期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
On the horizontal distribution of algal-bloom in Chaohu Lake and its formation process 被引量:7
1
作者 Yuan-Ying Chen Qing-Quan Liu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第5期656-666,共11页
Based on the remote sensing images of algae, the present work analyzes the horizontal distribution characteristics of algal blooms in Chaohu Lake, China, which also reveals the frequency of algal blooms under differen... Based on the remote sensing images of algae, the present work analyzes the horizontal distribution characteristics of algal blooms in Chaohu Lake, China, which also reveals the frequency of algal blooms under different wind directions. Further, an unstructured-grid, three-dimensional finite-volume coastal ocean model (FVCOM) is applied to investigate the wind-induced currents and the transport pro- cess to explain the reason why algal blooms occur at the detected places. We first deduce the primary distribution of biomass from overlaid satellite images, and explain the formation mechanism by analyzing the pollution sources, and simulating the flow field and transportation process under prevailing wind over Chaohu Lake. And then, we consider the adjustment action of the wind on the corresponding day and develop a two-time scale approach to describe the whole formation process of algae horizontal distribution in Chaohu Lake. That is, on the longer time scale, i.e., during bloom season, prevailing wind determines the primary distribution of biomass by inducing the characteristic flow field; on the shorter time scale, i.e., on the day when bloom occurs, the wind force adjusts the primary distribution of biomass to form the final distribution of algal bloom. 展开更多
关键词 Chaohu Lake Algal bloom Horizontal distri- bution - Wind-driven current Two-time scale process
下载PDF
Origin of diffraction fringes in two-dimensional photoelectron momentum distributions for single ionization of atoms in few-cycle intense laser pulses 被引量:4
2
作者 郭志坚 陈长进 周效信 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期223-229,共7页
We use the strong field approximation with a time window function controlling the release time of electrons to study the intra-cycle and inter-cycle interferences in few-cycle intense laser pulses impinging on He. The... We use the strong field approximation with a time window function controlling the release time of electrons to study the intra-cycle and inter-cycle interferences in few-cycle intense laser pulses impinging on He. The diffraction fringes, i.e., the vertical stripe-like structure, observed in the experimental two-dimensional photoelectron momentum distributions of Gopal et al. (2009 Phys. Rev. Lett. 103 053001) have been attributed to the interplay of the intra- and inter-cycle interferences. The pure numerical calculations by solving the time-dependent Schrrdinger equation are also performed and the results are compared with the experimental measurements directly. It has been found that the position of the stripe-like structure can be used to determine the duration of the laser pulses used in experiments. 展开更多
关键词 intra-cycle and inter-cycle interferences stripe-like structure two-dimensional momentum distri- butions
下载PDF
中国火山岩油气藏控制因素及分布规律 被引量:34
3
作者 侯连华 朱如凯 +3 位作者 赵霞 庞正炼 罗霞 毛治国 《中国工程科学》 北大核心 2012年第6期77-86,共10页
中国沉积盆地内主要发育石炭—二叠系、侏罗—白垩系和古近—新近系3套火山岩,火山岩大面积分布,烃源岩与火山岩伴生,形成良好的生储盖组合。东部盆地以中酸性岩为主,主要发育原生型火山岩储层;西部盆地以中基性岩为主,主要发育风化壳... 中国沉积盆地内主要发育石炭—二叠系、侏罗—白垩系和古近—新近系3套火山岩,火山岩大面积分布,烃源岩与火山岩伴生,形成良好的生储盖组合。东部盆地以中酸性岩为主,主要发育原生型火山岩储层;西部盆地以中基性岩为主,主要发育风化壳型储层,火山岩风化壳储层物性好于原生型储层物性,各种岩性、岩相均能形成有效储层。东部盆地主要发育岩性、断层—岩性油气藏;西部盆地主要发育地层型、构造—地层型、构造—岩性—地层复合型油气藏。松辽盆地深层持续沉降型断陷控制天然气区域分布,生烃断槽控制断陷内天然气分布,近邻生烃断槽的断裂构造带是天然气富集区带,优质火山岩储层控制天然气富集;新疆北部石炭系残留生烃凹陷控制油气平面分布,风化壳规模控制油气富集程度和规模,风化壳地层型有效圈闭控制油气成藏,正向构造背景控制油气运聚。指出中国火山岩有利勘探面积36万km2,预测火山岩中总资源量60亿t油当量以上,勘探潜力大。 展开更多
关键词 火山岩储层 火成岩油气藏 成藏控制因素 油气藏分布规律
下载PDF
模糊数的四则运算性质及其线性方程 被引量:12
4
作者 张兴芳 张风霞 孟广武 《模糊系统与数学》 CSCD 北大核心 2005年第1期93-99,共7页
讨论模糊数的加、减、乘、除的运算性质,提出模糊数线性方程的概念,并给出这种方程的一种解法。
关键词 模糊数 模糊数的四则运算 模糊数线性方程
下载PDF
西安地铁沿线地层温度冬季分布规律观测研究 被引量:5
5
作者 任建喜 韩强 +4 位作者 高虎艳 杨智国 周晓燕 冯晓光 高廷廷 《城市轨道交通研究》 北大核心 2012年第10期39-42,共4页
通过对西安地铁沿线的皂河一级阶地、黄土梁洼地、渭河一级阶地和渭河三级阶地等4个典型地貌单元的土壤进行地温观测研究,得到冬季不同地貌单元地层的恒温层位置和冬季地层地温的分布规律。观测结果表明:皂河一级阶地的恒温层在地表以下... 通过对西安地铁沿线的皂河一级阶地、黄土梁洼地、渭河一级阶地和渭河三级阶地等4个典型地貌单元的土壤进行地温观测研究,得到冬季不同地貌单元地层的恒温层位置和冬季地层地温的分布规律。观测结果表明:皂河一级阶地的恒温层在地表以下6m,恒温层温度为16℃;黄土梁洼地恒温层在地表以下7.5m,恒温层温度为17℃;渭河一级阶地恒温层在地表以下7.5m,恒温层温度为16℃;渭河三级阶地恒温层在地表以下7.5m,恒温层温度为16.5℃。研究结果可为地铁车站和区间隧道的空调工程设计提供参考。 展开更多
关键词 西安地铁 地层温度观测 分布规律
下载PDF
再谈启动压力梯度 被引量:20
6
作者 李传亮 朱苏阳 《岩性油气藏》 CSCD 2013年第4期1-5,共5页
启动压力梯度其实并不存在,它只是一种实验假象。通过分析启动压力梯度导致的一些错误结果,证明了启动压力梯度不存在。若存在启动压力梯度,当地层中未注入流体时,压力却可以升高,这违背了科学原理;地层将不存在静平衡压力,而是存在压... 启动压力梯度其实并不存在,它只是一种实验假象。通过分析启动压力梯度导致的一些错误结果,证明了启动压力梯度不存在。若存在启动压力梯度,当地层中未注入流体时,压力却可以升高,这违背了科学原理;地层将不存在静平衡压力,而是存在压力梯度不为0的压力分布,这与实际情况不符;地层压力将永远恢复不到原始地层压力,显然与实际情况也不相符;地层压力分布将出现动边界奇点,数学上将不能自洽;油气运移将无法进行,也就不会有油气聚集,实际情况并非如此;流体静止时将具有抗剪切能力,违背了流体力学的基本原理。 展开更多
关键词 低渗透油藏 渗流力学 启动压力梯度 压力分布 动边界 Darcy定律
下载PDF
TWO-DIMENSIONAL MATHEMATICAL MODEL OF COMBUSTION SPACE IN GLASS MELTING FURNACES
7
作者 吴锡琪 李立华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1994年第2期50-58,共9页
Under some assumptions and dividing the combustion space into several isothermal zones and isothermal surface elements, a two-dimensional mathematical model for combustion space in cross-fired glass melting furnaces w... Under some assumptions and dividing the combustion space into several isothermal zones and isothermal surface elements, a two-dimensional mathematical model for combustion space in cross-fired glass melting furnaces was constructed. The finite element method and the Gauss integration were used to calculate direct ex-change areas, and a inverse matrix was used to obtained the total ex-change areas. The temperature distributions were obtained by itera-tions. Some results were presented to show the effects of the fire tem-perature distribution, the convective -heat transfer coefficients and the heat losses through crown surfaces on the temperature distributions. 展开更多
关键词 glass melting furnace fire space temperature distri- bution finite element method
下载PDF
Particle size distribution and shape control of Au nanoparticles used for particle gun 被引量:1
8
作者 S. Kida M. Ichiji J. Watanabe I. Hirasawa 《Frontiers of Chemical Science and Engineering》 SCIE EI CAS CSCD 2013年第1期60-64,共5页
Au nanoparticles are expected for the media to transfer genes into plants. However, the control of particle size distribution (PSD) and shape of Au nanoparticles is too difficult to design and prepare particles with... Au nanoparticles are expected for the media to transfer genes into plants. However, the control of particle size distribution (PSD) and shape of Au nanoparticles is too difficult to design and prepare particles with suitable quality for the gene supporting media. Reduction crystal- lization experiments were performed in aqueous solution in order to clarify the effect of feeding conditions such as feeding profile, feeding rate, and feeding amount on PSD and shape of Au nanopartieles. Ascorbic acid (AsA) was selected as a reducing agent because it is safe for plants. Au particles of 50nm, 50-200nm, and 150-400nm were obtained in batch operation, single-jet, and double-jet, respectively. Moreover, in single-jet and double-jet, the mean size of the obtained Au particles increases with the decrease of feeding rate or the increase of feeding amount. It is concluded that PSD of Au nanoparticles can be controlled in the range of 50-400 nm by changing feeding conditions of AsA and HAuCl4 aqueous solution. 展开更多
关键词 reduction crystallization particle size distri- bution gene transferring media
原文传递
Uniqueness of Cycle Length Distributions of Certain Bipartite Graphs K_(n,n+7)-A(|A| ≤ 3)
9
作者 朱建明 喻文华 沙丹 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2008年第4期813-822,共10页
The cycle length distribution of a graph of order n is denoted by (c1,c2,...,cn), where ci is the number of cycles of length i. In this paper, we obtain that a graph G is uniquely determined by its cycle distribution ... The cycle length distribution of a graph of order n is denoted by (c1,c2,...,cn), where ci is the number of cycles of length i. In this paper, we obtain that a graph G is uniquely determined by its cycle distribution if: (1) G = Kn,n+7 (n ≥ 10); or (2) G = Kn,n+7 - A (|A| = 1,n ≥ 12); or (3) G = Kn,n+7 - A (|A| = 2,n ≥ 14); or (4) G = Kn,n+7 - (|A| = 3,n ≥ 16), where A - E(Kn,n+7). 展开更多
关键词 CYCLE cycle length distribution bipartite graph uniqueness of cycle length distri- bution.
下载PDF
Meromorphic Solutions of Systems of Higher-Order Algebraic Differential Equations in Complex Domain 被引量:1
10
作者 高凌云 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2001年第2期171-176,共6页
Using the Nevanlinna theory of the value distribution of meromorphic func- tions,we investigate the problem of the existence of admissible meromorphic solutions of a type of systems of higher-order algebraic different... Using the Nevanlinna theory of the value distribution of meromorphic func- tions,we investigate the problem of the existence of admissible meromorphic solutions of a type of systems of higher-order algebraic differential equations. 展开更多
关键词 meromorphic solutions systems of differential equations the value distri- bution.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部