Sulfur poisoning mechanism of three way catalytic converter and its grey relational analysis

Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.

Analysis of fluoxetine-induced plasticity mechanisms as a strategy for understanding plasticity related neural disorders

Fluoxetine hydrochloride,better known for its commercial name Prozac,is one of the most widely prescribed antidepressant drugs all over the world.This drug was considered a＂breakthrough drug＂for the treatment of depression because of its very high selectivity as a serotonin reuptake inhibitor and because it presented a lower side-effectprofile than previous drugs （Wong et al., 2005）.

Mechanism of Zhongtiao Aulacogen Related to Breakup of Columbia Supercontinent

The mechanism of the breakup of supercontinent is a scientific frontier in the field of supercontinent study.The rifting and breakup of supercontinent has long been considered to be related to mantle plume.Paleo-

Mechanical properties and constitutive behaviors of as-cast 7050 aluminum alloy from room temperature to above the solidus temperature

The mechanical properties and constitutive behaviors of as-cast AA7050 in both the solid and semi-solid states were determined using the on-cooling and in situ solidification approaches, respectively. The results show that the strength in the solid state tends to increase with decreasing temperature. The strain rate plays an important role in the stress–strain behaviors at higher temperatures, whereas the influence becomes less pronounced and irregular when the temperature is less than 250°C. The experimental data were fitted to the extended Ludwik equation, which is suitable to describe the mechanical behavior of the materials in the as-cast state. In the semi-solid state, both the strength and ductility of the alloy are high near the solidus temperature and decrease drastically with decreasing solid fraction. As the solid fraction is less than 0.97, the maximum strength only slightly decreases, whereas the post-peak ductility begins to increase. The experimental data were fitted to the modified creep law, which is used to describe the mechanical behavior of semi-solid materials, to determine the equivalent parameter fGBWL, i.e., the fraction of grain boundaries covered by liquid phase.

Mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions

To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.

Fatigue behaviour of welded joints assembled by longitudinal corrugated plates

Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the test S-N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints.

Expression analysis for candidate genes associated with eggshell mechanical property

Damaged eggshells result in losses of eggs.The genetic mechanism of variable eggshell strength is still unclear.The current study was conducted to verify whether the eggshell calcification related genes,CALB1,SPP1,DMP4,BMP2 and SLIT2,were associated with eggshell mechanical property.For this purpose quantitative PCR（q-PCR） analysis was performed to detect gene expression between two groups of hens laying strong and weak eggs.The hens were selected from 360 White Leghorn layers at 60 wk to ensure that the strong and weak eggs differed significantly in breaking strength but not in eggshell thickness and weight.Using this special strong/weak eggshell model,we found that the expression of CALB1 in the uterus of strong shell group was about 3-fold higher（P〈0.05） than that in weak shell group.The DMP4 expression was significantly higher（2-fold,P〈0.05） in the uterus of weak shell group than that in strong shell group.However,no difference was observed for genes of SPP1,SLIT2 and BMP2 between these two groups.The current study provides a new insight to investigate the association of candidate genes with eggshell mechanical property.

Role and related mechanism of S1P / S1P1 signal pathway during post conditioning of hypertrophic cardiomyocytes

Objective To study the role and mechanism of sphingosine-phosphate(S1P)/sphingosine-1-phosphate receptor 1(S1P1)signal pathway during post conditioning of hypertrophic cardiomyocytes.Methods Neonatal rat cardiomyocytes were isolated and cultured,then stimulated by norepinephrine(NE)to induce cardiomyocytes hypertrophy.Using tri-gas incubator to create

Relative humidity and temperature dependence of mechanical degradation of natural fiber composites^(?)

In this paper,the mechanical degradation of natural fiber composites is studied with the consideration of the relative humidity and the temperature.A nonlinear constitutive model is established,which employs an internal variable to describe the mechanical degradation related to the energy dissipation during moisture absorption.The existing experimental researches demonstrated that the mechanical degradation is an irreversible thermodynamic process induced by the degradation of fibers and the damages of interfaces between fiber and matrix,both of which depend on the variation of the relative humidity or the temperature.The evolution of the mechanical degradation is obtained through the determination of dissipation rates as a function of the relative humidity and the temperature.The theoretically predicted mechanical degradations are compared with experimental results of sisal fiber reinforced composites subject to different relative humidity and temperatures,and a good agreement is found.

Entanglement,Identical Particles and the Uncertainty Principle

A new uncertainty relation(UR) is obtained for a system of N identical pure entangled particles if we use symmetrized observables when deriving the inequality. This new expression can be written in a form where we identify a term which explicitly shows the quantum correlations among the particles that constitute the system. For the particular cases of two and three particles, making use of the Schwarz inequality, we obtain new lower bounds for the UR that are different from the standard one.