Elliptical cross-sectional projectiles have recently attracted attention because they fit the flattened shape of earth-penetrating weapons. This study aims to investigate a rigid elliptical cross-sectional projectile with different geometrical characteristics penetration into the semi-infinite concrete targets by implementing a theoretical method. The general geometric models of four types of elliptical cross-sectional projectiles are introduced; closed-form penetration equations are then derived based on the dynamic cavity-expansion theory. Furthermore, the present models are validated by comparing the predicted penetration depths with the predictions obtained using the semi-empirical formulae and test data; the maximum deviation from the test data is 15.8%. In addition, the deceleration, velocity, and displacement of the projectiles during the penetration process are obtained based on the present models, and the penetration performance of the four types of elliptical cross-sectional projectiles is discussed by comparing the penetration depths. The conical-nose elliptical cross-sectional projectile exhibits the best penetration performance than the other three types if the nose length is sufficiently large, and the ogive-nose elliptical cross-sectional projectile gradually exhibits its penetration performance advantage with the increase in the nose length.

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In this paper, acrylate-terminated polysiloxane was synthesised and used as raw materials for the synthesis of cationic core/shell polysiloxane acrylate emulsion, which was applied as binders in the pigment dyeing of cotton fabrics.The experimental results showed that: the cationic core/shell poly siloxane acrylate emulsion in this article is in nano size of 100nm. During the film formation of the emulsion, there are core-core and shell-shell fusion phenomena between the latex particles, and same poly siloxane chain aggregates on the surface of the film. When the emulsion is used in the pigment dyeing of cotton fabrics, the dyed cotton fabrics feel soft, and the soaping fastness and dry/wet rubbing fastness meet the national quality requirements, as soaping fastness can reach grade 4~5, dry rubbing fastness can reach grade 4~5, and wet rubbing fastness can reach grade 4.

The resorcinol diglycidyl acrylate (RDA) is firmly introduced to the surface of polyester (PET) fibers by a simple dip-rolling and baking method, and a free radical polymerization reaction is initiated on the surface of PET fabrics under ultraviolet light (UV) light to obtain three hydrogel layers with different structure, including polyacrylamide (PAAM), polyacrylic acid (PAAC) and poly-N-isopropylacrylamide (PNIPAAM). It is shown that the pretreatment-UV grafting method can be used to obtain hydrogel layers with porous structure on the surface of PET fabric, and all three hydrogel layers have better frictional properties than kelp. Among them, the friction coefficient of PET-PAAM surface can reach 0.02, which is 17% of the friction coefficient of kelp surface and 83% lower than that of the untreated PET fabric surface, giving the PET fabric surface excellent interfacial drag reduction characteristics. It can be applied to the surface of underwater activity equipment as well as ships to improve moving efficiency and reduce energy consumption.

Development of formaldehyde‐free stiffening finish agents is highly desirable in modern environmental‐friendly textile chemical processing technologies. Herein, two zwitterionic monomers are synthesized and used to synthesize a series of acrylate soap‐free emulsions. The prepared acrylate soap‐free emulsion was analyzed by nanoparticle size analyzer to determine grain size and PDI. The properties of polymer film obtained from emulsion were characterized by IR, DSC, and DMA. The results showed that zwitterionic monomer in acrylate emulsion can greatly improve the glass transition temperature (Tg) and initial tensile modulus of polymer film, and that ambient temperature had little effect on initial tensile modulus. It was found that when the amount of zwitterionic monomer is 3% of the total monomer dosage, the synthesized polymer emulsion can achieve the same stiffening effect as that of commercial stiffening agents. Meanwhile, the stiffness of finished fabric is less affected by the change in ambient temperature. The effective Tg increase and high initial tensile modulus of these zwitterionic polymers demonstrate their applicability in stiffening finish for seat belts.