发光多孔硅的制备及其电化学成膜机制研究

研究了阳极氧化法制备多孔硅的工艺，表面形貌及电化学成膜机制。     

手性配体交换乳状液膜选择性萃取扁桃酸对映体

基于手性配体交换反应,研究了在含有N-n-十二烷基-L-羟基脯氨酸和铜离子的配合物为手性配体的乳状液膜体系中选择性萃取扁桃酸对映体.考察了扁桃酸外消旋体浓度,手性萃取方向,有机溶剂和表面活性剂配比,从外水相到内水相pH值的梯度变化以及外水相的pH值变化对选择性萃取性能的影响,从而确定了合适的选择性萃取条件.     

CdSe/ZnSe量子点的制备及电化学发光性能

利用ZnSe半导体纳米材料晶体结构与CdSe相似、带隙更宽的特点,采用水热法合成了核-壳型CdSe/ZnSe量子点。结果表明：温度在70~160℃时,ZnSe壳逐渐包裹在CdSe核上,反应时间在0~4 h时,内壳在核上是均匀包裹的,当核壳摩尔比为1∶3时,CdSe/ZnSe QDs的电化学发光性能最强,其电化学发光强度是CdSe量子点的6倍,且发光信号稳定。     

铕(Ⅲ)激活铌酸钇的发光

在使用Li_2So_4作助熔剂的条件下,由相应的氧化物高温合成了Y_(1-x)Eu_xNbO_4(0≤x≤0.30),研究了各试样的光致发光。254nm紫外光激发下的发射光谱包括两个部分:位于330～480nm的弱发射谱带,相当于NbO_4基团的电荷转移态跃迁发射;在535～720nm之间有5组锐线状发射光谱,分别归属于Eu~(3+)的~5D_1—~7F_j(j=1,2,3)和~5D_o—~7F_j(j=1,2,3,4)跃迁发射,其中主发射峰是位于612.7nm的~5D_o—~7F_2跃迁发射。~5D_o—~7F_2发射的激发光谱包括NbO_4基团电荷转移态的强激发带,和一些Eu~(3+)f—f跃迁弱激发锐线谱。随着Eu~(3+)浓度的增大,两种激发都逐渐增强,这表明光致发光过程中存在着能量由NbO_4→Eu~(3+)的传递。当Eu~(3+)浓度大于0.15mol时发生发光的浓度猝灭。     

电化学腐蚀对Si：Er^3＋材料中Er^3＋发光的影响

利用离子注入技术在硅片表面制备了不同Ｅｒ＾３＋注入剂量的Ｓｉ：Ｅｒ＾３＋样品，研究了电化学过程对Ｓｉ：Ｅｒ＾３＋样品中Ｅｒ＾３＋发光的影响。样品低温红外光致发光实验证明：电化学过程同样在Ｓｉ：Ｅｒ＾３＋样品的硅基质晶体中引入了大量的深能级局域态，且这些局域态较难用退火方式进行控制。     

钴镍掺杂锰酸锂的电化学性能研究

采用固相烧结法分别制备了钴掺杂和镍掺杂锰酸锂锂离子电池正极材料,同时制备了纯相锰酸锂进行比较.用电感耦合等离子发射光谱仪、X射线衍射仪、电子扫描电镜和电池性能测试系统对产物的组成、结构特征、微观表面形貌和恒流充放电性能进行了表征.结果表明:所制备的掺杂锰酸锂LiMn0.9 Ni0.1O2、LiMn0.9 Co0.1O2的结晶度高,无杂质相,材料颗粒的粒径均匀、表面光滑;首次放电比容量分别为114.7mAh/g和110.8mAh/g(0.5mA/cm,2.8~4.4V,vs.Li+/Li);50次循环后,放电比容量为107.2mAh/g和103.3mAh/g,50次循环比容量保持率分别达到94.1%和95.4%.     

载铂钴酸镧的制备与电化学性能

采用乙二醇还原法在钴酸镧表面上沉积铂,制备了载铂20%的载铂钴酸镧复合材料Pt-LCO/C。采用X射线粉末衍射、透射电子显微镜研究了载铂钴酸镧的结构与形貌,发现铂在钴酸镧中的分散性好,获得的铂金属颗粒仅2nm,且颗粒大小均匀。采用循环伏安法研究了载铂钴酸镧复合材料的电化学性能和对甲醇的电化学氧化行为。研究表明,载铂钴酸镧复合材料具有很好的扩散性能,具有优良的电催化氧化甲醇的性能。     

化妆品和食品中曲酸的高效液相色谱——电化学安培检测方法

本文提出用高效液相色谱———安培检测食品或化妆品中曲酸的新方法。采用玻碳电极氧化电流1.1V检测,使用C18柱,流动相为20mMKH2PO4(pH=3)。在20μL进样下,检测限可达0.2ng,线形范围0.2ng~2μg。方法回收率为86~91%。方法具有选择性好,灵敏高的优点。     

Clean esterification of mandelic acid over Cs2.5H0.5PW12O40 supported on acid treated clay

Several esters of mandelic acid are valuable precursors in a number of processes. Esterification is rampantly employed in the production of fragrances, flavors, plastics, pharmaceuticals and plasticizers. For instance, methyl mandelate is used as a precursor in the synthesis of pemoline, a CNS stimulant, and also plays a vital role in artificial flavoring and perfumes. Esters are normally produced by reaction of carboxylic acids and alcohols catalyzed by homogeneous mineral acids, which are fraught with contamination of the product and post-treatment pollution problems. A process for clean esterification of mandelic acid with methanol to produce methyl mandelate was developed by using novel solid acids such as Cs_2.5H_0.5PW₁₂O₄₀/K-10 clay, UDCaT-1 and sulfated zirconia. All of them are reusable and efficient catalysts. However, the activity of Cs_2.5H_0.5PW₁₂O₄₀/K-10 clay was superior to the rest. Cs_2.5H_0.5PW₁₂O₄₀/K-10 clay is a recyclable nano-catalyst. The effects of various parameters were studied to deduce the intrinsic kinetics of the reaction.     

Ultraweak emission of the Eu(III) ions in cathodic generated electrochemiluminescence

High voltage cathodic generated electrochemiluminescence (ECL) of selected systems generating weak photon emission was studied. The investigated systems contained europium salts, and co-reactants: H₂O₂ and K₂S₂O₈.During the cathodic pulse polarization of an oxide-covered working aluminum electrode, hot electrons in metal may enter the conduction band of water through the oxide layer/solution interface and turn into hydrated electron after salvation. The ECL intensity and spectra was measured though a suitable cut-off filters, with a photon counting unit attached to a PC computer.On the basis of the analysis of the spectra in particular systems, emitters were identified and simplified scheme of the processes was proposed. The Eu(III)-specific electro generated luminescence is produced via several parallel mechanisms, which usually involve a type of the co-reactant, oxidation state changes of europium ions in aqueous solution and the influence of working electrode surface emission.     

高效毛细管电泳法测定杀菌防腐剂中的苯甲酸和水杨酸

本文研究了用高效毛细管电泳(HPCE)法测定苯甲酸和水杨酸的最佳分离条件。将该方法用于杀菌防腐剂中的苯甲酸和水杨酸的测定时,具有快速、简单、试剂用量少等特点。     

苦杏仁酸对褐飞虱取食行为影响的刺探电位测试分析

应用刺探电位图谱(EPG)技术研究了在液态人工饲料中褐飞虱(Nilaparvata lugens)口针的刺探行为,对出现的波形进行了定义,从各波形占总时间的比率、各波形的平均时间、能够产生N2波和E波的个体比例等方面进一步研究和分析了褐飞虱在不同质量浓度苦杏仁酸-蔗糖取食液中的取食行为,并应用铷元素标记法验证了EPG结果.结果表明,褐飞虱取食液态人工饲料主要出现5种波形,即N1波、N2波、N3波、E波以及非刺探波np波.在苦杏仁酸质量浓度为1.0 mg/ml时,褐飞虱取食的路径波(N2波)持续时间由空白对照的22.85 min显著延长到64.65 min,占总时间比率由对照组的10%上升至25%,而取食波(E波)缩短为9.75 min,占总时间比率由对照组的37%下降至4%,E波出现的频率由对照组100%下降至42%.苦杏仁酸对褐飞虱具有一定的拒食效果,随苦杏仁酸质量浓度的升高拒食效果更为明显,铷元素标记法测定的结果与EPG检测的E波结果基本一致,证实了EPG检测结果的可靠性.     

Chiral recognition of mandelic acid by L-MA derivative-modified sensor in liquid environment

This study demonstrates a new approach for the highly selective molecular recognition of chiral mandelic acid using an L-mandelic acid derivative with an optically active hydroxyl group as the selector. The proposed method is based on quartz crystal microbalance (QCM) detection combined with functional multilayer film techniques in a liquid environment. The present chiral recognition results suggest that the L-mandelic acid derivative is an excellent resolving agent for detecting chiral mandelic acid.     

固相萃取-液相色谱法测定糕点中脱氢乙酸、苯甲酸、山梨酸的方法研究

建立了固相萃取-高效液相色谱法测定糕点中的脱氢乙酸、苯甲酸、山梨酸的方法。实验结果表明,在(0.02～0.15)mg/mL时有良好的线性关系(r>0.997),相对标准偏差(RSD)为1.0%～2.5%,回收率96.2%～102.1%。该方法简单、快速、灵敏度高,并具有良好的精密度与准确度,可作为糕点中检测防腐剂的有效定量方法。     

Determination of DNA methylation using electrochemiluminescence with surface accumulable coreactant

Cytosine methylation in DNA was determined by an enzyme linked immunosorbent assay (ELISA) with electrochemiluminescence (ECL) detection and employed for the DNA methylation assay of a long and real genomic sample for the first time. The developed method employed an antimethyl cytosine antibody labeled with acetylcholinesterase, which was added to recognize single methylated cytosine in a DNA oligomer. The acetylcholinesterase converted acetylthiocholine (substrate) to thiocholine (product), which was accumulated on a gold electrode surface via gold-thiol binding. This surface accumulated preconcentration made it possible to observe bright and distinctive ECL by applying a potential to the gold electrode in the presence of a tris(2,2-bipyridyl)ruthenium complex luminophore when the analyte DNA contained a methylation region. Methyl-cytosine was measured quantitatively in the 1-100 pmol range, which exhibits sufficiently high sensitivity to achieve real DNA measurements without amplification by a polymerase chain reaction (PCR). The proposed ECL method also exhibited high selectivity for methyl-cytosine against nonmethylated cytosine, guanine, thymine, and adenine nucleotides. Finally, original and methylated DNA samples were clearly distinguished with our method using a real DNA bacteriophage sample (48,502 base pairs).     

膜去溶进样高分辨ICP-MS测定半导体级硝酸中杂质元素

利用高分辨电感耦合等离子体质谱测定半导体级高纯硝酸中的痕量金属杂质,用膜去溶进样系统直接进样,用标准加入法进行上机检测,无需前处理,快速,避免了在样品前处理时的污染问题。高分辨电感耦合等离子体质谱可以消除多分子离子干扰,降低检出限,提高定量准确性。方法的检出限为0.69～23.73ng/L,加标回收率为88.2%～106.0%,方法简单,结果可靠,适用于高纯硝酸中痕量元素的快速测定。     

Chemical oxidation of p-hydroxyphenylpyruvic acid in aqueous solution by capillary electrophoresis with an electrochemiluminescence detection system

A system of capillary electrophoresis with electrochemiluminescence detection (CE-ECL) together with UV spectroscopic and electrochemical methods were used to study the chemical oxidation of p-hydroxyphenylpyruvic acid (pHPP) by dissolved oxygen in aqueous solution. The pHPP was observed to be readily oxidized by dissolved oxygen in alkaline solution and yielded a compound that strongly enhanced the electrochemiluminescence of Ru(bpy)23+. This compound was separated and detected by a new CE-ECL system and revealed to be oxalate by being compared with an authentic sample of oxalate. The chemical oxidation mechanism of pHPP by dissolved oxygen was discussed in this paper.