A power management unit (PMU) chip supplying dual panel supply voltage, which has a low electro-magnetic interference (EMI) characteristic and is favorable for miniaturization, is designed. A two-phase charge pump...A power management unit (PMU) chip supplying dual panel supply voltage, which has a low electro-magnetic interference (EMI) characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELVSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. The PMU chip is designed with MagnaChip's 0.25 μ high-voltage process. The driving currents of ELVDD and ELVSS are more than 50 mA when a SPICE simulation is done.展开更多
This paper proposes a control method for avalanche photodiode(APD) reverse bias with temperature compensation and load resistance compensation. The influence of background light and load resistance on APD detection ci...This paper proposes a control method for avalanche photodiode(APD) reverse bias with temperature compensation and load resistance compensation. The influence of background light and load resistance on APD detection circuit is analyzed in detail. A theoretical model of temperature compensation and load resistance compensation is established,which is used for APD biasing circuit designing. It is predicted that this control method is especially suitable for LD laser range finder used on vehicles. Experimental results confirm that the design proposed in this paper can considerablely improve the performance of range finder.展开更多
Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is propose...Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.展开更多
A Y-band frequency doubler is analyzed and designed with GaAs planar Schottky diode, which is flip-chip solded into a 50 μm thick quartz substrate. Diode embedding impedance is found by full- wave analysis with lumpe...A Y-band frequency doubler is analyzed and designed with GaAs planar Schottky diode, which is flip-chip solded into a 50 μm thick quartz substrate. Diode embedding impedance is found by full- wave analysis with lumped port to model the nonlinear junction for impedance matching without the need of diode equivalent circuit model. All the matching circuit is designed "on-chip" and the mul- tiplier is self-biasing. To the doubler, a conversion efficiency of 6.1% and output power of 5.4mW are measured at 214GHz with input power of 88mW, and the typical measured efficiency is 4.5% in 200 - 225 GHz.展开更多
This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer (PSS) and Thyristor Controlled Br...This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer (PSS) and Thyristor Controlled Braking Resistor (TCBR). This coordination will enhance the stability of the inertial and torsional oscillatory modes. The study is performed on system-I of the second IEEE benchmark for simulation of Sub-Synchronous Oscillations, using eigenvalue analysis and verified by detailed digital simulation. A dynamic fundamental frequency model for TCBR is developed. The pole placement technique is used to design the control system of TCBR and PSS. The shaft torque's following a disturbance is computed and analyzed. The obtained results indicate that substantial damping is achieved by the proposed coordination.展开更多
ADCS (automated data collection system) is the element of MDMS (meter data management system) and a module in charge of collecting the data from DCUs (data collection units) or meters in AMI (advanced metering ...ADCS (automated data collection system) is the element of MDMS (meter data management system) and a module in charge of collecting the data from DCUs (data collection units) or meters in AMI (advanced metering infrastructure)-based interactive two-way communications infrastructure. In this study, ADCS's functions for K-AMI (Korean Advanced Metering Infrastructure) were analyzed and the logical design of ADCS which is suitable for the requirements was suggested. A massive data collection and management functions was defined as very important functions of ADCS to meet optimal data processing mechanism. ADCS was designed for support about the fuctions of data collection and transfer, large capacity data processing, interactive services, parallel processing, etc.. Also, ADCS has roles of protocols exchange and gateway for service support in addition to data collection in AMI environment.展开更多
Mycophenolic acid (MPA), an immunosuppressive drug, was determined in human plasma by a simple capillary zone electrophoresis (CZE) method. A bare fused-silica capillary with an internal diameter (i.d.) of 75/am...Mycophenolic acid (MPA), an immunosuppressive drug, was determined in human plasma by a simple capillary zone electrophoresis (CZE) method. A bare fused-silica capillary with an internal diameter (i.d.) of 75/am and an effective length of 50 cm was used for the separation. A 200 }aL plasma sample was deproteinized with 400 μL acetonitrile, and the supematant was directly injected into the capillary after a water plug at a pressure of 0.5 psi for 10 s. Boric acid (H3BO3, 200 mmol/L) solution adjusted to a pH of 8.60 with 1 mol/L sodium hydroxide (NaOH) solution was selected as the background electrolyte (BGE) through a uniform design. Calibration curve established on each day was linear over the MPA concentration range of 0.625-30.0 Bg/mL in human plasma with the correlation coefficient (r) larger than 0.9997. The limit of detection (LOD) was 0.200 ~tg/mL. Intra- and inter-day precisions at three concentrations within the calibration range were less than 4.45%. Plasma samples collected from 14 renal transplant recipients treated with the prodrug mycophenolate mofetil (MMF) were analyzed successfully by both the developed CZE technique and a validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technique. The mean absolute and relative differences between the concentrations measured by the two methods were -0.17 and -0.20%, respectively. In conclusion, the CZE method described here was validated to be accurate, precise, and economical for the clinical quantification of MPA.展开更多
This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophore...This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.展开更多
As an im portant branch of fiber-shaped energy storage devices, the fiber-shaped supercapacitor has been widely studied recently. However, it remains challenging to simultaneously achieve fast electron transport and e...As an im portant branch of fiber-shaped energy storage devices, the fiber-shaped supercapacitor has been widely studied recently. However, it remains challenging to simultaneously achieve fast electron transport and excellent ion accessibility in one single fiber electrode of the fibershaped supercapacitor. Herein, a novel family of amphiphilic core-sheath structured carbon nanotube composite fibers has been developed and applied to the fiber-shaped supercapacitor to address the above challenge. The polyaniline-modified hydrophilic sheath of the composite fiber electrode effectively enhanced the electrochemical property via advancing ion accessibility, while Au-deposited hydrophobic core demonstrated improved electrical conductivity by fast electron supply. On the basis of a synergistic effect, a remarkable specific capacitance of 324 F cm^-3 at 0.5 A cm^-3 and greatly enhanced rate performance were achieved, i.e” a 79% retention (256 F cm 3) at 50 A cm^-3. The obtained fiber-shaped supercapacitor finally displayed remarkable energy and power densities of 7.2 mW h cm 3 and 10 W cm^-3, respectively. The strategy developed herein also presents a general pathway towards novel fiber electrodes for high-performance wearable devices.展开更多
Two silicon-based ultraviolet (UV) and blue-extended photodiodes are presented, which were fabricated for light detection in the ultraviolet/blue spectral range. Stripe-shaped and octagon-ring-shaped structures were...Two silicon-based ultraviolet (UV) and blue-extended photodiodes are presented, which were fabricated for light detection in the ultraviolet/blue spectral range. Stripe-shaped and octagon-ring-shaped structures were designed to verify parameters of the UV-responsivity, UV-selectivity, breakdown voltage, and response time. The ultra-shallow lateral pn junction had been successfully realized in a standard 0.5-μm complementary metal oxide semiconductor (CMOS) process to enlarge the pn junction area, enhance the absorption of UV light, and improve the responsivity and quantum efficiency. The test results illustrated that the stripe-shaped structure has the lower breakdown voltage, higher UV-responsicity, and higher UV-selectivity. But the octagon-ring-shaped structure has the lower dark current. The response time of both structures was almost the same.展开更多
The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of tra...The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of traditional semiconductors. However, the realization of high performance 2D semiconductorbased field-effect transistors(FETs) has been a longstanding challenge in 2D electronics, which is mainly ascribing to the presence of significant Schottky barrier(SB) at metal-semiconductor interfaces. Here, an additional contact gate is induced in 2D ambipolar FET to realize near ideal reconfigurable FET(RFET)devices without restrictions of SB. Benefitting from the consistently high doping of contact region, the effective SB height can be maintained at ultra-small value during all operation conditions, resulting in the near ideal subthreshold swing(SS) values(132 mV/decade for MoTe2 RFET and 67 mV/decade for WSe2 RFET) and the relatively high mobility(28.6 cm2/(Vs) for MoTe2 RFET and 89.8 cm2/(V s) for WSe2 RFET). Moreover, the flexible control on the doping polarity of contact region enables the remodeling and switching of the achieved unipolar FETs between p-type mode and n-type mode. Based on such reconfigurable behaviors, high gain complementary MoTe2 inverters are further realized. The findings in this work push forward the development of high-performance 2D semiconductor integrated devices and circuits.展开更多
For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will...For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will inevitably lead to a substantial increase in the development cost.To improve the system price-performance ratio,a new kind of series-parallel hybrid system evolved from the series plug-in hybrid system is designed.According to the technical parameters of the selected components,the system model is established,and the vehicle dynamic property and pure electric drive economy are evaluated.Based on the dynamic programming,the energy management strategy for the drive system under the city driving cycle is developed,and the superiority validation of the system is completed.For the studied vehicle driven by the designed series-parallel plug-in hybrid system,compared with the one driven by the described series plug-in hybrid system,the dynamic property is significantly improved because of the multi-power coupling,and the fuel consumption is reduced by 11.4%with 10 city driving cycles.In a word,with the flexible configuration of the designed hybrid system and the optimized control strategy of the energy management,the vehicle performance can be obviously improved.展开更多
文摘A power management unit (PMU) chip supplying dual panel supply voltage, which has a low electro-magnetic interference (EMI) characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELVSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. The PMU chip is designed with MagnaChip's 0.25 μ high-voltage process. The driving currents of ELVDD and ELVSS are more than 50 mA when a SPICE simulation is done.
文摘This paper proposes a control method for avalanche photodiode(APD) reverse bias with temperature compensation and load resistance compensation. The influence of background light and load resistance on APD detection circuit is analyzed in detail. A theoretical model of temperature compensation and load resistance compensation is established,which is used for APD biasing circuit designing. It is predicted that this control method is especially suitable for LD laser range finder used on vehicles. Experimental results confirm that the design proposed in this paper can considerablely improve the performance of range finder.
基金supported by Program for New Century Excellent Talents in University(NCET)(2008)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality+1 种基金 (PHR(IHLB)) and Beijing Novel Research Star(2005B01)Ministry of Beijing Science and Technology
文摘Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.
基金Supported by the 12th Five-year Defense Pre-research Fund of China(No.51308030509)
文摘A Y-band frequency doubler is analyzed and designed with GaAs planar Schottky diode, which is flip-chip solded into a 50 μm thick quartz substrate. Diode embedding impedance is found by full- wave analysis with lumped port to model the nonlinear junction for impedance matching without the need of diode equivalent circuit model. All the matching circuit is designed "on-chip" and the mul- tiplier is self-biasing. To the doubler, a conversion efficiency of 6.1% and output power of 5.4mW are measured at 214GHz with input power of 88mW, and the typical measured efficiency is 4.5% in 200 - 225 GHz.
文摘This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer (PSS) and Thyristor Controlled Braking Resistor (TCBR). This coordination will enhance the stability of the inertial and torsional oscillatory modes. The study is performed on system-I of the second IEEE benchmark for simulation of Sub-Synchronous Oscillations, using eigenvalue analysis and verified by detailed digital simulation. A dynamic fundamental frequency model for TCBR is developed. The pole placement technique is used to design the control system of TCBR and PSS. The shaft torque's following a disturbance is computed and analyzed. The obtained results indicate that substantial damping is achieved by the proposed coordination.
文摘ADCS (automated data collection system) is the element of MDMS (meter data management system) and a module in charge of collecting the data from DCUs (data collection units) or meters in AMI (advanced metering infrastructure)-based interactive two-way communications infrastructure. In this study, ADCS's functions for K-AMI (Korean Advanced Metering Infrastructure) were analyzed and the logical design of ADCS which is suitable for the requirements was suggested. A massive data collection and management functions was defined as very important functions of ADCS to meet optimal data processing mechanism. ADCS was designed for support about the fuctions of data collection and transfer, large capacity data processing, interactive services, parallel processing, etc.. Also, ADCS has roles of protocols exchange and gateway for service support in addition to data collection in AMI environment.
基金Plan of Vitalizing Education Action Geared to the 21st Century(Plan 985)the 1st Phase Fund of Peking University 985 Project.
文摘Mycophenolic acid (MPA), an immunosuppressive drug, was determined in human plasma by a simple capillary zone electrophoresis (CZE) method. A bare fused-silica capillary with an internal diameter (i.d.) of 75/am and an effective length of 50 cm was used for the separation. A 200 }aL plasma sample was deproteinized with 400 μL acetonitrile, and the supematant was directly injected into the capillary after a water plug at a pressure of 0.5 psi for 10 s. Boric acid (H3BO3, 200 mmol/L) solution adjusted to a pH of 8.60 with 1 mol/L sodium hydroxide (NaOH) solution was selected as the background electrolyte (BGE) through a uniform design. Calibration curve established on each day was linear over the MPA concentration range of 0.625-30.0 Bg/mL in human plasma with the correlation coefficient (r) larger than 0.9997. The limit of detection (LOD) was 0.200 ~tg/mL. Intra- and inter-day precisions at three concentrations within the calibration range were less than 4.45%. Plasma samples collected from 14 renal transplant recipients treated with the prodrug mycophenolate mofetil (MMF) were analyzed successfully by both the developed CZE technique and a validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technique. The mean absolute and relative differences between the concentrations measured by the two methods were -0.17 and -0.20%, respectively. In conclusion, the CZE method described here was validated to be accurate, precise, and economical for the clinical quantification of MPA.
基金supported by AcRF Tier 1(RG 8/16,RG 133/14 and RG 13/15)from MOE,SingaporeSTU Scientific Research Foundation for Talents(NTF15005)+1 种基金STU Youth Research Fund(YR15001)the Foundation for Young Talents in Higher Education of Guangdong(2015KQNCX042)
文摘This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.
基金supported by the Ministry of Science and Technology (2016YFA0203302)the National Natural Science Foundation of China (21634003, 51573027, 51673043, 21604012, 21805044 and 21875042)+1 种基金Shanghai Science and Technology Committee (16JC1400702, 17QA1400400, 18QA1400700 and 18QA1400800)SHMEC (2017-01-07-00-07-E00062)
文摘As an im portant branch of fiber-shaped energy storage devices, the fiber-shaped supercapacitor has been widely studied recently. However, it remains challenging to simultaneously achieve fast electron transport and excellent ion accessibility in one single fiber electrode of the fibershaped supercapacitor. Herein, a novel family of amphiphilic core-sheath structured carbon nanotube composite fibers has been developed and applied to the fiber-shaped supercapacitor to address the above challenge. The polyaniline-modified hydrophilic sheath of the composite fiber electrode effectively enhanced the electrochemical property via advancing ion accessibility, while Au-deposited hydrophobic core demonstrated improved electrical conductivity by fast electron supply. On the basis of a synergistic effect, a remarkable specific capacitance of 324 F cm^-3 at 0.5 A cm^-3 and greatly enhanced rate performance were achieved, i.e” a 79% retention (256 F cm 3) at 50 A cm^-3. The obtained fiber-shaped supercapacitor finally displayed remarkable energy and power densities of 7.2 mW h cm 3 and 10 W cm^-3, respectively. The strategy developed herein also presents a general pathway towards novel fiber electrodes for high-performance wearable devices.
基金This work is supported by the State Key Program of National Natural Science of China (61233010), by the National Natural Science Foundation of China (61274043) and by the Program for New Century Excellent Talents in University of Ministry of Education of China (NCET- 11-0975). Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
文摘Two silicon-based ultraviolet (UV) and blue-extended photodiodes are presented, which were fabricated for light detection in the ultraviolet/blue spectral range. Stripe-shaped and octagon-ring-shaped structures were designed to verify parameters of the UV-responsivity, UV-selectivity, breakdown voltage, and response time. The ultra-shallow lateral pn junction had been successfully realized in a standard 0.5-μm complementary metal oxide semiconductor (CMOS) process to enlarge the pn junction area, enhance the absorption of UV light, and improve the responsivity and quantum efficiency. The test results illustrated that the stripe-shaped structure has the lower breakdown voltage, higher UV-responsicity, and higher UV-selectivity. But the octagon-ring-shaped structure has the lower dark current. The response time of both structures was almost the same.
基金supported by the National Natural Science Foundation of China (U19A2090, 51902098, 51972105, 51525202, and 61574054)the Hunan Provincial Natural Science Foundation (2018RS3051)。
文摘The newly emerged two-dimensional(2D) semiconducting materials, owning to the atomic thick nature and excellent optical and electrical properties, are considered as potential candidates to solve the bottlenecks of traditional semiconductors. However, the realization of high performance 2D semiconductorbased field-effect transistors(FETs) has been a longstanding challenge in 2D electronics, which is mainly ascribing to the presence of significant Schottky barrier(SB) at metal-semiconductor interfaces. Here, an additional contact gate is induced in 2D ambipolar FET to realize near ideal reconfigurable FET(RFET)devices without restrictions of SB. Benefitting from the consistently high doping of contact region, the effective SB height can be maintained at ultra-small value during all operation conditions, resulting in the near ideal subthreshold swing(SS) values(132 mV/decade for MoTe2 RFET and 67 mV/decade for WSe2 RFET) and the relatively high mobility(28.6 cm2/(Vs) for MoTe2 RFET and 89.8 cm2/(V s) for WSe2 RFET). Moreover, the flexible control on the doping polarity of contact region enables the remodeling and switching of the achieved unipolar FETs between p-type mode and n-type mode. Based on such reconfigurable behaviors, high gain complementary MoTe2 inverters are further realized. The findings in this work push forward the development of high-performance 2D semiconductor integrated devices and circuits.
基金supported by the National Natural Science Foundation of China(Grant No.51405259)China Postdoctoral Science Foundation funded project(Grant Nos.2014T70072&2013M530608)Colleges and Universities in Hebei Province Science and Technology Research Project(Grant No.QN2015056)
文摘For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will inevitably lead to a substantial increase in the development cost.To improve the system price-performance ratio,a new kind of series-parallel hybrid system evolved from the series plug-in hybrid system is designed.According to the technical parameters of the selected components,the system model is established,and the vehicle dynamic property and pure electric drive economy are evaluated.Based on the dynamic programming,the energy management strategy for the drive system under the city driving cycle is developed,and the superiority validation of the system is completed.For the studied vehicle driven by the designed series-parallel plug-in hybrid system,compared with the one driven by the described series plug-in hybrid system,the dynamic property is significantly improved because of the multi-power coupling,and the fuel consumption is reduced by 11.4%with 10 city driving cycles.In a word,with the flexible configuration of the designed hybrid system and the optimized control strategy of the energy management,the vehicle performance can be obviously improved.