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“心”“形”之辩——关于中国书法“心”与“形”对偶范畴之探讨
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作者 李彤 《南京艺术学院学报(美术与设计)》 CSSCI 北大核心 2023年第3期63-67,I0002,共6页
书法究竟是“心学”还是“形学”的问题便成为近几十年书学理论研究中一个经常被讨论的论题。将书论中的“心”与“形”两个范畴相对举,系统化地梳理其基本意涵,结构化地把握其理论旨趣,将使我们对书法中“心”与“形”这一对偶范畴有... 书法究竟是“心学”还是“形学”的问题便成为近几十年书学理论研究中一个经常被讨论的论题。将书论中的“心”与“形”两个范畴相对举,系统化地梳理其基本意涵,结构化地把握其理论旨趣,将使我们对书法中“心”与“形”这一对偶范畴有更为深刻的理解。就书法艺术而言,“心”是审美价值的根源,而“形”作为书法艺术的载体,规定和承载了主体心灵、情感的内容和抒发方式,“心”与“形”理应在个体的艺术实践中互相成就、互相塑造、有机统一。 展开更多
关键词 中国书法 结构
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隔震防倒塌支座及楼梯间位置对框架结构抗震性能的影响研究 被引量:8
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作者 常亚峰 梁兴文 +1 位作者 汪平 辛力 《地震工程学报》 CSCD 北大核心 2017年第6期996-1004,共9页
为研究梯段板下端设置隔震防倒塌支座和楼梯间位置对钢筋混凝土框架结构抗震性能的影响,利用ETABS软件建立不包括、包括隔震防倒塌支座的3种楼梯间布置方案,6个框架结构计算模型。通过模态分析、反应谱分析和Pushover分析,研究隔震防倒... 为研究梯段板下端设置隔震防倒塌支座和楼梯间位置对钢筋混凝土框架结构抗震性能的影响,利用ETABS软件建立不包括、包括隔震防倒塌支座的3种楼梯间布置方案,6个框架结构计算模型。通过模态分析、反应谱分析和Pushover分析,研究隔震防倒塌支座和楼梯间位置对框架结构的振型、内力及破坏机制的影响。结果表明:梯段板下端设置隔震防倒塌支座后,楼梯间位置对钢筋混凝土框架结构的扭转效应影响较小,且框架结构在两个主轴方向的动力特性比较接近;楼梯间框架柱内力均显著降低,但楼梯间布置在最边跨时,在垂直于梯跑方向地震作用下,框架结构边柱内力较大;框架梁对整体框架结构的耗能贡献较多,增强了框架结构的抗震性能,大震时楼梯构件严重破坏较晚,设置隔震防倒塌支座可保证楼梯整体稳定性。 展开更多
关键词 隔震防倒塌支座 钢筋混凝土框架结构 结构平面 楼梯 扭转
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矿用绞车钢丝绳超载保护装置研究 被引量:2
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作者 李明 贾秀芹 《机电产品开发与创新》 2011年第5期37-39,共3页
系统采用心形结构对煤矿绞车钢丝绳的实际承载力检测。煤矿绞车在工作过程中,由于被拉小车承载力突变使钢丝绳承受拉力超限被拉断,本文设计了在小车与钢丝绳之间加装心形拉力检测装置,控制系统以单片机为核心,基于无线电通讯技术,对心... 系统采用心形结构对煤矿绞车钢丝绳的实际承载力检测。煤矿绞车在工作过程中,由于被拉小车承载力突变使钢丝绳承受拉力超限被拉断,本文设计了在小车与钢丝绳之间加装心形拉力检测装置,控制系统以单片机为核心,基于无线电通讯技术,对心形结构中安装的压力传感器数据进行监控,实现了钢丝绳拉力的测量,实现超载保护的功能。 展开更多
关键词 矿用绞车 钢丝绳 超载保护 心形结构
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Quantum Chemical Studies on Proteins in the Reaction Center of Rhodobacter sphaeroides 被引量:1
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作者 徐红 马淑华 +3 位作者 沈玲玲 张晓东 张兴康 张启元 《Acta Botanica Sinica》 CSCD 2001年第6期565-570,共6页
The electronic structure of protein chains L and M in photosynthetic reaction center (PRC) of Rhodobacter sphaeroides (Van Niel) Imhoff, Truper et Pfennig) was studied by using the Overlapping Dimer Approximation meth... The electronic structure of protein chains L and M in photosynthetic reaction center (PRC) of Rhodobacter sphaeroides (Van Niel) Imhoff, Truper et Pfennig) was studied by using the Overlapping Dimer Approximation method and the Extended Negative Factor Counter method at ab initio level. The result indicated that: (1) Amino acid residues, the molecular orbitals of which composed the main components of frontier orbitals of protein chain L (M), are located at the random coil areas of chain L (alpha helix areas of chain M). Since the random coil is flexible and more easy to change its conformation in the electron transfer process and to reduce the energy of the system, and the structure of the alpha helix is reletively stable, this difference might be one of the causes for the electron transfer in photosynthetic reaction center (PRC) only takes place along the L branch. (2) The His residues which axially coordinated to the 'special pair' P and accessory chlorophyll molecules (ABChls) are essentially important for the E-LUMO levels of P and ABChl. But, the corresponding molecular orbitals of these His residues do not appear in the composition of frontier orbitals of protein chains. It means that the interaction between pigment molecules and protein chains do not influence the contribution to the frontier orbitals of protein chains explicitly, but influences the corresponding E-LUMO levels significantly. 展开更多
关键词 photosynthetic reaction center Rhodobacter sphaeroides electronic structure of protein ab initio Extended Negative Factor Counter method (ENFC)
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Existence and Uniqueness of Nested Regular Quadrilateral Central Configurations 被引量:2
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作者 LIUXue-fei 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2005年第1期59-64,共6页
Two cases of the nested configurations in R3 consisting of two regular quadrilaterals are discussed. One case of them do not form central configuration, the other case can be central configuration. In the second case ... Two cases of the nested configurations in R3 consisting of two regular quadrilaterals are discussed. One case of them do not form central configuration, the other case can be central configuration. In the second case the existence and uniqueness of the central configuration are studied. If the configuration is a central configuration, then all masses of outside layer are equivalent, similar to the masses of inside layer. At the same time the following relation between r(the ratio of the sizes) and mass ratio b = m/m must be satisfied in which the masses at outside layer are not less than the masses at inside layer, and the solution of this kind of central configuration is unique for the given ratio (6) of masses. 展开更多
关键词 N-body problems nested quadrilaterals central configurations existence and uniqueness
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Existence and uniqueness of a class of double pyramidal central configurations in six-body problems 被引量:1
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作者 LIUXuefei 《Journal of Chongqing University》 CAS 2004年第1期97-101,共5页
Under the necessary conditions for a double pyramidal central configuration with a diamond base to exist in the real number space, the existence and uniqueness of such configurations were studied by employing combined... Under the necessary conditions for a double pyramidal central configuration with a diamond base to exist in the real number space, the existence and uniqueness of such configurations were studied by employing combinedly the algebraic method and numerical calculation. It is found that there exists a planar curl triangle region G in a square Q such that any point in G and given by the ratio of the two diagonal lengths of the diamond base and the ratio of one diagonal length of the base to the height of the double pyramid configuration determines a unique double pyramid central configuration, while all points in Q-G have no referance to any central configuration. 展开更多
关键词 body problem double pyramidal central configuration existence and uniqueness
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Ethylene Polymerization Using Improved Polyethylene Catalyst 被引量:6
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作者 朱孝恒 郭子芳 +1 位作者 岑为 毛炳权 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第1期52-56,共5页
The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst(BRICI)and improved ... The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst(BRICI)and improved polyethylene catalyst.The effects of catalyst structure on kinetic behavior were examined.The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays(EDAX),and morphologies of catalyst particles and polymer products were examined by scanning electron microscope(SEM).Hydrogen response and copolymerization performance were investigated and compared with the two catalysts.The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented.The improved polyethylene catalyst showed higher activity,better hydrogen response and copolymerization performance. 展开更多
关键词 polyethylene catalyst POLYETHYLENE slurry polymerization process ethoxy group
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Existence and uniqueness for a class of nine-bodies central configurations
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作者 刘学飞 《Journal of Chongqing University》 CAS 2006年第1期53-56,共4页
On some necessary conditions for double pyramidal central configurations with concave heptagon for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with con... On some necessary conditions for double pyramidal central configurations with concave heptagon for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with concave heptagon base for nine-body problems is proved in this paper, and the range of the ratio cr of the circularity radius of the heptagon to the half-height of the double pyramidal central configuration involved in this class configurations is obtained, which is in the interval (√3/3,1.099 600 679), and the configuration involved in the bodies with any σ∈ (√3/3, 1.099 600 679) can form a central configuration which is a uniquely central configuration is proved. 展开更多
关键词 nine-body problem existence and uniqueness concave heptagon base double pyramidal central configuration.
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Influence of chemical composition and cold deformation on aging precipitation behavior of high nitrogen austenitic stainless steels 被引量:1
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作者 李花兵 姜周华 +2 位作者 冯浩 朱红春 张祖瑞 《Journal of Central South University》 SCIE EI CAS 2013年第12期3354-3362,共9页
The influence of chemical composition and cold deformation on aging precipitation behavior of 18Cr-16Mn-2Mo-I.IN (HNS-A), 18Cr-16Mn-I.3N (HNS-B), 18Cr-18Mn-2Mo-0.96N (HNS-C) and 18Cr-18Mn-2Mo-0.77N (I-INS-D) h... The influence of chemical composition and cold deformation on aging precipitation behavior of 18Cr-16Mn-2Mo-I.IN (HNS-A), 18Cr-16Mn-I.3N (HNS-B), 18Cr-18Mn-2Mo-0.96N (HNS-C) and 18Cr-18Mn-2Mo-0.77N (I-INS-D) high nitrogen austenitic stainless steels was investigated. The results show that the "nose" temperatures and incubation periods of the initial time-temperature-precipitation (TTP) curves of aged HNSs are found to be 850 ℃, 60 s; 850 ℃, 45 s; 850 ℃, 60 s and 900 ℃, 90 s, respectively. Based on the analysis of SAD patterns, the coarse cellular Cr2N precipitate which presents a lamellar structure has a hexagonal structure of a=0.478 nm and c=0.444 nm. The Z phase corresponding to a composition of Fe36Cr^2Mo10, is determined to be a body-centered cubic structure ofa=0.892 nm. The precipitating sensitivity presents no more difference with the nitrogen content increasing from 0.77% to 0.96%, but exhibits so obviously that the cellular precipitates nearly overspread the whole field. The addition of Mo element can restrain the TTP curves moving left and down, which means decreasing the sensitivity of aging precipitation. With increasing the cold deformation, the sensitivity of precipitation increases obviously. 展开更多
关键词 high nitrogen austenitic stainless steel aging precipitation time-temperature-precipitation curve chemical composition cold deformation
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Existence and uniqueness for a class of double pyramidal central configurations with a concave pentagonal base
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作者 刘学飞 《Journal of Chongqing University》 CAS 2003年第1期28-30,共3页
Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configu... Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with a concave pentagonal base in 7-body problems are proved and the range of the ratio between radius and half-height is obtained, within which the 7 bodies involved form a central configuration or form uniquely a central configuration. 展开更多
关键词 N-body problem existence and uniqueness concave pentagonal base double pyramidal central configuration
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