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Two polyoxovanadoborates with over 100 nuclei assembled from a {V_(14)Co_(12)B_(72)} cluster

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Science China Chemistry 2024年第8期67卷 2578-2585页

作者： Shuang-Xue Wu Yu-Jiao Dong Yang Yang Chao Qin Chun-Yi Sun Wei Guan xin-long wang Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Northeast Normal UniversityChangchun 130024China School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130013China Key Laboratory of Advanced Materials of Tropical Island Resources Hainan UniversityHaikou 570228China

Combining theoretical prediction and experimental exploration, the first sandwich-type polyoxovanadoborate(POVB) with an odd number of nuclei, [V_(11)B_(26)O_(73)(OH)_(10)]^(8-)(1), was discovered under hydrothermal conditions. Density-functional theory(DFT)gives a rationalization for the existence of this structure and the structural feature is consistent with the {V_NB_(2N+X)}(X = 2, 4, 6, 8)general formula. Excitingly, when Co and 1,10-phenanthroline(phen) are introduced into the synthesis of vanadoborates system,a 100-nuclei [Co_6(phen)_(10)(H_(2)O)_8][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·28H_(2)O(2) and a 102-nuclei [Co_6(phen)_(14)(H_(2)O)_(4)][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·23H_(2)O(3) with the same core structure of [V_(14)Co_(12)B_(72)]^(12-)are obtained. The vase-shaped [V_(14)Co_(12)B_(72)] polyanion is a multilayered sandwich-type structure containing seven distinct structural layers and is the largest known POVB. Furthermore, 2demonstrates exceptional thermal and chemical stability and serves as an efficient and stable catalyst for the photoreduction of carbon dioxide.

关键词： boronate metallic materials polyoxovanadoborates density functional theory photocatalysis CO_(2)reduction

Dimensional regulation in gigantic molybdenum blue wheels featuring{(W)Mo5}motifs for enhanced proton conductivity

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Nano Research 2024年第9期17卷 8261-8268页

作者： Yu-Lun Wu Jing Du Hai-Ying Zhang Ming-Jun Hou Qiao-Yue Li Wei-Chao Chen Kui-Zhan Shao Bo Zhu Chao Qin xin-long wang Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China Hebei Key Laboratory of Organic Functional Molecules National Demonstration Center for Experimental Chemistry EducationTesting and Analysis CenterCollege of Chemistry and Materials ScienceHebei Normal UniversityShijiazhuang 050024China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Dimensional regulation in polyoxometalates is an effective strategy during the design and synthesis of polyoxometalates-based high proton conductors,but it is not available to ***,the precise regulation of dimensionality has been realized in an unprecedented gigantic molybdenum blue wheel family featuring pentagonal{(W)Mo5}motifs through optimizing the molar ratio of Mo/W,including[Gd_(2)Mo_(124)W_(14)O_(422)(H_(2)O)62]38-(0D-{Mo_(124)W_(14)},1),[Mo_(126)W_(14)O441(H_(2)O)51]^(70-)(1D-{Mo_(126)W_(14)}n,2),and[Mo_(124)W_(14)O_(430)(H_(2)O)50]60-(2D-{Mo_(124)W_(14)}n,3).Such important{(W)Mo5}structural motif brings new reactivity into gigantic Mo blue *** are different numbers and sites of{Mo2}defects in each wheel-shaped monomer in 1-3,which leads to the monomers of 2 and 3 to form 1D and 2D architectures via Mo-O-Mo covalent bonds driven by{Mo2}-mediated H_(2)O ligands substitution process,respectively,thus achieving the controllable dimensional *** expected,the proton conductivity of 3 is 10 times higher than that of 1 and 1.7 times higher than that of *** continuous proton hopping sites in 2D network are responsible for the enhanced proton conductivity with lower activation *** study highlights that this dimensional regulation approach remains great potential in preparing polyoxometalates-based high proton conductive materials.

关键词： polyoxometalate molybdenum blue wheels Mo/W mixed-addenda polyoxometalates dimensional regulation proton conduction

Reconstruction of 3-D surface waves generated by moving submerged sphere based on stereo imaging principle

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Journal of Hydrodynamics 2020年第1期32卷 139-147页

作者： xin-long wang Gang Wei Hui Du Shao-dong wang Department of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China

A sailing ship can produce significant disturbances on the water surface,but the perturbation generated by a moving submerged source is much smaller due to the physical property of the free surface,as represented by the rigid-lid assumption,with the geometric displacement barely observed or *** on the stereo imaging principle,an experimental system for the three-dimensional measurement of the surface perturbation is built by assembling two charge coupled device(CCD)sensors,to measure the surface waves generated by a small submerged sphere,including the small-scale vertical displacements and the flow field on the water *** obtained results are consistent with those obtained by the theoretical analysis,and the measurement accuracy for the vertical displacements is improved by 50%compared to that of the direct optical method based on the image grey ***,the present measurement technique can be efficiently and precisely applied to other measurements of small-scale disturbances on a free surface.

关键词： Surface wake stereo imaging geometric reconstruction particle image velocimetry(PIV)

Orientations of Rare-earth-containing Heteropolyoxometalates with Different Sizes in the Interlayer of Synthetic Multibilayer Films

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Chinese Chemical Letters 2002年第9期13卷 887-890页

作者： Yong Hui wang xin long wang Chang Wen HU En Bo wang Institute of Polyoxometalate Chemistry Faculty of ChemistryNortheast Normal UniversityChangchun 130024

Three rare-earth-containing heteropolyoxometalates with different sizes, Na9[Eu(W5 O18)2], K13[Eu(SiW11O39)2], and K17[Eu(P2W17O61)2], have been incorporated by self-assembly into the interlayer of synthetic multibila... 详细信息

关键词： Rare-earth-containing heteropolyoxometalate synthetic multibilayer film DODA orientation.

Centroid-based sifting for empirical mode decomposition

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第2期12卷 88-95页

作者： Hong HONG xin-long wang Zhi-yong TAO Shuan-ping DU Key Laboratory of Modern Acoustics and Institute of Acoustics Nanjing University Nanjing 210093 China State Key Laboratory of Ocean Acoustics Hangzhou Applied Acoustics Research Institute Hangzhou 310012 China

A novel sifting method based on the concept of the 'local centroids' of a signal is developed for empirical mode decomposition (EMD), with the aim of reducing the mode-mixing effect and decomposing those modes whose frequencies are within an octave. Instead of directly averaging the upper and lower envelopes, as suggested by the original EMD method, the proposed technique computes the local mean curve of a signal by interpolating a set of 'local centroids', which are integral averages over local segments between successive extrema of the signal. With the 'centroid'-based sifting, EMD is capable of separating intrinsic modes of oscillatory components with their frequency ratio ν even up to 0.8, thus greatly mitigating the effect of mode mixing and enhancing the frequency resolving power. Inspection is also made to show that the integral property of the 'centroid'-based sifting can make the decomposition more stable against noise interference.

关键词： Sifting Empirical mode decomposition (EMD) Mode mixing effect Frequency resolution Local centroids Noise resistance

Ce(H_2O)_7Al(OH)_6Mo_6O_(18)·4H_2O: A New One-dimensional Zigzag Chainlike Structure of Anderson Cluster Linked by Cerium Ions

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Chemical Research in Chinese Universities 2005年第6期21卷 637-640页

作者： JIN Hua QI Yan-fei QIN Chao wang xin-long wang En-bo XU Lin Institute of Polyoxometalate Chemistry Faculty of Chemistry Northeast Normal University Changchun 130024 P. R. China

A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectrometry. Compound 1 exhibits a zigzag chain-like structure, which is constructed from an Anderson type anion and rare earth metal, Ce（ Ⅲ ）. These 1-D chains are further extended into a 3-D network by the aid of muhipoint hydrogen-bonding interactions.

关键词： One-pot reaction Zigzag chain-like polymer Rare earth metal Polyoxometalate

Detection of time varying pitch in tonal languages: an approach based on ensemble empirical mode decomposition

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第2期13卷 139-145页

作者： Hong HONG Xiao-hua ZHU Wei-min SU Run-tong GENG xin-long wang School of Electronic Engineering and Optoelectronic Techniques Nanjing University of Science and TechnologyNanjing 210094China State Key Laboratory of Modern Acoustics Institute of AcousticsNanjing UniversityNanjing 210093China

A method based on ensemble empirical mode decomposition (EEMD) is proposed for accurately detecting the time varying pitch of speech in tonal languages. Unlike frame-, event-, or subspace-based pitch detectors, the time varying information of pitch within the short duration, which is of crucial importance in speech processing of tonal languages, can be accurately extracted. The Chinese Linguistic Data Consortium (CLDC) database for Mandarin Chinese was employed as standard speech data for the evaluation of the effectiveness of the method. It is shown that the proposed method provides more accurate and reliable results, particularly in estimating the tones of non-monotonically varying pitches like the third one in Mandarin Chinese. Also, it is shown that the new method has strong resistance to noise disturbance.

关键词： Ensemble empirical mode decomposition Time varying pitch Tonal language Noise restraint

Visible Light-Induced[3+2]Annulation Reaction of Alkenes with Vinyl Azides:Direct Synthesis of Functionalized Pyrroles

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Chinese Journal of Chemistry 2024年第2期42卷 151-156页

作者： Ming Yang xin-Yu wang Jie wang Yu-long Zhao Jilin Province Key Laboratory of Organic Functional Molecular Design&Synthesis Faculty of ChemistryNortheast Normal UniversityChangchunJilin 130024China

A photocatalytic[3+2]annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye *** substrate scope and high functional group tolerance were demonstrated by more than 50 *** reaction provides a novel and efficient method for the synthesis of polyfunctionalized pyrroles under very mild metal-free conditions without other additives.

关键词： Photocatalysis Vinyl azides Alkenes Pyrroles Annulation Radical reactions

Two thin middle-crust low-velocity zones imaged in the Chuan-Dian region of southeastern Tibetan Plateau and their tectonic implications

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Science China Earth Sciences 2024年第5期67卷 1675-1686页

作者： long LI xin wang Guangbing HOU Yuan LING Yinshuang AI Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

Intracrustal low-velocity zones(LVZs)indicate a mechanically weak crust and are widely observed in the southeast margin of the Tibetan ***,their spatial distributions and formation mechanisms remain *** investigate their distribution and detailed morphology of the LVZs in the southeastern Tibetan Plateau,here we used teleseismic events and continuous waveform data recorded by 40 broadband seismic stations newly deployed in the Sichuan-Yunnan region from December 2018 to October 2020.A total of 12,924 high-quality P-wave receiver functions and 5–40 s fundamental Rayleigh surface wave phase velocity dispersion curves from ambient noise cross-correlation functions were *** Swave velocity model at a depth interval of 0–100 km in the study area was inverted by using the trans-dimensional Markov chain Monte Carlo strategy to jointly invert the complementary data of the receiver function waveform and Rayleigh surface wave phase velocity *** results show that there are two separate LVZs(~3.5 km/s)surrounding the rigid Daliangshan subblock at crustal depths of approximately 30–40 km,providing new constraints on the geometry of the LVZs in our study *** two LVZs obtained in this study may represent the middle crustal flow channels,through which the material in the center of the Tibetan Plateau extrudes to its southeast *** by the rigid Sichuan Basin and the spindle-like Daliangshan subblock,the material continues to flow southward through the mechanically weak middle crustal channels surrounding the Daliangshan *** addition,the existence of thin LVZs in the middle crust plays an important role in understanding the decoupling between the upper and lower crust in the study *** also provides new constraint on the complex tectonic deformation process of the southeastern margin of the Tibetan Plateau caused by the collision and compression of the Indian and the Eurasian plates.

关键词： Southeastern Tibetan Plateau Joint inversion Intracrustal low-velocity zone Mid-crustal channel flow