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排序方式: 共有421条查询结果,搜索用时 17 毫秒
1.
Nolte Steffen Fink Reinhard Krooss Bernhard M. Amann-Hildenbrand Alexandra Wang Yue Wang Moran Schmatz Joyce Klaver Jop Littke Ralf 《Transport in Porous Media》2021,137(3):519-553
Transport in Porous Media - To improve the understanding of gas transport processes in tight rocks (e.g., shales), systematic flow tests with different gases were conducted on artificial micro- to... 相似文献
2.
Da Wang Dr. Christian Richter Andreas Rühling Dr. Patrick Drücker Daniel Siegmund Prof. Dr. Nils Metzler‐Nolte Prof. Dr. Frank Glorius Prof. Dr. Hans‐Joachim Galla 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(43):15123-15126
A series of imidazolium salts bearing two alkyl chains in the backbone of the imidazolium core were synthesized, resembling the structure of lipids. Their antibacterial activity and cytotoxicity were evaluated using Gram‐positive and Gram‐negative bacteria and eukaryotic cell lines including tumor cells. It is shown that the length of alkyl chains in the backbone is vital for the antibiofilm activities of these lipid‐mimicking components. In addition to their biological activity, their surface activity and their membrane interactions are shown by film balance and quartz crystal microbalance (QCM) measurements. The structure–activity relationship indicates that the distinctive chemical structure contributes considerably to the biological activities of this novel class of lipids. 相似文献
3.
Cyclometalated Iridium(III) Complexes Containing Semicarbazone Ligands: Synthesis,Characterization, Photophysical and Biological Studies 下载免费PDF全文
Marion Graf Yvonne Gothe Nils Metzler‐Nolte Rafał Czerwieniec Karlheinz Sünkel 《无机化学与普通化学杂志》2015,641(10):1798-1802
The synthesis, crystal structure, photophysical properties, and biological activity of the novel bis‐cyclometalated complexes [Ir(ptpy)2(vnsc)] ( 2 ) and [Ir(ptpy)2(acsc)] ( 3 ) [ptpy = 2‐(p‐tolyl)pyridinato, vnsc = vanillin semicarbazone, acsc = acetone semicarbazone] are described. The new compounds were prepared by the reaction of [{Ir(μ‐Cl)(ptpy)2}2] ( 1 ) with the corresponding semicarbazone ligands under basic conditions. The molecular structure of compound 3 was confirmed by a single‐crystal X‐ray diffraction study. The complex crystallized from chloroform as a mono‐ solvate in the orthorhombic space group Pcab with eight molecules in the unit cell. 相似文献
4.
Cyclometalated Iridium(III) and Rhodium(III) Complexes Containing Naphthyridine Ligands: Synthesis,Characterization and Biological Studies 下载免费PDF全文
The synthesis, crystal structure, and biological activity of new bis‐cyclometalated compounds [M(ptpy)2(4‐chloro‐2‐methyl‐1,8‐naphthyridine)]PF6 [M = Rh ( 1 ); M = Ir ( 2 ); ptpy = 2‐(p‐tolyl)pyridinato] and [M(ptpy)2(2‐methyl‐1,8‐naphthyridine)]PF6 [M = Rh ( 3 ); M = Ir ( 4 )] are described. The new compounds were prepared by the reaction of [{M(μ‐Cl)(ptpy)2}2] (M = Rh, Ir) with the corresponding naphthyridine ligands. The molecular structures of compounds 1 , 3 , and 4 were confirmed by single‐crystal X‐ray diffraction studies. 相似文献
5.
L. -P. Nolte J. Makowski H. Stumpf 《Archive of Applied Mechanics (Ingenieur Archiv)》1986,56(2):145-160
Summary For the geometrically nonlinear first approximation theory of elastic shells three energy-consistent large rotation shell variants are constructed. The governing shell equations are derived as Euler-Lagrange equations of an associated variational principle of stationary total potential energy. The numerical applicability is considered for a highly nonlinear shell problem. To incorporate the presented theories into the frame of shell models published in the literature a comparative analysis is carried out for a large number of shell equations.
Zur Herleitung und vergleichenden Untersuchung von Schalentheorien für große Rotationen
Übersicht Im Rahmen der geometrisch-nichtlinearen ersten Schalenapproximation werden drei energiekonsistente Schalentheorien für große Rotationen hergeleitet. Die Schalengleichungen werden als Euler-Lagrange Gleichungen eines zugehörigen Variationsprinzips vom stationären Wert der potentiellen Gesamtenergie hergeleitet. Die numerische Anwendbarkeit wird anhand eines stark-nichtlinearen Schalenbeispiels nachgewiesen. Um die in dieser Arbeit hergeleiteten Theorien entsprechend einordnen zu können, wird für eine größere Zahl von in der Literatur angegebenen Schalengleichungen eine vergleichende Untersuchung mit numerischer Auswertung durchgeführt.相似文献
6.
Experiments were performed on the condensation of steam from steam-air mixtures in annular flow at a cooled inner tube. The range of investigation was varied for laminar and turbulent flow for 1.5 × 103 Re 1.3 × 104 and inlet concentrations 0.59 psteam/ptotal 0.95. The measurements, performed at an open test loop at ptotal ≈ 0.96 bar, allowed local heat and mass transfer coefficients to be evaluated for various inlet lengths in the 2 m long annulus. The steam concentration was measured locally inside the annulus with a newly developed dew-point probe. The heat flux was measured locally using the temperature gradient in the cooled inner tube.
Near the inlet region the experiments showed a slightly higher heat flux at the bottom of the tube compared to the top, although it is expected to be smaller there owing to a thicker liquid film. Far downstream from the inlet region the heat transfer at the top was higher than at the bottom. The reasons for these effects are discussed, yielding a better understanding of the thermal and fluid processes involved in condensation from vapor-gas mixtures. The measured data allow the development of correlations for predicting the local Nusselt and Sherwood numbers in a horizontal annular-flow chanbel. 相似文献
7.
Slippage of a Porphyrin Macrocycle over Threads of Varying Bulkiness: Implications for the Mechanism of Threading Polymers through a Macrocyclic Ring 下载免费PDF全文
Dr. Alexander B. C. Deutman Dr. Shaji Varghese Mohamed Moalin Dr. Johannes A. A. W. Elemans Prof. Alan E. Rowan Prof. Roeland J. M. Nolte 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):360-370
Threading of a polymer through a macrocyclic ring may occur directly, that is, by finding the end of the polymer chain, or by a process in which the polymer chain first folds and then threads through the macrocyclic ring in a hairpin‐like conformation. We present kinetic and thermodynamic studies on the threading of a macrocyclic porphyrin receptor ( H21 ) onto molecular threads that are blocked on one side and are open on the other side. The open side is modified by groups that vary in ease of folding and in bulkiness. Additionally, the threads contain a viologen binding site for the macrocyclic receptor, which is located close to the blocking group. The rates of threading of H21 were measured under various conditions, by recording as a function of time the quenching of the fluorescence of the porphyrin, which occurs when receptor H21 reaches the viologen binding site. The kinetic data suggest that threading is impossible if the receptor encounters an open side that is sterically encumbered in a similar way as a folded polymer chain. This indicates that threading of polymers through macrocyclic compounds through a folded chain mechanism is unlikely. 相似文献
8.
9.
S. D?ring S. Richter A. Tünnermann S. Nolte 《Applied Physics A: Materials Science & Processing》2011,105(1):69-74
We report on the temporal evolution of the percussion drilling process in deep laser drilling. Ultrashort laser pulses at
1030 nm and a duration of 8 ps were used to machine silicon while simultaneously imaging the silhouette of the hole using
an illumination wavelength above the band edge. We investigate the influence of the processing parameters fluence and pulse
energy on the depth and shape of the hole demonstrating different phases of the drilling process. In the first phase, a tapered
hole is formed with highly reproducible shape and depth. In the following, the evolution of the hole shape is irregular and
imperfections like bulges, changes of the drilling direction and the formation of multiple hole ends occur. In the final phase,
the maximum depth stays constant while the volume still increases due to enlargement of the hole diameter and the possible
formation of multiple hole ends. Deviations from the ideal hole shape occur primarily in the lower part of the hole. Their
extent can be reduced by increasing the amount of applied pulse energy. Moreover, the pulse energy is chiefly determining
the maximum achievable hole depth, which is largely independent of the focusing conditions and corresponding fluence. 相似文献
10.
Andreas Schwenke Philipp Wagener Stefan Nolte Stephan Barcikowski 《Applied Physics A: Materials Science & Processing》2011,104(1):77-82
The influence of fundamental and second harmonic wavelength on ablation efficiency and nanoparticle properties is studied
during picosecond laser ablation of silver, zinc, and magnesium in polymer-doped tetrahydrofuran. Laser ablation in stationary
liquid involves simultaneously the fabrication of nanoparticles by ablation of the target material and fragmentation of dispersed
nanoparticles by post irradiation. The ratio in which the laser pulse energy contributes to these processes depends on laser
wavelength and colloidal properties. For plasmon absorbers (silver), using the second harmonic wavelength leads to a decrease
of the nanoparticle productivity over process time along with exponential decrease in particle diameter, while using the fundamental
wavelength results in a constant ablation rate and linear decrease in particle diameter. For colloids made of materials without
plasmon absorption (zinc, magnesium), laser scattering is the colloidal property that limits nanoparticle productivity by
Mie-scattering of dispersed nanoparticle clusters. 相似文献