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The interactions of 2, 4-dinitrophenol and 2, 4-dichlorphenol with trypsin were investigated by fluorescence, synchronous
fluorescence, and three-dimensional fluorescence spectra techniques under physiological pH 7.40. The 2, 4-dinitrophenol and
2, 4-dichlorphenol effectively quenched the intrinsic fluorescence of trypsin via static quenching. The process of binding
2, 4-dinitrophenol and 2, 4-dichlorphenol with trypsin was a spontaneous molecular interaction procedure. The electrostatic
repulsion does favor the interaction between 2, 4-DNP and trypsin. However, the interaction of 2, 4-DCP and trypsin can be
explained on the basis of hydrogen bonding and van der Waals. The results of synchronous fluorescence spectroscopy and three-dimensional
fluorescence spectra indicated that the structure of these trytophan and tyrosine residues environments were altered by 2,
4-DNP and 2, 4-DCP. 相似文献
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室温下利用鞣酸(TA)既作还原剂又作保护剂,通过绿色还原方法制备了鞣酸包裹的金纳米粒子,并通过紫外可见光谱(UV-Vis)、透射电镜(TEM)、X射线衍射(XRD)、红外光谱(FTIR)等分别进行了表征和分析。结果表明,随着nTA/nHAuCl4比率的增加,紫外可见光谱显示鞣酸稳定的金溶胶最大吸收波长明显增大且吸收带变宽,而最大吸光率逐渐减小。TEM观察证实增加鞣酸用量会导致溶胶体系中花状金纳米聚集体的形成。实验发现,阳离子型表面活性剂十六烷基三甲基溴化铵(CTAB)对鞣酸保护的金纳米聚集体具有强烈的解聚集作用,在剧烈搅拌的条件下CTAB能使金纳米聚集体成功解聚为单分散状态的金纳米粒子,提高体系温度可明显促进CTAB对金纳米聚集体的解聚集作用。 相似文献
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Perturbation bounds of subspaces, such as eigen-spaces, singular subspaces, and canonical subspaces, have been extensively studied in the literature. In this paper, we study perturbations of some constrained subspaces of 1×2, 2×1, and 2×2 block matrices, in which only one of the sub-matrices can be changed. Such problems rise from the least squares–total least squares problem, the constrained least squares problem, and the constrained total least squares problem. 相似文献
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应用紫外光谱研究了离子液体和硝基苯的相互作用, 硝基苯的紫外光谱受离子液体的影响, 硝基的吸收峰红移, 末端吸收消失. 用循环伏安法研究硝基苯电还原过程中第2个电子转移的传递系数(α)随外界条件变化所呈现复杂的变化规律. 硝基苯和水的介电性质、硝基苯和水与离子液体的相互作用对α产生复杂影响. 硝基苯浓度增加使α减小, 离子液体的咪唑侧链增长也使α减小. 相同硝基苯浓度时, 水的浓度较低时, α随水的浓度增加变小; 水的浓度较高时, α随水的浓度增加稍微变大. 温度升高α值增大. 相似文献
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Xue-Rong Shi 《Nonlinear dynamics》2010,59(1-2):95-99
Bursting synchronization of Hind–Rose system is investigated. Two schemes with only a single controller are proposed to synchronize Hind–Rose chaotic system via the back-stepping method. Especially in the second scheme, only one state variable is contained in the controller. Based on Lyapunov stability theory, the sufficient conditions for synchronization are obtained analytically in both cases. Finally, numerical simulations are provided to show the effectiveness of the developed methods. 相似文献
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This work is concerned with anti-synchronization of Liu system and Lorenz system. Based on Lyapunov stability theory, different
controllers are designed to anti-synchronize the two non-identical chaotic systems, active control is used when parameters
are known, while the adaptive control law and the parameter update rule are derived via adaptive control when parameters are
uncertain. Moreover, the convergence speeds of the scheme can be adjusted by changing the control coefficients. Finally, numerical
simulations are also shown to verify the results. 相似文献