检索结果-南通市图书馆

A Generalized F-expansion Method and Its Application in High-Dimensional Nonlinear Evolution Equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第2X期44卷 307-310页

作者： CHEN Jiang HE Hong-Sheng yang kong-qing Department of Physics Lanzhou University Lanzhou 730000 China Institute of Applied Physics Jimei University Xiamen 361021 China

A generalized F-expansion method is introduced and applied to (3+ 1)-dimensional Kadomstev-Petviashvili(KP) equation. As a result, some new Jacobi elliptic function solutions of the equation are found, from which the trigonometric function solutions and the solitary wave solutions can be obtained. The method can also be extended to other types of nonlinear evolution equations in mathematical physics.

关键词： F-expansion method Jacobi elliptic function KP equation solitary wave solution trigonometric function solution

对声波和弹性波传播模拟的Hamilton系统方法

在线全文

学校读者我要写书评

暂无评论

物理学报 2003年第8期52卷 1984-1992页

作者：曹禹杨孔庆兰州大学物理系兰州730000

建立了离散化网格上的准粒子体系 ,引入此体系的Hamilton系统描述 ,用来模拟声波和弹性波的传播 .介绍了准粒子间相互作用的九点模型并给出互作用系数 .证明了Hamilton系统方法和声波、弹性波方程的关系 ,并给出两个方法中所使用物理量... 详细信息

建立了离散化网格上的准粒子体系 ,引入此体系的Hamilton系统描述 ,用来模拟声波和弹性波的传播 .介绍了准粒子间相互作用的九点模型并给出互作用系数 .证明了Hamilton系统方法和声波、弹性波方程的关系 ,并给出两个方法中所使用物理量的关系 .使用辛算法对给定的介质模型进行数值模拟 .

关键词：离散化网格准粒子体系 Hamilton系统声波弹性波传播模拟九点互作用模型辛算法

Response of Element Distribution of Various Organs of Maize to Fertilizer Application

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2010年第3期9卷 401-407页

作者： HU Hao, BAI You-lu, yang Li-ping, kong qing-bo, LU Yan-li, WANG Lei and WANG Zhi-yong Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/Key Laboratory of Plant Nutrition and Nutrient Cycling, Ministry of Agriculture, Beijing 100081, P.R.China Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences/Key Laboratory of Plant Nutrition and Nutrient Cycling Ministry of Agriculture Beijing 100081 P.R.China

The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effect on crop. Five fertilizer treatments： no fertilizer （CK）, nitrogen phosphorus fertilizer （NP）, nitrogen potassium fertilizer （NK）, phosphorus potassium （PK）, and nitrogen phosphorus potassium fertilizer （NPK） were designed. Field experiment on the response of biomass dry weight and N, P, K, Cu, Zn, Fe, and Mn element distribution of stem, leaf and seed of maize （Zea mays L.） to different fertilizer treatments application was carried out. The results showed that dry weight and element content of various organs of maize were different. N content of various organs followed this order leaf〉 seed 〉 stem; P content of various organs was seed 〉 leaf〉 stem; K content was stem 〉 leaf〉 seed; and Fe content was leaf〉 stem 〉 seed. Fertilizer application reduced the differences of N, P, K, and Fe contents of various organs, and changed the size order of the dry weight and the Cu and Zn contents of leaf, seed and stem. Except for individual treatment, the response direction of N, P and Fe elements to fertilizer application was similar to Cu and Zn. The response of element content of various organs of maize to different fertilizer combinations was also different. The response extent of N, P and K major elements to fertilizer application was larger than microelement of Cu, Zn, Fe, and Mn; the response extent of stem and leaf was larger than seed; the response to NPK fertilizer treatment was bigger than NP, NK and PK. In the whole, response differences of element distribution to various fertilizer treatments were not remarkable. Besides, element distribution of various organs of maize was also influenced by the mutual effect of fertilizer varieties. The response direction and extent of various element distributions to different fertilizer treatments had both similarit

关键词： element distribution fertilizer application maize

在线全文

学校读者我要写书评

暂无评论

中国铁路客运网网络性质的研究

物理学报 2006年第8期55卷 3906-3911页

作者：赵伟何红生林中材杨孔庆集美大学理学院厦门361021 兰州大学物理系兰州730000

中国铁路客运系统可以采用两种不同的网络构建方式来描述.一种是以铁路的站点作为“节点”,并以轨道作为“边”,这样生成的网络称为铁路地理网.统计显示该网络的平均群聚系数〈C〉近似为零,故该网络为树状网络.另一种是以站点作为“节点... 详细信息

中国铁路客运系统可以采用两种不同的网络构建方式来描述.一种是以铁路的站点作为“节点”,并以轨道作为“边”,这样生成的网络称为铁路地理网.统计显示该网络的平均群聚系数〈C〉近似为零,故该网络为树状网络.另一种是以站点作为“节点”,任意两个站点间只要有同一列车在这两个站点停靠,就可以认为这两个站点间有连线,这样生成的网络称为车流网.统计显示该网络有较大的平均群聚系数和较小的平均网络距离〈d〉,而且该网络节点的度分布基本上服从无标度幂律分布,故车流网为具有无标度性质的小世界网络.

关键词：铁路地理网车流网小世界无标度分布

在线全文

学校读者我要写书评

暂无评论

图形处理器通用计算的实现与验证

计算机工程与应用 2009年第33期45卷 67-69页

作者：齐记杨孔庆杨磊集美大学理学院复杂系统研究中心福建厦门361021 中国科学院近代物理研究所兰州730000

讨论了显示卡用于通用科学计算的问题,并以大型矩阵的基本运算问题详细比较了CPU和GPU计算之间的差别。在基本的矩阵运算中,运用适当的矩阵分块,GPU的计算速度比CPU快50倍左右。而且,显示卡低廉的价格为更多科研工作者实现大规模运算提... 详细信息

讨论了显示卡用于通用科学计算的问题,并以大型矩阵的基本运算问题详细比较了CPU和GPU计算之间的差别。在基本的矩阵运算中,运用适当的矩阵分块,GPU的计算速度比CPU快50倍左右。而且,显示卡低廉的价格为更多科研工作者实现大规模运算提供了可能。

关键词：图形处理器(GPU) 图形处理器通用计算技术(GPGPU) 中央处理器(CPU)

The School that Changes Mindsets

在线全文

学校读者我要写书评

暂无评论

China Today 2025年第1期74卷 62-64页

作者： GUO qing kong SIQI 不详

China’s highest-altitude primary school is not only teaching children of farmers and herders but their parents as *** Sinopec Primary School in Nagqu,a city in Xizang Autonomous Region in southwest China,is known as the school“the closest to the sky”due to its high-altitude location-a breathtaking 4,700 meters above sea *** by oil and gas giant Sinopec as part of its corporate social responsibility,the school opened in 2012 and has since become a microcosm of China’s drive for education,especially in remote and rural areas,to ensure that no one is left behind.

关键词： altitude farmers southwest

Study of synchronization on Geographical networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study of synchronization on Geographical networks

第二届全国复杂动态网络学术论坛

作者： Zhong-Cai Lin, Lei yang, kong-qing yang Institute of applied physics, Jimei University, Xiamen 361021 .China Department of physics, Lanzhou University, Gansu 730000, China Physics department. Centre for Nonlinear studies, and Beijing-Hong kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hongkong), Hong kong Baptist University, Hong kong, China

＜正＞The modification of geographical structure of a network changes its ***,the geographical structure means that the connecting-probability of two nodes is related to the spatial distance of the two *** this work,how the geographical structure affects its synchronization tendency is *** simulation results show that the synchronization tendency will be enhanced when a node can randomly connect to the further *** results support our understanding on the phenomena.

关键词： connecting-probability geographical structure network topology load synchronization

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

地震偏移成像不确定性分析初探

地球物理学进展 2007年第3期22卷 790-796页

作者：袁江华王秀闽张致付杨孔庆刘洪李幼铭中国科学院地质与地球物理研究所北京100029 中国地质大学地球物理与信息技术学院北京100083 集美大学复杂系统研究中心厦门361021

勘探地球物理领域存在大量宏观动力学过程的物理数学表达及尚待深入探索的不确定性事实,其中一类是源自对偶量的不可交换性或不可对易性.本文从地震偏移成像中的不确定性分析入手,探讨偏移成像中受到波场延拓过程不确定性的影响.文中给... 详细信息

勘探地球物理领域存在大量宏观动力学过程的物理数学表达及尚待深入探索的不确定性事实,其中一类是源自对偶量的不可交换性或不可对易性.本文从地震偏移成像中的不确定性分析入手,探讨偏移成像中受到波场延拓过程不确定性的影响.文中给出了若干深度偏移算法对Marmousi模型的偏移不确定度分布表达及图像显示;文中还对若干波场延拓方法,从不确定性估计的角度进行了比较.笔者认为对应用技术领域中的宏观不确定性分析,将有益于深化对宏观动力学过程的理性认识,也为偏移算法评价提供一种途径;重要的是,进行不确定性分析将有利于把握所用偏移算法的不确定度分布,继而有针对性地采取相应的改善措施,以期提高算法的整体确定性程度.

关键词：不确定性分析地震偏移成像 Marmousi模型对偶共轭变量深度偏移算法

Molecular dynamics simulations of the hydration of poly(vinyl methyl ether):Hydrogen bonds and quasi-hydrogen bonds

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2008年第8期51卷 736-742页

作者： WU RongLiang JI qing kong Bin yang XiaoZhen Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing 100080China

Atomistic detailed hydration structures of poly(vinyl methyl ether)(PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution functions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain,and there still exists a significant amount(10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentration as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer,which leads to inefficient contacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds,but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry(DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME,which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ～27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ～27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition,at the concentration of 86%,each ether oxygen atom bonded with water is assigned 1.56 water molecules on average,and 'free' water molecules emerge at the concentration of around 54%.

关键词： poly(vinyl methyl ether)(PVME) molecular dynamics computer simulation hydrogen bond quasi-hydrogen bond