246 research outputs found
Regional gradient controllability of ultra-slow diffusions involving the Hadamard-Caputo time fractional derivative
This paper investigates the regional gradient controllability for ultra-slow
diffusion processes governed by the time fractional diffusion systems with a
Hadamard-Caputo time fractional derivative. Some necessary and sufficient
conditions on regional gradient exact and approximate controllability are first
given and proved in detail. Secondly, we propose an approach on how to
calculate the minimum number of strategic actuators. Moreover, the
existence, uniqueness and the concrete form of the optimal controller for the
system under consideration are presented by employing the Hilbert Uniqueness
Method (HUM) among all the admissible ones. Finally, we illustrate our results
by an interesting example.Comment: 16 page
A Sandwich-Structured Hybrid Anode With Nitrogen-Doped Amorphous Carbon Nanoarrays Vertically Anchoring on Graphene Nanoplatelets for High Rate Li Storage
Graphene is not an ideal anode material of Li-ion batteries because of its low packing density and low initial Coulombic Efficiency although it shows much higher specific capacity than graphite. Herein, we report a sandwich-structured hybrid anode material which integrates the nitrogen-doped amorphous carbon nanoarrays on both sides of graphene nanoplatelets. The former provides high capacity and excellent rate capability, while the latter stabilizes the cycle performance, both of them brought out outstanding electrochemical properties to the hybrid anode. High discharge capacities of 562 and 217 mA h g−1 are obtained at current densities of 0.1 and 3 A g−1, respectively, which are much higher than those of the starting graphene nanoplatelets (404 and 81 mA h g−1, respectively). Moreover, a discharge capacity of 540 mA h g−1 is maintained after 300 cycles at 0.5 A g−1, demonstrating an excellent cycle stability. This study provides a facile process to prop up the 2 D graphene nanoplatelets with vertically aligned carbon nanoarrays, which may push forward the application of graphene as anode material of Li-ion batteries because of the avoided aggregation and additional Li storage capacity contributed by the N-doped amorphous carbon
Real-time visualization of clustering and intracellular transport of gold nanoparticles by correlative imaging.
Mechanistic understanding of the endocytosis and intracellular trafficking of nanoparticles is essential for designing smart theranostic carriers. Physico-chemical properties, including size, clustering and surface chemistry of nanoparticles regulate their cellular uptake and transport. Significantly, even single nanoparticles could cluster intracellularly, yet their clustering state and subsequent trafficking are not well understood. Here, we used DNA-decorated gold (fPlas-gold) nanoparticles as a dually emissive fluorescent and plasmonic probe to examine their clustering states and intracellular transport. Evidence from correlative fluorescence and plasmonic imaging shows that endocytosis of fPlas-gold follows multiple pathways. In the early stages of endocytosis, fPlas-gold nanoparticles appear mostly as single particles and they cluster during the vesicular transport and maturation. The speed of encapsulated fPlas-gold transport was critically dependent on the size of clusters but not on the types of organelle such as endosomes and lysosomes. Our results provide key strategies for engineering theranostic nanocarriers for efficient health management
Low Loss and Magnetic Field-tuned Superconducting THz Metamaterial
Superconducting terahertz (THz) metamaterial (MM) made from superconducting
Nb film has been investigated using a continuous-wave THz spectroscopy with a
superconducting split-coil magnet. The obtained quality factors of the resonant
modes at 132 GHz and 450 GHz are about three times as large as those calculated
for a metal THz MM operating at 1 K, which indicates that superconducting THz
MM is a very nice candidate to achieve low loss performance. In addition, the
magnetic field-tuning on superconducting THz MM is also demonstrated, which
offer an alternative tuning method apart from the existed electric, optical and
thermal tuning on THz MM
The role of the JAK2-STAT3 pathway in pro-inflammatory responses of EMF-stimulated N9 microglial cells
The Biocompatibility of Nanodiamonds and Their Application in Drug Delivery Systems
Nanodiamonds (NDs), as a new member of the carbon nanoparticles family, have attracted more and more attention in biomedicine recently due to their excellent physical and chemical properties. This paper summarizes the main results from the in vitro and in vivo safety assessments of NDs and reports the application of NDs in the development of drug delivery systems. In view of the NDs' characteristics of easy formation of a porous cluster structure in solution, an adsorption model for a variety of functional molecules on the ND clusters is proposed, which provides new ideas for developing a novel smart drug with various features such as sustained-release, targeting, and fluorescence imaging
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