Search

To overcome the trade-off between the devisable microstructure and the excellent tensile ductility of bulk metallic glass composites (BMGCs), a novel ex-situ and in-situ hybrid strategy is successfully proposed to design a series of the work-hardenable ductile Ti-based multilayered BMGCs (ML-BMGCs). The as-prepared ML-BMGCs, consisting of α-phases, β-phases and amorphous phases, exhibit a controllable multilayered structure of the Ti layers and the amorphous layers with alternative distribution. The size and volume fraction of the crystalline phases are tuned by Nb microalloying. It is found that the ML-BMGCs possess a suitable size and volume fraction of the crystalline phases when Nb microalloying content are 5% (at.) or 8% (at.), and they obtain an optimum combination of the specific strength of 243 MPa g kg-1 or 216 MPa g kg−1, and tensile plasticity of 4.33%±0.1% or 5.10%±0.1%. The deformation mechanism of the as-prepared ML-BMGCs during tension is also revealed. The ex-situ Ti layers and in-situ dendrites together effectively serve as absorbers to suppress the propagation of shear bands and multiply shear bands. And the deformation of ex-situ α-Ti phases by dislocation slip and the transformation from in-situ metastable β-Ti phase to orthorhombic α"-Ti during tension impart significant work-hardening capability to the ML-BMGCs. The present study provides a guidance of developing novel high-performance BMGCs with a controllable microstructure. [ABSTRACT FROM AUTHOR]

The aging of the population is becoming an increasingly severe issue. How can we develop caring services for the elderly and promote healthy aging? Investigating care preferences is an essential step in addressing this issue. A self-designed questionnaire was employed to collect data online. The impact of personal circumstances on care preferences was ascertained using the chi-squared test and multivariate logistic regression. An optimal parameters-based geographical detector was introduced to examine the influence of spatially heterogeneous regional factors on care preferences. The online survey produced 1178 valid questionnaires. Home-based elderly care was the preference of 91.9% of respondents, followed by community-based care and medical-nursing care; institutional care was the least preferred alternative. Age, education, living style, and health states of the elderly significantly influenced the preferred care option. When compared to home-based elderly care, older respondents (odds ratio [OR] = 3.776) preferred institutional care, highly educated respondents preferred community-based care (higher education: OR = 5.206; secondary education: OR = 3.049) and medical-nursing care (higher education: OR = 4.484); the elderly living alone (OR = 0.101) excluded institutional care, and the elderly living with their children excluded non-family care method of institutional care (OR = 0.031) and medical-nursing care (OR = 0.391). Regional medical resources and old-age security significantly affect the preferences of the elderly (q-statistic [q] > 0.5); local economic development significantly affects community-based care (q> 0.6); the availability of financial subsidies significantly affects home-based care and medical-nursing care (q> 0.9); and the availability of institutional resources significantly affects the preference for institutional care (q> 0.8). We found that it is necessary to improve the level of medical care given by non-family members and care facilities, vigorously develop new methods of elderly care, promote humanistic care in non-family care settings, and increase available regional medical resources, financial subsidies, and social security. This study integrates economic and social perspectives to examine and analyze retirement willingness, thereby broadening the scope of social surveys and research methodologies, and offering valuable insights with potential directive implications.

Up to now, the composition design in the field of Ti-based in-situdendrite reinforced bulk metallic glass composites (BMGCs) has been a great challenge. In this work, a simple but effective strategy is proposed to tailor the dendrite composition and volume fraction by using conventional Titanium alloy Ti–6Al–4V, and a series of in-situdendrite reinforced BMGCs (Z1-Z4) are prepared based on it. The dendrite volume fraction can be adjusted by changing the proportion of the Titanium alloy Ti–6Al–4V, while the compositions of the dendrites are highly correlated with Ti–6Al–4V. In these alloys, with the increase of the mass percent of the added Titanium alloy Ti–6Al–4V, the volume fraction of the dendrite phase increases monotonically from Z1 to Z4 alloy. Z1 alloy behaves like a BMG with a high yield strength and limited plasticity due to its small dendrite size. Z2-Z4 alloys show excellent plasticity and significant work-hardening ability, because the dendrite size is appropriate and the dendrites undergo stress-induced martensite transformation during compression. From Z2 to Z4 alloy, with the increase of dendrite volume fraction from 56% to 78%, the yield strength does not decrease, which is due to the gradually enhanced stability of the dendrites. This composition design strategy is effective and universal, which can provide a new perspective for the composition design and development of TiZr-based in-situdendrite reinforced BMGCs.