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低扭矩环锭纱的结构分析 被引量:8
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作者 郭滢 陶肖明 +1 位作者 徐宾刚 王善元 《东华大学学报(自然科学版)》 CAS CSCD 北大核心 2012年第2期164-169,共6页
从纤维在空间上的三维形态以及在纱线横截面上的分布分析了低扭矩环锭纱中纤维的三维结构特征.研究结果表明,低扭矩环锭纱中大量的纤维轨迹呈非同轴异形螺旋线,其螺旋轴线与纱线轴线不一致,且螺旋半径不断显著变化,同时,很多纤维片段的... 从纤维在空间上的三维形态以及在纱线横截面上的分布分析了低扭矩环锭纱中纤维的三维结构特征.研究结果表明,低扭矩环锭纱中大量的纤维轨迹呈非同轴异形螺旋线,其螺旋轴线与纱线轴线不一致,且螺旋半径不断显著变化,同时,很多纤维片段的螺旋线方向与纱线正常捻度方向相反.此外,低扭矩纱线中纤维在纱线横截面上的分布较为集中,有利于拉伸变形时纤维同时受力.低扭矩环锭纱的这些结构特征揭示了其独特的物理性能,即低残余扭矩、低捻度、高强力. 展开更多
关键词 低扭矩环锭纱 三维空间构型 非同轴异形螺旋线 局部反转 堆砌密度
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廊固凹陷构造特征及成因解析 被引量:9
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作者 刘国臣 陆克政 严俊君 《地质论评》 CAS CSCD 北大核心 1996年第S1期83-88,共6页
廊坊-固安凹陷(简称廊固凹陷)为第三纪断陷,构造位置属于渤海湾盆地西部、冀中坳陷北部的一个次级构造单元。该凹陷西以大兴断裂为界与大兴凸起相接,东以牛东-河西务主断裂为界,与武清凹陷相连。呈北东向延伸,长约70—80km,面积约2800k... 廊坊-固安凹陷(简称廊固凹陷)为第三纪断陷,构造位置属于渤海湾盆地西部、冀中坳陷北部的一个次级构造单元。该凹陷西以大兴断裂为界与大兴凸起相接,东以牛东-河西务主断裂为界,与武清凹陷相连。呈北东向延伸,长约70—80km,面积约2800km^2。该凹陷的发育受大兴断裂控制,下第三系呈典型的箕状凹陷。断陷内次级断层十分发育,特别是由于本区始新统—渐新统发育了厚达千余米的泥岩层,形成了固安-北寺垡和曹家务-柳泉2个泥岩上拱构造带,泥岩构造顶部则发育复杂的地堑断裂系。廊固凹陷典型的构造样式为基底卷入型张性断块组合,但从盖层构造变形特征分析,早第三纪末本区曾受到过挤压作用的影响。 展开更多
关键词 廊固凹陷 基底卷入型张性断块组合 泥岩上拱 局部性挤压
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STABILIZATION OF NONUNIFORM TIMOSHENKO BEAM WITH COUPLED LOCALLY DISTRIBUTED FEEDBACKS
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作者 YANQingxu HOUShuiHung +1 位作者 HUANGGuangdong WANLi 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2005年第3期419-428,共10页
The stabilization problem of a nonuniform Timoshenko beam system With coupled locally distributed feedback controls is studied. First, by proving the uniqueness of the solution to the related ordinary differential equ... The stabilization problem of a nonuniform Timoshenko beam system With coupled locally distributed feedback controls is studied. First, by proving the uniqueness of the solution to the related ordinary differential equations, we establish the asymptotic decay of the energy corresponding to the closed loop system. Then, by virtue of piecewise multiplier method, we prove the exponential decay of the closed loop system. 展开更多
关键词 locally distributed feedback control timoshenko beam C_0 semigroups exponential stability piecewise multiplier
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QUASI-LOCAL CONJUGACY THEOREMS IN BANACH SPACES
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作者 ZHANG WEIRONG MA JIPu 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2005年第4期551-558,共8页
Let f : U(x0) belong to E → F be a C^1 map and f'(x0) be the Frechet derivative of f at x0. In local analysis of nonlinear functional analysis, implicit function theorem, inverse function theorem, local surject... Let f : U(x0) belong to E → F be a C^1 map and f'(x0) be the Frechet derivative of f at x0. In local analysis of nonlinear functional analysis, implicit function theorem, inverse function theorem, local surjectivity theorem, local injectivity theorem, and the local conjugacy theorem are well known. Those theorems are established by using the properties: f'(x0) is double splitting and R(f'(x)) ∩ N(T0^+) = {0} near x0. However, in infinite dimensional Banach spaces, f'(x0) is not always double splitting (i.e., the generalized inverse of f(x0) does not always exist), but its bounded outer inverse of f'(x0) always exists. Only using the C^1 map f and the outer inverse To^# of f(x0), the authors obtain two quasi-local conjugacy theorems, which imply the local conjugacy theorem if x0 is a locally fine point of f. Hence the quasi-local conjugacy theorems generalize the local conjugacy theorem in Banach spaces. 展开更多
关键词 Frechet derivative Quasi-local conjugacy theorems Outer inverse Local conjugacy theorem
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