30,462 research outputs found
A digital definition method for manufacturing model of aircraft integral panel
The manufacturing model of aircraft integral panel is presented based on the analysis of its structure and manufacturing process. The manufacturing model for each key process consists of model for processing and model for workpiece to bridge digital design and fabricating. Model for workpiece is used to express the target part information at the end of some operation. Model for processing is used to describe the intermediate state information, and it aims to attain but is different the workpiece because of process factors. The definition flow of the manufacturing model is given. The modeling approach of integral panel part blank from shot peen forming part model orienting to NC cutting is proposed and exemplified. It is analyzed that the approaches above can define the models accurately and totally to meet the needs of process planning , NC fabricating and inspecting
Representations of Hopf Ore extensions of group algebras and pointed Hopf algebras of rank one
In this paper, we study the representation theory of Hopf-Ore extensions of
group algebras and pointed Hopf algebras of rank one over an arbitrary field
. Let H=kG(\chi, a,\d) be a Hopf-Ore extension of and a rank one
quotient Hopf algebra of , where is a field, is a group, is a
central element of and is a -valued character for with
. We first show that the simple weight modules over and
are finite dimensional. Then we describe the structures of all simple weight
modules over and , and classify them. We also consider the
decomposition of the tensor product of two simple weight modules over into
the direct sum of indecomposable modules. Furthermore, we describe the
structures of finite dimensional indecomposable weight modules over and
, and classify them. Finally, when is a primitive -th root of
unity for some , we determine all finite dimensional indecomposable
projective objects in the category of weight modules over .Comment: arXiv admin note: substantial text overlap with arXiv:1206.394
Measuring robustness of community structure in complex networks
The theory of community structure is a powerful tool for real networks, which
can simplify their topological and functional analysis considerably. However,
since community detection methods have random factors and real social networks
obtained from complex systems always contain error edges, evaluating the
robustness of community structure is an urgent and important task. In this
letter, we employ the critical threshold of resolution parameter in Hamiltonian
function, , to measure the robustness of a network. According to
spectral theory, a rigorous proof shows that the index we proposed is inversely
proportional to robustness of community structure. Furthermore, by utilizing
the co-evolution model, we provides a new efficient method for computing the
value of . The research can be applied to broad clustering problems
in network analysis and data mining due to its solid mathematical basis and
experimental effects.Comment: 6 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1303.7434 by other author
Cloning and expression of first gene for biodegrading microcystins by Sphingopyxis sp. USTB-05
Harmful cyanobacterial blooms (HCBs) in natural waters are a growing environmental problem worldwide because microcystins (MCs) produced by cyanobacteria are potent hepatotoxins and tumor promoters. MCs are resistant against physical and chemical factors. Thus, biodegradation is the most efficient method for removing MCs, and a number of bacterial strains, especially genus _Sphingomonas_, have been isolated for biodegrading MCs. Although the pathway, enzyme, and gene for biodegrading MCs by _Sphingomonas sp._ have been widely identified recently, no gene concerned with the biodegradation of MCs has been successfully cloned and expressed. In this study, we show that the first and most important gene of mlrA, containing 1,008 bp nucleotides in length, in the biodegradation pathway of MCs by _Sphingopyxis sp._ USTB-05, which encodes an enzyme MlrA containing 336 amino acid residues, is firstly cloned and expressed in _E. coli_ DH5α, with a cloning vector of pGEM-T easy and an expression vector of pGEX-4T-1. The encoded and expressed enzyme MlrA is responsible for cleaving the target peptide bond between 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-deca-4,6-dienoic acid (Adda) and Arg in the cyclic structure of microcystin-RR (MC-RR)and microcystin-LR(MC-LR), two typical and toxic types of MCs. Linear MC-RR and MC-LR are produced as the first products. These findings are important in constructing a new genetic bacterial strain for the efficient removal of MCs from the important water supplies and resolving the controversy on the biodegradation pathway of different types of MCs by genus _Sphingomonas_
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