The main factors that affected consumer purchase intention toward slimming underwear(SU) were investigated through the construction of a consumer behavior model. The constructed model was tested by structural equation...The main factors that affected consumer purchase intention toward slimming underwear(SU) were investigated through the construction of a consumer behavior model. The constructed model was tested by structural equation modeling. "Perceived risk" had a negative effect on the "attitude". "Perceived benefit" and "subjective norm" had positive impacts on the "attitude". And "attitude" significantly influenced consumer "purchase intention". However, "product knowledge" had no significant influence on the "purchase intention". The result provided initial framework for researchers to conduct further investigation and enlighten the SU enterprises to improve performance.展开更多
无损离子操纵结构(structures for lossless ion manipulations,SLIM)是一种在特殊背景气体下,利用静电场、射频电场、离子驱动电场共同作用实现对气相离子无损传输的新结构,在物质传输和分离方面有着广阔的应用前景。为了充分发挥SLIM...无损离子操纵结构(structures for lossless ion manipulations,SLIM)是一种在特殊背景气体下,利用静电场、射频电场、离子驱动电场共同作用实现对气相离子无损传输的新结构,在物质传输和分离方面有着广阔的应用前景。为了充分发挥SLIM在体积和成本上的优势,本研究研制了一款体积小、结构紧凑、成本经济的高频高压双极性射频(radio frequency,RF)电源。该电源使用隔离模块实现控制电路与功率电路的电气隔离,并采用以GaN金属-氧化物-半导体场效应管(MOSFET)为核心的半桥电路作为输出级。针对SLIM的容性负载特性,利用电阻-电感-电容(RLC)电路的滤波特性,实现双极性正弦脉冲电压的输出。经测试,该电源可输出频率1 MHz、峰-峰值420 V(±210 V)的双极性正弦射频高压信号。在实验室自建的基于行波(traveling wave,TW)的无损离子操纵结构(TW-SLIM)迁移谱实验平台上,以甲基膦酸二甲酯(DMMP)为样本,深入探究了射频电源幅值及频率对小分子离子传输效率的影响。结果表明,射频电源幅值及频率均会对TW-SLIM结构的离子传输效率产生影响,并存在1个最优值范围,这与COMSOL的仿真结果相吻合。该射频电源能够有效支持TW-SLIM平台的稳定运行,对推动基于SLIM的小分子迁移谱技术的小型化和便携化研发具有重要价值。展开更多
单边直线感应电机(Single-sided Linear Induction Motors,SLIMs)作为中低速磁悬浮列车的驱动装置,其推力和法向力的耦合控制特性以及系统的抗扰动能力,对于磁浮列车的牵引及悬浮系统动态运行极为重要。本文分别建立SLIM的最大推力点和...单边直线感应电机(Single-sided Linear Induction Motors,SLIMs)作为中低速磁悬浮列车的驱动装置,其推力和法向力的耦合控制特性以及系统的抗扰动能力,对于磁浮列车的牵引及悬浮系统动态运行极为重要。本文分别建立SLIM的最大推力点和法向力过零点的转差频率-电流控制模型,研究了将两者协同优化控制的变电流分段变转差频率(Variant-Current Variable Slip-Frequency,VCVSF)策略。建立了在稳态转差频率下的法向力控制电流与悬浮气隙的二维状态空间Popov超稳定模型,通过在线性环节增加前馈补偿器保证等价反馈系统严格正实,从而实现零点处法向力稳态振动的自收敛。实验研究验证了本文所提控制算法的有效性。展开更多
To correct the S-distortion in large deflection angle cathode-ray tubes （CRTs）,ideal deflection current waveforms are proposed to realize S-correction.Analysis was done for homogenous and non-homogenous magnetic fie...To correct the S-distortion in large deflection angle cathode-ray tubes （CRTs）,ideal deflection current waveforms are proposed to realize S-correction.Analysis was done for homogenous and non-homogenous magnetic fields, plane and curved screen.For the convenience of circuit design,high order sine waveforms are used to approach the ideal deflection current.After optimization,the deflection current is acceptably close to the ideal one,for a deflection angle range from 90° up to 140°.Harmonic current rank rises to four as the deflection angle reaches 140°.A ladder-type driving circuit to realize these sine wave series is also presented.Simulation and experiments prove the proposed method can correct the S-distortion in a very slim CRT.展开更多
文摘The main factors that affected consumer purchase intention toward slimming underwear(SU) were investigated through the construction of a consumer behavior model. The constructed model was tested by structural equation modeling. "Perceived risk" had a negative effect on the "attitude". "Perceived benefit" and "subjective norm" had positive impacts on the "attitude". And "attitude" significantly influenced consumer "purchase intention". However, "product knowledge" had no significant influence on the "purchase intention". The result provided initial framework for researchers to conduct further investigation and enlighten the SU enterprises to improve performance.
文摘无损离子操纵结构(structures for lossless ion manipulations,SLIM)是一种在特殊背景气体下,利用静电场、射频电场、离子驱动电场共同作用实现对气相离子无损传输的新结构,在物质传输和分离方面有着广阔的应用前景。为了充分发挥SLIM在体积和成本上的优势,本研究研制了一款体积小、结构紧凑、成本经济的高频高压双极性射频(radio frequency,RF)电源。该电源使用隔离模块实现控制电路与功率电路的电气隔离,并采用以GaN金属-氧化物-半导体场效应管(MOSFET)为核心的半桥电路作为输出级。针对SLIM的容性负载特性,利用电阻-电感-电容(RLC)电路的滤波特性,实现双极性正弦脉冲电压的输出。经测试,该电源可输出频率1 MHz、峰-峰值420 V(±210 V)的双极性正弦射频高压信号。在实验室自建的基于行波(traveling wave,TW)的无损离子操纵结构(TW-SLIM)迁移谱实验平台上,以甲基膦酸二甲酯(DMMP)为样本,深入探究了射频电源幅值及频率对小分子离子传输效率的影响。结果表明,射频电源幅值及频率均会对TW-SLIM结构的离子传输效率产生影响,并存在1个最优值范围,这与COMSOL的仿真结果相吻合。该射频电源能够有效支持TW-SLIM平台的稳定运行,对推动基于SLIM的小分子迁移谱技术的小型化和便携化研发具有重要价值。
文摘To correct the S-distortion in large deflection angle cathode-ray tubes （CRTs）,ideal deflection current waveforms are proposed to realize S-correction.Analysis was done for homogenous and non-homogenous magnetic fields, plane and curved screen.For the convenience of circuit design,high order sine waveforms are used to approach the ideal deflection current.After optimization,the deflection current is acceptably close to the ideal one,for a deflection angle range from 90° up to 140°.Harmonic current rank rises to four as the deflection angle reaches 140°.A ladder-type driving circuit to realize these sine wave series is also presented.Simulation and experiments prove the proposed method can correct the S-distortion in a very slim CRT.
