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231.
本文从符号学的角度来分析城市家具的设计,是对设计如何满足现代社会发展需求的探索,从功能到符号,从符号到设计,设计不再是绘画的附属,而是建立符号系统的过程. 相似文献
232.
E. E. Shalygina A. V. Vedyaev O. A. Shalygina I. A. Pogrebnaya A. Marty B. Gilles 《JETP Letters》1998,67(1):34-38
The results of an investigation of the magnetic and magnetooptical properties of Au/Cu-wedge/15-Å-NiFe sandwiches are reported.
Oscillations of the equatorial Kerr effect as a function of the copper wedge thickness are observed. The period of these oscillations
is found to be of the order of 5–6 Å. The experimentally observed oscillations of the equatorial Kerr effect are attributed
to a quantum size effect.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 1, 33–36 (10 January 1998) 相似文献
233.
1-(2,6-二溴-4-硝基苯)-3-(4-硝基苯)-三氮烯与锌的显色反应研究 总被引:7,自引:1,他引:6
研究了 1- (2 ,6-二溴 - 4 -硝基苯 ) - 3- (4 -硝基苯 ) -三氮烯 (DBNPNPT)与锌的显色反应。在表面活性剂Triton X- 10 0的存在下 ,p H=9.0— 11.0的 Na2 B4 O7- Na OH介质中 ,DBNPNPT与锌 ( )可生成橙黄色络合物。建立以 5 35 nm为参比波长 ,4 4 0 nm为测定波长的双峰双波长测定法 ,该络合物的表观摩尔吸光系数为 1.34× 10 5L· mol-1· cm-1。对葡萄糖酸锌中的锌直接测定 ,结果令人满意 相似文献
234.
The first author was supported by the Swiss National Sciences Foundation and the second author was partially supported by
contrat CEE GADGET.SC1-0105-C. 相似文献
235.
236.
In the first part of this paper, we enumerate exactly walks on the square lattice that start from the origin, but otherwise
avoid the half-line . We call them walks on the slit plane. We count them by their length, and by the coordinates of their endpoint. The corresponding three variable is algebraic of
degree 8. Moreover, for any point (i, j), the length for walks of this type ending at (i, j) is also algebraic, of degree 2 or 4, and involves the famous Catalan numbers.
Our method is based on the solution of a functional equation, established via a simple combinatorial argument. It actually
works for more general models, in which walks take their steps in a finite subset of ℤ2 satisfying two simple conditions. The corresponding are always algebraic.
In the second part of the paper, we derive from our enumerative results a number of probabilistic corollaries. For instance,
we can compute exactly the probability that an ordinary random walk starting from (i, j) hits for the first time the half-line at position (k, 0), for any triple (i, j, k). This generalizes a question raised by R. Kenyon, which was the starting point of this paper.
Taking uniformly at random all n-step walks on the slit plane, we also compute the probability that they visit a given point (k, 0), and the average number of visits to this point. In other words, we quantify the transience of the walks. Finally, we derive
an explicit limit law for the coordinates of their endpoint.
Received: 22 December 2001 / Revised version: 19 February 2002 / Published online: 30 September 2002
Both authors were partially supported by the INRIA, via the cooperative research action Alcophys.
Mathematics Subject Classification (2000): O5A15-60C05 相似文献
237.
This work extends to dismantable graphs many properties of dismantable posets dealing with products, exponentiation, existence of paths in a graph of all homomorphisms, fixed clique property, etc. We show that a poset is dismantlable in the sense of Rival if and only if its comparability graph is dismantlable, thus proving that, for posets, dismantlability is a comparability invariant. We establish the analogues for graphs of results of Duffus, Poguntke and Rival about fixed point sets and cores in posets. 相似文献
238.
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240.
α‐Peptide–Oligourea Chimeras: Stabilization of Short α‐Helices by Non‐Peptide Helical Foldamers
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Dr. Juliette Fremaux Laura Mauran Dr. Karolina Pulka‐Ziach Dr. Brice Kauffmann Dr. Benoit Odaert Dr. Gilles Guichard 《Angewandte Chemie (International ed. in English)》2015,54(34):9816-9820
Short α‐peptides with less than 10 residues generally display a low propensity to nucleate stable helical conformations. While various strategies to stabilize peptide helices have been previously reported, the ability of non‐peptide helical foldamers to stabilize α‐helices when fused to short α‐peptide segments has not been investigated. Towards this end, structural investigations into a series of chimeric oligomers obtained by joining aliphatic oligoureas to the C‐ or N‐termini of α‐peptides are described. All chimeras were found to be fully helical, with as few as 2 (or 3) urea units sufficient to propagate an α‐helical conformation in the fused peptide segment. The remarkable compatibility of α‐peptides with oligoureas described here, along with the simplicity of the approach, highlights the potential of interfacing natural and non‐peptide backbones as a means to further control the behavior of α‐peptides. 相似文献