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Microparticles with uniform anisotropic structures are widely used in physical, chemical, and biological fields owing to their ability to combine multiple functions on a micro-scale. Here, a microfluidic emulsion-based external gelation method was demonstrated for the first time to produce monodisperse Janus calcium alginate (Ca-alginate) hydrogel microparticles consisting of two compartments. This approach provided a fast reaction condition under which we could prepare magnetic Janus Ca-alginate microparticles with diameters ranging from 148 to 179 μm and a coefficient of variation (CV) less than 4%. Moreover, the boundaries between the two compartments were clear. In addition, the volume fraction of each compartment could be adjusted by varying the flow rate ratio between two dispersed phases. Next, we produced fluorescent Janus beads and magnetic-fluorescent Janus beads with an average diameter of ∼150 μm (CV

Unmanned tracked vehicle mostly use remote control. Communication delay and unclear images are easy to cause operator errors in operation, especially when starting on large uphill, safety accidents such as slipping and sideslip often occur. Aiming at the problem of uphill assist safety, on the basis of analyzing the longitudinal dynamics of the vehicle, a feedforward and feedback control method is proposed, the evaluation index of the big uphill assist performance is designed, the target driving force is obtained according to the uphill resistance and braking force, and the feedforward is designed The compensator calculates the feedforward driving force through the braking force, and then completes the feedback closed-loop control through the quasi-sliding mode controller. Through model simulation, this design method can help the unmanned tracked vehicle to start safely on the uphill, and the vehicle speed tracking effect is good, reducing the driver's control difficulty in uphill starting, and meeting the design requirements of the unmanned tracked vehicle's safe starting control on the uphill.

Two novel donor-acceptor (D-A) polymers based on two-dimensional conjugated alkylthienyl substituted benzo[1,2-b:4,5-b′]dithiophene and difluorine substituted isoindigo derivatives were synthesized with the structures as poly{6-(4,8-bis(4,5-dioctylthiophen-2-yl)-benzo[1,2-b:4,5-b′]-dithiophen-2-yl)−5,5′-difluoro-1,1′-dioctyl-isoindigo} (P1) and poly{5-(4,8-bis(4,5-dioctyl-thiophen-2-yl)-benzo[1,2-b:4,5-b′]-di-thiophen-2-yl)−4,6-difluoro-1,1′-dioctyl-isoindigo} (P2), respectively. Thermal stability, absorption properties, energy levels and photovoltaic properties of the polymers were intensively investigated. The symmetric polymer P1 showed broad absorption in comparison with the asymmetric polymer P2 both in solution and solid film, corresponding to their band gaps of 1.45 (P1) and 1.59 (P2) eV, respectively. The copolymers possessed similar high-lying highest occupied molecular orbital (HOMO) levels of – 5.34 (P1) and – 5.32 eV (P2). The performance of conventional solar cells based on copolymers/PCBM (PC61BM and PC71BM) films were investigated. All of P2-based PSCs delivered superior power conversion efficiencies (PCEs) and higher short circuit current (Jsc) than P1-based devices, where a best PCE up to 4.23% was obtained from P2/PC71BM device by THF solvent-vapor-annealing (SVA) treatment with an open-circuit voltage (Voc) of 0.88 V, a Jsc of 8.27 mA/cm2 and a fill factor (FF) of 0.578. The encouraging performance was attributed to its good miscibility, preferable nanophase separation and high mobilities, as well as efficient exciton dissociation with weak bimolecular and trap recombination. In this study, the incorporated position of fluorine atoms on IID-based copolymer influences not only the thin-film structure such as phase separation structure but also photophysical/electrochemical properties and photovoltaic performance, which highlights a new strategy for the design and synthesis of fluorinated D-A polymers.