The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases： the site-dependent flnite-chain discrete case and the site-independent cont...The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases： the site-dependent flnite-chain discrete case and the site-independent continuous one. The treatments in the two cases are proven to be consistent in theory and calculation. Discrete and continuous treatments of Holstein model both can yield a nonlinear equation to describe the charge migration in an actual long-range DNA chain. Our theoretical results of binding energy Eb, probability amplitude of charge carrier Ф and the relation between energy and charge-lattice coupling strength are in accordance with the available experimental results and recent theoretical calculations.展开更多
An optimized dual fiber Bragg grating （FBG） is proposed for 980-nm semiconductor lasers without thermoelectric coolers to restrict temperature-induced wavelength shift.The mathematical model of the temperature-induc...An optimized dual fiber Bragg grating （FBG） is proposed for 980-nm semiconductor lasers without thermoelectric coolers to restrict temperature-induced wavelength shift.The mathematical model of the temperature-induced wavelength shift of the laser with the dual FBG is built using the external cavity feedback rate equations.The external cavity parameters are optimized for achieving the stability mode-locking laser output.The spectral characteristics of the dual FBG stabilized laser are measured to range from 0 to 70 °C.The side mode suppression ratio （SMSR） is more than 45 dB,while the full-width at half-maximum （FWHM） is less than 1 nm.The peak wavelength shift is less than 0.1 nm.The dual FBG wavelength shift proportional coefficient is between 0.1086 and 0.4342.展开更多
A P^＋-nc-Si：H film（boron-doped nc-Si：H thin film） was used as a complex anode of an OLED.As an ideal candidate for the composite anode,the P^＋-nc-Si：H thin film has a good conductivity with a high work function...A P^＋-nc-Si：H film（boron-doped nc-Si：H thin film） was used as a complex anode of an OLED.As an ideal candidate for the composite anode,the P^＋-nc-Si：H thin film has a good conductivity with a high work function（- 5.7 eV） and outstanding optical properties of high reflectivity,transmission,and a very low absorption.As a result,the combination of the relatively high reflectivity of a P^＋-nc-Si：H film/ITO complex anode with the very high reflectivity of an Al cathode could form a micro-cavity structure with a certain Q to improve the efficiency of the OLED fabricated on it.An RGB pixel generated by microcavity OLEDs is beneficial for both the reduction of the light loss and the improvement of the color purity and the efficiency.The small molecule Alq would be useful for the emitting light layer（EML） of the MOLED,and the P^＋-nc-Si film would be used as a complex anode of the MOLED,whose configuration can be constructed as Glass/LTO/P^＋-nc-Si：H/ITO/MoO3/NPB/Alq/LiF/Al.By adjusting the thickness of the organic layer NPB/Alq,the optical length of the microcavity and the REB colors of the device can be obtained.The peak wavelengths of an OLED are located at 486,550,and 608 nm,respectively.The CIE coordinates are（0.21,0.45）,（0.33,0.63）,and（0.54,0.54）,and the full widths at half maximum（FWHM） are 35,32,and 39 nm for red,green,and blue,respectively.展开更多
Energy autonomy is key to the next generation portable and wearable systems for several applications.Among these,the electronic-skin or e-skin is currently a matter of intensive investigations due to its wider applica...Energy autonomy is key to the next generation portable and wearable systems for several applications.Among these,the electronic-skin or e-skin is currently a matter of intensive investigations due to its wider applicability in areas,ranging from robotics to digital health,fashion and internet of things(IoT).The high density of multiple types of electronic components(e.g.sensors,actuators,electronics,etc.)required in e-skin,and the need to power them without adding heavy batteries,have fuelled the development of compact flexible energy systems to realize self-powered or energy-autonomous e-skin.The compact and wearable energy systems consisting of energy harvesters,energy storage devices,low-power electronics and efficient/wireless power transfer-based technologies,are expected to revolutionize the market for wearable systems and in particular for e-skin.This paper reviews the development in the field of self-powered e-skin,particularly focussing on the available energy-harvesting technologies,high capacity energy storage devices,and high efficiency power transmission systems.The paper highlights the key challenges,critical design strategies,and most promising materials for the development of an energy-autonomous e-skin for robotics,prosthetics and wearable systems.This paper will complement other reviews on e-skin,which have focussed on the type of sensors and electronics components.展开更多
基金Project supported by the National Nature Science Foundation of China （Grant No 50272063） and the Foundation for Excellent Talents of Anhui Province, China （Grant No 2001Z016）.
文摘The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases： the site-dependent flnite-chain discrete case and the site-independent continuous one. The treatments in the two cases are proven to be consistent in theory and calculation. Discrete and continuous treatments of Holstein model both can yield a nonlinear equation to describe the charge migration in an actual long-range DNA chain. Our theoretical results of binding energy Eb, probability amplitude of charge carrier Ф and the relation between energy and charge-lattice coupling strength are in accordance with the available experimental results and recent theoretical calculations.
基金supported by the National High-Tech Research and Development ("863") Program of China (No.2006AA03Z348)the Key Program of Science and Technology Research of Shanghai Education Commission (No.10ZZ94)+1 种基金the Shanghai Leading Academic Discipline Project (No.S30502)the Shanghai Talents Developing Foundation (No.014)
文摘An optimized dual fiber Bragg grating （FBG） is proposed for 980-nm semiconductor lasers without thermoelectric coolers to restrict temperature-induced wavelength shift.The mathematical model of the temperature-induced wavelength shift of the laser with the dual FBG is built using the external cavity feedback rate equations.The external cavity parameters are optimized for achieving the stability mode-locking laser output.The spectral characteristics of the dual FBG stabilized laser are measured to range from 0 to 70 °C.The side mode suppression ratio （SMSR） is more than 45 dB,while the full-width at half-maximum （FWHM） is less than 1 nm.The peak wavelength shift is less than 0.1 nm.The dual FBG wavelength shift proportional coefficient is between 0.1086 and 0.4342.
基金supported by the National High Technology Research and Development Program of China(No.2004AA303570)the National Natural Science Foundation of China (No. 60437030)
文摘A P^＋-nc-Si：H film（boron-doped nc-Si：H thin film） was used as a complex anode of an OLED.As an ideal candidate for the composite anode,the P^＋-nc-Si：H thin film has a good conductivity with a high work function（- 5.7 eV） and outstanding optical properties of high reflectivity,transmission,and a very low absorption.As a result,the combination of the relatively high reflectivity of a P^＋-nc-Si：H film/ITO complex anode with the very high reflectivity of an Al cathode could form a micro-cavity structure with a certain Q to improve the efficiency of the OLED fabricated on it.An RGB pixel generated by microcavity OLEDs is beneficial for both the reduction of the light loss and the improvement of the color purity and the efficiency.The small molecule Alq would be useful for the emitting light layer（EML） of the MOLED,and the P^＋-nc-Si film would be used as a complex anode of the MOLED,whose configuration can be constructed as Glass/LTO/P^＋-nc-Si：H/ITO/MoO3/NPB/Alq/LiF/Al.By adjusting the thickness of the organic layer NPB/Alq,the optical length of the microcavity and the REB colors of the device can be obtained.The peak wavelengths of an OLED are located at 486,550,and 608 nm,respectively.The CIE coordinates are（0.21,0.45）,（0.33,0.63）,and（0.54,0.54）,and the full widths at half maximum（FWHM） are 35,32,and 39 nm for red,green,and blue,respectively.
基金This work was supported by the EPSRC Engineering Fellowship for Growth–PRINTSKIN(EP/M002527/1)and neuPRINTSKIN(EP/R029644/1).
文摘Energy autonomy is key to the next generation portable and wearable systems for several applications.Among these,the electronic-skin or e-skin is currently a matter of intensive investigations due to its wider applicability in areas,ranging from robotics to digital health,fashion and internet of things(IoT).The high density of multiple types of electronic components(e.g.sensors,actuators,electronics,etc.)required in e-skin,and the need to power them without adding heavy batteries,have fuelled the development of compact flexible energy systems to realize self-powered or energy-autonomous e-skin.The compact and wearable energy systems consisting of energy harvesters,energy storage devices,low-power electronics and efficient/wireless power transfer-based technologies,are expected to revolutionize the market for wearable systems and in particular for e-skin.This paper reviews the development in the field of self-powered e-skin,particularly focussing on the available energy-harvesting technologies,high capacity energy storage devices,and high efficiency power transmission systems.The paper highlights the key challenges,critical design strategies,and most promising materials for the development of an energy-autonomous e-skin for robotics,prosthetics and wearable systems.This paper will complement other reviews on e-skin,which have focussed on the type of sensors and electronics components.
