In diesem Beitrag wird anhand der Befragung von Eltern und Kindergartenlehrpersonen querschnittlich untersucht, ob und inwieweit die Anpassung der Kinder 12 Wochen nach dem Kindergartenstart gelingt. ...Wie sich zeigt, nehmen die Eltern beim Übergang vielfältige Herausforderungen wahr; die emotional-affektive Haltung ihres Kindes der Institution gegenüber beschreiben die Eltern meist positiv. Im Kindergarten zeigt jedes zweite Kind nach 12 Wochen sozial kompetentes und adaptives Verhalten (u.a. Sozialkontakte, Regeleinhaltung), 4-11% haben je nach Bereich grössere Anpassungsprobleme. Für jedes siebte Kind (15%) zeigen sich Verhaltensauffälligkeiten im (SDQ-)Risikobereich, die Daten zum Auftretenszeitpunkt sprechen für differenzielle Entstehungs- und Anpassungsprozesse. Die Befunde werden u.a. vor dem Hintergrund des herabgesetzten Eintritt (DIPF/Orig.)
À la lumière de l’enquête menée auprès des parents et du personnel des écoles premières, cet article cherche à déterminer si et dans quelle mesure l’adaptation des enfants fonctionne 12 semaines après leur première rentrée. Il s’avère que les parents sont confrontés à plusieurs défis au moment de la transition; la plupart d’entre eux jugent positive l’attitude émotionnelle et affective de leur enfant envers l’institution. À l’école enfantine, un enfant sur deux affiche un comportement socialement compétent et adapté au bout de 12 semaines (contacts sociaux, respect des règles, notamment). Quatre à 11 % des enfants rencontrent, selon le domaine,des problèmes d’adaptation. Un enfant sur sept (15 %) montre des signes comportementaux considérés comme à risque (SDQ). Les données sur le moment où survient ce comportement témoignent de processus d’apparition et d’adaptation différentiels. Les résultats sont discutés notamment dans le contexte de la baisse de l’âge d’entrée à l’école (depuis HarmoS). (DIPF/Orig.)
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•Unique rod-like porous Ni/C nanocomposites can be facially obtained.•Electromagnetic parameters can be tuned by carbonization temperature.•Impedance match is optimized to achieve ...reflection loss performance.•RL value of −23.4dB and effective frequency bandwidth of 4.68GHz can be achieved at 1.9mm.
In recent years, metal–organic-frameworks derived composites, especially magnetic nanoparticles embedded in porous carbon matrix have emerged as promising candidate for lightweight electromagnetic wave absorber. Nevertheless, investigation on the optimization of impedance matching in the microwave absorption properties is insufficient. In this work, impedance matching is optimized to achieve strongest absorption intensity and broaden the effective frequency bandwidth. In detail, electromagnetic parameters have been controlled through changing the carbonization temperature to fulfill optimized impedance matching. RL value of −51.8dB and an effective frequency bandwidth (fe) of 3.48GHz with a thickness of 2.6mm can be achieved by sample prepared at 500°C and RL value of −15.0dB and a fe of 4.72GHz with a thin thickness of 1.8mm can be reached by sample synthesized at 600°C. Comparative studies of each sample directly display the effect of impedance matching on the RL performance and possible attenuation mechanisms are also discussed. This work may deepen the understanding of the impedance matching and pave the way for the synthesis of high performance lightweight microwave absorber.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Using cotton as precursor to make sustainable lightweight microwave absorber.•Carbon-cotton was decorated by a flexible impregnation and annealing method.•Investigated the effect of ...temperature on the EMA properties of the media.•The RL value can reach −51.2 dB with bandwidth of 4.4 GHz at only 1.65 mm.
Nowadays, carbon materials derived from natural biomaterials have been drawn considerable attention because the biomaterials are vastly available, accessible and renewable. Hereinto, it is fascinating that employing cotton as carbonaceous precursors to fabricate novel sustainable lightweight microwave absorber due to its unique hierarchical macro-/microporous architecture. In current study, we adopt a sustainable route from biomass cotton to construct cotton/zeolitic imidazolate framework (ZIF-67) and subsequent sintering to fabricate carbon-cotton/Co@nanoporous carbon (NPC) products. The as-prepared composites showed definitely superior microwave absorption performance than the pristine carbon-cotton and Co@NPC. It is confirmed that a better impedance matching is the key factor to realize excellent absorption. When the sample filling ratio is as low as 25 wt% in paraffin matrix, the maximum reflection loss can achieve −60.0 dB at 8.48 GHz. Furthermore, via adjusting the thickness to only 1.65 mm, the optimal reflection loss can obtain −51.2 dB at 13.92 GHz with a broad bandwidth of 4.4 GHz. In addition, the annealing temperature for the composites was also investigated, which had significant influence on tuning absorption properties. Prospectively, our present work may provide a new guideline to design carbon composites from earth-abundant recyclable biomass materials as sustainable, lightweight and high-performance absorber.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Ternary hierarchical CoFe@C@MnO2 nanocubes were rationally synthesized.•The delicate structural design facilitates multiple interface polarization.•These CoFe@C@MnO2 nanocubes ...exhibit superior microwave absorption performances.•A minimum RL of −64 dB is achieved with a thickness of 1.3 mm.•The nanocubes can be used as high-performance microwave absorption materials.
The rational design of hierarchical structures with multi-heterogeneous components provides a promising pathway to develop advanced absorbers, but it remains a great challenge. Herein, we demonstrate the construction of three-layered CoFe@C@MnO2 hierarchical nanocubes to address this challenge, which involved the creation of metal organic framework-derived nanocubes consisting of CoFe nanoparticles embedded within porous carbon and the growth of MnO2 nanoparticles on the nanocubes. This delicate design not only enabled the synergistic effects of the magnetic loss of the magnetic CoFe and the intrinsic dielectric losses of the dielectric materials C and MnO2 but also facilitated multiple interface polarization and appropriate impedance matching. Benefiting from these structural and compositional features, the as-synthesized CoFe@C@MnO2 nanocubes achieved a minimum reflection loss of −64 dB at 15.6 GHz with a thickness of 1.3 mm and a maximum absorption bandwidth of 9.2 GHz from 8.8 to 18 GHz for −10 dB at a thickness of 1.6 mm.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The incremental changes and greater extremes of a changing climate will have operational, infrastructure and economic impacts for aviation. Given the criticality of aviation for global connectivity ...and mobility, it is vital that the sector understands and adequately adapts to these risks. This article presents a systematic review of the growing but somewhat dispersed academic literature on climate change impacts and adaptation in the aviation sector. Information was synthesised from 131 studies (published between January 2000 and November 2022) on eleven climate change effects and the associated impacts and potential adaptation measures. Six areas for action to address knowledge, awareness and implementation gaps were identified: (i) to broaden geographical coverage, particularly to address the current lack of studies addressing climate risks and responses in Central and South America, Africa and the Middle East; (ii) to extend knowledge of physical impacts; (iii) to address known-unknowns such as the risks associated with unprecedented or compound extreme events; (iv) to extend knowledge of adaptation including cost-benefit analysis and consideration of integrated mitigation and adaptation; (v) to identify and apply other relevant research; and (vi) for sector bodies to support and facilitate collaboration between researchers and practitioners to co-develop accessible user-oriented climate adaptation services.
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BFBNIB, NUK, PILJ, SAZU, UL, UM, UPUK
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•Fe3O4@LAS/RGO composites with uniform size were successfully synthesized.•Fe3O4@LAS/RGO composites have excellent microwave absorption performance and broad bandwidth.•The addition ...of lithium aluminum silicate glass-ceramic contributes to the synergy of dielectric loss and magnetic loss.•A multiple transmission-absorption mechanism was introduced for the material to effectively improve impedance matching.
For the first time, Fe3O4@LAS/RGO composites with uniform size and extraordinary electromagnetic wave absorption properties were successfully synthesized by a simple three-step method. The Fe3O4 nanospheres with a diameter of about 200 nm are tightly attached by the lithium aluminum silicate (LAS) glass-ceramic particles with a diameter of about 20 nm and evenly distributed among the graphene sheets. The method of coating a microwave absorber with a wave-transparent material introduces a multiple transmission-absorption mechanism for the material to effectively improve impedance matching. The input impedance Zin value (∼1.0) of Fe3O4@LAS/RGO is better and more stable than the Zin value (∼1.2) of Fe3O4/RGO. The RL values of Fe3O4@LAS/RGO could reach −65 dB at 12.4 GHz with a thickness of only 2.1 mm and the absorption bandwidth with RL values less than −10 dB (over 90% electromagnetic wave absorption) is up to 4 GHz at the corresponding thickness. The intrinsic properties of the component of Fe3O4@LAS/RGO composites and the composite structure of the material lead to a variety of microwave absorption mechanisms acting together to improve the microwave absorption properties of the composites.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Based on a longitudinal case study, this paper presents an ecosystem‐level process model of the interlocking key activities of the business model disruptor, other ecosystem participants (customers, ...partners, media, analysts), and the incumbent. Together these constitute a strategic process of ecosystem evolution from incumbent‐centred to disruptor‐centred. We identify the phenomenon of a ‘disruptor's gambit’, where the disruptor reveals its intentions early on through effective framing, followed by rapid adaptation of its business model to satisfy ecosystem needs. These processes generate a virtuous framing‐adaptation cycle, where feed‐forward and feedback enable rapid response to customers and partners, while engaging them as force multipliers during new ecosystem creation. Our findings suggest that framing constitutes a dynamic strategic process enabling disruptors to reduce uncertainty, dislodge powerful incumbents, and shape new ecosystems through business model innovation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
We implement a new survey of firms, focusing on their higher-order macroeconomic expectations. The survey provides a novel set of stylized facts regarding the relationship between ...first-order and higher-order expectations of economic agents, including how they adjust their beliefs in response to a variety of information treatments. We show how these facts can be used to calibrate key parameters of noisy-information models with infinite regress as well as to test predictions made by this class of models. We also consider a range of extensions to the basic noisy-information model that can potentially better reconcile theory and empirics. Although some extensions like level-k thinking are unsuccessful, incorporating heterogeneous long-run priors can address the empirical shortcomings of the basic noisy-information model.
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IZUM, KILJ, NUK, PILJ, SAZU, UL, UM, UPUK
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•3D ordered hollow carbon (3DOHC) is designed for microwave absorption (MA).•This 3DOHC has lightweight, superior MA property and wide absorption bandwidth.•The low content and ...lightweight of 3DOHC are beneficial to practical applications.
Herein, we demonstrate that amorphous carbon can be converted to lightweight superior MA materials only via a facile inside three dimensional ordered hollow (3DOH) architecture fabrication. The as-fabricated 3DOH carbon (3DOHC) blocks consist of ordered spherical voids formed by connected thin porous amorphous carbon walls. The diameter of the voids has a great influence on the MA performance, and a minimum reflection loss (RL) value of −66.24 dB is observed at 15.68 GHz for the 3DOHC blocks with inside void diameter of 500 nm (3DOHC-500) at a low filling rate of 5.0 wt% and absorber thickness of 1.6 mm. Moreover, the widest absorption bandwidth for RL values below −10 dB is 4.78 GHz when the absorber thickness is 1.7 mm while still keeping a low RL value of −45.85 dB. The enhancement of the MA performance of 3DOHC-500 based absorber can be attributed to the synergic effect of dielectric loss and impedance matching. The excellent MA performance combining with the low filling rates (2.5–5.0 wt%), thin thickness and lightweight (≤100 mg/cm−3) makes these 3DOHC-500 very promising candidate for practical MA applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
An excellent electromagnetic wave absorbing material (EWAM) should possess both wider effective absorption bandwidth (EB) and lower minimum reflection loss (RLmin), which depends on good impedance ...matching between the EWAMs and air and strong attenuation of electromagnetic wave (EW) inside the absorber. In this work, single-layer graphene/thermoplastic polyurethane (TPU) porous composites with different foam ratio and gradient foam ratio multilayer graphene/TPU porous composites with different number of layers were prepared. Not only were the EW-absorbing properties and mechanism of these composites investigated, but the mechanical properties were also examined. Compared to the single-layer samples with the same average foam ratios at the same thickness, the multilayer samples showed wider EB, 5.6, 4.6, 4.4 GHz for 3L, 4L and 5L, respectively. By designing the multilayer structure of gradient foam ratio, it provides a novel path for the preparation of EWAMs with strong absorption capacity, wider EB, light weight and excellent mechanical properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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