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951.
We consider particles prepared by a single slit diffraction experiment. For those particles the standard deviation σ
p
of the momentum is discussed. We find out that σ
p
=∞ is not an exception but a rather typical case. A necessary and sufficient condition for σ
p
<∞ is given. Finally, the inequality σ
p
Δx≥π
ℏ is derived and it is shown that this bound cannot be improved. 相似文献
952.
K.B. Liaskos 《Journal of Mathematical Analysis and Applications》2009,355(1):288-302
The equations for the evolution of electromagnetic fields in chiral media, in the time domain, are nonlocal in time. In this work we study the validity of a singular limit (local in time) approximation for these nonlocal in time equations, by estimating the size of the difference of the fields as predicted by both models. In particular, we establish an a priori estimate for this difference, depending on the time horizon, properties of the domain, spatial properties of the initial data and the source terms and the chirality measure β of the approximating model. 相似文献
953.
Our aim in this paper is mainly to prove some existence results for solutions of generalized variational-like inequalities
with (η,h)-pseudo-monotone type III operators defined on non-compact sets in topological vector spaces. 相似文献
954.
Hans Georg von Schnering Prof. Dr. Dr. h. c. Anke Zürn Jen‐Hui Chang Michael Baitinger Yuri Grin Prof. Dr. 《无机化学与普通化学杂志》2007,633(8):1147-1153
It is shown how the Periodic Nodal Surface PNS D*&Y** separates perfectly the two partial structures of the cubic cP124 type. Condensed metal‐centered [M@E20] pentagonal dodecahedra of covalently bonded E atoms form a 3‐connected net. This partial structure is embedded in a zeolite‐type labyrinth containing chains of the remaining metal atoms. The shape of this ensemble represents the principle of the intrinsic curvature of solids. The relations of the structure to the β‐manganese structure are discussed in detail. Furthermore, some details concerning the electron balance in the covalent E100 net are reported. 相似文献
955.
一类不能作为自同构群的有限群 总被引:3,自引:0,他引:3
本文证明了阶小于p9的有限交换p-群不能作为有限群的自同构群,从而推进了MacHale的结果. 相似文献
956.
A continuous map on a compact metric space, regarded as a dynamical system by iteration, admits invariant measures. For a closed relation on such a space, or, equivalently, an upper semicontinuous set-valued map, there are several concepts which extend this idea of invariance for a measure. We prove that four such are equivalent. In particular, such relation invariant measures arise as projections from shift invariant measures on the space of sample paths. There is a similarly close relationship between the ideas of chain recurrence for the set-valued system and for the shift on the sample path space.
957.
本文指出文献[1]中关于下半连续函数格LSC(X,R*)上Way-below关系的一个结论是错误的,并且给出一个修正的命题及其证明. 相似文献
958.
C. Baumstark-Khan M. Palm J. Wehner M. Okabe M. Ikawa G. Horneck 《Journal of fluorescence》1999,9(1):37-43
Generation of Chinese Hamster Ovary (CHO) cell lines stably expressing green fluorescent protein (GFP) was achieved using a plasmid vector that encoded the red-shifted pCX-xGFP under the control of a strong hybrid promoter composed of a CMV enhancer and a -actin/-globin gene promoter. Cotransfection of the promoter-less pSV2-Neo helper plasmid transmitting neomycin resistance was followed by selection with the antibiotic G418. Constitutive GFP expression could be visualized in living and fixed cells using fluorescence spectroscopy, fluorescence microscopy, and flow cytometry. DNA repair-proficient (AA8) and deficient (UV5) CHO strains were used for survival tests after UVC irradiation. Cells carrying the GFP construct (AA8-pGFP, UV5-pGFP) show the same response to UV irradiation (colony forming ability) as their nontransformed parental cell lines (AA8, UV5). Using GFP as a marker for cell viability, cells were harvested after certain postirradiation growth periods and the numbers of GFP expressing cells and fluorescence intensities were determined by FACS analysis. Generally, GFP fluorescence in irradiated cells is not seen when cell membranes are damaged (leak-out of the soluble GFP). Irradiated cells without membrane damage express GFP continuously (leading to a dose-dependent increase in GFP contents). 相似文献
959.
Stefan Milius 《Applied Categorical Structures》2003,11(3):287-312
We study (finite) coproducts and colimits of -chains in Rel(C), the 2-category of relations over a given category C. The former exist and are the same as in C provided that C is extensive. The latter do not exist for example in Rel(Set). However, the canonical construction of those colimits in the category of sets can be generalized to Rel(Set). The canonical cocone is shown to satisfy a 2-categorical universal property, namely that of an lax adjoint cooplimit. Sufficient conditions for any base category C to admit the construction are given.A necessary and sufficient condition for the construction to yield colimits of -chains in the category of maps of Rel(C) is also given. 相似文献
960.
In this paper, we consider analogs of the Cantor--Bernstein theorem for sets with binary relations. In Sec. 1, we prove an analog of this theorem for arbitrary binary relations; in Sec. 2, we consider an application; in Sec. 3, we study a class of relations with the Cantor-- Bernstein property and a class of exact relations, and prove that these classes are closed under certain operations. 相似文献