The chemo-mechanical coupling behavior of hydrogels incorporating entanglements of polymer chains

To describe precisely the chemo-mechanical coupling behavior of hydrogels, a general form of free energy density function is presented by considering chain entanglements and functionality of junctions. We use the chemical potential of the solvent and the deformation gradient of the network as the independent variables of the developed free energy function, and implement this material model in the finite element package, ABAQUS, to analyze several examples of chemo-mechanical equilibrium deformation behaviors of hydrogels. The influence of chain entanglements and junction functionality on the chemo-mechanical behavior of hydrogels is addressed based on our simulation. With the coded subroutine UHYPER, this work may provide a numerical tool to study complex phenomena in hydrogels.     

Analytical solutions of uniform extended dislocations and tractions over a circular area in anisotropic magnetoelectroelastic bimaterials

In this paper, we derive the analytical solutions in a three-dimensional anisotropic magnetoelectroelastic bimaterial space subject to uniform extended dislocations and tractions within a horizontal circular area. By virtue of the Stroh formalism and Fourier transformation, the final expression of solutions in the physical domain contains only line integrals over [0,2π] rather than infinite integrals. As the reduced cases, the half-space and homogeneous full-space solutions can be directly derived from the present solutions. Also, in terms of material domains, the present solutions can be reduced to the piezoelectric, piezomagnetic, purely elastic materials with different symmetries of material property. To carry out numerical calculations, Gauss quadrature is adopted. In the numerical examples, the effect of different loading locations on the response at the interface is analyzed. It is shown that, when the magnetic traction or electric dislocation is applied, the physical quantities on the interface may not decrease monotonically as the loading area moves away from the interface. The distributions of different in-plane physical quantities on the upper and lower interfaces under various extended horizontal loadings are compared and the differences are discussed. The work presented in this paper can serve as benchmarks for future numerical studies in related research fields.     

A single helicopter’s flying model in the low airspace with a parallel electrical wire network

In this paper, we use car-following theory to propose a model with consideration of multi-telegraph poles and electrical wires to describe a single helicopter’s flying behavior in the low airspace with a parallel electrical wire network. The numerical results show that the proposed model can describe the qualitative effects of the parallel electrical wire network on the evolutions of a helicopter’s speed, safe distances for the telegraph poles and electrical wires and safe sphere. These results can help us to better understand the helicopter’s flying behavior in the low airspace with a parallel electrical wire network.     

Poisson theory and integration method for a dynamical system of relative motion

This paper focuses on studying the Poisson theory and the integration method of dynamics of relative motion.Equations of a dynamical system of relative motion in phase space are given.Poisson theory of the system is established.The Jacobi last multiplier of the system is defined,and the relation between the Jacobi last multiplier and the first integrals of the system is studied.Our research shows that for a dynamical system of relative motion,whose configuration is determined by n generalized coordinates,the solution of the system can be found by using the Jacobi last multiplier if (2n 1) first integrals of the system are known.At the end of the paper,an example is given to illustrate the application of the results.     

γ radiation caused graphene defects and increased carrier density

We report on a micro-Raman investigation of inducing defects in mono-layer, bi-layer and tri-layer graphene by γ ray radiation. It is found that the radiation exposure results in two-dimensional (2D) and G band position evolution with the layer number increasing and D and D' bands rising, suggesting the presence of defects and related crystal lattice deformation in graphene. Bi-layer graphene is more stable than mono- and tri-layer graphene, indicating that the former is a better candidate in the application of radiation environments. Also, the DC electrical property of the mono-layer graphene device shows that the defects increase the carrier density.     

Joint probability generating function for degrees of active/passive random intersection graphs

Correlations of active and passive random intersection graphs are studied in this paper. We present the joint probability generating function for degrees of G ^active(n, m, p) and G ^passive(n, m, p), which are generated by a random bipartite graph G*(n, m, p) on n + m vertices.     

Diagnosis of electron temperature in Ar/O2 mixed gas and destruction of toluene/benzene by positive dc discharge plasma

The electron temperature (T_e) of positive dc corona plasma in Ar/O₂ atmosphere was diagnosed, and plasma decomposition of toluene/benzene was studied in a razor–plate reactor. Experimental results revealed that T_e would increase with corona current until it reached a peak value, and then decrease; the volume fraction of Ar (φ_Ar) in Ar/O₂ mixed gas also influenced T_e, the higher φ_Ar, the lower T_e. Though the decomposed volume fraction of toluene/benzene was positively related to the input power, the decomposition efficiency did not monotonically increase with the specific energy density. The highest energy yield reached 3.8 g-toluene/kWh and 2.4 g-benzene/kWh, respectively.     

A new dynamic model for heterogeneous traffic flow

Based on the property of heterogeneous traffic flow, we in this Letter present a new car-following model. Applying the relationship between the micro and macro variables, a new dynamic model for heterogeneous traffic flow is obtained. The fundamental diagram and the jam density of the heterogeneous traffic flow consisting of bus and car are studied under three different conditions: (1) without any restrictions, (2) under the action of the traffic control policy that restrains some private cars and (3) using bus to replace the private cars restrained by the traffic control policy. The numerical results show that our model can describe some qualitative properties of the heterogeneous traffic flow consisting of bus and car, which verifies that our model is reasonable.     

New Phenolic Components from Daphne giraldii

Two new bis‐coumarins, namely daphnogitin ( 1 ), daphnogirin ( 2 ), and a flavan‐3‐ol derivative, 5‐O‐methylafzelechin ( 3 ), together with eleven known compounds, daphnetoxin, 1,2‐dihydrodaphnetoxin, daphnetin, daphnoretin, daphneticin, isodaphneticin, trans‐2,3‐dihydro‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐(hydroxymethyl)‐9H‐pyrano[2,3‐f]‐1,4‐benzodioxin‐9‐one (= demethoxyisodaphneticin; 4b ), (+)‐pinoresinol, acuminatin, (−)‐dihydrosesamin, and isosalicifoline, were isolated from the leaves and stems of Daphne giraldii. Compound 4b was isolated for the first time as a natural product, and 1,2‐dihydrodaphnetoxin, daphneticin, isodaphneticin, (+)‐pinoresinol, acuminatin, (−)‐dihydrosesamin, and isosalicifoline were isolated for the first time from Daphne giraldii. The structures of the three new compounds were elucidated by spectroscopic analysis.     

解微分方程组的改进尤拉方法的改进

对改进尤拉方法解微分方程组的方法作了改进,改进的算法与原来算法的计算量一样,但精度比较高.