The development of wearable electronic systems has generated increasing demand for flexible power sources.Alkaline zinc(Zn)-based batteries,as one of the most mature energy storage technologies,have been considered as...The development of wearable electronic systems has generated increasing demand for flexible power sources.Alkaline zinc(Zn)-based batteries,as one of the most mature energy storage technologies,have been considered as a promising power source owing to their exceptional safety,low costs,and outstanding electrochemical performance.However,the conventional alkaline Zn-based battery systems face many challenges associated with electrodes and electrolytes,causing low capacity,poor cycle life,and inferior mechanical performance.Recent advances in materials and structure design have enabled the revisitation of the alkaline Zn-based battery technology for applications in flexible electronics.Herein,we summarize the up-to-date works in flexible alkaline Zn-based batteries and analyze the strategies employed to improve battery performance.Firstly,we introduce the three most reported cathode materials(including Ag-based,Ni-based,and Co-based materials)for flexible alkaline Zn-based batteries.Then,challenges and modifications in battery anodes are investigated.Thirdly,the recently advanced gel electrolytes are introduced from their properties,functions as well as advanced fabrications.Finally,recent works and the advantages of sandwich-type,fiber-type and thin film-type flexible batteries are summarized and compared.This review provides insights and guidance for the design of high-performance flexible Zn-based batteries for next-generation electronics.展开更多
Bread wheat(Triticum aestivum)is a staple food crop worldwide.The genetic dissection of important nutrient traits is essential for the biofortification of wheat to meet the nutritional needs of the world's growing...Bread wheat(Triticum aestivum)is a staple food crop worldwide.The genetic dissection of important nutrient traits is essential for the biofortification of wheat to meet the nutritional needs of the world's growing population.Here,45,298 single-nucleotide polymorphisms(SNPs)from 55K chip arrays were used to genotype a panel of 768 wheat cultivars,and a total of 154 quantitative trait loci(QTLs)were detected for eight traits under three environments by genome-wide association study(GWAS).Three QTLs(qMn-3B.1,qFe-3B.4,and qSe-3B.1/qFe-3B.6)detected repeatedly under different environments or traits were subjected to subsequent analyses based on linkage disequilibrium decay and the P-values of significant SNPs.Significant SNPs in the three QTL regions formed six haplotypes for qMn-3B.1,three haplotypes for qFe-3B.4,and three haplotypes for qSe-3B.1/qFe-3B.6.Phenotypic analysis revealed significant differences among haplotypes.These results indicated that the concentrations of several nutrient elements have been modified during the domestication of landraces to modern wheat.Based on the QTL regions,we identified 15 high-confidence genes,eight of which were stably expressed in different tissues and/or developmental stages.TraesCS3B02G046100 in qMn-3B.1 and TraesCS3B02G199500 in qSe-3B.1/qFe-3B.6 were both inferred to interact with metal ions according to the Gene Ontology(GO)analysis.TraesCS3B02G199000,which belongs to qSe-3B.1/qFe-3B.6,was determined to be a member of the WRKY gene family.Overall,this study provides several reliable QTLs that may significantly affect the concentrations of nutrient elements in wheat grain,and this information will facilitate the breeding of wheat cultivars with improved grain properties.展开更多
The performance evaluation of the process industry, which has been a popular topic nowadays, can not only find the weakness and verify the resilience and reliability of the process, but also provide some suggestions t...The performance evaluation of the process industry, which has been a popular topic nowadays, can not only find the weakness and verify the resilience and reliability of the process, but also provide some suggestions to improve the process benefits and efficiency. Nevertheless, the performance assessment principally concentrates upon some parts of the entire system at present, for example the controller assessment. Although some researches focus on the whole process, they aim at discovering the relationships between profit, society, policies and so forth, instead of relations between overall performance and some manipulated variables, that is, the total plant performance. According to the big data of different performance statuses, this paper proposes a hierarchical framework to select some structured logic rules from monitored variables to estimate the current state of the process. The variables related to safety and profits are regarded as key factors to performance evaluation. To better monitor the process state and observe the performance variation trend of the process, a classificationvisualization method based on kernel principal component analysis(KPCA) and self-organizing map(SOM) is established. The dimensions of big data produced by the process are first reduced by KPCA and then the processed data will be mapped into a two-dimensional grid chart by SOM to evaluate the performance status. The monitoring method is applied to the Tennessee Eastman process. Monitoring results indicate that off-line and on-line performance status can be well detected in a two-dimensional diagram.展开更多
Perovskite materials show exciting potential for light-emitting diodes(LEDs)owing to their intrinsically high photoluminescence efficiency and color purity.The research focusing on perovskite light-emitting diodes(PeL...Perovskite materials show exciting potential for light-emitting diodes(LEDs)owing to their intrinsically high photoluminescence efficiency and color purity.The research focusing on perovskite light-emitting diodes(PeLEDs)has experienced an exponential growth in the past six years.The maximum external quantum efficiency of red,green,and blue PeLEDs has surpassed 20%,20%,and 10%,respectively.Nevertheless,the current PeLEDs are still in the laboratory stage,and the key for further development of PeLEDs is large-area fabrication.In this paper,we briefly discuss the similarities and differences between manufacturing high-quality and large-area PeLEDs and perovskite solar cells.Especially,the general technologies for fabricating large-area perovskite films are also introduced.The effect of charge transport layers and electrodes on large-area devices are discussed as well.Most importantly,we summarize the advances of large-area(active area≥30 mm^(2))PeLEDs reported since 2017,and describe the methods for optimizing large-area PeLEDs reported in the literature.Finally,the development perspective of PeLEDs is presented for the goal of highly efficient and large-area PeLED fabrication.It is of great significance for the application of PeLEDs in future display and lighting.展开更多
Nanosecond(ns)pulsed dielectric barrier discharge(DBD)is considered as a promising method to produce controllable large-volume and high activity low-temperature plasma at atmospheric pressure,which makes it suitable f...Nanosecond(ns)pulsed dielectric barrier discharge(DBD)is considered as a promising method to produce controllable large-volume and high activity low-temperature plasma at atmospheric pressure,which makes it suitable for wide applications.In this work,the ns pulse power supply is used to excite Ar DBD and the influences of the pulse parameters(voltage amplitude,pulse width,pulse rise and fall times)on the DBD uniformity are investigated.The gas gap voltage(Ug)and conduct current(Ig)are separated from the measured voltage and current waveforms to analyze the influence of electrical parameters.The spectral line intensity ratio of two Ar excited species is used as an indicator of the electron temperature(Te).The time resolved discharge processes are recorded by an intensified charge-coupled device camera and a one-dimensional fluid model is employed to simulate the spatial and temporal distributions of electrons,ions,metastable argon atoms and Te.Combining the experimental and numerical results,the mechanism of the pulse parameters influencing on the discharge uniformity is discussed.It is shown that the space electric field intensity and the space particles'densities are mainly responsible for the variation of discharge uniformity.With the increase of voltage and pulse width,the electric field intensity and the density of space particles increased,which results in the discharge mode transition from non-uniform to uniform,and then non-uniform.Furthermore,the extension of pulse rise and fall times leads to the discharge transition from uniform to nonuniform.The results are helpful to reveal the mechanism of ns pulsed DBD mode transition and to realize controllable and uniform plasma sources at atmospheric pressure.展开更多
Strategic management oriented enterprise internal control is an inevitable choice after the enterprise develops to a certain scale,and it is also an important starting point for enterprises to adjust their own strateg...Strategic management oriented enterprise internal control is an inevitable choice after the enterprise develops to a certain scale,and it is also an important starting point for enterprises to adjust their own strategic layout and resource allocation.With the continuous expansion of the scope of internal control supervision,the traditional mode of internal control supervision has become more and more restricted.In view of this,the present study started from the necessity of internal control supervision from the overall and top-level perspectives,and analyzed the current problems in the internal control of enterprises from the perspective of strategic management.The problems include the lack of methods and tools of strategic management,insufficient awareness of strategic risk management,insufficient expansion of internal control objects,insufficient prior intervention in internal control supervision,etc.Finally,it came up with the idea of constructing strategic enterprise internal control,in order to provide an effective reference for the study of enterprise internal control.展开更多
Chiral metasurfaces have different electromagnetic responses with circularly polarized lights,showing as circular dichroism and optical activity.Here,a novel kind of all-silicon chiral metasurface is proposed by intro...Chiral metasurfaces have different electromagnetic responses with circularly polarized lights,showing as circular dichroism and optical activity.Here,a novel kind of all-silicon chiral metasurface is proposed by introducing destructive interference between achiral meta-atoms.The maximum value of circular dichroism spectra can reach 0.49.By adding an antireflective layer at the side of the silicon substrate,the maximum circular dichroism reaches 0.54.What is more,the bandwidth of circular dichroism greater than 0.4 reaches 0.15 THz.Two samples are fabricated to verify the feasibility of this scheme,and the experimental results are in good agreement with the simulations.In addition,the proposed scheme can also be used to generate various interesting functions,such as beam control and vortex generator.This flexible and efficient implementation solution of chiral metasurface can bring new ideas to the development of chiral devices in the future.展开更多
How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with hi...How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe_(2)O_(3) nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe_(2)O_(3) nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.展开更多
Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair ce...Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair cell function.ANSD represents up to 15%of individuals with hearing impairments.Through mutation screening,bioinformatic analysis and expression studies,we have previously identified several apoptosis-inducing factor(AIF)mitochondria-associated 1(AIFM1)variants in ANSD families and in some other sporadic cases.Here,to elucidate the pathogenic mechanisms underlying each AIFM1 variant,we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system and constructed AIF-wild type(WT)and AIF-mutant(mut)(p.T260A,p.R422W,and p.R451Q)stable transfection cell lines.We then analyzed AIF structure,coenzyme-binding affinity,apoptosis,and other aspects.Results revealed that these variants resulted in impaired dimerization,compromising AIF function.The reduction reaction of AIF variants had proceeded slower than that of AIF-WT.The average levels of AIF dimerization in AIF variant cells were only 34.5%-49.7%of that of AIF-WT cells,resulting in caspase-independent apoptosis.The average percentage of apoptotic cells in the variants was 12.3%-17.9%,which was significantly higher than that(6.9%-7.4%)in controls.However,nicotinamide adenine dinucleotide(NADH)treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells.Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD,and introduce NADH as a potential drug for ANSD treatment.Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.展开更多
Rare-earth zirconates with pyrochlore and fluorite structures have recently been identified as promising thermal barrier coating materials owing to their low thermal conductivities.In this study,six samples with the g...Rare-earth zirconates with pyrochlore and fluorite structures have recently been identified as promising thermal barrier coating materials owing to their low thermal conductivities.In this study,six samples with the general formula(NdSmEuGd)_((1-x)/2)Dy_(2x)Zr_(2)O_(7)were synthesized to further reduce the thermal conductivity.X-ray diffraction and Raman spectroscopy showed that the transition from an ordered pyrochlore to a disordered fluorite structure is due to cation and anion disorder.Transmission electron microscopy showed that anion disorder occurred before cation disorder.A modified mass disorder parameter was introduced into this system,which can describe the change in thermal conductivity well.This parameter can be a basis for designing more complex materials with lower thermal conductivities.展开更多
Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications.Bound states in the continuum(BICs)have been demonstrated to be...Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications.Bound states in the continuum(BICs)have been demonstrated to be associated with topological charge and vortex polarization singularities in momentum space.For conventional symmetric photonic crystal slabs(PhCSs),BIC is enclosed by linearly polarized far fields with winding angle of 2π,which is unfavorable for high-capacity and multi-functionality integration-optics applications.Here,we show that by breakingσz-symmetry of the PhCS,asymmetry in upward and downward directions and arbitrarily polarized BIC can be realized with a bilayer-twisted PhCS.It exhibits elliptical polarization states with constant ellipticity angle at every point in momentum space within the vicinity of BIC.The topological nature of BIC reflects on the orientation angle of polarization state,with a topological charge of 1 for any value of ellipticity angle.Full coverage of Poincarésphere(i.e.,-π/4≤X≤4 and-π/2≤ψ≤π/2)and higher-order Poincarésphere can be realized by tailoring the twist angles.Our findings may open up new avenues for applications in structured light,quantum optics,and twistronics for photons.展开更多
The microenvironment of the wound bed is essential in the regulation of wound repair.In this regard,strategies that provide a repairing favorable microenvironment may effectively improve healing outcomes.Herein,we att...The microenvironment of the wound bed is essential in the regulation of wound repair.In this regard,strategies that provide a repairing favorable microenvironment may effectively improve healing outcomes.Herein,we attempted to use electrical stimulation(ES)to boost the paracrine function of adipose-derived stem cells from rats(rASCs).By examining the concentrations of two important growth factors,VEGF and PDGF-AA,in the cell culture supernatant,we found that ES,especially 5𝜇A ES,stimulated rASCs to produce more paracrine factors(5𝜇A-PFs).Further studies showed that ES may modulate the paracrine properties of rASCs by upregulating the levels of TRPV2 and TRPV3,thereby inducing intracellular Ca^(2+) influx.To deliver the PFs to the wound to effectively improve the wound microenvironment,we prepared a heparinized PGA host-guest hydrogel(PGA-Hp hydrogel).Moreover,PGA-Hp hydrogel loaded with 5𝜇A-PFs effectively accelerated the repair process of the full-thickness wound model in rats.Our findings revealed the effects of ES on the paracrine properties of rASCs and highlighted the potential application of heparinized PGA host-guest hydrogels loaded with PFs derived from electrically stimulated rASCs in wound repair.展开更多
The step edges and intrinsic atomic structure of single-crystal substrate play a critical role in determining the growth pathways of transition metal dichalcogenide(TMD)grains,particularly whether the TMDs will grow i...The step edges and intrinsic atomic structure of single-crystal substrate play a critical role in determining the growth pathways of transition metal dichalcogenide(TMD)grains,particularly whether the TMDs will grow into wafer-scale single-crystal or anisotropic nanoribbons.Hereby,we investigate the growth behaviours of the MoS_(2)nanograins on(0001)and()sapphire substrates.On one hand,the step edges formed on the(0001)surface after thermal treatment are found to promote the macroscopic aggregation of MoS_(2)nanograins and to form unidirectional large triangular islands along with the<>steps in the annealing process,while on the pristine(0001)surface,the MoS_(2)nanograins grow into a random network-like pattern.Moreover,oxygen treatment on the substrate can further enhance the growth of MoS_(2)nanograins.Transmission electron microscopy and fast Fourier transform patterns reveal that the substrate could modulate the orientation of MoS_(2)nanograins during their growing process.On the other hand,the MoS_(2)nanograins on the surface could self-assemble into one-dimensional nanoribbons due to the strong structural anisotropy of the substrate.In addition,the ratio of Raman intensities for peaks that correspond to the and A1g phonon modes shows a linear relationship with the grain size due to the change of the“phonon confinement”.Moreover,new peaks located at 226 and 280 cm−1 can be observed in the off-resonant and resonant Raman spectra for the MoS_(2)nanograin samples,respectively,which can be attributed to the scatterings from the edges of as-fabricated MoS_(2)nanostructures.展开更多
Plant metabolites are important for plant development and human health.Plants of celery(Apium graveolens L.)with different-colored petioles have been formed in the course of long-term evolution.However,the composition...Plant metabolites are important for plant development and human health.Plants of celery(Apium graveolens L.)with different-colored petioles have been formed in the course of long-term evolution.However,the composition,content distribution,and mechanisms of accumulation of metabolites in different-colored petioles remain elusive.Using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS),1159 metabolites,including 100 lipids,72 organic acids and derivatives,83 phenylpropanoids and polyketides,and several alkaloids and terpenoids,were quantified in four celery cultivars,each with a different petiole color.There were significant differences in the types and contents of metabolites in celery with different-colored petioles,with the most striking difference between green celery and purple celery,followed by white celery and green celery.Annotated analysis of metabolic pathways showed that the metabolites of the different-colored petioles were significantly enriched in biosynthetic pathways such as anthocyanin,flavonoid,and chlorophyll pathways,suggesting that these metabolic pathways may play a key role in determining petiole color in celery.The content of chlorophyll in green celery was significantly higher than that in other celery cultivars,yellow celery was rich in carotenoids,and the content of anthocyanin in purple celery was significantly higher than that in the other celery cultivars.The color of the celery petioles was significantly correlated with the content of related metabolites.Among the four celery cultivars,the metabolites of the anthocyanin biosynthesis pathway were enriched in purple celery.The results of quantitative real-time polymerase chain reaction(q RT-PCR)suggested that the differential expression of the chalcone synthase(CHS)gene in the anthocyanin biosynthesis pathway might affect the biosynthesis of anthocyanin in celery.In addition,HPLC analysis revealed that cyanidin is the main pigment in purple celery.This study explored the differences in the types and contents of metabolites in celery cultivars with different-colored petioles and identified key substances for color formation.The results provide a theoretical basis and technical support for genetic improvement of celery petiole color.展开更多
基金financial support from the Australian Research Council(LP1900113)。
文摘The development of wearable electronic systems has generated increasing demand for flexible power sources.Alkaline zinc(Zn)-based batteries,as one of the most mature energy storage technologies,have been considered as a promising power source owing to their exceptional safety,low costs,and outstanding electrochemical performance.However,the conventional alkaline Zn-based battery systems face many challenges associated with electrodes and electrolytes,causing low capacity,poor cycle life,and inferior mechanical performance.Recent advances in materials and structure design have enabled the revisitation of the alkaline Zn-based battery technology for applications in flexible electronics.Herein,we summarize the up-to-date works in flexible alkaline Zn-based batteries and analyze the strategies employed to improve battery performance.Firstly,we introduce the three most reported cathode materials(including Ag-based,Ni-based,and Co-based materials)for flexible alkaline Zn-based batteries.Then,challenges and modifications in battery anodes are investigated.Thirdly,the recently advanced gel electrolytes are introduced from their properties,functions as well as advanced fabrications.Finally,recent works and the advantages of sandwich-type,fiber-type and thin film-type flexible batteries are summarized and compared.This review provides insights and guidance for the design of high-performance flexible Zn-based batteries for next-generation electronics.
基金This work was supported by grants from the Natural Science Foundation of Shandong Province,China(ZR2020MC096,ZR2021ZD31,and ZR2020MC151)the Agricultural Variety Improvement Project of Shandong Province,China(2021LZGC013 and 2022LZGC002).
文摘Bread wheat(Triticum aestivum)is a staple food crop worldwide.The genetic dissection of important nutrient traits is essential for the biofortification of wheat to meet the nutritional needs of the world's growing population.Here,45,298 single-nucleotide polymorphisms(SNPs)from 55K chip arrays were used to genotype a panel of 768 wheat cultivars,and a total of 154 quantitative trait loci(QTLs)were detected for eight traits under three environments by genome-wide association study(GWAS).Three QTLs(qMn-3B.1,qFe-3B.4,and qSe-3B.1/qFe-3B.6)detected repeatedly under different environments or traits were subjected to subsequent analyses based on linkage disequilibrium decay and the P-values of significant SNPs.Significant SNPs in the three QTL regions formed six haplotypes for qMn-3B.1,three haplotypes for qFe-3B.4,and three haplotypes for qSe-3B.1/qFe-3B.6.Phenotypic analysis revealed significant differences among haplotypes.These results indicated that the concentrations of several nutrient elements have been modified during the domestication of landraces to modern wheat.Based on the QTL regions,we identified 15 high-confidence genes,eight of which were stably expressed in different tissues and/or developmental stages.TraesCS3B02G046100 in qMn-3B.1 and TraesCS3B02G199500 in qSe-3B.1/qFe-3B.6 were both inferred to interact with metal ions according to the Gene Ontology(GO)analysis.TraesCS3B02G199000,which belongs to qSe-3B.1/qFe-3B.6,was determined to be a member of the WRKY gene family.Overall,this study provides several reliable QTLs that may significantly affect the concentrations of nutrient elements in wheat grain,and this information will facilitate the breeding of wheat cultivars with improved grain properties.
基金Supported by the National Natural Science Foundation of China(61590923,61422303,21376077)
文摘The performance evaluation of the process industry, which has been a popular topic nowadays, can not only find the weakness and verify the resilience and reliability of the process, but also provide some suggestions to improve the process benefits and efficiency. Nevertheless, the performance assessment principally concentrates upon some parts of the entire system at present, for example the controller assessment. Although some researches focus on the whole process, they aim at discovering the relationships between profit, society, policies and so forth, instead of relations between overall performance and some manipulated variables, that is, the total plant performance. According to the big data of different performance statuses, this paper proposes a hierarchical framework to select some structured logic rules from monitored variables to estimate the current state of the process. The variables related to safety and profits are regarded as key factors to performance evaluation. To better monitor the process state and observe the performance variation trend of the process, a classificationvisualization method based on kernel principal component analysis(KPCA) and self-organizing map(SOM) is established. The dimensions of big data produced by the process are first reduced by KPCA and then the processed data will be mapped into a two-dimensional grid chart by SOM to evaluate the performance status. The monitoring method is applied to the Tennessee Eastman process. Monitoring results indicate that off-line and on-line performance status can be well detected in a two-dimensional diagram.
基金Project supported by the Ningxia Key Project of Research and Development Plan(Grant No.2020BDE03013).
文摘Perovskite materials show exciting potential for light-emitting diodes(LEDs)owing to their intrinsically high photoluminescence efficiency and color purity.The research focusing on perovskite light-emitting diodes(PeLEDs)has experienced an exponential growth in the past six years.The maximum external quantum efficiency of red,green,and blue PeLEDs has surpassed 20%,20%,and 10%,respectively.Nevertheless,the current PeLEDs are still in the laboratory stage,and the key for further development of PeLEDs is large-area fabrication.In this paper,we briefly discuss the similarities and differences between manufacturing high-quality and large-area PeLEDs and perovskite solar cells.Especially,the general technologies for fabricating large-area perovskite films are also introduced.The effect of charge transport layers and electrodes on large-area devices are discussed as well.Most importantly,we summarize the advances of large-area(active area≥30 mm^(2))PeLEDs reported since 2017,and describe the methods for optimizing large-area PeLEDs reported in the literature.Finally,the development perspective of PeLEDs is presented for the goal of highly efficient and large-area PeLED fabrication.It is of great significance for the application of PeLEDs in future display and lighting.
基金supported by National Natural Science Foundation of China(Nos.52177148,51777091 and 52037004)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1449)。
文摘Nanosecond(ns)pulsed dielectric barrier discharge(DBD)is considered as a promising method to produce controllable large-volume and high activity low-temperature plasma at atmospheric pressure,which makes it suitable for wide applications.In this work,the ns pulse power supply is used to excite Ar DBD and the influences of the pulse parameters(voltage amplitude,pulse width,pulse rise and fall times)on the DBD uniformity are investigated.The gas gap voltage(Ug)and conduct current(Ig)are separated from the measured voltage and current waveforms to analyze the influence of electrical parameters.The spectral line intensity ratio of two Ar excited species is used as an indicator of the electron temperature(Te).The time resolved discharge processes are recorded by an intensified charge-coupled device camera and a one-dimensional fluid model is employed to simulate the spatial and temporal distributions of electrons,ions,metastable argon atoms and Te.Combining the experimental and numerical results,the mechanism of the pulse parameters influencing on the discharge uniformity is discussed.It is shown that the space electric field intensity and the space particles'densities are mainly responsible for the variation of discharge uniformity.With the increase of voltage and pulse width,the electric field intensity and the density of space particles increased,which results in the discharge mode transition from non-uniform to uniform,and then non-uniform.Furthermore,the extension of pulse rise and fall times leads to the discharge transition from uniform to nonuniform.The results are helpful to reveal the mechanism of ns pulsed DBD mode transition and to realize controllable and uniform plasma sources at atmospheric pressure.
文摘Strategic management oriented enterprise internal control is an inevitable choice after the enterprise develops to a certain scale,and it is also an important starting point for enterprises to adjust their own strategic layout and resource allocation.With the continuous expansion of the scope of internal control supervision,the traditional mode of internal control supervision has become more and more restricted.In view of this,the present study started from the necessity of internal control supervision from the overall and top-level perspectives,and analyzed the current problems in the internal control of enterprises from the perspective of strategic management.The problems include the lack of methods and tools of strategic management,insufficient awareness of strategic risk management,insufficient expansion of internal control objects,insufficient prior intervention in internal control supervision,etc.Finally,it came up with the idea of constructing strategic enterprise internal control,in order to provide an effective reference for the study of enterprise internal control.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.61675147,61735010,and 91838301)National Key Research and Development Program of China(Grant No.2017YFA0700-202)+1 种基金Basic Research Program of Shenzhen(Grant No.JCYJ2017041215-4447469)Program for Science&Technology Innovation Talents of Henan Province(Grant No.202102310001)。
文摘Chiral metasurfaces have different electromagnetic responses with circularly polarized lights,showing as circular dichroism and optical activity.Here,a novel kind of all-silicon chiral metasurface is proposed by introducing destructive interference between achiral meta-atoms.The maximum value of circular dichroism spectra can reach 0.49.By adding an antireflective layer at the side of the silicon substrate,the maximum circular dichroism reaches 0.54.What is more,the bandwidth of circular dichroism greater than 0.4 reaches 0.15 THz.Two samples are fabricated to verify the feasibility of this scheme,and the experimental results are in good agreement with the simulations.In addition,the proposed scheme can also be used to generate various interesting functions,such as beam control and vortex generator.This flexible and efficient implementation solution of chiral metasurface can bring new ideas to the development of chiral devices in the future.
基金This work was supported by the National Natural Science Foundation of China(Nos.21978198 and 22002052).
文摘How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe_(2)O_(3) nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe_(2)O_(3) nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.
基金the National Natural Science Foundation of China(Nos.32070584,81830028,31771398,82222016,and 8207040100)the Zhejiang Provincial Natural Science Foundation of China(No.LZ19C060001)the Fundamental Research Funds for the Central Universities(No.2019QNA6001)。
文摘Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair cell function.ANSD represents up to 15%of individuals with hearing impairments.Through mutation screening,bioinformatic analysis and expression studies,we have previously identified several apoptosis-inducing factor(AIF)mitochondria-associated 1(AIFM1)variants in ANSD families and in some other sporadic cases.Here,to elucidate the pathogenic mechanisms underlying each AIFM1 variant,we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system and constructed AIF-wild type(WT)and AIF-mutant(mut)(p.T260A,p.R422W,and p.R451Q)stable transfection cell lines.We then analyzed AIF structure,coenzyme-binding affinity,apoptosis,and other aspects.Results revealed that these variants resulted in impaired dimerization,compromising AIF function.The reduction reaction of AIF variants had proceeded slower than that of AIF-WT.The average levels of AIF dimerization in AIF variant cells were only 34.5%-49.7%of that of AIF-WT cells,resulting in caspase-independent apoptosis.The average percentage of apoptotic cells in the variants was 12.3%-17.9%,which was significantly higher than that(6.9%-7.4%)in controls.However,nicotinamide adenine dinucleotide(NADH)treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells.Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD,and introduce NADH as a potential drug for ANSD treatment.Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.
基金This work is supported by the National Key Technologies Research and Development Program of China(No.2018YFB0704400)Shanghai Technical Platform for Testing on Inorganic Materials(No.19DZ2290700).
文摘Rare-earth zirconates with pyrochlore and fluorite structures have recently been identified as promising thermal barrier coating materials owing to their low thermal conductivities.In this study,six samples with the general formula(NdSmEuGd)_((1-x)/2)Dy_(2x)Zr_(2)O_(7)were synthesized to further reduce the thermal conductivity.X-ray diffraction and Raman spectroscopy showed that the transition from an ordered pyrochlore to a disordered fluorite structure is due to cation and anion disorder.Transmission electron microscopy showed that anion disorder occurred before cation disorder.A modified mass disorder parameter was introduced into this system,which can describe the change in thermal conductivity well.This parameter can be a basis for designing more complex materials with lower thermal conductivities.
基金support from the National Natural Science Foundation of China(no.12204264)the Shenzhen Stability Support Program(no.WDZC20220810152404001)+2 种基金the Cross-Disciplinary Research Fund of Tsinghua Shenzhen International Graduate School(SIGS),Tsinghua University(JC2022001),and the startup funding in Tsinghua Shenzhen International Graduate School(SIGS),Tsinghua University(no.01030100006)support from the National Natural Science Foundation of China(No.62205246)the Fundamental Research Funds for the Central Universities.C-W.Q.acknowledges financial support from the NRF,Prime Minister's Office,Singapore under the Competitive Research Program Award(NRF-CRP26-2021-0063).
文摘Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications.Bound states in the continuum(BICs)have been demonstrated to be associated with topological charge and vortex polarization singularities in momentum space.For conventional symmetric photonic crystal slabs(PhCSs),BIC is enclosed by linearly polarized far fields with winding angle of 2π,which is unfavorable for high-capacity and multi-functionality integration-optics applications.Here,we show that by breakingσz-symmetry of the PhCS,asymmetry in upward and downward directions and arbitrarily polarized BIC can be realized with a bilayer-twisted PhCS.It exhibits elliptical polarization states with constant ellipticity angle at every point in momentum space within the vicinity of BIC.The topological nature of BIC reflects on the orientation angle of polarization state,with a topological charge of 1 for any value of ellipticity angle.Full coverage of Poincarésphere(i.e.,-π/4≤X≤4 and-π/2≤ψ≤π/2)and higher-order Poincarésphere can be realized by tailoring the twist angles.Our findings may open up new avenues for applications in structured light,quantum optics,and twistronics for photons.
基金supported by the National Natu-ral Science Foundation of China (T2288101,31971266,82272152,22075087)Guangdong Basic and Applied Basic Research Foundation (2022A1515011925)the Key Research and Development Program of Guangzhou (202007020002).
文摘The microenvironment of the wound bed is essential in the regulation of wound repair.In this regard,strategies that provide a repairing favorable microenvironment may effectively improve healing outcomes.Herein,we attempted to use electrical stimulation(ES)to boost the paracrine function of adipose-derived stem cells from rats(rASCs).By examining the concentrations of two important growth factors,VEGF and PDGF-AA,in the cell culture supernatant,we found that ES,especially 5𝜇A ES,stimulated rASCs to produce more paracrine factors(5𝜇A-PFs).Further studies showed that ES may modulate the paracrine properties of rASCs by upregulating the levels of TRPV2 and TRPV3,thereby inducing intracellular Ca^(2+) influx.To deliver the PFs to the wound to effectively improve the wound microenvironment,we prepared a heparinized PGA host-guest hydrogel(PGA-Hp hydrogel).Moreover,PGA-Hp hydrogel loaded with 5𝜇A-PFs effectively accelerated the repair process of the full-thickness wound model in rats.Our findings revealed the effects of ES on the paracrine properties of rASCs and highlighted the potential application of heparinized PGA host-guest hydrogels loaded with PFs derived from electrically stimulated rASCs in wound repair.
基金the financial support from the Australian Research Council Discovery Program(No.DP190103661).
文摘The step edges and intrinsic atomic structure of single-crystal substrate play a critical role in determining the growth pathways of transition metal dichalcogenide(TMD)grains,particularly whether the TMDs will grow into wafer-scale single-crystal or anisotropic nanoribbons.Hereby,we investigate the growth behaviours of the MoS_(2)nanograins on(0001)and()sapphire substrates.On one hand,the step edges formed on the(0001)surface after thermal treatment are found to promote the macroscopic aggregation of MoS_(2)nanograins and to form unidirectional large triangular islands along with the<>steps in the annealing process,while on the pristine(0001)surface,the MoS_(2)nanograins grow into a random network-like pattern.Moreover,oxygen treatment on the substrate can further enhance the growth of MoS_(2)nanograins.Transmission electron microscopy and fast Fourier transform patterns reveal that the substrate could modulate the orientation of MoS_(2)nanograins during their growing process.On the other hand,the MoS_(2)nanograins on the surface could self-assemble into one-dimensional nanoribbons due to the strong structural anisotropy of the substrate.In addition,the ratio of Raman intensities for peaks that correspond to the and A1g phonon modes shows a linear relationship with the grain size due to the change of the“phonon confinement”.Moreover,new peaks located at 226 and 280 cm−1 can be observed in the off-resonant and resonant Raman spectra for the MoS_(2)nanograin samples,respectively,which can be attributed to the scatterings from the edges of as-fabricated MoS_(2)nanostructures.
基金supported by the National Natural Science Foundation of China(No.32002027)。
文摘Plant metabolites are important for plant development and human health.Plants of celery(Apium graveolens L.)with different-colored petioles have been formed in the course of long-term evolution.However,the composition,content distribution,and mechanisms of accumulation of metabolites in different-colored petioles remain elusive.Using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS),1159 metabolites,including 100 lipids,72 organic acids and derivatives,83 phenylpropanoids and polyketides,and several alkaloids and terpenoids,were quantified in four celery cultivars,each with a different petiole color.There were significant differences in the types and contents of metabolites in celery with different-colored petioles,with the most striking difference between green celery and purple celery,followed by white celery and green celery.Annotated analysis of metabolic pathways showed that the metabolites of the different-colored petioles were significantly enriched in biosynthetic pathways such as anthocyanin,flavonoid,and chlorophyll pathways,suggesting that these metabolic pathways may play a key role in determining petiole color in celery.The content of chlorophyll in green celery was significantly higher than that in other celery cultivars,yellow celery was rich in carotenoids,and the content of anthocyanin in purple celery was significantly higher than that in the other celery cultivars.The color of the celery petioles was significantly correlated with the content of related metabolites.Among the four celery cultivars,the metabolites of the anthocyanin biosynthesis pathway were enriched in purple celery.The results of quantitative real-time polymerase chain reaction(q RT-PCR)suggested that the differential expression of the chalcone synthase(CHS)gene in the anthocyanin biosynthesis pathway might affect the biosynthesis of anthocyanin in celery.In addition,HPLC analysis revealed that cyanidin is the main pigment in purple celery.This study explored the differences in the types and contents of metabolites in celery cultivars with different-colored petioles and identified key substances for color formation.The results provide a theoretical basis and technical support for genetic improvement of celery petiole color.