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This review demonstrates the recent progress and future research prospect of hierarchical MoS2/graphene-based nanostructures for electrochemical energy storage.

Currently, absorbing materials with thin thickness, lightweight, and strong absorption are required to reduce electromagnetic pollution. Flower-like MoS2 (D) and Ni microsphere (M) with MoS2 (D/M) absorbers were successfully fabricated via hydrothermal and solvothermal methods. Structural, physiochemical, elemental, and magneto-optical studies of the D and D/M samples were evaluated. The bandgap for M, D, and D/M composite is 2.56 eV, 3.1 eV, and 3.7 eV respectively. Morphological studies confirm the shape of the Ni microsphere and flower-like structure of the MoS2 composite. D and D/M composite show synergistic performance in terms of effective bandwidth, absorption, and reflection loss. The RL from D is −24.5 dB for 1.5 mm thickness whereas the D/M sample shows −9 dB at 2.5 mm thickness. Double layer absorbers of D and D/M were simulated using CST software. The lower/upper layer of D and D/M with 1.5 mm lower and 0.5 mm upper layers’ arrangement depicted minimum reflection loss and depicted their use for Ku band application. Therefore, D and D/M composites with thin thickness and minimum reflection loss might be suggested for application in microwave absorption.

This review demonstrates the recent progress and future research prospect of hierarchical MoS2 nanostructures for electrochemical energy storage.

In this critical review, hierarchical Bi2MoO6 nanostructures as photocatalysts for photocatalytic degrading organic materials are reviewed in detail. Hierarchical nanostructures have attracted numerous attentions due to their multiple advantages such as porous structure, large surface area, efficient light harvesting and charge separation, which have considerable influences on the photocatalytic performance. Herein, the recent progress of hierarchical Bi2MoO6 nanostructures including primary, secondary and multiple structures is hilighted. Particularly, the morphologies, photocatalytic performance and mechanism of hierarchical Bi2MoO6 nanostructures are outlined. Finally, futher development strategy of Bi2MoO6 photocatalysts is suggested. Research into Bi2MoO6 will offer guidelines of designing hierarchical photocatalysts for environmental applications.

Hierarchical TiO2–Bi2MoO6 nanospheres as efficient visible-light responsive photocatalyst are fabricated by dispersing brookite TiO2 nanorods on the hierarchical Bi2MoO6 nanospheres, which provides visible-light absorption and large surface area. The morphologies, surface area and light absorption features of as-prepared TiO2–Bi2MoO6 can be rational controlled by varying the loading amount of TiO2 nanorods on hierarchical Bi2MoO6 nanospheres. As a result, the TiO2–Bi2MoO6-3 yields 380 ppm CO2 production for decomposing 2-propanol at 11 h under visible light irradiation, realizing 4.4 times enhancement of photocatalytic property with respect to pure TiO2 nanorods. Moreover, the three-dimensional hierarchical architecture enables the hybrid TiO2–Bi2MoO6 excellent cycling stability.

We study compressible isentropic Navier-Stokes-Poisson equations in ℝ3. With some appropriate assumptions on the density, velocity and potential, we show that the classical solution of the Cauchy problem for compressible unipolar isentropic Navier-Stokes-Poisson equations with attractive forcing will blow up in finite time. The proof is based on a contradiction argument, which relies on proving the conservation of total mass and total momentum.

Catalytic in-situ hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) has received a great interest in recent years. Different reaction parameters such as catalysts, reaction temperature, time, pressure, solvents and catalyst amount optimized to achieve the highest conversion of HMF and selectivity of the products. The highest conversion of HMF (98%) and selectivity of DMF (97%) were achieved with Ru/ZSM-5 catalyst at 180 °C under ethanol solvent system for 3 h in 250 psi H2. The high catalytic efficiency was attributed to the oxophilic nature and acidity of catalyst, whereas the selectivity towards DMF was attributed to the Bronsted acidity of Ru/ZSM-5 and its affinity towards the C-O bond. The catalyst exhibited high yield of DMF from in situ hydrogenation of HMF with ethanol as economical hydrogen donor. Reaction mechanism studies revealed that Ru/ZSM-5 is promoting in situ H2 production from ethanol. Catalyst recyclability on HMF conversion and DMF selectivity has examined.

Separation and recovery of high-purity Si powder from kerf-loss Si slurry waste is a critical challenge for the photovoltaic industry. A green surfactant poly (propylene glycol) bis (2-aminopropyl ether) (PEA) was employed as a collector to facilitate the separation of Si and SiC from kerf-loss Si waste during flotation process. Single flotation tests of Si and SiC were conducted using 5 × 10−6 mol/L PEA, respectively. The separation efficiencies of Si and SiC in conjunction with PEA adsorption mechanism were investigated. It was found that the maximum recoveries rate of SiC and Si were 90.59% (pH 9.00) and 80.93% (pH 1.96), respectively. Furthermore, the maximum Si grade was determined as 92.31% at pH 8.95 for the sinking part of the mixture generating excellent floatability and selectivity. Zeta potential measurements, FT-IR spectra, and XPS analyses demonstrated that PEA was present on the surface of Si and SiC through electrostatic and hydrogen-bond interactions. The adsorption mechanism was explained based on the results. This research provides an efficient and environmentally friendly route for the separation and recovery of high purity silicon from kerf-loss Si waste.

Fluorides have been widely applied in pharmaceutical, medicinal, and materials science as well as in fine chemical manufacturing. The performance of fluorides, however, can be markedly affected by the water content. One previous study (Maiti, A.; et al. Phys. Chem. Chem. Phys. 2008, 10, 5050) suggested that anhydrous 1,3-dimethylimidazolium fluoride ([DMIm]F) was unstable since the fluoride undergoes a self-decomposition reaction. Herein we first show quantum-chemical calculation evidence that although gas-phase [DMIm]F is unstable, the bulk phase of anhydrous [DMIm]F is quite stable. We then demonstrate the successful synthesis of the anhydrous [DMIm]F compound via the reaction between 1,3-dimethylimidazolium iodide and silver fluoride. Importantly, we find that anhydrous [DMIm]F possesses a high dissolution capability toward 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), although it is known that TATB is hardly dissolved in many common organic solvents. Our Born-Oppenheimer molecular dynamics (BOMD) simulations further show that the high dissolving ability of anhydrous [DMIm]F toward TATB can be attributed to the chemical reaction between the F- anion and the TATB molecules, which disrupts the strong hydrogen-bonding interaction among the TATB molecules. Alternatively, water molecules in hydrous [DMIm]F tend to form a hydration layer around the F- anion, thereby preventing F- from reacting with the TATB molecule. This result explains why TATB is barely dissolved in hydrous [DMIm]F.

In this paper we consider iteration of single-plateau functions, an important class of continuous functions with infinitely many forts, and investigate changes of number and length of plateaux under iteration. We use the indices flatness, plateau limit and limit length to formulate those changes. Furthermore, we compute flatness, plateau limit and limit length for all nine types of single-plateau functions.

An efficient [4 + 2] benzannulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes was achieved under metal-free reaction conditions selectively delivering a wide range of polyfunctional benzenes in high yields respectively (up to 94% yield).

Herein, we demonstrate the synthesis of Bi₂MoO6 nanosheet array followed with in-situ electrodepositing ZnO layer, resulting in Bi₂MoO6/ZnO heterojunction nanosheet array. The thickness of nanoparticle-based ZnO layer on the surface of Bi₂MoO6 nanosheets can be rational controlled by regulating the electrodepositing time. The combination of oriented Bi₂MoO6 nanosheet array and ZnO layer could not only enhance the conductivity and surface area but also facilitate the charge separation. As expected, the heterojunction electrode yields a photocurrent density of 430 µA/cm² at 0.8 VSCE, which is much higher than that of pristine Bi₂MoO6 and ZnO nanosheet array.

Transition metal dichalcogenides, especially MoS2 , have been regarded as promising cocatalysts for the hydrogen evolution reaction (HER) because of a near-zero Gibbs free energy for H+ absorption. However, the HER activity of MoS2 is profoundly restricted by acidic media. Co-doped MoS2 (Co-MoS2 ) nanosheets are found to enable the highly efficient solar H2 evolution of CdS nanowires (NWs) in alkalescent electrolyte. The content of Co in MoS2 is optimized to 2.8 % and the Co-MoS2 content in Co-MoS2 /CdS NWs hybrids is 2.5 wt %; the optimized Co-MoS2 /CdS NWs shows a high H2 evolution rate of 14.22 mmol g-1 h-1 and 71 % apparent quantum efficiency in the Na2 SO3 electrolyte. Moreover, the H2 generation enabled by the Co-MoS2 cocatalyst can exhibit universality in alkalescent electrolytes, such as triethanolamine (TEA) and disodium ethylenediaminetetraacetic acid (EDTA), exhibiting greater photocatalytic H2 generation than Pt/CdS. The design of Co-MoS2 /CdS sheds light on the development of highly efficient low-cost photocatalysts for solar H2 generation from water reduction.

Ordered hierarchical NiCo2O4/Bi2MoO6 nanorod arrays directly grown on Ti foil are fabricated by a facile two-step hydrothermal reaction. The heterostructured electrode enables synergistic effect for excellent electrochemical properties. Moreover, this unique three-dimensional nanostructure not only promotes the electron transfer and ion diffusion but also provides good structure stability. As the binder-free electrode, hierarchical NiCo2O4/Bi2MoO6 nanorods show high capacitance (0.94 F cm−2 at 5 mA cm−2) and good cycling stability (capacitance retention of 96.3%).

Herein, ordered TiO2-Ag3PO4 nanorods are fabricated by loading Ag3PO4 nanoparticles on the as-prepared brookite TiO2 nanorods. The amount of Ag3PO4 nanoparticles loaded on brookite TiO2 nanorods can be rationally optimized. These hybrid TiO2-Ag3PO4 nanorods could provide large surface area, extend the visible light absorption and facilitate the charge separation, leading to efficient visible-light-driven photocatalytic performance. When evaluated as photocatalysts under visible light illumination, all the hybrid TiO2-Ag3PO4 nanorods exhibit high photocatalytic activity for degrading 2-propanol. Particularly, TiO2-Ag3PO4-3 enables the best photocatalytic property, which yields high acetone production of 147 ppm at 3 h and CO2 production of 424 ppm at 11 h.

Heterojunction electrode requires thermodynamically favored band edge energetics to boost charge separation for efficient photoelectrochemical (PEC) water splitting. In this study, we report that TiO2 nanorods (NRs) doped with W, formed by solid state diffusion, can tune the band structure to construct a Type II staggered heterojunction with BiVO4. The W-TiO2/BiVO4 heterojunction overcomes the intrinsic energy barrier between BiVO4 and TiO2 NRs by downward shifting of conduction band position, exhibiting 4-times higher PEC performance (2.5 mA/cm2) than TiO2/BiVO4. Moreover, the photocurrent characteristics and photon-to-current conversion efficiency (IPCE) indicate that the W-TiO2/BiVO4 heterojunction retains the small onset potential of TiO2 and light harvesting capability of BiVO4. Especially, compared to popular WO3/BiVO4 heterojunction, the W-TiO2/BiVO4 heterojunction can present better stability towards long-term solar water splitting due to the compatibility of pH sensitivity. This study can shed a new insight on design of heterojunction by regulating band edge energetics for PEC water splitting.

With the continuous development of EHV (UHV) transmission lines，new lines often need to drill through the built lines，so it is urgent to study the type of diving towers. Based on typical weather conditions and commonly used ground wire models, the basic type and tower type selection of 110kV single and double circuit overpass towers in high altitude areas are studied, and two single and double circuit overpass tower schemes are planned and arranged. And according to the pole tower structure design and optimization theory, the 110kV single-circuit diving tower and the 110kV dual-circuit diving tower are optimized from the structural optimization layout and the pole tower structure node optimization design. The research results show that the single-circuit diving tower adopts the wine glass tower, and the wires are arranged horizontally, and the double-circuit diving tower effectively reduces the height of the tower. The dish-shaped tower is used, and the single-circuit wires are arranged in a triangle pattern, which provides a certain practical guiding significance for the 110kV diving-across technology application.

The digitization of power grid projects is a development requirement in the era of big data, as well as an inevitable requirement for the State Grid Corporation of China to build digital power grids and improve life-cycle management. Three-dimensional design establishes three-dimensional models of ground conductors, insulators, and fittings through line electrical majors, and completes line poles and towers in a three-dimensional scene; line structure majors should establish iron tower models and basic models; survey majors should conduct topography and landforms and ground objects to complete three-dimensional scene construction. It can make the circuit design results more intuitive, reduce the drawing work of repeated components, and improve the design efficiency.

An efficient [4 + 2] benzannulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes was achieved under metal-free reaction conditions selectively delivering a wide range of polyfunctional benzenes in high yields respectively (up to 94% yield).

Fluorides have been widely applied in pharmaceutical, medicinal, and materials science as well as in fine chemical manufacturing. The performance of fluorides, however, can be markedly affected by the water content. One previous study (Maiti, A.; et al.

Porous metals are recently gaining interest in various fields with lots of advantages of high conductivity, high surface area, good permeability and light weight properties. In present study, a novel three-dimensional porous nickel films (3DNFs) have been efficiently fabricated by controllable electrodeposition of Ni micro-particles using hydrogen bubbles as the template at ambient temperature and pressure. The morphologies and microstructures of products were analyze by field emission scanning electron microscopy (FESEM) and X-ray powder diffraction (XRD), respectively. The formation mechanism of 3DNFs was firstly explored by time sequential experiments. In addition, electrochemical measurements indicate that the obtained 3DNFs possess great electrocatalytic properties for methanol and ethanol oxidation reaction due to the high surface area and outstanding open porous structures. Thus, the great cycle life and catalytic properties of product indicate the great prospect of the promising catalyst with wide applications in catalysis, sensors and purification.

Well-ordered hierarchical Ag/Bi2MoO6 hollow nanoboxes are obtained through an artful hydrothermal method. Ag3PO4 nanocubes serve as growth templates and precursor sources of Ag. Ag3PO4 is reduced to Ag nanoparticles, which are dispersed on the nanosheet-built hierarchical Bi2MoO6 nanoboxes. With the investigation of intermediate products, the growth process of Ag/Bi2MoO6 is studied. Due to the hierarchical hollow structure and the introduction of Ag, the Ag/Bi2MoO6 nanoboxes exhibit enhanced visible-light absorption and photocatalytic performance compared to the pristine Bi2MoO6 microboxes.

In this study, hierarchical MoS2/MoO3 nanotubes are fabricated through an elegant method. MoO3 nanorods serve as not only growth templates but also Mo precursors. It is well established that bubble-like MoS2 hollow nanospheres are uniformly distributed on the MoO3 nanotubes. Ascribed to the unique architecture and synergistic effect of active materials, the as-prepared hierarchical MoS2/MoO3 nanotubes exhibit excellent electrochemical performance for energy storage. This work sheds light on the design of hybrid hierarchical nanotubes as electrochemical electrode materials through an elegant and feasible strategy, providing an idea for fabricating hybrid materials with a high capacitive ability.

A computational study with the M06-2X/B3LYP density functional is carried out to explore the effects of NH4OAc on the Cu(I)-catalyzed heterocyclization of α-acyl-α-alkynyl ketene dithioacetals to form 3-cyanofurans. The calculations suggest the following. (a) The use of CuBr as the catalyst decreases significantly the free energy barriers of intramolecular cyclization and intermolecular addition. (b) NH4OAc can be decomposed into NH3 and HOAc. NH3 as the proton shuttle is critical in the stepwise H+-transport process because it can greatly reduce the rate-determining free energy barrier of whole Cu(I)-catalyzed reactions (from 251.1 to 130.1 kJ mol−1). (c) HOAc also plays a role similar to that of NH3 in the H+-transport reactions. These studies are expected to improve our understanding of transition-metal-catalyzed reactions and provide guidance for the future design of new catalysts and new reactions.

Herein, the well-defined hollow Bi2MoO6 nanorods are facile prepared by a template-assisted hydrothermal reaction. The Ag2CrO4 nanorods are used as the growth template to support the Bi2MoO6 nanoparticle-based shell. Simultaneously, the Ag2CrO4 is reduced to Ag which can be etched by HNO3, producing the hollow Bi2MoO6 nanorods. Attributed to the hollow interior and nanoparticle-built structure, the hollow Bi2MoO6 nanorods exhibit large surface area and enhanced visible-light harvesting, resulting in excellent photocatalytic property.

Novel hierarchical NiCo2S4/MoS2 nanotube array directly grown on Ni foam is in-situ fabricated using the NiCo2O4 nanorod array as template. The hierarchical hybrid nanotubes not only provide good synergic effect of active materials and large surface area but also promote electron transfer, ion diffusion and structural stability. When evaluated as electrochemical electrode, the hierarchical NiCo2S4/MoS2 nanotubes exhibit high rate capability and cycling stability even at high current densities.

In this work, the branched MoS2 nanowires are synthesized by a facile and feasible reflux method. It is clearly that the MoS2 nanowires interconnect with each other, forming regular branched network. In this fabrication, the polyvinyl pyrrolidone (PVP) is used as surfactant which is critical for the formation of branched MoS2 wires. Without the PVP, only MoS2 nanoparticles can be obtained.

Granular particles can be induced to move against gravity upwards through a pipe or tube that is partially inserted under the powder free surface while subject to vertical vibration. This offers a new approach for transporting bulk material. In this paper, the effects of both vibration parameters and insertion depth of a pipe on particle motion are experimentally studied. A minimum vibration amplitude (A) and frequency (f) are necessary for particle motion to occur. There is a monotonic increase of the final rise height of the powder (heq) with increasing amplitude A. However, heq exhibits a non-monotonic dependence on frequency, f. There is an optimum frequency at which particles climb highest, and any further increase of frequency leads to a diminishment of this upwards motion. A phase diagram of particle movement is presented which shows that different zones of motion exist. This unique finding suggests that the mechanism of particle movement is caused by the creation and filling of voids under the tube. Particles cannot move upwards when the pipe insertion depth, hin is PACS number: 45.70.MG - granular flow

Practical application of nano/micro-composite is frequently hampered by the sophisticated fabrication process, expensive cost and easy loss of capacities due to hydrophilicity etc. This paper presents a facile method to fabricate a novel superhydrophobic nano-aluminum/copper (II) oxide composite via electrophoretic deposition (EPD) and followed by surface chemical modification using a low surface energy material-1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane. The stable EPD suspension consists of ethanol and acetyl-acetone. Surface morphology, wettability, and chemical composition were characterized using SEM, EDS, XRD, water contact and sliding angle measurements. The resulting surface, with water contact angle of ∼168°, is stable up to 12 months in ambient atmosphere and shows great exothermic performance. These results provide a new perspective for advancement of superhydrophobic surfaces in real industrial application.

We study Hermite–Fejer interpolation operators in spaces of weighted maximum norm, whose nodes are the zeros of Jacobi polynomials with indexes $$\alpha , \beta >-1$$. The approximation behaviour of those operators is presented by the so-called strong inequalities. Moreover, such strong inequalities are valid for any individual continuous function on $$[-1, 1]$$. The obtained result covers also the saturation of these operators.

Free surface fluctuations in the continuous casting mold were simulated using the three-dimensional Lattice Boltzmann method (LBM) coupled with free surface scheme. The LBM model was verified by the agreement between the calculated results and the measurements. The results indicated that free surface fluctuations at both sides of the mold were asymmetrical. Operation parameters of continuous caster played an essential role in the fluctuations of free surface. The distributions of free surface fluctuations were also quantified. The peak and trough fluctuations on both sides of the mold alternated thereon, accompanied by the stochastic formation of the vortices at the top mold. The simulation results suggest that the LBM models can offer a promising way to study free surface behaviour and related phenomena in a continuous casting mold.

Separation of refined silicon from Al&ndash, Si melt is still a puzzle for the solvent refining process, resulting in considerable waste of acid and silicon powder. A novel modified Czochralski method within the Al&ndash, Si alloy is proposed. After the modified Czochralski process, a large amount of refined Si particles was enriched around the seed crystalline Si and separated from the Al&ndash, Si melt. As for the Al&ndash, 28%Si with the pulling rate of 0.001 mm/min, the recovery of refined Si in the pulled-up alloy (PUA) sample is 21.5%, an improvement of 22% compared with the theoretical value, which is much larger 1.99 times than that in the remained alloy (RA) sample. The content of impurities in the PUA is much less than that in the RA sample, which indicates that the modified Czochralski method is effective to improve the removal fraction of impurities. The apparent segregation coefficients of boron (B) and phosphorus (P) in the PUA and RA samples were evaluated. These results demonstrate that the modified Czochralski method for the alloy system is an effective way to enrich and separate refined silicon from the Al&ndash, Si melt, which provide a potential and clean production of solar grade silicon (SoG-Si) for the future industrial application.

Well-ordered hierarchical Ag/Bi

Concerning iterative roots, a main difficulty comes from forts of continuous functions. A case of infinitely many forts is the class of functions with plateaus. In this paper we consider functions in this class and their iterative roots. We discuss on changes of plateaus under iteration and give a criterion to determine the clenched class. Then we find all iterative roots for clenched single-plateau functions.

In this work, the design and synthesis of ZnS/MoS2 hybrid nanoparticle film directly grown on Mo foil is reported by a one-step hydrothermal reaction. The as-prepared hybrid composite film exhibits a specific capacitance of 956.3 F g−1 at 10 mA cm−2 which is about 6.4 times of the pristine MoS2 film (150 F g−1 at 10 mA cm−2), and excellent cycling stability (85.7% capacity retention after 2000 cycles). Generally, the greatly enhanced electrochemical performance is attributed to the robust nanoparticle structure on Mo foil, providing large surface, close contact between the substrate and active materials, and low inner resistance. In addition, these two kinds of active materials provide a synergistic effect for the improved capacitive property.

Secondary bending moment and geometric nonlinearity should be taken into account in pipe tower design. Taking the 110kV double-circuit narrow-base steel pipe tower as an example, the 110 kV double-circuit narrow-base steel pipe tower is compared and analyzed through the tower structure design software and the general finite element software ANSYS. The analysis results show that the narrow-base steel tube tower should adopt a rigid-truss structure model, and the influence of the secondary bending moment of the main material and the geometric nonlinearity should be considered. The secondary bending moment effect accounts for about 10-20% of the strength stress of the steel pipe main material. Through comparative analysis, a number of design points are summarized, which provides a certain practical guiding significance for the design and application of the double-circuit narrow-base steel pipe tower.

With the rapid growth of the photovoltaic (PV) industry, the amount of the silicon waste has substantially increased, resulting in serious environmental problems. This waste mainly consists of the silicon waste powder from kerf loss slurry of wire saw wafer cutting process and the scrap pieces from silicon ingot casting process. To reduce the cost of crystalline Si production and relief the existing environmental pollutions, it is of significant interest to recover and recycle the silicon value from the Si waste. This paper presents a literature overview of the current technologies and research progress in the recovery and recycling of high purity silicon from the silicon wastes generated in the PV industry. First, the source and classification of Si wastes, including slicing silicon waste and scraps of Si ingots are summarized. Second, various techniques related to the separation and recovery of high purity Si from the waste are reviewed and compared based on the experimental results. The characteristics and advantages of different technologies are evaluated based on the current conditions. Third, the applications of silicon waste are explored in a detailed manner. Last, the assessment of different Si recovery technologies is elaborated. This review gives an outlook on the recycling and recovery of high purity silicon from the silicon waste, which shows great potential for further research in this field.