The character of structural changes in the surface layer of titanium carbide （TiC） with Ni-Cr alloy binder was investigated theoretically and experimentally after electron-beam treatment of the material surface. The...The character of structural changes in the surface layer of titanium carbide （TiC） with Ni-Cr alloy binder was investigated theoretically and experimentally after electron-beam treatment of the material surface. The thermal influence of the electron-beam irradiation on the surface layer microstructure of the composite fine-grained material was mathematically analyzed. Quantitative estimations of the depth of the zone in microstructural phase transformations were carried out. The microstructure and concentration profile of Ti distribution in the metallic binder over the cross section of the surface layer with microstructural phase transformations after electron-pulse treatment of the hard metal surface were experimentally investigated.展开更多
The effects of concentration and an oriented external electric field on the transformations of hydrogenbonded structures of trimesic acid(TMA) and terephthalic acid(TPA) have been investigated at a liquidsolid interfa...The effects of concentration and an oriented external electric field on the transformations of hydrogenbonded structures of trimesic acid(TMA) and terephthalic acid(TPA) have been investigated at a liquidsolid interface by scanning tunneling microscopy(STM).The triangular periodic TMA framework can be transformed into a flower-like structure by changing the STM sample bias sign in situ.Networks of TMA and TPA are porous at a negative substrate bias,but typically change to relatively compact forms when the polarity of the applied bias is reversed.This change is reversible if the applied bias is reversed.The effects have potentials to locally control the capture and release of analytes in host-vip systems and the 2D morphology in multicomponent layers.展开更多
Occupational structural transformation is a common pattern during the steady growth of GDP per capita in major economies worldwide.In recent years,there has been a decline in the employment share of goods occupation a...Occupational structural transformation is a common pattern during the steady growth of GDP per capita in major economies worldwide.In recent years,there has been a decline in the employment share of goods occupation and an increase in service occupation within the Chinese manufacturing industry,presenting a trend of occupational structural transformation and rapid development of service-oriented manufacturing.It is an important driving force and typical performance of the high-end,intelligent,and green development of the manufacturing industry.As a strategic general technology which leads the new round of technological revolution and industrial transformation,artificial intelligence(AI)has become a new fundamental force to accelerate the occupational structural transformation and service-oriented manufacturing development in China.Thus,this paper establishes a dynamic general equilibrium model with AI technology and occupational heterogeneity,showing the endogenous mechanism of occupational structural transformation.We find that when AI technology is biased towards goods occupation,and the elasticity of substitution between goods occupation and service occupation is less than 1,then AI will drive the transformation of occupational structure from goods to service within the manufacturing sector,increase the proportion of service-oriented manufacturing,improve labor productivity of manufacturing relative to service and stabilize the real output share of manufacturing.Promoting deeper integration of different occupations,intensifying R&D in AI technology and reducing labor mobility barriers between occupations can effectively accelerate the occupational structural transformation and industrial structural upgrading.We use theoretical analysis and numerical simulation method to show the theoretical mechanism by which AI affects occupational structural transformation and industrial structural transformation from a macroeconomic perspective,and put forward policy implications on how to promote the service-oriented manufacturing development and accelerate the construction of modern industrial system through AI innovation.展开更多
The intimate host-anion interactions will regulate thermodynamics and kinetics in the self-assembly of cationic cages mimicking biological counterparts.Herein,we report construction and transformation of three Pd(Ⅱ)-...The intimate host-anion interactions will regulate thermodynamics and kinetics in the self-assembly of cationic cages mimicking biological counterparts.Herein,we report construction and transformation of three Pd(Ⅱ)-based metal-organic cages(MOCs)depending on different anions.Stoichiometric conversions of the lantern-shaped MOC-34 into either octahedral MOC-35 or tricapped trigonal prism MOC-36 are induced by BF_(4)^(–)or NO_(3)^(–),respectively.MOC-36 is kinetically favored and can undergo quantitative conversion to the thermodynamically preferred MOC-35 upon heating,accelerated by excess BF_(4)^(–)to motivate dissociative dynamics of Pd-vertices and lower activation barrier of cage transformation.The vip encapsulation behaviors of MOC-35 and MOC-36 have also been tested.These results manifest a significance of host-anion dynamics beyond complementary anion template,shedding light on the understanding of intricate anion recognition in nature.展开更多
Based on Joseph Schumpeter’s theory of“creative destruction,”we constructed a multi-sectoral endogenous growth model that integrates the agriculture,manufacturing,and service sectors.Employing numerical simulation,...Based on Joseph Schumpeter’s theory of“creative destruction,”we constructed a multi-sectoral endogenous growth model that integrates the agriculture,manufacturing,and service sectors.Employing numerical simulation,we investigated the dynamic influence of technological innovation on the industrial structural transformation in two key aspects:the level of innovation and the research and development(R&D)efficiency within industries.Our findings indicate that technological innovation plays a pivotal role in advancing industrial structural transformation.Enhancements in both the level of innovation and R&D efficiency within industries are instrumental in fostering industrial structural transformation.Specifically,the enhancements in the level of innovation or R&D efficiency within the agricultural sector hasten its transition toward the manufacturing sector,while such enhancement within the manufacturing sector expedites its transition toward the service sector.However,such enhancements within the service sector tend to decelerate the transition from manufacturing to service.In light of this,it is essential to harness technological innovation to enhance the level of innovation and R&D efficiency in industries to facilitate the transition of traditional industries into high-value-added and emerging ones.Meanwhile,tailored technological innovation strategies should be implemented to boost a balanced industrial structural transformation within industries.展开更多
The latest economic data released by China’s National Bureau of Statistics for April 2025 underscores the country’s robust economic recovery and structural transformation.Industrial production surged by 6.1 percent ...The latest economic data released by China’s National Bureau of Statistics for April 2025 underscores the country’s robust economic recovery and structural transformation.Industrial production surged by 6.1 percent year on year,propelled by breakthroughs in advanced manufacturing,from high-tech industries to cutting-edge equipment sectors.展开更多
Under the guidance of national policies,the“coal to gas”project has become one of the important measures to promote the transformation of energy structure in China.Foshan,an important industrial town in Guangdong pr...Under the guidance of national policies,the“coal to gas”project has become one of the important measures to promote the transformation of energy structure in China.Foshan,an important industrial town in Guangdong province,the implementation of the“coal to gas”policy has demonstrated significance for the optimization of the national energy structure.Through the analysis of the change in Foshan’s energy consumption structure and the implementation of the policy,this paper found that there were some challenges in the policy implementation process,such as high economic cost,lagging infrastructure,low social acceptance,and lack of technical personnel.To address this,suggestions are put forward,including increasing financial subsidies,improving laws and regulations,promoting technological innovation,and encouraging social inclusion policies.These recommendations aim to provide guidance and reference for the remaining“coal to gas”projects and the development of clean energy.展开更多
The oxidation behavior of three biodiesels of different origins,viz.rapeseed oil derived biodiesel,soybean oil derived biodiesel and waste oil based biodiesel,were tested on an oxidation tester.The chemical compositio...The oxidation behavior of three biodiesels of different origins,viz.rapeseed oil derived biodiesel,soybean oil derived biodiesel and waste oil based biodiesel,were tested on an oxidation tester.The chemical compositions of the biodiesels were characterized by gas chromatography.Thereafter,the structural transformation of fatty acid methyl ester(FAME)of the biodiesels was analyzed by an infrared spectrometer and an ultraviolet absorption spectrometer.The results demonstrated that the oxidation behavior of biodiesels of different origins was closely related to the composition and distribution of FAMEs.Higher concentration of unsaturated FAME with multi-double bonds exhibited poorer oxidation resistance.Furthermore,cis-trans isomerization transformation occurred in the unsaturated FAME molecules and conjugated double-bond produced during the oxidation process of biodiesel.Greater cis-trans variations corresponded to deeper oxidation degree.The higher the content of unsaturated FAME with multi-double bonds in a biodiesel,the more the conjugated double bonds was formed.展开更多
A mixture of Ni and Fe oxides is among the most commonly active catalysts for the oxygen evolution reaction(OER)during the water oxidation process.In particular,Ni oxide incorporated with even a small amount of Fe lea...A mixture of Ni and Fe oxides is among the most commonly active catalysts for the oxygen evolution reaction(OER)during the water oxidation process.In particular,Ni oxide incorporated with even a small amount of Fe leads to substantively enhanced OER activity.However,the critical role of Fe species during the electrocatalytic process is still under evaluation.Herein,we report nickel(oxy)hydroxide incorporated with Fe through the surface reconstruction of a bimetallic metal-organic framework(NiFe-MOF)during the water oxidation process.The spectroscopic investigations with theoretical calculations reveal the critical role of Fe in promoting the formation of highly oxidized Ni^(4+),which directly correlates with an enhanced OER activity.Both the geometric and electronic structu res of the as-reconstructed Ni_(1-x)Fe_(x)OOH electrocatalysts can be delicately tuned by the Ni-Fe ratio of the bimetallic NiFe-MOF,further affecting the catalytic activity.As a result,the Ni_(1-x)Fe_(x)OOH derived from Ni_(0.9)Fe_(0.1)-MOF delivers low overpotentials of 260 mV at 10 mA cm^(-2)and 400 mV at 300 mA cm^(-2).展开更多
A new kind of polytriazoleimide containing bisphenyl-l,2,3-triazole （BPT） was synthesized by copper-catalyzed 1,3-dipolar cycloaddition of azides and alkynes （CuAAC） and polycondensation. The thermal stability and...A new kind of polytriazoleimide containing bisphenyl-l,2,3-triazole （BPT） was synthesized by copper-catalyzed 1,3-dipolar cycloaddition of azides and alkynes （CuAAC） and polycondensation. The thermal stability and degradation mechanism of the polytriazoleimide were investigated. The results show that the structure of BPT in polytriazoleimide transforms to phenylindole after thermal treatment, accompanying the release of NE.展开更多
In this paper,we performed an empirical study on the TFP effect of structural transformation based on panel data of economic growth in 169 countries across the world.Our findings are threefold:First,structural transfo...In this paper,we performed an empirical study on the TFP effect of structural transformation based on panel data of economic growth in 169 countries across the world.Our findings are threefold:First,structural transformation has an inverted U-shaped effect on TFP.When the degree of structural transformation is on the left side of the inflection point,structural transformation is conducive to softening industrial structure and inducing TFP;when the degree of structural transformation is on the right side of the inflection point,structural transformation will induce industrial hollowing out and inhibit TFP.Second,since the reform and opening up program was launched in 1978,China’s structural transformation has evolved from the stage of adaptation to the stage of strategic adjustment with an increasingly evident trend towards a service-based economy,but structural transformation remains on the left side of the inflection point of the inverted U-shaped curve,i.e.the TFP effect of structural transformation is positive.Third,TFP improvement lies at the heart of high-quality development.In pursuing high-quality development,China should lower growth rate expectations,attach greater importance to supply-side structural reforms,and accelerate structural transformation to promote TFP improvement.展开更多
An energy model for the structure transformation of pile-ups of grain boundary dislocations(GBD)at the triple-junction of the grain boundary of ultrafine-grain materials was proposed.The energy of the pile-up of the G...An energy model for the structure transformation of pile-ups of grain boundary dislocations(GBD)at the triple-junction of the grain boundary of ultrafine-grain materials was proposed.The energy of the pile-up of the GBD in the system was calculated by the energy model,the critical geometric and mechanical conditions for the structure transformation of head dislocation of the pile-up were analyzed,and the influence of the number density of the dislocations and the angle between Burgers vectors of two decomposed dislocations on the transformation mode of head dislocation was discussed.The results show when the GBD is accumulated at triple junction,the head dislocation of the GBD is decomposed into two Burgers vectors of these dislocations unless the angle between the two vectors is less than 90°,and the increase of applied external stress can reduce the energy barrier of the dislocation decomposition.The mechanism that the ultrafine-grained metal material has both high strength and plasticity owing to the structure transformation of the pile-up of the GBD at the triple junction of the grain boundary is revealed.展开更多
The synergy effect of alloy elements in bimetallic clusters can be used to tune the chemical and physical properties. Research on the influences of alloy concentration and distribution on the frozen structure of bimet...The synergy effect of alloy elements in bimetallic clusters can be used to tune the chemical and physical properties. Research on the influences of alloy concentration and distribution on the frozen structure of bimetallic clusters plays a key rolc in exploring new structural materials. In this paper, we study the influence of Ag concentration on the frozen structure of the （AgCo）561 cluster by using molecular dynamics simulation with a general embedded atom method. The results indicate that tt^e structure and chemical ordering of the （AgCo）561 cluster are strongly related to Ag concentration. Hcp-icosahedron structural transformation in the frozen （CoAg）561 cluster can be induced by changing Ag concentration. The chemical ordering also transforms to Janus-like Co Ag from core-shell Co-Ag.展开更多
The high-pressure polymorphs and structural transformation of Sn were experimentally investigated using angle- dispersive synchrotron x-ray diffraction up to 108.9 GPa. The results show that at least at 12.8 GPa β-Sn...The high-pressure polymorphs and structural transformation of Sn were experimentally investigated using angle- dispersive synchrotron x-ray diffraction up to 108.9 GPa. The results show that at least at 12.8 GPa β-Sn→bct structure transformation was completed and no two-phase coexistence was found. By using a long-wavelength x-ray, we resolved the diffraction peaks splitting and discovered the formation of a new distorted orthorhombic structure bco from the bct structure at 31.8 GPa. The variation of the lattice parameters and their ratios with pressure further validate the observation of the bco polymorph. The bcc structure appears at 40.9 GPa and coexists with the bco phase throughout a wide pressure range of 40.9 GPa-73.1 GPa. Above 73.1 GPa, only the bcc polymorph is observed, The systematically experimental investigation confirms the phase transition sequence of Sn asβ-Sn→bct→bco→bco ＋ bcc→bcc upon compression to 108.9 GPa at room temperature.展开更多
It is generally recognized that the formation and accumulation of iron oxides on the surface of zero-valent iron(Fe^(0))resulting in significant decrease of contaminant degradation rates during the long-term reactions...It is generally recognized that the formation and accumulation of iron oxides on the surface of zero-valent iron(Fe^(0))resulting in significant decrease of contaminant degradation rates during the long-term reactions.However,in this study,we found that the removal efficiencies of p-nitrophenol(PNP)by micro zero-valent iron(mFe^(0))could maintain at the satisfactory level in the process of continuous reactions(20 cycles).The removal rate constant(0.1779 min^(-1))of the 5th cycle was 6.74 times higher than that of the 1streaction(0.0264 min^(-1)),even the 20th cycle(0.0371 min^(-1))was higher than that of the 1st reaction.Interestingly,almost no dissolved iron was detected in the solution,and the total iron concentrations decreased dramatically with the process of continuous reactions.The results of scanning electron microscope and energy dispersive spectrometry(SEM-EDS)and X-ray diffraction(XRD)revealed that the structure and composition of corrosion products change from amorphous to highly crystal with the increase of the number of cycles.The corrosion products were mainly magnetite(Fe_(3)O_(4))and a small part of maghemite(γ-Fe_(2)O_(3)),which were in the form of micro sphe res on the surface of mFe^(0).The formation of surface oxidation shell hindered the release of Fe^(2+).X-ray photoelectron spectroscopy(XPS)results illustrated that partial Fe3O_(4) could be converted into y-Fe_(2)O_(3).Electrochemical analysis proved that the electron transfer rate of mFe^(0) increased with the formation of the oxides shell.However,the consumption of iron core and thicker oxide film weakened the electron transfer rate.Besides,the quenching experiments indicated that the reaction activity of mFe^(0) could be enhanced with the addition of scavengers.This study deepened the understanding of the structural transformation and radical production of mFe^(0) in continuous reactions.展开更多
Fe100-xPtx(x=30at.%-60at.%) nanocomposite films were deposited on natural-oxidized Si(100) substrates by magnetron sputtering. The as-deposited films were annealed between 373 and 1073 K. In situ X-ray diffraction sho...Fe100-xPtx(x=30at.%-60at.%) nanocomposite films were deposited on natural-oxidized Si(100) substrates by magnetron sputtering. The as-deposited films were annealed between 373 and 1073 K. In situ X-ray diffraction shows that the FePt nanocomposite films undergo a phase transformation from a disordered FCC phase to an ordered L10 phase between 673 and 773 K. The coercivity is 306 kA·m-1 whiles the average grain sizes is about 10 nm in the optimized FePt alloy film sample annealed at 673 K. The adjustable coercivity and fine grain size suggest that this FePt nanocomposites system is suitable as recording media at extremely high areal density.展开更多
A rare porous zinc-organic framework with ultrahigh thermal stability over 500℃ was obtained, which exhibits a CaF2-type topology formed by 8-connected tetranuclear Zn4 clusters and 4-connected phosphonocarboxylate l...A rare porous zinc-organic framework with ultrahigh thermal stability over 500℃ was obtained, which exhibits a CaF2-type topology formed by 8-connected tetranuclear Zn4 clusters and 4-connected phosphonocarboxylate ligands. Interestingly, the similar reactions to the 2 zinc-organic framework but in the absence of H2 O or by the replacement of Zn2＋with Co2＋can yield three different 3 D cluster-based frameworks but with the same CaF2-type topology.展开更多
Ni^(2+)/Cu^(2+)/SO_(4)^(2-)/polyvinyl alcohol precursor fibers with uniform diameters were prepared through electrospinning.Nickel-based composite nanoalloys containing Ni,Cu,and S were prepared through heat treatment...Ni^(2+)/Cu^(2+)/SO_(4)^(2-)/polyvinyl alcohol precursor fibers with uniform diameters were prepared through electrospinning.Nickel-based composite nanoalloys containing Ni,Cu,and S were prepared through heat treatment in an Ar atmosphere.The experimental results show that the main components of the prepared nanoalloys are NiCu,Ni_(3)S_(2),Ni,and C.The nanoalloys exhibit fine grain sizes about 200-500 nm,which can increase with increasing heat treatment temperature.Electrochemical test results show that the nickel sulfidemodified NiCu nanoalloy composites exhibit excellent oxygen evolution reaction properties,and the oxygen evolution reaction properties gradually improve with the increasing heat treatment temperature.The sample prepared at 1 000℃ for 40 min show a low overpotential of 423 mV and a small Tafel slope of 134 mV·dec^(-1) at a current density of 10 mA·cm^(-2).展开更多
Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a ca...Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a cancer-associated fibroblasts(CAFs)triggered structure-transformable nano-assembly(HSD-P@V),which can directionally deliver valsartan(Val,CAFs regulator)and doxorubicin(DOX,senescence inducer)to the specific targets.In detail,DOX is conjugated with hyaluronic acid(HA)via diselenide bonds(Se-Se)to form HSD micelles,while CAFs-sensitive peptide is grafted onto the HSD to form a hydrophilic polymer,which is coated on Val nanocrystals(VNs)surface for improving the stability and achieving responsive release.Once arriving at tumor microenvironment and touching CAFs,HSD-P@V disintegrates into VNs and HSD micelles due to sensitive peptide detachment.VNs can degrade the extracellularmatrix,leading to the enhanced penetration of HSD.HSD targets tumor cells,releases DOX to induce senescence,and recruits effector immune cells.Furthermore,senescent cells are cleared by the recruited immune cells to finish the integrated anti-tumor therapy.In vitro and in vivo results show that the nanoassembly remarkably inhibits tumor growth as well as lungmetastasis,and extends tumorbearing mice survival.This work provides a promising paradigm of programmed delivering multi-site nanomedicine for cancer immunotherapy.展开更多
A series of Ni-based catalysts were prepared via structural topological transformation from the Ni@Al_(2)O_(3)layered double hydroxides(LDHs)precursors,and applied for the deep catalytic hydrogenation saturation of py...A series of Ni-based catalysts were prepared via structural topological transformation from the Ni@Al_(2)O_(3)layered double hydroxides(LDHs)precursors,and applied for the deep catalytic hydrogenation saturation of pyrene in a high-pressure reactor.The pore structures,active species dispersion,surface morphology,amount and type of acid of the prepared catalysts were characterized by BET,XRD,SEM,TEM,XPS,SEM,NH_(3)-TPD and Py-IR.We studied the influence of physicochemical properties of Ni-based catalysts on the regularity and mechanism of deep hydrogenation of pyrene.Meanwhile,the synergy between Ni and Mo,and the interaction between active metals and support were discussed to further reveal the constitutive relationship during the hydrogenation reaction of pyrene.The results of the evaluation of the catalytic hydrogenation of pyrene show that the as-prepared NiMo mixed metal oxide(MMO)catalyst showed excellent catalytic activity:~95%pyrene conversion,90.12%for the selectivity of deep hydrogenation products(hexahydropyrene,decahydropyrene and hexadecahydropyrene).It was expected that the successfully preparation and utilization of NiMo-MMO catalyst could provide a theoretical basis for the design of this kind of catalysts for deep catalytic hydrogenation of polycyclic aromatic hydrocarbons(PAHs).展开更多
文摘The character of structural changes in the surface layer of titanium carbide （TiC） with Ni-Cr alloy binder was investigated theoretically and experimentally after electron-beam treatment of the material surface. The thermal influence of the electron-beam irradiation on the surface layer microstructure of the composite fine-grained material was mathematically analyzed. Quantitative estimations of the depth of the zone in microstructural phase transformations were carried out. The microstructure and concentration profile of Ti distribution in the metallic binder over the cross section of the surface layer with microstructural phase transformations after electron-pulse treatment of the hard metal surface were experimentally investigated.
基金supported by Science and Technology Project of Jiangxi Provincial Education Department(Nos.GJJ180942 and GJJ180941)National Natural Science Foundation of China(No.11664026)。
文摘The effects of concentration and an oriented external electric field on the transformations of hydrogenbonded structures of trimesic acid(TMA) and terephthalic acid(TPA) have been investigated at a liquidsolid interface by scanning tunneling microscopy(STM).The triangular periodic TMA framework can be transformed into a flower-like structure by changing the STM sample bias sign in situ.Networks of TMA and TPA are porous at a negative substrate bias,but typically change to relatively compact forms when the polarity of the applied bias is reversed.This change is reversible if the applied bias is reversed.The effects have potentials to locally control the capture and release of analytes in host-vip systems and the 2D morphology in multicomponent layers.
基金This study was supported by:The Late-Stage Support Program of the National Social Science Fund of China“Supply-Side Structural Reform and the Dual Structural Transformation of China's Economy”(Grant No.22FJLB009)The National Natural Science Fund of China for Young Scholars“The Dual Structural Transformation of China’s Economy:A Theoretical Analysis and Empirical Test Based on the Supply-Side Structural Reform”(Grant No.71703056).
文摘Occupational structural transformation is a common pattern during the steady growth of GDP per capita in major economies worldwide.In recent years,there has been a decline in the employment share of goods occupation and an increase in service occupation within the Chinese manufacturing industry,presenting a trend of occupational structural transformation and rapid development of service-oriented manufacturing.It is an important driving force and typical performance of the high-end,intelligent,and green development of the manufacturing industry.As a strategic general technology which leads the new round of technological revolution and industrial transformation,artificial intelligence(AI)has become a new fundamental force to accelerate the occupational structural transformation and service-oriented manufacturing development in China.Thus,this paper establishes a dynamic general equilibrium model with AI technology and occupational heterogeneity,showing the endogenous mechanism of occupational structural transformation.We find that when AI technology is biased towards goods occupation,and the elasticity of substitution between goods occupation and service occupation is less than 1,then AI will drive the transformation of occupational structure from goods to service within the manufacturing sector,increase the proportion of service-oriented manufacturing,improve labor productivity of manufacturing relative to service and stabilize the real output share of manufacturing.Promoting deeper integration of different occupations,intensifying R&D in AI technology and reducing labor mobility barriers between occupations can effectively accelerate the occupational structural transformation and industrial structural upgrading.We use theoretical analysis and numerical simulation method to show the theoretical mechanism by which AI affects occupational structural transformation and industrial structural transformation from a macroeconomic perspective,and put forward policy implications on how to promote the service-oriented manufacturing development and accelerate the construction of modern industrial system through AI innovation.
基金supported by the NKRD Program of China(No.2021YFA1500401)the National Natural Science Foundation of China(Nos.21821003,21890380)the LIRTP of Guangdong Pearl River Talents Program(No.2017BT01C161)。
文摘The intimate host-anion interactions will regulate thermodynamics and kinetics in the self-assembly of cationic cages mimicking biological counterparts.Herein,we report construction and transformation of three Pd(Ⅱ)-based metal-organic cages(MOCs)depending on different anions.Stoichiometric conversions of the lantern-shaped MOC-34 into either octahedral MOC-35 or tricapped trigonal prism MOC-36 are induced by BF_(4)^(–)or NO_(3)^(–),respectively.MOC-36 is kinetically favored and can undergo quantitative conversion to the thermodynamically preferred MOC-35 upon heating,accelerated by excess BF_(4)^(–)to motivate dissociative dynamics of Pd-vertices and lower activation barrier of cage transformation.The vip encapsulation behaviors of MOC-35 and MOC-36 have also been tested.These results manifest a significance of host-anion dynamics beyond complementary anion template,shedding light on the understanding of intricate anion recognition in nature.
基金supported by the project of the National Social Science Foundation of China entitled“Research on the Mechanism of Deep Integration of Modern Services Industry and Advanced Manufacturing Industry Driven by Digital Technology Innovation”(Project No.21BJY144).
文摘Based on Joseph Schumpeter’s theory of“creative destruction,”we constructed a multi-sectoral endogenous growth model that integrates the agriculture,manufacturing,and service sectors.Employing numerical simulation,we investigated the dynamic influence of technological innovation on the industrial structural transformation in two key aspects:the level of innovation and the research and development(R&D)efficiency within industries.Our findings indicate that technological innovation plays a pivotal role in advancing industrial structural transformation.Enhancements in both the level of innovation and R&D efficiency within industries are instrumental in fostering industrial structural transformation.Specifically,the enhancements in the level of innovation or R&D efficiency within the agricultural sector hasten its transition toward the manufacturing sector,while such enhancement within the manufacturing sector expedites its transition toward the service sector.However,such enhancements within the service sector tend to decelerate the transition from manufacturing to service.In light of this,it is essential to harness technological innovation to enhance the level of innovation and R&D efficiency in industries to facilitate the transition of traditional industries into high-value-added and emerging ones.Meanwhile,tailored technological innovation strategies should be implemented to boost a balanced industrial structural transformation within industries.
文摘The latest economic data released by China’s National Bureau of Statistics for April 2025 underscores the country’s robust economic recovery and structural transformation.Industrial production surged by 6.1 percent year on year,propelled by breakthroughs in advanced manufacturing,from high-tech industries to cutting-edge equipment sectors.
文摘Under the guidance of national policies,the“coal to gas”project has become one of the important measures to promote the transformation of energy structure in China.Foshan,an important industrial town in Guangdong province,the implementation of the“coal to gas”policy has demonstrated significance for the optimization of the national energy structure.Through the analysis of the change in Foshan’s energy consumption structure and the implementation of the policy,this paper found that there were some challenges in the policy implementation process,such as high economic cost,lagging infrastructure,low social acceptance,and lack of technical personnel.To address this,suggestions are put forward,including increasing financial subsidies,improving laws and regulations,promoting technological innovation,and encouraging social inclusion policies.These recommendations aim to provide guidance and reference for the remaining“coal to gas”projects and the development of clean energy.
基金the financial support from the National Natual Science Foundation of China(No.51375491)the Natural Science Foundation of Chongqing(Project No.2011JJA90020)the Science Foundation for Young Teachers of Logistical Engineering University
文摘The oxidation behavior of three biodiesels of different origins,viz.rapeseed oil derived biodiesel,soybean oil derived biodiesel and waste oil based biodiesel,were tested on an oxidation tester.The chemical compositions of the biodiesels were characterized by gas chromatography.Thereafter,the structural transformation of fatty acid methyl ester(FAME)of the biodiesels was analyzed by an infrared spectrometer and an ultraviolet absorption spectrometer.The results demonstrated that the oxidation behavior of biodiesels of different origins was closely related to the composition and distribution of FAMEs.Higher concentration of unsaturated FAME with multi-double bonds exhibited poorer oxidation resistance.Furthermore,cis-trans isomerization transformation occurred in the unsaturated FAME molecules and conjugated double-bond produced during the oxidation process of biodiesel.Greater cis-trans variations corresponded to deeper oxidation degree.The higher the content of unsaturated FAME with multi-double bonds in a biodiesel,the more the conjugated double bonds was formed.
基金supported by the National Natural Science Foundation of China(22105060)the Natural Science Foundation of Hebei Province(E2020205004)+1 种基金Funding from the Science Foundation of Hebei Normal University(L2020B13)the Science and Technology Project of Hebei Education Department(BJ2021028)。
文摘A mixture of Ni and Fe oxides is among the most commonly active catalysts for the oxygen evolution reaction(OER)during the water oxidation process.In particular,Ni oxide incorporated with even a small amount of Fe leads to substantively enhanced OER activity.However,the critical role of Fe species during the electrocatalytic process is still under evaluation.Herein,we report nickel(oxy)hydroxide incorporated with Fe through the surface reconstruction of a bimetallic metal-organic framework(NiFe-MOF)during the water oxidation process.The spectroscopic investigations with theoretical calculations reveal the critical role of Fe in promoting the formation of highly oxidized Ni^(4+),which directly correlates with an enhanced OER activity.Both the geometric and electronic structu res of the as-reconstructed Ni_(1-x)Fe_(x)OOH electrocatalysts can be delicately tuned by the Ni-Fe ratio of the bimetallic NiFe-MOF,further affecting the catalytic activity.As a result,the Ni_(1-x)Fe_(x)OOH derived from Ni_(0.9)Fe_(0.1)-MOF delivers low overpotentials of 260 mV at 10 mA cm^(-2)and 400 mV at 300 mA cm^(-2).
基金the financial support of Shanghai Leading Academic Discipline Project(No. B502)Fundamental Research Funds for the Central University
文摘A new kind of polytriazoleimide containing bisphenyl-l,2,3-triazole （BPT） was synthesized by copper-catalyzed 1,3-dipolar cycloaddition of azides and alkynes （CuAAC） and polycondensation. The thermal stability and degradation mechanism of the polytriazoleimide were investigated. The results show that the structure of BPT in polytriazoleimide transforms to phenylindole after thermal treatment, accompanying the release of NE.
文摘In this paper,we performed an empirical study on the TFP effect of structural transformation based on panel data of economic growth in 169 countries across the world.Our findings are threefold:First,structural transformation has an inverted U-shaped effect on TFP.When the degree of structural transformation is on the left side of the inflection point,structural transformation is conducive to softening industrial structure and inducing TFP;when the degree of structural transformation is on the right side of the inflection point,structural transformation will induce industrial hollowing out and inhibit TFP.Second,since the reform and opening up program was launched in 1978,China’s structural transformation has evolved from the stage of adaptation to the stage of strategic adjustment with an increasingly evident trend towards a service-based economy,but structural transformation remains on the left side of the inflection point of the inverted U-shaped curve,i.e.the TFP effect of structural transformation is positive.Third,TFP improvement lies at the heart of high-quality development.In pursuing high-quality development,China should lower growth rate expectations,attach greater importance to supply-side structural reforms,and accelerate structural transformation to promote TFP improvement.
基金financial supports from the National Natural Science Foundation of China(Nos.51161003,51561031)the Natural Science Foundation of Guangxi,China(No.2018GXNSFAA138150)。
文摘An energy model for the structure transformation of pile-ups of grain boundary dislocations(GBD)at the triple-junction of the grain boundary of ultrafine-grain materials was proposed.The energy of the pile-up of the GBD in the system was calculated by the energy model,the critical geometric and mechanical conditions for the structure transformation of head dislocation of the pile-up were analyzed,and the influence of the number density of the dislocations and the angle between Burgers vectors of two decomposed dislocations on the transformation mode of head dislocation was discussed.The results show when the GBD is accumulated at triple junction,the head dislocation of the GBD is decomposed into two Burgers vectors of these dislocations unless the angle between the two vectors is less than 90°,and the increase of applied external stress can reduce the energy barrier of the dislocation decomposition.The mechanism that the ultrafine-grained metal material has both high strength and plasticity owing to the structure transformation of the pile-up of the GBD at the triple junction of the grain boundary is revealed.
基金supported by the Science Foundation of Chongqing Committee of Education of China (Grant No. KJ111206)the Fund of Chongqing University of Arts and Sciences (Grant No. Z2011RCYJ05)
文摘The synergy effect of alloy elements in bimetallic clusters can be used to tune the chemical and physical properties. Research on the influences of alloy concentration and distribution on the frozen structure of bimetallic clusters plays a key rolc in exploring new structural materials. In this paper, we study the influence of Ag concentration on the frozen structure of the （AgCo）561 cluster by using molecular dynamics simulation with a general embedded atom method. The results indicate that tt^e structure and chemical ordering of the （AgCo）561 cluster are strongly related to Ag concentration. Hcp-icosahedron structural transformation in the frozen （CoAg）561 cluster can be induced by changing Ag concentration. The chemical ordering also transforms to Janus-like Co Ag from core-shell Co-Ag.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304294 and 11274281)the Science Fund from the National Laboratory of Shock Wave and Detonation Physics of China(Grant Nos.9140C670201140C67281 and 9140C670102150C67288)
文摘The high-pressure polymorphs and structural transformation of Sn were experimentally investigated using angle- dispersive synchrotron x-ray diffraction up to 108.9 GPa. The results show that at least at 12.8 GPa β-Sn→bct structure transformation was completed and no two-phase coexistence was found. By using a long-wavelength x-ray, we resolved the diffraction peaks splitting and discovered the formation of a new distorted orthorhombic structure bco from the bct structure at 31.8 GPa. The variation of the lattice parameters and their ratios with pressure further validate the observation of the bco polymorph. The bcc structure appears at 40.9 GPa and coexists with the bco phase throughout a wide pressure range of 40.9 GPa-73.1 GPa. Above 73.1 GPa, only the bcc polymorph is observed, The systematically experimental investigation confirms the phase transition sequence of Sn asβ-Sn→bct→bco→bco ＋ bcc→bcc upon compression to 108.9 GPa at room temperature.
基金the financial support from China Postdoctoral Science Foundation(No.2019T120843)Sichuan Science and Technology Program(No.2019YJ0091)。
文摘It is generally recognized that the formation and accumulation of iron oxides on the surface of zero-valent iron(Fe^(0))resulting in significant decrease of contaminant degradation rates during the long-term reactions.However,in this study,we found that the removal efficiencies of p-nitrophenol(PNP)by micro zero-valent iron(mFe^(0))could maintain at the satisfactory level in the process of continuous reactions(20 cycles).The removal rate constant(0.1779 min^(-1))of the 5th cycle was 6.74 times higher than that of the 1streaction(0.0264 min^(-1)),even the 20th cycle(0.0371 min^(-1))was higher than that of the 1st reaction.Interestingly,almost no dissolved iron was detected in the solution,and the total iron concentrations decreased dramatically with the process of continuous reactions.The results of scanning electron microscope and energy dispersive spectrometry(SEM-EDS)and X-ray diffraction(XRD)revealed that the structure and composition of corrosion products change from amorphous to highly crystal with the increase of the number of cycles.The corrosion products were mainly magnetite(Fe_(3)O_(4))and a small part of maghemite(γ-Fe_(2)O_(3)),which were in the form of micro sphe res on the surface of mFe^(0).The formation of surface oxidation shell hindered the release of Fe^(2+).X-ray photoelectron spectroscopy(XPS)results illustrated that partial Fe3O_(4) could be converted into y-Fe_(2)O_(3).Electrochemical analysis proved that the electron transfer rate of mFe^(0) increased with the formation of the oxides shell.However,the consumption of iron core and thicker oxide film weakened the electron transfer rate.Besides,the quenching experiments indicated that the reaction activity of mFe^(0) could be enhanced with the addition of scavengers.This study deepened the understanding of the structural transformation and radical production of mFe^(0) in continuous reactions.
基金This work was financially supported by the National Science Fund for Distinguished Young Scholars and the National Natural Science Foundation of China (No. 50325209, 50232030).
文摘Fe100-xPtx(x=30at.%-60at.%) nanocomposite films were deposited on natural-oxidized Si(100) substrates by magnetron sputtering. The as-deposited films were annealed between 373 and 1073 K. In situ X-ray diffraction shows that the FePt nanocomposite films undergo a phase transformation from a disordered FCC phase to an ordered L10 phase between 673 and 773 K. The coercivity is 306 kA·m-1 whiles the average grain sizes is about 10 nm in the optimized FePt alloy film sample annealed at 673 K. The adjustable coercivity and fine grain size suggest that this FePt nanocomposites system is suitable as recording media at extremely high areal density.
基金financially supported by the National Natural Science Foundations of China (Nos. 21303018, 21371033, and 21401195)the Natural Science Foundation for Young Scholars of Fujian Province (No. 2015J05041)Projects from State Key Laboratory of Structural Chemistry of China (Nos. 20150001 and 20160020)
文摘A rare porous zinc-organic framework with ultrahigh thermal stability over 500℃ was obtained, which exhibits a CaF2-type topology formed by 8-connected tetranuclear Zn4 clusters and 4-connected phosphonocarboxylate ligands. Interestingly, the similar reactions to the 2 zinc-organic framework but in the absence of H2 O or by the replacement of Zn2＋with Co2＋can yield three different 3 D cluster-based frameworks but with the same CaF2-type topology.
基金Funded by the Doctoral Fund of Chengdu University(No.2081919131)the Sichuan Science and Technology Program(No.2023YFG0229)。
文摘Ni^(2+)/Cu^(2+)/SO_(4)^(2-)/polyvinyl alcohol precursor fibers with uniform diameters were prepared through electrospinning.Nickel-based composite nanoalloys containing Ni,Cu,and S were prepared through heat treatment in an Ar atmosphere.The experimental results show that the main components of the prepared nanoalloys are NiCu,Ni_(3)S_(2),Ni,and C.The nanoalloys exhibit fine grain sizes about 200-500 nm,which can increase with increasing heat treatment temperature.Electrochemical test results show that the nickel sulfidemodified NiCu nanoalloy composites exhibit excellent oxygen evolution reaction properties,and the oxygen evolution reaction properties gradually improve with the increasing heat treatment temperature.The sample prepared at 1 000℃ for 40 min show a low overpotential of 423 mV and a small Tafel slope of 134 mV·dec^(-1) at a current density of 10 mA·cm^(-2).
基金was supported by National Natural Science Foundation of China(81972893,82172719)Natural Science Foundation of Henan(212300410071)Training program for young key teachers in Henan Province(2020GGJS019).
文摘Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a cancer-associated fibroblasts(CAFs)triggered structure-transformable nano-assembly(HSD-P@V),which can directionally deliver valsartan(Val,CAFs regulator)and doxorubicin(DOX,senescence inducer)to the specific targets.In detail,DOX is conjugated with hyaluronic acid(HA)via diselenide bonds(Se-Se)to form HSD micelles,while CAFs-sensitive peptide is grafted onto the HSD to form a hydrophilic polymer,which is coated on Val nanocrystals(VNs)surface for improving the stability and achieving responsive release.Once arriving at tumor microenvironment and touching CAFs,HSD-P@V disintegrates into VNs and HSD micelles due to sensitive peptide detachment.VNs can degrade the extracellularmatrix,leading to the enhanced penetration of HSD.HSD targets tumor cells,releases DOX to induce senescence,and recruits effector immune cells.Furthermore,senescent cells are cleared by the recruited immune cells to finish the integrated anti-tumor therapy.In vitro and in vivo results show that the nanoassembly remarkably inhibits tumor growth as well as lungmetastasis,and extends tumorbearing mice survival.This work provides a promising paradigm of programmed delivering multi-site nanomedicine for cancer immunotherapy.
基金supported by the National Natural Science Foundation of China(21536009)Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03)+1 种基金National Natural Science Foundation of China(22008198)the Special Scientific Research Plan Project of Education Ministry of Shaanxi Province,China(19JK0854).
文摘A series of Ni-based catalysts were prepared via structural topological transformation from the Ni@Al_(2)O_(3)layered double hydroxides(LDHs)precursors,and applied for the deep catalytic hydrogenation saturation of pyrene in a high-pressure reactor.The pore structures,active species dispersion,surface morphology,amount and type of acid of the prepared catalysts were characterized by BET,XRD,SEM,TEM,XPS,SEM,NH_(3)-TPD and Py-IR.We studied the influence of physicochemical properties of Ni-based catalysts on the regularity and mechanism of deep hydrogenation of pyrene.Meanwhile,the synergy between Ni and Mo,and the interaction between active metals and support were discussed to further reveal the constitutive relationship during the hydrogenation reaction of pyrene.The results of the evaluation of the catalytic hydrogenation of pyrene show that the as-prepared NiMo mixed metal oxide(MMO)catalyst showed excellent catalytic activity:~95%pyrene conversion,90.12%for the selectivity of deep hydrogenation products(hexahydropyrene,decahydropyrene and hexadecahydropyrene).It was expected that the successfully preparation and utilization of NiMo-MMO catalyst could provide a theoretical basis for the design of this kind of catalysts for deep catalytic hydrogenation of polycyclic aromatic hydrocarbons(PAHs).
