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Background: Urban forests are increasingly recognized as important tools in climate change mitigation and adaptation, prompting many cities to set tree canopy cover targets. However, current gaps in knowledge include understanding relationships and the feasibility of maximizing benefits between urban greening and other climate actions, such as densification. This study offers a data-driven and manageable framework for assessing current and anticipated future urban forestry conditions using spatial tree and built-form models. Methods: We spatially modelled 4 planting scenarios for increasing tree canopy cover by 2050 in a densifying neighbourhood in Vancouver, Canada, with low (< 10%) existing tree canopy. Results: Based on mortality assumptions, we aged out and replaced 1,853 to 2,445 trees since 2020. We added 6,079 to 11,726 trees across the 4 scenarios (10,228 to 15,823 total), increasing canopy cover from 7% in 2020 to a maximum of 16% by 2050. Despite rigorous tree planting, we were unable to achieve a 30% canopy cover target at neighbourhood scale. Tree replacement due to mortality was a major contributor to decreased canopy cover and volume in future scenarios. The 31% to 34% reduction in future canopy cover due to the replacement of aged-out trees was driven by changes on private parcels. Conclusion: Our systematic framework for generating and spatially modelling trees in a simulated future neighbourhood provides an opportunity for iteratively assessing multiple potential tree planting configurations. Future work for this project includes investigating social-ecological, outdoor shading, and building energy implications of various modelled urban forest strategies. [ABSTRACT FROM AUTHOR]

Background: Urban forests can provide nature-based solutions (NBS) to complex climate-change challenges via the provision of ecosystem services such as shade and cooling that offset increased risks of chronic diseases and excess mortality. They also confer indirect health benefits by providing regulating ecosystem services that can facilitate climate-change mitigation efforts: increased shade can encourage shifts to lower-carbon transportation methods such as walking and cycling, for example. However, in order to ensure that urban forests are both resilient to threats and confer the maximum possible benefits, we must be able to project decades into the future in order to understand the implications of current urban forestry decisions. Methods: This study outlines a framework for creating urban-forest scenario models and reports the results of a case study conducted to highlight the ways in which decisions made at each stage of the scenario-development process impact its outcomes and application. Our case study focused on a neighbourhood in Vancouver, Canada, that is simultaneously undergoing urban densification and aiming to significantly increase canopy cover by 2050. Three distinct aims were identified for the case study: maximizing publichealth benefits, selecting climate-resilient tree species, and integrating planting across public and private lands to advance diversity. To achieve these aims, baseline information on the neighbourhood's existing tree network was collected, entered into GIS software, and delineated based on a set of pre-identified characteristics. Next, a list of climate-adapted species was developed. This climate-adapted species list was then virtually "planted" across the neighbourhood, using a combination of machine-based and manual planting techniques. Finally, the resulting scenario model was quantitatively assessed to understand its composition and impacts. Results: Our study demonstrates that a salubrious, resilient, and diverse urban forest can be created via a strategic program that complements extant trees in the public domain with planting programs along blue-green streets and on private property. Conclusions: Achieving the urban tree trifecta will require collaboration among municipal departments and the development of a range of public and private initiatives, but it has the potential to maximize nature-based solutions in cities facing rapid shifts due to densification and climate change. [ABSTRACT FROM AUTHOR]

Background: Cities consume a disproportionate amount of energy for internal temperature regulation. Being able to reduce cities' cooling load on hot summer days can decrease energy consumption while improving occupants' thermal comfort. The urban canopy is an effective shading agent, adding cooling benefits to existing buildings and streets while providing other ecological and physiological values. Yet the building and street shading dynamic is a highly complex system that involves micro-level building components and macro-level variables. Introducing urban canopy to such a complex system creates another challenge, as urban canopy variables can also interact with buildings at both micro- and macro-levels. In order to accurately represent the urban canopy shading effect, it is necessary to account for the interactions among buildings, streets, and urban canopies. Methods: This study simulates the shading effect of urban canopy measured by aerial laser scanning (ALS) in the City of Vancouver, Canada, through the integration of a Radiance daylight simulation engine and geographic information system (GIS) data. All trees detected by ALS were included in the analysis. Results: The results indicate that street surfaces receive more solar irradiance reduction than building roofs and façades (i.e., exterior walls). Neighborhoods with less density and lower buildings were shaded noticeably better than areas with higher density and taller buildings. Among Vancouver's 22 neighborhoods, 2 neighborhoods, Kitsilano and the West End, demonstrated a promising sign where both building density/height and urban canopies are maintained. There was evidence of high canopy shading and high-density urban morphologies. Conclusion: Overall, this work provided an authentic canopy assessment from single building to city scale, creating opportunities to investigate intracity urban canopy variations, equality, and the balance between urban greening and urban densification. [ABSTRACT FROM AUTHOR]

The measurements of resistance under various applied voltages as well as the highly nonlinear current-voltage characteristics reveal that a small electric field is able to induce an insulating to metallic phase transition in LuFe2O4. The threshold field at which the phase transition occurs decreases exponentially with the increasing temperature. We interpret this transition as a consequence of the breakdown of the charge-ordered state triggered by applied electric field. This electrically driven phase transition results in a colossal electroresistance effect around room temperature which makes LuFe2O4 a very promising material for many applications. [ABSTRACT FROM AUTHOR]

An effective way for the improvement of resonance frequency was demonstrated by the orientation of CoFe2O4 nanocubes (NCs) after applying a magnetic field. The magnetic holography image of the oriented CoF2O4 NC arrays was obtained, and the vortex domain structure was found in single CoFe2O4 NCs, which greatly depends on dipolar interactions. Moreover, the cutting-off frequency of oriented CoFe2O4 NCs of 8.8 GHz is achieved with a slight increase in permeability at an extremely low mass fraction (about 10%). This work provides an effective way for optimizing the high-frequency properties of magnetic nanomaterials above GHz. [ABSTRACT FROM AUTHOR]

The influence of the varied thickness of antiferromagnetic (AFM) and ferrimagnetic (FiM) nanostructure in MnO@Mn3O4 core-shell nanoparticles (NPs) on the exchange bias effect has been investigated. The MnO@Mn3O4 core-shell NPs with varied radius of MnO core (RMnO) and thickness of Mn3O4 shell (TMn3O4) have been synthesized by in-situ oxidation of the pure MnO NPs in organic solution containing a mild oxidant at different temperatures. The exchange bias effect can be tuned by changing the RMnO (TMn3O4) of the MnO@Mn3O4 coreshell NPs. The strongest exchange coupling effect of both 17.2 and 25.0 nm MnO@Mn3O4 core-shell NPs occur when RMnO=TMn3O4 = R/2. It is expected that the finding of the control of exchange bias effect by varied RMnO and TMn3O4 in inverted core-shell NPs is helpful for the further understanding of the exchange bias mechanism. [ABSTRACT FROM AUTHOR]

Single-layertransition-metal dichalcogenides (TMDs) receive significant attentiondue to their intriguing physical properties for both fundamental researchand potential applications in electronics, optoelectronics, spintronics,catalysis, and so on. Here, we demonstrate the epitaxial growth ofhigh-quality single-crystal, monolayer platinum diselenide (PtSe2), a new member of the layered TMDs family, by a single stepof direct selenization of a Pt(111) substrate. A combination of atomic-resolutionexperimental characterizations and first-principle theoretic calculationsreveals the atomic structure of the monolayer PtSe2/Pt(111).Angle-resolved photoemission spectroscopy measurements confirm forthe first time the semiconducting electronic structure of monolayerPtSe2(in contrast to its semimetallic bulk counterpart).The photocatalytic activity of monolayer PtSe2film isevaluated by a methylene-blue photodegradation experiment, demonstratingits practical application as a promising photocatalyst. Moreover,circular polarization calculations predict that monolayer PtSe2has also potential applications in valleytronics. [ABSTRACT FROM AUTHOR]

The magnetic field-dependent transport of Pr0.6Ca0.4MnO3 has been investigated to expose the field-induced melting of orbital ordering. The critical field and critical temperature for the melting of the orbital ordered state depend on the orientation of the applied magnetic field, seemingly independent of the nature of the magnetic phase. The crystalline c axis is the hard axis of the field-induced melting, but in-plane anisotropy also exists, correlating with the anisotropic charge-exchange-(CE) type orbital-ordered structure. These findings demonstrate that the anisotropic melting coincides with the orbital ordering anisotropy, thus indicating a strong spin-orbital coupling. [ABSTRACT FROM AUTHOR]

At ultrafast timescales, the initial and final states of a first-order metal-insulator transition often coexist forming clusters of the two phases. Here, we report an unexpected third long-lived intermediate state emerging at the photoinduced first-order metal-insulator transition of La0.325Pr0.3Ca0.375MnO3, known to display submicrometer length-scale phase separation. Using magnetic force microscopy and time-dependent magneto-optical Kerr effect, we determined that the third state is a nanoscale mixture of the competing ferromagnetic metallic and charge-ordered insulating phases, with its own physical properties. This discovery bridges the two different families of colossal magnetoresistant manganites known experimentally and shows for the first time that the associated states predicted by theory can coexist in a single sample. [ABSTRACT FROM AUTHOR]

The hydrophilic hollow nano-spheres and hemispheres of Co are synthesized via ethylene glycol reduction of cobalt acetate in the presence of PVP and Pd nano-particle seeds. The dimensions of the hollow core can be tuned from 100 to 300 nm by controlling the amount of Pd nano-particle seeds. The morphology of the hollow materials strongly depends on the molar ratio of the amide unit in PVP over Co and the Mw of PVP. The hollow structure is formed when the ratio falls in the range 1-1.5 and the Mw is over 40 000. Based on the experimental data, a possible formation mechanism of Co hollow spheres is proposed. [ABSTRACT FROM AUTHOR]