High thermostability of phase change materials is the critical factor for producing phase change thermoregulated fiber (PCTF) by melt spinning. To achieve the production of PCTF from melt spinning, a composite phase change material with high thermostability was developed, and a sheath-core structure of PCTF was also developed from bicomponent melt spinning. The sheath layer was polyamide 6, and the core layer was made from a composite of polyethylene and paraffin. The PCTF was characterized by scanning electron microscopy (SEM), thermal analysis (TG), Fourier Transform Infra-Red (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and fiber strength tester. The results showed that the core material had a very high thermostability at a volatilization temperature of 235 °C, the PCTF had an endothermic and exothermic process in the temperature range of 20–30 °C, and the maximum latent heat of the PCTF reached 20.11 J/g. The tenacity of the PCTF gradually decreased and then reached a stable state with the increase of temperature from −25 °C to 80 °C. The PCTF had a tenacity of 343.59 MPa at 0 °C, and of 254.63 MPa at 25 °C, which fully meets the application requirements of fiber in textiles.

A current of 1.54 kA was obtained under a bias voltage of only 1.6 kV by employing a single photoconductive semiconductor switch (PCSS) excited by a laser diode (LD) with energy of 4 μJ. In this work, an opposed contact structure PCSS was used instead of a lateral structure one. We show that a avalanche multiplication rate of PCSS as high as 258 has been obtained. The effects of the electric field strength and of the capacitance on the current waveform were investigated. Moreover, the damping degree was calculated in combination with the current waveform. The calculation indicates that the current attenuation degree increases upon the increase of the capacitance for a fixed value of the electric field strength, whereas the current attenuation degree decreases upon the increase of electric field strength for a fixed charging capacitance. The results obtained in this work show that, by employing opposed contact structure PCSSs in combination with a relatively low bias voltage and laser pulse energy, high-current and long pulse power devices based on inexpensive and compact sources can be produced.