251,832 research outputs found
Study of mechanical response in embossing of ceramic green substrate by micro-indentation
Micro-indentation test with a micro flat-end cone indenter was employed to
simulate micro embossing process and investigate the thermo-mechanical response
of ceramic green substrates. The laminated low temperature co-fired ceramic
green tapes were used as the testing material ; the correlations of indentation
depth versus applied force and applied stress at the temperatures of 25 degrees
C and 75degrees C were studied. The results showed that permanent indentation
cavities could be formed at temperatures ranging from 25 degrees C to 75
degrees C, and the depth of cavities created was applied force, temperature and
dwell time dependent. Creep occurred and made a larger contribution to the
plastic deformation at elevated temperatures and high peak loads. There was
instantaneous recovery during the unloading and retarded recovery in the first
day after indentation. There was no significant pile-up due to material flow
observed under compression at the temperature up to 75 degrees C. The plastic
deformation was the main cause for formation of cavity on the ceramic green
substrate under compression. The results can be used as a guideline for
embossing ceramic green substrates.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
Overall properties of the Gaia DR1 reference frame
We compare quasar positions of the auxiliary quasar solution with ICRF2
sources using different samples and evaluate the influence on the {\it Gaia}
DR1 reference frame owing to the Galactic aberration effect over the
J2000.0-J20015.0 period. Then we estimate the global rotation between TGAS with
{\it Tycho}-2 proper motion systems to investigate the property of the {\it
Gaia} DR1 reference frame. Finally, the Galactic kinematics analysis using the
K-M giant proper motions is performed to understand the property of {\it Gaia}
DR1 reference frame. The positional comparison between the auxiliary quasar
solution and ICRF2 shows negligible orientation and validates the declination
bias of \mas~in {\it Gaia} quasar positions with respect to ICRF2.
Galactic aberration effect is thought to cause an offset \mas~of
the axis direction of {\it Gaia} DR1 reference frame. The global rotation
between TGAS and {\it Tycho}-2 proper motion systems, obtained by different
samples, shows a much smaller value than the claimed value \masyr. For
the Galactic kinematics analysis of the TGAS K-M giants, we find possible
non-zero Galactic rotation components beyond the classical Oort constants: the
rigid part \masyr~and the differential part
\masyr~around the axis of Galactic
coordinates, which indicates possible residual rotation in {\it Gaia} DR1
reference frame or problems in the current Galactic kinematical model.Comment: 6 pages, 1 figure. Accepted for publication in A&
: An Excellent Candidate of Tetraquarks
We analyze various possible interpretations of the narrow state
which lies 100 MeV above threshold. This interesting state
decays mainly into instead of . If this relative branching
ratio is further confirmed by other experimental groups, we point out that the
identification of either as a state or more generally
as a state in the representation is probably
problematic. Instead, such an anomalous decay pattern strongly indicates
is a four quark state in the representation
with the quark content . We discuss its
partners in the same multiplet, and the similar four-quark states composed of a
bottom quark . Experimental searches of other members
especially those exotic ones are strongly called for
Pipelined digital SAR azimuth correlator using hybrid FFT-transversal filter
A synthetic aperture radar system (SAR) having a range correlator is provided with a hybrid azimuth correlator which utilizes a block-pipe-lined fast Fourier transform (FFT). The correlator has a predetermined FFT transform size with delay elements for delaying SAR range correlated data so as to embed in the Fourier transform operation a corner-turning function as the range correlated SAR data is converted from the time domain to a frequency domain. The azimuth correlator is comprised of a transversal filter to receive the SAR data in the frequency domain, a generator for range migration compensation and azimuth reference functions, and an azimuth reference multiplier for correlation of the SAR data. Following the transversal filter is a block-pipelined inverse FFT used to restore azimuth correlated data in the frequency domain to the time domain for imaging
Do local manufacturing firms benefit from transactional linkages with multinational enterprises in China?
This paper examines the linkage effects of foreign direct investment (FDI) on firm-level productivity in Chinese manufacturing. It is found that FDI generates positive vertical linkage effects in Chinese manufacturing at both the national and regional levels, and limited positive horizontal spillovers at the regional level. While OECD firms gain from both vertical and (probably) horizontal linkages, Hong Kong, Macao and Taiwanese firms benefit only from backward linkage effects. In the domestic sector, in which we are most interested, both state-owned enterprises (SOEs) and non-SOEs are hurt by competition from foreign firms in the same industries. While SOEs gain from vertical linkages with foreign firms, non-SOEs are unable to do so. The patterns of productivity spillovers from FDI in Chinese manufacturing seem to be determined by one key factor – the technological capabilities of the firms involved. Important data limitations and policy implications of this research are discussed
Resonant systems for dynamic evaluation of pressure transducers
Tests were conducted with contrived inlet modulated sinusoidal pressure generator to study possible use in calibrating pressure sensors. Results indicate concept is feasible and applicable to transducer evaluation
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