STUDY ON THE NON-COVALENT INTERACTION OF APIGENIN MOLECULARLY IMPRINTED POLYMERS BY SPECTROMETRY

The non-covalent interaction between aPigenin （API） and different functional monomers （α-methylacrylic acid （MAA）, acrylamide （AM）, 2-vinylpyridine （2-Vpy） and combined functional monomers （AM/2-Vpy）） was determined by UV spectrometry, and a series of apigenin molecularly imprinted polymers （API-MIPs） was synthesized with different functional monomers through molecular imprinting technology. The relationship between the non-covalent interaction of template/functional monomer and absorption of MIPs also was studied. The results showed that the order of the strength of the non-covalent interaction between API and different functional monomers in tetrahydrofuran （THF） is as follows： 2-Vpy〉 AM/2-Vpy〉AM〉MAA, which is positive correlation to the absorption capability of corresponding MIPs, and 2-Vpy is the optimum functional monomer among the used monomer for preparing API- MIPs.     

Effect of compressed CO2 on the properties of lecithin reverse micelles

Lecithin is a very useful biosurfactant. In this work, the effects of compressed CO 2 on the critical micelle concentration (cmc) of lecithin in cyclohexane and solubilization of water, lysozyme, and PdCl 2 in the lecithin reverse micelles were studied. The micropolarity and pH value of the polar cores of the reverse micelles with and without CO 2 were also investigated. It was found that CO 2 could reduce the cmc of the micellar solution and enhance the capacity of the reverse micelles to solubilize water, the biomolecule, and the inorganic salt significantly. Moreover, the water pools could not be formed in the reverse micelles in the absence of CO 2 because of the limited amount of water solubilized. However, the water pools could be formed in the presence of CO 2 because large amounts of water could be solubilized. All of these provide more opportunity for effective utilization of this green surfactant. The possible mechanism for tuning the properties of the reverse micelles by CO 2 is discussed.     

Effect of compressed CO2 on the critical micelle concentration and aggregation number of AOT reverse micelles in isooctane

The effect of compressed CO2 on the critical micelle concentration (cmc) and aggregation number of sodium bis-2-ethylhexylsulfosuccinate (AOT) reverse micelles in isooctane solution was studied by UV/Vis and fluorescence spectroscopy methods in the temperature range of 303.2-318.2 K and at different pressures or mole fractions of CO2 (X(CO2)). The capacity of the reverse micelles to solubilize water was also determined by direct observation. The standard Gibbs free energy (DeltaGo(m)), standard enthalpy (DeltaHo(m)), and standard entropy (DeltaSo(m)) for the formation of the reverse micelles were calculated by using the cmc data determined. It was discovered that the cmc versus X(CO2) curve and the DeltaGo(m) versus X(CO2) curve for a fixed temperature have a minimum, and the aggregation number and water-solubilization capacity of the reverse micelles reach a maximum at the X(CO2) value corresponding to that minimum. These results indicate that CO2 at a suitable concentration favors the formation of and can stabilize AOT reverse micelles. A detailed thermodynamic study showed that the driving force for the formation of the reverse micelles is entropy.     

Crowding with nearest neighbors replacement for multiple species niching and building blocks preservation in binary multimodal functions optimization

This paper introduces a novel niching scheme called the q-nearest neighbors replacement (q-NNR) method in the framework of the steady-state GAs (SSGAs) for solving binary multimodal optimization problems. A detailed comparison of the main niching approaches are presented first. The niching paradigm and difference of the selection-recombination genetic algorithms (GAs) and the recombination-replacement SSGAs are discussed. Then the q-NNR is developed by adopting special replacement policies based on the SSGAs; a Boltzmann scheme for dynamically sizing the nearest neighbors set is designed to achieve a speed-up and control the proportion of individuals adapted to different niches. Finally, experiments are carried out on a set of test functions characterized by deception, epistasis, symmetry and multimodality. The results are satisfactory and illustrate the effectivity and efficiency of the proposed niching method.     

The performance of a fast testing system for illicit materials detection based on energy-dispersive X-ray diffraction technique

A prototype setup for detecting illicit materials by energy-dispersive X-ray diffraction (EDXRD) has been developed. The obtained results of NaCl by the equipment suggest that the total measurement system is reliable and can be used to detect different kinds of materials. The tests of TNT, methamphetamine and heroin are also performed on this equipment and the related EDXRD spectra are obviously influenced by the detecting angle and the X-ray sources. The detecting angle of 10° is more suitable for detecting TNT and methamphetamine, while 12° is better for heroin. Moreover, the curves of TNT, methamphetamine and heroin emitted by W target have more diffraction peaks than those emitted by Cu or Mo target, while the peak intensities of TNT and methamphetamine emitted by Mo are stronger than those emitted by Cu or W target. The curve of methamphetamine emitted by Mo target shows a special characteristic and exhibits a super strong diffraction peak located at 1.62 Å^{− 1}, which can be attributed to the effect arising from Mo kα and kβ.     

A new application of X‐ray scattering using principal component analysis – classification and identification of liquid precursor chemicals

X‐ray scattering (XRS) combined with principal component analysis has been utilized for classifying and identifying liquid precursor chemicals for the first time. The XRS spectra of some liquid precursor chemicals and normal materials were obtained by using an XRS system, and the profiles of scattering media distinctly reveal that the XRS spectra are unique corresponding to the specific liquid material. Furthermore, the obtained spectra were processed through principal component analysis by using the selected energy region in the spectra. The score plots of each substance were clustered together and almost coincident for the same liquid, implying good repeatability and reliability. As far as the different liquid materials are concerned, they could be classified into distinct groups according to their positions in the score plot. The score plots showed a clear classification and recognition of liquid precursor chemicals. This study demonstrates a possibility for analyzing different liquid materials, and it presents a new application for X‐ray spectroscopy. Copyright © 2012 John Wiley & Sons, Ltd.     

车载系统主被动联合振动控制研究

针对车载系统行进过程中产生的结构振动,提出被动隔振和主动减振相结合的方法对结构弹性振动和刚体振动进行抑制．一方面,针对结构弹性振动,在车载结构和车体之间安装隔振装置,选择合适的隔振器参数,对车载结构的弹性振动进行隔离．另一方面,结合刚体振动抑制的需求,进一步研究小阻尼隔振器带来的结构低频刚体振动．对隔振器和车载结构形成的新系统采用主动控制方法设计最优控制器,对这一类过驱动控制系统进行主动控制研究．通过主被动控制结合,实现车载结构全频段范围内的振动抑制,能够将系统刚体振动的位移均方根值抑制到无控制时的5%以下．     

Influence of uniaxial plastic deformation on surface magnetic field in steel

Under geomagnetic field, surface magnetization measurements were made on 1045 and a3 steels samples uniaxially deformed to differing magnitudes of plastic strain, to study the dependence of surface magnetic field and its distribution on plastic deformation. The results indicated initial increase in surface magnetic field with increasing plastic strain followed by a decrease at higher plastic deformation. At still higher plastic deformation, the surface magnetic field was found to be almost independent of plastic strain. In the middle part of the sample, the uneven plastic deformation interrupted the linear distribution of surface magnetic field. The behavior of surface magnetic field and its distribution with plastic deformation were largely controlled by the different mechanisms of interaction of domain walls with isolated dislocation, dislocation tangles and dislocation cellular structures.     

锌对动物免疫功能的影响

锌是机体必需的微量元素,它对动物免疫系统的正常发育和功能方面有重要作用。综述了微量元素锌对动物免疫器官、免疫细胞和免疫分子等的可能作用机制和对免疫功能的影响。