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In recent years, the synthesis and application of alkenes have attracted increased attention. Triphenylethenes (TriPEs) have lower molecular torsion than tetraphenylethenes (TPEs), which helps to balance the degree of conjugation and the aggregation-induced emission (AIE) effect. The geometry of double bonds has a significant impact on luminescence. Therefore, it is essential to provide a comprehensive summary of the stereoselective synthetic strategies for trisubstituted alkenes. In this review, common strategies for the stereoselective synthesis of alkenes are described, with an emphasis on the origin of stereoselectivity and the types of substrates. In addition, the AIE properties of TriPE and its applications in optoelectronic devices, stimuli-responsive materials, sensors, and therapies were discussed.

AbstractAluminum alloy materials have been extensively used in long-span roof structures, especially in coastal and industrial buildings containing corrosive matters. In this study, new-type aluminum alloy bolt-sphere joints were taken as research objects and evaluated through tensile test and numerical simulation. The tensile properties and failure mechanism of the aluminum alloy bolt-sphere joints were explored. A calculation formula for the tension capacity of aluminum alloy bolt-sphere joints was proposed. The following conclusions were drawn based on the test data and the numerical simulation results: (1) the tension capacity of aluminum alloy bolt-sphere joints is controlled by the tensile properties of seal plates and the uplift-resistant properties of stainless steel bolts; (2) as the thickness of the seal plate increases, its main tensile failure modes are the combined tensile and shear failures at the ring crush part of the aluminum pipe, the tensile failure at the ring crush part of the aluminum pipe, and the tensile failure of the stainless steel bolt; (3) the tensile failure modes of the bolts are mainly the rupture failure of the bolt member and the shear failure of the thread according to the different screwing depths of the bolts into the sphere; and (4) the screwing depth of the bolt into the sphere should be more than 1.6d(dis the diameter of the stainless steel bolt); (5) the proposed calculation formula is accurate and effective.