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基于BP神经网络的多基色打印机光谱特性化 被引量:13
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作者 何颂华 张刚 +1 位作者 陈桥 赵子琦 《包装工程》 CAS CSCD 北大核心 2014年第13期110-115,共6页
目的实现多基色打印机的光谱特性化。方法结合光谱降维和光谱重构方法建立了多基色打印机光谱特性化BP神经网络模型,并提出了基于人眼视觉特性加权的目标函数。结果在基于BP神经网络的多基色打印机光谱特性化中,当目标函数未进行人眼视... 目的实现多基色打印机的光谱特性化。方法结合光谱降维和光谱重构方法建立了多基色打印机光谱特性化BP神经网络模型,并提出了基于人眼视觉特性加权的目标函数。结果在基于BP神经网络的多基色打印机光谱特性化中,当目标函数未进行人眼视觉特性加权时,光谱精度和色度精度分别为0.0285和2.8614,当采用人眼视觉特性加权目标函数后,光谱精度和色度精度分别为0.0166和1.2247。结论在基于BP神经网络的多基色打印机光谱特性化中,使用基于人眼视觉特性加权的目标函数可兼顾光谱与色度2个因素,其光谱特性化效果更优。 展开更多
关键词 BP神经网络 多基色打印机 光谱特性化 目标函数 视觉特性加权
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氢对Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)块状非晶光谱特性的影响
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作者 彭德林 沈军 +1 位作者 孙剑飞 陈玉勇 《金属学报》 SCIE EI CAS CSCD 北大核心 2003年第6期569-572,共4页
利用电弧熔炼及铜模快速铸造的方法制备Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)块状非晶合金,通过电化学方法向块状非晶中充入氢。研究了充氢对该非晶态材料反射光谱、吸收光谱、透射光谱特性的影响。结果表明,充氢掺杂后,提高反... 利用电弧熔炼及铜模快速铸造的方法制备Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)块状非晶合金,通过电化学方法向块状非晶中充入氢。研究了充氢对该非晶态材料反射光谱、吸收光谱、透射光谱特性的影响。结果表明,充氢掺杂后,提高反射率,降低吸收率,降低红外光的透射率,并使反射峰向短波边移动。 展开更多
关键词 锆基块状非晶合金 光谱特性
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A new germacranolide from Carpesium cernuum
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作者 曹建新 潘远江 +4 位作者 许重阳 黄利夏 马淑红 代常亮 高婉婉 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第7期640-642,共3页
As a part of our interest in biologically active germacranolides from the genus Carpesium (Compositae), we have investigated the constituents of Carpesium cernuum. This paper reports the isolation and structural elu... As a part of our interest in biologically active germacranolides from the genus Carpesium (Compositae), we have investigated the constituents of Carpesium cernuum. This paper reports the isolation and structural elucidation of a new germacranolide, cernolide A (Compound 1), from the herb. The structure of Compound 1 was determined as 2α,3β-dihydroxy-9-angeloxygermacra-4-en-6,12-olide on the basis of spectral evidence. The skeleton of Compound 1 was elucidation by IR, MS, ^1H and ^13C NMR, COSY, HMQC and HMBC experiments. The stereochemistry of Compound 1 was deduced by ROESY spectral data. Finally, the procedures of extraction and isolation were described in detail. 展开更多
关键词 Carpesium cernuum COMPOSITAE SESQUITERPENOID 3β-dihydroxy-9-angeloxygermacra-4-en-6 12-olide
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Preparation of Ultrafine SiO2 Powder from Rice Husk and Properties of Its Infrared Spectrum
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作者 晋日亚 胡双启 谭迎新 《Journal of Measurement Science and Instrumentation》 CAS 2011年第3期226-229,共4页
This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and... This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing. 展开更多
关键词 rice husk ultrafine powder SIO2 infrared spectrum
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In situ Fourier Transform Infrared Spectroscopy Diagnostic for Characterization and Performance Test of Catalysts
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作者 Patrick Mountapmbeme Kouotou 田振玉 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第5期513-520,I0001,共9页
The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior... The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior (temperature-programmed reduction/temperatureprogrammed re-oxidation) as well as the catalytic properties of Co3O4 thin films. The syntheses of Co3O4 were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm-1 (υ1) and 650 cm-1 (υ2) respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co3O4 spinel. The lattice stability limit of Co3O4 was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ1 and υ2 as a function of the temperature. Moreover, Co3O4 has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO2 and H2O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co3O4 follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts. 展开更多
关键词 In situ Fourier transform infrared spectroscopy Diagnostic Thermal stability Redox property Catalytic mechanism
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Optical and Structural Properties of Carbon Nanotube-Rutile Heterostructures 被引量:3
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作者 Marianna Barbeno Pasquale Barone Alessandra Imbrogno Fang Xu Valentino Pingitore Assunta Bonanno 《Journal of Chemistry and Chemical Engineering》 2012年第10期942-950,共9页
The paper presents a study of the growth and characterization of carbon nanotube-rutile nanocomposites. The heterostructures were obtained with a chemical mixing method. Scanning electron microscope images show that t... The paper presents a study of the growth and characterization of carbon nanotube-rutile nanocomposites. The heterostructures were obtained with a chemical mixing method. Scanning electron microscope images show that the samples appear as a homogeneous powder of rutile with carbon nanotubes intercalated in interspaces between the TiO2 grains. Characterization by both X-ray photoelectron spectroscopy and cathodo-luminescence analysis show the formation of CO-Ti chemical bonds with a decrease of 0.8 eV in the band gap compared to pure rutile. The consequence of this band gap modification is a strong change in optical properties. Luminescence emission is drastically reduced and absorption in the visible range is increased of about 6% at very low concentration (1%) of carbon nanotubes. 展开更多
关键词 Carbon nanotubes RUTILE optical absorbance c-doping.
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Influence of Yttrium Implantation on Oxidation Behavior of Pure Nickel at 1000℃
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作者 姜世杭 靳惠明 +1 位作者 闫坤 宫泽祥 《Journal of Donghua University(English Edition)》 EI CAS 2005年第1期143-146,共4页
Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1 000℃ in air. The oxide scales formed on nickel substrates were performed using SEM and TEM. It was found that Y-implant... Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1 000℃ in air. The oxide scales formed on nickel substrates were performed using SEM and TEM. It was found that Y-implantation greatly improved the anti-oxidation ability of nickel both in isothermal and cyclic oxidizing experiments. Laser Raman microscopy was also used to study the stress status of oxide scales formed on nickel with and without yttrium. The main reason for the improvement in anti-oxidation and adhesion of oxide scale was Y-implantation greatly reduced the grain size of NiO and lowered the compressive stress within the scale. Yttrium implantation enhanced the adhesion of protective NiO oxide scale formed on nickel substrate. 展开更多
关键词 OXIDATION Ion-implantation Laser Raman Yttrium.
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Surface photovoltage phase spectroscopy study of the photo-induced charge carrier properties of TiO_(2) nanotube arrays 被引量:3
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作者 CHEN LiPing XIE TengFeng +2 位作者 WANG DeJun FAN ZhiYong JIANG TengFei 《Science China Chemistry》 SCIE EI CAS 2012年第2期229-234,共6页
By using the surface photovoltage (SPV) technique based on a lock-in amplifier, surface states located 3.1 eV below the conduction band of TiO_(2) have been detected in TiO_(2) nanotube arrays prepared by anodization ... By using the surface photovoltage (SPV) technique based on a lock-in amplifier, surface states located 3.1 eV below the conduction band of TiO_(2) have been detected in TiO_(2) nanotube arrays prepared by anodization of titanium foil in fluoride-based ethylene glycol solution. The photo-induced charge transportation behavior of TiO_(2) nanotube arrays was also studied by quali- tatively analyzing their SPV phase spectra measured under different external bias. When a negative bias was applied, carriers excited from surface states have the same transportation properties as those excited from the valence band; in contrast, when a positive bias was applied, these two kinds of photo-excited carriers exhibit different transportation behavior.. 展开更多
关键词 surface photovoltage phase spectra TiO_(2) nanotube arrays surface state charge carrier property
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Research on ultra-small textured surface of multicrystalline silicon solar cell 被引量:2
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作者 LI HaoFeng JIA Rui +8 位作者 DOU BingFei CHEN Chen XING Zhao YANG YongZhou DING WuChang MENG YanLong LIU XinYu YE TianChun LI ShangQing 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第4期952-956,共5页
The ultra-small textured surface of multicrystalline silicon solar cell,prepared by electroless chemical-etching method,shows an excellent anti-reflection property over a wide spectral bandwidth.A novel back surface p... The ultra-small textured surface of multicrystalline silicon solar cell,prepared by electroless chemical-etching method,shows an excellent anti-reflection property over a wide spectral bandwidth.A novel back surface protection method and front surface passivation method have been used in the multicrystalline solar cells with ultra-small textured surfaces.With these improvements,the back surface remains intact after the etch process and the efficient minority lifetime is apparently increased.The test result shows that the solar cell with ultra-small textured surface can obtain better electrical performances by these improvements. 展开更多
关键词 mc-Si solar cell ultra-small texture ANTI-REFLECTION surface passivation
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Effect of Radiant Spectral Characteristics on Performance of a Near-Infra-Red Heating Module
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作者 Ju-Hyun Kim Won-Taek Choi Minsub Han 《Journal of Thermal Science》 SCIE EI CAS CSCD 2011年第6期510-515,共6页
We simulated the heat transfer phenomena of the heating module that is primarily based on the radiant energy in the near-infra-red(NIR) domain.In the module,the power emitted by the lamp filament is distributed to the... We simulated the heat transfer phenomena of the heating module that is primarily based on the radiant energy in the near-infra-red(NIR) domain.In the module,the power emitted by the lamp filament is distributed to the lamp glass,reflector,and the target medium,which are cooled by an air flow.The radiant heat transfer is simulated by using the ray-tracing scheme,in which the spectral characteristics of the emission and the materials are incorporated.The heat transport from the lamp glass to the cooling air is analyzed by using the finite volume method.As the lamp-filament temperature rises in the range of 3000-3400K,the NIR radiant power on the target medium increases.However,the lamp-glass temperature also rises,and the proportion of the NIR power to the entire radiation has a peak in the temperature range.The spectral distributions of the absorbed energies in all the components in the module are highly non-uniform,and a monochromatic model of the radiant heat transfer may result in a significant discrepancy. 展开更多
关键词 Computational Fluid Dynamics(CFD) CURING DRYING Coating process
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The naturally occurring secolignans
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作者 Ying Zhang Xiaobo Li Mengyue Wang 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2019年第10期687-698,共12页
Naturally occurring secolignans have drawn the considerable attention because of their novel structures and diverse biological activities.In recent years,various natural secolignans with extensive bioactivities have b... Naturally occurring secolignans have drawn the considerable attention because of their novel structures and diverse biological activities.In recent years,various natural secolignans with extensive bioactivities have been reported in the literatures.In the present review,we summarized all the available information regarding the biosynthesis,distributions,separation methods,chemical structures,spectral characteristics,and biological activities of natural secolignans,and provided some valuable new insights for the further study. 展开更多
关键词 Secolignan BIOSYNTHESIS DISTRIBUTION SEPARATION Chemical structures Spectral characteristics Biological activity
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