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When microdroplets with quasi‐spherical contact angles coalesce together on a low‐adhesion substrate, the capillary‐inertial expansion of the liquid bridge induces a dramatic out‐of‐plane jumping event due to symmetry breaking. From the onset of merging, droplet jumping initiates after a capillary‐inertial time scale of tci∼1–100 ${t}_{\text{ci}}\sim 1\mbox{--}\,100$ μs with characteristic jumping speeds of order vj∼0.1 ${v}_{{\rm{j}}}\sim 0.1$ m/s. This coalescence‐induced jumping‐droplet effect is most commonly observed among a population of growing dew droplets on a superhydrophobic condenser, but can also occur by colliding deposited droplets together or during droplet sliding on fog harvesters. In this review, we cover the historical development of capillary‐inertial jumping droplets, summarize the decade‐long effort to rationalize the ultra‐low energy conversion efficiency and critical droplet size of the phenomenon, and then present 15 variations on a theme of jumping. Capillary‐inertial jumping droplets are not only a visceral illustration of the surprising power of surface tension at the microscale but they also have the potential to enhance phase‐change heat transfer, enable self‐cleaning surfaces, combat frost formation, harvest energy, and govern the rate of disease spread for wheat crops. [ABSTRACT FROM AUTHOR]

Ecological security is a vital component of regional security and significantly influences regional sustainable development. The assessment of ecological security is the cornerstone of relative research to coordinate ecological protection and economic developments. However, a framework that enables systematic assessment of the ecological security still needs further exploration. A framework that includes ecosystem organization (O), quality (Q), and services (S) was proposed to evaluate the ecological security in southeast Qinghai‐Tibet Plateau (QTP) in this study. Results showed that: (1) From 2000 to 2020, ecosystem organization in the study area showed an improving trend, with 61.33% of counties experiencing an increase in O value; (2) The ecosystem quality showed an increasing trend, with the proportion of increased areas amounting to 54.46%, and the significantly increased area occupied 3.38% of the study area; (3) The total trend of ecosystem services decreased, among them, habitat provision and soil conservation both presented an increasing trend, while water yield performed a decreased trend; (4) The ecological security in the southeast of QTP has been improved, which increased in north of the study area and decreased in south part. Overall, our study provided a novel view to characterize the physical status of the natural environment and enriched the methodology of ecological security assessment. More attention should be received by the different roles of ecosystem organization, quality, and services in ecological security in future studies, which is helpful to reflect the current situation and changing trends of regional ecological security more reasonably and comprehensively. [ABSTRACT FROM AUTHOR]

Rapid urbanization leads to fragmentation of landscape and destruction of the ecological security network. A sound ecological security network promotes connectivity between ecological sources and mitigates the degradation of an ecological system. However, when identifying the ecological sources of the ecological network, studies available in the current literature did not simultaneously consider the structures, functions, and values of ecological patches. Our study aimed to fill this research gap, and our objective was to improve the framework for assessing the ecological security network. We demonstrated the application of the proposed framework through a case‐study of the urban agglomeration around Hangzhou Bay (UAHB), a rapid urbanization region in Eastern China. We improved the identification method of ecological sources by integrating the evaluations of ecosystem services value and ecological sensitivity, while we screened ecological sources by using the rank‐size rule and the natural breaks method. Based on the screened ecological sources, the ecological corridors were reconstructed and optimized for the UAHB region. The results from this study showed that ecological network has actually improved in the UAHB in the last 20 years. However, the structure and function of the ecological security network were strongly influenced by human activities and urban sprawl. The ecological security network has deteriorated locally in eastern coastal areas of UAHB during the past 20 years with strong spatial variability in ecological security patterns. To maintain an environment with well‐protected ecological quality, we proposed a set of five measures to improve the sustainable development of the ecological system. [ABSTRACT FROM AUTHOR]

A two‐step sol–gel method is adopted to prepare an iron–calcium hybrid absorbent (Ca–Al–Fe) integrating iron catalysis component and inert support with CaO for calcium looping gasification. Effects of Ca–Al–Fe on cyclic CO2 capture reactivity, mechanical strength, and enhanced reforming of biomass tar model component (toluene) are investigated by comparing with three reference absorbents. Results show that main components of Ca–Al–Fe are CaO, mayenite (Ca12Al14O33), and brownmillerite (Ca2Fe2O5). Ca12Al14O33 plays key roles in keeping stable cyclic carbonation reactivity and significantly promotes mechanical strength of the novel absorbent. In comparison with other absorbents without coupling Ca12Al14O33 or Ca2Fe2O5, Ca–Al–Fe approaches the highest toluene conversion (around 60%) and has the lowest coke deposition (12.2 mg g−1), due to the synergetic influences of Ca2Fe2O5 and Ca12Al14O33, which significantly promotes hydrogen production while reducing CO2 yield in reforming syngas. In addition, influences of reaction conditions such as iron loading, reaction temperature, molar ratio of H2O to carbon in toluene, and absorbent particle size on toluene reforming are examined in the presence of Ca–Al–Fe. Potential reaction routes of toluene reforming are also analyzed and discussed. [ABSTRACT FROM AUTHOR]

Improved powders for capturing CO2 at high temperatures are required for H2 production using sorption-enhanced steam reforming. Here, we examine the relationship between particle structure and carbonation rate for two types of Na2ZrO3 powders. Hollow spray-dried microgranules with a wall thickness of 100-300 nm corresponding to the dimensions of the primary acetate-derived particles gave about 75 wt % theoretical CO2 conversion after a process-relevant 5 min exposure to 15 vol % CO2. A conventional powder prepared by solid-state reaction carbonated more slowly, achieving only 50 % conversion owing to a greater proportion of the reaction requiring bulk diffusion through the densely agglomerated particles. The hollow granular structure of the spray-dried powder was retained postcarbonation but chemical segregation resulted in islands of an amorphous Na-rich phase (Na2CO3) within a crystalline ZrO2 particle matrix. Despite this phase separation, the reverse reaction to re-form Na2ZrO3 could be achieved by heating each powder to 900 °C in N2 (no dwell time). This resulted in a very stable multicycle performance in 40 cycle tests using thermogravimetric analysis for both powders. Kinetic analysis of thermogravimetric data showed the carbonation process fits an Avrami-Erofeyev 2 D nucleation and nuclei growth model, consistent with microstructural evidence of a surface-driven transformation. Thus, we demonstrate that spray drying is a viable processing route to enhance the carbon capture performance of Na2ZrO3 powder. [ABSTRACT FROM AUTHOR]