Polycyclic aromatic hydrocarbons(PAHs),PANHs,and peptoids dust spectral calculations from the interstellar medium(ISM)are important for dust observations and theory.Our goal is to calculate the radiation spectrum of s...Polycyclic aromatic hydrocarbons(PAHs),PANHs,and peptoids dust spectral calculations from the interstellar medium(ISM)are important for dust observations and theory.Our goal is to calculate the radiation spectrum of spherical PAHs dust clusters in a vacuum containing ionized and applied in the presence of an electric field.We propose a new simple computational model to calculate the size of three-dimensional spherical dust clusters formed by different initial dust structures.By the Vienna Ab-initio Simulation Package code,the density functional theory with the generalized approximation was used to calculate the electron density gradient and obtain the radiation spectrum of dust.When the radius of spherical dust clusters is~[0.009-0.042]μm,the dust radiation spectrum agrees well with the Z=0.02 mMMP stellar spectra,and the PAHs radiation spectrum of NGC 4676 at wavelengths of(0-5]μm and(5-10]μm,respectively.In the ionized state,the N-PAH,C_(10)H_(9)N,2(C_(4)H_(4))^(1+),and peptoids 4(CHON),(C_(8)H_(10)N_(2)O_(5))^(1+)dust clusters at 3.3μm,while the 2(C_(22)H_(21)N_(3)O_(2))^(1+),4(CHON)dust clusters at 5.2μm have obvious peaks.There is a characteristic of part of PAHs and peptoids clusters radiation at the nearinfrared wavelength of 2μm.However,especially after applying an electric field to the dust,the emission spectrum of the dust increases significantly in the radiation wavelength range[3-10]μm.Consequently,the dust clusters of PAHs,PANHs,and peptoids of the radius size~[0.009-0.042]μm are likely to exist in the ISM.展开更多
Carbon nanotube(CNT)networks enable CNTs to be used as building blocks for synthesizing novel advanced materials,thus taking full advantage of the superior properties of individual CNTs.Multiscale analyses have to be ...Carbon nanotube(CNT)networks enable CNTs to be used as building blocks for synthesizing novel advanced materials,thus taking full advantage of the superior properties of individual CNTs.Multiscale analyses have to be adopted to study the load transfer mechanisms of CNT networks from the atomic scale to the macroscopic scale due to the huge computational cost.Among them,fully resolved structural features include the graphitic honeycomb lattice(atomic),inter-tube stacking(nano)and assembly(meso)of CNTs.On an atomic scale,the elastic properties,ultimate stresses,and failure strains of individual CNTs with distinct chiralities and radii are obtained under various loading conditions by molecular mechanics.The dependence of the cohesive energies on spacing distances,crossing angles,size and edge effects between two CNTs is analyzed through continuum modeling in nanoscale.The mesoscale models,which neglect the atomic structures of individual CNTs but retain geometrical information about the shape of CNTs and their assembly into a network,have been developed to study the multi-level mechanism of material deformation and microstructural evolution in CNT networks under stretching,from elastic elongation,strengthening to damage and failure.This paper summarizes the multiscale theories mentioned above,which should provide insight into the optimal assembling of CNT network materials for elevated mechanical performance.展开更多
Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the disco...Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by theoretical models. To bridge this gap, this study utilized machine learning techniques to efficiently identify new symbiotic star candidates. Three algorithms(XGBoost, LightGBM, and Decision Tree)were applied to a data set of 198 confirmed symbiotic stars and the resulting model was then used to analyze data from the LAMOST survey, leading to the identification of 11,709 potential symbiotic star candidates. Out of these potential symbiotic star candidates listed in the catalog, 15 have spectra available in the Sloan Digital Sky Survey(SDSS) survey. Among these 15 candidates, two candidates, namely V^(*)V603 Ori and V^(*)GN Tau, have been confirmed as symbiotic stars. The remaining 11 candidates have been classified as accreting-only symbiotic star candidates. The other two candidates, one of which has been identified as a galaxy by both SDSS and LAMOST surveys, and the other identified as a quasar by SDSS survey and as a galaxy by LAMOST survey.展开更多
Objective:Monocytes/macrophages,proinflammatory cytokines and chemokines are important in the pathogenesis of glomerulonephritis.Interleukin(IL)-13 has been shown to exert potent anti-inflammatory properties. This stu...Objective:Monocytes/macrophages,proinflammatory cytokines and chemokines are important in the pathogenesis of glomerulonephritis.Interleukin(IL)-13 has been shown to exert potent anti-inflammatory properties. This study was designed to investigate the effect of IL-13 on the expression of proinflammatory cytokines,chemokines and profibrogenic cytokines and the involved molecular mechanism in cultured human mesangial cells (HMCs).Methods:The expressions of proinflammatory cytokines,chemokines and profibrogenic cytokines were determined by ribonuclease protection assay(RPA).Activity of nuclear factor-kappa B(NF-κB)and activa- tor protein-1(AP-1)was examined by electrophoretic mobility shift assay(EMSA).NF-κB subunit p65 nuclear transportation and c-Jun N-terminal kinase(JNK)activity were assayed by immunoblot.Results:Recombinant IL-13 inhibited tumor necrosis factor-α(TNF-α),IL-1α,IL-1β,monocyte chemoattractant protein-1(MCP-1), IL-8,and transforming growth factor-β1(TGF-β1)mRNA expressions in a dose-dependent manner.Lipopoly-sacchorides(LPS)dramatically increased NF-κB DNA binding activity of HMCs,which was inhibited by IL-13 in a dose-dependent manner.LPS-activated NF-κB contained p50 and p65 dimers,but not c-Rel subunit.IL-13 blocked LPS-induced NF-κB subunit p65.LPS stimulated JNK/AP-1 activation,which was inhibited by IL-13 in a dose-dependent manner.Conclusion:IL-13 inhibits proinflammatory cytokines,chemokines,and profibrogenic cytokines synthesis by blocking NF-κB and JNK/AP-1 activation.These observations point to the importance of IL-13 in the modulation of inflammatory processes in the renal glomerulus.展开更多
For limited distortion source coding, it is generally considered that the minimum value of the coding average distortion is 0, and the maximum value is the minimum distortion value of making R(D) = 0. This is the defi...For limited distortion source coding, it is generally considered that the minimum value of the coding average distortion is 0, and the maximum value is the minimum distortion value of making R(D) = 0. This is the definition domain of the information rate distortion function. In this paper, the upper and lower bounds of the information rate distortion function R(D) are derived and computed for the typical sources. The results show that the lower bound of the coding average distortion D is related to the symbol distortion function, which can further improve the theory of limited distortion source coding.展开更多
Nanoscale defects,including cracks,circular holes,and the triangular-shaped defects,often occur in the growth of boron nitride nanosheets(BNNS).In this study,the fracture behavior of chiral BNNS with different crack-t...Nanoscale defects,including cracks,circular holes,and the triangular-shaped defects,often occur in the growth of boron nitride nanosheets(BNNS).In this study,the fracture behavior of chiral BNNS with different crack-tip shapes and the interactions of nanoscale crack-defects are studied using molecular dynamics(MD)simulations and finite element(FE)analysis.Both MD and FE results indicate that the fracture strength of BNNS with two crack tips(t=2)is significantly higher than that with one crack tip(t=1),in which the difference in zigzag(ZZ)direction is more obvious than that in armchair(AC)direction,mainly due to the fact that the change of bond angles near the crack tips is more substantial in the ZZ direction than those in the AC direction.Our results show that the fracture strength of BNNS strongly depends on crack-tip shapes,chiral angles,the defect-to-crack tip spacing and deflection angles.Checking against the current MD simulations and FE analysis shows the present results are reasonable.This study should be of great importance for enhancing the fracture performance of BNNS by modulating their crack-tip shapes and the interactions of nanoscale crack-defects.展开更多
基金the Independent Innovation Project for Postgraduates of Central South University(No.160171008)the National Natural Science Foundation of China(project No.U2031204)the project of Xinjiang(No.2021D01C075)。
文摘Polycyclic aromatic hydrocarbons(PAHs),PANHs,and peptoids dust spectral calculations from the interstellar medium(ISM)are important for dust observations and theory.Our goal is to calculate the radiation spectrum of spherical PAHs dust clusters in a vacuum containing ionized and applied in the presence of an electric field.We propose a new simple computational model to calculate the size of three-dimensional spherical dust clusters formed by different initial dust structures.By the Vienna Ab-initio Simulation Package code,the density functional theory with the generalized approximation was used to calculate the electron density gradient and obtain the radiation spectrum of dust.When the radius of spherical dust clusters is~[0.009-0.042]μm,the dust radiation spectrum agrees well with the Z=0.02 mMMP stellar spectra,and the PAHs radiation spectrum of NGC 4676 at wavelengths of(0-5]μm and(5-10]μm,respectively.In the ionized state,the N-PAH,C_(10)H_(9)N,2(C_(4)H_(4))^(1+),and peptoids 4(CHON),(C_(8)H_(10)N_(2)O_(5))^(1+)dust clusters at 3.3μm,while the 2(C_(22)H_(21)N_(3)O_(2))^(1+),4(CHON)dust clusters at 5.2μm have obvious peaks.There is a characteristic of part of PAHs and peptoids clusters radiation at the nearinfrared wavelength of 2μm.However,especially after applying an electric field to the dust,the emission spectrum of the dust increases significantly in the radiation wavelength range[3-10]μm.Consequently,the dust clusters of PAHs,PANHs,and peptoids of the radius size~[0.009-0.042]μm are likely to exist in the ISM.
基金Supported by National Natural Science Foundation of China(Grant Nos.11972171,11572140)Sixth Phase of Jiangsu Province“333 High Level Talent Training Project”Second Level Talents,111 Project(Grant No.B18027)+3 种基金Natural Science Foundation of Jiangsu Province(Grant No.BK20180031)Research Project of State Key Laboratory of Mechanical System and Vibration(Grant No.MSV201909)Fundamental Research Funds for the Central Universities(Grant No.JUSRP22002)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX19_1861).
文摘Carbon nanotube(CNT)networks enable CNTs to be used as building blocks for synthesizing novel advanced materials,thus taking full advantage of the superior properties of individual CNTs.Multiscale analyses have to be adopted to study the load transfer mechanisms of CNT networks from the atomic scale to the macroscopic scale due to the huge computational cost.Among them,fully resolved structural features include the graphitic honeycomb lattice(atomic),inter-tube stacking(nano)and assembly(meso)of CNTs.On an atomic scale,the elastic properties,ultimate stresses,and failure strains of individual CNTs with distinct chiralities and radii are obtained under various loading conditions by molecular mechanics.The dependence of the cohesive energies on spacing distances,crossing angles,size and edge effects between two CNTs is analyzed through continuum modeling in nanoscale.The mesoscale models,which neglect the atomic structures of individual CNTs but retain geometrical information about the shape of CNTs and their assembly into a network,have been developed to study the multi-level mechanism of material deformation and microstructural evolution in CNT networks under stretching,from elastic elongation,strengthening to damage and failure.This paper summarizes the multiscale theories mentioned above,which should provide insight into the optimal assembling of CNT network materials for elevated mechanical performance.
基金the generous support of the Natural Science Foundation of Xinjiang No. 2021D01C075the National Natural Science Foundation of China, project Nos. 12163005, 12003025, U2031204, 11863005, and 12288102+12 种基金the science research grants from the China Manned Space Project with No. CMS-CSST-2021-A10the Scientific Research Program of the Higher Education Institution of Xinjiang (No. XJEDU2022P003)supported by China National Astronomical Data Center (NADC) and Chinese Virtual Observatory (China-VO)supported by Astronomical Big Data Joint Research Center, co-founded by National Astronomical Observatories, Chinese Academy of Sciences and Alibaba CloudThis publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/ California Institute of TechnologyNEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of TechnologyWISE and NEOWISE are funded by the National Aeronautics and Space AdministrationThis publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technologyfunded by the National Aeronautics and Space Administration and the National Science FoundationGuo Shou Jing Telescope (the Large Sky Area MultiObject Fiber Spectroscopic Telescope LAMOST) is a National Major Scientific Project built by the Chinese Academy of SciencesFunding for the project has been provided by the National Development and Reform CommissionFunding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutionssupport and resources from the Center for High Performance Computing at the University of Utah。
文摘Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by theoretical models. To bridge this gap, this study utilized machine learning techniques to efficiently identify new symbiotic star candidates. Three algorithms(XGBoost, LightGBM, and Decision Tree)were applied to a data set of 198 confirmed symbiotic stars and the resulting model was then used to analyze data from the LAMOST survey, leading to the identification of 11,709 potential symbiotic star candidates. Out of these potential symbiotic star candidates listed in the catalog, 15 have spectra available in the Sloan Digital Sky Survey(SDSS) survey. Among these 15 candidates, two candidates, namely V^(*)V603 Ori and V^(*)GN Tau, have been confirmed as symbiotic stars. The remaining 11 candidates have been classified as accreting-only symbiotic star candidates. The other two candidates, one of which has been identified as a galaxy by both SDSS and LAMOST surveys, and the other identified as a quasar by SDSS survey and as a galaxy by LAMOST survey.
基金supported by grants from the National Natural Science Foundation of China(No.30872803 to Aihua Zhang,No.30772365 to Songming Huang)the Jiangsu Key Medical Talent Foundation(No.RC2007015 to Aihua Zhangthe Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China
文摘Objective:Monocytes/macrophages,proinflammatory cytokines and chemokines are important in the pathogenesis of glomerulonephritis.Interleukin(IL)-13 has been shown to exert potent anti-inflammatory properties. This study was designed to investigate the effect of IL-13 on the expression of proinflammatory cytokines,chemokines and profibrogenic cytokines and the involved molecular mechanism in cultured human mesangial cells (HMCs).Methods:The expressions of proinflammatory cytokines,chemokines and profibrogenic cytokines were determined by ribonuclease protection assay(RPA).Activity of nuclear factor-kappa B(NF-κB)and activa- tor protein-1(AP-1)was examined by electrophoretic mobility shift assay(EMSA).NF-κB subunit p65 nuclear transportation and c-Jun N-terminal kinase(JNK)activity were assayed by immunoblot.Results:Recombinant IL-13 inhibited tumor necrosis factor-α(TNF-α),IL-1α,IL-1β,monocyte chemoattractant protein-1(MCP-1), IL-8,and transforming growth factor-β1(TGF-β1)mRNA expressions in a dose-dependent manner.Lipopoly-sacchorides(LPS)dramatically increased NF-κB DNA binding activity of HMCs,which was inhibited by IL-13 in a dose-dependent manner.LPS-activated NF-κB contained p50 and p65 dimers,but not c-Rel subunit.IL-13 blocked LPS-induced NF-κB subunit p65.LPS stimulated JNK/AP-1 activation,which was inhibited by IL-13 in a dose-dependent manner.Conclusion:IL-13 inhibits proinflammatory cytokines,chemokines,and profibrogenic cytokines synthesis by blocking NF-κB and JNK/AP-1 activation.These observations point to the importance of IL-13 in the modulation of inflammatory processes in the renal glomerulus.
文摘For limited distortion source coding, it is generally considered that the minimum value of the coding average distortion is 0, and the maximum value is the minimum distortion value of making R(D) = 0. This is the definition domain of the information rate distortion function. In this paper, the upper and lower bounds of the information rate distortion function R(D) are derived and computed for the typical sources. The results show that the lower bound of the coding average distortion D is related to the symbol distortion function, which can further improve the theory of limited distortion source coding.
基金the National Natural Science Foundation of China under Grant Nos.10171094,10571001,and 30572285the Foundation of Nanjing Normal University under Grant No.2005101XGQ2B84+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China under Grant No.07KJD110093the Foundation of Anhui University under Grant No.02203105
文摘在有固定设计的概括线性模型，在假设和另外的整齐条件下面，最大的伪可能性评估者的 asymptotic 规度，是有自然连接功能的伪可能性方程的根，被获得，在的地方表示最小的特征值， X <SUB > i </SUB >是围住的p ×& #8201 ； q 退回 ors ，和 y <SUB > i </SUB >是q ×& #8201 ； 1 回答。
基金This work was supported by the National Natural Science Foundation of China[11972171,11572140,11972171,11572140].
文摘Nanoscale defects,including cracks,circular holes,and the triangular-shaped defects,often occur in the growth of boron nitride nanosheets(BNNS).In this study,the fracture behavior of chiral BNNS with different crack-tip shapes and the interactions of nanoscale crack-defects are studied using molecular dynamics(MD)simulations and finite element(FE)analysis.Both MD and FE results indicate that the fracture strength of BNNS with two crack tips(t=2)is significantly higher than that with one crack tip(t=1),in which the difference in zigzag(ZZ)direction is more obvious than that in armchair(AC)direction,mainly due to the fact that the change of bond angles near the crack tips is more substantial in the ZZ direction than those in the AC direction.Our results show that the fracture strength of BNNS strongly depends on crack-tip shapes,chiral angles,the defect-to-crack tip spacing and deflection angles.Checking against the current MD simulations and FE analysis shows the present results are reasonable.This study should be of great importance for enhancing the fracture performance of BNNS by modulating their crack-tip shapes and the interactions of nanoscale crack-defects.
