| Thesis Name：Measurement of the Phase Diagram of DNA Unzipping in the Temperature-Force Plane |
| Country：[CN] |
Usage：[Experimental] |
| Remarks： |
We separate double stranded lambda phage DNA by applying a fixed force at a constant temperature ranging from 15 to 50 °C, and measure the minimum force required to separate the two strands. The measurements also offer information on the free energy of double stranded DNA (dsDNA) at temperatures where dsDNA does not thermally denature in the absence of force. While parts of the phase diagram can be explained using existing models and free energy parameters, others deviate significantly. Possible reasons for the deviations between theory and experiment are considered. |
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| Thesis Name：Anomalous Diffusion in Living Yeast Cells |
| Country：[CN] |
Usage：[Experimental] |
| Remarks： |
The viscoelastic properties of the cytoplasm of living yeast cells were investigated by studying the motion of lipid granules naturally occurring in the cytoplasm. A large frequency range of observation was obtained by a combination of video-based and laser-based tracking methods. At time scales from 10–4 to 102 s, the granules typically perform subdiffusive motion with characteristics different from previous measurements in living cells. This subdiffusive behavior is thought to be due to the presence of polymer networks and membranous structures in the cytoplasm. Consistent with this hypothesis, we observe that the motion becomes less subdiffusive upon actin disruption. ©2004 The American Physical Society
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| Thesis Name：Scaling and Hierarchical Structures in DNA Sequences |
| Country：[CN] |
Usage：[Experimental; Theoretical] |
| Remarks： |
A method of analyzing DNA correlation structure is introduced. Density fluctuations of nucleotides are shown to display an extended self-similarity scaling when the scale varies between 100 and 8000 base pairs. The scaling is accurately described by a hierarchical structure model of She and Leveque [Phys. Rev. Lett. 72, 336 (1994)]. The derived model parameter is able to quantify moderately large-scale correlations which exist in a true DNA sequence but are absent in its randomly shuffled sequence and in a simulated model sequence by an evolution model of Hsieh et al. [Phys. Rev. Lett. 90, 018101 (2003)]. Finally, it is shown that varies with the evolution category and measures the organizational complexity of the genome. |
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| Thesis Name：Femtosecond Spectrotemporal Magneto-optics |
| Country：[CN] |
Usage：[Method; Experimental] |
| Remarks： |
A new method to measure and analyze the time and spectrally resolved polarimetric response of magnetic materials is presented. It allows us to study the ultrafast magnetization dynamics of a CoPt3 ferromagnetic film. The analysis of the pump-induced rotation and ellipticity detected by a broad spectrum probe beam shows that magneto-optical signals predominantly reflect the spin dynamics in ferromagnets. |
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| Thesis Name：Highly Fluorescent, Water-Soluble, Size-Tunable Gold Quantum Dots |
| Country：[CN] |
Usage：[Experimental] |
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Highly fluorescent, water-soluble, few-atom Au quantum dots have been created that behave as multielectron artificial atoms with discrete, size-tunable electronic transitions throughout the visible and near IR. Correlation of nanodot sizes with emission energies fits the simple relation, EFermi/N1/3, predicted by the jellium model. Providing the "missing link" between atomic and nanoparticle behavior in noble metals, these emissive, water-soluble Au nanoclusters open new opportunities for biological labels, energy transfer pairs, and light emitting sources in nanoscale optoelectronics. ©2004 The American Physical Society |
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| Thesis Name：The development of the research of peroxidases in mechanism and application |
| Country：[CN] |
Usage：[peroxidases in mechanism and application] |
| Remarks： |
On the basis of reading a large number of articles, we reviewed the development of the research in mechanism and application of several peroxidases. We made a compare the commonness and individuality of the peroxidases in the mechanism and the application. The insufficiency in the researches was pointed and a prospect of the researches, which we thought were necessary in these fields in the following years, was made in this review.
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| Thesis Name：Synthesis of derivatives of 2, 3, 5, 6-tetrachloromethylbenzene |
| Country：[CN] |
Usage：[Synthesis of derivatives] |
| Remarks： |
Synthesis of derivatives of 2, 3, 5, 6 - tetrachloro- methylbenzene with electron withdrawing groups was studied. Chlorination could not occur when there were two electron withdrawing groups in the para positions of benzene under designed condition. But if one of them was electron donating group such as methyl, high yield of chlorinated products could be gained in carbon tetrachloride and chlorosulphonic acid at a temperature from 50ºC to 55ºC, and catalyzed by iodine. The products were 2, 3, 5, 6-tetrachloro-4-methylbenzonitrile with yield of 96.3%, 2, 3, 5, 6 - tetrachloro-4- nitrotoluene with yield of 85.5%, 2, 3, 4, 5, 6-pentachloromethylbenzene with yield of 84.2%, and methyl 2, 3, 5, 6-tetrachloro-4-methylbenzoate with yield of 62.1%.
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| Thesis Name：Kinetics and mechanism of oxidation of 1,3-propylene glycol by dihydroxyditellutoargentate (III) in alkaline medium |
| Country：[CN] |
Usage：[Kinetics and mechanism of oxidation] |
| Remarks： |
The kinetics of oxidation of 1,3-propylene glycol(PG) by dihydroxyditellutoargentate(III) (DDA) was studied spectrophotometrically between 303.2K and 318.2K in alkaline medium. The reaction rate showed first order dependence in DDA and1.18-1.26 order in PG. It was found that the pseudo-first order rate constant kobs increased with an increase in concentration of [OH-] and a decrease in concentration of [TeO42-]. There was a negative salt effect and no free radical was detected. In view of this the dihydroxymonotelluratoargentate (III) species is assumed to be the active species. A plausible mechanism involving a two-electron transfer is proposed and the rate equations derived from mechanism can explain all experimental results. The activation parameters along with the rate constants of the rate-determining step were calculated.
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| Thesis Name：Visual detection of cysteine and homocysteine |
| Country：[CN] |
Usage：[Detection of cysteine] |
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Aldehyde moieties of xanthene dye react with cysteine and homocysteine producing their respective thiazolidines resulting in a colour change from yellow to brownish-orange.
There is little interference from other amino acids, amines and proteins with the selectivity of the dye to cysteine and homocysteine being confirmed by UV-vis absorbance measurements.
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| Thesis Name：Organic light-emitting diodes formed by soft contact lamination |
| Country：[CN] |
Usage：[Soft contact] |
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The method is based on physical lamination of thin metal electrodes supported by an elastomeric layer against an electroluminescent organic.
The technique of soft contact lamination (ScL) enables formation of electrical contacts at room temperature in ambient conditions. When the thin metal film and electroluminescent organic are sufficiently close van der Waals interactions pull them into intimate contact to complete the OLED.
In this study the elastomer used was PDMS (poly[dimethylsiloxane]) and the metal films were silver. The OLEDs formed by ScL display improved quantum efficiency compared to conventional devices. |
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