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101.
Yi-Lu Sun Ren-Jang Wu Yu-Ching Huang Pi-Guey Su Murthy Chavali Yi-Zhen Chen Chu-Chieh Lin 《Talanta》2007,73(5):857-861
In situ preparation of polypyrrole (Ppy) by photo-polymerization coated on a quartz crystal microbalance (QCM) as a low humidity sensor was reported. Different concentrations of Ppy films say 0 wt.% (as blank), 0.1, 1, and 10 wt.% were investigated to measure humidity concentrations between 14.7 and 5412.5 ppmv. The adsorption/desorption behavior was also examined at humidity concentration 510.2 ppmv. The sensitivities of 0, 0.1 and 1 wt.% Ppy films at 51.5 ppmv were 0.143, 0.219 and 0.427, respectively. For 1 wt.% Ppy, the highest sensitivity was obtained. The slope and correlation coefficients (R2) for 1 wt.% Ppy at the ranges of 14.7–898.6 ppmv were 0.0646 and 0.9909, respectively. A series of molecular simulations have been carried out to calculate bond energy for the water molecule interaction with Ppy, which was found to be 3 kcal/mol indicating the existence of hydrogen bonding during the sorption process. Based on Langmuir isotherm adsorption assumption, for 0.1 and 1 wt.% Ppy films, the association constants were 2606.30 and 5792.98, respectively. This larger association constant for 1 wt.% Ppy film explains higher sensitivity. 相似文献
102.
The Morita-Baylis-Hillman reaction of cyclohexenone and p-nitro benzaldehyde is catalyzed by carrier proteins such as serum albumins or enzymes such as certain lipases, conversion of up to 35% and enantioselectivities of up to 19% being observed. 相似文献
103.
Yuri Vlasov 《Mikrochimica acta》1991,104(1-6):363-377
MOSFET-sensors can be considered as membrane-oxide-semiconductor field-effect transistors. MOSFETs can be divided into ISFETs, GasFETs, BioFETs, these sensors being sensitive to ion, gas, biomolecules respectively and there is also a possibility to fabricate MOSFET reference electrode (RefFET). The development and theoretical treatment of various type of MOSFET-sensors are presented in this paper. 相似文献
104.
Tin dioxide SnO2−δ is a pronounced n-type electron conductor due to its oxygen deficiency. This study investigates the rate of chemical diffusion of oxygen in SnO2−δ single crystals, which is a crucial step in the overall stoichiometry change of the material. The chemical diffusion coefficient Dδ was determined from conductivity- and EPR-relaxation methods. The temperature dependence was found to be . The dependence on crystal orientation, dopant content and oxygen partial pressure was below experimental error. The latter observation leads to the conclusion that the chemical diffusion coefficient is close to the diffusion coefficient of oxygen vacancies. Along with the relaxation process resulting from the chemical diffusion of oxygen, additional processes were observed. One of these was attributed to complications in the defect chemistry of the material. The relevance of the results for the kinetics of drift processes of Taguchi sensors is discussed. 相似文献
105.
A piezoelectric nucleic acid sensor was constructed ofr detection of tumor necrosis factor gene.Two methods were employed for immobilization of nucleic acid probe on gold electrode of piezoelectric crystal.The results show that polyethyleneimine adbesion and glutaraldehyde cross-linking method has higher sensitivity,stability and selectivity than protein A method.The solid-phase nucleic acid hybridization of oligo unclecotides and tumor necrosis factor target gene sequence were monitorde using this sensor.Tumor necrosis factor gene sequence(580bp) was detected by this nucleic acid sensor for the first time. 相似文献
106.
Vlatakis G. Skarpelis G. Stratidaki I. Bouriotis V. Clonis Y. D. 《Applied biochemistry and biotechnology》1987,15(3):201-212
The resolution of restriction endonucleases from the same microorganism is conventionally achieved by lengthy fractionation
protocols. We now report effective single-step procedures that exploit dye-ligand chromatography for the resolution and purification
of restriction enzymes. After suitable initial screening, we demonstrated that resolution of two restriction activites can
be achieved in one chromatographic step, and further purification can subsequently be effected using selected dye-adsorbents.
Accordingly, we resolved in one step, Hpa I from Hpa II, Hind II from Hind III, and Sac I from Sac II. Furthermore, a three-step
Chromatographic procedure has been developed to purify EcoRV suitable for commercial exploitation, as judged by the “overdigestion”
and “cut-ligate-recut” quality control tests. 相似文献
107.
108.
Mn( )能与许多氮氧化合物形成配合物 ,Wilde对 Mn( )与 2 ,2 -联吡啶及 1 ,1 -二氮杂菲的均配配合物作过详细研究 [1,2 ] ;Mn( )与 2 ,2 -联吡啶 - 1 ,1 -二氧化物 ( bipy O2 )的配合物也有综述 [3] .Mn( )与 bipy O2 的配合物大多是以 Cl O- 4、NO- 3、[Pt Cl4 ]2 -为阴离子 ,少数是卤离子 .它们均形成配位体数目为 3的单核螯合物 ,这些配合物是在水或乙醇中合成的 .Mn( )与 bipy O2 的多核聚合物还未见报道 .本文用 DMF为溶剂 ,以无水 Mn Cl2 和 2 ,2 -联吡啶 - 1 ,1 -二氧化物为原料 ,合成了 Mn( )与bipy O2 的三聚… 相似文献
109.
110.