期刊文献+
共找到20,182篇文章
< 1 2 250 >
每页显示 20 50 100
An Approximation Method for Singular Trudinger-Moser Inequality
1
作者 ZHU Maochun XU Wenyan JIANG Rou 《应用数学》 北大核心 2025年第1期64-70,共7页
In this paper,we construct a power type functional which is the approximation functional of the Singular Trudinger-Moser functional.Moreover,we obtain the concentration level of the functional and show it converges to... In this paper,we construct a power type functional which is the approximation functional of the Singular Trudinger-Moser functional.Moreover,we obtain the concentration level of the functional and show it converges to the concentration level of singular Trudinger-Moser functional on the unit ball. 展开更多
关键词 Singular Trudinger-Moser inequality Approximation functional Concentration level
下载PDF
Environmental Inequality in China’s Urban Expansion:A Case Study of Guangzhou,China
2
作者 WANG Shaogu SHEN Jing 《Chinese Geographical Science》 2025年第1期187-202,共16页
Environmental inequality is a prevalent issue in developing countries undergoing urban expansion.Urban expansion induces the formation and evolution of environmental inequality by creating environmental and structural... Environmental inequality is a prevalent issue in developing countries undergoing urban expansion.Urban expansion induces the formation and evolution of environmental inequality by creating environmental and structural conditions that lead to the spatial relocation of environmental hazards and the socio-spatial segregation of different groups in developing countries.This study investigated the spatial patterns and temporal trends of environmental inequality under urban expansion in Guangzhou,a megacity in China.It considered how environmental disparities and socio-demographic attributes interact in terms of industrial pollution exposure using additive semiparametric quantile regression,combined with spatial visualisation,on the basis of the economic and population census data from 1990 to 2020.This study revealed that urban expansion sparked the spatial displacement of environmental risks and the social-spatial differentiation,exposing the peripheral regions and disadvantaged groups to higher environmental risks.A reciprocal transformation occurred between central and peripheral regions,as well as a process of redistributing environmental risks across social space.In the context of urban expansion in developing countries,the causes of environmental inequality shifted from individual socio-economic differences to structural factors,such as industrial layout and social division of labour in cities,leading to the spatial displacement and concealment of environmental inequality.This study provides insights and guidance for policymakers to address the issue of environmental inequality in the context of urban expansion. 展开更多
关键词 environmental inequality urban expansion spatiotemporal evolution additive semiparametric quantile regression Guangzhou China
下载PDF
Global inequality in built-up land per capita and its change trajectories between 1985 and 2020
3
作者 Jasper van Vliet Hang Yang +1 位作者 Vita Bakker Mengmeng Li 《Geography and Sustainability》 CSCD 2024年第4期541-547,共7页
Built-up land has increased rapidly in recent decades,thus aggravating the competition for land between multiple uses.The increase in urban land can be decomposed into changes in population and changes in built-up lan... Built-up land has increased rapidly in recent decades,thus aggravating the competition for land between multiple uses.The increase in urban land can be decomposed into changes in population and changes in built-up land per person.Yet,it is unclear how this decomposition differs by country and how this decomposition changes over time.Moreover,we don’t know whether these changes affect the inequality in built-up land per capita.Here,we analyze the global distribution of built-up land per capita in the year 2020,as well as the changes therein between 1985 and 2020.We find that built-up land per capita in 2020 differs by an order of magnitude between countries,ranging from 15 m^(2) per person in Ethiopia to 734 m^(2) per person in Australia.Moreover,we find a wide range of different change trajectories,including both increases and decreases in built-up land per capita and in total population.As the total area of urban land increased in all countries,decreases in urban land consumption reflect a situation where the population increases faster than the total amount of urban land.We also find a large inequality in urban land consumption across countries,as indicated by a Gini index of 0.47 in 1985,decreasing only slightly to 0.45 in 2020.These findings suggest the need for a regionally differentiated approach to reduce urban land take,focusing first on mitigating further increases in those countries that already have a high urban land consumption. 展开更多
关键词 Urban expansion Human settlements inequality Urban densification SDG 11 Sustainable development
下载PDF
AGGREGATE SPECIAL FUNCTIONS TO APPROXIMATE PERMUTING TRI-HOMOMORPHISMS AND PERMUTING TRI-DERIVATIONS ASSOCIATED WITH A TRI-ADDITIVEψ-FUNCTIONAL INEQUALITY IN BANACH ALGEBRAS
4
作者 Safoura Rezaei ADERYANI Azam AHADI +1 位作者 Reza SAADATI Hari M.SRIVASTAVA 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期311-338,共28页
In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better... In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better estimation for permuting tri-homomorphisms and permuting tri-derivations in unital C*-algebras and Banach algebras by the vector-valued alternative fixed point theorem. 展开更多
关键词 permuting tri-homomorphism in Banach algebra permuting tri-derivation on C*-algebra fixed point theorem Ulam-Hyers-Rassias stability aggregate special functions tri-additiveψ-functional inequality
下载PDF
Inequality of rural residents'income in China since the targeted poverty alleviation strategy:New trends,causes,and policy implications
5
作者 Qin Ji JianPing Yang +2 位作者 YuNan Chu HongJu Chen XinYu Guo 《Research in Cold and Arid Regions》 CSCD 2024年第4期201-213,共13页
Poverty and income inequality are problems faced by many countries including China.Since the implementation of Targeted Poverty Alleviation(TPA),absolute poverty has been eradicated,meanwhile,Chinese rural residents&#... Poverty and income inequality are problems faced by many countries including China.Since the implementation of Targeted Poverty Alleviation(TPA),absolute poverty has been eradicated,meanwhile,Chinese rural residents' income and inequality have experienced unprecedented new dynamics,but still,very few studies have focused on them.Hence,we attempt to examine the new trends in Chinese farmers' income inequality and to understand its causes during this period.We observe that China's urban-rural income ratio has been shrinking and the urban-rural inequality has been decreasing from 2014 to 2021.The reduction in the Theil index indicates a decrease in the regional inequality of farmers' income as well,and the decline in inter-regional inequality among eight economic zones contributes about 80% to increased equality.These new trends are caused by the fact that,with the TPA,the incomes of rural residents especially that in destitute areas,grew faster than that of urban residents and farmers in prosperous areas.The higher share of non-agricultural industry and agricultural mechanization level have significant positive impact on regional equality of farmers' income,while urban-rural dual structure has significant negative inhibitory effects.The lowest farmers' income and the highest inequality in the Northwest,and the slowest growth in the Northeast deserve more attention in rural Revitalization.From these findings,we propose four policy implications that would be applied to improve Chinese farmers' income equality,govern relative poverty,and achieve common prosperity in the post-poverty era. 展开更多
关键词 Rural residents'income inequality Urban-rural gap Regional disparity Targeted poverty alleviation
下载PDF
THE LOGARITHMIC SOBOLEV INEQUALITY FOR A SUBMANIFOLD IN MANIFOLDS WITH ASYMPTOTICALLY NONNEGATIVE SECTIONAL CURVATURE
6
作者 东瑜昕 林和子 陆琳根 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期189-194,共6页
In this note,we prove a logarithmic Sobolev inequality which holds for compact submanifolds without a boundary in manifolds with asymptotically nonnegative sectional curvature.Like the Michale-Simon Sobolev inequality... In this note,we prove a logarithmic Sobolev inequality which holds for compact submanifolds without a boundary in manifolds with asymptotically nonnegative sectional curvature.Like the Michale-Simon Sobolev inequality,this inequality contains a term involving the mean curvature. 展开更多
关键词 asymptotically nonnegative sectional curvature logarithmic Sobolev inequality ABP method
下载PDF
An analysis of inequality in physical health status of women in India:2015-2021
7
作者 Debolina Banerjee Tamal Krishna Kayal 《Global Health Journal》 2024年第4期213-221,共9页
Objective:We examine how inequality in women's health has changed in India and its major states between 2015 and 2021.We also attempt to identify the sources of any change in this inequality using a decomposition ... Objective:We examine how inequality in women's health has changed in India and its major states between 2015 and 2021.We also attempt to identify the sources of any change in this inequality using a decomposition analysis.In order to suggest suitable policies for reducing this inequality,we attempt to identify the factors that are strongly associated with it.Methods:We construct an index of women's health from five indicators using the principal component analysis.Based on this index we measure inequality in women's health using the coefficient of variation and the Theil index.To identify the sources of change in this inequality,we apply Theil decomposition technique.Results:We find that inequality in women's health has increased significantly in India between 2015 and 2021.During this period,this inequality has increased significantly in six states,while it has decreased significantly in five states.The decomposition analysis suggests that the increase in this inequality between 2015 and 2021 has been driven by an increase in interstate inequality.We also find a strong positive association between inequality in women's health and inequality in public health amenities and social development.Conclusion:We suggest that for reducing inequality in women's health in developing countries like India,policies should focus on eliminating disparities in income,female education and provision of public health amenities. 展开更多
关键词 Health inequality Physical health status of women INDIA Publichealthamenities Decomposition analysis
下载PDF
Weak and Strong Convergence of Self Adaptive Inertial Subgradient Extragradient Algorithms for Solving Variational Inequality Problems
8
作者 Yao Li Hongwei Liu Jiamin Lv 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第2期38-49,共12页
Many solutions of variational inequalities have been proposed,among which the subgradient extragradient method has obvious advantages.Two different algorithms are given for solving variational inequality problem in th... Many solutions of variational inequalities have been proposed,among which the subgradient extragradient method has obvious advantages.Two different algorithms are given for solving variational inequality problem in this paper.The problem we study is defined in a real Hilbert space and has L-Lipschitz and pseudomonotone condition.Two new algorithms adopt inertial technology and non-monotonic step size rule,and their convergence can still be proved when the value of L is not given in advance.Finally,some numerical results are designed to demonstrate the computational efficiency of our two new algorithms. 展开更多
关键词 variational inequality inertial method non-monotonic step size rule Lipschitz continuity pseudomonotone mapping
下载PDF
Fermions: Spin, Hidden Variables, Violation of Bell’s Inequality and Quantum Entanglement
9
作者 Doron Kwiat 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1613-1627,共15页
Using real fields instead of complex ones, it was recently claimed, that all fermions are made of pairs of coupled fields (strings) with an internal tension related to mutual attraction forces, related to Planck’s co... Using real fields instead of complex ones, it was recently claimed, that all fermions are made of pairs of coupled fields (strings) with an internal tension related to mutual attraction forces, related to Planck’s constant. Quantum mechanics is described with real fields and real operators. Schrodinger and Dirac equations then are solved. The solution to Dirac equation gives four, real, 2-vectors solutions ψ1=(U1D1)ψ2=(U2D2)ψ3=(U3D3)ψ4=(U4D4)where (ψ1,ψ4) are coupled via linear combinations to yield spin-up and spin-down fermions. Likewise, (ψ2,ψ3) are coupled via linear combinations to represent spin-up and spin-down anti-fermions. For an incoming entangled pair of fermions, the combined solution is Ψin=c1ψ1+c4ψ4where c1and c4are some hidden variables. By applying a magnetic field in +Z and +x the theoretical results of a triple Stern-Gerlach experiment are predicted correctly. Then, by repeating Bell’s and Mermin Gedanken experiment with three magnetic filters σθ, at three different inclination angles θ, the violation of Bell’s inequality is proven. It is shown that all fermions are in a mixed state of spins and the ratio between spin-up to spin-down depends on the hidden variables. 展开更多
关键词 FERMIONS SPIN Hidden Variables Bell’s inequality Violation Spin Entanglement
下载PDF
A Study of Triangle Inequality Violations in Social Network Clustering
10
作者 Sanjit Kumar Saha Tapashi Gosswami 《Journal of Computer and Communications》 2024年第1期67-76,共10页
Clustering a social network is a process of grouping social actors into clusters where intra-cluster similarities among actors are higher than inter-cluster similarities. Clustering approaches, i.e. , k-medoids or hie... Clustering a social network is a process of grouping social actors into clusters where intra-cluster similarities among actors are higher than inter-cluster similarities. Clustering approaches, i.e. , k-medoids or hierarchical, use the distance function to measure the dissimilarities among actors. These distance functions need to fulfill various properties, including the triangle inequality (TI). However, in some cases, the triangle inequality might be violated, impacting the quality of the resulting clusters. With experiments, this paper explains how TI violates while performing traditional clustering techniques: k-medoids, hierarchical, DENGRAPH, and spectral clustering on social networks and how the violation of TI affects the quality of the resulting clusters. 展开更多
关键词 CLUSTERING Triangle inequality Violations Traditional Clustering Graph Clustering
下载PDF
一类非线性互联系统鲁棒控制问题的求解方法
11
作者 孙延修 黎虹 刘业峰 《控制工程》 北大核心 2025年第1期119-125,共7页
含扰动的非线性互联系统的鲁棒控制问题一直是研究的热点。针对此问题,构建了一种非线性互联系统状态观测器,并基于观测器的状态估计值设计了一种状态反馈控制器。对状态估计误差与状态反馈闭环互联系统进行增广联合设计,构造了一种增... 含扰动的非线性互联系统的鲁棒控制问题一直是研究的热点。针对此问题,构建了一种非线性互联系统状态观测器,并基于观测器的状态估计值设计了一种状态反馈控制器。对状态估计误差与状态反馈闭环互联系统进行增广联合设计,构造了一种增广李雅普诺夫函数,给出了增广系统渐近稳定的充分条件,保证了状态估计误差趋于零,状态反馈闭环互联系统鲁棒镇定。最后,选取两类互联系统算例对所提控制方法进行仿真验证,仿真结果验证了所构建的状态观测器的可行性和基于估计状态的状态反馈控制器的有效性,所提控制方法为含扰动的非线性互联系统的鲁棒控制问题求解提供了一种参考。 展开更多
关键词 观测器 非线性互联系统 控制器 线性矩阵不等式 鲁棒镇定
下载PDF
收入不平衡、共享发展与居民幸福感
12
作者 陈福中 蒋国海 《东北大学学报(社会科学版)》 北大核心 2025年第1期41-52,87,共13页
改革开放以来,我国经济发展取得了举世瞩目的成就,但收入不平衡和共享发展程度较低的问题仍然较为突出,这在一定程度上不利于居民幸福感的提升.采用中国家庭追踪调查数据,实证检验了收入不平衡、共享发展与居民幸福感之间的关系.研究发... 改革开放以来,我国经济发展取得了举世瞩目的成就,但收入不平衡和共享发展程度较低的问题仍然较为突出,这在一定程度上不利于居民幸福感的提升.采用中国家庭追踪调查数据,实证检验了收入不平衡、共享发展与居民幸福感之间的关系.研究发现,收入不平衡与居民幸福感之间存在非线性的倒U型关系,并且共享发展发挥了重要的调节效应,使得共享发展程度较高的群体对收入不平衡更加包容,而且更易发挥收入不平衡对居民幸福感的提升作用.精准扶贫、乡村振兴和社会保障支出等政策也有助于提升居民幸福感对收入不平衡的包容度.因此,政府相关部门应积极实施有效举措降低收入不平衡、多措并举提升共享发展水平并着力落实扶贫类和保障类政策,进一步提升居民家庭的幸福感,加快实现共同富裕的伟大目标. 展开更多
关键词 收入不平衡 共享发展 居民幸福感 非线性关系 政策调节效应
下载PDF
数字金融对家庭消费相对剥夺的影响
13
作者 王立平 《中南财经政法大学学报》 北大核心 2025年第1期85-97,共13页
本文基于2014年、2016年、2018年和2020年中国家庭追踪调查(CFPS)数据,实证研究了数字金融对家庭消费相对剥夺的影响。研究发现:第一,数字金融的发展可以显著缓解家庭消费相对剥夺;第二,数字金融通过增加家庭收入、提高信贷可及性和增... 本文基于2014年、2016年、2018年和2020年中国家庭追踪调查(CFPS)数据,实证研究了数字金融对家庭消费相对剥夺的影响。研究发现:第一,数字金融的发展可以显著缓解家庭消费相对剥夺;第二,数字金融通过增加家庭收入、提高信贷可及性和增强社会资本三个机制来减轻家庭消费相对剥夺;第三,数字金融对家庭消费相对剥夺的影响会因家庭特征和城乡区域的不同而有所差异。从家庭特征来看,数字金融能够显著缓解中低收入家庭和户主是低学历家庭的消费相对剥夺。从城乡区域划分来看,数字金融的发展能显著缓解农村家庭的消费相对剥夺。扩展分析结果显示,数字金融能够显著缓解享受型和发展型消费相对剥夺,家庭数字金融参与度的提高能够减轻家庭的消费相对剥夺。本文的研究发现有助于理解数字金融发展与消费不平等之间的关系,为缓解家庭消费相对剥夺提供了实践启示。 展开更多
关键词 数字金融 消费不平等 家庭消费相对剥夺 信贷可及性 社会资本
下载PDF
基于扰动和输入饱和限制的连续时间系统预见跟踪控制
14
作者 李丽 叶辉 《应用数学》 北大核心 2025年第1期224-232,共9页
本文研究一类带有外部干扰和输入饱和的连续时间系统的预见控制问题.为了能成功地构造出连续时间输入饱和系统的误差系统,与以往对系统方程求导不同,本文利用状态平移方法代替状态求导,使得输入饱和连续时间系统的误差系统的构造成为可... 本文研究一类带有外部干扰和输入饱和的连续时间系统的预见控制问题.为了能成功地构造出连续时间输入饱和系统的误差系统,与以往对系统方程求导不同,本文利用状态平移方法代替状态求导,使得输入饱和连续时间系统的误差系统的构造成为可能.这样原系统的预见饱和控制就转化为误差系统的标准饱和控制问题.另外,针对原系统的误差系统,分别引入状态反馈和静态输出反馈,并改写输入向量以便利用可预见信号的未来信息.利用Lyapunov函数及LMI技巧,导出了闭环系统渐近稳定的充分条件.最后仿真例子表明了本文结果的有效性. 展开更多
关键词 预见控制 连续时间系统 输入饱和 状态反馈 输出反馈 线性矩阵不等式
下载PDF
化“数字”为“数治”:数字素养与村民社会治理参与
15
作者 王小华 吴双虹 《湖南农业大学学报(社会科学版)》 2025年第1期62-71,共10页
数字变革新时代,以“数字”驱动“数治”,是推动基层治理能力纵深发展的关键之举,为实现乡村治理体系和治理能力现代化带来了新机遇。利用中国家庭追踪调查(CFPS2022)数据,分析了数字素养对村民社会治理参与行为的影响效应。结果表明,... 数字变革新时代,以“数字”驱动“数治”,是推动基层治理能力纵深发展的关键之举,为实现乡村治理体系和治理能力现代化带来了新机遇。利用中国家庭追踪调查(CFPS2022)数据,分析了数字素养对村民社会治理参与行为的影响效应。结果表明,数字素养显著促进了村民的社会治理参与行为;数字素养的助推效应主要通过提升村民社会资本、改善村民政治态度两种渠道来实现。异质性分析表明,数字素养对不同特征村民的社会治理参与行为影响存在显著差异,针对女性、青年、受教育程度较高的群体,数字素养所带来的村民社会治理参与行为促进效应更明显。基于此,建议进一步加大数字乡村建设的实施力度、尽力弥合数字鸿沟、通过数字化转型驱动乡村治理升级、优化数字乡村治理的制度供给体系,以此推动乡村治理现代化的进程。 展开更多
关键词 数字素养 乡村数字治理 社会治理参与 数字不平等
下载PDF
Generalization of an elementary inequality in Fourier analysis 被引量:1
16
作者 ZHOU Guan-zhen 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2010年第1期43-47,共5页
The inequality sup n≥1|n∑k=1 sinkx/k|≤3√π,plays an important role in Fourier analysis and approximation theory. It has recently been generalized by Telyakovskii and Leindler. This paper further generalizes and ... The inequality sup n≥1|n∑k=1 sinkx/k|≤3√π,plays an important role in Fourier analysis and approximation theory. It has recently been generalized by Telyakovskii and Leindler. This paper further generalizes and improves their results by introducing a new class of sequences called γ-piecewise bounded variation sequence (γ-PBVS). 展开更多
关键词 PBV condition γ-PBVS inequality.
下载PDF
Further Improvement of Klamkin Inequality 被引量:1
17
作者 张晗方 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第3期55-60,共6页
In this paper, we use a geometric identity in the n-dimensional Euclidean space En and give the further improveme nt of Klamkin inequality in the space En.
关键词 Klamkin inequality SIMPLEX CIRCUMRADIUS INRADIUS
下载PDF
On a Class of Second Order Differential Inequality with Continuous Distributed Deviating Arguments
18
作者 王培光 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 1999年第4期337-341,共5页
Aim To study properties of solutions to a class of second order differential inequality with continuous distributed deviating arguments. Methods A direct analysis technique was used. Results and Conclusion Some suf... Aim To study properties of solutions to a class of second order differential inequality with continuous distributed deviating arguments. Methods A direct analysis technique was used. Results and Conclusion Some sufficient conditions that ensure a class of second order delay differential inequality having no eventually positive solutions were obtained, which generalized some given results. Using the results, some oscillatory criteria for solutions of the hyperbolic equation with distributed deviating arguments can be established. 展开更多
关键词 inequality distributed deviating arguments positive solution
下载PDF
New Majorized Results on Hilbert's Integral Inequality
19
作者 谢鸿政 吕中学 辛玉梅 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第4期69-75,共7页
In this paper, some new majorized results on Hilbert’s integral inequality are showed.
关键词 Hilbert’s integral inequality
下载PDF
A Study on China's Regional Income Inequality
20
作者 郑飞 汤兵勇 《Journal of China Textile University(English Edition)》 EI CAS 1999年第1期35-38,共4页
Using the targets such as absolute dispersion, ratio of high - low Income, coefficient of variation and Ginl coefficient, we analyze the China’s per capita income inequality from 1952 to 1995. We find the trends in t... Using the targets such as absolute dispersion, ratio of high - low Income, coefficient of variation and Ginl coefficient, we analyze the China’s per capita income inequality from 1952 to 1995. We find the trends in the China’s per capita Income differences, i.e., from 1952 to 1978 the differences increase; from 1978 to the early of 1990’ s decrease; and from the early of 1990’ s to 1995 a little increase. But in the light of absolute levels, the differences Increase from year to year. And we preliminarily analyze the cause of the regional per capita income inequality. 展开更多
关键词 REGIONAL ECONOMY PER capita INCOME GDP inequality.
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部