32 research outputs found

    Plant Functional Traits Are the Mediators in Regulating Effects of Abiotic Site Conditions on Aboveground Carbon Stock-Evidence From a 30 ha Tropical Forest Plot

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    Understanding the relative contribution of abiotic and biotic factors to the formation of ecosystem functioning across scales is vital to evaluate ecosystem services. Here, we elucidate the effects of abiotic site conditions (i.e., soil and topographic properties) and plant functional traits on variations of stand aboveground carbon (AGC) stock in an old-growth tropical montane rain forest. The response-effect framework in functional ecology is adopted in examining how plant functional traits respond to environmental changes and affect ecosystem functioning. We measured specific leaf area and wood density of 270 woody plant species and estimated stand AGC stocks in a 30-ha forest plot. The relationships among environmental factors (ENVIRONMENT), community-weighted means of functional traits (TRAITS) and stand AGC stocks across nested spatial scales were disentangled by structural equation modeling. The results showed that the stands composed of ‘acquisitive’ species (high specific leaf area and low wood density) had low AGC, whereas stands composed of ‘conservative’ species (low specific leaf area and high wood density) had high AGC. TRAITS responded to ENVIRONMENT and affected AGC directly. ENVIRONMENT had an indirect effect on AGC through its direct effect on TRAITS. TRAITS were more important than ENVIRONMENT in driving variations of AGC. The effects of TRAITS on AGC increased, while the effects of ENVIRONMENT on AGC decreased with the increase of spatial scales in the tropical montane rain forest. Our study suggests that plant functional traits are the mediators in regulating effects of abiotic site conditions on ecosystem functions

    Red Aesthetics, Intermediality and the Use of Posters in Chinese Cinema after 1949

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    Abstract: This article focuses on the aesthetic and affective techniques of saturation through which posters legitimated the Party-State in Mao’s China by closing the gap between everyday experience and political ideology. Propaganda posters were designed to put into practice the principle of unity, as conceptua- lised by Mao Zedong. The argument posits that while the “poster” is normally a printed edition of a painting or design intended for mass distribution in this way, the term may fairly be deployed to capture other cultural objects that function as “posters”, in that they provide public, political information that expresses or con- structs a political self in aesthetic form. This approach requires a metonymic understanding of a visual field in which cultural objects are interrelated and mutually reinforcing. The essay draws on recent in-depth interviews with poster artists of the 1960s and 1970s

    Microstructure, thermo-physical and mechanical properties of hypereutectic Al–10Ni-xSi alloys

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    The role of Si additions to the solidification process, microstructure evolution, thermo-physical and mechanical properties of hypereutectic Al–Ni alloy are systematically investigated. It reveals that the Si addition has a significant impact on the solidification process and microstructure of the alloy, and consequently the thermo-physical and mechanical properties. As the Si addition increases, the dendritic eutectic and blocky primary Si phases will be formed. It turns out that the thermal conductivity (TC) of the alloy degrades due to the precipitation of large and blocky Si phases, while the thermal expansion property is improved. The ultimate tensile strength (UTS) of the Al–10Ni-xSi alloys is improved initially, followed by degradation due to greater precipitation of the Si phase, the elongation (EI) is inevitably damaged. The alloy with 15 wt% Si exhibits the TC of 162 ± 3 W/(m·K) at 25 °C, CTE of 14.3 ± 0.1 × 10−6/K (@25–100 °C), UTS of 205 ± 5 MPa, EI of 3.9 ± 0.1% and Vickers hardness of 186 ± 4 HV. We successfully obtained an as-cast Al alloy with excellent thermo-physical and favorable mechanical properties, potentially for thermal management materials

    Exploring the life experiences of school‐aged children afflicted by tethered spinal cord syndrome: An interpretative qualitative study

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    Abstract Background Children affected by tethered cord syndrome (TCS) encounter multifaceted challenges encompassing educational, familial and social spheres, underscoring the significance of a holistic comprehension of their subjective emotional well‐being and life encounters. Nonetheless, healthcare professionals tend to prioritise the physical functionality of the afflicted individuals throughout the treatment and rehabilitation process, often neglecting the emotional experiences and requirements of these children as they transition into posthospitalization phases. Aim To advance the subjective experiences and perceptions of children with TCS upon reintegration into their families, educational institutions and wider societal contexts subsequent to their discharge from medical facilities. Methods The study was conducted at the Children's Hospital in Zhejiang. Twelve children aged 8–15 with TCS were included in the study. The research design used an interpretative qualitative approach, utilising semi‐structured interviews as the primary data collection method. Data analysis was performed using reflexive thematic analysis, facilitating a comprehensive exploration of emerging themes and patterns. Results Four major themes (and seven subthemes) were identified from the findings: (1) growing pains (a shameful secret, distance between ideal and reality); (2) inappropriate expressions of familial affection (knowing is not understanding, unspeakable guilt); (3) social estrangement (uncomfortable distinctions, familiar stranger) and (4) striving for independence and consistency. Conclusions Children affected by TCS exhibit internal sensitivity and challenges in self‐development, family dynamics and social interactions. They aspire to attain a future characterised by independence and freedom, akin to that of their typically developing peers. These findings can help health professionals, families and educators gain a deeper understanding of what it takes to be a child with TCS, and the findings can also serve as a platform for interventions that seek to promote self‐expression in these children so that they can experience life as a meaningful and positive process. Patient or Public Contribution This study received support from children with TCS and their guardians during data collection, as well as from the head nurse of the unit. Coresearchers also contributed to design, data collection, analysis and writing

    Electrochemical Evaluation of Stress Corrosion Cracking Susceptibility of Ti-6Al-3Nb-2Zr-1Mo Alloy Welded Joint in Simulated Deep-Sea Environment

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    Titanium alloys have high specific strength and excellent corrosion resistance and have been applied in deep-sea engineering fields. However, stress corrosion cracking may become one of the biggest threats to the service safety of a high-strength titanium alloy, as well as its weldment. In this work, stress corrosion cracking of a gas-tungsten-arc-welded Ti-6Al-3Nb-2Zr-1Mo (Ti6321) alloy influenced by the applied potentials in simulated deep-sea and shallow-sea environments was investigated by combining slow strain rate testing with electrochemical measurements. The results showed that the service environment and applied potential have a substantial effect on the stress corrosion cracking behavior of the Ti6321 welded joint. The Ti6321 welded joint exhibited higher stress corrosion susceptibility in a simulated deep-sea environment and at a strong polarization level owing to the diminishing protection of the passive film under passivation inhibition and the enhancement of the hydrogen effect. The fracture of a Ti6321 welded joint in the weld material could be attributed to the softening effect of the thick secondary α within the coarse-grained martensite. The electrochemical evaluation model of stress corrosion cracking susceptibility of a Ti6321 welded joint in a simulated marine environment was established by adding the criterion in the passivation region based on the literature model, and four potential regions corresponding to different stress corrosion cracking mechanisms were classified and discussed. Our study provides useful guidance for the deep-sea engineering applications of Ti6321 alloys and a rapid assessment method of stress corrosion risk

    Properties of red sandstone-limestone-cement ternary composites: Hydration mechanism, microstructure, and high-temperature damage

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    A significant amount of waste is generated during the sandstone mining process. This study explores the use of red sandstone waste as a supplementary cementitious material to address environmental concerns in cement production. The experimental methods include isothermal calorimetry, compressive strength testing, thermogravimetric analysis, X-ray diffraction, infrared spectroscopy, scanning electron microscopy, high-temperature damage testing (200, 600, and 900 °C), and mesoscopic image analysis. The experimental findings reveal the following: (1) Red sandstone powder enhanced cement hydration and optimized the samples' microstructure. (2) There is no significant difference in the effects of calcined and uncalcined red sandstone powders at 800 °C. (3) At 200 °C, the high-temperature damage of the samples containing red sandstone and limestone powders was reduced. This study is expected to positively impact the utilization of red sandstone waste and contribute to the reduction of carbon emissions in cement production

    Sustainable, High-Performance, and Biodegradable Plastics Made from Chitin

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    A high-performance biodegradable plastic was made from a chitin KOH/urea solution. The solution was transferred into a hydrogel by cross-linking using epichlorohydrin and ethanol immersion, and a chitin bioplastic was finally prepared by drying in a mold at 40 °C. The solution concentration positively impacts viscosity, crystallinity, and smoothness. A 4% chitin bioplastic exhibits high barrier properties, flame retardancy, high-temperature resistance, mechanical properties (tensile strength up to 107.1 MPa), and soil degradation properties. The chitin bioplastic can be completely degraded by microorganisms in 7 weeks. In addition, biosafety tests suggest that chitin is safe for cells and crops (wheat and mung beans). The chitin bioplastic was further applied to containers, straws, cups, and photoprotection, and it was found that the water resistance and transparency were comparable to those of commercial polypropylene plastics. Due to the excellent performance, safety, and sustainability of the chitin bioplastic, it is expected to become a good substitute for conventional fossil fuel-based plastics

    Sustainable, High-Performance, and Biodegradable Plastics Made from Chitin

    No full text
    A high-performance biodegradable plastic was made from a chitin KOH/urea solution. The solution was transferred into a hydrogel by cross-linking using epichlorohydrin and ethanol immersion, and a chitin bioplastic was finally prepared by drying in a mold at 40 °C. The solution concentration positively impacts viscosity, crystallinity, and smoothness. A 4% chitin bioplastic exhibits high barrier properties, flame retardancy, high-temperature resistance, mechanical properties (tensile strength up to 107.1 MPa), and soil degradation properties. The chitin bioplastic can be completely degraded by microorganisms in 7 weeks. In addition, biosafety tests suggest that chitin is safe for cells and crops (wheat and mung beans). The chitin bioplastic was further applied to containers, straws, cups, and photoprotection, and it was found that the water resistance and transparency were comparable to those of commercial polypropylene plastics. Due to the excellent performance, safety, and sustainability of the chitin bioplastic, it is expected to become a good substitute for conventional fossil fuel-based plastics
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