期刊文献+
共找到24篇文章
< 1 2 >
每页显示 20 50 100
The Martingale Hardy Type Inequalities for Dyadic Derivative and Integral 被引量:6
1
作者 JianYingNIE Xing Guo Nie GUO Wei LOU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2005年第6期1465-1474,共10页
Since the Leibniz-Newton formula for derivatives cannot be used in local fields, it is important to investigate the new concept of derivatives in Walsh-analysis, or harmonic analysis on local fields. On the basis of i... Since the Leibniz-Newton formula for derivatives cannot be used in local fields, it is important to investigate the new concept of derivatives in Walsh-analysis, or harmonic analysis on local fields. On the basis of idea of derivatives introduced by Butzer, Schipp and Wade, Weisz has proved that the maximal operators of the one-dimensional dyadic derivative and integral are bounded from the dyadic Hardy space Hp,q to Lp,q, of weak type (L1,L1), and the corresponding maximal operators of the two-dimensional case are of weak type (Hi, L1). In this paper, we show that these maximal operators are bounded both on the dyadic Hardy spaces Hp and the hybrid Hardy spaces H^#p 0〈p≤1. 展开更多
关键词 martingale Hardy space dyadic derivative dyadic integral Walsh-Fejer kernels p-atom quasi-local operator
原文传递
A quasi-local mass for 2-spheres with negative Gauss curvature 被引量:3
2
作者 ZHANG Xiao Institute of Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100080, China 《Science China Mathematics》 SCIE 2008年第9期1644-1650,共7页
We extend our previous definition of quasi-local mass to 2-spheres whose Gauss curvature is negative, and prove its positivity.
关键词 general relativity quasi-local mass POSITIVITY 53C27 53C50 83C60
原文传递
Energy in critical collapse
3
作者 Yu Hu Jun-Qi Guo +2 位作者 Junbin Li Cheng-Gang Shao Hongsheng Zhang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2023年第12期97-104,共8页
We study the energy issue in critical collapse.It is found that in critical collapse,the contribution from the material energy is greater than that from the gravitational energy.The quantity m/r plays an important rol... We study the energy issue in critical collapse.It is found that in critical collapse,the contribution from the material energy is greater than that from the gravitational energy.The quantity m/r plays an important role in identifying the formation of an apparent horizon in gravitational collapse,where m is the Misner-Sharp mass and r is the areal radius.We observe that in critical collapse,the maximum value of m/r fluctuates between 2/15 and 4/15.This denotes a large gap between critical collapse and black hole formation for which the criterion is m/r=1/2. 展开更多
关键词 quasi-local energy critical collapse numerical relativity
原文传递
A Re-Interpretation of Quasi-Local Mass 被引量:1
4
作者 Edwin Eugene Klingman 《Journal of Modern Physics》 2022年第4期347-367,共21页
Because the equivalence principle forbids local mass density, we cannot formulate general relativistic mass as an integral over mass density as in Newtonian gravity. This century-old problem was addressed forty years ... Because the equivalence principle forbids local mass density, we cannot formulate general relativistic mass as an integral over mass density as in Newtonian gravity. This century-old problem was addressed forty years ago by Penrose, and many papers have since extended the concept. Currently there is no satisfactory physical understanding of the nature of quasi-local mass. In this paper I review the key issues, the current status, and propose an alternative interpretation of the problem of local mass and energy density for gravity systems from an information perspective. 展开更多
关键词 quasi-local Mass Curved Space-Time Gravitational Energy Stress-Energy Tensor Encoding Information in Geometry Schwarzschild Metric
下载PDF
A Locally Conservative Energy-Momentum Tensor in the General Relativity Based on a Cosmological Model without Singularity 被引量:1
5
作者 Shihao Chen 《Journal of Modern Physics》 2016年第3期277-280,共4页
According to the conventional theory it is difficult to define the energy-momentum tensor which is locally conservative. The energy-momentum tensor of the gravitational field is defined. Based on a cosmological model ... According to the conventional theory it is difficult to define the energy-momentum tensor which is locally conservative. The energy-momentum tensor of the gravitational field is defined. Based on a cosmological model without singularity, the total energy-momentum tensor is defined which is locally conservative in the general relativity. The tensor of the gravitational mass is different from the energy-momentum tensor, and it satisfies the gravitational field equation and its covariant derivative is zero. 展开更多
关键词 Energy-Momentum Tensor of Gravitational Field locally Conservative Energy-Momentum Tensor in General Relativity Tensor of the Gravitational Mass quasi-local Energy-Momentum Tensor
下载PDF
A New Quasi-local Mass and Positivity
6
作者 Xiao ZHANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2008年第6期881-890,共10页
A new definition of quasi-local mass is proposed and its positivity is proved under certain conditions.
关键词 general relativity quasi-local mass POSITIVITY
原文传递
On limit behavior of quasi-local mass for ellipsoids at spatial infinity
7
作者 Xiaokai He Leong-Fai Wong Naqing Xie 《Communications in Theoretical Physics》 SCIE CAS CSCD 2020年第1期102-110,共9页
We discuss the spatial limit of the quasi-local mass for certain ellipsoids in an asymptotically flat static spherically symmetric spacetime.These ellipsoids are not nearly round but they are of interest as an admissi... We discuss the spatial limit of the quasi-local mass for certain ellipsoids in an asymptotically flat static spherically symmetric spacetime.These ellipsoids are not nearly round but they are of interest as an admissible parametrized foliation defining the Arnowitt–Deser–Misner mass.The Hawking mass of this family of ellipsoids tends to-∞.In contrast,we show that the Hayward mass converges to a finite value.Moreover,a positive mass type theorem is established.The limit of the mass has a uniform positive lower bound no matter how oblate these ellipsoids are.This result could be extended for asymptotically Schwarzschild manifolds.And numerical simulation in the Schwarzschild spacetime illustrates that the Hayward mass is monotonically increasing near infinity. 展开更多
关键词 quasi-local MASS asymptotically flat LIMIT BEHAVIOR
原文传递
Quasi-Local Energy Distribution and Thermodynamics of Reissner-Nordstrom Black Hole Surrounded by Quintessence 被引量:1
8
作者 Mahamat Saleh Bouetou Bouetou Thomas Timoleon Crepin Kofane 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第2期291-295,共5页
We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstr6m black hole space-time surrounded by quintessence. We use the quasi-local energy distribution from Einstein energy-momentum co... We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstr6m black hole space-time surrounded by quintessence. We use the quasi-local energy distribution from Einstein energy-momentum complex. We plot the variation of the energies, temperature and heat capacity with the state parameter related to the quintessence ωq. We show that due to the presence of quintessence, the total energy of the outer region as well as the temperature and heat capacity decreases with the increase of the density of quintessence, while the total energy of the black hole region increases. 展开更多
关键词 quasi-local energy distribution thermodynamics Reissner-NordstrSm black hole QUINTESSENCE
下载PDF
QUASI-LOCAL CONJUGACY THEOREMS IN BANACH SPACES
9
作者 ZHANG WEIRONG MA JIPu 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2005年第4期551-558,共8页
Let f : U(x0) belong to E → F be a C^1 map and f'(x0) be the Frechet derivative of f at x0. In local analysis of nonlinear functional analysis, implicit function theorem, inverse function theorem, local surject... Let f : U(x0) belong to E → F be a C^1 map and f'(x0) be the Frechet derivative of f at x0. In local analysis of nonlinear functional analysis, implicit function theorem, inverse function theorem, local surjectivity theorem, local injectivity theorem, and the local conjugacy theorem are well known. Those theorems are established by using the properties: f'(x0) is double splitting and R(f'(x)) ∩ N(T0^+) = {0} near x0. However, in infinite dimensional Banach spaces, f'(x0) is not always double splitting (i.e., the generalized inverse of f(x0) does not always exist), but its bounded outer inverse of f'(x0) always exists. Only using the C^1 map f and the outer inverse To^# of f(x0), the authors obtain two quasi-local conjugacy theorems, which imply the local conjugacy theorem if x0 is a locally fine point of f. Hence the quasi-local conjugacy theorems generalize the local conjugacy theorem in Banach spaces. 展开更多
关键词 Frechet derivative quasi-local conjugacy theorems Outer inverse local conjugacy theorem
原文传递
Banach空间值鞅上的拟局部算子 被引量:2
10
作者 任颜波 侯友良 《数学杂志》 CSCD 北大核心 2007年第6期725-730,共6页
本文研究了拟局部算子在几个Banach空间值鞅空间上的有界性.给出了几个有界性定理,证明了鞅空间的简单原子分解.得到几个极大算子和p均方算子的一系列鞅不等式以及鞅空间的包含关系.
关键词 Banach值鞅 简单原子分解 拟局部算子
下载PDF
基于网络资源流量的链路预测方法 被引量:1
11
作者 刘宇航 尹小庆 林云 《计算机工程》 CAS CSCD 北大核心 2022年第9期78-88,共11页
在复杂网络中,现有基于结构相似性的链路预测方法较少考虑全局和局部拓扑信息之间平衡性、准确度和复杂度之间平衡性以及网络资源动态流动的问题。将网络资源流量作为相似性判断依据,提出一种准局部链路预测方法。根据网络中节点重要性... 在复杂网络中,现有基于结构相似性的链路预测方法较少考虑全局和局部拓扑信息之间平衡性、准确度和复杂度之间平衡性以及网络资源动态流动的问题。将网络资源流量作为相似性判断依据,提出一种准局部链路预测方法。根据网络中节点重要性的不同来为它们分配对应的资源,以保证资源分配的合理性。针对网络资源提出一种动态流动机制,将节点对双向流动的资源之和作为相似程度的量化指标。引入节点对之间中间路径节点的概念,分析中间路径节点在资源流动过程中的稀释作用。在此基础上,计算初始资源量和稀释作用量从而得到网络资源流量方法的性能评估指标值。在Jazz、NS等11个真实世界的网络中进行实验,对比该方法与CN、Salton等常见基准方法在准确度和鲁棒性方面的性能表现,结果表明,所提方法能够充分利用准局部信息,既能考虑资源流动性又能解决平衡性问题,可有效提高链路预测性能。 展开更多
关键词 复杂网络 链路预测 资源流动 双向流量 准局部路径
下载PDF
一般阻尼随机微分方程的拟局部振荡算法 被引量:1
12
作者 宋艳丽 包景东 《计算物理》 CSCD 北大核心 2005年第1期1-6,共6页
 提出了一种模拟随机微分方程的拟局部振荡算法,即利用算符劈裂方法和势函数的泰勒展开,对噪声作用下耗散粒子的时间演化算符进行分解,得到了对应涨落行为的扩散算符和对应确定轨迹的漂移算符.其中局部简谐势场的涨落过程可获得解析解...  提出了一种模拟随机微分方程的拟局部振荡算法,即利用算符劈裂方法和势函数的泰勒展开,对噪声作用下耗散粒子的时间演化算符进行分解,得到了对应涨落行为的扩散算符和对应确定轨迹的漂移算符.其中局部简谐势场的涨落过程可获得解析解,而剩余的确定项则利用简单的Euler算法积分.应用到几个算例并与常用的两种算法相比较,结果表明:本算法随时间步长最稳定,可使用较大的时间步长. 展开更多
关键词 算符 随机微分方程 简谐势 时间演化 势函数 积分 算法 拟局 中局 一般
下载PDF
一类四阶发展方程的拟局部对称分类问题 被引量:1
13
作者 黄晴 王丽真 左苏丽 《西北大学学报(自然科学版)》 CAS CSCD 北大核心 2010年第2期207-209,共3页
目的研究一类四阶发展方程的拟局部对称分类问题。方法利用群分类方法。结果给出了容许拟局部对称的四阶发展方程及其所容许的对称。结论完成了四阶发展方程的拟局部对称分类问题。
关键词 四阶发展方程 拟局部对称 对称分类
下载PDF
模的系数环的约化 被引量:1
14
作者 廖贻华 易忠 《广西师范大学学报(自然科学版)》 CAS 2004年第2期22-24,共3页
在此讨论一个模的系数环约化为环的一个理想以及约化为环中单个元的问题,并给出一个模的系数环约化为环的一个理想以及约化为环中任意一个非零元的充分条件.
关键词 模的系数环 约化 拟局部环von Neumann正则环 内射余生成子
下载PDF
三维有挠率引力中的守恒荷
15
作者 魏诚浩 宁波 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 2019年第1期87-90,共4页
由于引力场的微分同胚不变性,定义能量一直是引力理论中的难题,人们为此发展了一系列方法.本文将Wald基于拉格朗日形式体系构造引力场的准局域能量的方法推广到三维有挠率引力的情形,给出了Mielke-Baekler (MB)模型中的守恒的能量与角动... 由于引力场的微分同胚不变性,定义能量一直是引力理论中的难题,人们为此发展了一系列方法.本文将Wald基于拉格朗日形式体系构造引力场的准局域能量的方法推广到三维有挠率引力的情形,给出了Mielke-Baekler (MB)模型中的守恒的能量与角动量,并计算了有挠率的BTZ黑洞解的守恒荷.所得结果与基于哈密顿形式体系的方法给出的守恒荷相一致. 展开更多
关键词 准局域能量 Mielke-Baekler模型 挠率 引力
下载PDF
非球对称情形箍猜想若干进展
16
作者 谢纳庆 《中国科学:数学》 CSCD 北大核心 2018年第6期835-842,共8页
本文简要地介绍了本文作者及其合作者最近几年在非球对称情形箍猜想研究方面的若干进展.
关键词 箍猜想 陷俘面 准局域质量
原文传递
具有特殊理想的结合环的构造
17
作者 熊惠萍 《南昌大学学报(理科版)》 CAS 1993年第3期76-78,共3页
本文证明了一个特殊理想是零环的结合环同构于亚直不可约环的亚直和。这些亚直不可约环或是零环,或有一个特殊理想是零环。在后一种情况下还得出,这种环必是拟局部环。
关键词 拟局部环 结合环 环论 构造
下载PDF
在线社交网络好友推荐方法的研究——基于非对称相似性方法
18
作者 徐少杰 孙仁诚 +1 位作者 吴舜尧 王晓杰 《青岛大学学报(自然科学版)》 CAS 2016年第1期66-70,共5页
考虑用户间影响的差异,从用户关注的兴趣点出发,及其他用户的消息或行为通过最短路径影响该用户的最大可能性,提出了基于非对称相似性的半局部拓扑指标,并将其应用于在线社交网络好友推荐。通过Facebook数据集验证了该方法,实验结果证明... 考虑用户间影响的差异,从用户关注的兴趣点出发,及其他用户的消息或行为通过最短路径影响该用户的最大可能性,提出了基于非对称相似性的半局部拓扑指标,并将其应用于在线社交网络好友推荐。通过Facebook数据集验证了该方法,实验结果证明,考虑了非对称相似性的好友推荐算法在准确率与召回率上都明显优于其他方法,从而证实了该方法的有效性。 展开更多
关键词 在线社交网络 好友推荐 非对称相似性 半局部拓扑相似性
下载PDF
关于Hermite-Fejér插值算子逼近度的渐近表示
19
作者 姜功建 《河北轻化工学院学报》 1993年第2期13-17,共5页
设H_n(f,x)是以Jacobi多项式J_n(x)的零点为基点的Hermite-Fejér插值算子,本文得到了H_n(f,x)的逼近度的渐近表示。
关键词 线性算子 H-F插殖
下载PDF
区域似大地水准面精化的方法探讨与精度分析 被引量:6
20
作者 布金伟 左小清 《测绘工程》 CSCD 2017年第6期40-45,共6页
阐述与GPS/水准高程拟合相关的基本理论及区域似大地水准面精化的原理与方法,并结合区域的具体实例,重点比较二次多项式曲面拟合法、三角剖分双线性内插法、加权平均推估法的精度情况,从中得到结论。实验表明,在没有足够重力数据的支持... 阐述与GPS/水准高程拟合相关的基本理论及区域似大地水准面精化的原理与方法,并结合区域的具体实例,重点比较二次多项式曲面拟合法、三角剖分双线性内插法、加权平均推估法的精度情况,从中得到结论。实验表明,在没有足够重力数据的支持下,三角剖分双线性内插法获得比较理想的精度,利用该方法精化似大地水准面获得的高程可以代替四等水准。 展开更多
关键词 GPS/水准 区域似大地水准面 二次多项式曲面拟合法 三角剖分双线性内插法 加权平均推估法
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部