•In-situ treatment of site soil using DJM technique and SPC binder is presented.•Solidified/stabilized soil exhibits satisfactory long-term performance after 326 days.•Leached concentrations of heavy ...metals and COD in soil are considerably reduced.•Soil resistance and acid neutralization capacity are remarkably improved.•In-situ field trial coincides well with lab study in strength/leaching properties.
In this study, in-situ treatment using dry jet mixing construction method and SPC (single superphosphate and calcium oxide) new binder are used to solidify/stabilize a heavy metal contaminated site soil with relatively high content of organic matters. Time-dependent field performance of the soils at 41 and 326 days after treatment is evaluated, which includes electrical conductivity (EC), leachability of heavy metals and chemical oxygen demand (COD), soil penetration resistance, acid neutralization capacity (ANC), and chemical speciation of heavy metals. The results indicate that the stabilized soils exhibit satisfactory performance which is comparable with the laboratory study. In-situ SPC treatment significantly decreases EC values and increases penetration resistance values of the soils. Leachability of lead, zinc, cadmium and COD decreases with increasing SPC content or curing time. Large percentages of heave metals in the soils are transformed from exchangeable fractions to residual fractions after treatment. These, coupled with the improved ANC, result in low heavy metal leachability in stabilized soils.
In recent years, metal halide perovskites have been widely investigated to fabricate photodetectors for image sensing due to the excellent photoelectric performance, tunable bandgap, and low‐cost ...solution preparation process. In this review, a comprehensive overview of the recent advances in perovskite photodetectors for image sensing is provided. First, the key performance parameters and the basic device types of photodetectors are briefly introduced. Then, the recent developments of image sensors on the basis of different dimensional perovskite materials, including 0D, 1D, 2D, and 3D perovskite materials, are highlighted. Besides the device structures and photoelectric properties of perovskite image sensors, the preparation methods of perovskite photodetector arrays are also analyzed. Subsequently, the single‐pixel imaging of perovskite photodetectors and the strategies to fabricate narrowband perovskite photodetectors for color discrimination are discussed. Finally, the potential challenges and possible solutions for the future development of perovskite image sensors are presented.
Metal halide perovskites are widely investigated in photodetection applications due to their remarkable photoelectric properties. Herein, an overview of the recent advances in perovskite photodetectors for image sensing is provided. The device structures, preparation methods, and photoelectric properties of image sensors based on different dimensional perovskites are highlighted. The single‐pixel imaging and narrowband detection of perovskite photodetectors are also discussed.
Hydrogen embrittlement in metals has posed a serious obstacle to designing strong and reliable structural materials for many decades, and predictive physical mechanisms still do not exist. Here, a ...new H embrittlement mechanism operating at the atomic scale in α-iron is demonstrated. Direct molecular dynamics simulations reveal a ductile-to-brittle transition caused by the suppression of dislocation emission at the crack tip due to aggregation of H, which then permits brittle-cleavage failure followed by slow crack growth. The atomistic embrittlement mechanism is then connected to material states and loading conditions through a kinetic model for H delivery to the crack-tip region. Parameter-free predictions of embrittlement thresholds in Fe-based steels over a range of H concentrations, mechanical loading rates and H diffusion rates are found to be in excellent agreement with experiments. This work provides a mechanistic, predictive framework for interpreting experiments, designing structural components and guiding the design of embrittlement-resistant materials.
A Physically Transient Form of Silicon Electronics Hwang, Suk-Won; Tao, Hu; Kim, Dae-Hyeong ...
Science (American Association for the Advancement of Science),
09/2012, Letnik:
337, Številka:
6102
Journal Article
Recenzirano
Odprti dostop
A remarkable feature of modern silicon electronics is its ability to remain physically invariant, almost indefinitely for practical purposes. Although this characteristic is a hallmark of ...applications of integrated circuits that exist today, there might be opportunities for systems that offer the opposite behavior, such as implantable devices that function for medically useful time frames but then completely disappear via résorption by the body. We report a set of materials, manufacturing schemes, device components, and theoretical design tools for a silicon-based complementary metal oxide semiconductor (CMOS) technology that has this type of transient behavior, together with integrated sensors, actuators, power supply systems, and wireless control strategies. An implantable transient device that acts as a programmable nonantibiotic bacteriocide provides a system-level example.
Accessible Summary
What is known on the subject?
Young‐onset dementia (YOD) refers to a phenomenon in which dementia symptoms appear under age 65. Diagnosing YOD is difficult and its progression is ...fast. Furthermore, it limits the socio‐economic careers of people living with YOD, regardless of their needs.
People living with YOD and their carers have unstable occupational status and their dependents also have to face a high burden of care. They claim that existing social support for dementia is limited to the elderly and is not suitable for them.
What the paper adds to existing knowledge?
The characteristics of non‐pharmacological intervention studies for people living with YOD and/or their carers so far, and an analysis of the needs supported via the applied interventions.
A theoretical basis and direction for the interventions to be studied in the future.
What are the implications for practice?
Research and intervention development should focus more on the needs of people living with YOD. In addition, it is necessary to understand and reflect on carers who directly care for people living with YOD.
A multidisciplinary programme that supports wide area of the needs should be developed.
Introduction
Young‐onset dementia (YOD) is a highly influential disease that exerts force on the normal life of those who still have to continue social life. Research has been lacking in spite of its seriousness, which accounts for about 9% of all dementia cases.
Aim
This study aimed to examine non‐pharmacological interventions for people living with YOD and/or their carers, and to analyse how those interventions support their needs.
Method
A scoping review methodology was utilized to search the studies examining interventions for people living with YOD and/or their carers, and in English or Korean. The information was extracted, summarized and analysed in CANE categories.
Results
Sixteen studies were included in the review. Five types of interventions were drawn. ‘Memory’ was the most covered part of the needs by the interventions.
Discussion
This study found that interventions currently do not match the needs of people living with YOD and their carers. Multidisciplinary research would be eligible to cover the subjects' wide range of the needs as much as possible.
Implications for Practice
We suggest the development of a specialized needs assessment tool and specialized interventions for people living with young‐onset dementia and their carers.
Alloy‐type anode materials are promising for sodium‐ion batteries owing to their high theoretical specific capacity. However, their practical application is limited by the rapid capacity decay ...resulted from drastic volume change upon sodium (Na) alloying/dealloying. Here, a facile fabrication of well‐aligned antimony tin (SbSn) alloy nanoarrays electrodeposited on copper (Cu) substrates is reported. Such a binary alloy possesses well‐defined triangular pyramid‐like structure, and the subsequent thermal annealing process develops an “alloy glue” at the root of the nanoarrays which generates a strong connection between the active alloy and the copper substrate. Density functional theory calculation results suggest that the as‐fabricated alloy offers an energetically favorable Na diffusion as compared to the individual metals, and the “alloy glue” provides a strong interaction between the substrate and SbSn. More importantly, based on finite‐element analysis, such a unique construction of the triangular pyramid‐like nanostructure not only creates a small difference in the Na+ concentration gradient, but also builds a uniform stress distribution that promotes both highly efficient Na+ diffusion and effective stress dissipation. Collectively, the optimized composition and geometry give rise to the enhanced high‐rate performance and prolonged cycle life of the current SbSn alloy nanoarrays.
Synthesis of SbSn nanoarrays via a template‐free electrodeposition method is demonstrated. Benefitting from the unique triangular pyramid‐like architecture, the SbSn nanoarrays offer uniform stress distribution and efficient Na diffusion, thus exhibiting excellent sodium storage performance with high reversible capacity and long‐term cycling stability.
Electrochemical CO2 conversion offers a promising route for value-added products such as formate, carbon monoxide, and hydrocarbons. As a result of the highly required overpotential for CO2 ...reduction, researchers have extensively studied the development of catalyst materials in a typical H-type cell, utilizing a dissolved CO2 reactant in the liquid phase. However, the low CO2 solubility in an aqueous solution has critically limited productivity, thereby hindering its practical application. In efforts to realize commercially available CO2 conversion, gas-phase reactor systems have recently attracted considerable attention. Although the achieved performance to date reflects a high feasibility, further development is still required in order for a well-established technology. Accordingly, this review aims to promote the further study of gas-phase systems for CO2 reduction, by generally examining some previous approaches from liquid-phase to gas-phase systems. Finally, we outline major challenges, with significant lessons for practical CO2 conversion systems.
Plant trichomes serve as a highly suitable model for investigating cell differentiation at the single‐cell level. The regulatory genes involved in unicellular trichome development in Arabidopsis ...thaliana have been intensively studied, but genes regulating multicellular trichome development in plants remain unclear. Here, we characterized Cucumis sativus (cucumber) trichomes as representative multicellular and unbranched structures, and identified Micro‐trichome (Mict), using map‐based cloning in an F₂ segregating population of 7,936 individuals generated from a spontaneous mict mutant. In mict plants, trichomes in both leaves and fruits, are small, poorly developed, and denser than in the wild type. Sequence analysis revealed that a 2,649‐bp genomic deletion, spanning the first and second exons, occurred in a plant‐specific class I homeodomain‐leucine zipper gene. Tissue‐specific expression analysis indicated that Mict is strongly expressed in the trichome cells. Transcriptome profiling identified potential targets of Mict including putative homologs of genes known in other systems to regulate trichome development, meristem determinacy, and hormone responsiveness. Phylogenic analysis charted the relationships among putative homologs in angiosperms. Our paper represents initial steps toward understanding the development of multicellular trichomes.
Abstract
The development of simple‐to‐operate methods for the preparation of indolizidine derivatives are of great importance. A mild one‐pot protocol for the 3+2 cycloaddition of ...isoquinolinium/pyridinium ylides and electron‐deficient alkenes using NaBH
3
CN as reductant has been developed. The protocol has a broad substrate scope (more than 40 examples) and provides various novel hexahydroindolizidine derivatives in high yields and excellent diastereoselectivities (up to >20/1).
PDF
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