A multivariable regression analysis of the in-situ stress field, which considers the non-linear deformation behavior of faults in practical projects, is presented based on a newly developed three-dimensional displacem...A multivariable regression analysis of the in-situ stress field, which considers the non-linear deformation behavior of faults in practical projects, is presented based on a newly developed three-dimensional displacement discontinuity method (DDM) program. The Bar- ton-Bandis model and the Kulhaway model are adopted as the normal and the tangential deformation model of faults, respectively, where the Mohr-Coulomb failure criterion is satisfied. In practical projects, the values of the mechanical parameters of rock and faults are restricted in a bounded range for in-situ test, and the optimal mechanical parameters are obtained from this range by a loop. Comparing with the traditional finite element method (FEM), the DDM regression results are more accurate.展开更多
With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges o...With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges on its poor intrinsic electronic conductivity and the controversial de/sodiation mechanism.Herein,a series of Zr-doped NVPF coated by N-doped carbon layer(~5 nm in thickness,homogenously)materials are fabricated by a sol-gel method,and the optimized heteroatom-doping amounts of Zr and N doping improve intrinsic properties on enlarging lattice distance and enhancing electronic conductivity,respectively.Specifically,among all samples of Na_(3) V_(2-x)Zr_(x)(PO_(4))_(2) F_(3)/NC(NVPF-Zr-x/NC,x=0,0.01,0.02,0.05,and 0.1),the optimized electrode of NVPF-Zr-0.02/NC delivers high reversible capacities(119.2 mAh g^(-1) at0.5 C),superior rate capability(98.1 mA h g^(-1) at 20 C)and excellent cycling performance.The structural evolution of NVPF-Zr-0.02/NC electrode,in-situ monitored by X-ray diffractometer,follows a step-wise Na-extraction/intercalation mechanism with reversible multi-phase changes,not just a solid-solutionreaction one.Full cells of NVPF-Zr-0.02/NC//hard carbon demonstrate high capacity(99.8 mA h g^(-1) at 0.5 C),high out-put voltage(3.5 V)and good cycling stability.This work is favorable to accelerate the development of high-performance cathode materials and explore possible redox reaction mechanisms of SIBs.展开更多
The Chang'e-3 Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the four payloads on the Yutu rover. After traversing the landing site during the first two lunar days, four different areas are detecte...The Chang'e-3 Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the four payloads on the Yutu rover. After traversing the landing site during the first two lunar days, four different areas are detected, and Level 2A and 2B ra- diance data have been released to the scientific community. The released data have been processed by dark current subtraction, correction for the effect of temperature, radiometric calibration and geometric calibration. We emphasize approaches for re- flectance analysis and mineral identification for in-situ analysis with VNIS. Then the preliminary spectral and mineralogical results from the landing site are derived. After comparing spectral data from VNIS with data collected by the Ma instrument and samples of mare that were returned from the Apollo program, all the reflectance data have been found to have similar absorption features near 1000 nm except lunar sample 71061. In addition, there is also a weak absorption feature between 1750-2400nm on VNIS, but the slopes of VNIS and Ma reflectance at longer wavelengths are lower than data taken from samples of lunar mare. Spectral parameters such as Band Centers and Integrated Band Depth Ratios are used to analyze mineralogical features. The results show that detection points E and N205 are mixtures of high-Ca pyroxene and olivine, and the composition of olivineat point N205 is higher than that at point E, but the compositions of detection points S3 and N203 are mainly olivine-rich. Since there are no obvious absorption features near 1250 nm, plagioclase is not directly identified at the landing site.展开更多
Lightweight hybrid structures of Al MMCs and titanium alloy dissimilar materials have great prospect in the defence industry application. So, it is necessary to join Al MMCs with Ti metal to achieve this structural de...Lightweight hybrid structures of Al MMCs and titanium alloy dissimilar materials have great prospect in the defence industry application. So, it is necessary to join Al MMCs with Ti metal to achieve this structural design. In this work, in-situ Ti B_(2)/7050 composite and TA2 were firstly attempted to join by TIG welding-brazing technique. The result was that the intact welding-brazing butt joint was successfully fabricated. The joint presents dual characteristics, being a brazing on TA2 side and a welding on Ti B_(2)/7050 side. At brazing joint side, ER4043 filler metal effectively wets on TA2 under TIG heating condition,and a continuous interfacial reaction layer with 1 e3 mm is formed at welded metal/TA2 interface. The whole interfacial reaction layers are composed of Ti(Al Si)3 intermetallic compounds(IMCs), but their morphologies at the different regions present obvious distinguishes. The microhardness of the reaction layers is as much as 141 e190 HV. At welding joints side, the fusion zone appears the equixaed crystal structure, and the grain sizes are much smaller than those of welded metal, which is attributed to the effect of Ti B2 particulates from the melted Ti B_(2)/7050 on acceleration formation and inhibiting growth for the new crystal nucleus. The tensile test results show that average tensile strength of the optimal welding-brazing joint is able to achieve 138 MPa. The failure of the tensile joint occurs by quasi-cleavage pattern, and the cracks initiate from the IMCs layer at the groove surface of TA2 and propagate into the welded metal.展开更多
This paper presents a generic procedure to implement a scalable and high performance data analysis framework for large-scale scientific simulation within an in-situ infrastructure. It demonstrates a unique capability ...This paper presents a generic procedure to implement a scalable and high performance data analysis framework for large-scale scientific simulation within an in-situ infrastructure. It demonstrates a unique capability for global Earth system simulations using advanced computing technologies (i.e., automated code analysis and instrumentation), in-situ infrastructure (i.e., ADIOS) and big data analysis engines (i.e., SciKit-learn). This paper also includes a useful case that analyzes a globe Earth System simulations with the integration of scalable in-situ infrastructure and advanced data processing package. The in-situ data analysis framework can provides new insights on scientific discoveries in multiscale modeling paradigms.展开更多
A novel copper complex [Cu2(L)(DMF)2](1, H4L =(1 Z,N?Z)-3,5-dibromo-N?-((3,5-dibromo-2-hydroxyphenyl)(hydroxy)methylene)-2-hydroxybenzohydrazonic acid which was synthesized by in-situ oxidation reaction...A novel copper complex [Cu2(L)(DMF)2](1, H4L =(1 Z,N?Z)-3,5-dibromo-N?-((3,5-dibromo-2-hydroxyphenyl)(hydroxy)methylene)-2-hydroxybenzohydrazonic acid which was synthesized by in-situ oxidation reaction derived from H2hdb(H2hdb = 6,6′-((1 E,1?E)-hydrazine-1,2-diylidenebis(methanylylidene)) bis(2,4-dibromophenol)) has been synthesized and characterized by IR, elemental analysis(CHN), TG and single-crystal X-ray diffraction. The single crystal belongs to monoclinic system, space group P21/c with a = 13.538(1), b = 3.912(1), c = 23.778(1)A°, β = 105.232(5)o, Mr = 857.08, V = 1214.9(1) A°^3, Z = 2, Dc = 2.343 g/cm^3, F(000) = 824, μ = 8.375 mm^–1, R = 0.0566, and w R = 0.1610. Compound 1 displays weak anti-ferromagnetic interactions through a η^1:η^1:η^1:η^1:η^1:η^1:μ2-L^4- bridging mode. Hirshfeld surface analysis revealed that complex 1 was supported mainly by Br···H and H···H intermolecular interactions.展开更多
In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points ...In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points and monitoring factors in thegraphic on the same factor axis can clearly express the intrinsic link between pollutantsand monitoring points and distribution characteristics.To determine the main monitoringpoint and the main monitoring indicators can reduce and optimize the number of monitoringpoints under the premise of ensuring the typical and representative of monitoring data.Using the correlation of pollutants can reduce the number of monitoring indicators and improvethe effectiveness of data collection.展开更多
The prediction of the stress field of deep-buried tunnels is a fundamental problem for scientists and engineers. In this study, the authors put forward a systematic solution for this problem. Databases from the World ...The prediction of the stress field of deep-buried tunnels is a fundamental problem for scientists and engineers. In this study, the authors put forward a systematic solution for this problem. Databases from the World Stress Map and the Crustal Stress of China, and previous research findings can offer prediction of stress orientations in an engineering area. At the same time, the Andersonian theory can be used to analyze the possible stress orientation of a region. With limited in-situ stress measurements, the Hock-Brown Criterion can be used to estimate the strength of rock mass in an area of interest by utilizing the geotechnical investigation data, and the modified Sheorey's model can subsequently be employed to predict the areas' stress profile, without stress data, by taking the existing in-situ stress measurements as input parameters. In this paper, a case study was used to demonstrate the application of this systematic solution. The planned Kohala hydropower plant is located on the western edge of Qinghai-Tibet Plateau. Three hydro-fracturing stress measurement campaigns indicated that the stress state of the area is SH - Sh 〉 Sv or SH 〉Sv 〉 Sh. The measured orientation of Sn is NEE (N70.3°-89°E), and the regional orientation of SH from WSM is NE, which implies that the stress orientation of shallow crust may be affected by landforms. The modified Sheorey model was utilized to predict the stress profile along the water sewage tunnel for the plant. Prediction results show that the maximum and minimum horizontal principal stres- ses of the points with the greatest burial depth were up to 56.70 and 40.14 MPa, respectively, and the stresses of areas with a burial depth of greater than 500 m were higher. Based on the predicted stress data, large deformations of the rock mass surrounding water conveyance tunnels were analyzed. Results showed that the large deformations will occur when the burial depth exceeds 300 m. When the burial depth is beyond 800 m, serious squeezing deformations will occur in the surrounding rock masses, thus requiring more attention in the design and construction. Based on the application efficiency in this case study, this prediction method proposed in this paper functions accurately.展开更多
Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since ...Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since lithium plating behavior is determined by diverse factors. In this contribution, we present a non-destructive electrochemical detection method based on transient state analysis and threeelectrode cell configuration. Through dividing the iR drop value by the current density, the as-obtained impedance quantity(R_(i)) can serve as a descriptor to describe the change of electrochemical reaction impedance on the graphite anode. The onset of lithium plating can be identified from the sharp drop of R_(i). Once the dendritic plated lithium occurs, the extra electrochemical reactions at the lithium interfaces leads to growing active area and reduced surface resistance of the anode. We proposed a protocol to operate the batteries under the limited capacity, which renders the cell with 98.2% capacity retention after 1000 cycles without lithium plating. The early-warning method has also been validated in in-situ optical microscopy batteries and practical pouch cells, providing a general but effective method for online lithium plating detection towards safe batteries.展开更多
CO_(2)+O_(2) in-situ leaching(ISL)of sandstonetype uranium ore represents the third generation of solution mining in China.In this study,reactive transport modeling of the interaction between hydrodynamic and geochemi...CO_(2)+O_(2) in-situ leaching(ISL)of sandstonetype uranium ore represents the third generation of solution mining in China.In this study,reactive transport modeling of the interaction between hydrodynamic and geochemical reactions is performed to enable better prediction and regulation of the CO_(2)+O_(2) in-situ leaching process of uranium.Geochemical reactions between mining solutions and rock,and the kinetic uranium dissolution controlled by O_(2)(aq)and bicarbonate(HCO_(3)-)are considered in the CO_(2)+O_(2) ISL reactive transport model of a typical sandstone-hosted uranium ore deposit in northern China.The reactive leaching of uranium is most sensitive to the spatial distribution of the mineralogical properties of the uranium deposit.Stochastic geostatistical models are used to represent the uncertainty on the spatial distribution of mineral grades.A Monte Carlo analysis was also performed to simulate the uranium production variability over an entire set of geostatistical realizations.The ISL stochastic simulation performed with the selected geostatistical realizations approximates the uranium production variability well.The simulation results of the ISL reactive transport model show that the extent of the uranium plume is highly dependent on mineralogical heterogeneity.The uncertainty analysis suggests the effect of uranium grade heterogeneity was found to be important to improve the accurate capture of the uncertainty.This study provides guidance for the accurate simulation and dynamic regulation of the CO_(2)+O_(2) leaching process of uranium at the scale of large mining areas.展开更多
Using PTFE as a chemical modifier, a method for the determination of trace impurities in high purity Nd_2O_3 by in-situ separation and electrothermal vaporization-inductively coupled plasma-atomic emission spectrometr...Using PTFE as a chemical modifier, a method for the determination of trace impurities in high purity Nd_2O_3 by in-situ separation and electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) was developed. The analyte-matrix separation and the temperature program of graphite furnace were investigated and optimized. The solid samples were directly introduced into graphite furnace in the form of slurry, where selective volatilization between the matrix and the analytes took place. The Nd matrix was retained in the graphite furnace during the evaporation step, while the trace analyte impurities were vaporized and removed. As a result, the matrix interference that is serious without the modifier is suppressed effectively. The achievable detection limits are (μg·g^(-1)): Ti 0.15, Mn 0.15, Ni 0.20, Co 0.54, respectively. The proposed method was applied to direct determination of trace impurities in high purity Nd_2O_3 with satisfactory results.展开更多
Many countries which seek to understand the acoustic performance of railway noise barriers have established standards for the conduct of in-situ experiments.However,there are no universally acknowledged receiver posit...Many countries which seek to understand the acoustic performance of railway noise barriers have established standards for the conduct of in-situ experiments.However,there are no universally acknowledged receiver positions for the evaluation of the barrier performance,a fact which may be leading to uncertainty over the noise reduction capabilities of available barriers.In terms of the descriptor of the barrier performance,the general recommendation is the A-weighted sound pressure level,although the latter is considered to underestimate low frequencies for railway noise barrier.Thus,in this study,the comparison of receiver positions and the descriptors among existing Chinese,ISO and European standards were investigated.Based upon a combination of diffraction theory and standards,a rearrangement of receiver positions and one-third-octave-band analysis were proposed.In addition,in line with improved methods,an in-situ measurement of insertion loss for a 1.5 mhigh railway noise barrier was designed and conducted.The results of the experiment validate as effective and applicable the new receiver positions.These results also suggest that one-third-octave-band analysis is indispensable.展开更多
Crystallization behavior and kinetics study of palm kernel oil (PKO) were investigated using differential scanning calorimetry (DSC) by controlling cooling and reheating rate within a certain range of temperature. The...Crystallization behavior and kinetics study of palm kernel oil (PKO) were investigated using differential scanning calorimetry (DSC) by controlling cooling and reheating rate within a certain range of temperature. The evolution of morphology and particle counts was analyzed by focused beam reflectance measurement (FBRM) and particles video microscope (PVM) at the nucleation stage during suspension crystallization. The particle counts and morphological evolution from needle-like aggregations to amorphous form from PVM were observed during the initial crystallization stage, which meant that a phase transition was likely to occur. This work can give a better understanding of complicated fat system crystallization behavior and provide some critical instructions to control fractionation process.展开更多
The thermal and dimensional stability of epoxy resin(EP)in-situ modified by cyanate ester(CE)and polydimethylsiloxane(PDMS)are investigated by means of experiments and numerical simulation.Thermal gravimetric analysis...The thermal and dimensional stability of epoxy resin(EP)in-situ modified by cyanate ester(CE)and polydimethylsiloxane(PDMS)are investigated by means of experiments and numerical simulation.Thermal gravimetric analysis(TGA)and differential scanning calorimeter(DSC)are used to analyze the heat resistance of the modified EP.The dimensional stability is characterized by the volume shrinkage of the series PDMS/CE/EP obtained by the density method.The chemical structure of the PDMS/CE/EP is analyzed by Fourier transform infrared spectroscopy(FTIR).The results of TGA and DSC indicate that the thermal stability of PDMS/CE/EP decreases firstly and then increases with the increase in the amount of CE.The addition of PDMS shows a slight effect on the thermal stability.The 40%CE makes the blending system exhibit the lowest initial decomposition temperature,which reduces by 15.5%and 40.8%compared with pure EP and CE,respectively.The FTIR results suggested that the influence of CE on the thermal stability of the modified EP is mainly ascribed to the generation of oxazolidinone ring with low thermal stability and the increase in the triazine ring with high thermal stability.The volume shrinkage measurement results show that the introduction of CE and PDMS are both beneficial to the improvement of the dimensional stability of the blending systems.The in-situ addition of 80%CE shows the lowest volume shrinkage of6.11%.The thermal stress distribution of PDMS/CE/EP generated during the solidification process is simulated by the finite element analysis.The results suggested that the introduction of 80%CE into EP results in the lowest thermal stress in the blending system,which indicates that the system has the lowest volume shrinkage,which agrees well with the experimental results.展开更多
Microstructures and mechanical properties of Ti-V micro-alloyed TRIP( transformation-induced plasticity) steel with different compositions were investigated by tensile test,scanning electron microscopy( SEM),trans...Microstructures and mechanical properties of Ti-V micro-alloyed TRIP( transformation-induced plasticity) steel with different compositions were investigated by tensile test,scanning electron microscopy( SEM),transmission electron microscopy( TEM),X-ray diffraction( XRD) and thermodynamic calculation( TC). The results indicated that the steel exhibited high ultimate tensile strength( 1 079MPa),sufficient ductility( 28%) and the highest product of strength and ductility( 30 212 MPa·%) heat treated after intercritical annealing at 800℃ for 3 min and bainitic annealing at 430 ℃ for 5 min. In addition,the change of volume fraction of retained austenite( VF-RA) versus tensile strain was measured using in-situ analysis by X-ray stress apparatus and micro-electronic universal testing machine. It was concluded that a-value could be used to evaluate the stability of retained austenite( S-RA) in the investigated Ti-V micro-alloyed TRIP steel. The smaller a-value indicated the higher stability of retained austenite( S-RA) and the higher mechanical properties of Ti-V micro-alloyed TRIP steel.展开更多
The supergiant Shuangjianzishan(SJZ) Ag-Pb-Zn deposit is in the southern segment of the Great Hinggan Range(SGHR), northeast China. Previous studies suggest the ore-forming material and fluid originated from the magma...The supergiant Shuangjianzishan(SJZ) Ag-Pb-Zn deposit is in the southern segment of the Great Hinggan Range(SGHR), northeast China. Previous studies suggest the ore-forming material and fluid originated from the magmatic system, and the mineralization age was consistent with the diagenetic age. However,the relationship between granitic magmatism and mineralization is still unclear in the SJZ. In this study, CH-O-He-Ar and in-situ S-Pb isotope analyses were conducted to determine the sources of ore-forming fluids and metals, which were combined with geochemistry data of SJZ granitoids from previous studies to constrain the relationship between the magmatism and the mineralization. The C-H-O-He-Ar-S-Pb isotopic compositions suggested the SJZ ore-forming material and fluids were derived from a magmatic source, which has mixed a small amount of mantle-derived materials. In addition, the disseminated sulfide from the syenogranite has comparable S-Pb isotopic composition with the sulfide minerals from ore veins,suggesting that the generation of the SJZ ore-forming fluids has a close relationship with the syenogranite magmatism. Combining with the geochemical characters of the syenogranite, the authors proposed that the mantle-derived fingerprint of the SJZ ore-forming fluid might be caused by the parent magma of the syenogranite, which was derived from partial melting of the juvenile lower crust, and underwent the residual melts segregated from a crystal mush in the shallow magma reservoir. The extraction of the syenogranite parent magma further concentrated the fertilized fluids, which was crucial to mineralization of the SJZ Ag-Pb-Zn deposit.展开更多
The outstanding tribological performance of transition metal dichalcogenides(TMDs)is attributed to their unique sandwich microstructure and low interlayer shear stress.This advantageous structure allows TMDs to demons...The outstanding tribological performance of transition metal dichalcogenides(TMDs)is attributed to their unique sandwich microstructure and low interlayer shear stress.This advantageous structure allows TMDs to demonstrate exceptional friction reduction properties.Furthermore,the incorporation of TMDs and amorphous carbon(a-C)in multi-layer structures shows excellent potential for further enhancing tribological and anti-oxidation properties.Amorphous carbon,known for its high ductility,chemical inertness,and excellent wear resistance,significantly contributes to the overall performance of these multi-layer coatings.To gain an in-depth understanding of the tribological mechanism and evolution of TMDs’multi-layer coatings,a dual in-situ analysis was carried out using a tribometer equipped with a 3D laser microscope and a Raman spectrometer.This innovative approach allowed for a comprehensive evolution of the tribological,topographical,and tribochemical characteristics of both single-layer WS_(2)and multi-layer WS_(2)/C coatings in real time.The findings from the dual in-situ tribotest revealed distinct failure characteristics between the single-layer WS_(2)coating and the multi-layer WS_(2)/C coating.The single-layer WS_(2)coating predominantly experienced failure due to mechanical removal,whereas a combination of mechanical removal and tribochemistry primarily influenced the failure of the multi-layer WS_(2)/C coating.The tribological evolution process of these two coatings can be classified into four stages on the basis of their tribological behavior:the running-in stage,stable friction stage,re-deposition stage,and lubrication failure stage.Each stage represents a distinct phase in the tribological behavior of the coatings and contributes to our understanding of their behavior during sliding.展开更多
Despite the intriguing merits of lithium-sulfur(Li-S) systems, they still suffer from the notorious‘‘shuttling-effect" of polysulfides. Herein, carbon materials with rational tailoring of morphology and pores w...Despite the intriguing merits of lithium-sulfur(Li-S) systems, they still suffer from the notorious‘‘shuttling-effect" of polysulfides. Herein, carbon materials with rational tailoring of morphology and pores were designed for strong loading/adsorption with the controlling of energy-storage ability.Through rational tailoring, it is strongly verified that such engineering of evolutions result in variational of sulfur immobilization in the obtained carbon. As expected, the targeted sample delivers a stable capacity of 925 m Ah g^(-1) after 100 loops. Supporting by the "cutting-off" manners, it is disclosed that mesopores in carbon possess more fascinated traits than micro/macropores in improving the utilization of sulfur and restraining Li_(2)S_x(4≤x≤8). Moreover, the long-chain polysulfide could be further consolidated by auto-doping oxygen groups. Supported by in-depth kinetic analysis, it is confirmed that the kinetics of ion/e-transfer during charging and discharging could be accelerated by mesopores, especially in stages of the formation of solid S_(8) and Li_(2)S, further improving the capacity of ion-storage in Li-S battery. Given this, the elaborate study provide significant insights into the effect of pore structure on kinetic performance about Li-storage behaviors in Li-S battery, and give guidance for improving sulfur immobilization.展开更多
The Sanjiu uranium ore field,located in the central of Zhuguangshan granitic batholith,is a newly discovered granite-related uranium ore field in South China.The main sulfide in the ore field is pyrite,which is closel...The Sanjiu uranium ore field,located in the central of Zhuguangshan granitic batholith,is a newly discovered granite-related uranium ore field in South China.The main sulfide in the ore field is pyrite,which is closely related to uranium mineralization.The textures major and trace elements,S-He-Ar isotopes compositions of pyrites in ores of different grade were observed and/or analyzed by optical microscope,scanning electron microscope,electron microprobe,laser ablation inductively coupled plasma mass spectrometry,and noble gas mass spectrometer(Helix-SFT).It is observed that these U-related pyrites are generally euhedral-subhedral with dissolution textures,anhedral variety with colloform texture veinlet and fine particles,and the color of the associated minerals is mostly dark hue,such as purple-black fluorite dark-red hematite,and dark-green chlorite,etc.The analytical results show that the average compositions of major elements in pyrite are FeS1.944.Pyrites are characterized by S-deficiency,low content of Co and Th,and Co/Ni>1which indicate that these ores are of low-temperature hydrothermal origin.We found that the higher the grade of ore,the more deficient in S,the more obvious negative δ^34S,and the higher REE content(close to U-rich granitic pluton)of pyrite.The S-He-Ar isotopic compositions of various varieties of pyrites indicate that the ore-forming fluids mainly come from crust-derived fluids and mixed with mantle-derived fluids.展开更多
Smith fir (Abies georgei var. smithii), which is the timberline constructive tree species in the cool slope of Mt. Sygera in the southeast ofTibet, plays a very important role in maintaining the timberline completen...Smith fir (Abies georgei var. smithii), which is the timberline constructive tree species in the cool slope of Mt. Sygera in the southeast ofTibet, plays a very important role in maintaining the timberline completeness and indicating global climate change. This study uses theinstrumental recorded meteorological data along the altitude from 3600 to 4400 m at every 200 m in the growing season, investigates the smithfir growth biomass from 2006 to 2010 in the same timberline ecotone, and makes a non-linear regression analysis to determine the relationshipbetween the alpine tree growth biomass and its in-situ environment condition. The results showed that the cool and warm slope share different airtemperature lapse rates, which were 0.48 C (100 m)1 in the warm slope and 0.54 C (100 m)1 in the cool slope, respectively. However, thedominant timberline tree species in the warm slope was Sabina saltuaria, and it can reach as high as 4570 m, which is approximately 170 mhigher than that in the cool slope. Moreover, the smith fir in the cool slope was only distributed in the range of elevation from approximately3600 to 4400 m. The altitude of approximately 3800 m was the appropriate altitude for the growing smith fir, where the mean air temperature inthe growing season was about 9.0 C, and the young smith fir tree can form more biomass. The results suggested that alpine forest chose asuitable environment where trees can grow more in the prolonged succession, but not in the warmer or cooler condition, it could be seen as abiological evidence for climate change.展开更多
基金financially supported by the Western Transport Technical Project of the Ministry of Transport, China (No. 2009318000046)
文摘A multivariable regression analysis of the in-situ stress field, which considers the non-linear deformation behavior of faults in practical projects, is presented based on a newly developed three-dimensional displacement discontinuity method (DDM) program. The Bar- ton-Bandis model and the Kulhaway model are adopted as the normal and the tangential deformation model of faults, respectively, where the Mohr-Coulomb failure criterion is satisfied. In practical projects, the values of the mechanical parameters of rock and faults are restricted in a bounded range for in-situ test, and the optimal mechanical parameters are obtained from this range by a loop. Comparing with the traditional finite element method (FEM), the DDM regression results are more accurate.
基金the National Natural Science Foundation of China(21975154)the Shanghai Municipal Education Commission(Innovation Program(2019-01-07-00-09E00021)+2 种基金Innovative Research Team of High-level Local Universities in Shanghaisupported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher LearningShanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power。
文摘With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges on its poor intrinsic electronic conductivity and the controversial de/sodiation mechanism.Herein,a series of Zr-doped NVPF coated by N-doped carbon layer(~5 nm in thickness,homogenously)materials are fabricated by a sol-gel method,and the optimized heteroatom-doping amounts of Zr and N doping improve intrinsic properties on enlarging lattice distance and enhancing electronic conductivity,respectively.Specifically,among all samples of Na_(3) V_(2-x)Zr_(x)(PO_(4))_(2) F_(3)/NC(NVPF-Zr-x/NC,x=0,0.01,0.02,0.05,and 0.1),the optimized electrode of NVPF-Zr-0.02/NC delivers high reversible capacities(119.2 mAh g^(-1) at0.5 C),superior rate capability(98.1 mA h g^(-1) at 20 C)and excellent cycling performance.The structural evolution of NVPF-Zr-0.02/NC electrode,in-situ monitored by X-ray diffractometer,follows a step-wise Na-extraction/intercalation mechanism with reversible multi-phase changes,not just a solid-solutionreaction one.Full cells of NVPF-Zr-0.02/NC//hard carbon demonstrate high capacity(99.8 mA h g^(-1) at 0.5 C),high out-put voltage(3.5 V)and good cycling stability.This work is favorable to accelerate the development of high-performance cathode materials and explore possible redox reaction mechanisms of SIBs.
基金Supported by the National Natural Science Foundation of China
文摘The Chang'e-3 Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the four payloads on the Yutu rover. After traversing the landing site during the first two lunar days, four different areas are detected, and Level 2A and 2B ra- diance data have been released to the scientific community. The released data have been processed by dark current subtraction, correction for the effect of temperature, radiometric calibration and geometric calibration. We emphasize approaches for re- flectance analysis and mineral identification for in-situ analysis with VNIS. Then the preliminary spectral and mineralogical results from the landing site are derived. After comparing spectral data from VNIS with data collected by the Ma instrument and samples of mare that were returned from the Apollo program, all the reflectance data have been found to have similar absorption features near 1000 nm except lunar sample 71061. In addition, there is also a weak absorption feature between 1750-2400nm on VNIS, but the slopes of VNIS and Ma reflectance at longer wavelengths are lower than data taken from samples of lunar mare. Spectral parameters such as Band Centers and Integrated Band Depth Ratios are used to analyze mineralogical features. The results show that detection points E and N205 are mixtures of high-Ca pyroxene and olivine, and the composition of olivineat point N205 is higher than that at point E, but the compositions of detection points S3 and N203 are mainly olivine-rich. Since there are no obvious absorption features near 1250 nm, plagioclase is not directly identified at the landing site.
基金supported by Basic Science Research Project of Colleges and Universities in Liaoning Province in China (No. LG201714)。
文摘Lightweight hybrid structures of Al MMCs and titanium alloy dissimilar materials have great prospect in the defence industry application. So, it is necessary to join Al MMCs with Ti metal to achieve this structural design. In this work, in-situ Ti B_(2)/7050 composite and TA2 were firstly attempted to join by TIG welding-brazing technique. The result was that the intact welding-brazing butt joint was successfully fabricated. The joint presents dual characteristics, being a brazing on TA2 side and a welding on Ti B_(2)/7050 side. At brazing joint side, ER4043 filler metal effectively wets on TA2 under TIG heating condition,and a continuous interfacial reaction layer with 1 e3 mm is formed at welded metal/TA2 interface. The whole interfacial reaction layers are composed of Ti(Al Si)3 intermetallic compounds(IMCs), but their morphologies at the different regions present obvious distinguishes. The microhardness of the reaction layers is as much as 141 e190 HV. At welding joints side, the fusion zone appears the equixaed crystal structure, and the grain sizes are much smaller than those of welded metal, which is attributed to the effect of Ti B2 particulates from the melted Ti B_(2)/7050 on acceleration formation and inhibiting growth for the new crystal nucleus. The tensile test results show that average tensile strength of the optimal welding-brazing joint is able to achieve 138 MPa. The failure of the tensile joint occurs by quasi-cleavage pattern, and the cracks initiate from the IMCs layer at the groove surface of TA2 and propagate into the welded metal.
文摘This paper presents a generic procedure to implement a scalable and high performance data analysis framework for large-scale scientific simulation within an in-situ infrastructure. It demonstrates a unique capability for global Earth system simulations using advanced computing technologies (i.e., automated code analysis and instrumentation), in-situ infrastructure (i.e., ADIOS) and big data analysis engines (i.e., SciKit-learn). This paper also includes a useful case that analyzes a globe Earth System simulations with the integration of scalable in-situ infrastructure and advanced data processing package. The in-situ data analysis framework can provides new insights on scientific discoveries in multiscale modeling paradigms.
基金financially supported by the Natural Science Foundation of Guangxi Province(No.2015GXNSFAA139031)the Program for the scientific research,technology development plan of Guilin(No.20150133-5)Program of the Collaborative Innovation Center for Exploration of Hidden Nonferrous Metal Deposits and Development of New Materials in Guangxi(No.gxysxtzx 2017-II-3)
文摘A novel copper complex [Cu2(L)(DMF)2](1, H4L =(1 Z,N?Z)-3,5-dibromo-N?-((3,5-dibromo-2-hydroxyphenyl)(hydroxy)methylene)-2-hydroxybenzohydrazonic acid which was synthesized by in-situ oxidation reaction derived from H2hdb(H2hdb = 6,6′-((1 E,1?E)-hydrazine-1,2-diylidenebis(methanylylidene)) bis(2,4-dibromophenol)) has been synthesized and characterized by IR, elemental analysis(CHN), TG and single-crystal X-ray diffraction. The single crystal belongs to monoclinic system, space group P21/c with a = 13.538(1), b = 3.912(1), c = 23.778(1)A°, β = 105.232(5)o, Mr = 857.08, V = 1214.9(1) A°^3, Z = 2, Dc = 2.343 g/cm^3, F(000) = 824, μ = 8.375 mm^–1, R = 0.0566, and w R = 0.1610. Compound 1 displays weak anti-ferromagnetic interactions through a η^1:η^1:η^1:η^1:η^1:η^1:μ2-L^4- bridging mode. Hirshfeld surface analysis revealed that complex 1 was supported mainly by Br···H and H···H intermolecular interactions.
基金Supported by the Public Welfare Research Program of State Environmental Protection Administration(200909065)
文摘In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points and monitoring factors in thegraphic on the same factor axis can clearly express the intrinsic link between pollutantsand monitoring points and distribution characteristics.To determine the main monitoringpoint and the main monitoring indicators can reduce and optimize the number of monitoringpoints under the premise of ensuring the typical and representative of monitoring data.Using the correlation of pollutants can reduce the number of monitoring indicators and improvethe effectiveness of data collection.
基金provided by the National Natural Science Foundation of China – China (No. 41274100)the Fundamental Research Fund for State Level Scientific Institutes (No. ZDJ2012-20)
文摘The prediction of the stress field of deep-buried tunnels is a fundamental problem for scientists and engineers. In this study, the authors put forward a systematic solution for this problem. Databases from the World Stress Map and the Crustal Stress of China, and previous research findings can offer prediction of stress orientations in an engineering area. At the same time, the Andersonian theory can be used to analyze the possible stress orientation of a region. With limited in-situ stress measurements, the Hock-Brown Criterion can be used to estimate the strength of rock mass in an area of interest by utilizing the geotechnical investigation data, and the modified Sheorey's model can subsequently be employed to predict the areas' stress profile, without stress data, by taking the existing in-situ stress measurements as input parameters. In this paper, a case study was used to demonstrate the application of this systematic solution. The planned Kohala hydropower plant is located on the western edge of Qinghai-Tibet Plateau. Three hydro-fracturing stress measurement campaigns indicated that the stress state of the area is SH - Sh 〉 Sv or SH 〉Sv 〉 Sh. The measured orientation of Sn is NEE (N70.3°-89°E), and the regional orientation of SH from WSM is NE, which implies that the stress orientation of shallow crust may be affected by landforms. The modified Sheorey model was utilized to predict the stress profile along the water sewage tunnel for the plant. Prediction results show that the maximum and minimum horizontal principal stres- ses of the points with the greatest burial depth were up to 56.70 and 40.14 MPa, respectively, and the stresses of areas with a burial depth of greater than 500 m were higher. Based on the predicted stress data, large deformations of the rock mass surrounding water conveyance tunnels were analyzed. Results showed that the large deformations will occur when the burial depth exceeds 300 m. When the burial depth is beyond 800 m, serious squeezing deformations will occur in the surrounding rock masses, thus requiring more attention in the design and construction. Based on the application efficiency in this case study, this prediction method proposed in this paper functions accurately.
基金supported by the National Natural Science Foundation of China(21808124,22075029)by Beijing Natural Science Foundation(JQ20004)+2 种基金by Scientific and Technological Key Project of Shanxi Province(20191102003)the Seed Fund of Shanxi Research Institute for Clean Energy(SXKYJF015)the Shuimu Tsinghua Scholar Program,and Tsinghua University Initiative Scientific Research Program。
文摘Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since lithium plating behavior is determined by diverse factors. In this contribution, we present a non-destructive electrochemical detection method based on transient state analysis and threeelectrode cell configuration. Through dividing the iR drop value by the current density, the as-obtained impedance quantity(R_(i)) can serve as a descriptor to describe the change of electrochemical reaction impedance on the graphite anode. The onset of lithium plating can be identified from the sharp drop of R_(i). Once the dendritic plated lithium occurs, the extra electrochemical reactions at the lithium interfaces leads to growing active area and reduced surface resistance of the anode. We proposed a protocol to operate the batteries under the limited capacity, which renders the cell with 98.2% capacity retention after 1000 cycles without lithium plating. The early-warning method has also been validated in in-situ optical microscopy batteries and practical pouch cells, providing a general but effective method for online lithium plating detection towards safe batteries.
基金jointly supported by the National Key Research and Development Program of China(No.2019YFC1804304)the National Natural Science Foundation of China(Nos.2167212,41772254)。
文摘CO_(2)+O_(2) in-situ leaching(ISL)of sandstonetype uranium ore represents the third generation of solution mining in China.In this study,reactive transport modeling of the interaction between hydrodynamic and geochemical reactions is performed to enable better prediction and regulation of the CO_(2)+O_(2) in-situ leaching process of uranium.Geochemical reactions between mining solutions and rock,and the kinetic uranium dissolution controlled by O_(2)(aq)and bicarbonate(HCO_(3)-)are considered in the CO_(2)+O_(2) ISL reactive transport model of a typical sandstone-hosted uranium ore deposit in northern China.The reactive leaching of uranium is most sensitive to the spatial distribution of the mineralogical properties of the uranium deposit.Stochastic geostatistical models are used to represent the uncertainty on the spatial distribution of mineral grades.A Monte Carlo analysis was also performed to simulate the uranium production variability over an entire set of geostatistical realizations.The ISL stochastic simulation performed with the selected geostatistical realizations approximates the uranium production variability well.The simulation results of the ISL reactive transport model show that the extent of the uranium plume is highly dependent on mineralogical heterogeneity.The uncertainty analysis suggests the effect of uranium grade heterogeneity was found to be important to improve the accurate capture of the uncertainty.This study provides guidance for the accurate simulation and dynamic regulation of the CO_(2)+O_(2) leaching process of uranium at the scale of large mining areas.
文摘Using PTFE as a chemical modifier, a method for the determination of trace impurities in high purity Nd_2O_3 by in-situ separation and electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) was developed. The analyte-matrix separation and the temperature program of graphite furnace were investigated and optimized. The solid samples were directly introduced into graphite furnace in the form of slurry, where selective volatilization between the matrix and the analytes took place. The Nd matrix was retained in the graphite furnace during the evaporation step, while the trace analyte impurities were vaporized and removed. As a result, the matrix interference that is serious without the modifier is suppressed effectively. The achievable detection limits are (μg·g^(-1)): Ti 0.15, Mn 0.15, Ni 0.20, Co 0.54, respectively. The proposed method was applied to direct determination of trace impurities in high purity Nd_2O_3 with satisfactory results.
基金supported in part by the National Natural Science Foundations of China (Nos.51708422, 51678446,51408434)China Scholarship Council and cole Nationale des Ponts et Chaussées,for providing necessary financial assistance to LI Qiutong to pursue her Ph.D.in France
文摘Many countries which seek to understand the acoustic performance of railway noise barriers have established standards for the conduct of in-situ experiments.However,there are no universally acknowledged receiver positions for the evaluation of the barrier performance,a fact which may be leading to uncertainty over the noise reduction capabilities of available barriers.In terms of the descriptor of the barrier performance,the general recommendation is the A-weighted sound pressure level,although the latter is considered to underestimate low frequencies for railway noise barrier.Thus,in this study,the comparison of receiver positions and the descriptors among existing Chinese,ISO and European standards were investigated.Based upon a combination of diffraction theory and standards,a rearrangement of receiver positions and one-third-octave-band analysis were proposed.In addition,in line with improved methods,an in-situ measurement of insertion loss for a 1.5 mhigh railway noise barrier was designed and conducted.The results of the experiment validate as effective and applicable the new receiver positions.These results also suggest that one-third-octave-band analysis is indispensable.
文摘Crystallization behavior and kinetics study of palm kernel oil (PKO) were investigated using differential scanning calorimetry (DSC) by controlling cooling and reheating rate within a certain range of temperature. The evolution of morphology and particle counts was analyzed by focused beam reflectance measurement (FBRM) and particles video microscope (PVM) at the nucleation stage during suspension crystallization. The particle counts and morphological evolution from needle-like aggregations to amorphous form from PVM were observed during the initial crystallization stage, which meant that a phase transition was likely to occur. This work can give a better understanding of complicated fat system crystallization behavior and provide some critical instructions to control fractionation process.
基金the Shanghai Aerospace Science and Technology Innovation Fund of China(No.SAST2019-122)。
文摘The thermal and dimensional stability of epoxy resin(EP)in-situ modified by cyanate ester(CE)and polydimethylsiloxane(PDMS)are investigated by means of experiments and numerical simulation.Thermal gravimetric analysis(TGA)and differential scanning calorimeter(DSC)are used to analyze the heat resistance of the modified EP.The dimensional stability is characterized by the volume shrinkage of the series PDMS/CE/EP obtained by the density method.The chemical structure of the PDMS/CE/EP is analyzed by Fourier transform infrared spectroscopy(FTIR).The results of TGA and DSC indicate that the thermal stability of PDMS/CE/EP decreases firstly and then increases with the increase in the amount of CE.The addition of PDMS shows a slight effect on the thermal stability.The 40%CE makes the blending system exhibit the lowest initial decomposition temperature,which reduces by 15.5%and 40.8%compared with pure EP and CE,respectively.The FTIR results suggested that the influence of CE on the thermal stability of the modified EP is mainly ascribed to the generation of oxazolidinone ring with low thermal stability and the increase in the triazine ring with high thermal stability.The volume shrinkage measurement results show that the introduction of CE and PDMS are both beneficial to the improvement of the dimensional stability of the blending systems.The in-situ addition of 80%CE shows the lowest volume shrinkage of6.11%.The thermal stress distribution of PDMS/CE/EP generated during the solidification process is simulated by the finite element analysis.The results suggested that the introduction of 80%CE into EP results in the lowest thermal stress in the blending system,which indicates that the system has the lowest volume shrinkage,which agrees well with the experimental results.
基金supported by the Shanghai Municipal Science and Technology Commission(Grant No.15DZ2260300,15DZ2260301)Shanghai Municipal Natural Science Foundation(17ZR1410400)
文摘Microstructures and mechanical properties of Ti-V micro-alloyed TRIP( transformation-induced plasticity) steel with different compositions were investigated by tensile test,scanning electron microscopy( SEM),transmission electron microscopy( TEM),X-ray diffraction( XRD) and thermodynamic calculation( TC). The results indicated that the steel exhibited high ultimate tensile strength( 1 079MPa),sufficient ductility( 28%) and the highest product of strength and ductility( 30 212 MPa·%) heat treated after intercritical annealing at 800℃ for 3 min and bainitic annealing at 430 ℃ for 5 min. In addition,the change of volume fraction of retained austenite( VF-RA) versus tensile strain was measured using in-situ analysis by X-ray stress apparatus and micro-electronic universal testing machine. It was concluded that a-value could be used to evaluate the stability of retained austenite( S-RA) in the investigated Ti-V micro-alloyed TRIP steel. The smaller a-value indicated the higher stability of retained austenite( S-RA) and the higher mechanical properties of Ti-V micro-alloyed TRIP steel.
基金supported financially by the China Geological Survey project [DD20160123 (DD-16-049, D1522), DD20160050, DD20190370]the Fundamental Research Funds for the Central Universities (310827171122)the National Natural Science Foundation of China (Grant 41672068)。
文摘The supergiant Shuangjianzishan(SJZ) Ag-Pb-Zn deposit is in the southern segment of the Great Hinggan Range(SGHR), northeast China. Previous studies suggest the ore-forming material and fluid originated from the magmatic system, and the mineralization age was consistent with the diagenetic age. However,the relationship between granitic magmatism and mineralization is still unclear in the SJZ. In this study, CH-O-He-Ar and in-situ S-Pb isotope analyses were conducted to determine the sources of ore-forming fluids and metals, which were combined with geochemistry data of SJZ granitoids from previous studies to constrain the relationship between the magmatism and the mineralization. The C-H-O-He-Ar-S-Pb isotopic compositions suggested the SJZ ore-forming material and fluids were derived from a magmatic source, which has mixed a small amount of mantle-derived materials. In addition, the disseminated sulfide from the syenogranite has comparable S-Pb isotopic composition with the sulfide minerals from ore veins,suggesting that the generation of the SJZ ore-forming fluids has a close relationship with the syenogranite magmatism. Combining with the geochemical characters of the syenogranite, the authors proposed that the mantle-derived fingerprint of the SJZ ore-forming fluid might be caused by the parent magma of the syenogranite, which was derived from partial melting of the juvenile lower crust, and underwent the residual melts segregated from a crystal mush in the shallow magma reservoir. The extraction of the syenogranite parent magma further concentrated the fertilized fluids, which was crucial to mineralization of the SJZ Ag-Pb-Zn deposit.
基金the fund of LICP Cooperation Foundation for Young Scholars(GrantNo.HZJJ22-03)the financial support provided by China National Natural Science Foundation(Grant No.52075521)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0470102)Natural Science Foundation of Shandong Province(Grant No.022HWYQ-096)LICP International Cooperative Scholarship,and the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Grant No.2020R1A2C2004714).
文摘The outstanding tribological performance of transition metal dichalcogenides(TMDs)is attributed to their unique sandwich microstructure and low interlayer shear stress.This advantageous structure allows TMDs to demonstrate exceptional friction reduction properties.Furthermore,the incorporation of TMDs and amorphous carbon(a-C)in multi-layer structures shows excellent potential for further enhancing tribological and anti-oxidation properties.Amorphous carbon,known for its high ductility,chemical inertness,and excellent wear resistance,significantly contributes to the overall performance of these multi-layer coatings.To gain an in-depth understanding of the tribological mechanism and evolution of TMDs’multi-layer coatings,a dual in-situ analysis was carried out using a tribometer equipped with a 3D laser microscope and a Raman spectrometer.This innovative approach allowed for a comprehensive evolution of the tribological,topographical,and tribochemical characteristics of both single-layer WS_(2)and multi-layer WS_(2)/C coatings in real time.The findings from the dual in-situ tribotest revealed distinct failure characteristics between the single-layer WS_(2)coating and the multi-layer WS_(2)/C coating.The single-layer WS_(2)coating predominantly experienced failure due to mechanical removal,whereas a combination of mechanical removal and tribochemistry primarily influenced the failure of the multi-layer WS_(2)/C coating.The tribological evolution process of these two coatings can be classified into four stages on the basis of their tribological behavior:the running-in stage,stable friction stage,re-deposition stage,and lubrication failure stage.Each stage represents a distinct phase in the tribological behavior of the coatings and contributes to our understanding of their behavior during sliding.
基金financially supported by National National Key Research and Development Program of China (2019YFC1907801, 2018YFC1900305, 2018YFC1901601, 2018YFC1901602)the Natural Science Foundation of China (52004334, 51622406, 51634009 and U1704252)+4 种基金National 111 Project (No. B14034)the National Key R&D Program of China (2018YFC1901901)the Collab-orative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources, Found of State Key Laboratory of Mineral Processing (BGRIMM-KJSKL-2017-13)the Fundamental Research Funds for the Central Universities of Central South University (2019zzts1712020zzts203)the Hunan Provincial Innovation Foundation for Postgraduate (CX20190227)。
文摘Despite the intriguing merits of lithium-sulfur(Li-S) systems, they still suffer from the notorious‘‘shuttling-effect" of polysulfides. Herein, carbon materials with rational tailoring of morphology and pores were designed for strong loading/adsorption with the controlling of energy-storage ability.Through rational tailoring, it is strongly verified that such engineering of evolutions result in variational of sulfur immobilization in the obtained carbon. As expected, the targeted sample delivers a stable capacity of 925 m Ah g^(-1) after 100 loops. Supporting by the "cutting-off" manners, it is disclosed that mesopores in carbon possess more fascinated traits than micro/macropores in improving the utilization of sulfur and restraining Li_(2)S_x(4≤x≤8). Moreover, the long-chain polysulfide could be further consolidated by auto-doping oxygen groups. Supported by in-depth kinetic analysis, it is confirmed that the kinetics of ion/e-transfer during charging and discharging could be accelerated by mesopores, especially in stages of the formation of solid S_(8) and Li_(2)S, further improving the capacity of ion-storage in Li-S battery. Given this, the elaborate study provide significant insights into the effect of pore structure on kinetic performance about Li-storage behaviors in Li-S battery, and give guidance for improving sulfur immobilization.
基金supported by the Science and Technology Research Project of China Nuclear Geology(No.2110400024)Uranium Geological Exploration Fund Project of China National Nuclear Corporation(No.J2012-03)+1 种基金Uranium Mine Exploration Project of Hunan Nuclear Geology(No.DK30620170512)Scientific Research Program of Hunan Nuclear Geology(No.KYQ-306-01)。
文摘The Sanjiu uranium ore field,located in the central of Zhuguangshan granitic batholith,is a newly discovered granite-related uranium ore field in South China.The main sulfide in the ore field is pyrite,which is closely related to uranium mineralization.The textures major and trace elements,S-He-Ar isotopes compositions of pyrites in ores of different grade were observed and/or analyzed by optical microscope,scanning electron microscope,electron microprobe,laser ablation inductively coupled plasma mass spectrometry,and noble gas mass spectrometer(Helix-SFT).It is observed that these U-related pyrites are generally euhedral-subhedral with dissolution textures,anhedral variety with colloform texture veinlet and fine particles,and the color of the associated minerals is mostly dark hue,such as purple-black fluorite dark-red hematite,and dark-green chlorite,etc.The analytical results show that the average compositions of major elements in pyrite are FeS1.944.Pyrites are characterized by S-deficiency,low content of Co and Th,and Co/Ni>1which indicate that these ores are of low-temperature hydrothermal origin.We found that the higher the grade of ore,the more deficient in S,the more obvious negative δ^34S,and the higher REE content(close to U-rich granitic pluton)of pyrite.The S-He-Ar isotopic compositions of various varieties of pyrites indicate that the ore-forming fluids mainly come from crust-derived fluids and mixed with mantle-derived fluids.
文摘Smith fir (Abies georgei var. smithii), which is the timberline constructive tree species in the cool slope of Mt. Sygera in the southeast ofTibet, plays a very important role in maintaining the timberline completeness and indicating global climate change. This study uses theinstrumental recorded meteorological data along the altitude from 3600 to 4400 m at every 200 m in the growing season, investigates the smithfir growth biomass from 2006 to 2010 in the same timberline ecotone, and makes a non-linear regression analysis to determine the relationshipbetween the alpine tree growth biomass and its in-situ environment condition. The results showed that the cool and warm slope share different airtemperature lapse rates, which were 0.48 C (100 m)1 in the warm slope and 0.54 C (100 m)1 in the cool slope, respectively. However, thedominant timberline tree species in the warm slope was Sabina saltuaria, and it can reach as high as 4570 m, which is approximately 170 mhigher than that in the cool slope. Moreover, the smith fir in the cool slope was only distributed in the range of elevation from approximately3600 to 4400 m. The altitude of approximately 3800 m was the appropriate altitude for the growing smith fir, where the mean air temperature inthe growing season was about 9.0 C, and the young smith fir tree can form more biomass. The results suggested that alpine forest chose asuitable environment where trees can grow more in the prolonged succession, but not in the warmer or cooler condition, it could be seen as abiological evidence for climate change.