Research on Anti-Fluctuation Control of Winding Tension System Based on Feedforward Compensation

In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tension output,this paper proposed a tension fluctuation rejection strategy based on feedforward compensation.In addition to the bias harmonic curve of the unknown state,the tension fluctuation also contains the influence of bounded noise.A tension fluctuation observer(TFO)is designed to cancel the uncertain periodic signal,in which the frequency generator is used to estimate the critical parameter information.Then,the fluctuation signal is reconstructed by a third-order auxiliary filter.The estimated signal feedforward compensates for the actual tension fluctuation.Furthermore,a time-varying parameters fractional-order PID controller(TPFOPID)is realized to attenuate the bounded noise in the fluctuation.Finally,TPFOPID is enhanced by TFO and applied to control a tension control system considering multi-source disturbances.The stability of the method is analyzed by using the Lyapunov theorem.Finally,numerical simulations verify that the proposed scheme improves the tracking ability and robustness of the system in response to tension fluctuations.

Analysis of the Clean Development Mechanism Considering the Environmental Co-benefits of Reducing Air Pollutants in China

An electricity generation planning model of the six major Chinese power grids was developed based on the General Algebraic Modeling System to evaluate and analyze the CDM （clean development mechanism）, including consideration of the environmental co-benefits of reductions in air pollutants （SO~, NO~ and particulate matter） achieved by advanced electricity generation technologies incorporating CCS （carbon capture and storage）. An objective function was developed that included revenue from sales of electric power, total system cost, the cost of CO2 transport and storage, and emissions reduction co-benefits for SOx, NO~, and particulate matter. The objective function was minimized using an optimization model. We also developed a method for evaluating and analyzing the potential for transferring advanced power generation technologies into the Chinese power system through the CDM. We found that： （1） thermal power generation is predominant in the Chinese electricity system and will remain so for a long time; （2） advanced thermal plants are being installed as a result of the CDM, which contribute to decreasing emissions of CO2 and other air pollutants; and （3） CCS projects have significant potential to reduce substantial and sustained CO2 emissions from the Chinese power and industrial sectors.

A topology optimization for finite 1D phononic structures with objective function involving tangential derivative quantities using TDBIE

The paper proposes a topology optimization method for 1D phononic structures to minimize the tangential component of particle velocity at the objective boundary.The tangential derivative of the boundary integral equation(TDBIE)is employed for the evaluation of the objective function involves the tangential derivative quantities.The topological derivative is derived through the adjoint method and the Neumann boundary condition of the adjoint field is obtained using the TDBIE.The average topological derivative which is obtained by calculating the average value of the topological derivative in each layer of design domains,is employed for the updating of the level set function.Numerical implementations demonstrate the proposed method is effective for the design of the 1D phononic crystals with the objective function involving tangential derivative quantities.

Recent advances of amorphous-phase-engineered metal-based catalysts for boosted electrocatalysis

Amorphous metal-based catalysts(AMCs)have sparked intense research interests in the field of electrocatalysis elicited by their hallmark features such as unlimited volume and morphology,manipulated electronic structures,enriched defects,and unsaturated surface atom coordination.Nevertheless,the manipulation of the amorphous phase in metal-based catalysts is so far impractical,and thus their electrocatalytic mechanism yet remains ambiguous.In this review,the latest advances in AMCs are systematically reviewed,covering amorphous-phase engineering strategy,structure manipulation,and amorphization of various material categories for electrocatalysis.Specifically,a series of applications of AMCs in electrocatalysis for the oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),and oxygen evolution reaction(OER)are summarized based on the classification criteria of substances.Finally,we put forward current challenges that have not yet been clarified in the field of AMCs,and propose possible solutions,particularly from the perspective of the evolution of electron microscopy.It is expected to promote the understanding of the amorphization-catalysis relationship and provide a guideline for designing high-performance electrocatalysts.