This study systematically investigated the coupling effects of confiningpressure and strain rate on the dynamic strength of granite through dynamic triaxial compression tests.A dynamic strength criterion was developed...This study systematically investigated the coupling effects of confiningpressure and strain rate on the dynamic strength of granite through dynamic triaxial compression tests.A dynamic strength criterion was developed to incorporate these coupling effects for further analysis.Moreover,the research thoroughly revealed the underlying mechanism by which these coupling effects influencethe rock strength.The results revealed that both confiningpressure and strain rate significantly enhanced the dynamic strength of rock;however,a mutual inhibition effect emerged under their coupling.Specifically,as the confiningpressure increased,the strengthening effect of strain rate gradually diminished.Conversely,increasing the strain rate weakened the strengthening effect of confiningpressure.The proposed strength criterion successfully predicted rock strength under various confiningpressures(0-225 MPa)and strain rates(10^(-6)-600 s^(-1)).It achieved an average prediction error of only 8.3%,which represents a 65%improvement in accuracy compared to models that consider confiningpressure and strain rate effects independently.At the micro-mechanism level,increasing confiningpressure and strain rate promoted crack propagation in a transgranular(TG)mode,thereby enhancing the overall rock strength.However,under the coupling effects,the interference and interaction of TG cracks weakened the overall strengthening effect.This indicated that the competitive interaction between confiningpressure and strain rate during crack propagation constitutes the intrinsic mechanism underlying their mutual inhibitory effect on rock strength.This study provides a more accurate theoretical basis for understanding the dynamic responses of rocks and contributes valuable insights for disaster prevention and control in deep rock engineering projects.展开更多
A new tintinnid ciliate,Salpingella subarctica Zhang,Li & Li,sp.nov.was discovered in waters from the subarctic north Pacific Ocean to the Arctic Ocean during six research cruises conducted between July and Septem...A new tintinnid ciliate,Salpingella subarctica Zhang,Li & Li,sp.nov.was discovered in waters from the subarctic north Pacific Ocean to the Arctic Ocean during six research cruises conducted between July and September over the past decade.Distinct lorica characteristics justify the establishment of this new species,distinguishing it from previously known species:an average lorica opening diameter(12.6 μm),an average posterior lorica opening diameter(3.6 μm),a smaller lorica length(41.8–69.5 μm),a prominent posterior opening,and 8–10 longitudinal fins extending parallelly from the opening to the posterior end.It occurred in water with temperature of-1.6–20.5℃ and salinity of 25.3–34.4,and preferred to salinity of 32,temperature of 11℃ in open ocean in Pacific Ocean,and 0℃ in Bering Sea and Chukchi Sea.展开更多
The discrete fracture system of a rock mass plays a crucial role in controlling the stability of rock slopes.To fully account for the geometric shape and distribution characteristics of jointed rock masses,terrestrial...The discrete fracture system of a rock mass plays a crucial role in controlling the stability of rock slopes.To fully account for the geometric shape and distribution characteristics of jointed rock masses,terrestrial laser scanning(TLS)was employed to acquire high-resolution point-cloud data,and a developed automatic discontinuity-identification technology was coupled to automatically interpret and characterize geometric information such as orientation,trace length,spacing,and set number of the discontinuities.The discrete element method(DEM)was applied to study the influence of the geometric morphology and distribution characteristics of discontinuities on slope stability by generating a discrete fracture network(DFN)with the same statistical characteristics as the actual discontinuities.Based on slope data from the Yebatan Hydropower Station,a simulation was conducted to verify the applicability of the automatic discontinuity identification technology and the discrete fracture network-discrete element method(DFN-DEM).Various geological parameters,including trace length,persistence,and density,were examined to investigate the morphological evolution and response characteristics of rock slope excavation under different joint combination conditions through simulation.The simulation results indicate that joint parameters affect slope stability,with density having the most significant impact.The impact of joint parameters on stability is relatively small within a reasonable range but becomes significant beyond a certain threshold,further validating that the accuracy of field geological surveys is critical for simulation.This study provides a scientific basis for the construction of complex rock slope models,engineering assessments,and disaster prevention and mitigation,which is of great value in both theory and engineering applications.展开更多
The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum(I.dunnianum)resulted in the isolation of five pairs of new lignans(1–5),and 7 known analogs(6–12).The separation of enantiomer mi...The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum(I.dunnianum)resulted in the isolation of five pairs of new lignans(1–5),and 7 known analogs(6–12).The separation of enantiomer mixtures 1–5 to 1a/1b–5a/5b was achieved using a chiral column with acetonitrile−water mixtures as eluents.The planar structures of 1–2 were previously undescribed,and the chiral separation and absolute configurations of 3–5 were reported for the first time.Their structures were determined through comprehensive spectroscopic data analysis[nuclear magnetic resonance(NMR),high-resolution electrospray ionization mass(HR-ESI-MS),infrared(IR),and ultraviolet(UV)]and quantum chemistry calculations(ECD).The new isolates were evaluated by measuring their inhibitory effect on NO in lipopolysaccharide(LPS)-stimulated BV-2 cells.Compounds 1a,3a,3b,and 5a demonstrated partial inhibition of NO production in a concentration-dependent manner.Western blot and real-time polymerase chain reaction(PCR)assays revealed that 1a down-regulated the messenger ribonucleic acid(mRNA)levels of tumor necrosis factorα(TNF-α),interleukin-6(IL-6),COX-2,and iNOS and the protein expressions of COX-2 and iNOS.This research provides guidance and evidence for the further development and utilization of I.dunnianum.展开更多
Organic metal halides with white-light emissions have shown significant application prospects in the fields of solid-state lighting and displays, but their structural design and synthesis remain a major challenge. Her...Organic metal halides with white-light emissions have shown significant application prospects in the fields of solid-state lighting and displays, but their structural design and synthesis remain a major challenge. Here, the material design concept of functional units has been applied to prepare a zero-dimensional (oD) organic anti-mony halide (1-BMP)_(5)(SbCl_(5))_(2)SbCl_(4) with two luminescent centers from the inorganic units and the organic units, emitting red emission about 670 nm and cyan emission about 508 nm respectively, combined to form white light. Based on the photoluminescence (PL), the time-resolved PL analysis and density functional theory (DFT) calculation, it is shown that the red and cyan emission comes from STEs related to inorganic units [SbCl_(5)]^(2-) and the fluorescence of organic cations 1-BMP^(+), respectively. This work provides new methods and ideas for the development of low-cost and eco-friendly white emission phosphors for single-component solid-state WLEDs.展开更多
Gel polymer electrolytes(GPEs)with high flame‐retardant concentration can remarkably reduce the thermal runaway risk of lithium metal batteries(LMBs).However,higher flame‐retardant content in GPEs always leads to in...Gel polymer electrolytes(GPEs)with high flame‐retardant concentration can remarkably reduce the thermal runaway risk of lithium metal batteries(LMBs).However,higher flame‐retardant content in GPEs always leads to increased leakage of active component and severe lithium corrosion,which greatly hinders the service life of LMBs.Herein,GPEs with high‐loading triphenyl phosphate(TPP)are originally fabricated by coaxial electrospinning and stabilized by dual confinement effects,including chemisorption of polyvinylidene fluoride‐hexafluoropropylene(PVDF‐HFP),and physical encapsulation of polyacrylonitrile(PAN)/PVDF‐HFP.These effects arise from the strong polar interactions between the−CF3 group in PVDF‐HFP and P=O group in TPP,as well as the superior anti‐swelling property of PAN.To mitigate TPP‐induced corrosion during cycling,the optimized Li anode is armored with LiF‐rich solid electrolyte interphase(SEI)layer through immersing it in fluoroethylene carbonate‐containing electrolyte.As expected,the corresponding Li||Li symmetric cells deliver long‐term stable cycling behavior over 2400 h at 0.5 mA cm−2,and the LiFePO4||Li batteries hold a high‐capacity retention ratio of 81.7%after 6000 cycles at 10 C with excellent flame retardancy.These findings offer new insight into designing the SEI layer for lithium metal in flame‐retardant electrolytes,thus promoting the development and application of high‐security LMBs.展开更多
Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. H...Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. Herein, we report a nitrogen-doped porous carbon derived from biomass pomelo peel as sulfur host material for Li-S batteries. The hierarchical porous architecture and the polar surface introduced by N-doping render a favorable combination of physical and chemical sulfur confinements as well as an expedite electron/ion transfer, thus contributing to a facilitated and stabilized sulfur electrochemistry. As a result, the corresponding sulfur composite electrodes exhibit an ultrahigh initial capacity of 1534.6 mAh g^-1, high coulombic efficiency over 98% upon 300 cycles, and decent rate capability up to 2 C. This work provides an economical and effective strategy for the fabrication of advanced carbonaceous sulfur host material as well as the significant improvement of Li-S battery performance.展开更多
MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect ...MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect on electrochemical performance. Herein, annealing MXene under hydrogen was employed for removing-F and turning-OH to-O terminations. We demonstrate that it improves the kinetics of Li-ion transport between the electrolyte and electrode. As a result, a lower interfacial charge transfer impedance was obtained. The electrochemical measurement exhibited that a nearly 2-fold increase of specific capacity was achieved for the annealed MXene.展开更多
MXenes have emerged as a new kind of 2D transition metal carbides,nitrides and carbonitrides.Origined from the unique 2D structure with a luxuriant combination of elements,MXenes drive a series of the investigations r...MXenes have emerged as a new kind of 2D transition metal carbides,nitrides and carbonitrides.Origined from the unique 2D structure with a luxuriant combination of elements,MXenes drive a series of the investigations related to energy storage and conversion,biometrics and sensing,lighting,purification and separation.For 2D layered MXene materials,the interspacing confined by the independent MXenes layers affords a distinct confinement space,which is similar to a nanoreactor that can be utilized for the storage of ions,nanoparticles,nanowires,and the materials with 2D or 3D structure.These fillings confined by MXene layers afford new opptunities for achieving improved properties and performance via complementary natural features,further the synergistic effect.Herein,we summarize the recent reports concerning with the confinded MXenes spacing and the fillings.The modification of interlayer distance lead by the intercalants were explored.We expect that our review may offer the route for a series of ongoing studies to address the MXenes.展开更多
Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Here...Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Herein,the cation intercalation and ion-exchange were well employed to achieve a K+and Ca2+intercalated V2CTxMXene.A larger interlayer distance and low F surface terminations were thereof obtained,which accelerates the ion transport and promotes the delicate surface of V2CTx MXene.As a result,a package of enhanced capacity,rate performance and cyclability can be achieved.Furthermore,the ion exchange approach can be extended to other 2 D layered materials,and both the interlayer control and the surface modification will be achieved.展开更多
Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels.This study demonstrates the integration of terrest...Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels.This study demonstrates the integration of terrestrial laser scanning(TLS)with distinct element method for rock mass characterization and stability analysis in tunnels.TLS records detailed geometric information of the surrounding rock mass by scanning and collecting the positions of millions of rock surface points without contact.By conducting a fuzzy K-means method,a discontinuity automatic identification algorithm was developed,and a method for obtaining the geometric parameters of discontinuities was proposed.This method permits the user to visually identify each discontinuity and acquire its spatial distribution features(e.g.occurrences,spac-ings,trace lengths)in great detail.Compared with hand mapping in conventional geotechnical surveys,the geometric information of discontinuities obtained by this approach is more accurate and the iden-tification is more efficient.Then,a discrete fracture network with the same statistical characteristics as the actual discontinuities was generated with the distinct element method,and a representative nu-merical model of the jointed surrounding rock mass was established.By means of numerical simulation,potential unstable rock blocks were assessed,and failure mechanisms were analyzed.This method was applied to detection and assessment of unstable rock blocks in the spillway and sand flushing tunnel of the Hongshiyan hydropower project after a collapse.The results show that the noncontact detection of blocks was more labor-saving with lower safety risks compared with manual surveys,and the stability assessment was more reliable since the numerical model built by this method was more consistent with the distribution characteristics of actual joints.This study can provide a reference for geological survey and unstable rock block hazard mitigation in tunnels subjected to complex geology and active rockfalls.展开更多
The notorious shuttle effect has long been obstructing lithium-sulfur(Li-S) batteries from yielding the expected high energy density and long lifespan.Herein,we develop a multifunctional polysulfide barrier reinforced...The notorious shuttle effect has long been obstructing lithium-sulfur(Li-S) batteries from yielding the expected high energy density and long lifespan.Herein,we develop a multifunctional polysulfide barrier reinforced by the graphitic carbon nitride/carbon nanotube(g-C_3 N_4/CNT) composite toward inhibited shuttling behavior and improved battery performance.The obtained g-C_3 N_4 delivers a unique spongelike architecture with massive ion transfer pathways and fully exposed active interfaces,while the abundant C-N heteroatomic structures impose strong chemical immobilization toward lithium polysulfides.Combined with the highly conductive agent,the g-C_3 N_4/CNT reinforced separator is endowed with great capability of confining and reutilizing the active sulfur within the cathode,thus contributing to an efficient and stable sulfur electrochemistry.Benefiting from these synergistic attributes,Li-S cells based on g-C_3 N_4/CNT separator exhibit an excellent cyclability with a minimum decay rate of 0.03% per cycle over 500 cycles and decent rate capability up to 2 C.Moreover,a high areal capacity of 7.69 mAh cm^(-2)can be achieved under a raised sulfur loading up to 10.1 mg cm^(-2).demonstrating a facile and efficient pathway toward superior Li-S batteries.展开更多
The three-dimensional(3D)pore structures and permeability of shale are critical for forecasting gas production capacity and guiding pressure differential control in practical reservoir extraction.However,few investiga...The three-dimensional(3D)pore structures and permeability of shale are critical for forecasting gas production capacity and guiding pressure differential control in practical reservoir extraction.However,few investigations have analyzed the effects of microscopic organic matter(OM)morphology and 3D pore nanostructures on the stress sensitivity,which are precisely the most unique and controlling factors of reservoir quality in shales.In this study,ultra-high nanoscale-resolution imaging experiments,i.e.focused ion beam-scanning electron microscopy(FIB-SEMs),were conducted on two organic-rich shale samples from Longmaxi and Wufeng Formations in northern Guizhou Depression,China.Pore morphology,porosity of 3D pore nanostructures,pore size distribution,and connectivity of the six selected regions of interest(including clump-shaped OMs,interstitial OMs,framboidal pyrite,and microfractures)were qualitatively and quantitatively characterized.Pulse decay permeability(PDP)measurement was used to investigate the variation patterns of stress-dependent permeability and stress sensitivity of shales under different confining pressures and pore pressures,and the results were then used to calculate the Biot coefficients for the two shale formations.The results showed that the samples have high OM porosity and 85%of the OM pores have the radius of less than 40 nm.The OM morphology and pore structure characteristics of the Longmaxi and Wufeng Formations were distinctly different.In particular,the OM in the Wufeng Formation samples developed some OM pores with radius larger than500 nm,which significantly improved the connectivity.The macroscopic permeability strongly depends on the permeability of OM pores.The stress sensitivity of permeability of Wufeng Formation was significantly lower than that of Longmaxi Formation,due to the differences in OM morphology and pore structures.The Biot coefficients of 0.729 and 0.697 were obtained for the Longmaxi and Wufeng Formations,respectively.展开更多
Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three s...Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three seas:the tropical West Pacific,the Bering Sea and the Arctic Ocean.Planktonic ciliate abundance had"bimodal-peak","surface-peak"and"DCM(deep chlorophyll a maximum layer)-peak"vertical distribution patterns in the tropical West Pacific,the Bering Sea and the Arctic Ocean,respectively.The abundance proportion of tintinnid to total ciliate in the Bering Sea(42.6%)was higher than both the tropical West Pacific(7.8%)and the Arctic Ocean(2.0%).The abundance proportion of small aloricate ciliates(10–20μm size-fraction)in the tropical West Pacific was highest in these three seas.The Arctic Ocean had higher abundance proportion of tintinnids in larger LOD(lorica oral diameter)size-class.Proportion of redundant species increased from the Arctic Ocean to the tropical West Pacific.Our result provided useful data to further understand ecology roles of planktonic ciliates in different marine habitats.展开更多
Although Si-based nanomaterials provide incomparable lithium ion storage ability in theory, it suffers from low initial Coulombic efficiency, electrical disconnection, and fracture due to huge volume changes after ext...Although Si-based nanomaterials provide incomparable lithium ion storage ability in theory, it suffers from low initial Coulombic efficiency, electrical disconnection, and fracture due to huge volume changes after extended cycles. As a result, it leads to a severe capacity fading and an increase in internal impedance. Herein, Ti-elemental MXene was employed as a matrix for the intermediate product of Si electrodes. The boundary between the inner core of pristine Si and its outer shell of amorphous Li x Si alloy was reconstructed. Smaller amorphous aggregates were observed in the MXene&Si hybrid electrode after 500 cycles by using transmission electron microscopy. Consequently, an enhanced specific capacity was achieved as MXene as a matrix enables loading amorphous Si.展开更多
Seismic wave interaction with a slippery rock joint with an arbitrary impinging angle is analytically studied based on the conservation of momentum on the wave fronts. Based on the displacement discontinuity method, t...Seismic wave interaction with a slippery rock joint with an arbitrary impinging angle is analytically studied based on the conservation of momentum on the wave fronts. Based on the displacement discontinuity method, the wave propagation equations are derived for incident P- and S-waves. By comparison, the calculated transmission and reflection coefficients for normal incident waves are the same as the existing results, which proves the wave propagation equation obtained in the paper is correct. The wave propagation derived in the context can be applied to incident waves with different waveforms. Stochastic seismic waves are then used to analyze the seismic wave interaction with the slippery rock joint, where the stochastic seismic waves are generated from frequency spectra. The parametric studies are carried out to investigate the effect of type, intensity and impinging angle of the incident seismic waves on the wave propagation across the slippery rock joint.展开更多
Two hydrophobic imidazolylidene-cyanoborane complexes were prepared by the introduction of{BH2 CN} into the molecular formula via treatment of imidazolium iodide and Na BH3 CN avoiding literature’s tedious and hazard...Two hydrophobic imidazolylidene-cyanoborane complexes were prepared by the introduction of{BH2 CN} into the molecular formula via treatment of imidazolium iodide and Na BH3 CN avoiding literature’s tedious and hazardous procedures. These two complexes were fully characterized using IR spectroscopy,1 H NMR and13C NMR spectroscopy and high-resolution mass spectrometer. The X-Ray structure of NHC-1 has been determined. NHC-2 was proved to be hypergolic with WFNA and displayed the attractive properties such as water immiscibility, wide liquid range（Tg= -22C）, short ignition delay time（13 ms）, high density（0.98 g/cm3）, good density impulse（r Isp, 347 s g cm-3）, showing the promising application potential as a fuel and an efficient fuel additive.展开更多
Trait structure is increasingly used in plankton ecology to understand diversity and biogeography.However,our knowledge of micro zooplankton(e.g.planktonic ciliates)trait structure and its variation with hydrography i...Trait structure is increasingly used in plankton ecology to understand diversity and biogeography.However,our knowledge of micro zooplankton(e.g.planktonic ciliates)trait structure and its variation with hydrography is limited.In this study,we analyzed planktonic ciliate trait structure in waters with different hydrography and deep Chlorophyll a maximum(DCM)layers over three seamounts:Yap,Mariana,and Caroline seamounts.Mariana seamount had a lower surface temperature than the Yap and Caroline seamounts.DCM layers over Mariana and Caroline seamounts were deeper than Yap seamount.There was a weak upwelling in upper 50 m around top of Mariana seamount.The ciliate distribution showed bimodal pattern(high abundance appeared in the surface and DCM layers)over three seamounts.At surface layer,the large size-fraction(>30μm)abundance proportion to aloricate ciliate over Yap seamount(44.4%)was higher than Mariana(32.8%)and Caroline(36.1%)seamounts.For tintinnid abundance proportion to total ciliate,Mariana(12.0%)and Caroline(11.5%)seamounts at about 100-m depth were higher than that of Yap seamount(6.4%).Vertically,tintinnid could be divided into 4 groups over the three seamounts.At30-m depth,group I(species occurring from surface to 100 m only)was dominant component over Yap and Caroline seamounts,while group IV(species occurring at every depth)changed into dominant component over Mariana seamount,the weak upwelling might be the reason.Salpingella faurei was the top dominant species,which corresponded to deeper DCM layers over Mariana and Caroline seamounts.Our results showed that the upwelling and the deeper DCM could influence the planktonic ciliate trait structure.展开更多
Phosphorus sulfide cage molecule based on P4S3 was investigated for the first time as anode material for the storage of alkali metal ions(Li+, Na+, K+). Such P4S3 sample was obtained in a large scale by a simple heati...Phosphorus sulfide cage molecule based on P4S3 was investigated for the first time as anode material for the storage of alkali metal ions(Li+, Na+, K+). Such P4S3 sample was obtained in a large scale by a simple heating reaction of low-cost rep P and S. X-ray diffraction refinement analysis indicates that P4S3 sample possesses a defect rich molecule crystal structure with S/P atom ratio of 0.74. The P4S3 anode delivered a high reversible capacity of 1266 m Ah g-1 for lithium-ion batteries at 0.1 A g-1 and good cycling performance. Experimental results demonstrated that the P4S3 anode undergoes a reversible Listorage reaction of P4S3+ 11 Li++ 11 e-←→ 0.5 Li4P2S6+ 3 Li3P during cycling. It also exhibited a high capacity of 1002 and 378 mAh g-1 at 0.1 A g-1 for Na+and K+storage, respectively. These properties suggest the promising application of P4S3 anode in high energy batteries.展开更多
The intercalation of foreign species into MXene, as an approach of tuning the interlayer environment, is employed to improve electrochemical ion storage behaviors. Herein, to understand the effect of confined ions by ...The intercalation of foreign species into MXene, as an approach of tuning the interlayer environment, is employed to improve electrochemical ion storage behaviors. Herein, to understand the effect of confined ions by the MXene layers on the performance of electrochemical energy storage, Zn^(2+) ions were employed to intercalate into MXene via an electrochemical technique. Zn^(2+) ions induced a shrink of the adjacent MXene layers. Meaningfully, a higher capacity of lithium ion storage was obtained after Zn^(2+) preintercalation. In order to explore the roles of the intercalated Zn^(2+) ions, the structural evolution, and the electronic migration among Zn, Ti and the surface termination were investigated to trace the origination of the higher Li^(+) storage capacity. The pre-intercalated Zn^(2+) ions lost electrons, meanwhile Ti of MXene obtained electrons. Moreover, a low-F surface functional groups was achieved. Contrary to the first shrink, after 200 cycles, a larger interlayer distance was monitored, this can accelerate the ion transport and offer a larger expansile space for lithium storage. This may offer a guidance to understand the roles of the confined ion by two-dimensional(2D) layered materials.展开更多
基金financiallysupported by the National Natural Science Foundation of China(Grant No.42577209)the Natural Science Foundation of Jiangsu Province(Grant No.BK20241489)the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(Grant No.SKLGME023009).
文摘This study systematically investigated the coupling effects of confiningpressure and strain rate on the dynamic strength of granite through dynamic triaxial compression tests.A dynamic strength criterion was developed to incorporate these coupling effects for further analysis.Moreover,the research thoroughly revealed the underlying mechanism by which these coupling effects influencethe rock strength.The results revealed that both confiningpressure and strain rate significantly enhanced the dynamic strength of rock;however,a mutual inhibition effect emerged under their coupling.Specifically,as the confiningpressure increased,the strengthening effect of strain rate gradually diminished.Conversely,increasing the strain rate weakened the strengthening effect of confiningpressure.The proposed strength criterion successfully predicted rock strength under various confiningpressures(0-225 MPa)and strain rates(10^(-6)-600 s^(-1)).It achieved an average prediction error of only 8.3%,which represents a 65%improvement in accuracy compared to models that consider confiningpressure and strain rate effects independently.At the micro-mechanism level,increasing confiningpressure and strain rate promoted crack propagation in a transgranular(TG)mode,thereby enhancing the overall rock strength.However,under the coupling effects,the interference and interaction of TG cracks weakened the overall strengthening effect.This indicated that the competitive interaction between confiningpressure and strain rate during crack propagation constitutes the intrinsic mechanism underlying their mutual inhibitory effect on rock strength.This study provides a more accurate theoretical basis for understanding the dynamic responses of rocks and contributes valuable insights for disaster prevention and control in deep rock engineering projects.
基金funded by the National Natural Science Foundation of China (42476143)Shandong Provincial Natural Science Foundation (ZR2022QD022)。
文摘A new tintinnid ciliate,Salpingella subarctica Zhang,Li & Li,sp.nov.was discovered in waters from the subarctic north Pacific Ocean to the Arctic Ocean during six research cruises conducted between July and September over the past decade.Distinct lorica characteristics justify the establishment of this new species,distinguishing it from previously known species:an average lorica opening diameter(12.6 μm),an average posterior lorica opening diameter(3.6 μm),a smaller lorica length(41.8–69.5 μm),a prominent posterior opening,and 8–10 longitudinal fins extending parallelly from the opening to the posterior end.It occurred in water with temperature of-1.6–20.5℃ and salinity of 25.3–34.4,and preferred to salinity of 32,temperature of 11℃ in open ocean in Pacific Ocean,and 0℃ in Bering Sea and Chukchi Sea.
基金We acknowledge the funding support from the National Key R&D Program of China(Grant No.2022YFC3080100)the National Natural Science Foundation of China(Grant No.42102316)the opening fund of State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University(Grant No.SKHL2306).
文摘The discrete fracture system of a rock mass plays a crucial role in controlling the stability of rock slopes.To fully account for the geometric shape and distribution characteristics of jointed rock masses,terrestrial laser scanning(TLS)was employed to acquire high-resolution point-cloud data,and a developed automatic discontinuity-identification technology was coupled to automatically interpret and characterize geometric information such as orientation,trace length,spacing,and set number of the discontinuities.The discrete element method(DEM)was applied to study the influence of the geometric morphology and distribution characteristics of discontinuities on slope stability by generating a discrete fracture network(DFN)with the same statistical characteristics as the actual discontinuities.Based on slope data from the Yebatan Hydropower Station,a simulation was conducted to verify the applicability of the automatic discontinuity identification technology and the discrete fracture network-discrete element method(DFN-DEM).Various geological parameters,including trace length,persistence,and density,were examined to investigate the morphological evolution and response characteristics of rock slope excavation under different joint combination conditions through simulation.The simulation results indicate that joint parameters affect slope stability,with density having the most significant impact.The impact of joint parameters on stability is relatively small within a reasonable range but becomes significant beyond a certain threshold,further validating that the accuracy of field geological surveys is critical for simulation.This study provides a scientific basis for the construction of complex rock slope models,engineering assessments,and disaster prevention and mitigation,which is of great value in both theory and engineering applications.
基金supported by the Basic Research Program of the Natural Science Fund-Frontier Leading Technology Basic Research Special Project(No.SBK2023050003)by the University Science and Technology Innovation Team of Department of Education of Guizhou Province(No.QJ[2023]099).
文摘The anti-inflammatory phytochemical investigation of the leaves of Illicium dunnianum(I.dunnianum)resulted in the isolation of five pairs of new lignans(1–5),and 7 known analogs(6–12).The separation of enantiomer mixtures 1–5 to 1a/1b–5a/5b was achieved using a chiral column with acetonitrile−water mixtures as eluents.The planar structures of 1–2 were previously undescribed,and the chiral separation and absolute configurations of 3–5 were reported for the first time.Their structures were determined through comprehensive spectroscopic data analysis[nuclear magnetic resonance(NMR),high-resolution electrospray ionization mass(HR-ESI-MS),infrared(IR),and ultraviolet(UV)]and quantum chemistry calculations(ECD).The new isolates were evaluated by measuring their inhibitory effect on NO in lipopolysaccharide(LPS)-stimulated BV-2 cells.Compounds 1a,3a,3b,and 5a demonstrated partial inhibition of NO production in a concentration-dependent manner.Western blot and real-time polymerase chain reaction(PCR)assays revealed that 1a down-regulated the messenger ribonucleic acid(mRNA)levels of tumor necrosis factorα(TNF-α),interleukin-6(IL-6),COX-2,and iNOS and the protein expressions of COX-2 and iNOS.This research provides guidance and evidence for the further development and utilization of I.dunnianum.
基金the National Natural Science Foundation of China(22476220,22336007)the China Postdoctoral Science Foundation(2024M753736)the Guangdong Basic Research Center of Excellence for Functional Molecular Engineering(31000-42080002).
文摘Organic metal halides with white-light emissions have shown significant application prospects in the fields of solid-state lighting and displays, but their structural design and synthesis remain a major challenge. Here, the material design concept of functional units has been applied to prepare a zero-dimensional (oD) organic anti-mony halide (1-BMP)_(5)(SbCl_(5))_(2)SbCl_(4) with two luminescent centers from the inorganic units and the organic units, emitting red emission about 670 nm and cyan emission about 508 nm respectively, combined to form white light. Based on the photoluminescence (PL), the time-resolved PL analysis and density functional theory (DFT) calculation, it is shown that the red and cyan emission comes from STEs related to inorganic units [SbCl_(5)]^(2-) and the fluorescence of organic cations 1-BMP^(+), respectively. This work provides new methods and ideas for the development of low-cost and eco-friendly white emission phosphors for single-component solid-state WLEDs.
基金supported by the National Natural Science Foundation of China (52404316, 52474325)the S&T program of Hebei Province(225A4404D)+3 种基金the Natural Science Foundation of Hainan Province (524RC475)the Collaborative Innovation Center of Marine Science and Technology of Hainan University (XTCX2022HYC14)the Xingtai City Natural Science Foundation (2023ZZ027)The Pico Electron Microscopy Center of Hainan University partially supported this study
文摘Gel polymer electrolytes(GPEs)with high flame‐retardant concentration can remarkably reduce the thermal runaway risk of lithium metal batteries(LMBs).However,higher flame‐retardant content in GPEs always leads to increased leakage of active component and severe lithium corrosion,which greatly hinders the service life of LMBs.Herein,GPEs with high‐loading triphenyl phosphate(TPP)are originally fabricated by coaxial electrospinning and stabilized by dual confinement effects,including chemisorption of polyvinylidene fluoride‐hexafluoropropylene(PVDF‐HFP),and physical encapsulation of polyacrylonitrile(PAN)/PVDF‐HFP.These effects arise from the strong polar interactions between the−CF3 group in PVDF‐HFP and P=O group in TPP,as well as the superior anti‐swelling property of PAN.To mitigate TPP‐induced corrosion during cycling,the optimized Li anode is armored with LiF‐rich solid electrolyte interphase(SEI)layer through immersing it in fluoroethylene carbonate‐containing electrolyte.As expected,the corresponding Li||Li symmetric cells deliver long‐term stable cycling behavior over 2400 h at 0.5 mA cm−2,and the LiFePO4||Li batteries hold a high‐capacity retention ratio of 81.7%after 6000 cycles at 10 C with excellent flame retardancy.These findings offer new insight into designing the SEI layer for lithium metal in flame‐retardant electrolytes,thus promoting the development and application of high‐security LMBs.
基金financially supported by the Natural Science Foundation of Beijing (No. L182062)the Beijing Nova program (Z171100001117077)+5 种基金the Yue Qi Young Scholar Project of China University of Mining & Technology (Beijing) (No. 2017QN17)the Fundamental Research Funds for the Central Universities (No.2014QJ02)the program for the Development of Science and Technology of Jilin Province (Nos. 20190201309JC and 20190101009JH)the Project of Development and Reform Commission of Jilin Province (No. 2019C042-1)the support from Natural Sciences and Engineering Research Council of Canada (NSERC)the University of Waterloo.
文摘Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. Herein, we report a nitrogen-doped porous carbon derived from biomass pomelo peel as sulfur host material for Li-S batteries. The hierarchical porous architecture and the polar surface introduced by N-doping render a favorable combination of physical and chemical sulfur confinements as well as an expedite electron/ion transfer, thus contributing to a facilitated and stabilized sulfur electrochemistry. As a result, the corresponding sulfur composite electrodes exhibit an ultrahigh initial capacity of 1534.6 mAh g^-1, high coulombic efficiency over 98% upon 300 cycles, and decent rate capability up to 2 C. This work provides an economical and effective strategy for the fabrication of advanced carbonaceous sulfur host material as well as the significant improvement of Li-S battery performance.
基金financial support provided by the National Key R&D Program of China (2016YFA0200400)the Jilin Province/Jilin University co-Construction Project-Funds for New Materials (SXGJSF2017-3, Branch-2/440050316A36)+4 种基金the National Natural Science Foundation of China (Grant nos. 91545119, 21761132025, 21773269 and 51372095)the Youth Innovation Promotion Association CAS (Grant no. 2015152)Strategic Priority Research Program of the Chinese Academy of Sciences Chinese Academy of Sciences (Grant nos. XDA09030103 and XDA09040203)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT)"Double-First Class" Discipline for Materials Science & Engineering
文摘MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect on electrochemical performance. Herein, annealing MXene under hydrogen was employed for removing-F and turning-OH to-O terminations. We demonstrate that it improves the kinetics of Li-ion transport between the electrolyte and electrode. As a result, a lower interfacial charge transfer impedance was obtained. The electrochemical measurement exhibited that a nearly 2-fold increase of specific capacity was achieved for the annealed MXene.
基金support provided by the National Natural Science Foundation of China(No.51932005)Liao Ning Revitalization Talents Program(XLYC1807175)+6 种基金the Joint Research Fund Liaoning Shenyang National Laboratory for Materials Science(SYNL)(20180510047)the Research Fund of SYNL(L2019F38)the Youth Innovation Promotion Association CAS(2015152)the Program for the Development of Science and Technology of Jilin Province(No.20190201309JC)the Project of Development and Reform Commission of Jilin Province(No.2019C042-1)2020 International Cooperation Project of the Department of Science and Technology of Jilin Provincethe Open Project Program of Wuhan National Laboratory for Optoelectronics(2018WNLOKF022)。
文摘MXenes have emerged as a new kind of 2D transition metal carbides,nitrides and carbonitrides.Origined from the unique 2D structure with a luxuriant combination of elements,MXenes drive a series of the investigations related to energy storage and conversion,biometrics and sensing,lighting,purification and separation.For 2D layered MXene materials,the interspacing confined by the independent MXenes layers affords a distinct confinement space,which is similar to a nanoreactor that can be utilized for the storage of ions,nanoparticles,nanowires,and the materials with 2D or 3D structure.These fillings confined by MXene layers afford new opptunities for achieving improved properties and performance via complementary natural features,further the synergistic effect.Herein,we summarize the recent reports concerning with the confinded MXenes spacing and the fillings.The modification of interlayer distance lead by the intercalants were explored.We expect that our review may offer the route for a series of ongoing studies to address the MXenes.
基金financial support provided by the National Natural Science Foundation of China(No.51932005)Liao Ning Revitalization Talents Program(XLYC1807175)+4 种基金the Joint Research Fund Liaoning Shenyang National Laboratory for Materials Science(SYNL)(20180510047)the Research Fund of SYNL(L2019F38)the Youth Innovation Promotion Association CAS(2015152)the Program for the Development of Science and Technology of Jilin Province(No.20190201309JC)the Project of Development and Reform Commission of Jilin Province(No.2019C042-1)。
文摘Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Herein,the cation intercalation and ion-exchange were well employed to achieve a K+and Ca2+intercalated V2CTxMXene.A larger interlayer distance and low F surface terminations were thereof obtained,which accelerates the ion transport and promotes the delicate surface of V2CTx MXene.As a result,a package of enhanced capacity,rate performance and cyclability can be achieved.Furthermore,the ion exchange approach can be extended to other 2 D layered materials,and both the interlayer control and the surface modification will be achieved.
基金support of the National Natural Science Foundation of China(Grant No.42102316)the Open Project of the Technology Innovation Center for Geological Environment Monitoring of Ministry of Natural Resources of China(Grant No.2022KFK1212005).
文摘Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels.This study demonstrates the integration of terrestrial laser scanning(TLS)with distinct element method for rock mass characterization and stability analysis in tunnels.TLS records detailed geometric information of the surrounding rock mass by scanning and collecting the positions of millions of rock surface points without contact.By conducting a fuzzy K-means method,a discontinuity automatic identification algorithm was developed,and a method for obtaining the geometric parameters of discontinuities was proposed.This method permits the user to visually identify each discontinuity and acquire its spatial distribution features(e.g.occurrences,spac-ings,trace lengths)in great detail.Compared with hand mapping in conventional geotechnical surveys,the geometric information of discontinuities obtained by this approach is more accurate and the iden-tification is more efficient.Then,a discrete fracture network with the same statistical characteristics as the actual discontinuities was generated with the distinct element method,and a representative nu-merical model of the jointed surrounding rock mass was established.By means of numerical simulation,potential unstable rock blocks were assessed,and failure mechanisms were analyzed.This method was applied to detection and assessment of unstable rock blocks in the spillway and sand flushing tunnel of the Hongshiyan hydropower project after a collapse.The results show that the noncontact detection of blocks was more labor-saving with lower safety risks compared with manual surveys,and the stability assessment was more reliable since the numerical model built by this method was more consistent with the distribution characteristics of actual joints.This study can provide a reference for geological survey and unstable rock block hazard mitigation in tunnels subjected to complex geology and active rockfalls.
基金supported by the National Natural Science Foundation of China (Nos. 21978110 and 51772126)the Natural Science Foundation of Beijing (No. L182062)+8 种基金the Organization Department of Beijing Talents Project (2018000021223ZK21)the Yue Qi Young Scholar Project of China University of Mining & Technology (Beijing) (No. 2017QN17)the Fundamental Research Funds for the Central Universities (No. 2014QJ02)the Jilin Province Science and Technology Department Program (Nos. 20200201187JC, 20190201309JC, and 20190101009JH)the ‘‘13th five-year” Science and Technology Project of Jilin Provincial Education Department (No. JJKH20200407KJ)the Jilin Province Development and Reform Commission Program (Nos. 2020C026-3 and 2019C042-1)the Jilin Province Fund for Talent Development Program (No. [2019] 874)the supports from Natural Sciences and Engineering Research Council of Canada (NSERC), the University of Waterloothe Waterloo Institute for Nanotechnology。
文摘The notorious shuttle effect has long been obstructing lithium-sulfur(Li-S) batteries from yielding the expected high energy density and long lifespan.Herein,we develop a multifunctional polysulfide barrier reinforced by the graphitic carbon nitride/carbon nanotube(g-C_3 N_4/CNT) composite toward inhibited shuttling behavior and improved battery performance.The obtained g-C_3 N_4 delivers a unique spongelike architecture with massive ion transfer pathways and fully exposed active interfaces,while the abundant C-N heteroatomic structures impose strong chemical immobilization toward lithium polysulfides.Combined with the highly conductive agent,the g-C_3 N_4/CNT reinforced separator is endowed with great capability of confining and reutilizing the active sulfur within the cathode,thus contributing to an efficient and stable sulfur electrochemistry.Benefiting from these synergistic attributes,Li-S cells based on g-C_3 N_4/CNT separator exhibit an excellent cyclability with a minimum decay rate of 0.03% per cycle over 500 cycles and decent rate capability up to 2 C.Moreover,a high areal capacity of 7.69 mAh cm^(-2)can be achieved under a raised sulfur loading up to 10.1 mg cm^(-2).demonstrating a facile and efficient pathway toward superior Li-S batteries.
基金supported by the National Key R&D Program of China(Grant No.2020YFA0711802)the Strategic Program of Chinese Academy of Sciences(Grant No.XDB10030400)。
文摘The three-dimensional(3D)pore structures and permeability of shale are critical for forecasting gas production capacity and guiding pressure differential control in practical reservoir extraction.However,few investigations have analyzed the effects of microscopic organic matter(OM)morphology and 3D pore nanostructures on the stress sensitivity,which are precisely the most unique and controlling factors of reservoir quality in shales.In this study,ultra-high nanoscale-resolution imaging experiments,i.e.focused ion beam-scanning electron microscopy(FIB-SEMs),were conducted on two organic-rich shale samples from Longmaxi and Wufeng Formations in northern Guizhou Depression,China.Pore morphology,porosity of 3D pore nanostructures,pore size distribution,and connectivity of the six selected regions of interest(including clump-shaped OMs,interstitial OMs,framboidal pyrite,and microfractures)were qualitatively and quantitatively characterized.Pulse decay permeability(PDP)measurement was used to investigate the variation patterns of stress-dependent permeability and stress sensitivity of shales under different confining pressures and pore pressures,and the results were then used to calculate the Biot coefficients for the two shale formations.The results showed that the samples have high OM porosity and 85%of the OM pores have the radius of less than 40 nm.The OM morphology and pore structure characteristics of the Longmaxi and Wufeng Formations were distinctly different.In particular,the OM in the Wufeng Formation samples developed some OM pores with radius larger than500 nm,which significantly improved the connectivity.The macroscopic permeability strongly depends on the permeability of OM pores.The stress sensitivity of permeability of Wufeng Formation was significantly lower than that of Longmaxi Formation,due to the differences in OM morphology and pore structures.The Biot coefficients of 0.729 and 0.697 were obtained for the Longmaxi and Wufeng Formations,respectively.
基金The National Natural Science Foundation of China under contract No.41706192the Science&Technology Basic Resources Investigation Program of China under contract No.2017FY100803+3 种基金the National Natural Science Foundation of ChinaShandong Joint Fund for Marine Science Research Centers under contract No.U1606404the CNRS-NSFC Joint Research Projects Program under contract No.NSFC 41711530149the 2017–2019 Sino-French Cai Yuanpei Programmethe National Natural Science Foundation of China under contract No.41706217
文摘Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three seas:the tropical West Pacific,the Bering Sea and the Arctic Ocean.Planktonic ciliate abundance had"bimodal-peak","surface-peak"and"DCM(deep chlorophyll a maximum layer)-peak"vertical distribution patterns in the tropical West Pacific,the Bering Sea and the Arctic Ocean,respectively.The abundance proportion of tintinnid to total ciliate in the Bering Sea(42.6%)was higher than both the tropical West Pacific(7.8%)and the Arctic Ocean(2.0%).The abundance proportion of small aloricate ciliates(10–20μm size-fraction)in the tropical West Pacific was highest in these three seas.The Arctic Ocean had higher abundance proportion of tintinnids in larger LOD(lorica oral diameter)size-class.Proportion of redundant species increased from the Arctic Ocean to the tropical West Pacific.Our result provided useful data to further understand ecology roles of planktonic ciliates in different marine habitats.
基金financial support provided by the Joint Foundation of Liaoning Province National Science FoundationShenyang National Laboratory for Materials Science (Grant No. 20180510047)+6 种基金the National Natural Science Foundation of China (Grant Nos. 91545119 , 21761132025 , 21773269 and 51872115)the Youth Innovation Promotion Association CAS (Grant No. 2015152)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, 2017TD-09)“Double-First Class” Discipline for Materials Science & EngineeringNatural Science Foundation of Anhui Province (1608085ME93)the Fundamental Research Funds for the Central Universities (JZ2018YYPY0305)the 111 Project “New Materials and Technology for Clean Energy” (B18018)
文摘Although Si-based nanomaterials provide incomparable lithium ion storage ability in theory, it suffers from low initial Coulombic efficiency, electrical disconnection, and fracture due to huge volume changes after extended cycles. As a result, it leads to a severe capacity fading and an increase in internal impedance. Herein, Ti-elemental MXene was employed as a matrix for the intermediate product of Si electrodes. The boundary between the inner core of pristine Si and its outer shell of amorphous Li x Si alloy was reconstructed. Smaller amorphous aggregates were observed in the MXene&Si hybrid electrode after 500 cycles by using transmission electron microscopy. Consequently, an enhanced specific capacity was achieved as MXene as a matrix enables loading amorphous Si.
基金Supported by the National Natural Science Foundation of China (11072257, 51025935, 40872188)the Key Projects in the National Sciences and Technology Pillar Program (2008DAB29B00)
文摘Seismic wave interaction with a slippery rock joint with an arbitrary impinging angle is analytically studied based on the conservation of momentum on the wave fronts. Based on the displacement discontinuity method, the wave propagation equations are derived for incident P- and S-waves. By comparison, the calculated transmission and reflection coefficients for normal incident waves are the same as the existing results, which proves the wave propagation equation obtained in the paper is correct. The wave propagation derived in the context can be applied to incident waves with different waveforms. Stochastic seismic waves are then used to analyze the seismic wave interaction with the slippery rock joint, where the stochastic seismic waves are generated from frequency spectra. The parametric studies are carried out to investigate the effect of type, intensity and impinging angle of the incident seismic waves on the wave propagation across the slippery rock joint.
基金the financial support from the National Natural Science Foundation of China (Nos. 21372027, 21376252)
文摘Two hydrophobic imidazolylidene-cyanoborane complexes were prepared by the introduction of{BH2 CN} into the molecular formula via treatment of imidazolium iodide and Na BH3 CN avoiding literature’s tedious and hazardous procedures. These two complexes were fully characterized using IR spectroscopy,1 H NMR and13C NMR spectroscopy and high-resolution mass spectrometer. The X-Ray structure of NHC-1 has been determined. NHC-2 was proved to be hypergolic with WFNA and displayed the attractive properties such as water immiscibility, wide liquid range（Tg= -22C）, short ignition delay time（13 ms）, high density（0.98 g/cm3）, good density impulse（r Isp, 347 s g cm-3）, showing the promising application potential as a fuel and an efficient fuel additive.
基金the Science&Technology Basic Resources Investigation Program of China(No.2017FY100803)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)+5 种基金the China Postdoctoral Science Foundation(No.2020M672149)the National Key Research and Development Program of China(No.2017YFA0603204)the CNRS-NSFC Joint Research Projects Program(No.NSFC 41711530149)the 2017-2019 Sino-French Cai Yuanpei Programthe International Cooperation Project-Dynamics and Function of Marine Microorganisms(No.ICP-DYF2M):Insight from Physics and Remote Sensing。
文摘Trait structure is increasingly used in plankton ecology to understand diversity and biogeography.However,our knowledge of micro zooplankton(e.g.planktonic ciliates)trait structure and its variation with hydrography is limited.In this study,we analyzed planktonic ciliate trait structure in waters with different hydrography and deep Chlorophyll a maximum(DCM)layers over three seamounts:Yap,Mariana,and Caroline seamounts.Mariana seamount had a lower surface temperature than the Yap and Caroline seamounts.DCM layers over Mariana and Caroline seamounts were deeper than Yap seamount.There was a weak upwelling in upper 50 m around top of Mariana seamount.The ciliate distribution showed bimodal pattern(high abundance appeared in the surface and DCM layers)over three seamounts.At surface layer,the large size-fraction(>30μm)abundance proportion to aloricate ciliate over Yap seamount(44.4%)was higher than Mariana(32.8%)and Caroline(36.1%)seamounts.For tintinnid abundance proportion to total ciliate,Mariana(12.0%)and Caroline(11.5%)seamounts at about 100-m depth were higher than that of Yap seamount(6.4%).Vertically,tintinnid could be divided into 4 groups over the three seamounts.At30-m depth,group I(species occurring from surface to 100 m only)was dominant component over Yap and Caroline seamounts,while group IV(species occurring at every depth)changed into dominant component over Mariana seamount,the weak upwelling might be the reason.Salpingella faurei was the top dominant species,which corresponded to deeper DCM layers over Mariana and Caroline seamounts.Our results showed that the upwelling and the deeper DCM could influence the planktonic ciliate trait structure.
基金the Natural Science Foundation of Shandong Province(ZR2017QB017)the Ph.D.Scientific Research Fund of Liaocheng University(No.318051406)+2 种基金the Natural Science Foundation of Shandong Province(ZR2016BQ41)the High Education Science and Technology Program of Shandong Province(J16LC03)the Cultivation Fund of Liaocheng University(318011615)。
文摘Phosphorus sulfide cage molecule based on P4S3 was investigated for the first time as anode material for the storage of alkali metal ions(Li+, Na+, K+). Such P4S3 sample was obtained in a large scale by a simple heating reaction of low-cost rep P and S. X-ray diffraction refinement analysis indicates that P4S3 sample possesses a defect rich molecule crystal structure with S/P atom ratio of 0.74. The P4S3 anode delivered a high reversible capacity of 1266 m Ah g-1 for lithium-ion batteries at 0.1 A g-1 and good cycling performance. Experimental results demonstrated that the P4S3 anode undergoes a reversible Listorage reaction of P4S3+ 11 Li++ 11 e-←→ 0.5 Li4P2S6+ 3 Li3P during cycling. It also exhibited a high capacity of 1002 and 378 mAh g-1 at 0.1 A g-1 for Na+and K+storage, respectively. These properties suggest the promising application of P4S3 anode in high energy batteries.
基金supported by the Development Plan of Science and Technology of Jilin Province (20190201309JC,YDZJ202101ZYTS187)the Project of Development and Reform Commission of Jilin Provinve (2019C042-1)+3 种基金the Science and Technology Research Project of Education Department of Jilin Province(JJKH20210453KJ, JJKH20210449KJ)the National Natural Science Foundation of China (51932005)the Liaoning Revitalization Talents Program (XLYC1807175)the Research Fund of Shenyang National Laboratory for Materials Science。
文摘The intercalation of foreign species into MXene, as an approach of tuning the interlayer environment, is employed to improve electrochemical ion storage behaviors. Herein, to understand the effect of confined ions by the MXene layers on the performance of electrochemical energy storage, Zn^(2+) ions were employed to intercalate into MXene via an electrochemical technique. Zn^(2+) ions induced a shrink of the adjacent MXene layers. Meaningfully, a higher capacity of lithium ion storage was obtained after Zn^(2+) preintercalation. In order to explore the roles of the intercalated Zn^(2+) ions, the structural evolution, and the electronic migration among Zn, Ti and the surface termination were investigated to trace the origination of the higher Li^(+) storage capacity. The pre-intercalated Zn^(2+) ions lost electrons, meanwhile Ti of MXene obtained electrons. Moreover, a low-F surface functional groups was achieved. Contrary to the first shrink, after 200 cycles, a larger interlayer distance was monitored, this can accelerate the ion transport and offer a larger expansile space for lithium storage. This may offer a guidance to understand the roles of the confined ion by two-dimensional(2D) layered materials.
