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5,18‐Dimesitylorangarin and its BF2 complex were synthesized by double SNAr reaction of 3,5‐dibromo‐BODIPY with 2‐pyrrolydipyrrin as the first examples of meso‐aryl‐substituted orangarin. These orangarins, delineated as [20]pentaphyrin(1.0.1.0.0), are strongly antiaromatic but rather stable. The free base orangarin was coupled by oxidation with MnO2 to give a 11,11′‐linked dimer, a cyclooctatetraene(COT)‐centered trimer, and a spiro‐trimer. Fused COT‐centered 3H‐orangarin dimer was oxidized to the corresponding 2H‐orangarin dimer, which was further coupled to give a triply COT‐centered 2H‐orangarin tetramer. 3H‐Orangarin oligomers are all antiaromatic as evinced by extremely low‐field‐shifted 1H NMR signals of the inner NH and ill‐defined absorption spectra with broad tails. In contrast, COT‐centered 2H‐orangarin dimer and tetramer show moderately low‐field‐shifted NH signals and intense NIR absorbance over 900 nm, suggesting effective π‐conjugation through the COT bridge and almost non‐antiaromatic character. These orangarin oligomers exhibit many reversible redox potentials owing to the intramolecular electronic interactions. Regardless of the different aromatic characters, all the orangarin monomers and oligomers exhibit very rapid excited‐state decays. [ABSTRACT FROM AUTHOR]

Starch and seed storage protein (SSP) composition profoundly impact wheat grain yield and quality. To unveil regulatory mechanisms governing their biosynthesis, transcriptome, and epigenome profiling is conducted across key endosperm developmental stages, revealing that chromatin accessibility, H3K27ac, and H3K27me3 collectively regulate SSP and starch genes with varying impact. Population transcriptome and phenotype analyses highlight accessible promoter regions' crucial role as a genetic variation resource, influencing grain yield and quality in a core collection of wheat accessions. Integration of time‐serial RNA‐seq and ATAC‐seq enables the construction of a hierarchical transcriptional regulatory network governing starch and SSP biosynthesis, identifying 42 high‐confidence novel candidates. These candidates exhibit overlap with genetic regions associated with grain size and quality traits, and their functional significance is validated through expression‐phenotype association analysis among wheat accessions and loss‐of‐function mutants. Functional analysis of wheat abscisic acid insensitive 3‐A1 (TaABI3‐A1) with genome editing knock‐out lines demonstrates its role in promoting SSP accumulation while repressing starch biosynthesis through transcriptional regulation. Excellent TaABI3‐A1Hap1 with enhanced grain weight is selected during the breeding process in China, linked to altered expression levels. This study unveils key regulators, advancing understanding of SSP and starch biosynthesis regulation and contributing to breeding enhancement. [ABSTRACT FROM AUTHOR]

With high aerodynamic efficiency and low observable design for flying wing configuration, the control ability decreases and the flying risk increases, especially during the takeoff and landing processes for unmanned aerial vehicle (UAV). To solve the nonlinear characteristic problem of the flying wing configuration at a high angle of attack (AoA) for a low aspect ratio flying wing UAV, a controllable region and stability analysis method is proposed in the paper. Firstly, the aerodynamic characteristics and static stability of a flying wing UAV are analyzed. Secondly, according to the characteristics of aerodynamic data, an efficient longitudinal trim state calculation method under the low‐speed range is proposed. The trim state contour map can be used effectively with the proposed trim state calculation method, which can further analyze the constraint relationship between different trim states and the controllable region of the UAV. Thirdly, the stability of different trim states is analyzed through the phase portrait between AoA and airspeed. With the analysis result, longitudinal attitude and AoA decoupling control laws are designed based on the incremental nonlinear dynamic inversion (INDI) method. The effectiveness and adaptability of the designed control methods are verified through simulation at high AoA. [ABSTRACT FROM AUTHOR]

A novel controller using fixed‐time sliding mode (FTSM) and fixed‐time disturbance observer (FTDO) is proposed to achieve trajectory tracking control of robotic manipulators. First, the mathematical model is established for robots with dynamic model uncertainties and external disturbances. An FTSM control strategy is presented where the integral terms of position errors are introduced into the existing sliding mode surface (SMS) to reduce the steady‐state error of the system. The exponential form in the integral terms can provide an appropriate control force for tracking systems when the position errors are far from the sliding surface for a long time. Then, an FTDO is designed to obtain a precise estimation of lumped disturbances which can be used to weaken the impact of disturbances on the control accuracy. Finally, the fixed‐time convergence properties of the tracking control system are demonstrated using Lyapunov stability theory. Simulation research is carried out to illustrate that the proposed control strategy has strong robustness and fast‐tracking speed. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) have been extensively researched and deployed in both military and civilian applications due to their tiny size, low cost, and great ease. Although UAVs working together on complicated jobs can significantly increase productivity and reduce costs, they can cause major issues with path planning. In complex environments, the path planning problem, which is a multiconstraint combinatorial optimization problem and hard to settle, requires considering numerous constraints and limitations and generates the best paths for each UAV to accomplish group tasks. In this paper, we study the path planning problem for multiple UAVs and propose a reinforcement learning algorithm: PERDE‐MADDPG based on prioritized experience replay (PER) and delayed update skills. First, we adopt a PER mechanism based on temporal difference (TD) error to enhance the efficiency of experience utilization and accelerate the convergence speed of the algorithm. Second, we use delayed updates in the process of updating network parameters to ensure stability in training multiple agents. Finally, we propose the PERDE‐MADDPG algorithm based on PER and delayed update skills, which is evaluated against the MATD3, MADDPG, and SAC methods in simulation scenarios to confirm its efficacy. [ABSTRACT FROM AUTHOR]