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Thermo-and ph-sensitive Polymer with Pendant spacer-linked Imidazole cycles

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chinese Journal of Polymer science 2024年第4期42卷 437-445页

作者： Natalya V.Zakharova stanislav N.Zelinskiy Mariya s.strelova Elena N.Danilovtseva Vadim V.Annenkov Institute of Macromolecular compounds of the Russian Academy of sciences Saint Petersburg199004Russia Limnological Institute of siberian Branch of the Russian Academy of sciences Irkutsk664033Russia

By the reaction of poly(acryloyl chloride) with N-(3-aminopropyl)imidazole, poly(N-(3-(1h-imidazol-1-yl)propyl)acrylamide) was synthesized. The new polymer contains an imidazole ring removed from the main chain by a spacer of five bonds. The structure and purity, molecular weight, hydrodynamic and thermosensitive properties of the obtained sample were studied by1h-and13c-NMR, FTIR spectroscopy, acid-base titration, light scattering, turbidimetry and viscometry. The observed ability of the imidazole-containing polymer to form and destroy associates in water-salt solutions at ph 6.6-7.4 and temperatures of 29-48℃ indicates that these are promising candidates for designing complex biomedical systems. The new polymer is able to form complexes with oligo-DNA more actively than poly(1-vinylimidazole), which is of interest for gene delivery applications. The polymer cross-linked with epichlorohydrin gives micro-relief coatings on the plastic surface, and the modified surface is able to attach negatively charged objects. This thermo-and ph-sensitive polymer modification can be applied to create finely controlled surfaces for cell culturing.

关键词： Imidazole-containing polymer Thermolability ph-sensitivity The modified surface DNA immobilization

solar light assisted photocatalysis of water using a zinc oxide semiconductor

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Journal of semiconductors 2013年第4期34卷 11-14页

作者： s.s.shinde c.h.Bhosale K.Y.Rajpure Electrochemical Materials Laboratory Department of PhysicsShivaji UniversityKolhapur 416004MaharashtraIndia

The photocatalytic decomposition of an eco-persistent AO7 dye with sunlight in an oxygenated aque- ous suspension has been studied under a nano-crystalline hexagonal ZnO photocatalyst. The effect of substrate temperature on the structural, morphological and photoactive properties has been investigated. The degradation of the AO7 dye is achieved using a photoelectrochemical reactor module equipped with ZnO synthesized electrodes. Kinetic parameters have been investigated in terms of a first order rate equation. The rate constant for this hetero- geneous photocatalysis was evaluated as a function of the initial concentration of original species. A substantial reduction in AO7 dye is achieved as analyzed from cOD and TOc studies. The mechanism for the degradation could be explained on the basis of the Langmuir-hinshelwood mechanism.

关键词： zinc oxide chemical kinetics photoelectrocatalysis organic species sunlight

The h_∞ synchronization of nonlinear Bloch systems via dynamic feedback control approach

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chinese Physics B 2011年第7期20卷 101-106页

作者： D.h. Ji J.h. Koo s.c. Won Ju h. Park Mobile communication Division Digital Media and Communications Samsung Electronics Co. Ltd 416-2 Maetan-Dong Suwon 443-803 Republic of Korea Department of Electronic and Electrical Engineering Pohang University of Science and Technology San 31 Hyoja-Dong Pohang 790-784 Republic of Korea Department of Electrical Engineering Yeungnam University 214-1 Dae-Dong Kyongsan 712-749 Republic of Korea

We consider an h∞ synchronization problem in nonlinear Bloch systems. Based on Lyapunov stability theory and linear matrix inequality formulation, a dynamic feedback controller is designed to guarantee asymptotic stability of the master-slave synchronization. Moreover, this controller reduces the effect of an external disturbance to the h∞ norm constraint. A numerical example is given to validate the proposed synchronization scheme.

关键词： h∞ synchronization Bloch system dynamic control linear matrix inequality

Physical properties of spray deposited cdTe thin films:PEc performance

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Journal of semiconductors 2011年第3期32卷 10-16页

作者： V.M.Nikale s.s.shinde c.h.Bhosale K.Y.Rajpure Electrochemical Materials Laboratory Department of PhysicsShivaji University

p-cdTe thin films were prepared by spray pyrolysis under different ambient conditions and characterized using photoelectrochemical（PEc）,X-ray diffraction（XRD）,scanning electron microscopy,energy-dispersive analysis by X-ray（EDAX）,and optical transmission *** different preparative parameters viz solution ph, solution quantity,substrate temperature and solution concentration have been optimized by the PEc technique in order to get good-quality photosensitive *** analysis shows the polycrystalline nature of the film,having cubic structure with strong（111） *** reveal that grains are uniformly distributed over the surface of the substrate indicating the well-defined growth of polycrystalline cdTe thin *** EDAX study for the sample deposited at optimized preparative parameters shows the nearly stoichiometric cd：Te *** absorption shows the presence of direct transition with band gap energy of 1.5 *** films exhibit the highest photocurrent of 2.3 mA,a photovoltage of 462 mV,a 0.48 fill factor and 3.4%efficiency for the optimized preparative parameters.

关键词： cdTe PEc temperature concentration structure morphology composition optical

Reactive wetting behaviors of sn/cu systems: A molecular dynamics study

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Nano-Micro Letters 2010年第2期2卷 60-67页

作者： J.Y.hsieh J.L.chen c.chen h.c.Lin s.s.Yang c.c.hwang Department of Mechanical Engineering Ming Hsin University of Science and Technology Institute of Precision Mechatronic Engineering Ming Hsin University of Science and Technology Department of Mechanical Engineering Wu Feng Institute of Technology Department of Information Management Meiho Institute of Technology Department of Engineering science National Cheng Kung University

Influences of temperature and sn-cu droplet's composition on reactive wettings of cu(100), cu(110), and cu(111) surfaces were analyzed, by using molecular dynamics(MD) calculations. As a result, the spreading on cu(110)(cu(100)) has the fastest(slowest) wetting kinetics. A higher temperature or a diluter cu content in the sn-cu alloy droplet results in a higher wettability. Moreover, this work has addressed a theory for positioning the interface separating the liquidus and solidus alloys in the spreading film to confirm the hypothesis that the reactive wetting will come to the end when the interface saturates with the temperature-dependent solidus weight fraction of cu.

关键词： Wetting surface alloying Molecular dynamics Droplet

Foam rolling and stretching do not provide superior acute flexibility and stiffness improvements compared to any other warm-up intervention: A systematic review with meta-analysis

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Journal of sport and health science 2024年第4期13卷 509-520页

作者： Konstantin Warneke Gerit Plöschberger Lars h.Lohmann Eric Lichtenstein Daniel Jochum stanislav D.siegel Astrid Zech David G.Behm Institute of sport science University of KlagenfurtKlagenfurt am Wörthersee 9020Austria Department of human Motion science and Exercise Physiology Friedrich Schiller UniversityJena 07749Germany Department sport Exercise and HealthUniversity of BaselBasel 4052Switzerland Department of health sciences and Technology ETH ZurichZurich 8092Switzerland school of human Kinetics and Recreation Memorial University of NewfoundlandSt.JohnsNL A1C 5S7Canada

Background:Acute improvement in range of motion(ROM)is a widely reported effect of stretching and foam rolling,which is commonly explained by changes in pain threshold and/or musculotendinous ***,these effects were also reported in response to various other active and passive interventions that induce responses such as enhanced muscle ***,we hypothesized that acute ROM enhancements could be induced by a wide variety of interventions other than stretching or foam rolling that promote an increase in muscle ***:After a systematic search in PubMed,Web of science,and sPORTDiscus databases,38 studies comparing the effects of stretching and foam rolling with several other interventions on ROM and passive properties were *** studies had 1134 participants in total,and the data analysis resulted in 140 effect sizes(Ess).Es calculations were performed using robust variance estimation model with ***:study quality of the included studies was classified as fair(PEDro score=4.58)with low to moderate certainty of *** showed no significant differences in ROM(Es=0.01,p=0.88),stiffness(Es=0.09,p=0.67),or passive peak torque(Es=-0.30,p=0.14)between stretching or foam rolling and the other identified *** plots revealed no publication ***:Based on current literature,our results challenge the established view on stretching and foam rolling as a recommended component of warm-up *** lack of significant difference between interventions suggests there is no need to emphasize stretching or foam rolling to induce acute ROM,passive peak torque increases,or stiffness reductions.

关键词： Range of motion Passive properties Muscletendon unit Muscle tissue

A numerical study on the influence of grain boundary oxides on dwell fatigue crack growth of a nickel-based superalloy

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Journal of Materials science & Technology 2022年第9期104卷 224-235页

作者： c.Z.Fang h.c.Basoalto M.J.Anderson h.Y.Li s.J.Williams P.Bowen Department of Materials science and Engineering University of SheffieldMappin StSheffield S13JDUK school of Metallurgy and Materials University of BirminghamEdgbastonBirmingham B152TTUK Institute of structural Materials Swansea UniversitySwansea SA18ENUK

A theoretical treatment on the oxide-controlled dwell fatigue crack growth of aγ'strengthened nickelbased superalloys is *** particular,this study investigates the influence of an externally applied load and variations in theγ'dispersion on the grain boundary oxide growth kinetics.A dislocation-based viscoplastic constitutive description for high temperature deformation is used to simulate the stress state evolution in the vicinity of a crack at elevated *** viscoplastic model explicitly accounts for multimodalγ'particle size distributions.A multicomponent mass transport formulation is used to simulate the formation/evolution of an oxide wedge ahead of the crack tip,where stress-assisted vacancy diffusion is assumed to *** resulting set of constitutive and mass transport equations have been implemented within a finite element *** of predicted compositional fields across the matrix/oxide interface are compared with experiments and shown to be in good *** indicate that the presence of a fineγ'size distribution has a strong influence on the predicted ow stress of the material and consequently on the relaxation in the vicinity of the crack-tip/oxide *** is shown that a unimodal dispersion leads to reduced oxide growth rates(parabolic behavior)when compared to a bimodal *** conditions for oxide formation are investigated and is associated with the prediction of compressive stresses within the oxide layer just ahead of the crack tip,which become progressively negative as the oxide wedge ***,mechanical equilibrium requirements induce tensile stresses at the tip of the oxide wedge,where failure of the oxide is *** time taken to reach this critical stress for oxide failure has been calculated,from which dwell crack growth rates are computationally *** predicted rates are shown to be in good agreement with available experimental data.

关键词： Nickel based superalloy Dwell crack growth Gamma prime creep Oxidation Dislocation-based modeling Multicomponent diffusion Finite element method

Tunable passively Q-switched ytterbium-doped fiber laser with mechanically exfoliated Gase saturable absorber

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chinese Optics Letters 2018年第2期16卷 93-97页

作者： h.Ahmad s.N.Aidit s.I.Ooi Z.c.Tiu Photonics Research centre University of Malaya

A tunable passively Q-switched ytterbium-doped fiber laser using few-layer gallium selenide（Gase） as a saturable absorber（sA） is *** few-layer Gase sA,which is fabricated by the mechanical exfoliation method,is able to generate a Q-switched fiber laser that has a maximum repetition rate of 92.6 khz and a minimum pulsed width of 2.3 μ*** highest pulse energy exhibited by the generated pulse is 18.8 nJ with a signal to noise ratio of ~40 *** tunability of the proposed laser covers from 1042 to 1082 nm,giving a tuning range of 40 nm.

关键词： Tunable passively Q-switched ytterbium-doped fiber laser with mechanically exfoliated Gase saturable absorber sA

Fabrication of ultrafine Nd-Fe-B powder by a modified reduction-diffusion process

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Rare Metals 2006年第Z2期25卷 223-226页

作者： JANG T.s. LEE D.h. chOI c.J. sEO W.s. LEE Y.h. Department of Electronic Materials Engineering Sunmoon University Korea Powder Materials Research center Korea Institute of Machinery and Materials Korea Advanced Materials Analysis & Evaluation center Korea Institute of Ceramic Engineering and Technology Korea

In order to obtain ultrafine Nd-Fe-B powder, a spray-dried precursor was treated by reduction-diffusion (R/D) process. And, unlike the conventional R/D process, calcium reduction that is a crucial step for the formation of Nd2Fe14B was performed without conglomerating the precursor with ca powder. By adopting this modified process, it is possible to synthesize the hard magnetic Nd2Fe14B at the reaction temperature as low as 850 ℃. The average size of Nd2Fe14B particles that are uniformly distributed in the optimally treated powder was st Nd2Fe14B particles were enclosed with thin layers of Nd-rich phase. Typical magnetic properties of such powder without eliminating impurity caO were ihc=～5.9 kOe, Br=～5.5 kG, and (Bh)max=～6 MGOe.

关键词： NdFeB powder spray drying reduction-diffusion process Nd2Fe14B magnetic powder