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排序方式: 共有396条查询结果,搜索用时 46 毫秒
41.
应用高等数学中对面积的曲面积分等方法,建立了垄作种植中半椭圆形、抛物线型和三角形垄的数学模型,比较了不同垄形、垄宽、垄高在增加单位土地表面积和突出地面垄体体积的效果. 相似文献
42.
Computer aided design (CAD) models often need to be processed due to the data translation issues and requirements of the downstream applications like computational field simulation, rapid prototyping, computer graphics, computational manufacturing, and real‐time rendering before they can be used. Automatic CAD model processing tools can significantly reduce the amount of time and cost associated with the manual processing. The topology generation algorithm, commonly known as CAD repairing/healing, is presented to detect commonly found geometrical and topological issues like cracks, gaps, overlaps, intersections, T‐connections, and no/invalid topology in the model, process them and build correct topological information. The present algorithm is based on the iterative vertex pair contraction and expansion operations called stitching and filling, respectively, to process the model accurately. Moreover, the topology generation algorithm can process manifold as well as non‐manifold models, which makes the procedure more general and flexible. In addition, a spatial data structure is used for searching and neighbour finding to process large models efficiently. In this way, the combination of generality, accuracy, and efficiency of this algorithm seems to be a significant improvement over existing techniques. Results are presented showing the effectiveness of the algorithm to process two‐ and three‐dimensional configurations. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
43.
陈计 《宁波大学学报(理工版)》1993,(1)
Erds和Klamkin在1973年建立了如下命题:若A,B,C是一个三角形的内角,λ≥2且0≤μ≤λ,则存在以cos~μ(A/λ),cos~μ(B/λ),cos~μ(C/λ)为边的三角形。本文把μ的范围延拓成0≤μ≤λ~2/2后,证明原结论照样成立。 相似文献
44.
Let f and g be elements of the isometry group Isom(H2) of the hyperbolic plane H2, and assume that one of them is orientation-reversing. We determine when the group (f,g) they generate is discrete; in particular, we obtain the classification of such groups. As an application to knot theory, we completely determine the tunnel number one Montesinos knots. 相似文献
45.
Defining nonlocality in a no-input closed quantum network scenario is a new area of interest nowadays. Gisin, in [Entropy 21, 325 (2019)], proposed a possible condition for non-tri-locality of the trivial no-input closed network scenario, triangle network, by introducing a new kind of joint measurement bases and a probability bound. In [npj Quantum Information (2020) 6:70] they found a shred of numerical evidence in support of Gisin's probability bound. Now based on that probability bound, it finds the nature of the correlation in a triangle network scenario. This study observes how far the probability lies from that Gisin's bound with every possible combination of entangled and local pure states distributed from three independent quantum sources. Here, it uses the generalized Elegant Joint Measurements bases for each party and find that there is a dependency of non-locality on the entanglement of these joint measurement bases. It also checks the probability bound for the polygon structure. 相似文献
46.
Ewan Davies Rmi de Joannis de Verclos Ross J. Kang Franois Pirot 《Random Structures and Algorithms》2020,57(3):730-744
We prove two distinct and natural refinements of a recent breakthrough result of Molloy (and a follow‐up work of Bernshteyn) on the (list) chromatic number of triangle‐free graphs. In both our results, we permit the amount of color made available to vertices of lower degree to be accordingly lower. One result concerns list coloring and correspondence coloring, while the other concerns fractional coloring. Our proof of the second illustrates the use of the hard‐core model to prove a Johansson‐type result, which may be of independent interest. 相似文献
47.
On Schwarzian Triangle Functions,Automorphic Forms and a Generalization of Ramanujan’s Triple Differential Equations 下载免费PDF全文
Li Chien Shen 《数学学报(英文版)》2018,34(11):1648-1662
Let G be the group of the fractional linear transformations generated by where m, n is a pair of integers with either n ≥ 2,m ≥ 3 or n ≥ 3,m ≥ 2; τ lies in the upper half plane H.
A fundamental set of functions f0, fi and f∞ automorphic with respect to G will be constructed from the conformal mapping of the fundamental domain of G. We derive an analogue of Ramanujan’s triple differential equations associated with the group G and establish the connection of f0, fi and f∞ with a family of hypergeometric functions. 相似文献
$$T(\tau ) = \tau + \lambda ,S(\tau ) = \frac{{\tau \cos \frac{\pi }{n} + \sin \frac{\pi }{n}}}{{ - \tau \sin \frac{\pi }{n} + \cos \frac{\pi }{n}}};$$
$$\lambda = 2\frac{{\cos \frac{\pi }{m} + \cos \frac{\pi }{n}}}{{\sin \frac{\pi }{n}}};$$
48.
In the present work, we first modify the Sprott's nonlinear love triangle model by introducing the competition term and find that the new system also exhibits chaotic behavior. Then, to make the model more realistic, we go further to construct its corresponding fractional-order system and get the necessary condition for the existence of chaotic attractors. Finally, based on an improved version of Adams Bashforth Moulton numerical algorithm, we validate the chaotic attractors of this new fractional-order love triangle system by computer simulations. 相似文献
49.
50.
厚薄板通用三角形位移元 总被引:1,自引:0,他引:1
本文构造出了一种具有九个自由度的厚薄板通用三角形位移单元,并给出了单元刚度矩阵显式。这种单元以其简洁的常规位移元列式可在相当宽的板厚变化范围内(包括板厚为零)获得很高的计算精度,其结果可与相应的矩形单元相比。而且不会出现剪切自锁。 相似文献