This study aims to investigate the efiect of the mesoscopic characteristics of mineral powder fillers on the rutting resistance of asphalt mortar.Extraction and sieving tests were used to obtain the buton rock asphalt...This study aims to investigate the efiect of the mesoscopic characteristics of mineral powder fillers on the rutting resistance of asphalt mortar.Extraction and sieving tests were used to obtain the buton rock asphalt(BRA)ash with particle size smaller than 0.075 mm,which is consistent with that of the conventional mineral powder.The mesoscopic characteristics of BRA ash and conventional mineral powder were measured by SEM image analysis and the osmotic free pressure water method.Mesoscopic structure models of structural and free asphalts in mortar were obtained.The 70#matrix asphalt was used to prepare two kinds of asphalt mortar with BRA ash and conventional mineral powders fillers.The rutting factor of the two asphalt mortars was tested by dynamic shear test(DSR).Test results show that the ash extracted from BRA has a similar mesoscopic classification with the conventional mineral powder.Still,its fractal dimensions are larger,indicating the particles in BRA ash have more complex shapes and rougher surfaces,which is beneficial for forming structural asphalt and subsequently increasing the rutting factor(G*/sinδ),i e,improving the rutting resistance of the asphalt mortar.展开更多
This paper proposes a design and fine-tuning method for mixed electric and magnetic coupling filters.It derives the quantitative relationship between the coupling coefficients(electric and magnetic coupling,i.e.,EC an...This paper proposes a design and fine-tuning method for mixed electric and magnetic coupling filters.It derives the quantitative relationship between the coupling coefficients(electric and magnetic coupling,i.e.,EC and MC)and the linear coefficients of frequencydependent coupling for the first time.Different from the parameter extraction technique using the bandpass circuit model,the proposed approach explicitly relatesEC and MC to the coupling matrix model.This paper provides a general theoretic framework for computer-aided design and tuning of a mixed electric and magnetic coupling filter based on coupling matrices.An example of a 7th-order coaxial combline filter design is given in the paper,verifying the practical value of the approach.展开更多
以压水堆控制棒导向筒(Control Rod Guide Tube,简称CRGT)导向鞘部件激光对接焊为研究对象,针对激光焊热源、导向鞘激光焊焊缝收缩量和激光焊焊接变形进行建模和分析。建立了压水堆导向鞘激光焊变形模拟技术,为控制棒导向筒产品激光焊...以压水堆控制棒导向筒(Control Rod Guide Tube,简称CRGT)导向鞘部件激光对接焊为研究对象,针对激光焊热源、导向鞘激光焊焊缝收缩量和激光焊焊接变形进行建模和分析。建立了压水堆导向鞘激光焊变形模拟技术,为控制棒导向筒产品激光焊接制造提供理论指导。具体内容包括:激光焊试验和热循环测试、宏观焊缝成形、残余应力测试、热源模型建立及参数确定、激光焊焊缝收缩模型的建立及焊接变形预测。最终获得了稳定的导向鞘激光焊工艺参数,经激光焊接的导向筒使用φ10.26 mm的落棒规以4～5 m/min的速度,可在0°、90°、180°、270°四个位置自由通过,摩擦力小于等于9.07 kg。展开更多
A new optimization method is proposed to realize the synthesis of duplexers.The traditional optimization method takes all the variables of the duplexer into account,resulting in too many variables to be optimized when...A new optimization method is proposed to realize the synthesis of duplexers.The traditional optimization method takes all the variables of the duplexer into account,resulting in too many variables to be optimized when the order of the duplexer is too high,so it is not easy to fall into the local solution.In order to solve this problem,a new optimization strategy is proposed in this paper,that is,two-channel filters are optimized separately,which can reduce the number of optimization variables and greatly reduce the probability of results falling into local solutions.The optimization method combines the self-adaptive differential evolution algorithm(SADE)with the Levenberg-Marquardt(LM)algorithm to get a global solution more easily and accelerate the optimization speed.To verify its practical value,we design a 5 G duplexer based on the proposed method.The duplexer has a large external coupling,and how to achieve a feed structure with a large coupling bandwidth at the source is also discussed.The experimental results show that the proposed optimization method can realize the synthesis of higher-order duplexers compared with the traditional methods.展开更多
基金Funded by the National Natural Science Foundation of China(No.51978088)。
文摘This study aims to investigate the efiect of the mesoscopic characteristics of mineral powder fillers on the rutting resistance of asphalt mortar.Extraction and sieving tests were used to obtain the buton rock asphalt(BRA)ash with particle size smaller than 0.075 mm,which is consistent with that of the conventional mineral powder.The mesoscopic characteristics of BRA ash and conventional mineral powder were measured by SEM image analysis and the osmotic free pressure water method.Mesoscopic structure models of structural and free asphalts in mortar were obtained.The 70#matrix asphalt was used to prepare two kinds of asphalt mortar with BRA ash and conventional mineral powders fillers.The rutting factor of the two asphalt mortars was tested by dynamic shear test(DSR).Test results show that the ash extracted from BRA has a similar mesoscopic classification with the conventional mineral powder.Still,its fractal dimensions are larger,indicating the particles in BRA ash have more complex shapes and rougher surfaces,which is beneficial for forming structural asphalt and subsequently increasing the rutting factor(G*/sinδ),i e,improving the rutting resistance of the asphalt mortar.
基金supported by the National Natural Science Foundation of China under Grant No.62001339.
文摘This paper proposes a design and fine-tuning method for mixed electric and magnetic coupling filters.It derives the quantitative relationship between the coupling coefficients(electric and magnetic coupling,i.e.,EC and MC)and the linear coefficients of frequencydependent coupling for the first time.Different from the parameter extraction technique using the bandpass circuit model,the proposed approach explicitly relatesEC and MC to the coupling matrix model.This paper provides a general theoretic framework for computer-aided design and tuning of a mixed electric and magnetic coupling filter based on coupling matrices.An example of a 7th-order coaxial combline filter design is given in the paper,verifying the practical value of the approach.
基金supported by the National Natural Science Foundation of China(NSFC)under project no.62071357the Fundamental Research Funds for the Central Unive rsities。
文摘A new optimization method is proposed to realize the synthesis of duplexers.The traditional optimization method takes all the variables of the duplexer into account,resulting in too many variables to be optimized when the order of the duplexer is too high,so it is not easy to fall into the local solution.In order to solve this problem,a new optimization strategy is proposed in this paper,that is,two-channel filters are optimized separately,which can reduce the number of optimization variables and greatly reduce the probability of results falling into local solutions.The optimization method combines the self-adaptive differential evolution algorithm(SADE)with the Levenberg-Marquardt(LM)algorithm to get a global solution more easily and accelerate the optimization speed.To verify its practical value,we design a 5 G duplexer based on the proposed method.The duplexer has a large external coupling,and how to achieve a feed structure with a large coupling bandwidth at the source is also discussed.The experimental results show that the proposed optimization method can realize the synthesis of higher-order duplexers compared with the traditional methods.
