767 research outputs found
On the Cauchy problem for a two-component Degasperis-Procesi system
This paper is concerned with the Cauchy problem for a two-component
Degasperis-Procesi system. Firstly, the local well-posedness for this system in
the nonhomogeneous Besov spaces is established. Then the precise blow-up
scenario for strong solutions to the system is derived. Finally, two new
blow-up criterions and the exact blow-up rate of strong solutions to the system
are presented
Design Change Model for Effective Scheduling Change Propagation Paths
Changes in requirements may result in the increasing of product development project cost and lead time, therefore, it is important to understand how requirement changes propagate in the design of complex product systems and be able to select best options to guide design. Currently, a most approach for design change is lack of take the multi-disciplinary coupling relationships and the number of parameters into account integrally. A new design change model is presented to systematically analyze and search change propagation paths. Firstly, a PDS-Behavior-Structure-based design change model is established to describe requirement changes causing the design change propagation in behavior and structure domains. Secondly, a multi-disciplinary oriented behavior matrix is utilized to support change propagation analysis of complex product systems, and the interaction relationships of the matrix elements are used to obtain an initial set of change paths. Finally, a rough set-based propagation space reducing tool is developed to assist in narrowing change propagation paths by computing the importance of the design change parameters. The proposed new design change model and its associated tools have been demonstrated by the scheduling change propagation paths of high speed train’s bogie to show its feasibility and effectiveness. This model is not only supportive to response quickly to diversified market requirements, but also helpful to satisfy customer requirements and reduce product development lead time. The proposed new design change model can be applied in a wide range of engineering systems design with improved efficiency
Bis[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]nickel(II)–aquaÂ[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinic acid]dithioÂcyanatoÂnickel(II) (1/1)
In the title cocrystal, [Ni(C11H10N3O2)2]·[Ni(NCS)2(C11H11N3O2)(H2O)], both NiII ions are in disorted octaÂhedral coordination environments. One NiII ion is coordinated by four N atoms and two O atoms from two tridentate 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate (DPP) ligands, while the other NiII ion is coordinated by a tridentate 6-((3,5-dimethyl-1H-pyrazol-1-yl))picolinic acid (DPPH) ligand and by two N atoms and one O atom from two thioÂcyanate and one water ligand, respectively. In the crystal structure, molÂecules are linked by interÂmolecular O—H⋯O and O—H⋯S hydrogen bonds, forming extended chains along [010]
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