Theorems on the limit analysis of finite deformation

A generalized variational principle (theorem 1) which is equivalent mathematically to the whole set of equations and conditions and must be satisfied by the limit analysis of finite deformation is proposed in this paper. It is also proved that the limit load deduced from theorem 1 will lie between the lower and upper bounds given by the bound theorems of finite deformation     

Generalized variational principles on nonlinear theory of elasticity with finite displacements

Two generalized variational principles on nonlinear theory of elasticity with finitedisplacements in which the σ_(ij),e_(i j)and u_i are all three kinds of independent functionsare suggested in this paper.It isproved that these two generalized variational principles areequivalent to each other if the stress-strain relation is satisfied as constraint.Some specialcases,i.e.generalized variational principles on nonlinear theory of elasticity with smalldeformation,on linear theory with finite deformation and on linear theory with smalldeformation together with the corresponding equivalent theorems are also obtained.All ofthem are related to the three kinds of independent variables.     

A method for establishing generalized variational principle

A method for establishing generalized variational principle is proposed in this paper. It is based on the analysis of mechanical meaning and it can be applied to problems in which the variational principles are needed but no corresponding variational principle is available. In this paper, the Hu-Washizu ’s generalized variational principle and the Hu’s generalized principle of complementary energy are derived from the mechanical meaning instead of from the generalization of the principle of minimum potenlial energy and the correct proofs of these two generaleed variational principles are given. It is also proved that this is wrong if one beleives that σ_ij, e_ij and ui are independent variables each other based on the reason that these three kinds of variables are all contained in these two generalized variational principles. The condition of using these two variational principles in a correct manner is also explained.     

Study on chemical-solution-deposited lanthanum zirconium oxide film based on the Taguchi method

A statistical route, Taguchi Design, applied to the analysis of experimental factors for coating lanthanum zirconium oxide films on metal substrates by inkjet printer is presented. The synthesis of lanthanum zirconium oxide precursor is derived from a chemical solution containing lanthanum acetate hydrate, zirconium propoxide, propionic acid, glacial acetic acid, and methanol anhydrous. Experimental factors analyzed by Taguchi Design show that the ratio of lanthanum acetate to propionic acid and the concentration of precursor used for inkjet printing are the dominant factors for the quality of films. With the deduced optimum conditions, lanthanum zirconium oxide films reveal good surface morphology and high out-of-plane alignment that is consistent with the Taguchi prediction.     

Effects of Reactive Species Produced by Electrolysis of Water Mist and Air through Non-Thermal Plasma on the Performance and Exhaust Gas of Gasoline Engines

Countries are paying increasing attention to environmental issues and are moving towards the goal of energy saving and carbon reduction. This research presents a method to analyse the effects of the use of non-thermal plasma (NTP) and water injection (WI) devices on the efficiency of internal combustion engines. The devices were installed on the intake manifold to investigate the effects of additional substances produced by electrolysis on the engine performance and exhaust emissions. According to the results, the addition of the NTP and WI devices affected the power efficiency and the rate of change of the brake-specific fuel consumption (BSFC) of the internal combustion engines. In addition, the change rate of hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) in the exhaust gases was affected. In conclusion, the study found that the additional substances generated by the NTP-electrolysed water mist or air influenced the fuel combustion efficiency and exhaust emissions.     

Metal–metal bonding and structures of trinickel and tricobalt dipyridylamido complexes from surface‐enhanced Raman spectra

We recorded surface‐enhanced Raman scattering (SERS) spectra of metal‐string complexes Co₃(dpa)₄ Cl₂ [di(2‐pyridyl)amido (dpa)], Ni₃(dpa)₄ Cl₂ and the oxidized form of the Ni₃ complex to determine their vibrational wavenumbers and to investigate their structures. For SERS measurements these complexes were adsorbed on silver nanoparticles in aqueous solution to eliminate the constraint of a crystal lattice and the complexes remain in thermal equilibrium. From our analysis of the vibrational normal modes we assigned the SERS lines at 242 and 276 cm⁻¹ to Ni₃ and Co₃ symmetric‐stretching modes of the symmetric form. For Co₃ (dpa)₄Cl₂ a Raman line at 383 cm⁻¹ was assigned to the Co Co stretching mode of the unsymmetric form. The wavenumber of the Ni₃ symmetric‐stretching mode of the oxidized form [Ni₃(dpa)₄]³⁺ is 274 cm⁻¹, greater than that for neutral Ni₃(dpa)₄Cl₂, in agreement with a prediction of delocalized molecular‐orbital theory that an electron is removed from an antibonding orbital after oxidation. The experimental data show that the SERS technique serves as an excellent tool to observe the variation of metal–metal bonding during an oxidation or reduction reaction. Copyright © 2010 John Wiley & Sons, Ltd.