101 research outputs found
Study on the Preparation of Stir Bars for Sorptive Extraction Based on Molecularly Imprinted Polymers and Its Extraction Performance
搅拌棒固相萃取(stirbarsorptiveextraction,SBSE)是在固相微萃取(solidphasemicroextraction,SPME)技术的基础上,由SandraP等在1999年提出的新型前处理技术,该技术是集萃取、富集、净化为一体,具有操作简便、萃取容量大、重现性好和环境友好等优点,目前已应用到多个领域。但在搅拌吸附过程中,SBSE对目标物质没有选择性萃取的能力。 分子印迹聚合物(molecularlyimprintedpolymers,MIPs)是一种三维网状聚合物,兼备了生物识别体系和化学识别体系的优点,具有选择性高、稳定性好、机械强度高、制备简单等特点,可选择性...Stir bar sorptive extraction (SBSE) is a novel sample preparation technique that was introduced by Sandra’s group based on the same principles as those of solid phase microextraction (SPME). SBSE integrates extraction, enrichment and purification into a signal step. Because of simple operation, higher sample capacity, good reproducibility and environmentally friendly characteristics, SBSE has been...学位:理学硕士院系专业:海洋与环境学院环境科学与工程系_环境科学学号:2262009115121
Determination of bisphenol A in environmental water samples by stir bar sorptive extraction based on molecularly imprinted polymer
以双酚A(bPA)为单体,利用整体材料“原位“聚合技术制备以分子印迹聚合物为涂层的吸附萃取搅拌棒(MIP-SbSE),然后与高效液相色谱(HPlC)-二极管阵列检测器联用,探讨其对环境水样bPA的选择萃取性能。优化萃取过程中吸附和解吸时间、解吸液种类以及基底PH值和离子强度对目标化合物的选择吸附性能。在最佳条件下,MIP-SbSE可对模板分子进行有效的选择吸附,线性范围为1.0~200μg/l,检出限(S/n=3)和定量限(S/n=10)分别为0.28μg/l和0.94μg/l。在实际水样分析中,具有良好的加标回收率,其值为96.0%~108.7%。研究结果表明,所建立的方法具有简便、灵敏和环境友好等特点。A new stir bar sorptive extraction (SBSE) based on molecularly imprinted polymer (MIP) with bisphenol A as template was prepared.Based on it,a simple,selective and sensitive method for the determination of bisphenol A (BPA) was developed combined with high performance liquid chromatography (HPLC) with diode array detection.To achieve the optimum extraction performance,several main parameters,including extraction and desorption time,the nature of desorption solvent,pH value and contents of inorganic salt in the sample matrix,were investigated.The optimized parameters for the extraction of BPA from water matrix with the MIP-SBSE are as follows: extraction and desorption time were 120 min and 10 min,respectively; the pH value of matrix was 10.0; using acetonitrile (including 1% acetic acid) as desorption solvent; no salt was added in the matrix.Under the optimized experimental conditions,the method showed good linearity between 1.0-200 μg/L.The detection limit (S/N=3) and quantification limit (S/N=10) of the proposed method for the BPA was 0.28 μg/L and 0.94 μg/L,respectively.The proposed method was successfully applied to the determination of the target compound in water samples.The recoveries of spiked target compound in real samples ranged from 96.0%-108.7%.The results indicated that the developed method possessed the advantages such as high sensitivity,simplicity,low cost and environmental friendliness.国家自然科学基金项目(No.20805039);福建省青年科技人才创新项目(No.2006F3117
用荷瘤裸鼠模型研制抗人肝癌单克隆抗体
1985年Watanabe等报道:用去胸腺载瘤小鼠的脾细胞与小鼠骨髓瘤细胞SP 2/0融合获得抗结肠癌单克隆抗体之后,利用荷瘤裸鼠模型成功研制抗人肿瘤单抗的报道已相继出现:但所获单抗多为IgM,IgG类的单抗得率不高,本工作采用多次手术大部切除瘤块的方法延长荷瘤裸鼠的成活期,获得一株抗人肝癌IgG类单抗、其研制过程和结果报道如下
表面氧浓度对负载型金属催化剂活化甲烷反应性能的影响
利用脉冲 质谱在线分析技术考察了无气相氧条件下负载型金属催化剂上脉冲CH4的反应结果表明 ,对于Rh/SiO2 催化剂 ,不管是氧化态还是还原态 ,除第 1次脉冲生成较多的CO2 外 ,从第 2次脉冲开始 ,只有CO生成 ;对于Ru/SiO2 催化剂 ,无论是氧化态还是还原态 ,每次脉冲均有一定量的CO2 生成 .这可能是由于Rh和Ru两种金属对氧的亲合力不同所致 .甲烷在负载型催化剂表面的活化以及产物的选择性主要受催化剂表面活性氧物种覆盖度的影响
甲烷在Rh/SiO_2催化剂表面解离的红外光谱研究
FT-IR spectroscopy is employed to investigate the methane dissociation and methane partial oxidation over the Rh/SiO 2 catalyst. When CH 4 is adsorbed onto the catalyst surface, it dissociates into adsorbed CH x (x=1~3) and atomic hydrogen on Rh surface. Atomic hydrogen can diffuse from Rh surface to SiO 2 surface where a proton exchange reaction of H with the surface Si-OH occurs, or it reacts with the lattice oxygen of SiO 2 to form new Si-OH
表面氧浓度对负载型金属催化剂活化甲烷反应性能的影响
利用脉冲 质谱在线分析技术考察了无气相氧条件下负载型金属催化剂上脉冲CH4的反应结果表明 ,对于Rh/SiO2 催化剂 ,不管是氧化态还是还原态 ,除第 1次脉冲生成较多的CO2 外 ,从第 2次脉冲开始 ,只有CO生成 ;对于Ru/SiO2 催化剂 ,无论是氧化态还是还原态 ,每次脉冲均有一定量的CO2 生成 .这可能是由于Rh和Ru两种金属对氧的亲合力不同所致 .甲烷在负载型催化剂表面的活化以及产物的选择性主要受催化剂表面活性氧物种覆盖度的影响
Analysis of buckling deformation of positive plates during formation at low temperature
[中文文摘]在低温条件蓄电池生产中,极板化成时经常产生正极板弯曲的现象。对此进行了研究,发现在低温下,电化学反应形成了致密的结晶,很难形成颗粒状的活性物质和分布均匀的孔隙,产生的应力无法释放;低温下化成的极板内部和极板外部的成分差异很大,也是产生应力的因素之一,这些应力导致了极板的变形。[英文文摘]During battery production at low temperature, buckling phenomenon of positive plates often
appeared due to the formation of plates. Research showed that electrochemical reaction formed the dense
crystals at low temperature. It is difficult to form the granular active materials and uniform distributed
porosity, so that the resulted stress could not be released. During formation at low temperature, the
difference of components between the internal and external plates was remarkable. This was also one of the
factors of resulting in stress which lead to the deformation of plates
第十八届美国理论与应用力学大会总结
1会议概况2018年6月5—9日,第18届美国理论与应用力学大会(18th U.S. National Congress of Theoretical and Applied Mechanics, USNCTAM2018)在美国芝加哥召开.本次大会由美国力学国家委员会和中国力学学会联合主办,旨在探讨和交流近四年世界范围内在理论和应用力学领域的基础研究、创新技术的最新进展,吸引了来自世界各地的近千名专家学
Effect of surface oxygen concentration on activation of methane over supported metal catalysts
Activation of methane over supported metal catalysts was investigated using MS-pulse technique on-line. Oxygen-free CH4 pulsing reactions were carried out over both Rh/SiO2 and Ru/SiO2 at 700 degreesC. Large amounts of CO and CO2 were observed at the first pulse of CH4 over oxidized Rh(O)/SiO2 catalyst. However, no CO2 formation was observed at the second pulse and thereafter. Similar to the response of Rh(O) /SiO2 catalyst, the intensity of CO and CO2 was strong at the first pulse over reduced Rh/SiO2 catalyst, and CO2 appeared also only at the first pulse over Rh/SiO2 catalyst. No CO2 was detected at the second pulse and thereafter. CH4 pulsing over Ru(O)/SiO2 catalyst also produced CO and CO2. CO and CO2 were detected from the first pulse I and their intensity was much stronger than that of CO and CO2 produced over Rh/SiO2 catalyst. However, unlike Rh/SiO2 catalyst, CO2 was formed at every pulse over Ru(O)/SiO2 catalyst. Pulsing CH4 over Ru/SiO2 catalyst also produced both CO and CO2 at every pulse. This difference between Rh and Ru catalysts may be due to the difference in the bond strength of Ru-O (528.4 kJ/mol) and Rh-O (405.1 kJ/mol) and in their relative oxygen affinities, Ru-0 can be more easily oxidized by O-2 than Rh-0 owing to the greater oxygen affinity of Ru. Surface oxygen should play an important role in the activation of methane and the product distribution
纪念五四宪法颁布暨全国人民代表大会成立五十周年理论研讨会纪要
今年 9月是五四宪法颁布、全国人民代表大会成立五十周年。五四宪法是新中国的第一部宪法 ,为我国的社会主义民主法制奠定了基础 ,具有划时代的意义。坚持和完善人民代表大会制度 ,是新的历史条件下推进政治体制改革和社会主义政治文明建设的重要内容。基于“以学术表达纪念、以纪念促进学术”的目的 ,中国社会科学院法学研究所于 2 0 0 4年 9月 5日举办了“纪念五四宪法颁布暨全国人民代表大会成立五十周年理论研讨会”。来自全国各地的 70余位代表莅临会议 ,研讨了诸多热点和前沿问题
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