排序方式: 共有93条查询结果,搜索用时 31 毫秒
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Huijing Zhang Maziar Afshar Dara Feili Helmut Seidel Karsten König 《Applied Physics A: Materials Science & Processing》2012,107(2):339-343
A near-infrared 12-fs laser scanning microscope was employed for structuring glass surfaces. A Ti–sapphire laser operated
at 85 MHz and emitted light pulses at wavelengths around 800 nm. A focused laser beam with a mean power of less than 27 mW,
corresponding to a maximal pulse energy of 318 pJ, was applied for line scanning at and beneath the surfaces of cover slips
as well as of a filter glass BG39. Periodic arrangements of dots along the processed lines were produced through digital control
of the scanner. Depending on the pulse energy and the scan speed, the diameter of the dots ranged from 550 nm down to 100 nm.
For the cover slips, the dots occur as cavities after wet chemical etching. For BG39, which exhibits strong near-infrared
absorption, both chains of cavities and bumps can be generated without any etching process. The result shows that structures
with a size down to 1/8λ can be generated, probably through nonlinear single-photon processes confined within the focal volume. 相似文献
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Maziar Sardashti Bernard A. Baldwin Daniel J. O'Donnell 《Journal of Polymer Science.Polymer Physics》1995,33(4):571-576
1H nuclear magnetic resonance (NMR) imaging techniques have been used to image the extrusion aid (EA) in polyethylene (PE) pipe samples. The resulting two-dimensional images show the distribution of EA within the pipe. EA is found to be uniformly distributed in a normal pipe. Examples of degraded pipes, due to exposure to extreme conditions, show migration of EA to the pipes' wall surfaces. NMR images of a normal pipe and two examples of damaged pipes are presented. The imaging technique and the results are discussed. © 1995 John Wiley & Sons, Inc. 相似文献
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Primal-dual interior-point methods (IPMs) have shown their power in solving large classes of optimization problems. However,
at present there is still a gap between the practical behavior of these algorithms and their theoretical worst-case complexity
results, with respect to the strategies of updating the duality gap parameter in the algorithm. The so-called small-update
IPMs enjoy the best known theoretical worst-case iteration bound, but work very poorly in practice. To the contrary, the so-called
large-update IPMs have superior practical performance but with relatively weaker theoretical results. In this paper we discuss
the new algorithmic variants and improved complexity results with respect to the new family of Self-Regular proximity based
IPMs for Linear Optimization problems, and their generalizations to Conic and Semidefinite Optimization
This research was supported by the MITACS project “New IPMs and Software for Convex Conic-Linear Optimization and Their Application
to Solve VLSI Circuit Layout Problems”, by an NSERC discovery grant, and the CRC program. The first author would also like
to thank the Iranian Ministry of Science, Research and Technology for supporting his research. 相似文献
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Arsalan Mirjafari Niloufar Mobarrez James H. Davis Jr Jalil Noei 《Comptes Rendus Chimie》2011,14(12):1065-1070
A wide variety of oximes were prepared from different types of alcohols with hydroxylamine hydrochloride using 1-methylimidaziloum nitrate, [Hmim][NO3], ionic liquid as a reaction medium and promoter under microwave irradiation. This protocol provides a one-pot oxime synthesis with high yields that is facile, eco-friendly and the ionic liquid can be recovered and reused. 相似文献
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Dr. Mingyan Ma Dr. Heshmat Noei Bernd Mienert Dr. Johanna Niesel Dr. Eckhard Bill Prof. Dr. Martin Muhler Prof. Dr. Roland A. Fischer Dr. Yuemin Wang Prof. Dr. Ulrich Schatzschneider Prof. Dr. Nils Metzler‐Nolte 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6785-6790
Crystals of MIL‐88B‐Fe and NH2‐MIL‐88B‐Fe were prepared by a new rapid microwave‐assisted solvothermal method. High‐purity, spindle‐shaped crystals of MIL‐88B‐Fe with a length of about 2 μm and a diameter of 1 μm and needle‐shaped crystals of NH2‐MIL‐88B‐Fe with a length of about 1.5 μm and a diameter of 300 nm were produced with uniform size and excellent crystallinity. The possibility to reduce the as‐prepared frameworks and the chemical capture of carbon monoxide in these materials was studied by in situ ultrahigh vacuum Fourier‐transform infrared (UHV‐FTIR) spectroscopy and Mössbauer spectroscopy. CO binding occurs to unsaturated coordination sites (CUS). The release of CO from the as‐prepared materials was studied by a myoglobin assay in physiological buffer. The release of CO from crystals of MIL‐88B‐Fe with t1/2=38 min and from crystals of NH2‐MIL‐88B‐Fe with t1/2=76 min were found to be controlled by the degradation of the MIL materials under physiological conditions. These MIL‐88B‐Fe and NH2‐MIL‐88B‐Fe materials show good biocompatibility and have the potential to be used in pharmacological and therapeutic applications as carriers and delivery vehicles for the gasotransmitter carbon monoxide. 相似文献
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Jalil Noei 《Tetrahedron letters》2008,49(49):6969-6971
The combination of TiCl3OTf with 1-butyl-3-methylimidazolium bromide is found to be an efficient and novel catalytic system for chemoselective one-pot transformation of arylaldoximes to their corresponding thioamides in high to excellent yields. 相似文献
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