Preparation of Sm_(0.5)Sr_(0.5)CoO_3-La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3 Composite Cathodes Using Wet-chemistry Method and the Characterization of Their Properties

用湿化学法制备了Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)中温固体氧化物燃料电池复合阴极,其中SSC用甘氨酸-硝酸盐法合成,LSGMC5用柠檬酸盐法合成.XRD结果表明,甘氨酸-硝酸盐法制备的SSC在焙烧温度大于1223K即表现为单一的钙钛矿结构.随焙烧温度的升高,SSC粉末颗粒增大,导致相应电极与电解质的结合变差.复合电极的性能显著依赖于SSC粉末的焙烧温度,其中含1223K焙烧SSC粉末的电极表现出最小的欧姆电阻以及电极电阻.973K、氧气中、1A·cm-2电流密度下该电极的极化过电位仅为0.077V,远小于固相法合成的电极.Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5) composite cathodes for intermediate temperature solid oxide fuel cells were prepared using wet-chemistry method. The SSC powders were prepared using the glycine-nitrate method and the LSGMC5 powders were synthesized using the citrate method. The XRD pattern of SSC powders calcined at temperatures higher than 1223 K corresponded to a desired perovskite structure. With the increase in calcining temperature, the size of the SSC particles increased, which leaded to a weak adhesion to the electrolyte for corresponding electrodes. The performance of the SSC-LSGMC5 composite electrodes depended strongly on the calcining temperature of SSC powders, and the electrodes based on SSC calcined at 1223 K exhibited the lowest ohmic resistance and polarization resistance. The overpotential at 973 K in oxygen under 1 A· cm-2 current density was as low as 0.077 V, which was much lower than that of electrodes prepared using solid-state reaction.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

Effect of preparation method for LSGMC5 on the performance of SSC-LSGMC5 composite cathodes

制备了Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)中温固体氧化物燃料电池(ITSOFC)复合阴极,其中LSGMC5用柠檬酸盐法和固相合成法合成。含有柠檬酸盐法合成的LSGMC5粉末的SSC-LSGMC5电极的氧还原电催化性能明显优于含固相合成法合成的LSGMC5的电极。随着焙烧温度的升高,柠檬酸盐法合成的LSGMC5粉末的颗粒变大,并致密化,导致相应SSC-LSGMC5复合电极与LSGMC5电解质的结合程度减弱以及氧还原电催化性能变差。复合阴极中柠檬酸盐法合成的LSGMC5粉末的最佳焙烧温度约为1 000℃。Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5) composite cathodes for intermediate temperature solid oxide fuel cell(ITSOFC) were prepared.LSGMC5 powders were synthesized by the citrate method and the solid-state reaction.The oxygen reduction electrocatalysis activity of SSC-LSGMC5 electrodes containing LSGMC5 prepared by the citrate method was much higher than that containing LSGMC5 prepared by the solid-state reaction.With the increasing of the sintering temperature,the size of the LSGMC5 particles prepared by the citrate method increased and the particles were densification.The contact between the corresponding SSC-LSGMC5 composite electrode and LSGMC5 electrolyte was weakened,and the oxygen reduction electrocatalysis activity was reduced.The optimum sintering temperature for LSGMC5 powders prepared by the citrate method in the composite cathode was about 1 000 ℃.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

Improving the performance of SOFCs cathode by using an interlayer based on the electrolyte material

利用在SSC-LSGMC5复合电极与LSGMC5电解质片之间加入与电解质相同材料的夹层的方法,提高了电极性能。不同温度下,在LSGMC5电解质片上印刷了厚度为2~5μm的LSGMC5薄膜,在薄膜上印刷了SSC-15%LSGMC5复合电极,并进行了表征。SEM结果表明:当夹层焙烧温度大于1 400℃时,夹层为致密结构,并与电解质完好地结合在一起,夹层与电极的结合程度远优于无夹层的电极|电解质界面。在700℃纯氧条件下,夹层(1 400℃焙烧)的引入,使电极极化电阻由0.38Ω.cm2减小至0.12Ω.cm2,1 A/cm2下的极化过电位由0.23 V减小至0.10 V。LSGMC5 interlayer was added between SSC-LSGMC5 composite electrode and LSGMC5 electrolyte flake,which had improved the cathode performance.The LSGMC5 interlayer was sintered on the LSGMC5 electrolyte flake at various temperatures,the thickness was about 2～5 μm.The SSC-15% LSGMC5 composite electrode was printed on the sintered interlayer and its performance was analyzed.SEM images exhibited that LSGMC5 interlayer well coated on the electrolyte was dense while the interlayer was sintered at a temperature higher than 1 400 ℃.The coating degree of the electrode｜interlayer interface sintered at high temperatures was better than that of the electrode｜electrolyte interface without an interlayer.The polarization resistance of cathode decreased from 0.38 Ω·cm~2 to 0.12 Ω·cm~2 and the polarization over-potential under 1 A/cm~2 decreased from 0.23 V to 0.10 V at 700 ℃ in oxygen by using an LSGMC5 interlayer calcined at 1 400 ℃.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资助项

Separation of terpenes and oxygenated compounds from citrus oil by supercritical CO_2 extraction

以冷榨柑橘精油为原料,采用gC/MS对柑橘精油原料进行定性及定量分析,确定了柑橘精油中的7种萜烯类化合物成分作为分离考察对象。实验探讨了超临界萃取压力、萃取温度、萃取时间和CO2流量等因素对含氧化合物分离效果的影响。实验结果表明,萃取相中萜烯类化合物的回收率总体上随着萃取压力、温度、时间和CO2流量的增大而增大。当萃取压力为12MPA,萃取温度为45℃,萃取时间为4H以及CO2流量为1.0l/MIn时,分离效果最佳,其萃取相中萜烯类化合物的回收率高达90.03%。Supercritical CO2 extraction was employed to separate terpenes and oxygenated compounds from citrus oil.The raw oil,the extract,and the raffinate were qualitatively and quantitatively analyzed by GC/MS,respectively,with the terpenes being represented by seven typical compounds.The influences of several experimental factors including extration pressure,extraction temperature,extraction time and CO2 flow rate on the separation of the oxygenated compounds were studied.The results indicate that the recovery rate of terpenes in the extract generally increases with the increasing of extraction pressure,temperature,time and CO2 flow rate.The optimum conditions for extracting terpenes are as follows: pressure 12 MPa,temperature 45 ℃,extraction time 4 h,and CO2 flow rate 1.0 L/min.Under these optimum conditions,the recovery rate of terpenes in the extract is 90.03%.福建省新世纪人才支持项目(0000-X04157

Composite microparticles of ibuprofen/lipid generated by supercritical fluids from their melts

采用CO2及N2辅助的气体饱和溶液微粒形成技术制备布洛芬/肉豆蔻酸、布洛芬/三棕榈酸甘油酯复合微粒,考察它们的形态、颗粒分布以及复合微粒中药物的溶出情况。N2辅助过程制得的布洛芬(质量分数5%)/肉豆蔻酸复合微粒与用该过程得到的纯肉豆蔻酸大小及粒径分布大致相同,而CO2辅助过程制得的布洛芬/肉豆蔻酸复合微粒却要比该过程得到的纯肉豆蔻酸的粒径要大,分布也较宽;CO2及N2辅助形成的布洛芬/肉豆蔻酸复合微粒无缓释效果。用N2辅助制备得到的含20%布洛芬(质量分数)的复合微粒保持了三棕榈酸甘油酯微粒化后的颗粒形貌,粒径更大;用CO2辅助制备得到的含20%布洛芬的复合微粒其粒径比三棕榈酸甘油酯微粒化后的颗粒粒径要小,粒径分布更窄;布洛芬/三棕榈酸甘油酯复合微粒具有缓释效果,而且用N2辅助制备的布洛芬含量为5%的复合微粒比布洛芬含量为20%的复合微粒溶出慢。Using the CO2-assisted and N2-assisted atomization processes,ibuprofen/lipid composite microparticles can be produced;the lipid includes myristic acid(MA) and tripalmitin(TP).The ibuprofen(5% in mass ratie)/MA composite microparticles show similar particle sizes to that of pure MA from the N2-assisted process,while the composite microparticles have a large particle size and particle size distribution,compared to that of pure MA from the CO2-assisted process.The dissolution reveals no controlled release of ibuprofen for the ibuprofen/MA composite microparticles either from the N2-assisted process or from the CO2-assisted process.For the ibuprofen/TP system,the obtained composite microparticles containing 20%(in mass) ibuprofen show similar particle morphology,while has a larger particle size(PS) than that of the pure myristic acid particles in the case of N2-assisted process.Nevertheless,the microparticles from the CO2-assisted process has a small PS and narrow PSD,compared to that of the pure myristic acid particles.The obtained ibuprofen/TP composite microparticles containing 5% or 20% ibuprofen show an evidently controlled drug release.For example,the drug release is only 20% in 500 min for the ibuprofen/TP microparticles containing 20% ibuprofen,prepared by the CO2-assisted process.国家自然科学基金资助项目(20406015);; 福建省新世纪优秀人才支持计划;; 福建省自然科学基金资助项目(2007J0167

Preparation of Tripalmitin Micronization by Supercritical Fluids Technique

利用气体饱和溶液微粒形成技术实验装置,分别用超临界n2和超临界CO2制备三棕榈酸甘油酯微粒,探讨压力、温度以及喷嘴大小等工艺参数对微粒(粒径、粒径分布和形貌)的影响。结果表明:n2辅助过程得到的微粒基本为球状;预膨胀压力越高,粒径越小,粒径分布越窄;100μM喷嘴下制得的微粒粒径最小,且分布较均匀。CO2辅助过程得到的微粒部分为球状,部分为针状和片状;预膨胀压力越高,粒径越小,粒径分布越窄;喷嘴直径大小对微粒平均粒径及粒径分布影响不大;预膨胀温度升高,颗粒的粒径稍微增大。CO2辅助过程得到的微粒粒径比n2辅助过程得到的微粒粒径稍大,但两者的粒径分布相差不大。Generation of tripalmitin microparticles from its melts was investigated by using both supercritical CO2 and supercritical N2.The effects of various operating conditions,such as the pre-expansion pressure,pre-expansion temperature,and nozzle size on the particle morphology,particle size and particle size distribution(PSD) were investigated.Results showed that microspheres were obtained from the N2-assisted process,the particle size decreased and PSD narrowed with the increasing of the pre-expansion pressure,nozzle size showed no obvious effect on the microparticles,and pre-expansion temperature should be less than 72 ℃ to obtain solid particles.From the CO2-assited process,spherical,lamellate and needle-like particles were obtained,the particle size decreased,PSD narrowed with the increasing of the pre-expansion pressure,nozzle size showed no obvious effect on the particles and the pre-expansion temperature slightly increased the average size of particles.Particles' PSD from supercritical CO2 was close to that from supercritical N2

Preparation of Sm0.5Sr0.5CoO3-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 composite cathodes using wet-chemistry method and the characterization of their properties

Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5) composite cathodes for intermediate temperature solid oxide fuel cells were prepared using wet-chemistry method. The SSC powders were prepared using the glycine-nitrate method and the LSGMC5 powders were synthesized using the citrate method. The XRD pattern of SSC powders calcined at temperatures higher than 1223 K corresponded to a desired perovskite structure. With the increase in calcining temperature, the size of the SSC particles increased, which leaded to a weak adhesion to the electrolyte for corresponding electrodes. The performance of the SSC-LSGMC5 composite electrodes depended strongly on the calcining temperature of SSC powders, and the electrodes based on SSC calcined at 1223 K exhibited the lowest ohmic resistance and polarization resistance. The overpotential at 973 K in oxygen under 1 A . cm(-2) current density was as low as 0.077 V, which was much lower than that of electrodes prepared using solid-state reaction

钛酸纳米管前驱体水热制备TiO_2:水热媒介对结晶度及光催化活性的影响

以钛酸纳米管为先驱体,180℃24 h同一水热条件下,利用H2O、HNO3、KBF4以及HNO3+KBF4的4种水热媒介溶液,制备了高结晶度高光催化活性的TiO2,并研究了水热媒介对TiO2结晶度、表面羟基和光催化活性的影响。通过扫描电镜(SEM)、X射线衍射(XRD)、红外测试(FTIR)、X射线光电子能谱(XPS)、紫外可见漫反射吸收光谱(UV-Vis)进行了结构表征。光催化活性通过降解甲基橙溶液进行了评价。结果表明,与其他3种媒介相比,HNO3+KBF4溶液为水热媒介制备的锐钛矿晶型TiO2,结晶度高,表面羟基含量高,因此,呈现高的光催化活性

Extraction of insecticidal toosendanin from meliaceae by supercritical CO_2

王宏涛(1968-),男,博士,副教授,主要研究方向为天然产物的提取分离等, E-mail: [email protected]。[中文文摘]苦楝素是楝科植物中制备植物源农药的主要杀虫成分。针对不同种源楝树的皮、叶及果实,采用溶剂浸提法提取筛选苦楝素含量较高的种源作为实验原料,采用乙醇提取,考察液固质量比、提取时间和提取次数等参数对苦楝素提取率的影响。当液固质量比为25∶1、提取时间为4 h、提取次数为3次时,苦楝素的提取率达18%。进一步采用超临界CO2萃取考察压力、温度、萃取时间、原料粒径和夹带剂等参数对苦楝素萃取率的影响,当温度为40℃、压力为20 MPa、时间为2.0 h、原料粒径为40目、夹带剂乙醇质量为CO2质量的12.5%时,苦楝素的萃取率达43.5%。在对萃取液结晶纯化中成功分离得到质量分数达98%的苦楝素。[英文文摘]Toosendanin is the main insecticidal component of meliaceae plants for producing botanical insecticides.The extraction of toosendanin from the parks,leaves and fruits of the various meliaceae plants was studied by using ethanol,and the part of the meliaceae plants with the maximal mass fraction of toosendanin was selected as experimental materials.The effects of the mass ratio of liquid to solid,extraction time,and extraction times on the yield of toosendan were investigated by using ethanol extraction method. The yield of toosendanin is up to 18% at them ass ratio of liquid to so lid of 25:1, extraction time of 4h and extract ing 3 times. The effects of pressure, temperature, extraction time, and the partic le size of materials and the dosage of mod if iers on the yield of toosendanin w ere investigated bym eans of supercritical CO2 extraction. The yield of toosendan in is up to 43.5% when ethanol is used as mod ifier with its mass 12.5% of CO2 mass at temperature 40,pressure 20 MPa,extraction time 2h and material particle size 40 mesh. The toosendanin crystal with mass fraction 98% was separated from the extracts by using crystalliza tionm ethod.福建省新世纪人才支持计划项

闽南肝癌高发区肝细胞癌与HBV复制的相关性分析

目的分析闽南肝癌高发区乙型肝炎病毒 (HBV)复制与原发性肝细胞癌 (PHCC)的关系。方法用实时荧光定量聚合酶链反应 (PQ- PCR)技术测定 6 1例 PHCC患者、40 7例不同病程的 HBV感染者及 17例健康人血清中 HBV DNA的含量 ,对照分析 HBV标志物 (HBVM) ,同时检测 PHCC患者抗 - HCV- Ig G和 HCV RNA。结果PHCC组 HBV DNA阳性率高达 80 .3% (49/ 6 1) ,高于其他肝病组 ,差异具显著性 (P<0 .0 2 ) ,HBV DNA含量各组间差异无显著性。PHCC组抗 - HCV- Ig G和 HVC RNA阳性率为 0。结论闽南肝癌高发区 PHCC患者 HBV DNA阳性率较高 ,HBV感染并持续复制 ,可能是该地区 PHCC的主要致病因