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New developments in control design techniques of logical control networks

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Frontiers of Information Technology & Electronic Engineering 2020年第2期21卷 220-233页

作者： Xiang-shan KONG Shu-ling WANG Hai-tao LI Fuad E.ALSAADI School of Mathematics and Statistics Shandong Normal UniversityJirian 250014China Department of Electrical and Computer Engineering King Abdulaziz UniversityJeddah 21589Saudi Arabia

The control design problem plays a fundamental role in the study of logical control networks(LCNs).This paper presents a detailed survey on new developments in control design techniques of LCNs.First,some preliminary results on the semi-tensor product method and LCNs are reviewed.Then,we move on to some new developments for control design techniques of LCNs,including the reachable set approach,the pinning control technique,the control Lyapunov function approach,the event-triggered control technique,and the sampled-data control technique.Finally,an illustrative example is given to demonstrate the effectiveness of these techniques.

关键词： Logical control network Control design Semi-tensor product of matrices

Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

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Research in Astronomy and Astrophysics 2021年第11期21卷 233-242页

作者： shan-xiang Wei De-Qing kong Qi-Ming Wang Key Laboratory of Lunar and Deep Space Exploration National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector,which will dramatically reduce the aperture efficiency of a radio telescope.To study the non-uniform temperature field of the main reflector of a large radio telescope,numerical calculations including thermal environment factors,the coefficients on convection and radiation,and the shadow boundary of the main reflector are first discussed.In addition,the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis.The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven,and the maximum of the root mean square temperature is 12.3℃.To verify the simulation results,an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day.At the same time,some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure.It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement,and the cosine similarity between the simulation and the measurement is above 90%.Despite the inevitable thermal imaging errors caused by large viewing angles,the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent.The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation.It is credible to calculate the temperature field of the main reflector through the finite element method.This work can provide valuable references for studying the thermal deformati

关键词： large radio telescope finite element analysis solar radiation shadow coverage temperature distribution

Effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope

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Research in Astronomy and Astrophysics 2021年第6期21卷 253-262页

The alidade’s non-uniform temperature field of a large radio telescope is very obvious under solar radiation.Estimating a radio telescope’s pointing errors,caused by the alidade deformation under solar radiation,is significant to improve the telescope’s pointing accuracy.To study the effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope,a temperature experiment is first carried out in a 70-m radio telescope on a sunny day.According to the measured results,the temperature distribution rule of the alidade is summarized initially.In addition,the alidade’s temperature field is calculated by finite element thermal analysis.The simulated results are proved to be in good agreement with the experimental results.Finally,the alidade deformation under solar radiation is computed by finite element thermalstructure coupling analysis.The telescope’s pointing errors caused by alidade deformation are estimated via the alidade’s node displacements.The final results show that the effect of alidade thermal behavior on the telescope’s elevation pointing errorsΔε2+Δεr is much more than the effect on the telescope’s crosselevation pointing errorsΔε1.The maximum ofΔε2+Δεr is more than 45″,while the maximum ofΔε1 is less than 6″.This study can provide valuable references for improving the pointing accuracy of large radio telescopes.

关键词： telescopes finite element analysis thermal behavior pointing accuracy

Interaction of radiation-induced defects with tungsten grain boundaries at across scales: a short review

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Tungsten 2020年第1期2卷 15-33页

作者： xiang‑Yan Li Yan‑Ge Zhang Yi‑Chun Xu Xue‑Bang Wu xiang‑shan kong Xian‑Ping Wang Qian‑Feng Fang Chang‑Song Liu Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031China Key Laboratory for Liquid‑Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China

As promising candidates for plasma-facing materials,tungsten-based materials suffer the irradiation of high-energy neutrons in addition to the hydrogen isotopes and helium irradiation and the high-thermal flux.Radiation-produced defects,e.***.self-interstitial atoms(SIAs)and vacancies(Vs),can induce the hardening and embrittlement of tungsten,meanwhile enhancing the retention of hydrogen isotopes and helium in tungsten.Reducing the grain size of materials to introduce a high density of defect sinks,e.g.,grain boundaries(GBs)prevalent in nano-/ultrafine-crystalline materials,was demonstrated to be an effective approach for mitigating irradiation damage in tungsten.In this paper,we reviewed the theoretical advances in exploring radiation-resistance of nano-structured tungsten at across scales.It was concentrated on the results of molecular dynamics,molecular statics,and the object kinetic Monte Carlo simulations on the fundamental interaction of the radiation-created Vs and SIAs with the GB.These mechanisms include GB-promoted V/SIA migration and SIA-V recombination,interstitial-emission induced annihilation,coupling of the V migration close to the GB with the SIA motion within the GB,and interstitial reflection by the locally dense GB structure.We proposed the remaining scientific issues on the defect-GB interactions at across scales and their relation to experimental observations.We prospected the possible trends for simulating the radiation damage accumulation and healing processes in nano-structured tungsten in terms of the development of the across-scale computational techniques and efficiency of the GB-enhanced tolerance of tungsten to irradiation under complex in-service conditions.

关键词： Nano-crystalline Grain boundary Radiation-resistance Self-healing Radiation damage Tungsten

Polymerization-Amplified Photoacoustic Signal by Enhancing Near-Infrared Light-Harvesting Capacity and Thermal-to-Acoustic Conversion

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Chinese Journal of Polymer Science 2022年第9期40卷 1090-1100页

作者： He-Qi Gao Jing-Tian Zhang Xin-Wen Qi Di Jiao Yu-Ning Hong Ke shan xiang-Long kong Dan Ding Key Laboratory of Bioactive Materials Ministry of Educationand College of Life SciencesNankai UniversityTianjin 300071China Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Department of Chemistry and Physics La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoria3086Australia shandong Artificial intelligence Institute and shandong Computer Science Center Qilu University of TechnologyJinan 250353China

As a frontier imaging technique for biomedical applications,photoacoustic(PA)imaging has been developed rapidly.The development of new design strategies and excellent PA imaging reagents to boost PA conversion is eagerly desirable for high quality PA imaging but complicated to realize.Herein,we develop a new strategy in which PA imaging reagents with better properties can be easily optimized by polymerization.A series of new PA imaging reagents were designed and synthesized.The polymerization strategy can effectively promote the PA signal by specifically increasing the thermal-to-acoustic conversion efficiency.As these materials shared the same building units,the optimized effectiveness of polymerization strategy in terms of near-infrared light-harvesting capacity and thermal-to-acoustic conversion efficiency are discussed,rationally.The polymers with intense intramolecular motion exhibit an amplified PA signal by elevating thermal-to-acoustic conversion and its higher light-harvesting capability at redshifted region.The simultaneously strong PA signal and photothermal conversion efficiency of p-TTmB NPs enable precise PA imaging and effective photothermal therapy.This work highlights a simple and available design guideline of polymerization for amplifying the PA effect and optimizing existing materials.

关键词： Intramolecular motion Thermal-to-acoustic conversion Photoacoustic imaging Photothermal conversion efficiency Polymerization

网络信息对旅游者决策影响研究——国内外研究比较的视角

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人文地理 2016年第5期31卷 7-16,112页

作者：魏宝祥孔闪闪西北师范大学旅游学院兰州730070 西北师范大学西北旅游市场与目的地发展研究中心兰州730070

网络信息对旅游者决策影响研究对旅游业信息化发展及旅游企业市场营销具有重要作用,已成为一大研究热点。本文对其国内外研究成果进行介绍、分析对比,结果表明:国外的网络信息对旅游者搜寻心理影响和网络评价信息、网络口碑信息对旅游... 详细信息

网络信息对旅游者决策影响研究对旅游业信息化发展及旅游企业市场营销具有重要作用,已成为一大研究热点。本文对其国内外研究成果进行介绍、分析对比,结果表明:国外的网络信息对旅游者搜寻心理影响和网络评价信息、网络口碑信息对旅游者决策影响等研究已经成熟,其中,旅游者网络信息搜寻创新心理、网络评价信息对旅游者决策影响因素等是研究热点。国内在网络评价信息对旅游者决策影响研究方面比较薄弱,在旅游者网络信息搜寻创新心理和旅游者网络口碑传播动机研究方面文献寥寥。国外研究视角和方法多样,尤其擅长运用心理学、传播学及社会学等研究方法展开微观层面研究,国内研究多是根据国外研究分析及国内相关情况展开。

关键词：研究综述旅游者决策影响网络信息

内蒙古额济纳旗地下水开采方案及允许开采量评价

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中国人口·资源与环境 2018年第S1期28卷 180-183页

作者：山永祥孔逊青海省核工业地质局青海西宁810016

为解决内蒙古额济纳旗城镇供水问题,在地下水供水水文地质勘察工作基础上,文章系统分析了地下水形成的自然条件、赋存条件,并对地下水的补给量和储存量进行了计算。通过对地下水允许开采量的评价,选定了合适的开采方案,可满足该地区未... 详细信息

为解决内蒙古额济纳旗城镇供水问题,在地下水供水水文地质勘察工作基础上,文章系统分析了地下水形成的自然条件、赋存条件,并对地下水的补给量和储存量进行了计算。通过对地下水允许开采量的评价,选定了合适的开采方案,可满足该地区未来需水量。

关键词：地下水开采方案允许开采量评价额济纳旗

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离农会让农户更愿意退出土地承包权吗?

中国软科学 2020年第11期 61-70页

作者：刘同山孔祥智南京林业大学农村政策研究中心\经济管理学院江苏南京210037 中国人民大学农业与农村发展学院北京100872

随着大量农村人口向城镇转移,中国农户出租农地、离开农业的现象日益普遍。为了考察农户"离农、进城"后是否愿意退出土地承包权,本文在构建经济性占有、情感性占有与农地退出意愿分析框架的基础上,利用黄淮海农区农户调查数据,采用内生... 详细信息

随着大量农村人口向城镇转移,中国农户出租农地、离开农业的现象日益普遍。为了考察农户"离农、进城"后是否愿意退出土地承包权,本文在构建经济性占有、情感性占有与农地退出意愿分析框架的基础上,利用黄淮海农区农户调查数据,采用内生处理Probit模型实证分析了离农对农户土地承包权退出意愿的影响。研究结果表明:部分离农或完全离农都会显著降低农户的土地承包权退出意愿;经济性占有状况越好,农户对土地的情感性占有需要越强,承包权退出意愿越弱;出租农地的离农行为,对农户土地承包权退出意愿有稳定可靠的负向作用。因此,如果政府不采取措施引导和支持"离农、进城"农户有偿退出农村土地,"不在地主"大量出现将难以避免。

关键词：农地出租不在地主土地承包权退出内生处理Probit模型

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确权颁证、子孙传承与农民的承包地转让意愿

中国人口·资源与环境 2019年第3期29卷 159-166页

作者：刘同山孔祥智南京林业大学经济管理学院江苏南京210037 中国人民大学农业与农村发展学院北京100872

农村土地承包权转让是当前中国农村土地制度改革的前沿领域。承包地确权登记颁证工作也正在快速推进。为了更好地理解农民与农村土地的关系从而推进相关改革,本文从农村土地兼具资源资产属性和乡土文化传承功能出发,理论分析了土地确权... 详细信息

农村土地承包权转让是当前中国农村土地制度改革的前沿领域。承包地确权登记颁证工作也正在快速推进。为了更好地理解农民与农村土地的关系从而推进相关改革,本文从农村土地兼具资源资产属性和乡土文化传承功能出发,理论分析了土地确权颁证、子孙情况对农民承包地转让意愿的影响。对中国黄淮海农区6省20县(市、区)998个样本农户的调查数据分析发现,如果一次性给予40年当地最高租金,分别有44. 7%和34. 2%的农民愿意把一部分承包地出售给国家或转让给本集体成员。基于上述调研数据,在将承包地转让分为"出售给政府"和"转让给本集体成员"两种方式后,本文采用可同时处理两个二元选择问题的BiProbit模型估计了是否有承包证以及拥有子孙情况对农民承包地转让意愿的影响,并把子孙情况从三分类变更为二分类进行了重新估计。研究发现:与没有土地承包证相比,拥有承包证的农民愿意把一部分承包地"出售给政府"或"转让给本集体成员"的概率分别高27. 0%、25. 4%;与没有子孙的农民相比,有子孙的农民愿意把一部分承包地"出售给政府"或"转让给本集体成员"的概率分别低25. 7%、26. 8%,上述结果都在5%的水平上显著。可见,确权颁证会强化农民的承包地转让意愿,但农村承包地仍然具有很强的乡土文化传承功能。承包地转让不只是纯法律意义上的物权关系的调整,还受到农民生活方式和乡土文化的影响。因此,需要根据不同类型农民尤其是没有子孙者的承包地转让意愿及差别化政策需求,稳妥有序地推进农村土地承包权转让工作。

关键词：确权颁证子孙传承承包地转让农民意愿