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Abstract To empirically verify whether financial risk affects global carbon emissions, this study investigates the financial risk-emission nexus by employing a global balanced panel dataset of 62 countries over the period 2003–2018. Furthermore, we explore the mediation effect of technological innovation on the financial risk-emission nexus. Fully considering potential regional heterogeneity and asymmetry, this study further analyzes the heterogeneous and asymmetric relationships among the variables, such as the difference between regional comprehensive economic partnership countries and other countries. The empirical results indicate that: (1) a mediation effect between financial risk and global carbon emissions exists; in other words, increased financial risk not only reduces global carbon emissions directly, but can also have an indirect impact in mitigating carbon emissions by promoting technological innovation; (2) the impacts of financial risk and technological innovation on global carbon emissions show significant regional heterogeneity; and (3) financial risk and technological innovation show asymmetry across different quantiles. To be specific, technological innovation and financial risk have a significant inhibitory effect on global carbon emissions only in the 10th quantile, while promoting carbon emissions in other quantiles.

Currently, the world is facing two significant challenges: low-carbon development and overcapacity. Government departments must reexamine their development strategy of energy industry. Implementing environmental regulatory policies and technological innovation can help alleviate coal industry’s overcapacity, while sustainable development requires joint actions of governments, enterprises, and the market. Based on the evolutionary game theory, this study constructs a tripartite evolutionary game model of local government, power industry, and coal enterprise. Under the premise of bounded rationality, the evolution path of each player in the game under the market incentive environmental regulation is analyzed, and the influence of the change of parameters of each player on the result is numerically simulated. The study found that strengthening environmental regulation by local governments is an inevitable choice to promote the transformation and upgrading of coal industry and power industry. In addition, reducing law enforcement costs and technological innovation costs are the fundamental point of the coordinated development of the three parties. Technological innovation in the power industry will reduce the probability of coal companies’ choosing clean production strategies, while seeking low-cost clean production technology and financial support is the key to coal companies’ optimization of production capacity.

Abstract The main purpose of the present research is to develop an environmentally more attractive process for the production of biodiesel by using a magnetic separable solid catalyst. To achieve this, hydroxyapatite-encapsulated γ-Fe 2 O 3 nanoparticles (HAp-γ-Fe 2 O 3 ) were prepared, and organic biguanide was then bound to the magnetic carrier via covalent attachments. The magnetic carrier and biguanide-functionalized HAp-γ-Fe 2 O 3 were fully characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectra, energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), vibrating-sample magnetometer (VSM) and nitrogen adsorption–desorption techniques. Results demonstrated that the biguanide was successfully immobilized on the HAp-γ-Fe 2 O 3 without damage to the morphology and structure of the HAp-γ-Fe 2 O 3 carrier. The so-prepared inorganic-organic hybrid nanocomposites exhibited a strong magnetic response and displayed better catalytic activities in the transesterification of soybean oil with methanol for the production of biodiesel. By using the methanol/oil molar ratio of 25:1 and catalyst loading of 3 wt%, the maximum oil conversion of 99.6% was achieved over the solid base catalyst at reflux of methanol after 3 h of reaction. Further, the solid catalyst could be recovered facilely by simple magnetic separation and maintains satisfactory catalytic activity after being recycled for five times.

Scientifically evaluating the level of low-carbon development in terms of theoretical and practical significance is extremely important to coal enterprise groups for implementing national energy-related systems. This assessment can assist in building institutional mechanisms that are conducive for the economic development of coal business cycle and energy conservation as well as promoting the healthy development of coal enterprises to realize coal scientific development and resource utilization. First, by adopting systematic analysis method, this study builds low-carbon development evaluation index system for coal enterprise groups. Second, to determine the weight serving as guideline and criteria of the index, analytic hierarchy process (AHP) is applied using integrated linear weighted sum method to evaluate the level of low-carbon development of coal enterprise groups. Evaluation is also performed by coal enterprise groups, and the process comprises field analysis and evaluation. Finally, industrial policies are proposed regarding the development of low-carbon coal conglomerate strategies and measures. This study aims mainly to guide the low-carbon development of coal enterprise groups, solve the problem of coal mining and the destruction of ecological environment, support the conservation of raw materials and various resources, and achieve the sustainable development of the coal industry.

During the Engineering Validation and Engineering Design Activities (EVEDA) phase (2007-2014) of the International Fusion Materials Irradiation Facility (IFMIF), an advanced engineering design of the High Flux Test Module (HFTM) has been developed with the objective to facilitate the controlled irradiation of steel samples in the high flux area directly behind the IFMIF neutron source. The development process addressed included manufacturing techniques, CAD, neutronic, thermal-hydraulic and mechanical anal- yses complemented by a series of validation activities. Validation included manufacturing of 1:1 parts and mockups, test of prototypes in the FLEX and HELOKA-LP helium loops of KIT for verification of the thermal and mechanical properties, and irradiation of specimen filled capsule prototypes in the BR2 test reactor. The prototyping activities were backed by several R&D studies addressing focused issues like han- dling of liquid NaK (as filling medium) and insertion of Small Specimen Test Technique (SSTT) specimens into the irradiation capsules. This paper provides an up-todate design description of the HFTM irradiation device, and reports on the achieved performance criteria related to the requirements. Results of the vali- dation activities are accounted for and the most important issues for further development are identified.

Purpose Autonomous mobile cleaning robots are widely used to clean solar panels because of their flexibility and high efficiency. However, gravity is a challenge for cleaning robots on inclined solar panels, and robots have problems such as high working power and short battery life. This paper aims to develop a following robot to improve the working time and efficiency of the cleaning robot. Design/methodology/approach The mechanical structure of the robot is designed so that it can carry a large-capacity battery and continuously power the cleaning robot. The robot determines its position and orientation relative to the edge of solar panel by using optoelectronic sensors. Based on the following distance, the robot changes its state between moving and waiting to ensure that supply cable will not drag. Findings Prototype following robot test results show that the following robot can stably follow the cleaning robot and supply continuous power to cleaning robot. The linear error of the following robot moving along the solar panel is less than 0.3 m, and the following distance between the robot and the cleaning robot is in 0.5–1.5 m. Practical implications The working time of cleaning robots and working efficiency is improved by using following robot, thereby reducing the labor intensity of workers and saving the labor costs of cleaning. Originality/value The design of the following robot is innovative. Following robot works with the existing cleaning robots to make up for shortcomings of the existing cleaning system. It provides a more feasible and practical solution for using robots to clean solar panels.

Voltage stability of power grid would be affected greatly by the connection of large-scale wind farms. Conventional continuous power flow method can not accurately simulate the system’s operation when wind farms are connected to power gird. A new continuous power flow method is proposed, considering auto-disconnection of large-scale wind farms. The step-size control segment is improved in this algorithm in order to simulate the operation characteristics of wind farm and determine the precise time when a certain wind farm is cut off.

Abstract Ammonia is a possible candidate as the fuel for solid oxide fuel cells (SOFCs). In this work, an anode-supported SOFC based on yttrium-stabled zircite (YSZ) thin-film electrolyte was fabricated by a simple dry-pressing process. Directly fueled by commercial liquefied ammonia, the single cell was tested at temperatures from 650 to 850 °C. The maximum power densities were 299 and 526 mW cm −2 at 750 and 850 °C, respectively, only slightly lower than that fueled by hydrogen. Analysis of open current voltages (OCVs) of the cell indicated the oxidation of ammonia within a SOFC is a two-stage process. Impedance spectra showed the cell fueled by ammonia had the same electrolyte resistances as that fueled by hydrogen, but a little larger interfacial polarization resistances. Further, the performances of the cell were essentially determined by the interfacial resistances under 750 °C.