Tổng hợp tất cả tài liệu, ebook, giáo trình Các Môn Đại Cương chọn lọc và hay nhất.
Sử dụng tính đối xứng Nếu mặt cắt có 2 trục đối xứng thì trọng tâm C của mặt cắt ấy là giao điểm của 2 trục đối xứng trên. CSử dụng tính đối xứng Nếu với bất cứ 1 điểm A nào trên mặt cắt đều tồn tại 1 điểm A’ đối xứng với nó qua 1 điểm C duy nhất thì C chính là tâm đối xứng của mặt cắt ấy. Tâm đối xứng của 1 mặt cắt chính là trọng tâm của ...
41 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 520 | Lượt tải: 0
1. Introduction One of effective approaches to the study of long - time behavior of infinite dimensional dynamical systems is based on the concept of inertial manifolds which was introduced by C. Foias, G. Sell and R. Temam (see [4] and the references therein). These inertial manifolds are finite dimensional Lipschitz ones, attract trajectories...
14 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 496 | Lượt tải: 0
If there is no trajectory of F starting at x can reach K , then. If x K then we set T x ( ) 0 . It is well-known that, under assumptions (F1) - (F3), the infimum in (1.2) is attained and the minimum time function T is lower semicontinuous [21]. The minimum time function is an important optimal value function of optimal control theory. This ...
9 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 440 | Lượt tải: 0
Abstract: Three Trichoderma isolates (THDU-1, THDU-2, and THDU-3) were isolated from the root zone area of healthy bananas on the farm in Ba Thuoc district, Thanh Hoa province. All of these isolates showed high inhibitory activity against soil borne diseases Rhizoctonia solani and Sclerotium rolfsii. Our study proposed a protocol of Trichoderma ...
5 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 359 | Lượt tải: 0
Abstract: A trial of Neolamarckia cadamba in Thanh Hoa province has the following results: Neolamarckia cadamba is the easy growing and photophillic tree, highly adaptable to natural conditions of Thuong Xuan, Nhu Thanh, and Tinh Gia which are representatives of the mountainous area, midland area and delta coastal area, respectively, in Thanh Ho...
11 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 359 | Lượt tải: 0
1. Introduction The perovskite manganites (La,Sr)MnB'O3, where B‟ stands for the transition elements have recently attracted a wide range of research in laboratories because of their potential applications in electric devices that operate based on colossal magnetoresistance effect (CMR) and magnetocaloric effect (MCE) [1-4]. Basically, the magnetic...
11 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 360 | Lượt tải: 0
1. Introduction Two-dimensional systems have many applications in different arears as geographical data processing, electrical circuit networks, power systems, energy exchange processes, multibody mechanics, process control, aerospace engineering and physical processes [18, 4, 9, 14]. In recent years, 2-D switched systems have attracted the att...
11 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 367 | Lượt tải: 0
1. Introduction Singular systems have many applications in reality such as electrical circuit network, power systems, aerospace engineering, network control, economic systems [6,19]. Therefore, these systems have been extensively studied over the past few decades and have yielded significant results. Using Lyapunov‟s approach to reach out to sc...
11 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 408 | Lượt tải: 0
Abstract: In this paper, we study the first initial boundary value problem for a class of quasilinear degenerate parabolic equations involving weighted p-Laplacian operators. The existence and uniqueness of a weak solution with respect to initial values is ensured by an application of the Faedo - Galerkin approximation and compact method. Moreov...
15 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 392 | Lượt tải: 0
Abstract: Consider a stochastic evolution equation containing Stratonovich-multiplicative white noise of the form where the partial differential operator A is positive definite, self-adjoint with a discrete spectrum; and the nonlinear part f satisfies the -Lipschitz condition with belonging to an admissible function space. We prove...
16 trang | Chia sẻ: thanhle95 | Ngày: 09/07/2021 | Lượt xem: 334 | Lượt tải: 0