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1.
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...  相似文献   

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<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...  相似文献   

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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...  相似文献   

4.
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...  相似文献   

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<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...  相似文献   

6.
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...  相似文献   

7.
<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...  相似文献   

8.
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...  相似文献   

9.
<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 ...  相似文献   

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<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,  相似文献   

12.
<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].  相似文献   

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<正>On-chip energy-storage devices play an important role in powering wireless environmental sensors and microelectrome chanical systems [1,2].Starting from the 1980s,on-chip energy-storage devices,including microbatteries and super capacitors,have been applied to power the real-time clock on a chip [3].These tiny batteries/supercapacitors enable the real-time clock to keep working when the electronics are off.In this way,electronic devices can be restarted with a valid time.With the develo...  相似文献   

15.
<正>Non-linear optics is a branch of optics that studies the intriguing and sometimes unexpected ways in which light and matter interact at high intensities, when the polarization density does not respond linearly to the electric field of the light. The pursuit of the perfect non-linear optical material has been ongoing ever since the pioneering experiment on second harmonic generation carried out by Franken in 1961 [1]. Indeed,  相似文献   

16.
<正>Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a huge impact on the world, causing millions of deaths and a serious blow to the global economy. SARS-CoV-2 can aack most body tissues with devastating consequences [1].e current global SARS-CoV-2 outbreak has exposed our shortcomings in the prevention and control of infectious diseases,  相似文献   

17.
<正>Human beings are the most intelligent living beings on Earth.Creating reconstructions of missing human limbs that can be naturally integrated into the human body is a lofty ambition and faces challenges in neuroscience,information science,mechanical and electronic engineering,and many other disciplines.Based on the development history of robotic prosthetic hands over the past 70 years,  相似文献   

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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...  相似文献   

20.
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...  相似文献   

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