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排序方式: 共有511条查询结果,搜索用时 15 毫秒
501.
502.
Dynamics of fracture in drying suspensions 总被引:1,自引:0,他引:1
Dufresne ER Stark DJ Greenblatt NA Cheng JX Hutchinson JW Mahadevan L Weitz DA 《Langmuir : the ACS journal of surfaces and colloids》2006,22(17):7144-7147
We investigate the dynamics of fracture in drying films of colloidal silica. Water loss quenches the nanoparticle dispersions to form a liquid-saturated elastic network of particles that relieves drying-induced strain by cracking. These cracks display intriguing intermittent motion originating from the deformation of arrested crack tips and aging of the elastic network. The dynamics of a single crack exhibits a universal evolution, described by a balance of the driving elastic power with the sum of interfacial power and the viscous dissipation rate of flowing interstitial fluid. 相似文献
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Adhesion of amorphous polymers as a function of temperature probed with AFM force-distance curves 总被引:1,自引:0,他引:1
Force-displacement curves have been obtained with a commercial atomic force microscope at different temperatures and probe rates on a thick film of poly(n-butyl methacrylate) and on two films of polystyrene with different molecular weight. In a previous publication [B. Cappella, S.K. Kaliappan, H. Sturm, Macromolecules 38 (2005)1874] the analysis of force-displacement curves has been focused on the stiffness and on the Young's modulus of the samples. In the present publication we consider the temperature dependence of the work of adhesion. We have obtained master curves of the work of adhesion at fixed maximum loads and, by comparing the results of the two analysis, we show that the work of adhesion follows the Williams-Landel-Ferry equation with the same coefficients previously found for the Young's modulus. Furthermore, we show that the temperature dependence of the work of adhesion of the polymers is a consequence of the temperature dependence of the tip-sample contact area and in the end of the temperature dependence of the stiffness and of the elastic-plastic properties of the samples. 相似文献
505.
Quasicrystals are aperiodic structures with long-range orientational order. Unlike crystals, quasicrystals can, in principle, possess any non-crystallographic rotational symmetry. However, only a few of these rotational symmetries have been observed. By using Monte Carlo simulations of colloidal particles in laser interference patterns with quasicrystalline symmetry, we compare the onset of quasicrystalline order for different rotational symmetries in two dimensions. We find that quasicrystals with 5-, 8-, 10-, and 12-fold rotational axes can be induced with lower laser intensities than quasicrystals with other non-crystallographic rotational symmetries. We relate this finding to the number of local symmetry centers in the respective interference patterns. 相似文献
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Justyna Gody Paula Zarba Dorota Stary Maria Kaleta Kamil J. Kuder Gniewomir Latacz Szczepan Mogilski David Reiner-Link Annika Frank Agata Doroz-Ponka Agnieszka Olejarz-Maciej Sylwia Sudo-Taaj Tobias Nolte Jadwiga Handzlik Holger Stark Anna Wickowska Barbara Malawska Katarzyna Kie-Kononowicz Dorota aewska Marek Bajda 《Molecules (Basel, Switzerland)》2023,28(1)
The multitarget-directed ligands demonstrating affinity to histamine H3 receptor and additional cholinesterase inhibitory potency represent a promising strategy for research into the effective treatment of Alzheimer’s disease. In this study, a novel series of benzophenone derivatives was designed and synthesized. Among these derivatives, we identified compound 6 with a high affinity for H3R (Ki = 8 nM) and significant inhibitory activity toward BuChE (IC50 = 172 nM and 1.16 µM for eqBuChE and hBuChE, respectively). Further in vitro studies revealed that compound 6 (4-fluorophenyl) (4-((5-(piperidin-1-yl)pentyl)oxy)phenyl)methanone) displays moderate metabolic stability in mouse liver microsomes, good permeability with a permeability coefficient value (Pe) of 6.3 × 10−6 cm/s, and its safety was confirmed in terms of hepatotoxicity in the HepG2 cell line. Therefore, we investigated the in vivo activity of compound 6 in the Passive Avoidance Test and the Formalin Test. While compound 6 did not show a statistically significant influence on memory and learning, it showed analgesic properties in both acute (ED50 = 20.9 mg/kg) and inflammatory (ED50 = 17.5 mg/kg) pain. 相似文献
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Auernhammer Julia Keil Tom Lin Binbin Schäfer Jan-Lukas Xu Bai-Xiang Biesalski Markus Stark Robert W. 《Cellulose (London, England)》2021,28(13):8313-8332
Cellulose - Modelling of single cellulose fibres is usually performed by assuming homogenous properties, such as strength and Young’s modulus, for the whole fibre. Additionally, the... 相似文献