The variation of the nonlinear contact stiffness induced by the elastic wheel-holding effect between the aircraft and tractor has an important effect on the vibration characteristics of an airfield towbarless traction...The variation of the nonlinear contact stiffness induced by the elastic wheel-holding effect between the aircraft and tractor has an important effect on the vibration characteristics of an airfield towbarless traction system,making it essential for ensuring the safety of this emerging towing-out mode.In this paper,the frequency evolutionary tendency of the traction system is studied and obtained considering the variation of nonlinear contact stiffness for the first time.A novel modal analysis method,based on a derived nonlinear contact relationship,is proposed to investigate the vibration characteristics for mechanical system.Frequency veering and mode exchange phenomena in the low-order modes are observed due to the variation of nonlinear contact stiffness.These findings are further validated by the experimental results of a scaled-down model.In addition,it is also found that the veering critical point will be shifted with the external loads.The study provides valuable insights into the vibration characteristics and frequency veering behavior of similar mechanism-based systems,such as towbarless traction system,and has important implications for improving their design and operational performance.展开更多
The Mg-Zn-Y-Nd alloy is a new type of degradable material for biomedical application. In the present study, Mg-6Zn-1.2Y-0.8Nd alloy was fabricated, and then extrusion and heat treatment were conducted to optimize its ...The Mg-Zn-Y-Nd alloy is a new type of degradable material for biomedical application. In the present study, Mg-6Zn-1.2Y-0.8Nd alloy was fabricated, and then extrusion and heat treatment were conducted to optimize its mechanical properties and cytocompatibility. The microstructure observation, mechanical property, degradation behavior and cytocompatibility tests were conducted on the Mg-Zn-Y-Nd alloy with three different states: as-cast(alloy C), as-extruded(alloy E) and extruded + heat treated(alloy EH).The results show that alloy C consists of coarse grains and continuous secondary phases. The extrusion process has caused incomplete recrystallization, and results in a mixed grain structure of elongated grains and small equiaxed grains(alloy E). The heat treatment process has promoted the recrystallization and homogenized the grain structure(alloy EH). Both the strength and ductility of the alloy has been improved by extrusion, but the following heat treatment has decreased the strength and increased the ductility.The degradation behavior of the alloy C and E alloys does not show much difference, but improves slightly in alloy EH, because the heat treatment has homogenized the microstructure and released the residual stress in the alloy. The directly and indirectly cell viability tests indicate that alloy EH exhibits the best cytocompatibility, which should be ascribed to its relative uniform degradation and low ion releasing rate. In summary, the combination of hot extrusion and heat treatment could optimize the mechanical property and cytocompatibility of the Mg-Zn-Y-Nd alloy together, which is beneficial for the future application of the alloy.展开更多
In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,fo...In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,followed by high-temperature sulfurization under a CS2 atmosphere.The effects of the sulfurization temperature,time,and doped proportion on the phase composition,color performance and temperature stability of γ-Ce2S3 were systematically studied.The results show that a stable γ-Ce2S3 red pigment can be obtained through Sr^2+and Dy^3+co-doping at 730℃ for 200 min.The diffraction peaks of all the samples shift to higher 2θ values with increasing doping proportion,indicating that part of the Dy^3+species enter the lattice and form a solid solution.The band gap of the samples remains practically constant at 2.01-2.04 eV,which causes their red color.The best red-color quality(L*=37.13,a*=34.77,b*=29.44) is achieved when the pigment has a Dy^3+/Ce^3+molar ratio of 0.15,and the material maintains its excellent red color(L*=31.49 a*=30.94 b*=25.33) after being heated at 410℃ for 30 min.展开更多
Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Partic...Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Particularly, various targets synthesized by hot pressing mixture of Cr, Al, and C powders at 650-1000 ℃ were used. It was found that regardless of the phase compositions and density of the com- posite targets, when the molar ratio of Cr：Al：C in the starting materials was 2：1：1, phase-pure crystalline Cr2AlC coatings were prepared by magnetron sputtering and post crystallization. The Cr2AIC coatings were dense and crack-free and had a duplex structure. The adhesion strength of the coating deposited on M38G superalloy from the 800 ℃ hot-pressed target and then annealed at 620 ℃ for 20 h in Ar exceeded 82 ± 6 MPa, while its hardness was 12 ± 3 GPa.展开更多
Chitosanases EAG1, a classical glycoside hydrolase from Bacillus ehimensis, is relatively unstable with higher temperature. This shortcoming seriously restricts its industrial application. Therefore, it is crucial to ...Chitosanases EAG1, a classical glycoside hydrolase from Bacillus ehimensis, is relatively unstable with higher temperature. This shortcoming seriously restricts its industrial application. Therefore, it is crucial to clarify the theoretical basis of thermo stability and to produce enzymes with high activity and stability. Using the structural modeling and molecular dynamical simulation, residues Leu84, Gly113, Asp116, Ala207 and Leu286 were believed to be the key residues for structural stability. Then the predicted residue Leu84 was mutated to ALA. It was shown that the L84A mutation can improve the thermal stability of chitosanases EAG1. Together with previous studies, mutations of G113C, D116C, A207C and L286C forms two sulfur bonds can change the thermal stability of EAG1. The results suggest that the thermal stability of EAG1 could be engineered by site-directed mutagenesis on the conserved residues. This protocol could be employed for improving thermal stability of other chitosanases EAG1.展开更多
The main aroma component of Luzhou-flavor Liquor is ethyl caproate, which is combined with appropriate amount of ethyl butyrate, ethyl acetate, ethyl lactate and so on. By adding the marine bacillus BC-2 (Accession nu...The main aroma component of Luzhou-flavor Liquor is ethyl caproate, which is combined with appropriate amount of ethyl butyrate, ethyl acetate, ethyl lactate and so on. By adding the marine bacillus BC-2 (Accession number: MK811408) to substrate sludge, the bacillus complex bacterial liquid (pit Mud Functional Bacterial liquid) has been modified. The complex bacterial liquid was used in the production of Luzhou-flavor Liquor and it dramatically promoted the content of health-beneficial ingredients in the new workshop. These results demonstrated that the marine bacillus BC-2 can effectively improve the quality and health benefit of Luzhou-flavor Liquor.展开更多
Analytical studies on the vibration and sound radiation characteristics of an asymmetric laminated rectangular plate are carried out in this paper. Theoretical formulations, in which the effects of thermal environment...Analytical studies on the vibration and sound radiation characteristics of an asymmetric laminated rectangular plate are carried out in this paper. Theoretical formulations, in which the effects of thermal environments are taken into account, are derived for the vibration and sound radiation based on both first-order shear deformation plate theory and Rayleigh integral. It is found that the natural frequencies, the resonant amplitudes of vibration response and the sound pressure level decrease with the temperature rising. The natural frequencies of asym- metric plates are smaller than those of symmetric plates and the velocity responses of asymmetric plates are larger than those of symmetric plates.展开更多
Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemica...Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemical stability,cost-effective and facile preparation,have attracted enormous interest for many applications.Also essential,the activation processes play a critical role to achieve these valuable properties.In this review,we provide a thorough analysis of the emerging nano-and microscopic carbon species with special morphology/textures and currently available types of chemical activation agents,and novel activation strategy to enhance electrochemical performance of activated carbon material in electrical energy storage devices including supercapacitor and alkaline ions batteries.A particular emphasis is set on recent advance in activated carbon materials with special morphology/textures for supercapacitors and sodium ion batteries.展开更多
In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK...In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).展开更多
In this work,we design a twisting metamaterial for longitudinal-torsional(L-T)mode conversion in pipes through exploring the theory of perfect transmodal FabryPerot interference(TFPI).Assuming that the axial and radia...In this work,we design a twisting metamaterial for longitudinal-torsional(L-T)mode conversion in pipes through exploring the theory of perfect transmodal FabryPerot interference(TFPI).Assuming that the axial and radial motions in pipes can be decoupled,we find that the metamaterial can be designed in a rectangular coordinate system,which is much more convenient than that in a cylindrical system.Numerical calculation with detailed microstructures shows that an efficient L-T mode conversion can be obtained in pipes with different radii.In addition,we fabricate mode-converting microstructures on an aluminum pipe and conduct ultrasonic experiments,and the results are in good agreement with the numerical calculations.We expect that the proposed LT mode-converting metamaterial and its design methodology can be applied in various ultrasonic devices.展开更多
Phytase is a kind of enzyme that hydrolyzes phytic acid and its salts to produce inositol and phosphoric acid. As a new feed additive, phytase has great potential in animal nutrition and environmental protection. Beca...Phytase is a kind of enzyme that hydrolyzes phytic acid and its salts to produce inositol and phosphoric acid. As a new feed additive, phytase has great potential in animal nutrition and environmental protection. Because of its good stability, large-scale production and high activity, microbial phytase has become a hot spot in industrial application. Here, we reported the predicted structure and enzymatic properties of a phytase from Bacillus subtilis, which was named as phyS. It was clear that the optimal temperature is 35°C, and the optimal pH is 8. Meanwhile, the enzyme activity was kept at above 90% in the range of pH 8 - 9, this result demonstrated that phyS is an alkaline phytase. This study lays a foundation for the extensive application of phyS.展开更多
The present study investigated whether replacing dietary rice straw with peanut vine(PEV)and Broussonetia papyrifera silage(BPS)reduces the use of soybean meal and explored its effects on the growth performance,blood ...The present study investigated whether replacing dietary rice straw with peanut vine(PEV)and Broussonetia papyrifera silage(BPS)reduces the use of soybean meal and explored its effects on the growth performance,blood biochemical indicators,serum metabolomics,and meat quality of fattening bulls.Forty-five Simmental crossbred bulls(initial body weight=484.29±8.49 kg)were randomly allotted into three dietary treatment groups(n=15):(1)CON,5%rice straw(DM basis);(2)PEV,5%peanut vine(DM basis);and(3)BPS,5%B.papyrifera silage(DM basis).The remaining roughage for all three treatment groups was supplemented with 25%corn silage(DM basis).The experiment lasted for 123 d,with the first 14 d serving as an adaptive period.Throughout the experiment,dietary BPS decreased the average daily dry matter intake(P<0.001)and feed cost(P<0.001).Serum metabolomics analysis showed that PEV affected the phenylalanine,tyrosine,and tryptophan biosynthesis pathways(P=0.021)and lysine degradation pathway(P=0.042),whereas BPS affected the phenylalanine,tyrosine and tryptophan biosynthesis pathways(P=0.004),lysine degradation pathway(P=0.012),and serotonergic synapse pathway(P<0.001).Regarding meat quality,the redness(P=0.025)and hue angle values(P<0.001)of the longissimus dorsi muscle were lower in the BPS group than in the CON and PEV groups.The yellowness of the longissimus dorsi muscle was lower in the BPS group than in the PEV group(P=0.024),and the shear force was lower in the PEV group than in the BPS group(P=0.014).However,lysine content in beef was higher in the BPS group than in the CON group(P=0.005).In conclusion,replacing rice straw with PEV and BPS reduced the use of soybean meal but had no adverse effects on growth performance.BPS affected the amino acid metabolism of bulls,thus decreasing feed intake and increasing the lysine content in meat.The PEV group showed better meat quality than the BPS group.展开更多
(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3(BSxBNT,x=0.3–V0.8)ceramics were prepared to investigate their structure,dielectric and ferroelectric properties.BSxBNT ceramics possess pure perovskite structure accompanied from a te...(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3(BSxBNT,x=0.3–V0.8)ceramics were prepared to investigate their structure,dielectric and ferroelectric properties.BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value,being confirmed by X-ray diffraction(XRD)and Raman results.The Tm corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110℃(x=0.3)to-45℃(x=0.8),across Tm=36℃(x=0.5)with a maximum dielectric constant(ɛr=5920@1 kHz)around room temperature.The saturated polarization Ps gradually while the remnant polarization Pr sharply decreases with the increase of x value,making the P-E hysteresis loop of BSxBNT ceramics goes slim.A maximum difference between Ps and Pr(Ps-Pr)is obtained for BSxBNT ceramics with x=0.5,at which a high recoverable energy density(Wrec=1.04 J/cm3)is achieved under an applied electric field of 100 kV/cm with an efficiency ofη=77%.Meanwhile,the varied temperature P-E loops,fatigue measurements,and electric breakdown characteristics for the sample with x=0.5 indicate that it is promising for pulsed power energy storage capacitor candidate materials.展开更多
Lead-free bulk ceramics for advanced pulsed power capacitors show relatively low recoverable energy storage density(Wrec)especially at low electric field condition.To address this challenge,we propose an A-site defect...Lead-free bulk ceramics for advanced pulsed power capacitors show relatively low recoverable energy storage density(Wrec)especially at low electric field condition.To address this challenge,we propose an A-site defect engineering to optimize the electric polarization behavior by disrupting the orderly arrangement of A-site ions,in which Ba_(0.105)Na_(0.325)Sr_(0.245−1.5x)□_(0.5x)Bi_(0.325)+xTiO_(3)(BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T,x=0,0.02,0.04,0.06,and 0.08)lead-free ceramics are selected as the representative.The BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T ceramics are prepared by using pressureless solid-state sintering and achieve large W_(rec)(1.8 J/cm^(3))at a low electric field(@110 kV/cm)when x=0.06.The value of 1.8 J/cm3 is super high as compared to all other W_(rec) in lead-free bulk ceramics under a relatively low electric field(<160 kV/cm).Furthermore,a high dielectric constant of 2930 within 15%fluctuation in a wide temperature range of 40–350℃is also obtained in BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T(x=0.06)ceramics.The excellent performances can be attributed to the A-site defect engineering,which can reduce remnant polarization(P_(r))and improve the thermal evolution of polar nanoregions(PNRs).This work confirms that the BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T(x=0.06)ceramics are desirable for advanced pulsed power capacitors,and will push the development of a series of Bi0.5Na0.5TiO3(BNT)-based ceramics with high W_(rec) and high-temperature stability.展开更多
Single-atom catalysts(SACs)have emerged as one of the most competitive catalysts toward a variety of important electrochemical reactions,thanks to their maximum atom economy,unique electronic and geometric structures....Single-atom catalysts(SACs)have emerged as one of the most competitive catalysts toward a variety of important electrochemical reactions,thanks to their maximum atom economy,unique electronic and geometric structures.However,the role of SACs supports on the catalytic performance does not receive enough research attentions.Here,we report an efficient route for synthesis of single atom Zn loading on the N-doped carbon nano-onions(ZnN/CNO).ZnN/CNO catalysts show an excellent high selectivity for CO_(2) electro-reduction to CO with a Faradaic efficiency of CO(FECO)up to 97%at -0.47 V(vs.reversible hydrogen electrode,RHE)and remarkable durability without activity decay.To our knowledge,ZnN/CNO is the best activity for the Zn based catalysts up to now,and superior to single atom Zn loading on the two-dimensional planar and porous structure of graphene substrate,although the graphene with larger surface area.The exact role of such carbon nano-onions(CNO)support is studied systematically by coupling characterizations and electrochemistry with density functional theory(DFT)calculations,which have attributed such good performance to the increased curvature.Such increased curvature modifies the surface charge,which then changes the adsorption energies of key intermediates,and improves the selectivity for CO generation accordingly.展开更多
Microwaves,which have a∼10-cm wavelength,can penetrate deeper into tissue than photons,heralding exciting deep tissue applications such as modulation or imaging via the thermoacoustic effect.Thermoacoustic conversion...Microwaves,which have a∼10-cm wavelength,can penetrate deeper into tissue than photons,heralding exciting deep tissue applications such as modulation or imaging via the thermoacoustic effect.Thermoacoustic conversion efficiency is however very low,even with an exogenous contrast agent.We break this low-conversion limit,using a split ring resonator to effectively collect and confine the microwaves into a submillimeter hot spot for ultrasound emission and achieve a conversion efficiency over 2000 times higher than other reported thermoacoustic contrast agents.Importantly,the frequency of emitted ultrasound can be precisely tuned and multiplexed by modulation of the microwave pulses.Such performance is inaccessible by a piezoelectric-based transducer or a photoacoustic emitter and,therefore,split ring resonators open up new opportunities to study the frequency response of cells in ultrasonic biomodulation.For applications in deep tissue localization,a split ring resonator can be used as a wireless,battery-free ultrasound beacon placed under a breast phantom.展开更多
Sustainable agricultural development is a topic of global concern aiming at satisfying food demand of the growing population while reducing impact on environment.Circular agriculture has become a promising development...Sustainable agricultural development is a topic of global concern aiming at satisfying food demand of the growing population while reducing impact on environment.Circular agriculture has become a promising development pattern with the advantages of complementing environmental resources,replacing feedback from outside system,and processing waste of bottom of system,etc.This study combined economic analysis,life cycle assessment and emergy accounting to evaluate sustainability of an integrated maize-pig system(IS)driven by indigenous microbes in Northeast China,compared with separated maize and pig system(SS).IS reduced input of concentrate feed,coal,vaccines,disinfectants,fertilizer and labor by 14.35%,100%,46.11%,100%,60.1%and 60.8%driven by indigenous microbes.Economic analysis results showed that IS has 82.88%higher profit than that of SS.The sum of potential environmental impacts of IS was lower than SS for 80.65%according to lifecycle assessment.The emergy results revealed that IS performed better sustainability.Internal feedback emergy for fertilizer and local resources for maize straw increasing of IS significantly improved emergy efficiency.The reduction resulted in nonrenewable resources decreased 33.01%than that of SS,and increased renewable resources by 67.81%,which reduced environmental load ratio of IS by 60.08%of IS.Meanwhile,these factors were the primary factors generating higher sustainability of IS.Overall,the integrated maize-pig system driven by indigenous microbes in this study can effectively alleviate the problems caused by agricultural waste and promote sustainable agricultural development.展开更多
Ab initio calculations of dielectronic recombination(DR)processes from the ground state 1s 2 of He-like argon ion through doubly excited states 1s2snl,1s2pnl(n=2 to 9)of Li-like argon ions are performed using the mult...Ab initio calculations of dielectronic recombination(DR)processes from the ground state 1s 2 of He-like argon ion through doubly excited states 1s2snl,1s2pnl(n=2 to 9)of Li-like argon ions are performed using the multi-configuration HatreeFock method with relativistic correction.The theoretical method and its corresponding computation will be outlined.For higher doubly excited states with n>9,the scaling law is used to extrapolate the Auger and radiative transition rates.The total and stateto-state cross sections with corresponding rate coefficients in the temperature from 102 eV to 106 eV are presented,as well as the DR strengths for all the separate resonances.Moreover,peculiarities of the DR from doubly excited 1s2s3l′configurations are analyzed and the contributions of two-electron-one-photo(TEOP)radiative transitions to the DR cross sections are also investigated,such as 1s2s^(2)→1s^(2)2p,due to the strong configuration interactions.Our theoretical results appear to be in excellent agreement with the previous and recent experimental measurements.展开更多
Facing the increasingly serious energy and environmental problems,the research and development of new energy storage technology and environment-friendly energy storage materials are imminent.As a typical lead-free fer...Facing the increasingly serious energy and environmental problems,the research and development of new energy storage technology and environment-friendly energy storage materials are imminent.As a typical lead-free ferroelectric with excellent dielectric properties,(Bi,Na)TiO_(3)(BNT)is supposed to be the most potential and competitive environment-friendly ceramic material and has become a research hotspot for dielectric energy storage in recent years.This paper first briefly introduces the basic physical principles and energy storage performance evaluation parameters of dielectric energy storage materials,then summarizes the critical research systems and related progress of BNT-based lead-free energy storage materials(bulk ceramics,films and multilayer ceramics)from the aspects of ions doping modification and multi-component composite optimization,and finally looks forward to the improvement direction and energy storage application prospect of BNT-based lead-free relaxor ferroelectric materials.展开更多
Multiplexing across donors has emerged as a popular strategy to increase throughput,reduce costs,overcome technical batch effects,and improve doublet detection in single-cell genomic studies.To eliminate additional ex...Multiplexing across donors has emerged as a popular strategy to increase throughput,reduce costs,overcome technical batch effects,and improve doublet detection in single-cell genomic studies.To eliminate additional experimental steps,endogenous nuclear genome variants are used for demultiplexing pooled single-cell RNA sequencing(scRNA-seq)data by several computational tools.However,these tools have limitations when applied to single-cell sequencing methods that do not cover nuclear genomic regions well,such as single-cell assay for transposase-accessible chromatin with sequencing(scATAC-seq).Here,we demonstrate that mitochondrial germline variants are an alternative,robust,and computationally efficient endogenous barcode for sample demultiplexing.We propose MitoSort,a tool that uses mitochondrial germline variants to assign cells to their donor origins and identify cross-genotype doublets in single-cell genomic datasets.We evaluate its performance by using in silico pooled mitochondrial scATAC-seq(mtscATAC-seq)libraries and experimentally multiplexed data with cell hashtags.MitoSort achieves high accuracy and efficiency in genotype clustering and doublet detection for mtscATAC-seq data,addressing the limitations of current computational techniques tailored for scRNA-seq data.Moreover,MitoSort exhibits versatility,and can be applied to various single-cell sequencing approaches beyond mtscATAC-seq provided that the mitochondrial variants are reliably detected.Furthermore,we demonstrate the application of MitoSort in a case study where B cells from eight donors were pooled and assayed by single-cell multi-omics sequencing.Altogether,our results demonstrate the accuracy and efficiency of MitoSort,which enables reliable sample demultiplexing in various single-cell genomic applications.MitoSort is available at https://github.com/tangzhj/MitoSort.展开更多
基金co-supported by the Key Projects of the Civil Aviation Joint Fund of the National Natural Science Foundation of China(No.U2033208)。
文摘The variation of the nonlinear contact stiffness induced by the elastic wheel-holding effect between the aircraft and tractor has an important effect on the vibration characteristics of an airfield towbarless traction system,making it essential for ensuring the safety of this emerging towing-out mode.In this paper,the frequency evolutionary tendency of the traction system is studied and obtained considering the variation of nonlinear contact stiffness for the first time.A novel modal analysis method,based on a derived nonlinear contact relationship,is proposed to investigate the vibration characteristics for mechanical system.Frequency veering and mode exchange phenomena in the low-order modes are observed due to the variation of nonlinear contact stiffness.These findings are further validated by the experimental results of a scaled-down model.In addition,it is also found that the veering critical point will be shifted with the external loads.The study provides valuable insights into the vibration characteristics and frequency veering behavior of similar mechanism-based systems,such as towbarless traction system,and has important implications for improving their design and operational performance.
基金the National Key Research and Development Program of China(No.2016YFC1102601)the Shenzhen Basic Research Project(JCYJ20170306141749970),the Shenzhen Basic Research Project(Nos.JCYJ2015052916222873,JCYJ20160407090231002,JCYJ20150625155931806 and JCYJ20160427100211076) for financial supportthe Shenzhen Technology Innovation Plan(Nos.CXZZ20140731091722497 and CXZZ20140419114548507)
文摘The Mg-Zn-Y-Nd alloy is a new type of degradable material for biomedical application. In the present study, Mg-6Zn-1.2Y-0.8Nd alloy was fabricated, and then extrusion and heat treatment were conducted to optimize its mechanical properties and cytocompatibility. The microstructure observation, mechanical property, degradation behavior and cytocompatibility tests were conducted on the Mg-Zn-Y-Nd alloy with three different states: as-cast(alloy C), as-extruded(alloy E) and extruded + heat treated(alloy EH).The results show that alloy C consists of coarse grains and continuous secondary phases. The extrusion process has caused incomplete recrystallization, and results in a mixed grain structure of elongated grains and small equiaxed grains(alloy E). The heat treatment process has promoted the recrystallization and homogenized the grain structure(alloy EH). Both the strength and ductility of the alloy has been improved by extrusion, but the following heat treatment has decreased the strength and increased the ductility.The degradation behavior of the alloy C and E alloys does not show much difference, but improves slightly in alloy EH, because the heat treatment has homogenized the microstructure and released the residual stress in the alloy. The directly and indirectly cell viability tests indicate that alloy EH exhibits the best cytocompatibility, which should be ascribed to its relative uniform degradation and low ion releasing rate. In summary, the combination of hot extrusion and heat treatment could optimize the mechanical property and cytocompatibility of the Mg-Zn-Y-Nd alloy together, which is beneficial for the future application of the alloy.
基金supported by the National Natural Science Foundation of China(51462010)the Natural Science Foundation of Jiangxi Province(20161BAB206132,20171ACB20022)the Science and technology program Foundation of Jingdezhen(2017GYZD019-012).
文摘In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,followed by high-temperature sulfurization under a CS2 atmosphere.The effects of the sulfurization temperature,time,and doped proportion on the phase composition,color performance and temperature stability of γ-Ce2S3 were systematically studied.The results show that a stable γ-Ce2S3 red pigment can be obtained through Sr^2+and Dy^3+co-doping at 730℃ for 200 min.The diffraction peaks of all the samples shift to higher 2θ values with increasing doping proportion,indicating that part of the Dy^3+species enter the lattice and form a solid solution.The band gap of the samples remains practically constant at 2.01-2.04 eV,which causes their red color.The best red-color quality(L*=37.13,a*=34.77,b*=29.44) is achieved when the pigment has a Dy^3+/Ce^3+molar ratio of 0.15,and the material maintains its excellent red color(L*=31.49 a*=30.94 b*=25.33) after being heated at 410℃ for 30 min.
基金supported by the National Natural Science Foundation of China under Grant Nos.51271191,51571205 and 51401209
文摘Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Particularly, various targets synthesized by hot pressing mixture of Cr, Al, and C powders at 650-1000 ℃ were used. It was found that regardless of the phase compositions and density of the com- posite targets, when the molar ratio of Cr：Al：C in the starting materials was 2：1：1, phase-pure crystalline Cr2AlC coatings were prepared by magnetron sputtering and post crystallization. The Cr2AIC coatings were dense and crack-free and had a duplex structure. The adhesion strength of the coating deposited on M38G superalloy from the 800 ℃ hot-pressed target and then annealed at 620 ℃ for 20 h in Ar exceeded 82 ± 6 MPa, while its hardness was 12 ± 3 GPa.
文摘Chitosanases EAG1, a classical glycoside hydrolase from Bacillus ehimensis, is relatively unstable with higher temperature. This shortcoming seriously restricts its industrial application. Therefore, it is crucial to clarify the theoretical basis of thermo stability and to produce enzymes with high activity and stability. Using the structural modeling and molecular dynamical simulation, residues Leu84, Gly113, Asp116, Ala207 and Leu286 were believed to be the key residues for structural stability. Then the predicted residue Leu84 was mutated to ALA. It was shown that the L84A mutation can improve the thermal stability of chitosanases EAG1. Together with previous studies, mutations of G113C, D116C, A207C and L286C forms two sulfur bonds can change the thermal stability of EAG1. The results suggest that the thermal stability of EAG1 could be engineered by site-directed mutagenesis on the conserved residues. This protocol could be employed for improving thermal stability of other chitosanases EAG1.
文摘The main aroma component of Luzhou-flavor Liquor is ethyl caproate, which is combined with appropriate amount of ethyl butyrate, ethyl acetate, ethyl lactate and so on. By adding the marine bacillus BC-2 (Accession number: MK811408) to substrate sludge, the bacillus complex bacterial liquid (pit Mud Functional Bacterial liquid) has been modified. The complex bacterial liquid was used in the production of Luzhou-flavor Liquor and it dramatically promoted the content of health-beneficial ingredients in the new workshop. These results demonstrated that the marine bacillus BC-2 can effectively improve the quality and health benefit of Luzhou-flavor Liquor.
基金Project supported by the National Natural Science Foundation of China(Nos.11321062,91016008 and 91216107)
文摘Analytical studies on the vibration and sound radiation characteristics of an asymmetric laminated rectangular plate are carried out in this paper. Theoretical formulations, in which the effects of thermal environments are taken into account, are derived for the vibration and sound radiation based on both first-order shear deformation plate theory and Rayleigh integral. It is found that the natural frequencies, the resonant amplitudes of vibration response and the sound pressure level decrease with the temperature rising. The natural frequencies of asym- metric plates are smaller than those of symmetric plates and the velocity responses of asymmetric plates are larger than those of symmetric plates.
基金financially supported by the Natural National Science Foundation of China(51972281)the foundation of State Key Laboratory of Metastable Materials Science and Technology in Yanshan University。
文摘Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemical stability,cost-effective and facile preparation,have attracted enormous interest for many applications.Also essential,the activation processes play a critical role to achieve these valuable properties.In this review,we provide a thorough analysis of the emerging nano-and microscopic carbon species with special morphology/textures and currently available types of chemical activation agents,and novel activation strategy to enhance electrochemical performance of activated carbon material in electrical energy storage devices including supercapacitor and alkaline ions batteries.A particular emphasis is set on recent advance in activated carbon materials with special morphology/textures for supercapacitors and sodium ion batteries.
基金Project supported by National Natural Science Foundation of China (51462010)Natural Science Foundation of Jiangxi Province(20161BAB206132,20171ACB20022)The Innovation fund of Jingdezhen Ceramic Institute (JYC-201803)。
文摘In this study,K+-doped γ-Ce2 S3 was successfully prepared via a gas-solid reaction method using CeO2,K2 CO3,and CS2 as raw materials.The effects of the suitable sulfide system and different molar ratios of K to Ce(nK/Ce=0-0.30) on the phase composition,crystal structure,chromaticity and thermal stability ofγ-Ce2 S3 were systematically investigated.Pure γ-Ce2 S3 was obtained by calcining the doped samples at840℃ for 150 min.After calcination at the same temperature the undoped K+samples exhibit a pure α-phase.Samples with a K/Ce molar ratio(nK/Ce) of 0.10-0.25 comprise only the γ-phase;and when nK/Ce exceeds 0.25,a new heterogeneous phase,KCeS2,emerges.For values of nK/Ce in the range of0-0.25,the γ-Ce2 S3 lattice parameters gradually increases with increasing K+ content.When nK/Ceexceedes 0.25,the lattice parameters remains unchanged.As nK/Ce increased,the synthesized color gradually changes from red to orange—red and finally,to yellow.The redness value a* reaches the maximum(L*=33.86,a*=36.68,b*=38.15) when nK/Ce=0.10,The nK/Ce=0.10 composition continues to exhibit the y-phase after heat treatment at 420℃ for 10 min in air.The K+doping fills the internal vacancies of γ-Ce2 S3 and formed a solid solution,which is beneficial for the stability of its lattice,thus improving the thermal stability of γ-Ce2 S3(from 350 to 420℃).
基金Project supported by the National Natural Science Foundation of China(Nos.U2033208,52192633)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2021JQ-006)+1 种基金the China Postdoctoral Science Foundation(No.2020TQ0241)the Innovative Scientific Program of China Nuclear Power Engineering Co.,Ltd。
文摘In this work,we design a twisting metamaterial for longitudinal-torsional(L-T)mode conversion in pipes through exploring the theory of perfect transmodal FabryPerot interference(TFPI).Assuming that the axial and radial motions in pipes can be decoupled,we find that the metamaterial can be designed in a rectangular coordinate system,which is much more convenient than that in a cylindrical system.Numerical calculation with detailed microstructures shows that an efficient L-T mode conversion can be obtained in pipes with different radii.In addition,we fabricate mode-converting microstructures on an aluminum pipe and conduct ultrasonic experiments,and the results are in good agreement with the numerical calculations.We expect that the proposed LT mode-converting metamaterial and its design methodology can be applied in various ultrasonic devices.
文摘Phytase is a kind of enzyme that hydrolyzes phytic acid and its salts to produce inositol and phosphoric acid. As a new feed additive, phytase has great potential in animal nutrition and environmental protection. Because of its good stability, large-scale production and high activity, microbial phytase has become a hot spot in industrial application. Here, we reported the predicted structure and enzymatic properties of a phytase from Bacillus subtilis, which was named as phyS. It was clear that the optimal temperature is 35°C, and the optimal pH is 8. Meanwhile, the enzyme activity was kept at above 90% in the range of pH 8 - 9, this result demonstrated that phyS is an alkaline phytase. This study lays a foundation for the extensive application of phyS.
基金supported by grants from the National Key Research and Development Program of China, China (2022YFA1304200)
文摘The present study investigated whether replacing dietary rice straw with peanut vine(PEV)and Broussonetia papyrifera silage(BPS)reduces the use of soybean meal and explored its effects on the growth performance,blood biochemical indicators,serum metabolomics,and meat quality of fattening bulls.Forty-five Simmental crossbred bulls(initial body weight=484.29±8.49 kg)were randomly allotted into three dietary treatment groups(n=15):(1)CON,5%rice straw(DM basis);(2)PEV,5%peanut vine(DM basis);and(3)BPS,5%B.papyrifera silage(DM basis).The remaining roughage for all three treatment groups was supplemented with 25%corn silage(DM basis).The experiment lasted for 123 d,with the first 14 d serving as an adaptive period.Throughout the experiment,dietary BPS decreased the average daily dry matter intake(P<0.001)and feed cost(P<0.001).Serum metabolomics analysis showed that PEV affected the phenylalanine,tyrosine,and tryptophan biosynthesis pathways(P=0.021)and lysine degradation pathway(P=0.042),whereas BPS affected the phenylalanine,tyrosine and tryptophan biosynthesis pathways(P=0.004),lysine degradation pathway(P=0.012),and serotonergic synapse pathway(P<0.001).Regarding meat quality,the redness(P=0.025)and hue angle values(P<0.001)of the longissimus dorsi muscle were lower in the BPS group than in the CON and PEV groups.The yellowness of the longissimus dorsi muscle was lower in the BPS group than in the PEV group(P=0.024),and the shear force was lower in the PEV group than in the BPS group(P=0.014).However,lysine content in beef was higher in the BPS group than in the CON group(P=0.005).In conclusion,replacing rice straw with PEV and BPS reduced the use of soybean meal but had no adverse effects on growth performance.BPS affected the amino acid metabolism of bulls,thus decreasing feed intake and increasing the lysine content in meat.The PEV group showed better meat quality than the BPS group.
基金This work was financially supported by National Natural Science Foundation of China(51767010)Science&Technology Key Research Project of Jiangxi Provincial Education Department(GJJ170760)Graduate Student Innovation Fund of Jiangxi Province(YC2018-S295).
文摘(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3(BSxBNT,x=0.3–V0.8)ceramics were prepared to investigate their structure,dielectric and ferroelectric properties.BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value,being confirmed by X-ray diffraction(XRD)and Raman results.The Tm corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110℃(x=0.3)to-45℃(x=0.8),across Tm=36℃(x=0.5)with a maximum dielectric constant(ɛr=5920@1 kHz)around room temperature.The saturated polarization Ps gradually while the remnant polarization Pr sharply decreases with the increase of x value,making the P-E hysteresis loop of BSxBNT ceramics goes slim.A maximum difference between Ps and Pr(Ps-Pr)is obtained for BSxBNT ceramics with x=0.5,at which a high recoverable energy density(Wrec=1.04 J/cm3)is achieved under an applied electric field of 100 kV/cm with an efficiency ofη=77%.Meanwhile,the varied temperature P-E loops,fatigue measurements,and electric breakdown characteristics for the sample with x=0.5 indicate that it is promising for pulsed power energy storage capacitor candidate materials.
基金This work was financially supported by the National Natural Science Foundation of China(No.51767010)the Key Project of Natural Science Foundation of Jiangxi Province of China(No.20212ACB204010)。
文摘Lead-free bulk ceramics for advanced pulsed power capacitors show relatively low recoverable energy storage density(Wrec)especially at low electric field condition.To address this challenge,we propose an A-site defect engineering to optimize the electric polarization behavior by disrupting the orderly arrangement of A-site ions,in which Ba_(0.105)Na_(0.325)Sr_(0.245−1.5x)□_(0.5x)Bi_(0.325)+xTiO_(3)(BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T,x=0,0.02,0.04,0.06,and 0.08)lead-free ceramics are selected as the representative.The BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T ceramics are prepared by using pressureless solid-state sintering and achieve large W_(rec)(1.8 J/cm^(3))at a low electric field(@110 kV/cm)when x=0.06.The value of 1.8 J/cm3 is super high as compared to all other W_(rec) in lead-free bulk ceramics under a relatively low electric field(<160 kV/cm).Furthermore,a high dielectric constant of 2930 within 15%fluctuation in a wide temperature range of 40–350℃is also obtained in BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T(x=0.06)ceramics.The excellent performances can be attributed to the A-site defect engineering,which can reduce remnant polarization(P_(r))and improve the thermal evolution of polar nanoregions(PNRs).This work confirms that the BNS_(0.245−1.5x)□_(0.5x)B_(0.325+x)T(x=0.06)ceramics are desirable for advanced pulsed power capacitors,and will push the development of a series of Bi0.5Na0.5TiO3(BNT)-based ceramics with high W_(rec) and high-temperature stability.
基金This work was supported by the National Key R&D Program of China(2020YFA0710404)the Beijing Natural Science Foundation(2182077)the National Natural Science Foundation of China(21477136,51972281,and 21703250).
文摘Single-atom catalysts(SACs)have emerged as one of the most competitive catalysts toward a variety of important electrochemical reactions,thanks to their maximum atom economy,unique electronic and geometric structures.However,the role of SACs supports on the catalytic performance does not receive enough research attentions.Here,we report an efficient route for synthesis of single atom Zn loading on the N-doped carbon nano-onions(ZnN/CNO).ZnN/CNO catalysts show an excellent high selectivity for CO_(2) electro-reduction to CO with a Faradaic efficiency of CO(FECO)up to 97%at -0.47 V(vs.reversible hydrogen electrode,RHE)and remarkable durability without activity decay.To our knowledge,ZnN/CNO is the best activity for the Zn based catalysts up to now,and superior to single atom Zn loading on the two-dimensional planar and porous structure of graphene substrate,although the graphene with larger surface area.The exact role of such carbon nano-onions(CNO)support is studied systematically by coupling characterizations and electrochemistry with density functional theory(DFT)calculations,which have attributed such good performance to the increased curvature.Such increased curvature modifies the surface charge,which then changes the adsorption energies of key intermediates,and improves the selectivity for CO generation accordingly.
基金The project was supported by an Ignition Award from Boston University to J.X.C.
文摘Microwaves,which have a∼10-cm wavelength,can penetrate deeper into tissue than photons,heralding exciting deep tissue applications such as modulation or imaging via the thermoacoustic effect.Thermoacoustic conversion efficiency is however very low,even with an exogenous contrast agent.We break this low-conversion limit,using a split ring resonator to effectively collect and confine the microwaves into a submillimeter hot spot for ultrasound emission and achieve a conversion efficiency over 2000 times higher than other reported thermoacoustic contrast agents.Importantly,the frequency of emitted ultrasound can be precisely tuned and multiplexed by modulation of the microwave pulses.Such performance is inaccessible by a piezoelectric-based transducer or a photoacoustic emitter and,therefore,split ring resonators open up new opportunities to study the frequency response of cells in ultrasonic biomodulation.For applications in deep tissue localization,a split ring resonator can be used as a wireless,battery-free ultrasound beacon placed under a breast phantom.
基金This work was supported by the Chinese Universities Scientific Fund[2021AC002].
文摘Sustainable agricultural development is a topic of global concern aiming at satisfying food demand of the growing population while reducing impact on environment.Circular agriculture has become a promising development pattern with the advantages of complementing environmental resources,replacing feedback from outside system,and processing waste of bottom of system,etc.This study combined economic analysis,life cycle assessment and emergy accounting to evaluate sustainability of an integrated maize-pig system(IS)driven by indigenous microbes in Northeast China,compared with separated maize and pig system(SS).IS reduced input of concentrate feed,coal,vaccines,disinfectants,fertilizer and labor by 14.35%,100%,46.11%,100%,60.1%and 60.8%driven by indigenous microbes.Economic analysis results showed that IS has 82.88%higher profit than that of SS.The sum of potential environmental impacts of IS was lower than SS for 80.65%according to lifecycle assessment.The emergy results revealed that IS performed better sustainability.Internal feedback emergy for fertilizer and local resources for maize straw increasing of IS significantly improved emergy efficiency.The reduction resulted in nonrenewable resources decreased 33.01%than that of SS,and increased renewable resources by 67.81%,which reduced environmental load ratio of IS by 60.08%of IS.Meanwhile,these factors were the primary factors generating higher sustainability of IS.Overall,the integrated maize-pig system driven by indigenous microbes in this study can effectively alleviate the problems caused by agricultural waste and promote sustainable agricultural development.
基金supported by the Chinese National Foundation of Sciences(Grant Nos.10344001 and 10174009)the Science and Technology Foundation of Chinese Academy of Engineering Physics,and National High-Tech ICF Committee in China。
文摘Ab initio calculations of dielectronic recombination(DR)processes from the ground state 1s 2 of He-like argon ion through doubly excited states 1s2snl,1s2pnl(n=2 to 9)of Li-like argon ions are performed using the multi-configuration HatreeFock method with relativistic correction.The theoretical method and its corresponding computation will be outlined.For higher doubly excited states with n>9,the scaling law is used to extrapolate the Auger and radiative transition rates.The total and stateto-state cross sections with corresponding rate coefficients in the temperature from 102 eV to 106 eV are presented,as well as the DR strengths for all the separate resonances.Moreover,peculiarities of the DR from doubly excited 1s2s3l′configurations are analyzed and the contributions of two-electron-one-photo(TEOP)radiative transitions to the DR cross sections are also investigated,such as 1s2s^(2)→1s^(2)2p,due to the strong configuration interactions.Our theoretical results appear to be in excellent agreement with the previous and recent experimental measurements.
基金supported by National Natural Science Foundation of China(52267002)Natural Science Foundation of Jiangxi Province(20212ACB204010)+1 种基金Science&Technology Research Project of Jiangxi Provincial Education Department(GJJ211301)the Graduate Innovation Fund of Jiangxi Province(YC2022-S884).
文摘Facing the increasingly serious energy and environmental problems,the research and development of new energy storage technology and environment-friendly energy storage materials are imminent.As a typical lead-free ferroelectric with excellent dielectric properties,(Bi,Na)TiO_(3)(BNT)is supposed to be the most potential and competitive environment-friendly ceramic material and has become a research hotspot for dielectric energy storage in recent years.This paper first briefly introduces the basic physical principles and energy storage performance evaluation parameters of dielectric energy storage materials,then summarizes the critical research systems and related progress of BNT-based lead-free energy storage materials(bulk ceramics,films and multilayer ceramics)from the aspects of ions doping modification and multi-component composite optimization,and finally looks forward to the improvement direction and energy storage application prospect of BNT-based lead-free relaxor ferroelectric materials.
基金supported by the National Key R&D Program of China(Grant No.2021YFA1102100)the National Natural Science Foundation of China(Grant Nos.32070644,32293190,32293191)to JX,and the Guangzhou Key Research and Development Program(Grant No.2023B03J1347)to YS and JX.
文摘Multiplexing across donors has emerged as a popular strategy to increase throughput,reduce costs,overcome technical batch effects,and improve doublet detection in single-cell genomic studies.To eliminate additional experimental steps,endogenous nuclear genome variants are used for demultiplexing pooled single-cell RNA sequencing(scRNA-seq)data by several computational tools.However,these tools have limitations when applied to single-cell sequencing methods that do not cover nuclear genomic regions well,such as single-cell assay for transposase-accessible chromatin with sequencing(scATAC-seq).Here,we demonstrate that mitochondrial germline variants are an alternative,robust,and computationally efficient endogenous barcode for sample demultiplexing.We propose MitoSort,a tool that uses mitochondrial germline variants to assign cells to their donor origins and identify cross-genotype doublets in single-cell genomic datasets.We evaluate its performance by using in silico pooled mitochondrial scATAC-seq(mtscATAC-seq)libraries and experimentally multiplexed data with cell hashtags.MitoSort achieves high accuracy and efficiency in genotype clustering and doublet detection for mtscATAC-seq data,addressing the limitations of current computational techniques tailored for scRNA-seq data.Moreover,MitoSort exhibits versatility,and can be applied to various single-cell sequencing approaches beyond mtscATAC-seq provided that the mitochondrial variants are reliably detected.Furthermore,we demonstrate the application of MitoSort in a case study where B cells from eight donors were pooled and assayed by single-cell multi-omics sequencing.Altogether,our results demonstrate the accuracy and efficiency of MitoSort,which enables reliable sample demultiplexing in various single-cell genomic applications.MitoSort is available at https://github.com/tangzhj/MitoSort.
