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Spherical Orthotomic and Spherical Antiothotomic

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Acta Mathematica Sinica,English Series 2007年第9期23卷 1673-1682页

作者： jian fei XIONG Department of Mathematics Qingdao University Qingdao 266071 P. R. China

In this paper the spherical orthotomic and the spherical antiorthotomic are defined and their local diffeomorphic types are determined.

关键词： spherical curve spherical orthotomic spherical antiorthotomic singularity

Hand-eye calibration with a new linear decomposition algorithm

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1363-1368页

作者： Rong-hua LIANG jian-fei MAO College of Information Engineering Zhejiang University of Technology Hangzhou 310032 China

To solve the homogeneous transformation equation of the form AX=XB in hand-eye calibration, where X represents an unknown transformation from the camera to the robot hand, and A and B denote the known movement transformations associated with the robot hand and the camera, respectively, this paper introduces a new linear decomposition algorithm which consists of singular value decomposition followed by the estimation of the optimal rotation matrix and the least squares equation to solve the rotation matrix of X. Without the requirements of traditional methods that A and B be rigid transformations with the same rotation angle, it enables the extension to non-rigid transformations for A and B. The details of our method are given, together with a short discussion of experimental results, showing that more precision and robustness can be achieved.

关键词： Homogeneous transformation equation Singular value decomposition (SVD) Optimal rotation matrix Rigid transformations

Asymptotic inference for AR(1) panel data

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Applied Mathematics(A Journal of Chinese Universities) 2020年第3期35卷 265-280页

作者： SHEN jian-fei PANG Tian-xiao School of Mathematical Sciences Zhejiang UniversityHangzhou 310027China

A general asymptotic theory is given for the panel data AR(1) model with time series independent in different cross sections. The theory covers the cases of stationary process, local to unity process, unit root process, mildly integrated, mildly explosive and explosive processes. It is assumed that the cross-sectional dimension and time-series dimension are respectively N and T. The results in this paper illustrate that whichever the process is, with an appropriate regularization, the least squares estimator of the autoregressive coefficient converges in distribution to a normal distribution with rate at least O(N-1/3). Since the variance is the key to characterize the normal distribution, it is important to discuss the variance of the least squares estimator. We will show that when the autoregressive coefficient ρ satisfies |ρ| 1. ρ = 1 is the critical point where the convergence rate changes radically. The transition process is studied by assuming ρ depending on T and going to 1. An interesting phenomenon discovered in this paper is that, in the explosive case, the least squares estimator of the autoregressive coefficient has a standard normal limiting distribution in the panel data case while it may not has a limiting distribution in the univariate time series case.

关键词： AR(1)model Least squares estimator Limiting distribution Non-stationray Panel data

Distortion Theorem for Bloch Mappings on the Unit Ball ■~n

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Acta Mathematica Sinica,English Series 2009年第10期25卷 1583-1590页

作者： jian fei WANG Tai Shun LIU College of Mathematics and Physics Information Engineering Zhejiang Normal University Jinhua 321004 P. R. China Department of Mathematics Huzhou Teachers College Huzhou 313000 P. R. China

In this paper, we obtain a version of subordination lemma for hyperbolic disk relative to hyperbolic geometry on the unit disk D. This subordination lemma yields the distortion theorem for Bloch mappings f ∈ H（B^n） satisfying ｜｜f｜｜0 = 1 and det f＇（0） = α ∈ （0, 1], where｜｜f｜｜0 = sup{（1 - ｜z｜^2 ）n＋1/2n det（f＇（z））[1/n ： z ∈ B^n}. Here we establish the distortion theorem from a unified perspective and generalize some known results. This distortion theorem enables us to obtain a lower bound for the radius of the largest univalent ball in the image of f centered at f（0）. When a = 1, the lower bound reduces to that of Bloch constant found by Liu. When n = 1, our distortion theorem coincides with that of Bonk, Minda and Yanagihara.

关键词： mapping distortion theorem Bloch mapping univalent ball hyperbolic distance holomorphic

DONOR-ACCEPTOR CONJUGATED COOLIGOMERS FOR SINGLE MOLECULE SOLAR CELLS

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Chinese Journal of Polymer Science 2013年第5期31卷 815-822页

作者： jian-fei Qu jian Liu Si-da Li Zhi-yuan Xie 耿延候 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences

Five novel donor-acceptor （D-A） conjugated cooligomers （F4B-hP, F5B-hP, F5B2[1,2]-hP, F5B2[I,3]-hP and F7B2[1,2]-hP） were synthesized. The absorption spectra of the cooligomers cover a wide range from 300 nm to 630 nm. The cooligomers could form films featured by alternating D-A lamellar nanostructures with the periods relative to the molecular lengths after thermal annealing or solvent vapor annealing. Single molecule solar cells were fabricated, and FSB-hP exhibited the best device performance. When the film of FSB-hP was thermally annealed, a power conversion efficiency （PCE） of 1.56% was realized. With solvent vapor annealing, the PCE could be further improved to 1.72% with a short-circuit current （J_SC） of 5.76 mA/cm2, an open-circuit voltage （Voc） of 0.87 V and a fill factor （FF） of 0.34.

关键词： Single molecule solar cells Monodisperse conjugated oligomers Lamellar nanostructures Bulk heterojunctionsolar cells.

Enhanced rate and specific capacity in nanorod-like core-shell crystalline NiMoO_(4)@amorphous cobalt boride materials enabled by Mott-Schottky heterostructure as positive electrode for hybrid supercapacitors

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Journal of Energy Chemistry 2023年第10期85卷 276-287,I0009页

作者： Jing-Feng Hou jian-fei Gao Ling-Bin Kong State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of TechnologyLanzhou 730050GansuChina School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050GansuChina

The supercapacitor electrode materials suffer from structure pulverization and sluggish electrode kinetics under high current ***,a unique NiMoO_(4)@Co-B heterostructure composed of highly conductive Co-B nanoflakes and a semiconductive NiMoO_(4) nanorod is designed as an electrode material to exert the energy storage effect on *** formed Mott-Schottky heterostructure is helpful to overcome the ion diffusion barrier and charge transfer resistance during charging and ***,this crystalline-amorphous heterogeneous phase could provide additional ion storage sites and better strain ***,the optimized NiMoO_(4)@Co-B hierarchical nanorods(the mass ratio of NiMoO_(4)/Co-B is 3:1)present greatly enhanced electrochemical characteristics compared with other components,and show superior specific capacity of 236.2 mA h g^(-1)at the current density of 0.5 A g^(-1),as well as remarked rate *** present work broadens the horizons of advanced electrode design with distinct heterogeneous interface in other energy storage and conversion field.

关键词： Crystalline-amorphous heterophase Mott-Schottky heterostructure Energy storage Nickel molybdate

Impact of initial fluctuations and nuclear deformations in isobar collisions

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Nuclear Science and Techniques 2024年第6期35卷 155-162页

作者： jian-fei Wang Hao-Jie Xu Fu-Qiang Wang Department of Modern Physics University of Science and Technology of ChinaHefei 230026China School of Science Huzhou UniversityHuzhou 313000China Strong-Coupling Physics International Research Laboratory(SPiRL) Huzhou UniversityHuzhou 313000China Department of Physics and Astronomy Purdue UniversityWest LafayetteIN 47907USA

Relativistic isobar^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zrcollisions have revealed intricate differences in their nuclear size and shape,inspiring unconventional studies of nuclear structure using relativistic heavy ion *** this study,we investigate the relative differences in the mean multiplicityR_()and the secondR_(ε2)and third-order eccentricityR_(ε3)between isobar collisions using initial state Glauber *** is found that initial fluctuations and nuclear deformations have negligible effects on R_()in most central collisions,while both are important for the R_(ε2)and R_(ε3),the degree of which is sensitive to the underlying nucleonic or sub-nucleonic degree of *** features,compared to real data,may probe the particle production mechanism and the physics underlying nuclear structure.

关键词： Relativistic isobar collisions Initial fluctuations Nuclear deformation

Electrolyte effect on electrochemical behaviors of manganese fluoride material for aqueous asymmetric and symmetric supercapacitors

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Rare Metals 2024年第3期43卷 1048-1061页

作者： Zheng-Hua He jian-fei Gao Ling-Bin Kong State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of TechnologyLanzhou730050China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou730050China

Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical ***,there are few reports about the wide potential window materials except Bi_(2)O_(3)and VO_(2).Therefore,the MnF_(2)synthesized by solvothermal reaction was served as the electrode for *** MnF_(2)exhibited electrochemical activity in alkaline solution in three-electrode system,especially with a wide potential window from-0.8 to+0.5 V in 2 mol·L^(-1)***,the assembled MnF_(2)//MnF_(2)symmetrical HSC had a potential window of 1.5 V,and it exhibited outstanding long-cycle ***,when MnF_(2)was taken as the negative and positive respectively,the potential windows of asymmetric devices CoMoO_(4)//MnF_(2)and MnF_(2)//Activated Carbon(AC)could reach 1.3 and 1.45 V,respectively,showing excellent cycle *** work shows that MnF_(2)material has great research value in HSC,and provides a new research direction for developing high-performance devices.

关键词： Manganese fluoride Potential window Hybrid supercapacitors Electrochemical performance

Dramatic impact of metric choice on biogeographical regionalization

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Plant Diversity 2020年第2期42卷 67-73页

作者： jian-fei Ye Yun Liu Zhi-Duan Chen State Key Laboratory of Systematic and Evolutionary Botany Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China Beijing Botanical Garden.Institute of Botany Chinese Academy of SciencesBeijing W0093China

For a quantitative biogeographical regionalization,the choice of an appropriate dissimilarity index to measure pairwise distances is *** different metrics have been used,but there is no specific study to test the impact of metric choice on biogeographical *** herein applied a hierarchical cluster analysis on the mean nearest taxon distance(MNTD)and the phylogenetic turnover component of the SФrensen dissimilarity index(pβsim)pairwise distances to generate two schemes of phylogenetic regio nalization of the Chinese flora,and then evaluated the effect of metric *** regionalization based on MNTD was influenced by richness differences,but regionalization based on pβsim can clearly reflect the evolutionary history of the Chinese *** provided a brief description of the five regions identified by pβsim,and the regionalization can help develop strategies to effectively conserve the taxa and floristic regions with different origins and evolutionary histories.

关键词： Angiosperms Chinese flora Dissimilarity index Distance metrics Spatial turnover