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Extraction behavior of bifunctional ionic liquid [N_(1888)][SOPAA] and TBP for rare earth elements

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Journal of Rare Earths 2016年第12期34卷 1252-1259页

作者：陈金清黄超王艳良黄彬孙晓琦 School of Metallurgy and Chemical Engineering Jiangxi University of Science & Technology xiamen Institute of Rare Earth Materials Haixi Institute Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Extraction and separation of yttrium in chloride medium using tri-n-octylmethylammonium（2-sec-octylphenoxy） acetate（[N（1888）][SOPAA]） as an extractant were studied in this article. Tri-n-butyl phosphate（TBP） was used as a phase modifier to accelerate phase separation and improve the stability of organic phase. The addition of TBP contributed to shortening phase separation time, increasing extraction capacity of rare earth elements（REEs） and decreasing viscosity of organic phase. The slope analysis method and infrared spectroscopy were conducted to investigate the ion-association extraction mechanisms. Extraction and stripping performances of the different systems were also compared. The article showed that the extraction performance of mixed [N（1888）][SOPAA] and TBP is superior to that of [N（1888）][SOPAA] for heavy rare earth element（HREE）.

关键词： rare earths extraction separation ionic liquid phase modifier

Environmental chemical stressors as epigenome modifiers:a new horizon in assessment of toxicological effects

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Chinese science Bulletin 2014年第4期59卷 349-355页

作者： Heqing Shen F.L.Martin Yanhua Su Key Laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences Centre for Biophotonics Lancaster Environment CentreLancaster University Department of Preventive Medicine School of Public Health of Xiamen University

In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ‘‘accessibility hypothesis' '. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference(RNAi) and other func- tional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic- modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations.

关键词：环境化学基因修饰压力源表观毒理效应评估 DNA甲基化相互作用

Geometric design and simulation of tooth profile using elliptical segments as its line of action

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Journal of Central South University 2015年第6期22卷 2119-2126页

作者：王建罗善明苏德瑜常雪峰 School of Mechanical & Automotive Engineering Xiamen University of Technology Key Laboratory of Precision Actuation and Transmission of Fujian Province University School of Electromechanical Engineering Hunan University of Science and Technology

A mathematical model of gear tooth profiles using the ellipse curve, whose curvature is convenient to control by changing the mathematical parameters as its line of action, was built based on the meshing theory. The equation of undercutting condition was derived from the model. A special epicycloidal tooth profile was also presented. An example gear drive with variation of the ellipse parameters was taken to illustrate the proposed method. The contact ratio of the gear drive designed by the proposed method was analyzed. A comparison of the property of the gear drive designed with the involute gear drive was also carried out. The results confirm that the proposed gear drive has higher contact ratio in comparison with the involute gear drive.

关键词： gear transmission tooth profile elliptical segment epicycloidal contact ratio

Synthesis,optical properties,and energy transfer of Ce^3＋,Tb^3＋ doped KLu2F7

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Journal of Rare Earths 2017年第1期35卷 58-62页

作者： CAO Chunyan XIE An School of Materials science and Engineering Xiamen University of Technology Xiamen 361024 China Key Laboratory of Functional Materials and Applications of Fujian Province Xiamen 361024 China

Ce^3＋, Tb^3＋ doped orthorhombic phases of KLu2F7 microcrystals with hexagonal disk morphology were synthesized by a hydrothermal method. Enhanced emissions of Tb^3＋ were observed in the Ce^3＋,Tb^3＋ co-doped KLu2F7 sample compared to the Tb^3＋ single-doped KLu2F7. The energy transfer efficiency from Ce^3＋ to Tb^3＋ was calculated by the photoluminescence intensity in the Ce^3＋,Tb^3＋ co-doped KLu2F7 samples. The average separations between Ce^3＋ and Tb^3＋ were calculated and the critical distance was 0.922 nm estimated by method of concentration quenching. The theoretical calculation proved the results. The theoretical analysis also suggested that the energy transfer from Ce^3＋ to Tb^3＋ in the KLu2F7 occurred predominantly via the dipole-quadrupole interaction. The KLu2F7 should be good host materials for emitters.

关键词： hydrothermal synthesis optical properties energy transfer rare earths

Modulate the electronic structure of Cu_(7)S_(4)nanosheet on TiO_(2)for enhanced photocatalytic hydrogen evolution

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Nano Research 2023年第4期16卷 4488-4493页

作者： Wenqiang Liu Huiping Peng Leigang Li Mingmin Wang Hongbo Geng Xiaoqing Huang State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China School of Materials Engineering Changshu Institute of TechnologyChangshu 215500China

TiO_(2)is a promising photocatalyst due to its high thermodynamic stability and ***,its applications have been still limited because of the high recombination rate of electron-hole ***,we show that by combining heterojunction construction and electronic structure regulation,the electron-hole pairs in TiO_(2)can be effectively separated for enhanced photocatalytic hydrogen *** optimized Cu_(7)S_(4)nanosheet decorated TiO_(2)achieves much enhanced H_(2)evolution rate(11.5 mmol·g−1·h−1),which is 13.8 and 4.2 times of that of TiO_(2)and Cu_(7)S_(4)/TiO_(2),*** results of photoluminescence spectroscopy,transient photocurrent spectra,ultraviolet-visible diffuse reflectance spectra,and electrochemical impedance spectroscopy collectively demonstrate that the enhanced photocatalytic performance of Air-Cu_(7)S_(4)/TiO_(2)is attributed to the effective separation of charge carriers and widened photoresponse *** electron paramagnetic resonance and X-ray photoelectron spectroscopy results indicate that the increase of Cu2+in the Cu_(7)S_(4)nanosheet after calcination can promote the charge *** work provides an effective method to improve the electron migration rate and charge separation of TiO_(2),which holds great significance for being extended to other material systems and beyond.

关键词： Cu_(7)S_(4)nanosheet Cu^(2+) electronic structure regulation heterojunction photocactalytic hydrogen evolution

The effect of hydrogen reduction of α-MnO_(2) on formaldehyde oxidation: The roles of oxygen vacancies

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Chinese Chemical Letters 2023年第3期34卷 171-174页

作者： Liping Zhou Chunying Wang Yaobin Li Xiaofeng Liu Hua Deng Wenpo Shan Hong He College of Resources and Environmental sciences Fujian Agriculture and Forestry UniversityFuzhou 350002China Center for Excellence in Regional Atmospheric Environment Key Laboratory of Urban Pollutant ConversionInstitute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control Ningbo Urban Environment Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesNingbo 315800China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

A series of α-MnO_(2) catalysts with various Mn valence states were treated by hydrogen reduction for different periods of time. Their catalytic capacity for formaldehyde(HCHO) oxidation was evaluated. The results indicated that hydrogen reduction dramatically improves the catalytic performance of α-MnO_(2) in HCHO oxidation. The α-MnO_(2) sample reduced by hydrogen for 2 h possessed superior activity and could completely oxidize 150 ppm HCHO to CO_(2) and H_(2)O at 70℃. Multiple characterization results illustrated that hydrogen reduction contributed to the production of more oxygen vacancies. The oxygen vacancies on the catalyst surface enhanced the adsorption, activation and mobility of O_(2) molecules, and thereby enhanced HCHO catalytic oxidation. This study provides novel insight into the design of outstanding MnO_x catalysts for HCHO oxidation at low temperature.

关键词： Hydrogen reduction α-MnO_(2) Formaldehyde oxidation Oxygen vacancies

Screening and Characterization of the High-Cellulase-Producing Strain Aspergillus glaucus XC9

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Frontiers in Biology 2006年第1期1卷 35-40页

作者： Xu Chang Long Minnan Wu Xiaobing Xu Huijuan Chen Zhongan Zhang Fengzhang Xu Liangshu Institute of Microbiology and Marine Medicine School of Life SciencesXiamen UniversityXiamen 361005China Haicang Waste Water Treatment Plant Xiamen 361026China

Cellulose is a kind of renewable resource that is abundant in *** can be degraded by microorganisms such as mildew.A mildew strain with high cellulase activity was isolated from mildewy maize cob and classified as Aspergillus glaucus XC9 by morphological and 18S rRNA gene sequence *** studied the effects of nitrogen source,initial pH,temperature,incubation time,medium composition,and surfactants on cellulase *** activities of carboxymethylcellulase(6,812 U/g dry koji)and filter paperase(172 U/g dry koji)were obtained in conditions as follows:initial pH,5.5–6.0;temperature,30℃;cultivation period,3–4 days;inoculum ratio,6%(vol/vol);sugarcane bagasse/wheat bran ratio,4:*** bagasse was used as substrate and mixed with wet koji at a 1:1(wt/wt)ratio,the yield of reducing sugars was 36.4%.The corresponding conversion rate of cellulose to reducing sugars went as high as 81.9%.The results suggest that *** XC9 is a preferred candidate for cellulase production.

关键词： Aspergillus glaucus cellulase activity saccharification

Pollution characteristics of organic and elemental carbon in PM_(2.5) in xiamen,China

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Journal of Environmental sciences 2011年第8期23卷 1342-1349页

作者： Fuwang Zhang Jinping Zhao Jinsheng Chen Ya Xu Lingling Xu Key Lab of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China. Graduate University of Chinese Academy of sciences Beijing 100049 China

xiamen, located on the southeastern coastal line of China, is undergoing rapid urbanization and industrialization, so its air quality has a trend of degradation. However, studies on level, temporal and spatial changes of fine particles （PM2.5） and their carbonaceous fractions are scarce. In this article, abundance, sources, seasonal and spatial variations, distribution of organic carbon （OC） and elemental carbon （EC） in PM2.5, were studied at suburban, urban and industrial sites in xiamen during four season-representative months in 2009-2010. PM2.5 samples were collected with middle volume sampler and were analyzed for OC and EC with thermal optical transmittance （TOT） method. Results showed that the annual average PM2.5 concentrations were 63.88-74.80 Ixg/m3 at three sites. While OC and EC concentrations were in the range of 15.81-19.73 [xg/m3 and 2.74-3.49 ~tg/m3, respectively, and clearly presented the summer minima and winter maxima in this study. The carbonaceous aerosol accounted for 42.8%-47.3% of the mass of PMzs. The annual average of secondary organic carbon （SOC） concentrations in xiamen were 9.23-11.36 ~g/m3, accounting for approximately 56% of OC. Strong correlations between OC and EC was found in spring （R2 = 0.50） and autumn （R2 = 0.73）, suggesting that there were similar emission and transport processes for carbonaceous aerosols in these two seasons, while weak correlations were found in summer （R2 = 0.33） and winter （R2 = 0.41）. The OCI＇EC ratios in PM2.5 varied from 2.1 to 8.7 with an annual average of 5.7, indicating that vehicle exhaust, coal smoke and biomass burning were main source apportionments of carbonaceous fractions in xiamen.

关键词： fine particle carbonaceous aerosol organic carbon elemental carbon xiamen

A facile and general approach for the synthesis of fluorescent silica nanoparticles doped with inert dyes

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Chinese science Bulletin 2011年第31期56卷 3242-3246页

作者： MU Xue WU ChuanLiu LAI JinPing CHEN JianBin ZHENG JinSheng LI Chong ZHAO YiBing Department of Chemistry and the Key Laboratory of Analytical sciences of xiamen University College of Chemistry and Chemical EngineeringXiamen University Xiamen 361005 China

A general and facile approach was developed for the synthesis of almost monodisperse fluorescent silica nanoparticles (NPs) doped with inert dyes, which are organic fluorophores that are strongly fluorescent but are hydrophobic or lack a covalent binding group. The prepared NPs were mesoporous and the dye molecules were encapsulated in the pores via hydrophobic interaction with the CTAB template. The NPs were stable and highly fluorescent in aqueous solution, and have potential applications in bioanalysis and fluorescence encoding.

关键词：有机荧光染料纳米颗粒惰性合成硅胶轻便纳米粒子疏水相互作用