Stakeholder theory has been widely used in business management research by scholars of various disciplines at home and abroad. Initially, stakeholder theory asserted that the growth of any company is ...inseparable from stakeholders, emphasizing the consideration of stakeholders when making or implementing decisions. However, in recent years, with the deepening of theoretical research, the scope of stakeholder theory research has been expanding, and environmental, social and governance (ESG) has become one of the important aspects of stakeholder theory research. This paper explores the relationship between ESG, and corporate performance based on stakeholder theory. Stakeholder theory suggests that by demonstrating strong ESG performance, companies can gain buy-in from both external and internal stakeholders. ESG can meet the needs of both external and internal stakeholders. As a result, it not only enhances the brand image, but also improves operational efficiency, which in turn improves the quality of sales and services. Ultimately, this helps to improve business performance.
Due to the presence of information asymmetry in various aspects of corporate management, the theory of signal transmission has been widely employed by scholars in disciplines such as management and ...economics, both in academia and practical applications. The theory emphasizes the transmission of signals to reduce information asymmetry in the market. It has been extensively studied and proven valuable in both domestic and international contexts. This paper explores the relationship between ESG performance and total factor productivity based on the signal transmission theory, examining the reasons for ESG formation and its impact on total factor productivity.
This paper proposes a difference discretization method (DDM) under a difference frame for the prediction of milling stability. In this method, the dynamic milling process is described by a delay ...differential equation (DDE) with two degrees of freedom rather than the traditional state-space form with a single discrete time delay. After discretization, only the velocity and acceleration in the DDE are approximated by the first- and second-order central difference for each smaller time interval, while the other items are kept unchanged. Then, the criterion for the optimal discretization interval number is put forward and derived based on the largest effective time interval (also called the critical time interval). The use of the critical time interval cannot only obtain sufficient accuracy, but also promotes as much efficiency as possible. Subsequently, a new DDM (NDDM) with varied discretization interval numbers as the milling rotating speeds is developed. Finally, the effectiveness of the proposed algorithm is demonstrated by using a benchmark example for a two-degrees-of- freedom milling model compared to the full discretization method (FDM) and the Hermite-interpolation full discretization method (HFDM). The results show that the proposed method has satisfactory stability charts and is able to increase the efficiency by 100% or more.
With the concept of carbon neutrality and carbon emissions peak, the Chinese government emphasize the importance of the application of renewable energy like photovoltaic energy. Internationally, some ...countries and regions already have ability to replace fossil energy with renewable resources such as wind, solar, wind, and hydrogen energy. This thesis focuses on photovoltaic energy and its applications. Photovoltaic energy usually uses monocrystalline silicon and polysilicon as raw materials, and this paper compares the advantages and disadvantages of both raw materials. The technology of building PV integration, which combines PV cells with buildings, and the technology that increases the conversion efficiency of PV cells by passivating the back contact of the emitting area are described in detail. In addition, this study illustrates the reasons that limit the development of photovoltaic cells under the current technology in terms of both self-factors and environmental factors. The self-factors are mainly the conversion rate of its own materials and energy consumption of meta-components, and the environmental factors are mainly the geographical location leading to the solar altitude angle and the amount of solar radiation. In the future, the global PV market will continue to maintain a rapid growth trend, driven by favorable factors such as the continued decline in the cost of photovoltaic power generation and the positive market orientation.
Highlights
Heterogeneous interface engineering is designed by electrospinning.
The introduction of Co
3
SnC
0.7
nanoparticles increased the loss mechanism.
Enhanced electromagnetic loss and improved ...impedance matching are achieved.
The absorbers exhibit high-efficient electromagnetic wave absorption performance.
Application of novel radio technologies and equipment inevitably leads to electromagnetic pollution. One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain high-performance microwave absorbers. Herein, we reported a one-dimensional
N
-doped carbon nanofibers material which encapsulated the hollow Co
3
SnC
0.7
nanocubes in the fiber lumen by electrospinning. Space charge stacking formed between nanoparticles can be channeled by longitudinal fibrous structures. The dielectric constant of the fibers is highly related to the carbonization temperature, and the great impedance matching can be achieved by synergetic effect between Co
3
SnC
0.7
and carbon network. At 800 °C, the necklace-like Co
3
SnC
0.7
/CNF with 5% low load achieves an excellent
RL
value of − 51.2 dB at 2.3 mm and the effective absorption bandwidth of 7.44 GHz with matching thickness of 2.5 mm. The multiple electromagnetic wave (EMW) reflections and interfacial polarization between the fibers and the fibers internal contribute a major effect to attenuating the EMW. These strategies for regulating electromagnetic performance can be expanded to other electromagnetic functional materials which facilitate the development of emerging absorbers.
As one of the most effective surface-enhanced infrared absorption (SEIRA) techniques, metal–insulator–metal structured metamaterial perfect absorbers possess an ultrahigh sensitivity and selectivity ...in molecular infrared fingerprint detection. However, most of the localized electromagnetic fields (i.e., hotspots) are confined in the dielectric layer, hindering the interaction between analytes and hotspots. By replacing the dielectric layer with the nanofluidic channel, we develop a sapphire (Al2O3)-based mid-infrared (MIR) hybrid nanofluidic-SEIRA (HN-SEIRA) platform for liquid sensors with the aid of a low-temperature interfacial heterogeneous sapphire wafer direct bonding technique. The robust atomic bonding interface is confirmed by transmission electron microscope observation. We also establish a design methodology for the HN-SEIRA sensor using coupled-mode theory to carry out the loss engineering and experimentally validate its feasibility through the accurate nanogap control. Thanks to the capillary force, liquid analytes can be driven into sensing hotspots without external actuation systems. Besides, we demonstrate an in situ real-time dynamic monitoring process for the acetone molecular diffusion in deionized water. A small concentration change of 0.29% is distinguished and an ultrahigh sensitivity (0.8364 pmol–1 %) is achieved. With the aid of IR fingerprint absorption, our HN-SEIRA platform brings the selectivity of liquid molecules with similar refractive indexes. It also resolves water absorption issues in traditional IR liquid sensors thanks to the sub-nm long light path. Considering the wide transparency window of Al2O3 in MIR (up to 5.2 μm), the HN-SEIRA platform covers more IR absorption range for liquid sensing compared to fused glass commonly used in micro/nanofluidics. Leveraging the aforementioned advantages, our work provides insights into developing a MIR real-time liquid sensing platform with intrinsic IR fingerprint selectivity, label-free ultrahigh sensitivity, and ultralow analyte volume, demonstrating a way toward quantitative molecule identification and dynamic analysis for the chemical and biological reaction processes.
Currently, the thermal management of electronics has been drawing growing attention. The use of latent heat emerges as an attractive means for intermittent heat dissipation. However, traditional ...phase change materials (PCMs) are limited by their relatively low enthalpies. In this paper, we demonstrate a passive thermal management strategy through the desorption process of water inside sorbents. The spontaneous adsorption enables self-recovery of working capacity at rest mode. The basic guideline for selecting proper sorbents is outlined. In the proof-of-concept test, we coated MIL-101(Cr) powders onto metallic substrates. The coating of 0.288 g achieved a temperature drop (maximum 8.6°C) for 25 min at a heating power of 1.5 W. The equivalent enthalpy of the coating can be up to 1,950 J/gcoating, indicating a significant improvement compared to that of traditional PCMs. Our results suggest that this strategy could find promising applications in a variety of practical scenes.
Display omitted
•A strategy of passive thermal management based on moisture sorption-desorption•Proof-of-concept demonstration of this strategy using MIL-101(Cr) coating•Higher equivalent enthalpy when compared with traditional PCMs•A simplified model to guide the material selection and system design
The efficient thermal management of electronic devices is essential, considering overheating is harmful to the efficiency and reliability of electronic components. In this work, we introduce a new strategy of transient thermal management, using solid sorbents, which can absorb moisture from the atmosphere and subsequently release moisture at a higher temperature. During the releasing process, a huge amount of heat is extracted to prevent the device from overheating. The cyclic water loading is the key criterion in screening candidate materials. Experimentally we demonstrate the outstanding performance of this strategy. The MIL-101(Cr) coating significantly outperforms traditional phase change materials. The sorbent coating can also be readily integrated with existing heat dissipation structures. This work paves a new pathway for transient thermal regulation. The challenge to large-scale deployment is to find cost-effective sorbents with outstanding sorption and thermophysical properties.
The application of traditional phase change materials (PCMs) in electronic thermal management is limited by their enthalpies. In this work, we adopt sorbents and their desorption processes to achieve efficient thermal management. The sorbents with high cyclic water loadings, such as MIL-101(Cr), significantly outperforms the traditional PCMs, by virtue of their high desorption heat during the temperature-induced desorption process.
Display omitted
•Preparation methods of graphene-like materials from biomass were summarized.•The mechanisms and product characteristics of different methods were discussed.•Common characterization ...instruments to determine the structure were discussed.•Tailored designs of graphene-like material need further investigation.
Two-dimensional graphene materials attracted much attention worldwide because of their superior performance in electronic devices, sensors, and energy storage. However, its application is limited by high cost and insufficient production. The work to find out a simple and environmentally friendly process is highly needed. Designed pyrolysis of biomass precursors can derive graphene-like materials. This review summarizes some typical preparation processes for graphene-like materials synthesis from biomass carbonization via pyrolysis, including salt-based activation, chemical blowing, template-based confinement, coupling with hydrothermal carbonization pretreatment, post exfoliation, and some other methods. The operation of these methods and the performance of obtained graphene-like materials were closely highlighted. The scalability of the techniques and the applications of the biomass graphene-like carbon were also discussed. Some advanced characterization methods, such as SEM, TEM, AFM, Raman, and XPS to determine the graphene-like structure and graphitization degree were also discussed. In the end, some current challenges and future perspectives of the synthesis of these graphene-like materials were concluded.
Inspired by natural biomolecular machines, synthetic molecular-level machines have been proven to perform well-defined mechanical tasks and measurable work. To mimic the function of channel proteins, ...we herein report the development of a synthetic molecular shuttle, 2rotaxane 3, as a unimolecular vehicle that can be inserted into lipid bilayers to perform passive ion transport through its stochastic shuttling motion. The 2rotaxane molecular shuttle is composed of an amphiphilic molecular thread with three binding stations, which is interlocked in a macrocycle wheel component that tethers a K+ carrier. The structural characteristics enable the rotaxane to transport ions across the lipid bilayers, similar to a cable car, transporting K+ with an EC50 value of 1.0 μM (3.0 mol % relative to lipid). We expect that this simple molecular machine will provide new opportunities for developing more effective and selective ion transporters.
In cutting process, chatter is an inevitable phenomenon that greatly affects workpiece surface quality, tool life and machining efficiency. The stiffness variation (SV) method has been proposed and ...applied in chatter suppression for a long time. However, the early studies focused on boring and turning with one degree of freedom. For milling process with two degrees of freedom, there is no related research about SV. In this paper, SV method is employed through modulating the stiffness around a nominal value in order to suppress milling chatter. The milling dynamic model of SV with two degrees of freedom is constructed. In this model, the classical delay differential equation (DDE), which governs the milling process, is replaced with a DDE with a time-varying stiffness term. The stability analysis with different SV is completed using the semi-discretization method (SDM) and results show that the stable region with SV is larger than that under most of the traditional conditions. The results of stability analysis are verified by time domain simulation. In addition, the influences on stability lobe diagram (SLD), which is caused by different waveforms, amplitudes and frequencies of SV, are also analyzed specifically. The analysis results can provide the optimal parameters combination for milling. Cutting experiments are implemented on a three-axis milling machine to validate the effectiveness of SV. In the experiment, piezoelectric stack actuators are used to modulate the stiffness with time-varying preload. The milling forces signals are acquired by data collecting instrument, whose root-mean-square (RMS) is used as the metric of cutting vibrations. Experiment results are in good agreement with theoretical prediction.
•The milling dynamic model of stiffness variation with two degrees of freedom is proposed.•The influences of different types of stiffness variation on stability lobe diagram are analyzed.•The model and analysis results are verified by a number of milling tests.
PDF
