نتایج جستجو برای: stepped tube

تعداد نتایج: 101757  

2007
Q. Zhang Y. Luo D. L. Hu B. F. Luo Y. S. Zeng

The bird aircraft strike hazard (BASH) is a worldwide problem to aviation, which deprives lots of properties and lives every year. Avian radar systems are necessary to be developed for avian surveillance and early warning. In this paper, the frequency-stepped chirp signal radar is utilized to obtain high range resolution for micro-Doppler features extraction by means of synthetic bandwidth. The...

2009
Jiin-Huarng Guo Wei-ming Luh

We report a simple stepped growth process for the synthesis of carbon nanotubes (CNTs) having excellent field emission properties. CNT growth was interrupted in the process. During the interruption, the catalyst was re-activated in-situ. This resulted in enhanced growth of the CNTs after the interruption and a film of CNTs re-grew on top of an existing CNT film at much higher rates. The enhance...

2005
CARLOS A. GONZALEZ HUBERT CHANSON

Current expertise in air-water turbulent flows on stepped chutes is limited to laboratory experiments at low to moderate Reynolds numbers on flat horizontal steps. In this study, highly turbulent air-water flows skimming down a large-size stepped chute were systematically investigated with a 22o slope. Turbulence manipulation was conducted using vanes or longitudinal ribs to enhance interaction...

Journal: :Physical review letters 2001
J Repp S Fölsch G Meyer K H Rieder

NaCl films on Cu(311) exhibit a remarkably strong and localized binding between adlayer and substrate. The binding sites of the ions in the NaCl film with respect to the Cu surface are determined from atomically resolved scanning tunneling microscopy images. A new model is proposed in which the binding mechanism is controlled by the charge modulation of a regularly stepped surface due to the Sm...

2002
Tom Brewster Chris Farentinos Douglas Ziedonis

The changing methadone population Chris Farentinos: The methadone population has changed. Today we are treating a jobless, skill-less population that is much more difficult to treat than the patients of decades past. Still, I am not sure I really see any difference in the effectiveness of methadone today compared to 10 years ago. I think you have one-third of people who will benefit, stay on me...

Journal: :Advanced Functional Materials 2014

2018
Gernot Füchsel Kun Cao Süleyman Er Egidius W F Smeets Aart W Kleyn Ludo B F Juurlink Geert-Jan Kroes

Stepped metal surfaces are usually assumed to exhibit an increased catalytic activity for bond cleavage of small molecules over their flat single-crystal counterparts. We present experimental and theoretical data on the dissociative adsorption of molecular hydrogen on copper that contradicts this notion. We observe hydrogen molecules to be more reactive on the flat Cu(111) than on the stepped C...

2008
Yimin Liu Huadong Meng Hao Zhang Xiqin Wang

High range resolution (HRR) profiling using stepped-frequency pulse trains suffers from range shift and the attenuation/dispersion of range profiles while the target of interest is moving. To overcome these two drawbacks, a new algorithm based on the maximum likelihood (ML) estimation is proposed in this paper. Without altering the conventional stepped-frequency waveform, this algorithm can est...

2008
Gang Li Huadong Meng Xiang-Gen Xia Ying-Ning Peng

Range and velocity estimation of moving targets using conventional steppedfrequencypulse radar may suffer from the range-Doppler coupling and the phasewrapping. To overcome these problems, this paper presents a new radar waveform namedmultiple stepped-frequency pulse trains and proposes a new algorithm. It is shown that byusing multiple stepped-frequency pulse trains and the robust phase unwrap...

2016
Karla Hemming

UNLABELLED Estimation of sample size and power for stepped wedge cluster randomised trials can be determined by one of a number of related methods. These include exact analytical approaches, design effects or simulation. A recent paper compared the design effect to the analytical method. There were some differences between the two approaches. We show here that these differences occur because th...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید