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Uncoupled state space solution to layered poroelastic medium with anisotropic permeability and compressible

Zhiyong AI, Wenze ZENG, Yichong CHENG, Chao WU

《结构与土木工程前沿(英文)》 2011年 第5卷 第2期   页码 171-179 doi: 10.1007/s11709-011-0103-0

摘要: This paper presents an uncoupled state space solution to three-dimensional consolidation of layered poroelastic medium with anisotropic permeability and compressible pore fluid. Starting from the basic equations of poroelastic medium, and introducing intermediate variables, the state space equation usually comprising eight coupled state vectors is uncoupled into two sets of equations of six and two state vectors in the Laplace-Fourier transform domain. Combined with the continuity conditions between adjacent layers and boundary conditions, the uncoupled state space solution of a layered poroelastic medium is obtained by using the transfer matrix method. Numerical results show that the anisotropy of permeability and the compressibility of pore fluid have remarkable influence on the consolidation behavior of poroelastic medium.

关键词: uncoupled state space solution     layered poroelastic medium     three-dimensional consolidation     anisotropic permeability     compressible pore fluid    

Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 287-291 doi: 10.1007/s11465-011-0230-2

摘要:

The dynamic responses of ferroelectric materials upon external mechanical and electrical stimulations are inherently nonlinear and coupled. In the current paper, a macroscopic differential model is constructed for the coupled hysteretic dynamics via modeling the orientation switching induced in the materials. A non-convex potential energy is constructed with both mechanic and electric field contributions. The governing equations are formulated as nonlinear ordinary differential equations by employing the Euler-Lagrange equation, and can be easily recast into a state space form. Hysteresis loops associated with stress induced polarization switching and butterfly-shaped behavior in ferroelectric materials are also successfully captured. The effects of mechanical loadings on the electrically induced switching are numerically investigated, as well as the mechanically-induced switching with various bias electric fields.

关键词: differential model     state space     electromechanical switching     butterfly effects     hysteresis    

基于状态空间法的铁路建设工程过程质量模型研究

鲁守东,周国华,陈海峰,赵国堂

《中国工程科学》 2014年 第16卷 第3期   页码 64-69

摘要:

在ISO9000过程“输入-输出”模型下,过程质量概念很难得到正确的阐释。从过程的“白箱”理论出发,以铁路建设工程的基本作业单元6M1E为例,给出了过程质量概念的科学涵义及过程质量模型。指出基本作业单元系统的过程包括工艺自然过程、作业过程、管理过程;基本作业单元系统的过程质量取决于3个子过程之间的相互联系和相互作用,同时还受到外界扰动输入因素的影响。最后以现浇预应力砼连续箱梁施工过程为例,阐述了该理论在铁路建设工程质量管理中的具体应用。

关键词: 铁路建设工程     “白箱”模型     状态转移方程     过程质量    

从控制论观点审视有限状态自动机的状态空间优化 Research Article

岳菊梅1,闫永义2,陈增强3,邓鹤2

《信息与电子工程前沿(英文)》 2021年 第22卷 第12期   页码 1551-1684 doi: 10.1631/FITEE.2000608

摘要: 现有大多数关于有限状态自动机(finite state machines, FSM)状态空间的优化方法不便甚至不能给出优化的数学意义。

关键词: 有限状态自动机;有限值系统;逻辑系统;逻辑网络;矩阵半张量积;空间优化    

The “Tiangong” Chinese Space Station project

Yang HONG

《工程管理前沿(英文)》 2018年 第5卷 第2期   页码 278-283 doi: 10.15302/J-FEM-2018202

关键词: manned space station     space station project     basic design    

Application and development of modern long-span space structures in China

Shilin DONG, Yang ZHAO, Dong XING

《结构与土木工程前沿(英文)》 2012年 第6卷 第3期   页码 224-239 doi: 10.1007/s11709-012-0166-6

摘要: Modern long-span space structures, developed during the 1970s and 1980s, are light and effective structures based on new technologies and light-weight high-strength materials, such as membranes and steel cables. These structures include air-supported membrane structures, cable-membrane structures, cable truss structures, beam string structures, suspen-domes, cable domes, composite structures of cable dome and single-layer lattice shell, Tensairity structures and so forth. For the premodern space structures widely used since the mid-twentieth century (such as thin shells, space trusses, lattice shells and ordinary cable structures), new space structures have been developed by the combination of different structural forms and materials. The application of prestressing technology and the innovation of structural concepts and configurations are also associated with modern space structures, including composite space trusses, open-web grid structures, polyhedron space frame structures, partial double-layer lattice shells, cable-stayed grid structures, tree-type structures, prestressed segmental steel structures and so forth. This paper provides a review of the structural characteristics and practical applications in China of modern rigid space structures, modern flexible space structures and modern rigid-flexible combined space structures.

关键词: modern long-span space structures     rigid space structures     flexible space structures     rigid-flexible combined space structures     application and development    

基于RTK GPS系统的结构安全监测系统研究

王人鹏,姚连璧,孟晓林

《中国工程科学》 2011年 第13卷 第3期   页码 63-70

摘要:

利用GPS系统在线监测获取的大量结构响应数据,完成了大量数据处理工作,得到了结构响应的时间序列。在此基础上,完成了结构响应的谱分析,初步建立了结构响应的状态空间模型及ARMA(autoregressive moving average method)模型。计算分析结果与大桥通车试验的实测结果及有限元模型预测结果相当吻合。研究表明,基于结构响应的状态空间模型及ARMA模型是评估结构动力性能的有力工具,同时进一步验证了通过RTK GPS系统建立结构安全监测系统的可能性。

关键词: RTK GPS系统     时间序列     状态空间模型     ARMA模型     有限元模型    

统筹空间科学、空间技术、空间应用协调发展的思考

周建平,吴季

《中国工程科学》 2023年 第25卷 第2期   页码 59-66 doi: 10.15302/J-SSCAE-2023.02.007

摘要:

我国航天事业因历史原因和投入限制,在初期以空间技术、空间应用为主,对空间科学重视不足,空间科学、空间技术、空间应用基本上是独立发展的;着眼新时期航天强国建设,需要将空间技术的发展深度融合到空间科学、空间应用中去,从而创造新的机遇和成就。本文剖析了空间科学、空间技术、空间应用的基本内涵并明确三者的相互关系,在系统分析国际空间科学、空间技术、空间应用的整体态势,细致梳理我国相关领域发展情况的基础上,论证了统筹我国空间科学、空间技术、空间应用协调发展的必要性,凝练了三者协调发展面临的主要问题。空间科学、空间技术、空间应用之间既有需求交叉,又可互促带动,应在规划、部署、实施的全过程中进行统筹考虑:发挥新型举国体制优势,在统一管理下做好顶层规划;坚持创新驱动发展战略,以技术进步抢占国际航天制高点;支持空间领域基础研究,培育高水平的科学家和工程师队伍;加强资源统筹协调,促进空间应用数据的合理开放和充分利用。

关键词: 航天事业;空间科学;空间技术;空间应用;协调发展;数据开放共享    

空间物理和空间天气探测与研究

王赤

《中国工程科学》 2008年 第10卷 第6期   页码 41-45

摘要:

空间物理学是1957年人造卫星发射成功后迅速发展起来的一门交叉学科。近50年来,空间已成为人类生存的第四环境,其重要性日益突出。20世纪90年代初,空间物理学与空间应用的密切结合产生了专门研究和预报空间环境中灾害性过程及其变化规律,减轻或防止空间灾害并为人类活动服务的空间天气学。文章简要总结了国外及国内空间物理和空间天气探测的历程和发展趋势,并提出对我国未来空间物理和空间天气探测发展规划和探测路线图的几点建议。

关键词: 空间物理     空间天气     空间物理探测     发展规划    

深空安全研究现状与未来发展

吴克,张哲,杨文飞,何建峰,张天柱,简抗抗,吴伟仁

《中国工程科学》 2022年 第24卷 第4期   页码 240-248 doi: 10.15302/J-SSCAE-2022.04.023

摘要: Managing space radiation risk in the new era of space exploration [R].Managing space radiation risk in the new era of space exploration [R].Human space exploration the next fifty years [J].Human space exploration the next fifty years [J].Human space exploration the next fifty years [J].

关键词: 深空安全     空间辐射威胁     行星保护     太空遗产保护     空间立法    

Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive

《化学科学与工程前沿(英文)》   页码 1623-1631 doi: 10.1007/s11705-022-2202-y

摘要: The number of active components and their dispersion degree are two key factors affecting the performance of adsorbents. Here, we report a simple but efficient strategy for dispersing active components by using a confined space, which is formed by mesoporous silica walls and templates in the as-prepared SBA-15 (AS). Such a confined space does not exist in the conventional support, calcined SBA-15, which does not contain a template. The Cu and Zn precursors were introduced to the confined space in the AS and were converted to CuO and ZnO during calcination, during which the template was also removed. The results show that up to 5 mmol·g–1 of CuO and ZnO can be well dispersed; however, severe aggregation of both oxides takes place in the sample derived from the calcined SBA-15 with the same loading. Confined space in the AS and the strong interactions caused by the abundant hydroxyl groups are responsible for the dispersion of CuO and ZnO. The bimetallic materials were employed for the adsorptive separation of propene and propane. The samples prepared from the as-prepared SBA-15 showed superior performance to their counterparts from the calcined SBA-15 in terms of both adsorption capacity of propene and selectivity for propene/propane.

关键词: bimetallic adsorbents     confined space     mesoporous silica     propene/propane separation    

Corrosion damage assessment and monitoring of large steel space structures

Bo CHEN, You-Lin XU, Weilian QU,

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 354-369 doi: 10.1007/s11709-010-0088-0

摘要: Large steel space structures, when exposed to a harsh corrosive environment, are inevitably subjected to atmospheric corrosion and stress corrosion cracking. This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion. The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced. The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking. Based on the results, the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.

关键词: large steel space structure     atmospheric corrosion     stress corrosion cracking     corrosion damage     damage assessment     monitoring system    

我国航天的成就与发展

王礼恒

《中国工程科学》 2008年 第10卷 第12期   页码 10-12

摘要:

概述了国际航天发展的现状,对国际航天发展的新趋向“新世纪航天新计划”及其特点进行了概括,同时客观地总结了我国航天事业发展所取得的辉煌成就,在此基础上充分地展望了我国航天事业未来的发展愿景。

关键词: 中国航天     航天新计划     中国航天成就    

Advances in tissue state recognition in spinal surgery: a review

Hao Qu, Yu Zhao

《医学前沿(英文)》 2021年 第15卷 第4期   页码 575-584 doi: 10.1007/s11684-020-0816-3

摘要: Spinal disease is an important cause of cervical discomfort, low back pain, radiating pain in the limbs, and neurogenic intermittent claudication, and its incidence is increasing annually. From the etiological viewpoint, these symptoms are directly caused by the compression of the spinal cord, nerve roots, and blood vessels and are most effectively treated with surgery. Spinal surgeries are primarily performed using two different techniques: spinal canal decompression and internal fixation. In the past, tactile sensation was the primary method used by surgeons to understand the state of the tissue within the operating area. However, this method has several disadvantages because of its subjectivity. Therefore, it has become the focus of spinal surgery research so as to strengthen the objectivity of tissue state recognition, improve the accuracy of safe area location, and avoid surgical injury to tissues. Aside from traditional imaging methods, surgical sensing techniques based on force, bioelectrical impedance, and other methods have been gradually developed and tested in the clinical setting. This article reviews the progress of different tissue state recognition methods in spinal surgery and summarizes their advantages and disadvantages.

关键词: spinal surgery     tissue state recognition     image     force sensing     bioelectrical impedance    

Effectiveness of state incentives for promoting wind energy: A panel data examination

Deepak SANGROYA,Jogendra NAYAK

《能源前沿(英文)》 2015年 第9卷 第3期   页码 247-258 doi: 10.1007/s11708-015-0364-8

摘要: Over the last decade, India has started to concentrate earnestly on renewable energy. The Indian government, as well as different state governments, are adopting policy instruments such as feed in tariff, captive consumption, renewable purchase obligation and generation based incentive etc. aimed at renewable energy development. This paper evaluates the effectiveness of state level incentives for the development of wind energy in India. Fixed effect panel data modelling technique of econometric analysis is used to analyse the data of 26 Indian states in 11 years. The results show that feed in tariff and captive consumption are the significant predictors of wind energy development. However, renewable purchase obligation does not affect wind energy significantly.

关键词: India     wind energy development     state incentives     econometric analysis     panel data    

标题 作者 时间 类型 操作

Uncoupled state space solution to layered poroelastic medium with anisotropic permeability and compressible

Zhiyong AI, Wenze ZENG, Yichong CHENG, Chao WU

期刊论文

Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

期刊论文

基于状态空间法的铁路建设工程过程质量模型研究

鲁守东,周国华,陈海峰,赵国堂

期刊论文

从控制论观点审视有限状态自动机的状态空间优化

岳菊梅1,闫永义2,陈增强3,邓鹤2

期刊论文

The “Tiangong” Chinese Space Station project

Yang HONG

期刊论文

Application and development of modern long-span space structures in China

Shilin DONG, Yang ZHAO, Dong XING

期刊论文

基于RTK GPS系统的结构安全监测系统研究

王人鹏,姚连璧,孟晓林

期刊论文

统筹空间科学、空间技术、空间应用协调发展的思考

周建平,吴季

期刊论文

空间物理和空间天气探测与研究

王赤

期刊论文

深空安全研究现状与未来发展

吴克,张哲,杨文飞,何建峰,张天柱,简抗抗,吴伟仁

期刊论文

Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive

期刊论文

Corrosion damage assessment and monitoring of large steel space structures

Bo CHEN, You-Lin XU, Weilian QU,

期刊论文

我国航天的成就与发展

王礼恒

期刊论文

Advances in tissue state recognition in spinal surgery: a review

Hao Qu, Yu Zhao

期刊论文

Effectiveness of state incentives for promoting wind energy: A panel data examination

Deepak SANGROYA,Jogendra NAYAK

期刊论文