112 research outputs found
CONTRIBUTION OF MORPHOLOGICAL AWARENESS TO WORD SEGMENTATION AMONG ADULT L2 CHINESE SPEAKERS
The current study aims to investigate the causal correlation between Chinese morphological awareness and word segmentation among intermediate adult speakers who learn Chinese as their second language (L2). In particular, we intend to determine the role of a potential mediator, vocabulary knowledge in this relationship. A total of 45 intermediate adult L2 Chinese speakers participated in the experiment and finished three separate tasks on Chinese morphological awareness, Chinese word segmentation, and vocabulary size. The logistic regression on the results of Chinese morphological awareness task fails to prove that the L2 Chinese speakers are sensitive to the degree of compositionally of Chinese compounds. Multi-linear regressions were conducted to test the mediation effects, and the results demonstrate that: (1) Chinese morphological awareness didn’t directly predict participants performance in word segmentation; (2) Chinese morphological awareness didn’t indirectly exert a strong effect on word segmentation via vocabulary knowledge. Although the current study didn’t find evidence to verify the relationship between morphological awareness and word segmentation nor the mediation effects of vocabulary knowledge, it establishes a foundation for future research design and implementation.Master of Art
Hypoglycemic, hypolipidemic and antioxidant effects of iridoid glycosides extracted from: Corni fructus: Possible involvement of the PI3K-Akt/PKB signaling pathway
Iridoid glycosides (CIG) are the major component of Corni fructus. In this work, we researched the antioxidative, hypoglycemic and lowering blood lipids effects of CIG on diabetic mice induced by a high-fat diet (HFD) and streptozotocin (STZ). Furthermore, to investigate the molecular mechanism of action, the phosphorylation and protein expression of phosphoinositide 3-kinase (PI3K) and its downstream proteins, such as insulin receptor (INSR), protein kinase B (Akt/PKB) and glucose transporter 4 (GLUT4) have been detected. The results showed that CIG significantly improved oral glucose tolerance in diabetic mice. Biochemical indices also revealed that CIG had a positive effect on lipid metabolism and oxidative stress. In addition, CIG can significantly enhance the expression level of the PI3K-Akt/PKB pathway related proteins in skeletal muscle, which is the key pathway of insulin metabolism. These findings show that CIG can improve the hyperglycemia and hyperlipidemia of HFD-STZ-induced diabetic mice through the PI3K-Akt/PKB signaling pathway, and CIG might be a potential medicine or functional food for type 2 diabetes mellitus remedies. © 2018 The Royal Society of Chemistry
Fragile phase stability in (1-x)Pb(Mg1/3Nb2/3O3)-xPbTiO3 crystals: A comparisons of [001] and [110] field-cooled phase diagrams
Phase diagrams of [001] and [110] field-cooled (FC)
(1-x)Pb(Mg1/3Nb2/3O3)-xPbTiO3 or PMN-xPT crystals have been constructed, based
on high-resolution x-ray diffraction data. Comparisons reveal several
interesting findings. First, a region of abnormal thermal expansion above the
dielectric maximum was found, whose stability range extended to higher
temperatures by application of electric field (E). Second, the rhombohedral (R)
phase of the ZFC state was replaced by a monoclinic MA in the [001] FC diagram,
but with monoclinic MB in the [110] FC. Third, the monoclinic MC phase in ZFC
and [001] FC diagram was replaced by an orthorhombic (O) phase in the [110] FC.
Finally, in the [001] FC diagram, the phase boundary between tetragonal (T) and
MA was extended to lower PT contents (x=0.25); whereas in the [110] FC diagram,
this extended region was entirely replaced by the O phase. These results
clearly demonstrate that the phase stability of PMN-xPT crystals is quite
fragile, depending not only on modest changes in E, but also on the direction
along which that E is applied.Comment: 13 pages, 8 figures, 1 tabl
Monitoring of Tsunami/Earthquake Damages by Polarimetric Microwave Remote Sensing Technique
Polarization characterizes the vector state of EM wave. When interacting with polarized wave, rough natural surface often induces dominant surface scattering; building also presents dominant double-bounce scattering. Tsunami/earthquake causes serious destruction just by inundating the land surface and destroying the building. By analyzing the change of surface and double-bounce scattering before and after disaster, we can achieve a monitoring of damages. This constitutes one basic principle of polarimetric microwave remote sensing of tsunami/earthquake. The extraction of surface and double-bounce scattering from coherency matrix is achieved by model-based decomposition. The general four-component scattering power decomposition with unitary transformation (G4U) has been widely used in the remote sensing of tsunami/earthquake to identify surface and double-bounce scattering because it can adaptively enhance surface or double-bounce scattering. Nonetheless, the strict derivation in this chapter conveys that G4U cannot always strengthen the double-bounce scattering in urban area nor strengthen the surface scattering in water or land area unless we adaptively combine G4U and its duality for an extended G4U (EG4U). Experiment on the ALOS-PALSAR datasets of 2011 great Tohoku tsunami/earthquake demonstrates not only the outperformance of EG4U but also the effectiveness of polarimetric remote sensing in the qualitative monitoring and quantitative evaluation of tsunami/earthquake damages
Dynamic origin of the morphotropic phase boundary - Soft modes and phase instability in 0.68Pb(Mg1/3Nb2/3O3)-0.32PbTiO3
We report neutron inelastic scattering on single crystal
0.68Pb(Mg1/3Nb2/3O3)-0.32PbTiO3 (PMN-0.32PT), a relaxor ferroelectric material
that lies within the compositional range of the morphotropic phase boundary
(MPB). Data were obtained between 100 K and 600 K under zero and non-zero
electric field applied along the cubic [001] direction. The lowest energy,
zone-center, transverse optic phonon is strongly damped and softens slowly at
high temperature; however the square of the soft mode energy begins to increase
linearly with temperature as in a conventional ferroelectric, which we term the
soft mode "recovery," upon cooling into the tetragonal phase at TC. Our data
show that the soft mode in PMN-0.32PT behaves almost identically to that in
pure PMN, exhibiting the same temperature dependence and recovery temperature
even though PMN exhibits no well-defined structural transition (no TC). The
temperature dependence of the soft mode in PMN-0.32PT is also similar to that
in PMN-0.60PT; however in PMN-0.60PT the recovery temperature equals TC. These
results suggest that the temperature dependence and the energy scale of the
soft mode dynamics in PMN-xPT are independent of concentration on the Ti-poor
side of the MPB, but scale with TC for Ti-rich compositions. Thus the MPB may
be defined in lattice dynamical terms as the concentration where TC first
matches the recovery temperature of the soft mode. High-resolution x-ray
studies show that the cubic-to-ferroelectric phase boundary shifts to higher
temperatures by an abnormal amount within the MPB region in the presence of an
electric field. This suggests that an unusual instability exists within the
apparently cubic phase at the MPB.Comment: 13 pages, 6 figure
Structural studies of Fe0.81Ga0.19 by reciprocal space mapping
Reciprocal lattice mapping has been performed on Fe0.81Ga0.19 crystals by ω–ω/2θ, Ψ–ϕ, and ω–ϕ scans. A strong elongation of the 〈001〉c peak was found along the〈110〉c direction. ω scans revealed short lateral correlation lengths ξ along 〈110〉cand strong diffuse scattering along the 〈001〉c. Multiple domains with monoclinic symmetry (angle ∼190°) were observed by Ψ–ϕ and ω–ϕ scans on the (001)c face, and were also tilted with respect to each other. The results show an average cubic structure with orthorhombic structural modulations, and two structural domain states that result in a limiting monoclinic symmetry
A low frequency mechanical transmitter based on magnetoelectric heterostructures operated at their resonance frequency
Magneto-elasto-electric (ME) coupling heterostructures, consisting of piezoelectric layers bonded to magnetostrictive ones, provide for a new class of electromagnetic emitter materials on which a portable (area ~ 16 cm 2 ) very low frequency (VLF) transmitter technology could be developed. The proposed ME transmitter functions as follows: (a) a piezoelectric layer is first driven by alternating current AC electric voltage at its electromechanical resonance (EMR) frequency, (b) subsequently, this EMR excites the magnetostrictive layers, giving rise to magnetization change, (c) in turn, the magnetization oscillations result in oscillating magnetic fields. By Maxwell’s equations, a corresponding electric field, is also generated, leading to electromagnetic field propagation. Our hybrid piezoelectric-magnetostrictive transformer can take an input electric voltage that may include modulation-signal over a carrier frequency and transmit via oscillating magnetic field or flux change. The prototype measurements reveal a magnetic dipole like near field, demonstrating its transmission capabilities. Furthermore, the developed prototype showed a 10 4 times higher efficiency over a small-circular loop of the same area, exhibiting its superiority over the class of traditional small antennas
Construction of urban wetland ecological landscape planning model based on MSPA analysis method
The traditional method does not accurately select the ecological landscape pattern index of urban wetland, which leads to the problems of low accuracy and long planning time, in order to solve this problem, an urban wetland ecological landscape planning model based on MSPA analysis method is constructed. By analyzing the basic components of urban wetland ecological landscape, such as patch density, aggregation index, dispersion index, average fractal dimension, landscape segmentation, shape index, spread index and Shannon diversity index, MSPA analysis method is used to extract the core area, patch area and ring of urban wetland. According to the extraction results, the minimum function of cloud fusion transformation of three-dimensional wetland ecological landscape is calculated, and the function is used to calculate the three-dimensional translation transformation amount and rotation matrix of three-dimensional wetland ecological landscape model. The data in the three-dimensional model are used for wetland ecological landscape planning, so as to complete the construction of wetland ecological landscape planning model. The simulation results show that the urban wetland ecological landscape planning accuracy of the model is high and the planning time is short
Intermediate ferroelectric orthorhombic and monoclinic MB phases in [110]- electric field cooled Pb(Mg1/3Nb2/3)O3-30%PbTiO3 crystals
Structural phase transformations of [110] electric field cooled
Pb(Mg1/3Nb2/3)O3-30%PbTiO3 (PMN-30%PT) crystals have been performed by x-ray
diffraction in a field-cooled (FC) condition. A phase sequence of
cubic(C)-tetragonal(T)-orthorhombic (O)-monoclinic (MB) was found on
field-cooling (FC); and a R-MB-O one was observed with increasing field
beginning from the zero field-cooled (ZFC) condition at room temperature. The
application of the [110] electric field induced a dramatic change in the phase
sequence in the FC condition, compared to the corresponding data for PMN-30%PT
crystals in a [001] field, which shows that the phase sequence in the FC
condition is altered by the crystallographic direction along which a modest
electric field (E) is applied. Only when E is applied along [110] are
intermediate O and MB phases observed.Comment: 10 pages, 8 figure
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