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In this paper, based on distributed transfer function method (DTFM), the closed-form analytical solutions for vibrations of Euler–Bernoulli beam and frame structures with arbitrary number of cracks are studied. First, generalized DTFM is employed to characterize the dynamical model for a single cracked beam and its analytical solutions for eigenvalue problem and frequency response are obtained. Then, a new DTFM cracked element that encapsulates one crack of arbitrary location inside the beam is proposed. Using the DTFM cracked element and global dynamic stiffness matrix assembly technique, damaged frame structures of arbitrary form can be modeled for vibration analysis. Previous analytical methods only addressed low-frequency vibration of simple cracked beam structures, the proposed method can yield analytical solutions in the medium- and high-frequency regions, which is critical for the small crack detection in complex frames. Lastly, three numerical examples are given to illustrate the correctness and effectiveness of the DTFM in analyzing natural frequencies, modal shapes and frequency responses for cracked structures. By comparing with the Finite Element Method (FEM) and benchmarks from literatures, we proved that the DTFM has better performances in terms of accuracy and efficiency. [ABSTRACT FROM AUTHOR]

The flow behavior of alumina-forming austenitic steel was studied using axisymmetric hot compression on a Gleeble-3500 thermomechanical simulator. The temperature range was 900-1200 °C, and strain rate range was 0.1-100 s−1. The microstructures after deformation were investigated by electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM). The deformation temperature and strain rate have a significant influence on the flow stress. A constitutive equation, describing the flow stress as a function of deformation temperature and strain rate, has been developed, and the hot deformation activation energy was confirmed as 579.4 kJ/mol. Dynamic recrystallization (DRX) progress had been finished after increasing hot deformation temperature to 1100 °C at a strain rate of 100 s−1, leading to the obvious transformation from low-angle grain boundaries (LAGBs) to high-angle grain boundaries (HAGBs), and a relatively stable fraction of HAGBs was obtained. At a strain rate of 100 s−1, the β-fiber at {011}<211> transited to {112}<111> (C orientation), and finally a recrystallized orientation of {100}<100> formed after absolute DRX. GDRX is the primary DRX mechanism, but DDRX mechanism is dominant with the increase in deformation temperature at a high strain rate of 100 s−1. [ABSTRACT FROM AUTHOR]

The strengthening and fracture mechanisms of Fe–20Ni–14Cr–2Cu alumina-forming austenitic (AFA) steel during creeping at 973 K/130 MPa were systematically investigated. Microstructural observations show that during creep after priorly aged at 973 K for different times, three main types of precipitates, i.e., Laves, B2-NiAl, and σ phases, are found in Fe–20Ni–14Cr–2Cu AFA steel. Laves and B2-NiAl phases dispersed in austenitic matrix contribute to the creep properties of AFA steel due to their small particle sizes, while the coarsening of hard-brittle σ phase in δ-ferrite region seems to be the main reason for creep failure. The Fe–20Ni–14Cr–2Cu AFA steel priorly aged for 1000 h possesses excellent creep property at 973 K with the minimum steady-state creep rate of 7.64 × 10–6 s−1 and the longest creep life of 329.5 h. The contribution of Laves and B2-NiAl phases to creep strength of AFA steel at 973 K/130 MPa after priorly aged for 1000 h is 261.2 MPa. [ABSTRACT FROM AUTHOR]

Abstract: A series of branched polyesteramides (PEAs) were synthesized from adipic acid, hexamethylene diamine, 1,4-butanediol and caprolactam by melt polycondensation using glycerol as branching agent. The obtained copolymers, with glycerol contents of 0–0.9wt% (LPEA–PEAg10) were characterized by FTIR, 1H NMR, DSC and viscometry. The FTIR and 1H NMR spectra demonstrated the formation of ester and amide bonds. DSC data indicated the melting and crystallization temperatures decrease with increasing glycerol content. Water absorption experiments suggested no distinct difference in hydrophilicity between these branched PEAs. Alkaline hydrolysis of PEA films was conducted in pH 11.0 NaOH solution at 37, 50 or 80°C, respectively. The tests showed that PEAs degraded quickly in alkali and the degradation rate increased with the medium temperature. PEA films underwent slow degradation in pH 7.0 phosphate buffer saline (PBS) at 37°C. The degradation was monitored by weight loss, viscometry, DSC, FTIR and 1H NMR analysis. The results showed that branching substantially enhanced the degradation. Structural analyses revealed that ester/amide ratio decreased with incubation time, suggesting the degradation occurs mainly on the ester bonds. During the degradation, the melt temperature and crystallinity of the copolymers increased slightly with the degradation time. [Copyright &y& Elsevier]

G115 martensitic steel is anticipated to be one of the preferred candidate materials in ultra-super critical (USC) power plants with steam temperatures above 650°C. Microstructure evolutions and mechanical properties of G115 martensitic steel after applying various heat treatment processes were investigated. The results demonstrate that the main precipitate in G115 martensitic steel after applying various heat treatment processes is M 23 C 6 phase with Cr enrichment. The time required for M 23 C 6 phase precipitation decreases with increasing secondary normalizing temperature and the extension in holding time according to its precipitation-temperature-time (PTT) curves. Volume fraction of M 23 C 6 phase increases with increasing secondary normalizing temperature and holding time, which strengthens the inhibitory effect of precipitates on dislocations recovery and laths growth. Therefore, G115 martensitic steel can obtain the best mechanical properties after applying the highest secondary normalizing temperature and the longest holding time. In the current work, the excellent strength of G115 martensitic steel mainly derives from precipitates strengthening and laths strengthening. • Volume fraction of M 23 C 6 phases increases with increasing secondary normalizing temperature and the extension in holding time. • Dislocations recovery and laths growth are inhibited by M 23 C 6 phases. • The strongest factor increasing G115 steel's yield strength is lath strengthening. [ABSTRACT FROM AUTHOR]

Alumina-forming austenitic (AFA) steel, a promising candidate for use in high-temperature components of ultra-supercritical power plants, has high creep strengths and outstanding high-temperature corrosion resistance. The effects of microstructural evolution on the mechanical properties of Fe-20Ni-14Cr-3Al alumina-forming austenitic (3Al-AFA) steel with micro-cold deformation were investigated by multiple characterization methods, and the micro-cold deformation process was analyzed by conducting compression experiments. Tensile properties and hardness were also examined. The results show that the reduction of deformation has significant influences on the increase in the density of dislocation, the reduction of grain size, and the distribution of precipitates, which play an essential role in the enhancement of mechanical properties. As the reduction of deformation increases, the density of dislocations rises, the fragmentation of grains results in a reduction of grain size, and the distribution of precipitates at the grain boundaries gradually increases, which causes a rise in strength and a decrease in elongation. Since the elastic deformation range expands with an increase in deformation before the strain reaches 5 ​% of the CR0 sample in the compression test, the variation in the average grain aspect ratio between a reduction of 2 ​% and 6 ​% is relatively small. It contributes more to hardness and strength when the grain aspect ratio is high. [ABSTRACT FROM AUTHOR]

• The mathematical model of the reachable domain of the contingency return trajectories. • Reachable domain calculation method of the contingency return trajectories based on interval analysis. • Parameter characteristic analysis of reachable domain. The investigation on reachable domain based on interval analysis is performed, which is aimed for the contingency return trajectories during the circumlunar flight stage in manned lunar landing engineering. First, the issue of contingency return trajectory, which adopts a non-coplanar maneuver during the circumlunar flight phase, is expounded upon. The mathematical model of the reachable domain of contingency return trajectories is established. Second, the contingency return trajectory is designed. An improved interval branch and bound algorithm is introduced and a reachable domain calculation method of the contingency return trajectories is proposed. Third, in numerical simulations, by comparing the reachable domain obtained by the traditional brute force method, the accuracy of the method presented in this paper is verified. It also indicates that this method has a higher calculation efficiency. Finally, numerous simulations are conducted to discuss the parameter characteristic of reachable domain by adopting this method. The study conclusions can serve as an important reference for the selection and decision of contingency return trajectory plans in the future manned lunar landing engineering. [ABSTRACT FROM AUTHOR]

Microstructural evolutions during hot deformation and annealing of alumina-forming austenitic (AFA) steel were investigated using electron backscatter diffraction (EBSD). Tensile properties of deformed and as-received AFA steels were also tested. The yield strength and ultimate tensile stress of deformed AFA steel increase gradually with the increase in rolling reduction, while the fracture elongation decreases rapidly. Specifically, after hot-rolling with the reduction of 40%, the yield strength of the annealed specimen is high to 773.2 MPa, and the fracture elongation of this sample is about 43.6%. The excellent mechanical properties can be attributed to the smaller average grain, larger Schmid factor and coincident site lattice (CSL) boundaries. Such a rapid decline of the elongation of AFA steel occurs due to increasing low angle grain boundaries (LAGB, <15°), the crystal defects and the degree of work hardening with the increase in rolling deformation. An approachable strategy to improve the tensile properties of annealed samples is to effectively hinder the dislocation motion during annealing at 700 °C when few LAGBs could transform into high angle grain boundaries (HAGB, >15°). [ABSTRACT FROM AUTHOR]

Abstract Microstructural evolution of modified 2.5Al alumina-forming austenitic steel after isothermal aging at 973 K was investigated by scanning electron microscope (SEM), and X-ray diffraction (XRD). Tensile and vicker's hardness tests were also carried out to study mechanical properties during isothermal aging. The average particle diameter of precipitates was statistically measured and the kinetic model was employed to describe the coarsening of precipitates. The results show that the precipitation sequence of Laves and NiAl phases was related to aging time, and precipitated after 20 h and 100 h in this work, respectively. The average particle diameter of precipitates continuously increased with aging time. And the coarsening rate of the precipitates decreased at 1000 h due to the exhaustion of Nb atoms in matrix. The precipitation of NiAl and Laves phases plays an important role in mechanical properties. The hardness and the work hardening rate continuously increased. In contrast, the elongation gradually decreased. The above results indicated that the effect of aging strengthening. The room-temperature yield strength firstly sluggish increased and then gradually decreased, finally increased significantly due to the increase in σ gb , the decrease in σ dis and σ ss , and the change in σ ppt. [ABSTRACT FROM AUTHOR]

Co‐based superalloys with the advantages of high melting point, high‐temperature mechanical properties, and large resistance under hot corrosion environment are potential candidates for turbine engine components. The isothermal oxidation behavior of Co–Ni–Al‐based superalloy with the addition of Mo and Cr in dry air at 1073 and 1173 K was investigated. The results showed that similar three‐layer oxides structures were composed of Co‐containing oxides, complex oxides rich in Co and Al, and Al2O3 layer formed on both 2Mo and 2Cr Co–Ni–Al‐based superalloys, and Mo‐containing oxides also existed in the subsurface. The oxides in the outer layer transferred from Co3O4 to denser CoO with the increase in temperature. The γ'‐free zone formed under the Al2O3 layer due to the depletion of Al. Co–Ni–Al‐based superalloys need to conquer a large energy barrier at an earlier stage of oxidation and exhibit good oxidation resistance at 1073 K. [ABSTRACT FROM AUTHOR]

A novel Co 3 O 4 @C composite with a three-dimensional (3D) interconnected network morphology was successfully fabricated by anchoring cobalt oxide nanocrystals onto porous carbon originating from starch hydrogels via freeze drying, precarbonization and thermal treatment in an aqueous system. Benefiting from unique structural features, the optimized electrode delivers an excellent capacitance of 1314.0 F g−1 (1 A g−1) and outstanding durability in terms of capacity preservation (93.5% over 10,000 cycles). In addition, an asymmetric supercapacitor consisting of DF-2 and active carbon exhibits an energy density of 149.1 Wh⋅kg−1 at 800 W kg−1 while maintaining great stability. The observed excellent performance is attributed to the unique 3D network, good conductivity and high surface-to-volumetric ratio of the carbon skeleton derived from the starch gel, which has wide scope for applications. [ABSTRACT FROM AUTHOR]

The microstructural evolutions of the alumina-forming austenitic (AFA) steel subjected to different cold-rolled reductions and then aging at 700 °C were investigated by multiple characterization methods, and the mechanical properties were also examined. The results show that the increased dislocations (especially, edge dislocations) after cold rolling can effectively enhance the volume fraction and refine the particle size of precipitates during initial aging and subsequently accelerate the coarsening rate of precipitates in the AFA steel, resulting in a high coarsening exponent. The coarsening rate of B2–NiAl phase is higher than that of Laves phase. Excellent mechanical properties with a combination of yield strength (1152 ± 32 MPa) and elongation (44.8 ± 4.1%) of cold rolled AFA steel after aging for 2 h can be obtained due to co-strengthening contribution derived from dislocations and precipitates. With the duration of aging, the dislocation strengthening constantly decreases, the effect of precipitation strengthening is contrarily larger than that of dislocations. • The deformed dislocations evolved into high-density dislocation networks with the increase in cold-rolled reductions. • A large number of nano-scaled Laves phase and B2–NiAl phase precipitated around the dislocations during aging. • The coarsening rate of B2–NiAl phase was larger than that of Laves phase in the AFA steel. • The strengthening contribution from precipitates was larger than that from dislocations with the increase in aging time. [ABSTRACT FROM AUTHOR]

Alumina-forming austenitic (AFA) steel exhibits excellent high-temperature properties and has attracted significant attention in thermal power generation industry. Microstructure evolutions and yield strengths of 20Ni-AFA steel during isothermal aging are investigated. The results show that five types of phases are found in 20Ni-AFA steel during isothermal ageing: NbC, L1 2 -Ni 3 Al, M 23 C 6 , B2-NiAl and Laves phases. Addition of Cu causes precipitation of L1 2 -Ni 3 Al phase in 20Ni-AFA steel at the early stage of isothermal aging. L1 2 -Ni 3 Al phase grows and gradually transforms into B2-NiAl phase which possesses a more stable structure with the extension in isothermal aging time. The transformation leads to yield strengths of 20Ni-AFA steel to decrease anomalously during 24-120 h isothermal aging. Yield strengths of 20Ni-AFA steel increase again as isothermal aging time continues to increase. [ABSTRACT FROM AUTHOR]

Hollow flower-type mesoporous silica microspheres (designated as HFMSs) with tunable smaller pores and lager pores in the shell have been successfully synthesized via a structural difference-based selective etching treatment of solid silica core/mesoporous silica shell (sSiO@mSiO) microspheres. The structure of sSiO@mSiO microspheres could evolve to rattle-type, hollow structure, flower-type structure, and peanut-type structure from core/shell structure just by varying the etching agent from NaCO solution to ammonia solution and adjusting the concentration of etching agent, respectively. Transmission electron microscopy, scanning electron microscopy, and nitrogen adsorption-desorption analysis are applied to characterize the synthesized samples. The mechanism of such a structural evolution is explained in this work. [ABSTRACT FROM AUTHOR]

The stabilization of polyesteramide (PEA) was studied by TGA, melt index and intrinsic viscosity. Primary antioxidant A1010 (0.6 wt.%) combined with 0.2 wt.% of hydroperoxide decomposer A168 is effective in stabilizing PEA; but the holding life of PEA in the extruder barrel is only 30 min, and the antioxidants are completely consumed when it is extruded four times. Fillers including heavy calcium carbonate (HCC), tricalcium phosphate (TCP) and talc affect both the thermal stability and mechanical properties of the resultant composites, which are discussed in detail. The Turcsanyi model can best describe the composition dependence of tensile strength of the HCC and talc filled PEA, and the Sato-Furukawa can best predict the Young''s modulus of HCC filled PEA, but is poor for the talc-filled material [Copyright &y& Elsevier]

The aim of the present study was to analyze the expression levels of angiopoietin-like 4 (ANGPTL4) in breast cancer to investigate the association between ANGPTL4 and breast cancer. Immunohistochemistry was performed on formalin-fixed paraffin-embedded tissues, including 205 invasive ductal carcinoma (IDC) of no special type, 40 normal breast, 40 atypical ductal hyperplasia (ADH) and 40 ductal carcinomas in situ (DCIS) tissues. The non-parametric Kruskal-Wallis test was used to evaluate the differential expression of ANGPTL4 and clinicopathological parameters in breast cancer. Kaplan-Meier analysis and Cox regression analysis were used to evaluate the association between the expression levels of ANGPTL4 and the prognosis of breast cancer. The results revealed that ANGPTL4 expression was higher in IDC (63.4%; 130/205) compared with in normal breast tissues (17.5%; 7/40), ADH (30%; 12/40) and DCIS (37.5%; 15/40). The clinical significance of ANGPTL4 expression was analyzed in a total of 205 IDC tissues, and high expression levels of ANGPTL4 were positively associated with pathological stage (P<0.001), tumor size (P<0.001), histological grade (P<0.001), lymph node metastasis (P<0.001), distant metastasis (P<0.001) and local recurrence (P<0.001). Kaplan-Meier analysis revealed that patients with high ANGPTL4 expression had a shorter overall survival (OS; P<0.001) and disease-free survival (DFS; P<0.001) compared with patients with low ANGPTL4 expression. Multivariate Cox regression analysis revealed that ANGPTL4 was an independent prognostic factor for breast cancer OS (P=0.034) and DFS (P=0.011). The results of the present study demonstrated that ANGPLT4 was associated with malignant progression and poor prognosis of breast cancer, suggesting that ANGPLT4 may be a novel therapeutic target for breast cancer. [ABSTRACT FROM AUTHOR]

Microstructural evolutions of the 4Al alumina-forming austenitic steel after cold rolling with different reductions from 5% to 30% and then annealing were investigated using electron backscattering diffraction (EBSD), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile properties and hardness were also measured. The results show that the average grain size gradually decreases with an increase in the cold-rolling reduction. The low angle grain boundaries (LAGBs) are dominant in the cold-rolled samples, but high angle grain boundaries (HAGBs) form in the annealed samples, indicating that the grains are refined under the action of dislocations. During cold rolling, high-density dislocations are initially introduced in the samples, which contributes to a large number of dislocations remaining after annealing. With the sustaining increase in cold-rolled deformation, the samples exhibit more excellent tensile strength and hardness due to the decrease in grain size and increase in dislocation density, especially for the samples subjected to 30% cold-rolling reduction. The contribution of dislocations on yield strength is more than 60%. [ABSTRACT FROM AUTHOR]

While solid polymer electrolytes are poised to be the key component of next-generation solid-state batteries, the low Li+ transference number of the polymer electrolytes limits their practical applications. Here, porous boron-containing covalent organic frameworks with different surface areas were synthesized and employed as functional additives for enhancing the Li+ transference number of the polymer electrolytes. The boron-containing frameworks enable strong adsorption of the anions of the lithium salt, leading to a significantly enhanced Li+ transference number of the polymer electrolyte containing COF additives. It is observed that solid-state cells assembled with the COF-containing polymer electrolytes exhibited remarkably decreased overpotentials and enhanced rate performances, which opens up new ways to apply porous organics in next-generation solid-state batteries. [ABSTRACT FROM AUTHOR]

Microstructure evolutions of Ni-Ti-Nb-Al alloys with different Al addition subjected to casting and solution-treatment have been investigated using scanning electron microscope (SEM) and X-ray diffraction (XRD). The alloys were prepared by vacuum arc melting, and then solution-treated at 1273 K for 20 h. The alloys with 3 at.% Al addition and Al-free show a microstructure consisting by B2-NiTi matrix phase and soft β-Nb precipitate. With increasing Al addition, Al 3 Ti phase firstly forms, and Ni 3 Al only can be found in the 7 at.% Al alloy. The addition of Al promotes the diffusion of Nb during casting and solution-treatment, resulting in the refinement of β-Nb precipitate. For the as-cast alloys, the macro-hardness values increase with the increase in Al content and slightly increase after solution-treatment. [ABSTRACT FROM AUTHOR]

The discovery of ordered γ' phase in Co-Al-W based superalloys opens up a pathway for the development of novel Cobalt-based superalloys. γ' phase from binary compounds was calculated by first-principles methods, and the third alloying elements were also considered to stabilize and strengthen γ' phase, the ordered γ' phase with higher stability and more excellent mechanical properties was confirmed herein in novel Cobalt-based superalloys. The formation energies and lattice parameters of Co-X (X = Al, Mo, Nb, Ta, Ti, V, W) and Co-Ti-Z (Z = Al, V, Cr, Mo, Ta, W) were calculated, the results show that X = Ti and Z = Mo are better choices. The doping of Mo can stabilize the ordered L1 2 -γ' phase and improve the mechanical properties of the γ' phase when Mo occupies Ti sites. The occupying preference of alloying elements in Co 3 Ti lattice is analyzed, Al and Cr prefer to occupy Co sites in L1 2 -Co 3 Ti lattice, while V, Mo, Ta and W prefer to occupy Ti sites. The as-cast microstructure of the five superalloys is typical dendrite with γ/γ' two-phase region in the inter-dendrite. Besides, segregation phenomenon can be observed in the as-cast microstructure of the superalloys, and Ti prefers to enriched in the inter-dendrite, while other elements tend to be distributed in the dendritic arms. • The formation energy of different structure in Co-X binary system was calculated, and Co 3 Ti is the most strengthening γ' phase. • Al and Cr prefer to occupy the Co sites, while V, Mo, Ta and W tend to occupy the Ti sites in L1 2 -Co 3 Ti lattice. • Except for Al, other alloying elements in current work tend to occupy the Ti sites in D0 19 -Co 3 Ti lattice. • Co-Ti-Mo based superalloys have typical dendrite structure in as-cast state with occurrence of elements segregation. [ABSTRACT FROM AUTHOR]

High temperature tensile behaviors of two W-free Co-Ni-Al-based γ'-strengthened superalloys at 773 K ~ 1073 K were investigated. The tensile strength and elongation of two superalloys decrease with increasing temperature. The fracture mechanism changes from dimple fracture to brittle fracture. A detailed observation of the fracture shows that the intermediate temperature embrittlement caused by decohesion of slip plane plays a significant role in reducing high temperature performance. Both superalloys reach to peak yield strength at 923 K. Occurance of yield strength anomaly (YSA) is derived from the synergistic effects of dislocation locking strengthening and dynamic strain aging strengthening. Dislocation cross-slipping hinders the dislocation migration. Dislocations' unpinning to the moving solutes increases the yield strength at 723 K ~ 973 K. A rapid weakening of grain boundaries strength decreases the yield strength at 1073 K. • Yield strength anomaly was synergistically affected by dislocation locking and dynamic strain aging. • Intergranular fracture was caused by the decrease of grain / twin boundaries strength and decohesion of slip plane. • The yield strength increased with increasing dislocation locks' densities while the ductility decreased due to ITB effect. [ABSTRACT FROM AUTHOR]

Alumina-forming austenitic (AFA) steel with great application potential in components of power plants has been developed due to its excellent high-temperature properties and corrosion resistance. Evolution of precipitates was characterized using multiple methods, and its effect on mechanical properties of Fe–20Ni–14Cr–3Al alumina-forming austenitic (3Al-AFA) steel after isothermal-aging at 973K was also assessed. The results showed that the particle size and volume fraction of precipitates (mainly Laves, B2–NiAl and σ phase) increase with the duration of isothermal-aging. The volume fraction of δ-ferrite increases significantly also with the extension of isothermal-aging time, which is regarded as a harmful factor to mechanical properties of AFA steel. The strength and Vickers hardness firstly increase and then decrease with the extension of isothermal-aging time, which is inversely proportional to the elongation at the initial stage of isothermal-aging. Both strength and elongation decrease with the isothermal-aging time between 500 h and 1000 h due to the δ-ferrite and coarse precipitates therein. Cr element firstly prone to segregate and diffuse in δ-ferrite, which promotes the diffusions of other alloying elements from matrix to δ-ferrite, resulting in the coarsening of precipitates in δ-ferrite region. The highest yield strength (1171 MPa) is achieved when the size of Laves and B2–NiAl precipitates in matrix is about 100–150 nm. [ABSTRACT FROM AUTHOR]

The microstructural evolution of the alumina-forming austenitic (AFA) steel subjected to different cold rolling reductions during creep test at 973 K and 120 MPa was investigated by multiple characterization methods, and the high temperature creep property was also examined. It was found that the creep property of CR10 sample is not satisfactory although cold rolling truly improved it. The creep cavities were observed to nucleate at the interface between B2–NiAl phase and σ phase in the δ-ferrite. The serious coarsening of B2–NiAl phase and σ phase in δ-ferrite was considered as the main factors for the decline of creep property. In addition, the results also suggested that the shape of B2–NiAl phase changes from round to plate with increasing creep time, which resulted from the increase of elastic strain energy. Simultaneously, it was noteworthy that σ phase always grows adjacent to plate-shape B2–NiAl phase, which indicates the coarsening of σ phase is inseparable from that of B2–NiAl phase. [ABSTRACT FROM AUTHOR]

Purpose To examine the level of and factors influencing expectations regarding aging (ERA) among older Chinese adults, and to determine whether leisure-time exercise mediates the association between ERA and functional health status. Methods A population-based, cross-sectional design was utilized in this study. A total of 550 participants completed the face-to-face interview via a questionnaire addressing ERA, physical health conditions, personality and psychological factors, leisure-time exercise, and functional health status. Results More than four fifths of the older adults felt that having more aches and pains (88.0%), lower levels of energy (82.7%), and being forgetful (82.5%) were an accepted part of aging, and 74.7% of participants reported it to be true that 'being depressed is normal for older adults.' The regression model showed that depression and self-mastery were factors that influence ERA among older Chinese adults (β = −0.26, p = .000; β = 0.15, p = .000). The Instrument Activity of Daily Life and World Health Organization Disability Assessment scores were not associated with ERA. Leisure-time exercise mediated the relationship between ERA and functional health status. Conclusions Older adults generally consider body function decline to be an expected part of aging. Personality and psychological factors, rather than physical health conditions, were the factors that were considered to be most influential on ERA among Chinese older adults. These findings suggest that community interventions taking into account leisure-time exercise could be influential in improving the ERA and functional health status of older adults. Clinical Relevance For community nurses and other primary care providers, the findings of the present study may facilitate the subsequent design of community-based participatory intervention to improve ERA, as well as potentially improve the functional health status of older adults. [ABSTRACT FROM AUTHOR]

Alumina-forming austenitic (AFA) steel with high creep strengths and excellent high-temperature corrosion resistance has a promising potential being applied to high-temperature components of ultra-supercritical power plants. The effect of Cu addition on microstructure and tensile properties of Fe–20Ni–14Cr alumina-forming austenitic (AFA) steel after aging at 973 K has been investigated using various morphology microscopic characterizations and tensile test. The obtained results show that Cu addition promotes the formation of nanoscale B2–NiAl phase in AFA steel, which further increases the tensile strength and ductility of the materials to 1464 MPa and ductility of 23.81%, respectively. By occupying Fe and Ni atoms locations in the nanoscale B2–NiAl phase of AFA steel, Cu atoms reduce the chemical driving force of the nanoscale B2–NiAl phase growth. Such phenomenon results in reduction of the corresponding phase formation energy, and thus improves the phase stability. The occupancy behavior of Cu and its effect on the particle size in nanoscale B2–NiAl phase were quantitatively evaluated by first-principle calculation. The present research work proves that the precipitation strengthening plays a dominant role in the yield strength improvement of AFA steel. • Cu atoms occupy the positions of Fe and Ni atoms preferentially during solid solution into the B2-NiAl phase. • Cu addition leads to an excellent combination of tensile strength and ductility of 4Al-2Cu-AFA steel. • The partitioning of Cu into B2-NiAl phase increases yield strength of 4Al-2Cu-AFA steel. [ABSTRACT FROM AUTHOR]

Abstract: A steric hindrance colloidal microspheres approach (SHCMA) has been developed for the fabrication of ordered Pt or Pt/Ag nanoparticles composite interconnected hollow hemispheres via colloidal lithography and physical vapor deposition. Monolayer ordered silica or silica/Ag nanoparticles composite microspheres partly embedded into the polydimethylsiloxane (PDMS) were used as template, and Pt was sputtered on it. Due to the PDMS stamp functionalized as a steric hindrance substrate, which guaranteed that the ordered silica or silica/Ag nanoparticles composite microspheres were only coated with Pt film on the sides that exposed in air. After removing the template particles, large area ordered interconnected Pt or Pt/Ag nanoparticles composite hollow hemispheres were generated. The fabricated Pt hollow hemispheres have flat bottoms and are flexible and robust enough to be easily folded. In addition to successfully solving the challenge about ordered structure construction of the hollow Pt or Pt/Ag nanoparticles composite hemispheres here, we also could finely control the wall thickness of these hemispheres easily by changing the sputtering time or current. [Copyright &y& Elsevier]

In this paper, a new kind of aliphatic biodegradable polyesteramide copolymers P(CL/AU)x/y based on &epsiv;-caprolactone and 11-aminoundecanoic acid were synthesized by the melt polycondensation method. Hydrolytic degradation behavior of P(CL/AU) copolymers were studied by using FTIR, 1H-NMR and DSC. Chemical compositions, macromolecular weight, thickness of the test sample, and pH of the degradation medium have great effect on degradation rate. The degradation rate decreased with increase in aminoundecanoic acid content, macromolecular weight, and thickness of the test samples, but increased with incubation temperature and pH of the degradation medium. The degradation mechanism was studied according to the mathematical model developed by professor Go¨pferich. [Copyright &y& Elsevier]

The microstructural evolution and creep behavior of aged 2.5Al alumina-forming austenitic (AFA) steel were investigated by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The average particle size, volume fraction of precipitates and dislocation density were statistically measured to evaluate the contribution of precipitation strengthening and dislocation strengthening to the creep strength. The results suggested that the phase boundaries between Laves and B2–NiAl were incoherent interface, and both B2–NiAl and Laves were main strengthened phases in aged 2.5Al-AFA steel. The creep results indicated that the sample aged for 1000 h exhibited creep capability with the smallest creep strain and steady-state creep rate. The isothermal aging treatment can be considered as an effective way to improve the creep strength of 2.5Al-AFA steel. [ABSTRACT FROM AUTHOR]

The effects of the relative content of Al and Ti, and the addition of 2 at.% Cr or Mo to partly substitute Co on the microstructure and mechanical properties of Co–Ni–Al–Ti superalloy were investigated. The microstructures of five as-cast superalloys showed that γ'-(Co,Ni) 3 (Al,Ti) precipitates segregated on γ-Co matrix and exhibited dendritic morphology. After aging, nano-sized γ'-(Co,Ni) 3 (Al,Ti) precipitates uniformly precipitated on γ-Co matrix. Ni, Al, Ti and Mo atoms partitioned preferentially to γ′ phase, while Co and Cr atoms partitioned preferentially to γ matrix phase. The increase in Ti content, and the addition of 2 at.% Cr or Mo all increased the volume fraction and the average size of γ′ phase. The lattice misfit increased with the concentration of Ti and the addition of 2 at.% Mo, but decreased with the addition of 2 at.% Cr. With increasing aging time, the size of γ′ phase and lattice misfit increased, while γ′ phase volume fraction increased firstly, and then decreased after reaching the maximum at 100 h. The lattice misfit plays a key role on vicker's hardness in the time of 20 h–100 h aging, while γ′ phase volume fraction plays a decisive role in vicker's hardness after 100 h aging. [ABSTRACT FROM AUTHOR]