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Preparation, characterization and photocatalytic activities of boron- and cerium-codoped TiO_2

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Journal of Environmental Sciences 2007年第1期19卷 90-96页

作者： wei Chao-hai TANG xin-hu LIANG Jie-rong TAN Shu-ying institute of Environmental Science South China University of Technology Guangzhou 510640 China Department of Environrnental Engineering Jinan University Guangzhou 510632 China

Boron- and cerium-codoped TiO2 photocatalysts were synthesized using modified sol-gel reaction process and characterized by X- ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, particle size distribution （PSD）, diffuse reflectance spectra （DRS）, and Brunauer-Emmett-Teller （BET）. The photocatalytic activities were evaluated by monitoring the degradation of dye Acid Red B （ARB）. The results showed that the prepared photocatalysts were mixed oxides mainly consisting of titania, ceria, and boron oxide. The structure of TiO2 could be transformed from amorphous to anatase and then to rutile by increasing calcination temperature; the transformation being accompanied by the growth of particle size without any obvious change in phase structure of CeO2. The XPS of B1.6Ce1.0-TiO2 prepared at 500℃ showed that a few boron atoms were incorporated into titania and ceria lattice, whereas others existed as B2O3. Cerium ions existed in two states, Ce^3＋ and Ce^4＋, and the atomic ratio of Ce^3＋/Ce^4＋ was 1.86. When boron and cerium were doped, the UV-Vis adsorption band wavelength showed an obvious shift toward the visible range （〈526 nm）. As the atomic ratio of Ce/Ti increased to 1.0, the absorbance edge wavelength increased to 481 nm. The absorbance edge wavelength decreased for higher cerium doping levels （Ce/Ti=2.0）. The particles size ranged from 122 to 255 nm with a domain at 168 nm （39.4%）. The degradation of ARB dye indicated that the photocatalytic activities of boron- and cerium-codoped TiO2 were much higher than those of P25 （a standard TiO2 powder）. The activities increased as the boron doping increased, whereas decreased when the Ce/Ti atomic ratio was greater than 0.5. The optimum atomic ratio of B/Ti and Ce/Ti was 1.6 and 0.5, respectively.

关键词： titania ceria boron oxide photocatalytic activity Acid Red B

Experimental Study on Wear Performance and Oil Film Characteristics of Surface Textured Cylinder Liner in Marine Diesel Engine

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 158-167页

作者： Zhi-wei Guo Cheng-Qing Yuan Xiu-Qin Bai xin-Ping Yan Reliability Engineering Institute National Engineering Research Center for Water Transportation Safety Key Laboratory of Marine Power Engineering&Technology(Ministry of Transport) Wuhan University of Technology

It is of a vital importance to reduce the frictional losses in marine diesel engines. Advanced surface textures have provided an e ective solution to friction performance of rubbing pairs due to the rapid development of surface engineering techniques. However,the mechanisms through which textured patterns and texturing methods prove beneficial remains unclear. To address this issue,the tribological system of the cylinder liner?piston ring(CLPR) is investigated in this work. Two types of surface textures(Micro concave,Micro V?groove) are processed on the cylinder specimen using di erent processing methods. Comparative study on the friction coe cients,worn surface texture features and oil film characteristics are performed. The results demonstrate that the processing method of surface texture a ect the performance of the CLPR pairs under the specific testing conditions. In addition the micro V?groove processed by CNCPM is more favorable for improving the wear performances at the low load,while the micro?con?cave processed by CE is more favorable for improving the wear performances at the high load. These findings are in helping to understand the e ect of surface texture on wear performance of CLPR.

关键词： Cylinder liner?piston ring(CLPR) Surface texture structure Frictional and wear characteristic Oil film characteristic

Numerical study on the turbulent mixing of planar shock-accelerated triangular heavy gases interface

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Acta Mechanica Sinica 2018年第5期34卷 855-870页

作者： wei-Gang Zeng Jian-Hua Pan Yu-xin Ren Yu-Tao Sun Department of Engineering Mechanics School of AerospaceTsinghua UniversityBeijing 100084China Institute of Applied Physics and Computational Mathematics Beijing 100094China

The interaction of a planar shock wave with a triangle-shaped sulfur hexafluoride (SF6) cylinder surrounded by air is numerically studied using a high resolution finite volume method with minimum dispersion and controllable dissipation *** vortex dynamics of the Richtmyer-Meshkov instability and the turbulent mixing induced by the KelvinHelmholtz instability are discussed.A modified reconstruction model is proposed to predict the circulation for the shock triangular gas-cylinder interaction *** typical stages leading the shock-driven inhomogeneity flow to turbulent mixing transition are *** the decoupled length scales and the broadened inertial range of the turbulent kinetic energy spectrum in late time manifest the turbulent mixing transition for the present *** analysis of variable-density energy transfer indicates that the flow structures with high wavenumbers inside the Kelvin-Helmholtz vortices can gain energy from the mean flow in ***,small scale flow structures are generated therein by means of nonlinear ***,the occasional 'pairing' between a vortex and its neighboring vortex will trigger the merging process of vortices and,finally,create a large turbulent mixing zone.

关键词： Richtmyer-Meshkov instability Kelvin-Helmholtz instability Length scale Turbulent mixing

Facile synthesis of α-difluoromethyl α-propargylamines from CF_2H-substituted N-tert-butanesulfinyl ketimines

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Chinese Chemical Letters 2012年第3期23卷 277-280页

作者： Hui Chen wei Yu xin Hua Guo wei Dong Meng Yan Gen Huang College of Chemistry Chemical Engineering and BiotechnologyDonghua UniversityShanghai 201620China

Stereoselective approach for preparation ofα-difluoromethylα-propargylamines has been developed.1,2-Addition of lithium acetylides to diverse chiral difluoromethylated（S）-N-tert-butanesulfinyl ketimines by using Ti（O^iPr）_4 as catalyst and THF as solvent afforded N-tert-butanesulfinamides in good to excellent yields（51-93%） and good diastereoselectivities（dr.85：15 to 93：7）.The N-tert -butanesulfinyl group can be readily cleaved under mild acidic condition（4 mol/L HCl in dioxane） to provide the correspondingα-difiuoromethylα-propargylamine in excellent yields（90-95%）.

关键词： Diasteroselectivity Difluoromethyl Propargylamine 1 2-Addition Sulfinamides

Numerical and experimental analysis of AC loss for CFETR CS model coil

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Nuclear Science and Techniques 2017年第10期28卷 79-86页

作者： wei Zhou xin-Yu Fang Jin Fang Yan-Chao Liu Bo Liu School of Electrical Engineering Beijing Jiaotong University Department of Electrical and Computer Engineering University of Victoria Institute of Plasma Physics Chinese Academy of Sciences

The central solenoid(CS) is an important component of China Fusion Engineering Test Reactor, for producing, forming and stabilizing plasma in the superconducting tokamak. It is a complicated work to design and manufacture the large superconducting CS magnet, so it is meaningful to design a central solenoid model coil(CSMC) and analyze its electromagnetic properties in advance. In this paper, the structure, design parameters and magnetic field distribution of the CS model coil are discussed. The peak power of radial and axial turn conductors and time bucket loss are analyzed by using piecewise-linear method. The CSMC AC loss with different Nb3 Sn CICCs and AC loss of ITER CS coil are compared. The special electrometric method to measure AC loss of the CS model coil for future reference is presented.

关键词： CS模型线圈交流损耗实验堆数值分析托卡马克等离子体磁铁设计 Nb3Sn 聚变工程

剔络养血明目汤对正常眼压性青光眼患者眼部血流的影响

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中国中医眼科杂志 2024年第6期34卷 525-529页

作者：侯文博冯俊李欣王玮中国中医科学院眼科医院北京100040

目的观察剔络养血明目汤对正常眼压性青光眼(NTG)患者眼部血流的影响。方法纳入2018年6月—2021年12月中国中医科学院眼科医院诊治的NTG患者32例(63只眼),辨证为瘀血阻络证。随机分为治疗组20例(39只眼)和对照组12例(24只眼)。对照组予... 详细信息

目的观察剔络养血明目汤对正常眼压性青光眼(NTG)患者眼部血流的影响。方法纳入2018年6月—2021年12月中国中医科学院眼科医院诊治的NTG患者32例(63只眼),辨证为瘀血阻络证。随机分为治疗组20例(39只眼)和对照组12例(24只眼)。对照组予银杏叶片和甲钴胺片口服;治疗组在对照组的基础上联合剔络养血明目汤口服。2组均观察28 d。分别于治疗前、后检测受试者的视神经总扫描区域的血流密度(VD1)及视盘周围毛细血管区域的血流密度(VD2),视网膜中央动脉(CRA)和睫状后短动脉(SPCA)的收缩峰值速度(PSV)、舒张末期速度(EDV)和阻力指数(RI)。结果2组治疗前VD1、VD2、EDV、PSV和RI比较,差异均无统计学意义(P>0.05);且对照组治疗后VD1、VD2、CRA和SPCA的PSV、EDV、RI与治疗前比较,差异均无统计学意义(P>0.05)。(1)VD:治疗组治疗后VD1、VD2均较治疗前升高,差异均有统计学意义(tVD1=6.739、tVD2=8.285,均P=0.000)。治疗后2组间VD1、VD2比较,差异无统计学意义(P>0.05)。治疗组治疗前、后的VD1差值与VD2差值均高于对照组,差异均有统计学意义(tVD1=5.599、tVD2=6.210,均P=0.000)。(2)眼部血管血流动力学参数:治疗组治疗后CRA的EDV较治疗前增加、RI较治疗前降低,差异均有统计学意义(tEDV=3.096,P=0.003;tRI=2.446,P=0.017);治疗后2组间CRA的各指标比较,差异均无统计学意义(P>0.05)。治疗组治疗后SPCA的PSV、EDV均较治疗前增加,差异均有统计学意义(tPSV=2.481,P=0.015;tEDV=2.315,P=0.023);治疗后2组间SPCA的各指标比较,差异均无统计学意义(P>0.05)。结论剔络养血明目汤可改善NTG患者的眼部血流,尤其是视神经血流。

关键词：正常眼压性青光眼血流密度剔络养血明目汤

Highly selective CO methanation over amorphous Ni-Ru-B/ZrO_2 catalyst

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Chinese Chemical Letters 2009年第8期20卷 889-892页

作者： Qi Hai Liu xin Fa Dong wei Ming Lin School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 China

Amorphous Ni-Ru-B/ZrO2 catalyst was prepared by the means of chemical reduction, and selective CO methanation as a strategy for CO removal in fuel processing applications was investigated over the amorphous Ni-Ru-B/ZrO2 catalyst. The result showed that, at the temperature of 210-230 ℃, the catalyst was shown to be capable of reducing CO in a hydrogen-rich reformate to less than 10 ppm, while keeping the CO2 conversion below 1.55% and the hydrogen consumption below 6.50%. ？2009 xin Fa Dong. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Selective methanation CO Amorphous Ni-Ru-B/ZrO2 catalyst

Bifunctional metal–organic frameworks toward photocatalytic CO2reduction by post-synthetic ligand exchange

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Rare Metals 2019年第5期38卷 413-419页

作者： Xiao-Hui Chen Qin wei Jin-Dui Hong Rong Xu tian-Hua Zhou School of Chemical Engineering Fuzhou UniversityFuzhou 350002China School of Chemical and Biomedical Engineering Nanyang Technological UniversitySingapore 637459Singapore State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Photocatalytic reduction of CO2 to useful fuel has been identified as a promising strategy to address the energy and environmental *** of welldefined photocatalysts toward CO2 reduction has attracted increasing interest to gain insight into the reactive ***,by post-synthetic ligand exchange,a bifunctional Re-based metal–organic framework(MOF)was successfully *** not only serves as a photosensitizer but also acts as a catalyst for photochemical reduction of ***,it is found that a Re-based MOF containing 30%Re-based ligands displays improved activity compared to MOF with 100%Re-based *** work provides clues to the design and synthesis of bifunctional MOFs toward photocatalytic CO2 reduction.

关键词： Photocatalysis Metal-organic framework(MOF) CO2 reduction Post-synthesis

Dynamic interplay between dislocations and precipitates in creep aging of an Al-Zn-Mg-Cu alloy

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Advances in Manufacturing 2019年第1期7卷 15-29页

作者： Heng Li tian-Jun Bian Chao Lei Gao-wei Zheng Yu-Fei Wang State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 People's Republic of China

Abstract Creep age forming (CAF) is an advanced forming technology used for manufacturing large complex integrated panel components. However, in creep aging (CA), unlike in sole creep or aging procedure, the dislocation movement and the precipitation process occur simultaneously, leading to difficulty in understanding of the dynamic interplay between these two phenomena. In this work, taking 7050 Al alloy, a typical Al-Zn-Mg-Cu alloy, as the test material, an experimental scheme combining pre-deformation, artificial aging (AA), and tensile/ compressive CA is designed to decouple and reveal the dynamic interaction mechanism of both phenomena. From AA experiments, the static interaction between dislocations and precipitates is studied, and then their dynamic interactions in CA and each evolution are comparatively investigated. The research shows that both total strain and strain rate increase with the increase in pre-deformation in tensile and compressive CA. However, the total creep strain in compressive CA is larger than that in tensile CA. In additional, the more the dislocations are induced, the sparser and more heterogeneous the overall distribution of precipitates becomes. For dynamic interplay, in the first stage of CA (I), under thermal-mechanical loading, the GP zones and η phases gradually nucleate and grow, while the effect of dislocation multiplication is dominant compared with dislocation annihilation, leading to an increase in total dislocation density. Soon, the dislocation movement is gradually hindered by tangling, pile-up, and the precipitates that have grown on the dislocation lines, this decreases the mobile dislocation density and results in a significant decrease in creep rate. In the second stage (II), the precipitates grow further, especially those lying on the dislocation lines;the effects of pinning and hindrance are enhanced until the dislocation multiplication and annihilation reach a dynamic equilibrium, and the total and mobile dislocatio

关键词： Creep aging (CA) Dynamic interplay Dislocation Precipitate Pre-deformation Al-Zn-Mg-Cu alloy