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In terms of our new exact definition of partial Lagrangian and approximate Euler-Lagrange-type equation, we investigate the nonlinear wave equation with damping via approximate Noether-type symmetry operators associated with partial Lagrangians and construct its approximate conservation laws in general form. 相似文献
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Residual symmetry,interaction solutions,and conservation laws of the(2+1)-dimensional dispersive long-wave system 下载免费PDF全文
We explore the(2+1)-dimensional dispersive long-wave(DLW) system. From the standard truncated Painlev′e expansion, the B¨acklund transformation(BT) and residual symmetries of this system are derived. The introduction to an appropriate auxiliary dependent variable successfully localizes the residual symmetries to Lie point symmetries. In particular, it is verified that the(2+1)-dimensional DLW system is consistent Riccati expansion(CRE) solvable. If the special form of(CRE)-consistent tanh-function expansion(CTE) is taken, the soliton-cnoidal wave solutions and corresponding images can be explicitly given. Furthermore, the conservation laws of the DLW system are investigated with symmetries and Ibragimov theorem. 相似文献
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针对优化服务功能链(Service Function Chain,SFC)可靠性时资源利用率低的问题,提出了特征关联的服务功能链可靠性优化算法。首先,从底层节点的资源可用率、周边资源密集度、全网中心性评价其作为虚拟网络功能(Virtual Network Function,VNF)实例备选节点的优势,从VNF实例的节点度数与带宽流量评价其作为备选对象的优势。其次,逐个对优越性最高的VNF实例选择备份底层节点,直到所有SFC的可靠性满足客户要求。在为VNF实例选择备份底层节点时,提出了基于资源特征关联感知的备份节点选择算法,将当前VNF实例所映射的底层节点与其他待备份VNF实例的底层节点的邻接节点进行关联,为当前VNF实例选择最优备份底层节点的同时,减少为其他待备份VNF实例选择备份底层节点时链路的开销。仿真结果表明,相比于已有算法,该SFC可靠性优化算法下备份实例数降低了约29%,备份带宽资源消耗降低了约42%,SFC接受率提升了约12%。 相似文献
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搀杂六铝酸盐LaMxAl12-xO19+δ上甲烷催化燃烧研究 总被引:4,自引:1,他引:4
采用共沉淀法制备了系列金属Mn搀杂的六铝酸盐LaMnxAl12-xO19+δ(x分别为0, 0.5, 1.0, 1.5, 2.0, 5.0)催化剂, 采用BET, TG-DTA, XRD进行了物性表征, 并以甲烷催化燃烧为目标反应, 研究了Mn搀杂量对催化剂活性的影响. 结果表明 LaAl12O19+δ催化活性较低, 随着Mn的引入, 催化活性逐步提高. 当x=1.5时, 催化活性达到最大值, 为理想搀杂量. 焙烧温度对晶型及催化活性有重要影响, 1200 ℃时可以形成完整的六铝酸盐晶型, 并具较高的催化性能. 所得较好催化剂起燃温度T10%为418 ℃, T90%为663 ℃. 相似文献
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负载金的纳米管钛酸光催化氧化一氧化碳 总被引:3,自引:0,他引:3
用化学方法制备了负载金的纳米管钛酸(Au/H2Ti2O4(OH)2)光催化剂,并用TEM,XPS,XRD和DRS等技术对催化剂进行了表征. 结果表明,经573 K处理后,纳米管钛酸表面及管内均有零价的金颗粒存在. 与纳米管钛酸(H2Ti2O4(OH)2)相比,Au/H2Ti2O4(OH)2具有明显的CO光催化氧化活性,但在暗态时无活性. 经分析认为,暗态时Au与纳米管相互接触的周界处不活泼,故催化剂无CO催化氧化活性; 紫外光照射下,纳米管激发产生e--h+对,e-从纳米管转移到Au0上, 使纳米管和Au-在接触周界处产生相互作用,形成活性位,导致CO催化氧化反应发生. 相似文献
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As an extension to the derivative-dependent functional variable separation approach, the approximate derivative-dependent functional variable separation approach is proposed, and it is applied to study the generalized diffusion equations with perturbation. Complete classification of these perturbed equations which admit approximate derivative-dependent functional separable solutions is obtained. As a result, the corresponding approximate derivative-dependent functional separable solutions to some resulting perturbed equations are derived by way of examples. 相似文献
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Approximate Generalized Conditional Symmetries for the Perturbed Nonlinear Diffusion-Convection Equations 总被引:1,自引:0,他引:1 下载免费PDF全文
The concept of approximate generalized conditional symmetry (A GCS) as a generalization to both approximate Lie point symmetry and generalized conditional symmetry is introduced, and it is applied to study the perturbed nonlinear diffusion-convection equations. Complete classification of those perturbed equations which admit cerrain types of AGCSs is derived. Some approximate solutions to the resulting equations can be obtained via the AGCS and the corresponding unperturbed equations. 相似文献