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The rough representation and measurement of quotient structure in algebraic quotient space model 被引量:5
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作者 陈林书 Wang Jiayang 《High Technology Letters》 EI CAS 2017年第3期293-297,共5页
Granular computing is a very hot research field in recent years. In our previous work an algebraic quotient space model was proposed,where the quotient structure could not be deduced if the granulation was based on an... Granular computing is a very hot research field in recent years. In our previous work an algebraic quotient space model was proposed,where the quotient structure could not be deduced if the granulation was based on an equivalence relation. In this paper,definitions were given and formulas of the lower quotient congruence and upper quotient congruence were calculated to roughly represent the quotient structure. Then the accuracy and roughness were defined to measure the quotient structure in quantification. Finally,a numerical example was given to demonstrate that the rough representation and measuring methods are efficient and applicable. The work has greatly enriched the algebraic quotient space model and granular computing theory. 展开更多
关键词 空间模型 度量方法 商结构 代数 计算理论 等价关系 数值算例 粗糙度
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Theoretical Studies on the Molecular Structures and Thermodynamic Properties of Polychlorinated Fluorenes 被引量:2
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作者 曾小兰 张秀兰 +1 位作者 王岩 陈东辉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第4期647-654,共8页
Geometric structures of 135 polychlorinated fluorene (PCFR) molecules were optimized using density functional theory (DFT) at the B3LYP/6-311G** level and their thermodynamic properties in the ideal gas state we... Geometric structures of 135 polychlorinated fluorene (PCFR) molecules were optimized using density functional theory (DFT) at the B3LYP/6-311G** level and their thermodynamic properties in the ideal gas state were calculated. The relations of these thermodynamic properties with the number and position of chlorine atoms were also explored, from which the relative stability of PCFR congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation (Δr,fGθ). The results show that the geometric configuration of PCFR isomers is determined by the position of chlorine atoms. There exist two types of intramolecular weak interactions, i.e., C–H···Cl and Cl···Cl interactions in PCFR molecules. The change of ΔfHθ and ΔfGθ of most stable PCFR isomers with increasing the number of chlorine atoms is different from that in most unstable PCFR congeners. The values of ΔfHθ and ΔfGθ for PCFR isomers with the same number of chlorine atoms strongly depend on the position of chlorine atoms and the relative stability of PCFR congeners is mainly determined by intramolecular delocalized π bond and Cl···Cl nuclear repulsive interaction. 展开更多
关键词 polychlorinated fluorenes (PCFRs) molecular structures thermodynamic properties relative stability density functional theory (DFT)
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Theoretical Studies on the Molecular Structures and Thermodynamic Properties of Polychlorinated Acenaphthylenes 被引量:1
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作者 曾小兰 张秀兰 +1 位作者 张义东 姜永 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第3期300-307,共8页
Geometric structures of 135 polychlorinated acenaphthylene (PCAC) molecules were optimized using density functional theory (DFT) at the B3LYP/6-311G^** level and some thermodynamic properties of them in the idea... Geometric structures of 135 polychlorinated acenaphthylene (PCAC) molecules were optimized using density functional theory (DFT) at the B3LYP/6-311G^** level and some thermodynamic properties of them in the ideal gas state were calculated. The relations of these thermodynamic properties with the number and position of chlorine atoms were also explored, from which the relative stability of PCAC congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation (△r,fGθ). The results show that all PCAC isomers have planar geometric configuration. There exists intramolecular Cl···Cl weak interaction in some PCAC molecules. The change of △fHθ and fGθ of most stable PCAC isomers with increasing the number of chlorine atoms is different from that in the least stable PCAC congeners. The values of fHθ and fGθ for PCAC isomers with the same number of chlorine atoms show a strong dependence on the position of chlorine atoms and the relative stability of PCAC congeners has close relation with the intramolecular Cl···Cl nuclear repulsive interaction. 展开更多
关键词 polychlorinated acenaphthylenes (PCACs) molecular structures thermodynamicproperties relative stability density functional theory (DFT)
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Morphological Group Theory of Material Structure
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作者 Ziqiang Zhou 《Journal of Applied Mathematics and Physics》 2018年第1期69-89,共21页
The correct formulation and understanding of micro-images is one of the difficulties that occur to microstructures science today, which need to develop a new appropriate mathematics for micro-images of matter system. ... The correct formulation and understanding of micro-images is one of the difficulties that occur to microstructures science today, which need to develop a new appropriate mathematics for micro-images of matter system. Here I study the image mathematics and physics description of micro-images of material system by topology, set theory, symbolic logic and show that there is a naturally morphological equation, that is a law of qualitative structure of matter system, the law of the unity of two kinds of morphological structure (Jordan and hidden structure), which can be used to describe not only the common feature of different correlated matter, but also to correct classify the micro-images into different classes, so that to study the morphology groups for materials science and Algebraic geometry. The morphology equation can be found a number of applications for the observation and analysis of micro-images of material system and other natural sciences, some important basic concepts of algebraic geometry can also be newly explained by the morphology equation, such as: 1) To construct the image-mathematical language and to construct the image mathematics model (IMM) for microstructures;2) To construct complex geometric structures (Concave polygon) then analyze these complex shape structure by analytic geometry and algebraic geometry, to study complicated operators on complicated spaces;3) A new explanation for the logical basis, concept definition and proof way of algebraic geometry and uses it to analyze morphological structure of the new and parent phase and the problem of Hodge’s theory and structure type, and points out that there may be a counterexamples for Hodge’s conjecture. 展开更多
关键词 MORPHOLOGICAL EQUATION MORPHOLOGICAL Function algebraic GEOMETRY Model Complex GEOMETRIC structures Hodge CONJECTURE
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Theoretical Studies on the Molecular Structures and Thermodynamic Properties of Polychlorinated Fluoranthenes
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作者 曾小兰 王红军 +1 位作者 王岩 王慧娟 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第4期539-549,共11页
DFT-B3LYP/6-311G** method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene(PCFRT) congeners and calculate their thermo-dynamic properties in the ideal gas state,such as ... DFT-B3LYP/6-311G** method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene(PCFRT) congeners and calculate their thermo-dynamic properties in the ideal gas state,such as heat capacity at constant volume(Cv),entropy(S),standard enthalpy of formation(ΔfH) and standard Gibbs free energy of formation(ΔfG).The relations of Cv,S,ΔfH and ΔfG with the number and position of chlorine atoms have also been explored,from which the relative stability of PCFRT congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation(Δr,fG).It was found that some of the PCFRT isomers are in a nonplanar configuration and there are intramolecular Cl…Cl weak interactions in some of the isomers.With increasing the number of chlorine atoms,the values of ΔfH and ΔfG of the most stable PCFRT isomers decrease initially and then increase.The values of ΔfH and ΔfG of PCFRT congeners with the same number of chlorine atoms show a strong dependence on the positions of chlorine atoms.The relative thermodynamic stability of PCFRT isomers is determined mainly by intramolecular adjacent Cl…Cl nuclear repulsive interaction between Cl atoms at two different six-membered rings.Most PCFRT congeners are easier to form thermodynamically than their parent compound. 展开更多
关键词 polychlorinated fluoranthene(PCFRT) molecular structure thermodynamic property relative stability density functional theory(DFT)
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Enhancing the Efficiency of the Management of Real Estate Companies through Organizational Structures
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作者 Marian Maria-Liliana 《Open Journal of Applied Sciences》 CAS 2022年第10期1687-1697,共11页
The article represents research on ways to make the management of real estate companies more efficient, starting from their structural organization. The organizational structure of the enterprise is a basic component ... The article represents research on ways to make the management of real estate companies more efficient, starting from their structural organization. The organizational structure of the enterprise is a basic component of the general structure of the company and reflects the “anatomy of the enterprise” and the way of its conception, detailing, and implementation directly influence the activities required to achieve the objectives of the enterprise. On closer examination of a series of organizational charts of real estate management companies, the author observed a tendency to use organizational structures that are inefficient. The main objectives of this article are to bring into the practice of real estate management a model of beneficial organizational structure, both for the real estate management companies and for the construction companies that, besides the building activity, also deal with the management of their own real estate, and to emphasize the particular importance of the organizational structure of the company. The appreciation of the organizational structure represents the process of knowledge, understanding, and explanation of the existing situation through a detailed analysis of the factors that influence its condition through: the enterprise development strategy;the type and complexity of services;the size of the enterprise;the quality of human resources;the changes that take place in the external environment of the company, and last but not least, the legal framework and the statutes of the enterprise. 展开更多
关键词 Management of Real Estate Companies Organizational structure Organizational Chart Functional structure Organizational Relations Hierarchical Weighting Real Estate Project
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基于改进TOPSIS灰色关联投影法的主网网架结构评价 被引量:16
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作者 梁海平 田圣双 +2 位作者 李秋燕 刘英培 张文朝 《电力自动化设备》 EI CSCD 北大核心 2019年第4期63-69,共7页
针对目前主网网架结构缺少全面客观评价的现状,提出一种基于改进逼近理想解法(TOPSIS)灰色关联投影法的主网网架结构评价方法。定义归一化代数连通度指标,选取归一化代数连通度、负荷平均最短供电距离、输电网网损、电压越限节点比例、... 针对目前主网网架结构缺少全面客观评价的现状,提出一种基于改进逼近理想解法(TOPSIS)灰色关联投影法的主网网架结构评价方法。定义归一化代数连通度指标,选取归一化代数连通度、负荷平均最短供电距离、输电网网损、电压越限节点比例、重载线路比例、电压稳定裕度指标构建主网网架评价体系;使用主客观最优组合赋权法确定各评价指标权重,并采用改进TOPSIS灰色关联投影法计算各网架的综合评分。以IEEE 118节点系统及某市级电网主网架为例进行计算分析,结果验证了所提方法能够客观有效地对主网网架结构进行评价。 展开更多
关键词 主网结构评价 归一化代数连通度 主客观组合赋权法 逼近理想解法 灰色关联投影法
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武汉都市圈乡村地域系统结构与功能演变及耦合优化
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作者 孟春妍 孔雪松 《中国土地科学》 CSCD 北大核心 2024年第5期68-78,共11页
研究目的:基于“人—地—域”与“三生空间”视角,分析2010—2020年武汉都市圈乡村地域系统结构与功能的时空演变特征,系统探讨结构与功能的耦合关系及其优化路径。研究方法:指标评价法和弹性系数模型。研究结果:(1)武汉都市圈乡村地域... 研究目的:基于“人—地—域”与“三生空间”视角,分析2010—2020年武汉都市圈乡村地域系统结构与功能的时空演变特征,系统探讨结构与功能的耦合关系及其优化路径。研究方法:指标评价法和弹性系数模型。研究结果:(1)武汉都市圈乡村地域系统结构与功能指数空间格局相对稳定,2010—2020年结构与功能指数整体呈现波动上升趋势。(2)根据结构与功能指数变化及弹性系数的组合特征,将武汉都市圈乡村地域划分为6种类型。(3)协调增长区应找准特色发展主轴,巩固脱贫攻坚成果;双减区应变被动虹吸为主动承接,依托特色引领产业发展;结构滞后增长区和结构减—功能增反向区应借助区位优势打造品牌,实现转型发展;功能滞后增长区和结构增—功能减反向区应推动农村农业现代化,改善农村人居环境。研究结论:乡村地域系统结构与功能存在显著的阶段性和分异性耦合特征,通过制定针对性分区优化策略,促进乡村地域系统结构与功能的协调发展。 展开更多
关键词 乡村结构 乡村功能 弹性系数模型 耦合关系 武汉都市圈
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Studies of Structural and Thermodynamic Properties for Polychlorinated Thianthrenes by Density Functional Theory 被引量:1
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作者 刘辉 孙萍 +2 位作者 柳红霞 王遵尧 王连生 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第10期1255-1260,共6页
The structural and thermodynamic (PCTAs) in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G* level using Gaussian 98 pr... The structural and thermodynamic (PCTAs) in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G* level using Gaussian 98 program. Based on the output data of Gaussian, the isodesmic reactions were designed to calculate standard enthalpy of formation (△fH^θ) and standard free energy of formation (△fH^θ) of PCTAs congeners. The relations of these thermodynamic parameters with the number and position of C1 atom substitution (Npcs) were discussed, and it was found that there exists high correlation between thermodynamic parameters (total energy (TE), zero-point vibrational energy (ZPE), thermal correction to energy (Eth), heat capacity at constant volume (Cv^θ), entropy (S^θ), enthalpy (H^θ), free energy (G^θ), standard enthalpies of formation (△fH^θ) and standard Gibbs energies of formation (△fG^θ)) and Npcs. On the basis of the relative magnitude of their △fG^θ, the order of relative stability of PCTA congeners was theoretically proposed. In addition, the correlations between structural parameters and Npcs were also discussed. The good correlations were found between molecular average polarizability (α), energy of the highest occupied molecular orbital (EHOMO), molecular volume (Vm) and Npcs, and all R^2 values are larger than 0.95. Moreover, it was supposed that the isomer groups with higher toxicity should be Tri-CTA and TCTA. 展开更多
关键词 polychlorinated thianthrenes density functional theory (DFT) the number and position of CI atom substitution (Npcs) structural and thermodynamic parameters relative stability
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An improved damaging model for structured clays
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作者 姜岩 雷华阳 +1 位作者 郑刚 徐舜华 《Journal of Central South University》 SCIE EI CAS 2008年第S2期76-80,共5页
An improved damaging model formulated within the framework of bounding surface for structured clays was proposed. The model was intended to describe the effects of structure degradation due to geotechnical loading. Th... An improved damaging model formulated within the framework of bounding surface for structured clays was proposed. The model was intended to describe the effects of structure degradation due to geotechnical loading. The predictive capability of the model was compared with those of triaxial compression test on Tianjin soft clays. The results show that, by incorporating a new damage function into the model, the reduction of elastic bulk and shear modulus with elastic deformations and the reduction of plastic bulk modulus and shear modulus with plastic deformations are able to be appreciable. Before the axial strain reaches 15%, the axial strain computed from the model is smaller than that from the test under the drained condition. Under the undrained condition, after the axial strain reaches 1%, the axial strain increases quickly because of the complete loss of structure and stiffness; and the result computed from the model is nearly equal to that from the model without the incorporation of the damage function due to less plastic strain under undrained condition test. 展开更多
关键词 structureD clays CONSTITUTIVE RELATION SOIL structure bounding surface DAMAGE function
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Deformed oscillator algebra for quantum superintegrable systems in two-dimensional Euclidean space and on a complex two-sphere
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作者 H.Panahi Z.Alizadeh 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期175-180,共6页
In this work, we study superintegrable quantum systems in two-dimensional Euclidean space and on a complex twosphere with second-order constants of motion. We show that these constants of motion satisfy the deformed o... In this work, we study superintegrable quantum systems in two-dimensional Euclidean space and on a complex twosphere with second-order constants of motion. We show that these constants of motion satisfy the deformed oscillator algebra. Then, we easily calculate the energy eigenvalues in an algebraic way by solving of a system of two equations satisfied by its structure function. The results are in agreement to the ones obtained from the solution of the relevant Schroedinger equation. 展开更多
关键词 superintegrable systems constants of motion deformed oscillator algebra structure function
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<i>Ab-Initio</i>Self-Consistent Density Functional Theory Description of Rock-Salt Magnesium Selenide (MgSe)
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作者 Blaise Awola Ayirizia Yuriy Malozovsky +2 位作者 Lashounda Franklin Uttam Bhandari Diola Bagayoko 《Materials Sciences and Applications》 2020年第7期401-414,共14页
We report results on electronic, transport, and bulk properties of rock-salt magnesium selenide (MgSe), from density functional theory (DFT) calculations. We utilized a local density approximation (LDA) potential and ... We report results on electronic, transport, and bulk properties of rock-salt magnesium selenide (MgSe), from density functional theory (DFT) calculations. We utilized a local density approximation (LDA) potential and the linear combination of atomic orbitals formalism (LCAO). We followed the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF), to perform a generalized minimization of the energy, down to the actual ground state of the material. We describe the successive, self-consistent calculations, with augmented basis sets, that are needed for this generalized minimization. Due to the generalized minimization, our results have the full, physical content of DFT, as per the second DFT theorem [AIP Advances, 4, 127104 (2014)]. Our calculated, indirect bandgap of 2.49 eV, for a room temperature lattice constant of 5.460 <span style="white-space:nowrap;">&Aring;</span>, agrees with experimental findings. We present the ground-state band structure, the related total and partial densities of states, DOS and PDOS, respectively, and electron and hole effective masses for the material. Our calculated bulk modulus of 63.1 GPa is in excellent agreement with the experimental value of 62.8 ± 1.6 GPa. Our predicted equilibrium lattice constant, at zero temperature, is 5.424 <span style="white-space:nowrap;">&Aring;</span>, with a corresponding indirect bandgap of 2.51 eV. We discuss the reasons for the agreements between our findings and available, corresponding, experimental ones, particularly for the band gap, unlike the previous DFT results obtained with ab-initio LDA or GGA potentials. 展开更多
关键词 Density Functional theory Generalized Energy Minimization Ground State Band structure Band Gap Related Properties
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Examining Mathematics Anxiety of Undergraduates Using a Brain-Based Measurement, EEG
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作者 Anderson Norton Youngmin Seok Sangsook Choi-Koh 《Journal of Behavioral and Brain Science》 2019年第5期195-209,共15页
This paper reports on an investigation of mathematics anxiety (MA) among 40 Korean undergraduate students, using cognitive neuroscience. In Spring 2015, we collected data on correct response rates and reaction times f... This paper reports on an investigation of mathematics anxiety (MA) among 40 Korean undergraduate students, using cognitive neuroscience. In Spring 2015, we collected data on correct response rates and reaction times from computer-based activities related to quadratic functions. We also measured brain response through event related potentials (ERP). Results demonstrate that students with higher mathematics anxiety (HMA) took more time than students with lower mathematics anxiety (LMA), both in translating equations to graphs and in translating graphs to equations. Moreover, based on analysis of ERP, brain waves of the HMA group recorded higher amplitude. In specific, both groups showed higher amplitude in translation from graphs to equation than vice versa. Higher amplitudes indicate greater demands on working memory, which we discuss in the concluding section, especially with regard to MA. 展开更多
关键词 ALGEBRA ELECTROENCEPHALOGRAPHY EVENT-RELATED Potentials Function Mathematics ANXIETY NEUROIMAGING Undergraduate
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Geometric Interpretation of the Origin of the Universe
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作者 Bohdan Lev 《Journal of Modern Physics》 2022年第2期89-99,共11页
An approach to the theory of geometrization of the Universe is proposed. The wave function of the Universe is represented by the Clifford number with the transfer rules that have the structure of the Dirac equation fo... An approach to the theory of geometrization of the Universe is proposed. The wave function of the Universe is represented by the Clifford number with the transfer rules that have the structure of the Dirac equation for any manifold. Solutions of this equation may be obtained in terms of the geometric interpretation. A new model is proposed that can explain the manifestation of the dark energy and dark matter in the Universe as a geometrical entity with a mechanism involving the spontaneous symmetry breaking. 展开更多
关键词 Clifford Algebra Wave Function Geometric Interpretation Structural Equations
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化疗相关认知障碍磁共振成像研究进展
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作者 陈晴晴 沈晶 +2 位作者 朱贞洋 姜斌 伍建林 《磁共振成像》 CAS CSCD 北大核心 2023年第6期85-88,共4页
化疗相关认知障碍(chemotherapy-related cognitive impairment, CRCI)是指非中枢神经系统肿瘤化疗后引起的脑认知功能损害,其严重影响患者生活质量。随着MRI技术蓬勃兴起,结构和功能MRI已成为探究CRCI神经机制有效方法并不断取得进展... 化疗相关认知障碍(chemotherapy-related cognitive impairment, CRCI)是指非中枢神经系统肿瘤化疗后引起的脑认知功能损害,其严重影响患者生活质量。随着MRI技术蓬勃兴起,结构和功能MRI已成为探究CRCI神经机制有效方法并不断取得进展。影像组学和人工智能在CRCI脑影像数据分析研究中亦得到逐渐发展和完善,并取得可观成果。本文就上述多模态MRI领域的CRCI研究进展予以综述,并探讨其临床价值,旨在为今后解读CRCI详细神经病理机制提供MRI新视野和新策略。 展开更多
关键词 化疗相关认知障碍 磁共振成像 结构磁共振成像 功能磁共振成像 多模态磁共振成像 影像组学 人工智能
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根治性前列腺切除术中尿控相关结构解剖及术中保护技巧
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作者 何民心 田庚 +1 位作者 种铁 付德来 《现代泌尿外科杂志》 CAS 2023年第12期1086-1091,共6页
根治性前列腺切除术(RP)是治疗早期前列腺癌的标准方法,但术后往往发生尿失禁等并发症,严重影响患者生活质量。术中尿控结构的保护及重建是降低尿失禁发生率,帮助患者恢复尿控功能的重要手段。本文对RP的手术方式、尿控相关结构(膀胱颈... 根治性前列腺切除术(RP)是治疗早期前列腺癌的标准方法,但术后往往发生尿失禁等并发症,严重影响患者生活质量。术中尿控结构的保护及重建是降低尿失禁发生率,帮助患者恢复尿控功能的重要手段。本文对RP的手术方式、尿控相关结构(膀胱颈、功能尿道、相关支持结构以及神经与血管)解剖及术中保护技巧进行综述,为实现早期前列腺癌治疗“五连胜”提供参考。 展开更多
关键词 前列腺癌 根治性前列腺切除术 尿失禁 尿控相关结构 膀胱颈保留 膀胱颈重建术 膀胱颈折叠术 功能尿道
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Boros-Moll多项式序列递推关系的代数证明
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作者 窦裕杰 王佳合 +1 位作者 邓晓明 吕仑 《河北科技大学学报》 CAS 北大核心 2023年第4期368-373,共6页
为了拓展Boros-Moll多项式序列递推关系的基本理论,研究了Boros-Moll多项式序列递推关系新的证明方法。首先,对Boros-Moll多项式序列满足的递推关系进行适当变形、分拆;其次,将满足的递推关系式构造为3个部分和的差式;最后,运用代数方... 为了拓展Boros-Moll多项式序列递推关系的基本理论,研究了Boros-Moll多项式序列递推关系新的证明方法。首先,对Boros-Moll多项式序列满足的递推关系进行适当变形、分拆;其次,将满足的递推关系式构造为3个部分和的差式;最后,运用代数方法、构造法等数学方法得出3个部分的和均为零,进一步得到Boros-Moll多项式序列递推关系的一个新的证明方法。结果表明,在Boros-Moll多项式序列递推关系中,对其结构进行巧妙变形、分拆,再证明相应的引理成立,可得出一个新的证明方法。研究结果丰富了Boros-Moll多项式序列递推关系的相关理论,为Boros-Moll多项式序列在组合数学、社会科学、信息论等领域的应用提供了理论参考。 展开更多
关键词 组合数学 Boros-Moll多项式序列 递推关系 代数证明 构造法
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RNA Regulations and Functions Decoded by Transcriptome-wide RNA Structure Probing 被引量:3
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作者 meiling piao lei sun qiangfeng cliff zhang 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2017年第5期267-278,共12页
RNA folds into intricate structures that are crucial for its functions and regulations. To date, a multitude of approaches for probing structures of the whole transcriptome, i.e., RNA struc- turomes, have been develop... RNA folds into intricate structures that are crucial for its functions and regulations. To date, a multitude of approaches for probing structures of the whole transcriptome, i.e., RNA struc- turomes, have been developed. Applications of these approaches to different cell lines and tissues have generated a rich resource for the study of RNA structure-function relationships at a systems biology level. In this review, we first introduce the designs of these methods and their applications to study different RNA structuromes. We emphasize their technological differences especially their unique advantages and caveats. We then summarize the structural insights in RNA functions and regulations obtained from the studies of RNA structuromes. And finally, we propose potential directions for future improvements and studies. 展开更多
关键词 RNA structure probing RNA structurome RNA secondary structure structure-function relation-ship RNA regulation
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乳腺癌化疗相关认知障碍患者的脑结构及静息态功能MRI研究进展
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作者 曹帅男 陈飞 戴真煜 《磁共振成像》 CAS CSCD 北大核心 2023年第12期121-126,共6页
乳腺癌患者在接受化疗后常出现化疗相关认知障碍(chemotherapy-related cognitive impairment,CRCI),越来越多的证据表明,CRCI的出现主要是由于大脑结构及功能的改变。MRI可以显示灰质体积/密度的减少、皮质厚度减低、白质微观结构的破... 乳腺癌患者在接受化疗后常出现化疗相关认知障碍(chemotherapy-related cognitive impairment,CRCI),越来越多的证据表明,CRCI的出现主要是由于大脑结构及功能的改变。MRI可以显示灰质体积/密度的减少、皮质厚度减低、白质微观结构的破坏及脑功能或网络连接的异常。本文将脑灰、白质结构成像及静息态功能MRI(resting state functional magnetic resonance imaging,rs-fMRI)技术在乳腺癌CRCI中的相关研究进展进行综述,主要包括三维T1加权成像(three-dimensional T1 weighted imaging,3D-T1WI)、扩散加权成像(diffusion weighted imaging,DTI)在乳腺癌CRCI患者脑灰、白质异常中的研究和rs-fMRI在乳腺癌CRCI患者的脑低频振幅(amplitude of low frequency fluctuation,ALFF)、局部一致性(regional homogeneity,ReHo)、功能连接(functional connectivity,FC)和脑网络改变方面的研究。评估神经成像标志物与乳腺癌化疗轨迹中的认知功能之间的关联,探索CRCI的神经生物学机制,为CRCI提供相对客观的神经影像学标志物。 展开更多
关键词 乳腺癌 化疗相关认知障碍 磁共振成像 结构磁共振成像 功能磁共振成像
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大数据分区管理模型及其应用研究 被引量:12
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作者 张文燚 项连志 王小芳 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2014年第3期353-360,共8页
针对大数据分区管理技术缺乏普遍适用的形式化数据分区模型的问题,引入一个包含痕迹代数系统、结构化状态关系代数系统、多结构化状态关系代数系统的大数据范畴,作为支持大数据分区管理及其相关应用研究的基础理论模型;在此基础上,给出... 针对大数据分区管理技术缺乏普遍适用的形式化数据分区模型的问题,引入一个包含痕迹代数系统、结构化状态关系代数系统、多结构化状态关系代数系统的大数据范畴,作为支持大数据分区管理及其相关应用研究的基础理论模型;在此基础上,给出了以满足"本地充足"为目标的,由基于活动场景和实体实例标识的大数据切片规则,以及面向活动场景的切片分配规则构成的,支持大数据分区管理和快速查询响应的形式化数据分区模型TSEI-PS。TSEI-PS已经在住房和城乡建设部的信息资源统一规划和国家住房信息系统建设中得到了应用。 展开更多
关键词 大数据 形式化数据分区 本地充足 痕迹代数 结构化状态关系代数 多结构化状态关系代数 范畴
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