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Lead-free 0.99[(1−x)(Bi0.5Na0.5)TiO3-x(Bi0.5K0.5)TiO3]–0.01Ta piezoelectric ceramics were prepared by a conventional solid-state reaction process. The ferroelectric properties, and strain behaviors were characterized. Increase of the (Bi0.5K0.5)TiO3 content induces a phase transition from coexistence of ferroelectric tetragonal and rhombohedral to a relaxor pseudocubic phase. Accordingly, the ferroelectric order is disrupted significantly with the increase of (Bi0.5K0.5)TiO3 content and the destabilization of the ferroelectric order is accompanied by an enhancement of the unipolar strain, which peaks at a value of 0.35% (corresponding to a large signal d33 of 438 pm/V) in samples with 20 mol% (Bi0.5K0.5)TiO3 content. Temperature dependent measurements of both polarization and strain from room temperature to 120 °C suggested that the origin of the large strain is due to a reversible field-induced nonpolar pseudocubic-to-polar ferroelectric phase transformation.

In this paper, a BN-Gr-BN planar heterojunction is established, and the BN-Gr-BN planar heterojunction is used as reinforcing materials for copper-based materials. The coupling effects of defects and temperature on mechanical properties of the graphene-h-BN/copper vertically-stacked heterostructures were investigated. The results show the BN-Gr-BN heterojunction layer exerts a strengthening influence on the Young’ modulus as well as the load transfer ability, thereby enhancing the stability capacity and the plasticity of composite system under axial tension. the introduce of BN-Gr-BN heterojunction layer gives rise to geometrical imperfections at interface, which in turn causes a reduction in the ultimate tensile strength and the associated facture strain. The positive effects of BN-Gr-BN heterojunction layer overpower their negative effects on the mechanical behavior of composite system. The adverse and strengthening effects induced by the BN-Gr-BN heterojunction layer are also strongly dependent of temperature. The present results can serve as a guide for diversified structure design and defect control.

By using the coincidence degree theorem, we obtain a new result on the existence of solutions for a class of fractional differential equations with periodic boundary value conditions, where a certain nonlinear growth condition of the nonlinearity needs to be satisfied. Furthermore, we study another class of differential equations of fractional order with periodic boundary conditions at resonance. A new result on the existence of positive solutions is presented by use of a Leggett–Williams norm-type theorem for coincidences. Two examples are given to illustrate the main result at the end of this paper.

The folding patterns and deployment dynamic characteristics of conical inflatable capsule structures were investigated. A six-fold-line method of packing a conical shell surface was designed. The fold-line layouts and relation formulas of the fold angles were determined. The folded state of the inflatable capsule structure was parametrically modeled; then, the deployment dynamic analysis model was established using ANSYS/LS-DYNA software. The dynamic characteristics of the inflatable capsule structure in orbit were numerically simulated. Thus, the deployment configurations and the time history curves of the dynamic characteristics were obtained. The results verified the feasibility of the fold pattern and the deployment dynamic analysis model. The influences of the residual gases from the packing process on the subsequent deployment process were investigated. The results indicated that a small amount of residual gas can lead to structures that cannot deploy smoothly, and two methods were presented to avoid this challenge. These works provide technical support for the structural designs of this type of inflatable capsule structure.

Background and purpose Simvastatin is a 3-hydroxy-3-methylglutaryl CoA reductase inhibitor with multiple targets and effects. It protects neurons in the brain, but its protective effects on photoreceptors are unclear. In this study, we evaluated the neuroprotective effect of simvastatin on photoreceptors exposed to stress induced by all-trans-retinal (atRAL). Experimental approach AlamarBlue and LDH assays were used to evaluate the viability and metabolic activity of Y79 cells (a retinoblastoma cell line) exposed to atRAL-induced stress with or without simvastatin pretreatment. Changes in cellular ROS were evaluated using flow cytometry and mitochondrial stress markers JC-1 and HSP60. Changes in levels of two photoreceptor-specific markers, cone-rod homeobox protein (CRX) and interphotoreceptor retinoid binding protein (IRBP), were evaluated with western blot. The results were validated in ex vivo human retinal explants and a mouse model of photoreceptor degeneration. Key results Simvastatin improved mitochondrial function, alleviated oxidative stress and up-regulated the photoreceptor-specific markers IRBP and its upstream regulator CRX in Y79 cells and ex vivo human retinal explants under atRAL-induced stress. Simvastatin attenuated photoreceptor degeneration in association with up-regulation of IRBP and CRX expression after knockdown of IRBP in a murine model. Conclusion and implications Our findings suggest that simvastatin has a novel role in protecting photoreceptors from atRAL-induced stress. Simvastatin treatment resulted in up-regulation of IRBP and its upstream transcription factor CRX in Y79 cells, ex vivo human retinal explants, and murine retinas in vivo. Further studies of simvastatin to treat photoreceptor degeneration are warranted.

The Retinal Pigment Epithelium (RPE) is a monolayer of cells located above the choroid. It mediates human visual cycle and nourishes photoreceptors. Hypoxia-induced oxidative stress to RPE is a vital cause of retinal degeneration such as the Age-related Macular Degeneration. Most of these retinal diseases are irreversible with no efficient treatment, therefore protecting RPE cells from hypoxia stress is an important way to prevent or slow down the progression of retinal degeneration. Betulinic acid (BA) and betulin (BE) are pentacyclic triterpenoids with anti-oxidative property, but little is known about their effect on RPE cells. We investigated the protective effect of BA, BE and their derivatives against cobalt chloride-induced hypoxia stress in RPE cells. Human ARPE-19 cells were exposed to BA, BE and their eighteen derivatives (named as H3 H20) that we customized through replacing moieties at C3 and C28 positions. We found that cobalt chloride reduced cell viability, increased Reactive Oxygen Species (ROS) production as well as induced apoptosis and necrosis in ARPE-19 cells. Interestingly, the pretreatment of 3-O-acetyl-glycyl- 28-O-glycyl-betulinic acid effectively protected cells from acute hypoxia stress induced by cobalt chloride. Our immunoblotting results suggested that this derivative attenuated the cobalt chloride-induced activation of Akt, Erk and JNK pathways. All findings were further validated in human primary RPE cells. In summary, this BA derivate has protective effect against the acute hypoxic stress in human RPE cells and may be developed into a candidate agent effective in the prevention of prevalent retinal diseases.

The classical swine fever virus C-strain vaccine (C-strain vaccine) plays a vital role in preventing and controlling the spread of classical swine fever (CSF). However, the protective mechanisms of C-strain vaccine and cellular immunity conferred by T cell receptors (TCRs) are less well defined. We aimed to analyse the association between the complementarity determining region 3 (CDR3) spectratype of αβTCR in CD4+ T cells and C-strain vaccine; and to find conserved CDR3 amino acid motifs in specific TCR α- and β-chains. We found that the CDR3 spectratype showed dynamic changes correlating with C-strain vaccine immunisation and that TCR AV5S/8–3S/8–4S/14/38 and BV4S/6S/7S/15S/30 gene families showed clonal expansion in immunised pigs. The sequences of CDR3 from these clonally expanded T cells indicated a high frequency of the ‘KLX’ motif in the TCR α chain and the ‘GGX’ motif in β chain, and Jα39, Jα43, Jβ2.5 and Jβ2.3 genes were also found in high frequency. To the best of our knowledge, this is the first report describing the dynamic changes of αβTCRs and conserved CDR3 amino acid motifs in CD4+ T cells from C-strain vaccine-immunised pigs, which will provide a basis for the development of high-efficiency epitope vaccines.

In this paper, a three-dimensional spiral cochlear Finite Element (FE) model was established by using PATRAN software based on the experimental data of synchronous light source imaging from Shanghai Institute of Applied Physics, Chinese Academy of Sciences. The acoustic-solid-liquid coupling analysis was carried out by NASTRAN software and the effects of fissura ante fenestra sclerosis on spiral cochlea were simulated in the paper. The satisfactory agreements between simulated results of ratio of displacement at 12 mm from Basilar Membrane (BM) to that at the vestibular window and experimental data in the literature confirm the validity of the FE model. Comparing the frequency response of the basilar membrane of normal and diseased ears, it can be found that greater hearing loss occurs at low frequency (100-600 Hz) and high frequency (2000-10000 Hz), but the hearing loss is less in the middle frequency. In this paper, the numerical simulation is used to make up for the lack of related researches and it provides a new way for clinical treatment of cochlear lesions.

Space-deployable habitat modules provide artificial habitable environments for astronauts and will be widely used for the construction of future space stations and lunar habitats. A novel structural design concept of space-deployable habitat modules consisting of flexible composite shells and deployable trusses has been proposed. Geometric relationships of deployable trusses based on two types of scissor elements were formulated. Flexible composite shells of space habitat modules were designed, and a nonlinear FEA model using ANSYS software was described. Considering folding efficiencies, stiffness, and strength of the structures, the influences of design parameters were analyzed and the final design scheme of space-deployable habitat modules was determined. After detailing the structural designs, low-speed impact dynamic responses between the structures and a stainless steel cylinder were simulated. The analysis results show that dynamic responses are only significant at the point of low-speed impact. The works will provide technical supports for structural designs and engineering applications of space-deployable habitat modules.

In this article, a new numerical technique is proposed for solving the two-dimensional time fractional subdiffusion equation with nonhomogeneous terms. After a transformation of the original problem, standard central difference approximation is used for the spatial discretization. For the time step, a new fractional alternating direction implicit (FADI) scheme based on the L1 approximation is considered. This FADI scheme is constructed by adding a small term, so it is different from standard FADI methods. The solvability, unconditional stability and H1 norm convergence are proved. Finally, numerical examples show the effectiveness and accuracy of our proposed method. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2015

Many novel materials exhibit a property of different elastic moduli in tension and compression. One such material is graphene, a wonder material, which has the highest strength yet measured. Investigations on buckling problems for structures with different moduli are scarce. To address this new problem, firstly, the nondimensional expression of the relation between offset of neutral axis and deflection curve is derived based on the phased integration method, and then using the energy method, load-deflection relation of the rod is determined; Secondly, based on the improved constitutive model for different moduli, large deformation finite element formulations are developed and combined with the arc-length method, finite element iterative program for rods with different moduli is established to obtain buckling critical loads; Thirdly, material mechanical properties tests of graphite, which is the raw material of graphene, are performed to measure the tensile and compressive elastic moduli, moreover, buckling tests are also conducted to investigate the buckling behavior of this kind of graphite rod. By comparing the calculation results of the energy method and finite element method with those of laboratory tests, the analytical model and finite element numerical model are demonstrated to be accurate and reliable. The results show that it may lead to unsafe results if the classic theory was still adopted to determine the buckling loads of those rods composed of a material having different moduli. The proposed models could provide a novel approach for further investigation of non-linear mechanical behavior for other structures with different moduli.

Inducible nitric oxide synthase (iNOS) critically contributes to the development of endotoxin-mediated inflammation. It can be induced by cytokines or endotoxins via distinct signaling pathways. Lipopolysaccharide (LPS) triggers iNOS expression through activation of the inhibitor of κB-α (IκB-α)-nuclear factor κB (NF-κB) cascade, whereas interferon-γ (IFN-γ) acts primarily through Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1). Methylene blue (MB), an agent used clinically to treat numerous ailments, has been shown to reduce NO accumulation through suppression of iNOS activity. But it remains unclear whether MB affects iNOS induction. This knowledge gap is addressed in the present study using cultured cells and endotoxemic mice. With mouse macrophages, MB treatment prevented the LPS- and/or IFN-γ-stimulated iNOS protein expression. Real-time PCR experiments showed that iNOS mRNA transcription was robustly blocked by MB treatment. The inhibitory effect of MB on iNOS expression was confirmed in vivo in endotoxemic mice. Further analysis showed that MB had no significant effect on IκB-α degradation and NF-κB or STAT1 phosphorylation in LPS/IFN-γ-stimulated cells. The nuclear transport of active NF-κB or STAT1 was also not affected by MB treatment. But MB treatment markedly reduced the binding of NF-κB and STAT1 to their DNA elements. Chromatin immunoprecipitation assays confirmed that MB reduced NF-κB and STAT1 bindings to iNOS promoter inside the cell. These studies show that MB attenuates transcriptional factor binding amid iNOS mRNA transcription, providing further insight into the molecular mechanism of MB in disease therapy. J. Cell. Biochem. 116: 1730–1740, 2015. © 2015 Wiley Periodicals, Inc.

Using the methods of variable separation and eigenfunction expansion for velocity potentials, an analytical expression for the composite structure of a submerged cylinder over a coaxial, bottom-mounted cylinder in finite depth is developed. This model is also applicable for the isolated submerged truncated cylinder by careful choice of bottom cylinder height. The exciting forces on the submerged cylinder obtained by the proposed analytical solution and the boundary element method (BEM) agree well with each other, which shows good reliability of the analytical expression. Based on the proposed model, the effects of wave force on submerged cylinder owing to the existence of topographical obstacles of different sizes are investigated. The results show that various geometrical parameters of the bottom cylinder alter wave force on the upper cylinder significantly. Considering the impact of barrier, horizontal wave force and vertical wave force on submerged cylinder arrive there are several peaks at different f...

Dihydromyricetin (DMY) displays a range of biological properties. However, whether DMY attenuates cardiomyocyte hypertrophy is unknown.To investigate whether DMY had potential therapeutic value to protect against angiotensin II (Ang II)-induced cardiomyocyte hypertrophy.Neonatal rat cardiomyocytes were pretreated with DMY (0-320 μM) followed with Ang II (100 nM) stimulation for 24 h, and then degree of hypertrophy was evaluated by cell surface analysis. Levels of reactive oxygen species (ROS) were measured with 2',7'-dichlorfluorescein-diacetate (DCFH-DA) fluorescent staining. Antioxidative activity was evaluated by malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, and total antioxidant capacity (T-AOC). Cyclic guanosine monophosphate (cGMP) was determined with a radioimmunoassay.Pre-incubation with DMY (20, 40, 80, and 160 μM) for 8 h, 12 h, 24 h, or 48 h decreased cell surface areas. It down-regulated mRNA expression of atrial natriuretic factor (1.95- to 1.24-fold) and β-myosin heavy chains (3.51- to 2.32-fold), reduced levels of MDA as well as increased SOD activity and T-AOC. Expression of SOD and thioredoxin were enhanced by DMY, whereas p22(phox) and phosphorylation of mitogen-activated protein kinases were inhibited. Content of cGMP (0.54- to 0.80-fold) and phosphorylation of endothelial nitric oxide synthase at serine 1177 (0.70- to 1.05-fold) were augmented by DMY. Moreover, attenuating effect of DMY on hypertrophy was abolished when NO production was inhibited by l-NAME.Attenuating effects of DMY on Ang II-induced cardiomyocyte hypertrophy related to antioxidative activity in a NO-dependent manner.

In order to investigate the effects of RhoA/ROCK signaling in macrophage differentiation, we used 100 ng/mL PMA to induce macrophage differentiation from U937 cells in vitro. The observation of cell morphology and the expression of CD68 and SR-A were performed to confirm the differentiation induced by PMA. Western blot analysis showed that the expression of ROCK1 and ROCK2 and the phosphorylation of MYPT1 were significantly increased after PMA treatment. Pulldown assay showed that the activation of RhoA was obviously enhanced when U937 cells were treated with PMA. In order to further demonstrate whether RhoA/ROCK signaling could mediate the macrophage differentiation induced by PMA, we successfully suppressed the expression of RhoA, ROCK1 and ROCK2 by performing siRNA technology in U937 cells, respectively. The macrophage differentiation and the expression of CD68 and SR-A were significantly inhibited by the suppression of RhoA, ROCK1 or ROCK2 in PMA-induced U937 cells, indicating that the macrophage differentiation induced by PMA is associated with RhoA/ROCK signaling pathway. In addition, we pretreated U937 cells with Y27632 (ROCK inhibitor, 20 μM) for 30 min and then observed the macrophage differentiation induced by PMA. The result illustrated that Y27632 pretreatment obviously inhibited PMA-induced differentiation and the expression of CD68 and SR-A. In conclusion, the activation of RhoA/ROCK signaling is responsible for the macrophage differentiation induced by PMA.

The classical swine fever virus C-strain vaccine (C-strain vaccine) plays a vital role in preventing and controlling the spread of classical swine fever (CSF). However, the protective mechanisms of C-strain vaccine and cellular immunity conferred by T cell receptors (TCRs) are less well defined. We aimed to analyse the association between the complementarity determining region 3 (CDR3) spectratype of αβTCR in CD4+ T cells and C-strain vaccine; and to find conserved CDR3 amino acid motifs in specific TCR α- and β-chains. We found that the CDR3 spectratype showed dynamic changes correlating with C-strain vaccine immunisation and that TCR AV5S/8–3S/8–4S/14/38 and BV4S/6S/7S/15S/30 gene families showed clonal expansion in immunised pigs. The sequences of CDR3 from these clonally expanded T cells indicated a high frequency of the ‘KLX’ motif in the TCR α chain and the ‘GGX’ motif in β chain, and Jα39, Jα43, Jβ2.5 and Jβ2.3 genes were also found in high frequency. To the best of our knowledge, this is the first report describing the dynamic changes of αβTCRs and conserved CDR3 amino acid motifs in CD4+ T cells from C-strain vaccine-immunised pigs, which will provide a basis for the development of high-efficiency epitope vaccines.

2,3,4',5-tetrahydroxystilbene 2-O-β-D-glucoside (TSG), a resveratrol analog with glucoside, is purified from a traditional Chinese herbal medicine polygonum multiflorum. It has been extensively studied in last decade and known to exert strong anti-inflammatory, anti-oxidative, anti-apoptotic, and free radical scavenging activities, and therefore has been listed as a potential agent for disease therapies. Recent studies extend well-beyond effects of TSG on the injury of neurons, cardiomyocytes and endothelial cells, and report important functions of TSG in a lot of pathophysiological conditions. For example, TSG has been shown to prevent the production of pro-inflammatory cytokines in microglia and macrophages in vitro, and ameliorate pro-inflammatory responses in animal models with neurodegeneration, atherosclerosis, and rat paw or ear oedema. TSG can prevent the proliferation of vascular smooth cells, gastrointestinal dysfunctions, platelet aggregation, osteoblastic injury, diabetic nephropathy and melanogenesis. TSG is also indicated to facilitate long-term potentiation and learning and memory in both normal and pathological conditions. These effects to some extent enrich the understanding about the role of TSG in disease prevention and therapy. However, to date, we still have no outlined knowledges about the pharmacological effects of TSG, though the role of TSG in aging and Alzheimer's disease has been reviewed in recent years. Here, we summarize the current pharmacological developments of TSG as well as its possible mechanisms in disease prevention and therapy, aiming to push the understanding about the protective role of TSG as well as its preclinical assessment of novel applications.

Purpose – The purpose of this paper is to solve temperature stress for bending beam with different moduli under different constraints subject to nonlinear temperature. Design/methodology/approach – The equations of neutral axis position, normal stress, and displacement of bending beam with different moduli subjected to nonlinear temperature were derived based on different moduli elasticity theory. Meanwhile, iterative procedure was programmed to solve the nonlinear equations. The analytical solution can return back into the result of the same modulus theory, and the analytical solution was compared with finite element numerical solution. It shows that the analytical model proposed in this paper is reliable to use. Furthermore, the influence of different moduli characteristics on the temperature stress and deformation is discussed. Findings – The mechanical behavior of the bending beam with different moduli subject to nonlinear temperature is quite different from the one that is subjected to force. The bending beam maybe exist two neutral axis, and the reasonable selection of tension modulus and compression modulus can improve the distribution of the normal stress and reduce the maximum tensile stress or the maximum compressive stress. Originality/value – The crack produced by temperature stress will affect the integrity and the durability of the structure. The solution for temperature problem with different moduli theory is rarely reported at home and board. In view of this, this paper will do some exploratory research-temperature stress for bending beam with different moduli.

Background: Endothelial cell dysfunction triggered by oxidized low-density lipoprotein (oxLDL) is the main event occurring during the development of atherosclerosis. 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an active component of the rhizome extract from Polygonum multiflorum, exhibits significant anti-atherosclerotic activity. However, the protective effects of TSG against oxLDL-induced endothelial dysfunction have not been clarified. We investigated the cytoprotective effects of TSG in human umbilical vein endothelial cells (HUVECs) and explored underlying mechanisms. Methods and Results: TSG pretreatment markedly attenuated oxLDL-mediated loss of cell viability, release of lactate dehydrogenase (LDH), cell apoptosis, and monocyte adhesion. OxLDL increased vimentin mRNA and protein levels, vimentin cleavage, caspase-3 activation, adhesion molecules levels and their colocalization with vimentin in HUVECs. These alterations were attenuated by pretreatment with TSG. Meanwhile, TSG inhibited both the expression of TGFβ1 and the phosphorylation of Smad2 and Smad3, and TSG suppressed the nuclear translocation of Smad4 induced by oxLDL. Using shRNA, oxLDL-induced cell apoptosis and monocyte adhesion were significantly inhibited by vimentin suppression in HUVECs. Conclusions: These results suggest that TSG protects HUVECs against oxLDL-induced endothelial dysfunction through inhibiting vimentin expression and cleavage, and the expression of adhesion molecules and their colocalization with vimentin. The interruption of TGFβ/Smad pathway and caspase-3 activation appears to be responsible for the downregulation of TSG on vimentin expression and fragmentation, respectively.

In this paper, a novel planar graphene/h-BN heterostructure (PG/h-BN) is established. The geometric defects were created in the novel planar graphene/h-BN heterostructure. The mechanical properties of PG/h-BN in the presence of geometric defects have been studied, and the effects of dimensions and positions of geometric defects on mechanical properties have also been investigated by using molecular dynamics method. The results show that defective PG/h-BN decreases with the increase in the diameter of the geometric defects. Meanwhile, planar heterojunction with square nanoholes are more prone to stress concentration than planar heterojunction with circular nanoholes. In addition, in the presence of geometric defects, the failure strain and strength of planar heterojunction more affected by geometric defects than Young's modulus. It is very important for the defects to regulate the physical properties of planar heterojunctions.

The enzyme φC31 integrase from Streptomyces phage has been documented as functional in mammalian cells and, therefore, has the potential to be a powerful gene manipulation tool. However, the activity of this enzyme is cell-type dependent. The more active mutant forms of φC31 integrase are required. Therefore, a rapid and effective method should be developed to detect the intracellular activity of φC31 integrase. We devised in this study an integrase-inversion cassette that contains the enhanced green fluorescent protein (EGFP) gene and the reverse complementary DsRed gene, which are flanked by attB and reverse complementary attP. This cassette can be inverted by φC31 integrase, thereby altering the fluorescent protein expression. Thus, φC31 integrase activity can be qualitatively or quantitatively evaluated based on the detected fluorescence. Furthermore, this cassette-based method was applied to several cell types, demonstrating that it is an efficient and reliable tool for measuring φC31 integrase activity in mammalian cells.

Based on the normal CT scan image of human right ear, numerical model has been established combined with self-compiling program. The nonlinear constitutive relation of real middle ear material has been included, and sound - solid and liquid - solid coupling method have been adopted to simulate the sound transmission process from external auditory canal to tympanic membrane, auditory ossicle chain, and eventually to the inner ear. Frequency response and sound transmission behavior has been obtained, and numerical calculation results have been verified by comparing the calculation results with the experimental data. The amplitude, vibration velocity, and stress distribution of middle ear have been analyzed by the model, and the most easy damage part of the tympanic membrane and ossicular chains owing to stress concentration have been obtained in sound transmission of middle ear, which exposes the inner relationship between mechanical behavior of middle ear and pathological changes.

Many civil-engineering materials and novel materials developed in recent years exhibit a property of different elastic moduli in tension and compression. One such material is graphene, a wonder material, which has the highest strength yet measured. However, the dominant failure of structures composed of this high-strength material is often attributed to buckling problems. Investigations on buckling problems for structures with different moduli are scarce. To address this new problem, the present paper develops a semianalytical method for the critical buckling loads of variable–cross section slender rods with different moduli. Based on the variational principle, a differential equation of the deflection of these structures is derived for the first time. By developing a nonlinear iterative program and using the variational iteration method, the critical buckling loads are obtained. Then, buckling tests and numerical simulation were conducted for slender rods made from graphite with different moduli....

Two calculation models are established for inner soil pressure of opened bottom elliptical barrel structure (OBEBS) using penetration of negative pressure method. One model is for construction stage, pressure of inner soil in cabins at this stage was divided into three zones: active zone, transition zone and passive zone. The other model is for operational stage, pressure of inner soil in cabins at this stage was divided into two zones: active zone and passive zone. The theoretical analytical solutions of inner soil pressure for construction stage and operational stage were derived. The analytical formulas derived in this paper and finite element method were used to analyze the inner soil pressure of OBEBS at same time and condition. The models were used to calculate the carrying capacity of the former site and settlement of the structure. The models of inner soil pressure provided a scientific method for design and construction of the new multi-position structure.

In this study, we focused mainly on establishing a new sensitive method to identify location of damages in Service Bridge. The improved method of combination of Autoregressive models (AR) and autoregressive models with exogenous inputs (ARX) was applied to identify the damage in Service Bridge. Firstly, an improved AR-ARX model was established for damage identification of bridge on service. Secondly, the detailed steps of identifying location of damages are explained using proposed damage diagnosis method. Finally,the improved AR-ARX model was used to identify location of damage in a two-span steel beam. The results of calculated showed the damage diagnosis method based on improved AR-ARX model that considered the ambient excitation is much more powerful and accurate than AR-ARX method. So the proposed method can apply to bridge damage detection with few acceleration sensors. This study laid the foundation for the bridge identification.

Based on structure principle of shear connector, a new type of perfobond hoop has been proposed. The mechanical advantage of PBH has been compared to traditional shear connector by mechanical analysis. According to the measurement and reinforcement requirement suggested by ECSS, the finite element model has been established. The important design parameters which have influence on carrying capacity of PBH shear connector have been analyzed, such as concrete strength, hole numbers, bore diameter, bar diameter and the thickness of steel plate with hole. Carrying capacity calculation expression of PBH shear connector was put forward by regression analysis. The calculation expression has been verified by four groups of shear resistance experiments and the test results agree well with the calculated value by the expression.

In this study, we want to find out the relationship between the bridge natural frequency and the bridge foundation scour depth. The Improved Ibrahim Time Domain (IITD) method and the finite element models are applied to solve the problem. Firstly, IITD method was described in detail for using to solve the natural frequency at ambient excitation. Secondly, the detailed steps of expiring the relationship between bridge natural frequencies and foundation scour depth are explained using IITD method and finite element techniques. Finally, the natural frequency of Qujiang Bridge is calculated at different scour depth. The detailed analysis of the natural frequency of the bridge with the variation of scour depth can able to explore the impact of bridge scour damage for structural safe operation. The results of calculated showed the IITD method that considered the ambient excitation is much more powerful and accurate than Irahim Time Domain (ITD) method. So IITD can apply to bridge scour damage detection with finite element techniques. This study laid the foundation for the bridge scour identification.

The embedded large-diameter cylinder had been widely used in coastal engineering since it could be embedded into ground directly without excavation. A 3D elastic-plastic finite element model has been established to analyze the distribution and development of the friction resistance on large-diameter cylinder under the wave load. The results show that the development of friction on different areas of the cylinder is unsynchronized. The friction resistance first developed on the outer surface of the structure, after that, the inner friction began to develop. Only in certain areas the firction resistance can achieve ultimate value at the ultimate state.

The mechanical models of Perfobond Hoop (PBH) and Perfobond Leiste (PBL) shear connector were compared, based on their structure traits. PBH shear connector is more reasonable than PBL shear connector in mechanic. Then, the carrying capacities of the two forms of shear connectors were compared. It shows by the experimental result that PBH shear connector is superior to PBL shear connector in carrying capacity. The model of the experiment specimen were established using finite element method, then, the FEM model was verified by comparing it with the experiment results. Furthermore, the factors which may have influence on carrying capacity of PBH shear connector were

This paper presents the study of negative skin friction of the superlong pile caused by the soil settlement under large-scale surcharge loading. Based on the displacement equilibrium principle and transfer matrix method, with the introduction of a load transfer model considering shaft resistance softening, the analytical model of negative skin friction of superlong pile under surcharge loading is established by considering the three-dimensional consolidation settlement along the pile under surcharge loading, the compression deformation of pile, and the soil settlement around pile-end. Three-dimensional Biot consolidation is used to derive the settlement of soil surrounding pile and the settlement formula is simplified by using the Laplace and Hankel integral transform. Furthermore, the analysis is conducted for an engineering example using the theoretical model and FEM simulation method. The results are also compared with the corresponding measured data. The characteristics of negative skin friction of superlong pile under surcharge loading are obtained, and the effect of soil parameters on negative skin friction is discussed as well, which can offer valuable reference for the design of superlong piles.

Email Address: zhangxiaozhong@126.com Abstract: Reliable prediction of traffic loads is essential for bridge planning and design. In the study, an improved unbiased Grey Markov forecasting model is applied to predict traffic loads on highway bridges. The comparison between the predicted results and existing practical measurements indicates that high accuracy can be achieved by using the developed model for bridge load prediction. The developed model shows great promise in structural design and durability assessment of highway bridges.

Many engineering materials exhibit different elastic properties under the extension and compression. Among these materials, the concrete is a typical material which has different extension modulus and compression modulus. Based on different modulus theory, mechanical analysis was performed in this paper for reinforced concrete beams, stress formula was deduced, and the corresponding formula was applied to concrete structures with second-class crack control, which has improved the original crack control conditions in the code for design of concrete structures in China based on the classical modulus theory.

Many novel materials, developed in recent years, have obvious properties with different modulus of elasticity in tension and compression. The ratio of their tensile modulus to compressive modulus is as high as five times. Nowadays, it has become a new trend to study the mechanical properties of these bimodular materials. At the present stage, there are extensive studies related to the strength analysis of bimodular structures, but the investigation of the buckling stability problem of bimodular rods seems to cover new ground. In this article, a semi-analytical method is proposed to acquire the buckling critical load of bimodular slender rod. By introducing non-dimensional parameters, the position of neutral axis of the bimodular rod in the critical state can be determined. Then by combining the phased integration method, the deflection differential equation of bimodular pin-ended slender rod is deduced. In addition, the buckling critical load is obtained by solving this equation. An example, which is conducted by comparing the calculation results between the three of the methods including the laboratory tests, numerical simulation method and the method we developed here, shows that the method proposed in the present work is reliable to use. Furthermore, the influence of bimodular characteristics on the stability is discussed and analyzed.

The calculation and analysis of single pile settlement was one of the important geotechnical engineering issues, and many geotechnical engineers and scholars investigated and formed a systematic analysis method. Among the existing methods of analysis methods, the elasticity theory method was relatively mature. However, the traditional elasticity theory method could not consider the slip properties between pile and soil, and did not match the actual working properties of pile foundation. In this paper, based on Mindlin's solution, the pile is assumed to be elastic and the relationship between shear stress and relative displacement at the pile-soil interface is assumed to follow hyperbolic function, then series equations were derived and solved by Finite Difference Method. Two cases were demonstrated and the computed results agreed very well with testing data. The advantage of the analysis method proposed was that the interaction of pile and pile, and pile and soil can be considered.

In order to research on the stress change and influencing factor of whole construction process of simply supported to Continuous system T-beam bridge, combined with Guizhou Bai-long bridge, the stress change is carried out the real time inspection in each construction stage, and the finite element model is established to analyse Stress changes in whole construction process. The monitoring value is ​​more consistent with the theoretical value in each stage , monitoring dates and theoretical calculations showed that pre-stressed is the main factor of stress changes in construction process.Pre-stressed tension in negative moment region has obvious influence on the stress of middle span, the stress of top and bottom plates in wet joints will be equivalent after tendons tension in negative moment Region.

Taking Tianjin Yonghe bridge for example, the finite element method is adopted to simulate each stages of cable replacement process, the dates of tension, the alignment of main beam and the change of stress before and after cable replacement are compared and analysed, The measured value is greatly consistent with calculated value, Stress state of the bridge has been greatly improved, the weight of main beam bearing by the cable will be shared by a few closed cable after unloading, so the cables which are more serious corroded should be replaced.

Currently, super-long piles are designed based on the theory of normal long piles. There is no recognized reasonable mechanical model for qualitative analysis. In this paper, based on load transfer function method, an improved load transfer model is proposed, which gives consideration to both the degradation of skin friction and the asynchronous work between lateral friction resistance and pile-tip resistance caused by pile-soil slip. By applying it in various working conditions, the corresponding pile-soil displacement and axial force of super-long piles are derived. Finally, the proposed model is validated by comparing its analytical solutions to the results of FEM and practical survey of super-long piles, and it provides a new efficient approach for the study of the mechanical behavior of super-long single pile.

Conclusion:A good short-term hearing improvement is gained by partial ossicular replacement prostheses with several common various materials.A better sound transmission in lower frequencies is obtained by partial ossicular replacement prostheses with hydroxyapatite ceramics, stainless steel and alumina ceramics.However,A better sound transmission in higher frequencies is gained by partial ossicular replacement prostheses with porous polyethylene and polytetrafluoroethylene.Considering a long-term effect on hearing improvement,they are better materials on hearing restoration because titanium, polytetrafluoroethylene and hydroxyapatite ceramics have a good biocompatibility for the patients.And these conclusions can provide certain reference values for human ear clinical studies.Objectives:This paper qualitatively and quantitatively studied the effect of partial ossicular replacement prostheses (PORPs) with several various materials on hearing restoration.Methods:The CT data of the right ear from a normal human body was digitalized and imported into PATRAN to establish a three dimension finite element mode1by self-compiling program,and then a frequency response analysis was made for the model using NASTRAN to study the effect of partial ossicular replacement prostheses with several various materials on hearing restoration.Results:the model was carried through a harmonic response analysis of normal ear structure and confirmed by the consistency in the calculated and experimental data after comparision.

Based on the bearing capacity behavior and load transfer mechanism of super-long pile in soft soil, the three-stage hyperbolic softening model is presented as the load transfer function of pile-side soil, and tri-linear model is introduced to simulate the characteristics of sediments in pile end. The differential equations are established by dealing with the states of static equilibrium, with considering the character of layered stratum and pile-soil interaction. The analytical solutions on different states are obtained by power series. Based on transfer matrix method, soil mechanics and elastic theory, a set of analytical equations and calculating method for the axial load-settlement curve of pile top in layered ground are established. Lastly, the calculating parameters are obtained by theoretically approaching to actually measure load-settlement curve in soft soil area. The calculating contrast to adjacent test pile is carried out by the method and the results are satisfactory.

In this paper, a three-stage softening load transfer model, based on existing experimental data of super-long piles, is proposed; the hyperbola load transfer model is adopted to simulate the nonlinear deformation of pile-tip soil; and the elastic-plastic model of concrete is introduced, giving consideration to the super-long pile shaft deformation under heavy axial loads. Then the models above are implemented into pile-soil load transfer differential equation, and after being solved by iteration method, the nonlinear method for load transfer model of super-long pile in layered soil is established. After that programming of the model calculation is worked out. By comparison with engineering instance, it is shown that the method proposed in this paper is convenient and reliable in engineering practice.

In this paper, based on pile-soil interaction, the calculating method for the negative skin friction of pile in layered soil is proposed. Two load conditions, axial load on the top and overloading on soil around pile are presented, respectively. The transfer matrix method is used to analyze the first condition, while the soil consolidation theory and finite difference method are used to investigate the second condition numerically. The results can offer valuable references for both theoretical research and engineering design of long pile bearing larger negative skin friction.

In this paper, a nonlinear three-dimensional finite element model for super-long pile and soil interaction is established. In this model, contact elements are applied to simulate the nonlinear behavior of interaction of super-long pile and soil. A nonlinear elastic constitutive model for concrete is employed to analyze stress-strain relation of pile shaft under the axial load and the Duncan-Chang’s nonlinear constitutive model is used to reflect nonlinear and inelastic properties of soil. The side friction resistance, axial force, pile-tip resistance, and developing trend of soil plastic deformation are obtained and compared with measured results from static load tests. It is demonstrated that a super-long pile has the properties of degradation of side friction resistance and asynchronous action between side and pile-tip resistance, which is different from piles with a short to medium length.

Materials with different modulus in tension and compression have a wide application in engineering practice, especially the composite materials developed in recent years, which have properties of different tension-compression modulus. To exploring the general features of mechanical properties of structures with different modulus, the dimensionless equation of finite element was deduced for structure with different modulus, and corresponding finite element program was developed .the stresses of the cantilever beam by program of the theory with different modulus. The impacts on member stresses resulted from the change of structure size, external load and the ratio of different modulus are compared and analyzed. Finally, we have drawn a conclusion that the property of different modulus of the material is very important to its stress, and have given out suggestions on the optimization of state of structural stress.

According to the vibration characteristics of the round window membrane, a mechanical model that contains round window membrane and the soft tissue is established. The Euler equation of the whole of round window membrane and the soft tissue and the complementary boundary conditions are derived by the variational principle. Combined with the Bessel function, the analytical solution of the total displacement of round window membrane and the soft tissue is obtained by using Mathematica. The results are in good agreement with experimental data, which confirms the validity of the analytical solution of the model. At the same time, the effect of different thicknesses and different elastic modulus of soft tissue on the total displacement of round window membrane and soft tissue is studied by analytical method. The results show that with the thickening of the soft tissue, the total displacement of round window membrane and the soft tissue decreased gradually. However, with the decrease of elastic modulus of the soft tissue, the total displacement of round window membrane and the soft tissue increased gradually. Furthermore, the relationship between thickness and elastic modulus of the soft tissue and the corresponding range selection is achieved, which can evaluate the transmission performance of round window membrane efficiently and provide theoretical basis for the reverse excitation of artificial prosthesis.

In this work, we have developed a novel choline biosensor on the basis of immobilization of choline oxidase (ChOx) by the attractive materials layered double hydroxides (LDHs). Amperometric detection of choline was evaluated by holding the modified electrode at 0.5 V (vs. SCE). Due to the special properties of LDHs ([Zn3-Al-Cl]), such as chemical inertness, high porosity, and swelling property, the [Zn3-Al-Cl]/ChOx modified electrode exhibited an enhanced analytical performance. The biosensor provided a linear response to choline over a concentration range from 3.7 × 10−6 to 6.3 × 10−4 M with a low detection limit of 3 × 10−7 M based on S/N=3. The apparent Michaelis-Menten constant was calculated to be 1.38 mM. In addition, the interaction between ChOx and LDHs has also been investigated using FT-IR spectroscopy.