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81.
X. M. Chen J. X. Shao Z. H. Yang H. Q. Zhang Y. Cui X. Xu G. Q. Xiao Y. T. Zhao X. A. Zhang Y. P. Zhang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):281-286
Al K-shell X-ray yields are measured with highly charged Arq+ ions
(q=12–16) bombarding against aluminium. The energy range of the Ar
ions is from 180 to 380 keV. K-shell ionization cross sections of aluminium are also obtained from the yields data.
The experimental data is explained within the framework of 2pπ
-2pσ rotational coupling. When Ar ions with 2p-shell vacancies are
incident on aluminium, the vacancies begin to reduce. Meanwhile, collisions
against Al atoms lead to the production of new 2p-shell vacancies of Ar
ions. These Ar 2p-shell vacancies will transfer to the 1s orbit of an Al
atom via 2pπ-2pσ rotational coupling leading to the emission of
a K-shell X-ray of aluminiun. A model is constructed based on the base of
the above physical scenario. The calculation results of the model are in
agreement with the experimental results. 相似文献
82.
We present what we believe to be the first morphological evidence for the occurrence of surface pre-melting on the Si(1 1 1) surface. Our results complement the extensive previous evidence from diffraction and ion scattering techniques for the presence of pre-melted (liquid-like) layers on Si(1 1 1) below the bulk melting temperature and also suggest how atomic steps are involved in the initiation of such layers. Our results are based on atomic force microscopy studies of morphologies that are preserved when surfaces are annealed in a range of high temperatures and then rapidly cooled to room temperature for observation. A unique feature of the experiments is the use of specially prepared atomically flat or very low step density surfaces; this allows us to see how the liquid-like morphologies are associated with the steps and also allows the high temperature structures to survive the cooling process without being absorbed into the steps which normally would exist on a surface vicinal to (1 1 1). Quenched-in structures ascribed to pre-melting also act as sinks for diffusing ‘excess’ adatoms generated by the (1 × 1) to (7 × 7) transition and this leads to the formation of dendritic islands. 相似文献
83.
Kevin Dal Pont Jean‐François Gérard Eliane Espuche 《Journal of Polymer Science.Polymer Physics》2013,51(13):1051-1059
In this work, a novel nanocomposite series based on styrene‐butadiene rubber (SBR latex) and alpha‐zirconium phosphate(α‐ZrP) lamellar nanofillers is successfully prepared. The α‐ZrP lamellar filler is modified at the cation exchange capacity by γ‐aminopropyltrimethoxysilane and the filler surface modification is first discussed. A significant improvement of the mechanical properties is obtained by using the surface modified nanofillers. However, no modification of the gas barrier properties is observed. The impact of addition of bis(triethoxysilylpropyl)tetrasulfide (TESPT) as coupling agent in the system is discussed on the nanofiller dispersion state and on the filler–matrix interfacial bonding. Simultaneous use of modified nanofillers and TESPT coupling agent is found out with extraordinary reinforcing effects on both mechanical and gas barrier properties and the key factors at the origin of the improvement of these properties are identified. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1051–1059 相似文献
84.
A simple replacement approach is used to construct new symmetric and affine designs from projective or affine spaces. This
is used to construct symmetric designs with a given automorphism group, to study GMW designs, and to construct new affine
designs whose automorphism group fixes a point and has just two point- and block-orbits.
相似文献
85.
86.
We consider the model of the one-dimensional cookie random walk when the initial cookie distribution is spatially uniform
and the number of cookies per site is finite. We give a criterion to decide whether the limiting speed of the walk is non-zero.
In particular, we show that a positive speed may be obtained for just three cookies per site. We also prove a result on the
continuity of the speed with respect to the initial cookie distribution.
相似文献
87.
E.B.Manoukian 《理论物理通讯》2013,(12):677-686
The paper represents a rigorous treatment of the underlying quantum theory, not just in words but providing the underlying technical details, as to why matter occupies so large a volume and its intimate connection with the Pauli exclusion principle, as more and more matter is put together, as well as of the contraction or shrinkage of "bosonic matter", upon collapse, for which the Panli exclusion is abolished. From the derived explicit bounds of integrals of powers of the particle number densities, explicit bounds on probabilities of the occurrences of the events just described are extracted. These probabilities lead one to infer the change of the "size" or extension of such matter, upon expansion or contraction, respectively, as their content is increased. 相似文献
88.
根据我国现行的税法,个人所得税纳税采用九级累进税率.年工资和年终奖在速算扣除数个数上存在不同,使得对于相同的税前年收入,如果采用不同的年工资和年终奖分配方案会产生不同的税后实际所得.通过简化变量和缩小有效解区域,以及一系列严格的数学推导,得到了任意年收入下,月工资和年终奖的最优分配方案,使得在现有税制下,纳税额最小,税后收入最大.这个最优方案避免了税金负效应现象,保证了纳税公平性,有利于国家税务监管,企业员工薪金分配和个人纳税筹划;具有广阔的应用前景. 相似文献
89.
Blue vitriol (copper(II) sulfate pentahydrate), CuSO4·5H2O has been chosen and investigated for its effectiveness as a flame-retardant, when impregnated into cotton fabric (cotton
with a plain structure; woven 180 g m−2, with 22 numbers of yarns per 10 mm). Using the vertical flame test, the extent of resistance to burning of the specimens
has been determined. The impregnation was accomplished via dipping and stirring of bone-dried, weighed fabrics into the individual
and suitable concentrations of the salt at room temperature. Afterwards the samples were squeeze rolled and dried horizontally
at 110°C for 30 min in an oven and cooled in a desiccator and reweighed with an analytical precision. They were then kept
under ordinary conditions overnight prior the fulfillment of the vertical flame test. The efficient quantities of the aforesaid
salt expressed in g per 100 g dry fabric have been determined in an average figure of 12.75%. Estimation of uniformity in
a selected sample was carried out via a spectrophotometer and results are in favor of the heterogeneous distribution of the
salt in the fabric’s middle sectors. However initial and final parts of specimen showed to be rather uniformed. Thermogravimetric
analysis of the pure cotton and the treated ones with insufficient and effective amounts of the salt were fulfilled and their
thermograms were compared and commented. The results obtained for the effect of copper(II) sulfate comply with ‘The Dust or
Wall Effect Theory’. This action is also assigned to the condensed phase retardation. 相似文献
90.