Dear Editor,This letter investigates the cooperative localization problem for multiple autonomous underwater vehicles(AUVs)in underwater anchor-free environments,where AUV localization errors grow without bound due to...Dear Editor,This letter investigates the cooperative localization problem for multiple autonomous underwater vehicles(AUVs)in underwater anchor-free environments,where AUV localization errors grow without bound due to the accumulated errors in inertial measurements(termed accumulated errors hereafter)and the lack of anchors(with known positions).展开更多
Acute lung injury(ALI)was characterized by excessive reactive oxygen species(ROS)levels and inflammatory response in the lung.Scavenging ROS could inhibit the excessive inflammatory response,further treating ALI.Herei...Acute lung injury(ALI)was characterized by excessive reactive oxygen species(ROS)levels and inflammatory response in the lung.Scavenging ROS could inhibit the excessive inflammatory response,further treating ALI.Herein,we designed a novel nanozyme(P@Co)comprised of polydopamine(PDA)nanoparticles(NPs)loading with ultra-small Co,combining with near infrared(NIR)irradiation,which could efficiently scavenge intracellular ROS and suppress inflammatory responses against ALI.For lipopolysaccharide(LPS)induced macrophages,P@Co+NIR presented excellent antioxidant and anti-inflammatory capacities through lowering intracellular ROS levels,decreasing the expression levels of interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)as well as inducing macrophage M2 directional polarization.Significantly,it displayed the outstanding activities of lowering acute lung inflammation,relieving diffuse alveolar damage,and up-regulating heat shock protein 70(HSP70)expression,resulting in synergistic enhanced ALI therapy effect.It offers a novel strategy for the clinical treatment of ROS related diseases.展开更多
Stretchability is a crucial property of flexible all-in-one supercapacitors.This work reports a novel hydrogel electrolyte,polyacrylamidedivinylbenzene-Li2SO4(PAM-DVB-Li)synthesized by using a strategy of combining hy...Stretchability is a crucial property of flexible all-in-one supercapacitors.This work reports a novel hydrogel electrolyte,polyacrylamidedivinylbenzene-Li2SO4(PAM-DVB-Li)synthesized by using a strategy of combining hydrophobic nodes and hydrophilic networks as well as a method of dispersing hydrophobic DVB crosslinker to acrylamide monomer/Li2SO4 aqueous solution by micelles and followedγ-radiation induced polymerization and crosslinking.The resultant PAM-DVB-Li hydrogel electrolyte possesses excellent mechanical properties with 5627±241%stretchability and high ionic conductivity of 53±3 mS cm^(-1).By in situ polymerization of conducting polyaniline(PANI)on the PAM-DVB-Li hydrogel electrolyte,a novel all-in-one supercapacitor,PAM-DVB-Li/PANI,with highly integrated structure is prepared further.Benefiting from the excellent properties of hydrogel electrolyte and the all-in-one structure,the device exhibits a high specific capacitance of 469 mF cm^(-2) at 0.5 mA cm^(-2),good cyclic stability,safety,and deformation damage resistance.More importantly,the device demonstrates a superior tensile resistance(working normally under no more than 300%strain,capacitance stability in 1000 cycles of 1000%stretching and 10 cycles of 3000%stretching)far beyond that of other all-in-one supercapacitors.This work proposes a novel strategy to construct tensile-resistant all-in-one flexible supercapacitors that can be used as an energy storage device for stretchable electronic devices.展开更多
In anchor-free environments,where no devices with known positions are available,the error growth of autonomous underwater vehicle(AUV)localization and target tracking is unbounded due to the lack of references and the...In anchor-free environments,where no devices with known positions are available,the error growth of autonomous underwater vehicle(AUV)localization and target tracking is unbounded due to the lack of references and the accumulated errors in inertial measurements.This paper aims to improve the localization and tracking accuracy by involving current information as extra references.We first integrate current measurements and maps with belief propagation and design a distributed current-aided message-passing scheme that theoretically solves the localization and tracking problems.Based on this scheme,we propose particle-based cooperative localization and target tracking algorithms,named CaCL and CaTT,respectively.In AUV localization,CaCL uses the current measurements to correct the predicted and transmitted position information and alleviates the impact of the accumulated errors in inertial measurements.With target tracking,the current maps are applied in CaTT to modify the position prediction of the target which is calculated through historical estimates.The effectiveness and robustness of the proposed methods are validated through various simulations by comparisons with alternative methods under different trajectories and current conditions.展开更多
Purpose: This study aims to explore whether content originality and user experience have positive effects on online news readers’ satisfaction with the mobile apps service.Design/methodology/approach: Data was collec...Purpose: This study aims to explore whether content originality and user experience have positive effects on online news readers’ satisfaction with the mobile apps service.Design/methodology/approach: Data was collected via a Web-based survey. Data analysis of this study can be divided into two stages. In the first stage, a descriptive statistical analysis was conducted based on a sample of 612 respondents. In the second stage, the correlation among content originality, user experience and satisfaction was analyzed based on a sample of 377 mobile news apps users. Findings: Results of the first stage showed that social media and mobile news apps were the most important tools for users to access news, and different types of media were playing complementary roles in information transmission. Users held a positive attitude toward their mobile news reading experience and they described news they read on mobile apps with such words as "interesting", "instant", "positive", "profound", and "ironic". Results of the second stage confirmed our hypothesis that content originality and user experience both had positive impacts on user satisfaction.Research limitations: The questionnaires were distributed entirely online, so the sample may not be representative of the general population being studied and thus undermine the reliability and generalization of the findings to some extent. Moreover, this study adopted only one method(survey) and more methods such as interviews can be used to improve the accuracy of the results.Practical implications: The findings of this study can not only provide insights into a better understanding of users’ mobile reading behavior, but also help mobile information service providers attract more users.Originality/value: This is one of the first studies to explore the effects of content originality and user experience on online news readers’ satisfaction with the mobile apps service.展开更多
The FUT2 loss-of-function mutations are highly prevalent and are associated with inflammatory bowel disease(IBD).To investigate the impact of FUT2 loss-of-function mutation on the gut microbiota in patients with IBD,8...The FUT2 loss-of-function mutations are highly prevalent and are associated with inflammatory bowel disease(IBD).To investigate the impact of FUT2 loss-of-function mutation on the gut microbiota in patients with IBD,81 endoscopically confirmed IBD patients were genotyped and divided into 3 groups:homozygous for functional FUT2 genes(SeSe),with one copy of non-functional FUT2 gene(Sese),or homozygous for non-functional FUT2 genes(sese).Escherichia,which attaches to fucosylated glycoconjugates,was the only abundant genus exhibiting decreased abundance in sese patients.Compared with SeSe or Sese patients,sese patients exhibited higher abundance in CD8+inducing Alistipe and Phascolarctobacterium and Th17 inducing Erysipelotrichaceae UCG-003.Counter-intuitively,butyrate-producing bacteria were more abundant in sese patients.Consistently,metabolomics analysis found higher levels of butyrate in sese patients.Our data support the hypothesis that FUT2 loss-of-function mutation participates in the IBD pathogenesis by decreasing binding sites for adherent bacteria and thus altering the gut microbiota.Decreased abundances of adherent bacteria may allow the overgrowth of bacteria that induce inflammatory T cells,leading to intestinal inflammation.As FUT2 loss-of-function mutations are highly prevalent,the identification of T cell inducing bacteria in sese patients could be valuable for the development of personalized microbial intervention for IBD.展开更多
In a recent paper[Jiang,et al.,Science 370,1447(2020)],it was reported that zero reflection or Klein tunneling can be observed for normally incident quasiparticles upon a potential barrier constructed by two phononic ...In a recent paper[Jiang,et al.,Science 370,1447(2020)],it was reported that zero reflection or Klein tunneling can be observed for normally incident quasiparticles upon a potential barrier constructed by two phononic crystals(PCs)with Dirac cone band structures.Here,we develop a firstprinciples approach for accurate computation of the reflection of quasiparticles by a potential step with two PCs at normal incidence.Strikingly,it is found that minimal reflection of quasiparticles(R_(m)=0.8%)occurs at an energy below the potential step,while moderate reflection(R_(d)=17%)remains at the center energy of the potential step,even with the PCs adopted by Jiang et al.A physical model is presented to understand such phenomena,where the zigzag interface in the step serves as a graded antireflection layer and reflection increases dramatically near the band gap of PCs.Two solutions are also shown for realizing lower R_(d)or even ideal Klein tunneling in PCs,with reducing the difference between the two PCs or enhancing the antireflection effect of the interface.Our work reveals the effects of the zigzag interface and band gap on Klein tunneling in PCs,which will be inspiring for exploring more fascinating phenomena of quasiparticles in classical wave systems.展开更多
Magnesium is generally known to degrade in aqueous environments by an electrochemical reaction.The corrosion products of magnesium include hydrogen gas,Mg^(2+),and Mg(OH)_(2).Here,we summarize the published literature...Magnesium is generally known to degrade in aqueous environments by an electrochemical reaction.The corrosion products of magnesium include hydrogen gas,Mg^(2+),and Mg(OH)_(2).Here,we summarize the published literature describing the corrosion characteristics of magnesium,and the antitumor properties of magnesium-associated corrosion products,aiming to induce the therapeutic properties of magnesium and magnesium alloys in solid tumors.The therapeutic potential of corrosion products of magnesium is enormous.Hydrogen gas exhibits antioxidant and anti-inflammatory properties,which amount to potential anti-tumor characteristics.Mg(OH)_(2),which creates a localized alkaline microenvironment,represents a second approach for anti-tumor therapy with magnesium metal.Upregulated concentrations of Mg^(2+)ions in the local tumor microenvironment remodelling are considered a third approach for anti-tumor therapy.Therefore,we speculate about the different physical forms of magnesium that could create an anti-tumor microenvironment upon tumor interventional therapy,a technique that precisely places anti-tumor implants like particles and stents.Finally,we present our viewpoints on the potential use of magnesium in diverse solid tumor therapies to inhibit tumor progression.展开更多
Natural gas is widely used because it is environmentally friendly,particularly in reducing carbon emission and improving the Air Quality Index(AQI)around densely populated cities.China has initiated a coal-to-gas proj...Natural gas is widely used because it is environmentally friendly,particularly in reducing carbon emission and improving the Air Quality Index(AQI)around densely populated cities.China has initiated a coal-to-gas project(CGP)to improve the air quality in northern China.As a subcompany of China National Petroleum Corporation,PetroChina Natural Gas Marketing North Company has been focusing on natural gas resource allocation while considering numerous issues such as ensuring the bottom line of livelihood requirements in winter and the performance of economic indicators for an entire calendar year in the northern part of China.Therefore,the accurate prediction of natural gas consumption is important to PetroChina Natural Gas Marketing North Company.It has become a challenge to forecast natural gas consumption because the natural gas market has changed considerably because of the CGP.Natural gas consumption cannot be forecasted using conventional models.This study analyzes the characteristics of the CGP based on the data obtained from rural individual users and company users.Based on the analysis,the gas consumption in winter is predicted using two different forecasting approaches.The methods presented in this paper provide a basis for formulating effective measures for natural gas scheduling in the northern part of China.展开更多
Recently,increasing evidence suggests that DNA methylation plays a crucial role in fruit ripening.However,the role of DNA methylation in regulating specific traits,such as flavor,remains unclear.Here,we report a role ...Recently,increasing evidence suggests that DNA methylation plays a crucial role in fruit ripening.However,the role of DNA methylation in regulating specific traits,such as flavor,remains unclear.Here,we report a role of DNA methylation in affecting furanone biosynthesis in strawberry.Strawberry quinone oxidoreductase(FaQR)is a key enzyme in furanone biosynthesis.There are four FaQR homologs in strawberry cultivar‘Yuexin’,and one of them,FaQR3,contributes∼50%of FaQR transcripts,indicating a major role of FaQR3 in furanone biosynthesis.Through characterization of levels of DNA methylation and FaQR3 transcript and furanone contents during fruit ripening and after the application of DNA methylation inhibitor,we found that the DNA methylation level of the FaQR3 promoter was negatively correlated with FaQR3 expression and furanone accumulation,suggesting that DNA methylation may be involved in furanone biosynthesis through adjusting FaQR3 expression,and responded to different temperatures consistently.In addition,transient expression of a gene in the RNA-directed DNA methylation(RdDM)pathway,FaAGO4,and enrichment analysis of the 24-nucleotide siRNAs suggested that DNA methylation in the FaQR3 promoter is mediated by the RdDM pathway.Transient RNA interference(RNAi)of FaDML indicated that the demethylation pathway may be involved in regulating furanone accumulation.These findings provide new insights into the role of DNA methylation and demethylation in affecting flavor quality in strawberry during fruit ripening.展开更多
A novel triaxial vibration method is developed for the real-time characterization of the solid particle size distribution(PsD)in pneumatic particulate flow,which is critical for chemical industry.In this work,the part...A novel triaxial vibration method is developed for the real-time characterization of the solid particle size distribution(PsD)in pneumatic particulate flow,which is critical for chemical industry.In this work,the particle-wall collision and friction behaviours were analysed by the time-domain statistical and timefrequency joint methods to narrow the high-frequency response range by the initial experiment of free fall for a single particle,interparticle,and multiple particles.Subsequently,verification experiments of PSD characterization in pneumatic flow were performed.First,the quantitative triaxial energy response model that considers the particle size,shape,and mass factors were established.Second,a good agreement of the particle number identification was found between the triaxial vibration energy and mean particle size of 150-550μm.Moreover,the performance with the best accuracy was focused on a range of 42-43 kHz in the x-axis and z-axis and 36.8-38.8 kHz in the y-axis.Finally,the individual particle energy was inversely analysed by the triaxial vibration response within the optimized frequency bands,and the PSD was characterized in real-time by a low error rate,that is,5.2% from the XZ-axis direction of sand(42-43 kHz)and 5.6% from the XYZ-axis of glass(30.9-33.9 kHz,46.2-47.2 kHz,38.3-41.3 kHz for each axis response).Therefore,this research complements the existing approaches for PsD characterization in particulate multiphase flow.展开更多
This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an ...This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.展开更多
Recently,dimensionless figure of merit(ZT)beyond 1.0 has been demonstrated in diamondoid Cu_(2)SnSe_(3),positioning it as a low-cost and ecofriendly thermoelectric alternative,and sparking intense interest in further ...Recently,dimensionless figure of merit(ZT)beyond 1.0 has been demonstrated in diamondoid Cu_(2)SnSe_(3),positioning it as a low-cost and ecofriendly thermoelectric alternative,and sparking intense interest in further optimizing its thermoelectric properties.However,its intrinsic monoclinic structure and the compact packing of tetrahedral coordination lead to a light valence band and high thermal conductivity,which impede further performance improvement in Cu_(2)SnSe_(3).Thus,developing effective approaches to altering the local structure of Cu_(2)SnSe_(3)is important for further optimizing its thermoelectric performance.Herein,we identified and thoroughly investigated the atomic off-centering behavior in Cu_(2)SnSe_(3),and demonstrated the electronic and phonon transport properties of Cu_(2)SnSe_(3)can be significantly enhanced by carefully modifying its monoclinic lattice into a distorted zinc-blende cubic structure via introducing Cd and off-centering Ag elements.This structure transition leads to band convergence and a reduction in the deformation potential of the material,resulting in a 7-fold enhancement in the density-of-state effective mass and an 85%increase in carrier mobility.Additionally,the off-centering effect results in strong acoustic-optical phonon scattering and an ultra-low lattice thermal conductivity of 0.3 W m^(-1)K^(-1).Consequently,a maximum ZT of 1.3 was obtained at 800 K for the Cu_(1.85)Ag_(0.15)Sn_(0.9)Cd_(0.1)Se_(3).展开更多
Relaxor ferroelectrics are the primary candidates for high-performance energy storage dielectric capacitors.Here,stress engineering,which was realized by optimizing the lattice mismatch between(Na_(0.5)Bi_(0.5))TiO_(3...Relaxor ferroelectrics are the primary candidates for high-performance energy storage dielectric capacitors.Here,stress engineering,which was realized by optimizing the lattice mismatch between(Na_(0.5)Bi_(0.5))TiO_(3)film and SrRuO_(3)/(La_(0.5)Sr_(0.5))CoO_(3)bottom electrodes,was used to enhance the energy storage performance of(Na_(0.5)Bi_(0.5))TiO_(3)relaxor ferroelectric film.As a result,in-plane compressive stress caused by the lattice mismatch between(Na_(0.5)Bi_(0.5))TiO_(3)film and(La_(0.5)Sr_(0.5))CoO_(3)bottom electrode leads to a large Wrec of 45.7 J/cm^(3)with h of 79.4%at 2000 kV/cm in(Na_(0.5)Bi_(0.5))TiO_(3)film,which is 54.4%higher than that of(Na_(0.5)Bi_(0.5))TiO_(3)film with in-plane tensile stress.In addition,the Wrec of(Na_(0.5)Bi_(0.5))TiO_(3)film with in-plane compressive stress shows good thermal stability and frequency stability with variations of 5.8%at 30-120℃and 6.9%at 0.2-20.0 kHz.This work may provide some new perspectives for the design of dielectric capacitors with high energy storage performance.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering usin...The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants.This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angleθ_(23).The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory(TAO)detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site,local and global nuclear reactors,JUNO and TAO detector responses,expected event rates and spectra of signals and backgrounds,and systematic uncertainties of analysis inputs.We find that a 3σmedian sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years×26.6 GW thermal power.展开更多
variety of ways to antagonize host defense through eliminating IFN-signaling intracellularly for decades.However,the way by viruses target IFN-signaling extracellularly has not been discovered.Infection by both corona...variety of ways to antagonize host defense through eliminating IFN-signaling intracellularly for decades.However,the way by viruses target IFN-signaling extracellularly has not been discovered.Infection by both coronavirus SARS-CoV-2 and enterovirus 71(EV71 or EV-A71)can cause severe diseases such as neurological disorders and even death in children.展开更多
High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of ...High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of complex samples,especially those involving environmental and pathogen-monitoring ones.Commercial library preparation kits for amplicon sequencing,which generally require multiple steps,including adapter ligation and indexing,are expensive and time-consuming,especially for applications at a large scale.To overcome these limitations,a“one-step PCR approach”has been previously proposed for constructions of amplicon libraries using long fusion primers.However,efficient amplifications of target genes and accurate demultiplexing of pooled sequencing data remain to be addressed.To tackle these,we present an integrative protocol for one-step PCR amplicon library construction(OSPALC).High-quality reads have been generated by this approach to reliably identify species compositions of mock bacterial communities and environmental samples.With this protocol,the amplicon library is constructed through one regular PCR with long primers,and the total cost per DNA/cDNA sample decreases to just 7%of the typical cost via the multi-step PCR approach.Empirically tested primers and optimized PCR conditions to construct OSPALC libraries for 16S rDNA V4 regions are demonstrated as a case study.Tools to design primers targeting at any genomic regions are also presented.In principle,OSPALC can be readily applied to construct amplicon libraries of any target genes using DNA or RNA samples,and will facilitate research in numerous fields.展开更多
Thermoelectric materials have a wide range of application because they can be directly used in refrigeration and power generation. And the Bi_(2)Te_(3) stand out because of its excellent thermoelectric performance and...Thermoelectric materials have a wide range of application because they can be directly used in refrigeration and power generation. And the Bi_(2)Te_(3) stand out because of its excellent thermoelectric performance and are used in commercial thermoelectric devices. However, n-type Bi_(2)Te_(3) has seriously hindered the development of Bi_(2)Te_(3)-based thermoelectric devices due to its weak mechanical properties and inferior thermoelectric performance. Therefore, it is urgent to develop a high-performance n-type Bi_(2)Te_(3) polycrystalline. In this work, we employed interstitial Cu and the hot deformation process to optimize the thermoelectric properties of Bi_(2)Te_(2.7)Se_(0.3), and a high-performance thermoelectric module was fabricated based on this material. Our combined theoretical and experimental effort indicates that the interstitial Cu reduce the defect density in the matrix and suppresses the donor-like effect, leading to a lattice plainification effect in the material. In addition, the two-step hot deformation process significantly improves the preferred orientation of the material and boosts the mobility. As a result, a maximum ZT of 1.27 at 373 K and a remarkable high ZT_(ave) of 1.22 across the temperature range of 300–425 K are obtained. The thermoelectric generator(TEG, 7-pair) and thermoelectric cooling(TEC, 127-pair) modules were fabricated with our n-type textured Cu_(0.01)Bi_(2)Te_(2.7)Se_(0.3) coupled with commercial p-type Bi_(2)Te_(3). The TEC module demonstrates superior cooling efficiency compared with the commercial Bi_(2)Te_(3) device, achieving a ΔT of 65 and 83.4 K when the hot end temperature at 300 and 350 K, respectively. In addition, the TEG module attains an impressive conversion efficiency of 6.5% at a ΔT of 225 K, which is almost the highest value among the reported Bi_(2)Te_(3)-based TEG modules.展开更多
Since the discovery of generalized Snell’s law in 2011[1],metasurfaces have opened up the mainstream of arbitrary wavefront manipulation in electromagnetism.Using a gradient-index metasurface,the parallel wavenumber ...Since the discovery of generalized Snell’s law in 2011[1],metasurfaces have opened up the mainstream of arbitrary wavefront manipulation in electromagnetism.Using a gradient-index metasurface,the parallel wavenumber kx of reflected wave can be not equal to the incident one(kx=ξ+k0sinθi,where k0 andθi are the incident wavenumber and angle,andξis the phase gradient of metasurface in its supercell)[1].Whenξ>k0,the reflected wave becomes a surface wave bounded on the metasurface(where|kx|>k0,kz is imaginary,and z is normal to the metasurface)[2].However,as research of metasurfaces continually evolves,some articles have pointed out that such graded metasurfaces suffer from a series of problems[3-6].In particular,multiple metallic resonators are adopted in a subwavelength supercell,resulting in impedance mismatch,moderate conversion efficiency,wave absorption,and fabrication complexity.Hence,although the approach of graded metasurfaces has been demonstrated in the microwave regime,it is hard to extend to infrared and optical ranges with shorter wavelengths.To solve this problem,Ra’di et al.[7]devised metagratings with periodic arrays of bianisotropic scatterers and showed that they enable wave front engineering with unitary efficiency and significantly lower fabrication demands.展开更多
基金the National Natural Science Foundation of China(62203299,62373246)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2022MS008,SL2020ZD206,SL2022MS010)。
文摘Dear Editor,This letter investigates the cooperative localization problem for multiple autonomous underwater vehicles(AUVs)in underwater anchor-free environments,where AUV localization errors grow without bound due to the accumulated errors in inertial measurements(termed accumulated errors hereafter)and the lack of anchors(with known positions).
基金financially supported by the Key Research&Development Program of Guangxi(No.GuiKeAB22080088)the Joint Project on Regional High-Incidence Diseases Research of Guangxi Natural Science Foundation(No.2023GXNSFDA026023)+3 种基金the Natural Science Foundation of Guangxi(No.2023JJA140322)the National Natural Science Foundation of China(No.82360372)the High-level Medical Expert Training Program of Guangxi“139 Plan Funding(No.G202003010)the Medical Appropriate Technology Development and Popularization and Application Project of Guangxi(No.S2020099)。
文摘Acute lung injury(ALI)was characterized by excessive reactive oxygen species(ROS)levels and inflammatory response in the lung.Scavenging ROS could inhibit the excessive inflammatory response,further treating ALI.Herein,we designed a novel nanozyme(P@Co)comprised of polydopamine(PDA)nanoparticles(NPs)loading with ultra-small Co,combining with near infrared(NIR)irradiation,which could efficiently scavenge intracellular ROS and suppress inflammatory responses against ALI.For lipopolysaccharide(LPS)induced macrophages,P@Co+NIR presented excellent antioxidant and anti-inflammatory capacities through lowering intracellular ROS levels,decreasing the expression levels of interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)as well as inducing macrophage M2 directional polarization.Significantly,it displayed the outstanding activities of lowering acute lung inflammation,relieving diffuse alveolar damage,and up-regulating heat shock protein 70(HSP70)expression,resulting in synergistic enhanced ALI therapy effect.It offers a novel strategy for the clinical treatment of ROS related diseases.
基金financial support from National Natural Science Foundation of China(No.12375336,11875078)。
文摘Stretchability is a crucial property of flexible all-in-one supercapacitors.This work reports a novel hydrogel electrolyte,polyacrylamidedivinylbenzene-Li2SO4(PAM-DVB-Li)synthesized by using a strategy of combining hydrophobic nodes and hydrophilic networks as well as a method of dispersing hydrophobic DVB crosslinker to acrylamide monomer/Li2SO4 aqueous solution by micelles and followedγ-radiation induced polymerization and crosslinking.The resultant PAM-DVB-Li hydrogel electrolyte possesses excellent mechanical properties with 5627±241%stretchability and high ionic conductivity of 53±3 mS cm^(-1).By in situ polymerization of conducting polyaniline(PANI)on the PAM-DVB-Li hydrogel electrolyte,a novel all-in-one supercapacitor,PAM-DVB-Li/PANI,with highly integrated structure is prepared further.Benefiting from the excellent properties of hydrogel electrolyte and the all-in-one structure,the device exhibits a high specific capacitance of 469 mF cm^(-2) at 0.5 mA cm^(-2),good cyclic stability,safety,and deformation damage resistance.More importantly,the device demonstrates a superior tensile resistance(working normally under no more than 300%strain,capacitance stability in 1000 cycles of 1000%stretching and 10 cycles of 3000%stretching)far beyond that of other all-in-one supercapacitors.This work proposes a novel strategy to construct tensile-resistant all-in-one flexible supercapacitors that can be used as an energy storage device for stretchable electronic devices.
基金supported in part by the National Natural Science Foundation of China(62203299,61773264,61922058,61803261,61801295)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2020ZD206,SL2020MS010,SL2020MS015)。
文摘In anchor-free environments,where no devices with known positions are available,the error growth of autonomous underwater vehicle(AUV)localization and target tracking is unbounded due to the lack of references and the accumulated errors in inertial measurements.This paper aims to improve the localization and tracking accuracy by involving current information as extra references.We first integrate current measurements and maps with belief propagation and design a distributed current-aided message-passing scheme that theoretically solves the localization and tracking problems.Based on this scheme,we propose particle-based cooperative localization and target tracking algorithms,named CaCL and CaTT,respectively.In AUV localization,CaCL uses the current measurements to correct the predicted and transmitted position information and alleviates the impact of the accumulated errors in inertial measurements.With target tracking,the current maps are applied in CaTT to modify the position prediction of the target which is calculated through historical estimates.The effectiveness and robustness of the proposed methods are validated through various simulations by comparisons with alternative methods under different trajectories and current conditions.
文摘Purpose: This study aims to explore whether content originality and user experience have positive effects on online news readers’ satisfaction with the mobile apps service.Design/methodology/approach: Data was collected via a Web-based survey. Data analysis of this study can be divided into two stages. In the first stage, a descriptive statistical analysis was conducted based on a sample of 612 respondents. In the second stage, the correlation among content originality, user experience and satisfaction was analyzed based on a sample of 377 mobile news apps users. Findings: Results of the first stage showed that social media and mobile news apps were the most important tools for users to access news, and different types of media were playing complementary roles in information transmission. Users held a positive attitude toward their mobile news reading experience and they described news they read on mobile apps with such words as "interesting", "instant", "positive", "profound", and "ironic". Results of the second stage confirmed our hypothesis that content originality and user experience both had positive impacts on user satisfaction.Research limitations: The questionnaires were distributed entirely online, so the sample may not be representative of the general population being studied and thus undermine the reliability and generalization of the findings to some extent. Moreover, this study adopted only one method(survey) and more methods such as interviews can be used to improve the accuracy of the results.Practical implications: The findings of this study can not only provide insights into a better understanding of users’ mobile reading behavior, but also help mobile information service providers attract more users.Originality/value: This is one of the first studies to explore the effects of content originality and user experience on online news readers’ satisfaction with the mobile apps service.
基金supported by Guangdong Province“Pearl River Talent Plan”Innovation and Entrepreneurship Team Project 2019ZT08Y464(to L.Z.)the National Natural Science Foundation of China 81770571(to L.Z.),82000536(to N.J.)+2 种基金National Postdoctoral Program for Innovative Talents of China BX20190393(to N.J.)China Postdoctoral Science Foundation 2019M663252(to N.J.)Fundamental Research Funds for the Central Universities 19ykzd01(to L.Z.),and 20kypy07(to N.J.)。
文摘The FUT2 loss-of-function mutations are highly prevalent and are associated with inflammatory bowel disease(IBD).To investigate the impact of FUT2 loss-of-function mutation on the gut microbiota in patients with IBD,81 endoscopically confirmed IBD patients were genotyped and divided into 3 groups:homozygous for functional FUT2 genes(SeSe),with one copy of non-functional FUT2 gene(Sese),or homozygous for non-functional FUT2 genes(sese).Escherichia,which attaches to fucosylated glycoconjugates,was the only abundant genus exhibiting decreased abundance in sese patients.Compared with SeSe or Sese patients,sese patients exhibited higher abundance in CD8+inducing Alistipe and Phascolarctobacterium and Th17 inducing Erysipelotrichaceae UCG-003.Counter-intuitively,butyrate-producing bacteria were more abundant in sese patients.Consistently,metabolomics analysis found higher levels of butyrate in sese patients.Our data support the hypothesis that FUT2 loss-of-function mutation participates in the IBD pathogenesis by decreasing binding sites for adherent bacteria and thus altering the gut microbiota.Decreased abundances of adherent bacteria may allow the overgrowth of bacteria that induce inflammatory T cells,leading to intestinal inflammation.As FUT2 loss-of-function mutations are highly prevalent,the identification of T cell inducing bacteria in sese patients could be valuable for the development of personalized microbial intervention for IBD.
基金supported by the National Key Research and Development Program of China(Nos.2023YFA1406901 and 2018YFA0306201).
文摘In a recent paper[Jiang,et al.,Science 370,1447(2020)],it was reported that zero reflection or Klein tunneling can be observed for normally incident quasiparticles upon a potential barrier constructed by two phononic crystals(PCs)with Dirac cone band structures.Here,we develop a firstprinciples approach for accurate computation of the reflection of quasiparticles by a potential step with two PCs at normal incidence.Strikingly,it is found that minimal reflection of quasiparticles(R_(m)=0.8%)occurs at an energy below the potential step,while moderate reflection(R_(d)=17%)remains at the center energy of the potential step,even with the PCs adopted by Jiang et al.A physical model is presented to understand such phenomena,where the zigzag interface in the step serves as a graded antireflection layer and reflection increases dramatically near the band gap of PCs.Two solutions are also shown for realizing lower R_(d)or even ideal Klein tunneling in PCs,with reducing the difference between the two PCs or enhancing the antireflection effect of the interface.Our work reveals the effects of the zigzag interface and band gap on Klein tunneling in PCs,which will be inspiring for exploring more fascinating phenomena of quasiparticles in classical wave systems.
基金supported by the Open Funds for Shaanxi Provincial Key Laboratory of Infection and Immune Diseases(2022-KFZD-1)Natural Science Basic Research Program of Shaanxi(2021JM-080,2022JQ-832)the National Natural Science Foundation of China(82203047)
文摘Magnesium is generally known to degrade in aqueous environments by an electrochemical reaction.The corrosion products of magnesium include hydrogen gas,Mg^(2+),and Mg(OH)_(2).Here,we summarize the published literature describing the corrosion characteristics of magnesium,and the antitumor properties of magnesium-associated corrosion products,aiming to induce the therapeutic properties of magnesium and magnesium alloys in solid tumors.The therapeutic potential of corrosion products of magnesium is enormous.Hydrogen gas exhibits antioxidant and anti-inflammatory properties,which amount to potential anti-tumor characteristics.Mg(OH)_(2),which creates a localized alkaline microenvironment,represents a second approach for anti-tumor therapy with magnesium metal.Upregulated concentrations of Mg^(2+)ions in the local tumor microenvironment remodelling are considered a third approach for anti-tumor therapy.Therefore,we speculate about the different physical forms of magnesium that could create an anti-tumor microenvironment upon tumor interventional therapy,a technique that precisely places anti-tumor implants like particles and stents.Finally,we present our viewpoints on the potential use of magnesium in diverse solid tumor therapies to inhibit tumor progression.
基金supported by the National Natural Science Foundation of China (No. 51504271)
文摘Natural gas is widely used because it is environmentally friendly,particularly in reducing carbon emission and improving the Air Quality Index(AQI)around densely populated cities.China has initiated a coal-to-gas project(CGP)to improve the air quality in northern China.As a subcompany of China National Petroleum Corporation,PetroChina Natural Gas Marketing North Company has been focusing on natural gas resource allocation while considering numerous issues such as ensuring the bottom line of livelihood requirements in winter and the performance of economic indicators for an entire calendar year in the northern part of China.Therefore,the accurate prediction of natural gas consumption is important to PetroChina Natural Gas Marketing North Company.It has become a challenge to forecast natural gas consumption because the natural gas market has changed considerably because of the CGP.Natural gas consumption cannot be forecasted using conventional models.This study analyzes the characteristics of the CGP based on the data obtained from rural individual users and company users.Based on the analysis,the gas consumption in winter is predicted using two different forecasting approaches.The methods presented in this paper provide a basis for formulating effective measures for natural gas scheduling in the northern part of China.
文摘Recently,increasing evidence suggests that DNA methylation plays a crucial role in fruit ripening.However,the role of DNA methylation in regulating specific traits,such as flavor,remains unclear.Here,we report a role of DNA methylation in affecting furanone biosynthesis in strawberry.Strawberry quinone oxidoreductase(FaQR)is a key enzyme in furanone biosynthesis.There are four FaQR homologs in strawberry cultivar‘Yuexin’,and one of them,FaQR3,contributes∼50%of FaQR transcripts,indicating a major role of FaQR3 in furanone biosynthesis.Through characterization of levels of DNA methylation and FaQR3 transcript and furanone contents during fruit ripening and after the application of DNA methylation inhibitor,we found that the DNA methylation level of the FaQR3 promoter was negatively correlated with FaQR3 expression and furanone accumulation,suggesting that DNA methylation may be involved in furanone biosynthesis through adjusting FaQR3 expression,and responded to different temperatures consistently.In addition,transient expression of a gene in the RNA-directed DNA methylation(RdDM)pathway,FaAGO4,and enrichment analysis of the 24-nucleotide siRNAs suggested that DNA methylation in the FaQR3 promoter is mediated by the RdDM pathway.Transient RNA interference(RNAi)of FaDML indicated that the demethylation pathway may be involved in regulating furanone accumulation.These findings provide new insights into the role of DNA methylation and demethylation in affecting flavor quality in strawberry during fruit ripening.
基金supported by Shandong Provincial Natural Science Foundation(grant No.ZR2021ME001)the National Natural Science Foundation of China(grant No.52104015).
文摘A novel triaxial vibration method is developed for the real-time characterization of the solid particle size distribution(PsD)in pneumatic particulate flow,which is critical for chemical industry.In this work,the particle-wall collision and friction behaviours were analysed by the time-domain statistical and timefrequency joint methods to narrow the high-frequency response range by the initial experiment of free fall for a single particle,interparticle,and multiple particles.Subsequently,verification experiments of PSD characterization in pneumatic flow were performed.First,the quantitative triaxial energy response model that considers the particle size,shape,and mass factors were established.Second,a good agreement of the particle number identification was found between the triaxial vibration energy and mean particle size of 150-550μm.Moreover,the performance with the best accuracy was focused on a range of 42-43 kHz in the x-axis and z-axis and 36.8-38.8 kHz in the y-axis.Finally,the individual particle energy was inversely analysed by the triaxial vibration response within the optimized frequency bands,and the PSD was characterized in real-time by a low error rate,that is,5.2% from the XZ-axis direction of sand(42-43 kHz)and 5.6% from the XYZ-axis of glass(30.9-33.9 kHz,46.2-47.2 kHz,38.3-41.3 kHz for each axis response).Therefore,this research complements the existing approaches for PsD characterization in particulate multiphase flow.
基金Supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+20 种基金the CAS Center for Excellence in Particle Physics,Wuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique(F.R.S-FNRS)FWO under the"Excellence of Science-EOS"in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo and ANID Millennium Science Initiative Program—ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+in Germanythe Joint Institute of Nuclear Research(JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation(RSF)National Natural Science Foundation of China(NSFC)research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn University and Suranaree University of Technology in Thailandthe University of California at Irvinethe National Science Foundation in USA。
文摘This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.
基金supported by the National Natural Science Foundation of China(52471217)the Young Scientists Fund of the National Natural Science Foundation of China(52403348)+4 种基金the National Natural Science Foundation of China(52450001,52250090,52371208,52002042,51772012,51571007 and 12374023)the National Key Research and Development Program of China(2023YFB3809400)the National Science Fund for Distinguished Young Scholars(51925101)the Beijing Natural Science Foundation(JQ18004)the Overseas Expertise Introduction Project for Discipline Innovation(111Project)(B17002)。
文摘Recently,dimensionless figure of merit(ZT)beyond 1.0 has been demonstrated in diamondoid Cu_(2)SnSe_(3),positioning it as a low-cost and ecofriendly thermoelectric alternative,and sparking intense interest in further optimizing its thermoelectric properties.However,its intrinsic monoclinic structure and the compact packing of tetrahedral coordination lead to a light valence band and high thermal conductivity,which impede further performance improvement in Cu_(2)SnSe_(3).Thus,developing effective approaches to altering the local structure of Cu_(2)SnSe_(3)is important for further optimizing its thermoelectric performance.Herein,we identified and thoroughly investigated the atomic off-centering behavior in Cu_(2)SnSe_(3),and demonstrated the electronic and phonon transport properties of Cu_(2)SnSe_(3)can be significantly enhanced by carefully modifying its monoclinic lattice into a distorted zinc-blende cubic structure via introducing Cd and off-centering Ag elements.This structure transition leads to band convergence and a reduction in the deformation potential of the material,resulting in a 7-fold enhancement in the density-of-state effective mass and an 85%increase in carrier mobility.Additionally,the off-centering effect results in strong acoustic-optical phonon scattering and an ultra-low lattice thermal conductivity of 0.3 W m^(-1)K^(-1).Consequently,a maximum ZT of 1.3 was obtained at 800 K for the Cu_(1.85)Ag_(0.15)Sn_(0.9)Cd_(0.1)Se_(3).
基金supported by the National Natural Science Foundation of China(No.52472125,No.52073144 and No.51802068)the Natural Science Foundation of Hebei Province,China(No.E2021201044)Special Funds of 2023 Jiangsu Provincial Science and Technology Plan(First Batch of Innovation Capacity Building Plan).
文摘Relaxor ferroelectrics are the primary candidates for high-performance energy storage dielectric capacitors.Here,stress engineering,which was realized by optimizing the lattice mismatch between(Na_(0.5)Bi_(0.5))TiO_(3)film and SrRuO_(3)/(La_(0.5)Sr_(0.5))CoO_(3)bottom electrodes,was used to enhance the energy storage performance of(Na_(0.5)Bi_(0.5))TiO_(3)relaxor ferroelectric film.As a result,in-plane compressive stress caused by the lattice mismatch between(Na_(0.5)Bi_(0.5))TiO_(3)film and(La_(0.5)Sr_(0.5))CoO_(3)bottom electrode leads to a large Wrec of 45.7 J/cm^(3)with h of 79.4%at 2000 kV/cm in(Na_(0.5)Bi_(0.5))TiO_(3)film,which is 54.4%higher than that of(Na_(0.5)Bi_(0.5))TiO_(3)film with in-plane tensile stress.In addition,the Wrec of(Na_(0.5)Bi_(0.5))TiO_(3)film with in-plane compressive stress shows good thermal stability and frequency stability with variations of 5.8%at 30-120℃and 6.9%at 0.2-20.0 kHz.This work may provide some new perspectives for the design of dielectric capacitors with high energy storage performance.
基金Supported by the Chinese Academy of Sciences,the National Key R&D Program of Chinathe CAS Center for Excellence in Particle Physics,Wuyi University,and the TsungDao Lee Institute of Shanghai Jiao Tong University in China+3 种基金the Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Italian-Chinese collaborative research program MAECI-NSFC,the Fond de la Recherche Scientifique(F.R.S-FNRS)and FWO under the“Excellence of Science–EOS”in Belgium,the Conselho Nacional de Desenvolvimento Cient´ıfico e Tecnol`ogico in Brazil,the Agencia Nacional de Investigacion y Desarrollo and ANID-Millennium Science Initiative Program-ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Association,and the Cluster of Excellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR)and Lomonosov Moscow State University in Russia,the joint Russian Science Foundation(RSF)and National Natural Science Foundation of China(NSFC)research program,the MOST and MOE in Taiwan,China,the Chulalongkorn University and Suranaree University of Technology in Thailand,University of California at Irvine and the National Science Foundation in the US。
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants.This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angleθ_(23).The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory(TAO)detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site,local and global nuclear reactors,JUNO and TAO detector responses,expected event rates and spectra of signals and backgrounds,and systematic uncertainties of analysis inputs.We find that a 3σmedian sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years×26.6 GW thermal power.
基金The work was partially supported by grants from The Science Technology and Innovation Committee of Shenzhen Municipality[JCYJ20180507181627057]RGC General Research Fund of Hong Kong Special Administrative Region[11104020]Strategic funds from The City University of Hong Kong to M.He.
文摘variety of ways to antagonize host defense through eliminating IFN-signaling intracellularly for decades.However,the way by viruses target IFN-signaling extracellularly has not been discovered.Infection by both coronavirus SARS-CoV-2 and enterovirus 71(EV71 or EV-A71)can cause severe diseases such as neurological disorders and even death in children.
基金supported by the National Natural Science Foundation of China(31961123002,31872228)the Fundamental Research Funds for the Central Universities of China(202041001)+1 种基金the Young Taishan Scholars Program of Shandong Province(tsqn201812024)the National Science Foundation(DEB-1927159).
文摘High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of complex samples,especially those involving environmental and pathogen-monitoring ones.Commercial library preparation kits for amplicon sequencing,which generally require multiple steps,including adapter ligation and indexing,are expensive and time-consuming,especially for applications at a large scale.To overcome these limitations,a“one-step PCR approach”has been previously proposed for constructions of amplicon libraries using long fusion primers.However,efficient amplifications of target genes and accurate demultiplexing of pooled sequencing data remain to be addressed.To tackle these,we present an integrative protocol for one-step PCR amplicon library construction(OSPALC).High-quality reads have been generated by this approach to reliably identify species compositions of mock bacterial communities and environmental samples.With this protocol,the amplicon library is constructed through one regular PCR with long primers,and the total cost per DNA/cDNA sample decreases to just 7%of the typical cost via the multi-step PCR approach.Empirically tested primers and optimized PCR conditions to construct OSPALC libraries for 16S rDNA V4 regions are demonstrated as a case study.Tools to design primers targeting at any genomic regions are also presented.In principle,OSPALC can be readily applied to construct amplicon libraries of any target genes using DNA or RNA samples,and will facilitate research in numerous fields.
基金supported by the National Science Fund for Distinguished Young Scholars (51925101)the National Natural Science Foundation of China (52250090,52371208,52002042,51772012,51571007,and 12374023)+3 种基金Beijing Natural Science Foundation (JO18004)the 111 Project (B17002)the support from the Tencent Xplorer Prizepartially supported by the EPIC facility of Northwestern University’s NUANCE Center。
文摘Thermoelectric materials have a wide range of application because they can be directly used in refrigeration and power generation. And the Bi_(2)Te_(3) stand out because of its excellent thermoelectric performance and are used in commercial thermoelectric devices. However, n-type Bi_(2)Te_(3) has seriously hindered the development of Bi_(2)Te_(3)-based thermoelectric devices due to its weak mechanical properties and inferior thermoelectric performance. Therefore, it is urgent to develop a high-performance n-type Bi_(2)Te_(3) polycrystalline. In this work, we employed interstitial Cu and the hot deformation process to optimize the thermoelectric properties of Bi_(2)Te_(2.7)Se_(0.3), and a high-performance thermoelectric module was fabricated based on this material. Our combined theoretical and experimental effort indicates that the interstitial Cu reduce the defect density in the matrix and suppresses the donor-like effect, leading to a lattice plainification effect in the material. In addition, the two-step hot deformation process significantly improves the preferred orientation of the material and boosts the mobility. As a result, a maximum ZT of 1.27 at 373 K and a remarkable high ZT_(ave) of 1.22 across the temperature range of 300–425 K are obtained. The thermoelectric generator(TEG, 7-pair) and thermoelectric cooling(TEC, 127-pair) modules were fabricated with our n-type textured Cu_(0.01)Bi_(2)Te_(2.7)Se_(0.3) coupled with commercial p-type Bi_(2)Te_(3). The TEC module demonstrates superior cooling efficiency compared with the commercial Bi_(2)Te_(3) device, achieving a ΔT of 65 and 83.4 K when the hot end temperature at 300 and 350 K, respectively. In addition, the TEG module attains an impressive conversion efficiency of 6.5% at a ΔT of 225 K, which is almost the highest value among the reported Bi_(2)Te_(3)-based TEG modules.
文摘Since the discovery of generalized Snell’s law in 2011[1],metasurfaces have opened up the mainstream of arbitrary wavefront manipulation in electromagnetism.Using a gradient-index metasurface,the parallel wavenumber kx of reflected wave can be not equal to the incident one(kx=ξ+k0sinθi,where k0 andθi are the incident wavenumber and angle,andξis the phase gradient of metasurface in its supercell)[1].Whenξ>k0,the reflected wave becomes a surface wave bounded on the metasurface(where|kx|>k0,kz is imaginary,and z is normal to the metasurface)[2].However,as research of metasurfaces continually evolves,some articles have pointed out that such graded metasurfaces suffer from a series of problems[3-6].In particular,multiple metallic resonators are adopted in a subwavelength supercell,resulting in impedance mismatch,moderate conversion efficiency,wave absorption,and fabrication complexity.Hence,although the approach of graded metasurfaces has been demonstrated in the microwave regime,it is hard to extend to infrared and optical ranges with shorter wavelengths.To solve this problem,Ra’di et al.[7]devised metagratings with periodic arrays of bianisotropic scatterers and showed that they enable wave front engineering with unitary efficiency and significantly lower fabrication demands.
