期刊文献+
共找到4,299篇文章
< 1 2 215 >
每页显示 20 50 100
Linear QSAR Regression Models for the Prediction of Bioconcentration Factors of Chloroanilines in Fish by Density Functional Theory 被引量:16
1
作者 冯长君 杨伟华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第6期830-834,共5页
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
关键词 CHLOROANILINES bioconcentration factor density functional theory quantum chemical describers quantitative structure-activity relationship
下载PDF
New weighting factors assignment of evidence theorybased one vidence distance 被引量:3
2
作者 ChenLiangzhou ShiWenkang DuFeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第2期273-278,共6页
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
关键词 evidence theory rule of combination weighting factors evidence distance.
下载PDF
Application of the Third Theory of Quantification in Screening Sensitive Geological Factors Influencing Coal and Gas Outburst 被引量:2
3
作者 吴财芳 曾勇 张许良 《Journal of China University of Mining and Technology》 2003年第1期66-71,共6页
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
关键词 the third theory of quantification reaction degree sensitive geological factor gas outburst forecast
下载PDF
Impact of meteorological factors on the incidence of influenza in Beijing: A 35-year retrospective study based on Yunqi theory 被引量:2
4
作者 Hong Wang Xuan Zhang +5 位作者 Zhili Gao Ling Han Zhongdi Liu Long Yan Mingyue Li Juan He 《Journal of Traditional Chinese Medical Sciences》 2018年第3期264-270,共7页
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
关键词 INCIDENCE of INFLUENZA METEOROLOGICAL factors Yunqi theory BACK-PROPAGATION artificial NEURAL network
下载PDF
The core ideology of Ecological Marxism:Marx is the pioneer of internal factors theory of ecological environment
5
作者 Liu Sihua 《Ecological Economy》 2007年第4期346-354,共9页
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
关键词 Marx Natural environment Ecological economics theory of internal factors
下载PDF
On Dynamic Social Factors for Development of China’s Human Rights Theory
6
作者 FAN JIZENG 《The Journal of Human Rights》 2011年第4期20-22,共3页
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
关键词 On Dynamic Social factors for Development of China s Human Rights theory
下载PDF
Supporting factors model for the sustainable step development of supply chain:An empirical study from China with grounded theory
7
作者 Xiaohong CHEN Chunfang LU +4 位作者 Weihua LIU Siyu WANG Shangsong LONG Jingcheng QIU Yujie WANG 《Frontiers of Engineering Management》 CSCD 2024年第2期311-325,共15页
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
关键词 supply chain sustainable development supporting factors grounded theory
原文传递
Period-doubling bifurcation in two-stage power factor correction converters using the method of incremental harmonic balance and Floquet theory 被引量:4
8
作者 Wang Fa-Qiang Zhang Hao Ma Xi-Kui 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期153-162,共10页
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
关键词 two-stage power factor correction converter incremental harmonic balance Floquet theory period-doubling bifurcation
下载PDF
Correlation between Chromatograph Capacity Factors and Structural Parameters of Indole Derivatives 被引量:1
9
作者 ZHENG Qing WANG Zun-Yao +1 位作者 SUN Li YU Bin 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第12期1381-1386,共6页
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
关键词 indole derivatives quantitative structure-retention relationship (QSRR) chromatograph capacity factor (CCF) reversed phased high performance liquid chroma-tograph (RP-HPLC) density functional theory (DFT) self-consistent reaction field(SCRF)
下载PDF
Hybrid data-driven framework for shale gas production performance analysis via game theory, machine learning, and optimization approaches 被引量:2
10
作者 Jin Meng Yu-Jie Zhou +4 位作者 Tian-Rui Ye Yi-Tian Xiao Ya-Qiu Lu Ai-Wei Zheng Bang Liang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第1期277-294,共18页
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
关键词 Shale gas Production performance DATA-DRIVEN Dominant factors Game theory Machine learning Derivative-free optimization
下载PDF
Electricity Price Influence Factors Analysis Using Stochastic Matrix for Real-Time Electricity Price Forecasting
11
作者 ZHOU Tiehua LIU Wenqiang +1 位作者 CHEN Zhiyuan WANG Ling 《Journal of Donghua University(English Edition)》 EI CAS 2018年第5期399-405,共7页
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
关键词 STOCHASTIC MATRIX theory REAL-TIME ELECTRICITY price(RTEP) correlation analysis influence factors
下载PDF
Research on Influence Factors of Pig Farmers' Ecological Farming Behavior: Based on the TPB and SEM
12
作者 Chengying HAN Zhenhong QI +1 位作者 Dongmin ZHANG Xinrui LI 《Asian Agricultural Research》 2016年第2期19-27,共9页
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
关键词 Ecological FARMING BEHAVIOR Influence factors PIG FARMERS theory of PLANNED Behavior(TPB) Structural Equation Model(SEM)
下载PDF
Energy Spectrum, g Factors, Strain-Induced Level-Splittings and R-Line Thermal Shift of MgO:V^(2+)
13
作者 ZHANG Zheng-Jie MA Dong-Ping 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第8期511-516,共6页
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
关键词 improved ligand-field theory electron-phonon interaction energy spectrum strain-induced split-ting thermal shift g factor
下载PDF
Analytical Solution for Bending Stress Intensity Factor from Reissner’S Plate Theory
14
作者 Lalitha Chattopadhyay 《Engineering(科研)》 2011年第5期517-524,共8页
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
关键词 REISSNER Plate theory INTEGRAL TRANSFORM Stress INTENSITY factor SINGULAR INTEGRAL Equation
下载PDF
A Study of New Consumption from the Perspective of Mediatization:Essence, Contributing Factors, and Reinvention of Rules
15
作者 Chen Shi 《Contemporary Social Sciences》 2022年第4期39-57,共19页
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
关键词 new consumption mediatization theory ESSENCE contributing factors practice rules
下载PDF
Research on the Influence Factors and Struction of University Teachers Leader-Member Exchange
16
作者 Cuihua Liu 《International English Education Research》 2014年第3期65-68,共4页
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
关键词 University Teachers LMX theory Structural factors
下载PDF
An Extended Fuzzy-DEMATEL System for Factor Analyses on Social Capital Selection in the Renovation of Old Residential Communities
17
作者 Guoshuai Sun Xiuru Tang +1 位作者 Shuping Wan Jiao Feng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期1041-1067,共27页
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
关键词 Social capital selection fuzzy-DEMATEL influencing factors renovation of old residential communities grounded theory
下载PDF
Role of vascular endothelial growth factor B in nonalcoholic fatty liver disease and its potential value
18
作者 Yu-Qi Li Lei Xin +2 位作者 Yu-Chi Zhao Shang-Qi Li Ya-Nuo Li 《World Journal of Hepatology》 2023年第6期786-796,共11页
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
关键词 Nonalcoholic fatty liver disease Vascular endothelial growth factor B "Twohit"theory "Multiple-hit"theory OBESITY
下载PDF
基于扎根理论的政府开放数据价值影响因素研究 被引量:2
19
作者 马捷 栾泽权 +1 位作者 张超 孙文晶 《情报理论与实践》 CSSCI 北大核心 2024年第5期87-95,共9页
[目的/意义]政府开放数据价值是数字经济情境下个体数据行为嬗变的反馈性标志。从政府开放数据使用者视角识别其价值要素,对于促进政府数据管理水平,提升数据交易常态化具有理论和实践意义。[方法/过程]利用会议、访谈与网络数据获取原... [目的/意义]政府开放数据价值是数字经济情境下个体数据行为嬗变的反馈性标志。从政府开放数据使用者视角识别其价值要素,对于促进政府数据管理水平,提升数据交易常态化具有理论和实践意义。[方法/过程]利用会议、访谈与网络数据获取原始资料,结合扎根理论,构建“三维—多层”的数据价值影响因素模型,涵盖121个初始概念、30项范畴和9项主范畴,各领域受访者共33位。[结果/结论]个体感知数据价值影响因素主要涉及需求、进路、市场化三个维度,综合考察各项主范畴,针对数据价值的内在关联以及外部机制,可以提炼出直接、间接、跨层、双元4种关系结构。这个过程在理论上弥补了传统政务体系下政府开放数据与个体需求二元割裂之不足,延展了政府开放数据的价值使用行为与价值释放路径。 展开更多
关键词 政府开放数据 数据价值 影响因素 扎根理论 数据交易
下载PDF
数字化转型能提升农业企业全要素生产率吗? 被引量:6
20
作者 金绍荣 唐诗语 任赞杰 《改革》 CSSCI 北大核心 2024年第2期131-148,共18页
基于2007—2020年我国A股上市农业企业的微观数据,实证分析数字化转型对农业企业全要素生产率的影响及其机制。研究表明,数字化转型有利于提升农业企业的全要素生产率。机制检验表明,数字化转型通过提高资金利用率、降低超额雇员率、增... 基于2007—2020年我国A股上市农业企业的微观数据,实证分析数字化转型对农业企业全要素生产率的影响及其机制。研究表明,数字化转型有利于提升农业企业的全要素生产率。机制检验表明,数字化转型通过提高资金利用率、降低超额雇员率、增大研发投入来提高农业企业全要素生产率。调节效应检验表明,营商环境不确定性、行业竞争强度加剧将削减数字化转型对农业企业全要素生产率的提升效果。异质性检验表明,数字化转型对小规模农业企业、处于成长期和成熟期的农业企业、国有农业企业、两职分离的农业企业全要素生产率的提升作用更为显著。为此,政府等治理主体应完善数字基础设施,营造良好营商环境和市场竞争秩序,优化农业企业数字化转型的外部环境;同时农业企业也要根据自身发展实际,科学配置资金、技术、劳动力等资源,选择适宜的数字化转型路径。 展开更多
关键词 农业企业 数字化转型 企业全要素生产率 资源编排理论
下载PDF
上一页 1 2 215 下一页 到第
使用帮助 返回顶部