查看更多>>摘要：The question of whether an ideal network exists with global scalability in its full life cycle has always been a first-principles problem in the research of network systems and architectures.Thus far,it has not been possible to scientifically practice the design criteria of an ideal network in a unimorphic network system,making it difficult to adapt to known services with clear application scenarios while supporting the ever-growing future services with unexpected characteristics.Here,we theoretically prove that no unimorphic network system can simultaneously meet the scalability requirement in a full cycle in three dimensions-the service-level agreement(S),multiplexity(M),and variousness(Ⅴ)-which we name as the"impossible SMV triangle"dilemma.It is only by transforming the current network development paradigm that the contradiction between global scalability and a unified network infrastructure can be resolved from the perspectives of thinking,methodology,and practice norms.In this paper,we propose a theoretical framework called the polymorphic network environment(PNE),the first principle of which is to separate or decouple application network systems from the infrastructure environment and,under the given resource conditions,use core technologies such as the elementization of network baselines,the dynamic aggregation of resources,and collaborative software and hardware arrangements to generate the capability of the"network of networks."This makes it possible to construct an ideal network system that is designed for change and capable of symbiosis and coexistence with the generative network mor-pha in the spatiotemporal dimensions.An environment test for principle verification shows that the gen-erated representative application network modalities can not only coexist without mutual influence but also independently match well-defined multimedia services or custom services under the constraints of technical and economic indicators.
查看更多>>摘要：The rapid development of the global economy and population growth are accompanied by the production of numerous waste textiles.This leads to a waste of limited resources and serious environmental pollu-tion problems caused by improper disposal.The rational recycling of wasted textiles and their transfor-mation into high-value-added emerging products,such as smart wearable devices,is fascinating.Here,we propose a novel roadmap for turning waste cotton fabrics into three-dimensional elastic fiber-based thermoelectric aerogels by a one-step lyophilization process with decoupled self-powered temperature-compression strain dual-parameter sensing properties.The thermoelectric aerogel exhibits a fast compression response time of 0.2 s,a relatively high Seebeck coefficient of 43 μV·K-1 and an ultra-low thermal conductivity of less than 0.04 W.m-1·K-1.The cross-linking of trimethoxy(methyl)silane(MTMS)and cellulose endowed the aerogel with excellent elasticity,allowing it to be used as a compres-sive strain sensor for guessing games and facial expression recognition.In addition,based on the thermo-electric effect,the aerogel can perform temperature detection and differentiation in self-powered mode with the output thermal voltage as the stimulus signal.Furthermore,the wearable system,prepared by connecting the aerogel-prepared array device with a wireless transmission module,allows for tempera-ture alerts in a mobile phone application without signal interference due to the compressive strains gen-erated during gripping.Hence,our strategy is significant for reducing global environmental pollution and provides a revelatory path for transforming waste textiles into high-value-added smart wearable devices.
查看更多>>摘要：Biodegradable polylactic acid(PLA)melt-blown nonwovens are attractive candidates to replace non-degradable polypropylene melt-blown nonwovens.However,it is still an extremely challenging task to prepare PLA melt-blown nonwovens with sufficient mechanical properties for practical application.Herein,we report a simple strategy for the large-scale preparation of biodegradable PLA/poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)melt-blown nonwovens with high strength and excellent toughness.In this process,a small amount of PHBV is added to PLA to improve the latter's crystallization rate and crystallinity.In addition,when the PHBV content increases from 0 to 7.5 wt％,the diameters of the PLA/PHBV melt-blown fibers decrease significantly(with the proportion of nanofibers increasing from 7.7％to 42.9％).The resultant PLA/PHBV(5 wt％PHBV)melt-blown nonwovens exhibit the highest mechanical properties.The tensile stress,elongation,and toughness of PLA/PHBV(5 wt％PHBV)melt-blown nonwovens reach 2.5 MPa,45％,and 1.0 MJ·m-3,respectively.More importantly,PLA/PHBV melt-blown nonwovens can be completely degraded into carbon dioxide and water after four months in the soil,making them environmentally friendly.A general tensile-failure model of melt-blown nonwovens is proposed in this study,which may shed light on mechanical performance enhancement for nonwovens.
查看更多>>摘要：Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100％,with nano-TiO2 encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environ-mental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.
查看更多>>摘要：This study demonstrates the feasibility and effectiveness of utilizing native soils as a resource for inocula to produce n-caproate through the chain elongation(CE)platform,offering new insights into anaerobic soil processes.The results reveal that all five of the tested soil types exhibit CE activity when supplied with high concentrations of ethanol and acetate,highlighting the suitability of soil as an ideal source for n-caproate production.Compared with anaerobic sludge and pit mud,the native soil CE system exhib-ited higher selectivity(60.53％),specificity(82.32％),carbon distribution(60.00％),electron transfer effi-ciency(165.00％),and conductivity(0.59 ms·cm-1).Kinetic analysis further confirmed the superiority of soil in terms of a shorter lag time and higher yield.A microbial community analysis indicated a positive correlation between the relative abundances of Pseudomonas,Azotobacter,and Clostridium and n-caproate production.Moreover,metagenomics analysis revealed a higher abundance of functional genes in key microbial species,providing direct insights into the pathways involved in n-caproate formation,including in situ CO2 utilization,ethanol oxidation,fatty acid biosynthesis(FAB),and reverse beta-oxidation(RBO).The numerous functions in FAB and RBO are primarily associated with Pseudomonas,Clostridium,Rhodococcus,Stenotrophomonas,and Geobacter,suggesting that these genera may play roles that are involved or associated with the CE process.Overall,this innovative inoculation strategy offers an efficient microbial source for n-caproate production,underscoring the importance of considering CE activity in anaerobic soil microbial ecology and holding potential for significant economic and environmental ben-efits through soil consortia exploration.
查看更多>>摘要：As a precise and versatile tool for genome manipulation,the clustered regularly interspaced short palin-dromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)platform holds promise for modifying fish traits of interest.With the aim of reducing transgene introgression and controlling reproduction,upscaled disease resistance and reproductive intervention in catfish species have been studied to lower the poten-tial environmental risks of the introgression of escapees as transgenic animals.Taking advantage of the CRISPR/Cas9-mediated system,we succeeded in integrating the cathelicidin gene(As-Cath)from an alliga-tor(Alligator sinensis)into the target luteinizing hormone(lh)locus of channel catfish(Ictalurus punctatus)using two delivery systems assisted by double-stranded DNA(dsDNA)and single-stranded oligodeoxynu-cleotides(ssODNs),respectively.In this study,high knock in(KI)efficiency(22.38％,64/286)but low on-target events was achieved using the ssODN strategy,whereas adopting a dsDNA as the donor template led to an efficient on-target KI(10.80％,23/213).The on-target KI of As-Cath was instrumental in establishing the lh knockout(LH-_As-Cath+)catfish line,which displayed heightened disease resistance and reduced fecundity compared with the wild-type(WT)sibling fish.Furthermore,administration of human chorionic gonadotropin(HCG)and luteinizing hormone-releasing hormone analogue(LHRHa)can restore the repro-duction of the transgenic fish line.Overall,we replaced the lh gene with an alligator cathelicidin transgene and then administered hormone therapy to move towards complete reproductive control of disease-resistant transgenic catfish in an environmentally responsible manner.This strategy not only effectively improves consumer-valued traits but also guards against unwanted introgression,providing a break-through in aquaculture genetics to confine fish reproduction and prevent the establishment of transgenic or domestic genotypes in the natural environment.
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