Presents the synthesis of Copolyimide containing triarylamine and NLO chromophore in backbone by azo coupling of 4 nitrobenzenediazonium tetrafloroborate to copoly(amic acid) in organic solvent and characterized by IR...Presents the synthesis of Copolyimide containing triarylamine and NLO chromophore in backbone by azo coupling of 4 nitrobenzenediazonium tetrafloroborate to copoly(amic acid) in organic solvent and characterized by IR and UV Vis spectra, which had high glass transition temperatrue and big second order nonlinear optical coefficient x (2) .展开更多
A new candidate [Cu（PPh3）2Him]Br （1, PPh3 =triphenylphosphine, Him= 1-H-imidazole） for nonlinear optical （NLO） materials has been synthesized and characterized crystallographically. The third-order NLO optical p...A new candidate [Cu（PPh3）2Him]Br （1, PPh3 =triphenylphosphine, Him= 1-H-imidazole） for nonlinear optical （NLO） materials has been synthesized and characterized crystallographically. The third-order NLO optical properties were measured by the Z-scan technique with an 8 ns pulsed laser at 532 nm. Compound 1 exhibits strong NLO absorptive abilities [a2=（61±5）×10^-12] and effective self-focusing performance [n2=（15±3）×10^-18 m^2·W^-1] in 1.01×10^-4 molodm 3 DMF solution. The compound also exhibits luminescence in DMF solution at room temperature and shows narrow emission with maximum at 382 nm. The electronic structure and photoluminescent process were investigated by means of TD-DFT calculations. The results suggest that the contribution to the frontier orbitals from the Cu-Br σ bond plays a crucial role in its linear optical properties, and the origin of luminescence is attrib- utable to the π＊ → n transitions.展开更多
在无线通信定位中,无线信号中引入的非视距(Non-Line of Sight,NLOS)误差会严重降低系统的定位精度。针对上述问题,首先引入信息阈值和缩放因子,细分非视距误差的影响程度,对卡尔曼迭代过程中的增益进行更为精准的实时调整,利用改进后...在无线通信定位中,无线信号中引入的非视距(Non-Line of Sight,NLOS)误差会严重降低系统的定位精度。针对上述问题,首先引入信息阈值和缩放因子,细分非视距误差的影响程度,对卡尔曼迭代过程中的增益进行更为精准的实时调整,利用改进后的卡尔曼滤波算法更大程度上消除了NLOS误差和系统测量误差;其次引入基于测距残差的加权系数对线性位置线(Linear Line of Position,LLOP)和Taylor定位方法的计算结果进行综合处理,进一步提高定位精度和稳健性。实验结果表明,在NLOS环境下,所提算法优于经典的LLOP算法、Chan算法、LLOP-Taylor算法和基于卡尔曼滤波的LLOP算法。展开更多
针对复杂室内环境下超宽带(Ultra WideBand,UWB)信号传播的非视距(Non Line Of Sight,NLOS)误差问题,本文提出了一种基于无迹卡尔曼滤波(Unscented Kalman Filter,UKF)的环境自适应UWB/DR室内定位方法.该方法通过建立自适应UKF滤波模型,...针对复杂室内环境下超宽带(Ultra WideBand,UWB)信号传播的非视距(Non Line Of Sight,NLOS)误差问题,本文提出了一种基于无迹卡尔曼滤波(Unscented Kalman Filter,UKF)的环境自适应UWB/DR室内定位方法.该方法通过建立自适应UKF滤波模型,将UWB定位信息和航迹推算(Dead Reckoning,DR)定位信息进行融合.依据新息和高斯分布的3σ原则来对UWB定位结果进行非视距检测,再通过新息的实时估计协方差和理论协方差来构建环境适应系数,进而用此系数动态修正UWB定位的观测噪声,使得观测噪声自适应真实环境,降低NLOS误差对融合定位结果的影响.实验结果表明,该方法能有效减小UWB定位的NLOS误差,并且由于环境适应系数的创新引入,比UKF定位和粒子滤波定位(Particle Filtering,PF)有更高的定位精度和更强的抗NLOS误差性能.展开更多
The geometrical structures and stability of non-conjugated C5H10 and C3H8N2 singlet and triplet diradical molecules have been investigated at the UCCSD/6-311g^＊＊ level. The effects of molecular structure, radical po...The geometrical structures and stability of non-conjugated C5H10 and C3H8N2 singlet and triplet diradical molecules have been investigated at the UCCSD/6-311g^＊＊ level. The effects of molecular structure, radical position, amount of Hartree Hork （HF） exchange and spin multiplicity on the nonlinear optical （NLO） coefficients have been also investigated. The reliable UCCSD results show that the triplets of all diradical molecules are more stable compared to their singlet analogues. In addition, the αs and βtot values of C5H10 and C3H8N2 triplet diradical mo-lecules have been investigated by the UBHandHLYP, UB3LYP, UBLYP, UHF and UCCSD methods. The investigation shows that the variations in αs and βtot values are closely connected to the amount of HF exchange. The increasing amount of HF exchange results in monotonic decreases in αs and βtot values, while the αs and βtot values of singlet diradical molecules and the γs of C5H10 and C3H8N2 singlet and triplet diradical molecules have been studied by the UBHandHLYP method. The results illustrate that the NLO coefficients for our studied non-conjugated carbon and nitrogen diradical species can be tuned by molecular structure, radical position and spin multiplicity, which are very significant for designing NLO materials.展开更多
Treatment of a W/Cu/S precursor[Et_(4)N][Tp*WS_(3)(CuBr)_(3)](1)with three equiv.of CuCN in DMF/MeCN/benzonitrile(or α-tolunitrile)yielded two[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)]-based coordination polymers,[Tp*WS_(3)Cu_(3)...Treatment of a W/Cu/S precursor[Et_(4)N][Tp*WS_(3)(CuBr)_(3)](1)with three equiv.of CuCN in DMF/MeCN/benzonitrile(or α-tolunitrile)yielded two[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)]-based coordination polymers,[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)(CN)_(3)Cu]_(2)•2DMF(2•2DMF)and[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)(CN)_(3)Cu(α-tolunitrile)]_(2)•3MeCN(3•3MeCN),respectively.Structural analysis revealed that 2 adopts a 2D network with a 4.8^(2) topology while 3 has a 1D ladder-type chain.The third-order nonlinear optical responses of 2 and 3 in DMF were 10 times enhanced compared to those of the precursor cluster 1.展开更多
When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping(5%/mol MgO:LiNbO_(3))under the condition of total reflection,semi-degenerate four-wave mixing(FWM)i...When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping(5%/mol MgO:LiNbO_(3))under the condition of total reflection,semi-degenerate four-wave mixing(FWM)is generated.On this basis,a more sophisticated frequency conversion process on the interface of nonlinear crystal has been researched.The generation mechanism of FWM is associated with the fundamental waves reflected on the inner surface of the nonlinear crystal.Analysis of the phase-matching mechanism confirms that the FWM is radiated by the third-order nonlinear polarized waves,which are stimulated by the third-order nonlinear susceptibility coefficient of the nonlinear crystal.Theoretically calculated and experimentally measured corresponding data have been presented in this article.These results are expected to provide new inspiration for further experimental and theoretical research on frequency conversion in nonlinear crystals.展开更多
hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) mat...hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, 1H-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and 11.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33 values) are 2.91×10 8esu and 6.14×10 8esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after 10h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.展开更多
文摘Presents the synthesis of Copolyimide containing triarylamine and NLO chromophore in backbone by azo coupling of 4 nitrobenzenediazonium tetrafloroborate to copoly(amic acid) in organic solvent and characterized by IR and UV Vis spectra, which had high glass transition temperatrue and big second order nonlinear optical coefficient x (2) .
基金Acknowledgement This work was supported by the NSF of China （No. 20871072）, the NSF of Shandong Province （No. 2009ZRA02071）, the Scientific Development Plan of University in Shandong Province （No. J09LB53）, and the Doctoral Science Foundation of QUST.
文摘A new candidate [Cu（PPh3）2Him]Br （1, PPh3 =triphenylphosphine, Him= 1-H-imidazole） for nonlinear optical （NLO） materials has been synthesized and characterized crystallographically. The third-order NLO optical properties were measured by the Z-scan technique with an 8 ns pulsed laser at 532 nm. Compound 1 exhibits strong NLO absorptive abilities [a2=（61±5）×10^-12] and effective self-focusing performance [n2=（15±3）×10^-18 m^2·W^-1] in 1.01×10^-4 molodm 3 DMF solution. The compound also exhibits luminescence in DMF solution at room temperature and shows narrow emission with maximum at 382 nm. The electronic structure and photoluminescent process were investigated by means of TD-DFT calculations. The results suggest that the contribution to the frontier orbitals from the Cu-Br σ bond plays a crucial role in its linear optical properties, and the origin of luminescence is attrib- utable to the π＊ → n transitions.
文摘在无线通信定位中,无线信号中引入的非视距(Non-Line of Sight,NLOS)误差会严重降低系统的定位精度。针对上述问题,首先引入信息阈值和缩放因子,细分非视距误差的影响程度,对卡尔曼迭代过程中的增益进行更为精准的实时调整,利用改进后的卡尔曼滤波算法更大程度上消除了NLOS误差和系统测量误差;其次引入基于测距残差的加权系数对线性位置线(Linear Line of Position,LLOP)和Taylor定位方法的计算结果进行综合处理,进一步提高定位精度和稳健性。实验结果表明,在NLOS环境下,所提算法优于经典的LLOP算法、Chan算法、LLOP-Taylor算法和基于卡尔曼滤波的LLOP算法。
文摘针对复杂室内环境下超宽带(Ultra WideBand,UWB)信号传播的非视距(Non Line Of Sight,NLOS)误差问题,本文提出了一种基于无迹卡尔曼滤波(Unscented Kalman Filter,UKF)的环境自适应UWB/DR室内定位方法.该方法通过建立自适应UKF滤波模型,将UWB定位信息和航迹推算(Dead Reckoning,DR)定位信息进行融合.依据新息和高斯分布的3σ原则来对UWB定位结果进行非视距检测,再通过新息的实时估计协方差和理论协方差来构建环境适应系数,进而用此系数动态修正UWB定位的观测噪声,使得观测噪声自适应真实环境,降低NLOS误差对融合定位结果的影响.实验结果表明,该方法能有效减小UWB定位的NLOS误差,并且由于环境适应系数的创新引入,比UKF定位和粒子滤波定位(Particle Filtering,PF)有更高的定位精度和更强的抗NLOS误差性能.
基金Supported by the National Natural Science Foundation of China (20873017)the Natural Science Foundation of Jilin Province (20101154)
文摘The geometrical structures and stability of non-conjugated C5H10 and C3H8N2 singlet and triplet diradical molecules have been investigated at the UCCSD/6-311g^＊＊ level. The effects of molecular structure, radical position, amount of Hartree Hork （HF） exchange and spin multiplicity on the nonlinear optical （NLO） coefficients have been also investigated. The reliable UCCSD results show that the triplets of all diradical molecules are more stable compared to their singlet analogues. In addition, the αs and βtot values of C5H10 and C3H8N2 triplet diradical mo-lecules have been investigated by the UBHandHLYP, UB3LYP, UBLYP, UHF and UCCSD methods. The investigation shows that the variations in αs and βtot values are closely connected to the amount of HF exchange. The increasing amount of HF exchange results in monotonic decreases in αs and βtot values, while the αs and βtot values of singlet diradical molecules and the γs of C5H10 and C3H8N2 singlet and triplet diradical molecules have been studied by the UBHandHLYP method. The results illustrate that the NLO coefficients for our studied non-conjugated carbon and nitrogen diradical species can be tuned by molecular structure, radical position and spin multiplicity, which are very significant for designing NLO materials.
基金the National Natural Science Foundation of China(Nos.21373142 and 21371126)the Qin-Lan Project and the“333”Project of Jiangsu Province(No.BRA2012139)the Priority Academic Program Development of Jiangsu Higher Education Institutions,and the“SooChow Scholar”Program of Soochow University.
文摘Treatment of a W/Cu/S precursor[Et_(4)N][Tp*WS_(3)(CuBr)_(3)](1)with three equiv.of CuCN in DMF/MeCN/benzonitrile(or α-tolunitrile)yielded two[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)]-based coordination polymers,[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)(CN)_(3)Cu]_(2)•2DMF(2•2DMF)and[Tp*WS_(3)Cu_(3)(μ_(3)-DMF)(CN)_(3)Cu(α-tolunitrile)]_(2)•3MeCN(3•3MeCN),respectively.Structural analysis revealed that 2 adopts a 2D network with a 4.8^(2) topology while 3 has a 1D ladder-type chain.The third-order nonlinear optical responses of 2 and 3 in DMF were 10 times enhanced compared to those of the precursor cluster 1.
基金This work was supported by the National Natural Science Foundation of China(Nos.61125503,61235009,and 61801520)the Foundation for Development of Science and Technology of Shanghai(No.13]C1408300)+1 种基金the Natural Science Foundation of Hunan Province(Nos.2019JJ50756 and 2018JJ3521)the Scientific Research Project of Hunan Province Education Department(No.20B144).
文摘When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping(5%/mol MgO:LiNbO_(3))under the condition of total reflection,semi-degenerate four-wave mixing(FWM)is generated.On this basis,a more sophisticated frequency conversion process on the interface of nonlinear crystal has been researched.The generation mechanism of FWM is associated with the fundamental waves reflected on the inner surface of the nonlinear crystal.Analysis of the phase-matching mechanism confirms that the FWM is radiated by the third-order nonlinear polarized waves,which are stimulated by the third-order nonlinear susceptibility coefficient of the nonlinear crystal.Theoretically calculated and experimentally measured corresponding data have been presented in this article.These results are expected to provide new inspiration for further experimental and theoretical research on frequency conversion in nonlinear crystals.
基金Plan Project of Science and Technology of Guangzhou City (2002J1-C0061) The First Author: XI Hongxia(1968-)
文摘hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, 1H-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and 11.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33 values) are 2.91×10 8esu and 6.14×10 8esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after 10h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.
