Negative thermal expansion(NTE) behavior has roused wide interest for the control of thermomechanical properties of functional *** NTE behaviors have been found in kinds of compounds,it remains challenging for polymer...
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Negative thermal expansion(NTE) behavior has roused wide interest for the control of thermomechanical properties of functional *** NTE behaviors have been found in kinds of compounds,it remains challenging for polymers to achieve intrinsic NTE *** this work,we systematically studied the conformational change of dibenzocyclooctadiene(DBCOD) derivatives between chair(C) and twist-boat(TB) forms based on density-functional theo ry(DFT) calculations,and found clear evidence of the relationship between the structure of DBCOD units and the thermal contraction behavior of the related *** order to obtain the polymer with NTE property,two conditions should be met for the thermal contracting DBCOD related units as follows:(i) the TB conformation can turn into C conformation as the temperature increases,and(ii) the volume of C conformation is smaller than that of TB *** rule should offer a guidance to exploration of the new intrinsic NTE polymers in the future.
In this work, we demonstrated upconversion imagers integrated with shortwave infrared photodetectors paired with an electron blocking layer. The use of electron blocking layer screened charge injection to prevent reco...
In this work, we demonstrated upconversion imagers integrated with shortwave infrared photodetectors paired with an electron blocking layer. The use of electron blocking layer screened charge injection to prevent recombination in photosensitive layer. The characteristics of each electron blocking layer were analyzed in aspects of noise and detectivity. For the optimized device, the parasitic luminance in the dark was efficiently suppressed, and the photon-to-photon efficiency was increased. The electron blocking layer used in this work is generally applicable for upconversion imagers using different absorption and emitting materials.
The world is eager to find a solution to reduce the phenomenon of climate change and transition to sustainable and renewable resources in all facets of our lives as we live in this period. Climate change and the emiss...
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Natural rubber (NR) has been utilized in several products from its interesting unique properties. This study aimed to develop the pressure-sensitive adhesives (PSA) as the transdermal patches from NR by two-roll mill ...
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In light-matter strong coupling regime, we observe long-range photodetection response at room temperature mediated by organic exciton-polaritons, which results from strong interactions between organic excitons and low...
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Microplastics are a growing environmental concern, with a large body of evidence documenting substantial distribution of plastic material in virtually all environmental compartments. Countermeasures that help to bind,...
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COVID-19 outbreaks and becomes serious from 2019 winter. Taking body temperature, wearing masks, recording footprint and avoiding crowds become important tasks and require a lot of manpower support for the prevention ...
COVID-19 outbreaks and becomes serious from 2019 winter. Taking body temperature, wearing masks, recording footprint and avoiding crowds become important tasks and require a lot of manpower support for the prevention of the epidemic in every. In this study, we have integrated the infrared thermometer devices to measure people temperature and the people identities through RGB images at the entrance of buildings. Using the computer vision and deep learning methods, we would like to build a 24/7 and region-wide coverage assistance system to automatically record the footprint of a specific people in the building. We also detect if people taking off their masks in the yard at any time. The processing videos are grabbed from the existing CCTV systems. The developed system also locates the crowd and calculate the number of people in a specified area, and the manager can know the number of people and control the access in real time. It will reduce the burden of manpower. In addition, we have optimized the system performance to handle multiple camera videos and to reduce the hardware cost at the same time.
It is well known that armor prevents failures of behind-armor targets by reducing the force in an impact event and thereby providing protection under certain impact events. However, the kinetic energy associated with ...
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Computational music research plays a critical role in advancing music production, distribution, and understanding across various musical styles in the world. Despite the immense cultural and religious significance, th...
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This study looks at how reactive SiO2 contributes to high-performance alkali-activated binders (HPAAB), which provide an eco-friendly and affordable option compared to commercial repair materials (CRM). A total of 11 ...
This study looks at how reactive SiO2 contributes to high-performance alkali-activated binders (HPAAB), which provide an eco-friendly and affordable option compared to commercial repair materials (CRM). A total of 11 mixtures were investigated: one control mixture composed of high-calcium fly ash (HFA) without reactive SiO2 additive, and 10 modified mixtures, each incorporating one type of reactive SiO2 material—either fine, medium, or large nano-SiO2 at dosages of 1, 2, and 3%wt, or rice-husk ash (RHA) at a dosage of 2%wt. Each mixture included only one type of reactive SiO2 additive. A 10-molar sodium hydroxide solution combined with a sodium silicate solution was employed as the liquid activator. Experimental evaluations were carried out to assess the setting time, compressive strength, bonding strength, and the interface zone between the repair material and normal concrete substrate. Test results indicated that adding 2% nano-SiO2 and 2% RHA notably enhanced the mechanical properties and bond quality of the HPAAB paste. This enhancement was attributed to the generation of additional reaction products within the matrix, thus resulting in performance comparable to those of CRMs. Additionally, a cost and life-cycle analysis indicated that HPAABs, especially those incorporating RHA, were more cost-effective and exhibited up to 23 times lower CO2 emissions compared to CRMs. Although the role of reactive SiO2 in alkali-activated binders is well established, the novelty of this work offers HPAAB-based repair materials with optimized reactive SiO2 contents. These materials have demonstrated potential as effective alternatives for concrete repair and rehabilitation, offering enhanced bonding performance, greater cost efficiency, and a reduced carbon footprint in comparison to CRMs. These results provide valuable insights for advancing the application of alkali-activated binders in the construction industry.
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