A structural topological optimization method for multi-displacement constraints and any initial topology configuration

In density-based topological design, one expects that the final result consists of elements either black （solid material） or white （void）, without any grey areas. Moreover, one also expects that the optimal topology can be obtained by starting from any initial topology configuration. An improved structural topological optimization method for multidisplacement constraints is proposed in this paper. In the proposed method, the whole optimization process is divided into two optimization adjustment phases and a phase transferring step. Firstly, an optimization model is built to deal with the varied displacement limits, design space adjustments, and reasonable relations between the element stiffness matrix and mass and its element topology variable. Secondly, a procedure is proposed to solve the optimization problem formulated in the first optimization adjustment phase, by starting with a small design space and advancing to a larger deign space. The design space adjustments are automatic when the design domain needs expansions, in which the convergence of the proposed method will not be affected. The final topology obtained by the proposed procedure in the first optimization phase, can approach to the vicinity of the optimum topology. Then, a heuristic algorithm is given to improve the efficiency and make the designed structural topology black/white in both the phase transferring step and the second optimization adjustment phase. And the optimum topology can finally be obtained by the second phase optimization adjustments. Two examples are presented to show that the topologies obtained by the proposed method are of very good 0/1 design distribution property, and the computational efficiency is enhanced by reducing the element number of the design structural finite model during two optimization adjustment phases. And the examples also show that this method is robust and practicable.

Systematic rationalization approach for multivariate correlated alarms based on interpretive structural modeling and Likert scale

Alarm flood is one of the main problems in the alarm systems of industrial process. Alarm root-cause analysis and alarm prioritization are good for alarm flood reduction. This paper proposes a systematic rationalization method for multivariate correlated alarms to realize the root cause analysis and alarm prioritization. An information fusion based interpretive structural model is constructed according to the data-driven partial correlation coefficient calculation and process knowledge modification. This hierarchical multi-layer model is helpful in abnormality propagation path identification and root-cause analysis. Revised Likert scale method is adopted to determine the alarm priority and reduce the blindness of alarm handling. As a case study, the Tennessee Eastman process is utilized to show the effectiveness and validity of proposed approach. Alarm system performance comparison shows that our rationalization methodology can reduce the alarm flood to some extent and improve the performance.

The Impact of the“Belt and Road”Initiative on Industrial Structure Upgrading Along the Corridor

The“Belt and Road”initiative functions as a novel impetus for China’s external economic development within the framework of the new normal of economic growth.By leveraging panel data from 30 provinces and regions across China for the period of 2010 to 2020,this research assesses the influence of the“Belt and Road”initiative on the enhancement of the industrial structure along its trajectory.The findings indicate that:the most notable influence on the rationalization and progress of the industrial structure is observed in the eastern region,with the central region following suit,whereas the western region has yet to exhibit a significant transformation.The analysis delves into the role of technological innovation,concluding that the initiative primarily catalyzes optimization and upgrading through the effect of technological advancement.The study advances several pertinent policy recommendations to support and enhance these developments.

Multivariate Rational Response Surface Approximation of Nodal Displacements of Truss Structures

Polynomial-basis response surface method has some shortcomings for truss structures in structural optimization,concluding the low fitting accuracy and the great computational effort. Based on the theory of approximation, a response surface method based on Multivariate Rational Function basis(MRRSM) is proposed. In order to further reduce the computational workload of MRRSM, focusing on the law between the cross-sectional area and the nodal displacements of truss structure, a conjecture that the determinant of the stiffness matrix and the corresponding elements of adjoint matrix involved in displacement determination are polynomials with the same order as their respective matrices, each term of which is the product of cross-sectional areas, is proposed. The conjecture is proved theoretically for statically determinate truss structure, and is shown corrected by a large number of statically indeterminate truss structures. The theoretical analysis and a large number of numerical examples show that MRRSM has a high fitting accuracy and less computational effort. Efficiency of the structural optimization of truss structures would be enhanced.

Size structure of urban agglomerations in China:rationality evaluation,patterns, and implications

This paper establishes a diagnostic model for assessing the rationality of size structure of urban agglomerations(UAs) in China. The model is designed to determine from a three-dimensional index including size distribution index(SDI), size compactness index(SCI), and size efficiency index(SEI). The spatio-temporal pattern of size structure involving the studied 19 UAs and its implications are explored. The results indicate that size structure of China's UAs advanced from a low rationality development stage to a moderate rationality development stage in 1995-2015.Among them, the SDI and SEI were reasonably high, and the SCI was relatively low. Spatially, the high rationality UAs were distributed across eastern China, while the low rationality UAs were located in western China. UAs with positive size structure possessed typically a dual-or multicenter urban structure, while UAs with negative size structure usually presented as a single-center structure. The evolutionary trajectories of rationality of size structure of UAs can be summarized as four different stages. Our findings suggest that, in addition to consolidating the status of national-level UAs, the development of regional-level UAs should be promoted. Also, the fostering focus and direction should be oriented toward an UA with dual-or multicenter spatial structure.

Dynamic Evaluation of Rationality of Land Use Structure in the Changsha-Zhuzhou-Xiangtan Area

The rationality of land use structure was evaluated with dynamic TOPSIS method based on changing data of land use from 2008 to 2011 in the Changsha-Zhuzhou-Xiangtan area. The results showed that during 2008- 2011,the rationality of land use structure was totally high,the dynamic value hi of Changsha,Zhuzhou,Xiangtan and the Changsha-Zhuzhou-Xiangtan area was 0. 7954,0. 7821,0. 8245 and0. 8186,respectively; the value Ci( tk) reflecting the rationality of land use structure at different time points was rapidly increased,and the gap between regions was not big and shrinking. According to the grey relational analysis,the change of different land use types had different effects on the rationality of land use structure: transportation land,the land for cities,towns and villages and the land for mining and industry are most highly correlated with the rationality of land use structure,while arable land,woodland,water area and water conservancy facility land have also an important impact on the rationality of land use structure; controlling the excessive growth of transportation land,the land for cities,towns and villages and the land for mining and industry,protecting arable land,forest land,water area and water conservancy facility land,and moderately increasing the garden plot,plays a decisive role in optimizing the land use structure in the Changsha-Zhuzhou-Xiangtan area.

Tree-Shaped Timber Structural System

This paper lbcuses on the main characteristics of a tree-shaped timber structural system or simply tree-shaped. One of them is the complexity of its steel connections, responsible for the joint of bar elements, compounding a complex structural system, which requires the application of the CYPECAD software version 2007 to solve the calculations problems. Its efficiency was confirmed by a variety of laboratory tests carried out with the whole structure. The tree-shaped is a timber structure that can be used in a large number of destinations, including residences, malls, sheds, hangars, etc.. Originally, it was conceived based on the well-known masterpiece ＂Sagrada Familia＂, whose author was Architect Antoni Gaudi I Cornet （1852-1926） in Barcelona/Spain. It was designed at the end of 19th century and its construction is still not finished. Gaudi inverted the logical order of the gothic concepts, i.e., light weights below and heavy weights above. Based on this concept, he always had in mind the figure of a tree in nature. The tree-shaped follows the same idea, using timber pieces connected by steel plates. Theoretical and numerical analyses have shown its efficiency and lightness for use in timber structures.

THE RATIONALISM THEORY AND ITS FINITE ELEMENT ANALYSIS METHOD OF SHELL STRUCTURES

In this paper, a kind of rationalism theory of shell is established which is of different mechanic characters in tension and in compression, and the finite element numerical analysis method is also described.

Synthesis and Structural Characterizations of the Heteronuclear Cubane-like Cluster W_2Ag_2S_4(tdt)_2(PPh_3)_2·CH_2Cl_2

A new heterometallic cluster W2Ag2S4(tdt)2(PPh3)2·CH2Cl2(H2tdt=H2CH3C6H3S2)(Ⅱ) has been prepared from the reaction of a well-defined molecular building block W2S4(tdt)22-(I) with Ag complex. The compound has been characterized by X-ray diffraction study, IR., UV-Vis Spectroscopy and cyclic voltammetry.Crystallographic data for the compound are: space group P21/n,a=17.234(4), b=17.622(4), c=19. 094(4) A,β= 99. 22(2)°,V=5704(2) A3, Z=4,final R=0. 042 and Rw=0. 049 for 5983 independent reflections with I≥3σ(I) The structure analysis reveals that the cluster contains a cubane-like core [W2Ag2S4]4+ . The coordination geometry of each tungsten atom is a square pyramid just as that in the building block. Two types of metal-metal bonds of W-W bond and W-Ag bond exist in the core. The distance between two Ag atoms is out of the range of bonding.

基于BIM技术的装配式住宅装修构造设计

装配式住宅是建筑行业中新建住宅应用率较高的建设形式,然而受到生产技术、设计理念的影响,装配式建筑装修时方法较为传统,存在资金、资源、人力浪费严重,施工过程污染高等问题。为充分展现装配式住宅优势,应将基于计算机技术的BIM信息技术手段融入到装修构造设计环节,在装修模块库创建与管理的基础上,可视化分析装配式住宅装修构造设计的缺陷问题,从而有针对性地展开设计优化,以此提升装配式住宅装修构造设计的科学性与合理性,打造高品质的装配式住宅装修工程。

书写理性与感知的《建筑史》

19世纪法国工程师兼建筑史学家奥古斯特·舒瓦西,著有两卷本的巨著—《建筑史》。此书将建造作为贯穿几千年建筑历史的线索,一经出版便引起了学界的巨大反响,并长期作为建筑历史教学的参考文献,对部分现代主义运动先驱及我国近代建筑师理念的形成产生了较为深刻的影响。然而限于语言藩篱、文献缺乏等原因,舒瓦西的著作鲜为国内研究学者所研读,更无针对其写作特点及现代影响的系统性研究发表。本文通过对法文原著及多语言研究成果的阅读与梳理,对舒瓦西的成长历程及建筑历史编纂的原则与基础进行了初步的分析与总结,并得出《建筑史》中结构理性主义、地域视野及如画思想的具体表现与成因,以期进一步追溯与探讨其与现代主义理论的关联。

京津冀数字经济对产业结构升级的影响研究

随着数字技术的发展,以数字经济作为新引擎驱动产业结构升级已经成为共识。为探究京津冀地区数字经济在产业结构升级中发挥的作用,首先进行理论机制分析,之后构建固定效应模型。利用京津冀地区2013—2020年的面板数据,系统分析了数字经济对产业结构升级影响的直接效应和中介效应。结果表明:京津冀地区数字经济发展显著促进了产业结构升级;金融发展是京津冀地区数字经济推动产业结构升级的重要传导路径。据此提出建议:京津冀地区应大力推进数字经济发展,积极引导数字经济赋能金融发展,进而促进产业结构转型升级。

土地财政抑制产业结构合理化实证分析

利用2001年—2019年全国267座城市的面板数据,构建固定效应模型,研究土地财政与产业结构合理化之间的关系,并进一步分析土地财政对产业结构演进影响的区域差异性,可以发现:(1)从全国范围来看,土地财政对我国产业结构合理化进程产生明显的抑制作用;(2)分区域来看,土地财政促进了东部地区的产业结构合理化,但对中部地区具有明显的抑制作用,对西部地区的作用则不显著;(3)经济发展水平和固定资产投资在一定程度上促进了产业结构合理化发展,而交通基础设施、对外开放水平、人力资本存量和人口总量对产业结构合理化具有一定的抑制作用。

机器人应用对制造业结构升级的影响

基于机器人应用与制造业结构升级关系的独特演变规律,文章深入探究了机器人应用如何影响制造业结构升级。研究发现,机器人应用对制造业结构升级具有有限促进作用,只带来制造业结构合理化,而不会带来制造业结构高度化。针对机器人应用与制造业结构合理化的进一步机制检验和异质性分析表明,改善劳动力配置是机器人应用促进制造业结构合理化的重要途径;机器人应用对制造业结构合理化的促进作用在东部地区和劳动力成本较高地区表现得更为强烈。

创新型人力资本对产业结构升级影响的实证研究--基于技术进步的中介效应

在绿色高质量发展的时代背景下,技术创新带来的技术进步是人力资本引导产业结构调整的重要驱动力。基于2005—2020年我国30个省份的面板数据,以技术进步为中介变量建立中介效应回归模型,通过全区域和分区域回归分析,研究创新型人力资本通过技术进步传导路径影响产业结构转型升级的作用机制。研究表明:1)各区域产业结构布局仍存在较大提升空间,都有增加教育、科技投资以提升创新型人力资本存量和质量从而推动产业结构调整升级的需求,且越是经济发达地区,在推动产业结构调整时对创新型人力资本的存量和质量要求越高。2)创新型人力资本能够显著促进全区域范围内技术进步,而欠发达地区创新型人力资本的技术进步效应要明显优于发达地区,发展落后地区创新型人力资本的技术进步效应不明显。3)创新型人力资本可以通过技术进步完全中介效应推动区域整体产业结构合理化发展,但不利于产业结构高级化。分区域来看,发达地区自主创新能力强,自主创新对创新型人力资本提出的高要求会弱化创新型人力资本对产业结构调整升级的间接效应,强化创新型人力资本对产业结构调整升级的直接效应,从而以遮掩效应呈现创新型人力资本对产业结构的间接效应;较发达地区通过技术进步中介效应呈现创新型人力资本对产业结构的间接效应,但因主要以吸收领悟外来技术和在此基础上的模仿创新为技术进步来源,间接效应程度稍低;欠发达地区因“西部大开发”的政策效应驱动,创新型人力资本能够直接影响产业结构调整升级。4)进一步探究创新型人力资本对产业结构调整升级的潜在影响机制,发现投资率对除中部地区以外的创新型人力资本影响产业结构调整升级均具有显著的正向调节效应,金融发展水平对除西部地区以外的创新型人力资本影响产业结构高级化均具有显著的正向调节效应,而对创新型人力资本影响产业结构合理化主要在区域整体和西部地区具有显著的正向调节效应。基于上述研究结果,建议加强创新型人力资本前瞻性培育,积极建立区域人才联合培养机制,加快提升自主技术创新能力,不断优化产业发展外部环境。

新质生产力对共同富裕的影响——基于城乡收入差距的视角

新质生产力的发展进步为实现城乡共同富裕注入新动能。基于2010—2022年我国30个省区市的面板数据,检验新质生产力对城乡共同富裕的影响及作用机制。分析结果表明:新质生产力的发展进步能够有效缩小城乡收入差距,促进共同富裕目标的实现,这一结果在经过内生性检验、稳健性检验后仍成立;异质性检验结果证实对于不同地区而言,新质生产力对城乡共同富裕的驱动作用存在异质性;中介效应检验结果证实产业结构合理化和产业结构高级化在新质生产力驱动共同富裕的过程中发挥部分中介作用。

产业结构、资源错配与绿色全要素生产率

基于2005—2020年长三角地区41个城市的面板数据,从资源错配视角,运用双向固定效应和中介效应模型研究产业结构合理化和高级化对绿色全要素生产率的影响机制。研究发现:(1)产业结构合理化显著抑制了绿色全要素生产率,而高级化显著促进了绿色全要素生产率。(2)从中介效应来看,资本配置不足时,产业结构高级化通过缓解资本错配促进了城市绿色全要素生产率。(3)按城镇化率分组回归,发现不同城镇化类型城市的影响效果存在差异。因此,政府和相关部门应鼓励企业转型升级;加强金融体系建设以减少资本错配,并结合本地资源和发展优势,制定差异化的产业政策,推动绿色全要素生产率的提升。

“可知”到“可感”——结构理性的知觉转向与结构的诗意呈现

该文基于建筑本体与表现的关系,回顾17~20世纪后结构变化发展,阐述结构理性逐渐拓展为强调知觉体验的建构体系,从荷载清晰可视向综合文化地域的复杂性迈进。以结构诗意化表现为切入点,揭示结构与感知的关系,结合案例分析,从结构的模糊表达、结构与空间叠合、结构与材料工艺等方面阐述结构知觉化设计策略,为当代结构的诗意呈现提供设计思路。

数字经济发展对安徽省制造业转型升级影响研究

为探究数字化转型如何推动制造业高质量发展,基于2011—2021年安徽省16地市面板数据,采用熵值法测度各地市数字经济发展水平,运用中介效应和面板门槛模型考察作用机制。研究结果显示,数字经济通过提升地区产业高级化和合理化促进制造业转型升级;科技创新发展水平在数字经济促进产业结构升级中起重要中介作用;经济高质量发展地区数字经济影响制造业转型升级效果更加显著,呈现边际效应递增的非线性特征。