Cable-strut structures are flexible structures which are very sensitive to their shape variation. Addition of actuators in selected members of cable-strut structures provides an efficient way to control the structural shape, thus enhances the structural performance. Although a large number of research studies have been performed to achieve shape control via linear force method, it has been proved that nonlinear force method is more accurate due to the existence of nonlinearity characters in cable-strut structures. The aim of this article is proposing an approach based on the nonlinear force method to change the shape of cable-strut structures under external load with respect to different control targets. The formulas and calculation procedure of structure’s nonlinear response to external load and length variation of members are established based on nonlinear force method. Then, solving strategy for determining the minimum required number of actuators and testing the feasibility for arrangement plan of actuators is provided for different control targets. Two numerical cases are demonstrated using the proposed approach to obtain the structural behavior before and after the control process. The effectiveness of the algorithm can be verified through numerical results.

Herein, we report the facile synthesis and properties of a chiral perylene diimide (PDI)-embedded conjugated macrocycle (cyclo[6]paraphenylene-1,7-perylene diimide, [6]CPP-PDI 1,7 ) by Pd-catalyzed Suzuki coupling and a subsequent reductive aromatization reaction in two steps. The PDI-embedded conjugated macrocycle showed a significant redshift (>110 nm for absorption) compared to the PDI molecule. Moreover, efficient resolution of chiral enantiomers with (P)/(M)-[6]CPP-PDI 1,7 was achieved by high-performance liquid chromatography, and their chiral properties were investigated by circular dichroism spectroscopy. The realization of [6]CPP-PDI 1,7 expands the scope of the precise synthesis of PDI-embedded chiral conjugated macrocycles and explores its unique physical properties.

Kinematically indeterminate systems are geometrically unstable. Considering that there is only tiny elastic deformation in the process of the mechanism motion, the method to simulate kinematic paths of kinematically indeterminate systems without considering elastic deformation is studied in this paper. Based on the equilibrium matrix theory, mechanism displacement is decomposed into combinatorial displacement of independent inextensional mechanisms and displacement resulted from the length modifications of members. The reasonable combination coefficient of inextensional mechanisms is determined by the gradient of the potential energy. An analysis algorithm is developed to simulate the kinematic paths of rigid pin-bar assemblies. The validity and accuracy of the algorithm proposed in this paper is illustrated by three typical examples.

With the rapid development of China’s social economy, it is the most important task for the water conservancy industry to make use of the existing water conservancy engineering measures to carry out the research on river basin flood control dispatching. Large-scale joint operation of river basins usually needs to consider meteorological and hydrological conditions, historical flood data, multireservoir engineering conditions, and multiple flood control targets, which is a complex decision-making problem. Therefore, electing the optimal operation model of reservoir flood control optimization is very important. In this paper, Luanhe River Basin is taken as the research area, and three kinds of constraints, namely, water balance constraint, reservoir flood control capacity constraint, and water release decision constraint, are set to construct the flood control optimization model. Taking the minimum square of the sum of reservoir discharge and interval flood discharge as the objective function, genetic algorithm (GA), particle swarm optimization (PSO), Spider swarm optimization (SSO), and grey wolf optimization (GWO) are introduced into flood control optimal operation to seek the minimum value of objective function, and the results are compared and analyzed. Through the analysis of optimization results, the optimization ability and convergence effect of grey wolf optimization algorithm are better than those of genetic algorithm and particle algorithm, and the results are more stable than those of spider swarm algorithm. It has a good model structure and can make full use of the results of three wolf groups for optimization. Through the analysis of scheduling results, the results of genetic algorithm and particle swarm optimization algorithm are similar, while those of spider swarm optimization algorithm and grey wolf optimization algorithm are similar and slightly better than those of the first two. Moreover, the search range of grey wolf optimization algorithm for solving long sequence problems is wider and the calculation time is shorter. Therefore, the grey wolf optimization algorithm can be applied to solve the flood control operation optimization model of Panjiakou Reservoir Group.