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Differential evolution (DE) is a heuristic global search algorithm based on population. It has exhibited great adaptability in solving continuous-domain problems, but sometimes suffered from insufficient local search ability and being trapped in local optimum when dealing with complicated optimization problems. To solve these problems, an improved differential evolution algorithm with population diversity mechanism based on covariance matrix (CM-DE) is proposed. First, a new parameter adaptation strategy is used to adapt the control parameters, in which the scale factor F is updated according to the improved wavelet basis function in the early stage and Cauchy distribution in the later stage and the crossover rate C R is generated according to normal distribution. The diversity of population and convergence speed are improved by employing the method above. Second, the perturbation strategy is incorporated into crossover operator to enhance the search ability of DE. Finally, the covariance matrix of the population is constructed, where the variance in the covariance matrix is used as indicator to measure the similarity between individuals in the population in order to prevent the algorithm from falling into local optimum resulted by low population diversity. The CM-DE is compared with the state-of-art DE variants including LSHADE (Tanabe and Fukunaga, 2014), jSO [1] , LPalmDE [2] , PaDE [3] and LSHADE-cnEpSin [4] under 88 test functions from CEC2013 [5] , CEC2014 [6] and CEC2017 (Wu et al., 2017) test suites. From the experiment results, it is obvious that among 30 benchmark functions from CEC2017 on 50D optimization, the CM-DE algorithm has 22, 20, 24, 23, 28 better performances comparing with LSHADE, jSO, LPalmDE, PaDE, and LSHADE-cnEpsin. For CEC2017 on 30D optimization, the proposed algorithm secures better performance on 19 out of 30 benchmark functions in terms of convergence speed. In addition, a real-world application is also used to verify the feasibility of the proposed algorithm. The experiment results validate the highly competitive performance in terms of solution accuracy and convergence speed. • A new parameter adaptation mechanism is proposed to adjust the scale factor F and crossover rate CR. The experiment results show that the new parameter adaptation mechanism improves the exploration ability of the proposed algorithm. • In order to prevent prematureness, a perturbation strategy is incorporated into the crossover strategy, which firstly constructs a new crossover operation between the mutant vector and target vector based on the t-distribution probability density function; secondly, the information of the outstanding individuals is used to guide the search direction. • By calculating the covariance matrix of the population, the variance in the covariance matrix is used to determine the diversity of individuals in the current population. In the iterative process, a counter is set to count the number of variances in each dimension that is less than the set condition. When the counter meets the predefined threshold, a simple competition mechanism is used to increase the diversity of the population by perturbing the t-distribution or the Cauchy distribution for all stagnant individuals. [ABSTRACT FROM AUTHOR]

Benefit distribution of hybrid renewable energy system is related to the sustainability of its operation, and the distribution method of adjusting the share of power generation may affect its low-carbon effect. In order to investigate the method of benefit distribution that does not hinder renewable energy consumption, a two-stage dispatching model for hybrid wind-photovoltaic-thermal power system is established, and the ancillary service market is introduced to coordinate optimization. The first stage model aims at the equilibrium of power generation profits of power producers. Then in the second stage, the equilibrium profits are transformed into constraint, and the day-ahead dispatching model is constructed with the objective of minimizing comprehensive power purchase costs and maximizing renewable energy utilization after considering the balance of economy and social responsibility. The case study results are proved that the ancillary service market combined with profits guarantee constraint can optimize the benefit distribution of power producers without affecting the consumption of renewable energy as much as possible. The proposed strategy is more suitable for the areas where the power supply structure is still dominated by thermal power. Changes in dispatching results under different ancillary service prices are discussed, and management recommendations are put forward in the end. [ABSTRACT FROM AUTHOR]

The existing literature demonstrates that the multi-energy combined power-dispatching system is crucial for resolving the mismatch between the installed capacity and the power generation through renewable energy. However, our knowledge of the impact mechanism of climate policies on this system is still limited. To address this gap, cost-accounting models that consider price fluctuation based on carbon emissions trading and renewable portfolio standards in China are proposed and applied to the integrated wind–photovoltaic–thermal power-dispatching system in Xinjiang. The scenarios analysis showed that in terms of reducing emissions, carbon emissions trading is more effective in cases with a high installed proportion of renewable power, whereas renewable portfolio standards are the opposite, as they are better in two cases in terms of energy saving. The sensitivity analysis indicates that the effect of renewable portfolio standards on the penetration rate of renewable power is constant. There is some potential for the design optimization of these two policies in China, and the characteristics of the power structure should be considered. These results can help the dispatching department in evaluating the impact of carbon emissions trading and renewable portfolio standards to optimize the dispatching strategy and provide directions for policy makers to improve the design. • Explore the interaction of carbon emissions trading and renewable portfolio standards. • Build costs accounting models for climate policies based on fluctuating price. • Analyze the dual effect of the policies in different hybrid power dispatching systems. • Propose policy recommendations to promote the application of policies in China. [ABSTRACT FROM AUTHOR]

• Establishing a dispatch model for integrated wind-photovoltaic-thermal power system. • Dynamic carbon emissions trading system applications in power market is considered. • Comprehensive benefits of five dispatch modes are compared. • Optimal mode was investigated using case study transmission project (China). To transmit renewable energy on-grid over a large-scale power transmission system, an optimal dispatch model for a multi-energy power generation system is essential. This paper proposed a multi-energy hybrid power dispatch model for an integrated wind-photovoltaic-thermal power system. We consider five different dispatch modes and a dynamic carbon emissions trading system. Design of the modes was based on dispatch objectives. Power dispatch was based on interactive planning of power units and carbon emissions trading. To compare the modes, a comprehensive benefit evaluation index for dispatching is established. The proposed model was applied to supporting power supply system of the Tianzhong ultra-high voltage direct-current transmission project in Xinjiang, China. The results confirmed that high-efficiency mode is an optimal dispatch mode for the power transmission system, and has the most significant benefits. The impact on the optimal mode of the renewable energy penetration rate and carbon emissions trading system, as the two main factors, were further investigated. It was found that high-efficiency mode could maximize existing renewable energy generation and reduce coal consumption and carbon emission used for power generation and has a positive effect on carbon reduction. However, initial quotas need to be controlled more strictly than prices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Atomic layer deposition (ALD) used to fabricate metal–organic framework (MOF) materials is reviewed. • Seven combined methods using ALD technology and MOF synthesis are discussed. • Applications of MOF materials related to ALD technology are summarized. • New directions and perspectives for ALD-related MOF materials are provided. Atomic layer deposition (ALD) technology is an effective nanofabrication method used for various nanomaterials and thin films at the atomic level. Metal-organic framework (MOF) materials have a high porosity and specific surface area, and have been widely used in the fields of adsorption, separation, catalysis, sensors and devices. When ALD meets MOFs, some new combination methods can appear. In this review, the advances in MOFs synthesis related to ALD are summarized. These new synthetic methods of MOFs can be divided into seven categories: MOF gas-phase growth via ALD/MLD, MOF solvothermal growth on ALD metal oxide, MOF solvothermal growth and assembled on ALD metal oxide, MOF liquid-phase epitaxy growth on ALD metal oxide, MOF conversion from ALD metal oxide, MOF conversion via hydroxyl double salt from ALD metal oxide and MOF modification via ALD. Meanwhile, the upscaling applications of these ALD-related MOFs, such as in adsorption, separation, catalysis and energy, have further been reviewed. The perspectives of ALD based MOFs have also been provided. Such efforts are expected to provide guidance for developing new synthetic methods of MOFs related to ALD technology and thereby lead to new applications of ALD-related MOFs. [ABSTRACT FROM AUTHOR]

Substituting renewable energy for coal power under the carbon neutrality goal is an inevitable path for power system transformation, while the high share of renewable energy leads to a rapid rise in system flexibility demand. Currently, coal-fired power is still one of the most economical and reliable large-scale flexible resources in China. Therefore, the issue of how to mitigate the conflict between cleanliness and flexibility for coal-fired power is urgent to be solved. Accordingly, this paper established an optimization framework for the retirement and technology adoption of coal-fired power units with high spatial-temporal resolution, and the regional carbon emission budget is estimated from a top-down perspective. Secondly, a dynamic carbon quota allocation method considering technological innovation and adoption is proposed. The carbon trading cost of the units is evaluated from a bottom-up perspective, to realize the interaction between the obligatory policy constraints of the top-level target and the flexible incentives of the market mechanism. Finally, the empirical analysis was conducted in the Beijing-Tianjin-Hebei region of China. The optimal solution achieved by proposed method results in a substantial 27% reduction in total costs while keeping the increase in carbon emissions below 3%. By analyzing the dynamic evolution path of coal and the scale of diffusion of multi-type technologies, the differences in the roles coal power assuming at various stages of decarbonization are discussed. The robustness of the model and the validity of the proposed method were verified by comparing the dynamic/static carbon quota allocation. Overall, this study provides an effective optimization model for investigating the low-carbon technology adoption timing for coal power in Beijing-Tianjin-Hebei region, and offers valuable insights for other coal-dominated emerging economies seeking for power system transformation roadmap in the forthcoming net-zero carbon age. • A decision-making optimization model of CCPs low-carbon technology is proposed. • A dynamic CET system with upper-lower layer interaction is introduced. • The proposed dynamic CET system results in 27% reduction in total costs. • The high-resolution data of coal power in Beijing-Tianjin-Hebei region are used. • The strategy to solve the conflict between cleanliness and flexibility is given. [ABSTRACT FROM AUTHOR]

At present, vigorously developing wind power, photovoltaic and other renewable energy has become one of the effective ways to deal with carbon dioxide emissions and energy supply and demand gap. Bringing renewable energy into the optimal configuration of power supply structure and reducing carbon emissions at the root will help promote the construction of clean, low-carbon, safe and efficient modern energy system. Therefore, starting from the theory of low-carbon economy, based on the traditional power planning model, this paper considers various uncertainties, introduces social welfare theory, and proposes the optimization scheme of thermal-solar-wind power system. The model is then applied to Southern Xinjiang supporting power project to study the investment behavior of low-carbon power, and the optimal low-carbon power decision-making behavior considering social benefits based on welfare is obtained. The results show that the proposed optimal configuration scheme of hybrid power can achieve the equilibrium between economic and social benefits, improve energy utilization efficiency and provide decision-making reference for policy makers. • A multi-objective power planning optimization model considering social benefits and economic cost was proposed. • Multi-uncertainty and interactions among multiple random variables were examined. • Solutions of various scenarios and different credibility levels were analyzed. • The optimization model can achieve better economic benefits while improving energy efficiency. [ABSTRACT FROM AUTHOR]

The objective of the traditional dispatching optimization model is to find the most economical scheduling mode, while ignoring the efficient use of renewable energy. To properly arrange thermal power generation and renewable energy power generation, this paper constructs an optimization model of the combined wind–photovoltaic (PV)–thermal dispatching system under a carbon emissions trading (CET) mechanism. The contribution of this paper is twofold. First, a dispatching optimization model is proposed, which not only considers the total cost but also takes into account the impact of the renewable energy spillage rate on the dispatching system. As a factor affecting renewable energy consumption, a carbon emissions trading mechanism has also been introduced into the dispatching system. The second contribution is to develop a model for predicting the output of renewable energy generation. Then, the optimization model is applied to the auxiliary power dispatching system of the Tianzhong ±800 kV UHV DC transmission channel in Xinjiang. The results indicate that under a carbon emissions trading mechanism, thermal power generation will be limited by the carbon emissions cost, thereby reducing the total cost of the system. Optimizing the spillage rate increases the share of renewable energy in the dispatching system, resulting in a 3.5% reduction in the actual spillage rate. The proposed model alleviates the serious problem of electricity being abandoned in the existing scheduling mode and helps to realize economical low-carbon dispatching of the power system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Aluminum precursors bearing alkyl, hydrogen, halide, alkoxy and amino ligands were designed and investigated for Al 2 S 3 atomic layer deposition (ALD). • Amino ligands of aluminum precursors have the self-catalytic role and accelerate the reaction of Al 2 S 3 ALD. • Unlike the concerted elimination of the first amino ligand of aluminum precursors, the elimination of the second amino ligands on the surface is a stepwise process. As a unique nanotechnology, atomic layer deposition (ALD) has been extensively used for the preparation of various nanomaterials. An effective precursor is a prerequisite to ALD success. Herein, we designed and introduced alkyl, hydrogen, halide, alkoxy and amino ligands to aluminum precursors and investigated reaction mechanisms of Al 2 S 3 ALD through density functional calculations. The results show that aluminum precursors with alkyl, hydrogen and halide ligands are kinetically disadvantageous and with alkoxy groups are thermodynamically unfavorable and Al precursors bearing amino groups are thermodynamically and kinetically favorable for Al 2 S 3 ALD. The activity of trimethylaluminum (TMA) on the sulfydrylated surface is lower than that on the hydroxylated surface. The reaction barriers of the aluminum precursors bearing amino ligands on the sulfydrylated surface are obviously lower than that of TMA. Similarly, the barrier of the H 2 S reaction on the aminated surface is much lower than that on the methylated surface. All of the amino groups have a self-catalytic role and accelerate the reaction of Al 2 S 3 ALD. These insights into aluminum precursors bearing amino ligands for Al 2 S 3 ALD can provide theoretical guidance for the discovery of new precursors and the ALD preparation of other aluminum and sulfur compounds. [ABSTRACT FROM AUTHOR]

A series of liquid hydrocarbons (alkylbenzenes, alkanes, and alkenes) were obtained by a synergetic deoxy reforming (SDR) process of cellulose and linoleic acid methyl ester (LAME) at 350 °C and 4–6 MPa in a closed system without external source of hydrogen. The liquid product was obtained with a yield of 15 wt% at a LAME/cellulose ratio of 0.2. In contrast, the direct deoxy reforming of cellulose produces oil that contains plenty of phenols and oxygen-containing compounds. Due to the insufficiency of water employed (30 wt%), a radical reaction pathway was proposed. Quantum chemical calculations indicate that the radicals from LAME interfere with the reactions of the intermediate products from cellulose, being responsible for the removal of phenols and the formation of hydrocarbons. The SDR process offers an embryonic insight in an alternative technique for preparation of hydrocarbon fuels. [ABSTRACT FROM AUTHOR]

Microaeration (dosing small quantities of air or oxygen) is an effective approach to facilitate anaerobic digestion (AD) process and has gained increased attention in recent years. The underlying mechanisms of the facilitation effect of microaeration on AD process were reviewed in terms of accelerating hydrolysis, scavenging hydrogen sulfide, and affecting microbial diversity. Process parameters and control strategies were summarized to reveal considerable factors in implementing microaeration-based AD process. In addition, current applications, including lab-, pilot- and full-scale level cases, were summarized to provide guidance for further improvement in large-scale applications. The challenges and future perspectives were also highlighted to promote the development of AD process associated with microaeration. Unlabelled Image • Microaeration in AD system facilitates processing efficiency and system stability. • The presence of oxygen leads to a high yield of facultative acidogens and excreted enzymes. • Microaeration rate is the foremost parameter connected to the AD performance. • The combination of aeration and AD has been applied in full-scale implementation successfully. [ABSTRACT FROM AUTHOR]