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Chinese Journal of Structural Chemistry 2007年第5期26卷 572-574页

作者： tan Ting-feng Department of Materials Science ＆ Engineering Tianjin Institute of Urban Construction Tianjin 300384 China

The title compound 2 （C30H27N3O, Mr = 445.55） has been synthesized and its structure was determined by X-ray crystallography method. The crystal is of monoclinic, space group P21/c with a = 17.520（15）, b = 8.640（7）, c = 15.439（13） A, β = 98.642（14）°, V = 2310（3） 3, Dc = 1.281 g/cm^3, μ = 0.780 mm^-1, F（000） = 944, Z = 4, the final R = 0.0671 and wR = 0.1790 for 1952 observed reflections with Ⅰ 〉 2σ（Ⅰ）. X-ray analysis revealed that the interatomic distance of C（20）O（1） is 1.464（4） , longer than that of the normal C-O bond （1.41～1.43 A） in the six-membered heterocycle, but this kind of change coincides with other spiro compounds. The six-membered heterocycle containing spiro Csp3-O is nonplanar. The UV-vis spectra of the title compound in polymer films showed that it exhibits excellent photochromic property.

关键词： spirooxazine crystal structure photochromism

On λ-Power Distributional n-Chaos

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Chinese Annals of Mathematics,Series B 2017年第5期38卷 1119-1130页

作者： Heman FU feng tan School of Mathematics and Statistics Zhaoqing University School of Mathematical Sciences South China Normal University

For each real number λ∈ [0, 1], λ-power distributional chaos has been in- troduced and studied via Furstenberg families recently. The chaoticity gets stronger and stronger as A varies from 1 to 0, where 1-power distributional chaos is exactly the usual distributional chaos. As a generalization of distributional n-chaos,λ-power distributional n-chaos is defined similarly. Lots of classic results on distributional chaos can be improved to be the versions of λ-power distributional n-chaos accordingly. A practical method for distinguishing 0-power distributional n-chaos is given. A transitive system is constructed to be 0-power distributionally n-chaotic but without any distributionally （n ＋ 1）-scrambled tuples. For each λ∈ [0, 1], ）,-power distributional n-chaos can still appear in minimal systems with zero topological entropy.

关键词： Furstenberg family λ-power distributional n-chaos Minimal system Topological entropy

Stabilization of linear time-varying systems with state and input constraints using convex optimization

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Journal of Systems Engineering and Electronics 2016年第3期27卷 649-655页

作者： feng tan Mingzhe Hou Guangren Duan Center for Control Theory and Guidance Technology Harbin Institute of Technology

The stabilization problem of linear time-varying systems with both state and input constraints is considered. Sufficient conditions for the existence of the solution to this problem are derived and a gain-switched（gain-scheduled） state feedback control scheme is built to stabilize the constrained timevarying system. The design problem is transformed to a series of convex feasibility problems which can be solved efficiently. A design example is given to illustrate the effect of the proposed algorithm.

关键词： linear time-varying stabilization state constraints convex optimization

Higher-order expansions of powered extremes of logarithmic general error distribution

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 47-54页

作者： tan Xiao-feng LI Li-hui School of Mathematics and Statistics Southwest UniversityChongqing 400715China

In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥***-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing *** is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v).

关键词： logarithmic general error distribution convergence rate higher-order expansion powered ex-treme

Arsenite oxidation by three types of manganese oxides

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Journal of Environmental Sciences 2006年第2期18卷 292-298页

作者： feng Xiong-han ZU Yan-qun tan Wen-feng LIU Fan College of Resources and Environment Huazhong Agricultural University Wuhan 430070 China College of Resources and Environment Yunnan Agricultural University Kunming 650201 China

Oxidation of As（Ⅲ） by three types of manganese oxides and the effects ofpH, ion strength and tartaric acid on the oxidation were investigated by means of chemical analysis, equilibrium redox, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Three synthesized Mn oxide minerals, bimessite, cryptomelane, and hausmannite, which widely occur in soil and sediments, could actively oxidize As（Ⅲ） to As（Ⅴ）. However, their ability in As（Ⅲ）-oxidation varied greatly depending on their structure, composition and surface properties. Tunnel structured cryptomelane exhibited the highest ability of As （Ⅲ） oxidation, followed by the layer structured birnessite and the lower oxide hausmannite. The maximum amount of As （Ⅴ） produced by the oxidation was in the order （mmol/kg） of cryptomelane （824.2）〉 bimessite （480.4）〉 hausmannite （117.9）, As pH increased from the very low value（pH 2.5）, the amount of As（Ⅲ） oxidized by the tested Mn oxides was firstly decreased, then negatively peaked in pH 3.0 6.5, and eventually increased remarkably. Oxidation of As（Ⅲ） by the Mn oxides had a buffering effects on the pH variation in the solution. It is proposed that the oxidative reaction processes between As （Ⅲ） and biruessite（or cryptomelane） are as follows：（1） at lower pH condition：（MnO2）x＋ H3AsO3 ＋ 0.5H^＋=0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋Mn〉^2＋（MnO2）x-1 ＋ H2O; （2） at higher pH condition：（MnO2）x ＋ H3AsO3 = 0.5H2AsO4^- ＋ 0.5HAsO4^2- ＋ 1.5H^＋＋（MnO2）x-1. MnO. With increase of ion strength, the As（Ⅲ） oxidized by bimessite and cryptomelane decreased and was negatively correlated with ion strength. However, ion strength had little influence on As （Ⅲ） oxidation by the hausmarmite. The presence of tartaric acid promoted oxidation of As（Ⅲ） by birnessite. As for cryptomelane and hansmannite, the same effect was observed when the concentration of tartaric acid was below 4 mmol/L, otherwise the oxidized As（Ⅲ） decreased. These findings are of great significance in improving our understanding

关键词： oxidation of As(Ⅲ) As(Ⅴ) Mn oxides pH ion strength tartaric acid

Loading and wrinkling analysis of membrane structures

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Science China(Technological Sciences) 2011年第10期54卷 2597-2604页

作者： YANG QingShan tan feng WANG Xiaofeng School of Civil Engineering Beijing Jiaotong University Beijing 100044 China

Loading analysis,as one of the most crucial procedures in the assessment of safety of the membrane structures,is to check the adequacy of structural stiffness and the extent of membrane stress and deformation,thus ensuring the structural stability and avoiding the wrinkling of membrane *** this paper,the analysis procedures are presented and the wrinkling of membrane structure,representing a major behavioral performance of the structure,is included with the modified constitutive relationship *** for the judgment of the membrane wrinkling,the principal stress-strain criteria are ***,an integrated algorithm is developed,in which the Newton-Raphson method and updated Lagrange formulation are *** the proposed algorithm,two fabric roof structures are *** show that the presented method is feasible and reliable.

关键词： membrane structure loading analysis wrinkling analysis modified constitutive relationship

A study on wrinkling characteristics and dynamic mechanical behavior of membrane

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Acta Mechanica Sinica 2012年第1期28卷 201-210页

作者： Yun-Liang Li Ming-Yu Lu Hui-feng tan Yi-Qiu tan School of Transportation Science and Engineering Harbin Institute of Technology150090 HarbinChina Post-doctoral Research Center in Civil Engineering Harbin Institute of Technology150090 HarbinChina Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong KongChina Center for Composite Materials and Structure Harbin Institute of Technology150001 HarbinChina

An eigenvalue method considering the membrane vibration of wrinkling out-of-plane deformation is introduced, and the stress distributing rule in membrane wrinkled area is analyzed. A dynamic analytical model of rectangular shear wrinkled membrane and its numerical analysis approach are also developed. Results indicate that the stress in wrinkled area is not uniform, i.e. it is larger in wrinkling wave peaks along wrinkles and two ends of wrinkle in vertical direction. Vibration modes of wrinkled membrane are strongly correlated with the wrinkling configurations. The rigidity is larger due to the heavier stress in the part of wrinkling wave peaks. Therefore, wave peaks are always located at the node lines of vibration mode. The vibration frequency obviously increases with the vibration of wave peaks.

关键词： Space membrane structure Wrinkle Vibration

Relations between Mass Change and Frequency Shift of a QCM Sensor in Contact with Viscoelastic Medium

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Chinese Physics Letters 2013年第5期30卷 22-24页

作者： tan feng HUANG Xian-He School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731

We investigate frequency shift of a quartz crystal microbalance(QCM)sensor introduced by mass effect,and properties of material of its coated viscoelastic film are *** validity of the Sauerbrey relation cannot be held if the viscoelastic properties of the contacting medium are *** the QCM sensor with a viscoelastic film works in the gas phase,the viscoelastic properties will introduce an extra mass *** in the liquid phase,the missing mass effect can be *** experimental results demonstrate that the QCM sensor is sensitive to the viscoelastic properties of the coating *** of the viscoelastic contacting medium should be considered.

关键词： Shift QCM viscoelastic

Experiment and evaluation of wrinkling strain in a corner tensioned square membrane

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Acta Mechanica Sinica 2014年第3期30卷 430-436页

作者： Lan Lan Chang-Guo Wang Hui-feng tan Center for Composite Materials National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsHarbin Institute of Technology

Prediction of wrinkling characteristics is strongly correlated with the strain perpendicular to wrinkling direc- tion. In this paper, the strain field of wrinkled membrane is tested by VIC-3D system based on the digital image correlation technique. Experimental results are validated by the tension wrinkling simulation. The experimental strain perpendicular to wrinkling direction is analyzed in depth. The wrinkling strain of a square wrinkled membrane under corner tension is extracted from experimental strain perpendicular to wrinkling direction. A quantitative characterization format of the experimental wrinkling strain is proposed. A modified prediction method of wrinkling amplitude is presented based on the experimental wrinkling strain. The re- sults show that the precision of modified prediction model has improved 13.2% compared with the classical prediction model. The results reveal that the modified model can give an accurate prediction of the wrinkling amplitude.

关键词： Membrane structure. Wrinkle Wrinkling strain.Digital image correlation Wrinkling amplitude

Multi-Axis Attention With Convolution Parallel Block for Organoid Segmentation

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1295-1297页

作者： Pengwei Hu Xun Deng feng tan Lun Hu Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of SciencesUrumqi 830011 University of Chinese Academy of Sciences Beijing 100049 Xinjiang Laboratory of Minority Speech and Language Information Processing Urumqi 830011China Merck KGaA Darmstadt 64293Germany

Dear Editor,This letter presents an organoid segmentation model based on multi-axis attention with convolution parallel *** adeptly captures dynamic dependencies within bright-field microscopy images,improving global ... 详细信息

关键词： letter convolution organo