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Noncentrosymmetric K_(2)Mn_(3)(SO_(4))_(3)F_(2)·4H_(2)O and Rb_(2)Mn_(3)(SO_(4))_(3)F_(2)·2H_(2)O with pseudo-KTP structures

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Chinese Chemical Letters 2021年第1期32卷 263-265页

作者： Yang Zhou Yanqiang Li Qingran Ding youchao liu Yangxin Chen Xitao liu Xiaoying Huang Lina Li Sangen Zhao Junhua Luo College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

Two fluoride sulfates,K_(2)Mn_(3)(SO_(4))_(3)F_(2)·4H_(2)O(Ⅰ) and Rb_(2)Mn_(3)(SO_(4))_(3)F_(2)·2H_(2)O (Ⅱ) are obtained by water solution ***-crystal X-ray diffraction analysis indicated that they crystallize in space groups of Cmc2_(1.)Their structures feature a pseudo-KTP structure consisting of interconnecting[Mn_(3)(SO_(4))3F_(2)(H_(2)O)2]_(∞) layers,which are further packing along the a axis with alkali metal cations balancing the *** structure relationships between the two compounds are *** generation measurements manifest that Ⅰ and Ⅱ have similar second-harmonic generation responses of about 0.2 and 0.25 times that of KH_(2)PO_(4).

关键词： Sulfate Second harmonic generation Crystal structure X-ray diffraction Thermogravimetric analysis

Achieving Intrinsic Dual-Band Excitonic Luminescence from a Single Three-Dimensional Perovskite Nanoparticle Through Ni^(2+)-Mediated Halide Anion Exchange

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CCS Chemistry 2024年第2期6卷 415-426页

作者： Licheng Yu youchao Wei Yuanchao Lei Caiping liu Yongsheng liu Maochun Hong State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002 Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China FuzhouFujian 350108 School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210

Rapid halide anion exchange easily occurring in metal-halide perovskite nanoparticles(NPs)makes it nearly impossible to create a single three-dimensional(3D)CsPbX_(3)(X=Cl,Br,I)NP that simultaneously comprises two separate perovskite *** circumvent this problem,we first propose a Ni^(2+)-mediated halide anion-exchange strategy in zero-dimensional(0D)Ni^(2+)-doped Cs_(4)PbBr_(6)(Cs_(4)PbBr_(6):Ni)perovskites to achieve ultra-stable 3D CsPbX_(3)NPs with two coexisting different perovskite individuals of CsPbCl_(3)and/or CsPbBr_(3).By combining the experimental results with first-principles calculations,we confirm that the completely isolated[PbBr_(6)]4−octahedra in 0D Cs_(4)PbBr_(6):Ni NPs can restrict rapid halide anion exchange and the anion diffusion preferentially proceeds in the proximity of substitutional NiPb centers,namely[NiBr_(6)]4−octahedra in a meta-stable state,rather than in the 0D Cs_(4)PbBr_(6)and residual 3D CsPbBr_(3)regions,thereby delivering intrinsic dual-band excitonic luminescence from a single 3D CsPbX_(3)NP with a more stable and efficient CsPbCl_(3)component as compared to its counterparts synthesized using conventional *** new insights regarding the precise control of halide anion exchange enable the preparation of a new type of high-efficiency perovskite materials with suppressed anion interdiffusion for prospective optoelectronic devices.

关键词： excitonic luminescence three-dimensional CsPbX_(3) perovskite nanoparticle halide anion exchange impurity doping

Nonpolar Na_(10)Cd(NO_(3))_(4)(SO_(3)S)_(4) Exhibits a Large Second-Harmonic Generation

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CCS Chemistry 2022年第2期4卷 526-531页

作者： youchao liu Youquan liu Zheshuai Lin Yanqiang Li Qingran Ding Xin Chen Lina Li Sangen Zhao Maochun Hong Junhua Luo State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002 Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190 University of the Chinese Academy of Sciences Beijing 100049 Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China FuzhouFujian 350108

Conventional wisdom says that nonpolar structures do not favorably produce strong second-harmonic generation(SHG)responses since the polarization in their microscopic functional groups are ***,we report the first nonlinear optical thiosulfate,Na_(10)Cd(NO_(3))_(4)(SO_(3)S)_(4),which crystallizes in a nonpolar space group of P−***,this thiosulfate exhibits a strong SHG response of about 4.2 times that of the benchmark KH2PO4,which is larger than those of polar *** to first-principles calculations and a flexible dipole model,the SHG enhancement is mainly ascribed to the larger flexibility of the S=S bond in the SO_(3)S tetrahedra in comparison with the S–O bond in the SO4 *** findings indicate that constructing flexible bonds is an effective strategy to design highperformance nonlinear optical materials regardless of polarity.

关键词： nonlinear optical material secondharmonic generation crystal structure structure-property relationships thiosulfate

Maximizing the linear and nonlinear optical responses of alkaline tricyanomelaminate

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Fundamental Research 2023年第6期3卷 974-978页

作者： Yanqiang Li Qingchen Wu Zheshuai Lin youchao liu Yang Zhou Xin Chen Minjuan Li Maochun Hong Junhua Luo Sangen Zhao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

High-performance bi-functional materials are in urgent demand for the next-generation integrated optical *** this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical responses,namely Cs_(3)C_(6)N_(9)•H_(2)O(I),from its analogue Na_(3)C_(6)N_(9)•3H_(2)O by a facile ion exchange *** contrast to Na_(3)C_(6)N_(9)•3H_(2)O,I realizes an optimal arrangement of𝜋π-conjugated(C_(6)N_(9))3−anion groups in its crystal *** a result,the second-order nonlinear optical(NLO)response is greatly enhanced from nearly zero of Na_(3)C_(6)N_(9)•3H_(2)O to∼9.8×KH_(2)PO_(4)of ***,I exhibits a giant linear optical anisotropic response(***)of 0.52 at the wavelength of 550 *** responses are almost the largest among the inorganic compounds ofπ-conjugated rings,which indicates that I has great potential as a bi-functional optical *** and theoretical analyses reveal the microscopic origin of excellent optical *** work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals.

关键词： Nonlinear optical response Second harmonic generation Birefringence Tricyanomelaminate Structure-property relationship Inorganic chemistry

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基于密度自适应邻域相似图的半监督谱聚类

计算机应用研究 2020年第9期37卷 2604-2609页

作者：刘友超张曦煌江南大学物联网工程学院江苏无锡214122

谱聚类是基于谱图划分理论的一种聚类算法,传统的谱聚类算法属于无监督学习算法,只能利用单一数据来进行聚类。针对这种情况,提出一种基于密度自适应邻域相似图的半监督谱聚类(DAN-SSC)算法。DAN-SSC算法在传统谱聚类算法的基础上结合... 详细信息

谱聚类是基于谱图划分理论的一种聚类算法,传统的谱聚类算法属于无监督学习算法,只能利用单一数据来进行聚类。针对这种情况,提出一种基于密度自适应邻域相似图的半监督谱聚类(DAN-SSC)算法。DAN-SSC算法在传统谱聚类算法的基础上结合了半监督学习的思想,很好地解决了传统谱聚类算法无法充分利用所有数据,不得不对一些有标签数据进行舍弃的问题;将少量的成对约束先验信息扩散至整个空间,使其能更好地对聚类过程进行指导。实验结果表明,DAN-SSC算法具有可行性和有效性。

关键词：谱聚类密度自适应邻域相似图半监督学习

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基于自然最近邻相似图的谱聚类

计算机应用研究 2020年第1期37卷 30-33,39页

作者：刘友超张曦煌江南大学物联网工程学院江苏无锡214122

传统谱聚类算法经常在处理一些结构复杂的数据集时效果不太理想,并且其相似度矩阵构造时参数的选取往往需要依靠多次实验及个人经验。在这种情况下,提出一种基于自然最近邻相似图的谱聚类(NSG-SC)算法。自然最近邻是一种新颖的最近邻概... 详细信息

传统谱聚类算法经常在处理一些结构复杂的数据集时效果不太理想,并且其相似度矩阵构造时参数的选取往往需要依靠多次实验及个人经验。在这种情况下,提出一种基于自然最近邻相似图的谱聚类(NSG-SC)算法。自然最近邻是一种新颖的最近邻概念,可以有效地避免K最近邻以及ε-最近邻方法需要人为设置参数的缺点。该算法构造相似度矩阵时依靠数据集自身的特性进行搜索,避免了参数选取不当以及离散点所带来的影响,更加真实地反映了数据集的结构关系。实验结果表明,提出的NSG-SC算法具有可行性和有效性。

关键词：谱聚类自然最近邻相似图相似度矩阵

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不溶物对绝缘子污闪的影响

中国电机工程学报 2017年第11期37卷 3331-3338页

作者：刘又超蒋兴良张欢熊云杨忠毅国网湖南省电力公司检修公司湖南省长沙市410004 输配电装备及系统安全与新技术国家重点实验室(重庆大学) 重庆市沙坪坝区400044

绝缘子表面在自然条件下会积累各种不同类型的污秽成分,而其中不溶物会对绝缘子污闪电压产生一定影响。该文选用7片标准悬式瓷和玻璃绝缘子串作为研究对象,试验研究了其在不同不溶物下的交流闪络特性,结合不溶物不同类型及颗粒直径下的... 详细信息

绝缘子表面在自然条件下会积累各种不同类型的污秽成分,而其中不溶物会对绝缘子污闪电压产生一定影响。该文选用7片标准悬式瓷和玻璃绝缘子串作为研究对象,试验研究了其在不同不溶物下的交流闪络特性,结合不溶物不同类型及颗粒直径下的绝缘子污秽试验测量结果,分析了不溶物对绝缘子闪络电压的影响。结果表明:不同不溶物类型对污闪电压的影响有差异,但不同种类的不溶物基本不会对可溶物的影响指数产生影响;不溶物颗粒直径对污闪电压存在一定影响,在绝缘子类型,盐灰密与污秽成分相同条件下,污闪电压随不溶物粒径的增大而增大。因此,在绝缘子污闪研究中,不能仅用高岭土或者硅藻土模拟灰密得到的试验结果来分析评判所有不溶物对绝缘子闪络的影响,需要综合考虑不溶物的各种成分类型以及其粒径大小等多种因素的影响。

关键词：绝缘子污秽成分不溶物闪络电压颗粒直径

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某无人机机载加固电子设备机箱结构设计

机械与电子 2017年第3期35卷 55-57页

作者：刘有超西南电子技术研究所四川成都610036

设计了某适用无人机平台的加固电子设备机箱的结构,主要是从机箱的总体布局设计、热设计、抗振动冲击设计、电磁兼容设计、三防设计等方面,介绍了该机箱的设计方法。该机箱已经过了各种试验验证,满足工程使用需求。

关键词：加固机箱结构设计热设计抗振动冲击设计

Frequency Regulation of VSC-MTDC System with Offshore Wind Farms

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 275-286页

作者： Haoyu liu Chongru liu North China Electric Power University Beijing 102206China

Frequency regulation of voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC)system with offshore wind farms enhances the frequency stability by compensating the power for a disturbed AC ***,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC ***,it is difficult for the frequency control of the wind farms to manage changes in wind speed;and the risk of wind-turbine stalls is ***,based on the kinetic energy of wind turbines and the power margin of the converters,the frequency-regulation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stage and restoration stage is switched according to the wind speed.A hierarchical zoning frequency-regulation scheme is designed to use the frequency-regulation resources of different links in the MTDC system with wind *** simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.

关键词： Wind generation voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC) frequency regulation cooperative control adaptive control variable wind speed