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拟紧元和连续格
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作者 李庆国 李纪波 《数学物理学报(A辑)》 CSCD 北大核心 2008年第6期1251-1255,共5页
在连续格中,引入了拟紧元和拟基的概念,在研究了它们的基本性质的基础上,给出了连续格的一种表示定理.
关键词 紧元 拟基 代数格 算术格 完备 ∏↑-半环.
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C—代数A中的L_(A)—紧元及其特性
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作者 张伦传 周金顺 《滨州学院学报》 1995年第4期34-37,共4页
在本文中,我们引入了C^(n)—代数A中“L_(A)—紧元”的概念,刻画了L_(A)—紧元的特性.其中定理2.4包含了文献[1]中命题2.12.12及文献[2]中性质2.3.13.
关键词 L—紧元 Liminal C—代数 不可约*表示 纯态
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格等式类格的对偶紧元
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作者 董克诚 《河北大学学报(自然科学版)》 CAS 1995年第4期1-5,共5页
本文的结果归纳成两个定理。阐明了格的有穷个元生成的子格至多是可数的;给出格等式类格的对偶紧元的一个特征性质。这些对于研究格等式类格具有重要意义。
关键词 对偶紧元 等式类格 格多项式
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Z-代数格和Z-代数交结构 被引量:1
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作者 李庆国 李纪波 《模糊系统与数学》 CSCD 北大核心 2008年第3期54-57,共4页
讨论Z-代数格,Z-代数交结构以及Z-代数闭包算子之间的关系,得到了格L上的Z-代数闭包算子与带顶元的Z-代数交结构之间存在一一对应关系,并且每一个Z-代数格都与带顶元的Z-代数交结构同构。
关键词 Z-代数闭包算子 Z-代数交结构 Z-代数格 Z-紧元
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C~*-代数上的初等算子
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作者 侯晋川 高明杵 《山西师范大学学报(自然科学版)》 1993年第1期78-80,共3页
设a、b为C-代数中的两个元,上线性映射M<sub>a.b</sub>:x→axb称为的一个乘子,而S=sum from i=1 to n M<sub>a<sub>i</sub>.b<sub>i</sub></sub>称为上的初等算子。如果M<sub>a.... 设a、b为C-代数中的两个元,上线性映射M<sub>a.b</sub>:x→axb称为的一个乘子,而S=sum from i=1 to n M<sub>a<sub>i</sub>.b<sub>i</sub></sub>称为上的初等算子。如果M<sub>a.a</sub>是上的紧、有限秩、一秩映射,则分别称a是中的紧元、有限维元、一维元;如果对任意x,y∈,xay=0蕴涵xa=0或ay=0,则称a为中的single元,如果C-代数中的任两个非零理想的积仍是非零的,则称是素的,近年来对于C-代数上乘子及初等算子有不少文献作了深入探讨, 展开更多
关键词 初等算子 理想的积 有限维 线性映射 一维元 紧元 乘子 NEUMANN 子及 无限维
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Ultra-tight GPS/INS integration based long-range rocket projectile navigation method 被引量:4
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作者 赵捍东 李志鹏 张会锁 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第2期153-160,共8页
Accurate navigation is important for long-range rocket projectile's precise striking. To obtain stable and high-per- formance navigation result, a ultra-tight global positioning system/inertial navigation system (GP... Accurate navigation is important for long-range rocket projectile's precise striking. To obtain stable and high-per- formance navigation result, a ultra-tight global positioning system/inertial navigation system (GPS/INS) integration based nav- igation approach is proposed. The accurate short-time output of INS is used by GPS receiver to assist in acquisition of signal, and output information of INS and GPS is fused based on federated filter. Meanwhile, the improved cubature Kalman filter with strong tracking ability is chosen to serve as the local filter, and then the federated filter is enhanced based on vector sharing theory. Finally, simulation results show that the navigation accuracy with the proposed method is higher than that with traditional methods. It provides reference for long-range rocket projectile navigation. 展开更多
关键词 long-range rocket projectile global position system inertial measuring unit ultra-tight integration
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紧生成的偏序集
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作者 穆欢 张昆龙 《中央民族大学学报(自然科学版)》 2020年第2期44-48,共5页
本文根据格上紧元的定义,在偏序集中给出了紧元的三种定义方法,并对其等价性进行了证明。在偏序集中紧元定义的基础上,得到证明了紧元的相关性质。然后在偏序集中给出了格中没有的强紧元的定义,在此定义的基础上,分别提出证明了:满足升... 本文根据格上紧元的定义,在偏序集中给出了紧元的三种定义方法,并对其等价性进行了证明。在偏序集中紧元定义的基础上,得到证明了紧元的相关性质。然后在偏序集中给出了格中没有的强紧元的定义,在此定义的基础上,分别提出证明了:满足升链条件的偏序集是强紧元的;强紧元的偏序集不一定是紧生成的偏序集。并推广证明了格中紧元的相关性质:如紧生成偏序集的子集一定是紧生成的偏序集;每个紧生成的偏序集P都是弱原子的;若偏序集中的元都是紧元当且仅当偏序集满足升链条件。给出了偏序集中上连续、下连续的概念,并证明了每个紧生成的偏序集都是上连续的。 展开更多
关键词 偏序集 紧元
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Two-Dimensional Breather Lattice Solutions and Compact-Like Discrete Breathers and Their Stability in Discrete Two-Dimensional Monatomic β-FPU Lattice
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作者 XU Quan TIAN Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期153-156,共4页
We restrict our attention to the discrete two-dimensional monatomic β-FPU lattice. We look for two- dimensional breather lattice solutions and two-dimensional compact-like discrete breathers by using trying method an... We restrict our attention to the discrete two-dimensional monatomic β-FPU lattice. We look for two- dimensional breather lattice solutions and two-dimensional compact-like discrete breathers by using trying method and analyze their stability by using Aubry's linearly stable theory. We obtain the conditions of existence and stability of two-dimensional breather lattice solutions and two-dimensional compact-like discrete breathers in the discrete two- dimensional monatomic β-FPU lattice. 展开更多
关键词 β-FPU lattice two-dimensional breather lattice solution two-dimensional compact-like discrete breather
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Pharmarcogenetic Mechanism of ACE liD Polymorphism Adversely Responding to ACE Inhibitors in Regulating the ACE Promoter Activity in Neurons 被引量:1
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作者 Yuan-Han Yang Hsueh-Wei Chang +4 位作者 Wei-Chiao Chang Yu-Cheng Shih Ke-Li Tsai I Chien Shyh-Jong Wu 《Journal of Pharmacy and Pharmacology》 2016年第8期419-431,共13页
The ACE (angiotensin converting enzyme) inhibitors are not only drugs widely prescribed drugs in cardiovascular diseases, but also potentially therapeutic agents in dementia. Based on the findings that the ACE inhib... The ACE (angiotensin converting enzyme) inhibitors are not only drugs widely prescribed drugs in cardiovascular diseases, but also potentially therapeutic agents in dementia. Based on the findings that the ACE inhibitors could activate the c-Jun N-terminal kinase signal to increase the ACE gene expression and that the Alu element of the human ACE gene involved in regulating ACE promoter activity, we aimed to investigate whether there are different pharmacogenetic responses of ACE I/D polymorphism to the ACE inhibitors in neurons. The three reporter vectors, pACEpro(0-SEAP, p-I-ACEpro-SEAP, and p-D-ACEpro-SEAP were used to examine the transcriptional activity of the vectors responding to the lisinopril treatment using a transient-transfection method in SH-SY5Y cells. Our results showed that lisinopril increased the promoter activity of an ACE gene by 16.7%. Additionally, we found the lisinopril enhanced the ACE promoter activity of the I-form vector by 17.2%, but adversely reduced that of the D-form vector by 16.8%, as compared with the respective control without the lisinopril treatment. Firstly, our findings had proved that the UD polymorphism of ACE gene contrarily responds to the ACE inhibitors in regulating the ACE expression in neurons, which provide a novel insight suggesting genetic testing to tailor the treatment regimens in AD (Alzheimer's disease) patients. 展开更多
关键词 ACE inhibitors ACE I/D polymorphism Aizheimer's disease PHARMACOGENETICS promoter activity.
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The application of corset element in fashion design
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作者 Zhong wei 《International Journal of Technology Management》 2014年第9期10-12,共3页
This article is focused on the fashion that inspired by corset and create a collection of the same kind that can reflect the needs of today' s consumers. In mixing and matching today' s a past corset' s elements wi... This article is focused on the fashion that inspired by corset and create a collection of the same kind that can reflect the needs of today' s consumers. In mixing and matching today' s a past corset' s elements with today' s sportive fashion.Since nowadays, people' s lifestyle is freer, casual and personal than before. Consumer' s wearing concept was also definitely different from the past.It is necessary to create the new direction for today' s consumers to satisfy the new mode of their lifestyle and the change of their wearing concept. 展开更多
关键词 CORSET CONSUMER wearing concept
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Market Analysis of Typical Products in Italy: Bivariate Statistical Relationships Between Qualitative Variables
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作者 Lanfranchi Maurizio Giannetto Carlo Zirilli Agata Alibrandi Angela 《Chinese Business Review》 2012年第1期65-74,共10页
The denominations of origin being perceived by the consumers in terms of both intrinsic qualities and of extrinsic qualities, have contributed in no uncertain manner to the increase of the typical products in question... The denominations of origin being perceived by the consumers in terms of both intrinsic qualities and of extrinsic qualities, have contributed in no uncertain manner to the increase of the typical products in question, positively influenced also by the noted emergencies coming from verified alimentary alarms during the beginning of the XXI century. The objective of this paper, is to determine the habits of purchase of typical and traditional products of the people of Messina (Sicily, Italy). To do this a "motivational" survey was carried out by traditional methodology of descriptive researches. The adopted methodology of research was quantitative and random. The random research strives to identify the factors that depend on the behaviour of purchase and the appraisal of the existing relationships of cause-effect in a determined population. The interviewed were given a questionnaire composed of 17 questions on their knowledge of the typical products characteristics, the frequency of consumption, the monthly amounts destined to the purchase, the motivations that push them to the purchase of typical products rather than pre-packed. Methodologically, our statistical analysis has been performed using the log-likelihood ratio test in order to investigate the existence of association between the joint distributions of qualitative measured variables. 展开更多
关键词 typical products market analysis statistical analysis log-likelihood ratio test
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Prying Force Assessment Using Nonlinear Finite Element Model
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作者 Hesham Sobhy Sayed Mohammed Hassanien Serror 《Journal of Civil Engineering and Architecture》 2010年第7期56-65,共10页
Steel connection design using pre-tensioned bolts depends significantly on the value of the Prying forces exerted from the end plate. The Egyptian Code ECP (205) suggested a formula that can determine the Prying for... Steel connection design using pre-tensioned bolts depends significantly on the value of the Prying forces exerted from the end plate. The Egyptian Code ECP (205) suggested a formula that can determine the Prying force value. In this research, the Prying force is numerically computed in a T-Stub connection using nonlinear finite element techniques. The model uses plane stress four node elements with two degrees of freedom per node to simulate the flange of the T-Stub. The bolts are simulated using a truss element with large deformation capability to allow modeling of the pretension force. Surface to surface gap elements are used in order to simulate the contact between the T-Stub and the supporting element. Parametric study on the end plate thickness, bolt size, bolt arrangement and pretension forces is performed in order to calibrate the Code formula. The parametric study covers all the practical ranges of the variables. The study revealed that the Code formula, inaccurately, determines the Prying force in a certain range. Moreover, a new equation for the prying force is developed using regression analysis on the finite element results. 展开更多
关键词 Prying force finite element regression analysis new equation code requirements
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Z-半代数格及Z-半Scott拓扑
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作者 李冰 刘妮 《模糊系统与数学》 CSCD 北大核心 2015年第3期1-7,共7页
在Z-双小于关系的基础上定义了Z-紧元并依此引入了Z-半代数格及强Z-代数格的概念,证明了一定条件下Z-半代数格的闭包算子的像还是Z-半代数格,强Z-代数格与其Z-紧元集的Z-理想集是同构的。最后,研究了Z-半连续格和Z-半Scott拓扑的基本性质。
关键词 Z-紧元 Z-半代数格 Z-半Scott拓扑 收缩
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泡沫灭火器原理的实验改进 被引量:1
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作者 白桂斌 《中学化学教学参考》 2015年第2X期61-61,共1页
泡沫灭火器原理的实验是人教版九年级化学上册第七单元"燃烧及其利用"中课题l"燃烧和灭火"中的一个探究性实验。教师在做这个实验时易出现橡皮塞冲出、试管破损、漏液等现象,并且喷射水柱不稳定、方向易变,实验效... 泡沫灭火器原理的实验是人教版九年级化学上册第七单元"燃烧及其利用"中课题l"燃烧和灭火"中的一个探究性实验。教师在做这个实验时易出现橡皮塞冲出、试管破损、漏液等现象,并且喷射水柱不稳定、方向易变,实验效果不理想。对此,笔者进行了如下改进。一、仪器及药品仪器:500 mL矿泉水瓶1个、Φ15 mm×100 mm的试管1支(或相似大小、形状的塑料制品)、长竹筷(或长木条)一根。药品:食用白醋、食用碱、厨房洗涤剂。二、实验装置实验装置如附图所示。三、实验步骤1.在矿泉水瓶盖上均匀打几个小孔。2.往矿泉水瓶中装入约200 mL白醋, 展开更多
关键词 泡沫灭火器 矿泉水瓶 药品仪器 橡皮塞 塑料制品 漏液 食用碱 人教版 紧元 科学探究能力
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一时“兴奋” 终身遗恨——记世界体坛的反兴奋剂斗争
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作者 王元敬 《瞭望》 北大核心 1992年第30期24-25,共2页
自从1960年罗马第17届奥运会上,一名丹麦自行车选手由于服用了兴奋剂暴毙于赛场上之后,以“公平竞赛”为原则的奥运会就开始笼罩上一层阴影。 从此,使用兴奋剂的事件犹如“瘟疫”一般,迅速蔓延开来。
关键词 反兴奋剂 公平竞赛 检测中心 紧元 寨基 违禁药物
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工商银行吉林省分行活化产成品取得成效
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《中国城市金融》 北大核心 1990年第8期62-63,共2页
工商银行威海会议以后,工商银行吉林省分行召开了全省分支行行长会议,认真贯彻、落实总行会议精神,向全省工业信贷专业提出“统一思想、振奋精坤、集中力量,千方百计搞活产成品资金”的号召,并决定从今年四月开始,全省工业信贷工作的重... 工商银行威海会议以后,工商银行吉林省分行召开了全省分支行行长会议,认真贯彻、落实总行会议精神,向全省工业信贷专业提出“统一思想、振奋精坤、集中力量,千方百计搞活产成品资金”的号召,并决定从今年四月开始,全省工业信贷工作的重点要迅速转移到搞活产成品资金上来。 展开更多
关键词 工商银行 产成品资金 行长会议 物资部门 商业经营 市场信息 紧元 产销衔接 压缩库存 产品销售
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Calculation of Strain Amplification Matrix for Strain Invariant Failure Theory Based on Representative Volume Element Models with Periodical Boundary Condition 被引量:1
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作者 赵剑 汪海 +1 位作者 吕新颖 谢宗蕻 《Journal of Shanghai Jiaotong university(Science)》 EI 2017年第5期523-529,共7页
Strain invariant failure theory (SIFT) is a micro-mechanics-based failure theory for multi-scale failure analysis of composite materials originally proposed by Gosse and Christensen. In this paper, the approach for ob... Strain invariant failure theory (SIFT) is a micro-mechanics-based failure theory for multi-scale failure analysis of composite materials originally proposed by Gosse and Christensen. In this paper, the approach for obtaining strain amplification matrix which is a key step for the execution of SIFT is improved by adopting representative volume element (RVE) finite element models considering periodical boundary condition, based on which more actual deformation mode is reflected. The deformation modes and strain data at the characteristic points of the centroid cell of multi-cell RVE model are analyzed and taken as a reference. It can be concluded that more reasonable deformation mode and relationship between the micro-mechanical and macro-mechanical strain states are obtained by employing the new model. Finally, numerical examples are provided to illustrate the determination of strain amplification factors within the RVEs considering periodical boundary condition at the characteristic points. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany. 展开更多
关键词 Boundary conditions DEFORMATION Finite element method STRAIN Volume measurement
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Numerical Method on Load Sharing Problem of Thick Laminate Joints
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作者 刘龙权 陈昆昆 +2 位作者 张俊琪 刘无瑕 汪海 《Journal of Shanghai Jiaotong university(Science)》 EI 2014年第1期95-101,共7页
Accurately and efficiently predicting the load sharing of multi^bolt thick laminate joints is necessary to quicken the optimization of the large-scale structures over various design variables, and a two-dimensional ... Accurately and efficiently predicting the load sharing of multi^bolt thick laminate joints is necessary to quicken the optimization of the large-scale structures over various design variables, and a two-dimensional (2D) finite element method (FEM) is introduced to meet such a demand. The deformation contributions of the joint zone are analyzed and calculated separately, including the shearing deformation of the fasteners shank, the bending deformation of the fasteners shank, and the bearing deformation of the fasteners and joint plates. These deformations are all transferred and incorporated into the components of the fastener's flexibility. In the 2D finite element model, the flexibilities of the beam elements and bush elements are used to simulate different components of the fastener's flexibility. The parameters of the beam elements which include the bending moment of inertia and intersection area, and the parameters of the bush elements which include the stiffness in different directions, are all obtained through equalizing the fasteners flexibilities. In addition, the secondary bending effect introduced by the single-lap joints is also taken into account to verify the flexibilities of the fasteners in practical application. The proposed FEM is testified to be more accurate than the traditional 2D FEMs and more efficient than the three-dimensional (3D) FEM in solving load sharing problem of multi-bolt single-lap thick laminate joints. With the increase of joint plates' thickness, the advantages of the proposed method tend to be more obvious. The proposed 2D FEM is an effective tool for designing bolted joints in large-scale composite structures. 展开更多
关键词 load sharing thick laminate fastener flexibility finite element single-lap
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Stress intensity factors under combined bending and torsion moments
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作者 Al Emran ISMAIL Ahmad Kamal ARIFFIN +3 位作者 Shahrum ABDULLAH Mariyam Jameelah GHAZALI Mohammed ABDULRAZZAQ Ruslizam DAUD 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2012年第1期1-8,共8页
This paper discusses stress intensity factor (SIF) calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and re... This paper discusses stress intensity factor (SIF) calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and relative crack depths, a/D, ranging from 0.1 to 0.6 were considered. Since the loading was non-symmetrical for torsion loadings, a whole finite element model was constructed. Then, the individual and combined bending and torsion loadings were remotely applied to the model. The equivalent SIF method, F*EQ, was then used explicitly to combine the individual SIFs from the bending and torsion loadings. A comparison was then carried out with the combined SIF, F*FE, obtained using the finite element analysis (FEA) under similar loadings. It was found that the equivalent SIF method successfully predicted the combined SIF for Mode I. However, discrepancies between the results determined from the different approaches occurred when Fm was involved. It was also noted that the predicted F* EE using FEA was higher than the F*EQ predicted through the equivalent SIF method due to the difference in crack face interactions. 展开更多
关键词 Stress intensity factor (SIF) Combined loadings Finite element analysis (FEA) Surface cracks Round solid bars
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