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51.
52.
Peter Gregorčič Rok Petkovšek Janez Možina Griša Močnik 《Applied Physics A: Materials Science & Processing》2008,93(4):901-905
We present an optodynamic measurement of a laser-induced cavitation bubble and its oscillations based on a scanning technique
using a laser beam-deflection probe. The deflection of the beam was detected with a fast quadrant photodiode which was built
into the optical probe. The applied experimental setup enabled us to carry out one- or two-dimensional scanning of the cavitation
bubble, automatic control of the experiment, data acquisition and data processing. Shadow photography was used as a comparative
method during the experiments. 相似文献
53.
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55.
首先制备了α-MnO2纳米花簇、β-MnO2纳米针和δ-MnO2微米颗粒三种不同晶型的MnO2粉末材料,对其结构、形貌及吸附除铵能力进行了表征和测试.结果表明,层间距(7.2Å)大于NH4+直径(2.96Å)和水合NH4+直径(6.62Å)的δ-MnO2相比其他两种晶型的MnO2有更高的NH4+吸附量;接着研究采用KMnO4原位氧化还原法在石墨毡(GF)上直接生长超薄δ-MnO2纳米片(MnO2NPs)阵列构筑了石墨毡载纳米MnO2(MnO2NPs/GF)多级结构材料,制备简单,无须成型造粒就可直接用作除铵净水材料,研究结果表明,MnO2NPs/GF不仅具有较高的吸附量(15 mg·g-1)与良好的选择性,同时还展现了优异的快速吸附和稳定的循环使用性能.MnO2NPs/GF对水中NH4+的吸附符合准二级动力学模型,其吸附等温线符合Langmuir吸附等温式,是吸附-离子交换法除铵的理想材料. 相似文献
56.
J. Říkovská A. Machová W. D. Hamilton J. Dupák Chan Chen Mo M. Finger N. A. Lebedev B. S. Neganov V. N. Pavlov A. F. Shchus 《Czechoslovak Journal of Physics》1979,29(6):620-639
The anisotropy of the angular distribution of gamma-rays from the decay of156Tb, oriented in a gadolinium matrix at low temperatures, has been measured at the angles of 0 and π/2 with respect to the applied magnetic field direction in the range of temperatures from 14·6 to 68·4 mK. The temperature dependence of anisotropy was measured for the first time. The parameters of hyperfine magnetic dipole and electric quadrupole splittings have been determined and the values of the magnetic dipole moment ¦Μ156¦=(9·6±1·3)×10?27 J/T and the electric quadrupole momentQ 156=(2·9±0·9)×10?28 m2 of the156Tb ground state have been calculated. Multipole mixing ratios andB(E2) branching ratios of many gamma-ray transitions occurring in156Gd have been found and the results have been discussed in terms of the rotational-vibration and pairing-plus-quadrupole models. 相似文献
57.
Asymptotic solution for a perturbed mechanism of western boundary undercurrents in the Pacific 总被引:1,自引:0,他引:1 下载免费PDF全文
This paper consider a class of perturbed mechanism for the western
boundary undercurrents in the Pacific. The model of generalized
governing equations is studied. Using the perturbation method, it
constructs the asymptotic solution of the model. And the accuracy of
asymptotic solution is proved by the theory of differential
inequalities. Thus the uniformly valid asymptotic expansions of the
solution are obtained. 相似文献
58.
非奇异H-矩阵的新判据 总被引:1,自引:0,他引:1
1引言与记号设A=(a_(ij))∈C~(n×n),记N={1,2,…,n},∧_i(?)∧_i(A)=sum from j≠i|a_(ij)|,S_i(?)S_i(A)=sum from j≠i|a_(ij)|,(?)i,j∈N。若|a_(ij)>∧_i(A),(?)i∈N,则称A为严格对角占优矩阵。 相似文献
59.
GENERALIZED SOLUTION OF SINGULARLY PERTURBED PROBLEMS FOR REACTION DIFFUSION EQUATIONS 总被引:2,自引:0,他引:2
Yao Jingsun Mo Jiaqi 《Annals of Differential Equations》2006,22(1):81-86
The singularly perturbed initial boundary value problem for reaction diffusion equation is considered. Under suitable conditions the existence, uniqueness and asymptotic behavior of the generalized solution for the problems are studied. 相似文献
60.
Controlled growth and field emission of vertically aligned AlN nanostructures with different morphologies 下载免费PDF全文
The controllable growth of three different morphologies of AlN
nanostructures (nanorod, nanotip and nanocrater) arrays are
successfully realized by using chemical vapour deposition (CVD)
technology. All three nanostructures are of single crystal h-AlN
with a growth orientation of [001]. Their growth is attributed to
the vapour-liquid-solid (VLS) mechanism. To investigate the factors
affecting field emission (FE) properties of AlN nanostructures, we
compare their FE behaviours in several aspects. Experimental results
show that AlN nanocrater arrays possess the best FE properties, such
as a threshold field of 7.2~V/μm and an emission current
fluctuation lower than 4%. Moreover, the three AlN nanostructures
all have good field emission properties compared with a number of
other excellent cathode nanomaterials, which suggests that they are
future promising FE nanomaterials. 相似文献