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Preparation of (Ti, Sn)O_2 Nano-Composite Photocatalyst by Supercritical Fluid Dry Combination Technology

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Journal of Materials Science & Technology 2005年第2期21卷 191-195页

作者： Jingchang ZHANG, Qing LI and Weiliang CAO Institute of modern Catalysis, The key laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, china Lab. of Controllable Chem. Reactions Inst. of Modern Catalysis Beijing Univ. of Chem. Technol. Beijing 100029 China

A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%-30.1%) were prepared from TiCI4 and SnCl4·5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination technology. Characterizations with X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) showed that, in addition to anatase type TiO2, a new active phase (Ti, Sn)O2 (with particle size of 2.0-4.3 nm) formed, and there were no SnO2 crystals observed in the range of the doping concentration studied. Photo-catalytic reaction of phenol was used as a model reaction to evaluate the catalytic activities of the obtained catalysts. Compared with pure TiO2 or Ti-Sn catalyst prepared with general sol-gel method, Ti-Sn nano-composite photo-catalyst thus obtained showed significant improvement in catalytic activity. The photo-catalytic degradation rate of phenol could reach as high as 93.5% after 7 h. The preparation conditions of the new phase (Ti, Sn)O2 were investigated and its catalytic mechanism was proposed. The photo-catalytic particles prepared using SCFD combination technology exhibited small particle size, large surface area and high activity.

关键词： Anatase TiO2 (Ti, Sn)O2 Photo-catalytic Supercritical fluid dry method Solid-phase reaction

Analysis of forest backscattering characteristics based on polarization coherence tomography

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Science china(Technological Sciences) 2010年第S1期53卷 166-175页

作者： LUO HuanMin 1,LI XiaoWen 1,2,CHEN ErXue 3,CHENG Jian 4 & CAO ChunXiang 21 Institute of Geo-Spatial Information Science and Technology,University of Electronic Science and Technology of china,chengdu 610054,china 2 State key laboratory of Remote Sensing Science,Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University,Beijing 100101,china 3Institute of Forest Resources Information Technique of Chinese Academy of Forestry,Beijing 100091,china 4 School of Electronic Engineering,University of Electronic Science and Technology of china,chengdu 610054,china State key Lab Remote Sensing Sci Beijing 100101 Peoples R China Beijing Normal Univ Beijing 100101 Peoples R China Univ Elect Sci & Technol china Inst Geospatial Informat Sci & Technol Chengdu 610054 Peoples R China Chinese Acad Forestry Inst Forest Resources Informat Tech Beijing 100091 Peoples R China Univ Elect Sci & Technol china Sch Elect Engn Chengdu 610054 Peoples R China

It is difficult to make an inventory of vertical profiles of forest structure parameters in field ***,analysis and understanding of forest backscattering characteristics contribute to estimation and detection of forest vertical structure because of the close relationships between backscattering characteristics and structure *** vertical structure function in the complex interferometric coherence definition,which represents the vertical variation of microwave scattering with the penetration depth at a point in the 2-D radar image and can be used to analyze the forest backscattering characteristics,can be reconstructed from polarization coherence tomography(PCT).Based on PCT,the paper analyzes the forest backscattering characteristics and explores the inherent relationship between the result of PCT and the forest structure parameters from numerical simulation of Random Volume over Ground model(RVoG),Polarimetric SAR interferometry(PolInSAR)simulation of forest scene and PolInSAR data at L-band of the test site ***,the effects of the extinction coefficient and surface-to-volume scattering ratio in RVoG model on vertical backscattering characteristics are analyzed by means of numerical ***,by applying PCT to L-band POLInSAR simulations of forest scene,different variations of vertical backscattering due to different extinction coefficients and the ratios of surface-to-volume scattering resulting from different polarizations,forest types and densities are displayed and *** a concept of relative average backscattering intensity is presented,and the factors which affect its vertical distribution are also *** results show that there is high sensitivity of the vertical distribution of forest relative average backscattering intensity to the polarization,forest type and ***,based on repeat pass DLR E-SAR L-band airborne POLInSAR data,the capability of PCT technology for detection

关键词： backscattering characteristic POLInSAR PCT vertical structure function

The characteristic properties of PEDOT nano-particle based on reversed micelle method

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Science china(Technological Sciences) 2010年第9期53卷 2355-2362页

作者： ZHENG HuaJing,JIANG YaDong,XU JianHua & YANG YaJie State key laboratory of Electronic Thin Films & Integrated Devices,School of Optoelectronic Information,University of Electronic Science and Technology of china,chengdu 610054,china 1. State key laboratory of Electronic Thin Films & Integrated Devices School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu 610054 China

Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),this paper focuses on the preparation and the materials properties of PEDOT nanoparticles made by reversed micelle *** on optical,electrical and the thermal stability of PEDOT nanoparticles were carried *** main results were as follows: The small-sized PEDOT nanoparticles were prepared by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,fourier-transform infrared (FT-IR) spectrum,scanning electron microscopy (SEM) and so *** Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the good orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles compared with the conventional ***,the gas sensitivity of nanoparticles deposited on quartz crystal microbalance (QCM) was studied and the nanopartices deposited device exhibited excellent sensitivity to HCl gas at low *** sensitivity of the nanoparticles by the reverse micelle was better than that of the common PEDOT particles.

关键词： poly (3 4-ethylenedioxythiophene) conducting polymer reversed micelle n-particle photoelectric properties thermal stability

A study on water film in saturated sand

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International Journal of Sediment Research 2010年第3期25卷 221-232页

作者： LU X. B.1 and CUI P.2 1 Dr., laboratory for Hydraulic and Ocean Engineering, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, china, 2 Prof., key laboratory for Mountain Hazard and Earth Surface Process, Institute of Mountain Hazard and Environment, Chinese Academy of Sciences, chengdu 610041, china, [a] Dr. Laboratory for Hydraulic Ocean Engineering Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China [b] Prof. Key Laboratory for Mountain Hazard Earth Surface Process Institute of Mountain Hazard Environment Chinese Academy of Sciences Chengdu 610041 China

Water film can serve as a sliding surface and cause landslides on gentle slopes. The development of "water film" in saturated sand is analyzed numerically and theoretically based on a quasi-three-phase model. It is shown that stable water films initiate and grow if the choking state (where the fluid velocity decreases to near zero) remains steady in a liquefied sand column. Discontinuity can occur in pore water velocity, grain velocity and pore pressure after the initiation of a water film. However, the discontinuity and water film can disappear once the choking state is changed. The key to the formation of water film is the choking in the sand column caused by eroded fine grains.

关键词： Saturated sand Water film Liquefaction

A Probabilistic View of Debris Flow

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Journal of Mountain Science 2008年第2期5卷 91-97页

作者： LI Yong SU Pengcheng CUI Peng HU Kaiheng key laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences Chengdu 610041 Sichuan P.R.China Institute of Mountain Hazards and Environment CAS Chengdu P. R. China

Most debris flows occur in valleys of area smaller than 50 km2. While associated with a valley, debris flow is by no means a full-valley event but originates from parts of the valley, i.e., the tributary sources. We propose that debris flow develops by extending from tributaries to the mainstream. The debris flow observed in the mainstream is the confluence of the tributary flows and the process of the confluence can be considered as a combination of the tributary elements. The frequency distribution of tributaries is found subject to the Weibull form (or its generalizations). And the same distribution form applies to the discharge of debris flow. Then the process of debris flow is related to the geometric structure of the valley. Moreover, viewed from a large scale of water system, all valleys are tributaries, which have been found to assume the same distribution. With each valley corresponding to a debris flow, the distribution can be taken as the frequency distribution of debris flow and therefore provides a quantitative description of the fact that debris flow is inclined to occur at valley of small size. Furthermore, different parameters appear in different regions, suggesting the regional differentials of debris flow potential. We can use the failure rate, instead of the size per se, to describe the risk of a valley of a given area. Finally we claim that the valleys of debris flow in different regions are in the similar episode of evolution.

关键词： Debris flow tributary probability distribution risk assessment

Engineering of electronic and optical properties of ZnO thin films via Cu doping

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Chinese Physics B 2013年第4期22卷 491-494页

作者：张国恒邓小燕薛华向钢 key laboratory for Electronic Materials of the State national Affairs Commission of PRC School of Electrical Engineering Northwest University for Nationality Department of Physics and key laboratory for Radiation Physics and Technology of Ministry of Education Sichuan University

ZnO thin films doped with different Cu concentrations are fabricated by reactive magnetron sputtering technique. XRD analysis indicates that the crystal quality of the ZnO：Cu film can be enhanced by a moderate level of Cu-doping in the sputtering process. The results of XPS spectra of zinc, oxygen, and copper elements show that Cu-doping has an evident and complicated effect on the chemical state of oxygen, but little effect on those of zinc and copper. Interestingly, further investigation of the optical properties of ZnO：Cu samples shows that the transmittance spectra exhibit both red shift and blue shift with the increase of Cu doping, in contrast to the simple monotonic behavior of the Burstein–Moss effect. Analysis reveals that this is due to the competition between oxygen vacancies and intrinsic and surface states of oxygen in the sample. Our result may suggest an effective way of tuning the bandgap of ZnO samples.

关键词： ZnO thin films Cu doping optical properties bandgap tuning

Magnetic and dielectric properties of low temperature fired ferrite/ceramic composite materials

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Progress in Natural Science:Materials International 2011年第1期21卷 21-26页

作者： Wei-wei LING~(1,2),Huai-wu ZHANG~1,Ying HE~1,Yuan-xun LI~1,Yun-yan WANG~1 1.State key laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of china,chengdu 610054,china 2.Department of Communication Engineering,chengdu University of Information Technology, chengdu 610225,china [a] State key laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China [b] Department of Communication Engineering Chengdu University of Information Technology Chengdu 610225 China

Ni-Cu-Zn ferrite/CaTiO3and Ni-Cu-Zn ferrite/BaTiO3composites which can be applied in low temperature co-fired ceramic（LTCC） technology were synthesized by conventional solid-state reaction at temperature lower than 950℃.Influence of the microstructures and the gap parameterδ/D on the complex permeability of the above two composites was *** modifiedδ/D values of the above two composites show a good fit to the magnetic circuit *** dielectric properties of the composites were predicted by the Maxwell-Garnctt effective medium theory and the discrepancy between measured and calculated values was analyzed.

关键词： ferrite/ceramic composite low temperature co-fired ceramic(LTCC) solid-state reaction magnetic properties dielectric properties

^(137)Cs Redistribution in Thin Stony Soil of a Carbonate Rock Slope in Southwest china

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Pedosphere 2011年第1期21卷 37-45页

作者： LI Hao ZHANG Xin-Bao WANG Kc-Lin WEN An-Bang Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 (China) Graduate University Chinese Academy of Sciences Beijing 100049 (China) State key laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 (China) Institute of Subtropical Agriculture Chinese Academy of Sciences Changsha 410125 (China)

The fallout radionuclide cesium-137(137 Cs) has been widely employed as a tracer for assessment of soil loss from thick uniform soils;however,few studies have been conducted on thin stony soils on slopes underlain by carbonate rocks which are widely distributed in karst *** derived from 137 Cs measurement of soil samples collected along a carbonate rock slope with thin stony soil where neither soil erosion nor deposition occurred was used to investigate the characteristics of 137 Cs redistribution in a karst area of Southwest *** results indicated that the 137 Cs inventories of the surface soil on the slope studied were much lower than that of the local 137 Cs reference inventory and the 137 Cs activities were much higher than those on slopes with thick uniform *** spatial distribution of 137 Cs inventories was characterized by considerable *** high 137 Cs depletion in the stony soil of the slope studied was mainly because a considerable proportion of the fallout input of 137 Cs could be lost with runoff and the dissolution of carbonate particles in the soil promoted the loss of 137 *** demonstrated that the rates of soil loss could not be estimated from the degree of depletion of the 137 Cs inventory relative to the local reference inventory for the thin stony soil of the rocky slope underlain by carbonate rocks in the study area in the way that has been widely used in areas with thick uniform soils.

关键词： carbonate dissolution, ^137Cs fallout, ^137Cs inventory karst area runoff

A new perylene diimide-based colorimetric and fluorescent sensor for selective detection of Cu^(2+) cation

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Science china Chemistry 2009年第4期52卷 518-522页

作者： YAN LiWei,YANG Li,LAN JingBo & YOU JingSong key laboratory of Green Chemistry and Technology of Ministry of Education,College of Chemistry,and State key laboratory of Biotherapy,West china Hospital,West china Medical School,Sichuan University,chengdu 610064,china 1. key laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry and State Key Laboratory of Biotherapy West China Hospital West China Medical School Sichuan University Chengdu 610064 China

A new perylene diimide (PDI) ligand (1) functionalized with a dipicolylethylenediamine (DPEN) moiety was synthesized and first used as a colorimetric and fluorometric dual-channel sensor to specifically detect the presence of Cu2+ over a wide range of other cations. The solution of 1 (10 μmol/L) upon ad-dition of Cu2+ displayed distinguishing pink color compared with other cations including K+,Ni2+,Ca2+,Mn2+,Na+,Sr2+,Zn2+,Co2+,Cd2+,Mg2+,Cr3+,Ag+,and Ba2+,indicating the sensitivity and selectivity of 1 to Cu2+. Thus,the advantage of this assay is that naked-eye detection of Cu2+ becomes possible. More-over,among these metal ions investigated,only Cu2+ quenched more than half fluorescent intensity of 1. The ESI-TOF spectrum of a mixture of 1 and CuCl2 in combination of the fluorescence titration spectra of 1 (10 μmol/L) upon addition of various amounts of Cu2+ revealed the formation of a 2︰1 metal-ligand complex through the metal coordination interaction.

关键词： perylene diimide (PDI) colorimetric fluorescent sensor copper ion