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"Thin thickness", "lightweight", "wide absorption bandwidth" and "strong absorption" are the new standards of contemporary science and technology for microwave absorption(MA) material. In this study, N-doped-rGO/g-C3N4 MA material...
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"Thin thickness", "lightweight", "wide absorption bandwidth" and "strong absorption" are the new standards of contemporary science and technology for microwave absorption(MA) material. In this study, N-doped-rGO/g-C3N4 MA material was prepared for the first time by simple heat treatment, which the N atoms were doped into rGO and g-C3N4 was dispersed on the surface of N-doped-rGO, and its density is only 0.035 g/cm3. The impedance matching of the N-doped-rGO/g-C3N4 composite was well adjusted by decreasing the dielectric constant and attenuation constant due to the g-C3N4 semiconductor property and the graphite-like structure. Moreover, the distribution of g-C3N4 among N-doped-rGO sheets can produce more polarization effect and relaxation effect by increasing the lamellar spacing. Furthermore, the polarization loss of N-doped-rGO/g-C3N4 could be increased successfully by doping N atoms and g-C3N4. Ultimately, the MA property of N-doped-rGO/g-C3N4 composite was optimized significantly, with a loading of 5 wt%, the N-doped-rGO/g-C3N4 composite exhibited the RLmin of-49.59 dB and the effective absorption bandwidth could reach 4.56 GHz when the thickness was only 1.6 mm. The "thin thickness", "lightweight", "wide absorption bandwidth" and "strong ab-sorption" of MA material are actually achieved by the N-doped-rGO/g-C3N4.
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This study proposes an improved artificial potential field (APF) by considering the cooperative control of local obstacle avoidance and path tracking for automated vehicles. We established the path gravitational potential field (G...
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This study proposes an improved artificial potential field (APF) by considering the cooperative control of local obstacle avoidance and path tracking for automated vehicles. We established the path gravitational potential field (GPF) based on the scheduled path (SP), including the lateral and longitudinal GPFs, to enable the automated vehicle to quickly return to the SP and track after obstacle avoidance, while maintaining control of speed for the entire process. To address the local optimal solution problem of the classical APF, we proposed a sub-target-point selection strategy based on the information of obstacles and SP and established the GPF of the sub-target points. Thus, the automated vehicle can avoid obstacles and quickly return to the SP. Furthermore, the relative velocity of the automated vehicle and the obstacle was used to establish the velocity repulsion potential field (RPF), which improved the adaptability of the APF to dynamic obstacles. The simulation results indicate that the improved APF is capable of cooperative control of path tracking and local obstacle avoidance.
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The realization of spontaneous sub-ambient cooling in daytime typically requires the solar reflectance and thermal emittance of passive daytime radiative cooling (PDRC) material to be > 90%. Toward real-world ap-plications, howeve...
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The realization of spontaneous sub-ambient cooling in daytime typically requires the solar reflectance and thermal emittance of passive daytime radiative cooling (PDRC) material to be > 90%. Toward real-world ap-plications, however, to achieve high optical performance and excellent durability, PDRC coating is often cost-prohibitive due to its high thickness (500 mu m or higher). To solve the contradiction between high optical per-formance and thin thickness of PDRC coating, the idea of introducing masking layer for PDRC coating is proposed in this paper to prepare the water-based double-layer PDRC coating and explore its long-term outdoor appli-cation potential. The PDRC coating can achieve high solar reflectance (94.0%) and "atmospheric transparent spectrum window" emittance (93.0%), while the thickness and cost are only 40% and 60% of existing water-based PDRC coating. The PDRC coating shows efficient cooling performance when applied as the external coating of large temporary buildings, with maximum temperature reduction of 20.8 degrees C and 5.0 degrees C on the roof/ indoor, which are equal to or greater than recorded values. The 150-day large-scale outdoor application shows that the coating has excellent durability, which offers a reference for the long-term outdoor application of PDRC coating. The application of the PDRC coating on rooftops of containers can achieve a cooling energy savings of up to 15.3% compared to conventional steel roofs, translating to an annual energy savings of 413.2 MJ and a reduction of approximately 114 kg in carbon dioxide emissions, which provide compelling evidence for the ability of PDRC coating to mitigate carbon emissions and address global climate change.
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Abstract Carbon fiber reinforced composites have attracted lots of attention in many fields. However, on account of the poor infiltration of resin to carbon fiber, the weak interface performance between fiber and resin has been re...
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Abstract Carbon fiber reinforced composites have attracted lots of attention in many fields. However, on account of the poor infiltration of resin to carbon fiber, the weak interface performance between fiber and resin has been restricting the interface properties of composites. In recent progress, the review attaches more importance to the introduction of the third phase monomer, which mainly uses physical and chemical methods to assemble nanomaterials (such as carbon nanotubes, graphene, etc.) on the carbon fiber surface to modify the interface structure of the carbon fiber reinforced composites, and all of them have been demonstrated in this paper. Furthermore, the effects of introducing nanomaterials on the structure of the fiber/resin interface and the relationship between multi‐scale interface structure and properties have been investigated. It can be seen that the design idea of researchers mainly uses one or more theories to improve the interface properties of carbon fiber reinforced composites, such as transition layer, chemical bonding, mechanical interlocking, infiltration, diffusion, and adsorption. In brief, this work provides some novel insights for the preparation of carbon fiber reinforced composites with excellent interlaminar shear strength.
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Due to the discharge of oily wastewater, there is an urgent need to develop advanced oil/water separation materials having the characteristic of versatility and cost-efficiency in an eco-friendly manner. In this work, we used natu...
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Due to the discharge of oily wastewater, there is an urgent need to develop advanced oil/water separation materials having the characteristic of versatility and cost-efficiency in an eco-friendly manner. In this work, we used natural corn stalks as a raw material to prepare a versatile platform for oil/water separation. The corn stalks without treatment can separate efficiently light oil/water mixtures with a high flux, which is attributed to underwater superoleophobicity and interconnective porous structure. In addition, an enlarged membrane was prepared by combining multiple corn stalks to achieve a higher flow rate of oil/water separation (30 mL/min) relative to a single corn stalk. More interestingly, the local corn stalk can be used directly to separate oil/water mixtures through removing part of stem marrow. After modifying with polydimethylsiloxane (PDMS) and hydrophobic silicon dioxide (SiO2), a corn stalk@PDMS@SiO2 membrane (CPSM) was obtained to achieve heavy oil/water separation owing to the wetting state transition from superhydrophilicity to superhydrophobicity. The XPS measurement reveals the chemical information of superhydrophiobic coating. Moreover, the CPSM could successfully separate water-in-1, 2-dichloroethane emulsion and selectively absorb oils. The developed corn stalk-based materials originate from nature, are simple to prepare, and realize efficient separation for multiple types of oil/water mixtures.
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Purpose The purpose of this study aims to develop and test a motives-mass customization (MC) capability-performance model by dividing MC capability into product-oriented MC capability and service-oriented MC capability. Design/met...
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Purpose The purpose of this study aims to develop and test a motives-mass customization (MC) capability-performance model by dividing MC capability into product-oriented MC capability and service-oriented MC capability. Design/methodology/approach This research tests the hypothesized relationships using survey data from 277 Chinese manufacturing firms. Findings The results indicate that instrumental, relational and moral motives all have significantly positive impacts on product-oriented and service-oriented MC capability. The authors also find that product-oriented MC capability partially mediates the impacts of relational and moral motives on operational, environmental and economic performance, while service-oriented MC capability partially mediates the impacts of instrumental, relational and moral motives on operational, market, environmental and economic performance. Originality/value This study complements the existing MC literature by describing MC capability into two dimensions: product-oriented MC capability and service-oriented MC capability.
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The study aims to determine how price fluctuations in metallic resource supplies impact China's environmental performance. This research evaluates the impact of the price volatility of nickel, aluminum, gold, and aluminum on envir...
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The study aims to determine how price fluctuations in metallic resource supplies impact China's environmental performance. This research evaluates the impact of the price volatility of nickel, aluminum, gold, and aluminum on environmental performance in China from 2001 to 2019 to provide an answer to this topic. By examining the robustness of outcomes, the conventional DCC-GARCH approach clarifies the study findings and offers wide policy implications for the most recent topicality CS-ARDL. According to the study, the fluctuation in metal prices significantly influences the nation's GDP. The research's findings show that over the sample period, the price volatility of metallic resources was 23%, and this shift implied a 17.24% change in environmental performance. The findings of the study so ensure that every effort will be made to prevent environmental instability by supporting financial resource volatility recovery via governmental agencies, environmental ministries, and departments. The research has several policy implications, including the necessity for different government aid programs and financial agreements that guarantee environmental growth and resilience. The research's policy recommendations are intended to lessen the impact of structural events and increase environmental effectiveness. Research on financial resource recovery is dispersed and understudied despite the issue having a growing corpus of literature.
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The new high nickel cathode LiNi1-x-yMnxAlyO2 (NMA) has attracted the attention of researchers, but the high rate performance has shortcoming compared to the conventional cobalt-cathode. In this paper, NaAlO2 was used as the alumi...
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The new high nickel cathode LiNi1-x-yMnxAlyO2 (NMA) has attracted the attention of researchers, but the high rate performance has shortcoming compared to the conventional cobalt-cathode. In this paper, NaAlO2 was used as the aluminum source to effectively inhibit the preferential precipitation of Al(OH)3 and the chemical composition was uniformly distributed in particles. LiNi0.80Mn0.1Al0.1O2 (NMA80), LiNi0.90Mn0.05Al0.05O2 (NMA90) and LiNi0.95Mn0.025Al0.025O2 (NMA95) cobalt-free materials were synthe-sized by this optimized chemical co-precipitation method and calcinations and all three materials show high crystallinity and purity. The electrochemical performance and phase characterization analysis of Ni-Mn-Al materials were carried out and the effects of Al and Mn elements on the materials were investigated. The specific capacity of NMA95 is 210.6 mAh/g at 0.1 C under a voltage range of 2.75-4.30 V and NMA90 can also reach 201.1 mAh/g. In addition, NMA95 and NMA90 also have excellent specific capacity at 1 C, the discharge capacity are 195.3 and 183.2 mAh/g respectively. However, the cyclic stability of NMA95 at 1 C is slightly inadequate with 81.10% retention rate and NMA90 is the best with 95.52% retention rate. As for NMA80, the overall capacity is low. In particular, the rate performance of NMA90 is much higher than the other two materials. The discharge capacity of NMA90 can still reach 172.3 mAh/g at 5 C high discharge rate. Excellent specific capacity at high rate is promising for the development of fast charging technology. NaAlO2 effectively control the precipitation rate of Al, and the rate performance of the synthetic material is opti-mized. It is expected that performance of NMA for next-generation lithium-ion batteries could be improved by this process.(c) 2023 Elsevier B.V. All rights reserved.
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Two star-shaped quaternary ammonium compounds, named as T-P-EDA and T-P-DETA, were synthesized with the melamine as the hydrophobic core and the quaternary ammonium moieties as the hydrophilic sub-core. Moreover, they were fully c...
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Two star-shaped quaternary ammonium compounds, named as T-P-EDA and T-P-DETA, were synthesized with the melamine as the hydrophobic core and the quaternary ammonium moieties as the hydrophilic sub-core. Moreover, they were fully characterized by the FT-IR, H-1 NMR, TGA and their demulsification properties were systemically investigated. It was found that both of the compounds showed higher demulsification efficiency than traditional linear cationic demulsifier (CW-01) in breaking the polymer flooding oil-in-water (O/W) emulsions. Notably, for a 1500 mg/L oil containing emulsion, it achieved similar to 99.5% oil removal ratio in 10 min at 30 degrees C by adding 80 mg/L T-P-EDA or T-P-DETA, while the oil removal rate of CW-01 was 93.5% at the same conditions. Furthermore, the interfacial tension, turbidity, and zeta potential measurements were performed, which indicated that the electrostatic interaction and hydrogen bonding between the demulsifiers and the surfactants were the driving forces for the enhancement of demulsification efficiency. T-P-EDA and T-P-DETA may potentially serve as the faster, more efficient and inexpensive demulsifiers.
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Based on the merits and demerits of conventional methods for fabricating TiO2@carbon nanofibers (TiO2@CNFs) composites, the composites were prepared via a foaming-assisted electrospinning strategy and subsequent thermal treatment....
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Based on the merits and demerits of conventional methods for fabricating TiO2@carbon nanofibers (TiO2@CNFs) composites, the composites were prepared via a foaming-assisted electrospinning strategy and subsequent thermal treatment. Betaine was used as the foaming agent and assembled with TiO2 before electrospinning. It was found that the foaming agent of betaine introduced within the solutions played a crucial role on the migration of TiO2 nanoparticles to the surface of CNFs, enabling their regular movement when the carbonization temperature increased from 400 to 1000 degrees C. The TiO2 loading amount on the surface of CNFs increased gradually with an enhanced temperature, resulting in an increase in specific surface area from 30.09 to 419.8 m(2) g(-1). In addition, the obtained TiO2@CNFs composites exhibited excellent hydrophilicity and high degree of graphitization. Accordingly, when the carbonization temperature increased, the composites presented an enhanced photocatalytic activity toward the degradation of rhodamine B. Hence, a novel method for preparing TiO2@CNFs composites with tailored TiO2 loading amount could be envisioned.
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