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1.
Martin Mason 《世界电子元器件》2006,(2):34-34,36,37,53
设计工程师面临的挑战 在今天的市场上,产品迅速上市的压力愈来愈大,但产品的使用寿命却不断缩短。产品设计稳定于12-18个月的周期不再存在,取而代之的是产品每6个月便会更新。缩短的使用寿命给OEM厂商带来更大的压力,需要更迅速及高效地把新设计推向市场。有研究指出,产品的推出若延迟4周,便会失去约14%的市场份额。 相似文献
2.
Mason G.M. Hamilton D.C. Walpole P.H. Heuerman K.F. James T.L. Lennard M.H. Mazur J.E. 《Geoscience and Remote Sensing, IEEE Transactions on》1993,31(3):549-556
The SAMPEX (Solar, Anomalous, and Magnetospheric Particle Explorer) LEICA instrument is designed to measure ~0.5-5-MeV/nucleon solar and magnetospheric ions over the range from He-Ni. The instrument is a time-of-flight (TOF) mass spectrometer, which measures particle TOF over an ~0.5-m path and the residual energy deposited in an array of Si solid state detectors. Large-area microchannel plates are used, resulting in a large geometrical factor for the instrument (0.6 cm2 sr), which is essential for accurate compositional measurements in small solar flares and in studies of precipitating magnetospheric heavy ions 相似文献
3.
Emulsions of perfluorotributylamine (FTBA) and perflubron were evaluated for their utility in 19F echo planar imaging. Fluorine images of the emulsions were obtained in a phantom and two mice that had been predosed. Both agents, but particularly perflubron, show potential for fluorine echo planar studies because of the long spin-spin relaxation times of the CF3 resonances. High resolution thin slice images obtained in as little as 26.6 ms are presented. 相似文献
4.
The design and evaluation of an optically triggered, fully integrated sample and hold circuit (OS/H) is described. Measured results are presented that demonstrate operation of this circuit at 250 Ms/s and with effective resolution approaching 8 bits. The integrated circuit, which measures 2.1 mm×1.4 mm, is realized in -1.0-V threshold, 20-GHz ft GaAs MESFET technology, consumes approximately 200 mW of power, and requires one optical address. The OS/H will find applications in high precision, hybrid, and integrated signal processing systems where high speed, high levels of parallelism, and low timing jitter are important. Measured results of a series photoconducting (Auston switch) OS/H realized in the same technology are presented for comparison purposes 相似文献
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Amir Abbas Matin Ramin Maleki Mir Ali Farajzadeh Khalil Farhadi Reza Hosseinzadeh Abolghasem Jouyban 《Chromatographia》2007,66(5-6):383-387
A new method for extraction and analysis of acetone in human urine based on headspace solid phase microextraction using a
mixture of activated carbon and zeolite as sorbents in a PVC matrix coated on a silver wire and its application to the determination
of ketone bodies is described. Unlike commercial fibers, which are coated on fused silica, the coating adheres strongly to
the silver wire and is thermally stable up to 250 °C. After optimization of coating composition and microextraction conditions
the fiber was used for the analysis of acetone in human urine. 相似文献
7.
B. M. Forster J. M. Bailey G. A. Beer J. L. Beveridge J. H. Brewer W. N. Hardy T. M. Huber K. R. Kendall A. R. Kunselman J. A. Macdonald G. M. Marshall G. R. Mason A. Olin M. Senba J. B. Warren 《Hyperfine Interactions》1991,65(1-4):1007-1013
Muonic hydrogen isotopes (μ− p, μ− d, and μ−t) are simple quantum mechanical systems ideally suited for studies of numerous fundamental phenomena in electroweak and strong
interactions as well as in applied areas such as muon chemistry or muon catalyzed fusion.
Emission of muonic hydrogen isotopes into vacuum helps to overcome the limitations which are normally imposed on conventional
investigations with gaseous and liquid targets. A proof of principle experiment for this new technique was performed at TRIUMF
last year. Negative muons with 30 MeV/c momentum were stopped in a thin film of solid hydrogen and produced very low energy μ−d in vacuum. The distribution center of the normal velocity components of emitted μ−d atoms was measured to be ∼1 cm/μs. The yield of μ−d in vacuum is an increasing function of H2 film thickness δ up to a value of δ≥1 mm. 相似文献
8.
We discuss equivalent definitions of holomorphic second-order cusp forms and prove bounds on their Fourier coefficients. We
also introduce their associated L-functions, prove functional equations for twisted versions of these L-functions and establish a criterion for a Dirichlet series to originate from a second order form. In the last section we
investigate the effect of adding an assumption of periodicity to this criterion.
2000 Mathematics Subject Classification Primary—11F12, 11F66
G. Mason: Research supported in part by NSF Grant DMS 0245225.
C. O’Sullivan: Research supported in part by PSC CUNY Research Award No. 65453-00 34. 相似文献
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