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951.
用原子吸收法对使用T(Cu)200和T(Cu)220型宫内节育器妇女的围排卵期宫颈粘液中铜离子浓度进行测定,以自身未带器前(O期)为对照。结果,带器者在第1,3,6,12,18个月宫颈粘液铜离子的平均浓度分别为;3.188,2.695,2.323,2.247,2.116μg/g粘液湿重,与未带器前含铜量(0.818)相比,均有非常显著性差异(P<0.01),铜离子释放量随时间延长而逐渐减少。 相似文献
952.
以二乙氨基乙基交联葡聚糖凝胶为基质的铝荧光传感层 总被引:1,自引:0,他引:1
本文基于Al^3+离子对电价键固定在二乙氨基乙基交联葡聚糖凝胶上的水杨基荧光 酮的可逆荧光淬灭作用,研制了测定Al^3+离子浓度的荧光传感层。 相似文献
953.
团簇结构测量是团簇科学研究中的一个重要课题。文章对近几年发展的注入离子漂移管技术进行了详细介绍与分析,该技术是上前测量团簇结构近似程度最高的技术,已在C,Si,Ge及Al等原子团簇的结构研究中获得广泛应用,并取得了许多重要结果。 相似文献
954.
Pramana - In the present work computer simultations of the back sputtering of low energy neon ions with low impact parameter and the penetration of the same for higher values of the impact... 相似文献
955.
We analyze a scheme, originally suggested by Smoluchowski, by which a diffusion coefficientD can be estimated by measuring the number of particles occupying a fixed region of a surface at various times. An expression is derived relating the variance of the estimated valueD to several experimental parameters. This expression is evaluated numerically to determine how statistical uncertainty depends on adjustable variables. Particular attention is given to experiments involving locomotion of migrating leukocytes. 相似文献
956.
Birczyński A Lalowicz ZT Olejniczak Z Stoch G Petelenz B 《Solid state nuclear magnetic resonance》2005,28(2-4):142-159
Partially deuterated ammonium compounds contain ammonium ion isotopomers with relative abundances given by the binomial distribution of protons and deuterons. All isotopomers with deuterons contribute characteristic deuteron NMR spectra at 5K. Experimental NMR spectra were separated and respective contributions of isotopomers were determined. The derived contributions agree with expected values for a given deuteration in the case of ammonium hexafluorophosphate. In ammonium hexachlorotellurate both NH2D2+ and about 50% of NH3D+ ions are rigid, while the remaining NH3D+ perform limited jumps. NHD3+ and ND4+ ions undergo tunnelling rotation, NH3D+ ions perform either jumps about C2 axis or limited jumps, but some stay rigid in ammonium hexachlorostannate. NH2D2+, NHD 3+ and ND4+ undergo rotational tunnelling. In the case of ammonium perchlorate, the NH3D+ ions perform either jumps about C3 axis or limited jumps whilst some remain rigid. Very low values of activation energies were derived for all spectral components from the temperature dependence of their spectra, up to about 20K, which indicates an incoherent tunnelling nature of the observed dynamic processes. The diverse mobility of NH3D+ ions appears to be the most interesting and new feature. 相似文献
957.
V.?N.?PopokEmail author A.?L.?Stepanov V.?B.?Odzhaev 《Journal of Applied Spectroscopy》2005,72(2):229-234
We have investigated the process of metal nanoparticle (NP) synthesis in SiO2 by implanting Ag+ ions with an energy of 30 keV depending on the dose ((2–8)·1016 cm−2) and the ionic current density (4–15 µA/cm2). Analysis of the composite materials formed was performed with the use of optical spectroscopy and atomic-force microscopy (AFM). The NPs synthesized in the glass demonstrate a characteristic absorption line associated with the surface plasma resonance effect. A correlation of the spectral shift of the lines caused by a change in the NP size with the diameter of the hemispherical asperities on the SiO2 surface registered by the AFM method has been revealed. It has been found that for the case of a fixed current density in the ion beam the silver NP sizes remain practically unaltered with increasing ion dose up to a certain value (6·1016 cm−2), and only an increase in the concentration of NPs is observed thereby. However, a further increase in the dose causes a decrease in both the NP density and size. On the other hand, at a fixed high dose an increase in the ionic current density leads to a gradual enlargement of the NPs. We have considered the mechanisms explaining the change in the NP sizes with increasing dose and ionic current density and evaluated the possibilities of carrying out controlled synthesis by varying the implantation conditions.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 2, pp. 218–223, March–April, 2005. 相似文献
958.
K.?V.?Zubowa A.?V.?Zubow V.?A.?ZubowEmail author 《Journal of Applied Spectroscopy》2005,72(6):840-847
Using the flicker-noise method (FNM), we investigated the oscillations of clusters in aqueous solutions of NaCl in the range
of concentrations from 0.1 to 26.0 mass %. It has been established that in the solutions oscillators whose masses are similar
to the masses of the models of aggregates of solvate clusters of ion pairs (SCIP) of salt with a different water content are
present. In diluted solutions (<10%), the elementary SCIP has the form NaCl· 40H2O. For the entire range of concentrations the SCIPs are given by structures based on the cubic system of the sodium chloride
system. The base structure for them is a cube formed from 12 SCIPs of salt. The largest cluster revealed by the FNM method
for all investigated concentrations of salt had a mass of ≈1.5 million D. The presence of NaCl in water leads to a collapse
of its cluster structure, except for the smallest clusters (H2O)10…11, whose concentration increases with temperature or solution concentration. The distribution of SCIPs changes dramatically
at a temperature above 300 K. The possible structures of SCIPs are given and the mechanism of their formation is discussed.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 766–772, November–December, 2005. 相似文献
959.
In this paper we rigorously establish the existence of the mobility coefficient for a tagged particle in a simple symmetric exclusion process with adsorption/desorption of particles, in a presence of an external force field interacting with the particle. The proof is obtained using a perturbative argument. In addition, we show that, for a constant external field, the mobility of a particle equals to the self-diffusivity coefficient, the so-called Einstein relation. The method can be applied to any system where the environment has a Markovian evolution with a fast convergence to equilibrium (spectral gap property). In this context we find a necessary relation between forward and backward velocity for the validity of the Einstein relation. This relation is always satisfied by reversible systems. We provide an example of a non-reversible system, where the Einstein relation is valid.This revised version was published online in March 2005 with corrections to the page numbers. 相似文献
960.