A miniaturized broadband Wilkinson power divider is proposed. Micro-strip branch lines are introduced to replace multiple resistors used in multi-stage Wilkinson power dividers to increase the bandwidth of single-stag...A miniaturized broadband Wilkinson power divider is proposed. Micro-strip branch lines are introduced to replace multiple resistors used in multi-stage Wilkinson power dividers to increase the bandwidth of single-stage Wilkinson power dividers. To demonstrate its performance, an improved single-stage Wilkinson power divider with four micro-strip branch lines was designed. Simulated results show that the insert loss is better than 3.2 dB, the input return loss, output return loss, and isolation are better than 15 dB respectively, across a 76% bandwidth from 18 to 40 GHz. .展开更多
In order to reduce the "trial-mold" risk and cost,numerical simulation method was applied to micro injection molding weld line development investigation. The micro tensile specimen which has the size of 0.1 ...In order to reduce the "trial-mold" risk and cost,numerical simulation method was applied to micro injection molding weld line development investigation. The micro tensile specimen which has the size of 0.1 mm(depth) ×0.4 mm(width) ×12 mm(length) in test area was selected as the objective part,and polypropylene(PP) as the experimental material. Respectively with specific commercial software(Mold Flow) and general computational fluid dynamic(CFD) software(Comsol Multiphysics) ,the simulation experiments for development of weld line in micro injection molding process were executed and the real comparison experiments were also carried out. The results show that during micro injection molding process,the specific commercial software for normal injection molding process is not valid to describe the micro flow process,the shape of flow front in micro cavity flowing which is important in weld line developing study and the contact angle due to surface tension are not able to be simulated. In order to improve the simulation results for micro weld line development,the general CFD software,which is more flexible in user defining function,is applied. The results show better effects in describing micro fluid flow behavior. As a conclusion,as for weld line forming process,the numerical simulation method can give a characteristic analysis results for processing parameters optimizing in micro injection molding process;but for both kinds of softwares quantitative analysis cannot be obtained unless the boundary condition and micro fluid mathematic model are improved in the future.展开更多
In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bu...In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h<sub>2</sub> equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The results of simulations have been compared with those calculated by the Ansoft HFSS software, and they are in good concordance, validating the method of analysis used. The second model is based on the calculation of the effective permittivity of the medium containing the thick conductor. This medium consists of a metallic region of complex relative permittivity , the rest of this medium is filled with air e<sub>r</sub><sub>2</sub> = 1. The effective permittivity e<sub>eff</sub> calculated from these two relative permittivity e<sub>r</sub><sub>2</sub> and . Comparing the simulation results of this new formulation of the iterative method with those calculated by the software Ansoft HFSS shows that they are in good matching which validates the second model.展开更多
A modularized, network, reconfigurable architecture and design method of embedded control module is proposed. This control module uses a TMS320F2812 chip as the core, and intro- duces modularization, network, reconfig...A modularized, network, reconfigurable architecture and design method of embedded control module is proposed. This control module uses a TMS320F2812 chip as the core, and intro- duces modularization, network, reconfigurable theory to the design of control module to better meet the flexible and reconfigurable control need of assembly line. The design method of the control module is verified by constructing a control experiment based on controlling of precision x - y displace- ment platform through a CAN bus. Experimental results show that the controlling repeat position accuracy of precision x - y platform by control module is 0. 5 μm and the position error is less than 1μm which meet the needs of micro-adjustment pose of assembly line.展开更多
In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of str...In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.展开更多
Objective To establish stable prostate cancer bone metastasis cell line overexpressing microRAN-145 (miR-145)for the study of the mechanism of miR-145 in bone metastasis.Methods pMSCV-miR-145 plasmids and retroviruses...Objective To establish stable prostate cancer bone metastasis cell line overexpressing microRAN-145 (miR-145)for the study of the mechanism of miR-145 in bone metastasis.Methods pMSCV-miR-145 plasmids and retroviruses of pMSCV-vector展开更多
A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirr...A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection.Tunable diode laser spectroscopy(TDLS) and photoacoustic spectroscopy(PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile.The target gas is 0.01% acetylene(C2H2) in a nitrogen host gas.The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp,and an erbium-doped fibre amplifier(EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio(SNR).A SNR of about 35 is obtained with 100 mW laser power from the EDFA.Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.展开更多
文摘A miniaturized broadband Wilkinson power divider is proposed. Micro-strip branch lines are introduced to replace multiple resistors used in multi-stage Wilkinson power dividers to increase the bandwidth of single-stage Wilkinson power dividers. To demonstrate its performance, an improved single-stage Wilkinson power divider with four micro-strip branch lines was designed. Simulated results show that the insert loss is better than 3.2 dB, the input return loss, output return loss, and isolation are better than 15 dB respectively, across a 76% bandwidth from 18 to 40 GHz. .
基金Project(ZI648/13-1) supported by German Research FoundationProject(D/06/00373) supported by German Academic Exchange Service
文摘In order to reduce the "trial-mold" risk and cost,numerical simulation method was applied to micro injection molding weld line development investigation. The micro tensile specimen which has the size of 0.1 mm(depth) ×0.4 mm(width) ×12 mm(length) in test area was selected as the objective part,and polypropylene(PP) as the experimental material. Respectively with specific commercial software(Mold Flow) and general computational fluid dynamic(CFD) software(Comsol Multiphysics) ,the simulation experiments for development of weld line in micro injection molding process were executed and the real comparison experiments were also carried out. The results show that during micro injection molding process,the specific commercial software for normal injection molding process is not valid to describe the micro flow process,the shape of flow front in micro cavity flowing which is important in weld line developing study and the contact angle due to surface tension are not able to be simulated. In order to improve the simulation results for micro weld line development,the general CFD software,which is more flexible in user defining function,is applied. The results show better effects in describing micro fluid flow behavior. As a conclusion,as for weld line forming process,the numerical simulation method can give a characteristic analysis results for processing parameters optimizing in micro injection molding process;but for both kinds of softwares quantitative analysis cannot be obtained unless the boundary condition and micro fluid mathematic model are improved in the future.
文摘In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h<sub>2</sub> equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The results of simulations have been compared with those calculated by the Ansoft HFSS software, and they are in good concordance, validating the method of analysis used. The second model is based on the calculation of the effective permittivity of the medium containing the thick conductor. This medium consists of a metallic region of complex relative permittivity , the rest of this medium is filled with air e<sub>r</sub><sub>2</sub> = 1. The effective permittivity e<sub>eff</sub> calculated from these two relative permittivity e<sub>r</sub><sub>2</sub> and . Comparing the simulation results of this new formulation of the iterative method with those calculated by the software Ansoft HFSS shows that they are in good matching which validates the second model.
基金Supported by National Defense Basic Scientific Research Project(A092000000)High Quality CNC Machine Tool and Basic Manufacturing Equipment Scientific Major Project(2012ZX04010-061)
文摘A modularized, network, reconfigurable architecture and design method of embedded control module is proposed. This control module uses a TMS320F2812 chip as the core, and intro- duces modularization, network, reconfigurable theory to the design of control module to better meet the flexible and reconfigurable control need of assembly line. The design method of the control module is verified by constructing a control experiment based on controlling of precision x - y displace- ment platform through a CAN bus. Experimental results show that the controlling repeat position accuracy of precision x - y platform by control module is 0. 5 μm and the position error is less than 1μm which meet the needs of micro-adjustment pose of assembly line.
文摘In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.
文摘Objective To establish stable prostate cancer bone metastasis cell line overexpressing microRAN-145 (miR-145)for the study of the mechanism of miR-145 in bone metastasis.Methods pMSCV-miR-145 plasmids and retroviruses of pMSCV-vector
基金Financial support from National High Technology Research and Development Programof China(Grant No.:2007A A06Z1122007AA03Z446)
文摘A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection.Tunable diode laser spectroscopy(TDLS) and photoacoustic spectroscopy(PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile.The target gas is 0.01% acetylene(C2H2) in a nitrogen host gas.The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp,and an erbium-doped fibre amplifier(EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio(SNR).A SNR of about 35 is obtained with 100 mW laser power from the EDFA.Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.
