18,690 research outputs found
Interpolation function of the genocchi type polynomials
The main purpose of this paper is to construct not only generating functions
of the new approach Genocchi type numbers and polynomials but also
interpolation function of these numbers and polynomials which are related to a,
b, c arbitrary positive real parameters. We prove multiplication theorem of
these polynomials. Furthermore, we give some identities and applications
associated with these numbers, polynomials and their interpolation functions.Comment: 14 page
Pressure effects on the heavy-fermion antiferromagnet CeAuSb2
The f-electron compound CeAuSb2, which crystallizes in the ZrCuSi2-type
tetragonal structure, orders antiferromagnetically between 5 and 6.8 K, where
the antiferromagnetic transition temperature T_N depends on the occupancy of
the Au site. Here we report the electrical resistivity and heat capacity of a
high-quality crystal CeAuSb2 with T_N of 6.8 K, the highest for this compound.
The magnetic transition temperature is initially suppressed with pressure, but
is intercepted by a new magnetic state above 2.1 GPa. The new phase shows a
dome shape with pressure and coexists with another phase at pressures higher
than 4.7 GPa. The electrical resistivity shows a T^2 Fermi liquids behavior in
the complex magnetic state, and the residual resistivity and the T^2
resistivity coefficient increases with pressure, suggesting the possibility of
a magnetic quantum critical point at a higher pressure.Comment: 5 pages, 5 firure
Structure-specified H∞ loop shaping control for balancing of bicycle robots: A particle swarm optimization approach
In this paper, the particle swarm optimization (PSO) algorithm was used to design the structure-specified H∞ loop shaping controllers for balancing of bicycle robots. The structure-specified H∞ loop shaping controller design normally leads to a complex optimization problem. PSO is an efficient meta-heuristic search which is used to solve multi-objectives and non-convex optimizations. A model-based systematic procedure for designing the particle swarm optimization-based structure-specified H∞ loop shaping controllers was proposed in this research. The structure of the obtained controllers are therefore simpler. The simulation and experimental results showed that the robustness and efficiency of the proposed controllers was gained when compared with the proportional plus derivative (PD) as well as conventional H∞ loop shaping controller. The simulation results also showed a better efficiency of the developed control algorithm compared to the Genetic Algorithm based one
Correlation effects in CaCu3Ru4O12
We have investigated the electronic structure of CaCu3Ru4O12 and LaCu3Ru4O12
using soft x-ray photoelectron and absorption spectroscopy together with band
structure and cluster configuration interaction calculations. We found the Cu
to be in a robust divalent ionic state while the Ru is more itinerant in
character and stabilizes the metallic state. Substitution of Ca by La
predominantly affects the Ru states. We observed strong correlation effects in
the Cu 3d states affecting the valence band line shape considerably. Using
resonant photoelectron spectroscopy at the Cu L3 edge we were able to unveil
the position of the Zhang-Rice singlet states in the one-electron removal
spectrum of the Cu with respect to the Ru-derived metallic bands in the
vicinity of the chemical potential
Cell Patterning with Mucin Biopolymers
The precise spatial control of cell adhesion to surfaces is an endeavor that has enabled discoveries in cell biology and new possibilities in tissue engineering. The generation of cell-repellent surfaces currently requires advanced chemistry techniques and could be simplified. Here we show that mucins, glycoproteins of high structural and chemical complexity, spontaneously adsorb on hydrophobic substrates to form coatings that prevent the surface adhesion of mammalian epithelial cells, fibroblasts, and myoblasts. These mucin coatings can be patterned with micrometer precision using a microfluidic device, and are stable enough to support myoblast differentiation over seven days. Moreover, our data indicate that the cell-repellent effect is dependent on mucin-associated glycans because their removal results in a loss of effective cell-repulsion. Last, we show that a critical surface density of mucins, which is required to achieve cell-repulsion, is efficiently obtained on hydrophobic surfaces, but not on hydrophilic glass surfaces. However, this limitation can be overcome by coating glass with hydrophobic fluorosilane. We conclude that mucin biopolymers are attractive candidates to control cell adhesion on surfaces.European Commission (Marie Curie International Outgoing Fellowship for Career Development, “BIOMUC”)National Institutes of Health (U.S.) (NIH Grant 1R01GM100473)National Science Foundation (U.S.) (award number DMR-819762)National Science Foundation (U.S.) (NSF Grant OCE-0744641-CAREER)National Science Foundation (U.S.) (Award DMR-0819762)Samsung Scholarship FoundationMassachusetts Institute of Technology (Startup funds)Massachusetts Institute of Technology (Junior Faculty award
Effects of pressure on the ferromagnetic state of the CDW compound SmNiC2
We report the pressure response of charge-density-wave (CDW) and
ferromagnetic (FM) phases of the rare-earth intermetallic SmNiC2 up to 5.5 GPa.
The CDW transition temperature (T_{CDW}), which is reflected as a sharp
inflection in the electrical resistivity, is almost independent of pressure up
to 2.18 GPa but is strongly enhanced at higher pressures, increasing from 155.7
K at 2.2 GPa to 279.3 K at 5.5 GPa. Commensurate with the sharp increase in
T_{CDW}, the first-order FM phase transition, which decreases with applied
pressure, bifurcates into the upper (T_{M1}) and lower (T_c) phase transitions
and the lower transition changes its nature to second order above 2.18 GPa.
Enhancement both in the residual resistivity and the Fermi-liquid T^2
coefficient A near 3.8 GPa suggests abundant magnetic quantum fluctuations that
arise from the possible presence of a FM quantum critical point.Comment: 5 pages, 5 figure
Impact of different definitions of clear-sky flux on the determination of longwave cloud radiative forcing: NICAM simulation results
Using one month of the cloud-resolving Nonhydrostatic Icosahedral
Atmospheric Model (NICAM) simulations, we examined the impact of different
definitions of clear-sky flux on the determination of longwave cloud
radiative forcing (CRF). Because the satellite-like cloud-free composite
preferentially samples drier conditions relative to the all-sky mean state,
the conventional clear-sky flux calculation using the all-sky mean state in
the model may represent a more humid atmospheric state in comparison to the
cloud-free state. The drier bias is evident for the cloud-free composite in
the NICAM simulations, causing an overestimation of the longwave CRF by
about 10% compared to the NICAM simulated longwave CRF. Overall, water
vapor contributions of up to 10% of the total longwave CRF should be
taken account for making model-generated cloud forcing comparable to the
satellite measurements
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