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51.
A graph of order n is said to be 3-placeable if there are three edge-disjoint copies of this graph in Kn. An (n, n − 1)-graph is a graph of order n with n − 1 edges. In this paper we characterize all the (n, n − 1)-graphs which contain no cycles of length 3 or 4 and which are 3-placeable. © 1996 John Wiley & Sons, Inc. 相似文献
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Based on the Michael reaction of multifunctional acetoacetates with multiacrylates, in the presence or absence of dimethacrylates, tailor made matrix materials can be prepared. This can be achieved in a one- or two-step process. The Michael addition (first step) can be followed by radiation curing of excessive acrylate (second step). 相似文献
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Norbert Schuch J. Ignacio Cirac Michael M. Wolf 《Communications in Mathematical Physics》2006,267(1):65-92
We investigate bosonic Gaussian quantum states on an infinite cubic lattice in arbitrary spatial dimensions. We derive general properties of such states as ground states of quadratic Hamiltonians for both critical and non-critical cases. Tight analytic relations between the decay of the interaction and the correlation functions are proven and the dependence of the correlation length on band gap and effective mass is derived. We show that properties of critical ground states depend on the gap of the point-symmetrized rather than on that of the original Hamiltonian. For critical systems with polynomially decaying interactions logarithmic deviations from polynomially decaying correlation functions are found. 相似文献
57.
Paul Erdős Norbert Sauer Jonathan Schaer Joel Spencer 《Journal of Combinatorial Theory, Series B》1975,18(2):180-183
The graph G has star number n if any n vertices of G belong to a subgraph which is a star. Let f(n, k) be the smallest number m such that the complete graph on m vertices can be factorized into k factors with star number n. In the present paper we prove that . 相似文献
58.
Unexpected dimerization of 1,3‐dimethyl‐5‐methylenebarbituric acid revealed by a combined experimental and computational study 下载免费PDF全文
Bernd Doser Kamal Sweidan Norbert Kuhn Christian Ochsenfeld 《Journal of Physical Organic Chemistry》2015,28(5):354-357
A comparison of experimental and calculated 13C‐nuclear magnetic resonance chemical shifts reveals the molecular structure of a dimer that was obtained by an unexpected dimerization of 1,3‐dimethyl‐5‐methylenebarbituric acid. Furthermore, the puckering angle of the cyclobutane unit linking the six‐membered rings is discussed in detail. The influence of substituents on 1,3‐position of the cyclobutane ring on the puckering angle is demonstrated based on 1,1,3,3‐tetramethylcyclobutane. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
59.
Nitrogen‐Doped Ordered Mesoporous Carbon Supported Bimetallic PtCo Nanoparticles for Upgrading of Biophenolics 下载免费PDF全文
Dr. Guang‐Hui Wang Dr. Zhengwen Cao Dr. Dong Gu Norbert Pfänder Ann‐Christin Swertz Bernd Spliethoff Hans‐Josef Bongard Dr. Claudia Weidenthaler Dr. Wolfgang Schmidt Dr. Roberto Rinaldi Prof. Dr. Ferdi Schüth 《Angewandte Chemie (International ed. in English)》2016,55(31):8850-8855
Hydrodeoxygenation (HDO) is an attractive route for the upgrading of bio‐oils produced from lignocellulose. Current catalysts require harsh conditions to effect HDO, decreasing the process efficiency in terms of energy and carbon balance. Herein we report a novel and facile method for synthesizing bimetallic PtCo nanoparticle catalysts (ca. 1.5 nm) highly dispersed in the framework of nitrogen‐doped ordered mesoporous carbon (NOMC) for this reaction. We demonstrate that NOMC with either 2D hexagonal (p6m) or 3D cubic (Im m) structure can be easily synthesized by simply adjusting the polymerization temperature. We also demonstrate that PtCo/NOMC (metal loading: Pt 9.90 wt %; Co 3.31 wt %) is a highly effective catalyst for HDO of phenolic compounds and “real‐world” biomass‐derived phenolic streams. In the presence of PtCo/NOMC, full deoxygenation of phenolic compounds and a biomass‐derived phenolic stream is achieved under conditions of low severity. 相似文献
60.
5-Aminolevulinic acid derivatives in photomedicine: Characteristics, application and perspectives 总被引:3,自引:0,他引:3
The introduction of lipophilic derivatives of the naturally occurring heme precursor 5-aminolevulinic acid (5-ALA) into photomedicine has led to a true revival of this research area. 5-ALA-mediated photodynamic therapy (PDT) and fluorescence photodetection (FD) of neoplastic disease is probably one of the most selective cancer treatments currently known in oncology. To date, this method has been assessed experimentally for the treatment of various medical indications. However, the limited local bioavailability of 5-ALA has widely prevented its use in daily clinical practice. Although researchers were already aware of this drawback early during the development of 5-ALA-mediated PDT, only recently have well-established concepts in pharmaceutical science been adapted to investigate ways to overcome this drawback. Recently, two derivatives of 5-ALA, methylaminolevulinate (MAL) and hexylaminolevulinate (HAL), gained marketing authorization from the regulatory offices in Europe and Australia. MAL is marketed under the trade name Metvix for the treatment of actinic keratosis and difficult-to-treat basal cell carcinoma. HAL has recently been launched under the trade name Hexvix to improve the detection of superficial bladder cancer in Europe. This review will first present the fundamental concepts underlying the use of 5-ALA derivatives in PDT and FD from a chemical, biochemical and pharmaceutical point of view. Experimental evidences from preclinical data on the improvements and limits observed with 5-ALA derivatives will then be introduced. The state-of-the-art from clinical studies with 5-ALA esters will be discussed, with special emphasis placed on the process that led to the development of MAL in dermatology and to HAL in urology. Finally, we will discuss promising medical fields in which use of 5-ALA derivatives might potentially lead to further use of this methodology in photomedicine. 相似文献