As one of the important ways to achieve sustainable economic development, enterprise green innovation will also have an important impact on the future development of enterprises. Through the analysis, it is found that green innovation can realize the sustainable development of enterprises. However, green innovation has the characteristics of high risk and double externality, so the enthusiasm of enterprise green innovation is relatively low. As the decision maker of enterprises, the characteristics of management will have an important impact on green innovation. This paper studies the influence of Managerial Overconfidence on green innovation. This paper first studies the impact of management overconfidence on enterprise risk-taking ability, and finds that management overconfidence can improve enterprise risk-taking ability. Then it studies the impact of enterprise risk-taking ability on green innovation. The higher the enterprise risk-taking ability is, the more conducive to the implementation of green innovation activities. Through theoretical analysis, this paper concludes that management overconfidence can further promote the green innovation of enterprises by improving the risk-taking ability of enterprises.
The reliability of mobile packet data transmission in multi-input multi-output (MIMO) communication systems is degraded by time-varying multi-path channel fading. This so-called Doppler-effect can be mitigated by using a shorter packet length and/or inserting more pilot training symbols and frequently tracking the channel at the receiver at the cost of additional rate overhead. A judicious choice of the packet length according to channel conditions aims at achieving a tradeoff between reliability and overhead to maximize the achievable throughput. We present an analytical framework for optimizing the packet length in mobile MIMO systems to maximize throughput taking into account channel estimation and Doppler effects. As a case study, we consider the Alamouti space-time block code (STBC) for 2 transmit antennas over Rayleigh flat-fading channels and determine the optimum packet length as a function of input SNR and Doppler rate. Furthermore, we investigate the effect of various system design parameters on the optimum packet length and achievable throughput such as signal constellation size, number of receive antennas, and receiver detection algorithm.
As an emerging post-lithium battery technology, aluminum ion batteries (AIBs) have the advantages of large Al reserves and high safety, and have great potential to be applied to power grid energy storage. But current graphite cathode materials are limited in charge storage capacity due to the formation of stage-4 graphite-intercalated compounds (GICs) in the fully charged state. Herein, we propose a new type of cathode materials for AIBs, namely polycyclic aromatic hydrocarbons (PAHs), which resemble graphite in terms of the large conjugated π bond, but do not form GICs in the charge process. Quantum chemistry calculations show that PAHs can bind AlCl4- through the interaction between the conjugated π bond in the PAHs and AlCl4-, forming on-plane interactions. The theoretical specific capacity of PAHs is negatively correlated with the number of benzene rings in the PAHs. Then, under the guidance of theoretical calculations, anthracene, a three-ring PAH, was evaluated as a cathode material for AIBs. Electrochemical measurements show that anthracene has a high specific capacity of 157 mAh g-1 (at 100 mA g-1 ) and still maintains a specific capacity of 130 mAh g-1 after 800 cycles. This work provides a feasible "theory guides practice" research model for the development of energy storage materials, and also provides a new class of promising cathode materials for AIBs.
Batteries based on divalent metals, such as the Zn/Zn2+ pair, represent attractive alternatives to lithium-ion chemistry due to their high safety, reliability, earth-abundance, and energy density. However, archetypal Zn batteries are bulky, inflexible, non-rechargeable, and contain a corrosive electrolyte. Suppression of the anodic growth of Zn dendrites is essential for resolution of these problems and requires materials with nanoscale mechanics sufficient to withstand mechanical deformation from stiff Zn dendrites. Such materials must also support rapid transport Zn2+ ions necessary for high Coulombic efficiency and energy density, which makes the structural design of such materials a difficult fundamental problem. Here, we show that it is possible to engineer a solid Zn2+ electrolyte as a composite of branched aramid nanofibers (BANFs) and poly(ethylene oxide) by using the nanoscale organization of articular cartilage as a blueprint for its design. The high stiffness of the BANF network combined with the high ionic conductivity of soft poly(ethylene oxide) enable effective suppression of dendrites and fast Zn2+ transport. The cartilage-inspired composite displays the ionic conductance 10× higher than the original polymer. The batteries constructed using the nanocomposite electrolyte are rechargeable and have Coulombic efficiency of 96–100% after 50–100 charge–discharge cycles. Furthermore, the biomimetic solid-state electrolyte enables the batteries to withstand not only elastic deformation during bending but also plastic deformation. This capability make them resilient to different type of damage and enables shape modification of the assembled battery to improve the ability of the battery stack to carry a structural load. The corrugated batteries can be integrated into body elements of unmanned aerial vehicles as auxiliary charge-storage devices. This functionality was demonstrated by replacing the covers of several small drones with corrugated Zn/BANF/MnO2 cells, resulting in the extension of the total flight time. These findings open a pathway to the design and utilization of corrugated structural batteries in the future transportation industry and other fields of use.
Nowadays it is still of great demand to find a feasible, inexpensive and green material for industrial enzyme immobilization for wastewater treatment. In this work, horseradish peroxidase (HRP) was successfully immobilized on glutaraldehyde activated carbon nanospheres. Compared with free HRP, the immobilized one showed better tolerance of temperature and pH. Meanwhile the storability and reusability were also greatly improved after immobilization. The immobilized HRP could be used for removal of several phenolic compounds from an aqueous solution and exhibited excellent removal efficiency, especially for chlorophenols, 4‐methoxyphenol, and bisphenol A. The immobilization could also make the enzyme more tolerant of ions and preserve its bioactivity. Moreover, by the introduction of support‐enzyme interaction a remarkably enhanced biodegradation was observed. The biodegradation of phenols with electron‐donor groups were found to be doubled after immobilization on active carbon nanospheres. These findings might be useful for further construction of immobilized enzymes for industrial applications, which exhibit excellent stability together with high activity.
The energy systems in Portugal and Spain are closely connected, among which the power and gas grids are mutually standby and provide support to each other. According to the characteristics of the cross-border energy systems, this study conducted the research of the energy development and utilization in the two countries, and carried out the modeling and simulation of the whole cross-border energy grids. For the first time, the scenario of "Portugal-Spain" electricity-gas coupling system was established on an independently developed simulation platform—Integrated Energy System Analysis Software (IESAS), including the grids structure of the power and gas networks and the key coupling equipment elements. Besides, based on the software, the energy flow calculation of the "Portugal-Spain" energy networks were completed. The power network includes 888 buses, 1018 AC transmission lines and 323 loads. The natural gas network includes 200 gas nodes and 215 natural gas pipelines. This work provides a solid foundation for the optimization the load dispatching and the large-scale utilization of renewable energy between the two countries.
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