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181.
Tsutomu Hoshino Ushiho Matsumoto Nobuyuki Harada Toshio Goto 《Tetrahedron letters》1981,22(37):3621-3624
Natural anthocyanidin 3,5-diglucosides show exciton coupling type of CD in neutral aqueous solutions, indicating the chiroptical stacking of anthocyanidin chromophores. A minor change of substituents on the anthocyanidin alters the chiral direction of stacking. Commelinin also consists of such chiroptically stacked molecules. 相似文献
182.
The structural transformation that occurs in the cadmium hydroxide decomposition reaction has the morphological and crystallographic character of a martensitic transformation. The authors predict the shape of the oxide crystallites produced during the reaction, viz., small platelets developed parallel to the (111) oxide planes. The difficulty in assessing their shape by analysis of X-ray diffraction line profiles is discussed. Electron microscope and X-ray diffraction results are presented and it is shown that the oxide crystallite shape is dependent on whether the precursor is hydroxide or carbonate. 相似文献
183.
Let be a polynomial ring, where is a field, and G be a simple graph on n vertices. Let be the vertex cover ideal of G. Herzog, Hibi and Ohsugi have conjectured that all powers of vertex cover ideals of chordal graph are componentwise linear. Here we establish the conjecture for the special case of trees. We also show that if G is a unicyclic vertex decomposable graph, then symbolic powers of are componentwise linear. 相似文献
184.
Asahi Takaoka 《Discrete Mathematics》2018,341(12):3281-3287
Consider two horizontal lines in the plane. A point on the top line and an interval on the bottom line define a triangle between two lines. The intersection graph of such triangles is called a simple-triangle graph. This paper shows a vertex ordering characterization of simple-triangle graphs as follows: a graph is a simple-triangle graph if and only if there is a linear ordering of the vertices that contains both an alternating orientation of the graph and a transitive orientation of the complement of the graph. 相似文献
185.
Quy Thuong Lê 《Comptes Rendus Mathematique》2017,355(10):1041-1045
In this note, using Cluckers–Loeser's theory of motivic integration, we prove the integral identity conjecture with framework a localized Grothendieck ring of varieties over an arbitrary base field of characteristic zero. 相似文献
186.
Silicon sensors have been used in High Energy Physics for about 25 years. They have been continuously improved to meet new requirements and challenges. Based on a simple detection principle many different types of silicon sensors have been developed. This article gives an introduction to the basic properties of silicon sensors and the related readout electronics. Then several silicon sensor types are described, which are the building blocks of detectors for tracking and scintillator readout. Besides reviewing state of the art sensor types some new developments will be discussed. This includes extremely radiation hard sensors, novel sensors for photon counting and especially trends to integrate sensor and readout electronics into monolithic devices. Finally some selected examples of large detector systems in existing or planned experiments will be reviewed. 相似文献
187.
The aim of this paper is to evaluate the effects of uncertain-but-bounded parameters on the dynamic response of structures. By combining the interval mathematics and the finite element analysis, the mass matrix, damping matrix, stiffness matrix and the external loads are represented as interval matrices and vector. With the help of the optimization theory, we present the vertex solution theorem for determining both the exact upper bounds or maximum values and the exact lower bounds or minimum values of the dynamic response of structures, in which these parameters reach their extreme values on the boundary of the interval mass, damping, stiffness matrices and the interval extemal loads vector. Three examples are used to illustrate the computational aspects of the presented vertex solution theorem. 相似文献
188.
We investigate the relationship between two kinds of vertex colorings of graphs: unique-maximum colorings and conflict-free colorings. In a unique-maximum coloring, the colors are ordered, and in every path of the graph the maximum color appears only once. In a conflict-free coloring, in every path of the graph there is a color that appears only once. We also study computational complexity aspects of conflict-free colorings and prove a completeness result. Finally, we improve lower bounds for those chromatic numbers of the grid graph. 相似文献
189.
A k-edge-weighting w of a graph G is an assignment of an integer weight, w(e) ∈ {1,…,k}, to each edge e. An edge-weighting naturally induces a vertex coloring c by defining c(u) = Σ
e∋u
w(e) for every u ∈ V (G). A k-edge-weighting of a graph G is vertex-coloring if the induced coloring c is proper, i.e., c(u) ≠ c(v) for any edge uv ∈ E(G). When k ≡ 2 (mod 4) and k ⩾ 6, we prove that if G is k-colorable and 2-connected, δ(G) ⩾ k − 1, then G admits a vertex-coloring k-edge-weighting. We also obtain several sufficient conditions for graphs to be vertex-coloring k-edge-weighting.
相似文献
190.
We give some bounds on the injective chromatic number. 相似文献