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It has been challenging to achieve multi-photochromic systems without affecting the individual photoswitching properties of the constituent units. Herein, we present the design and synthesis of a new family of platinum-acetylide dendrimers containing up to twenty-one photochromic dithienylethene (DTE) units that exhibit both high photochromic efficiency and individual switching properties. Upon irradiation with ultraviolet (UV) and visible (vis) light, the resultant metallodendrimers display high conversion yield and good fatigue resistance. More interestingly, cyclization-cycloreversion kinetics revealed that the photochromic property of each DTE unit in these metallodendrimers is unaffected by its neighbor and the full ring-closure of up to twenty-one DTE units in one single dendrimer has been achieved.

Owing to their entropy stabilization and multi-principal effect, transition-metal-based high-entropy oxides are attracting extensive attention as an effective family of anode materials for lithium ion batteries (LIBs). Herein, spinel-type (Al0.2CoCrFeMnNi)0.58O4-δ HEO nanocrystalline powder with high concentration of oxygen vacancies is successfully prepared by the method of solution combustion synthesis (SCS), and explored as a novel anode active material for LIBs. As compared to (CoCrFeMnNi)0.6O4-δ, the inactive Al3+-doped (Al0.2CoCrFeMnNi)0.58O4-δ anode provides more than twice the reversible specific capacity of 554 mAh g−1 after 500 cycles at a specific current of 200 mA g−1, accompanied with good rate capability (634 mAh g−1 even at 3 A g−1) and cycling performance. The enhanced electrochemical properties can be attributed to that inactive Al3+-doping resulted into the more space for Li+ intercalation and deintercalation, enhanced structural stability, and the improved electronic conductivity and Li+ diffusivity.

To investigate the effects of Cr doping on the microstructure and tribological properties of multi-layered diamond-like carbon (DLC) films, Cr-DLC films with Cr contents ranging from 0 to 22 at.% were deposited on 0Cr19Ni10 stainless steel and Si wafer surfaces by unbalanced magnetron sputtering. The thickness of the transition layer is 180 nm and the Cr-DLC film ranging from 1.3 to 1.5 µm. The microstructure, mechanical and tribological properties of the films were systematically investigated at room temperature in atmospheric environment. Results show that increasing the Cr target current can effectively improve the incident particle density and reduce surface roughness. As a strong carbon metal, Cr has significant influence on the structure and properties of the film for bonding with carbon atoms during deposition. High-energy Cr particles are favorable for films to increase the sp3 hybrid bond ratio and reduce internal stress. The high-hardness sp3 hybrid phase, Cr carbide, oxide dispersion can effectively improve the mechanical properties of the film, but overdoping is detrimental for mechanical properties of the film. The internal stress shows a continuous trend of decreasing with the increasing Cr content and it reduced up to 80% compared with pure DLC films. The films prepared with Cr sputtering current of 0.4 A demonstrate the best tribological properties, and the friction coefficient and wear rate are 0.15 and 2.9 × 10−7 mm3/Nm, respectively.

In order to obtain the optimal collocation of two important technological parameters in the spinning process, the multi-response surface method was used to optimise the experimental results. Through the orthogonal design of the two factors and four levels of factor encoding, 16 groups of orthogonal experiments were designed; the experimental results were fit using the curve fitting toolbox of Matlab; a regression equation of yarn quality indicators, and in addition to a three-dimensional surface chart, an optimal scheme of the roving twist factor and spinning drafting for a roving twist factor of 110 were established; a spinning back draft of 1.5 was obtained based on experimental results of the response surface analysis and variance regression analysis. Experiments on the optimal scheme were carried out to verify the practicability of the results obtained by this method. The results show that application of the multiple response surface method to the optimisation of process parameters is of practical significance. This method can be applied for the optimisation of other process parameters.

The absorption coefficient of dusty plasma is deduced on the basis of considering the influence of dust particles electric potential, and its absorption characteristic in the near infrared region is discussed. The involved results manifest that the absorption coefficient of dusty plasma with the dust particles potential is considered is obviously bigger than that of not considered in the given temperature, pressure and frequency ranges, which proves the influence of dust particles potential can not be omitted. Besides, the results also indicate that the maximal absorption ability of the dusty plasma does not occur where the maximal electron number density (plasma resonance frequency) appears. Consequently, two conditions, which determine where the maximal absorption appears, are presented by a series of theoretical deduction.

We consider the transverse electric (TE) plasmonic modes supported by black phosphorene (BP) in a parallel waveguide structure with left-handed material (LHM) instead of the conventional right-handed dielectric material. The existence condition of the TE BP surface plasmon polariton (SPP) is I m σ > 0 . When an electric field is polarized along one of the two orthogonal crystal axes, the anisotropic symmetric and anti-symmetric plasmonic modes depend on the incident optical energy, the chemical potential, and the distance between two BP sheets can be observed. The symmetric mode has a more extensive effective refractive index, which possesses stronger field confinement. With a decreasing distance d between two BP sheets, the coupling strength between the two separate BPSPP waves increases. When d is small enough, the anti-symmetric mode root does not exist. LHMs can be used to realize a TE BPSPP mode to enhance the localization of the BPSPP, which is a practical method in optoelectronic devices based on black phosphorene.

A high-performance Si@SiO2@C anode material for Li-ion batteries was obtained by a novel synthetic strategy based on a mechanical milling and molten salt coactivated magnesiothermic reduction at a low temperature of 200 °C, only using rice husk as the Si and C sources. The anode material obtained presented an electrochemically favorable architecture, in which crystalline Si particles with a size of ~15 nm were uniformly embedded in the amorphous carbon and SiO2 matrix. The amount of the Si, SiO2 and C components in the anode material was determined to be about 17.2, 24.5 and 58.3 wt%, respectively. Electrochemical analyses demonstrated that the Si@SiO2@C anode material showed excellent electrochemical performance, delivering a reversible capacity of 1277.3 mAh g−1 at a current density of 0.1 A g−1, still possessing a high capacity of 910.2 mAh g−1 when increasing current density to 5 A g−1. After cycled for 200 cycles at 1.0 A g−1, the anode still preserved a reversible capacity of 973.1 mAh g−1, showing a capacity retention of 93.1% and a Coulumbic efficiency higher than 99.7%. Importantly, the synthetic strategy is not only more facile and cost effective, but also more environmentally friendly, compared with those recently reported. Thus it is promising to be applied for large-scale transformation of rice husk to high-performance Si@C-based anode materials for Li-ion batteries.

MoS2 film plays an important role in the field of space lubrication due to its excellent tribological properties, but the complex and changeable space environment has increasingly higher requirements for the lubricating layer. In order to improve the spatial tribological properties of the MoS2 film, the Mo-X (X = Pb, PTFE, C) binary composite films were prepared by radio frequency magnetron sputtering technology. Then, Mo/MoS2–Pb–PbS, Mo/MoS2-PTFE and Mo/MoS2–C films were obtained through the treatment of binary films by “low-temperature ion sulfurizing” technology. The structure, morphology and composition properties of the three films were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).The tribological properties of the three films were tested through ultraviolet (UV), atomic oxygen (AO) and high-vacuum simulated space environment, and the results showed that the Mo/MoS2–Pb–PbS film has better comprehensive spatial tribological properties. The Mo/MoS2–Pb–PbS film was applied to practical bearings, which were simulated for life test after exposure to space environment. The wear life of the new bearing is an order of magnitude higher than that of the active bearing. Therefore, Mo/MoS2–Pb–PbS film has broad application prospects in the field of space solid lubrication.

Yttria stabilized zirconia (YSZ) nanocrystals were prepared by hydrothermal synthesis and were calcinated at different temperatures and with different isothermal hold time. X-ray diffraction via whole powder pattern modeling approach was used to study the grain growth as well as the evolution of grain size distribution of YSZ nanocrystals. Results show that YSZ nanocrystals start to grow along with the grain size distribution broadening at about 300 °C. The grain growth rate and the grain size distribution of YSZ nanocrystals are dependent on the calcination temperature and the isothermal hold time. The grain growth exponent and the active energy of grain growth were calculated. Grain rotation induced grain coalescence is suggested as the predominant way of grain growth of YSZ nanocrystals.

We propose a facile synthesis approach for nitrogen doped porous carbon and demonstrate a novel pore-forming method that iron nanoclusters act as a template or activator at different carbonization temperatures based on Fe3+-poly(4-vinyipyridine) (P4VP) coordination. P4VP will completely decompose even in an inert atmosphere, but under the coordination and catalysis of Fe3+, it can be converted to carbon at a very low temperature (400 °C). The aggregation of iron nanoclusters in the carbonization process showed different pore-forming methods at different temperatures. The as-prepared materials possess high specific surface area (up to 1211 m2 g–1), large pore volume (up to 0.96 cm3 g–1), narrow microporosity, and high N content (up to 9.9 wt %). Due to these unique features, the materials show high CO2 uptake capacity and excellent selectivity for CO2/N2 separation. The CO2 uptake capacity of NDPC-2-600 is up to 6.8 and 4.3 mmol g–1 at 0 and 25 °C; the CO2/N2 (0.15/0.85) selectivity at 0 and 25 °C also rea...

Superhydrophobicity and high elasticity are the two key properties of oil-absorption porous materials. The hydrophobic graphene/carbon black coating on the skeleton of a melamine sponge facilitated the surface to form the micro/nanoscale roughness. The resulting sponge thus was superhydrophobic. Moreover, it inherited the extremely high elasticity of raw melamine sponge, which showed no plastic deformation even after 1000 compression/relaxing cycles. To our knowledge, this was the first superhydrophobic graphene-based porous monolith with such a high elasticity. Its absorbed oils could be recycled by simple squeezing and it was also regenerated by squeezing because of the high elasticity. In addition, it showed a high absorption capacity for common oil contaminations and its fabrication was facile. Therefore, it is really an excellent absorbent for the practical absorption of oil contaminations from water.

The variable speed hydrodynamic couplings are widely used in soft-starting of scraper conveyor and belt conveyor in coal mine machinery. In order to analyze the internal flow field, torque characteristics and blade wheel strength of the hydrodynamic coupling under full filling condition, the flow field model of pump and turbine was established. The numerical simulation of internal flow field in the hydrodynamic coupling was carried out by using the computational fluid dynamics (CFD) software CFX. The characteristics of velocity streamline and pressure field distribution in 5% relative slip between pump and turbine under full filling condition was analyzed, and the torque characteristics of hydrodynamic coupling at different speed ratios were obtained. Finally, based on the one-way fluid-solid interaction theory, the finite element strength model of the blade wheel was established, the equivalent stress distribution and overall deformation state of the blade wheel under extreme working condition were obtained. The results show that the internal flow state and torque characteristics of hydrodynamic coupling can be predicted by the numerical simulation. The simulation results provide a technical support for the blade wheel strength analysis and control system design of the variable speed hydrodynamic coupling. Besides, the finite element strength analysis provides a theoretical basis for the structural optimization design of the hydrodynamic coupling.

We demonstrate a new low-frequency transverse electric SPP in the terahertz (THz)/sub-THz regime in a dielectric-graphene-dielectric structure. The TE SPP is generated by the strong nonlinear response in graphene. Furthermore, unlike any other known SPPs located outside the radiation zone, a significant part of the low frequency TE SPP mode falls in the radiation zone.

Cement emulsified asphalt mixture (CEAM) is a semi-flexible pavement material, which is formed by the organic combination of aggregate, cement, emulsified asphalt and water. The compaction process of CEAM includes demulsification of emulsified asphalt, hydration of cement, evaporation of water, and formation of a three-dimensional interwoven network of aggregate, cement and asphalt. Therefore, it has different compaction deformation characteristics from the hot asphalt mixture. In order to explore the theoretical model of compaction process parameters for pavement (PCPP), which are based on compaction deformation characteristics and strain energy theory, effective compaction work (ECW) was defined as the compaction work consumed by viscoplastic compression displacement of the material. The mechanical response is studied by compressive testing and a calculation model for lab-scale effective compaction work (LECW) is established for CEAM. Furthermore, a calculation model for effective compaction work in pavement (PECW) is established based on the work-energy equivalence principle and roller compaction datas. In addition, a prediction model of PCPP for target dense degree (TDD) is obtained by the equivalence of LECW and PECW, and the introduction of energy absorption efficiency (EAE). Moreover, the PCPP combination modes during three stages, i.e., initial compaction, re-compaction and final compaction, of the roller are determined according to the compaction deformation characteristics of CEAM material. Based on the compaction combinations modes, the compaction process parameters combinations (CPPC) during the three compaction stages for the TDD are derived from the prediction model. The reliability of the proposed model is verified by a road compaction test. The CPPC results reveal the reliability of established LECW and PECW models. However, the EAE of vibration compaction in the prediction model is revised to be 76.05% after the road compaction test. The prediction model and introduction of EAE provide a theoretical baseline for the parametric design of compaction and construction process of CEAM and other pavement materials.

We investigate the longitudinal optical conductivity of spatially separated few-layer graphene analytically and numerically. Each layer could be monolayer or bilayer graphene. The density–density correlation function has been screened by the dielectric function using the random phase approximation, which includes the inter-layer Coulomb coupling. In the presence of the potential function between the layers, the carrier densities in each layer can be tuned respectively. In these two-dimensional layered structures, the main contributions to the optical conductivity are from the intra- and inter-band transition channels in a same layer. In the infrared region, the Drude optical conductivity was observed by the unscreened intra-band transition process. But in the presence of the inter-layer Coulomb interaction, one peak structure of the optical conductivity is observed which can be modified by the dielectric environment. From the number of turning points and the turning positions, the carrier density, the Fermi wavevector, and the layered structure can be determined.

Ultrathin Ni Co Al layered double hydroxide (LDH) sheets directly grew on reduced graphene oxide (RGO) nanosheets by a facile hydrothermal route in a mixed solvent of water and ethylene glycol, yielding the RGO/Ni 0.75−x Co x Al 0.25 -LDH (x = 0, 0.05, 0.15) composites. Structural analyses revealed that the resulting composites presented a unique morphology of crumpled silk veil waves, in which the ultrathin Ni 0.75−x Co x Al 0.25 -LDH sheets, composed of 2–3 host layers, were entangled with the rippled RGO nanosheets. Electrochemical analyses demonstrated that the RGO/Ni 0.70 Co 0.05 Al 0.25 -LDH composite showed superior supercapacitive performance, as compared with the pure Ni 0.70 Co 0.05 Al 0.25 -LDH and the RGO/Ni 0.75−x Co x Al 0.25 -LDH (x = 0, 0.15) composites. It exhibited not only ultrahigh cycling stability and good rate capability, but also considerably high specific capacitance. It possessed a high specific capacitance of 1544 F g −1 at current densities of 1 A g −1 , still delivering a high capacitance of 1081 F g −1 at an increased current density of 40 A g −1 . After cycled at 10 A g −1 for 2000 cycles, it retained a capacitance of 1343 F g −1 without capacitance decay observed. The superb supercapacitive performance along with the facile synthesis method adopted suggested that the RGO/Ni 0.70 Co 0.05 Al 0.25 -LDH composite was promising for supercapacitor applications.

The initial stress concentration resulting from the needle-punching effect is a fundamental issue in the longitudinal strength model for laminated carbon/carbon composites. In the present work, this stress distribution is obtained by combining the finite difference method with the shear-lag model. The effect of the needled hole size on the stress concentration is investigated. The broken width is more significant than the separated length for the improvement of the stress concentration degree. The increase of the fiber volume fraction is shown to decrease the overload area. Random needling distributions are compared to the ordered one. Few interactions of each needled area are found in the ordered distribution and the stress concentration is decreased in these random needling distributions. Finally it is concluded that the enlarging of each needled hole, especially the accumulation of broken fibers, during the cyclic process of overlaying laminates and punching is the prime reason for tensile strength reduction under the condition of high needling density. Keywords: Carbon/carbon composites, Needle punching, Stress concentrations, Modelling

A new parameter, i.e., tearing toughness, was employed to characterize the mechanical properties of some ductile metals (Cu, Cu–2 wt% Be, Cu–Al alloys, and some steels) by using three-leg trousers tearing tests. The experimental results demonstrate that their tearing toughness is not a physical constant and shows a close relationship with the materials’ types and microstructures. It can be inferred that the tearing toughness of different ductile metals has their respective variation range, expectantly, and may be represented by the comprehensive mechanical properties of strength and ductility for various ductile materials.

Using the Kubo formalism, the intraband optical conductivity of black phosphorene (BP) with an anisotropic energy spectrum is obtained. The presence of BP in an infinite sandwich between two dielectric media supports the transverse magnetic (TM) BP surface plasmon polariton (SPP) wave. Thereby, the effective indices n eff for TM BP SPP mode exhibits a linear relation with the incident frequency, which can be tuned by the chemical potential as well as by the dielectric medium surrounding the BP layer. The sublinear dependence of the reciprocal of n eff on the chemical potential indicates the effective masses in the armchair and zigzag directions are dependent on the carrier wave vector. Moreover, the effective mass in the armchair direction is more dispersive. The anisotropic optoelectronic features in BP offer more tunability in the design and application of optoelectronic devices as an isotropic system like graphene.

A nano-sized Si anode material was synthesized by a novel and highly efficient route of ball-milling assisted low-temperature aluminothermic reduction at 150–180 °C in a eutectic NaCl/KCl/AlCl3 mixture, using white carbon black and coarse-grained Al powder as the starting materials. After extending the duration of ball-milling assisted aluminothermic reduction to 10 h, the obtained Si yield reached as high as 94%. The synthesized nano-Si mainly consisted of irregular porous agglomerates constructed by ultrafine primary particles with a particle size less than 50 nm. The nano-Si anode showed a superior electrochemical performance. Its maximum discharge and charge capacities at a current density of 0.05 A g−1 were 3075 and 2597 mAh g−1, respectively, leading to a high initial Coulumbic efficiency of 84.5%. The nano-Si anode exhibited reversible capacities of 2458 mAh g−1 at 0.2 A g−1, and of 1169 mAh g−1 at a high current density of 5 A g−1. After cycling at 1 A g−1 for 400 cycles, it still delivered a high reversible capacity of 804 mAh g−1. The synthetic strategy, which is not only facile and highly efficient, but also low-cost and environmentally benign, is thus promising to be applied for mass production of nano-Si anode materials for next-generation Li-ion batteries.

Air gap membrane distillation experiments of different temperature and mass flow rate of working fluid were done for the use of solar power and setting up the mathematical model of AGMD’ heat and mass transfer. The calculation correctness of mathematical model was discussed and the thermal efficiency of membrane distillation system was calculated. The results showed that the experimental flux of membrane distillation reached 49kg/m2·h and the biggest relative error is less than 9% between results of experiment and mathematical model calculation. The mathematical model can be used to forecast the process parameters of membrane distillation. The highest thermal efficiency of this system is 68% and the main influencing factors of thermal efficiency are temperature and mass flow rate of working fluid.

Yttria-stabilized zirconia (YSZ) hollow sphere (HS) powder is a novel potential feedstock material for the plasma spraying of next generation advanced thermal barrier coatings with low thermal conductivity and high sintering resistibility. In this study, YSZ HS powders were prepared by plasma treatment with/without a heat preservation zone around the flying path of the particles during plasma flame. The results of the scanning electron microscopy of YSZ HS powders showed that HS prepared with a heat preservation zone during the plasma process exhibited a regular spherical morphology and a homogeneous thin shell structure. Due to the sufficient heating of the shell regions, the HS powder presented a well densified shell structure. Furthermore, the mechanism of formation of the HS powder with reduced shell thickness was also discussed based on the analysis of the evolution of the powder structure. This kind of hollow sphere powder with a very thin shell structure provides a new alternative feedstock material for the development of next generation high performance thermal barrier coatings.

The evolution of crystalline structure of YSZ nanoparticles during co-precipitation synthesis was studied by X-ray diffraction via Rietveld refinement. Results show that the transformation of hydroxides to tetragonal nanoparticles is dependent on the calcination temperature. The tetragonal nanoparticles transformed at low calcination temperature have a distortion lattice; the lattice parameters vary with the increase of calcination temperature and are recovered when calcinated at temperature of 1200 °C. The grain size of tetragonal nanoparticles slightly decreases first and then increases with increasing of calcination temperature. The reasons that caused the distortion of lattice were discussed and the activation energy of grain growth was calculated.

A Co–Ni doped LiMn 2 O 4 spinel cathode material with a nominal stoichiometry of LiMn 1.95 Co 0.025 Ni 0.025 O 4 was synthesized by a sol–gel mediated solid-state route at a low temperature of 650 °C, using a highly dispersed ultra-fine Mn 3 O 4 as the Mn source. Also, a pelletizing process was adopted to optimize its morphology. It was revealed that the Co–Ni doped LiMn 2 O 4 obtained consisted of porous nanoparticles-constructed LiMn 1.95 Co 0.025 Ni 0.025 O 4 granules with a size of 30–50 μm, which combined the favorable characteristics of both nano-sized and bulk materials, i.e. considerably large specific surface area and high tap density. The cathode material exhibited excellent electrochemical performance. Notably, its rate capability was extraordinarily high, which was superior to that of pristine or doped LiMn 2 O 4 materials ever reported. It showed a discharge capacity of 119 mA h g −1 at a current rate of 0.2 C (1 C = 148 mA g −1 ), and retained a capacity of 111 mA h g −1 at 10 C, presenting a 93% capacity retention. After 200 cycles at 1 C and 25 °C, it delivered a capacity of 112 mA h g −1 , retaining 97% of its initial capacity. After 100 cycles at 1 C and 55 °C, it showed a capacity of 110 mA h g −1 , preserving 96% of its initial capacity. The excellent electrochemical performance together with the facile synthesis process allowed the synthesized LiMn 1.95 Co 0.025 Ni 0.025 O 4 to be a promising cathode material for high-power Li-ion batteries.

Conjugated block copolymers with tunable properties have attract considerable research interests in recent years. Herein, we report a series of novel block copolymers containing conjugated poly(3-hexylthiophene) (P3HT) and poly(triethyl glycol allene) (PTA) segments which were synthesized in one pot using nickel complex as a single catalyst via distinct polymerization mechanisms. Interestingly, the P3HT-b-PTA diblock copolymers exhibit excellent thermoresponsive properties in water, and the lower critical solution temperature (LCST) is dependent on polymer concentration and the block ratio. Moreover, the diblock copolymers showed pH-responsive properties in CHCl3 with the emission color shuttled between orange and deep green upon the alternate additions of trifluoroacetic acid and triethylamine. Both P3HT-b-PTA and P3HT-b-PTA-b-P3HT block copolymers exhibit solvatochromism properties. The emission of the block copolymers can be facilely tuned through variation on solvents with the emission color spanned w...

In this paper, the longitudinal optical conductivity in bilayer graphene was calculated analytically and numerically. In addition to the quadratic terms in the effective-mass approximation Hamiltonian, the linear term, which relates to the indirect interlayer coupling, was included. The nonparabolic energy dispersion was obtained. Two intra- and inter-band transition channels for optical transition via carriers absorbing the optical energy are observed. The inter-band transition offers the main contribution and is almost a constant when the optical energy is larger than two times the Fermi energy. In the presence of the complex energy and pseudospin angle relationship, doing the numerical integration to the wavevector k, the contribution of the intra-band optical transition to the optical conductivity ( σ xx intra ( ω ) ) is strengthened in the low optical energy region, while the analytical results with parabolic energy curves contribute less to σ xx intra ( ω ) . In addition, the optical conductivity also depends on the electron density (or gate voltage) and the broadening width.

The longitudinal optical conductivity in bilayer graphene is calculated using the dielectric function by defining the density operator theoretically, while the effect of the broadening width determined by the scattering sources on the optical conductivity is also investigated. Some features, such as chirality, energy dispersion and density of state (DOS) in bilayer graphene, are similar to those in monolayer graphene and a traditional two-dimensional electron gas (2DEG). Therefore, in this paper, the bilayer graphene optical conductivity is compared with the results in these two systems. The analytical and numerical results show that the optical conductivity per graphene layer is almost a constant and close to e 2 / ( 4 ℏ ) , which agrees with the experimental results.

Residual stress generated in the body parts during stamping process influences on its structural strength and stiffness partly. In this paper, the formality, stiffness and strength of hood-outer panel had been analysis based on Autoform and Altair-hypermesh, and the diagrams of major strain and plastic strain are shown. Compared the results by Geomagic Qualify; there are the same areas of stress concentration from the results. According to this, the body parts can be optimized to get excellent preference of stiffness and strength.

A shell/core Co-incorporated LiMn 2 O 4 cathode material was synthesized by a facile modified sol–gel process, using highly dispersed Mn 3 O 4 nanoparticles as the Mn source. Structural characterization revealed that the shell layer, which was 5–10 nm thick, and composed of spinel LiMn 1.83 Co 0.17 O 4 , grew homogeneously on the spinel LiMn 2 O 4 core with a size of ~50 nm. Electrochemical results showed that electrochemical performance of the shell/core cathode material compared favorably with that of the Co-doped LiMn 2 O 4 counterparts. Also its rate capability and cycling performance were apparently superior to those of pristine LiMn 2 O 4 synthesized under the same conditions. The shell/core cathode material exhibited a discharge capacity of 127 mAh g −1 at a current rate of 0.5 C (where 1 C=148 mA g −1 ), and retained a capacity of 103 mAh g −1 at 10 C, showing 81% capacity retention. After 200 cycles at 1 C and 25 °C, it delivered a capacity of 123 mAh g −1 , retaining 98% of its initial capacity. After 100 cycles at 1 C and 55 °C, it showed a capacity of 118 mAh g −1 , preserving 94% of its initial capacity. Its excellent electrochemical performance along with the facile synthesis process allowed the shell/core cathode material to serve as a promising cathode for high-performance Li-ion batteries.

A reduced graphene oxide/Ni(OH)2 composite with excellent supercapacitive performance was synthesized by a facile hydrothermal route without organic solvents or templates used. XRD and SEM results reveal that the nickel hydroxide, which crystallizes into hexagonal β-Ni(OH)2 nanoflakes with a diameter less than 200 nm and a thickness of about 10 nm, is well combined with the reduced graphene oxide sheets. Electrochemical performance of the synthesized composite as an electrode material was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. Its specific capacitance is determined to be 1672 F/g at a scan rate of 2 mV/s, and 696 F/g at a high scan rate of 50 mV/s. After 2000 cycles at a current density of 10 A/g, the composite exhibits a specific capacitance of 969 F/g, retaining about 86% of its initial capacitance. The composite delivers a high energy density of 83.6 W·h/kg at a power density of 1.0 kW/kg. The excellent supercapacitive performance along with the easy synthesis method allows the synthesized composite to be promising for supercapacitor applications.

Sludge with large production is difficult to be dewatered without any pretreatment. Pretreatment with ultrasound and microwave can adjust the structure of sludge and change the water form, therefore increase the water content which could be dispelled easily. Dewaterability and morphological of sludge from sewage treatment plant including microwave and ultrasound were studied. Capillary Suction Time (CST), viscosity, Settle Volume (SV), water content, Chemical Oxygen Demand (COD), Zeta potential and morphological characteristics were tested. After microwave modification, the particle size of sludge ranged from 33.55μm to 28.98μm, and fractal dimension was about 2.8. Microscopic image analysis showed that the particle of sludge became coarse. After ultrasound modification, the particle size of sludge ranged from 33.55μm to 9.44μm, fractal dimension was about 2.9. Thus, the smaller particles were observed after ultrasound. The gray associate degree coefficient of viscosity and moisture content is the bigest. Through the analysis of dewatering characteristics of sludge and water content, a model which contributes to predict moisture content of sludge online was established.

Surface plasmon polariton (SPP) can be applied in light emission, sensing and imaging. In this work, by using a structure in which graphene is sandwiched between two dielectric mediums, we demonstrate a nonlinear response mechanism for generating low frequency transverse electric (TE) SPP in the terahertz (THz)/sub-THz regime. Furthermore, unlike any other known SPPs located outside the light cone, a significant part of the nonlinear low frequency TE SPP mode revealed here falls in the light cone. Therefore, it is possible to couple the SPP directly with light without structural modifications, making it a possible radiation source in low frequencies.

To provide good performance of spatial and energy measurement for the experiments at the HIRFL-CSR, a double-sided silicon strip detector (DSSD) has been designed as the pixel detector. Performance of the DSSD has been characterized in a vacuum chamber with the alpha source. The reverse leakage current of the DSSD is measured to be ~3 nA/cm2⋅ 100 μm at the full depleted voltage and the energy resolution of each strip is better than 1%. Besides, the energy information of charge sharing events can be well measured. In this paper, the design, manufacture and performance characterization of the DSSD will be discussed.

Cui-Hong Chen, Deyao Wu, Zhe Li, Rui Zhang, Chun-Guang Kuai, Xue-Ru Zhao, Cun-Ku Dong, Shi-Zhang Qiao, Hui Liu and Xi-Wen Du

We have investigated quasi-confined (QC) optical resonant Raman scattering in GaN nanowires (NWs) with ring geometry. We consider the Frohlich electron–phonon interaction in the framework of the dielectric continuum approach. The selection rules are studied. For small ring radius, our results show that the main contribution to the differential cross section (DCS) comes from high-frequency of the QC phonons, with a minor contribution from the LO phonons. The peak of the DCS is mainly attributed to the electron-QC coupling strength can get the maximum value as the anisotropic effect of wurtzite nitride crystal. Moreover, the lower orders of the QC phonons, the larger the DCS.

Porous nanoparticles-constructed granule LiMn2O4 spinel was achieved by a solid-state reaction at a relatively low temperature of 600 °C, using a highly reactive Mn3O4 as manganese source, prepared by a precipitation-oxidation process. The granule LiMn2O4, well-crystallized with negligible oxygen deficiency, combines the advantages of nano-structured and bulk materials, exhibiting excellent electrochemical performance and a high tap density of 2.05 g cm−3. Importantly, its cycling performance, especially at elevated temperatures, compares favorably with that of the doped or surface-coated LiMn2O4 materials reported. Also, it shows superior rate capability and cycling performance to the dispersive nanoparticle LiMn2O4 synthesized under the same conditions. The granule LiMn2O4 exhibits a discharge capacity of 121 mAh g−1 at a current rate of 1 C (where 1 C = 148 mA g−1), and retains a capacity of 103 mAh g−1 at 15 C, showing 85% capacity retention. After 200 cycles at 1 C and 25 °C, it delivers a capacity of 119 mAh g−1, retaining 98% of its initial capacity. After 100 cycles at 1 C and 55 °C, it shows a capacity of 114 mAh g−1, preserving 95% of its initial capacity. Due to its excellent electrochemical performance and facile synthesis process adopted, the granule LiMn2O4 can serve as a promising cathode for high-performance Li-ion batteries.

We present a new derivative method for phase information extraction in off-axis quantitative phase imaging (QPI). Similar to other rapid derivative method, this method only uses the interference term, the 1st and 2nd order derivatives of a single interferogram in QPI, but the assumption in our method is different from that of other derivative method. And this method can be used to optimize small spatial frequency processing capability in slightly off-axis QPI. We illustrate the proposed method with theory and simulation experiment of a ball, and prove our method by comparing our simulation results with the experimental results of the red blood cell and the skin cancer cell, respectively.

Within the framework of the dielectric continuum model and Loudons uniaxial crystal model, the quasi-confined (QC) phonon modes and corresponding Frohlich-like Hamiltonian in GaN nanowires with ring geometry are investigated. The dispersion relations and electron-QC phonon coupling strength are calculated numerically. Results reveal that the dispersions of the QC modes are obvious only when the wave number kz and the azimuthal quantum number m are small. Meanwhile, the behaviors of QC modes reducing to surface optical phonon modes are observed. Moreover, the lower-order QC modes in the higher frequency region make more contributions to the electron-QC phonon coupling strengths. Furthermore, the electron-QC coupling functions sometimes can get the maximum value at certain kz and m, which is attributed to the “modulating” effect of the dielectric functions ratio (ϵz/ϵt) due to the anisotropy of the wurtzite nitride crystals.

We have investigated one phonon resonant Raman scattering in GaN nanowires (NWs) with ring geometry. We consider the Frohlich electron–phonon interaction in the framework of the dielectric continuum approach. The selection rules are studied. For the GaN NWs with small radius, results reveal that the main contribution to the differential cross-section (DCS) stems from the surface optical (SO) phonons especially from the high-frequency of SO phonons, with a minor contribution from the longitudinal optical (LO) phonons. Meanwhile, dispersions of the two branches of the SO phonon modes are obvious when the wire is thin. Moreover, compared to GaAs NWs, the GaN NWs make more contribution to the DCS in the small quantum size.

Atomic emission spectrometry with high accuracy, short lag time, and low detection limit, it has been widely applied in various fields. The application of atomic emission spectrometry in the converter steelmaking process has an important significance to improve the smelting of speed and steel quality. This article describes the principle of atomic emission spectroscopy (AES) analysis. Spectra obtained by the experimental for qualitative analysis, detected molten steel containing titanium element.

Measuring shape of bubbles is very important in many industrial processes, because that its behavior in the fluid is closely related to its morphology. Phase microscopy imaging (PMI) method is one of the best useful methods in this field. In the paper, considering on PMI idea, it is put out a new method which improves an ordinary light microscope into a dual function that can do both PMI and its ordinary microscopy function. Its optical structure is designed by using Mach-Zehnder interferometer method which can be added on the platform of ordinary microscope. A glass hole (bubble) is used as a sample to do phase microscopy imaging via the improved device. The results of the experiment and theory show that the phase distribution of bubble is closely related to the shape of it, which is very useful to detect the bubble’s behavior in the flow field. Besides bubbles, the improved microscope can be also used to observe the phase body such as cells.

A reduced graphene oxide/β-Ni(OH) 2 composite with excellent supercapacitive performance was prepared by a facile chemical precipitation. Reduced graphene oxide was ultrasonically dispersed in a Ni(NO 3 ) 2 solution, forming a suspension. Then let the prepared suspension stand for 0.5 h and 24 h, respectively, followed by stirring and adding NaOH solution into it for obtaining two types of composites. It was found that the standing time notably affected morphology and supercapacitive performance of the resulting composites. The composite derived from the 24 h-standing suspension presented an ideal morphology with nano-sized β-Ni(OH) 2 particles homogeneously growing on the reduced graphene oxide sheets. The composite exhibited ultra-large specific capacitance, high rate capability and good cycling stability in 6 mol L −1 KOH electrolyte. Its maximum specific capacitance was 2134 F g −1 at a scan rate of 2 mV s −1 , and a large specific capacitance of 882 F g −1 was still preserved at a high scan rate of 70 mV s −1 . After 2000 cycles at a current density of 10 A g −1 , the composite delivered a specific capacitance of 1141 F g −1 , retaining about 81% of its initial capacitance. The high performance and the simple synthesis route allowed the obtained composite to be promising for supercapacitor applications.

We have presented a theoretical study on electron resonant Raman scattering (ERRS) process associated with the bulk longitudinal optical (LO), surface optical (SO) and quasi-confined (QC) phonon modes in a free-standing wurtzite nanowire (NW). We consider the Frohlich electron–phonon interaction in the framework of the dielectric continuum model. Numerical calculations on the GaN material reveal that differential cross-section (DCS) is sensitive to the wire size. The bulk LO and high-frequency quasi-confined (QC+) phonons make main contributions to the DCS and the impact of the SO phonon can be negligible in the ERRS process. Moreover, scattering intensity of the bulk LO phonon is strongly enhanced as the incident photon energy approaches the energy band-gap of the GaN.

We report the electron resonant Raman scattering (ERRS) process related to the longitudinal optical (LO), interface optical (IO) and quasi-confined (QC) phonons in a cylindrical GaN–AlN quantum well wire (QWW). We present the differential cross-section (DCS) and study the selection rules. Results reveal that the emitted photon frequency decreases with increasing the radius because of the size-selective Raman scattering effect and the built-in electric field. The contribution to the DCS mainly stems from the GaN-type LO (LO1), QC and IO phonons when the wire is thin, but the LO1 and QC phonons are dominant for the thick wire.

The effect of doping V on the electronic structure and magnetic properties of Mn 3 Al has been studied by density functional calculations. It is found that the V atoms for all the doped compounds prefer to enter into the B sites, and further they tend to enter into the (A, C) sites in Mn 3 Al. The calculations show that the alloys (Mn 12− x V x )Al 4 ( x =0, 1, 2, 3, 4, 5, 6, 7) are ferrimagnetic whereas V 2 MnAl ( x =8) is nonmagnetic. The compounds of x =0, 1, 2, 3, 4 exhibit the half-metallic character, and the compound of x =5 shows a nearly half-metallicity since the Fermi level slightly touches the valence bands. For x =6 and 7, the spin polarization is 59% and 69%, respectively. The reason is mainly attributed to the behavior of Mn(A,C)/V(A,C) atoms.

Two polymer carriers of reticulated rosin group were synthesized to immobilize amylase in this paper, the nature of immobilized amylase was inspected. Results indicated that the optimal temperature for immobilize amylase was 40 °C, the optimal pH was 6.4, thermal stability and acid-base stability was superior to free amylase, 17% of the amylase activity existed after been used six times.

Ultra-fine Mn–Ni–Cu oxides (MNCO) are obtained by calcining a solid-state coordination derived oxalate Mn 0.68 Ni 0.22 Cu 0.10 C 2 O 4 · n H 2 O at 250–450 °C. The obtained MNCO present micron-sized agglomerates composed of primary particles with a size of ∼200 nm. The 250 °C- and 350 °C-obtained MNCO are poorly crystallized with a structure of α-MnO 2 , while the 450 °C-obtained MNCO contain multiphase oxides with structures of α-MnO 2 , γ-MnO 2 and Mn 2 O 3 . Electrochemical properties are investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in 6 mol L −1 KOH electrolyte. The MNCO electrodes exhibit good supercapacitive performance, superior to that of powder-based MnO 2 electrodes. At a scan rate of 2 mV s −1 , the 250 °C-, 350 °C-, and 450 °C-obtained MNCO electrodes deliver capacitance values of 490, 293 and 205 F g −1 , respectively. At a current density of 1000 mA g −1 , the 250 °C-, 350 °C-, and 450 °C-obtained MNCO symmetrical capacitors exhibit capacitance values of 368, 286, and 135 F g −1 , respectively, retaining about 75, 81 and 87% of their initial capacitance values after 500 cycles, respectively.

Mesoporous Mn–Ni oxides with the chemical compositions of Mn1-x Ni x O δ (x = 0, 0.2, and 0.4) were prepared by a solid-state reaction route, using manganese sulfate, nickel chloride, and potassium hydroxide as starting materials. The obtained Mn–Ni oxides, mainly consisting of the phases of α- and γ-MnO2, presented irregular mesoporous agglomerates built from ultra-fine particles. Specific surface area of Mn1–x Ni x O δ was 42.8, 59.6, and 84.5 m2 g−1 for x = 0, 0.2, and 0.4, respectively. Electrochemical properties were investigated by cyclic voltammetry and galvanostatic charge/discharge in 6 mol L−1 KOH electrolyte. Specific capacitances of Mn1-x Ni x O δ were 343, 528, and 411 F g−1 at a scan rate of 2 mV s−1 for x = 0, 0.2, and 0.4, respectively, and decreased to 157, 183, and 130 F g−1 with increasing scan rate to 100 mV s−1, respectively. After 500 cycles at a current density of 1.24 A g−1, the symmetrical Mn1–x Ni x O δ capacitors delivered specific capacitances of 160, 250, and 132 F g−1 for x = 0, 0.2, and 0.4, respectively, retaining about 82%, 89%, and 75% of their respective initial capacitances. The Mn0.8Ni0.2O δ material showed better supercapacitive performance, which was promising for supercapacitor applications.