Global weirding at mass extinction horizonsOA

<正>A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].     

Theory and classification of mass extinction causationOA

Theory regarding the causation of mass extinctions is in need of systematization, which is the focus of this contribution. Every mass extinction has both an ultimate cause, i.e. the trigger that leads to various climato-environmental changes, and one or more proximate cause(s), i.e. the specific climato-environmental changes that result in elevated biotic mortality. With regard to ultimate causes, strong cases can be made that bolide(i.e. meteor) impacts, large igneous province(LIP) eruptions an...     

Photodegradable polar-functionalized polyethylenesOA

The degradation of plastics has attracted much attention from the global community.Polyethylenes(PEs),as the most abundant synthetic plastics,are most frequently studied.PE is non-degradable and non-polar because of the sole presence of the pure hydrocarbon components.Concurrent incorporation of both in-chain cleavable and functional groups into the PE chain is an effective pathway to overcome the non-degradable and non-polar issue;however,the method for achieving this pathway remains elusive.He...     

Graphene for gold extractionOA

<正>Gold is a unique element,characterized not only by limited,though still reasonable,availability (useful for monetary applications) but also for its rather unique properties useful for many industries [1]:chemical inertness,high electrical conductivity,plasticity,etc.As gold reserves in Earth’s crust diminish with traditional minings’urban mining’that recycles gold from gold-containing wastes (such as electronic waste,e-waste) has emerged as an important supply method for gold sustainabi...     

Climbing robots for manufacturingOA

Robotized intelligent manufacturing is a growing trend in the manufacturing of large and complex components in aviation,aerospace,marine engineering and other industries.With their expansive workspaces and flexible deployment,climbing manufacturing robots can create a revolutionary manufacturing paradigm for large and complex components.This paper defines the climbing manufacturing robot based on the application status of climbing robots and then analyzes four key technical re quirements:adhesio...     

The heterogeneity-diversity-system performance nexusOA

Ever-growing human population and nutritional demands,supply chain disruptions,and advancing climate change have led to the re alization that changes in diversity and system performance are intimately linked.Moreover,diversity and system performance depend on heterogeneity.Mitigating changes in system performance and promoting sustainable living conditions requires transformative decisions.Here,we introduce the heterogeneity-diversity-system performance(HDP) nexus as the conceptual basis upon wh...     

Three Gorges Dam: friend or foe of riverine greenhouse gases?OA

Dams are often regarded as greenhouse gas(GHG) emitters. However, our study indicated that the world’s largest dam, the Three Gorges Dam(TGD), has caused significant drops in annual average emissions of CO₂, CH₄ and N₂O over 4300 km along the Yangtze River, accompanied by remarkable reductions in the annual export of CO₂(79%), CH₄(50%) and N₂O(9%) to the sea. Since the commencement of its operation in 2003, the TGD has altered the...     

Van der Waals superlatticesOA

<正>Semiconductor technology has enabled many essential devices,including transistors for computing and communication,diodes for solid-state lighting and photovoltaics.Behind all these devices,the material foundation is a series of highly elaborated heterostructures and superlattices[1].To this end,integrating different materials into heterostructures or superlattices with well-defined spatial modulation of chemical compositions and electronic structures is central for generating designed e...     

Superscattering of water wavesOA

Inspired by the concept of superscattering in optics,we for the first time theoretically predict and experimentally demonstrate the superscattering phenomenon in water waves.The subwavelength superscatterer is constructed by multi-layered concentric cylinders with an inhomogeneous depth profile.The superscatterer breaks the long-held single-channel scattering limit by several times and thus significantly enhances the total scattering strength.The underlying mechanism originates from the near deg...     

Anthropogenic monoterpenes aggravating ozone pollutionOA

Monoterpenes have been known to have a critical influence on air quality and climate change through their impact on the formation of fine particles.Here we present field evidence that monoterpene oxidations largely enhanced local ozone production in a regional site in eastern China.The observed monoterpene was most likely from biomass burning rather than biogenic emissions,as indicated by the high correlation with CO at night-time,and the observed ratio of these two species was consistent with p...     

What are species and how are they formed?OA

<正>In this issue of NSR,four papers address various aspects of speciation.The fifth one,to appear in the next issue,is on biodiversity and should ultimately be about speciation as well.As has always been the case in speciation research,the conclusion depends on what’species’are.This is true for Wang et al.[1] on post-speciation gene flow,Ma et al.[2] on hybridization speciation,Sun et al.[3] on sympatric speciation and Fan et al.[4]on species diversity.The conclusions would all be quite di...     

Competition on robust deep learningOA

<正>PROBLEM In recent years,the rapid development of artificial intelligence (AI) technology,especially machine learning and deep learning, is profoundly changing human production and lifestyle.In various fields,such as robotics,face recognition,autonomous driving and healthcare,AI is playing an important role.However,although AI is promoting the technological revolution and industrial progress,its security risks are often overlooked.Previous studies have found that the wellperforming deep ...     

Evolution of artificial ion channelsOA

<正>Protein ion channels on a cell membrane generate action potentials for cellular signal transduction, and regulate biological activities during life. Since the discovery of the asymmetric ion transport phenomenon in quartz nanopipettes by Bard and colleagues [1], synthetic nanofluidic materials and devices have attracted a lot of research interests from the scientific community,     

New progress in zeolite synthesis and catalysisOA

The rational design synthesis of zeolite catalysts with effective,environmentally benign and atom-economic routes is a major topic in the field of microporous materials,as it would avoid the high labor cost and inefficiency of traditional trial-and-error methods in developing new structures and dispel environmental concerns regarding the industrial mass production of zeolites.Catalytic applications of zeolite materials have expanded from conventional single functionalities,such as solid acids or...     

Ecological restoration for sustainable development in ChinaOA

Facing the need for transdisciplinary research to promote ecological restoration that achieves both social and ecological benefits,research on past restoration efforts that have directly or indirectly contributed to regional or national sustainable development warrants reassessment.Using China as an example,in this review,we address three basic research questions that can be summarized as follows:ecological restoration—of what,for whom and to what purpose?Accordingly,a landscape pattern—ecosyste...     

Organic semiconductor-incorporated two-dimensional halide perovskitesOA

<正>Recently,the search for novel two-dimensional (2D) organic-inorganic halide perovskite materials has come to a renaissance.There is significant interest not only in terms of their intriguing optoelectronic properties,but also their structural diversity and improved stability.The 2D perovskite structure can be visualized as atomically thin slabs cut from 3D parent structures along different crystal directions that are sandwiched between two layers of large organic cations.The bulky organ...     

Testing flexible polymer solar cells in near-spaceOA

<正>Since the big success of the Vanguard1 mission,being the first solar-powered satellite,the use of solar cells in space developed very rapidly.Today,conventional solar cell technologies for space are based on silicon and GaAs modules.If significantly higher power conversion efficiencies (PCEs) are required,     

Challenges and opportunities in remote sensing-based crop monitoring: a reviewOA

Building a more resilient food system for sustainable development and reducing uncertainty in global food markets both require concurrent and near-real-time and reliable crop information for decision making.Satellite-driven crop monitoring has become a main method to derive crop information at local, regional,and global scales by revealing the spatial and temporal dimensions of crop growth status and production.However, there is a lack of quantitative, objective, and robust methods to ensure the...