Wentao Peng

In order to improve the efficiency and decision-making ability of airport operation support, the realization of estimation about service time of flight ground support can reduce the time and economic losses caused by flight delays. Considering the complexity and particularity of the service process, this article started from the analysis of the flight ground support process and constructed a mathematical model of the service time. The method of Principal Component Analysis (PCA) was used to reduce the correlation between variables, and a service time prediction model of flight ground support based on Deep Neural Network (DNN) was established. Finally, the flight support operation data of an airport were selected for simulation and verification. Experimental results show that the average absolute error of service time prediction can reach 2.709 min, the proposed model can effectively estimate the service time of flight support and has higher accuracy.

Reversible addition–fragmentation chain-transfer (RAFT) polymerization is a powerful tool for the precise formation of macromolecular building blocks that can be used for the construction of well-defined nanocomposites. Especially when combining RAFT polymers with uniform inorganic/metallic nanoparticles, a vast variety of complex nanocomposites become available that may find applications especially in the field of life sciences, e.g., bio-imaging, drug delivery or cancer-therapy, but also in areas such as energy conversion or catalysis. RAFT polymerization not only provides the possibility to control the size and the macromolecular architecture of the polymer building blocks, but inherently delivers highly functional end-groups that can often directly be employed as linker-sites for installing the polymeric components into the final nanocomposites. This review describes recent advances in this vivid field and concentrates on innovations in the fabrication method and design strategies for polymer/inorganic nanohybrids. The methodology of synthesizing RAFT polymer with the aim of surface functionalization and the design options for anchoring RAFT polymer on surfaces are covered. A series of core–shell nanostructures with the focus on novel functionalities brought by RAFT polymer brushes will be reviewed with focus on the detailed macromolecular design for each specific application's scenario. Examples of ordered nano-assemblies using RAFT polymer linkers will be reviewed in order to demonstrate the advantages of RAFT polymer for introducing different morphologies, interactions and chirality to the final functional nanostructures.

Linear and four-arm star polystyrene samples prepared by RAFT polymerization were grafted to gold surfaces directly via their thiocarbonylthio-end groups. Nanoscale polymer patterns were subsequently formed via constrained dewetting. The patterned polymer films then served as a template for the precise arrangement of gold nanoparticles in a monolayer with a well-defined and regular structure. Using star polymers as a linker between the planar gold surface and the particles, the structural stability of the arranged particles can be further enhanced. The surface-bound nanocomposite films made of polymer and nanoparticles can also reversibly switch their nanostructures by simple wetting or dewetting treatment.

In mizellarer Katalyse wurden chemoselektive C‐H‐Arylierungen durch einen vielseitigen, wohl definierten Rutheniumkatalysator ermöglicht. Diese Strategie eröffnete einen praktischen Zugang zu C‐H‐arylierten Ferrocenen, toleriert eine Vielzahl an funktionellen Gruppen und ermöglicht eine breite Anwendung durch schwache Koordination. Die Nachhaltigkeit der C‐H‐Arylierung zeigt sich besonders in der herausragenden Atomökonomie und den Recyclingstudien. Detaillierte computerchemische Studien untermauern einen durch Thioketon assistierten leichtgängigen C‐H Aktivierungsschritt.

Chemoselective C−H arylations were accomplished through micellar catalysis by a versatile single‐component ruthenium catalyst. The strategy provided expedient access to C−H‐arylated ferrocenes with wide functional‐group tolerance and ample scope through weak chelation assistance. The sustainability of the C−H arylation was demonstrated by outstanding atom‐economy and recycling studies. Detailed computational studies provided support for a facile C−H activation through thioketone assistance.

Integrating the properties of magnetite nanoparticles (MNPs) and high‐density polymer brushes in one structure requires sophisticated synthetic designs and effective chemical approaches. A simple and versatile strategy for the fabrication of hydrophilic‐polymer‐capped magnetite‐core‐silica‐shell nanohybrids with well‐defined structure employing reverse microemulsion technique and reversible addition–fragmentation chain transfer (RAFT) polymerization is presented. The high‐density polymer brush allows precise patterning of the magnetic nanohybrids with a tunable interparticle distance ranging from 20 nm to 80 nm by controlling the polymer size. The high structural precision provides a near stand‐alone state of the MNPs in the nanohybrids with effectively inhibited magnetic interaction, as shown by superconducting quantum interference device (SQUID) measurements.

We report an efficient synthesis route for the formation of gold/silver-core–PE-shell nanohybrids in a simple self-assembly approach using PE with strong aurophilicity and argentophilicity, via thiol- and trithiocarbonate terminated moieties. This united the unique properties of polyethylene (PE) with gold and silver nanoparticles, using the well-defined end-group design of PE. These nanocomposites showed a similar solubility as PE, as confirmed by dynamic light scattering, and could be fully incorporated into a polyethylene matrix with different particle contents, as visualized by transmission electron microscopy. Using UV/vis-spectroscopy, we observed reversible, thermoresponsive aggregation/deaggregation properties in the nanohybrids, validating the strong and effective anchoring of PE on gold/silver surfaces.

The hierarchical self-assembly of distinct nanoelements into precisely ordered nanostructures requires efficient and flexible fabrication strategies. Herein, we report the precise fabrication of bimetallic gold-planet–silver-satellite nanoparticle-arrangements employing RAFT star polymers as particle linker connecting gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) with judiciously modified surface activity. The strengths of this approach include the adjustability of interparticle distances by tailoring the star polymer molar mass. The prepared nanoassemblies have well-defined structures in which a planet AuNP (∼13 nm) is encompassed by several satellite AgNPs (∼8 nm), thus incorporating the properties of both AuNPs and AgNPs, as confirmed by transmission electron microscopy and UV–vis spectra. Our results highlight the general applicability of RAFT star polymers as a nanosynthesis platform for synthesizing noble metal nanocomposites.

Polycyclic polymers made from cyclic (ABC)_n-multiblock-copolymers that may undergo self-complementary hydrogen bonds within the individual rings show extraordinary material properties.