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Development of antifouling membrane to separate oil–water emulsions by low energy consumption approach is an urgent demand. Herein, we report for the first time a grass-like structured composite membrane from array growth of nickel cobalt layered double hydroxide (NiCo-LDH) onto the polydopamine modified polyvinylidene fluoride (PVDF) membrane surface via simple hydrothermal strategy. The surface morphology of as-prepared membrane has controlled by hydrothermal time. The obtained NiCo-LDH/PVDF composite membrane exhibits superhydrophilicity/underwater superoleophobicity for separating both surfactant-free and surfactant-stabilized oil–water emulsions by capillary effect under the driving of gravity. Moreover, with the advantages of antifouling performance, the membrane displays outstanding cyclic performance for long-term application, which is promising for practical oily wastewater treatment.

The worldwide oily wastewater is one of the most serious environmental problems. The current membrane separation technology has received an increasing attention toward oil/water emulsions separation. Here, a high-efficient superhydrophilic and underwater superoleophobic membrane with improved antifouling property was fabricated based on modified halloysite nanotubes anchored at polyvinylidene fluoride/graphene oxide membrane surface via polydopamine adhesive. The composite membrane exhibited an outstanding antifouling performance as well as high pure water flux (1500 L m−2 h−1) under gravity driven. Besides, the as-prepared composite membrane could separate both surfactant-free and surfactant-stabilized oil/water emulsions with separation efficiency up to 99.5%. Moreover, this facile preparation and eco-friendly composite membrane provides promising practical application toward environmental remediation.

Here we have successfully fabricated the superhydrophilic and underwater superoleophobic PVDF/Al2O3/PAM membranes by constructed "needle-shaped" PAM on the PVDF/Al2O3 hybrid membranes surface through ATRP technology. The modified membranes were characterized by the Fourier-transform infrared (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS) that the AIP has been hydrolyzed to Al2O3 and AM has successfully polymerized on the membrane surface. When the PVDF/Al2O3/PAM membranes were applied in oil/water emulsion separation, the separation efficiencies were more than 99.1% and the maximum flux of the emulsion was 5874L/ m/2/h/bar. In the anti-fouling performance experiment, the flux recovery ration (FRR) of the PVDF/Al2O3/PAM membranes could still reach 83.46% after eight cycles. Therefore, the PVDF/Al2O3/PAM membranes have high separation efficiency and high flux performance for separating oil-water emulsions, and steadily anti-oil performance is suitable for practical applications.

Lithium resources are attractive for different applications because of their specific properties. Therefore, it is more significant to find a cost-effective and environment-friendly method to selective adsorption and recovery of Li+. In this work, a renewable and easy degradable CA/CS hybrid membrane was modified with polydopamine as adhesion layer to anchored TiO2. The simple imprinting process could be realized by hydrolysis polymerization. The adsorption process followed Langmuir isotherm model and pseudo-second-order kinetic equation were researched in detail. The results displayed the maximum adsorption capacity is 20.08 mg g−1 for Li+. The selectivity factors of Li+ to Na+, K+, Mg2+ and Ca2+ are 1.78, 2.43, 2.60 and 3.61, respectively, which mainly attributed to imprinting effect. The LIICMs also exhibited the superior reusability and durability. Thus, the LIICMs provide a powerful tool for selective separation and recovery of Li+ from mixed solutions.

A new PVDF@pDA@SiO2 nanocomposite membrane was fabricated by virtue of the surface modification of polydopamine anchored SiO2 on PVDF membrane through a facile and eco-friendly preparation process. It possessed the superior superhydrophilicity/underwater superoleophobicity properties and presented the outstanding antifouling oil performance and high-efficiency separation ability for oil-water emulsions, which mainly resulted from its special surface micro-nano structure and pore induced capillarity phenomenon. Furthermore, the PVDF@pDA@SiO2 nanocomposite membrane also exhibited the splendid separation performance, regeneration ability and universality for various oil-water emulsions separation. In addition, the oil-water emulsion separation mechanism was discussed in depth. This work might provide a significant guidance for large-scale production and application of this nanocomposite membrane in the fields of wastewater recovery and drinking water treatment.

In China, the electricity industry is currently undergoing significant transform towards deregulation and competition. The long-term generation investment in electricity market has received more attention. A multi-level generation planning model in electricity market is proposed in this paper. The upper level problem of this model is the non-cooperative game equilibrium problem of generation investment decision, and the middle level problem is the profit maximization problem of multi-stage generation investment for individual generation company. Considering the fluctuation of system load, the lower level problem is a multi-scenario and multi-period market clearing problem. In view of the complexity of the model, this paper proposes a nested genetic algorithm to solve it. First, considering the integer programming characteristics of generation planning, a two-level nested genetic algorithm is used to deal with the upper level game problem and the middle level investment profit maximization problem. Then, linear programming is used to solve the lower level multi-scenario multi-period market clearing problem. The case results of graver-6 and IEEE 118 bus system validate the proposed model and the algorithms.

When equipped with thermal energy storage (TES), concentrating solar power (CSP) plants can provide both energy benefit and flexibility benefit for power systems. It is capable of shifting generation to periods with insufficient solar irradiation, providing ancillary services, and supplying firm capacity at peak load periods. In this paper, we focus on the operation behavior of CSP when simultaneously participating in three types of electricity market—energy market, ancillary service (AS) market, and capacity market. The results of case study show the quantified flexibility benefit of CSP in electricity markets. The optimal configuration of CSP in terms of TES and solar multiple (SM) is also analyzed.

The authors describe a fluorescence based assay for determination of the macrolid antibiotic erythromycin (ERY). It is based in the use of fluorescent gold nanoclusters (AuNCs) coated first with silica (to obtain AuNC@SiO2) and then with a molecularly imprinted polymer (MIP). The MIP was synthesized from 3-aminopropyltriethoxysilane as the functional monomer, ERY as the template, and tetraethoxysilane as the cross-linker via a sol-gel process that leads to surface imprinting. By using this method, the strong fluorescence of AuNCs was maintained in the resultant MIPs. After optimization of the experimental conditions, the signal (measured at excitation/emission wavelengths of 396/585 nm) decreases linearly with increasing concentration of ERY in the 0.1 to 11.9 μM ERY concentration range. The limit of detection is 12 nM, and the imprinting factor is 4.0. The method was successfuly applied to the determination of ERY in spiked human urine and saliva.

Reinforced concrete beams tend to elongate after flexural cracking and yielding; however, the elongation is restrained by the surrounding structural components in a RC moment frame. Experim...

With the access of large-scale new energy sources, the impact of multi-mode power supplies on the operation mode is gradually increasing. A multi-scenario model for grid planning under large-scale new energy access is established in this paper. In the general idea of the model, the cluster attribute variables that can describe the grid planning are first filtered from the large-scale multi-scenario data set. Then, the dimensions of the generator node and the load node of the characteristic variables in the multi-scenario data set are reduced using the principal component analysis method; taking each moment in the multi-scenario data set as a scenario sample and the active power of the generating set and the load node after the dimension reduction as attributes, the improved K-means algorithm is used for cluster analysis to select representative real scenarios from the clustering results as typical scenarios; the extracted typical scenarios are evaluated and analyzed according to the results of the power flow calculation.

The transmission pricing mechanism of “permitted cost + reasonable benefits” and the marketing measures such as electricity transaction will have a profound influence on the existing grid planning model and method. How to build a scientific and reasonable economic evaluation index system and method of the power grid planning scheme has been one of the hot issues. This paper builds a grid planning scheme economic evaluation index system and method that is suitable for the reform of China's transmission and distribution price. Firstly, combining with the actual situation of the power market in a province of our country, analyzing the influence mechanism and mode of the transmission cost control mode factors on power grid investment and power grid planning; on this basis, a multi-dimensional economic evaluation index system for power grid planning that comprehensively considers asset utilization, market contribution, and supervision objective is constructed; Secondly, an improved comprehensive evaluation model based on entropy weight method is proposed. Finally, the calculation and analysis of the examples are built on the actual conditions of the province's electricity market and grid planning data. The results demonstrate that the method is effective.

This paper presents a new approach for solving the multi-year co-optimized generation and transmission expansion planning problem with renewable energy resources in geographic information systems (GIS). The proposed optimization model is to determine when (which year), where (which cell), and what (which type) generators and transmission lines will be built for minimizing the sum of investment costs, operation costs (including energy and emission costs), and load shedding costs during the planning horizon. Prevailing constraints include power balance requirements, branch limits, power limits of generators, and construction limits of cells. A two-step approach to combine Dijkstra's algorithm and mixed-integer linear programming (MILP) is introduced for solving the large-scale optimization problem. The effectiveness of the proposed approach is validated by numerical case studies on a 9-bus system.

Development of superhydrophilic, stable and cost-effective composite membranes for efficient oil-water emulsion separation is highly desirable. Herein, an irregular rod-like composite membrane was prepared through 3-aminopropyltriethoxysilane (APTES) modification, followed by acrylamide polymerization with atomic transfer radical polymerization (ATRP). The as-prepared membrane exhibits superhydrophilicity/underwater superoleophobicity due to its irregular rod-like structure and pores-induced capillary actions. The composite membrane has demonstrated sufficient stability in acidic, alkaline and salty environments due to the polymerization of acrylamide. Moreover, the as-prepared composite membrane has effectively separated various oil-water emulsions and demonstrated high permeation and superior flux recovery. The present work demonstrates that the ATRP-assisted composite membrane is a promising material in a wide range of applications, such as industrial wastewater recovery and drinking water treatment.

This paper proposes a multi-objective optimal planning model of access location and access capacity for large-scale integrated wind power generation considering the mutual restriction between the planning of large-scale wind power plants and the planning of power system network. In this model, the power flow equilibrium degree, investment costs and active network loss are taken as the optimization goals. The improved differential evolution (IDE) algorithm is applied to calculate the Pareto optimal solution set of wind power’s access planning. With the solution results described by the Pareto pattern, all the alternative solutions are then ranked based on the entropy weight method and the final compromised solution is selected by the method of technique for order preference by similarity to ideal (TOPSIS). And the proposed optimal planning model is tested based on a practical planning need of large-scale integrated wind power generation in an actual power grid of China in 2020. The simulation results show that applied with the proposed optimization model and matching algorithm, the planning scheme of large-scale wind power’s access location and access capacity under complex and practical power system circumstances has been successfully optimized.