Wyniki wyszukiwania - Biblioteka Nauki

1

Statistical Parameters Applied to the Analysis of Partial Discharge Signals in Power Cables

100%

Guo C. , Huang C. , Yao L. , Jiang X.

|

tom R. 86, nr 3

282-285

EN

To analyze the partial discharge signals in power cables, statistics method is investigated according to the experiment data of defect models. Phase resolved partial discharge graphics and associated pulse distributions are acquired to show the characteristics of defect PD events. 28 statistical parameters are extracted and employed to find the different representation of the defect models in power cables. The results show that statistics method and are useful and effective in the partial discharge signals analysis.

PL

Do analzy sygnału częściowego wyładowania w kablach użyto metod statystycznych. Rozkład statystyczny impulsu wyładowania pozwala na określenie defektu. 28 parametrów statystycznych zostało wydobytych i wykorzystanych do określania rodzaju defektu w kablu. Wyniki wskazują że metody statystyczne są dobrym narzędziem analizy sygnału częściowego wyładowania.

2

A Coupled Smoothed Finite Element-Boundary Element Method for Structural-Acoustic Analysis of Shell

100%

Tian W. , Yao L. , Li L.

|

tom Vol. 42, No. 1

49--59

EN

Nowadays, the finite element method (FEM) – boundary element method (BEM) is used to predict the performance of structural-acoustic problem, i.e. the frequency response analysis, modal analysis. The accuracy of conventional FEM/BEM for structural-acoustic problems strongly depends on the size of the mesh, element quality, etc. As element size gets greater and distortion gets severer, the deviation of high frequency problem is also clear. In order to improve the accuracy of structural-acoustic problem, a smoothed finite-element/boundary-element coupling procedure (SFEM/BEM) is extended to analyze the structural-acoustic problem consisting of a shell structure interacting with the cavity in this paper, in which the SFEM and boundary element method (BEM) models are used to simulate the structure and the fluid, respectively. The governing equations of the structural-acoustic problems are established by coupling the SFEM for the structure and the BEM for the fluid. The solutions of SFEM are often found to be much more accurate than those of the FEM model. Based on its attractive features, it was decided in the present work to extend SFEM further for use in structural-acoustic analysis by coupling it with BEM, the present SFEM/BEM is implemented to predict the vehicle structure-acoustic frequency response analysis, and two numerical experiments results show that the present method can provide more accurate results compared with the standard FEM/BEM using the same mesh. It indicates that the present SFEM/BEM can be widely applied to solving many engineering noise, vibration and harshness (NVH) problems with more accurate solutions.

3

Removal efficiency and the mineralization mechanism during enhanced bioventing remediation of oil-contaminated soils

75%

Jia J. , Zhao S. , Hu L. , Wang Y. , Yao L. , Liu Y. , Yuan Z.

|

nr 5

EN

The environmental challenge of crude oil-contaminated soil is difficult to address due to its complicated components and the mechanism of material transformation. In order to study the bioremediation of soil contaminated by crude oil, we designed five simulation test systems: a sterilization system, an oxygenated and water-controlled system, a nitrogen (N)/phosphorus (P) adjusted system, a broth-added system, and a double-broth-added system. The results show that the highest removal of crude oil from soil was increased to 34.23% by regulating the micro-ecological environment after 91 days in a simulation system. Regulating N and P can effectively strengthen the mineralization action of microorganisms on crude oil. Biodegradation had the most effect on the removal of oil, accounting for more than 58% of the total removal. Moreover, mineralization was dominant in biodegradation. Degradation of crude oil components was alkanes-based, accounting for 50 to 80% of total oil removal. By regulating moisture, temperature, oxygen content, N/P levels, and enrichment broth, the half-life of crude oil in a simulation system can be shortened to 182 days.

4

Assessment of environmental microbial effects of insect-resistant transgenic Populus × euramericana cv. ‘74/76’ based on high-throughput sequencing

75%

Fan J. , Dong Y. , Yu X. , Yao L. , Li D. , Wang J. , Yang M.

|

nr 11

5

Genetic characterisation and local genotypes of canine parvovirus strains collected from pet dogs in Central and Eastern China during 2018–2019

63%

Hu W. , Zheng L. , Xu X. , Liu Q. , Ji J. , Yao L. , Kan Y. , Bi Y.

|

nr 4