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Composition optimization and performance prediction for ultra-stable water-based aerosol based on thermodynamic entropy theory
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作者 Tingting Kang Canjun Yan +6 位作者 Xinying Zhao Jingru Zhao Zixin Liu Chenggong Ju Xinyue Zhang Yun Zhang Yan Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期437-446,共10页
Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of th... Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets.Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion.However,the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost.And the stabilization time of the aerosol is still only 30 min,which could not meet the requirements of the perdurable interference.Herein,to improve the stability of water-based aerosol and optimize the complex formulation efficiently,a theoretical calculation method based on thermodynamic entropy theory is proposed.All the factors that influence the shielding effect,including polyol,stabilizer,propellant,water and cosolvent,are considered within calculation.An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition,providing enough time for fighting the electro-optic weapon.Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed,which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process,and gives rise to an enhanced stability of the water-based aerosol.The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability,and provides the powerful guarantee to the homeland security. 展开更多
关键词 Ultra-stable Water-based aerosol Thermodynamic entropy composition optimization Performance prediction
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Improvement of xylanase production by Aspergillus niger XY-1 using response surface methodology for optimizing the medium composition 被引量:7
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作者 Yao-xing XU Yan-li LI Shao-chun XU Yong LIU Xin WANG Jiang-wu TANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第7期558-566,共9页
Objective: To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF). Methods: Statistical methodology including the Plackett-Burman design (PBD) and t... Objective: To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF). Methods: Statistical methodology including the Plackett-Burman design (PBD) and the central composite design (CCD) was employed to investigate the individual crucial component of the medium that significantly affected the enzyme yield. Results: Firstly, NaNO3, yeast extract, urea, Na2CO3, MgSO4, peptone and (NH4)2SO4 were screened as the significant factors positively affecting the xylanase production by PBD. Secondly, by valuating the nitrogen sources effect, urea was proved to be the most effective and economic nitrogen source for xylanase production and used for further optimization. Finally, the CCD and response surface methodology (RSM) were applied to determine the optimal concentration of each sig-nificant variable, which included urea, Na2CO3 and MgSO4. Subsequently a second-order polynomial was determined by multiple regression analysis. The optimum values of the critical components for maximum xylanase production were obtained as follows: x1 (urea)=0.163 (41.63 g/L), x2 (Na2CO3)=?1.68 (2.64 g/L), x3 (MgSO4)=1.338 (10.68 g/L) and the predicted xylanase value was 14374.6 U/g dry substrate. Using the optimized condition, xylanase production by Aspergillus niger XY-1 after 48 h fermentation reached 14637 U/g dry substrate with wheat bran in the shake flask. Conclusion: By using PBD and CCD, we obtained the optimal composition for xylanase production by Aspergillus niger XY-1 in SSF, and the results of no additional expensive medium and shortened fermentation time for higher xylanase production show the potential for industrial utilization. 展开更多
关键词 XYLANASE Optimization of medium composition Plackett-Burman design (PBD) Central composite design (CCD) Response surface methodology (RSM). Aspergillus niger XY- 1
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Almost Sure Convergence of Proximal Stochastic Accelerated Gradient Methods
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作者 Xin Xiang Haoming Xia 《Journal of Applied Mathematics and Physics》 2024年第4期1321-1336,共16页
Proximal gradient descent and its accelerated version are resultful methods for solving the sum of smooth and non-smooth problems. When the smooth function can be represented as a sum of multiple functions, the stocha... Proximal gradient descent and its accelerated version are resultful methods for solving the sum of smooth and non-smooth problems. When the smooth function can be represented as a sum of multiple functions, the stochastic proximal gradient method performs well. However, research on its accelerated version remains unclear. This paper proposes a proximal stochastic accelerated gradient (PSAG) method to address problems involving a combination of smooth and non-smooth components, where the smooth part corresponds to the average of multiple block sums. Simultaneously, most of convergence analyses hold in expectation. To this end, under some mind conditions, we present an almost sure convergence of unbiased gradient estimation in the non-smooth setting. Moreover, we establish that the minimum of the squared gradient mapping norm arbitrarily converges to zero with probability one. 展开更多
关键词 Proximal Stochastic Accelerated Method Almost Sure Convergence Composite Optimization Non-Smooth Optimization Stochastic Optimization Accelerated Gradient Method
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Composition Optimization and Microstructure Design in MOFs-Derived Magnetic Carbon-Based Microwave Absorbers:A Review 被引量:12
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作者 Honghong Zhao Fengyuan Wang +3 位作者 Liru Cui Xianzhu Xu Xijiang Han Yunchen Du 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第12期383-415,共33页
Magnetic carbon-based composites are the most attractive candidates for electromagnetic(EM)absorption because they can terminate the propagation of surplus EM waves in space by interacting with both electric and magne... Magnetic carbon-based composites are the most attractive candidates for electromagnetic(EM)absorption because they can terminate the propagation of surplus EM waves in space by interacting with both electric and magnetic branches.Metal-organic frameworks(MOFs)have demonstrated their great potential as sacrificing precursors of magnetic metals/carbon composites,because they provide a good platform to achieve high dispersion of magnetic nanoparticles in carbon matrix.Nevertheless,the chemical composition and microstructure of these composites are always highly dependent on their precursors and cannot promise an optimal EM state favorable for EM absorption,which more or less discount the superiority of MOFs-derived strategy.It is hence of great importance to develop some accompanied methods that can regulate EM properties of MOFs-derived magnetic carbon-based composites e ectively.This review comprehensively introduces recent advancements on EM absorption enhancement in MOFs-derived magnetic carbon-based composites and some available strategies therein.In addition,some challenges and prospects are also proposed to indicate the pending issues on performance breakthrough and mechanism exploration in the related field. 展开更多
关键词 Magnetic carbon-based composites Metal–organic frameworks composition optimization Microstructure design EM absorption enhancement
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Enhanced recovery of zinc and lead by slag composition optimization in rotary kiln 被引量:3
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作者 Hong-fu LIN Wei WENG +1 位作者 Shui-ping ZHONG Guan-zhou QIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第9期3110-3122,共13页
High-efficiency recovery of Zn and Pb from silicon-rich zinc leaching residues is realized in a rotary kiln.Characterizations by means of XRD,SEM,EDS and ICP reveal that the leaching residue contains 12.4 wt.%SiO_(2),... High-efficiency recovery of Zn and Pb from silicon-rich zinc leaching residues is realized in a rotary kiln.Characterizations by means of XRD,SEM,EDS and ICP reveal that the leaching residue contains 12.4 wt.%SiO_(2),16.1 wt.%Zn,and 7.4 wt.%Pb.Thermodynamic analysis shows that metallic vapor of Zn and Pb can be easily generated from the zinc leaching residue at 1150-1250°C inside the rotary kiln.Viscosities and melting points of 13 slag compositions were analyzed and three slag compositions(47wt.%SiO_(2)-23wt.%CaO-30wt.%FeO,40wt.%SiO_(2)-28wt.%CaO-32wt.%FeO,and 40wt.%SiO_(2)-30wt.%CaO-30wt.%FeO)possessed the desirable physical properties,with the melting point and viscosity in the range of 1150-1280°C and 0.2-0.5 Pa·s,respectively.The industrial tests show that adopting the optimized slag composition can contribute to very high recovery rates of Zn and Pb(97.3%for Zn and 94.5%for Pb),corresponding to slags with very low average contents of Zn and Pb(0.51 wt.%Zn and 0.45 wt.%Pb).The National-Standard leaching tests of the water-quenched slags result in 1.82 mg/L Zn,~0.01 mg/L Cu,0.0004 mg/L As,~0.01 mg/L Cd,0.08 mg/L Pb,and~0.02 mg/L Hg in the leachate,verifying the detoxification of the zinc leaching residue at the same time. 展开更多
关键词 zinc leaching residues metals recovery rotary kiln slag composition optimization DETOXIFICATION
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Study on the Optimal Composition of Chitosan/Nano-TiO_2 Composite Film and Its Application in the Preservation of Jinqiu Pear 被引量:2
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作者 Xiqin TAO Mingli WANG 《Agricultural Biotechnology》 CAS 2015年第3期20-23,26,共5页
Water permeability can be used as a parameter to evaluate the effects of chitosan / nano-TiO2 composite film on the preservation of fruits and vegetables. In this study, using water permeability as the objective funct... Water permeability can be used as a parameter to evaluate the effects of chitosan / nano-TiO2 composite film on the preservation of fruits and vegetables. In this study, using water permeability as the objective function, an L9 (3)3 orthogonal experiment was conducted with addition amounts of chitosan, nano-TiO2 and glycerin as three factors at three levels. According to the experimental results, when the percentages of chitosan, nano-TiO2 and glycerin in chitosan / nano-TiO2 composite film was 2%, 0.03% and 2.5%, respectively ( i. e. , there were 2.0 g of chitosan, 0.03 g of nano-TiO2 and 2.5 g of glycerin per 1130 g composite film solution), the water permeability of chitesan / nano-TiO2 composite fdm reached the minimum. Chitosan / nano-TiO2 composite film prepared with the optimal composition was used for preservation of Jinqiu pear. The water loss rate, respiratory intensity and good fruit rate of preserved Jinqiu pear were determined, which indicated that the prepared chitosan / nano-TiO2 composite film exhibited good preservative effects. 展开更多
关键词 CHITOSAN NANO-TIO2 Optimal composition Jinqiu pear PRESERVATION
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Service composition based on discrete particle swarm optimization in military organization cloud cooperation 被引量:2
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作者 An Zhang Haiyang Sun +1 位作者 Zhili Tang Yuan Yuan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第3期590-601,共12页
This paper addresses the problem of service composition in military organization cloud cooperation(MOCC). Military service providers(MSP) cooperate together to provide military resources for military service users... This paper addresses the problem of service composition in military organization cloud cooperation(MOCC). Military service providers(MSP) cooperate together to provide military resources for military service users(MSU). A group of atom services, each of which has its level of quality of service(QoS), can be combined together into a certain structure to form a composite service. Since there are a large number of atom services having the same function, the atom service is selected to participate in the composite service so as to fulfill users' will. In this paper a method based on discrete particle swarm optimization(DPSO) is proposed to tackle this problem. The method aims at selecting atom services from service repositories to constitute the composite service, satisfying the MSU's requirement on QoS. Since the QoS criteria include location-aware criteria and location-independent criteria, this method aims to get the composite service with the highest location-aware criteria and the best-match location-independent criteria. Simulations show that the DPSO has a better performance compared with the standard particle swarm optimization(PSO) and genetic algorithm(GA). 展开更多
关键词 service composition cloud cooperation discrete particle swarm optimization(DPSO)
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Optimized Composition of Functional Bacteria for Bioremediation of Sediment Environment of Shrimp Culture
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作者 李秋芬 辛福言 +2 位作者 邹玉霞 陈民山 唐启升 《Marine Science Bulletin》 CAS 2004年第2期60-65,共6页
After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different... After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single -strain groups. Three-strain groups are better than two-strain groups, and four-strain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1 % in 114 h. It is suggested that multi-species bacteria be used as functional bacteria in bioremediation of mariculture environment. 展开更多
关键词 optimized composition functional bacteria BIODEGRADATION BIOREMEDIATION shrimp culture environment
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Service Composition Instantiation Based on Cross-Modified Artificial Bee Colony Algorithm
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作者 Lei Huo Zhiliang Wang 《China Communications》 SCIE CSCD 2016年第10期233-244,共12页
Internet of things(IoT) imposes new challenges on service composition as it is difficult to manage a quick instantiation of a complex services from a growing number of dynamic candidate services. A cross-modified Arti... Internet of things(IoT) imposes new challenges on service composition as it is difficult to manage a quick instantiation of a complex services from a growing number of dynamic candidate services. A cross-modified Artificial Bee Colony Algorithm(CMABC) is proposed to achieve the optimal solution services in an acceptable time and high accuracy. Firstly, web service instantiation model was established. What is more, to overcome the problem of discrete and chaotic solution space, the global optimal solution was used to accelerate convergence rate by imitating the cross operation of Genetic algorithm(GA). The simulation experiment result shows that CMABC exhibited faster convergence speed and better convergence accuracy than some other intelligent optimization algorithms. 展开更多
关键词 optimization of service composition optimal service instantiation artificial bee colony algorithm swarm algorithm cross strategy
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Multi-Strategy Improvement of Sparrow Search Algorithm for Cloud Manufacturing Service Composition
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作者 ZHOU Liliang LI Ben +2 位作者 YU Qing DAI Guilan ZHOU Guofu 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2024年第4期323-337,共15页
In existing research,the optimization of algorithms applied to cloud manufacturing service composition based on the quality of service often suffers from decreased convergence rates and solution quality due to single-... In existing research,the optimization of algorithms applied to cloud manufacturing service composition based on the quality of service often suffers from decreased convergence rates and solution quality due to single-population searches in fixed spaces and insufficient information exchange.In this paper,we introduce an improved Sparrow Search Algorithm(ISSA)to address these issues.The fixed solution space is divided into multiple subspaces,allowing for parallel searches that expedite the discovery of target solutions.To enhance search efficiency within these subspaces and significantly improve population diversity,we employ multiple group evolution mechanisms and chaotic perturbation strategies.Furthermore,we incorporate adaptive weights and a global capture strategy based on the golden sine to guide individual discoverers more effectively.Finally,differential Cauchy mutation perturbation is utilized during sparrow position updates to strengthen the algorithm's global optimization capabilities.Simulation experiments on benchmark problems and service composition optimization problems show that the ISSA delivers superior optimization accuracy and convergence stability compared to other methods.These results demonstrate that our approach effectively balances global and local search abilities,leading to enhanced performance in cloud manufacturing service composition. 展开更多
关键词 cloud manufacturing service composition optimization quality of service sparrow search algorithm
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Composite Structural Optimization by Genetic Algorithm and Neural Network Response Surface Modeling 被引量:13
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作者 徐元铭 李烁 荣晓敏 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2005年第4期310-316,共7页
Neural-Network Response Surfaces (NNRS) is applied to replace the actual expensive finite element analysis during the composite structural optimization process. The Orthotropic Experiment Method (OEM) is used to s... Neural-Network Response Surfaces (NNRS) is applied to replace the actual expensive finite element analysis during the composite structural optimization process. The Orthotropic Experiment Method (OEM) is used to select the most appropriate design samples for network training. The trained response surfaces can either be objective function or constraint conditions. Together with other conven- tional constraints, an optimization model is then set up and can be solved by Genetic Algorithm (GA). This allows the separation between design analysis modeling and optimization searching. Through an example of a hat-stiffened composite plate design, the weight response surface is constructed to be objective function, and strength and buckling response surfaces as constraints; and all of them are trained through NASTRAN finite element analysis. The results of optimization study illustrate that the cycles of structural analysis ean be remarkably reduced or even eliminated during the optimization, thus greatly raising the efficiency of optimization process. It also observed that NNRS approximation can achieve equal or even better accuracy than conventional functional response surfaces. 展开更多
关键词 neural network genetic algorithm response surface composite structural optimization
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A Simultaneous Optimization Method for the Structure and Compo-sition Differences of a Mass Exchange Network 被引量:3
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作者 陈理 高志辉 +1 位作者 都健 姚平经 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第2期254-261,共8页
This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of comp... This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of composition interval diagram (CID) with mathematical programming.The total cost target consists of the capital cost of the process units and the operating cost for mass separating agents (MS.As). The value of total cost varies considerablv with the composition differences, so the values of e should be optimized in order to obtain minimum TAC of a MEN. This articleconsiders ε as a set of unequal variables for each equilibrium equation of a rich-lean stream pair, employing them to build the CID and mathematical model, which optimizes the structure and composition differences simultaneously. Two examples are applied to illustrate the proposed method and the results demonstrate that the approach introduced by this article is simpler and more convenient than the methods in previous literatures. 展开更多
关键词 mass exchange network optimal composition difference total annualized cost
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Concurrent multi-scale design optimization of composite frame structures using the Heaviside penalization of discrete material model 被引量:6
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作者 Jun Yan Zunyi Duan +1 位作者 Erik Lund Guozhong Zhao 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第3期430-441,共12页
This paper deals with the concurrent multi-scale optimization design of frame structure composed of glass or carbon fiber reinforced polymer laminates. In the composite frame structure, the fiber winding angle at the ... This paper deals with the concurrent multi-scale optimization design of frame structure composed of glass or carbon fiber reinforced polymer laminates. In the composite frame structure, the fiber winding angle at the micro-material scale and the geometrical parameter of components of the frame in the macro-structural scale are introduced as the independent variables on the two geometrical scales. Considering manufacturing requirements, discrete fiber winding angles are specified for the micro design variable. The improved Heaviside penalization discrete material optimization interpolation scheme has been applied to achieve the discrete optimization design of the fiber winding angle. An optimization model based on the minimum structural compliance and the specified fiber material volume constraint has been established. The sensitivity information about the two geometrical scales design variables are also deduced considering the characteristics of discrete fiber winding angles. The optimization results of the fiber winding angle or the macro structural topology on the two single geometrical scales, together with the concurrent two-scale optimization, is separately studied and compared in the paper. Numerical examples in the paper show that the concurrent multi-scale optimization can further explore the coupling effect between the macro-structure and micro-material of the composite to achieve an ultralight design of the composite frame structure. The novel two geometrical scales optimization model provides a new opportunity for the design of composite structure in aerospace and other industries. 展开更多
关键词 Composite frame structure Multi-scale optimization Topology optimization Fiber winding angle Structural compliance
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Contrastive analysis and crashworthiness optimization of two composite thin-walled structures 被引量:4
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作者 谢素超 周辉 +1 位作者 梁习锋 任鑫 《Journal of Central South University》 SCIE EI CAS 2014年第11期4386-4394,共9页
For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can b... For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can be completely absorbed or dissipated for the aim of safety. Two composite structures(circumscribed circle structure and inscribed circle structure) were constructed. In addition, comparison and optimization of the crashworthy characteristic of the two structures were carried out based on the method of explicit finite element analysis(FEA) and Kriging surrogate model. According to the result of Kriging surrogate model, conclusions can be safely drawn that the specific energy absorption(SEA) and ratio of specific energy absorption to initial peak force(REAF) of circumscribed circle structure are lager than those of inscribed circle structure under the same design parameters. In other words, circumscribed circle structure has better performances with higher energy-absorbing ability and lower initial peak force. Besides, error analysis was adopted and the result of which indicates that the Kriging surrogate model has high nonlinear fitting precision. What is more, the SEA and REAF optimum values of the two structures have been obtained through analysis, and the crushing results have been illustrated when the two structures reach optimum SEA and REAF. 展开更多
关键词 contrastive analysis crashworthiness optimization composite structure Kriging surrogate model finite element analysis
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DEVELOPING A NEW GENERATION OF HIGH PERFORMANCE COMPOSITE CEMENT 被引量:1
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作者 黄新 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2000年第3期73-78,共6页
This paper proposed a new generation of high performance composite cement which is designed according to the optimization of composition and structure of cement paste and is manufactured by blending the differ ent com... This paper proposed a new generation of high performance composite cement which is designed according to the optimization of composition and structure of cement paste and is manufactured by blending the differ ent components with special composite techniques. Each of these components has its different special property, and should be compatible with each other and match each other, and the properties of them are complementary mutually. At present, such kind of high performance composite cement can be manufactured with high reactivity cement clinker, ground granulated blast - furnace slag, high grade fly ash, silica fume etc.. 展开更多
关键词 composite cement optimization of composition and structure DESIGN MANUFACTURE
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STACKING SEQUENCE OPTIMIZA-TION OF LAMINATED COMPOSITE CYLINDER SHELL FOR MAXIMAL BUCKLING LOAD 被引量:4
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作者 TANG Qian LIAO Xiaoyun GAO Zhan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第4期31-34,共4页
A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling l... A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling load. The proposed optimization algorithm applies both finite element analysis and the mode-pursuing sampling (MPS)method. The algorithms suggest the optimal stacking sequence for achieving the maximal buckling load. The procedure is implemented by integrating ANSYS and MATLAB. The stacking sequence designing for the symmetric angle-ply three-layered and five-layered composite cylinder shells is presented to illustrate the optimization process, respectively. Compared with the genetic algorithms, the proposed optimization method is much faster and efficient for composite staking sequence plan. 展开更多
关键词 Composite Laminated cylindrical shell Stacking sequence optimization Buckling load Sampling algorithms
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Isolation of Cordyceps ophioglossoides L2 from Fruit Body and Optimization of Fermentation Conditions for Its Mycelial Growth 被引量:6
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作者 许勤勤 吕龙贤 +3 位作者 陈少云 郑静 郑高利 李永泉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期278-285,共8页
A strain isolated from the fruiting body of a fungus parasitized on Elaphomyces was identified as Cordyceps ophioglossoides based on the morphological characteristics and the analysis of ITS-5.8s rDNA sequence. The op... A strain isolated from the fruiting body of a fungus parasitized on Elaphomyces was identified as Cordyceps ophioglossoides based on the morphological characteristics and the analysis of ITS-5.8s rDNA sequence. The optimal medium, composition (g·L^-1), containing sucrose 66.0, yeast powder 10.0, silkworm chrysalises digest 30.0, MgSO4· 7H2O 0.4, and KH2PO4 0.4, Was found using fractional factorial design ancl a central composite design, and the optimization of cultural conditions obtained a result of seed age 6 days, inoculum size 6% (by volume), initial pH 5.6, temperature 24℃, shaking speed 160 ·'min^-1 by one-factor-at-a-time method. The maximum biomass reached about 20.2 g·L^-1 after 90 hours culture under the optimal conditions. Elementary nharmaeclogical actlwtties showed that mycelia of C. ophioglossoides L2 from submerged culture promoted Uterus growth in estrogen- depleted mice. In the 15-litre scale-up fermentation, the mycelial biomass was around 19.1 g·L^-1, indicating a promising prospect for this biotechnoloagy and the potency to develoo its medical value. 展开更多
关键词 Cordyceps ophioglossoides identification fermentation optimization fractional factorial design central composite design
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Experimental Design as a Tool for the Development of Citric Acid Production by Yarrowia lipolytica Using Glycerol as a Feedstock
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作者 Luana V. da Silva Camila B. Tavares Roberta dos R. Ribeiro Fernando L. P. Pessoa Maria Alice Z. Coelho Priscilla F. F. Amaral 《Journal of Food Science and Engineering》 2013年第8期435-446,共12页
Due to the scarcity of fossil fuels in the world, there is increasing interest in the commercial production of biodiesel, which leads to obtaining large amounts of glycerol as a byproduct. If not disposed of properly,... Due to the scarcity of fossil fuels in the world, there is increasing interest in the commercial production of biodiesel, which leads to obtaining large amounts of glycerol as a byproduct. If not disposed of properly, glycerol can generate environmental impact. One of the promises, the application of the crude glycerol is the production of citric acid by microbial fermentation. Citric acid is industrially produced by a submerged fermentation process with Aspergillus niger, using sucrose as carbon source, but due to increased demand for citric acid, alternative processes using renewable sources or waste materials as substrates and the cultivation of yeast strains are being studied. The aim of the study was to determine the best culture condition for maximum citric acid synthesis and lower isocitric acid production from crude glycerol through experimental design tool. For this purpose, the yeast strain Yarrowia lipolytica IMUFRJ-50682 was cultivated in nitrogen-limited glycerol-based media. Therefore, glycerol and yeast extract concentrations and agitation speed were evaluated as independent variables. With pure glycerol, the highest citric acid production achieved was 16.5 g/L with an isocitric acid production of 7.7% (in relation to citric acid). With crude glycerol, citric acid production reduced to 6.7 g/L because of higher biomass yield. Therefore, an increase in the initial carbon to nitrogen molar ratio from 714 to 1,561 was necessary to increase citric acid production to 9.2 g/L, reducing isocitric acid production and to achieve a yield of 0.41 g of citric acid per glycerol consumed. In this condition, less nitrogen source was used, reducing production costs. 展开更多
关键词 Yarrowia lipolytica crude glycerol media composition optimization citric acid experimental design.
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A New Nonmonotonic Trust Region Algorithm for A Class of Unconstrained Nonsmooth Optimization
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作者 欧宜贵 侯定丕 《Northeastern Mathematical Journal》 CSCD 2002年第4期335-342,共8页
This paper presents a new trust region algorithm for solving a class of composite nonsmooth optimizations. It is distinguished by the fact that this method does not enforce strict monotonicity of the objective functio... This paper presents a new trust region algorithm for solving a class of composite nonsmooth optimizations. It is distinguished by the fact that this method does not enforce strict monotonicity of the objective function values at successive iterates and that this method extends the existing results for this type of nonlinear optimization with smooth, or piecewise smooth, or convex objective functions or their composition. It is proved that this algorithm is globally convergent under certain conditions. Finally, some numerical results for several optimization problems are reported which show that the nonmonotonic trust region method is competitive with the usual trust region method. 展开更多
关键词 nonmonotonic strategy trust region method composite nonsmooth optimization
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Composition optimization and electrochemical characteristics of Co-free Fe-containing AB_5-type hydrogen storage alloys through uniform design 被引量:6
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作者 晁栋梁 陈云贵 +2 位作者 朱昌荣 吴朝玲 朱丁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第4期361-366,共6页
In order to reduce the cost of ABs-type hydrogen storage alloys, effects of substitution of Ce for La (A side) and Fe, Mn, Al for Ni (B side) on structural and electrochemical properties of (LaCe);(NiFeMnAl)s ... In order to reduce the cost of ABs-type hydrogen storage alloys, effects of substitution of Ce for La (A side) and Fe, Mn, Al for Ni (B side) on structural and electrochemical properties of (LaCe);(NiFeMnAl)s alloys were studied systematically. To make component uniform and operation easy, uniform design (UD) method was introduced into the study of composition optimization of Co-free Fe-containing ABs-type alloys for the first time. X-ray diffraction (XRD) results showed that the designed alloys were of single CaCus-type structure phase. The replacement of Fe had a severe effect on electrochemical capacity, and the substitution of Fe and A1 had a synergetic action among the unit cell volume, cycling stability and high rate discharge property. Interestingly, it was found that the hydrogen storage alloys with excessively high plateau pressure showed a tilted line in Nyquist plot instead of the semicircle, and the current decayed rapidly to near zero at the beginning of the step in constant potential step (CPS), indicating that electrochemical impedance spectra (EIS) and CPS cannot accurately measure the electrochemical kinetics process of the hydrogen storage alloys with excessively high plateau pressure. 展开更多
关键词 hydrogen storage alloy CO-FREE Fe-containing composition optimization electrochemical characteristics uniform design rare earths
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