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Amorphous aerogels with the microscopic nanoscale three-dimensional meshes provide superb platforms for investigating unique physicochemical properties. In order to enhance the physical, thermal and mechanical performances, one efficient and common approach is integrating diverse functional materials. Herein, we report a simple strategy to fabricate the amorphous silicon doped Y2O3 aerogels with the post-gelation method under the N2/EtOH supercritical atmosphere. The impact of Si concentration on the nonlinear optical properties is investigated for the first time. The maximum modulation depth is 1.65 % with a saturation intensity of 0.78 MW cm−2 with the 1-ps laser excitation at 1590 nm. Finally, we incorporated the silicon-doped Y2O3 aerogel based saturable absorber (SA) into an erbium-doped fiber laser (EDFL) and achieved various mode-locking operations at different wavelengths in the super C band, in terms of the conventional soliton, harmonic soliton molecules pulses, and dual-wavelength soliton mode-locking. Overall, this work confirms that amorphous silicon-doped Y2O3 aerogels are good nonlinear optical materials and pave a way for the ultrafast photonic and nonlinear optical applications with amorphous materials in near future.

Ultralow-density (35–60 mg·cm–3) Yb2O3 nanofibrous membranes (YbFMs) with a multilayer structure were successfully prepared for the first time using Yb-acetylacetone coordination polymer as a precursor. Thanks to the high ceramic yield (62.1%) and excellent spinnability of the precursor, the YbFMs exhibited outstanding flexibility, which does not cause damage even when bent or knotted. The tensile strength of the YbFMs was 1.69 MPa, and the maximum elongation could reach 33%. Notably, the YbFMs exhibited robust fatigue resistance, retaining 87.2% of the initial stress even after 500 buckling cycles and preserving 84.75% of the initial stress in compression resilience. Moreover, the YbFMs exhibited flexibility and compressive performance in the temperature range of −196–1350 °C. The thermal conductivity of the YbFMs was 28.9–34.6 mW·m–1·K–1. At a hot surface temperature of 1350 °C, the 6 mm thick YbFMs could reduce the back temperature by about 1070 °C. Thus, YbFMs are expected to be a flexible insulation material at extremely high temperatures. [ABSTRACT FROM AUTHOR]

Amorphous aerogels with the microscopic nanoscale three-dimensional meshes provide superb platforms for investigating unique physicochemical properties. In order to enhance the physical, thermal and mechanical performances, one efficient and common approach is integrating diverse functional materials. Herein, we report a simple strategy to fabricate the amorphous silicon doped Y2O3 aerogels with the post-gelation method under the N2/EtOH supercritical atmosphere. The impact of Si concentration on the nonlinear optical properties is investigated for the first time. The maximum modulation depth is 1.65 % with a saturation intensity of 0.78 MW cm−2 with the 1-ps laser excitation at 1590 nm. Finally, we incorporated the silicon-doped Y2O3 aerogel based saturable absorber (SA) into an erbium-doped fiber laser (EDFL) and achieved various mode-locking operations at different wavelengths in the super C band, in terms of the conventional soliton, harmonic soliton molecules pulses, and dual-wavelength soliton mode-locking. Overall, this work confirms that amorphous silicon-doped Y2O3 aerogels are good nonlinear optical materials and pave a way for the ultrafast photonic and nonlinear optical applications with amorphous materials in near future. [ABSTRACT FROM AUTHOR]

Taking the high⁃voltage disconnector of the GW46 type as research object, this research first use Solidworks to build its three-dimensional simplified model, then use ABAQUS to simulate the mechanical characteristics of the disconnector over a wide temperature range, analyzing the influence of the clamping force between the dynamic and static contacts on temperature, the contact pressure between the dynamic and static contacts of the high⁃voltage disconnector of the GW46 type increases with the ambient temperature, and the contact pressure becomes smaller. Compared simulation results with experimental data, the error is less than 5%. Analysis shows that using the ABAQUS to simulation analysis of temperature rise of the high⁃voltage disconnector of the GW46 type, it can be determined that the contact pressure between the dynamic and static contacts changes with temperature. It avoids the complexity of the traditional theoretical calculation of query parameters and tedious calculations, and provides strong reference evidence for improving the reliability of the high⁃voltage disconnector of the GW46 type.

High CO2 concentration in atmosphere causes serious environmental issues, and carbon capture and storage technologies have attracted attention as a means to reduce the atmospheric CO2 concentration. Metal-organic frameworks (MOFs) can potentially be used for CO2 adsorption, but their poor stability and microporosity limit their applications. Herein, a novel strategy was proposed to combine a cellulose aerogel and hierarchically-porous MOFs (HP-MOFs) with larger pores. According to this strategy, a series of microcrystalline cellulose/HP-UIO-66-NH2 hybrid aerogels (MC-HUN-X) was constructed by adding a modulator (monocarboxylic acid, MA), followed by the in-situ growth of HP-UIO-66-NH2 on a cellulose aerogel. By adjusting the chain length of MA, the structure–function relationship between pore size and the CO2 adsorption capacity of MC-HUN-X was explored. The results showed that the CO2 adsorption capacity increased first and then decreased upon increasing the MOFs pore size, while the adsorption selectivity of CO2 continuously increased. Among all samples, MC-HUN-4 with a moderate pore size had the highest CO2 adsorption capacity (1.90 mmol/g at 298 K and 1 bar) and adsorption selectivity (13.02 and 2.40 for CO2/N2 and CO2/CH4). The combination with a cellulose aerogel endowed MC-HUN-X with excellent mechanical stability and reusability. Cellulose/HP-UIO-66-NH2 hybrid aerogel with larger aperture sizes of MOF showed excellent adsorption capacity and selectivity for CO2, and the combination with aerogel could effectively improve the mechanical stability and reusability. [ABSTRACT FROM AUTHOR]