RESUMO
Cloud computing technology is widely used at present. However, cloud computing servers are far from terminal users, which may lead to high service request delays and low user satisfaction. As a new computing architecture, fog computing is an extension of cloud computing that can effectively solve the aforementioned problems. Resource scheduling is one of the key technologies in fog computing. We propose a resource scheduling method for fog computing in this paper. First, we standardize and normalize the resource attributes. Second, we combine the methods of fuzzy clustering with particle swarm optimization to divide the resources, and the scale of the resource search is reduced. Finally, we propose a new resource scheduling algorithm based on optimized fuzzy clustering. The experimental results show that our method can improve user satisfaction and the efficiency of resource scheduling.
RESUMO
The development of biodegradable and robust dielectric capacitors with high breakdown strength and energy density are indispensable. Herein, the high strength chitosan/edge hydroxylated boron nitride nanosheets (BNNSs-OH) dielectric film was fabricated via combining the dual chemically-physically crosslinking and the drafting orientation strategy, which could induced BNNSs-OH and chitosan crosslinked network alignment within the film via covalent and hydrogen bonding interaction, leading to the comprehensive reinforcement of tensile strength from 126 to 240 MPa, the Eb from 448 to 584 MV m-1, the in-plane thermal conductivity from 1.46 to 5.95 W m-1 K-1 and energy storage density from 7.22 to 13.71 J cm-1, superior than the comprehensive evaluation of the reported polymer dielectrics. The dielectric film could be completely degraded in soil in 90 days, which opened a new path for the development of next-generation environment-friendly dielectrics with excellent mechanical and dielectric properties.
RESUMO
Cellulose as the most abundant renewable polymer displays great potential to substitute the petroleum-derived synthetic polymers. However, cellulose is difficult to be melted or dissolved, which greatly restricts its development and utilization. Herein, the "green" alkali/urea aqueous system for cellulose dissolution is briefly summarized by illustrating the dissolving mechanism. The comparison of cellulose fibers from different solvent is presented. In addition, the recent achievements for the efficient and "green" preparation of regenerated cellulose fibers from alkali/urea system are also summarized. By investigating the effects of experimental conditions and technical parameters on the structure and performance of regenerated cellulose fibers, the improved fiber mechanical properties and the decreased production costs are achieved. Moreover, the preparation and application of cellulose-based functional fibers from alkali/urea system are also reviewed, together with the urgent challenges and future development perspectives, which provide the novel approach for the high value-added development and utilization of cellulose fibers.
Assuntos
Álcalis , Ureia , Celulose/química , Polímeros , Resistência à Tração , Ureia/química , Difração de Raios XRESUMO
With aging of population, changing of living habits, and intake of high-fat diet, more and more people have been suffering from cardio-cerebral apoplexy. The synchronous treatment of cardio-cerebral conditions based on an integral strategy may bring benefit to the better clinical efficacy. The simultaneously-targeting delivery of active molecules by nanoscale carriers to heart and brain remains unmet problem. The physiological difference of targets between heart and brain makes it a huge challenge which one targeting ligand modification acquires the delivery of two organs and treatment, simultaneously. Traditionally, dually targeting strategies are introduced to enhance the selectivity for one aimed tissue and delivery efficiency of these particles. However, the interference between two targeting ligands on the surface of nanoscale carriers may influence the affinity of these ligands with their receptors or transporters, resulting to the change distribution of carriers. Herein, we observed that how anti-cardiac troponin I (cTnI) antibody (Ab) conjugated with the linker, polyethylene glycol (PEG), on the surface of liposomes influenced the affinity of mannose derivatives with transporter and regulated distribution of these vesicles in the heart and brain. The dually targeting liposomes can target to the heart and brain tissue simultaneously by the regulation length of PEG chain linking with p -pentanoic acid phenyl-α-D-acetylmannosamine (Ac4MAN). These results may bring benefit to design the multi-modification of nanocarriers and the treatment of cardio-cerebral diseases.