期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
二维晶粒短长程拓扑相关性的相场法研究
1
作者 李洁 梁冬梅 +1 位作者 张义灵 罗志荣 《热加工工艺》 CSCD 北大核心 2018年第20期58-62,共5页
采用相场法研究了二维晶粒的拓扑特性。对105363个晶粒的边数、面积分布和短长程拓扑相关性进行定量表征。结果表明,晶粒边数分布为对数正态分布;晶粒的边数与晶粒面积呈正相关;中心晶粒与近邻晶粒的短程拓扑相关性较强,而与长程拓扑相... 采用相场法研究了二维晶粒的拓扑特性。对105363个晶粒的边数、面积分布和短长程拓扑相关性进行定量表征。结果表明,晶粒边数分布为对数正态分布;晶粒的边数与晶粒面积呈正相关;中心晶粒与近邻晶粒的短程拓扑相关性较强,而与长程拓扑相关性较弱。 展开更多
关键词 拓扑特性 短长程 晶粒边数 相场法
下载PDF
Repeat Sequences and Base Correlations in Human Y Chromosome Palindromes 被引量:1
2
作者 金能智 刘子贤 +1 位作者 齐燕姣 邱文元 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第3期255-261,339,共8页
On the basis of information theory and statistical methods, we use mutual information, n- tuple entropy and conditional entropy, combined with biological characteristics, to analyze the long range correlation and shor... On the basis of information theory and statistical methods, we use mutual information, n- tuple entropy and conditional entropy, combined with biological characteristics, to analyze the long range correlation and short range correlation in human Y chromosome palindromes. The magnitude distribution of the long range correlation which can be reflected by the mutual information is PS〉PSa〉PSb (P5a and P5b are the sequences that replace solely Alu repeats and all interspersed repeats with random uneorrelated sequences in human Y chromosome palindrome 5, respectively); and the magnitude distribution of the short range correlation which can be reflected by the n-tuple entropy and the conditional entropy is PS〉P5a〉PSb〉random uncorrelated sequence. In other words, when the Alu repeats and all interspersed repeats replace with random uneorrelated sequence, the long range and short range correlation decrease gradually. However, the random nncorrelated sequence has no correlation. This research indicates that more repeat sequences result in stronger correlation between bases in human Y chromosome. The analyses may be helpful to understand the special structures of human Y chromosome palindromes profoundly. 展开更多
关键词 Human Y chromosome PALINDROME Mutual information Long range correlation Short range correlation
下载PDF
Discussion on the parameters of design waves 被引量:3
3
作者 王言英 《Journal of Marine Science and Application》 2008年第3期162-167,共6页
In order to respond the discredit on the design wave standard and to recommend new consideration on design wave parameters, based on the long-term distribution of statistic characteristics of waves and the short-term ... In order to respond the discredit on the design wave standard and to recommend new consideration on design wave parameters, based on the long-term distribution of statistic characteristics of waves and the short-term probability properties of sea state defined by giving the return period, the calculation of the return period, the height, the period, and the oceanic wave parameters of the design wave and the forecasting methods are discussed in this paper. To provide references for the operation reliability of floating structures in the extreme sea state, the method of determining the design wave parameters is resurveyed. A proposal is recommended that the design wave, which can be either significant wave with 500-year of the return period, or the maximum wave with 1/N of exceeding probability, 100-year of the return period, can be applied in the engineering design practice. 展开更多
关键词 ocean waves short-term distribution long-term distribution design waves
下载PDF
Short—Time Critical Behavior Affected by Weakly Long—Range Interactions
4
作者 CHENYuan LIZhi-Bing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第4期475-479,共5页
The theoretic renormalization group approach is applied to the study of short-time critical behavior of the Ginzburg–Landau model with weakly long-range interactions . The system initially at a high temperature is fi... The theoretic renormalization group approach is applied to the study of short-time critical behavior of the Ginzburg–Landau model with weakly long-range interactions . The system initially at a high temperature is firstly quenched to the critical temperature and then released to an evolution with a model A dynamics. A double expansion in and with of order is employed, where is the spatial dimension. The asymptotic scaling laws and the initial slip exponents and for the order parameter and the response function respectively are calculated to the second order in for close to 2. 展开更多
关键词 Ginzburg-Landau model short-time critical dynamics weakly long-range interactions
下载PDF
Quasi-periodic and Non-periodic Waves in (2q-1)-Dimensional Nonlinear Systems
5
作者 TANG Xiao-Yan LOU Sen-Yue 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4X期583-588,共6页
New exact quasi-periodic and non-periodic solutions for the (2+ 1)-dimensional nonlinear systems are studied by means of the multi-linear variable separation approach (MLVSA) and the Jacobi elliptic functions wit... New exact quasi-periodic and non-periodic solutions for the (2+ 1)-dimensional nonlinear systems are studied by means of the multi-linear variable separation approach (MLVSA) and the Jacobi elliptic functions with the space-time-dependent modulus. Though the result is valid for all the MLVSA solvable models, it is explicitly shown for the long-wave and short-wave interaction model. 展开更多
关键词 quasi-periodic waves non-periodic waves multi-linear variable separation approach the longwave and thort-wave interaction model
下载PDF
抑郁症患者情绪加工皮层间连接削弱:基于多变量自回归模型的相干分析
6
作者 徐珍珠 魏玲 +1 位作者 麻蔓芳 李颖洁 《生物物理学报》 CAS CSCD 北大核心 2013年第2期133-142,共10页
主要研究抑郁症和正常人在不同情绪认知任务下大脑功能性连接的差异。作者选取了12个抑郁症患者和12个正常被试进行正负情绪面孔搜索的认知任务,并同时记录头皮脑电。应用基于多变量自回归模型的相干分析方法计算了delta(1~3.5 Hz)、th... 主要研究抑郁症和正常人在不同情绪认知任务下大脑功能性连接的差异。作者选取了12个抑郁症患者和12个正常被试进行正负情绪面孔搜索的认知任务,并同时记录头皮脑电。应用基于多变量自回归模型的相干分析方法计算了delta(1~3.5 Hz)、theta(4~7 Hz)、alpha(8~13 Hz)频带15个导联之间的连接,以及前额、顶枕区短距离连接和左右半球前额-顶枕区长距离连接。结果发现:1)刺激后1~200 ms,抑郁症患者在前额区delta、theta、alpha频带的短距离连接强度显著低于正常组,左前额-顶枕区delta、theta频带的长距离连接强度也明显低于正常组;2)正性情绪刺激下,正常人前额区delta、theta、alpha频带的短距离连接强度比负性情绪刺激下显著高,左前额-顶枕区delta、theta频带的长距离连接和右前额-顶枕区alpha频带的长距离连接强度比负性情绪刺激下也显著高。病人组情绪差异不明显。综上,前额区连接和左前额-顶枕区长距离连接的减小反映了病人在情绪认知任务下该神经网络功能性连接不充分,这可能揭示了抑郁症情绪加工障碍的机制。 展开更多
关键词 事件相关脑电 抑郁症 相干 情绪 短长程连接
原文传递
Existence of Global Attractor for LS Type Equations
7
作者 张瑞凤 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2006年第4期708-714,共7页
The global attractor problem of the long-short wave equations with periodic boundary condition was studied. The existence of global attractor of this problem was proved by means of a uniform a priori estimate for time.
关键词 long-short wave equations a priori estimate global attractor.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部