An expression for energy transfer probability （η） between host （TPD） and guest （Ir（ppy）3） phosphorescent systems is proposed,and the energy transfer process in doped organic electrophosphorescent （EP） devic...An expression for energy transfer probability （η） between host （TPD） and guest （Ir（ppy）3） phosphorescent systems is proposed,and the energy transfer process in doped organic electrophosphorescent （EP） devices is discussed. The results show that （1） The rate of the triplet energy transfer （KHG and KGH） exponentially increases with the host-guest molecular distance （R）, and KHG decreases quickly as the intermolecular distance of the guest （RGG） increases. In addition,the KHG/KGH ratio of the dopant system increases when R or RGG is reduced; （2） The energy transfer probability approximately linearly decreases as R increases from 0.8 to 1.2nm,and the variation of RGG can be neglected when R〈1.1nm. For 1. 1nm〈R〈l. 2nm, RGG （〈1.6nm） plays an increasingly important role when 71 drops with the latter＇ （3） η increases when the Forster energy transfer rate increases or Gibb＇s energy declines.展开更多
A scheme to design a simultaneous multichannel receiver is proposed to process multichannel signals in parallel, which is achieved by exploiting the attractive characteristics of a fast filter bank（ FFB）, such as ca...A scheme to design a simultaneous multichannel receiver is proposed to process multichannel signals in parallel, which is achieved by exploiting the attractive characteristics of a fast filter bank（ FFB）, such as cascaded structure, high frequency selectivity and lowcomputational complexity. Based on the minimization of the objective function, quantified in terms of the total number of multiplications required, subject to prescribed allowable ripples in the passband and stopband, the impulse response coefficients of the prototype filter in each stage are obtained to meet the requirements of the overall specifications for each channel at the receiver side. Simulations and experimental results on the frequency modulation（ FM） broadcast mutlichannel signal receiving system with the FM range from88 to 108 MHz, built upon the proposed FFB structure, are performed to verify its performance. Those results indicate that the proposed scheme is efficient in FM audio indexing applications and has a lower computational complexity, which is approximately 66. 4% of the weighted overlap and add（ WOLA） filter banks based solution.展开更多
The microstrip dual-mode filter （DMF） with conventional coupling structure has some limitations in- eluding the port coupling strength limited by fabrication tolerance and the existence of serious second order spuri...The microstrip dual-mode filter （DMF） with conventional coupling structure has some limitations in- eluding the port coupling strength limited by fabrication tolerance and the existence of serious second order spuri- ous band. Therefore, a novel DMF with a offset-feed bended coupling structure and a stepped-impedance dual- mode resonator is proposed for coupling enhancement and spurious response suppression. Based on the analysis of the change of spur frequencies and the current distribution of spur resonant modes, all spurs near passband of the cascaded DMF can be fully suppressed by optimizing the structure parameters of parasite resonators, which bene- fits from the inherent well-controlled transmission zeros. Experimental results show that the proposed DMF ex- hibits lower insertion loss ,much sharper rate of cutoff and wider spur-free stop band compared with conventional DMF. This design is applicable for spur suppression in wideband communication.展开更多
An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase curr...An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.展开更多
This report describes an equivalent doping profile transformation method with which the avalanche breakdown voltage of the asymmetric linearly graded junction was analytically predicted.The maximum breakdown voltage a...This report describes an equivalent doping profile transformation method with which the avalanche breakdown voltage of the asymmetric linearly graded junction was analytically predicted.The maximum breakdown voltage and the different depletion layer extension on the diffused side and substrate side are demonstrated in the report.The report shows the equivalent doping profile method is valid to predict the breakdown voltage of the complex P N junction.The analytical results agree with the experimental breakdown voltage in comparison with the abrupt junction and symmetric linearly graded junction approximations.展开更多
We report a wavelength tunable electro-absorption modulated DBR laser based on a combined method of SAG and QWI. The threshold current is 37mA and the output power at 100mA gain current is 3.5mW. When coupled to a sin...We report a wavelength tunable electro-absorption modulated DBR laser based on a combined method of SAG and QWI. The threshold current is 37mA and the output power at 100mA gain current is 3.5mW. When coupled to a single-mode fiber with a coupling efficiency of 15% ,more than a 20dB extinction ratio is observed over the change of EAM bias from 0 to -2V. The 4.4nm continuous wavelength tuning range covers 6 channels on a 100GHz grid for WDM telecommunications.展开更多
This paper presents an SG-DBR with a monolithically integrated SOA fabricated using quantum-well intermixing （QWI） for the first time in China's Mainland. The wavelength tuning range covers 33nm and the output p...This paper presents an SG-DBR with a monolithically integrated SOA fabricated using quantum-well intermixing （QWI） for the first time in China's Mainland. The wavelength tuning range covers 33nm and the output power reaches 10mW with an SOA current of 50mA. The device can work at available channels with SMSR over 35dB.展开更多
Polyaniline（PANI） nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors （PLi/C） based on Li-doping polyaniline and activated carbon e...Polyaniline（PANI） nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors （PLi/C） based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors （PLi/PLi） based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance （REs） of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor （5.5 Ω）. Moreover, it can be seen that EtgNBF4 organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPFr.展开更多
文摘An expression for energy transfer probability （η） between host （TPD） and guest （Ir（ppy）3） phosphorescent systems is proposed,and the energy transfer process in doped organic electrophosphorescent （EP） devices is discussed. The results show that （1） The rate of the triplet energy transfer （KHG and KGH） exponentially increases with the host-guest molecular distance （R）, and KHG decreases quickly as the intermolecular distance of the guest （RGG） increases. In addition,the KHG/KGH ratio of the dopant system increases when R or RGG is reduced; （2） The energy transfer probability approximately linearly decreases as R increases from 0.8 to 1.2nm,and the variation of RGG can be neglected when R〈1.1nm. For 1. 1nm〈R〈l. 2nm, RGG （〈1.6nm） plays an increasingly important role when 71 drops with the latter＇ （3） η increases when the Forster energy transfer rate increases or Gibb＇s energy declines.
基金The National Natural Science Foundation of China(No.61201173,61271058,61401094)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110092110008)+1 种基金the Natural Science Foundation of Jiangsu Province(No.SBK201140040,BK2011060,BK20140645)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China
文摘A scheme to design a simultaneous multichannel receiver is proposed to process multichannel signals in parallel, which is achieved by exploiting the attractive characteristics of a fast filter bank（ FFB）, such as cascaded structure, high frequency selectivity and lowcomputational complexity. Based on the minimization of the objective function, quantified in terms of the total number of multiplications required, subject to prescribed allowable ripples in the passband and stopband, the impulse response coefficients of the prototype filter in each stage are obtained to meet the requirements of the overall specifications for each channel at the receiver side. Simulations and experimental results on the frequency modulation（ FM） broadcast mutlichannel signal receiving system with the FM range from88 to 108 MHz, built upon the proposed FFB structure, are performed to verify its performance. Those results indicate that the proposed scheme is efficient in FM audio indexing applications and has a lower computational complexity, which is approximately 66. 4% of the weighted overlap and add（ WOLA） filter banks based solution.
基金Supported by the National Natural Science Foundation of China under Grant(60921063)the National Program on Key Basic Research Project(973Program)(2010CB327400)the National Science and Technology Major Project(2010ZX03007-002-01)~~
文摘The microstrip dual-mode filter （DMF） with conventional coupling structure has some limitations in- eluding the port coupling strength limited by fabrication tolerance and the existence of serious second order spuri- ous band. Therefore, a novel DMF with a offset-feed bended coupling structure and a stepped-impedance dual- mode resonator is proposed for coupling enhancement and spurious response suppression. Based on the analysis of the change of spur frequencies and the current distribution of spur resonant modes, all spurs near passband of the cascaded DMF can be fully suppressed by optimizing the structure parameters of parasite resonators, which bene- fits from the inherent well-controlled transmission zeros. Experimental results show that the proposed DMF ex- hibits lower insertion loss ,much sharper rate of cutoff and wider spur-free stop band compared with conventional DMF. This design is applicable for spur suppression in wideband communication.
文摘An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.
文摘This report describes an equivalent doping profile transformation method with which the avalanche breakdown voltage of the asymmetric linearly graded junction was analytically predicted.The maximum breakdown voltage and the different depletion layer extension on the diffused side and substrate side are demonstrated in the report.The report shows the equivalent doping profile method is valid to predict the breakdown voltage of the complex P N junction.The analytical results agree with the experimental breakdown voltage in comparison with the abrupt junction and symmetric linearly graded junction approximations.
文摘We report a wavelength tunable electro-absorption modulated DBR laser based on a combined method of SAG and QWI. The threshold current is 37mA and the output power at 100mA gain current is 3.5mW. When coupled to a single-mode fiber with a coupling efficiency of 15% ,more than a 20dB extinction ratio is observed over the change of EAM bias from 0 to -2V. The 4.4nm continuous wavelength tuning range covers 6 channels on a 100GHz grid for WDM telecommunications.
基金the National Natural Science Foundation of China(Nos.90401025,60736036,60706009,60777021)the State Key Development Program for Basic Research of China(Nos.2006CB604901,2006CB604902)the National High Technology Research and Development Program of China(Nos.2006AA01Z256,2007AA03Z419,2007AA03Z417)~~
文摘This paper presents an SG-DBR with a monolithically integrated SOA fabricated using quantum-well intermixing （QWI） for the first time in China's Mainland. The wavelength tuning range covers 33nm and the output power reaches 10mW with an SOA current of 50mA. The device can work at available channels with SMSR over 35dB.
基金Project(2008AA03Z207) supported by the National High-Tech Research and Development Program of China
文摘Polyaniline（PANI） nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors （PLi/C） based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors （PLi/PLi） based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance （REs） of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor （5.5 Ω）. Moreover, it can be seen that EtgNBF4 organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPFr.
