The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristi...The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristics of the PCM clearly indicate that four states can be stored in this stacked film structure. Qualitative analysis indicates that the multiple-state storage capability of this stacked film structure is due to successive crystallizations in different Si-Sb-Te layers triggered by different amplitude currents.展开更多
Si-doped Ge2Sb2Te5 films have been prepared by dc magnetron co-sputtering with Ge2Sb2Te5 and Si targets. The addition of Si in the Ge2Sb2Te5 film results in the increase of both crystallization temperature and phasetr...Si-doped Ge2Sb2Te5 films have been prepared by dc magnetron co-sputtering with Ge2Sb2Te5 and Si targets. The addition of Si in the Ge2Sb2Te5 film results in the increase of both crystallization temperature and phasetransition temperature from face-centred-cubic （fcc） phase to hexagonal （hex） phase. The resistivity of the Ge2Sb2Te5 film shows a significant increase with the Si doping. When doping 11.8 at.% of Si in the film, the resistivity after 460℃ annealing increases from 1 to 11 mΩ.cm and dynamic resistance increase from 64 to 99Ω compared to the undoped Ge2Sb2Te5 film. This is very helpful to writing current reduction of phase-change random access memory.展开更多
Fluorescein/polyvinyl pyrrolidone （PVP） composite nanofibers with different fluorescein loadings （with a weight concentration of 0-5.0%） are fabricated via electrospinning. Morphologies, structures and photolumine...Fluorescein/polyvinyl pyrrolidone （PVP） composite nanofibers with different fluorescein loadings （with a weight concentration of 0-5.0%） are fabricated via electrospinning. Morphologies, structures and photoluminescent （PL） prop- erties of these straight, helical or wavelike fibers are characterized by scanning electron microscopy （SEM）, fluorescence microscopy and a spectrophotometer. It is found that the maximum emission of the as-spun fluorescein/PVP fibers occurs at 510 nm. The PL intensity of the composite fiber increases with fluorescein concentration, then fluorescence quenching appears when the concentration reaches 1.67%. The mechanism of fluorescence quenching of fiuorescein is discussed. In addition, the composite fibers exhibit a much stronger PL intensity than fluorescein/PVP bulk film owing to larger specific surface area, which makes them promising materials for biomedical applications such as probes and sensors.展开更多
Polar codes have become increasingly popular recently because of their capacity achieving property.In this paper,a memory efficient stage-combined belief propagation(BP) decoder design for polar codes is presented.Fir...Polar codes have become increasingly popular recently because of their capacity achieving property.In this paper,a memory efficient stage-combined belief propagation(BP) decoder design for polar codes is presented.Firstly,we briefly reviewed the conventional BP decoding algorithm.Then a stage-combined BP decoding algorithm which combines two adjacent stages into one stage and the corresponding belief message updating rules are introduced.Based on this stage-combined decoding algorithm,a memory-efficient polar BP decoder is designed.The demonstrated decoder design achieves 50%memory and decoding latency reduction in the cost of some combinational logic complexity overhead.The proposed decoder is synthesized under TSMC 45 nm Low Power CMOS technology.It achieves 0.96 Gb/s throughput with 14.2mm^2 area when code length N=2^(16)which reduces 51.5%decoder area compared with the conventional decoder design.展开更多
Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition technique.The grains form a texture of bar-like arrays along S...Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition technique.The grains form a texture of bar-like arrays along Sr Ti O_3110directions for the film thickness above 350 nm,in contrast to spherical grains for the reduced film thickness below 220 nm.X-ray diffraction patterns show that the highly ordered bar-like grains are the ensemble of two lattice-matched monoclinic（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components above a critical film thickness.Otherwise,the phase decomposes into the random mixture of Bi_2Ti_2O_（7 ）and Bi_4Ti_3O_（4 ）spherical grains in thinner films.The critical thickness can increase up to 440 nm as the films are deposited on LaNiO_3-buffered SrTiO_（3 ）substrates.The electrical measurements show the dielectric enhancement of the multi-components,and comprehensive charge injection into interfacial traps between（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components occurs under the application of a threshold voltage for the realization of high-charge storage.展开更多
文摘The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristics of the PCM clearly indicate that four states can be stored in this stacked film structure. Qualitative analysis indicates that the multiple-state storage capability of this stacked film structure is due to successive crystallizations in different Si-Sb-Te layers triggered by different amplitude currents.
文摘Si-doped Ge2Sb2Te5 films have been prepared by dc magnetron co-sputtering with Ge2Sb2Te5 and Si targets. The addition of Si in the Ge2Sb2Te5 film results in the increase of both crystallization temperature and phasetransition temperature from face-centred-cubic （fcc） phase to hexagonal （hex） phase. The resistivity of the Ge2Sb2Te5 film shows a significant increase with the Si doping. When doping 11.8 at.% of Si in the film, the resistivity after 460℃ annealing increases from 1 to 11 mΩ.cm and dynamic resistance increase from 64 to 99Ω compared to the undoped Ge2Sb2Te5 film. This is very helpful to writing current reduction of phase-change random access memory.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11074138,11004114,60906054, and50825206)the Shandong Provincial Natural Science Foundation for Distinguished Young Scholars,China (Grant No. JQ201103)+2 种基金the Taishan Scholars Program of Shandong Province, Chinathe National Basic Research Program of China (Grant No. 2012CB722705)the National High Technology Research and Development Program of China (Grant No. 2011AA100706)
文摘Fluorescein/polyvinyl pyrrolidone （PVP） composite nanofibers with different fluorescein loadings （with a weight concentration of 0-5.0%） are fabricated via electrospinning. Morphologies, structures and photoluminescent （PL） prop- erties of these straight, helical or wavelike fibers are characterized by scanning electron microscopy （SEM）, fluorescence microscopy and a spectrophotometer. It is found that the maximum emission of the as-spun fluorescein/PVP fibers occurs at 510 nm. The PL intensity of the composite fiber increases with fluorescein concentration, then fluorescence quenching appears when the concentration reaches 1.67%. The mechanism of fluorescence quenching of fiuorescein is discussed. In addition, the composite fibers exhibit a much stronger PL intensity than fluorescein/PVP bulk film owing to larger specific surface area, which makes them promising materials for biomedical applications such as probes and sensors.
基金jointly supported by the National Nature Science Foundation of China under Grant No.61370040 and 61006018the Fundamental Research Funds for the Central Universities+1 种基金the Priority Academic Program Development of Jiangsu Higher Education InstitutionsOpen Project of State Key Laboratory of ASIC & System(Fudan University)12KF006
文摘Polar codes have become increasingly popular recently because of their capacity achieving property.In this paper,a memory efficient stage-combined belief propagation(BP) decoder design for polar codes is presented.Firstly,we briefly reviewed the conventional BP decoding algorithm.Then a stage-combined BP decoding algorithm which combines two adjacent stages into one stage and the corresponding belief message updating rules are introduced.Based on this stage-combined decoding algorithm,a memory-efficient polar BP decoder is designed.The demonstrated decoder design achieves 50%memory and decoding latency reduction in the cost of some combinational logic complexity overhead.The proposed decoder is synthesized under TSMC 45 nm Low Power CMOS technology.It achieves 0.96 Gb/s throughput with 14.2mm^2 area when code length N=2^(16)which reduces 51.5%decoder area compared with the conventional decoder design.
基金Supported by the Basic Research Project of Shanghai Science and Technology Innovation Action under Grant No 17JC1400300the National Key Basic Research Program of China under Grant No 2014CB921004+1 种基金the National Natural Science Foundation of China under Grant No 61674044the Program of Shanghai Subject Chief Scientist under Grant No 17XD1400800
文摘Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition technique.The grains form a texture of bar-like arrays along Sr Ti O_3110directions for the film thickness above 350 nm,in contrast to spherical grains for the reduced film thickness below 220 nm.X-ray diffraction patterns show that the highly ordered bar-like grains are the ensemble of two lattice-matched monoclinic（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components above a critical film thickness.Otherwise,the phase decomposes into the random mixture of Bi_2Ti_2O_（7 ）and Bi_4Ti_3O_（4 ）spherical grains in thinner films.The critical thickness can increase up to 440 nm as the films are deposited on LaNiO_3-buffered SrTiO_（3 ）substrates.The electrical measurements show the dielectric enhancement of the multi-components,and comprehensive charge injection into interfacial traps between（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components occurs under the application of a threshold voltage for the realization of high-charge storage.
