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Optimization of time-delayed feedback control of seismically excited building structures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 330-337页

作者： xue-ping li Wei-qiu ZHU Zu-guang YING Department of Mechanics School of Aeronautics and Astronautics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

An optimization method for time-delayed feedback control of partially observable linear building structures subjected to seismic excitation is proposed. A time-delayed control problem of partially observable linear building structure under horizontal ground acceleration excitation is formulated and converted into that of completely observable linear structure by using separation principle. The time-delayed control forces are approximately expressed in terms of control forces without time delay. The control system is then governed by Itoe stochastic differential equations for the conditional means of system states and then transformed into those for the conditional means of modal energies by using the stochastic averaging method for quasi-Hamiltonian systems. The control law is assumed to be modal velocity feedback control with time delay and the unknown control gains are determined by the modal performance indices. A three-storey building structure is taken as example to illustrate the proposal method and the numerical results are confirmed by using Monte Carlo simulation.

关键词： Time-delayed feedback control Stochastic averaging method Hamiltonian Earthquake

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米糠绿茶低热量曲奇饼干的配方优化

粮食与饲料工业 2024年第2期 32-36,42页

作者：柴云雷平丽雪吴迪常雪涵绥化学院食品与制药工程学院黑龙江绥化152061

为开发营养低热量的曲奇饼干,拓展米糠的应用领域,研究在单因素试验基础上,以感官评分为响应值,以米糠粉添加量、绿茶粉添加量、赤藓糖醇添加量和黄油添加量为考察因素,通过Box-Behnken试验设计进行响应面优化分析,确定最佳制作配方。... 详细信息

为开发营养低热量的曲奇饼干,拓展米糠的应用领域,研究在单因素试验基础上,以感官评分为响应值,以米糠粉添加量、绿茶粉添加量、赤藓糖醇添加量和黄油添加量为考察因素,通过Box-Behnken试验设计进行响应面优化分析,确定最佳制作配方。结果表明,当米糠粉添加量为11%、绿茶粉添加量为3%、赤藓糖醇添加量为38%、黄油添加量为89%时,感官评分最高,为92.9分。在此条件下制得的曲奇饼干色泽自然、香味浓郁、花纹清晰且口感酥脆。

关键词：米糠粉绿茶粉赤藓糖醇曲奇饼干响应面

Thermal Expansion Coefficients of Thin Crystal Films

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Communications in Theoretical Physics 2005年第5X期44卷 921-924页

作者： HUANG Jian-ping WU xue-Zhong li Sheng-Yi Mechatronics Engineering Institute National University of Defense Science and Technology Changsha 410073 China

The formulas for atomic displacements and Hamiltonian of a thin crystal film in phonon occupation number representation are obtained with the aid of Green's function theory. On the basis of these results, the formulas for thermal expansion coefficients of the thin crystal film are derived with the perturbation theory, and the numerical calculations are carried out. The results show that the thinner films have larger thermal expansion coefficients.

关键词： thermal expansion coefficients thin crystal film Green's function perturbation theory

Rainbow Pancyclicity in a Collection of Graphs Under the Dirac-type Condition

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 269-274页

作者： Lu-yi li ping li xue-liang li Center for Combinatorics and LPMC Nankai UniversityTianjin 300071China School of Mathematics and Statistics Shaanxi Normal UniversityXi’an 710062China

Let G={Gi:i∈[n]} be a collection of not necessarily distinct n-vertex graphs with the same vertex set V,where G can be seen as an edge-colored(multi)graph and each Gi is the set of edges with color i.A graph F on V is called rainbow if any two edges of F come from different Gis’.We say that G is rainbow pancyclic if there is a rainbow cycle Cℓof lengthℓin G for each integerℓ2[3,n].In 2020,Joos and Kim proved a rainbow version of Dirac’s theorem:Ifδ(Gi)≥2/n for each i∈[n],then there is a rainbow Hamiltonian cycle in *** this paper,under the same condition,we show that G is rainbow pancyclic except that n is even and G consists of n copies of Kn/2,n/*** result supports the famous meta-conjecture posed by Bondy.

关键词： rainbow Hamiltonian cycle rainbow pancyclic meta-conjecture

The 266-nm ultraviolet-beam generation of all-fiberized super-large-mode-area narrow-linewidth nanosecond amplifier with tunable pulse width and repetition rate

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Chinese Physics B 2022年第3期31卷 292-298页

作者： Shun li ping-xue li Min Yang Ke-Xin Yu Yun-Chen Zhu xue-Yan Dong Chuan-Fei Yao Institute of Ultrashort Pulsed Laser and Application Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

We report on a compact, stable, all-fiberized narrow-linewidth(0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fiberized nanosecond amplifier architecture, which consists of Yb-doped fiber preamplifiers and a super-large-mode-area Yb-doped fiber power amplifier. The fiber amplifier with a core of 50 μm is used to raise the threshold of the stimulated Brillouin scattering(SBS) effect and to obtain high output power and single pulse energy. Using lithium triborate(LBO) crystal and betabarium borate(BBO) crystal for realizing the second-harmonic generation(SHG) and fourth-harmonic generation(FHG),we achieve 17 μJ(1.73 W) and 0.66 μJ(66 mW), respectively, at wavelengths of 532 nm and 266 nm and a repetition rate of 100 kHz with pulse width of 4 ns. This source has great potential applications in fluorescence research and solar-blind ultraviolet optical communication.

关键词： nanosecond all-fiber amplifier narrow-linewidth ultraviolet beam generation tunable pulse width and repetition rate

Photocatalytic Characterization of TiO_2 Supported on Active Carbon

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Chinese Chemical Letters 2001年第6期12卷 549-550页

作者： xue ping li Feng YIN Yuan liN Jing Bo ZHANG Xu Rui XIAO Laboratory of Photochemistry Center for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100080

The Photocatalytic characterization of TiO2 supported on active carbon was investigated for photocatalytic decomposition of dichloroacetic acid. It was found that TiO2 / AC exhibited a higher photocatalytic activity than pure TiO2. The reason is that active carbon acting as powerful adsorbent supports makes high concentration environments of organic pollutant molecules around TiO2 particles.

关键词： Photocatalysis TiO2 active carbon

Influence of optical nonlinearity on combining efficiency in ultrashort pulse fiber laser coherent combining system

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Chinese Physics B 2022年第6期31卷 342-348页

作者： Yun-Chen Zhu ping-xue li Chuan-Fei Yao Chun-Yong li Wen-Hao Xiong Shun li Institute of Ultrashort Pulsed Laser and Application Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Department of Physics Durham UniversitySouth RoadDurham DH13LEUK

The influence of optical nonlinearity on combining efficiency in ultrashort pulse fiber laser coherent combining system is investigated theoretically and *** the theoretical work,a new theoretical algorithm is presented for the coherent combining efficiency,which can be used to quantify the spectral coherence decay induced by optical nonlinearity imbalance between the *** spectral information of the sub-beam is obtained by numerically solving the nonlinear Schrödinger equation(NLSE)in this algorithm to ensure an accurate *** the experimental work,the coherent combining of two all-fiber picosecond lasers is achieved,and the influence of imbalanced optical nonlinearity on the combining efficiency is studied,which agrees with the theoretical *** paper reveals the physical mechanism for the influence of optical nonlinearity on the combining efficiency,which is valuable for the coherent combining of ultrashort pulse fiber laser beams.

关键词： coherent beam combination spectral coherence optical nonlinearity

Dual Z-scheme Bi_(3)TaO_(7)/Bi_(2)S_(3)/SnS_(2)photocatalyst with high performance for Cr(Ⅵ)reduction and TC degradation under visible light irradiation

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Rare Metals 2022年第7期41卷 2417-2428页

作者： Jing-Jing Xu Hao-Yu Gu Min-Dong Chen xue-ping li Hong-Wen Zhao Hong-Bin Yang Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Nanjing 210044China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing 210044China Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials Nanjing 210044China School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Nanyang Technological University Singapore 639798Singapore

Ternary direct dual Z-scheme Bi_(3)T_(a)O_(7)/Bi_(2)S_(3)/SnS_(2) photocatalyst was successfully prepared by hydrothermal *** composite photocatalysts exhibited high photocatalytic performance on both Cr(Ⅵ)reduction and tetracycline(TC)degradation under the irradiation of visible *** results manifested that the photogenerated charge transfer efficiency was improved after forming the dual Z-scheme *** a result,the composite catalysts exhibited higher photocat-alytic degradation efficiency than the corresponding single *** apparent rate constant(k)value of the best sample BBS-3 for TC degradation was 0.0403 min^(-1),which was 40 times,8 times,and 18 times higher than that of single *** the k value of BBS-3 for the Cr(Ⅵ)reduction was 0.0249 min^(-1),it was about 23 times,7 times,and 18 times that of single *** experiments indicated that the BBS-3 had good photocat-alytic ***,the possible mechanism on Cr(Ⅵ)reduction and TC degradation was proposed based on the experimental results.

关键词： Photocatalysis Dual Z-scheme Heterojunction Heavy metal Organic pollutant

An All-Fiberized Chirped Pulse Amplification System Based on Chirped Fiber Bragg Grating Stretcher and Compressor

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Chinese Physics Letters 2022年第2期39卷 36-42页

作者： Ming-Xiao Wang ping-xue li Yang-Tao Xu Yun-Chen Zhu Shun li Chuan-Fei Yao Institute of Ultrashort Pulsed Laser and Application Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

We report an all-fiberized chirped pulse amplification system without any bulk *** stretcher and compressor are chirped fiber Bragg gratings inscribed in a 6/125μm single-mode fiber and a 30/250μm largemode-area *** fabrication system of chirped fiber Bragg gratings was designed and built by *** width of the linear exposure spot was controlled according to the different fiber sizes to improve the fabrication quality,and the parameters of chirped fiber Bragg gratings were fine-tuned during the fabrication to achieve the overall system’s spectral *** fiber circulators with the same fiber sizes as the chirped fiber Bragg gratings were employed to auxiliarily achieve the pulse stretching and *** dispersion accumulations provided by the stretcher and compressor are 129.8 ps and 90.8 *** power amplifiers were composed of the two-stage 10/130μm fiber pre-amplifier and the 30/250μm fiber main *** proposed chirped pulse amplification system with no spatial light is the true sense of an all-fiberized chirped pulse amplification structure and shows the main trend in development of ultrashort pulse fiber lasers.

关键词： fiber amplifier compressor