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光触媒技术原理与国内研究现状 被引量:3
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作者 史乔升 汪光文 +1 位作者 程湛 张存 《科技视界》 2017年第1期14-15,共2页
光触媒技术是一项新兴的空气净化技术。本文对光触媒技术的原理进行了介绍,并按照装置类型对国内的光触媒研究进行了介绍,探讨了拓展反应表面的不同方式。本文为之后此领域的研究提供了一定的借鉴意义。
关键词 光触 媒光 催化氧化
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Enhancement effect of phase-conjugate waves of third order nonlinear medium in the Bragg microcavity 被引量:1
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作者 JIANG Mei-ping CHEN Guang +3 位作者 SHEN Xiao-ming GHEN Xian-feng NI Chong-wen SHI Du-fang 《Optoelectronics Letters》 EI 2006年第1期78-81,共4页
The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a (AB)^N (D)^2 (BA)^N Bragg microcavity made of one-dimensional photonic crystals is studied. The gain fac... The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a (AB)^N (D)^2 (BA)^N Bragg microcavity made of one-dimensional photonic crystals is studied. The gain factor of the phase-conjugate wave is derived when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode. Because of stronger resonance enhancement to incident pump beam given by the Bragg microcavity, the enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium inside Bragg microcavity is more outstanding than that caused by the naked third order nonlinear optical medium. The theoretical analysis and the numerical calculation show the Bragg microcavity with larger number N of periods is identical with a Fabry-Perot cavity when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode. 展开更多
关键词 非线性光媒介 相位共轭波 微观空穴 晶体光学
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Light energy conversion device for photocatalyst 2.0%WO_3-TiO_2 with oxygen vacancies for water splitting
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作者 童海霞 陈启元 +1 位作者 胡慧萍 尹周澜 《Journal of Central South University》 SCIE EI CAS 2010年第5期943-946,共4页
Using carbon felt, polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device, the photocatalytic activity of catalyst 2.0%WO3-TiO2 (2%WO3 compounding TiO2) with oxygen vacancies ... Using carbon felt, polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device, the photocatalytic activity of catalyst 2.0%WO3-TiO2 (2%WO3 compounding TiO2) with oxygen vacancies was studied through the water splitting for O2 evolution, using a high pressure mercury lamp as the light source and Fe^3+ as the electron acceptor in two different devices: an ordinary photolysis device with catalyst powder suspending through a magnetic stirrer and a self-assembly light energy conversion device. The results show that after 12 h irradiation, the photocatalytic activity of 2.0%WO3-TiO2 with oxygen vacancies in the self-assembly light energy conversion device is higher than that of the ordinary photolysis device, and the amount of oxygen evolution is about 12 and 9 mmol/L respectively in these two devices. After 12 h, the rates of 02 evolution are slow in each device and the photocatalyst almost loses the photoactivity in the ordinary photolysis device. So, compared with the ordinary photocatalytic device, the rate of oxygen evolution and the life time of the catalyst are improved in the self-assembly light energy conversion device. 展开更多
关键词 light energy conversion device photocatalytic activity 02 evolution oxygen vacancy photo splitting water
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Traffic Scheduling in WDM Passive Optical Network with Delay Guarantee
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作者 邱绍峰 范戈 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第3期242-244,259,共4页
WDM passive optical network becomes more favorable as the required bandwidth increases, but currently few media access control algorithms adapted to WDM acc ess network. This paper presented a new scheduling algorithm... WDM passive optical network becomes more favorable as the required bandwidth increases, but currently few media access control algorithms adapted to WDM acc ess network. This paper presented a new scheduling algorithm for bandwidth shari ng in WDM passive optical networks, which provides per-flow delay guarantee and supports variable-length packets scheduling. Through theoretical analysis and simulation, the end-to-end delay bound and throughput fairness of the algori thm was demonstrated. 展开更多
关键词 wavelength division multiplexing passive optical network media access control protocol
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Experimental study and kinetic analysis of oxidant-free thermal-assisted UV digestion utilizing supported nano-TiO_2 photocatalyst for detection of total phosphorous 被引量:1
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作者 董甜 佟建华 +2 位作者 边超 孙楫舟 夏善红 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第1期93-99,共7页
A novel thermal-assisted ultra-violet(UV) photocatalysis digestion method for the determination of total phosphorus(TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion wer... A novel thermal-assisted ultra-violet(UV) photocatalysis digestion method for the determination of total phosphorus(TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion were conducted using a 365 nm wavelength UV light and Ti O2 particles as the photocatalyst. Sodium tripolyphosphate and sodium glycerophosphate were used as the typical components of TP and the digested samples were then determined by spectrophotometry after phosphomolybdenum blue reaction. The effects of operational parameters such as reaction time and temperature were studied for the digestion of TP and the kinetic analysis of two typical components was performed in this paper. The pseudo-first-order rate constants k of two phosphorus compounds at different temperatures were obtained and the Arrhenius equation was employed to explain the effect of temperature on rate constant k. Compared with the conventional thermal digestion method for TP detection, it was found that the temperature was decreased from 120 °C to 60 °C with same conversion rate and time in this thermal-assisted UV digestion method, which enabled the digestion process work at normal pressure. Compared with the individual ultra-violet(UV) photocatalysis process, the digestion time was also decreased from several hours to half an hour using the thermal-assisted UV digestion method. This method will not lead to secondary pollution since no oxidant was needed in the thermal-assisted UV photocatalysis digestion process, which made it more compatible with electrochemical detection of TP. 展开更多
关键词 Thermal-assisted Ultra-violet digestion Ti O2 Oxidant-free Kinetic analysis
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Average cluster sizes and cluster size distributions of superfine nickel particles in light media
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作者 李敬生 杜飞虎 王娟 《Journal of Central South University》 SCIE EI CAS 2009年第3期399-404,共6页
Effects of shear rates on average cluster sizes (ACSs) and cluster size distributions (CSDs) in uni- and bi-systems of partly charged superfine nickel particles were investigated by Brownian dynamics, and clustering p... Effects of shear rates on average cluster sizes (ACSs) and cluster size distributions (CSDs) in uni- and bi-systems of partly charged superfine nickel particles were investigated by Brownian dynamics, and clustering properties in these systems were compared with those in non-polar systems. The results show that the ACSs in bi-polar systems are larger than those in the non-polar systems. In uni-polar systems the behavior of clustering property differs: at the lower ionic concentration (10%), repulsive force is not strong enough to break clusters, but may greatly weaken them. The clusters are eventually cracked into smaller ones only when concentration of uni-polar charged particles is large enough. In this work, the ionic concentration is 20%. The relationship between ACS and shear rates follows power law in a exponent range of 0.176-0.276. This range is in a good agreement with the range of experimental data, but it is biased towards the lower limit slightly. 展开更多
关键词 ionic concentration average cluster sizes cluster size distribution power law
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Using Unmanned Underwater Vehicles as Research Platforms in Coastal Ocean Studies 被引量:3
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作者 HOUWeilin KendallL.Carder +2 位作者 DavidK.Costello DUKeping LIUZhishen 《Journal of Ocean University of Qingdao》 2003年第2期211-217,共7页
The advantages of using unmanned underwater vehicles in coastal ocean studies are emphasized. Two types of representative vehicles, remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) from Universi... The advantages of using unmanned underwater vehicles in coastal ocean studies are emphasized. Two types of representative vehicles, remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) from University of South Florida, are discussed. Two individual modular sensor packages designed and tested for these platforms and field measurement results are also presented. The bottom classification and albedo package, BCAP, provides fast and accurate estimates of bottom albedos, along with other parameters such as in-water remote sensing reflectance. The real-time ocean bottom optical topographer, ROBOT, reveals high-resolution 3-dimentional bottom topography for target identification. Field data and results from recent Coastal Benthic Optical Properties field campaign, 1999 and 2000, are presented. Advantages and limitations of these vehicles and applications of modular sensor packages are compared and discussed. 展开更多
关键词 unmanned underwater vehicle (UUV) remotely operated vehicle (ROV) autonomous underwater vehicle (AUV) bottom classification and albedo package (BCAP) real-time ocean bottom optical topographer (ROBOT)
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Dual Adaptive Turbo Coded Modulation for Integrated Multimedia Service Transmission
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作者 左健存 宋文涛 +1 位作者 罗汉文 徐友云 《Journal of Donghua University(English Edition)》 EI CAS 2004年第1期72-77,共6页
This paper proposes a cross-layer dual adaptive coded modulation architecture using turbo codes for mobile multimedia communication, which adapts to both the varying channel characteristics and the QoS of various mult... This paper proposes a cross-layer dual adaptive coded modulation architecture using turbo codes for mobile multimedia communication, which adapts to both the varying channel characteristics and the QoS of various multimedia services simultancously to increase the average system throughput substantially. A pragmatic channeladaptive turbo coded modulation schcme, which comes within 2.5 dB of the Shannon limit, is optimally designed, and then a QoS-adaptive scheme is superimposed to build the dual adaptive architecture. Simulation results show that the novel dual adaption reduces the gap from the fading channel capacity to 2 dB when assuming different services occur in equal probability and the service duration follows exponential distribution. 展开更多
关键词 Dual adaption Turbo coded modulation Fading channels Multimedia services Spectral efficiency
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Predicting Influence of Social Media Exposure on Drinking Intention among Thai Youths
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作者 Jantima K. Kheokao Anchalee Pichedpan +2 位作者 Siritorn Yingrengreung Tassanee Krirkgulthom Prapas Thana 《Journalism and Mass Communication》 2014年第8期478-485,共8页
New face drinkers and social media use gain popularity among adolescents in Thailand. Previous studies support relationships between exposures to marketing communications on alcohol consumption. This study proposed to... New face drinkers and social media use gain popularity among adolescents in Thailand. Previous studies support relationships between exposures to marketing communications on alcohol consumption. This study proposed to examine influence of exposure to social media and drinking intention. Participants comprised of 2,565 students grade 4th-12th from randomly selected 11 provinces across Thailand. Drinking intention was at moderate level for students who ever drink (mean = 3.66, SD = 1.06), low level among never drink (mean = 2.43, SD = .81), and overall students (mean = 2.85, SD = 1.08). The ever drink group were moderately communicated through Facebook (mean = 3.17, SD = 1.56) and Line (mean = 2.53, SD = 1.58). Regression analysis revealed weak but significant relationship of social media that explain 1.3%-5.2% of drinking intention among Thai students. Therefore, more study is needed to effectively understand and regulate the use of social media and prevention or delaying youth from using alcohol. 展开更多
关键词 social media DRINKING ALCOHOL ADOLESCENT INTENTION
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Kinetic Modeling of the Photocatalytic Reduction of Cr(VI) in the Presence of Dye Using Composite Photocatalyst
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作者 Kwena Yvonne Pete Maurice Stephen Onyango +1 位作者 Mika Sillanpaa Aoyi Ochieng 《Journal of Chemistry and Chemical Engineering》 2014年第9期918-924,共7页
The photocatalytic properties of surface TiO2 supported zeolite in a semi batch reactor for the reduction of Cr(VI) in the presence of methyl orange dye were investigated. The prepared composite photocatalyst was ch... The photocatalytic properties of surface TiO2 supported zeolite in a semi batch reactor for the reduction of Cr(VI) in the presence of methyl orange dye were investigated. The prepared composite photocatalyst was characterized by SEM-EDS (scanning electron microscopy and energy dispersive spectroscopy). The effects of operating parameters such as the pH and concentration of Cr(VI) in the absence and presence of dye were evaluated. The Cr(VI) reduction was more efficient in the ternary system (Cr(VI)/dye/TiO2-zeolite) than that of the corresponding binary system (Cr(VI)/TiO2-zeolite). The extent of metal reduction after 210 min of irradiation was 68% at pH = 3 for the ternary system. In order to optimize the effectiveness of the composite photocatalyst on the photocatalytic reduction of Cr(VI), kinetics and isotherm models were applied. The kinetics of Cr(VI) in the presence of dye on TiO2/zeolite composite photocatalyst followed the pseudo-first-order model while the equilibrium data correlated reasonably well with Freundlich isotherm. 展开更多
关键词 Composite photocatalyst Cr(VI) DYE KINETICS isotherm.
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Atomic Coherent Trapping and Properties of Trapped Atom
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作者 YANG Guo-Jian XIA Li-Xin XIE Min 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3X期556-560,共5页
Based on the theory of velocity-selective coherent population trapping, we investigate an atom-laser system where a pair of counterpropagating laser fields interact with a three-level atom. The influence of the parame... Based on the theory of velocity-selective coherent population trapping, we investigate an atom-laser system where a pair of counterpropagating laser fields interact with a three-level atom. The influence of the parametric condition on the properties of the system such as velocity at which the atom is selected to be trapped, time needed for finishing the coherent trapping process, and possible electromagnetically induced transparency of an altrocold atomic medium, etc., is studied. 展开更多
关键词 velocity selective coherent population trapping ultracold atom
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A High Performance Cobalt-Doped ZnO Visible Light Photocatalyst and Its Photogenerated Charge Transfer Properties 被引量:16
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作者 Yongchun Lu Yanhong Lin +3 位作者 Dejun Wang Lingling Wang Tengfeng Xie Tengfoi Jiang 《Nano Research》 SCIE EI CAS CSCD 2011年第11期1144-1152,共9页
Highly photocatalytically active cobalt-doped ZnO (ZnO:Co) nanorods have been prepared by a facile hydrothermal process. X-ray diffraction, X-ray photoelectron spectroscopy, Raman scattering and UV-vis diffuse refl... Highly photocatalytically active cobalt-doped ZnO (ZnO:Co) nanorods have been prepared by a facile hydrothermal process. X-ray diffraction, X-ray photoelectron spectroscopy, Raman scattering and UV-vis diffuse reflectance spectroscopy confirmed that the dopant ions substitute for some of the lattice zinc ions, and furthermore, that Co〉 and Co〉 ions coexist. The as-prepared ZnO:Co samples have an extended light absorption range compared with pure ZnO and showed highly efficient photocatalytic activity, only requiring 60 rain to decompose -93% of alizarin red dye under visible light irradiation (λ 〉 420 nm), The photophysical mechanism of the visible photocatalytic activity was investigated with the help of surface photovoltage spectroscopy. The results indicated that a strong electronic interaction between the Co and ZnO was present, and that the incorporation of Co promoted the charge separation and enhanced the charge transfer ability and, at the same time, effectively inhibited the recombination of photogenerated charge carriers in ZnO, resulting in high visible light photocatalytic activity. 展开更多
关键词 ZnO:Co visible light irradiation surface photovoltage PHOTOCATALYSIS
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Synthesis, characterization and photocatalytic application of H_3PW_(12)O_(40)/BiVO_4 composite photocatalyst 被引量:3
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作者 ZHANG Jin LI Chuang +3 位作者 WANG Bing CUI Hao ZHAI JianPing LI Qin 《Science China Chemistry》 SCIE EI CAS 2013年第9期1285-1292,共8页
A series of H3PW12O40/BiVO4 composite with different H3PW12O40 loadings were prepared using a hydrothermal and impregnation method. The prepared composites were characterized by XRD, Raman, SEM, XPS, and DRS technique... A series of H3PW12O40/BiVO4 composite with different H3PW12O40 loadings were prepared using a hydrothermal and impregnation method. The prepared composites were characterized by XRD, Raman, SEM, XPS, and DRS techniques. The bandgap of the composite was narrower compared with the as-prepared pure BiVO4 . As a novel photocatalytic material, the photocatalytic performance of the H3PW12O40/BiVO4 composite was investigated by the degradation of methylene blue (MB) dye solution under visible light irradiation and compared with that of pure BiVO4 . The results revealed that the introduction of H3PW12O40 could improve the photocatalytic performance and different concentrations of H3PW12O40 resulted in different photocatalytic activities. The highest activity was obtained by the sample with a loading HPW concentration of 10 wt%. The reason for the enhanced photocatalytic activities of H3PW12O40/BiVO4 samples was also discussed in this paper. Moreover, the H3PW12O40/BiVO4 composites retained the catalytic activity after four repeated experiments. 展开更多
关键词 bismuth vanadate (BiVO 4 heteropoly acid (HPA) PHOTOCATALYSIS visible-light-responsive composite materials
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Visible-light-promoted and photocatalyst-free trifluoromethylation of enamides 被引量:1
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作者 Hao Wang Yuanzheng Cheng Shouyun Yu 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第2期195-198,共4页
An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation withou... An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields. 展开更多
关键词 ENAMIDE PHOTOCHEMISTRY visible light TRIFLUOROMETHYLATION radical
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Phase Properties of Photon-Added Coherent States for Nonharmonic Oscillators in a Nonlinear Kerr Medium
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作者 F.Jahanbakhsh G.Honarasa 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第4期387-392,共6页
The potential of nonharmonic systems has several applications in the field of quantum physics. The photonadded coherent states for annharmonic oscillators in a nonlinear Kerr medium can be used to describe some quantu... The potential of nonharmonic systems has several applications in the field of quantum physics. The photonadded coherent states for annharmonic oscillators in a nonlinear Kerr medium can be used to describe some quantum systems. In this paper, the phase properties of these states including number-phase Wigner distribution function,Pegg-Barnett phase distribution function, number-phase squeezing and number-phase entropic uncertainty relations are investigated. It is found that these states can be considered as the nonclassical states. 展开更多
关键词 photon-added nonharmonic oscillators phase properties Kerr medium
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Terahertz generation based on four-wave mixing difference frequency by resonance-enhanced third-order nonlinear of media 被引量:1
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作者 张少华 姚建铨 +3 位作者 周睿 温午麒 徐德刚 王鹏 《Optoelectronics Letters》 EI 2011年第6期415-418,共4页
Using nanosecond pulse near-infrared and mid-infrared laser pulses as the pump source, we obtain terahertz wave sources via four-wave difference frequency mixing. From the coupled wave theory, we analyze the four-wave... Using nanosecond pulse near-infrared and mid-infrared laser pulses as the pump source, we obtain terahertz wave sources via four-wave difference frequency mixing. From the coupled wave theory, we analyze the four-wave mixing process of GaSe crystal and alkali metal vapor in detail, get the analytical expression of terahertz wave output power, and discuss the conditions for achieving phase matching. By adjusting the pump frequency, the third-order nonlinear polarization of alkali metal vapor is resonance-enhanced. This program offers a new type of high-power terahertz radiation source. 展开更多
关键词 Alkali metals Four wave mixing Infrared devices Optical parametric oscillators Optical pumping VAPORS
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