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991.
Tran NT Stork JR Pham D Olmstead MM Fettinger JC Balch AL 《Chemical communications (Cambridge, England)》2006,(10):1130-1132
Trimeric green [(i-PrNC)12Rh(I)3]Cl3.4.5H2O, monomeric [(C6H11NC)4Rh(I)](BPh4) and [(i-PrNC)4Rh(I)](BPh4) (both yellow), and red, dimeric [(C6H11NC)8Rh(I)2]Cl2.0.5C6H6.2H2O have been crystallized. 相似文献
992.
Elastomeric stamp deformation has been utilized for the contact printing (CP) of self-assembled monolayers (SAMs) and, more recently, polymers and proteins. Here, we take advantage of this well-studied phenomenon to fabricate a series of new metal thin-film patterns not present on the original stamp. The rounded patterns are of nanoscale thickness, long-range order, and are created from elastomeric stamps with only straight-edged features. The metal was printed onto the surface of an alpha,omega-alkanedithiol self-assembled monolayer (SAM). The new shapes are controlled by a combination of stamp geometry design and the application of external pressure. Previously published rules on stamp deformation for contact printing of SAMs are invalid because the coating is instead a thin-metal film. This method represents a new pathway to micropatterning metal thin films, leading to shapes with higher complexity than the original lithographic masters. 相似文献
993.
Vergne C Boury-Esnault N Perez T Martin MT Adeline MT Tran Huu Dau E Al-Mourabit A 《Organic letters》2006,8(11):2421-2424
[reaction: see text] Four C(11)N(5) diketopiperazine metabolites named verpacamides A (6), B (7), C (8), and D (9) consisting of a proline-arginine dipeptide skeleton have been isolated from the marine sponge Axinella vaceleti. Verpacamides A-D are a sequence of metabolites showing the transformation of proline and arginine into the oxidized guanidinyl-cyclo(Pro-Pro) 8 and 9. Compounds 6-9 are structurally and chemically related to C(11)N(5) pyrrole-2-aminoimidazole metabolites also isolated from the Axinellidae and Agelasidae families of sponges and exemplified by dispacamide A (4) and dibromophakellin (10). 相似文献
994.
We have prepared polycrystalline samples of Zn(C3H3N2)2 by a liquid-mix technique. Characterization of the obtained samples has been performed with the aid of elemental, thermogravimetric, infrared spectra and X-ray powder diffraction analysis. We have measured electric permittivity (ε′, ε″), ac-conductivity (σac), magnetic susceptibility (χ) and specific heat (Cp). The obtained data indicate that this material is a new diamagnetic insulator. A maximum around is found in CpT−3, and it is suggested that in addition to the Debye lattice contribution, there exists a low-frequency mode assigned as an Einstein mode contribution to the total specific heat. As a main result of the study, we found ε′ to be constant in a wide temperature range and to have a small value of 2.3 at room temperature. This feature in combination with other properties like crystallization, good thermal stability (up to 400°C), weak moisture sensitivity and simple synthesis makes Zn(C3H3N2)2 to be a promising candidate for good insulating material in various applications. 相似文献
995.
Multispectral images such as multispectral chemical images or multispectral satellite images provide detailed data with information in both the spatial and spectral domains. Many segmentation methods for multispectral images are based on a per-pixel classification, which uses only spectral information and ignores spatial information. A clustering algorithm based on both spectral and spatial information would produce better results.
In this work, spatial refinement clustering (SpaRef), a new clustering algorithm for multispectral images is presented. Spatial information is integrated with partitional and agglomeration clustering processes. The number of clusters is automatically identified. SpaRef is compared with a set of well-known clustering methods on compact airborne spectrographic imager (CASI) over an area in the Klompenwaard, The Netherlands. The clusters obtained show improved results. Applying SpaRef to multispectral chemical images would be a straight-forward step. 相似文献
996.
997.
Let (X,p) be a metric space with a K-valued non-Archimedean metric p . In this paper, we prove the existence and approximation of a fixed point for operators F:X→X satisfying the contractive condition in the form p(F(x),F(y))?Q[p(x,y)], where Q:K→K is an increasing operator. Then, we study the generalized Ulam–Hyers stability of fixed point equations. We next obtain an extension of the Krasnoselskii fixed point theorem for the sum of two operators. Finally, an application to functional equations is given. 相似文献
998.
Tran NG Kalyvas H Skodje KM Hayashi T Moënne-Loccoz P Callan PE Shearer J Kirschenbaum LJ Kim E 《Journal of the American Chemical Society》2011,133(5):1184-1187
Cellular dinitrosyl iron complexes (DNICs) have long been considered NO carriers. Although other physiological roles of DNICs have been postulated, their chemical functionality outside of NO transfer has not been demonstrated thus far. Here we report the unprecedented dioxygen reactivity of a N-bound {Fe(NO)(2)}(10) DNIC, [Fe(TMEDA)(NO)(2)] (1). In the presence of O(2), 1 becomes a nitrating agent that converts 2,4,-di-tert-butylphenol to 2,4-di-tert-butyl-6-nitrophenol via formation of a putative iron-peroxynitrite [Fe(TMEDA)(NO)(ONOO)] (2) that is stable below -80 °C. Iron K-edge X-ray absorption spectroscopy on 2 supports a five-coordinated metal center with a bound peroxynitrite in a cyclic bidentate fashion. The peroxynitrite ligand of 2 readily decays at increased temperature or under illumination. These results suggest that DNICs could have multiple physiological or deleterious roles, including that of cellular nitrating agents. 相似文献
999.
Nguyen Bich Huy Tran Dinh Thanh 《Journal of Mathematical Analysis and Applications》2004,290(1):123-131
We apply general results on operator equations in ordered spaces and properties of the principal eigenvalues for weighted semi-linear equations to prove the existence of a global continua of positive solutions and eigenvalue intervals to the problem (?(x′))′+λf(t,x,x′)=0 in (0,1), x(0)=x(1)=0, where ?(x)=|x|p−2x, p>1, λ>0. 相似文献
1000.
C Guillot M.C Desjonquères D Chauveau G Tréglia J Lecante D Spanjaard Tran Minh Duc 《Solid State Communications》1984,50(5):393-396
We compare the hydrogen and thermally induced reconstructions of W(100) by means of surface core level spectroscopy and analyse the energy positions of the spectral lines in the framework of existing theoretical models. Surprisingly, our results for both reconstructions differ more than would be expected from previous admitted structural models. 相似文献