Differential pulse-position modulation(DP PM)can achieve a good compromise between power and bandwidth requirements.However,the output sequence has undetectable insertions and deletions.This paper proposes a successiv...Differential pulse-position modulation(DP PM)can achieve a good compromise between power and bandwidth requirements.However,the output sequence has undetectable insertions and deletions.This paper proposes a successive cancellation(SC)decoding scheme based on the weighted levenshtein distance(WLD)of polar codes for correcting insertions/deletions in DPPM systems.In this method,the WLD is used to calculate the transfer probabilities recursively to obtain likelihood ratios,and the low-complexity SC decoding method is built according to the error characteristics to match the DPPM system.Additionally,the proposed SC decoding scheme is extended to list decoding,which can further improve error correction performance.Simulation results show that the proposed scheme can effectively correct insertions/deletions in the DPPM system,which enhances its reliability and performance.展开更多
在光无线通信系统中,调制与解调技术是其中关键部分。在常用的调制解调技术中,脉冲位置调制(PPM)技术具有良好的传输性能、比较好的抗干扰能力。在深入研究脉冲位置调制(PPM)技术的原理后,为了进一步提高系统的传输能力和抗干扰能力,提...在光无线通信系统中,调制与解调技术是其中关键部分。在常用的调制解调技术中,脉冲位置调制(PPM)技术具有良好的传输性能、比较好的抗干扰能力。在深入研究脉冲位置调制(PPM)技术的原理后,为了进一步提高系统的传输能力和抗干扰能力,提出了在脉冲位置调制(PPM)技术基础上的改进方案,即差分脉冲调制(DPPM)技术。使用ALTERA公司生产的CYCLONE IV系列的FPGA作为编程芯片,使用Verilog HDL语言在Quartus II 11.0软件上编写程序。展开更多
The heterotrinuclear compound [PdCu2(tdt)(μ-dppm)2(MeCN)4](ClO4)2?2/3H2O 1 (tdt = 3,4-toluenedithiolate, dppm = bis(diphenylphosphino)methane) has been prepared and characterized by X-ray structural analysis. Compoun...The heterotrinuclear compound [PdCu2(tdt)(μ-dppm)2(MeCN)4](ClO4)2?2/3H2O 1 (tdt = 3,4-toluenedithiolate, dppm = bis(diphenylphosphino)methane) has been prepared and characterized by X-ray structural analysis. Compound 1 crystallizes in trigonal system, space group R3c with a = b = 34.4275(3), c = 32.6700(5) ?, V = 33534.4(7) ?3, Mr = 1527.21, Z = 18, Dc = 1.361 g/cm3, F(000) = 13974, μ(MoKα) = 1.069 mm-1, the final R = 0.0703 and wR = 0.1389 for 8375 observed reflections with I>2σ(I). The dithiolate tdt displays a chelating and bridging coordination mode, which chelates a PdII and bridges two Cu? atoms. The PdII center is located in an approximate square-planar environment with S2P2 donors, and each Cu? center exhibits a tetrahedral geometry.展开更多
The silver-dppm complex, [Ag2（dppm）2（NMP）2]（SbF6）2-4H2O-3CH2Cl2 1 （NMP = 2- （4-dimethylaminophenyl）imidazo（4,5-f）（1,10）phenanthroline, dppm = diphenylphosphinomethane）, was synthesized and its structure ...The silver-dppm complex, [Ag2（dppm）2（NMP）2]（SbF6）2-4H2O-3CH2Cl2 1 （NMP = 2- （4-dimethylaminophenyl）imidazo（4,5-f）（1,10）phenanthroline, dppm = diphenylphosphinomethane）, was synthesized and its structure was determined by X-ray diffraction. The crystal belongs to monoclinic, space group C2/c, Mr = 2461.61, a = 21.57（10）, b = 22.48（6）, c = 22.53（6）A, β= 101.29（2）°, V= 10713（64）A^3, Z= 4, Dc= 1.526 g/cm^3,μ= 1.141mm^-1, F（000） = 4920, R =0.0664 and wR = 0.1774 for 8524 observed reflections （1 〉 2σ（I））. Complex 1 exists as a centrosymmetric dimmer. The two dppm molecules bridge two AgNMP moieties to form an eight-membered Ag2P4C2 metallacyclic ring with ligand NMP chelating to each Ag. It appears photoluminescence （λmax = 625 nm） at room temperature and makes red shift compared with free ligand NMP （λmax = 522 nm）. DFF calculation indicates that the emission of 1 originates from singlet metal-perturbed ILCT excited state.展开更多
Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized thr...Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized through elemental analyses, ICP, IR(4000-200 cm^(-1), CsI disc.), ^(31)P-NMR spectra. Their electronic conductivities, oxidation and reduction potentials were measured. Preliminary studies show that both of the two complexes have chlorobridging and phosphorus-bridging structures.展开更多
3D NAND中工艺结构是导致器件失效的重要因素之一,其中,选择性外延生长(SEG)的生长高度也是导致失效的一个重要参数。因此,提出了一种新的关于SEG高度引起器件失效的模型、失效概率的计算方法,并由此计算预测每百万缺陷数(DPPM)。该算...3D NAND中工艺结构是导致器件失效的重要因素之一,其中,选择性外延生长(SEG)的生长高度也是导致失效的一个重要参数。因此,提出了一种新的关于SEG高度引起器件失效的模型、失效概率的计算方法,并由此计算预测每百万缺陷数(DPPM)。该算法涉及多种数学模型如泊松分布、正态分布等,同时对3D NAND中不同层次的失效概率进行计算。根据该算法可以得到DPPM与SEG高度的关系,并对SEG高度最优值、DPPM对不同区域的SEG高度的敏感性进行了研究。展开更多
基金supported by National Natural Science Foundation of China(No.61801327).
文摘Differential pulse-position modulation(DP PM)can achieve a good compromise between power and bandwidth requirements.However,the output sequence has undetectable insertions and deletions.This paper proposes a successive cancellation(SC)decoding scheme based on the weighted levenshtein distance(WLD)of polar codes for correcting insertions/deletions in DPPM systems.In this method,the WLD is used to calculate the transfer probabilities recursively to obtain likelihood ratios,and the low-complexity SC decoding method is built according to the error characteristics to match the DPPM system.Additionally,the proposed SC decoding scheme is extended to list decoding,which can further improve error correction performance.Simulation results show that the proposed scheme can effectively correct insertions/deletions in the DPPM system,which enhances its reliability and performance.
文摘在光无线通信系统中,调制与解调技术是其中关键部分。在常用的调制解调技术中,脉冲位置调制(PPM)技术具有良好的传输性能、比较好的抗干扰能力。在深入研究脉冲位置调制(PPM)技术的原理后,为了进一步提高系统的传输能力和抗干扰能力,提出了在脉冲位置调制(PPM)技术基础上的改进方案,即差分脉冲调制(DPPM)技术。使用ALTERA公司生产的CYCLONE IV系列的FPGA作为编程芯片,使用Verilog HDL语言在Quartus II 11.0软件上编写程序。
基金This work was supported by NSF of Fujian Province (E0310029 and E0420002)
文摘The heterotrinuclear compound [PdCu2(tdt)(μ-dppm)2(MeCN)4](ClO4)2?2/3H2O 1 (tdt = 3,4-toluenedithiolate, dppm = bis(diphenylphosphino)methane) has been prepared and characterized by X-ray structural analysis. Compound 1 crystallizes in trigonal system, space group R3c with a = b = 34.4275(3), c = 32.6700(5) ?, V = 33534.4(7) ?3, Mr = 1527.21, Z = 18, Dc = 1.361 g/cm3, F(000) = 13974, μ(MoKα) = 1.069 mm-1, the final R = 0.0703 and wR = 0.1389 for 8375 observed reflections with I>2σ(I). The dithiolate tdt displays a chelating and bridging coordination mode, which chelates a PdII and bridges two Cu? atoms. The PdII center is located in an approximate square-planar environment with S2P2 donors, and each Cu? center exhibits a tetrahedral geometry.
基金This work was support by National Basic Research Program of China (No: 2004CB720605) and the Natural Science Foundation of China (No. 20173064 and 90203017).
文摘The silver-dppm complex, [Ag2（dppm）2（NMP）2]（SbF6）2-4H2O-3CH2Cl2 1 （NMP = 2- （4-dimethylaminophenyl）imidazo（4,5-f）（1,10）phenanthroline, dppm = diphenylphosphinomethane）, was synthesized and its structure was determined by X-ray diffraction. The crystal belongs to monoclinic, space group C2/c, Mr = 2461.61, a = 21.57（10）, b = 22.48（6）, c = 22.53（6）A, β= 101.29（2）°, V= 10713（64）A^3, Z= 4, Dc= 1.526 g/cm^3,μ= 1.141mm^-1, F（000） = 4920, R =0.0664 and wR = 0.1774 for 8524 observed reflections （1 〉 2σ（I））. Complex 1 exists as a centrosymmetric dimmer. The two dppm molecules bridge two AgNMP moieties to form an eight-membered Ag2P4C2 metallacyclic ring with ligand NMP chelating to each Ag. It appears photoluminescence （λmax = 625 nm） at room temperature and makes red shift compared with free ligand NMP （λmax = 522 nm）. DFF calculation indicates that the emission of 1 originates from singlet metal-perturbed ILCT excited state.
文摘Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized through elemental analyses, ICP, IR(4000-200 cm^(-1), CsI disc.), ^(31)P-NMR spectra. Their electronic conductivities, oxidation and reduction potentials were measured. Preliminary studies show that both of the two complexes have chlorobridging and phosphorus-bridging structures.
