modeling Light propagation within human head to deduce spatial sensitivity distribution(SSD)is important for Near-infrared spectroscopy(NIRS)/imaging(NIRI)and diffuse correlation tomography.Lots of head models have be... Modeling Light propagation within human head to deduce spatial sensitivity distribution(SSD)is important for Near-infrared spectroscopy(NIRS)/imaging(NIRI)and diffuse correlation tomography.Lots of head models have been used on this issue,including layered head model,artificial simplified head model,MRI slices described head model,and visible human head model.Hereinto,visible Chinese human(VCH)head model is considered to be a most faithful presentation of anatomical structure,and has been highlighted to be employed in modeling light propagation.However,it is not practical for all researchers to use VCH head models and actually increasing number of people are using magnet resonance imaging(MRI)head models.Here,all the above head models were simulated and compared,and we focused on the effect of using di®erent head models on predictions of SSD.Our results were in line with the previous reports on the effect of cerebral cortex folding geometry.Moreover,the in fluence on SSD increases with thefidelity of head models.And surprisingly,the SSD percentages in scalp and gray matter(region of interest)in MRI head model were found to be 80%and 125%higher than in VCH head model.MRI head models induced nonignorable discrepancy in SSD estimation when compared with VCH head model.This study,as we believe,is the first to focus on comparison among full serials of head model on estimating SSD,and provided quantitative evidence for MRI head model users to calibrate their SSD estimation. 展开更多
关键词 visible chinese human functional near-infrared spectroscopy Monte Carlo simulation head model spatial sensitivity distribution
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Ultraviolet-visible spectral properties of nanometer zinc oxide colloidal solution
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作者 刘建本 陈上 +3 位作者 吴竹青 肖卓炳 张永康 黄伯云 《Journal of Central South University of Technology》 2003年第1期49-52,共4页
Nanometer zinc oxide was prepared by solid phase reaction. And the ultraviolet visible spectral properties of nanometer zinc oxide colloidal solution dispersed in both water and oil phases were studied. The results sh... Nanometer zinc oxide was prepared by solid phase reaction. And the ultraviolet visible spectral properties of nanometer zinc oxide colloidal solution dispersed in both water and oil phases were studied. The results show that the absorbance of the colloidal solution to ultraviolet light increases with the decrease of wavelength and reaches about 2.5 at the wavelength of 200 nm. When the mass fraction of nanometer zinc oxide becomes lower, the transmittance of the colloidal solution to visible light gets higher, and it is much higher than that of normal zinc oxide under the same conditions, indicating that nanometer zinc oxide dispersed in both water and oil phases has high transmittance to visible light and good shield to ultraviolet light. Therefore it is suitable for the replacement of organic ultraviolet absorber and titanium dioxide in cosmetics. 展开更多
关键词 NANOMETER ZnO ULTRAVIOLET -visible spectrum COLLOIDAL solution
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气溶胶谱分段拟合对能见度计算的影响
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作者 庄子波 杨晓婷 台宏达 《大气与环境光学学报》 CAS CSCD 2024年第3期301-313,共13页
针对气溶胶谱分布函数拟合中存在的偏差严重影响能见度计算精度的问题,提出了一种采用Junge谱与Deirmendjian谱结合的分段拟合方法来提高气溶胶谱分布函数的精度,并在大气环境模拟舱内进行了实验验证。首先,在大气模拟舱内生成了气溶胶... 针对气溶胶谱分布函数拟合中存在的偏差严重影响能见度计算精度的问题,提出了一种采用Junge谱与Deirmendjian谱结合的分段拟合方法来提高气溶胶谱分布函数的精度,并在大气环境模拟舱内进行了实验验证。首先,在大气模拟舱内生成了气溶胶多峰谱分布,建立了气溶胶谱分布的参数化模型。然后,对比分析了所提综合谱分段拟合方法和单一谱函数法拟合谱函数的相对误差和相关系数。最后,基于相对偏差和相关性评估了所提方法计算能见度的精度。结果表明利用所提方法计算获得的能见度与观测值的平均相对偏差为4.87%,相关性R^(2)=0.9847,证明其拟合结果具有较好的准确性、稳定性,且与实际观测值具有较好一致性。 展开更多
关键词 散射 分段拟合 气溶胶谱分布 数浓度 能见度
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基于可见/近红外光谱与化学计量学的杏品种无损鉴别方法 被引量:2
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作者 高峰 邢雅阁 +2 位作者 罗华平 张远华 郭玲 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第1期44-51,共8页
新疆南疆是全国杏种植面积最大的地区,杏品种繁多。在杏果品市场中,不同品种杏的品质和价格差异较大,以次充好、品质参差不齐等现象严重制约了新疆杏果业的发展。为探究利用可见/近红外光谱快速检测杏品种的可行性,基于样品的可见/近红... 新疆南疆是全国杏种植面积最大的地区,杏品种繁多。在杏果品市场中,不同品种杏的品质和价格差异较大,以次充好、品质参差不齐等现象严重制约了新疆杏果业的发展。为探究利用可见/近红外光谱快速检测杏品种的可行性,基于样品的可见/近红外光谱与化学计量学方法,对新疆南疆地区的6个品种杏进行定性判别分析,建立一种杏品种的无损鉴别方法。采用光谱仪采集6个品种杏(“黄杏”、“橄榄杏”、“小白杏”、“小米杏”、“库买提杏”、“小吊干杏”)在350~1 000 nm(VIS/NIR)和1 000~2 500 nm(NIR)两个范围内的光谱数据,去除原始光谱首端的噪声后,对保留的光谱使用Savitzky-Golay(SG)卷积平滑和多元散射校正(MSC)处理以消除光谱存在的干扰信息,采用主成分分析(PCA)、竞争性自适应重加权算法(CARS)、随机蛙跳(RF)、连续投影算法(SPA)对原始光谱降维,结合线性判别法(LDA)、朴素贝叶斯(NB)、 K最近邻(KNN)和支持向量机(SVM)对全光谱和降维后光谱建模对比。结果表明:基于全光谱数据建立的模型有较为准确的分类结果,在VIS/NIR范围,SVM模型分类正确率为95.7%, NIR范围内,LDA模型分类正确率为97.8%;采用PCA、 CARS-SPA、 RF-SPA与SPA方法对光谱数据降维后,模型仍能保持较高的分类精度,在VIS/NIR范围,PCA-LDA模型的分类正确率为97.8%, NIR范围内,RF-SPA-LDA模型的分类正确率高达95.7%。不同模型的结果表明,VIS/NIR范围内的模型分类效果优于NIR范围内模型;4种降维方法中,PCA方法降维效果最优;4种分类器中,LDA与SVM模型的正确率高于NB与KNN模型,更适用于杏品种的鉴别。结果表明,基于VIS/NIR范围光谱结合主成分分析和线性判别法可以实现杏品种的快速无损鉴别,为杏果实的在线分拣鉴定提供了新途径。 展开更多
关键词 可见光光谱 近红外光谱 化学计量学 品种鉴别
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生物质炭和有机肥配施对水稻土溶解性有机质光谱学特征的影响 被引量:1
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作者 梁栋 周巧林 +6 位作者 张辉 马洪波 宁运旺 张永春 徐聪 焦加国 汪吉东 《土壤学报》 CAS CSCD 北大核心 2024年第4期1123-1133,共11页
为探究生物质炭对水稻土壤溶解性有机质(DOM)的影响及其与有机肥配施的协同效应,通过5年连续定位试验,探讨了生物质炭施用5年后不同施肥处理:对照(CK)、生物质炭(BC)、化肥(F)、生物质炭+化肥(F+BC)、化肥+有机肥(25%氮替代,MF)和化肥+... 为探究生物质炭对水稻土壤溶解性有机质(DOM)的影响及其与有机肥配施的协同效应,通过5年连续定位试验,探讨了生物质炭施用5年后不同施肥处理:对照(CK)、生物质炭(BC)、化肥(F)、生物质炭+化肥(F+BC)、化肥+有机肥(25%氮替代,MF)和化肥+生物质炭+有机肥(25%氮替代,MF+BC)对水稻产量和土壤pH、全氮、有效磷、速效钾、有机碳、易氧化有机碳(ROC)及溶解性有机碳的影响。采用紫外-可见光谱、荧光光谱结合平行因子分析方法对土壤中DOM的光谱特征和荧光组分进行表征,分析了DOM的紫外光吸收系数和紫外光斜率系数以及荧光指数、腐殖化指数、生物指数和富里酸、色氨酸、胡敏酸相对含量。结果表明:施用生物质炭和有机肥均能有效提高水稻产量,缓解土壤酸化,并且MF+BC处理水稻产量和土壤有效磷含量最高。水稻产量与DOM生物可利用性、芳香化程度、腐殖化程度、色氨酸组分含量和亲水性呈显著正相关(P<0.05)。提高DOM生物可利用性和腐殖化程度均表现为有机肥大于生物质炭。生物质炭显著增加DOM富里酸和色氨酸组分含量,并且促进了水稻土中ROC向难氧化有机碳转化;而有机肥有效增加DOM富里酸、色氨酸、胡敏酸和ROC含量。生物质炭和有机肥协同配施对提升水稻产量及增加ROC、DOM富里酸和色氨酸含量、芳香化程度、腐殖化程度和生物可利用性方面具有交互作用。综上所述,在本研究条件下生物质炭配施有机肥在水稻增产和水稻土有机碳及DOM组分功能多样性提升方面具有长期效应。 展开更多
关键词 生物质炭 有机肥 溶解性有机质 紫外-可见光谱 三维荧光光谱 交互作用
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周环取代基对酞菁在不同基质中光谱性能的影响
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作者 秦静 王可栋 +2 位作者 胡雪芳 陈肖媛 刘超 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第10期2953-2958,共6页
将不同周环取代基的金属酞菁均采用溶胶-凝胶(Sol-gel)工艺法掺入二氧化硅(SiO2)凝胶玻璃基质中,制备了金属酞菁掺杂的复合凝胶玻璃。系统研究了酞菁铅系列、酞菁铝系列和酞菁锌系列中不同周环取代基种类和位置对酞菁在N,N-二甲基酰胺(D... 将不同周环取代基的金属酞菁均采用溶胶-凝胶(Sol-gel)工艺法掺入二氧化硅(SiO2)凝胶玻璃基质中,制备了金属酞菁掺杂的复合凝胶玻璃。系统研究了酞菁铅系列、酞菁铝系列和酞菁锌系列中不同周环取代基种类和位置对酞菁在N,N-二甲基酰胺(DMF)溶液和二氧化硅凝胶玻璃基质中的紫外-可见吸收光谱的影响,以检测不同周环取代基的种类和位置对酞菁在不同基质中的存在状态及其影响因素。首先研究了周环取代基种类的影响:在DMF溶液中,不同周环取代基-CP、-OAr、 t-Bu的引入,均可使大环π电子形成更大的共轭体系,使最大电子吸收波长产生红移;在复合凝胶玻璃中,掺杂金属酞菁以多聚物的形式存在,使其紫外-可见光谱中的特征吸收峰均变得弥散;研究了周环取代基位置的影响:对酞菁铝系列研究了周环取代基-OAr分别在α和β位时,α-AlTPOPcCl和β-AlTPOPcCl在DMF溶液和二氧化硅复合凝胶玻璃中的紫外-可见吸收光谱,结果表明:在DMF溶液中,由于电子共轭效应,α位的取代基相比β位其特征峰有所红移;在复合凝胶玻璃中,α-AlTPOPcCl的紫外-可见吸收光谱与其在DMF溶液中几乎相同,说明α-AlTPOPcCl在这两种基质中以单体形式存在,而β-AlTPOPcCl在复合凝胶体系中吸收光谱峰型弥散,说明该酞菁在复合体系中多以团聚体形式存在。研究结果为进一步研究酞菁掺杂复合凝胶玻璃的光学性能奠定了基础,为非线性光限幅性能材料及器具的研究奠定了理论基础。 展开更多
关键词 酞菁 复合凝胶玻璃 紫外-可见吸收光谱
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投弃式雾能见度剖面仪的设计原理与应用
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作者 赵进平 陈萍 +8 位作者 刘一林 陈显尧 门雅彬 徐俊臣 衣立 李涛 王晓宇 栾亮 高琳 《中国海洋大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第10期167-178,共12页
精准观测大气能见度是研究雾的重要基础,我们将雾引起的大气能见度变化简称为雾能见度。现有的大气能见度仪较重,无法由探空气球携带升空;由于观测手段的限制,迄今对雾的垂向结构研究很少,本文提出利用自然光探测雾能见度的方案。为获... 精准观测大气能见度是研究雾的重要基础,我们将雾引起的大气能见度变化简称为雾能见度。现有的大气能见度仪较重,无法由探空气球携带升空;由于观测手段的限制,迄今对雾的垂向结构研究很少,本文提出利用自然光探测雾能见度的方案。为获取大气的垂向衰减系数,研制了一种体积小、重量轻、传输距离远的投弃式微型辐照度计,由探空气球携带升空,实现雾能见度的垂向剖面探测,我们将该仪器系统命名为“投弃式雾能见度剖面仪”。投弃式雾能见度剖面仪既能实现对大气辐照度的精确测量,又具有重量轻、造价低的特点,成为探测雾能见度垂向特征的一种新手段。本文还提出精确测量大气辐照度所涉及的两个创新性算法——谱辐照度的反演算法和仪器摆动的校正算法。在此基础上利用获取的太阳辐射在垂向的漫衰减系数,成功反演出雾能见度的垂向分布。实际观测结果表明,雾在垂直方向上有丰富的信息,也有空间上的明显差异,需要深入研究。雾能见度剖面仪可为深入研究雾的垂向结构提供宝贵数据,有重要的应用价值。 展开更多
关键词 雾能见度 剖面探测仪 垂向结构 辐照度 衰减系数 多光谱
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