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High-purity fused silica has been implanted with 60-keV helium ions at the fluence of 1.5·1017 cm–2. The effects of helium-ion implantation on optical properties of silica samples before and after helium implantation have been investigated by infrared (IR), photoluminescence (PL), and ultraviolet-visible (UV-vis) spectrophotometer. After helium-ion implantation, X-ray photoelectron spectroscopy (XPS) results indicate that Si 2p peak is shifted to higher binding energy. An obvious PL band at 500 nm is observed, and the PL intensity is significantly decreased. However, the intensity of IR and optical absorption is increased greatly by ion implantation. A mechanism for the effects of helium implantation on optical properties of fused silica is discussed.

Lithium-sulfur (Li-S) batteries are severely hindered by the low sulfur utilization and short cycling life, especially at high rates. One of the effective solutions to address these problems is to improve the sulfiphilicity of lithium polysulfides (LiPSs) and the lithiophilicity of the lithium anode. However, it is a great challenge to simultaneously optimize both aspects. Herein, by incorporating the merits of strong absorbability and high conductivity of SnS with good catalytic capability of ZnS, a ZnS-SnS heterojunction coated with a polydopamine-derived N-doped carbon shell (denoted as ZnS-SnS@NC) with uniform cubic morphology was obtained and compared with the ZnS-SnS2@NC heterostructure and its single-component counterparts (SnS@NC and SnS2@NC). Theoretical calculations, ex situ XANES, and in situ Raman spectrum were utilized to elucidate rapid anchoring-diffusion-transformation of LiPSs, inhibition of the shuttling effect, and improvement of the sulfur electrochemistry of bimetal ZnS-SnS heterostructure at the molecular level. When applied as a modification layer coated on the separator, the ZnS-SnS@NC-based cell with optimized lithiophilicity and sulfiphilicity enables desirable sulfur electrochemistry, including high reversibility of 1149 mAh g-1 for 300 cycles at 0.2 C, high rate performance of 661 mAh g-1 at 10 C, and long cycle life with a low fading rate of 0.0126% each cycle after 2000 cycles at 4 C. Furthermore, a favorable areal capacity of 8.27 mAh cm-2 is maintained under high sulfur mass loading of 10.3 mg cm-2. This work furnishes a feasible scheme to the rational design of bimetal sulfides heterostructures and boosts the development of other electrochemical applications.

Lithium-sulfur (Li-S) batteries have been hindered by the shuttle effect and sluggish polysulfide conversion kinetics. Here, a P-doped nickel tellurium electrocatalyst with Te-vacancies (P⊂NiTe

We report a simple one-step hydrothermal strategy for the fabrication of a C-MoS2/rGO composite with both large surface area and high porosity for the use as advanced electrode material in lithium–sulfur batteries. Double modified defect-rich MoS2 nanosheets are successfully prepared by introducing reduced graphene oxide (rGO) and amorphous carbon. The conductibility of the cathodes can be improved through the combination of amorphous carbon and rGO, which could also limit the dissolution of polysulfides. After annealing at different temperatures, it is found that the C-MoS2/rGO-6-S composite annealed at 600 °C yields a noticeably enhanced performance of lithium–sulfur batteries, with a high specific capacity of 572 mAh·g−1 at 0.2C after 550 cycles, and 551 mAh·g−1 even at 2C, much better than that of MoS2-S nanosheets (249 mAh·g−1 and 149 mAh·g−1) and C-MoS2/rGO-S composites (334 mAh·g−1 and 382 mAh·g−1). Our intended electrode design protocol and annealing process may pave the way for the construction of other high-performance metal disulfide electrodes for electrochemical energy storage.

Lithium-sulfur (Li-S) batteries featuring high-energy densities are identified as a hopeful energy storage system but are strongly impeded by shuttle effect and sluggish redox chemistry of sulfur cathodes. Herein, annealed melamine foam loaded 2H/1T MoS

Barrier breaking scheme has a direct influence on barrier breaking effect and operational processes. However, the formulation of such scheme is limited by multiple factors, and it is difficult to assess the quality of the scheme. To solve this issue, based on the analyses of influencing factors over the barrier breaking action of Barrier Breaking Detachment, an evaluation index system for barrier breaking schemes is established from four perspectives of barrier breaking method, barrier breaking equipment, barrier breaking personnel and barrier breaking explosive. The evaluation method for barrier breaking schemes is also explored, and a barrier breaking scheme evaluation model based on intuitionistic fuzzy set and TOPSIS is built. Finally, with a barrier breaking task implemented by Barrier Breaking Detachment during a military drill as an example, the candidate schemes are evaluated based on training data, and the effectiveness of the model is validated.

Bridge blasting by engineers is a special and professional operation. It is difficult to assess the merits of the blasting scheme. By analyzing the influencing factors of bridge blasting, the evaluation index system of bridge blasting scheme based on blasting personnel, blasting target and blasting tool is constructed, and the evaluation method of military bridge blasting scheme is also studied in this paper. The evaluation model of military bridge blasting scheme based on BP neural network is established. Finally, the military bridge blasting task implemented by an engineer detachment is given as an example. The candidate scheme is evaluated based on relevant training data, and the effectiveness of the model is verified.

This study demonstrates quick and efficient removal of different dyes from wastewater by using MoS2/CuS nanosheet composites (NCs) as adsorbent. The MoS2/CuS NCs are prepared by a facile hydrothermal route, and the composites exhibit high adsorption capacity with 273.23, 432.68, 98.78, and 211.18 mg/g for rhodamine B (RhB), methylene blue (MB), methyl orange (MO), and rhodamine 6G dyes (RhB 6G), respectively. This is ascribed to its high specific surface area (106.27 m2/g) and small mesopores (2.299 nm) which provide numerous adsorption sites and uniform coverage for dye molecules. High adsorption efficiency is obtained for RhB (93.8%), MB (100%), and RhB 6G (84.73%), except for MO (48.9%) at the adsorption equilibrium time at the solution concentration of 80 mg/L. The adsorption of MoS2/CuS NCs can be well described by the pseudo-second-order kinetic model, and the adsorption isotherm at the equilibrium fits well with the Langmuir model. The rapid and efficient adsorption ensures MoS2/CuS NCs to be a bro...

Inert ion beams with large incident angle were used for layer by layer etching of chemical-mechanical polished fused silica. The evolution of the impurities, subsurface defects, surface roughness, and surface molecular structure after ion beam etching and their effects on the laser-induced damage threshold (LIDT) were investigated to understand the laser damage mechanism of fused silica. The impurity elements are mainly distributed at a depth of 0–200 nm of the sample surface, which will strongly absorb ultraviolet (UV) laser energy. The result is consistent with the measurement of weak photothermal absorption. After 500 nm removal of the fused silica surface, the deposition layer of polishing powder is removed, and the subsurface defects are exposed. Correspondingly, the amount and size of the defects reach the maximum, and result in the greastest surface roughness and deterioration of surface quality, which enhances the local optical field. As the removal depth increases, the passivation and removal of subsurface defects lead to a decrease in surface roughness and improvement of surface quality. In addition, the density of structural defects and the Si O Si bond angle will decrease after ion beam etching, which yields a densified and strengthened surface of fused silica. The results indicate that metallic impurities are the key factors that limit the improvement of LIDT. Moreover, subsurface defects restrict the further enhancement of LIDT. Therefore, ion beam etching can be developed to remove subsurface damage for improving the laser resistant capacity of fused silica.

The laser damage resistance of fused silica optics depends significantly on the surface quality. In this work, anisotropic etching with inert ion beams at various ion incident angles was performed to investigate the evolution of the fused silica surface. The results show that the surface is smoothed when the incident angle is below [Formula: see text]. However, the fused silica surface starts to become coarse owing to the formation of nanostructures on the surface when the incident angle exceeds [Formula: see text]. Further, ion beam etching at a large incident angle of [Formula: see text] removes subsurface defects and less induces nanostructures, resulting in reduction of the surface roughness. The concentrations of impurities and defects are both significantly reduced after ion beam etching. The surface quality, subsurface and surface defects, and surface impurities determine the variation in the laser damage threshold of fused silica with the ion incident angle. The results demonstrate successful application of ion beam etching to improve the laser damage resistant characteristics of fused silica optics. Ion beam etching is a very versatile tool that provides physical erosion to anisotropically mitigate surface damage of fused silica.

Three kinds of Al-TiO2 samples and pure TiO2 samples were synthesized via a modified polyacrylamide gel route using different aluminum salts, including Al2(SO4)3∙18H2O, AlCl3, and Al(NO3)3∙9H2O under identical conditions. The influence of different aluminum salts on the phase purity, morphologies, thermal stability of anatase and photocatalytic properties of the as-prepared Al-TiO2 nanoparticles were studied. The energy gap (Eg) of Al-TiO2 nanoparticles decreases due to Al ion doping into TiO2. The photocatalytic activities of the Al-TiO2 samples were investigated by the degradation of acid orange 7 dye in aqueous solution under simulated solar irradiation. The Al-TiO2 nanoparticles prepared from Al(NO3)3∙9H2O exhibit the best photocatalytic activity among the four kinds of samples, followed in turn by the Al-TiO2 nanoparticles prepared with AlCl3, Al2(SO4)3∙18H2O and pure TiO2. The different performances are attributed to complex effects of Eg, particle size, surface morphology, phase purity and the defect sites of the Al-TiO2 nanoparticles.

The ability of MoS2nanomaterials as adsorbent and photocatalytic materials of methylene blue (MB) dye after [Formula: see text]-ray irradiation is investigated. The MoS2nanomaterials are prepared by a simple hydrothermal route, and then irradiated with Co-60 gamma radioisotope at different doses of 1, 10, 100, 1000 kGy. All the samples are characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Diffusivity Reflectance Spectroscopy (DRS) and Brunauer–Emmet–Teller (BET). The XRD analysis shows no change in crystal structure of MoS2nanomaterials after irradiation. The DRS analysis indicates the optical bandgap increases from 1.73 to 1.82, 1.86, 1.94 and 2.00 eV, respectively. The performance of the dye-absorbing solutions and the photocatalytic dye solutions before and after irradiation is compared. After [Formula: see text]-ray irradiation, the adsorption capacity of the MoS2nanomaterials degrades, which can be attributed to the decreased specific surface area, from 77.060 to 48.812, 35.855, 38.789 and 27.137 m2/g, respectively. The photocatalytic degradation ability for the MB solution also decreases due to the increase of optical bandgap of the samples after [Formula: see text]-ray irradiation.