Density functional theory(DFT)-B3LYP level with the 6-311G**(d,p) basis set was used to calculate a set of molecular quantum chemical descriptors of 12 chloroanilines. Quantitative structure-activity relationshi...Density functional theory(DFT)-B3LYP level with the 6-311G**(d,p) basis set was used to calculate a set of molecular quantum chemical descriptors of 12 chloroanilines. Quantitative structure-activity relationship(QSAR) models of the bioconcentration factors(BCF) of the anilines in fish were established using some of the following calculated descriptors: EHOMO, ENHOMO, ELUMO, ENLUMO, ΔE1(= ELUMO- EHOMO), ΔE2(= ENLUMO- ENHOMO), dipole moment(μ), molecular volume(V), vibrational energy of 0 K(Ev), thermodynamic energy(E), heat capacity(Cv), entropy(Sm) and the charge of benzene ring(Qph). Using the variable selection and leaps-and-bounds regression, the quantum chemical descriptors derived directly from the molecular structures were employed to develop a linear QSAR model between the bioconcentration factors(BCF) and two descriptors(Sm, ENHOMO) of 12 chloroanilines. Statistically, the most significant one is a two-parameter linear equation with the correlation coefficient(R^2) of 0.981 and cross-validated correlation coefficient(Rcv^2) of 0.967. The established QSAR model has good stability and predictability based on the results from Rcv2 of leave-one-out cross-validation, AIC, FIT and tα/2. The quantum chemical analyses were performed from two aspects of frontier molecular orbital and entropy. The results show that two structural describers are crucial to the bioconcentration activity of chloroanilines.展开更多
Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict ...Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict information exists. Based on the analysis of some modified methods, Assigning the weighting factors according to the intrinsic characteristics of the existing evidence sources is proposed, which is determined on the evidence distance theory. From the numerical examples, the proposed method provides a reasonable result with good convergence efficiency. In addition, the new rule retrieves to the Yager's formula when all the evidence sources contradict to each other completely.展开更多
The principles of the third theory of quantification were discussed. The concept and calculation method of reaction degree were put forward, which have extended the applying range and scientificalness of the primary r...The principles of the third theory of quantification were discussed. The concept and calculation method of reaction degree were put forward, which have extended the applying range and scientificalness of the primary reaction. Taking the Zhongmacun mine as an example, the geological factors affecting coal and gas outburst were researched. Eight sensitive factors for the outburst of coal and gas were screened out from 11 geological factors using the method of unit classification and the third theory of quantification. On the basis of this, the Zhongmacun coal mine was classified into several divisions. The practice shows that it is feasible to apply the third theory of quantification to gas geology, which offers a new thought to screen the sensitive geological factors of gas outburst forecast.展开更多
Objective:To analyze the impact of meteorological factors on the incidence of influenza based on the Yunqi theory in Beijing area,and to establish an effective forecast modelMethods:Monthly data on the incidence of in...Objective:To analyze the impact of meteorological factors on the incidence of influenza based on the Yunqi theory in Beijing area,and to establish an effective forecast modelMethods:Monthly data on the incidence of influenza from 1970 to 2004 and daily data on the meteorological factors (including daily averages of temperature,wind speed,relative humidity,vapor pressure,and daily total precipitation) from 1966 to 2004 were collected and processed under the traditional Chinese medicine (TCM) theory of six qi.A back-propagation artificial neural network was then performed to analyze the data.Results:The highest incidence of influenza occurs in the sixth qi (the period of December and January),which is characterized by dryness and coldness.Altogether six models were successfully established.Climatic data used were of the same year,one year prior,two years prior,and three years prior to the influenza data respectively.The last two models involve climatic data of the previous three years plus the current year and of the past four years plus the current year.Finally,we determined the fifth model has the highest forecast accuracy (49%).Conclusions:Meteorological factors can exert an influence on the incidence of influenza,which corresponds to TCM theory that 'the pestilence occurred three years after the abnormal climatic changes'.This study may generate interest among the public health community and other TCM theories can be applied so that public health measures can be taken to prevent and control influenza,particularly during the winter months.展开更多
This paper from the unified visual angle of philosophy and economics has observed Marx's theory of ecological economics, clarified the misunderstanding on Marx's theory of nature and ecological environmental t...This paper from the unified visual angle of philosophy and economics has observed Marx's theory of ecological economics, clarified the misunderstanding on Marx's theory of nature and ecological environmental thought at home and abroad for a long time, studied systematically and deeply the Marx's thought that natural and ecological environment is external condition and internal elements of human social economic growth, confirmed firstly Marx is the forerunner who established the theory of internal cause of natural ecological environment. It is of far-reaching academic and practical significance.展开更多
China's mainstream human rights theory has undergone tremendous changes since the reform-and-opening scheme was kicked off in the early 1980s. "Human rights," which used to be seen as a concept of capitalist ideolo...China's mainstream human rights theory has undergone tremendous changes since the reform-and-opening scheme was kicked off in the early 1980s. "Human rights," which used to be seen as a concept of capitalist ideology, is now an important part of the Chinese system of socialist values.展开更多
The ongoing stability of supply chains faces significant challenges from trade protectionism,anti-globalization trends,and the COVID-19 pandemic.To remain resilient in this dynamic market environment,supply chains mus...The ongoing stability of supply chains faces significant challenges from trade protectionism,anti-globalization trends,and the COVID-19 pandemic.To remain resilient in this dynamic market environment,supply chains must evolve through iterative upgrades and transition to a higher level of sustainability,a process termed“step development.”The current literature,however,offers limited insights into achieving such step development in supply chain sustainability and its critical supporting elements.This study,grounded in theory,involved interviews with representatives from eight diverse Chinese enterprises.We introduce a model delineating supporting factors and a roadmap for Sustainable Step Development of Supply Chains(SSDSC).Our findings highlight three pivotal categories of support for SSDSC:institutional,technological,and social factors.Additionally,we observed that external influences in these categories positively modulate their internal counterparts.The study identifies industrial technology,digital intelligence technology,corporate responsibility,and stakeholder needs as key elements in this process.We conclude by offering theoretical and practical recommendations to foster SSDSC.展开更多
In this paper, period-doubling bifurcation in a two-stage power factor correction converter is analyzed by using the method of incremental harmonic balance (IHB) and Floquet theory. A two-stage power factor correcti...In this paper, period-doubling bifurcation in a two-stage power factor correction converter is analyzed by using the method of incremental harmonic balance (IHB) and Floquet theory. A two-stage power factor correction converter typically employs a cascade configuration of a pre-regulator boost power factor correction converter with average current mode control to achieve a near unity power factor and a tightly regulated post-regulator DC-DC Buck converter with voltage feedback control to regulate the output voltage. Based on the assumption that the tightly regulated postregulator DC-DC Buck converter is represented as a constant power sink and some other assumptions, the simplified model of the two-stage power factor correction converter is derived and its approximate periodic solution is calculated by the method of IHB. And then, the stability of the system is investigated by using Floquet theory and the stable boundaries are presented on the selected parameter spaces. Finally, some experimental results are given to confirm the effectiveness of the theoretical analysis.展开更多
Sixteen indole derivatives have been computed at B3LYP/6-31 IG^** level using density functional theory (DFF). Based on linear solvation energy theory, the structural parameters were employed to present correlatio...Sixteen indole derivatives have been computed at B3LYP/6-31 IG^** level using density functional theory (DFF). Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor (CCF) and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk'w and slope S of CCF were obtained, from which the correlation coefficients of lgk'w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw' increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices.展开更多
A comprehensive and precise analysis of shale gas production performance is crucial for evaluating resource potential,designing a field development plan,and making investment decisions.However,quantitative analysis ca...A comprehensive and precise analysis of shale gas production performance is crucial for evaluating resource potential,designing a field development plan,and making investment decisions.However,quantitative analysis can be challenging because production performance is dominated by the complex interaction among a series of geological and engineering factors.In fact,each factor can be viewed as a player who makes cooperative contributions to the production payoff within the constraints of physical laws and models.Inspired by the idea,we propose a hybrid data-driven analysis framework in this study,where the contributions of dominant factors are quantitatively evaluated,the productions are precisely forecasted,and the development optimization suggestions are comprehensively generated.More specifically,game theory and machine learning models are coupled to determine the dominating geological and engineering factors.The Shapley value with definite physical meaning is employed to quantitatively measure the effects of individual factors.A multi-model-fused stacked model is trained for production forecast,which provides the basis for derivative-free optimization algorithms to optimize the development plan.The complete workflow is validated with actual production data collected from the Fuling shale gas field,Sichuan Basin,China.The validation results show that the proposed procedure can draw rigorous conclusions with quantified evidence and thereby provide specific and reliable suggestions for development plan optimization.Comparing with traditional and experience-based approaches,the hybrid data-driven procedure is advanced in terms of both efficiency and accuracy.展开更多
Real-time electricity price( RTEP) influence factor extraction is essential to forecasting accurate power system electricity prices. At present,new electricity price forecasting models have been studied to improve pre...Real-time electricity price( RTEP) influence factor extraction is essential to forecasting accurate power system electricity prices. At present,new electricity price forecasting models have been studied to improve predictive accuracy,ignoring the extraction and analysis of RTEP influence factors. In this study,a correlation analysis method is proposed based on stochastic matrix theory.Firstly, an augmented matrix is formulated, including RTEP influence factor data and RTEP state data. Secondly, data correlation analysis results are obtained given the statistical characteristics of source data based on stochastic matrix theory.Mean spectral radius( MSR) is used as the measure of correlativity.Finally,the proposed method is evaluated in New England electricity markets and compared with the BP neural network forecasting method. Experimental results show that the extracted index system comprehensively generalizes RTEP influence factors,which play a significant role in improving RTEP forecasting accuracy.展开更多
China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In ...China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In this process,farmers' behavior will play a key role. On the basis of summarizing development connotation and characteristics of ecological agriculture,using survey data of 323 pig farmers in 6 provinces,based on the Theory of Planned Behavior( TPB) it introduced individual characteristics and external environment constraint variables,and made an empirical analysis on factors influencing intention and behavior of pig farmers' ecological farming using the Structural Equation Model( SEM). Results indicate:( i) ecological farming intention of pig farmers has the largest direct effect on their ecological farming behavior;( ii)ecological farming cognition of pig farmers has significant positive effect on their ecological farming behavior;( iii) external environment has the largest indirect effect on their ecological farming behavior,followed by the overall effect,and external environment has significant positive effect on ecological farming attitude and cognition of pig farmers;( iv) individual characteristics( educational level and income level) of pig farmers influence ecological farming behavior of pig farmers through their ecological farming attitude and intention,but the degree of influence is limited.展开更多
Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved...Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, the R line, t^322T1 and t^322T2 lines, t^22(^3T1)e^4T2, t^22(^3T1)e^4T1 and t2e^2(^4A2)4T1 bands, g factors of t^32 ^4A2 and t32E, four strain-induced level-splittings and R-line thermal shift of MgO:V^2+ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO:V^2+, the contributions due to electronphonon interaction (EPI) come from the first-order term; the contributions from the second-order and higher terms are insignificant. In thermal shift of R line of MgO:V^2+, the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.展开更多
Plate-type structural members are commonly used in engineering applications like aircraft, ships nuclear reactors etc. These structural members often have cracks arising from manufacture or from material defects or st...Plate-type structural members are commonly used in engineering applications like aircraft, ships nuclear reactors etc. These structural members often have cracks arising from manufacture or from material defects or stress concentrations. Designing a structure against fracture in service involves consideration of strength of the structure as a function of crack size, dimension and the applied load based on principles of fracture mechanics. In most of the engineering structures the plate thickness is generally small and in these cases though the classical plate theory has provided solutions, the neglect of transverse shear deformation leads to the limitation that only two conditions can be satisfied on any boundary whereas we have three physical boundary conditions on an edge of a plate. In this paper this incompatibility is eliminated by using Reissner plate theory where the transverse shear deformation is included and three physically natural boundary conditions of vanishing bending moment, twisting moment and transverse shear stress are satisfied at a free boundary. The problem of estimating the bending stress distribution in the neighbourhood of a crack located on a single line in an elastic plate of varying thickness subjected to out-of-plane moment applied along the edges of the plate is examined. Using Reissner’s plate theory and integral transform technique, the general formulae for the bending moment and twisting moment in an elastic plate containing cracks located on a single line are derived. The thickness depended solution is obtained in a closed form for the case in which there is a single crack in an infinite plate and the results are compared with those obtained from the literature.展开更多
Most of the existing literature on the emergence of new consumption and its essence is based on the discussion of micro consumption phenomena. This paper takes new consumption phenomena in the digital media-dominated ...Most of the existing literature on the emergence of new consumption and its essence is based on the discussion of micro consumption phenomena. This paper takes new consumption phenomena in the digital media-dominated polymedia environment as the object of study to review the theoretical history of “mediatization,” and explores new consumption’s emergence, essence, and related issues systematically through deductive reasoning. More specifically, this paper is to first interpret the mediatization theory and then analyze two dimensions(i.e., the formation of mediatized consumption and the resultant reinvention of practice rules) from the perspective of media affordances. On this basis, we conclude mediatized consumption’s essence, forms, and practice rules. This study indicates that new consumption is essentially mediatized consumption, which concerns “media-shaped consumption” and “consumption-shaped media,” and that new consumption has two representations;consumption-oriented media and banal consumption. Media affordances make new consumption fields human-oriented, connecting “people” and “things,” and are becoming a major contributor to the formation of mediatized consumption. Thus, the practice rules concerning “people, goods, and fields” in the new consumption sector are reinvented;the social interactions in the “middle region” are highlighted;the imaginative, narrative, and social characteristics of goods are emphasized;and the cross-field integration of consumption is realized.展开更多
The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college ...The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college teachers. In this paper, the "impact factor structure of university teachers LMX Questionnaire" for four universities 808 subjects was investigated. By exploratory factor analysis and confirmatory factor analysis, it found that the structure of university teachers LMX factors includes five dimensions: values, attitudes up, personality characteristics, switching behavior, objective situations. The questionnaire has good reliability and validity.展开更多
China has been promoting the renovation of old residential communities vigorously.Due to the financial pressure of the government and the sustainability of the renovation of old residential communities,public-private ...China has been promoting the renovation of old residential communities vigorously.Due to the financial pressure of the government and the sustainability of the renovation of old residential communities,public-private partnerships(PPP)have already gained attention.The selection of social capital is key to improving the efficiency of the PPP model in renovating old residential communities.In order to determine the influencing factors of social capital selection in the renovation of old residential communities,this paper aims to find an effective approach and analyze these factors.In this paper,a fuzzy decision-making and trial evaluation laboratory(fuzzy-DEMATEL)technique is extended and amore suitable systemis developed for the selection of social capital using the existing group decisionmaking theory.In the first stage,grounded theory is used to extract the unabridged key influencing factors for social capital selection in the renovation of old residential communities.Secondly,by considering the impact of expert weights,the key influencing factors are identified.The interactions within these influencing factors are discussed and the credibility of the results is verified by sensitivity analysis.Finally,these key influencing factors are sorted by importance.Based on the results,the government should focus on a technical level,organizationalmanagement abilities,corporate reputation,credit status,etc.This study provides the government with a theoretical basis and a methodology for evaluating social capital selection.展开更多
Nonalcoholic fatty liver disease(NAFLD)refers to fatty liver disease caused by liver injury factors other than alcohol.The disease is characterized by diffuse fat infiltration,including simple steatosis(no inflammator...Nonalcoholic fatty liver disease(NAFLD)refers to fatty liver disease caused by liver injury factors other than alcohol.The disease is characterized by diffuse fat infiltration,including simple steatosis(no inflammatory fat deposition),nonalcoholic fatty hepatitis,liver fibrosis,and so on,which may cause liver cirrhosis,liver failure,and even liver cancer in the later stage of disease progression.At present,the pathogenesis of NAFLD is still being studied.The"two-hit"theory,represented by lipid metabolism disorder and inflammatory reactions,is gradually enriched by the"multiple-hit"theory,which includes multiple factors,such as insulin resistance and adipocyte dysfunction.In recent years,vascular endothelial growth factor B(VEGFB)has been reported to have the potential to regulate lipid metabolism and is expected to become a novel target for ameliorating metabolic diseases,such as obesity and type 2 diabetes.This review summarizes the regulatory role of VEGFB in the onset and development of NAFLD and illustrates its underlying molecular mechanism.In conclusion,the signaling pathway mediated by VEGFB in the liver may provide an innovative approach to the diagnosis and treatment of NAFLD.展开更多
基金co-financed by the National Natural Science Foundation of China(21075138)special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(13K02ESPCT)
文摘Density functional theory(DFT)-B3LYP level with the 6-311G**(d,p) basis set was used to calculate a set of molecular quantum chemical descriptors of 12 chloroanilines. Quantitative structure-activity relationship(QSAR) models of the bioconcentration factors(BCF) of the anilines in fish were established using some of the following calculated descriptors: EHOMO, ENHOMO, ELUMO, ENLUMO, ΔE1(= ELUMO- EHOMO), ΔE2(= ENLUMO- ENHOMO), dipole moment(μ), molecular volume(V), vibrational energy of 0 K(Ev), thermodynamic energy(E), heat capacity(Cv), entropy(Sm) and the charge of benzene ring(Qph). Using the variable selection and leaps-and-bounds regression, the quantum chemical descriptors derived directly from the molecular structures were employed to develop a linear QSAR model between the bioconcentration factors(BCF) and two descriptors(Sm, ENHOMO) of 12 chloroanilines. Statistically, the most significant one is a two-parameter linear equation with the correlation coefficient(R^2) of 0.981 and cross-validated correlation coefficient(Rcv^2) of 0.967. The established QSAR model has good stability and predictability based on the results from Rcv2 of leave-one-out cross-validation, AIC, FIT and tα/2. The quantum chemical analyses were performed from two aspects of frontier molecular orbital and entropy. The results show that two structural describers are crucial to the bioconcentration activity of chloroanilines.
文摘Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict information exists. Based on the analysis of some modified methods, Assigning the weighting factors according to the intrinsic characteristics of the existing evidence sources is proposed, which is determined on the evidence distance theory. From the numerical examples, the proposed method provides a reasonable result with good convergence efficiency. In addition, the new rule retrieves to the Yager's formula when all the evidence sources contradict to each other completely.
文摘The principles of the third theory of quantification were discussed. The concept and calculation method of reaction degree were put forward, which have extended the applying range and scientificalness of the primary reaction. Taking the Zhongmacun mine as an example, the geological factors affecting coal and gas outburst were researched. Eight sensitive factors for the outburst of coal and gas were screened out from 11 geological factors using the method of unit classification and the third theory of quantification. On the basis of this, the Zhongmacun coal mine was classified into several divisions. The practice shows that it is feasible to apply the third theory of quantification to gas geology, which offers a new thought to screen the sensitive geological factors of gas outburst forecast.
基金This work was granted by the National Natural Science Foundation of China(81072896 and 81704198).
文摘Objective:To analyze the impact of meteorological factors on the incidence of influenza based on the Yunqi theory in Beijing area,and to establish an effective forecast modelMethods:Monthly data on the incidence of influenza from 1970 to 2004 and daily data on the meteorological factors (including daily averages of temperature,wind speed,relative humidity,vapor pressure,and daily total precipitation) from 1966 to 2004 were collected and processed under the traditional Chinese medicine (TCM) theory of six qi.A back-propagation artificial neural network was then performed to analyze the data.Results:The highest incidence of influenza occurs in the sixth qi (the period of December and January),which is characterized by dryness and coldness.Altogether six models were successfully established.Climatic data used were of the same year,one year prior,two years prior,and three years prior to the influenza data respectively.The last two models involve climatic data of the previous three years plus the current year and of the past four years plus the current year.Finally,we determined the fifth model has the highest forecast accuracy (49%).Conclusions:Meteorological factors can exert an influence on the incidence of influenza,which corresponds to TCM theory that 'the pestilence occurred three years after the abnormal climatic changes'.This study may generate interest among the public health community and other TCM theories can be applied so that public health measures can be taken to prevent and control influenza,particularly during the winter months.
文摘This paper from the unified visual angle of philosophy and economics has observed Marx's theory of ecological economics, clarified the misunderstanding on Marx's theory of nature and ecological environmental thought at home and abroad for a long time, studied systematically and deeply the Marx's thought that natural and ecological environment is external condition and internal elements of human social economic growth, confirmed firstly Marx is the forerunner who established the theory of internal cause of natural ecological environment. It is of far-reaching academic and practical significance.
文摘China's mainstream human rights theory has undergone tremendous changes since the reform-and-opening scheme was kicked off in the early 1980s. "Human rights," which used to be seen as a concept of capitalist ideology, is now an important part of the Chinese system of socialist values.
基金phased research achievement of the Major Program of the Chinese Academy of Engineering(Grant No.2022-JB-01)supported by Major Program of the National Social Science Foundation of China(Grant No.22&ZD139).
文摘The ongoing stability of supply chains faces significant challenges from trade protectionism,anti-globalization trends,and the COVID-19 pandemic.To remain resilient in this dynamic market environment,supply chains must evolve through iterative upgrades and transition to a higher level of sustainability,a process termed“step development.”The current literature,however,offers limited insights into achieving such step development in supply chain sustainability and its critical supporting elements.This study,grounded in theory,involved interviews with representatives from eight diverse Chinese enterprises.We introduce a model delineating supporting factors and a roadmap for Sustainable Step Development of Supply Chains(SSDSC).Our findings highlight three pivotal categories of support for SSDSC:institutional,technological,and social factors.Additionally,we observed that external influences in these categories positively modulate their internal counterparts.The study identifies industrial technology,digital intelligence technology,corporate responsibility,and stakeholder needs as key elements in this process.We conclude by offering theoretical and practical recommendations to foster SSDSC.
基金supported by the National Natural Science Foundation of China (Grant No.51007068)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20100201120028)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe State Key Laboratory of Electrical Insulation and Power Equipment of China (Grant No.EIPE10303)
文摘In this paper, period-doubling bifurcation in a two-stage power factor correction converter is analyzed by using the method of incremental harmonic balance (IHB) and Floquet theory. A two-stage power factor correction converter typically employs a cascade configuration of a pre-regulator boost power factor correction converter with average current mode control to achieve a near unity power factor and a tightly regulated post-regulator DC-DC Buck converter with voltage feedback control to regulate the output voltage. Based on the assumption that the tightly regulated postregulator DC-DC Buck converter is represented as a constant power sink and some other assumptions, the simplified model of the two-stage power factor correction converter is derived and its approximate periodic solution is calculated by the method of IHB. And then, the stability of the system is investigated by using Floquet theory and the stable boundaries are presented on the selected parameter spaces. Finally, some experimental results are given to confirm the effectiveness of the theoretical analysis.
基金This work was supported by the National Basic Research Program of China (2003CB415002) and the China Postdoctoral Science Foundation (No. 2003033486) and the Natural Science Research Fund of University in Jiangsu (04KJB150149)
文摘Sixteen indole derivatives have been computed at B3LYP/6-31 IG^** level using density functional theory (DFF). Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor (CCF) and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk'w and slope S of CCF were obtained, from which the correlation coefficients of lgk'w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw' increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices.
基金This work was supported by the National Natural Science Foundation of China(Grant No.42050104)the Science Foundation of SINOPEC Group(Grant No.P20030).
文摘A comprehensive and precise analysis of shale gas production performance is crucial for evaluating resource potential,designing a field development plan,and making investment decisions.However,quantitative analysis can be challenging because production performance is dominated by the complex interaction among a series of geological and engineering factors.In fact,each factor can be viewed as a player who makes cooperative contributions to the production payoff within the constraints of physical laws and models.Inspired by the idea,we propose a hybrid data-driven analysis framework in this study,where the contributions of dominant factors are quantitatively evaluated,the productions are precisely forecasted,and the development optimization suggestions are comprehensively generated.More specifically,game theory and machine learning models are coupled to determine the dominating geological and engineering factors.The Shapley value with definite physical meaning is employed to quantitatively measure the effects of individual factors.A multi-model-fused stacked model is trained for production forecast,which provides the basis for derivative-free optimization algorithms to optimize the development plan.The complete workflow is validated with actual production data collected from the Fuling shale gas field,Sichuan Basin,China.The validation results show that the proposed procedure can draw rigorous conclusions with quantified evidence and thereby provide specific and reliable suggestions for development plan optimization.Comparing with traditional and experience-based approaches,the hybrid data-driven procedure is advanced in terms of both efficiency and accuracy.
基金National Natural Science Foundation of China(No.61701104)the “13th Five Year Plan” Research Foundation of Jilin Provincial Department of Education,China(No.JJKH2017018KJ)
文摘Real-time electricity price( RTEP) influence factor extraction is essential to forecasting accurate power system electricity prices. At present,new electricity price forecasting models have been studied to improve predictive accuracy,ignoring the extraction and analysis of RTEP influence factors. In this study,a correlation analysis method is proposed based on stochastic matrix theory.Firstly, an augmented matrix is formulated, including RTEP influence factor data and RTEP state data. Secondly, data correlation analysis results are obtained given the statistical characteristics of source data based on stochastic matrix theory.Mean spectral radius( MSR) is used as the measure of correlativity.Finally,the proposed method is evaluated in New England electricity markets and compared with the BP neural network forecasting method. Experimental results show that the extracted index system comprehensively generalizes RTEP influence factors,which play a significant role in improving RTEP forecasting accuracy.
基金Supported by Project of National Natural Science Foundation(41171436)Key Project of National Social Science Foundation(14AZD002)
文摘China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In this process,farmers' behavior will play a key role. On the basis of summarizing development connotation and characteristics of ecological agriculture,using survey data of 323 pig farmers in 6 provinces,based on the Theory of Planned Behavior( TPB) it introduced individual characteristics and external environment constraint variables,and made an empirical analysis on factors influencing intention and behavior of pig farmers' ecological farming using the Structural Equation Model( SEM). Results indicate:( i) ecological farming intention of pig farmers has the largest direct effect on their ecological farming behavior;( ii)ecological farming cognition of pig farmers has significant positive effect on their ecological farming behavior;( iii) external environment has the largest indirect effect on their ecological farming behavior,followed by the overall effect,and external environment has significant positive effect on ecological farming attitude and cognition of pig farmers;( iv) individual characteristics( educational level and income level) of pig farmers influence ecological farming behavior of pig farmers through their ecological farming attitude and intention,but the degree of influence is limited.
文摘Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, the R line, t^322T1 and t^322T2 lines, t^22(^3T1)e^4T2, t^22(^3T1)e^4T1 and t2e^2(^4A2)4T1 bands, g factors of t^32 ^4A2 and t32E, four strain-induced level-splittings and R-line thermal shift of MgO:V^2+ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO:V^2+, the contributions due to electronphonon interaction (EPI) come from the first-order term; the contributions from the second-order and higher terms are insignificant. In thermal shift of R line of MgO:V^2+, the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.
文摘Plate-type structural members are commonly used in engineering applications like aircraft, ships nuclear reactors etc. These structural members often have cracks arising from manufacture or from material defects or stress concentrations. Designing a structure against fracture in service involves consideration of strength of the structure as a function of crack size, dimension and the applied load based on principles of fracture mechanics. In most of the engineering structures the plate thickness is generally small and in these cases though the classical plate theory has provided solutions, the neglect of transverse shear deformation leads to the limitation that only two conditions can be satisfied on any boundary whereas we have three physical boundary conditions on an edge of a plate. In this paper this incompatibility is eliminated by using Reissner plate theory where the transverse shear deformation is included and three physically natural boundary conditions of vanishing bending moment, twisting moment and transverse shear stress are satisfied at a free boundary. The problem of estimating the bending stress distribution in the neighbourhood of a crack located on a single line in an elastic plate of varying thickness subjected to out-of-plane moment applied along the edges of the plate is examined. Using Reissner’s plate theory and integral transform technique, the general formulae for the bending moment and twisting moment in an elastic plate containing cracks located on a single line are derived. The thickness depended solution is obtained in a closed form for the case in which there is a single crack in an infinite plate and the results are compared with those obtained from the literature.
基金a phased research result of the“New Changes in Media and New Consumerism”(18BXW085)a program funded by the National Social Science Fund of China(NSSFC)。
文摘Most of the existing literature on the emergence of new consumption and its essence is based on the discussion of micro consumption phenomena. This paper takes new consumption phenomena in the digital media-dominated polymedia environment as the object of study to review the theoretical history of “mediatization,” and explores new consumption’s emergence, essence, and related issues systematically through deductive reasoning. More specifically, this paper is to first interpret the mediatization theory and then analyze two dimensions(i.e., the formation of mediatized consumption and the resultant reinvention of practice rules) from the perspective of media affordances. On this basis, we conclude mediatized consumption’s essence, forms, and practice rules. This study indicates that new consumption is essentially mediatized consumption, which concerns “media-shaped consumption” and “consumption-shaped media,” and that new consumption has two representations;consumption-oriented media and banal consumption. Media affordances make new consumption fields human-oriented, connecting “people” and “things,” and are becoming a major contributor to the formation of mediatized consumption. Thus, the practice rules concerning “people, goods, and fields” in the new consumption sector are reinvented;the social interactions in the “middle region” are highlighted;the imaginative, narrative, and social characteristics of goods are emphasized;and the cross-field integration of consumption is realized.
文摘The leader - member exchange theory is one of the leading and the hot topic in recent years of the study of Western leaders. Structural studies of LMX factors have important theoretical and practical value in college teachers. In this paper, the "impact factor structure of university teachers LMX Questionnaire" for four universities 808 subjects was investigated. By exploratory factor analysis and confirmatory factor analysis, it found that the structure of university teachers LMX factors includes five dimensions: values, attitudes up, personality characteristics, switching behavior, objective situations. The questionnaire has good reliability and validity.
基金supported by the National Natural Science Foundation of China(No.62141302)the Humanities Social Science Programming Project of the Ministry of Educa-tion of China(No.20YJA630059)+2 种基金the Natural Science Foundation of Jiangxi Province of China(No.20212BAB201011)the China Postdoctoral Science Foundation(Grant No.2019M662265)the Research Project of Economic and Social Development in Liaoning Province(Grant No.2022lslybkt-053).
文摘China has been promoting the renovation of old residential communities vigorously.Due to the financial pressure of the government and the sustainability of the renovation of old residential communities,public-private partnerships(PPP)have already gained attention.The selection of social capital is key to improving the efficiency of the PPP model in renovating old residential communities.In order to determine the influencing factors of social capital selection in the renovation of old residential communities,this paper aims to find an effective approach and analyze these factors.In this paper,a fuzzy decision-making and trial evaluation laboratory(fuzzy-DEMATEL)technique is extended and amore suitable systemis developed for the selection of social capital using the existing group decisionmaking theory.In the first stage,grounded theory is used to extract the unabridged key influencing factors for social capital selection in the renovation of old residential communities.Secondly,by considering the impact of expert weights,the key influencing factors are identified.The interactions within these influencing factors are discussed and the credibility of the results is verified by sensitivity analysis.Finally,these key influencing factors are sorted by importance.Based on the results,the government should focus on a technical level,organizationalmanagement abilities,corporate reputation,credit status,etc.This study provides the government with a theoretical basis and a methodology for evaluating social capital selection.
文摘Nonalcoholic fatty liver disease(NAFLD)refers to fatty liver disease caused by liver injury factors other than alcohol.The disease is characterized by diffuse fat infiltration,including simple steatosis(no inflammatory fat deposition),nonalcoholic fatty hepatitis,liver fibrosis,and so on,which may cause liver cirrhosis,liver failure,and even liver cancer in the later stage of disease progression.At present,the pathogenesis of NAFLD is still being studied.The"two-hit"theory,represented by lipid metabolism disorder and inflammatory reactions,is gradually enriched by the"multiple-hit"theory,which includes multiple factors,such as insulin resistance and adipocyte dysfunction.In recent years,vascular endothelial growth factor B(VEGFB)has been reported to have the potential to regulate lipid metabolism and is expected to become a novel target for ameliorating metabolic diseases,such as obesity and type 2 diabetes.This review summarizes the regulatory role of VEGFB in the onset and development of NAFLD and illustrates its underlying molecular mechanism.In conclusion,the signaling pathway mediated by VEGFB in the liver may provide an innovative approach to the diagnosis and treatment of NAFLD.