Search

As the sustainable economy has become more of a consensus, supply chain members, both manufacturer (e.g., Apple, Huawei, Xiaomi, Nike, and P&G) and retailer (e.g., Uniqlo, Walmart, and Bravo), are concentrated on corporate social responsibility (CSR). The literature in this area has investigated the role of CSR, but the optimal preference for CSR concern of supply chain members is not well understood, especially when manufacturer sells directly by implementing encroachment. This paper studies the optimal preference for CSR concern of supply chain members with considering manufacturer encroachment. We develop the supply chain with a manufacturer (M) and a retailer (R), where the manufacturer sells products via a retail channel which in turn sells them to the final consumers. The manufacturer can also implement encroachment to meet consumers directly. Meanwhile, by considering the manufacturer or retailer may have CSR concern, we explore four scenarios using a game‐theoretic framework. Several interesting findings are as follows. First, for the sake of profits, retailer CSR should be encouraged, which may achieve Pareto improvement under certain conditions. Notably, manufacturer encroachment may narrow the "win–win" situation. While for the sake of environmental protection and consumer well‐being, manufacturer CSR should be encouraged. Second, manufacturer implementing encroachment may not be blind, because it may be worse for itself when retailer has CSR concern. Third, manufacturer CSR may aggravate the cannibalization effect of encroaching, while retailer CSR may relieve it. [ABSTRACT FROM AUTHOR]

Due to the intrinsic safety and cost effectiveness, aqueous Zn‐ion batteries (AZIBs) are considered a promising candidate for future energy storage systems. However, the widespread implementation of AZIBs faces significant obstacles due to various undesirable side reactions, including hydrogen evolution reaction (HER), corrosion, and uncontrolled dendrite growth at the anodes. Here, 4‐hydroxybenzoic acid sodium salt (PHB) is employed in the ZnSO4 electrolyte to enable highly‐reversible zinc anodes. PHB has a greater tendency to bind with the Zn surface, resulting in increased steric effects within the electrolyte. As a result, it hinders the direct interaction between anode and water while facilitating the uniform plating of Zn2+. Zn/Zn batteries with PHB additives realized more than 1600 h stable cycling life under 1 mA cm−2 and 1 mAh cm−2. Moreover, Zn/Cu batteries with PHB additives achieved a reversible plating/stripping process for over 500 cycles with high average CE of 98.6 %. In addition, the assembled Zn/NH4V4O10 batteries with PHB additive yielded 80.5 mAh g−1 after 1000 cycles at 10 A g−1. The inexpensive and effective application of PHB as an electrolyte additive has the potential to significantly enhance the stability and dependability of ZIBs. [ABSTRACT FROM AUTHOR]

Dielectric film capacitors for high‐temperature energy storage applications have shown great potential in modern electronic and electrical systems, such as aircraft, automotive, oil exploration industry, and so on, in which polymers are the preferred materials for dielectric capacitors. This review tries to summarize the recent progress in the field of energy storage based on heat‐resistant all‐organic polymers from the perspective of their operating temperatures. Based on this, a summary of commonly used and latest research on high‐temperature polymers is conducted, and they are classified into different heat‐resistant insulation grades, consequently providing a new perspective for high‐temperature polymers dielectric research, especially on the selection of them under different occasions. Emphasis is placed on the influencing factors of polymer performance and ways to develop high‐temperature polymers. Especially, properties under high temperature including dielectric constant and loss, glass transition temperature, and energy density are summarized, inspiring researchers devoting further efforts in this area. A future prospect in this field is also discussed. [ABSTRACT FROM AUTHOR]

The abundance of sodium resources provides the basis for the large‐scale application of sodium‐ion batteries (SIBs) in the field of energy storage. Among the cathode candidates for SIBs, oxide materials stand out because of their ease of synthesis, environmental friendliness and high capacity. According to the crystal structure, oxide cathode materials can be mainly classified as P2, P3, O3 and tunnel phases. Benefiting from the combined advantages of different phases, composite oxide cathode materials have been widely studied due to the enhanced both cycling and rate performance. In this review, we analyzed the three key issues of phase regulation, electrochemical performance and reaction mechanism based on the recent progress for composite oxide cathode materials. The composite oxide cathode materials will be one of the most competitive and attractive cathodes for SIBs. [ABSTRACT FROM AUTHOR]

Water electrolysis is a promising method for sustainable hydrogen production. The exploration of noble metal free bifunctional electrocatalysts with both good hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic activity is crucial for efficient overall water splitting. The design of electrocatalysts to enhance electrocatalytic performance for both HER and OER is still a big challenge. Long Ni3Si2 nanowires have been in‐situ grown on Ni foam by low pressure chemical vapor deposition. A facile hydrothermal method was then adopted to grow Ni3S2@MoS2@Ni3Si2 seaweed‐like structures with high active sites on the Ni3Si2 blades and high charge transport along central stipes. The as‐produced Ni3S2@MoS2@Ni3Si2 seaweed‐like hybrid structures have been demonstrated to have both excellent HER and OER catalytic performance as integrated electrodes. Low overpotentials of 84 mV (η10)/283 mV (η50) and Tafel slopes of 36.0/53.7 mV dec−1 have been achieved for HER/OER, respectively. Excellent long‐term stabilities have been obtained for both HER and OER. [ABSTRACT FROM AUTHOR]

Compared with lithium‐ion batteries (LIBs), aqueous zinc batteries (AZIBs) have received extensive attention due to their safety and cost advantages in recent years. The cathode determines the electrochemical performance of AZIBs to a large extent. Vanadium‐based materials exhibit excellent capacity when used as AZIB cathodes. However, unexpected structural stress is inevitably induced during cycling and high current densities, which can gradually lead to structural deterioration and capacity decay. In fact, the stress/strain distribution in nanomaterials is crucial for electrochemical performance. In this work, the optimized stress distribution of the hierarchical hollow structure is verified by the finite element simulation of COMSOL software firstly. Guided by this model, a simple solvothermal method to synthesize hierarchical hollow vanadium oxide nanospheres (VO‐NSs), consisting of ≈10 nm ultrathin nanosheets and ≈500 nm hollow inner cavities, is employed. And a highly disordered structure is introduced to the VO‐NSs by in situ electrochemical oxidation, which can also weaken the structural stress during Zn2+ insertion and extraction. Benefiting from this unique structure, VO‐NSs exhibit high‐rate and stable Zn2+ storage capability. The strategy of engineering‐driven material design provides new insights into the development of AZIB cathodes. [ABSTRACT FROM AUTHOR]

The hollow sphere structure has attracted various attention in the catalytic field due to its high specific surface. The good dispersion and morphology of hollow spheres are important to provide high active sites. It is a big challenge to control the morphology and distribution of the active materials during synthesis. Serious deformation and uneven distribution of the spheres were usually obtained due to inappropriate templates. A facile one‐step hydrothermal method using micelles of triblock copolymer surfactant P123 was adopted to in‐situ grow Ni3S2/MoS2 porous hollow spheres on Ni foam with uniform distribution. The as‐produced Ni3S2/MoS2 porous hollow spheres have been demonstrated to have excellent oxygen evolution reaction catalytic performance as integrated electrodes. Low overpotentials of 314 mV and 337 mV have been achieved at current densities of 50 mA cm−2 and 100 mA cm−2 with a Tafel slope of 57 mV dec−1 and an excellent long‐term stability, which is better than other Ni‐base material. [ABSTRACT FROM AUTHOR]

A molecular probe is demonstrated to be an effective semi‐invasive technique to measure the local environments of biomaterials. Environmental probes based on fluorescence intensity and lifetime are well studied as temperature sensors. However, usually both fluorescence intensity and lifetime of reported molecular probes depend on various local environments, such as temperature, pH, and ionic strength. It is a big challenge to distinguish the specific environmental effects on the fluorescence. Herein, the violet phosphorus quantum dots (VPQDs) are demonstrated to be effective fluorescence molecular probes to distinguish temperature or pH environment variation. The fluorescence intensity and bandwidth of VPQDs are demonstrated to be linearly correlated to a wide range of temperatures (283–363 K), while the fluorescence lifetime of VPQDs is demonstrated to be temperature‐independent. However, the fluorescence lifetime is demonstrated to be linearly correlated to pH value. Additionally, good water dispersibility, superior photo‐ and thermal stability, and excellent reversibility are also obtained by VPQDs. More importantly, the high sensitivity of fluorescence intensity to temperature instead of pH environments and the high sensitivity of fluorescence lifetime to pH environments instead of temperature allow VPQDs to be distinguishable biosensors to temperature and pH environments. [ABSTRACT FROM AUTHOR]

This study concerns thermal stimulated healable epoxy‐based semi‐interpenetrating networks (semi‐IPNs). The crosslinking degree was adjusted using different curing agents to demonstrate its influence on healability. In addition to tensile properties, this study focuses on the influence of healing efficiency on dielectric performance, especially leakage current, following mechanical damage. We propose that there exists an inverse relationship between the degree of crosslinking degree and healing. A maximum healing efficiency of 93% is obtained calculated from volume resistivity change. We find that the variable Tg of the semi‐IPN crosslinking network based on epoxy resin, rather than the variable Tm of the thermoplastic, determines the temperature boundary for healing. We further suggest that the healing efficiency could be influenced simultaneously by the network structure and the quantity of poly(ε‐caprolactone). These results suggest that semi‐IPNs can be used to develop healable insulating materials for electrical applications. [ABSTRACT FROM AUTHOR]

Semiconducting layered violet phosphorus, the most stable phosphorus allotrope, has recently been successfully produced with large single crystal sizes and high yields. A promising anisotropy is expected by the reduced symmetry of violet phosphorus in various properties. The in‐plane crystallographic anisotropy and cleavage edge orientation are especially important to the exfoliated 2D structures for their electronic, photonic, magnetic, and mechanic applications. However, the anisotropy of violet phosphorus has not been studied. Here, a fast and nondestructive way is reported to identify the crystallographic orientation of 2D violet phosphorus nanoflakes by a single polarized Raman spectrum. The 2D violet phosphorus nanoflakes have been found to have preferred in‐plane cleavage edges along ‐[P2][P8][P2][P9]‐ tubular strands with <1, 1, 0> edge alignment. The b‐axis (a‐axis) direction has been demonstrated to be easily identified that forms an angle of 45° or 135° from the cleavage edge by the intensity of Ag mode, especially the appearance or disappearance of 491 cm–1, under parallel configuration using polarized Raman scattering. A simple and fast method has been developed to identify the crystallographic orientation of violet phosphorus nanoflakes by a single Raman spectrum to obtain the corresponding a‐axis and b‐axis. [ABSTRACT FROM AUTHOR]

Rare earth resources applied in numerous novel materials, are increasingly scarce in worldwide. Meanwhile, great attention has been focused on the blue rare‐earth‐free fluorescent phosphors as an excitation source of near‐ultraviolet (NUV) chips, which are available in white‐light‐emitting diodes (WLEDs) that combined with yellow commercial phosphors. Many solutions have been found to improve the photoluminescence quantum yield (PLQY) of phosphor. In this study, we effectively increased PLQY by introducing indium ion to vanadate garnet phosphor forming a series of LiCa3−XMgV3O12: xIn3+ (x = 0.01, 0.02, 0.04, 0.06, 0.08, and 0.10). The resultant In‐doped vanadate garnet phosphors exhibit a relative increase in PLQY, and the optimal phosphors is LiCa2.98MgV3O12: 0.02In3+ with a PLQY as high as 67.4%. These In‐doped vanadate garnet phosphors have a broad emission at 480 under 320 nm where near UV‐light excitation. It is revealed that the distortion of V‐V and V‐O bond length in [VO4] crystal structure and unit cell volume data of phosphors have an extensive influence on PLQY. Therefore, these novel vanadate garnet phosphors can be the essential blue color choice for WLED devices application in illumination. [ABSTRACT FROM AUTHOR]

Dielectric films are the foundation of power electronic equipment for energy storage in capacitors. However, typical dielectric films exhibit undesirable energy storage density and thermal stability, limiting its further application in the advanced field. For both pure polymers and composites‐based dielectrics, the macromolecular matrix greatly determines the performances. This paper summarizes the research progress of all‐organic polymer materials for the dielectric application from the perspective of molecular structure design. Systematic comparisons on properties, including dielectric constant and dielectric loss, glass transition temperature, and energy density are given, expecting to inspire researchers to devote further efforts in this area. An outlook for the future of all‐polymer dielectrics is also presented. [ABSTRACT FROM AUTHOR]

Few‐layer porous graphene is a promising material for a variety of fields. However, the synthesis of few‐layer porous graphene is a great challenge. Here we report a feasible green path to produce few‐layer porous graphene, which was exfoliated from high‐pressure graphite balls onto microspheres with rough surfaces by a mild rolling transfer process. Ordinary ball milling equipment was adopted for the low‐speed (100 rpm) ball–microsphere rolling transfer process. The rolling time (<10 min) was controlled to obtain porous graphene instead of graphene. The porous graphene on the exfoliating microspheres was then easily dispersed in solution by bath sonication. The product contains very few impure functional groups. The hole size and layer distribution of the few‐layer porous graphene have been demonstrated to be 2.37±1.17 nm and 2.4±0.7 layers, respectively, and can be adjusted by redesigning the surface of the microspheres. [ABSTRACT FROM AUTHOR]

Black phosphorene has attracted much attention as a semiconducting two‐dimensional material. Violet phosphorus is another layered semiconducting phosphorus allotrope with unique electronic and optoelectronic properties. However, no confirmed violet crystals or reliable lattice structure of violet phosphorus had been obtained. Now, violet phosphorus single crystals were produced and the lattice structure has been obtained by single‐crystal x‐ray diffraction to be monoclinic with space group of P2/n (13) (a=9.210, b=9.128, c=21.893 Å, β=97.776°). The lattice structure obtained was confirmed to be reliable and stable. The optical band gap of violet phosphorus is around 1.7 eV, which is slightly larger than the calculated value. The thermal decomposition temperature was 52 °C higher than its black phosphorus counterpart, which was assumed to be the most stable form. Violet phosphorene was easily obtained by both mechanical and solution exfoliation under ambient conditions. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) is a promising anode for lithium‐ion batteries (LIBs) due to its long lifespan and high rate capability, arising from its excellent structural stability upon lithium intercalation‐deintercalation, but suffers from low conductivity and diffusivity. In contrast, germanium (Ge) possesses high specific theoretical capacity (1600 mA h g−1) as well as high electrical conductivity and high Li+ diffusivity, but the large volume changes upon cycling and the high price still impede its practical application. Herein, with the objective to overcome the drawbacks of TiO2‐based anode materials, Ge/TiO2@C nanotablets with a small amount of Ge content are successfully prepared by annealing C4H12GeO4/MIL‐125 mixtures in Ar/H2 atmosphere. Benefiting from the well‐dispersion of Ge nanoparticles within the TiO2@C matrices, the composites exhibit superior electrochemical performance when examined as a LIB anode material, delivering high reversible capacities of 502/258 mA h g−1 after 200/500 cycles at current densities of 200/500 mA g−1, respectively. Notably, the Ge/TiO2@C shows enhanced surface/pore features and demonstrates improved conductivity, lithium diffusion and specific capacities, owing to the introduction of Ge component. [ABSTRACT FROM AUTHOR]

The special interactions with NO2 make MoS2 promising sensors. Effective gas adsorption and active sites of MoS2 are crucial for high performance sensors. However, studies of the interactions of MoS2 with gas have been focused on the physisorption of basal planes. In this article, chemisorption modes, with O,O‐bidentate or N‐monodentate bonding, on the (1–1 0) surfaces of MoS2 structures have been explored in addition to physisorption. The active sites of MoS2 nanosensors have been predicted to be edge sites of (1–1 0) surfaces and further confirmed by the different sensing performances of vertically and parallelly aligned MoS2 hybrids. Chemisorption mode with N‐monodentate bonding has also been calculated to be effective for MoS2 nanosensors by a two‐probe system simulation and further confirmed by in‐situ Raman and in‐situ diffuse reflectance infrared Fourier transform experiments. High sensitivity and selectivity have also been obtained by the vertical aligned MoS2 hybrids. [ABSTRACT FROM AUTHOR]

A long‐term data set of energetic proton omnidirectional integral fluxes with an 8‐s resolution from National Oceanic and Atmospheric Administration (NOAA) Polar Operational Environmental Satellites (POES) and EUMETSAT MetOp satellites from 1978 to 2014 has been investigated comprehensively to capture the data bifurcations, calibration inconsistency, and some erroneous data. There are two categories of the data bifurcations. The upper and lower branches of both bifurcations can be clearly separated by magnetic local time or by magnetic latitude. The calibration inconsistency of POES and MetOp proton omnidirectional integral fluxes (>16 MeV) is solved by fitting the data from each pair of two satellites using a third‐degree polynomial function. The fitted curve is almost independent of Lm, B/B0, and time in the valid range. By these fitted functions, the >16 MeV proton omnidirectional integral fluxes from other POES and MetOp satellites are recalibrated to the NOAA‐15 measurements that are adopted as the reference standard. Analyses of the recalibrated data at the geomagnetic equator for about 3.5 solar cycles indicate that the maximal and minimal yearly values of >16 MeV proton omnidirectional integral fluxes are in 1987 and in 2002, respectively. By comparisons with the AP8 model predictions, the ratios of the observations in 1987 (in 2002) to the AP8 MIN (AP8 MAX) predictions are mainly within 0.5‐3 (0.1‐2), showing a dependence on Lm and B/B0. Key Points: Energetic proton data from NOAA POES and EUMETSAT MetOp satellites need further correction and recalibration for long‐duration scientific studiesCompared to rough correction factors regularly used, polynomial functional fits are shown to improve cross calibrationDifferences between the observations and the AP8 model predictions depend on Lm and B/B0 [ABSTRACT FROM AUTHOR]

Graphene‐coated silicon nanoparticles with polydopamine buffers have been designed and successfully fabricated as anodes for lithium ion batteries, where the polydopamine was grown on the silicon nanoparticles and then coated with graphene layers. The expansion cavities for silicon nanoparticles during charging and discharging process are provided by the polydopamine buffer layers. The outermost graphene coating layers not only keep the pulverized silicon particles together without disintegration, but also improve the electric conductivity of silicon nanoparticles. Silicon nanoparticles of an industrial product level with different size distributions and oxidation layers were used in this work. High electrochemical performances with specific capacities of 1100 mAh g−1 were achieved by the designed silicon composites with polydopamine and graphene after 550 cycles at a current rate of 200 mA g−1. Graphene‐coated silicon nanoparticles with polydopamine buffers have been designed and successfully fabricated as anodes for lithium ion batteries. A specific capacity around 1100 mAh g−1 has been achieved by the Si@PDA@Gra anodes at a current rate of 200 mA g−1 after 600 cycles. Silicon nanoparticles of an industrial product level could be used without further treatment. [ABSTRACT FROM AUTHOR]

Surface discharge inception voltage (SDIV) with epoxy silicon carbide nanocomposite material in LN2 medium is about three times higher than that in air. Under AC voltage that SDIV increases with increase in wt% of silicon carbide (SIC) material in epoxy nanocomposites. Dielectric measurements indicates an increase in temperature of the specimen and the weight percentage of SIC filler in epoxy resin increases the permittivity of the material. Also, irrespective of percentage of SiC in epoxy resin, the tan(δ) reduces with increase in frequency and the converse at room temperature. The UHF signal measured during surface discharge activity in air/LN2 medium has frequency content in the range of 0.5-1.5 GHz. The charge decay characteristics of epoxy SiC nanocomposites indicate the deposited charge is less and the charge decay time reduces with increase in wt% of SiC in epoxy resin. The surface roughness caused due to surface discharge activity is high under negative DC voltage compared with positive DC/AC voltage. The phase resolved partial discharge (PRPD) analysis indicates discharges occur at the near peak of the AC voltage on inception of surface discharge and at higher stress it appears at the rising portion of AC voltage. POLYM. ENG. SCI., 57:1349-1355, 2017. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]