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Herein, we report on the growth of Cr4+–Li2CaGeO4 crystals by the flux growth method from the flux of LiCl, as well as on the effect of doping Li2CaGeO4 with Cr4+ ions on the NIR region spectral properties and crystal structure. The results quantified the occupancy of Cr4+ in Ge4+ sites. The emission spectrum presented broad bands in the NIR region, i.e., 1000–1500 nm excited by 980 nm, with maximum peaks at 1200 nm at room temperature caused by the transition of 3T2→3A2 in Cr4+ ions. The lifetime decreased with the Cr4+ ion doping concentration, specifically from 14.038 to 12.224 ms. The chemical composition and the valence state of chromium in Li2CaGeO4 were analyzed using X-ray photoelectron spectroscopy, which showed that the chromium in Li2CaGeO4 was tetravalent and no trivalent chromium was found. Therefore, the Cr4+–Li2CaGeO4 crystal has a great potential and future in optical applications.

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The partial fiber breaking in the warp yarn of three-dimensional (3D) woven fabrics needs to be urgently reduced considering the large shedding displacement and repeated yarn frictions in the fabricating process. A kinematical model of the heald frame was established in order to analyze the impact and wear of the warp yarn in the shedding process of 3D weaving. The variation tendency of the friction force between the yarn and heddle eye was obtained and the variable acceleration trajectory of the heald frame based on minimizing the friction and impact load on the yarn was derived. The experimental results showed that the fiber breakage rate in one warp yarn using the derived curve trajectory reduced drastically. The research results are beneficial to the theoretical design of the shedding system of weaving machines for 3D woven fabric.