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Nonlinear robust control of a quadrotor helicopter with finite time convergence

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Control Theory and Technology 2018年第2期16卷 133-144页

作者： Guozhou ZHENG bin xian School of Electrical and Information Engineering Tianjin University Tianjin 300072 China

In this paper, the control problem for a quadrotor helicopter which is subjected to modeling uncertainties and unknown external disturbance is investigated. A new nonlinear robust control strategy is proposed. First, a nonlinear complementary filter is developed to fuse the raw data from the onboard barometer and the accelerometer to decrease the negative effects from the noise associated with the low-cost onboard sensors Then the adaptive super-twisting methodology is combined with a backstepping method to formulate the nonlinear robust controller for the quadrotor＇s attitude angles and the altitude position. Lyapunov based stability analysis shows that finite time convergence is ensured for the closed-loop operation of the quadrotor＇s roll angle, pitch angle, row angle and the altitude position. Real-time flight experimental results, which are performed on a quadrotor flight testbed, are included to demonstrate the good control performance of the proposed control methodology.

关键词： Quadrotor nonlinear control finite time convergence real-time experiment

Translocation of a Self-propelled Polymer through a Narrow Pore

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Chinese Journal of Polymer Science 2022年第12期40卷 1670-1678,I0010页

作者： Chao Wang Han-xian Hu Yan-li Zhou bin Zhao Meng-Bo Luo Department of Physics Taizhou UniversityTaizhou 318000China Department of Physics Zhejiang UniversityHangzhou 310027China

Recent studies indicate that active polymers often show curious conformational and dynamical ***,rigid polymers with self-propelled tangential forces can move directionally and even push a *** by this,the tran slocation of an active bead-spring polymer through a narrow pore is studied simulationly in this *** bead of the polymer is propelled by a tangential active force(f) along the contour of the *** results show that the active polymer translocates through the pore in a railway-motion *** tran slocation velocity v of the polymer is determined only by f,resulting that the translocation time(r) as a function of the polymer length(N)and the active force fcan be expressed as τ∝ Nf,which is independent of the rigidity of the *** results indicate that the tran slocation dynamics of active polymers is quite different from that of passive polymers.

关键词： Active polymer Translocation Dynamics Simulation

Controllable four-wave mixing response in a dual-cavity hybrid optomechanical system

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Chinese Physics B 2021年第5期30卷 406-411页

作者： Lei Shang bin Chen li-li Xing Jian-bin Chen Hai-bin Xue Kang-xian Guo Department of Physics College of Physics and OptoelectronicsTaiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan 030024China Department of Physics School of Physics and Material ScienceGuangzhou UniversityGuangzhou 510006China

We systematically investigate the four-wave mixing(FWM)spectrum in a dual-cavity hybrid optomechanical system,which is made up of one optical cavity with an ensemble of two-level atoms and another with a mechanical *** this work,we propose that the hybrid dual-cavity optomechanical system can be employed as a highly sensitive mass sensor due to the fact that the FWM spectrum generated in this system has a narrow spectral width and the intensity of the FWM can be easily tuned by controlling the coupling strength(cavity-cavity,atom-cavity).More fascinatingly,the dual-cavity hybrid optomechanical system can also be used as an all-optical switch in view of the easy on/off control of FWM signals by adjusting the atom-pump detuning to be positive or *** proposed schemes have great potential applications in quantum information processing and highly sensitive detection.

关键词： four-wave mixing dual-cavity optomechanical system atomic ensemble

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海上救援无人方舱水动力性能分析

大连理工大学学报 2025年第1期65卷 56-66页

作者：李铁骊黄珍秋周燹大连理工大学船舶工程学院辽宁大连116024

空投方舱的方形系数过大,使得方舱在航行时艏摇、横摇、纵摇严重,水动力性能较差,需针对方舱的入水航行问题进行水动力性能分析,并为其设计优选附体,改善方舱的稳定性.根据确定的方舱主尺度、船型参数以及重心位置可行域,利用CFD方法研... 详细信息

空投方舱的方形系数过大,使得方舱在航行时艏摇、横摇、纵摇严重,水动力性能较差,需针对方舱的入水航行问题进行水动力性能分析,并为其设计优选附体,改善方舱的稳定性.根据确定的方舱主尺度、船型参数以及重心位置可行域,利用CFD方法研究方舱的水动力性能,包括快速性、耐波性、航向稳定性等,为方舱设计并优化附体.其中快速性方面,计算固定吃水、纵倾时的阻力以及空载、设计载况下放开纵摇和垂荡的静水阻力;耐波性主要计算空载、设计载况下的波浪增阻和自由横摇衰减时间,增加舭龙骨以改善横摇稳定性;航向稳定性主要计算方舱艏摇衰减时间,并加装艏艉鳍改善其航向稳定性;最后对加装优选附体的方舱进行分析对比,并完成实船阻力、功率预估.通过加装附体的方式对方舱进行优化,水动力性能分析证明了其动力和推进系统可行性,初步确定加装优选附体的方舱模型,为后续总体设计及其设备选取提供技术参考.

关键词：无人艇救援方舱水动力性能快速性耐波性航向稳定性附体优化设计

High Gain Lateral Semi-Insulating GaAs Photoconductive Switch Triggered by 1064nm Laser Pulses

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Chinese Physics Letters 2002年第3期19卷 351-354页

作者： Shi Wei, Zhang xian-bin Department of Applied Physics Xi"an University of Technology

We report on the experimental results of a lateral semi-insulating GaAs photoconductive switch, with a gap of 8 mm between two electrodes, triggered by 1064 nm laser pulses at a wavelength beyond the GaAs absorption edge. Both the linear and nonlinear modes of the switch were observed when it was triggered by light pulses with an energy of 1.9 mJ and a pulse width of 60 ns, and operated at high voltages of 3 and 5 kV. The results show that when the semi-insulating GaAs photoconductive switch operates under an electrical field of 4.37 kV/cm, it will enter into the linear mode first, and then the switch will undergo the nonlinear mode (lock-on) after a delay of about 20-100 ns. It is worth noticing that the delay time under high light energy is longer than that in the low optical energy. The non-intrinsic absorption mechanism is discussed. EL2 deep level defects and double-photon absorption in GaAs may play a key part in the absorption process.

关键词： Gallium arsenide

Establishment of a human hepatoma multidrug resistant cell line in vitro

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World Journal of Gastroenterology 2010年第18期16卷 2291-2297页

作者： Zhou, Yuan ling, xian-Long li, Shi-Wei li, Xin-Qiang Yan, bin Third Mil Med Univ Xinqiao Hosp Dept Gastroenterol Chongqing 400037 Peoples R China

AIM:To establish a multidrug-resistant hepatoma cell line(SK-Hep-1),and to investigate its biological ***:A highly invasive SK-Hep-1 cell line of human hepatocellular carcinoma,also known as malignant hepatoma was incubated with a high concentration of cisplatin(CDDP) to establish a CDDP-resistant cell subline(SK-Hep-1/CDDP).The 50% inhibitory dose(IC50) values and the resistance indexes [(IC50 SK-Hep-1/CDDP)/(IC50 SK-Hep-1)] for other chemotherapeutic agents and the growth curve of cells were all evaluated using cell counting kit-8 *** distribution of the cell cycles were detected by flow *** of acquired multidrug resistance P-glycoprotein(MDR1,ABCB1) and multidrug resistance-associated protein 1(MRP1,ABCC1) was compared with that in parent cells by Western blotting and immunofluorescence combined with laser scanning confocal ***:The SK-Hep-1/CDDP cells(IC50 = 70.61 ± 1.06 μg/mL) was 13.76 times more resistant to CDDP than the SK-Hep-1 cells(IC50 = 5.13 ± 0.09 μg/mL),and CDDP-resistant cells also demonstrated cross-resistance to many anti-tumor agents such as doxorubicin,5-fluorouracil and *** morphologies were determined in both SK-Hep-1 and SK-Hep-1/CDDP *** cell cycle distribution of the SK-Hep-1/CDDP cell line exhibited a significantly increased percentage of cells in S(42.2% ± 2.65% vs 27.91% ± 2.16%,P line SK-Hep-1/CDDP was closely related to the overexpression of MDR1 and MRP1.

关键词： Hepatoma Cell line Multidrug resistance In vitro Cisplatin

Stress Distribution in the Cruciform Specimen under Transverse Tension Stress for SiC/Ti-6Al-4V Composites

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稀有金属材料与工程 2009年第A03期38卷 33-36页

作者： Yang Yanqing Yuan Meini li Jiankang Huang bin Luo xian State Key Lab of Solidification Northwestern Polytechnical University Xi＇an 710072 China

The cruciform specimen was selected to obtain the transverse tensile behavior of SiC fiber reinforced titanium matrix composites. Moreover, the means of combining the unilaterally coupled finite element method with the transverse tensile test was developed to evaluate the interfacial normal bond strength of composites. The results showed that the initial non-linearity in the transverse stress-strain curve of SiC/Ti-6Al-4V occurs at the stress of 350 MPa. The means of combining the unilaterally coupled finite element method with the transverse tensile test is an effective method to predict the interfacial normal bond strength of composites. In addition, the interface failure mechanism of composites was analyzed in detail.

关键词：钛基复合材料物理性能应力有限元分析

Lanthanide-Hypophosphite Frameworks with Guanidinium Guest Showing High Proton Conductivity

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Chinese Journal of Chemistry 2021年第12期39卷 3381-3385页

作者： Quan-Wen li Zhao-Yang li Kai li bin Xia Na li xian-He Bu School of Materials Science and Engineering National Institute for Advanced MaterialsTianjin Key Laboratory of Metal and Molecule-Based Material ChemistryNankai UniversityTianjin 300350China State Key Laboratory of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

Proton-conductive metal-organic frameworks(MOFs)have attracted great attention for their promising application in membrane fuel *** explore proton-conductive MOFs with high performance,here we present four lanthanide-hypophosphite frameworks with distinct amine *** complexes possess a general formula[AH][Gd_(2)(H_(2)PO_(2))_(7)(AH=protonated amines)].Due to the rich hydrogen bond networks,complex 1 with guanidinium as guest shows high proton conductivity of 1.75×10^(-2) S·cm^(-1) at a relative humidity of 97%(368 K).We also studied the magnetic properties of complex 1 and reveal that the hypophosphite ligand transfers weak antiferromagnetic interactions between Gd^(3+)ions.

关键词： Lanthanides Hypophosphite Metal-organic frameworks Proton transport Magnetic properties

Thermodynamic analysis and formula optimization of steel slag-based ceramic materials by FACTsage software

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International Journal of Minerals,Metallurgy and Materials 2013年第4期20卷 379-385页

作者： xian-bin Ai Hao Bai li-hua Zhao Da-qiang Cang Qi Tang State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Foshan Oceano Ceramic Co. Ltd.

Using steel slag as a main raw material of ceramics is considered as a high value-added way. However, the relationship among the initial composition, ceramic microstructure, and macroscopic properties requires further study. In this paper, a series of ceramics with different slag ratios （0-70wt%） were designed, and the software FACTsage was introduced to simulate the formation of crystalline phases. The simulation results indicate that mullite is generated but drastically reduced at the slag ratios of 0-25wt%, and anorthite is the dominant crystalline phase in the slag content of 25wt%-45wt%. When the slag ratio is above 45wt%, pyroxene is generated more than anorthite. This is because increasing magnesium can promote the formation of pyroxene. Then, the formula with a slag content of 40wt% was selected and optimized. X-ray diffraction results were good consistent with the simulation results. Finally, the water absorption and bending strength of optimized samples were measured.

关键词： ceramic materials steel slag phase composition thermodynamics optimization