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1

The effect of hollow glass microspheres on the properties of high silica glass fiber fabric/liquid silicone rubber composite sheet

Chen S., Qin Y., Song Y., Wang B.

Polimery

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2018

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T. 63, nr 3

178--184

EN

In this study, high silica glass fiber fabric/liquid silicone rubber (HSGFF/LSR) composite sheet filled with hollow glass microspheres (HGM) was prepared. The effects of HGM content on the mechanical, thermal insulation and dynamic mechanical properties of the composite sheet were investigated. The results showed that the compatibility and interfacial properties between HGM and the matrix were improved after the HGM was treated with a silane coupling agent, KH550. Composite, in which the HGM content was 7 % by weight, shows the most advantageous mechanical, insulating and damping properties.

PL

Na bazie tkaniny z włókien kwarcowych (HSGFF) nasyconej ciekłym kauczukiem silikonowym (LSR) otrzymywano kompozyty napełniane mikrosferami szklanymi (HGM). Badano wpływ dodatku mikrosfer na właściwości mechaniczne, izolacyjność cieplną i właściwości dynamiczno-mechaniczne kompozytowych arkuszy. Stwierdzono, że modyfikacja mikrosfer szklanych za pomocą silanowego czynnika sprzęgającego KH550 poprawiła kompatybilność i oddziaływania międzyfazowe cząsteczek HGM i nasyconej ciekłym kauczukiem tkaniny z włókien szklanych. Najkorzystniejsze właściwości mechaniczne, izolacyjne i tłumiące wykazywał kompozyt, w którym zawartość HGM wynosiła 7 % mas.

2

A two-dimensional finite element model of the grain boundary based on thermo-mechanical strain gradient plasticity

Song Y., Voyiadjis G. Z.

Journal of Theoretical and Applied Mechanics

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2018

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Vol. 56 nr 2

377--391

EN

In this work, a two-dimensional finite element model for the grain boundary flow rule is developed based on the thermo-mechanical gradient-enhanced plasticity theory. The proposed model is temperature-dependent. A special attention is given to physical and micromechanical nature of dislocation interactions in combination with thermal activation on stored and dissipated energy. Thermodynamic conjugate microforces are decomposed into energetic and dissipative components. Correspondingly, two different grain boundary material length scales are present in the proposed model. Finally, numerical examples are solved in order to explore characteristics of the proposed grain boundary flow rule.

3

Wave fields in the stratified fluid-saturated porous half-space induced by dislocation sources

Song Y., Shi J.

Archives of Mechanics

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2017

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Vol. 69, nr 6

435--449

EN

In this study, the wave fields induced by both tensile and shear displacement dislocations in stratified fluid-saturated porous media are computed by using the reflection and transmission matrix method. The components of the source discontinuity vector across the source plane to describe those tensile and shear faults are explicitly displayed by using the surface vector harmonics. Numerical examples for a two layer model subjected to tensile and shear dislocations are provided. From the waveforms of surface displacements, the arrivals of transmitted and converted PS and SP waves at the interface of the two layer model can be clearly observed.

4

Effects of three pesticides on superoxide dismutase and glutathione-S-transferase activities and reproduction of Daphnia magna

Song Y., Chen M., Zhou J.

Archives of Environmental Protection

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2017

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Vol. 43, no. 1

80--86

EN

Applying pesticides to crops is one of the causes of water pollution by surface runoff, and chlorpyrifos, trifluralin and chlorothalonil are used respectively as insecticide, herbicide and fungicide for crop plants widely. To explore effects of three pesticides on aquatic organisms, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities were determined after 24 h and 48 h exposure of D. magna with ages of 6–24 h to several low concentrations of chlorpyrifos (0.36, 0.72, 1.43, 2.86, 5.72 μg∙L−1), trifluralin (0.17, 0.33, 0.66, 1.33, 2.65 mg∙L−1) and chlorothalonil (0.09, 0.18, 0.36, 0.72, 1.43 mg∙L−1) respectively. Main reproductive parameters including first pregnancy time, first brood time, the number of first brood and total fecundity after 21 d exposures at the same concentrations of pesticides as described above were also measured. The results showed that the activities of GST increased in lower concentrations and decreased in higher concentrations after 24 h exposure to three pesticides, respectively. The activities of SOD showed the same changes after 48 h exposure. With the time prolonged, the activities of GST decreased while the activities of SOD increased. After 21 d exposure, the first pregnancy time and first brood time were delayed, while the number of the first brood and total fecundity per female decreased with increasing concentrations. These results corroborated that GST activity was more sensitive to those pesticides than SOD activity, and there was a significant relationship between total fecundity and pesticides-dose(r>0.94, n=6), GST activity after 48 h exposure and total fecundity after 21 d exposure (r>0.92, n=6).

5

Semi-analytical solution for free vibration differential equations of curved girders

Song Y., Chai X.

Archives of Civil Engineering

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2017

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Vol. 63, nr 1

115--132

EN

In this paper, a semi-analytical solution for free vibration differential equations of curved girders is proposed based on their mathematical properties and vibration characteristics. The solutions of in-plane vibration differential equations are classified into two cases: one only considers variable separation of non-longitudinal vibration, while the other is a synthesis method addressing both longitudinal and non-longitudinal vibrationusing Rayleigh’s modal assumption and variable separation method. A similar approach is employed for the out-of-plane vibration, but further mathematical operations are conducted to incorporate the coupling effect of bending and twisting. In this case study, the natural frequencies of a curved girder under different boundary conditions are obtained using the two proposed methods, respectively. The results are compared with those from the finite element analysis (FEA) and results show good convergence.

PL

Jako wspólna płaszczyzna wcześniejszych badań, wynikowe równania różniczkowe drgań opracowane na podstawie statycznych równań różniczkowych Vlasowa dotyczących zakrzywionych dźwigarów nie posiadają ścisłego wyprowadzenia [1-7]. Ostatnimi czasy zastosowano metody fizyki matematycznej w celu wyprowadzenia równań różniczkowych drgań zakrzywionych dźwigarów oraz w celu udowodnienia równań, lecz rozwiązanie nadal nie zostało opracowane [8-16]. Równania różniczkowe drgań zakrzywionych dźwigarów zostały wyprowadzone zgodnie z zasadą Hamiltona oraz równaniem Lagrange’a i mają zastosowanie jedynie do zakrzywionych belek Timoshenko w osiowym układzie współrzędnych. W niniejszej pracy zaproponowano pół-analityczne rozwiązanie dla równań różniczkowych swobodnych drgań zakrzywionych dźwigarów, w oparciu o ich właściwości matematyczne i charakterystyki drgań. Przede wszystkim przyjęto podstawowe założenia dla zakrzywionego dźwigara, w tym 1) zakrzywiony dźwigar ma stały przekrój i promień krzywizny, jak również jednorodny materiał; 2) przekrój poprzeczny zakrzywionego dźwigara ma pionową oś symetrii, a centroid zbiega się z środkiem ścinania; 3) promień krzywizny zakrzywionego dźwigara jest znacznie większy niż rozmiar, długość i wysokość przekroju poprzecznego.

6

A New Graph Theoretic Approach for Protein Threading

Song Y., Qu J., Xu Y., Cai L.

Fundamenta Informaticae

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2016

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Vol. 145, nr 2

151--170

EN

In this paper, we develop a novel graph theoretic approach for protein threading. In order to perform the protein sequence-structure alignment in threading both efficiently and accurately, we develop a graph model to describe the tertiary structure of a protein family and the alignment between a sequence and a family can be efficiently computed with a dynamic programming algorithm when the tree width of the graph model is a small integer. Our experiments show that this new approach is significantly faster than existing tools for threading and can achieve comparable prediction accuracy.

7

Sustainable Development Integrated in the Concept of Resilence

Bloesch J, Hauff M, Mainzer K, Mohan S V, Renn O, Risse V, Song Y., Takeuchi K, Wilderer P A

Problemy Ekorozwoju

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2015

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Vol. 10, nr 1

7--14

EN

The purpose of sustainable development is to minimize the likelihood of dynamic natural and/or man-made systems to exceed tipping points, when exposed to disturbances. In effect, the systems are protected from losing identity and integrity. The authors of this paper suggest accepting resilience thinking as a basis of setting sustainability goals and reaching the respective targets. The resilience theory provides the method needed to maintain identity and integrity, and to manage system´s dynamics. Of concern are three interwoven systems: environment, society and economy, forming a complex super-system coined eco-social triad. Sustainable development of the triad applies to each of the three sub-systems despite conflicting interests of the various actors within each. Resilience is expressed by the ability of natural or man-made systems to respond dynamically to changes of ambient conditions with the aim to retain their inherent function, structure and feedbacks. To manage such changes and associated disturbances a repetitive sequence of processes (also called adaptive cycle) needs to be executed. In ecosystems these cycles are self-regulated and characterized by recycling of materials and energy. In systems dominated by humans adaptive cycles are characterized by phases such as re-evaluation, reorientation and re-commencement. The concept of adaptive cycles and adaptive management embedded in the resilience theory is considered a promising method to satisfy sustainability goals and reach respective targets.

PL

Celem zrównoważonego rozwoju jest zminimalizowanie prawdopodobieństwa przekroczenia punktów krytycznych dynamicznych systemów naturalnych i/lub sztucznych (co może się zdarzyć, gdy systemy te są narażone na zakłócenia). W rezultacie uzyskują one ochronę przed utratą tożsamości i integralności. Autorzy niniejszego artykułu sugerują przyjęcie podejścia zgodnego z koncepcją resilencji podczas wyznaczania celów prowadzących ku zrównoważoności. Teoria resilencji odnosi się do umiejętności, dzięki któremu systemy utrzymują tożsamość i integralność, a także prawidłowo zarządzają własną dynamiką. W obszarze zainteresowania znajdują się trzy przeplatające się systemy: środowisko, społeczeństwo i ekonomia, tworzące złożony super-system określany jako eko-społeczna triada. Zrównoważony rozwój triady dotyczy każdego z trzech podsystemów, pomimo sprzecznych interesów różnych podmiotów działających w ramach każdego z nich. Resilencja wyraża się w zdolności systemów naturalnych do dynamicznego reagowania na zmiany warunków w ich otoczeniu, w celu zachowania funkcjonalności, struktury i zapewnienia właściwego sprzężenia zwrotnego. Aby zarządzać takimi zmianami i związanymi z nimi zaburzeniami wymagana jest powtarzalna sekwencja działań (zwana także cyklem adaptacyjnym). W ekosystemach takie cykle charakteryzuje samoregulacja oraz recykling materiałów i energii. W systemach zdominowanych przez ludzkie cykle adaptacyjne występują fazy ponownej oceny, reorientacji i ponownego rozpoczęcia. Idea cyklów adaptacyjnych i adaptacyjnego zarządzania zawarte w teorii resilencji można uznać za obiecującą metodę prowadząca do zapewnienia celów zgodnych ze zrównoważonym rozwojem.

8

Contribution to the UN Post-2015 Development Agenda Based on the Concept of Resilience

Bloesch J., Hauff M., Mainzer K., Mohan S. V., Renn O., Risse V., Song Y., Takeuchi K., Wilderer P. A.

Problemy Ekorozwoju

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2015

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Vol. 10, nr 2

7--13

EN

The authors of this paper suggest applying the concept of resilience in the process of setting up Sustainable Development Goals (SDGs) to be implemented in the United Nations Post-2015 Development Agenda. Referring to the synopsis of the scientific basis of resilience and sustainability presented by Bloesch et al., the proposed general goals and specific targets of sustainable development are introduced and discussed. The aims of the SDGs and the corresponding targets can only materialize when applying as guiding principles advanced knowledge (science), transfer of knowledge and skills (education and training), encouragement of creativity and ethical values (governance and policy). Moreover, the fundamental values of ecosystem function are to be acknowledged as well as the need to balance the three sub-systems of the eco-social triad. It appears necessary to focus on integrative resilience. The Post-2015 Development Agenda should stress the crucial role of self-regulation in ecosystems, and a corresponding cognitive regulation of social and economic systems with the aim to ensure system´s stability within given thresholds.

PL

Autorzy sugerują zasadność włączenia koncepcji resilencji w proces tworzenia Celów Rozwoju Zrównoważonego (Sustainable Development Goals, SDGs) i dokumentu ONZ Agenda Rozwojowa Post-2015. Odwołując się do naukowych podstaw resilencji i zrównoważoności, przedstawionych przez Bloescha, zaproponowano i omówiono tak ogólne, jak i szczegółowe cele zrównoważonego rozwoju. Są one możliwe do osiągnięcia tylko wtedy, gdy za zasady przewodnie uznane zostaną wiedza (nauka), przekazywanie wiedzy i umiejętności (edukacja i szkolenia), wzmacniania kreatywności i przestrzeganie zasad etycznych (zarządzanie i polityka). Co więcej, należy uwzględnić także podstawowe wartości funkcjonalne pełnione przez ekosystemy oraz potrzebę utrzymania równowagi pomiędzy trzema podsystemami eko-społecznej triady. Niezbędnym wydaje się skoncentrowanie na resilencji. Agenda Rozwojowa Psot-2015 powinna podkreślać decydującą rolę samo-regulacji ekosystemów i analogicznych regulacji systemów społecznych i ekonomicznych, gdzie celem jest zapewnienie stabilności systemów w danych warunkach.

9

Corneal hyper-viscoelastic model: derivations, experiments, and simulations

Su P., Yang Y., Song Y

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 2

73--84

EN

Purpose: The aim of this study is to propose a method to construct corneal biomechanical model which is the foundation for simulation of corneal microsurgery. Methods: Corneal material has two significant characteristics: hyperelastic and viscoelastic. Firstly, Mooney–Rivlin hyperelastic model of cornea obtained based on stored-energy function can be simplified as a linear equation with two unknown parameters. Then, modified Maxwell viscoelastic model of the cornea, whose analytical form is consistent with the generalized Prony-series model, is proposed from the perspective of material mechanics. Results: Parameters of the model are determined by the uniaxial tensile tests and the stress-relaxation tests. Corneal material properties are simulated to verify the hyper-viscoelastic model and measure the effectiveness of the model in the finite element simulation. On this basis, an in vivo model of the corneal is built. And the simulation of extrusion in vivo cornea shows that the force is roughly nonlinearly increasing with displacement, and it is consistent with the results obtained by extrusion experiment of in vivo cornea. Conlusions: This paper derives a corneal hyper-viscoelastic model to describe the material properties more accurately, and explains the mathematical method for determination of the model parameters. The model is an effective biomechanical model, which can be directly used for simulation of trephine and suture in keratoplasty. Although the corneal hyper-viscoelastic model is taken as the object of study, the method has certain adaptability in biomechanical research of ophthalmology.

10

An Amplitude-normalized Pseudo Well-log Construction Method and its Application on AVO Inversion in a Well-absent Marine Area

Fan Ch., Song Y., Zhang Y., Jiang Z.

Acta Geophysica

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2015

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Vol. 63, no. 3

761--775

EN

AVO inversion is hard to be efficiently applied in unexploited fields due to the insufficiency of well information. For the sake of AVO inversion in a well-absent area, the most conventional method is to construct pseudo well-logs by defining seismic processing velocity as the P-velocity and computing S-velocity and density using empirical formulas, yet the resolution of the corresponding earth models and final inverted results could be extremely low, and a rough formula could destroy the inversion thoroughly. To overcome this problem, an amplitudenormalized pseudo well-log construction method that reconstructs pseudo well-logs in accordance with computed P-wave reflection amplitudes and nearby drilling data is proposed in this paper. It enhances the inversion resolution efficiently with respect to the real elastic parameter relationships, so that the corresponding AVO inversion results are reasonably improved. In summary, the proposed method is successfully applied in the AVO inversion of a well-absent marine area, and could be valuable in the early phase, particularly of the offshore hydrocarbon exploration.

11

Load-deflection relations of t-section rails under lateral loads

Song Y., Yu Z

Journal of Theoretical and Applied Mechanics

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2013

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Vol. 51 nr 1

195--202

EN

This paper studies the load-deflection relations of T-section rails under lateral loads based on elastic-plastic theory. A linear-hardening model and an elastic-plastic power-exponent hardening model of the material are adopted in this study. The analytical expressions for the load-deflection relations in the loading process are given. Compared with the experimental results, it is found that the load-deflection curves calculated with the elastic-plastic powerexponent hardening model are closer to the experimental results than those with the linearhardening model.

PL

W pracy zaprezentowano charakterystyki obciążeniowo-odkształceniowe obciążanych poprzecznie szyn o przekroju teowym otrzymane na podstawie teorii lepkosprężystości. W badaniach przyjęto model materiału o liniowym oraz potęgowym umocnieniu. Podano analityczne wyrażenia dla krzywych obciążenia w funkcji odkształcenia. W wyniku weryfikacji eksperymentalnej stwierdzono, że charakterystyki obciążeniowo-odkształceniowe otrzymane przy zastosowaniu modelu z potęgowym umocnieniem materiału są bliższe rezultatom doświadczalnym niż w przypadku modelu z umocnieniem liniowym.

12

Springback prediction in T-section beam bending process using neural networks and finite element method

Song Y., Yu Z.

Archives of Civil and Mechanical Engineering

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2013

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Vol. 13, no. 2

229--241

EN

In this paper, three point bending method is used for the T-section beam bending process. The prediction model of springback is developed using artificial neural network approach. The corresponding loading stroke that can theoretically eliminate the residual deflection of a beam after springback is determined. Application examples indicate that the proposed approach could achieve an allowable straightness error. Numerical simulations using finite element method are also performed to investigate the effect of material properties on springback. A neural network for identification of material parameters is developed by the simulation data. Besides, the residual stress distributions across the beam section are analyzed. The finite element model is validated with experimental results of springback.

13

Reflection of magneto-thermo-elastic waves from a rotating elastic half-space in generalized thermoelasticity under three theories

Othman M. I. A., Song Y.

Mechanics and Mechanical Engineering

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2011

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Vol. 15, nr 1

5-24

EN

The model of the equations of generalized magneto-thermoelasticity based on Lord-Shulman theory (LS) with one relaxation time, Green-Lindsay theory (GL) with two relaxation times, as well as the classical dynamical coupled theory (CD), is used to study the electro-magneto-thermoplastic interactions in a semi-infinite perfectly conducting solid. The entire elastic medium is rotating with a uniform angular velocity. There an initial magnetic field acts parallel to the plane boundary of the half-space. Reflection of magneto-thermoplastic waves under generalized thermoelasticity theory is employed to study the reflection of plane harmonic waves from a semi-infinite rotating elastic solid in a vacuum. The expressions for the reflection coefficients, which are the relations of the amplitudes of the reflected waves to the amplitude of the incident waves, are obtained. Similarly, the reflection coefficients ratios variation with the angle of incident under different conditions are shown graphically. Comparisons are made with the results predicted by the three theories in the presence and absence of rotation.

14

Effect of growth time on the morphologies of vapour grown carbon fibres and a suggested mechanism of growth

Zhang H., Shi J., Song Y., Zhao J., Wang K., Guo Q., Zhai G., Liu L.

Materials Science Poland

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2009

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Vol. 27, No. 3

885--890

EN

The microstructure of vapour grown carbon fibres is two-double layered. This paper addresses the question of morphology transformation of vapour grown carbon fibres. Special attention is given to developing understanding of the growth mechanism of the outer layer of the fibres. The influence of growth time on the morphologies of as-prepared carbon fibres was investigated using scanning electron microscopy. Results showed that with the prolongation of reaction time, their morphology changed from linear fibres to carbon micro-bead chains and then again to thicker linear fibres, which led to the increase of the carbon fibres diameters from 200 nm to several micrometers. Furthermore, several kinds of carbon fibres with special morphology such as carbon micro-beads, chains, etc., could be obtained by adjusting the growth time. A growth mechanism, henceforth referred to as fibre-bead-thicker fibre, for the outer layer of vapour grown carbon fibres is proposed.

15

Measurement of wet steam in a 300 mw direct air cooling steam turbine

Cai X, Niu F, Ning T, Ning T, Wu G, Song Y

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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2008

|

nr 133

77--86

EN

For study the wet steam flow in the direct air-cooling steam turbine, measurements were carried out in a 300MW turbine with a newly developed combined probe. The wetness in the direct air-cooling steam turbine is lower and varies not much along the blade height. Droplets size distribution and mean diameter are smaller too comparing to water-cooling steam turbine. The measured relative inner efficiencies of LP obtained by the probe agree well with the results obtained by thermal performance test.

16

Removal of trivalent chromium from aqueous solutions by amphiphilic core-shell poly(methyl acrylate)/silk sericin nanospheres

Song Y., Jin Y., Sun J., Wei D.

Polimery

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2007

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T. 52, nr 11-12

880-884

EN

Well-defined, core-shell poly(methyl acrylate/silk sericin) (PMA-SS) nanospheres, ranging from 100 to 150nm in diameter, were prepared via a direct graft copolymerisation of methyl acrylate (MA) with silk sericin (SS). The polymerisation was induced by a small amount of tert-butyl hydroperoxide (TBHP) in water at temp. 353K. The PMA-SS core-shell nanospheres were used as adsorbent in a series of batch adsorption experiments for the removal of trivalent chromium from aqueous solutions. The experimental results showed that PMA-SS nanospheres were an effective adsorbent for trivalent chromium from aqueous solution, and the maximum amount of adsorption reached 4.876mg Cr3+/g of sorbent within the experimental range. With the increase in pH values of solutions, the adsorption increased obviously, while the addition of electrolyte had a little effect on the adsorption. The adsorption equilibrium was reached after about 3h. The adsorption of trivalent chromium by PMA-SS nanospheres was significantly higher than that done by SS powder under the same adsorption conditions.

PL

Metodą bezpośredniej kopolimeryzacji szczepionej akrylanu metylu (MA) na serycynie (SS) otrzymano nanosfery typu rdzeń-otoczka (PMA-SS) o średnicach zawierających się w przedziale 100-150nm (rys. 1 i 2). Kopolimeryzację prowadzono w temp. 353K w roztworze wodnym i inicjowano za pomocą wodoronadtlenku tert-butylu (TBHP). Zbadano zdolność otrzymanych nanosfer PMA-SS do adsorbowania Cr3+ z roztworów wodnych. Stwierdzono, że ilość zaadsorbowanego Cr3+ rośnie wraz ze wzrostem stężenia początkowego roztworu (Co) osiągając wartość 4,876mg Cr3+/g sorbentu w temp. 293K w przypadku roztworu o pH=6,0 i Co=3,5mg Cr3+/L (rys. 3). Zaobserwowano, że w badanym przedziale pH od 4,0 do 6,0 adsorpcja wyraźnie rośnie ze wzrostem pH (rys. 4). Badania wykazały także, że ilość zaadsorbowanego Cr3+ nieznacznie wzrasta pod wpływem dodania do roztworu niewielkiej ilości KCl jako dodatkowego elektrolitu (rys. 5). Na podstawie badań kinetyki adsorpcji określono, że równowaga jest osiągana po ok. 3 godz. Na zakończenie porównano wyniki adsorpcji Cr3+ za pomocą nanosfer PMA-SS z wynikami uzyskanymi w takich samych warunkach z zastosowaniem jako adsorbenta samego proszku SS i stwierdzono zdecydowanie większą efektywność adsorpcji w pierwszym przypadku.

17

Sliding mode control with directly learned feedforward compensation

Xu J.-X., Song Y.

Applied Mathematics and Computer Science

|

1998

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Vol. 8, no 1

89-100

EN

A new control method synthesizing direct learning control (DLC) with sliding mode control (SMC) is proposed for the tracking problem of a class of non-linear high order systems. Sliding mode control is used to provide the control system with indispensable robustness in the presence of strong system uncertainties. A new learning control method, the direct learning control method, is developed and used to generate the desired feedforward compensation for SMC. It can be shown that the combined scheme can successfully retain the advantages of both control methods. By virtue of SMC, the global asymptotic stability is ensured. Meanwhile, DLC provides an effective way to anticipate the necessary control signals for a new trajectory in terms of past control profiles which may correspond to different trajectories. In comparison with SMC alone, the synthesized control scheme achieves higher tracking accuracy and smoother control efforts.