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排序方式: 共有651条查询结果,搜索用时 31 毫秒
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A. Nieminen J. Huikari A. Jokinen J. Äystö J. Billowes P. Campbell E.C.A. Cochrane 《Hyperfine Interactions》2000,127(1-4):507-510
An ion beam cooler has been constructed and tested at the IGISOL mass separator facility at the University of Jyväskylä. The cooler is designed to improve the ion optical properties of radioactive ion beams produced with fission-, light-ion fusion and heavy ion fusion ion guides. The performance of the device has been tested in off- and on-line conditions. It has been shown that the emittance and energy spread of the ion beam can be decoupled from the ion guide parameters with high transmission efficiency. 相似文献
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Nonequivalence transformation of λ‐matrix eigenproblems and model embedding approach to model tuning
William R. Ferng Wen‐Wei Lin Daniel J. Pierce Chern‐Shuh Wang 《Numerical Linear Algebra with Applications》2001,8(1):53-70
In this paper we present some theory for a non‐equivalence transformation of matrix eigenvalues for λ‐matrix polynomials. Application of this transformation to eigenvalue embedding for model tuning on a realistic industry problem is illustrated. The new approach has several advantages such as flexibility, efficiency, and structure‐preservation. A numerical experiment on a pseudosimulation data set from The Boeing Company is reported. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
645.
Ronald M. Gurge Markus Hickl Gernot Krause Paul M. Lahti Bin Hu Zhou Yang Frank E. Karasz 《先进技术聚合物》1998,9(8):504-510
An alternating block copolymer, poly(1,8-octanedioxy-2,6-dimethoxy-1,4-phenylene-1,2-ethenylene-1,4-phenylene-1,2-ethenylene-1,4-phenylene-1,2-ethenylene-3,5-dimethoxy-1,4-phenylene), 1 , was synthesized, and characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography differential scanning calorimetry ultraviolet and elemental analysis. Light-emitting single-layer test diodes using this soluble, processible copolymer as the active layer (i.e. indium tin oxide/ 1 /Ca,Al) emit green light with a luminescent spectral maximum at 513 nm. The single-layer device had a brightness of about 80 cd/m2 at a current density of 100 mA/cm2 with an internal quantum efficiency of 0.3% photon/electron. Optimization of the light-emitting properties of 1 was achieved through variation of a key Wittig polymerization step in the synthesis, using trialkyl rather than triaryl phosphonium salts in an appropriate solvent mixture to achieve nearly regiospecific trans-olefination. This provided an improvement over earlier procedures, which require a post-Wittig isomerization to minimize the presence of electroluminescence-inhibiting cis-bonds. © 1998 John Wiley & Sons, Ltd. 相似文献
646.
Gia Petriashvili Mauro D. L. Bruno Erica Fuoco Riccardo Barberi 《Molecular Crystals and Liquid Crystals》2019,684(1):82-88
AbstractIn the last decade, the possibility to use liquid crystal droplets as optical micro-cavities and lasers has attracted much attention since it paves the way for many applications in the field of sensors or tunable photonics. Several techniques can be used to obtain small micro-resonators as, for example, dispersing a cholesteric liquid crystal inside an immiscible isotropic fluid to create an emulsion. Since liquid crystals are extremely sensitive to external factors as temperature or external fields, laser tuning can be easily achieved. Here, we report on the possibility to tune the laser emission from dye doped cholesteric liquid crystals microdroplets dispersed in a glycerol matrix in presence of nitric acid molecules in the emulsion. Using a fluorescent dye with pH dependent optical properties, the emitted laser wavelength can be tuned in a range of 60?nm. This effect could find applications for the development of spectroscopy based sensors. 相似文献
647.
对音叉作受迫振动的规律及音叉振动周期与双臂质量的关系进行了研究,自制了新型的音叉受迫振动与共振实验仪,该仪器不仅可以手工调节做实验,而且可以实现计算机实时测量. 相似文献
648.
Dr. Ruiyi Zhang Dr. Ya Gao Prof. Lan Chen Prof. Dexing Li Prof. Guanglu Ge 《Chemphyschem》2023,24(21):e202300429
Combustible gas-gas reactions usually do not occur spontaneously upon mixing without ignition or other triggers to lower the activation energy barrier. Nanobubbles, however, could provide such a possibility in solution under ambient conditions due to high inner pressure and catalytic radicals within their boundary layers. Herein, a tunable gas-gas reaction strategy via bulk nanobubble pathway is developed by tuning the interface charge of one type of bulk nanobubble and promoting its fusion and reaction with another, where the reaction-accompanied size and number concentration change of the bulk nanobubbles and the corresponding thermal effect clearly confirm the occurrence of the nanobubble-based H2/O2 combustion. In addition, abundant radicals can be detected during the reaction, which is considered to be critical to ignite the gas reaction during the fusion of nanobubbles in water at room temperature. Therefore, the nanobubble-based gas-gas reactions provide a safe and efficient pathway to produce energy and synthesize new matter inaccessible under mild or ambient conditions. 相似文献
649.
Frontiers of Physics - Nonreciprocal microwave devices, in which the transmission of waves is non-symmetric between two ports, are indispensable for the manipulation of information processing and... 相似文献
650.