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Aluminum/Polytetrafluoroethylene (Al/PTFE) is a representative energetic material, which can be used in many fields including defense weapon fragments, insensitive penetrator or oil-well perforation. However, the insufficient mechanical strength of traditional ingredient has seriously restricted its penetration ability, and traditional additives improve its compressive strength at the expense of reactivity. Hence, innovative component design and advanced manufacturing technology should be applied to Al/PTFE composite. In this investigation, TiH2as a new reinforcement is introduced into Al/PTFE to improve both strength and reactivity. Quasi-static and dynamic compressive tests were conducted, and the impact reaction process was recorded by high-speed camera. The results shown Al/PTFE/TiH2composites are all elasto-plastic materials, significant strain hardening and strain rate hardening phenomenon were observed. The compressive strength increased first and then decreased with increase in TiH2content, reached the maximum of 185.1 MPa at the strain rate of 5000 s−1when TiH2content was 30 %, which increased by 30.4 % compared to traditional Al/PTFE. A newly-developed drop-weight device was used to quantitatively characterize reactivity, and the reaction efficiency reached 8.2 % when TiH2content was 30 %, increased by 43.2 % compared to Al/PTFE. The formation of oriented PTFE nano-fibers was considered the important strengthening mechanism. The established Johnson–Cook model was agreed well with experimental results. Combining the results of thermogravimetry-differential scanning calorimetry (TG-DSC) tests with X-ray diffraction (XRD) analysis of reaction residues, the reaction mechanism was clarified. The impact initiation reaction was in a mechano-chemical manner and the reactivity was speculated to be the results of multiple actions between Al/PTFE and TiH2.

As the basis for prehensile manipulation, it is vital to enable robots to grasp as robustly as humans. Our innate grasping system is prompt, accurate, flexible, and continuous across spatial and temporal domains. Few existing methods cover all these properties for robot grasping. In this article, we propose AnyGrasp for grasp perception to enable robots these abilities using a parallel gripper. Specifically, we develop a dense supervision strategy with real perception and analytic labels in the spatial–temporal domain. Additional awareness of objects' center-of-mass is incorporated into the learning process to help improve grasping stability. Utilization of grasp correspondence across observations enables dynamic grasp tracking. Our model can efficiently generate accurate, 7-DoF, dense, and temporally-smooth grasp poses and works robustly against large depth-sensing noise. Using AnyGrasp, we achieve a 93.3% success rate when clearing bins with over 300 unseen objects, which is on par with human subjects under controlled conditions. Over 900 mean-picks-per-hour is reported on a single-arm system. For dynamic grasping, we demonstrate catching swimming robot fish in the water.

Chemical etching was employed to fabricate Ag nanowire @ nano-grooves on silicon to increase light harvesting. Ag nanowire @ nano-groove structures (300 nm to 1.7 μm in size) were obtained by controlling the etching time. A significant increase in the surface roughness was achieved around the Ag nanowire @ grooves with an etching time of 10–30 min. According to finite difference time domain simulations, a significant increase in both the light intensity and light path length were observed with the Ag nanowire @ nano-groove nano-structures on the silicon substrate. Increasing the opening sizes of the grooves to ~ 255 nm and the roughness of the Ag nanowire and groove surface to ~ 30 nm further enhanced the light harvesting abilities. This work not only provides a deeper insight into metal assisted silicon etching, but also indicates a possible way to enhance the light harvesting abilities of thin film solar cells.

In this study, Mg-6%Al-1%Sn-1%In (wt%) alloy is fabricated with the conventional casting method. Then an alloy sheet with a thickness of 2 mm is obtained by hot extrusion with the extrusion ratio of 47.5:1. After annealing at 200degC, 250degC or 300degC, respectively, the alloy sheets are ready for further testing. Microstructures and discharge behaviors of the alloys under different conditions are investigated by morphology observation and electrochemical measurements. The Mg-Al-Sn-In alloy annealed at 200degC exhibits better discharge performance because of uniform microstructure, fine grains, little crystalline defects, fine Mg17Al12 and Mg2Sn precipitates. AZ31, Mg-6%Al-1%Sn and Mg-6%Al-1%In alloys prepared by the same craft are used for comparisons. The result shows that the discharge property of the Mg-Al-Sn-In alloy with 200degC annealing treatment is superior to that of other alloys. Detailed reasons of this result are revealed by polarization test, electrochemical impedance test and corroded morphology. It is shown that the simple primary battery, using the 200degC annealed Mg-Al-Sn-In alloy sheets as anodes, can provide 1.527 V average voltage and its specific energy reaches 98.3 Whkg[?]1. Thus, the 200degC annealed Mg-Al-Sn-In alloy has the potential application value for seawater-activated battery.

In this work, we synthesized MnO2/CeO2electrocatalysts by in situ decoration of α–MnO2with CeO2particles during a one-step hydrothermal process. The morphology, composition, and electrochemical properties were studied in the context of application to the oxygen reduction reaction (ORR) and Mg-air battery. According to the results, α–MnO2/CeO2microfibres exhibited better ORR performance than α–MnO2microfibres due to the synergistic result between the introduction of Ce3+in CeO2lattice and the enhancement of Mn3+content in MnO2lattice. α–MnO2/CeO2microfibres provided a higher surface area and more catalytic active sites than α–MnO2microfibres by controlling the molar ratio of Ce3+/Mn7+for the precursor. When the mole ratio of Ce3+and Mn7+in the precursors was 10%, the four-electron transfer process of the MnO2/CeO2microfibres (MC-140-12-10) was found to be similar to that of the 20 wt% Pt/C commercial catalysts. MC-140-12-10 microfibres also showed the excellent long-term stability after 25,000 s and superior Mg–air battery performances than α–MnO2. Hence, the work paves the way for developing Mg-air batteries through a simple synthesis and cost-effective ORR catalyst.

A binder-free AgCl@Ag (SPL-A) cathode was prepared via a facile one-step synthesis by the in situ growth of AgCl active material on the surface of Ag foil substrate. Compared with the AgCl cathode (SPL-B) prepared by the traditional smelting-rolling method, the coarse-grained particulates of AgCl in AgCl@Ag cathode facilitated the permeation of the electrolyte. In addition, it exhibited a preferred growth orientation of the (111), (222), and (311) crystal planes to reduce the charge transfer resistance. The electrochemical behaviors of the optimized SPL-A-24 cathode (prepared with reaction time of 24 h) and the SPL-B cathode were also compared. The galvanostatic discharge results showed that SPL-A-24 cathode had a more positive electrode potential than SPL-B cathode (−0.06 V vs −0.19 V at 50 mA cm−2). Moreover, SPL-A cathode exhibited a stable discharge process that SPL-B cathode could not achieve at 100 mA cm−2and 250 mA cm−2. The magnesium seawater-activated battery assembled with SPL-A-24 cathode displayed a shorter time to reach the voltage plateau (0.2 s), a higher maximum discharge voltage (1.69 V), a larger specific power (255.5 mWh g−1), and higher specific capacity (167.7 mAh g−1) at the discharge current density of 50 mA cm−2.

In this study, Mg-6%Al-1%Sn-1%In (wt%) alloy is fabricated with the conventional casting method. Then an alloy sheet with a thickness of 2 mm is obtained by hot extrusion with the extrusion ratio of 47.5:1. After annealing at 200°C, 250°C or 300°C, respectively, the alloy sheets are ready for further testing. Microstructures and discharge behaviors of the alloys under different conditions are investigated by morphology observation and electrochemical measurements. The Mg-Al-Sn-In alloy annealed at 200°C exhibits better discharge performance because of uniform microstructure, fine grains, little crystalline defects, fine Mg17Al12and Mg2Sn precipitates. AZ31, Mg-6%Al-1%Sn and Mg-6%Al-1%In alloys prepared by the same craft are used for comparisons. The result shows that the discharge property of the Mg-Al-Sn-In alloy with 200°C annealing treatment is superior to that of other alloys. Detailed reasons of this result are revealed by polarization test, electrochemical impedance test and corroded morphology. It is shown that the simple primary battery, using the 200°C annealed Mg-Al-Sn-In alloy sheets as anodes, can provide 1.527 V average voltage and its specific energy reaches 98.3 Whkg−1. Thus, the 200°C annealed Mg-Al-Sn-In alloy has the potential application value for seawater-activated battery.