Amorphous solids exhibit scale-free avalanches,even under small external loading,and thus can work as suitable systems to study critical behavior and universality classes.The abundance of scale-free avalanches in the ...Amorphous solids exhibit scale-free avalanches,even under small external loading,and thus can work as suitable systems to study critical behavior and universality classes.The abundance of scale-free avalanches in the entire elastic tension regime of bulk metallic glass(BMG)samples has been experimentally observed using acoustic emission(AE)measurements.In this work,we compare the statistics of avalanches with those of earthquakes,and find that they both follow the Gutenberg–Richter law in the statistics of energies and Omori’s law of aftershock rates,and share the same characteristics in the distribution of recurrence times.These resemblances encourage us to propose the term“glass-quake”to describe avalanches in elastically loaded BMGs.Furthermore,our work echoes the potential universality of critical behavior in disordered physical systems from atomic to planetary scales,and motivates the use of elastic loaded BMGs as valuable laboratory simulators of seismic dynamics.展开更多
Bulk geochemistry,Sr,Nd,and O-H isotope systematics are reported for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore d...Bulk geochemistry,Sr,Nd,and O-H isotope systematics are reported for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore district,Southern Cameroon,Metzimevin iron ore deposit is a hematite-magnetite BIF system,dominated by SiO_(2)+Fe_(2)O_(3)(97.1 to 99.84 wt%),with low concentrations of clastic elements e.g.,Al_(2)O_(3),TiO_(2),and HFSE,depicting a nearly pure chemical precipitate.The REE+Y signature of the iron deposit displays strong positive Eu anomaly,strong negative Ce anomaly,and chondritic to superchondritic Y/Ho ratios,suggestive of formation by mixed seawater-high temperature hydrothermal fluids in oxidising environment.The^(87)Sr/^(86)Sr ratios of the BIF are higher than the maximum^(87)Sr/^(86)Sr evolution curves for all Archean reservoirs(bulk silicate earth,Archean crust and Archean seawater),indicating involvement of continentally-derived components during BIF formation and alteration.TheƐ_(Nd)(t)(+2.26 to+3.77)and Nd model age indicate that chemical constituents for the BIF were derived from undifferentiated crustal source,between 3.002 and 2.88 Ga.The variable and diverse O and H isotope data(−1.9‰to 17.3‰and−57‰to 136‰respectively)indicate that the Metzimevin iron ore formed initially from magmatic plumes and later enriched by magmatic-metamorphic-modified meteoric fluids.Mass balance calculations indicate mineralisation by combined leaching and precipitation,with an average iron enrichment factor of>2.67 and SiO_(2)depletion factor of>0.99.This is associated with an overall volume reduction of 28.27%,reflecting net leaching and volume collapse of the BIF protholith.展开更多
We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density...We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density functional theory.The results show that there are band crossings in the Z-L(armchair)direction.展开更多
The oceanic trace metals iron(Fe),nickel(Ni),copper(Cu),zinc(Zn),and cadmium(Cd)are crucial to marine phytoplankton growth and global carbon cycle,and the analysis of their stable isotopes can provide valuable insight...The oceanic trace metals iron(Fe),nickel(Ni),copper(Cu),zinc(Zn),and cadmium(Cd)are crucial to marine phytoplankton growth and global carbon cycle,and the analysis of their stable isotopes can provide valuable insights into their biogeochemical cycles within the ocean.However,the simultaneous isotopic analysis of multiple elements present in seawater is challenging because of their low concentrations,limited volumes of the test samples,and high salt matrix.In this study,we present the novel method developed for the simultaneous analysis of five isotope systems by 1 L seawater sample.In the developed method,the NOBIAS Chelate-PA1 resin was used to extract metals from seawater,the AG MP-1M anion-exchange resin to purify Cu,Fe,Zn,Cd,and the NOBIAS Chelate-PA1 resin to further extract Ni from the matrix elements.Finally,a multi-collector inductively coupled plasma mass spectroscope(MC-ICPMS)was employed for the isotopic measurements using a doublespike technique or sample-standard bracketing combined with internal normalization.This method exhibited low total procedural blanks(0.04 pg,0.04 pg,0.21 pg,0.15 pg,and 3 pg for Ni,Cu,Fe,Zn,and Cd,respectively)and high extraction efficiencies(100.5%±0.3%,100.2%±0.5%,97.8%±1.4%,99.9%±0.8%,and 100.1%±0.2%for Ni,Cu,Fe,Zn,and Cd,respectively).The external errors and external precisions of this method could be considered negligible.The proposed method was further tested on the seawater samples obtained from the whole vertical profile of a water column during the Chinese GEOTRACES GP09 cruise in the Northwest Pacific,and the results showed good agreement with previous related data.This innovative method will contribute to the advancement of isotope research and enhance our understanding of the marine biogeochemical cycling of Fe,Ni,Cu,Zn,and Cd.展开更多
Introducing high-valence Ta element is an essential strategy for addressing the structu ral deterioration of the Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathode,but the enlarged Li/Ni cation mixing leads to the infe...Introducing high-valence Ta element is an essential strategy for addressing the structu ral deterioration of the Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathode,but the enlarged Li/Ni cation mixing leads to the inferior rate capability originating from the hindered Li~+migration.Note that the non-magnetic Ti~(4+)ion can suppress Li/Ni disorder by removing the magnetic frustration in the transition metal layer.However,it is still challenging to directionally design expected Ta/Ti dual-modification,resulting from the complexity of the elemental distribution and the uncertainty of in-situ formed coating compounds by introducing foreign elements.Herein,a LiTaO_3 grain boundary(GB)coating and bulk Ti-doping have been successfully achieved in LiNi_(0.834)Co_(0.11)Mn_(0.056)O_(2) cathode by thermodynamic guidance,in which the structural formation energy and interfacial binding energy are employed to predict the elemental diffusion discrepancy and thermodynamically stable coating compounds.Thanks to the coupling effect of strengthened structural/interfacial stability and improved Li~+diffusion kinetics by simultaneous bulk/GB engineering,the Ta/Ti-NCM cathode exhibits outstanding capacity retention,reaching 91.1%after 400 cycles at 1 C.This elaborate work contributes valuable insights into rational dual-modification engineering from a thermodynamic perspective for maximizing the electrochemical performances of NCM cathodes.展开更多
Prezygotic isolation is important for successful fertilization in rice, significantly affecting yield. This study focused on F_(5:6) generation plants derived from inter-subspecific crosses(Nipponbare × KDML105) ...Prezygotic isolation is important for successful fertilization in rice, significantly affecting yield. This study focused on F_(5:6) generation plants derived from inter-subspecific crosses(Nipponbare × KDML105) with low(LS) and high seed-setting rates(HS), in which normal pollen fertility was observed. However, LS plants showed a reduced number of pollen grains adhering to the stigma and fewer pollen tubes reaching the ovules at 4-5 h post-pollination, compared with HS plants. Bulked segregant RNA-Seq analysis of pollinated pistils from the HS and LS groups revealed 249 and 473 differentially expressed genes(DEGs), respectively. Kyoto Encyclopedia of Genes and Genomes analysis of the HS and LS-specific DEGs indicated enrichment in metabolic pathways, pentose and glucuronate interconversions, and flavonoid biosynthesis. Several of these DEGs exhibited co-expression with pollen development genes and formed extensive clusters of co-expression networks. Compared with LS pistils, enzyme genes controlling pectin degradation, such as OsPME35 and OsPLL9, showed similar expression patterns, with higher levels in HS pistils pre-pollination. Os02g0467600, similar to cinnamate 4-hydroxylase gene(CYP73), involved in flavonoid biosynthesis, displayed higher expression in HS pistils post-pollination. Our findings suggest that OsPME35, OsPLL9, and Os02g0467600 contribute to prezygotic isolation by potentially modifying the stigma cell wall(OsPME35 and OsPLL9) and controlling later processes such as pollen-stigma adhesion(Os02g0467600) genes. Furthermore, several DEGs specific to HS and LS were co-localized with QTLs and functional genes associated with spikelet fertility. These findings provide valuable insights for further research on rice spikelet fertility, ultimately contributing to the development of high-yielding rice varieties.展开更多
There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical pro...There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical properties.Idealized supercell simulations are produced using the WRF model coupled with“full”Hebrew University spectral bin MP(HU-SBM),and NSSL and Thompson bulk MP(BMP)schemes.HU-SBM downdrafts are typically weaker than those of the NSSL and Thompson simulations,accompanied by less rain evaporation.HU-SBM produces more cloud ice(plates),graupel,and hail than the BMPs,yet precipitates less at the surface.The limiting mass bins(and subsequently,particle size)of rimed ice in HU-SBM and slower rimed ice fall speeds lead to smaller melting-level net rimed ice fluxes than those of the BMPs.Aggregation from plates in HU-SBM,together with snow–graupel collisions,leads to a greater snow contribution to rain than those of the BMPs.Replacing HU-SBM’s fall speeds using the formulations of the BMPs after aggregating the discrete bin values to mass mixing ratios and total number concentrations increases net rain and rimed ice fluxes.Still,they are smaller in magnitude than bulk rain,NSSL hail,and Thompson graupel net fluxes near the surface.Conversely,the melting-layer net rimed ice fluxes are reduced when the fall speeds for the NSSL and Thompson simulations are calculated using HU-SBM fall speed formulations after discretizing the bulk particle size distributions(PSDs)into spectral bins.The results highlight precipitation sensitivity to storm dynamics,fall speed,hydrometeor evolution governed by process rates,and MP PSD design.展开更多
Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires ener...Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires energy-state matching between the donor and acceptor at the BHJ interfaces.Thus,both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT.In this study,an effective method for quantifying the hot state matching of OPVs was developed.The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor(MF)calculated from the modified optical density of the BHJ.Furthermore,the correlation between the open-circuit voltage(Voc)of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF.The OPVs with small absolute MF values exhibited high Voc values.This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs.Because the MF indicates the degree of energy-state matching,which is a critical factor for suppressing energy loss,it can be used to estimate the Voc loss in OPVs.展开更多
目的:比较Fuji IX GP玻璃离子水门汀、3M ESPE Filtek^(TM) Bulk Fill Flowable树脂、VOCO Polofil Supra树脂及Beautiful Flow Plus F03树脂修复根面龋的临床疗效。方法:选取后牙根面龋患者128例(422颗患牙),按照充填修复材料分为A组(F...目的:比较Fuji IX GP玻璃离子水门汀、3M ESPE Filtek^(TM) Bulk Fill Flowable树脂、VOCO Polofil Supra树脂及Beautiful Flow Plus F03树脂修复根面龋的临床疗效。方法:选取后牙根面龋患者128例(422颗患牙),按照充填修复材料分为A组(Fuji IX GP玻璃离子水门汀修复)34例、B组(3M ESPE Filtek^(TM) Bulk Fill Flowable树脂修复)29例、C组(VOCO Polofil Supra树脂修复)35例、D组(Beautiful Flow Plus F03树脂修复)30例。手术治疗后随访6个月,比较4组患者牙髓活力、材料密合性、充填物表面磨损及充填物完好性情况。结果:术后6个月,4组患者牙髓活力均正常。A组、B组、C组、D组材料密合性好的患牙占比分别为75.49%、90.74%、88.57%、97.20%,A组低于B组、C组、D组,差异均有统计学意义(P<0.05);B组与D组、C组与D组比较,差异均有统计学意义(P<0.05),B、C组之间差异无统计学意义(P>0.05)。A组、B组、C组、D组充填物表面无磨损的患牙占比分别为77.45%、95.37%、94.29%、99.07%,A组占比低于B组、C组及D组,差异均有统计学意义(P<0.05);B组与C组、B组与D组、C组与D组间比较,差异均无统计学意义(P>0.05)。A组、B组、C组、D组充填物完好的患牙占比分别为91.18%、97.22%、97.14%、99.07%,A组占比低于D组,差异有统计学意义(P<0.05)。其他组之间比较,差异均无统计学意义(P>0.05)。结论:4种材料对牙髓活力均无影响,树脂类材料在密合性、表面磨损情况以及完好性上均优于Fuji IX GP玻璃离子水门汀。三种树脂类材料中Beautiful Flow Plus F03在密闭性方面优于其他两种树脂。展开更多
Here,we report a mixed GAI and MAI(MGM)treatment method by forming a 2D alternating-cation-interlayer(ACI)phase(n=2)perovskite layer on the 3D perovskite,modulating the bulk and interfacial defects in the perovskite f...Here,we report a mixed GAI and MAI(MGM)treatment method by forming a 2D alternating-cation-interlayer(ACI)phase(n=2)perovskite layer on the 3D perovskite,modulating the bulk and interfacial defects in the perovskite films simultaneously,leading to the suppressed nonradiative recombination,longer lifetime,higher mobility,and reduced trap density.Consequently,the devices’performance is enhanced to 24.5%and 18.7%for 0.12 and 64 cm^(2),respectively.In addition,the MGM treatment can be applied to a wide range of perovskite compositions,including MA-,FA-,MAFA-,and CsFAMA-based lead halide perovskites,making it a general method for preparing efficient perovskite solar cells.Without encapsulation,the treated devices show improved stabilities.展开更多
Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,wh...Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,which is attributed to lower count of slip systems associated with the hcp crystal structure.To address these limitations,several new magnesium alloys and also many processing strategies have been developed and reported in the literature.ZE41 Mg is an alloy with significant quantities of zinc(Zn)and rare earth(RE)elements and has emerged as a promising material for aerospace,automotive,electronics,biomedical and many other industries.To make this alloy more competitive and viable,it should possess better mechanical and corrosion properties.Hence,the current paper reviews the effect of bulk mechanical processing on grain refinement,microstructural modification,and corresponding changes in the mechanical behaviour of ZE41Mg alloy.Further,the effect of various surface modification techniques on altering the surface microstructure and surface properties such as wear and corrosion are also briefly summarized and presented.This review also discusses the challenges and the future perspectives in developing high-performing ZE41 Mg alloys.展开更多
Energy density can be substantially raised and even maximized if the bulk of an electrode material is fully utilized.Transition metal oxides based on conversion reaction mechanism are the imperative choice due to eith...Energy density can be substantially raised and even maximized if the bulk of an electrode material is fully utilized.Transition metal oxides based on conversion reaction mechanism are the imperative choice due to either constructing nanostructure or intercalation pseudocapacitance with their intrinsic limitations.However,the fully bulk utilization of transition metal oxides is hindered by the poor understanding of atomic-level conversion reaction mechanism,particularly it is largely missing at clarifying how the phase transformation(conversion reaction)determines the electrochemical performance such as power density and cyclic stability.Herein,α-Fe_(2)O_(3) is a case provided to claim how the diffusional and diffusionless transformation determine the electrochemical behaviors,as of its conversion reaction mechanism with fully bulk utilization in alkaline electrolyte.Specifically,the discharge productα-FeOOH diffusional from Fe(OH)2 is structurally identified as the atomic-level arch criminal for its cyclic stability deterioration,whereas the counterpartδ-FeOOH is theoretically diffusionless-like,unlocking the full potential of the pseudocapacitance with fully bulk utilization.Thus,such pseudocapacitance,in proof-of-concept and termed as conversion pseudocapacitance,is achieved via diffusionless-like transformation.This work not only provides an atomic-level perspective to reassess the potential electrochemical performance of the transition metal oxides electrode materials based on conversion reaction mechanism but also debuts a new paradigm for pseudocapacitance.展开更多
Many database applications currently deal with objects in a metric space.Examples of such objects include unstructured multimedia objects and points of interest(POIs)in a road network.The M-tree is a dynamic index str...Many database applications currently deal with objects in a metric space.Examples of such objects include unstructured multimedia objects and points of interest(POIs)in a road network.The M-tree is a dynamic index structure that facilitates an efficient search for objects in a metric space.Studies have been conducted on the bulk loading of large datasets in an M-tree.However,because previous algorithms involve excessive distance computations and disk accesses,they perform poorly in terms of their index construction and search capability.This study proposes two efficient M-tree bulk loading algorithms.Our algorithms minimize the number of distance computations and disk accesses using FastMap and a space-filling curve,thereby significantly improving the index construction and search performance.Our second algorithm is an extension of the first,and it incorporates a partitioning clustering technique and flexible node architecture to further improve the search performance.Through the use of various synthetic and real-world datasets,the experimental results demonstrated that our algorithms improved the index construction performance by up to three orders of magnitude and the search performance by up to 20.3 times over the previous algorithm.展开更多
Introduction: Dental composite resin materials are being increasingly used for a variety of purposes and more recently as a dentine replacement material. Objectives: SDR (Dentsply) is a flowable, high-resin composite ...Introduction: Dental composite resin materials are being increasingly used for a variety of purposes and more recently as a dentine replacement material. Objectives: SDR (Dentsply) is a flowable, high-resin composite material designed to minimise the effect of the high shrinkage through the use of a flexible monomer. However the resultant properties of this material may be a factor that affects the clinical performance. Methods: Tests were carried out on SDR and two other commonly used resin-based composite materials (Herculite XRV, Kerr and Spectrum TPH, Dentsply) including: depth of cure according to ISO 4049, degree of cure using Fourier Transform Infrared Spectroscopy (FTIR), compressive strength using a Universal testing Machine, water uptake, interaction with Coca-ColaTM and analysis of thermal transitions using Differential Scanning Calorimetry (DSC). Results: SDR exhibited a high depth of cure at 4.0 mm and no difference in degree of cure in comparison with the other two dental composites. Compressive strength results varied between materials but were significantly lower for SDR (P < 0.05). Water uptake was similar for all materials but elution was significantly greater for SDR and interaction with Coca-Cola showed greatest change for SDR. Conclusions: There are some statistically significant variations between the physical properties of the materials which are attributed to the monomer type and lower amount of filler in the flowable composite that may explain the published clinical outcomes.展开更多
Objectives: Resin-based composites are the most widely used dental restorative materials. Bulk-fill resin composites are of rising interest as they can be clinically applied in thicker increments compared to conventio...Objectives: Resin-based composites are the most widely used dental restorative materials. Bulk-fill resin composites are of rising interest as they can be clinically applied in thicker increments compared to conventional composites. The purpose of the study was to evaluate the flexural fatigue strength of a conventional and bulk-filled resin composite placed incrementally or non-incrementally. Methods: Resin composite specimens were fabricated using either a conventional (Brilliant EverGlow?) or a bulk-fill (Fill-Up!<sup>TM</sup>) resin composite by either non-incremental filling (2 × 2 × 25 mm<sup>3</sup>) or in increments of (1 × 2 × 25 mm<sup>3</sup>). Specimens were stored in distilled water for 24 h or thermocycled for 5000 cycles. The static flexural strength (σ), flexural fatigue limit (FFL) after 105 cycles and post-fatigue flexural strength (PFσ) were measured. Data were analyzed using ANOVA, with a post-hoc Tukey’s test to compare mean FFL (p σ and PFσ compared to conventional composites regardless of incremental cure or thermocycling (p σ and FFL for conventional composites but not bulk-filled composites. There was no significant difference in PFσ compared to σ after 24 h storage, but a significant increase in PFσ after thermocycling (p < 0.05). Conclusions: The type of composite rather than incremental placement had a greater effect on flexural strength, suggesting that operator placement technique had less influence than material selection. Thermocycling in combination with cyclic loading caused a strengthening effect in the composites, likely due to the absorption and dissipation of stresses, thereby enhancing resistance to fracture.展开更多
Objective:Analyzing the influence of different filling methods on the microleakage of posterior teeth during the treatment of bulk resin filling.Methods:From January 2019 to January 2020,68 patients with posterior too...Objective:Analyzing the influence of different filling methods on the microleakage of posterior teeth during the treatment of bulk resin filling.Methods:From January 2019 to January 2020,68 patients with posterior tooth filling(123 teeth)in our hospital were selected and randomly assigned into three groups(A,B,and C),with 41 teeth in each group.Group A received bulk posterior teeth filling resin treatment,group B received Charisma®resin filling treatment and group C received FX-Ⅱfilling treatment.The curative effect and microleakage of posterior teeth between the groups were compared.Results:Comparison of treatment efficiency in group A(97.56%),group B(85.37%)and group C(73.17%)shows that P<0.05;comparison of microleakage value and operation time of group A,group B and group C shows that P<0.05.Conclusions:In resin filling treatment,bulk posterior tooth filling resin material should be selected for its high hardness,strong edge adhesion,and natural effects.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51801122 and 52071210)the Science Challenge Project(Grant No.TZ2018001)the Science and Technology Commission of Shanghai(Grant No.21ZR1430800).
文摘Amorphous solids exhibit scale-free avalanches,even under small external loading,and thus can work as suitable systems to study critical behavior and universality classes.The abundance of scale-free avalanches in the entire elastic tension regime of bulk metallic glass(BMG)samples has been experimentally observed using acoustic emission(AE)measurements.In this work,we compare the statistics of avalanches with those of earthquakes,and find that they both follow the Gutenberg–Richter law in the statistics of energies and Omori’s law of aftershock rates,and share the same characteristics in the distribution of recurrence times.These resemblances encourage us to propose the term“glass-quake”to describe avalanches in elastically loaded BMGs.Furthermore,our work echoes the potential universality of critical behavior in disordered physical systems from atomic to planetary scales,and motivates the use of elastic loaded BMGs as valuable laboratory simulators of seismic dynamics.
文摘Bulk geochemistry,Sr,Nd,and O-H isotope systematics are reported for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore district,Southern Cameroon,Metzimevin iron ore deposit is a hematite-magnetite BIF system,dominated by SiO_(2)+Fe_(2)O_(3)(97.1 to 99.84 wt%),with low concentrations of clastic elements e.g.,Al_(2)O_(3),TiO_(2),and HFSE,depicting a nearly pure chemical precipitate.The REE+Y signature of the iron deposit displays strong positive Eu anomaly,strong negative Ce anomaly,and chondritic to superchondritic Y/Ho ratios,suggestive of formation by mixed seawater-high temperature hydrothermal fluids in oxidising environment.The^(87)Sr/^(86)Sr ratios of the BIF are higher than the maximum^(87)Sr/^(86)Sr evolution curves for all Archean reservoirs(bulk silicate earth,Archean crust and Archean seawater),indicating involvement of continentally-derived components during BIF formation and alteration.TheƐ_(Nd)(t)(+2.26 to+3.77)and Nd model age indicate that chemical constituents for the BIF were derived from undifferentiated crustal source,between 3.002 and 2.88 Ga.The variable and diverse O and H isotope data(−1.9‰to 17.3‰and−57‰to 136‰respectively)indicate that the Metzimevin iron ore formed initially from magmatic plumes and later enriched by magmatic-metamorphic-modified meteoric fluids.Mass balance calculations indicate mineralisation by combined leaching and precipitation,with an average iron enrichment factor of>2.67 and SiO_(2)depletion factor of>0.99.This is associated with an overall volume reduction of 28.27%,reflecting net leaching and volume collapse of the BIF protholith.
基金supported by the National Natural Science Foundation of China(Grant Nos.12104216,12241403,and 61974061)the National Key R&D Program of China(Grant No.2021YFB3601600)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20140054)。
文摘We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density functional theory.The results show that there are band crossings in the Z-L(armchair)direction.
基金The National Key Research and Development Program of China under contract No.2022YFE0136500the National Nature Science Foundation of China under contract Nos 41890801 and 42076227the Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University under contract No.21TQ1400201.
文摘The oceanic trace metals iron(Fe),nickel(Ni),copper(Cu),zinc(Zn),and cadmium(Cd)are crucial to marine phytoplankton growth and global carbon cycle,and the analysis of their stable isotopes can provide valuable insights into their biogeochemical cycles within the ocean.However,the simultaneous isotopic analysis of multiple elements present in seawater is challenging because of their low concentrations,limited volumes of the test samples,and high salt matrix.In this study,we present the novel method developed for the simultaneous analysis of five isotope systems by 1 L seawater sample.In the developed method,the NOBIAS Chelate-PA1 resin was used to extract metals from seawater,the AG MP-1M anion-exchange resin to purify Cu,Fe,Zn,Cd,and the NOBIAS Chelate-PA1 resin to further extract Ni from the matrix elements.Finally,a multi-collector inductively coupled plasma mass spectroscope(MC-ICPMS)was employed for the isotopic measurements using a doublespike technique or sample-standard bracketing combined with internal normalization.This method exhibited low total procedural blanks(0.04 pg,0.04 pg,0.21 pg,0.15 pg,and 3 pg for Ni,Cu,Fe,Zn,and Cd,respectively)and high extraction efficiencies(100.5%±0.3%,100.2%±0.5%,97.8%±1.4%,99.9%±0.8%,and 100.1%±0.2%for Ni,Cu,Fe,Zn,and Cd,respectively).The external errors and external precisions of this method could be considered negligible.The proposed method was further tested on the seawater samples obtained from the whole vertical profile of a water column during the Chinese GEOTRACES GP09 cruise in the Northwest Pacific,and the results showed good agreement with previous related data.This innovative method will contribute to the advancement of isotope research and enhance our understanding of the marine biogeochemical cycling of Fe,Ni,Cu,Zn,and Cd.
基金supported by the National Natural Science Foundation of China (52374299,52304320 and 52204306)the Outstanding Youth Foundation of Hunan Province (2023JJ10044)+1 种基金the Key Project of Hunan Provincial Department of Education (22A0211)the Natural Science Foundation of Hunan Province (2023JJ40014)。
文摘Introducing high-valence Ta element is an essential strategy for addressing the structu ral deterioration of the Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathode,but the enlarged Li/Ni cation mixing leads to the inferior rate capability originating from the hindered Li~+migration.Note that the non-magnetic Ti~(4+)ion can suppress Li/Ni disorder by removing the magnetic frustration in the transition metal layer.However,it is still challenging to directionally design expected Ta/Ti dual-modification,resulting from the complexity of the elemental distribution and the uncertainty of in-situ formed coating compounds by introducing foreign elements.Herein,a LiTaO_3 grain boundary(GB)coating and bulk Ti-doping have been successfully achieved in LiNi_(0.834)Co_(0.11)Mn_(0.056)O_(2) cathode by thermodynamic guidance,in which the structural formation energy and interfacial binding energy are employed to predict the elemental diffusion discrepancy and thermodynamically stable coating compounds.Thanks to the coupling effect of strengthened structural/interfacial stability and improved Li~+diffusion kinetics by simultaneous bulk/GB engineering,the Ta/Ti-NCM cathode exhibits outstanding capacity retention,reaching 91.1%after 400 cycles at 1 C.This elaborate work contributes valuable insights into rational dual-modification engineering from a thermodynamic perspective for maximizing the electrochemical performances of NCM cathodes.
基金supported by the Agricultural Research Development Agency of Thailand (Grant No.PRP6405030280)Research Promotion fund for International and Educational Excellence, Thailand (Grant No.08/2562)。
文摘Prezygotic isolation is important for successful fertilization in rice, significantly affecting yield. This study focused on F_(5:6) generation plants derived from inter-subspecific crosses(Nipponbare × KDML105) with low(LS) and high seed-setting rates(HS), in which normal pollen fertility was observed. However, LS plants showed a reduced number of pollen grains adhering to the stigma and fewer pollen tubes reaching the ovules at 4-5 h post-pollination, compared with HS plants. Bulked segregant RNA-Seq analysis of pollinated pistils from the HS and LS groups revealed 249 and 473 differentially expressed genes(DEGs), respectively. Kyoto Encyclopedia of Genes and Genomes analysis of the HS and LS-specific DEGs indicated enrichment in metabolic pathways, pentose and glucuronate interconversions, and flavonoid biosynthesis. Several of these DEGs exhibited co-expression with pollen development genes and formed extensive clusters of co-expression networks. Compared with LS pistils, enzyme genes controlling pectin degradation, such as OsPME35 and OsPLL9, showed similar expression patterns, with higher levels in HS pistils pre-pollination. Os02g0467600, similar to cinnamate 4-hydroxylase gene(CYP73), involved in flavonoid biosynthesis, displayed higher expression in HS pistils post-pollination. Our findings suggest that OsPME35, OsPLL9, and Os02g0467600 contribute to prezygotic isolation by potentially modifying the stigma cell wall(OsPME35 and OsPLL9) and controlling later processes such as pollen-stigma adhesion(Os02g0467600) genes. Furthermore, several DEGs specific to HS and LS were co-localized with QTLs and functional genes associated with spikelet fertility. These findings provide valuable insights for further research on rice spikelet fertility, ultimately contributing to the development of high-yielding rice varieties.
基金This research was primarily supported by a NOAA Warn-on-Forecast(WoF)grant(Grant No.NA16OAR4320115).
文摘There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical properties.Idealized supercell simulations are produced using the WRF model coupled with“full”Hebrew University spectral bin MP(HU-SBM),and NSSL and Thompson bulk MP(BMP)schemes.HU-SBM downdrafts are typically weaker than those of the NSSL and Thompson simulations,accompanied by less rain evaporation.HU-SBM produces more cloud ice(plates),graupel,and hail than the BMPs,yet precipitates less at the surface.The limiting mass bins(and subsequently,particle size)of rimed ice in HU-SBM and slower rimed ice fall speeds lead to smaller melting-level net rimed ice fluxes than those of the BMPs.Aggregation from plates in HU-SBM,together with snow–graupel collisions,leads to a greater snow contribution to rain than those of the BMPs.Replacing HU-SBM’s fall speeds using the formulations of the BMPs after aggregating the discrete bin values to mass mixing ratios and total number concentrations increases net rain and rimed ice fluxes.Still,they are smaller in magnitude than bulk rain,NSSL hail,and Thompson graupel net fluxes near the surface.Conversely,the melting-layer net rimed ice fluxes are reduced when the fall speeds for the NSSL and Thompson simulations are calculated using HU-SBM fall speed formulations after discretizing the bulk particle size distributions(PSDs)into spectral bins.The results highlight precipitation sensitivity to storm dynamics,fall speed,hydrometeor evolution governed by process rates,and MP PSD design.
基金National Research Foundation of Korea,Grant/Award Number:2022R1A6A1A03051158BrainLink Program,Grant/Award Number:2022H1D3A3A01077343Nano Material Technology Development Program,Grant/Award Number:2021M3H4A1A02057007。
文摘Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires energy-state matching between the donor and acceptor at the BHJ interfaces.Thus,both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT.In this study,an effective method for quantifying the hot state matching of OPVs was developed.The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor(MF)calculated from the modified optical density of the BHJ.Furthermore,the correlation between the open-circuit voltage(Voc)of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF.The OPVs with small absolute MF values exhibited high Voc values.This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs.Because the MF indicates the degree of energy-state matching,which is a critical factor for suppressing energy loss,it can be used to estimate the Voc loss in OPVs.
文摘目的:比较Fuji IX GP玻璃离子水门汀、3M ESPE Filtek^(TM) Bulk Fill Flowable树脂、VOCO Polofil Supra树脂及Beautiful Flow Plus F03树脂修复根面龋的临床疗效。方法:选取后牙根面龋患者128例(422颗患牙),按照充填修复材料分为A组(Fuji IX GP玻璃离子水门汀修复)34例、B组(3M ESPE Filtek^(TM) Bulk Fill Flowable树脂修复)29例、C组(VOCO Polofil Supra树脂修复)35例、D组(Beautiful Flow Plus F03树脂修复)30例。手术治疗后随访6个月,比较4组患者牙髓活力、材料密合性、充填物表面磨损及充填物完好性情况。结果:术后6个月,4组患者牙髓活力均正常。A组、B组、C组、D组材料密合性好的患牙占比分别为75.49%、90.74%、88.57%、97.20%,A组低于B组、C组、D组,差异均有统计学意义(P<0.05);B组与D组、C组与D组比较,差异均有统计学意义(P<0.05),B、C组之间差异无统计学意义(P>0.05)。A组、B组、C组、D组充填物表面无磨损的患牙占比分别为77.45%、95.37%、94.29%、99.07%,A组占比低于B组、C组及D组,差异均有统计学意义(P<0.05);B组与C组、B组与D组、C组与D组间比较,差异均无统计学意义(P>0.05)。A组、B组、C组、D组充填物完好的患牙占比分别为91.18%、97.22%、97.14%、99.07%,A组占比低于D组,差异有统计学意义(P<0.05)。其他组之间比较,差异均无统计学意义(P>0.05)。结论:4种材料对牙髓活力均无影响,树脂类材料在密合性、表面磨损情况以及完好性上均优于Fuji IX GP玻璃离子水门汀。三种树脂类材料中Beautiful Flow Plus F03在密闭性方面优于其他两种树脂。
基金supported by the National Key Research and Development Program of China(2021YFB3800103)the Fundamental Research Funds for the Central Universities(000-0903069032)the National Natural Science Foundation of China(52203237).
文摘Here,we report a mixed GAI and MAI(MGM)treatment method by forming a 2D alternating-cation-interlayer(ACI)phase(n=2)perovskite layer on the 3D perovskite,modulating the bulk and interfacial defects in the perovskite films simultaneously,leading to the suppressed nonradiative recombination,longer lifetime,higher mobility,and reduced trap density.Consequently,the devices’performance is enhanced to 24.5%and 18.7%for 0.12 and 64 cm^(2),respectively.In addition,the MGM treatment can be applied to a wide range of perovskite compositions,including MA-,FA-,MAFA-,and CsFAMA-based lead halide perovskites,making it a general method for preparing efficient perovskite solar cells.Without encapsulation,the treated devices show improved stabilities.
文摘Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,which is attributed to lower count of slip systems associated with the hcp crystal structure.To address these limitations,several new magnesium alloys and also many processing strategies have been developed and reported in the literature.ZE41 Mg is an alloy with significant quantities of zinc(Zn)and rare earth(RE)elements and has emerged as a promising material for aerospace,automotive,electronics,biomedical and many other industries.To make this alloy more competitive and viable,it should possess better mechanical and corrosion properties.Hence,the current paper reviews the effect of bulk mechanical processing on grain refinement,microstructural modification,and corresponding changes in the mechanical behaviour of ZE41Mg alloy.Further,the effect of various surface modification techniques on altering the surface microstructure and surface properties such as wear and corrosion are also briefly summarized and presented.This review also discusses the challenges and the future perspectives in developing high-performing ZE41 Mg alloys.
基金This research is supported by the National Natural Science Foundation of China (51932003,51872115)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province (20200801001GH)+5 种基金Program for the Development of Science and Technology of Jilin Province (20190201309JC)the Jilin Province/Jilin University Co-Construction Project-Funds for New Materials (SXGJSF2017-3,Branch-2/440050316A36)Project for Self-innovation Capability Construction of Jilin Province Development and Reform Commission (2021C026)the Open Project Program of Wuhan National Laboratory for Optoelectronics (2018WNLOKF022)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT,2017TD-09)the Fundamental Research Funds for the Central Universities JLU,and“Double-First Class”Discipline for Materials Science&Engineering.
文摘Energy density can be substantially raised and even maximized if the bulk of an electrode material is fully utilized.Transition metal oxides based on conversion reaction mechanism are the imperative choice due to either constructing nanostructure or intercalation pseudocapacitance with their intrinsic limitations.However,the fully bulk utilization of transition metal oxides is hindered by the poor understanding of atomic-level conversion reaction mechanism,particularly it is largely missing at clarifying how the phase transformation(conversion reaction)determines the electrochemical performance such as power density and cyclic stability.Herein,α-Fe_(2)O_(3) is a case provided to claim how the diffusional and diffusionless transformation determine the electrochemical behaviors,as of its conversion reaction mechanism with fully bulk utilization in alkaline electrolyte.Specifically,the discharge productα-FeOOH diffusional from Fe(OH)2 is structurally identified as the atomic-level arch criminal for its cyclic stability deterioration,whereas the counterpartδ-FeOOH is theoretically diffusionless-like,unlocking the full potential of the pseudocapacitance with fully bulk utilization.Thus,such pseudocapacitance,in proof-of-concept and termed as conversion pseudocapacitance,is achieved via diffusionless-like transformation.This work not only provides an atomic-level perspective to reassess the potential electrochemical performance of the transition metal oxides electrode materials based on conversion reaction mechanism but also debuts a new paradigm for pseudocapacitance.
基金the National Research Foundation of Korea(NRF,www.nrf.re.kr)grant funded by the Korean government(MSIT,www.msit.go.kr)(No.2018R1A2B6009188)(received by W.-K.Loh).
文摘Many database applications currently deal with objects in a metric space.Examples of such objects include unstructured multimedia objects and points of interest(POIs)in a road network.The M-tree is a dynamic index structure that facilitates an efficient search for objects in a metric space.Studies have been conducted on the bulk loading of large datasets in an M-tree.However,because previous algorithms involve excessive distance computations and disk accesses,they perform poorly in terms of their index construction and search capability.This study proposes two efficient M-tree bulk loading algorithms.Our algorithms minimize the number of distance computations and disk accesses using FastMap and a space-filling curve,thereby significantly improving the index construction and search performance.Our second algorithm is an extension of the first,and it incorporates a partitioning clustering technique and flexible node architecture to further improve the search performance.Through the use of various synthetic and real-world datasets,the experimental results demonstrated that our algorithms improved the index construction performance by up to three orders of magnitude and the search performance by up to 20.3 times over the previous algorithm.
文摘Introduction: Dental composite resin materials are being increasingly used for a variety of purposes and more recently as a dentine replacement material. Objectives: SDR (Dentsply) is a flowable, high-resin composite material designed to minimise the effect of the high shrinkage through the use of a flexible monomer. However the resultant properties of this material may be a factor that affects the clinical performance. Methods: Tests were carried out on SDR and two other commonly used resin-based composite materials (Herculite XRV, Kerr and Spectrum TPH, Dentsply) including: depth of cure according to ISO 4049, degree of cure using Fourier Transform Infrared Spectroscopy (FTIR), compressive strength using a Universal testing Machine, water uptake, interaction with Coca-ColaTM and analysis of thermal transitions using Differential Scanning Calorimetry (DSC). Results: SDR exhibited a high depth of cure at 4.0 mm and no difference in degree of cure in comparison with the other two dental composites. Compressive strength results varied between materials but were significantly lower for SDR (P < 0.05). Water uptake was similar for all materials but elution was significantly greater for SDR and interaction with Coca-Cola showed greatest change for SDR. Conclusions: There are some statistically significant variations between the physical properties of the materials which are attributed to the monomer type and lower amount of filler in the flowable composite that may explain the published clinical outcomes.
文摘Objectives: Resin-based composites are the most widely used dental restorative materials. Bulk-fill resin composites are of rising interest as they can be clinically applied in thicker increments compared to conventional composites. The purpose of the study was to evaluate the flexural fatigue strength of a conventional and bulk-filled resin composite placed incrementally or non-incrementally. Methods: Resin composite specimens were fabricated using either a conventional (Brilliant EverGlow?) or a bulk-fill (Fill-Up!<sup>TM</sup>) resin composite by either non-incremental filling (2 × 2 × 25 mm<sup>3</sup>) or in increments of (1 × 2 × 25 mm<sup>3</sup>). Specimens were stored in distilled water for 24 h or thermocycled for 5000 cycles. The static flexural strength (σ), flexural fatigue limit (FFL) after 105 cycles and post-fatigue flexural strength (PFσ) were measured. Data were analyzed using ANOVA, with a post-hoc Tukey’s test to compare mean FFL (p σ and PFσ compared to conventional composites regardless of incremental cure or thermocycling (p σ and FFL for conventional composites but not bulk-filled composites. There was no significant difference in PFσ compared to σ after 24 h storage, but a significant increase in PFσ after thermocycling (p < 0.05). Conclusions: The type of composite rather than incremental placement had a greater effect on flexural strength, suggesting that operator placement technique had less influence than material selection. Thermocycling in combination with cyclic loading caused a strengthening effect in the composites, likely due to the absorption and dissipation of stresses, thereby enhancing resistance to fracture.
文摘Objective:Analyzing the influence of different filling methods on the microleakage of posterior teeth during the treatment of bulk resin filling.Methods:From January 2019 to January 2020,68 patients with posterior tooth filling(123 teeth)in our hospital were selected and randomly assigned into three groups(A,B,and C),with 41 teeth in each group.Group A received bulk posterior teeth filling resin treatment,group B received Charisma®resin filling treatment and group C received FX-Ⅱfilling treatment.The curative effect and microleakage of posterior teeth between the groups were compared.Results:Comparison of treatment efficiency in group A(97.56%),group B(85.37%)and group C(73.17%)shows that P<0.05;comparison of microleakage value and operation time of group A,group B and group C shows that P<0.05.Conclusions:In resin filling treatment,bulk posterior tooth filling resin material should be selected for its high hardness,strong edge adhesion,and natural effects.