摘要：The rational design of polymer acceptors with strong and broad absorption is critical to improve photovoltaic *** this work,a new polymer acceptor PY9-T based on heptacyclic benzotriazole(Y9-C16)as a building block and thiophene unit as the linking unit was synthesized,which exhibited a low bandgap(1.37 eV)and a high extinction coefficient of the neat film(1.44×10^(5) cm^(−1)).When PY9-T was blended with the wide bandgap polymer donor PBDB-T,the all-polymer solar cells(APSCs)showed a high power conversion efficiency(PCE)of 10.45%with both high open circuit voltage of 0.881 V and short-circuit current density of 19.82 mA/cm^(2).In addition,APSCs based on PY9-T show good thermal stability,as evidenced by slight changes morphologies when annealed at 100℃.These results suggest that Y9-C16 provides a new building block to develop efficient and stable polymer acceptors.

摘要：The consensus problem for general linear multi-agent systems （MASs） under directed topology is investigated. First, a novel consensus protocol based on proportional-integral-derivative （PID） control is proposed. Second, the consensus problem is converted into an asymptotic stability problem through transformations. Third, through a state projection method the consensus condition is proved and the explicit expression of the consensus function is given. Then, a Lyapunov function is constructed and the gain matrices of the protocol are given based on the linear matrix inequality. Finally, two experiments are conducted to explain the advantages of the method. Simulation results show the effectiveness of the proposed algorithm.

摘要：A novel Cu?6.5Ni?1Al?1Si?0.15Mg?0.15Ce alloy with super-high strength was designed and its corrosion behavior in3.5%NaCl solution at25°C was investigated by the means of SEM observation,TEM observation and XPS *** alloy after solution treatment,80%cold rolling and aging at450°C for1h had the best comprehensive properties with hardness of HV314,electrical conductivity of19.4%IACS,tensile strength of1017MPa,and average annual corrosion rate of0.028mm/*** oxides and chloride products formed at first,followed by the formation of dyroxides *** alloy showed super-high strength,good electrical conductivity and corrosion resistant because Ni2Si hindered the precipitation of large NiAl at the grain boundary and the denickelefication of the alloy.

摘要：china’s high-speed railways are always facing the potential damage risk induced by strong *** the route design concept of“using bridge instead of embankment”has also greatly increased the probability of high speed trains moving on bridges when a strong earthquake *** the past decades,a bunch of theoretical and numerical studies have been conducted in the seismic dynamic field of high-speed ***,the effective dynamic test system for verifying the given method and theoretical results is still ***,a novel dynamic test system(DTS)consisting of a shaking table array and a train-pass-bridge reduced-scale model is proposed in this *** some crucial technical problems discussion,the effectiveness of similar design scheme and the feasibility of reduced-scale DTS are elaborated,and then the detailed DTS structures are given and displayed as *** this basis,the demonstration tests are conducted and compared with the numerical *** results show that the proposed DTS is accurate and ***,the DTS can provide a new physical simulation approach to study the high-speed train’s running safety on bridges under earthquakes and can also provide a reference for the construction of related systems.

摘要：The H_∞ performance analysis and controller design for linear networked control systems(NCSs) are *** NCSs are considered a linear continuous system with time-varying interval input delay by assuming that the sensor is time-driven and the logic Zero-order-holder(ZOH) and controller are *** on this model,the delay interval is divided into two equal subintervals for H_∞ performance *** improved H_∞ stabilization condition is obtained in linear matrix inequalities(LMIs) framework by adequately considering the information about the bounds of the input delay to construct novel Lyapunov–Krasovskii functionals(LKFs).For the purpose of reducing the conservatism of the proposed results,the bounds of the LKFs differential cross terms are properly estimated without introducing any slack matrix ***,the H_∞ controller is reasonably designed to guarantee the robust asymptotic stability for the linear NCSs with an H_∞ performance level γ.Numerical simulation examples are included to validate the reduced conservatism and effectiveness of our proposed method.

摘要：Aiming at determining the thermal contact resistance of ball screws,a new analytical method combining the minimum excess principle with the MB fractal theory is proposed to estimate thermal contact resistance of ball screws considering microscopic fractal characteristics of contact *** minimum excess principle is employed for normal stress ***,the MB fractal theory is adopted for thermal contact *** effectiveness of the proposed method is validated by self-designed *** comparison between theoretical and experimental results demonstrates that thermal contact resistance of ball screws can be obtained by the proposed *** this basis,effects of fractal parameters on thermal contact resistance of ball screws are ***,effects of the axial load on thermal contact resistance of ball screws are also *** conclusion can be drawn that the thermal contact resistance decreases along with the fractal dimension D increase and it increases along with the scale parameter G increase,and thermal contact resistance of ball screws is retained almost constant along with axial load increase before the preload of the right nut turns into zero in *** application of the proposed method is also conducted and validated by the temperature measurement on a self-designed test bed.

摘要：Many vehicle platoons are interrupted while traveling on roads,especially at urban signalized *** reason for such interruptions is the inability to exchange real-time information between traditional human-driven vehicles and intersection ***,this paper develops a Markov chain-based model to recognize platoons.A simulation experiment is performed in Vissim based on field data extracted from video recordings to prove the model’s *** videos,recorded with a high-definition camera,contain field driving data from three Tesla vehicles,which can achieve Level 2 autonomous *** simulation results show that the recognition rate exceeds 80%when the connected and autonomous vehicle penetration rate is higher than *** a vehicle is upstream or downstream of an intersection also affects the performance of platoon *** platoon recognition model developed in this paper can be used as a signal control input at intersections to reduce the unnecessary interruption of vehicle platoons and improve traffic efficiency.

摘要：Certain non-metallic granules （NMG） were selected as the research object. It was proposed to conduct the volume compression experiments as well as those on the NMG physical properties at high stress levels. Then, not only the volume compression ratio curve but also the extended Drucker-Prager linear model were obtained. In addition, through the friction strength tests, parameters of the Mohr-Coulomb model were gained, which proved in basic agreement with those of the extended Drucker-Prager linear model. Additionally, curves of the friction coefficients between the NMG and the sheet metal trader different pressures were also obtained. Based on the material performance experiments, numerical analysis in respect of flexible-die forming process with solid granule medium （SGM） was conducted. The die and device for experiments of solid granule medium forming （SGMF） on sheet metal were designed and manufactured. Typical parabolic parts were successfully trial-produced. The tests and simulation results show that the sheet formability is significantly improved for the extraordinary friction performance during interaction between the SGM and the sheet metal surface. The process control and die structure are simple, and the shaped work-pieces enjoy many advantages, such as satisfactory surface quality and favorable die fitability, which offers a brand-new method and means for processing and preparation of sheet metals.

摘要：The application of multiple UAVs in complicated tasks has been widely explored in recent *** to the advantages of flexibility,cheapness and consistence,the performance of heterogeneous multi-UAVs with proper cooperative task allocation is superior to over the single ***,several constraints should be satisfied to realize the efficient cooperation,such as special time-window,variant equipment,specified execution ***,a proper task allocation in UAVs is the crucial point for the final *** task allocation problem of the heterogeneous UAVs can be formulated as a multi-objective optimization problem coupled with the UAV *** this end,a multi-layer encoding strategy and a constraint scheduling method are designed to handle the critical logical and physical *** addition,four optimization objectives:completion time,target reward,UAV damage,and total range,are introduced to evaluate various allocation ***,to efficiently solve the multi-objective optimization problem,an improved multi-objective quantum-behaved particle swarm optimization(IMOQPSO)algorithm is *** this algorithm,a modified solution evaluation method is designed to guide algorithmic evolution;both the convergence and distribution of particles are considered comprehensively;and boundary solutions which may produce some special allocation plans are ***,adaptive parameter control and mixed update mechanism are also introduced in this ***,both the proposed model and algorithm are verified by simulation experiments.

摘要：Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-boring machine(TBM)cutter-head and the assembled radius layout of the disc *** solve these problems,an adaptive design method for studying cutter layout was *** the bearing stress of the outermost gage disc cutter as an index,the profile of the cutter-head was *** a genetic algorithm and based on the principles of equal life and equal wear,the assembled radii of the cutters were optimally *** conditions of non-interference between the cutters,manholes,muck buckets and welding lines were given when a star layout pattern was used on *** cutter-head comprehensive evaluation model was established by adopting relative optimization improvement degree of evaluation indices to achieve dimensional *** the MB264-311-8030 mm tape TBM cutter-head,the calculations show that compared with the original layout scheme,among the 51 disc cutters,the largest gap of the cutters’assembled radiuses is only 25.8 mm,which is 0.64%of the cutter-head’s radius and is *** cutter-head’s unbalanced radial force decreases by 62.41%,the overturning moment decreases by 33.22%,and the cutter group’s centroid shift increases by only 18.48%.Each index is better than or approximately equal to the original cutter-head layout scheme,and the equivalent stress and deformation are both smaller;these results fully verify the feasibility and effectiveness of the method.