The current electromagnetic environment brings a growing demand for efficient microwave absorption(MA)materials.Ti_(3)C_(2)T_(x)MXene,one of the 2D transition-metal carbides,is considered to be a promising MA material...The current electromagnetic environment brings a growing demand for efficient microwave absorption(MA)materials.Ti_(3)C_(2)T_(x)MXene,one of the 2D transition-metal carbides,is considered to be a promising MA material owing to its superior dielectric properties and structural processability.In order to further improve the MA performance and environmental adaptability of Ti_(3)C_(2)T_(x)MXene,Ti_(3)C_(2)T_(x)MXene-based MA materials enhanced by composition and structure design have been extensively studied and the regu-lation ideas for its MA properties can be outlined as component optimization and structure manipulation strategies based on the microwave absorption mechanism.Herein,we briefly introduced the microwave absorption mechanism and focused on the design strategies of Ti_(3)C_(2)T_(x)MXene-based MA materials based on recent advances.In addition,the prospects of Ti_(3)C_(2)T_(x)MXene-based MA materials were also discussed.展开更多
Fiber-reinforced composite materials have excellent specific stiffness,specific strength,and other properties,and have been increasingly widely used in the field of advanced structures.However,the design space dimensi...Fiber-reinforced composite materials have excellent specific stiffness,specific strength,and other properties,and have been increasingly widely used in the field of advanced structures.However,the design space dimensions of fiber-reinforced composite materials will expand explosively,bringing challenges to the efficient analysis and optimal design of structures.In this paper,the authors propose an explicit topology optimization method based on the moving morphable components for designing the fiber-reinforced material.We constrain the intersection area between components to guarantee the independence of each component and avoid the situation that one component is cut by other components.Adding the fiber orientation angle as a design variable,the method can optimize the structural layout and the fiber orientation angle concurrently under the given number of fiber layers and layer thickness.We use two classical examples to verify the feasibility and accuracy of the proposed method.The optimized results are in good agreement with the designs obtained by the 99-line code.The authors also popularize the proposed method to engineering structure.The results manifest that the proposed method has great value in engineering application.展开更多
Based on improved multi-objective particle swarm optimization（MOPSO） algorithm with principal component analysis（PCA） methodology, an efficient high-dimension multiobjective optimization method is proposed, which,...Based on improved multi-objective particle swarm optimization（MOPSO） algorithm with principal component analysis（PCA） methodology, an efficient high-dimension multiobjective optimization method is proposed, which, as the purpose of this paper, aims to improve the convergence of Pareto front in multi-objective optimization design. The mathematical efficiency,the physical reasonableness and the reliability in dealing with redundant objectives of PCA are verified by typical DTLZ5 test function and multi-objective correlation analysis of supercritical airfoil,and the proposed method is integrated into aircraft multi-disciplinary design（AMDEsign） platform, which contains aerodynamics, stealth and structure weight analysis and optimization module.Then the proposed method is used for the multi-point integrated aerodynamic optimization of a wide-body passenger aircraft, in which the redundant objectives identified by PCA are transformed to optimization constraints, and several design methods are compared. The design results illustrate that the strategy used in this paper is sufficient and multi-point design requirements of the passenger aircraft are reached. The visualization level of non-dominant Pareto set is improved by effectively reducing the dimension without losing the primary feature of the problem.展开更多
High enzymatic activity is required for laccase applications.Central composite design （CCD）-based response surface methodology （RSM） can effectively increase the enzymatic activity of Pleurotus ostreatus P40 in li...High enzymatic activity is required for laccase applications.Central composite design （CCD）-based response surface methodology （RSM） can effectively increase the enzymatic activity of Pleurotus ostreatus P40 in liquid substrate fermentation.Initial screening of the nutritional components was performed using a Plackett-Burman design.The variables,namely,bran,bagasse,Tween 80,and yeast extract,were found to have statistically significant effects on laccase activity.These variables were further optimized using CCD-based RSM.Optimal concentrations for the maximum laccase activity were 8.144 2 g/L bran,50 g/L bagasse,0.424 1 mL/L Tween 80,and 2.832 5 g/L yeast extract.Under optimized conditions,the maximum measured laccase activity reached 96 480 U/L,which was close to the predicted value （104 830 U/L） by RSM.Therefore,RSM can be used to optimize culture components for laccase activity from Pieurotus ostreatus P40.展开更多
Panicle swarm optimization （PSO） is an optimization algorithm based on the swarm intelligent principle. In this paper the modified PSO is applied to a kernel principal component analysis （ KPCA ） for an optimal ke...Panicle swarm optimization （PSO） is an optimization algorithm based on the swarm intelligent principle. In this paper the modified PSO is applied to a kernel principal component analysis （ KPCA ） for an optimal kernel function parameter. We first comprehensively considered within-class scatter and between-class scatter of the sample features. Then, the fitness function of an optimized kernel function parameter is constructed, and the particle swarm optimization algorithm with adaptive acceleration （CPSO） is applied to optimizing it. It is used for gearbox condi- tion recognition, and the result is compared with the recognized results based on principal component analysis （PCA）. The results show that KPCA optimized by CPSO can effectively recognize fault conditions of the gearbox by reducing bind set-up of the kernel function parameter, and its results of fault recognition outperform those of PCA. We draw the conclusion that KPCA based on CPSO has an advantage in nonlinear feature extraction of mechanical failure, and is helpful for fault condition recognition of complicated machines.展开更多
As the turbine inlet total temperature of the turbofan engine continues to increase,it is key to ensuring the long-term reliability of aeroengines that the components matching effectively to achieve the expected avera...As the turbine inlet total temperature of the turbofan engine continues to increase,it is key to ensuring the long-term reliability of aeroengines that the components matching effectively to achieve the expected average gas temperature.However,over temperature in turbine inlet is a common challenge in advanced engine development.To solve this problem,this paper proposes a new idea of a component matching optimization method to control average gas temperature.This method couples the optimization method with the adaptive performance model,which is built using accurate component characteristics and internal/external bypass mass flow rate within the engine test.Experiment methods of component characteristics measurement in different operating status under the condition of the whole engine are also developed,which capture the entire characteristics maps rather than the mini maps along the operating line.It also establishes calculation method of the core mass flow rate based on the critical characteristics of the high-pressure turbine.Tests have shown that by applying the component matching optimization method,the turbine inlet average gas temperature of a high-performance twin-spool mixed turbofan engine was reduced by 50 Ke60 K under the same thrust,ensuring fulfillment of the performance indexes.展开更多
The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base edit...The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.展开更多
Objective: to analyze the influence of optimized recruitment mode of component blood donation on blood donor retention and blood safety. Methods: 100 randomly selected blood donors recruited from machine collected com...Objective: to analyze the influence of optimized recruitment mode of component blood donation on blood donor retention and blood safety. Methods: 100 randomly selected blood donors recruited from machine collected components were studied. The medical observation began in March 2021 and ended in March 2022. They were divided into the control group (50 cases, conventional blood donation recruitment mode) and the observation group (50 cases, optimized blood donation recruitment mode) by double blind method, and the effects of the two groups were compared. Results: the qualified rate of primary screening test and the reaction rate of blood test in the observation group were better than those in the control group (P < 0.05). Conclusion: the optimized recruitment model of component blood donation can increase the number of blood donors and ensure the safety of blood supply, which is worthy of promotion.展开更多
A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has ...A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has robustness to uncertainty of frequency, which makes it practical in engineering. Several time optimal and time-fuel optimal control strategies are designed for a kind of single flexible link. Simulation results validate the feasibility of our method.展开更多
An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis （PCA） and multiple discriminant analysis （MDA） is presented in this paper. In this framework, features...An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis （PCA） and multiple discriminant analysis （MDA） is presented in this paper. In this framework, features are extracted from the optimal random image components using greedy approach. These feature vectors are then projected to subspaces for dimensionality reduction which is used for solving linear problems. The design of Gabor filters, PCA and MDA are crucial processes used for facial feature extraction. The FERET, ORL and YALE face databases are used to generate the results. Experiments show that optimal random image component selection （ORICS） plus MDA outperforms ORICS and subspace projection approach such as ORICS plus PCA. Our method achieves 96.25%, 99.44% and 100% recognition accuracy on the FERET, ORL and YALE databases for 30% training respectively. This is a considerably improved performance compared with other standard methodologies described in the literature.展开更多
基金financially supported by the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Inno-vation Team of Structural-Functional Polymer Composites),and the Special Financial of Shandong Province(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Mate-rials and Construction of Shandong Provincial Talent Teams(No.37000022P990304116449)).
文摘The current electromagnetic environment brings a growing demand for efficient microwave absorption(MA)materials.Ti_(3)C_(2)T_(x)MXene,one of the 2D transition-metal carbides,is considered to be a promising MA material owing to its superior dielectric properties and structural processability.In order to further improve the MA performance and environmental adaptability of Ti_(3)C_(2)T_(x)MXene,Ti_(3)C_(2)T_(x)MXene-based MA materials enhanced by composition and structure design have been extensively studied and the regu-lation ideas for its MA properties can be outlined as component optimization and structure manipulation strategies based on the microwave absorption mechanism.Herein,we briefly introduced the microwave absorption mechanism and focused on the design strategies of Ti_(3)C_(2)T_(x)MXene-based MA materials based on recent advances.In addition,the prospects of Ti_(3)C_(2)T_(x)MXene-based MA materials were also discussed.
基金supports from the National Key Research and Development Plan(2020YFB1709401)the National Natural Science Foundation of China(11872138,11702048),Dalian Young TechStar Project(2019RQ045,2019RQ069)and the Scientific Research Fund Project of Education Department of Liaoning Province(JDL2020021).
文摘Fiber-reinforced composite materials have excellent specific stiffness,specific strength,and other properties,and have been increasingly widely used in the field of advanced structures.However,the design space dimensions of fiber-reinforced composite materials will expand explosively,bringing challenges to the efficient analysis and optimal design of structures.In this paper,the authors propose an explicit topology optimization method based on the moving morphable components for designing the fiber-reinforced material.We constrain the intersection area between components to guarantee the independence of each component and avoid the situation that one component is cut by other components.Adding the fiber orientation angle as a design variable,the method can optimize the structural layout and the fiber orientation angle concurrently under the given number of fiber layers and layer thickness.We use two classical examples to verify the feasibility and accuracy of the proposed method.The optimized results are in good agreement with the designs obtained by the 99-line code.The authors also popularize the proposed method to engineering structure.The results manifest that the proposed method has great value in engineering application.
基金supported by the National Natural Science Foundation of China (No.11402288)
文摘Based on improved multi-objective particle swarm optimization（MOPSO） algorithm with principal component analysis（PCA） methodology, an efficient high-dimension multiobjective optimization method is proposed, which, as the purpose of this paper, aims to improve the convergence of Pareto front in multi-objective optimization design. The mathematical efficiency,the physical reasonableness and the reliability in dealing with redundant objectives of PCA are verified by typical DTLZ5 test function and multi-objective correlation analysis of supercritical airfoil,and the proposed method is integrated into aircraft multi-disciplinary design（AMDEsign） platform, which contains aerodynamics, stealth and structure weight analysis and optimization module.Then the proposed method is used for the multi-point integrated aerodynamic optimization of a wide-body passenger aircraft, in which the redundant objectives identified by PCA are transformed to optimization constraints, and several design methods are compared. The design results illustrate that the strategy used in this paper is sufficient and multi-point design requirements of the passenger aircraft are reached. The visualization level of non-dominant Pareto set is improved by effectively reducing the dimension without losing the primary feature of the problem.
基金National Science&Technology Pillar Program of China(No.2012BAC02B04)National Natural Science Foundation of China(No.41201306)
文摘High enzymatic activity is required for laccase applications.Central composite design （CCD）-based response surface methodology （RSM） can effectively increase the enzymatic activity of Pleurotus ostreatus P40 in liquid substrate fermentation.Initial screening of the nutritional components was performed using a Plackett-Burman design.The variables,namely,bran,bagasse,Tween 80,and yeast extract,were found to have statistically significant effects on laccase activity.These variables were further optimized using CCD-based RSM.Optimal concentrations for the maximum laccase activity were 8.144 2 g/L bran,50 g/L bagasse,0.424 1 mL/L Tween 80,and 2.832 5 g/L yeast extract.Under optimized conditions,the maximum measured laccase activity reached 96 480 U/L,which was close to the predicted value （104 830 U/L） by RSM.Therefore,RSM can be used to optimize culture components for laccase activity from Pieurotus ostreatus P40.
基金supported by National Natural Science Foundation under Grant No.50875247Shanxi Province Natural Science Foundation under Grant No.2009011026-1
文摘Panicle swarm optimization （PSO） is an optimization algorithm based on the swarm intelligent principle. In this paper the modified PSO is applied to a kernel principal component analysis （ KPCA ） for an optimal kernel function parameter. We first comprehensively considered within-class scatter and between-class scatter of the sample features. Then, the fitness function of an optimized kernel function parameter is constructed, and the particle swarm optimization algorithm with adaptive acceleration （CPSO） is applied to optimizing it. It is used for gearbox condi- tion recognition, and the result is compared with the recognized results based on principal component analysis （PCA）. The results show that KPCA optimized by CPSO can effectively recognize fault conditions of the gearbox by reducing bind set-up of the kernel function parameter, and its results of fault recognition outperform those of PCA. We draw the conclusion that KPCA based on CPSO has an advantage in nonlinear feature extraction of mechanical failure, and is helpful for fault condition recognition of complicated machines.
文摘As the turbine inlet total temperature of the turbofan engine continues to increase,it is key to ensuring the long-term reliability of aeroengines that the components matching effectively to achieve the expected average gas temperature.However,over temperature in turbine inlet is a common challenge in advanced engine development.To solve this problem,this paper proposes a new idea of a component matching optimization method to control average gas temperature.This method couples the optimization method with the adaptive performance model,which is built using accurate component characteristics and internal/external bypass mass flow rate within the engine test.Experiment methods of component characteristics measurement in different operating status under the condition of the whole engine are also developed,which capture the entire characteristics maps rather than the mini maps along the operating line.It also establishes calculation method of the core mass flow rate based on the critical characteristics of the high-pressure turbine.Tests have shown that by applying the component matching optimization method,the turbine inlet average gas temperature of a high-performance twin-spool mixed turbofan engine was reduced by 50 Ke60 K under the same thrust,ensuring fulfillment of the performance indexes.
基金supported by the Beijing Scholars Program[BSP041]。
文摘The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.
文摘Objective: to analyze the influence of optimized recruitment mode of component blood donation on blood donor retention and blood safety. Methods: 100 randomly selected blood donors recruited from machine collected components were studied. The medical observation began in March 2021 and ended in March 2022. They were divided into the control group (50 cases, conventional blood donation recruitment mode) and the observation group (50 cases, optimized blood donation recruitment mode) by double blind method, and the effects of the two groups were compared. Results: the qualified rate of primary screening test and the reaction rate of blood test in the observation group were better than those in the control group (P < 0.05). Conclusion: the optimized recruitment model of component blood donation can increase the number of blood donors and ensure the safety of blood supply, which is worthy of promotion.
基金This project is supported by National 211 Project.
文摘A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has robustness to uncertainty of frequency, which makes it practical in engineering. Several time optimal and time-fuel optimal control strategies are designed for a kind of single flexible link. Simulation results validate the feasibility of our method.
文摘An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis （PCA） and multiple discriminant analysis （MDA） is presented in this paper. In this framework, features are extracted from the optimal random image components using greedy approach. These feature vectors are then projected to subspaces for dimensionality reduction which is used for solving linear problems. The design of Gabor filters, PCA and MDA are crucial processes used for facial feature extraction. The FERET, ORL and YALE face databases are used to generate the results. Experiments show that optimal random image component selection （ORICS） plus MDA outperforms ORICS and subspace projection approach such as ORICS plus PCA. Our method achieves 96.25%, 99.44% and 100% recognition accuracy on the FERET, ORL and YALE databases for 30% training respectively. This is a considerably improved performance compared with other standard methodologies described in the literature.
