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二阶不稳定时滞过程的二次优化控制及结构整形 被引量:3
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作者 余艳 王钦若 +1 位作者 项国波 黄旭明 《信息与控制》 CSCD 北大核心 2016年第2期223-228,共6页
针对一类二阶不稳定时滞系统的抗扰动鲁棒性和动态响应问题,提出二次优化控制结构整形的方法来实现其优化控制.首先运用二次优化控制原理,设计系统的无穷维控制器和观测器.然后再用增强局部反馈Kf的结构整形方法,来消除其过渡过程中出... 针对一类二阶不稳定时滞系统的抗扰动鲁棒性和动态响应问题,提出二次优化控制结构整形的方法来实现其优化控制.首先运用二次优化控制原理,设计系统的无穷维控制器和观测器.然后再用增强局部反馈Kf的结构整形方法,来消除其过渡过程中出现的微振现象.最后通过实例仿真与内模滤波器PID(proportionalintegral-derivative)、改进型Smith两种方案作对比研究,证明了本文方法在跟踪响应以及抗扰动鲁棒性方面的优越性. 展开更多
关键词 二阶不稳定时滞过程 二次优化控制 结构整形 鲁棒性
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4f结构脉冲整形器失调对光场空间分布的影响 被引量:2
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作者 陈瑜婷 张诗按 +3 位作者 孙真荣 王祖赓 徐至展 李儒新 《量子光学学报》 CSCD 2004年第2期73-76,共4页
利用零色散脉冲整形装置的模型,从理论上详细讨论了4f结构脉冲整形装置中第一光栅和第一凸透镜之间距离失调、两凸透镜之间距离失调以及第二凸透镜与第二光栅之间距离失调对输出脉冲空间特性的影响。
关键词 4f结构脉冲整形 脉冲整形 失调
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功能性鼻整形的发展历程与临床进展 被引量:4
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作者 余庆雄 宋楠 +2 位作者 戴传昌 李圣利 张天宇 《中国耳鼻咽喉颅底外科杂志》 CAS CSCD 2024年第1期41-48,共8页
现代鼻整形技术发展至今历时百余年,期间耳鼻咽喉科医生和整形外科医生分别在各自领域推动鼻整形的发展。本文介绍了现代鼻整形技术的发展历程与临床进展,包括由鼻科学中发展出的功能性鼻整形和整形外科学中发展出的美容性鼻整形。鼻整... 现代鼻整形技术发展至今历时百余年,期间耳鼻咽喉科医生和整形外科医生分别在各自领域推动鼻整形的发展。本文介绍了现代鼻整形技术的发展历程与临床进展,包括由鼻科学中发展出的功能性鼻整形和整形外科学中发展出的美容性鼻整形。鼻整形技术由开始的切除性鼻整形发展至结构性鼻整形,以及近几年提出的保留性鼻整形,功能保护的重要性在鼻整形中愈来愈被认识。随着学科的发展与融合,功能性鼻整形的理念有待进一步拓展,以适应未来鼻整形领域的发展。 展开更多
关键词 整形 功能性鼻整形 结构性鼻整形 保留性鼻整形 鼻腔通气
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波形梁钢护栏旧板翻新方法 被引量:1
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作者 陈玉贤 乔东兴 +2 位作者 周琪玲 王文斌 张应龙 《兰州石化职业技术大学学报》 2024年第1期32-35,共4页
针对公路改建或扩建时,原公路所用的旧波形护栏被大量报废的问题,研发了一项护栏翻新技术。该技术的工艺流程主要包括翻新准备、旧板挑选、旧板结构整形、旧板除漆除锈、环氧锌基聚酯复合涂层喷涂以及成品包装码垛。技术的关键点在于旧... 针对公路改建或扩建时,原公路所用的旧波形护栏被大量报废的问题,研发了一项护栏翻新技术。该技术的工艺流程主要包括翻新准备、旧板挑选、旧板结构整形、旧板除漆除锈、环氧锌基聚酯复合涂层喷涂以及成品包装码垛。技术的关键点在于旧护栏板结构整形、旧板除漆除锈和环氧锌基聚酯复合涂层喷涂三部分,可使旧护栏板满足防撞等级要求、外观要求和使用性能要求,有效解决了旧护栏板的报废处理而带来的资源消耗和浪费问题。通过护栏板翻新技术,使翻新后的护栏板满足使用要求,实现旧护栏板的再利用,从而节约钢铁资源,减少护栏的加工工序,降低了公路的建设成本,具备一定的经济效益和社会效益。 展开更多
关键词 波形护栏 结构整形 除漆除锈 抛丸 表面处理 喷涂翻新
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公路波形梁钢护栏改造技术
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作者 王振盛 《设备管理与维修》 2023年第10期94-95,共2页
结合工程实例,总结某公路所用的波形梁钢护栏改造工艺原理,对施工准备工作、旧板清理、挑选、码堆、旧板结构整形、旧板冲孔、旧板打磨清洗、高性能水性环氧富锌底漆的制备、底漆喷涂工艺、面漆喷涂、成品包装码堆等改造施工工艺进行分... 结合工程实例,总结某公路所用的波形梁钢护栏改造工艺原理,对施工准备工作、旧板清理、挑选、码堆、旧板结构整形、旧板冲孔、旧板打磨清洗、高性能水性环氧富锌底漆的制备、底漆喷涂工艺、面漆喷涂、成品包装码堆等改造施工工艺进行分析,并对其进行质量验收。结果表明,此改造技术为公路波形梁钢护栏的翻新改造提供了实践经验,降低公路的运营成本。 展开更多
关键词 公路 波形梁钢护栏 翻新 结构整形 喷涂
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Morphology effect of zirconia support on the catalytic performance of supported Ni catalysts for dry reforming of methane 被引量:5
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作者 李伟作 赵忠奎 +1 位作者 焦艳华 王桂茹 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第12期2122-2133,共12页
An immature pinecone shaped hierarchically structured zirconia (ZrO2-ipch) and a cobblestone-like zirconia nanoparticulate (ZrO2-cs), both with the monoclinic phase (m-phase), were synthesized by the facile hydr... An immature pinecone shaped hierarchically structured zirconia (ZrO2-ipch) and a cobblestone-like zirconia nanoparticulate (ZrO2-cs), both with the monoclinic phase (m-phase), were synthesized by the facile hydrothermal method and used as the support for a Ni catalyst for the dry reforming of methane (DRM) with CO2. ZrO2-ipch is a much better support than ZrO2-cs and the traditional ZrO2 irregular particles made by a simple precipitation method (ZrO2-ip). The supported Ni catalyst on ZrO2-ipch (Ni/ZrO2-ipch) exhibited outstanding catalytic activity and coke-resistant stability compared to the ones on ZrO2-cs (Ni/ZrO2-cs) and ZrO2-ip (Ni/ZrO2-ip). Ni/ZrO2-ip exhibited the worst catalytic performance. The origin of the significantly enhanced catalytic performance was revealed by characterization including XRD, N2 adsorption measurement (BET), TEM, H2-TPR, CO chemisorption, CO2-TPD, XPS and TGA. The superior catalytic activity of Ni/ZrO2-ipch to Ni/ZrO2-cs or Ni/ZrO2-ip was ascribed to a higher Ni dispersion, increased reducibility, enhanced oxygen mo- bility, and more basic sites with a higher strength, which were due to the unique hierarchically structural morphology of the ZrO2-ipch support. Ni/ZrO2-ipch exhibited better stability for the DRM reaction than Ni/ZrO2-ip, which was ascribed to its higher resistance to Ni sintering due to a strengthened metal-support interaction and the confinement effect of the mesopores and coke deposition resistance. The higher coking resistance of Ni/ZrO2-ipch for the DRM reaction in comparison with Ni/ZrOz-ip orignated from the coke-removalabitity of the higher amount of lattice oxygen and more basic sites, confirmed by XPS and CO2-TPD analysis, and the stabilized Ni on the Ni/ZrO2-ipch catalyst by the confinement effect of the mesopores of the hierarchical ZrO2-ipch sup- port. The superior catalytic performance and coking resistance of the Ni/ZrO2-ipch catalyst makes it a promising candidate for synthesis gas production from the DRM reaction. 展开更多
关键词 Ni-based catalystZrO2 supportHierarchical structure Morphology effect Dry reforming of methane Synthesis gas Coke resistance
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Suburbanization and Subcentering of Population in Beijing Metropolitan Area:A Nonparametric Analysis 被引量:3
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作者 SUN Tieshan HAN Zhenhai +1 位作者 WANG Lanlan LI Guoping 《Chinese Geographical Science》 SCIE CSCD 2012年第4期472-482,共11页
This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic... This study focuses on the suburbanization and subcentering of population and examines the nature of spatial restructuring in terms of the population distribution in the Beijing metropolitan area.Instead of the classic density function approach,we employ the nonparametric analysis to characterize the spatial pattern of population densities in the Beijing metropolitan area and identify the suburban subcenters.Our findings suggest that the population has spread with rapid urban growth in the Beijing metropolitan area,and the compact urban form has been replaced by a more dispersed polycentric spatial distribution.However,compared with the decentralization of western cities,the spatial extent of the decentralization of population in the Beijing metropolitan area is quite limited.The rapid growth of population in the near suburbs has expedited the sprawl of the central city,with a larger central agglomeration of population dominating the metropolitan area.In this sense,the spatial pattern of the Beijing metropolitan area is still characterized by the continuous compactness.However,our findings do provide the evidence that the city has been turning to a polycentric structure.We find significant population subcenters have emerged in the suburbs of Beijing since the 1980s.But the polycentricity emerged in the Beijing metropolitan area is very different by nature from that observed in Western cities.The subcenters emerged are adherent to the development scheme planned for the city,so it can be referred to as the so called 'planned polycentricity'. 展开更多
关键词 SUBURBANIZATION population subcenters POLYCENTRICITY urban spatial structure Beijing metropolitan area
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Safe Space of Ideology
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作者 Wojciech Barttomiej Zielifiski 《Journal of Philosophy Study》 2014年第7期486-491,共6页
Our studies about safety in society lead us to the most popular book by Karl Mannheim: Ideology and Utopia. This work envisages the discrepancies between social knowledge and the material world itself. The crucial co... Our studies about safety in society lead us to the most popular book by Karl Mannheim: Ideology and Utopia. This work envisages the discrepancies between social knowledge and the material world itself. The crucial conclusion reads as follows: Our image of reality is mostly based on our interests and desires and does not rely on thorough research. There are two types of such representations: utopia and ideology. The first of them, less interesting for us, is the type of ideas which can revolutionize a social being. The second one is a particular set of visions which can never be realized but on the other hand they act as common knowledge (general knowledge of the world)--stabilizing the social structure by presenting it with a holistic image of the world. Taking the above into consideration, how is it possible that representations, being so distant from reality (creating a completely separate "world"), basically enable efficient functioning in it? Ideology, being the foundation of the society's functioning space, should always be tautological, in the sense that for the participants of the given world's image (creation as it is), it should define the being in a comprehensive and adequate way (in Thomas Aquinas spirit). What is more, it would always be true. We should also mention that the main tools of ideology, understood this way, are specific definitions and the extrapolation of sense. The purpose of this lecture is to prove that it is possible for ideology to come to life, only when the individuals who acknowledge it will consider their image of reality proper. The above ideological system should be understood as the obviousness of description of the surrounding world which in return makes unreflective functioning in reality possible. This obviousness of the presented world will be referred to as social safety. 展开更多
关键词 IDEOLOGY safety KNOWLEDGE EPISTEMOLOGY Karl Mannheim Karol Marx LINGUISTICS
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保留性鼻整形临床研究进展及对东方人鼻整形应用的探讨 被引量:5
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作者 孙一丹 安阳 +1 位作者 李东 赵振民 《中国美容整形外科杂志》 CAS 2021年第5期274-276,318,共4页
鼻整形术的发展通常与术式的创新密切相关。为了改善鼻功能和获得美学效果,近年来,保留性鼻整形术在西方鼻整形界得到了广泛应用。世界各地的整形外科医师也对保留性鼻整形的手术方法和适应证展开了广泛的探讨,特别是鼻尖和鼻背的保留... 鼻整形术的发展通常与术式的创新密切相关。为了改善鼻功能和获得美学效果,近年来,保留性鼻整形术在西方鼻整形界得到了广泛应用。世界各地的整形外科医师也对保留性鼻整形的手术方法和适应证展开了广泛的探讨,特别是鼻尖和鼻背的保留问题。现对目前西方保留性鼻整形手术的临床应用进展、鼻整形手术的适应证、禁忌证及并发症作一综述,并对保留性鼻整形在东方人应用的可行性进行探讨。 展开更多
关键词 保留性鼻整形 结构性鼻整形 适应症 并发症 临床进展
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论公路项目波形梁钢护栏旧板翻新技术 被引量:1
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作者 郑彬 《交通科技与管理》 2022年第15期70-72,共3页
为实现公路改扩建工程中波形梁钢护栏的循环利用引入旧板翻新技术,其基本原理是先清理校直波形梁钢护栏,再采用喷涂工艺翻新,其关键在于旧板校直、涂料喷涂,可有效改善旧板外观,确保旧板满足防撞要求,解决波形梁护栏旧板直接报废带来的... 为实现公路改扩建工程中波形梁钢护栏的循环利用引入旧板翻新技术,其基本原理是先清理校直波形梁钢护栏,再采用喷涂工艺翻新,其关键在于旧板校直、涂料喷涂,可有效改善旧板外观,确保旧板满足防撞要求,解决波形梁护栏旧板直接报废带来的资源浪费问题,减少环境污染,降低公路改扩建工程造价。基于此,文章针对公路项目波形梁钢护栏旧板翻新技术进行研究,结合实例项目对其工艺原理、流程及操作要点进行分析,并提出相关质量控制措施。 展开更多
关键词 波形梁钢护栏 旧板翻新 结构整形 喷涂翻新 水性环氧富锌底漆
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SPECIAL ISSUE: DISTRIBUTION OF NATIONAL INCOME IN A TRANSITIONAL ECONOMY Changes in the labor share of GDP: a U-shaped curve 被引量:3
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作者 David Daokui Li Liu Linlin Wang Hongling 《Social Sciences in China》 2009年第4期131-153,共23页
In this paper, we try to find some general rules and the structural factors that cause a fall in labor economic growth in countries all over the world, the by a U-shaped curve in which the tuming point is for labor sh... In this paper, we try to find some general rules and the structural factors that cause a fall in labor economic growth in countries all over the world, the by a U-shaped curve in which the tuming point is for labor share in primary distribution share. We show that, in the process of evolution of labor share is characterized $6,000 per capita GDP (in PPP, 2000). We develop a model to explain this phenomenon that provides an in-depth explanation for Kuznets' inverted U hypothesis. Our findings indicate that the evolution of China's labor share is basically consistent with the model we have constructed. In addition, sectoral composition and the relative bargaining power of labor are also factors influencing labor share. These findings imply that labor share of primary distribution in China may enter an upward trajectory over the next two years. This process may be accelerated by the central government's policies for dealing with global financial crisis and by structural adjustment. 展开更多
关键词 primary distribution labor share bargaining power of labor
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