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221.
Michael Christ 《偏微分方程通讯》2013,38(10):1695-1707
If m {3,4,5,...} then the partial differential operator in R3 fails to be analytic hypoelliptic. This results from the existence of parameters C such that the ordinary differential equation has a nontrivial solution which remains bounded as 相似文献
222.
Dr. Yong Hu Dr. Carmen M. Domínguez M. Sc. Sophina Christ Prof. Dr. Christof M. Niemeyer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19178-19182
We report on the directed postsynthetic functionalization of soft DNA nanocomposite materials with proteins. Using the example of the functionalization of silica nanoparticle-modified DNA polymer materials with agonists or antagonists of the epidermal growth factor receptor EGFR cell membrane receptor, we demonstrate that hierarchically structured interfaces to living cells can be established. Owing to the modular design principle, even complex DNA nanostructures can be integrated into the materials, thereby enabling the high-precision arrangement of ligands on the lower nanometer length scale. We believe that such complex biohybrid material systems can be used for new applications in biotechnology. 相似文献
223.
Eva‐Maria Christ Sophie S. Müller Elena Berger‐Nicoletti Holger Frey 《Journal of polymer science. Part A, Polymer chemistry》2014,52(19):2850-2859
Synthesis and characterization of novel hydroxyl‐functionalized oxetane‐inimers with varied alkyl chain length—3‐hydroxymethyl‐3‐methoxymethyloxetane, 3‐hydroxymethyl‐3‐propoxymethyloxetane, and 3‐hexoxymethyl‐3‐hydroxymethyloxetane—is reported. Cationic ring‐opening polymerization of these latent, cyclic AB2‐monomers leads to hyperbranched (hb) polyether polyols with degrees of branching between 34 and 69%, confirmed by inverse‐gated (IG) 13C NMR spectroscopy. The hyperbranching polymerization yielded apparent molecular weights (Mn) ranging from 500 to 2500 g mol?1 (size exclusion chromatography). Remarkably, by copolymerization of 1,1,1‐tris(4‐hydroxyphenyl)ethane as a “focal” unit, polymerization under slow monomer addition conditions lead to higher apparent molecular weights up to 11,220 g mol?1. The end groups of the hb polymers were studied via matrix‐assisted laser desorption/ionization time of flight mass and NMR spectrometry. By varying the alkyl chain length, tailoring of the solubility and glass transition temperatures of the materials is possible. Potential applications range from macroinitiators with defined polarity to tailoring of surface properties of antifouling materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2850–2859 相似文献
224.
Thomas Christ Volker Stümpflen Joachim H. Wendorff 《Macromolecular rapid communications》1997,18(2):93-98
We prepared light emitting diodes with a discotic main chain polymer doped with a tristilbene amine derivative. X-ray investigations showed the formation of a hexagonal columnar structure in the annealed devices. This increased order leads to a significant reduction of the onset voltage for light emission down to 4 · 105 V/cm. 相似文献
225.
The lattice parameters of Bi1–xSbx single crystals were measured for 0 ≦ x ≦ 1 by a special X-ray diffractometer technique using reflections chosen so that minimum errors were achieved. Corrections for thermal expansion and refraction were applied. The antimony concentration was determined by means of electron microprobe analysis. The dependences of the lattice parameters on x (in nm) can be described with good approximation by a = 0.45469 – 0.02398x and c = 1.186294 – 0.058632 [1 + 1.26 (x−1 – 1)]−1, resp. The behaviour of the parameter a is in agreement with the earlier study by CUCKA and BARRETT , whereas their linear expression for c(x) (0 ≦ x ≦ 0.3) was not confirmed. 相似文献
226.
NiTi alloys open up new fields of application on the basis of their distinctive thermomechanical properties. Many options of practical application of shape memory alloys are imaginable. For example catheters or stents made of NiTi play an important role in medical technology. Thus the further development and optimisation of simulation tools for shape memory alloys (SMA) structures will play an important role in the future. Based on the powerful material model of Helm [1] the present contribution focuses on the coupling between mechanical and thermal fields. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
227.
Ulrich Christ 《Macromolecular Symposia》2002,187(1):759-770
This paper describes low VOC coating systems successfully implemented and operating in two industrial branches. For Light Alloy Wheels, the innovative coating process comprises ecofriendly chromium-free surface pre-treatment, epoxy polyester powder primer, water-borne base coat and acrylate powder clear coat. The coating process as an example for agricultural machinery includes iron phosphatizing surface pre-treatment for steel substrates; the coating system itself consists of a water-borne stove-type dip priming operation (for all objects). Finish coat type (Plant I): 2-component water-borne PUR top coat; (Plant II): TGIC-free polyester powder top coat. These new coating systems have proved successful in existing series production. All technical requirements and the provisions of the VOC Regulations are fully complied with. 相似文献