期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
基于小波变换法定义的波群参数 被引量:1
1
作者 刘思 柳淑学 +1 位作者 俞聿修 李金宣 《海洋学报》 CAS CSCD 北大核心 2010年第2期148-154,共7页
通过小波变换分析的波能过程定义了两个描述波浪群性的参数,由数值模拟波浪和实测波浪资料对其与常用的波群参数进行对比分析,结果表明基于小波波能过程定义的群性参数是有效的,从而展示了小波变换用于在时频域上分析波群的能力。详... 通过小波变换分析的波能过程定义了两个描述波浪群性的参数,由数值模拟波浪和实测波浪资料对其与常用的波群参数进行对比分析,结果表明基于小波波能过程定义的群性参数是有效的,从而展示了小波变换用于在时频域上分析波群的能力。详细探讨了波浪记录长度对群性参数稳定性的影响,分析结果表明,波浪观测长度对于波群参数的影响较大,在考虑波浪群性的波浪模拟及分析时,建议模拟时间长度应在400-500个波以上。 展开更多
关键词 小波变换 波群 群性参数 时频域
下载PDF
改进的海浪波包谱 被引量:11
2
作者 刘思 柳淑学 俞聿修 《水道港口》 2010年第4期229-235,共7页
结合实测波浪资料对描述波浪群性的主要特征参数进行了统计和相关性分析,结果表明波群的高度特征和长度特征之间相关性较弱。在此基础上根据渤海和珠江口两地的波浪观测数据,采用合理的无因次化方式,拟合得到一个适于风浪的波包谱经验... 结合实测波浪资料对描述波浪群性的主要特征参数进行了统计和相关性分析,结果表明波群的高度特征和长度特征之间相关性较弱。在此基础上根据渤海和珠江口两地的波浪观测数据,采用合理的无因次化方式,拟合得到一个适于风浪的波包谱经验公式。该公式同时考虑了群高与群长两方面的因素,只要给出波要素和波群的特征参数便可确定波包谱形,便于应用,根据对实测资料波群参数的分析结果,与俞聿修等人先前建议的波包谱公式相比,该公式中给出了更合理的参数取值原则。 展开更多
关键词 波群 群性参数 波包谱
下载PDF
江苏辐射沙洲南翼海域风浪的波包谱分析 被引量:1
3
作者 虞丹君 冯卫兵 杨斌 《应用海洋学学报》 CAS CSCD 北大核心 2015年第1期10-16,共7页
基于江苏沿海辐射沙洲南翼实测波浪资料,采用波包线理论计算实测波包谱,利用改进的公式对无因次化平均波包谱曲线进行拟合,得到了一个能够反映辐射沙洲南翼海域风浪波包能量分布的波包谱经验公式.同时,考虑了基于波包线理论的群高参数... 基于江苏沿海辐射沙洲南翼实测波浪资料,采用波包线理论计算实测波包谱,利用改进的公式对无因次化平均波包谱曲线进行拟合,得到了一个能够反映辐射沙洲南翼海域风浪波包能量分布的波包谱经验公式.同时,考虑了基于波包线理论的群高参数和群长参数,结合实测资料初步建议了此海域群高及群长参数的取值.此外,结合相关统计参数对波包谱经验公式进行了简化,并将计算所得的谱峰值和零阶矩与实测统计值进行对比验证,谱峰值相对误差范围为0.1%-80.0%,均值为23.5%,零阶矩的相对误差范围为0.0%-23.5%,均值为5.0%.从总体上来说,经验公式确定的波包谱与实测波包谱符合较好,对今后辐射沙洲南翼海域的波群理论研究及工程建设具有一定的参考价值. 展开更多
关键词 物理海洋学 波包谱 波群 群性参数 辐射沙洲
下载PDF
多向不规则波群传播的数值模拟 被引量:6
4
作者 刘思 张永良 《清华大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第12期1289-1295,共7页
波群的模拟是与波群有关的数值和物理模型试验的前提。实际的波浪是多向的不规则波,为了在实验水池中模拟多向不规则波群,该文首先根据给定的波要素、群性参数和方向分布参数,给出了多向不规则波群的数值模拟方法,在此基础上利用有限元... 波群的模拟是与波群有关的数值和物理模型试验的前提。实际的波浪是多向的不规则波,为了在实验水池中模拟多向不规则波群,该文首先根据给定的波要素、群性参数和方向分布参数,给出了多向不规则波群的数值模拟方法,在此基础上利用有限元法求解改进的Boussinesq方程的数值计算模型,建立了数值水池在指定位置模拟所要求群性的多向不规则波的入射波浪边界条件的计算方法。典型算例表明:按照该文建议的方法确定入射波浪边界条件而建立的数值模型,可以在水池指定位置处产生满足给定群性要求的多向不规则波浪。此外,对多向不规则波群的传播进行了数值研究。 展开更多
关键词 多向波 波群 群性参数 数值模拟
原文传递
DEGENERATE SEMI-GROUP METHODS FOR THE EXPONENTIAL STABILITY OF THE FIRST ORDER SINGULAR DISTRIBUTED PARAMETER SYSTEMS 被引量:13
5
作者 Zhaoqiang GE Guangtian ZHU Dexing FENG 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2008年第2期260-266,共7页
Exponential stability of the first order singular distributed parameter systems is discussedin the light of degenerate semi-group methods,which is described by the abstract developing equationin Hilbert space.The nece... Exponential stability of the first order singular distributed parameter systems is discussedin the light of degenerate semi-group methods,which is described by the abstract developing equationin Hilbert space.The necessary and sufficient conditions concerning the exponential stability of thefirst order singular distributed parameter systems are given. 展开更多
关键词 Degenerate semi-group exponential stability first order singular distributed parameter systems.
原文传递
THE COMPLETE LANGLANDS PARAMETERS CORRESPONDING TO THE REPRESENTATIONS OF THE CLASSICAL GROUPS WITH INTEGRAL REGULAR INFINITESIMAL CHARACTERS
6
作者 HOUZIXIN ZHAOQIANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1996年第1期53-62,共10页
The authors determine all the complete Langlands parameters corresponding to the representations of the classical groups with integral regular infintesimal characters, and get all L-packts in that case.
关键词 L-packet Complete Langlands parameter Classical group
原文传递
Qualitative analysis for a Wolbachia infection model with diffusion 被引量:7
7
作者 HUANG Mu Gen YU Jian She +1 位作者 HU Lin Chao ZHENG Bo 《Science China Mathematics》 SCIE CSCD 2016年第7期1249-1266,共18页
We consider a reaction-diffusion model which describes the spatial Wolbachia spread dynamics for a mixed population of infected and uninfected mosquitoes. By using linearization method, comparison principle and Leray-... We consider a reaction-diffusion model which describes the spatial Wolbachia spread dynamics for a mixed population of infected and uninfected mosquitoes. By using linearization method, comparison principle and Leray-Schauder degree theory, we investigate the influence of diffusion on the Wolbachia infection dynamics.After identifying the system parameter regions in which diffusion alters the local stability of constant steadystates, we find sufficient conditions under which the system possesses inhomogeneous steady-states. Surprisingly,our mathematical analysis, with the help of numerical simulations, indicates that diffusion is able to lower the threshold value of the infection frequency over which Wolbachia can invade the whole population. 展开更多
关键词 dengue fever Wolbachia infection dynamics cytoplasmic incompatibility mechanism attractive region Turing instability non-constant steady-states
原文传递
Optimization of Pyrolysis Properties using TGA and Cone Calorimeter Test
8
作者 Won-Hee Park Kyung-Beom Yoon 《Journal of Thermal Science》 SCIE EI CAS CSCD 2013年第2期168-173,共6页
The present paper describes an optimization work to obtain the properties related to a pyrolysis process in the solid material such as density, specific heat, conductivity of virgin and char, heat of pyrolysis and kin... The present paper describes an optimization work to obtain the properties related to a pyrolysis process in the solid material such as density, specific heat, conductivity of virgin and char, heat of pyrolysis and kinetic parameters used for deciding pyrolysis rate. A repulsive particle swarm optimization algorithm is used to obtain the pyrolysis-related properties. In the previous study all properties obtained only using a cone calorimeter but in this paper both the cone calorimeter and thermo gravimetric analysis (TGA) are used for precisely optimizing the pyrolysis properties. In the TGA test a very small mass is heated up and conduction and heat capacity in the specimen is negligible so kinetic parameters can first be optimized. Other pyrolysis-related properties such as virgin/char specific heat and conductivity and char density are also optimized in the cone calorimeter test with the already decided parameters in the TGA test. 展开更多
关键词 Pyrolysis properties Thermogravimetric analysis Cone calorimeter Repulsive particle swarmoptimization
原文传递
Dynamics of populations with two sexes
9
作者 M. Cecilia Perez E. Adriana Saavedra Mariano A. Ferrari 《International Journal of Biomathematics》 2015年第4期127-144,共18页
A mathematical model is presented in order to describe the dynamics of polygamous populations, bearing in mind single individuals of both sexes and the development of reproductive groups. In this context, the descript... A mathematical model is presented in order to describe the dynamics of polygamous populations, bearing in mind single individuals of both sexes and the development of reproductive groups. In this context, the description leads us to consider positive homogeneous dynamical systems, establishing conditions for the stationary state existence and its local stability. A fourth pre-reproductive stage was considered, i.e. males and females spend part of their lives before being in condition to reproduce, as a first step to consider more general models. Finally, we parametrized the proposed model using southern elephant seal data, to analyze the direct applicability to a real population. 展开更多
关键词 Dynamical systems two-sex model mating system local stability.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部