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Electric vehicle battery recharging on the swapping mode has grown up as an important option other than the plug-in recharging mode in China, given that several auto giants have been dedicated in constructing their battery swapping systems. However, the lack of effective operational methods on battery recharging and transportation scheduling has aroused a big challenge on the practical application of the swapping mode, which enables the necessity of our work. This study proposes a joint optimization model of recharging and scheduling of electric vehicle batteries with a dynamic electricity price system which is able to identify the optimal charging arrangement (the recharging time and the quantity of recharging batteries) as well as the optimal transportation arrangement (the transportation time and the quantity of transporting batteries). For the validation purpose, a numerical study is implemented based on dynamic electricity prices in Beijing. A sensitivity analysis of parameters is carried out to increase the robustness and provide more managerial insights of the model.

We determined the role of endophytic bacteria of C. equietifolia, involved in synthesis of allelochemicals. The root endophytic bacteria were isolated and their biological activity was studied to determine their allelopathic potential in fermentation broth. Twenty one species of endophytic bacteria were isolated from the C. equisetifolia roots, of which Bacillus were the dominant genus, Acinetobacter and Staphylococcus were other dominant genera. These 21 endophytic bacteria inhibited the seeds germination of C. equisetifolia, among which Bacillus amyloliquefaciens was most inhibitory. Main allelopathic components of fermentation broth of 3-endophytic bacteria (Bacillus amyloliquefaciens, Bacillus aryabhattai and Paenibacillus glycanilyticus) with strongest allelopathic potential were rich in phenols, esters, organic acids, aldehydes, alcohols, ketones etc. Among them, two allelopathic substances [2,2'-methylenebis[6-(1,1-dimethylethyl)-4-methyl-Phenol and 1,2,3,4-Butanetetrol] were present in both endophytic bacteria fermentation broth and in root and soil extracts. These results confirmed that the secondary metabolites of C. equisetifolia root endophytic bacteria were allelopathic.

With the development of metro, the vibration and noise induced by metro trains have been paid more and more attention. In this paper, an algorithm is tried to study the transmission rule of the vibration. Firstly, a space due to underground moving loads is adopted as the model of the metro. The dynamic response of a point ξ is expressed as the periodic analyze solution. Secondly, combined with numerical computation, the dynamic response of a point ξ in the ground surface is given. Finally, the effect of sub-rail parameters to the dynamic response of ground due to metro train are calculated and analyzed in time domain and frequency domain.

LoRaWAN (Long Range Wide Area Network) is designed for long-range but low power consumption, low data rate, and low sampling frequency IoT applications. Many IoT applications (including agriculture, weather monitoring, rural area monitoring, smart city applications) have enormous demands on image or video capturing. A large amount of data, such as image, audio, and video, is not suitable to be transmitted through LoRaWAN. Although In this research, a compression and image recovery algorithm (CIRA) has been developed and implemented in a LoRaWAN-based camera system. The compression process of CIRA called CIRAJpeg can compress an image from a high-quality QVGA resolution $\sim 2.7$ KB to $\sim 27$ KB with an image recovery feature and transmit through the LoRaWAN network. With pixel position detection, CIRAJpeg can identify the position of lost packets. Then, CIRA uses the previously received image to recover the lost parts for the preview before. Those lost packets will be resent in the next sampling cycle to reconstruct the full image. CIRA provides user-friendly, long-range but low power consumption features for low sampling, low data loss application for high-quality QVGA image capturing through LoRaWAN. Experiments for different image transmissions by LoRaWAN are presented.

Advanced Space-based Solar Observatory (ASO-S), developed by Chinese Academy of Sciences, is utilized for observing the solar magnetic field, coronal mass ejection, and solar flare, as well as studying the relationships among them. As one of the three scientific payloads on ASO-S, Hard X-ray Imager (HXI) is designed for solar hard X-ray imaging with outstanding temporal and spatial resolutions. The spectrometer is an important part of HXI and used to measure the incident photon with a dynamic range of 30–200 keV after Fourier modulation by the collimator. It consists of 99 detector units and front-end electronics (FEE). The FEE can process all the 99 detector units' signals independently in less than 2 μs. The noise of charge measure is less than 500 fC for a dynamic range of 20 pC–900 pC. In this paper, the implementation of FEE is introduced, including the design of electronics, quality control, and performance tests. All these tests show that the FEE can meet the HXI mission requirements.

Isoprene, a dominant biogenic volatile organic compound that is mainly emitted by trees, has a significant impact on the atmospheric chemistry. Regional to global changes in biogenic isoprene emission associated with vegetation variations between 2000 and 2015 were estimated using the MEGAN model with satellite land cover data for inputs in this study. The satellite data estimates of land cover changes were compared to results from previous investigators that have either conducted regional studies or have used lower resolution land cover data. The analysis indicates that tree coverage increases of >5% occurred in 13% of locations including in central China and Europe. In contrast, a decrease of >5% was observed in about 5% of locations, especially in tropical regions. The trends in global tree coverage from 2000 to 2015 resulted in a global isoprene emission decrease of only 1.5%, but there were significant regional variations. Obvious decreases in tree coverage in some tropical areas (e.g., Amazon Basin, Western Africa, Southeast Asia) resulted in a similar to 10% reduction of regional isoprene emission due to agricultural expansion. Distinct increments of isoprene emission (5-10%) were mainly found in Northeast China and India and were associated with afforestation efforts. Deforestation and afforestation associated with managed plantations does not only affect the total forest coverage but also impacts average isoprene emission capacity, which can result in accelerated isoprene emission variations. Consequently, isoprene variation assessments are needed that not only account for changes in vegetation fractions but also consider the changes in plant species compositions of forests and other landscapes.

Polycrystalline-BiFeO3(BFO)/Co bilayers were grown by pulsed laser deposition (PLD) and magnetron sputtering, with fast laser annealing under magnetic field. The enhanced exchange bias (EB) had been found in the BFO/Co bilayers (Appl. Surf. Sci. 367 (2016) 418). In order to reveal the origin of the enhanced EB in the samples, X-ray absorption Spectroscopy (XAS) of Fe 2p, Co 2p and O 1s were performed. The Co 2p XAS indicated the increase of Co oxidation state and the Fe 2p XAS of sample A and B under laser annealing processes showed that crystal field splitting energy decreased and led to the weakening of spin-orbit coupling with the increasing of the laser fluence. It was considered that the appearance of the oxidation state of Co and Fe2+ ions and the existence of the unidirectional anisotropy due to the laser fluence was responsible for the results and also for the enhanced EB.

Due to the poor self-regeneration of brain tissue, stem cell transplantation therapy is purported to enable the replacement of lost neurons after traumatic brain injury (TBI). The main challenge of brain regeneration is whether the transplanted cells can survive and carry out neuronal functions in the lesion area. The brain is a complex neuronal network consisting of various types of cells that significantly influence on each other, and the survival of the implanted stem cells in brain is critically influenced by the surrounding cells. Although stem cell-based therapy is developing rapidly, most previous studies just focus on apply single type of stem cells as cell source. Here, we found that co-culturing human umbilical cord mesenchymal stem cells (hUC-MSCs) directly with the activated astrocytes benefited to the proliferation and neuron differentiation of hUC-MSCs in vitro. In this study, hUC-MSCs and the activated astrocytes were seeded in RADA16-BDNF peptide scaffold (R-B-SPH scaffold), a specifical self-assembling peptide hydrogel, in which the environment promoted the differentiation of typical neuron-like cells with neurites extending in three-dimensional directions. Moreover, the results showed co-culture of hUC-MSCs and activated astrocytes promoted more BDNF secretion which may benefit to both neural differentiation of ectogenic hUC-MSCs and endogenic neurogenesis. In order to promote migration of the transplanted hUC-MSCs to the host brain, the hUC-MSCs were forced with CXC chemokine receptor 4 (CXCR4). We found that the moderate-sized lesion cavity, but not the large cavity caused by TBI was repaired via the transplantation of hUC-MSCs CXCR4 and activated astrocytes embedded in R-B-SPH scaffolds. The functional neural repair for TBI demonstrated in this study is mainly due to the transplantation system of double cells, hUC-MSCs and activated astrocytes. We believe that this novel cell transplantation system offers a promising treatment option for cell replacement therapy for TBI. Statement of Significance In this reach, we specifically linked RGIDKRHWNSQ, a functional peptide derived from BDNF, to the C-terminal of RADARADARADARADA (RADA16) to structure a functional self-assembling peptide hydrogel scaffold, RADA16-BDNF (R-B-SPH scaffold) for the better transplantation of the double cell unit. Also, the novel scaffold was used as cell-carrier for transplantation double cell unit (hUC-MSCs/astrocyte) for treating traumatic brain injury. The results of this study showing that R-B-SPH scaffold was pliancy and flexibility to fit the brain lesion cavity and promotes the outgrowth of axons and dendrites of the neurons derived from hUC-MSCs in vitro and in vivo, indicating the 3D R-B-SPH scaffold provided a suitable microenvironment for hUC-MSC survival, proliferation and differentiation. Also, our results showing the double-cells transplantation system (hUC-MSCs/astrocyte) may be a novel cell-based therapeutic strategy for neuroregeneration after TBI with potential value for clinical application.

Significance Despite Darwin’s recognition of the importance of intrasexual competition, the topic of female competition has been largely ignored. Economists, looking for reasons why women are rarely found in top jobs, have accumulated experimental evidence pointing to women’s lower desire to compete than men. Consistent with newer interdisciplinary hypotheses about female competition, our experimental results show that women can compete as much as men once we change the experimental reward medium to something more in line with women’s goal: the benefit of one’s children. Our results have important policy implications: a change in the workplace incentive structure could induce more women to enter workplace competitions. Such findings matter for a broader group of scientists including biologists, anthropologists, psychologists, economists, and sociologists.

The cryogenic magnetic properties and magnetocaloric effects of Er3Ni2-type Nd3Rh2 (space group R-3, N148, hR45), and Y3Rh2-type RE3Rh2 (RE = Ho, Er) (space group I4/mcm, N140, tI140) have been investigated in detail. For the Nd3Rh2 compound, two second-order magnetic transitions, a ferromagnetic-antiferromagnetic transition followed by an antiferromagnetic-paramagnetic transition with temperature increasing, are observed at Tt = 13 K and TN = 17 K, respectively. For the RE3Rh2 (RE = Ho, Er) compounds, it exhibits a ferromagnetic ordering around the Curie temperature 23 K and 8 K, respectively. The reciprocal magnetic susceptibility of RE3Rh2 (RE = Ho, Er) obey the Curie-Weiss law in the paramagnetic region, the values of the effective magnetic moment are determined to be 10.30 μB/Ho3+ and 10.62 μB/Er3+, and the corresponding paramagnetic Curie temperatures are 13 K and 4.5 K, respectively. The maximum values of magnetic entropy changes for RE3Rh2 (RE = Nd, Ho and Er) are achieved to be 3.78 J/kg K, 14.01 J/kg K and 20.01 J/kg K with an effect refrigerant capacity values of 68 J/kg, 382 J/kg and 267 J/kg for a field change of 0–5 T, respectively. Large magnetocaloric effects indicate the potentiality of the RE3Rh2 (RE = Nd, Ho and Er) compounds as candidates in low temperature magnetic refrigerant.

The effect of Nb on interlamellar spacing of pearlite in high-carbon steel and redistribution of Nb atoms between ferrite and cementite was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atom probe tomography (APT). The results of the experiments suggest that Nb atoms were incorporated in the cementite lattice forming Nb-alloyed cementite, which was present as a solute. The segregation of Nb atoms at the ferrite/cementite boundary forms non-equilibrium chemical boundaries. It is proposed that Nb exhibits a strong solute drag effect, which is effective in preventing migration of interphase boundary, leading to the refinement of pearlite interlamellar spacing.

A pollen model that simulates the timing and production of wind-dispersed allergenic pollen by terrestrial, temperate vegetation has been developed to quantify how pollen occurrence may be affected by climate change and to investigate how pollen can interact with anthropogenic pollutants to affect human health. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model is driven by local meteorological conditions and is designed to be sensitive to climate shifts, as well as flexible with respect to the vegetation species and plant functional types (trees, grasses, etc.) represented and the climate zones simulated. The initial focus for the model is the simulation of the pollen emission potential of important allergenic tree and grass species that typically flower between March–June in Southern California (S. CA), which is characterized by moderate Mediterranean and oceanic climate zones as well as regions of arid desert and arid steppe. Vegetation cover and species composition data are obtained from numerous datasets and a database of allergenic vegetation species, their pollen production potential and relative allergenicities has been developed. For the selected allergenic species and spring-early summer simulation period, temperature is the main driver controlling the timing of pollen release, while precipitation (and temperature, for some species) controls the magnitude of pollen produced. The model provides species-specific pollen potential maps for each day of the simulation period; these are then used by a pollen transport model to simulate ambient pollen concentrations as described in a companion paper (Zhang et al., 2013a), which also presents model evaluation results for the S. CA model domain. The STaMPS model was also used to quantify the possible impact of climate change on pollen season under the IPCC SRES A1B scenario as simulated by the ECHAM5 global climate model. Current (1995–2004) and future (2045–2054) meteorological conditions downscaled using the Weather Research and Forecasting (WRF) model were used to drive STaMPS and generate estimates of the relative magnitude and timing of pollen season for important allergenic tree and grass species that bloom from March through June in a larger domain that covers all of CA and Nevada. Differences in the simulated timing and magnitude of pollen season for the selected allergenic species under current and future climate scenarios are presented. The results suggest that across all of the simulated species, pollen season starts an average of 5–6 days earlier under predicted future climatic conditions with an associated average annual domain-wide temperature increase of about 1°C compared to simulated current conditions. Differences in the amount of pollen produced under the two scenarios vary by species and are affected by the selected simulation period (1 March–30 June). Uncertainties associated with the STaMPS model and future model development plans are also discussed.

Lithium ion batteries (LIBs) represent one of the most promising solutions for environmentally friendly transportation such as electric vehicles. The demand for high energy density, low cost and environmentally friendly batteries makes high-capacity cathode materials very attractive for future LIBs. Layered LiNi x Co y Mn z O2 ( x + y + z =1), Li-rich oxides and Li-V-O compounds have attracted much attention due to their high capacities in recent years. In this review, we focus on the state-of-the-art research activities related to LiNi x Co y Mn z O2, Li-rich oxides and Li-V-O compounds, including their structures, reaction mechanisms during cycling, challenges and strategies that have been studied to improve their electrochemical performances.

A series of xLiV3O8·yLi3V2(PO4)3/rGO (x : y = 2 : 1, 3 : 1, 1 : 1, 1 : 2, and 1 : 3) composites are synthesized by simple mechanical mixing of LiV3O8 and Li3V2(PO4)/rGO, which are prepared by the hydrothermal method and the sol–gel route, respectively. From scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs, the composites are found to be a mixture of rod-like LiV3O8 particles and flower-shaped Li3V2(PO4)/rGO. Among these composites, the 2LiV3O8·Li3V2(PO4)/rGO electrode delivers an initial discharge capacity of 197 mA h g−1 at a current density of 100 mA g−1 between 2.0 V and 4.3 V, and shows the best comprehensive electrochemical property. The diffusion coefficients of Li ions in the 2LiV3O8·Li3V2(PO4)/rGO electrode are in the range of 10−11.5 to 10−9.5 cm2 s−1 obtained using the galvanostatic intermittent titration technique (GITT).

A novel peanut-like hierarchical micro/nano-lithium-rich cathode material Li1.2Mn0.54Ni0.18Co0.08O2 has been successfully synthesized via a facile solvothermal method combined with a calcination process. XRD patterns show that the as-prepared sample has high crystallinity and a well-formed layered structure. As a cathode material for Li-ion batteries, this oxide exhibits high capacity, good cyclic stability and superior rate capability. It delivers a discharge capacity of 229.9 mA h g−1 at a current density of 200 mA g−1 between 2.0 and 4.8 V with a high capacity retention of 94.2% after 100 cycles. High reversible discharge capacities of 198.3, 167.5 and 145 mA h g−1 are obtained at 400, 1000 and 2000 mA g−1, respectively. This excellent electrochemical performance is attributed to the hierarchical micro/nanostructure.

A colored phenotype is an important feature of ornamental fish. In mammals, microphthalmia-associated transcription factor (MITF) was found to regulate the development of melanocytes. In this study, the mitfa cDNA was first cloned from the Japanese ornamental (Koi) carp (Cyprinus carpio L.), an important ornamental freshwater fish. The full-length cDNA of the mitfa gene contains 1634 bp, coding for 412 amino acids in Koi. The identity degree of mitfa amino acid sequences between the Koi carp and zebrafish is 92.9%. We tested the expression of the mitfa gene in several varieties of Koi using reverse transcription-polymerase chain reaction and found that the mitfa gene is highly expressed in the skin tissues of the Taisho sanke and the Procypris merus. Interestingly, the mitfa gene was also expressed in the Kohaku and Yamabaki ogon, although melanocytes were not observed in the skin. Koi carp embryos were transparent and colorless, while after hatching, different types of pigment cells successively emerged in a fixed order. In Taisho sanke, melanocytes first appeared in the trunk at approximately 12 days of age. Subsequently, there was a large area of melanocytes by 30 days of age. The expression level of the mitfa mRNA was low in early embryos and newly hatched larvae, and increased to high levels in 30-day-old fry. The results show that the mitfa gene is involved in regulating fish body color in the development of both melanocytes and pigment cells.

Micro arc oxidation (MAO) is an effective method to improve the corrosion resistance of magnesium alloys. In order to reveal the influence of alloying element Ca and CaCO 3 electrolyte on the formation process and chemical compositions of MAO coatings on binary Mg-1.0Ca alloy, anodic coatings after different anodizing times were prepared on binary Mg-1.0Ca alloy in a base solution containing 3 g/L sodium hydroxide and 15 g/L sodium phytate with and without addition of CaCO 3 . The coating formation was studied by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results show that Mg-1.0Ca alloy is composed of two phases, the Mg phase and Mg 2 Ca phase. After treating for 5 s, the coating began to develop and was preferentially formed on the area nearby Mg 2 Ca phase, which may be resulted from the intrinsic electronegative potential of the Mg phase than that of Mg 2 Ca phase. Anodic coatings unevenly covered the total surface after 20 s. After 80 s, the coatings were uniformly developed on Mg-1.0Ca alloy with micro pores. During MAO process, some sodium phytate molecules are hydrolyzed into inorganic phosphate. CaCO 3 has minor influence on the calcium content of the obtained MAO coatings.

Rational design and fabrication of advanced sulfur cathodes is highly desirable for the development of high performance lithium–sulfur (Li–S) batteries. Herein, we report Co(OH)2 as a new stabilizer for the sulfur cathode by constructing a cobalt hydroxide-covered sulfur/conductive carbon black (CCB) electrode with the help of thermal and hydrothermal treatments. In this composite, (Co(OH)2@S/CCB), the sublimed sulfur is anchored in the CCB, followed by a uniform coating of Co(OH)2 nanosheets. As cathode materials of lithium–sulfur batteries, the as-prepared Co(OH)2@S/CCB electrode exhibits remarkable electrochemical performances with a high capacity of 1026 mA h g−1 at 0.1C (1C = 1675 mA g−1) and 829 mA h g−1 at 1C. Moreover, it maintains high coulombic efficiencies above 97% after 200 cycles at 1C, much higher than those of the S/CCB counterpart electrode (85%). After 200 cycles at 1C, a high capacity retention of 71.2% is obtained, better than that of the S/CCB electrode (20.2%). The enhanced performance is mainly due to the Co(OH)2 layer which helps to inhibit the shuttle diffusion of polysulfides, resulting in improved capacity retention and cycling life.

A porous Co3O4 nanoflake array film grown on nickel foam is prepared by a hydrothermal synthesis for pseudo-capacitor application. The pseudocapacitive behavior of the Co3O4 nanoflake array is investigated by cyclic voltammograms (CV), galvanostatic charge–discharge tests and electrochemical impedance spectroscopy (EIS) in 2 M KOH at different temperatures. The specific capacity is 210, 289 and 351 F g−1 at 2 A g−1 tested at −5 °C, 25 °C and 60 °C, respectively, corresponding to that of 184, 243 and 242 F g−1 at 20 A g−1. After 4000 cycles at 2 A g−1, the remaining specific capacity is 187, 342 and 124 F g−1 tested at −5 °C, 25 °C and 60 °C. It shows that with increasing the temperature from −5 °C to 60 °C, the specific capacity increases, while the cycling stability becomes worse. The operation temperature has a pronounced influence on the pseudocapacitive performance of Co3O4 nanoflake array.

Hydrogenated amorphous carbon (a-C:H) films were deposited by the middle frequency pulsed magnetron sputtering method using a graphite target in a mixed methane and argon plasma. The effects of substrate bias on the microstructure, surface morphology, mechanical, electrical and optical properties of the a-C:H films were investigated. It has been found that the sp 3 fraction in the a-C:H films increases with increasing substrate bias from 0 to 150 V. AFM measurements show that the RMS surface roughness of the films decreases with increasing substrate bias from 0 to 150 V. The correlation between the sp 3 fraction and surface roughness of the a-C:H films is revealed, and the mechanism on it is suggested in this paper. Nanoindentation, electrical and optical measurements indicate that the nanohardness, electrical resistivity and optical band gap increase with increasing substrate bias from 0 to 150 V. The results above are useful for the practical application of a-C:H films.

We present here a detailed study of the oxidation resistance of chemical vapor deposition (CVD) graphene. The results reveal that CVD graphene shows an excellent performance as a passivation layer below 200 °C, but the protection ability degenerates rapidly with increasing the air temperature. Our work demonstrates for the first time that the most adverse effect on the degeneration of oxidation resistance in high temperature air comes from wrinkles but not others, such as Cu grain boundaries, periodic surface depressions due to Cu surface reconstruction induced by the graphene overlay, graphene domain boundaries, which are always believed the primary factor for inferior quality of the CVD graphene at present. In addition, we found that the distribution of the wrinkles in CVD graphene depended on the Cu crystal structure, and the results of the Electron-backscatter diffraction indicate that the folded wrinkles always appear on Cu (0 0 1) facets, while the standing collapsed wrinkles appear more easily on the Cu (1 1 1) facets.

One-dimension MnCo 2 O 4 nanowire arrays are synthesized on nickel foam by a facile hydrothermal method. The MnCo 2 O 4 nanowires are highly crystalline with an average diameter of 70 nm and exhibit excellent properties for electrochemical energy storage. Impressively, the MnCo 2 O 4 nanowire array exhibits noticeable pseudocapacitive performance with a high capacitance of 349.8 F g −1 at 1 A g −1 and 328.9 F g −1 at 20 A g −1 as well as excellent cycling stability. As an anode material for Li-ion batteries, the MnCo 2 O 4 nanowire array delivers an initial specific discharge capacity of 1288.6 mAh g −1 at 100 mA g −1 , with reversible capacity retention of 92.7% after 50 cycles. The outstanding electrochemical performances are mainly attributed to its nanowire array architecture which provides large reaction surface area, fast ion and electron transfer and good structure stability.

Anodic coatings were obtained by micro arc oxidation on aluminum alloy 2024-T3 in a solution containing only 10 g/L sodium phytate. The morphology, composition, structure and corrosion resistance of anodic coatings were systematically investigated. The results show that the working voltage continually increases during 3 min and bright sparks appear after 25 s. Anodic coatings are evenly formed on the substrate and about 2 μm thick. XPS and XRD analyses reveal that the obtained coatings are mainly composed of α-Al2O3 and γ-Al2O3. Compared with the substrate, the corrosion resistance of the anodized aluminum alloys is improved.

A hierarchically Fe2O3@Co3O4 nanowire array is prepared by the aid of hydrothermal synthesis and sacrificial hydrolysis method. The obtained nanowire array shows hierarchical porosity and large surface area. The resulted Fe2O3@Co3O4 nanowire array is evaluated as an anode material for Li ion batteries, which exhibits high capacity and good cycle stability (1005.1 mAh g−1 after 50 cycles at a current density of 200 mA g−1) and an excellent rate performance, mainly owing to the unique hierarchical nanowire architecture and an elegant synergistic effect of two electrochemically active materials. The developed strategy can be readily generalized to construct other multifunctional hybrid nanostructures, which will be promising materials for high-performance electrochemical devices.

Macroporous Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials with high crystallinity and hexagonal ordering are synthesized by aerogel template followed by solid state reaction. High discharge capacities of 244.0 mA h g−1 and 153.9 mA h g−1 are obtained for the Li-rich layered oxide synthesized at 800 °C at current densities of 200 mA g−1 and 2000 mA g−1 between 2.0 V and 4.8 V. Increasing the synthesis temperature to 900 °C, the macroporous Li1.2Mn0.54Ni0.13Co0.13O2 delivers a high discharge capacity of 220.2 mA h g−1 at a current density of 200 mA g−1 with a capacity retention of 89.1% after 50 cycles, 129.8 mA h g−1 at a current density of 2000 mA g−1 and almost no capacity fading after 120 cycles. The diffusion coefficients of Li+ in the Li-rich layered oxide determined by galvanostatic intermittent titration technique are in the range of 5.0 × 10−18−8.0 × 10−14 cm2 s−1. Electrochemical impedance spectroscopy indicates that the macroporous structure with good particle contact of the layered oxide can improve its rate capability and cyclic stability.

Porous NiCo2O4 hetero-structure arrays on nickel foam are prepared by a facile hydrothermal method. The morphology of the arrays changes with the growth time. After hydrothermal synthesis for 8 h in combination with annealing treatment, the NiCo2O4 array presents a nanoflake–nanowire hetero-structure. The porous NiCo2O4 hetero-structure array exhibits the excellent pseudocapacitive properties in 2 M KOH, with a high capacitance of 891 F g−1 at 1 A g−1 and 619 F g−1 at 40 A g−1 before activation as well as excellent cycling stability. The specific capacitance can achieve a maximum of 1089 F g−1 at a current density of 2 A g−1, which can still retain 1058 F g−1 (97.2% retention) after 8000 cycles. The enhanced pseudocapacitive performances are mainly attributed to its unique hetero-structure which provides fast ion and electron transfer, large reaction surface area and good strain accommodation.

The influences of four factors including NaOH concentration, sodium phytate concentration, treatment time and duty cycle on properties of anodic coatings formed on Mg–1.0Ca alloy were systematically investigated using the Taguchi experiment. The effect order of factors on the corrosion resistance is ranked as sodium phytate concentration > treatment time > duty cycle > NaOH concentration, while the sequence on the coating thickness is sodium phytate concentration > treatment time > NaOH concentration > duty cycle. The increasing sodium phytate concentration is benefit for the corrosion resistance of the anodized magnesium alloys by developing thick coating with stable composition.

Li-rich layered oxide Li[Li0.2Mn0.54Ni0.13Co0.13]O2 is synthesized by combustion reaction using alcohol as both solvent and fuel. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the oxide synthesized at 800 °C exhibits perfect crystallinity and lattice ordering, and has particle sizes of 50–150 nm. The layered oxide delivers an initial discharge capacity of 290.1 mAh g−1 at a current density of 20 mA g−1 after activation, and exhibits improved rate capability with high discharge capacities of 238.6 and 165.0 mAh g−1 at current densities of 200 and 2000 mA g−1 in the voltage range of 2.0–4.8 V, respectively. Low Li-ion diffusion coefficient of 1.07 × 10−14−1.01 × 10−16 cm2 s−1 is calculated by galvanostatic intermittent titration technique (GITT) during the initial discharge process, indicating that the improved rate capability is mainly attributed to the small particle sizes of the Li-rich oxide.

LiF is successful used to modify the surface of layered LiNi 1/3 Co 1/3 Mn 1/3 O 2 via a wet chemical method followed by an annealing process. The lattice structure of LiNi 1/3 Co 1/3 Mn 1/3 O 2 is not changed distinctly after modification and part of F − dopes into the surface lattice of the oxide. The LiF-modified oxide exhibits capacity retentions of 97.5% at 0.1 C at room temperature and 93.5% at 1 C at 60 °C after 50 cycles, and delivers a high discharge capacity of 137 mAh g −1 at 10 C at room temperature. Furthermore, it has reversible capacities of 124.4 mAh g −1 at 1 C at 0 °C and 85.6 mAh g −1 at 0.1 C at −20 °C, respectively. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests show that the LiF-modified layer can reduce the dissolution of metal ions in the electrode and enhance the conductivity of the oxide surface through partly F-substitution. LiF modification will be promising for the application of layered oxide for lithium ion batteries.

A unique cobalt nanomountain array supported Si film was successfully fabricated by the combination of electrodeposition and radiofrequency magnetron sputtering. The nanostructured Si film with a proper thickness shows excellent cyclic performance with a high discharge capacity of 1917.8 mAh g −1 after 100 cycles at 0.1 C, also presents high rate capability with revisable capacities of 1953.3 mAh g −1 at 0.5 C and 1166.1 mAh g −1 at 3 C. The improved electrochemical performance can be attributed to the strengthening adhesion of the Si film to the cobalt nanomountain arrays and the formation of an island structure within the film, which provide good mechanical support and electron conducting pathway. The well-designed nanostructured Si electrode is a promising material for application of lithium ion batteries.

MgO-coated Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 was synthesized via melting impregnation method followed by a solid state reaction. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) show that the MgO layer is well coated on the surface of the layered oxide particles. Although the initial discharge capacity of Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 with proper MgO modification decreases compared to the bare one, the 2 wt.% MgO coated cathode exhibits the excellent cycling stability with capacity retention of 96.4% at a current density of 200 mA g −1 after 100 cycles at room temperature and 94.3% after 50 cycles at 60 °C. Electrochemical impedance spectroscopy (EIS) shows that the thin MgO layer mainly reduces the charge transfer resistance and stabilizes the surface structure of active material during cycling. Melting impregnation method is promising for MgO coating to improving the cycling stability of Li-rich layered oxide cathode for Li-ion batteries.

Well-formed Li 1.131 Mn 0.504 Ni 0.243 Co 0.122 O 2 cathode materials are synthesized via freeze drying followed by a solid state reaction at temperatures of 750–900 °C. Among these oxides, the one synthesized at 800 °C delivers the highest initial discharge capacity of 246.5 mAh g −1 at 0.1 C (1 C = 200 mA g −1 ) between 2.5 V and 4.8 V. Enhancing the discharge rate to 1 C, initial capacity of 197.8 mAh g −1 is obtained, and 78.8% capacity is retained after 50 cycles. Furthermore, the diffusion coefficients of Li + in the lithium-rich layered oxide are about 10 −14 cm 2 s −1 and 10 −15 cm 2 s −1 for the initial charge platform at 3.90 V and 4.55 V, respectively, determined by galvanostatic intermittent titration technique (GITT). The Li 1.131 Mn 0.504 Ni 0.243 Co 0.122 O 2 prepared by freeze drying is a promising cathode material for lithium ion batteries.

We present a fast and robust sparse time-invariant Radon transform (RT) in the mixed frequency-time domain. In the proposed method, the 2D alternating split Bregman algorithm is introduced to solve the optimization problem. Two proximity operators are applied to promote the robustness and sparseness of the RT in the time domain, while the forward and inverse RTs are computed in the frequency domain. With high efficiency and easy implementation, the proposed method is resistant to the outliers. The synthetic and real data examples demonstrate the better performance of the proposed method when applied on the noise-contaminated data, compared with the traditional non-robust RTs.

CaF 2 -coated LiMn 1/3 Ni 1/3 Co 1/3 O 2 cathode material is prepared via a wet chemical process followed by a solid state reaction. High-resolution transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) show that the well coated CaF 2 layer has a thickness of 4–8 nm, and no interaction of chemical bonding is observed. The CaF 2 -coated LiMn 1/3 Ni 1/3 Co 1/3 O 2 exhibits discharge capacity retention of 98.1% at 0.1 C after 50 cycles and high initial discharge capacity of 146.3 mAh g −1 at 5 C. Furthermore, even at an elevated charge–discharge rate of 5 C, capacity retention maintains above 85%. Electrochemical impedance spectroscopy (EIS) shows that the CaF 2 coating can stabilize the surface structure and reduce the charge transfer resistance. The CaF 2 modification has a promising application in improving the performance of layered oxide cathode materials for Li-ion batteries.

We report a silicon/graphene-sheet hybrid film prepared by combining electrophoretic deposition and radiofrequency magnetron deposition methods. The constructed hybrid film shows rough morphology with wrinkles and scrolling edges. As anode material for lithium ion batteries, the silicon/graphene-sheet hybrid film exhibits enhanced electrochemical performances with weaker polarization, higher capacity, better rate capability and cycling performance as compared to the bare silicon film. The silicon/graphene-sheet hybrid film delivers a high initial reversible capacity of 2204 mAh g−1 and quite good cycling life (capacity maintenance is 87.7%) after 150 cycles. The graphene-sheet in the hybrid film is responsible for the improvement of the electrochemical properties. The introduction of the graphene-sheet film not only enhances the adhesion between silicon and the current collector, but also alleviates the structure degradation caused by volume expansion and the shrinkage of silicon film during lithium-ion insertion/extraction, resulting in improved electrochemical performances. Keywords: Silicon, Graphene, Lithium ion battery, Magnetron sputtering

A three-dimensional (3D) porous nano-Ni supported Si composite film is successfully fabricated by the combination of hydrogen bubble template electrodeposition of porous nano-Ni film and radiofrequency magnetron sputtering amorphous silicon. As anode for lithium-ion batteries, the 3D porous Ni/Si composite film shows noticeable electrochemical performance with high capacity of 2444 mAh g −1 at a current density of 0.84 A g −1 , superior capacity retention of 83% after 100 cycles, as well as excellent rate capability with 1420 and 1273 mAh g −1 at charge–discharge current densities of 4.2 A g −1 and 8.4 A g −1 after 100 cycles, respectively. The enhanced electrochemical performance is mainly attributed to the highly porous conductive architecture, which provides good mechanical support and electron conducting pathway for active silicon and alleviates the structure degradation caused by volume expansion during the cycling process.