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研究了氮氧源大气压等离子体射流对表面大肠杆菌灭活作用,分析了氮氧源大气压等离子体射流的光谱性质。结果表明,在放电电压为6.8kV,气体流速为4L?min?1,处理3min时,氮氧比为1:4的大气压等离子体射流对大肠杆菌的灭活率达到98.4%,接近氧气源大气压等离子体射流灭菌效果。通过大气压等离子体射流发射光谱(OES)分析了氮氧源大气压等离子体射流中活性物质,进而解释大肠杆菌微生物灭活机理,认为NO?γ、OI、?OH等活性物质在表面大肠杆菌灭活过程中起到了重要作用。这将为大气压氮氧等离子体射流在环境卫生、微生物灭活等方面的应用研究提供实验基础和技术支持。 相似文献
165.
污泥内层和外层胞外聚合物的三维荧光光谱特性研究 总被引:4,自引:0,他引:4
运用三维荧光光谱技术对污泥LB-EPS和TB-EPS的荧光特性进行了研究.实验结果表明,在污泥LB-EPS和TB-EPS中都有三个明显的荧光峰,分别为Peak B(λex/λem=270~280 nm/345~360 nm),Peak C(λex/λem=330~340 nm/410~430 am)和Peak D(λex/λem=390 nm/450~470 nm).其中Peak B为类蛋白荧光(Protein-like)、Peak C为可见区类富里酸荧光(Visible fulvic-like)、Peak D为类腐殖酸荧光(Humic-like).从各荧光峰的荧光强度来分析,LB-EPS和TB-EPS中的主要成分都为类蛋白,然后依次为富里酸和腐殖酸.浓度和pH值对污泥LB-EPS和TB-EPS的三维荧光特性都有很大的影响,但影响程度略有区别,表明作为外层的胞外聚合物,LB-EPS表现出与TB-EPS不全相同的化学结构. 相似文献
166.
Oettel M Domínguez A Tasinkevych M Dietrich S 《The European physical journal. E, Soft matter》2009,28(2):99-111
The elastic and capillary interactions between a pair of colloidal particles trapped on top of a nematic film are studied
theoretically for large separations d. The elastic interaction is repulsive and of quadrupolar type, varying as d-5. For macroscopically thick films, the capillary interaction is likewise repulsive and proportional to d-5 as a consequence of mechanical isolation of the system comprised of the colloids and the interface. A finite film thickness
introduces a nonvanishing force on the system (exerted by the substrate supporting the film) leading to logarithmically varying
capillary attractions. However, their strength turns out to be too small to be of importance for the recently observed pattern
formation of colloidal droplets on nematic films. 相似文献
167.
W. Pogosov M. Combescot 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,68(2):183-192
By using the composite many-body theory for Frenkel excitons we have recently developed, we here derive the ground state energy
of N Frenkel excitons in the Born approximation through the Hamiltonian mean value in a state made of N identical Q = 0 excitons. While this quantity reads as a density expansion in the case of Wannier excitons, due to many-body effects induced
by fermion exchanges between N composite particles, we show that the Hamiltonian mean value for N Frenkel excitons only contains
a first order term in density, just as for elementary bosons. Such a simple result comes from a subtle balance, difficult
to guess a priori, between fermion exchanges for two or more Frenkel excitons appearing in Coulomb term and the ones appearing
in the N exciton normalization factor – the cancellation being exact within terms in 1/Ns where Ns is the number of atomic sites in the sample. This result could make us naively believe that, due to the tight binding approximation
on which Frenkel excitons are based, these excitons are just bare elementary bosons while their composite nature definitely
appears at various stages in the precise calculation of the Hamiltonian mean value. 相似文献
168.
Q. Xu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(3):387-392
The effects of the non-rotating wave approximation (non-RWA) on the
spontaneous emission of a V-type three-level atom are studied, where the
excited states are coupled to a common ground state by a weak laser field
and the upper-level doublet is driven by a strong microwave field. When the
non-RWA is applied to the interaction of the atom with the microwave field,
for some values of the parameters involved, the spontaneous emission
spectrum is comprised of a central peak and a series of sidebands with a
constant spacing of the microwave frequency, and the central peak and/or
sidebands can be split into two components. The physical interpretation of
the spectral characteristics is given in light of the dressed states. 相似文献
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