A new microreactor with continuous serially connected micromixers(CSCM)was tailored for the coprecipitation process to synthesize Fe_(3)O_(4) nanoparticles.Numerical simulation reveals that the two types of CSCM micro...A new microreactor with continuous serially connected micromixers(CSCM)was tailored for the coprecipitation process to synthesize Fe_(3)O_(4) nanoparticles.Numerical simulation reveals that the two types of CSCM microchannels(V-typed and U-typed)proposed in this work exhibited markedly better mixing performances than the Zigzag and capillary microchannels due to the promotion of Dean vortices.Complete mixing was achieved in the V-typed microchannel in 2.7 s at an inlet Reynolds number of 27.Fe_(3)O_(4) nanoparticles synthesized in a planar glass microreactor with the V-typed microchannel,possessing an average size of 9.3 nm and exhibiting superparamagnetism,had obviously better dispersity and uniformity and higher crystallinity than those obtained in the capillary microreactor.The new CSCM microreactor developed in this work can act as a potent device to intensify the synthesis of similar inorganic nanoparticles via multistep chemical precipitation processes.展开更多
In order to apply the knowledge based engineering to solve the low efficiency of serialized design,by analyzing the top-down design characteristics,a composite representation method for the design knowledge is propose...In order to apply the knowledge based engineering to solve the low efficiency of serialized design,by analyzing the top-down design characteristics,a composite representation method for the design knowledge is proposed.The object-knowledge is expressed by framework,and the construction principles of the framework are given,the design knowledge element is used to express the process-knowledge.Then the knowledge reasoning model for design decision-making is established.Finally,a case shows that the proposed method and model are effective.展开更多
The increasing trends in SoCs and SiPs technologies demand integration of large numbers of buses and metal tracks for interconnections. On-Chip SerDes Transceiver is a promising solution which can reduce the number of...The increasing trends in SoCs and SiPs technologies demand integration of large numbers of buses and metal tracks for interconnections. On-Chip SerDes Transceiver is a promising solution which can reduce the number of interconnects and offers remarkable benefits in context with power consumption, area congestion and crosstalk. This paper reports a design of a new Serializer and Deserializer architecture for basic functional operations of serialization and deserialization used in On-Chip SerDes Transceiver. This architecture employs a design technique which samples input on both edges of clock. The main advantage of this technique which is input is sampled with lower clock (half the original rate) and is distributed for the same functional throughput, which results in power savings in the clock distribution network. This proposed Serializer and Deserializer architecture is designed using UMC 180 nm CMOS technology and simulation is done using Cadence Spectre simulator with a supply voltage of 1.8 V. The present design is compared with the earlier published similar works and improvements are obtained in terms of power consumption and area as shown in Tables 1-3 respectively. This design also helps the designer for solving crosstalk issues.展开更多
针对工业机器人在高度制造领域精度不高的问题,本文提出了一种基于POE模型的工业机器人运动学参数二次辨识方法。阐述了基于指数积(Product of exponential, POE)模型的运动学误差模型构建方法,并建立基于POE误差模型的适应度函数;为实...针对工业机器人在高度制造领域精度不高的问题,本文提出了一种基于POE模型的工业机器人运动学参数二次辨识方法。阐述了基于指数积(Product of exponential, POE)模型的运动学误差模型构建方法,并建立基于POE误差模型的适应度函数;为实现高精度的参数辨识,提出了一种二次辨识方法,先利用改进灰狼优化算法(Improved grey wolf optimizer, IGWO)实现运动学参数误差的粗辨识,初步将Staubli TX60型机器人的平均位置误差和平均姿态误差分别从(0.648 mm, 0.212°)降低为(0.457 mm, 0.166°);为进一步提高机器人的精度性能,再通过LM(Levenberg-Marquard)算法进行参数误差的精辨识,最终将Staubli TX60型机器人平均位置误差和平均姿态误差进一步降低为(0.237 mm, 0.063°),机器人平均位置误差和平均姿态误差分别降低63.4%和70.2%。为了验证上述二次辨识方法的稳定性,随机选取5组辨识数据集和验证数据集进行POE误差模型的参数误差辨识,结果表明提出的二次辨识方法能够稳定、精确地辨识工业机器人运动学参数误差。展开更多
基金the financial support from the National Natural Science Foundation of China(21808059)the Fundamental Research Funds for the Central Universities(JKA01221712).
文摘A new microreactor with continuous serially connected micromixers(CSCM)was tailored for the coprecipitation process to synthesize Fe_(3)O_(4) nanoparticles.Numerical simulation reveals that the two types of CSCM microchannels(V-typed and U-typed)proposed in this work exhibited markedly better mixing performances than the Zigzag and capillary microchannels due to the promotion of Dean vortices.Complete mixing was achieved in the V-typed microchannel in 2.7 s at an inlet Reynolds number of 27.Fe_(3)O_(4) nanoparticles synthesized in a planar glass microreactor with the V-typed microchannel,possessing an average size of 9.3 nm and exhibiting superparamagnetism,had obviously better dispersity and uniformity and higher crystallinity than those obtained in the capillary microreactor.The new CSCM microreactor developed in this work can act as a potent device to intensify the synthesis of similar inorganic nanoparticles via multistep chemical precipitation processes.
基金the outsourcing project of the AECC Sichuan Gas Turbine Establishment and the science and technology project of Sichuan province(grant number 2019YFG0312)。
文摘In order to apply the knowledge based engineering to solve the low efficiency of serialized design,by analyzing the top-down design characteristics,a composite representation method for the design knowledge is proposed.The object-knowledge is expressed by framework,and the construction principles of the framework are given,the design knowledge element is used to express the process-knowledge.Then the knowledge reasoning model for design decision-making is established.Finally,a case shows that the proposed method and model are effective.
文摘The increasing trends in SoCs and SiPs technologies demand integration of large numbers of buses and metal tracks for interconnections. On-Chip SerDes Transceiver is a promising solution which can reduce the number of interconnects and offers remarkable benefits in context with power consumption, area congestion and crosstalk. This paper reports a design of a new Serializer and Deserializer architecture for basic functional operations of serialization and deserialization used in On-Chip SerDes Transceiver. This architecture employs a design technique which samples input on both edges of clock. The main advantage of this technique which is input is sampled with lower clock (half the original rate) and is distributed for the same functional throughput, which results in power savings in the clock distribution network. This proposed Serializer and Deserializer architecture is designed using UMC 180 nm CMOS technology and simulation is done using Cadence Spectre simulator with a supply voltage of 1.8 V. The present design is compared with the earlier published similar works and improvements are obtained in terms of power consumption and area as shown in Tables 1-3 respectively. This design also helps the designer for solving crosstalk issues.
文摘针对工业机器人在高度制造领域精度不高的问题,本文提出了一种基于POE模型的工业机器人运动学参数二次辨识方法。阐述了基于指数积(Product of exponential, POE)模型的运动学误差模型构建方法,并建立基于POE误差模型的适应度函数;为实现高精度的参数辨识,提出了一种二次辨识方法,先利用改进灰狼优化算法(Improved grey wolf optimizer, IGWO)实现运动学参数误差的粗辨识,初步将Staubli TX60型机器人的平均位置误差和平均姿态误差分别从(0.648 mm, 0.212°)降低为(0.457 mm, 0.166°);为进一步提高机器人的精度性能,再通过LM(Levenberg-Marquard)算法进行参数误差的精辨识,最终将Staubli TX60型机器人平均位置误差和平均姿态误差进一步降低为(0.237 mm, 0.063°),机器人平均位置误差和平均姿态误差分别降低63.4%和70.2%。为了验证上述二次辨识方法的稳定性,随机选取5组辨识数据集和验证数据集进行POE误差模型的参数误差辨识,结果表明提出的二次辨识方法能够稳定、精确地辨识工业机器人运动学参数误差。
