119 research outputs found
ENANTIOSELECTIVE EXTRACTION OF RACEMIC OFLOXACIN BY DI(2-ETHYLHEXYL)PHOSPHORIC ACID AND TARTARIC ACID DERIVATIVES AS MIXED COMPLEX CHIRAL SELECTORS
Trajectory Generation and Tracking Control for Aggressive Tail-Sitter Flights
We address the theoretical and practical problems related to the trajectory
generation and tracking control of tail-sitter UAVs. Theoretically, we focus on
the differential flatness property with full exploitation of actual UAV
aerodynamic models, which lays a foundation for generating dynamically feasible
trajectory and achieving high-performance tracking control. We have found that
a tail-sitter is differentially flat with accurate aerodynamic models within
the entire flight envelope, by specifying coordinate flight condition and
choosing the vehicle position as the flat output. This fundamental property
allows us to fully exploit the high-fidelity aerodynamic models in the
trajectory planning and tracking control to achieve accurate tail-sitter
flights. Particularly, an optimization-based trajectory planner for
tail-sitters is proposed to design high-quality, smooth trajectories with
consideration of kinodynamic constraints, singularity-free constraints and
actuator saturation. The planned trajectory of flat output is transformed to
state trajectory in real-time with consideration of wind in environments. To
track the state trajectory, a global, singularity-free, and
minimally-parameterized on-manifold MPC is developed, which fully leverages the
accurate aerodynamic model to achieve high-accuracy trajectory tracking within
the whole flight envelope. The effectiveness of the proposed framework is
demonstrated through extensive real-world experiments in both indoor and
outdoor field tests, including agile SE(3) flight through consecutive narrow
windows requiring specific attitude and with speed up to 10m/s, typical
tail-sitter maneuvers (transition, level flight and loiter) with speed up to
20m/s, and extremely aggressive aerobatic maneuvers (Wingover, Loop, Vertical
Eight and Cuban Eight) with acceleration up to 2.5g
Synaptic signalling in a network of dopamine neurons:What prevents proper inter-cellular crosstalk?
Open access via the Jisc Wiley Agreement Acknowledgements: This work was supported by the Chancellorâs Fellow Grant and the Moray Endowment Grant to SS. YC and TK were supported by Medical Research Council (Award Number: MR/K017276/1) and UK Centre for Mammalian Synthetic Biology. The authors gratefully acknowledge the financial support of NHS Research Scotland (NRS), through Edinburgh Clinical Research Facility. Authors thank Prof. Andrey Abramov (UCL) for his valuable suggestions on design of this study and Scott Denham from the Mass Spectrometry Core for his technical expertise and assistance in this work.Peer reviewedPublisher PD
Unusual double-peak specific heat and spin freezing in a spin-2 triangular lattice antiferromagnet FeAlSe
We report the properties of a triangular lattice iron-chalcogenide
antiferromagnet FeAlSe. The spin susceptibility reveals a
significant antiferromagnetic interaction with a Curie-Weiss temperature
{\Theta} ~ -200K and a spin-2 local moment. Despite a large spin and a
large |{\Theta}|, the low-temperature behaviors are incompatible with
conventional classical magnets. No long-range order is detected down to 0.4K.
Similar to the well-known spin-1 magnet NiGaS, the specific heat of
FeAlSe exhibits an unusual double-peak structure and a T
power law at low temperatures, which are attributed to the underlying
quadrupolar spin correlations and the Halperin-Saslow modes, respectively. The
spin freezing occurs at ~ 14K, below which the relaxation dynamics is probed by
the ac susceptibility. Our results are consistent with the early theory for the
spin-1 system with Heisenberg and biquadratic spin interactions. We argue that
the early proposal of the quadrupolar correlation and gauge glass dynamics may
be well extended to FeAlSe. Our results provide useful insights
about the magnetic properties of frustrated quantum magnets with high spins.Comment: 7 pages, 4 figure
Engineering synucleinopathy-resistant human dopaminergic neurons by CRISPR-mediated deletion of the <i>SNCA</i> gene
Creating Visible-to-Near-Infrared Mechanoluminescence in Mixed-Anion Compounds SrZn 2 S 2 O and SrZnSO
Abstract(#br)Mechanoluminescence (ML) materials featuring light emission in response to mechanical stimulus have shown promising applications in damage diagnosis, dynamic force detection, and information storage. However, their applications are greatly limited by a very small number of available ML materials as well as unsatisfied ML spectra. In this paper, we developed novel ML materials with intense ML and super-broad visible-to-near-infrared (470-1600 nm) spectra by incorporating lanthanide ions or transition metals into mixed-anion compounds SrZn 2 S 2 O and SrZnSO. These mixed-anion compounds show a linear relationship between ML intensity and applied force, allowing them to be used in non-contact/multi-touch stress sensing. Moreover, the mixed-anion compounds exhibit multiband near-infrared ML enabling a significant bright-field stress sensing approach without the interference of ambient light. This work offers a unique insight for discovering new ML materials and enriching the ML spectral range, thereby promoting their potential applications in stress intelligent sensors, electronic skins, and human-machine interfaces
Association of GALC, ZNF184, IL1R2 and ELOVL7 With Parkinsonâs Disease in Southern Chinese
Study Objectives: The aim of the study was to investigate the relationship between 22 single nucleotide polymorphisms (SNPs) and Parkinsonâs disease (PD) in the Chinese population.Methods: A total of 250 PD patients and 240 healthy controls were recruited. The SNaPshot technique and the polymer chain reaction were used to detect 22 SNPs.Results: rs8005172 of GALC, rs9468199 of ZNF184 and rs34043159 of IL1R2, were associated with PD (rs8005172: p = 0.009, OR = 0.69, allele model, p = 0.010, additive model, p = 0.015, OR = 2.17, dominant model; p = 0.020, OR = 2.11, dominant model after adjustment; p = 0.036, OR = 1.47, recessive model after adjustment; rs9468199: p = 0.008, OR = 1.52, allele model, p = 0.008, additive model, p = 0.007, OR = 0.22, recessive model, p = 0.005, OR = 0.20, recessive model after adjustment; rs34043159: p = 0.034, OR = 1.31, allele model, p = 0.036, additive model).Conclusion: Our study revealed that GALC, ZNF184, and IL1R2 were associated with PD in the southern Chinese population. GALC was also associated with LOPD. ELOVL7 and ZNF184 were associated with EOPD. In addition, trends of association to PD, between SATB1, NMD3, and FGF20, were also found.Statement of Significance: Genetic play an important role in the pathogenesis factors of Parkinsonâs disease (PD). We found that GALC, ZNF184, and IL1R2 were associated with PD. GALC was also associated with late onset of PD, while ELOVL7 and ZNF184 were associated with early onset PD. This study is the first to find an association between GALC, ZNF184, and rs2280104 with PD
Spin-phonon scattering-induced low thermal conductivity in a van der Waals layered ferromagnet CrSiTe
Layered van der Waals (vdW) magnets are prominent playgrounds for developing
magnetoelectric, magneto-optic and spintronic devices. In spintronics,
particularly in spincaloritronic applications, low thermal conductivity
() is highly desired. Here, by combining thermal transport measurements
with density functional theory calculations, we demonstrate low down
to 1 W m K in a typical vdW ferromagnet CrSiTe. In
the paramagnetic state, development of magnetic fluctuations way above
33 K strongly reduces via spin-phonon scattering,
leading to low 1 W m K over a wide temperature
range, in comparable to that of amorphous silica. In the magnetically ordered
state, emergence of resonant magnon-phonon scattering limits below
2 W m K, which would be three times larger if magnetic
scatterings were absent. Application of magnetic fields strongly suppresses the
spin-phonon scattering, giving rise to large enhancements of . Our
calculations well capture these complex behaviours of by taking the
temperature- and magnetic-field-dependent spin-phonon scattering into account.
Realization of low which is easily tunable by magnetic fields in
CrSiTe, may further promote spincaloritronic applications of vdW
magnets. Our theoretical approach may also provide a generic understanding of
spin-phonon scattering, which appears to play important roles in various
systems.Comment: 14 pages, 6 figures, accepted for publication in Advanced Functional
Material
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