Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storag...Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.展开更多
The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college ...The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college teachers. In this paper, the ＂impact factor structure of university teachers LMX Questionnaire＂ for four universities 808 subjects was investigated. By exploratory factor analysis and confirmatory factor analysis, it found that the structure of university teachers LMX factors includes five dimensions： values, attitudes up, personality characteristics, switching behavior, objective situations. The questionnaire has good reliability and validity.展开更多
A procedure to recognize individual discontinuities in rock mass from measurement while drilling(MWD)technology is developed,using the binary pattern of structural rock characteristics obtained from in-hole images for...A procedure to recognize individual discontinuities in rock mass from measurement while drilling(MWD)technology is developed,using the binary pattern of structural rock characteristics obtained from in-hole images for calibration.Data from two underground operations with different drilling technology and different rock mass characteristics are considered,which generalizes the application of the methodology to different sites and ensures the full operational integration of MWD data analysis.Two approaches are followed for site-specific structural model building:a discontinuity index(DI)built from variations in MWD parameters,and a machine learning(ML)classifier as function of the drilling parameters and their variability.The prediction ability of the models is quantitatively assessed as the rate of recognition of discontinuities observed in borehole logs.Differences between the parameters involved in the models for each site,and differences in their weights,highlight the site-dependence of the resulting models.The ML approach offers better performance than the classical DI,with recognition rates in the range 89%to 96%.However,the simpler DI still yields fairly accurate results,with recognition rates 70%to 90%.These results validate the adaptive MWD-based methodology as an engineering solution to predict rock structural condition in underground mining operations.展开更多
The structure factors of any crystal structure can be simulated from its atomic coordinates (and temperature factors) in a SHELXL-97 run on a dummy hkl in which only the scale factor is refined. The squares of the str...The structure factors of any crystal structure can be simulated from its atomic coordinates (and temperature factors) in a SHELXL-97 run on a dummy hkl in which only the scale factor is refined. The squares of the structure factors are retrieved from the fcf, and such simulated data are used in the revision of the space groups of several incorrectly-refined crystal structures. Two cases, a P1 to P1 revision and a chemically-incorrect structure that is refined in a correct space group, are discussed.展开更多
We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve ...We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve the Gross-Pitaevskii equation and then the corresponding Bogoliubov equations. Our results show that three-body interactions can change both the Bogoliubov band structure and the dynamical structure factor dramatically, especially in the case of the two-body interaction being relatively small. Furthermore, when the optical lattice is strong enough, the analytical results, combined with the sum-rule approach, help us to understand that： the effects of three-body interactions on the static structure Ihctor can be significantly amplified by an optical lattice. Our predictions should be observable within the current Bragg spectroscopy experiment.展开更多
Diffusion has been systematically described as the main mechanism of chloride transport in reinforced concrete（RC） structure, especially when the concrete is in a saturated state. However, the single mechanism of di...Diffusion has been systematically described as the main mechanism of chloride transport in reinforced concrete（RC） structure, especially when the concrete is in a saturated state. However, the single mechanism of diffusion is not able to describe the actual chloride ingress in the nonsaturated concrete. Instead, it is dominated by the interaction of diffusion and convection. With the synergetic effects of various factors taken into account, this study aimed to modify and develop an analytical convection- diffusion coupling model for chloride transport in nonsaturated concrete. The model was verified by simulation of laboratory tests and field measurement. The results of comparison study demonstrate that the analytical model developed in this study is efficient and accurate in predicting the chloride profiles in the nonsaturated concrete.展开更多
Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instr...Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.展开更多
The role that a learner＇s native language plays in his or her second language acquisition （SLA） has been the focus of many researchers in the past few decades. The article provides a brief review of the literature ...The role that a learner＇s native language plays in his or her second language acquisition （SLA） has been the focus of many researchers in the past few decades. The article provides a brief review of the literature on the importance and the factors of native language influence in SLA.展开更多
Taking the hot working die steel （HWDS） 4Cr3Mo2NbVNi as an example, the phase electron structures （PES） and the biphase interface electron structures （BIES） of Mo2C and V4 C3 , which are two kinds of important c...Taking the hot working die steel （HWDS） 4Cr3Mo2NbVNi as an example, the phase electron structures （PES） and the biphase interface electron structures （BIES） of Mo2C and V4 C3 , which are two kinds of important carbides precipitated during tempering in steel were calculated, on the basis of the empirical electron theory of solids and molecules and the improved TFD theory. The influence of Mo2 C and V4 C3 on the mechanical properties of HWDS has been analyzed at electron structure level, and the fundamental reason that the characteristic of the PES and the BIES of carbides decides the behavior of them has been revealed.展开更多
The compressive behaviour of paper honeycombs is studied by means of an experimental analysis. Experiment results show how geometry aspects of hexagonal paper honeycombs, e.g. the height of paper honeycomb, the thickn...The compressive behaviour of paper honeycombs is studied by means of an experimental analysis. Experiment results show how geometry aspects of hexagonal paper honeycombs, e.g. the height of paper honeycomb, the thickness and length of honeycomb cell-wall, the drawing ratio of hexagonal honeycomb, affect the compressive properties of the paper honeycombs. It is in good agreement with the theory model. The constraint factor K of the critical buckling stress is mainly determined by the length of honeycomb cell-wail. It can be described as K=1.54 for B type paper honeycombs and K=3.32 for D type paper honeycombs. The plateau stress is the power exponent function of the thickness to length ratio of honeycomb cell-wall, and the experiment results show that the constant is 13.2 and the power exponent is 1.77. The research results can be used to characterize and improve efficiently the compressive properties of paper honeycombs.展开更多
Developing electrochemical energy storage devices with high energy and power densities,long cycling life,as well as low cost is of great significance.Hybrid metal-ion capacitors(MICs),commonly consisting of high energ...Developing electrochemical energy storage devices with high energy and power densities,long cycling life,as well as low cost is of great significance.Hybrid metal-ion capacitors(MICs),commonly consisting of high energy battery-type anodes and high power capacitor-type cathodes,have become a trade-off between batteries and supercapacitors.Tremendous efforts have been devoted to searching for high-performance electrode materials due to poor rate capability of anodes,low capacity of cathodes,and interior sluggish kinetic match.Carbon materials with large surface area,good electrical conductivity and stability have been considered to be ideal candidates for electrodes of MICs.In this review,the advanced carbon materials directly as cathodes and anodes of MICs are systematically summarized.Then,the key structural/chemical factors including the structure engineering,porous characteristics,and heteroatom incorporation for improving electrochemical performance of carbon materials are highlighted.Additionally,the challenges and opportunities for future research on carbon materials in MICs are also proposed.展开更多
In the analysis of how environmental regulation affects the comparative advantage of trade,existing literature ignores industry's inherent heterogeneity, which draws remarkably different conclusions. In view of th...In the analysis of how environmental regulation affects the comparative advantage of trade,existing literature ignores industry's inherent heterogeneity, which draws remarkably different conclusions. In view of this, the paper analyzed the mechanism of environmental regulation on the export quality of different industries from the perspective of factor input structure heterogeneity. Based on the panel data of China's manufacturing industry, the paper used the system generalized method of moments method to examine the heterogeneity influence of environmental regulation on manufacturing export quality. The study found that, first, environmental regulation affected the export quality upgrade of the manufacturing sector through offset effect and compensation effect, and the direction of the impact would mainly depend on the industry's factor input structure. Second, for industries with larger fixed-asset investment(FAI) ratio in the factor input structure, the current environmental regulation policy was not conducive to the export quality upgrading of the industries. However, there was a significant U-shaped dynamic relationship between them. As environmental regulations became stricter, when regulatory stringency went beyond the inflection point, the policy would promote the upgrading of export quality. But for industries with smaller proportion of FAI, environmental regulation exerted a favorable impact on the export quality upgrade, following a J-shaped marginal growth curve.Third, for industries with different factor input structure, their export quality had been effectively upgraded as expected by factors like human capital investment, independent R&D, technology introduction, and foreign direct investment; but raising per capita capital stock and expanding enterprise size did not produce significant direct impact on export quality upgrade. These conclusions remained robust after using different measurement methods and replacing with other variables. Therefore, this paper suggests that governments should take industry heterogeneity into consideration and formulate differentiated hierarchical environmental policies.Besides, they should strengthen the enforcement of the current environmental regulation policies. By doing so, enterprises are forced to improve their technology and product quality so that they can better cope with rising compliance costs, eliminate backward industries, and resolve excess capacity. In this way, the economic structure would be transformed and upgraded from the supply side.展开更多
Ferroelectric lead-free BaTi_(1-x)Zr_(x)O_(3)ceramic powder samples with various compositions(x=0,0.04,0.06)have been synthesized by conventional high-temperature solid-state reaction method at 1450℃for 10 h.Influenc...Ferroelectric lead-free BaTi_(1-x)Zr_(x)O_(3)ceramic powder samples with various compositions(x=0,0.04,0.06)have been synthesized by conventional high-temperature solid-state reaction method at 1450℃for 10 h.Influences of Zr doping on the inter-atomic bonding and charge density distributions inside the lattice structure of BaTiO_(3)were analyzed through powder X-ray diffraction(XRD)and maximum entropy method.Lattice parameter and cell volume values are found to be increasing with the incorporation of Zr content.Calculated average grain sizes are found to be in the range of 23-28 nm.Maximum entropy mapping of electron density analysis reveals the reduction in ionic nature along Ba-O bond and the enhancement of covalent nature along Ti-O bond.Energy band gap values were determined from ultraviolet-visible(UV-Vis)spectra.Surface morphology and microstructures of the samples were analyzed from scanning electron microscopy(SEM)micrographs.Particles with irregular sizes were observed in all the prepared ceramics.Stoichiometry of the samples was further confirmed by energydispersive X-ray spectroscopy(EDAX).展开更多
The effect of rare earth （RE） on bainite trans- formation mechanism is not yet unified in the academia. Therefore, further studying the effect of RE on bainite transformation mechanism will have important guiding si...The effect of rare earth （RE） on bainite trans- formation mechanism is not yet unified in the academia. Therefore, further studying the effect of RE on bainite transformation mechanism will have important guiding significance for the development of bainite steels. In this paper, using differential dilatometer （DIL805A/D）, heat treatment was performed and C-curve was drawn. The effect of phase structure factor on bainite transformation under two different fractions of RE in Si-Mn-Mo bainite steels was investigated by the empirical electron theory （EET） of solids, molecules, dilatometry, and metallogra- phy. Experimental results show that RE makes Fe-C- RE segregation structural unit of Si-Mn-Mo bainite steels increase, i.e., the values of phase structure factor （na, FDC） increase, and delay bainite transformation due to the drag effect resulting from the segregation of RE ferrite island interphase and the retardation of RE to carbon diffusion in Si-Mn-Mo bainite steels. Beside this, C-curve is shifted to right and down, and microstructures of bainite ferrite and substructures are finer.展开更多
The splitter is an important component of water-based cooling systems used to extract heat from computer boards.In the present study,the flow characteristics of a 16-splitter structure were numerically simulated and c...The splitter is an important component of water-based cooling systems used to extract heat from computer boards.In the present study,the flow characteristics of a 16-splitter structure were numerically simulated and compared with experimental results to verify the reliability of the numerical simulation method.Accordingly,the concept of splitter structural coefficients was proposed.Based on the results of this study,we recommend a selection range of 5≤k≤6 for the structure factor k of the splitter;after optimization,the maximum deviation of the splitter outlet flow was reduced from the original value of 100%to 8.3%.展开更多
Background： Insulin-like factor 2（IGF2） plays an important role in embryonic growth process by modulating intermediary metabolism and cell proliferation. Folic acid is involved in one carbon metabolism and contribu...Background： Insulin-like factor 2（IGF2） plays an important role in embryonic growth process by modulating intermediary metabolism and cell proliferation. Folic acid is involved in one carbon metabolism and contributes to DNA methylation which is related to gene expression. The purpose of this study was to explore whether folic acid could regulate IGF2 expression via epigenetic mechanism and further promote embryonic growth of new-hatched broilers.Methods： In the present study, 360 fertile eggs were selected and randomly assigned to four treatments. On11 embryonic day of incubation（E11）, 0, 50, 100 and 150 μg folic acid were injected into eggs respectively.After hatched, growth performance of broilers were calculated. Hepatic IGF2 expression, methylation level and chromatin structure of promoter region were analyzed.Results： Results have showed that IGF2 expression was up-regulated in 150 μg folic acid group（P 〈 0.05） and other two dose of folic acid did not affect gene expression（P 〉 0.05）. Meanwhile, methylation level of IGF2 promoter were lower in 100 and 150 μg groups, which was consistent with lower expression of DNA methyltransferase1（DNMT1）（P 〈 0.05）. What＇s more, chromatin looseness of IGF2 promoter was higher in 150 μg group than control group（P 〈 0.05）. Further, birth weight（BW）, liver and bursa index of new-hatched chickens in 150 μg folic acid group were higher than the other groups（P 〈 0.05）. There were positive correlations between hepatic IGF2 expression and BW and organs index（P 〈 0.05）.Conclusion： In conclusion, our data have demonstrated that 150 μg folic acid injection on E11 could up-regulate IGF2 expression by modulating DNA hypomethylation and improving chromatin accessibility in the gene promoter region,and ulteriorly facilitate embryonic growth and organ development of broilers.展开更多
The community characteristics of macrobenthos in the Huanghe（Yellow River） Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes（1-month） in macroben...The community characteristics of macrobenthos in the Huanghe（Yellow River） Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes（1-month） in macrobenthic community structure in response to water and sediment discharge regulation（WSDR） in 2011.Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances（5, 10, 20, and 40 km）from the mouth of the Huanghe Estuary before（mid-June）, during（early-July）, and after（mid-July） WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively.Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods（Annelida, Mollusca, Arthropoda, and Echinodermata）. However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982,demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term（3 decadal）and short term（1-month） impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.展开更多
Multicollinearity in factor analysis has negative effects, including unreliable factor structure, inconsistent loadings, inflated standard errors, reduced discriminant validity, and difficulties in interpreting factor...Multicollinearity in factor analysis has negative effects, including unreliable factor structure, inconsistent loadings, inflated standard errors, reduced discriminant validity, and difficulties in interpreting factors. It also leads to reduced stability, hindered factor replication, misinterpretation of factor importance, increased parameter estimation instability, reduced power to detect the true factor structure, compromised model fit indices, and biased factor loadings. Multicollinearity introduces uncertainty, complexity, and limited generalizability, hampering factor analysis. To address multicollinearity, researchers can examine the correlation matrix to identify variables with high correlation coefficients. The Variance Inflation Factor (VIF) measures the inflation of regression coefficients due to multicollinearity. Tolerance, the reciprocal of VIF, indicates the proportion of variance in a predictor variable not shared with others. Eigenvalues help assess multicollinearity, with values greater than 1 suggesting the retention of factors. Principal Component Analysis (PCA) reduces dimensionality and identifies highly correlated variables. Other diagnostic measures include the condition number and Cook’s distance. Researchers can center or standardize data, perform variable filtering, use PCA instead of factor analysis, employ factor scores, merge correlated variables, or apply clustering techniques for the solution of the multicollinearity problem. Further research is needed to explore different types of multicollinearity, assess method effectiveness, and investigate the relationship with other factor analysis issues.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22171102 and 22090044)the National Key R&D Program of China(Nos.2021YFF0500502 and 2023YFA1506304)+2 种基金the Jilin Province Science and Technology Development Plan(No.20230101024JC)the"Medicine+X"crossinnovation team of Bethune Medical Department of Jilin University"Leading the Charge with Open Competition"construction project(No.2022JBGS04)the Jilin University Graduate Training Office(Nos.2021JGZ08 and 2022YJSJIP20).
文摘Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.
文摘The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college teachers. In this paper, the ＂impact factor structure of university teachers LMX Questionnaire＂ for four universities 808 subjects was investigated. By exploratory factor analysis and confirmatory factor analysis, it found that the structure of university teachers LMX factors includes five dimensions： values, attitudes up, personality characteristics, switching behavior, objective situations. The questionnaire has good reliability and validity.
基金conducted under the illu MINEation project, funded by the European Union’s Horizon 2020 research and innovation program under grant agreement (No. 869379)supported by the China Scholarship Council (No. 202006370006)
文摘A procedure to recognize individual discontinuities in rock mass from measurement while drilling(MWD)technology is developed,using the binary pattern of structural rock characteristics obtained from in-hole images for calibration.Data from two underground operations with different drilling technology and different rock mass characteristics are considered,which generalizes the application of the methodology to different sites and ensures the full operational integration of MWD data analysis.Two approaches are followed for site-specific structural model building:a discontinuity index(DI)built from variations in MWD parameters,and a machine learning(ML)classifier as function of the drilling parameters and their variability.The prediction ability of the models is quantitatively assessed as the rate of recognition of discontinuities observed in borehole logs.Differences between the parameters involved in the models for each site,and differences in their weights,highlight the site-dependence of the resulting models.The ML approach offers better performance than the classical DI,with recognition rates in the range 89%to 96%.However,the simpler DI still yields fairly accurate results,with recognition rates 70%to 90%.These results validate the adaptive MWD-based methodology as an engineering solution to predict rock structural condition in underground mining operations.
文摘The structure factors of any crystal structure can be simulated from its atomic coordinates (and temperature factors) in a SHELXL-97 run on a dummy hkl in which only the scale factor is refined. The squares of the structure factors are retrieved from the fcf, and such simulated data are used in the revision of the space groups of several incorrectly-refined crystal structures. Two cases, a P1 to P1 revision and a chemically-incorrect structure that is refined in a correct space group, are discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11004200 and 11274315)
文摘We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve the Gross-Pitaevskii equation and then the corresponding Bogoliubov equations. Our results show that three-body interactions can change both the Bogoliubov band structure and the dynamical structure factor dramatically, especially in the case of the two-body interaction being relatively small. Furthermore, when the optical lattice is strong enough, the analytical results, combined with the sum-rule approach, help us to understand that： the effects of three-body interactions on the static structure Ihctor can be significantly amplified by an optical lattice. Our predictions should be observable within the current Bragg spectroscopy experiment.
基金Funded by the National Natural Science Foundation of China(Nos.51278304,U1134209,U1434204&51422814)the National Basic Research Program(973 Program)of China(No.011-CB013604)the Technology Research and Development Program(Basic Research Project)of Shenzhen(Nos.JCYJ20120613174456685&JCYJ20130329143859418)
文摘Diffusion has been systematically described as the main mechanism of chloride transport in reinforced concrete（RC） structure, especially when the concrete is in a saturated state. However, the single mechanism of diffusion is not able to describe the actual chloride ingress in the nonsaturated concrete. Instead, it is dominated by the interaction of diffusion and convection. With the synergetic effects of various factors taken into account, this study aimed to modify and develop an analytical convection- diffusion coupling model for chloride transport in nonsaturated concrete. The model was verified by simulation of laboratory tests and field measurement. The results of comparison study demonstrate that the analytical model developed in this study is efficient and accurate in predicting the chloride profiles in the nonsaturated concrete.
基金supported by the Center for Advanced Systems Understanding(CASUS),financed by Germany’s Federal Ministry of Education and Research(BMBF)and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentfunding from the European Research Council(ERC)under the European Union’s Horizon 2022 research and innovation programme(Grant Agreement No.101076233,“PREXTREME”)funding from the European Union’s Just Transition Fund(JTF)within the project Röntgenlaser-Optimierung der Laserfusion(ROLF),Contract No.5086999001,co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament.
文摘Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.
文摘The role that a learner＇s native language plays in his or her second language acquisition （SLA） has been the focus of many researchers in the past few decades. The article provides a brief review of the literature on the importance and the factors of native language influence in SLA.
基金ItemSponsored by National Natural Science Foundation of China (50271030) Provincial Natural Science Foundation ofLiaoning Province of China (972072)
文摘Taking the hot working die steel （HWDS） 4Cr3Mo2NbVNi as an example, the phase electron structures （PES） and the biphase interface electron structures （BIES） of Mo2C and V4 C3 , which are two kinds of important carbides precipitated during tempering in steel were calculated, on the basis of the empirical electron theory of solids and molecules and the improved TFD theory. The influence of Mo2 C and V4 C3 on the mechanical properties of HWDS has been analyzed at electron structure level, and the fundamental reason that the characteristic of the PES and the BIES of carbides decides the behavior of them has been revealed.
基金This project is supported by Guangdong Provincial Key Laboratory Foundation of Higher Education Institutions, China.
文摘The compressive behaviour of paper honeycombs is studied by means of an experimental analysis. Experiment results show how geometry aspects of hexagonal paper honeycombs, e.g. the height of paper honeycomb, the thickness and length of honeycomb cell-wall, the drawing ratio of hexagonal honeycomb, affect the compressive properties of the paper honeycombs. It is in good agreement with the theory model. The constraint factor K of the critical buckling stress is mainly determined by the length of honeycomb cell-wail. It can be described as K=1.54 for B type paper honeycombs and K=3.32 for D type paper honeycombs. The plateau stress is the power exponent function of the thickness to length ratio of honeycomb cell-wall, and the experiment results show that the constant is 13.2 and the power exponent is 1.77. The research results can be used to characterize and improve efficiently the compressive properties of paper honeycombs.
基金financially supported by the National Natural Science Foundation of China(Nos.51872005,52072002 and 22108003)the Natural Science Foundation of Anhui Provincial Education Department(No.KJ2021A0401)+1 种基金WanJiang Scholar ProgramAnhui International Research Center of Energy Materials Green Manufacturing and Biotechnology。
文摘Developing electrochemical energy storage devices with high energy and power densities,long cycling life,as well as low cost is of great significance.Hybrid metal-ion capacitors(MICs),commonly consisting of high energy battery-type anodes and high power capacitor-type cathodes,have become a trade-off between batteries and supercapacitors.Tremendous efforts have been devoted to searching for high-performance electrode materials due to poor rate capability of anodes,low capacity of cathodes,and interior sluggish kinetic match.Carbon materials with large surface area,good electrical conductivity and stability have been considered to be ideal candidates for electrodes of MICs.In this review,the advanced carbon materials directly as cathodes and anodes of MICs are systematically summarized.Then,the key structural/chemical factors including the structure engineering,porous characteristics,and heteroatom incorporation for improving electrochemical performance of carbon materials are highlighted.Additionally,the challenges and opportunities for future research on carbon materials in MICs are also proposed.
文摘In the analysis of how environmental regulation affects the comparative advantage of trade,existing literature ignores industry's inherent heterogeneity, which draws remarkably different conclusions. In view of this, the paper analyzed the mechanism of environmental regulation on the export quality of different industries from the perspective of factor input structure heterogeneity. Based on the panel data of China's manufacturing industry, the paper used the system generalized method of moments method to examine the heterogeneity influence of environmental regulation on manufacturing export quality. The study found that, first, environmental regulation affected the export quality upgrade of the manufacturing sector through offset effect and compensation effect, and the direction of the impact would mainly depend on the industry's factor input structure. Second, for industries with larger fixed-asset investment(FAI) ratio in the factor input structure, the current environmental regulation policy was not conducive to the export quality upgrading of the industries. However, there was a significant U-shaped dynamic relationship between them. As environmental regulations became stricter, when regulatory stringency went beyond the inflection point, the policy would promote the upgrading of export quality. But for industries with smaller proportion of FAI, environmental regulation exerted a favorable impact on the export quality upgrade, following a J-shaped marginal growth curve.Third, for industries with different factor input structure, their export quality had been effectively upgraded as expected by factors like human capital investment, independent R&D, technology introduction, and foreign direct investment; but raising per capita capital stock and expanding enterprise size did not produce significant direct impact on export quality upgrade. These conclusions remained robust after using different measurement methods and replacing with other variables. Therefore, this paper suggests that governments should take industry heterogeneity into consideration and formulate differentiated hierarchical environmental policies.Besides, they should strengthen the enforcement of the current environmental regulation policies. By doing so, enterprises are forced to improve their technology and product quality so that they can better cope with rising compliance costs, eliminate backward industries, and resolve excess capacity. In this way, the economic structure would be transformed and upgraded from the supply side.
文摘Ferroelectric lead-free BaTi_(1-x)Zr_(x)O_(3)ceramic powder samples with various compositions(x=0,0.04,0.06)have been synthesized by conventional high-temperature solid-state reaction method at 1450℃for 10 h.Influences of Zr doping on the inter-atomic bonding and charge density distributions inside the lattice structure of BaTiO_(3)were analyzed through powder X-ray diffraction(XRD)and maximum entropy method.Lattice parameter and cell volume values are found to be increasing with the incorporation of Zr content.Calculated average grain sizes are found to be in the range of 23-28 nm.Maximum entropy mapping of electron density analysis reveals the reduction in ionic nature along Ba-O bond and the enhancement of covalent nature along Ti-O bond.Energy band gap values were determined from ultraviolet-visible(UV-Vis)spectra.Surface morphology and microstructures of the samples were analyzed from scanning electron microscopy(SEM)micrographs.Particles with irregular sizes were observed in all the prepared ceramics.Stoichiometry of the samples was further confirmed by energydispersive X-ray spectroscopy(EDAX).
基金financially supported by the Technology Innovation Fund of the Ministry of Science and Technology of China(No.04C26215200858)
文摘The effect of rare earth （RE） on bainite trans- formation mechanism is not yet unified in the academia. Therefore, further studying the effect of RE on bainite transformation mechanism will have important guiding significance for the development of bainite steels. In this paper, using differential dilatometer （DIL805A/D）, heat treatment was performed and C-curve was drawn. The effect of phase structure factor on bainite transformation under two different fractions of RE in Si-Mn-Mo bainite steels was investigated by the empirical electron theory （EET） of solids, molecules, dilatometry, and metallogra- phy. Experimental results show that RE makes Fe-C- RE segregation structural unit of Si-Mn-Mo bainite steels increase, i.e., the values of phase structure factor （na, FDC） increase, and delay bainite transformation due to the drag effect resulting from the segregation of RE ferrite island interphase and the retardation of RE to carbon diffusion in Si-Mn-Mo bainite steels. Beside this, C-curve is shifted to right and down, and microstructures of bainite ferrite and substructures are finer.
文摘The splitter is an important component of water-based cooling systems used to extract heat from computer boards.In the present study,the flow characteristics of a 16-splitter structure were numerically simulated and compared with experimental results to verify the reliability of the numerical simulation method.Accordingly,the concept of splitter structural coefficients was proposed.Based on the results of this study,we recommend a selection range of 5≤k≤6 for the structure factor k of the splitter;after optimization,the maximum deviation of the splitter outlet flow was reduced from the original value of 100%to 8.3%.
基金supported by the Natural Science Foundation of China (No. 31272464)the Program for New Century Excellent Talents (NCET-12-0476)the Program for Shaanxi Science & Technology (2014 K01-18-02, 2015NY149, 2015KTCQ02-19)
文摘Background： Insulin-like factor 2（IGF2） plays an important role in embryonic growth process by modulating intermediary metabolism and cell proliferation. Folic acid is involved in one carbon metabolism and contributes to DNA methylation which is related to gene expression. The purpose of this study was to explore whether folic acid could regulate IGF2 expression via epigenetic mechanism and further promote embryonic growth of new-hatched broilers.Methods： In the present study, 360 fertile eggs were selected and randomly assigned to four treatments. On11 embryonic day of incubation（E11）, 0, 50, 100 and 150 μg folic acid were injected into eggs respectively.After hatched, growth performance of broilers were calculated. Hepatic IGF2 expression, methylation level and chromatin structure of promoter region were analyzed.Results： Results have showed that IGF2 expression was up-regulated in 150 μg folic acid group（P 〈 0.05） and other two dose of folic acid did not affect gene expression（P 〉 0.05）. Meanwhile, methylation level of IGF2 promoter were lower in 100 and 150 μg groups, which was consistent with lower expression of DNA methyltransferase1（DNMT1）（P 〈 0.05）. What＇s more, chromatin looseness of IGF2 promoter was higher in 150 μg group than control group（P 〈 0.05）. Further, birth weight（BW）, liver and bursa index of new-hatched chickens in 150 μg folic acid group were higher than the other groups（P 〈 0.05）. There were positive correlations between hepatic IGF2 expression and BW and organs index（P 〈 0.05）.Conclusion： In conclusion, our data have demonstrated that 150 μg folic acid injection on E11 could up-regulate IGF2 expression by modulating DNA hypomethylation and improving chromatin accessibility in the gene promoter region,and ulteriorly facilitate embryonic growth and organ development of broilers.
基金The Public Science and Technology Research Funds Projects of Ocean under contract No.200905019the Taishan Scholars Station of Aquatic Animal Nutrition and Feed under contract No.HYK201004
文摘The community characteristics of macrobenthos in the Huanghe（Yellow River） Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes（1-month） in macrobenthic community structure in response to water and sediment discharge regulation（WSDR） in 2011.Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances（5, 10, 20, and 40 km）from the mouth of the Huanghe Estuary before（mid-June）, during（early-July）, and after（mid-July） WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively.Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods（Annelida, Mollusca, Arthropoda, and Echinodermata）. However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982,demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term（3 decadal）and short term（1-month） impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary.
文摘Multicollinearity in factor analysis has negative effects, including unreliable factor structure, inconsistent loadings, inflated standard errors, reduced discriminant validity, and difficulties in interpreting factors. It also leads to reduced stability, hindered factor replication, misinterpretation of factor importance, increased parameter estimation instability, reduced power to detect the true factor structure, compromised model fit indices, and biased factor loadings. Multicollinearity introduces uncertainty, complexity, and limited generalizability, hampering factor analysis. To address multicollinearity, researchers can examine the correlation matrix to identify variables with high correlation coefficients. The Variance Inflation Factor (VIF) measures the inflation of regression coefficients due to multicollinearity. Tolerance, the reciprocal of VIF, indicates the proportion of variance in a predictor variable not shared with others. Eigenvalues help assess multicollinearity, with values greater than 1 suggesting the retention of factors. Principal Component Analysis (PCA) reduces dimensionality and identifies highly correlated variables. Other diagnostic measures include the condition number and Cook’s distance. Researchers can center or standardize data, perform variable filtering, use PCA instead of factor analysis, employ factor scores, merge correlated variables, or apply clustering techniques for the solution of the multicollinearity problem. Further research is needed to explore different types of multicollinearity, assess method effectiveness, and investigate the relationship with other factor analysis issues.
