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Chaotic Oscillator in Frequency by Using Tunable Laser with Fibre Bragg Grating

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Chinese Physics Letters 2008年第3期25卷 1142-1144页

作者：吕国辉王慧莹姜旭丁群庄培栋 College of Electronic Engineering Heilongjiang University Harbin 150080 The Center of Computation Heilongjiang University Harbin 150080

A novel chaotic oscillator in wavelength domain by using a tunable fibre laser is proposed. The generator of chaos in wavelength is composed of fibre Bragg grating （FBG） with hybrid delayed feedback loop which induces wavelength nonlinearity. The dynamical regime of wavelength is ruled by a differential difference equation. We give the numerical simulation of the experimental setup and discuss its application in an optical encryption system.

关键词： supernova explosion proto-neutron star shock wave

Dual Strengthened Control of Recrystallization Behavior on CVCDE Magnesium Alloy Containing Characteristic Structure

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Acta Metallurgica Sinica(English Letters) 2023年第11期36卷 1805-1821页

作者： Nan Bian Feng Li Wentao Niu Chao Li Yuanqi Li School of Materials science and Chemical Engineering Harbin University of Science and TechnologyHarbin150040China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin150080China heilongjiang Provincial Key Laboratory of Light Metal Materials Modification and Green Forming Technology Harbin University of Science and TechnologyHarbin150040China

Various characteristic structures in typical magnesium alloys,including dislocation cells,substructures and twins,have an important influence on the dynamic recrystallization behavior,and the DRX(dynamic recrystallization)behavior is closely related to the grain refinement and texture weakening of the hot deformed ***,this study reveals the influence of the above characteristic structures on the dynamic recrystallization behavior of magnesium alloys,which have great significance for regulating the high-performance hot deformed microstructure of magnesium alloys and optimizing the macro mechanical *** this study,continuous variable channel direct extrusion(CVCDE)magnesium alloy was prepared by CVCDE,and its macro mechanical properties including hardness and uniaxial tension were *** thermoplastic deformation behavior and texture evolution of magnesium alloy with characteristic structure were analyzed by electron back-scattering diffraction *** is found that the dislocation recombination was realized by deformation mechanism(slip,climb and cross slip),the formation of grain substructure in coarse grains and the induction of recrystallization by twins promote the recrystallization behavior in hot deformed structures more adequate,which effectively improves the degree of microstructure refinement and deformation uniformity.

关键词： Characteristic structure Continuous variable channel direct extrusion(CVCDE) Dynamic recrystallization Regulation Mechanical property

Synthesis, Characterization of Mesoporous Al-Mg Composite Oxide and Catalytic Performance for Oxyethylation of Fatty Alcohol

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Chemical Research in Chinese Universities 2005年第5期21卷 601-605页

作者： SONG Wei-ming DENG Qi-gang ZHOU De-rui ZHAO De-feng State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 P. R. China College of Chemistry and Chemical Engineering Qiqihar University Qiqihar 161006 P. R. China College of science Harbin Institute of Technology Harbin 150001 P. R. China

A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylenediamine. The XRD, nitrogen adsorption-desorption and TEM studies indicate that the composite has a hexagonal framework structure and an average pore diameter of 2. 6 nm. The TG/DTA spectra indicate that the decomposition and the removal of the occluded surfactant of the sample take place in a range of 230-550 ℃. The mesoporous Al-Mg composite oxide exhibites a highly catalytic activity for the oxyethylation of fatty alcohols. Narrow-range distributed ethoxylates are formed in the presence of the mesoporous Al-Mg composite oxide catalyst. The distribution selectivity coefficient（Cx） is 24 when the mesoporous Al-Mg composite oxide was used as a catalyst for the oxyethylation of octanol and the average adduct degree of ethoxylates is 6. 4.

关键词： Mesoporous Al-Mg composites oxide Characterization Oxyethylation Narrow-range distribution

Multiwalled Carbon Nanotubes Modified with Silylated-salicylaldimine Co(II) and Pd(II) Complexes as Precatalysts in Ethylene Oligomerization

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Chemical Research in Chinese Universities 2022年第2期38卷 552-561页

作者： XUE Jingqi LI Feng ZHAI Xue LI Dan GUO Lijun LI Cuiqin Provincial Key Laboratory of Oil&Gas Chemical Technology College of Chemistry&Chemical EngineeringNortheast Petroleum UniversityDaqing 163318P.R.China

MWCNTs-Co(II) and Pd(II) were prepared through grafting silylated-salicylaldimine Pd(II) and Co(II) on multiwalled carbon nanotubes(MWCNTs) for ethylene oligomerization. The structures of the two MWCNTs-supported catalysts were characterized by means of scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, thermogravimetric analyses(TGA) and nitrogen adsorption and desorption. And the influence of the supported pattern on the catalytic properties for ethylene oligomerization was investigated. The results revealed that the silylated-salicylaldimine complexes were grafted on the inner and outer surfaces of the carbon nanotubes and the pore size and BET surface area of MWCNTs decreased. Compared with the homogeneous catalysts, the two MWCNTs-supported catalysts had higher selectivity for hexene and 1-hexene in the presence of diethylaluminum chloride(DEAC) with a small molecule size due to confinement effect. MWCNTs-Pd exhi-bited higher activity and higher selectivity for C8+ olefin compared to MWCNTs-Co due to electronic factors. The catalytic activities of MWCNTs-Pd and MWCNTs-Co decreased from 24.18×105g·(mol Pd·h)–1 and 20.57×105g·(mol Co·h)–1 to 19.79×105g·(mol Pd·h)–1 and 13.14×105g·(mol Co·h)–1 after the third recycle reaction, respectively.

关键词： Ethylene oligomerization Multiwalled carbon nanotube Confinement effect Heterogeneous catalyst

Synthesis and characterization of high strength polyimide/silicon nitride nanocomposites with enhanced thermal and hydrophobic properties

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Chinese Journal of Chemical Engineering 2021年第4期34卷 446-453页

作者： Tadele Daniel Mekuria Lei Wang Chunhong Zhang Ming Yang Qingtao Lv Diaa Eldin Fouad Polymer Materials Research Center Key Laboratory of Superlight Materials and Surface TechnologyMinistry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Chemistry Department College of Natural and Computational SciencesAssosa UniversityEthiopia

Polyimide(PI)composite films were synthesized incorporating amino modified silicon nitride(Si_(3)N_(4))nanoparticles into PI matrix via in situ polymerization *** mechanical and thermal performances as well as the hydrophobic properties of the as prepared composite films were investigated with respect to the dosage of the filler in the PI *** to Thermogravimetric(TGA)analysis,meaningful improvements were achieved in T5(5%weight loss temperature)and T10(10%weight loss temperature)up to 54.1℃ and 52.4℃,respectively when amino functionalized nano Si_(3)N_(4) particles were introduced into the PI *** differential scanning calorimetry(DSC)results revealed that the glass transition temperature(Tg)of the composites was considerably enhanced up to 49.7℃ when amino functionalized Si_(3)N_(4) nanoparticles were incorporated in the PI *** to the neat PI,the PI/Si_(3)N_(4) nanocomposites exhibited very high improvement in the tensile strength as well as Young’s modulus up to 105.4%and 138.3%,*** to the neat PI,the composites demonstrated highly decreased water absorption behavior which showed about 68.1%enhancement as the content of the nanoparticles was increased to 10 wt%.The SEM(Scanning electron microscope)images confirmed that the enhanced thermal,mechanical and water proof properties are essentially attributed to the improved compatibility of the filler with the matrix and hence,enhanced distribution inside the matrix because of the amino groups on the surface of Si_(3)N_(4) nanoparticles obtained from surface functionalization.

关键词： Silicon nitride(Si_(3)N_(4))nanoparticles Polyimide composites Mechanical properties Thermal properties Hydrophobicity

Biological function of resveratrol and its application in animal production:a review

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Journal of Animal science and Biotechnology 2023年第3期14卷 864-886页

作者： Qingwei Meng Jiawei Li Chunsheng Wang Anshan Shan College of Animal science and Technology Northeast Agricultural UniversityHarbin150030China

With the prohibition of antibiotics in feed,plant functional substances have been widely studied as feed ***,a natural stilbene,and a non-flavonoid polyphenol found in plants,possesses antioxidant,anti-inflammatory,and metabolic regulatory *** generated intense scientific and public interest,primarily due to its widely reported ability to prevent cancer,delay aging and alleviate related metabolic ***,resveratrol has been studied and applied as a feed additive in animal *** review focuses on the outline of the absorption and metabolism and biological functions of resveratrol and summarizes the application of dietary resveratrol in animal production up to the present,including pigs,poultry,and *** pigs,dietary resveratrol improved intestinal health,mitochondrial function,meat quality,and *** poultry,studies have shown that dietary resveratrol improves growth performance and meat and egg quality and alleviates heat stress induced adverse *** are few studies on dietary resveratrol in ruminants;however previous studies have indicated that dietary resveratrol increases nutrient digestibility and reduces methane emissions in *** is hoped that this review could provide a specific theoretical basis and research ideas for the research and application of resveratrol.

关键词： Animal production Biological function Health Pigs Poultry Resveratrol Ruminants

Comprehensive optimization of piezoelectric coefficient and depolarization temperature in Mn-doped Bi_(0.5)Na_(0.5)TiO_(3)-Bi_(0.5)K_(0.5)TiO_(3)-BaTiO_(3)lead-free piezoceramics

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Journal of Materials science & Technology 2024年第5期172卷 255-263页

作者： Huashan Zheng Enwei Sun Huajie Luo Xiaoyu Zhang Yixiao Yang Bin Yang Rui Zhang Shantao Zhang Wenwu Cao Condensed Matter science and Technology Institute School of Instrumentation Science and EngineeringHarbin Institute of TechnologyHarbin150080China Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China National Laboratory of Solid State Microstructures Department of Materials Science and EngineeringCollege of Engineering and Applied Science&Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China Department of Mathematics and Materials Research Institute The Pennsylvania State UniversityUniversity ParkPennsylvania16802United States of America

Lead-free Bi_(_(0.5))Na_(_(0.5))TiO_(3)(BNT)piezoelectric ceramics have the advantages of large coercive fields and high Curie *** the improvement of piezoelectric coefficient(d 33)is usually accompanied by a huge sacrifice of depolarization temperature(T d).In this work,a well-balanced performance of d 33 and T d is achieved in MnO_(2)-doped 0.79(Bi_(_(0.5))Na_(_(0.5))TiO_(3))-0.14(Bi_(0.5)K_(0.5)TiO_(3))-0.07BaTiO_(3)ternary *** in-corporation of 0.25 mol%MnO_(2)enhances the d 33 by more than 40%,while T d remains almost unchanged(i.e.,d 33=181 pC/N,T d=184℃).X-ray diffraction(XRD)shows that an appropriate fraction of the small axis-ratio ferroelectric phase(pseudo-cubic,P c)coexists with the long-range ferroelectric phase(tetrag-onal,T)under this MnO_(2)*** force microscopy(PFM)has revealed a special domain configuration,namely large striped and layered macro domains embedded with small *** study provides a distinctive avenue to design BNT-based piezoelectric ceramics with high piezoelectric performance and temperature stability.

关键词： BNT-BKT-BT ceramics Mn doping Piezoelectric Depolarization temperature Phase structure

Quantitative defect regulation of heterostructures for sulfur catalysis toward fast and long lifespan lithium-sulfur batteries

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Nano Research 2022年第9期15卷 7925-7932页

作者： Saisai Qiu Xinqi Liang Shuwen Niu Qingguo Chen Gongming Wang Minghua Chen Key Laboratory of Engineering Dielectric and Applications(Ministry of Education) School of Electrical and Electronic EngineeringHarbin University of Science and TechnologyHarbin 150080China Hefei National Laboratory for Physical science at the Microscale Department of ChemistryUniversity of Science&Technology of ChinaHefei 230026China

The advancement of lithium-sulfur(Li-S)batteries is severely retarded by lithium polysulfides(LiPSs)shuttling behavior and sluggish redox ***,the heterogeneous composite with defective Bi_(2)Se_(3−x)nanosheets and porous nitrogen-doped carbon(Bi_(2)Se_(3−x)/NC)is prepared by selenizing bismuth metal-organic frameworks as a multifunctional sulfur *** highly efficient immobilization-conversion on LiPSs is realized by the synergistic effect of structure construction strategy and defect *** is found that Bi_(2)Se_(3−x)with the suitable amount of selenium vacancies achieves the best electrochemical performance due to the advantages of its structure and *** results confirm the intrinsic correlation between defects and catalysis,which are revealed by computational and experimental *** to these superiorities,the developed sulfur electrodes exhibited admirable stability and a fairly lower capacity decay rate of approximately 0.0278%per cycle over 1,000 cycles at a 3 C *** at the high sulfur loading of 6.2 mg·cm^(−2),the cathode still demonstrates a high discharge capacity of 455 mAh·g^(−1)at 1 *** work may enlighten the development of mechanism investigation and design principles regarding sulfur catalysis toward high-performance Li-S batteries.

关键词： lithium-sulfur(Li-S)batteries lithium polysulfides(LiPSs) shuttle effect redox kinetics selenium vacancy sulfur catalysis

Dynamic Event-triggered State Estimation for Nonlinear Coupled Output Complex Networks Subject to Innovation Constraints

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IEEE/CAA Journal of Automatica Sinica 2022年第5期9卷 941-944页

作者： Jun Hu Chaoqing Jia Hui Yu Hongjian Liu Department of Applied Mathematics Harbin University of Science and TechnologyHarbin 150080 School of Automation Harbin University of Science and TechnologyHarbin 150080China Department of Applied Mathematics Harbin University of Science and TechnologyHarbin 150080China School of Mathematics and Physics Anhui Polytechnic UniversityWuhu 241000China

Dear editor,This letter investigates the recursive state estimation(RSE)problem for a class of coupled output complex networks via the dynamic event-triggered communication mechanism(DETCM)and innovation constraints(ICs).Firstly,a DETCM is employed to regulate the transmission ***,in order to improve the reliability of network communication,a saturation function is introduced to constrain the measurement outliers.A new RSE method is provided such that,for all output coupling,DETCM and ICs,an upper bound of state estimation error covariance(SEEC)is presented in a recursive form,whose trace can be minimized via parameterizing the state estimator gain matrix(SEGM).Moreover,the theoretical analysis is given to guarantee that the error dynamic is uniformly ***,a simulation example is illustrated to show the effectiveness of the proposed RSE method.

关键词： method estimation recursive