In this work, a metal bar fine-cropping system is designed to study the influence load control strategies based on theoretical and cropping experiments. The principle of the new cropping system and mechanical compositions system are introduced. Three different load control strategies are designed based on duralumin alloy AlCu4Mg1 bar, and the optimal loading order is determined under them. According to a new proposed cross-section quality evaluation method, the test results show constant stress intensity factor range of external load ([Formula: see text]), linear decreasing cyclic load of appropriate time coefficient ([Formula: see text]) can obtain better cropping effect and the best quality is obtained by the loading cycle ([Formula: see text]).

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High-density (～1010 cm-2) silicon nanowires are grown directly from n-(111) single crystal silicon based on solid-liquid-solid mechanism by using Au-Al films as metallic catalyst. The results indicate that the optimal parameters to realize Si nanowires with high density and uniform distribution are as follows. The thickness of Au-Al film is between 5 and 15 nm, the temperature is 1100℃, and the flow of N2 is 1.5 L/min. The diameters and lengths of the formed Si nanowires are 100 nm and from several micrometers to sereral tens of micrometerss, respectively. Then Eu-doped Si nanowires are studied. The influences of the different lengths of Si nanowires, doping temperature (900-1100℃), and doping time (15-60 min) on the luminescence of Eu3 + are experimentally investigated. The morphologies and microstructures of the SiNWs, the photoluminescence properties and growth crystall orientations are characterized and analyzed by the scanning electron microscopy, the Hitachi F-4600 fluorescence spectrophotometer and X-ray powder diffraction. The results show that the Eu-doped Si nanowires have a stronly red luminescencent with an emission peak position at 619 nm (5D0→7F2) when the doping temperature is 1000℃, the grow time of SiNWs is 30 min, and the optimal excitation wavelength is 395 nm. At the same time, there are four emission bands of 576 nm (5D0→7F0), 596 nm (5D0→7F1), 658 nm (5D0→7F3), and 708 nm (5D0→7F4) that are observed. Compared with the scenario of the silicon substrate, the Eu-doped Si nanowires present strong red light emission. The photoluminescence properties of Eu-doped Si nanowires have potential applications in the lighting and the silicon optoelectronic integration. However, the parameters of Si nanowires such as diameter, density, surface morphology have great influences on the photoluminescence properties of Eu-doped Si nanowires, which are necessary to be further studied.