Effects of aging on the microstructure of a Cu-Al-Ni-Mn shape memory alloy

The influence of aging on the microstructure and mechanical properties of Cu-11.6wt%Al-3.9wt%Ni-2.5wt%Mn shape memory alloy（SMA） was studied by means of scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray diffractometer,and differential scanning calorimeter（DSC）.Experimental results show that bainite,γ2,and α phase precipitates occur with the aging effect in the alloy.After aging at 300°C,the bainitic precipitates appear at the early stages of aging,while the precipitates of γ2 phase are observed for a longer aging time.When the aging temperature increases,the bainite gradually evolves into γ2 phase and equilibrium α phase（bcc） precipitates from the remaining parent phase.Thus,the bainite,γ2,and α phases appear,while the martensite phase disappears progressively in the alloy.The bainitic precipitates decrease the reverse transformation temperature while the γ2 phase precipitates increase these temperatures with a decrease of solute content in the retained parent phase.On the other hand,these precipitations cause an increasing in hardness of the alloy.

Factor Structure of the Center for Epidemiologic Studies Depression Scale in South Korea

Results of previous studies from North America reported that only 14 out of the 20 items from the Center for Epidemiologic Studies Depression Scale (CES-D) were required to assess negative affect, somatic symptoms, and anhedonia. However, it remains unclear whether this three-factor structure of the CES-D would be valid in South Korea. The purpose of this study is to examine the validity of the three-factor structure with a Korean version of the CES-D. The participants were Korean college students (N = 215), elementary school teachers (N = 234), and parents of elementary school students (N = 230). Confirmatory factor analysis was performed to examine the scale’s validity. Results indicated that the three-factor structure showed acceptable fit to data (comparative fit index = 0.95;root mean square error of approximation = 0.06). The findings indicated that the three-factor structure of the CES-D was valid in South Korea.

Dust Retention Ability of Plants as a Factor Improving Environment Air

It is well known that air in industrial cities contains a significant amount of dust particles, smoke, and toxic gases. The increased number of vehicles has a direct impact on air quality resulting in the emission of exhaust gases, and the increase of dust concentration in air. In this article, we are describing the dust retention ability of plants depending on their leaf structure. Plant species were classified into three groups according to their dust-holding capacities. Dust retaining ability of plant species in conditions of high, average and low dust conditions described.

I_2-CONVERGENCE AND I_2-CAUCHY DOUBLE SEQUENCES

In this article, we prove a decomposition theorem for L2-convergent double sequences and introduce the notions of L2-Cauchy and L2＊-Cauchy double sequence, and then study their certain properties. Finally, we introduce the notions of regularly （L2,L）- convergence and （L2, L）-Cauchy double sequence.

Formulaic Language in Spoken EFL Teaching

This paper discusses the role of formulaic language in the teaching of English as a foreign language,and in particular in the decoding of the spoken production of native speakers(NSs).

Characterization of Microstructural and Morphological Properties in As-deposited Ta/NiFe/IrMn/CoFe/Ta Multilayer System

Surface morphology and its relationship with microstructure in Ta/NiFe/IrMn/CoFe/Ta multilayer system deposited by pulsed DC magnetron sputtering have been investigated in dependence of Ta buffer and NiFe seed layer thicknesses using atomic force microscopy. The structural parameters such as grain size, dislocation density, texture and strain were calculated. For each surface, a self-affinity behavior with mean fractal dimensions in the range of 2.03-2.18 was found. Additionally, it was also observed that the surface of all samples has locally smooth textured surface structure in the short range. The texture aspect parameter and texture direction index have been obtained for isotropy/anisotropy surface texture. A significant relationship between the surface texture and the strength of the 〈111〉 texture in IrMn layer has been found. The analysis indicated that the surface roughness is strongly affected by the thicknesses of the NiFe seed and Ta buffer layers.

A recollement construction of Gorenstein derived categories

We first give an equivalence between the derived category of a locally finitely presented category and the derived category of contravariant functors from its finitely presented subcategory to the category of abelian groups, in the spirit of Krause＇s work [Math. Ann., 2012, 353： 765-781]. Then we provide a criterion for the existence of recollement of derived categories of functor categories, which shows that the recollement structure may be induced by a proper morphism defined in finitely presented subcategories. This criterion is then used to construct a recollement of derived category of Gorenstein injective modules over CM-finite 2-Gorenstein artin algebras.

Effect of Applied Current Density on Morphological and Structural Properties of Electrodeposited Fe-Cu Films

A detailed study has been carried out to investigate the effect of applied current density on the composition, crystallographic structure, grain size, and surface morphology of Fe-Cu films. X-ray diffraction （XRD） results show that the films consist of a mixture of face-centered cubic （fcc） Cu and body centered cubic （bcc） ^-Fe phases. The average crystalline size of both Fe and Cu particles decreases as the applied current density becomes more negative. Compositional analysis of Fe-Cu films indicates that the Fe content within the films increases with decreasing current density towards more negative values. Scanning electron microscopy （SEM） and atomic force microscopy （AFM） have been used to investigate the surface morphology of Fe-Cu films. It is observed that the surface morphology of the films changes from dendritic structure to a cauliflower structure as the applied current density becomes more negative. The surface roughness and grain size of the Fe-Cu films decrease with decreasing applied current density towards more negative values.

Optimization of Electrical Conductivity of SA-graphene Nanocomposites Using Response Surface Methodology

Synthesis and characterization of 4-{(E)-[(5-bromo-2-hydroxyphenyl)methylidene]amino}-N-carbamimidoylbenzene-1-sulfonamide(SA) and its composites with graphene(SA-GF) were performed. Compound SA and SA-GF were characterized by FTIR and 1H NMR. The GF dispersion in the composites was analyzed by means of scanning electron microscopy(SEM) for morphology. Thermal properties of SA and nanocomposites were investigated using differential thermal analysis(DTA) and thermogravimetric analysis(TGA). The optimum electrical conductivity of the new sulfonamide-based Schiff base was determined to be 1.78×10–5 S/cm at a frequency of 9923 Hz, an applied voltage of –19 V, a mass fraction of 9.38% for graphene loading using a central composite design in the response surface methodology. The significance of the selected parameters(frequency, voltage and GF amount) in the model was determined by the analysis of variance(ANOVA). The results showed that frequency and graphene loading represent important model terms and have considerable effects on the conductivity of SA.

Promising Effects of an Intervention: Young Children’s Literacy Gains and Changes in Their Home Literacy Activities from a Bilingual Family Literacy Program in Canada

The goal of this paper was to examine promising effects of a bilingual family literacy program: to track the changes of families’ literacy activities through a bilingual family literacy intervention, and to examine the children literacy gains in both Chinese and English across socioeconomic sub-groups. The intervention was an eight-week, two hours per week, literacy program in three Chinese communities in Toronto. Parents, with their children, participated in the program. The extremely high attendance rate provided evidence that families enjoyed the family literacy intervention and felt that the sessions were worthwhile. For their families’ literacy activities, the three sites followed the same trend: reaching the peak of activity at week four, slightly dropping down at weeks five and six, and then increasing to a second peak at week seven or week eight. Results also showed that across the three groups, children of mothers with lower education levels made fewer gains in their English expressive vocabularies and their Chinese expressive vocabularies, than children whose mothers had a higher level of education.