期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
Reciprocal Distance Laplacian Eigenvalue Distribution Based on Graph Parameters
1
作者 CUI Jiaxin MA Xiaoling 《新疆大学学报(自然科学版中英文)》 CAS 2024年第5期562-570,共9页
Let G be a connected graph of order n and m_(RD)^(L)_(G)I denote the number of reciprocal distance Laplacian eigenvaluesof G in an interval I.For a given interval I,we mainly present several bounds on m_(RD)^(L)_(G)I ... Let G be a connected graph of order n and m_(RD)^(L)_(G)I denote the number of reciprocal distance Laplacian eigenvaluesof G in an interval I.For a given interval I,we mainly present several bounds on m_(RD)^(L)_(G)I in terms of various structuralparameters of the graph G,including vertex-connectivity,independence number and pendant vertices. 展开更多
关键词 reciprocal distance Laplacian eigenvalue VERTEX-CONNECTIVITY independence number pendant vertices
下载PDF
混合流水线
2
作者 郭万中 《管理现代化》 1984年第2期16-20,共5页
混合流水线,不仅在日本,而且在西欧一些国家也在日益采用。自从长春第一汽车厂将其从日本介绍到我国以来,引起很多企业的重视,有的企业并加以试验,取得了一定效果。一、混合流水线是多品种。
关键词 生产方法 装配流水线 多品种 倒数值 小批量生产 可变流水线 混合流 搭配方式 流水线平衡 节拍
下载PDF
Numerical Simulation of Dynamic Response and Collapse for Steel Frame Structures Subjected to Blast Load 被引量:4
3
作者 张秀华 段忠东 张春巍 《Transactions of Tianjin University》 EI CAS 2008年第B10期523-529,共7页
The progressive collapse of steel frame structures under the blast load was investigated using LS-DYNA. The multi-material Eulerian and Lagrangian coupling algorithm was adopted. A flu-id-structure coupling finite ele... The progressive collapse of steel frame structures under the blast load was investigated using LS-DYNA. The multi-material Eulerian and Lagrangian coupling algorithm was adopted. A flu-id-structure coupling finite element model was established which consists of Lagrange element for simulating steel frame structures and concrete ground, multiple ALE element for simulating air and TNT explosive material. Numerical simulations of the blast pressure wave propagation, struc-tural dynamic responses and deformation, and progressive collapse of a five-story steel frame structure in the event of an explosion near above ground were performed. The numerical analysis showed that the Lagrangian and Eulerian coupling algorithm gave good simulations of the shock wave propagation in the mediums and blast load effects on the structure. The columns subjected to blast load may collapse by shear yielding rather than by flexural deformation. The columns and joints of steel beam to column in the front steel frame structure generated enormous plastic defor-mation subjected to intensive blast waves, and columns lost carrying capacity, subsequently lead-ing to the collapse of the whole structure. The approach coupling influence between struc-tural deformation and fluid load well simulated the progressive collapse process of structures, and provided an effective tool for analyzing the collapse mechanism of the steel frame structure under blast load. 展开更多
关键词 blast load progressive collapse steel frame structures numerical simulation finite element
下载PDF
Numerical Simulation for Progressive Collapse of Continuous Girder Bridge Subjected to Ship Impact 被引量:3
4
作者 田力 黄飞 《Transactions of Tianjin University》 EI CAS 2014年第4期250-256,共7页
The three-stage simulation method based on LS-DYNA was introduced in this study to simulate the progressive collapse of a continuous girder bridge after a ship-bridge collision. The pile-soil dynamic interaction and t... The three-stage simulation method based on LS-DYNA was introduced in this study to simulate the progressive collapse of a continuous girder bridge after a ship-bridge collision. The pile-soil dynamic interaction and the initial stress and deformation of the whole bridge before the collision were considered. By analyzing the damage, deformation, stress distribution and collapse process of the whole bridge, the results show that the displacement response of the cap beam lags behind the pile cap. The response order of the whole bridge's components depends on their distances from the collision region. The plastic deformation of soil around piles has a positive effect on delaying the further increase in the displacement of piles. The impacted pier's losing stability and its superstructure's excessive deformation are the main reasons leading to the progressive collapse of the continuous girder bridge. 展开更多
关键词 numerical simulation progressive collapse ship-bridge collision continuous girder bridge pile-soil interaction
下载PDF
Effect of a single weak lithological structure on the height of a collapsing roof in a deep soft rock roadway 被引量:2
5
作者 YANG Jun 《Mining Science and Technology》 EI CAS 2010年第6期820-824,共5页
Besides the cross sections of roadways and the tendency and obliquity of roadway axes, the major controlling factors affecting the height of a collapsing roof include the weak lithological structure of surrounding roc... Besides the cross sections of roadways and the tendency and obliquity of roadway axes, the major controlling factors affecting the height of a collapsing roof include the weak lithological structure of surrounding rocks. This thesis analyzes the effect of two single and weak lithological structures of both sides and the roof on the height of a collapsing roof in a deep soft rock road- way. Using the two-dimensional UDEC3.1 software, a numerical structures of both sides of a roadway and of two weak lithological simulation was carried out on the models of weak lithological structures of roof of different depths. We reconstruct the overall processes from a break-away layer, bending, subsidence and the cracking of a collapsing roof. We also illustrate the distribution characteristics of displacement fields in the surrounding rock after the roof collapse in a deep soft rock roadway. The results of our numerical simulations indicate that the form of a roof collapse is side-expanding when the roadway is a weak structure at both sides The height of the roof collapse is related to the lithological combination of the roof when the roadway is a weak structure of the roof. 展开更多
关键词 single and weak lithological structure height of roof collapse numerical simulation
下载PDF
A CONSTRUCTIVE PROOF OF THE INVERSION FORMULA FOR ZONAL FUNCTIONS ON SL(2, R) 被引量:3
6
作者 XIAO CHANGBAI ZHENG WEIXING SU WEIYI (Department of Mathematics, Nanjing University Nanjing 210093, China.) 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1996年第1期81-88,共8页
A constructive proof is given for the inversion formula for zonal functions on SL(2, R). A concretely constructed sequence of zonal drictions are proved to satisfy the inversion formula obtained by Harish-Chandra for ... A constructive proof is given for the inversion formula for zonal functions on SL(2, R). A concretely constructed sequence of zonal drictions are proved to satisfy the inversion formula obtained by Harish-Chandra for compact supported infinitely differentiable zonal functions.Making use of the property of this sequence somehow similar to that of approxination kernels,the authors deduce that the inversion formula is true for continuous zonal functions on SL(2, R)under some condition. The classical result can be viewed as a corollary of the results here. 展开更多
关键词 Inversion formula Zonal function Approximation kernel
原文传递
Forecasting Gas Consumption Based on a Residual Auto-Regression Model and Kalman Filtering Algorithm 被引量:9
7
作者 ZHU Meifeng WU Qinglong WANG Yongqin 《Journal of Resources and Ecology》 CSCD 2019年第5期546-552,共7页
Consumption of clean energy has been increasing in China.Forecasting gas consumption is important to adjusting the energy consumption structure in the future.Based on historical data of gas consumption from 1980 to 20... Consumption of clean energy has been increasing in China.Forecasting gas consumption is important to adjusting the energy consumption structure in the future.Based on historical data of gas consumption from 1980 to 2017,this paper presents a weight method of the inverse deviation of fitted value,and a combined forecast based on a residual auto-regression model and Kalman filtering algorithm is used to forecast gas consumption.Our results show that:(1)The combination forecast is of higher precision:the relative errors of the residual auto-regressive model,the Kalman filtering algorithm and the combination model are within the range(–0.08,0.09),(–0.09,0.32)and(–0.03,0.11),respectively.(2)The combination forecast is of greater stability:the variance of relative error of the residual auto-regressive model,the Kalman filtering algorithm and the combination model are 0.002,0.007 and 0.001,respectively.(3)Provided that other conditions are invariant,the predicted value of gas consumption in 2018 is 241.81×10~9 m^3.Compared to other time-series forecasting methods,this combined model is less restrictive,performs well and the result is more credible. 展开更多
关键词 residual auto-regressive model Kalman filtering algorithm inverse fitting value deviation method combined forecast
原文传递
Comparisons between centrifuge and numerical modeling results for slope toppling failure 被引量:19
8
作者 CHEN ZuYu GONG WenJun +4 位作者 MA GuoWei WANG Jie HE Lei XING YiChuan XING JianYing 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第9期1497-1508,共12页
This paper presents series studies on the toppling mechanism by centrifuge tests and numerical simulations. Two different discrete element methods, i.e., the continuum-based discrete element method(CDEM) and the disco... This paper presents series studies on the toppling mechanism by centrifuge tests and numerical simulations. Two different discrete element methods, i.e., the continuum-based discrete element method(CDEM) and the discontinuous deformation analysis(DDA), are adopted. The modeling results show that both the methods can accurately capture the failure modes of the centrifuge tests, including three distinct zones and two failure surfaces. Comparisons are made between the physical test and numerical simulation results. The critical inclination angle of the tilting table where the slope models are fixed on can be moderately predicted by the two methods, with different degrees of precision. The error between the test results and the simulated results is within 1% for the slope models without rock-bridges by both CDEM and DDA. However, it is amplified for the staggered-joint models that simulate the rock-bridges. With DDA, the average error is about 5%, and the maximum error is up to 17%. While with CDEM, the errors for the aligned-joint models are ranged from 1% to 6%, and it is from 10% to 29% for the staggered-joint models. The two numerical methods show the capability in simulating toppling failure of blocky rock mass with and without rock-bridges. The model with rock-bridges which provides a certain bending resistance is more stable than the one without any rock-bridge. In addition, the two failure surfaces were observed, which is different from the common understanding that only one failure surface appears. 展开更多
关键词 rock slope model toppling failure rock-bridge centrifuge test continuum based discrete element method discontinuous deformation analysis
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部