The drug supervision methods based on near-infrared spectroscopy analysis are heavily dependent on the chemometrics model which characterizes the relationship between spectral data and drug categories.The preliminary ...The drug supervision methods based on near-infrared spectroscopy analysis are heavily dependent on the chemometrics model which characterizes the relationship between spectral data and drug categories.The preliminary application of convolution neural network in spectral analysis demonstrates excellent end-to-end prediction ability,but it is sensitive to the hyper-parameters of the network.The transformer is a deep-learning model based on self-attention mechanism that compares convolutional neural networks(CNNs)in predictive performance and has an easy-todesign model structure.Hence,a novel calibration model named SpectraTr,based on the transformer structure,is proposed and used for the qualitative analysis of drug spectrum.The experimental results of seven classes of drug and 18 classes of drug show that the proposed SpectraTr model can automatically extract features from a huge number of spectra,is not dependent on pre-processing algorithms,and is insensitive to model hyperparameters.When the ratio of the training set to test set is 8:2,the prediction accuracy of the SpectraTr model reaches 100%and 99.52%,respectively,which outperforms PLS DA,SVM,SAE,and CNN.The model is also tested on a public drug data set,and achieved classification accuracy of 96.97%without preprocessing algorithm,which is 34.85%,28.28%,5.05%,and 2.73%higher than PLS DA,SVM,SAE,and CNN,respectively.The research shows that the SpectraTr model performs exceptionally well in spectral analysis and is expected to be a novel deep calibration model after Autoencoder networks(AEs)and CNN.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
Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissi...Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissions in the Xuzhou Metropolitan Area from 2000 to 2014, with a focus on their relationships and driving factors. Our research indicates that carbon emission intensity from industrial structures in the Xuzhou Metropolitan Area at first showed an increasing trend, which then decreased. Furthermore, the relationship between emissions and industrial economic growth has been trending toward absolute decoupling. From the perspective of the center-periphery, the Xuzhou Metropolitan Area formed a concentric pattern, where both progress towards low emissions and the level of technological advancement gradually diminished from the center to the periphery. In terms of variation across provinces, the ISCB index in the eastern Henan has decreased the slowest, followed by the southern Shandong and the northern Anhui, with the northern Jiangsu ranking last. During this period, resource-and labor-intensive industries were the primary growth industries in the northern Anhui and the eastern Henan, while labor-intensive industries dominated the southern Shandong and capital-intensive industries dominated the northern Jiangsu. In terms of city types, the spatial pattern for industrial structure indicates that recession resource-based cities had higher carbon emission intensities than mature resource-based cities, followed by non-resource-based cities and regenerative resource-based cities. Generally, the industrial structure in the Xuzhou Metropolitan Area has transformed from being resource-intensive to capital-intensive, and has been trending toward technology-intensive as resource availability has been exploited to exhaustion and then been regenerated. Industrial structure has been the leading factor causing heterogeneity of carbon emission intensities between metropolitan cities. Therefore, the key to optimizing the industrial structure and layout of metropolitan areas is to promote industrial structure transformation and improve the system controlling collaborative industrial development between cities.展开更多
Land, as a key factor of production, is an appropriate indicator of national and regional economic structure transformation. Land use in the Changjiang （Yangtze） River Basin （CRB） since the 1950s has experienced t...Land, as a key factor of production, is an appropriate indicator of national and regional economic structure transformation. Land use in the Changjiang （Yangtze） River Basin （CRB） since the 1950s has experienced these changes. Industrialization has been the most powerful force of the change in the regional development of the CRB. Virtually all regional resources were put into this effort to modernize the industrial production and urban construction systems of the CRB whose industrialization and urbanization has been a success story, with impressive structural change in both production and land use. These changes are evident ih modem urban areas, but even more in traditionally rural areas. The regression analysis of regional development in the CRB over an extended period shows that the dominant factor in regional land use change is widespread industrialization in rural areas rather than the expansion of urban area. Thus, urbanization has had a limited influence on land use change in the CRB. A major task in realizing more sustainable land use in the future development of CRB is to relocate industrial activities from rural to urban areas.展开更多
Orthorhombic LiMnO2 cathode materials were synthesized successfully at lower temperature by sol-gel method. When LiMnO2 precursor prepared by sol-gel method was fired in air, the product was a mixture of spinel struct...Orthorhombic LiMnO2 cathode materials were synthesized successfully at lower temperature by sol-gel method. When LiMnO2 precursor prepared by sol-gel method was fired in air, the product was a mixture of spinel structure LiMn2O4 and rock-salt structure Li2MnO3, whereas in argon single-phase orthorhombic LiMnO2 could obtain at the range of 750℃ to 920℃. The substitution of Mn by Zn2+ or Co3+ in LiMnO2 led to the structure of LiMnO2 transiting to Qα-LiFeO2. The results of electrochemical cycles indicated that the discharged capacity of orthorhombic-LiMnO2 was smaller at the initial stages, then gradually increased with the increasing of cycle number, finally the capacity stabilized to certain value after about 10th cycles. This phenomenon reveals that there is an activation process for orthorhombic LiMnO2 cathode materials during electrochemical cycles, which is a phase transition process from orthorhombic LiMnO2 to tetragonal spinel Li2Mn2O4. The capacity of orthorhombic LiMnO2 synthesized at lower temperature is larger than that synthesized at high temperature.展开更多
It has been recognized that a small amount of propane mixed with methane can change greatly in not only the thermodynamics but also the structural properties of gas hydrate.However,its mechanism is still not well unde...It has been recognized that a small amount of propane mixed with methane can change greatly in not only the thermodynamics but also the structural properties of gas hydrate.However,its mechanism is still not well understood yet.In this research,structure-Ⅱ(sⅡ)hydrate is synthesized using a methanepropane gas mixture with an initial mole ratio of 99:1,and it is found that large(5~(12)6~4)cages are cooccupied by multiple gases based on the rigid structure analysis of neutron diffraction data.The first principles calculation and molecular dynamics simulation are conducted to uncover the molecular mechanism for sⅡmethane-propane hydrate formation,revealing that the presence of propane inhibits the formation of structure-Ⅰ(sⅠ)hydrate but promotes sⅡhydrate formation.The results help to understand the accumulation mechanism of natural gas hydrate and benefit to optimize the condition for gas storage and transportation in hydrate form.展开更多
Scarcity of land resources and transformation of industrial structure is a pair of contradictory elements.We derive the characteristics of land use structure and industrial structure transformation in Xining City usin...Scarcity of land resources and transformation of industrial structure is a pair of contradictory elements.We derive the characteristics of land use structure and industrial structure transformation in Xining City using Transformation Coefficient(TC):first,in the period 1999-2000,the land use structure coefficient(θ1) declined by 79.55%,but the overall evolution trend is gentle;second,the transformation coefficient of industrial structure(θ2) tended to decline ceaselessly on the whole,a decrease of 36.09%(overall,the transformation coefficient of industrial structure is slightly greater than the land use structure coefficient);third,the inter-annual variation of the two experienced ups and downs(in the period 1999-2007,the inter-annual variation was great and in the period 2008-2010,the inter-annual variation tended to be gentle).On the basis of autocorrelation and co-integration model,we draw the following conclusions through analysis:first,the land use structure in Xining City plays a role in promoting industrial structure transformation;second,there is a long-term equilibrium relationship between the two.Finally,relevant policy recommendations are put forward for the industrial development in Xining City.展开更多
Designing multicomponent integration catalysts(MICs)has been a promising strategy for improving electrocatalytic hydrogen evolution reaction(HER)due to the highly active interfaces as well as electronic synergy.Nevert...Designing multicomponent integration catalysts(MICs)has been a promising strategy for improving electrocatalytic hydrogen evolution reaction(HER)due to the highly active interfaces as well as electronic synergy.Nevertheless,many fundamental questions such as their actual active species and the influence on long-term stability remain to be answered.Herein,we present the structural evolution from a pseudotri-component electrocatalyst of nitrogen-doped carbon supported nickel/vanadium nitride/vanadium oxide(Ni-VN-V_(2)O_(3)/NC)nanorods to the heterostructural nickel/vanadium nitride(Ni-VN/NC)nanosheets during chemical or electrochemical processes.The self-reconstructed Ni-VN/NC exhibits a robust stability under alkaline conditions,while maintaining initial efficient HER activity with a low overpotential of 76 mV at the current density of 10 mA cm^(-2).Theoretical calculations and quasi-in-situ spectroscopic technology unveil the redistribution of electrons on the synergistic active interface,which synchronously optimizes the affinities for hydrogen,hydroxide,and water molecules,thereby remarkably accelerating the HER kinetics by reducing the barrier of Volmer step.展开更多
In order to investigate the ion irradiation effect on the corrosion behavior and microstructure of Zircaloy-4, the Zircaloy-4 film were prepared by electron beam deposition on the Zircaloy-4 specimen surface and irra...In order to investigate the ion irradiation effect on the corrosion behavior and microstructure of Zircaloy-4, the Zircaloy-4 film were prepared by electron beam deposition on the Zircaloy-4 specimen surface and irradiated by Kr ions using an accelerator at an energy of 300 keV with the dose from 1×1015 to 3×1016ions/cm2. The post-irradiation corrosion tests were conducted to rank the corrosion resistance of the resulting specimens by potentiodynamic polarization curve measurements in a 0.5 mol/L H2SO4 water so- lution at room temperature. Transmission electron microscopy (TEM) was employed to examine the microstructural change in the surface. The potentiodynamic tests show that with the irradiation dose increasing, the passive current density, closely related to the surface corrosion resistance, decreases firstly and increases subsequently. The mechanism of the corrosion behavior transformation is due to the amorphous phase formation firstly and the amorphous phase destruction and the polycrystalline structure formation in the irradiated surface subsequently.展开更多
304 austenitic stainless steel was cold rolled in the range of 20%-80%reductions and then annealed at 700-900°C for 60 sto obtain nano/ultrafine-grained（NG/UFG）structure.Transmission electron microscopy,electro...304 austenitic stainless steel was cold rolled in the range of 20%-80%reductions and then annealed at 700-900°C for 60 sto obtain nano/ultrafine-grained（NG/UFG）structure.Transmission electron microscopy,electron backscatter diffraction and X-ray diffraction were used to characterize the resulting microstructures.The results showed that with the increase of cold reduction,the content of martensite was increased.The steel performed work hardening during cold-working owing to the occurrence of strain induced martensite which nucleated in single shear bands.Further rolling broke up the lath-type martensite into dislocation-cell type martensite because of the formation of slip bands.Samples annealed at 800-960°C for 60 swere of NG/UFG structure with different percentage of nanocrystalline（60-100 nm）and ultrafine（100-500 nm）grains,submicron size（500-1000 nm）grains and micron size（〉1000 nm）grains.The value of the Gibbs free energy exhibited that the reversion mechanism of the reversion process was shear controlled by the annealing temperature.For a certain annealing time during the reversion process,austenite nucleated first on dislocation-cell type martensite and the grains grew up subsequently and eventually to be micrometer/submicrometer grains,while the nucleation of austenite on lath-type martensite occurred later resulting in nanocrystalline/ultrafine grains.The existence of the NG/UFG structure led to a higher strength and toughness during tensile test.展开更多
The microstructure of CdI2 thin film grown during vapor-phase deposition was investigated by scanning electron microscopy (SEM). The thin film deposited on Si crystal consists of numerous sunflower-like aggregates. Th...The microstructure of CdI2 thin film grown during vapor-phase deposition was investigated by scanning electron microscopy (SEM). The thin film deposited on Si crystal consists of numerous sunflower-like aggregates. These aggregates display well self-assembly characteristics. The size of Sunflower-like aggregates is between 12 and 44 μm. Each sunflower-like aggregate is surrounded with many adjacent wings-'petals'. The structure of central region of the 'sunflower' is obviously difFerent from that of the 'petal'. Electron spectroscopy for chemical analysis (ESCA) was employed in determining the chemical valence of the thin film. Self-organization efFect is used to explain the coring growth process of CdI2 thin film展开更多
A simple model of the closely packed structure for system of hard-sphere particles interacting via the long-range Newtonian type attraction is suggested. Based on density functional theory, the exact equation of ...A simple model of the closely packed structure for system of hard-sphere particles interacting via the long-range Newtonian type attraction is suggested. Based on density functional theory, the exact equation of state is obtained and the mutual transformations of the crystal structures in such systems are studied. The description takes into account the fact impossibility of hard-sphere particles which have the same spatial occupation place.展开更多
This paper uses the panel data of 17 cities in Shandong Province from 2003 to 2018 to construct a panel model to empirically study the impact of foreign direct investment(FDI)on the industrial structure.The results sh...This paper uses the panel data of 17 cities in Shandong Province from 2003 to 2018 to construct a panel model to empirically study the impact of foreign direct investment(FDI)on the industrial structure.The results show that two-way investment,financial industry development,and policy variables have significant roles in promoting the advancement of the industrial structure in the province.In the future implementation of the“Going Global”strategy in Shandong Province,the cooperation between two-way investment and the financial industry should be strengthened,the level of regional financial development should be improved,and the impact of two-way investment on the optimization and upgrading of the industrial structure should be reinforced.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
This study examines the influence of microfinance institutions’(MFIs)financial innovation on structural transformation.For this purpose,we considered a household survey from Nepal.The survey collected data on various...This study examines the influence of microfinance institutions’(MFIs)financial innovation on structural transformation.For this purpose,we considered a household survey from Nepal.The survey collected data on various individual and household characteristics,borrowing patterns,and occupations over the years.The key question focused on occupations before and after borrowing,a categorical response variable indicating 1 for occupational change after borrowing and 0 otherwise.Therefore,we use logistic regression to estimate the probability of occupational change,given two measures of financial innovation:loan purpose and size.The results show that the number of households involved in agriculture significantly decreased,with the majority switching to businesses and convenience stores,indicating a shift to the manufacturing and service sectors.These findings suggest that MFIs contribute to local-level structural transformation by enabling borrowers to move away from traditional employment.This study has important implications for policymakers,development practitioners,and academics interested in promoting economic development through microfinancing in low-income countries.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
The synthesized molecular clusters featuring the cubic[4Fe–4S]core have been studied for several decades,as they serve as true analogs of the active components in ferritin within biological systems.Such a model clust...The synthesized molecular clusters featuring the cubic[4Fe–4S]core have been studied for several decades,as they serve as true analogs of the active components in ferritin within biological systems.Such a model cluster has been extensively investigated in various fields,including structural modulation,catalysis,and self-assembly under laboratory conditions,with the aim of gaining an in-depth understanding of their roles in biological functions.Herein,we revisited three well-known[Fe_(4)S_(4)(SR)_(4)]^(2–)molecules,namely[Me_(4)N]_(2)[Fe_(4)S_(4)(SR)_(4)](R=o-MBT,m-MBT,p-MBT),and successfully established their single crystal structures that remain unknown prior to this work.Interestingly,it is revealed that the position of the substituent methyl group has an obvious steric effect on the arrangement of the ligand around the[4Fe–4S]core,which further influences their overall packing patterns in single crystals.In addition,this work unveils two new structure transformation behaviors for the[Fe_(4)S_(4)(SR)_(4)]^(2–)system:i)the monomeric[Fe(SR)_(4)]^(2–)and tetrameric[Fe_(4)S_(4)(SR)_(4)]^(2–)can be interconverted,and ii)[Fe_(4)S_(4)(SR)_(4)]^(2–)can be transferred into an intriguing iron-oxide complex Na_(2)Fe_(6)O(OMe)_(18)·6MeOH in a well-controlled oxidizing environment.展开更多
The strength-ductility trade-off has been the most challenging problem for structural metals for centuries.Nanoprecipitation strengthening is an ideal approach to enhance the strength without significantly sacrificing...The strength-ductility trade-off has been the most challenging problem for structural metals for centuries.Nanoprecipitation strengthening is an ideal approach to enhance the strength without significantly sacrificing the ductility.Stable nanoprecipitates have been successfully acquired by nanostructural design,but the number density of nanoprecipitates cannot be further increased.Researchers attempted to enhance number density by introducing highly potent nucleation sites(e.g.,dislocations).However,there remains controversy over the influence of dislocations on the nucleation and growth of coherent nanoprecipitates with minimized nucleation barrier.Here,Cu-rich nanoprecipitates in an HSLA steel,as a typical type of coherent nanoprecipitates,are investigated.By combining analytical calculation and experiments,we show that dislocations are harmful for the formation of large numbered Cu-rich nanoprecipitates in a certain density range.Insufficient dislocations deprive solute atoms which decrease homogenous precipitation that cannot be compensated by the increase in heterogeneous precipitation.Under such circumstance,Cu-rich nanoprecipitates have smaller number density but larger size and higher fraction of incoherent structures due to rapid Ostwald ripening.As a result,by controlling dislocation density,the yield strength is increased by 24%without obvious loss in ductility as compared with traditional solution-quench-age process.Our work would help to optimize composition and processing routes that fully exploit the nanoprecipitation strengthening effect.展开更多
Reaction temperature is one of the key parameters in the synthesis of metal-organic frameworks （MOFs）. Though there is no convergence with regard to the various experimental parameters, reaction temperature has been...Reaction temperature is one of the key parameters in the synthesis of metal-organic frameworks （MOFs）. Though there is no convergence with regard to the various experimental parameters, reaction temperature has been found to have remarkable influence on the formation and structure of MOFs, especially toward the control of topology and dimensionality of the MOF structures. Theoretically, the reaction temperature affects directly the reaction energy barrier in reaction thermodynamics and the reaction rate in the reaction kinetics. This review aims to show the influence of reaction temperature on crystal growth/assembly, structural modulation and transformation of MOFs, and to provide primary information and insights into the design and assernblv of desired MOFs.展开更多
Eu3＋-WO3 nanoparticles were successfully prepared by the modified method of Pechini. The prepared samples were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution tra...Eu3＋-WO3 nanoparticles were successfully prepared by the modified method of Pechini. The prepared samples were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution transmission electron microscopy （HRTEM）, and UV-vis spectroscopy. Results showed that the Eu3＋-WO3 nanoparticles, which had an average external diameter of 10–25 nm, were composed of the different shapes of puncheon and catenary after being pretreated by pH, pressure vessal, and surfactant. Moreover, structural transformation matrix contained different crystals of anorthic and orthorhombic structure. The photocatalytic activities of the nanoparticles were evaluated by photocatalytic decomposition of rhodamine B. Eu3＋-WO3 nanoparticles were more efficient than WO3 and TiO2 on sunlight use ratio. Photocatalysis experiments indicated that the Eu3＋-WO3 nanoparticles exhibited the highest photocatalytic activity.展开更多
基金supported by the National Natural Science Foundation of China(61906050,21365008)Guangxi Technology R&D Program(2018AD11018)Innovation Project of GUET Graduate Education(2021YCXS050).
文摘The drug supervision methods based on near-infrared spectroscopy analysis are heavily dependent on the chemometrics model which characterizes the relationship between spectral data and drug categories.The preliminary application of convolution neural network in spectral analysis demonstrates excellent end-to-end prediction ability,but it is sensitive to the hyper-parameters of the network.The transformer is a deep-learning model based on self-attention mechanism that compares convolutional neural networks(CNNs)in predictive performance and has an easy-todesign model structure.Hence,a novel calibration model named SpectraTr,based on the transformer structure,is proposed and used for the qualitative analysis of drug spectrum.The experimental results of seven classes of drug and 18 classes of drug show that the proposed SpectraTr model can automatically extract features from a huge number of spectra,is not dependent on pre-processing algorithms,and is insensitive to model hyperparameters.When the ratio of the training set to test set is 8:2,the prediction accuracy of the SpectraTr model reaches 100%and 99.52%,respectively,which outperforms PLS DA,SVM,SAE,and CNN.The model is also tested on a public drug data set,and achieved classification accuracy of 96.97%without preprocessing algorithm,which is 34.85%,28.28%,5.05%,and 2.73%higher than PLS DA,SVM,SAE,and CNN,respectively.The research shows that the SpectraTr model performs exceptionally well in spectral analysis and is expected to be a novel deep calibration model after Autoencoder networks(AEs)and CNN.
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Under the auspices of the National Natural Science Foundation of China(No.41371146,41671123)National Social Science Foundation of China(No.13BJY067)
文摘Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissions in the Xuzhou Metropolitan Area from 2000 to 2014, with a focus on their relationships and driving factors. Our research indicates that carbon emission intensity from industrial structures in the Xuzhou Metropolitan Area at first showed an increasing trend, which then decreased. Furthermore, the relationship between emissions and industrial economic growth has been trending toward absolute decoupling. From the perspective of the center-periphery, the Xuzhou Metropolitan Area formed a concentric pattern, where both progress towards low emissions and the level of technological advancement gradually diminished from the center to the periphery. In terms of variation across provinces, the ISCB index in the eastern Henan has decreased the slowest, followed by the southern Shandong and the northern Anhui, with the northern Jiangsu ranking last. During this period, resource-and labor-intensive industries were the primary growth industries in the northern Anhui and the eastern Henan, while labor-intensive industries dominated the southern Shandong and capital-intensive industries dominated the northern Jiangsu. In terms of city types, the spatial pattern for industrial structure indicates that recession resource-based cities had higher carbon emission intensities than mature resource-based cities, followed by non-resource-based cities and regenerative resource-based cities. Generally, the industrial structure in the Xuzhou Metropolitan Area has transformed from being resource-intensive to capital-intensive, and has been trending toward technology-intensive as resource availability has been exploited to exhaustion and then been regenerated. Industrial structure has been the leading factor causing heterogeneity of carbon emission intensities between metropolitan cities. Therefore, the key to optimizing the industrial structure and layout of metropolitan areas is to promote industrial structure transformation and improve the system controlling collaborative industrial development between cities.
基金Under the auspices of Knowledge Innovation Program of Chinese Academy of Sciences (No. KCZX2-307-01)
文摘Land, as a key factor of production, is an appropriate indicator of national and regional economic structure transformation. Land use in the Changjiang （Yangtze） River Basin （CRB） since the 1950s has experienced these changes. Industrialization has been the most powerful force of the change in the regional development of the CRB. Virtually all regional resources were put into this effort to modernize the industrial production and urban construction systems of the CRB whose industrialization and urbanization has been a success story, with impressive structural change in both production and land use. These changes are evident ih modem urban areas, but even more in traditionally rural areas. The regression analysis of regional development in the CRB over an extended period shows that the dominant factor in regional land use change is widespread industrialization in rural areas rather than the expansion of urban area. Thus, urbanization has had a limited influence on land use change in the CRB. A major task in realizing more sustainable land use in the future development of CRB is to relocate industrial activities from rural to urban areas.
基金supported by the National Natural Science Foundation of China under grant No.59972026.
文摘Orthorhombic LiMnO2 cathode materials were synthesized successfully at lower temperature by sol-gel method. When LiMnO2 precursor prepared by sol-gel method was fired in air, the product was a mixture of spinel structure LiMn2O4 and rock-salt structure Li2MnO3, whereas in argon single-phase orthorhombic LiMnO2 could obtain at the range of 750℃ to 920℃. The substitution of Mn by Zn2+ or Co3+ in LiMnO2 led to the structure of LiMnO2 transiting to Qα-LiFeO2. The results of electrochemical cycles indicated that the discharged capacity of orthorhombic-LiMnO2 was smaller at the initial stages, then gradually increased with the increasing of cycle number, finally the capacity stabilized to certain value after about 10th cycles. This phenomenon reveals that there is an activation process for orthorhombic LiMnO2 cathode materials during electrochemical cycles, which is a phase transition process from orthorhombic LiMnO2 to tetragonal spinel Li2Mn2O4. The capacity of orthorhombic LiMnO2 synthesized at lower temperature is larger than that synthesized at high temperature.
基金supported by the National Key Research and Development Program of China(2016YFA0401503 and 2018YFA0305700)the National Natural Science Foundation of China(11575288,91934303,21935001 and 11775011)+4 种基金the Strategic Priority Research ProgramKey Research Program of Frontier Sciences of the Chinese Academy of Sciences(XDB33000000,XDB25000000 and QYZDBSSW-SLH013)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y202003)the China Geological Survey(DD20190234)the Scientific Instrument Developing Project(ZDKYYQ20170001)of the Chinese Academy of Sciences。
文摘It has been recognized that a small amount of propane mixed with methane can change greatly in not only the thermodynamics but also the structural properties of gas hydrate.However,its mechanism is still not well understood yet.In this research,structure-Ⅱ(sⅡ)hydrate is synthesized using a methanepropane gas mixture with an initial mole ratio of 99:1,and it is found that large(5~(12)6~4)cages are cooccupied by multiple gases based on the rigid structure analysis of neutron diffraction data.The first principles calculation and molecular dynamics simulation are conducted to uncover the molecular mechanism for sⅡmethane-propane hydrate formation,revealing that the presence of propane inhibits the formation of structure-Ⅰ(sⅠ)hydrate but promotes sⅡhydrate formation.The results help to understand the accumulation mechanism of natural gas hydrate and benefit to optimize the condition for gas storage and transportation in hydrate form.
基金Supported by National Natural Science Foundation Project(41101098)Youth Project of Xianning University(KY10044,KY10043)
文摘Scarcity of land resources and transformation of industrial structure is a pair of contradictory elements.We derive the characteristics of land use structure and industrial structure transformation in Xining City using Transformation Coefficient(TC):first,in the period 1999-2000,the land use structure coefficient(θ1) declined by 79.55%,but the overall evolution trend is gentle;second,the transformation coefficient of industrial structure(θ2) tended to decline ceaselessly on the whole,a decrease of 36.09%(overall,the transformation coefficient of industrial structure is slightly greater than the land use structure coefficient);third,the inter-annual variation of the two experienced ups and downs(in the period 1999-2007,the inter-annual variation was great and in the period 2008-2010,the inter-annual variation tended to be gentle).On the basis of autocorrelation and co-integration model,we draw the following conclusions through analysis:first,the land use structure in Xining City plays a role in promoting industrial structure transformation;second,there is a long-term equilibrium relationship between the two.Finally,relevant policy recommendations are put forward for the industrial development in Xining City.
基金supported by the National Natural Science Foundation of China(21901089,21901088,22161021 and 91622105)the Jiangxi Provincial Department of Science and Technology(20192BBEL50017,20172BCB22008 and 20192ACB20013)+1 种基金the support of Jiangxi Province(jxsq2018106041)the‘‘Young Elite Scientists Sponsorship Program”by CAST。
文摘Designing multicomponent integration catalysts(MICs)has been a promising strategy for improving electrocatalytic hydrogen evolution reaction(HER)due to the highly active interfaces as well as electronic synergy.Nevertheless,many fundamental questions such as their actual active species and the influence on long-term stability remain to be answered.Herein,we present the structural evolution from a pseudotri-component electrocatalyst of nitrogen-doped carbon supported nickel/vanadium nitride/vanadium oxide(Ni-VN-V_(2)O_(3)/NC)nanorods to the heterostructural nickel/vanadium nitride(Ni-VN/NC)nanosheets during chemical or electrochemical processes.The self-reconstructed Ni-VN/NC exhibits a robust stability under alkaline conditions,while maintaining initial efficient HER activity with a low overpotential of 76 mV at the current density of 10 mA cm^(-2).Theoretical calculations and quasi-in-situ spectroscopic technology unveil the redistribution of electrons on the synergistic active interface,which synchronously optimizes the affinities for hydrogen,hydroxide,and water molecules,thereby remarkably accelerating the HER kinetics by reducing the barrier of Volmer step.
文摘In order to investigate the ion irradiation effect on the corrosion behavior and microstructure of Zircaloy-4, the Zircaloy-4 film were prepared by electron beam deposition on the Zircaloy-4 specimen surface and irradiated by Kr ions using an accelerator at an energy of 300 keV with the dose from 1×1015 to 3×1016ions/cm2. The post-irradiation corrosion tests were conducted to rank the corrosion resistance of the resulting specimens by potentiodynamic polarization curve measurements in a 0.5 mol/L H2SO4 water so- lution at room temperature. Transmission electron microscopy (TEM) was employed to examine the microstructural change in the surface. The potentiodynamic tests show that with the irradiation dose increasing, the passive current density, closely related to the surface corrosion resistance, decreases firstly and increases subsequently. The mechanism of the corrosion behavior transformation is due to the amorphous phase formation firstly and the amorphous phase destruction and the polycrystalline structure formation in the irradiated surface subsequently.
基金supported by the National Natural Science Foundation of China(Grant No.51474031)
文摘304 austenitic stainless steel was cold rolled in the range of 20%-80%reductions and then annealed at 700-900°C for 60 sto obtain nano/ultrafine-grained（NG/UFG）structure.Transmission electron microscopy,electron backscatter diffraction and X-ray diffraction were used to characterize the resulting microstructures.The results showed that with the increase of cold reduction,the content of martensite was increased.The steel performed work hardening during cold-working owing to the occurrence of strain induced martensite which nucleated in single shear bands.Further rolling broke up the lath-type martensite into dislocation-cell type martensite because of the formation of slip bands.Samples annealed at 800-960°C for 60 swere of NG/UFG structure with different percentage of nanocrystalline（60-100 nm）and ultrafine（100-500 nm）grains,submicron size（500-1000 nm）grains and micron size（〉1000 nm）grains.The value of the Gibbs free energy exhibited that the reversion mechanism of the reversion process was shear controlled by the annealing temperature.For a certain annealing time during the reversion process,austenite nucleated first on dislocation-cell type martensite and the grains grew up subsequently and eventually to be micrometer/submicrometer grains,while the nucleation of austenite on lath-type martensite occurred later resulting in nanocrystalline/ultrafine grains.The existence of the NG/UFG structure led to a higher strength and toughness during tensile test.
文摘The microstructure of CdI2 thin film grown during vapor-phase deposition was investigated by scanning electron microscopy (SEM). The thin film deposited on Si crystal consists of numerous sunflower-like aggregates. These aggregates display well self-assembly characteristics. The size of Sunflower-like aggregates is between 12 and 44 μm. Each sunflower-like aggregate is surrounded with many adjacent wings-'petals'. The structure of central region of the 'sunflower' is obviously difFerent from that of the 'petal'. Electron spectroscopy for chemical analysis (ESCA) was employed in determining the chemical valence of the thin film. Self-organization efFect is used to explain the coring growth process of CdI2 thin film
文摘A simple model of the closely packed structure for system of hard-sphere particles interacting via the long-range Newtonian type attraction is suggested. Based on density functional theory, the exact equation of state is obtained and the mutual transformations of the crystal structures in such systems are studied. The description takes into account the fact impossibility of hard-sphere particles which have the same spatial occupation place.
基金the phased result of the general project“Analysis of the Impact of Shandong Province’s Two-Way Investment on the Transformation and Upgrading of Industrial Structure under the Background of‘High-Quality Development’”and the 2020 Shandong Province Key R&D Program(Soft Science Project)(Project Number:2020RKB01339).
文摘This paper uses the panel data of 17 cities in Shandong Province from 2003 to 2018 to construct a panel model to empirically study the impact of foreign direct investment(FDI)on the industrial structure.The results show that two-way investment,financial industry development,and policy variables have significant roles in promoting the advancement of the industrial structure in the province.In the future implementation of the“Going Global”strategy in Shandong Province,the cooperation between two-way investment and the financial industry should be strengthened,the level of regional financial development should be improved,and the impact of two-way investment on the optimization and upgrading of the industrial structure should be reinforced.
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.
文摘This study examines the influence of microfinance institutions’(MFIs)financial innovation on structural transformation.For this purpose,we considered a household survey from Nepal.The survey collected data on various individual and household characteristics,borrowing patterns,and occupations over the years.The key question focused on occupations before and after borrowing,a categorical response variable indicating 1 for occupational change after borrowing and 0 otherwise.Therefore,we use logistic regression to estimate the probability of occupational change,given two measures of financial innovation:loan purpose and size.The results show that the number of households involved in agriculture significantly decreased,with the majority switching to businesses and convenience stores,indicating a shift to the manufacturing and service sectors.These findings suggest that MFIs contribute to local-level structural transformation by enabling borrowers to move away from traditional employment.This study has important implications for policymakers,development practitioners,and academics interested in promoting economic development through microfinancing in low-income countries.
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.
基金supported by the Fundamental Research Funds for the Central Universities(22120240204 and 22120240039)the National Natural Science Foundation of China(22301219,Z.Z.,22101205,H.H.)。
文摘The synthesized molecular clusters featuring the cubic[4Fe–4S]core have been studied for several decades,as they serve as true analogs of the active components in ferritin within biological systems.Such a model cluster has been extensively investigated in various fields,including structural modulation,catalysis,and self-assembly under laboratory conditions,with the aim of gaining an in-depth understanding of their roles in biological functions.Herein,we revisited three well-known[Fe_(4)S_(4)(SR)_(4)]^(2–)molecules,namely[Me_(4)N]_(2)[Fe_(4)S_(4)(SR)_(4)](R=o-MBT,m-MBT,p-MBT),and successfully established their single crystal structures that remain unknown prior to this work.Interestingly,it is revealed that the position of the substituent methyl group has an obvious steric effect on the arrangement of the ligand around the[4Fe–4S]core,which further influences their overall packing patterns in single crystals.In addition,this work unveils two new structure transformation behaviors for the[Fe_(4)S_(4)(SR)_(4)]^(2–)system:i)the monomeric[Fe(SR)_(4)]^(2–)and tetrameric[Fe_(4)S_(4)(SR)_(4)]^(2–)can be interconverted,and ii)[Fe_(4)S_(4)(SR)_(4)]^(2–)can be transferred into an intriguing iron-oxide complex Na_(2)Fe_(6)O(OMe)_(18)·6MeOH in a well-controlled oxidizing environment.
基金the National Natural Science Foundation of China(nos.51571117,51731006,92163215 and 52174364)。
文摘The strength-ductility trade-off has been the most challenging problem for structural metals for centuries.Nanoprecipitation strengthening is an ideal approach to enhance the strength without significantly sacrificing the ductility.Stable nanoprecipitates have been successfully acquired by nanostructural design,but the number density of nanoprecipitates cannot be further increased.Researchers attempted to enhance number density by introducing highly potent nucleation sites(e.g.,dislocations).However,there remains controversy over the influence of dislocations on the nucleation and growth of coherent nanoprecipitates with minimized nucleation barrier.Here,Cu-rich nanoprecipitates in an HSLA steel,as a typical type of coherent nanoprecipitates,are investigated.By combining analytical calculation and experiments,we show that dislocations are harmful for the formation of large numbered Cu-rich nanoprecipitates in a certain density range.Insufficient dislocations deprive solute atoms which decrease homogenous precipitation that cannot be compensated by the increase in heterogeneous precipitation.Under such circumstance,Cu-rich nanoprecipitates have smaller number density but larger size and higher fraction of incoherent structures due to rapid Ostwald ripening.As a result,by controlling dislocation density,the yield strength is increased by 24%without obvious loss in ductility as compared with traditional solution-quench-age process.Our work would help to optimize composition and processing routes that fully exploit the nanoprecipitation strengthening effect.
基金supported by the National Natural Science Foundation of China(Nos.91122001 and 21331002)the National Basic Research Program of China(No.2010CB923303)
文摘Reaction temperature is one of the key parameters in the synthesis of metal-organic frameworks （MOFs）. Though there is no convergence with regard to the various experimental parameters, reaction temperature has been found to have remarkable influence on the formation and structure of MOFs, especially toward the control of topology and dimensionality of the MOF structures. Theoretically, the reaction temperature affects directly the reaction energy barrier in reaction thermodynamics and the reaction rate in the reaction kinetics. This review aims to show the influence of reaction temperature on crystal growth/assembly, structural modulation and transformation of MOFs, and to provide primary information and insights into the design and assernblv of desired MOFs.
文摘Eu3＋-WO3 nanoparticles were successfully prepared by the modified method of Pechini. The prepared samples were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution transmission electron microscopy （HRTEM）, and UV-vis spectroscopy. Results showed that the Eu3＋-WO3 nanoparticles, which had an average external diameter of 10–25 nm, were composed of the different shapes of puncheon and catenary after being pretreated by pH, pressure vessal, and surfactant. Moreover, structural transformation matrix contained different crystals of anorthic and orthorhombic structure. The photocatalytic activities of the nanoparticles were evaluated by photocatalytic decomposition of rhodamine B. Eu3＋-WO3 nanoparticles were more efficient than WO3 and TiO2 on sunlight use ratio. Photocatalysis experiments indicated that the Eu3＋-WO3 nanoparticles exhibited the highest photocatalytic activity.
