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To achieve excellent electromagnetic wave (EMW) absorption properties, the microstructure design of the absorber is critical. In this work, six kinds of N-Ni/C nanostructures with different morphologies were prepared by one-step hydrothermal method and high temperature carbonization by adjusting the types of nickel salts and reaction solvents. The EMW absorption performance of six different morphologies of N-Ni/C nanostructures was compared and analyzed. Among them, it is found that the nanoflower-like N-Ni/C composite has excellent dielectric loss and magnetic loss synergistic effect due to its polycrystalline structure, and can obtain excellent EMW absorption performance. The minimum reflection loss value at a thickness of 1.9 mm is −59.56 dB at 16.88 GHz, and the effective absorption bandwidth value reaches 6.0 GHz at a thickness of 2.2 mm. Our research shows that different morphologies and multiple lattice structures of nanostructures with the same composition have a significant influence on EMW absorption performance, which provides new research ideas for developing high-performance EMW absorbing materials. [ABSTRACT FROM AUTHOR]

Seepage prevention and reinforcement of sandy soft soil layer are the important subjects in geotechnical engineering. A set of constant pressure permeable grouting device has been developed to study the diffusion rule of new permeable polymer in sandy soil layer. Based on the orthogonal experimental design, the effects of grouting pressure, grouting time, sand moisture content and sand porosity on the diffusion of new permeable polymer in sand are studied. Through the establishment of spatial coordinate system, the diffusion range of permeable polymer slurry is studied. The experimental results show that: the main and secondary order affecting the diffusion range of permeable polymer in the X-axis and Y-axis are sand porosity, grouting pressure, grouting time, and sand moisture content. The primary and secondary orders of influencing factors on the Z-axis diffusion range of permeable polymer are sand porosity, grouting time, grouting pressure, and sand moisture content. The effects of grouting pressure, grouting time, sand layer porosity on permeable polymer diffusion and the effect of permeable polymer on soil displacement during diffusion are studied by COMSOL numerical analysis software. The results of numerical analysis show that the grouting pressure, grouting time, and porosity of sand layer promote the diffusion of permeable polymer. The slight deformation of soil mass and small disturbance to soil layer can be caused by slurry during diffusion process. A function model between slurry diffusion range and grouting parameters are established, and verified by numerical simulation for comparison. The results show that the numerical simulation values of permeable polymer grouting results in the three comparison scenarios A1, A2 and A3 are greater than the theoretical calculation values, and the difference between them is not significant. The difference between the calculated value and the theoretical value of the three comparison schemes are 6.3%, 11.7% and 7.39%, respectively. [ABSTRACT FROM AUTHOR]

We consider the 1 s 2 s 1 , 3 S states of the two-electron three-dimensional quantum dot with a Gaussian one-body potential, - V 0 exp (- λ r 2) . For a single electron, a simple scaling relation allows the reduction into a one-parameter problem in terms of V 0 λ . However, for the two-electron system, the interelectronic repulsion term, 1 r 12 , frustrates this simple scaling transformation, so we face a genuine two-parameter system. We pay particular attention to the location and nature of the critical well-depths, at which the binding energy of the second electron vanishes. Several observations are noteworthy: For all λ , the triplet critical well-depth is lower than that in the singly excited singlet state. Hence, there exists a finite range of well-depths for which the triplet is bound and the singlet is not, a feature that can possibly be applied in some device. Above its critical well-depth, the triplet state energy is always lower than that of the singly excited singlet. Both well-depths are considerably higher than the critical well-depth in the ground state. The expectation value of the interelectronic repulsion is always lower in the triplet, like the harmonic quantum dot but unlike He-like atoms, the two-particle Debye (Yukawa) atom, or the confined He atom. In the infinite well-depth ( V 0 ) limit, keeping the well-width 1 λ constant, the energies and other expectation values of the bound states of the two-electron Gaussian quantum dot approach those of a non-interacting harmonic two-electron system. [ABSTRACT FROM AUTHOR]

Salt wastes containing halides from the molten salt reactor system are unstable during storage. These waste should be immobilized. In this paper, a glass–ceramic wasteform containing SrF2 is prepared from iron phosphate glass and fluorapatite (FAP) ceramic powder by a two-step sintering process. The results of XRD and SEM showed that main crystalline phase in samples is fluorapatite with Sr, and a large number of amorphous phase wrapped around the FAP. The result of product consistency test showed that the glass–ceramic sample has a good leaching resistance for wasteform long-term storage. [ABSTRACT FROM AUTHOR]

Levels of heavy metals and polybrominated diphenyl ethers (PBDEs) were determined in fishes sampled in Jilin Songhua Lake, China. Concentrations and congener profiles of these contaminants varied by fish type. The highest concentrations of Zn, Cu, Mn, and Cd were found in three omnivorous fish (Carassius carassius, Hypomesus olidus, and Hemiculter leucisculus). The highest concentrations of Ni, Cr, and Hg were found in Silurus asotus and Hemibarbus maculatus which are two kinds of carnivorous fish. The minimum total concentration of the seven PBDEs of fish was 0.093 ng/g wet weight (ww) in Ctenopharyngodon idellus, while the maximum, 0.342 ng/g ww, was detected in Aristichthys nobilis. Of all the congeners, BDE 28 and 47 were dominant. The estimated daily intake (EDI) of these metals and PBDEs via consuming the fishes was estimated to be 1.159–10.121 μg/kg bw/day and 0.046–0.597 ng/kg bw/day, respectively. The total hazard quotients (THQs) of both types of pollutants were far below 1, indicating that the health risks of these pollutants were low for the people who consumed the fish species from the Songhua Lake. [ABSTRACT FROM AUTHOR]

Chopped basalt fibre (BF)-reinforced silicone rubber/fluorine rubber composites were investigated to improve their mechanical and thermal properties, in which the blend of silicone rubber (MVQ) and fluorine rubber (FKM) was used as a matrix of the composites, the BF was used as a reinforcement, and the coupling agents of KH550 (3-amino propyltriethoxysilane), KH590 (3-mercaptopropyl trimethoxysilane) and Si69 (bis(3-triethoxysilylpropyl) tetrasulfane) were used as the compatibiliser. The effect of length and content of the BF, and the type of coupling agent on the mechanical properties of composites were discussed. The results confirm that the mechanical and thermal properties of the KH590-BF/MVQ/FKM composites were optimal when the BF was 7 phr (parts per hundred rubber) with a length of 12 mm, and treated with coupling agent KH590 of 2.0 phr. Further compatibility between the BF and MVQ/FKM was optimum. The glass transition temperature (Tg) reduced from − 19.2 °C to − 28.0 °C, while the application range of KH590-BF/MVQ/FKM composites was widened. [ABSTRACT FROM AUTHOR]

Enhanced visible light photocatalytic activity of BiWO photocatalyst modified with different ratio of polyvinyl pyrrolidone (PVP) was synthesized by a facile solvothermal process. The as-prepared photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra and photoluminescence spectra. The results indicated that the addition of PVP could control the particle morphology of bismuth tungstate catalyst to form high phase purity of BiWO. The solvent-thermal reaction time was critical in deciding the structure and shapes of the catalysts, and the optimal solvent-thermal reaction time was 24 h. The photocatalytic activities of the PVP-BiWO catalysts were determined by photocatalytic degradation of tetracycline hydrochloride (TCH) in aqueous solution under visible light irradiation. Optical properties and the TCH degradation results showed that PVP-BiWO catalysts exhibited enhanced photodegradation for TCH under visible-light irradiation. Among them, P5 (PVP % = 1.0 wt%) exhibited the best photocatalytic activity for degradation ratio of TCH reaching 86.88 % in 90 min. [ABSTRACT FROM AUTHOR]

A novel fluoride ion adsorbent, which uses natural clay modified by lanthanum and aluminum, was successfully prepared. The adsorbent was characterized by scanning electron microscope, BET surface area measurement, and X-ray photoelectron spectroscopy. Batch experiments were carried out to investigate the adsorbent performance for fluoride ion. Fluoride ion adsorbent onto modified clay followed the pseudo-second order kinetic model with the correlation coefficient value of 0.9846. The isotherm data was well fitted to the Langmuir model. The adsorption capacity of the modified clay was 1.3033 mg/g. The optimum pH value for fluoride ion removal was 6. The modified clay adsorbent can be regenerated by KAl(SO4)2·12H2O. Six times’ regeneration experiments showed that the regeneration rate of the modified clay still higher than 80 %, and the mass loss rate lower than 10 %. The modified clay performed strong adsorption capacity for fluoride ion and high regeneration rate. It could be a cost-effective adsorbent to remove fluoride from groundwater in undeveloped regions. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented related to a study which highlighted structural insights into Rhino-mediated germline piRNA cluster formation.

This letter presents a novel atomic force microscopy (AFM)-based nanomanufacturing method combining the tip scanning with the high-precision stage movement to fabricate nanochannels with ladder nanostructure at the bottom by continuous scanning with a fixed scan size. Different structures can be obtained according to the matching relation of the tip feeding velocity and the precision stage moving velocity. This relationship was first studied in detail to achieve nanochannels with different ladder nanostructures at the bottom. Machining experiments were then performed to fabricate nanochannels on an aluminum alloy surface to demonstrate the capability of this AFM-based fabrication method presented in this study. Results show that the feed value and the tip orientation in the removing action play important roles in this method which has a significant effect on the machined surfaces. Finally, the capacity of this method to fabricate a large-scale nanochannel was also demonstrated. This method has the potential to advance the existing AFM tip-based nanomanufacturing technique of the formation these complex structures by increasing the removal speed, simplifying the processing procedure and achieving the large-scale nanofabrication. [ABSTRACT FROM AUTHOR]

Copper-carbon core-shell nanoparticles were synthesized on a large scale by metal-organic chemical vapor deposition using copper (II) acetylacetonate as precursor. It was shown that the thickness of carbon shell and the diameter of copper cores could be easily tuned from 1.5 to 7.9 nm and from 15 to 21 nm, respectively, by controlling the reaction temperature and the flow of carrier gas in the synthesis process. The ultraviolet-visible absorption and fluorescence spectral analyses demonstrated that the thickness and crystallinity of the carbon shells had a significant effect on the surface-plasmon resonance band and the fluorescence emission properties of the copper nanocores, which suggested that the carbon shells could remarkably change the surface electronic states of the copper cores. [ABSTRACT FROM AUTHOR]

This article describes the multifunctional applications of TiO2. It substantiates the universality of the anodization process to grow well-ordered TiOxnanotube (T–NT) of hollow cylindrical shape on a variety of planar and nonplanar substrates. It highlights an approach to effectively bring down the cost of anodization via utilization of a small volume of electrolyte. The multifunctionality of these nanostructures is highlighted through representative examples that illustrate wide ranging optical, electronic, and catalytic properties. Combining the T–NT with other materials such as metals and photoactive additives to form composite nanostructures has been shown to benefit photocatalysis, photovoltaics, biological processes, and environment-related applications. This article also demonstrates the applicability of T–NT as an agent to produce dissolved oxygen in simulated blood—an application that can assist in the development of artificial lungs. Key results from the research group, collaborations, and recent articles are highlighted. [ABSTRACT FROM AUTHOR]