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Impact point prediction guidance of ballistic missile in high maneuver penetration condition

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Defence Technology（防务技术） 2023年第8期26卷 213-230页

作者： Yong Xian Le-liang Ren Ya-jie Xu shao-peng li Wei Wu Da-qiao Zhang Xi'an Research Institute of High Technology Xi'an710025China Department of Automation Tsinghua UniversityBeijing100084China

An impact point prediction(IPP) guidance based on supervised learning is proposed to address the problem of precise guidance for the ballistic missile in high maneuver penetration *** accurate ballistic trajectory model is applied to generate training samples,and ablation experiments are conducted to determine the mapping relationship between the flight state and the impact *** the same time,the impact point coordinates are decoupled to improve the prediction accuracy,and the sigmoid activation function is improved to ameliorate the prediction ***,an IPP neural network model,which solves the contradiction between the accuracy and the speed of the IPP,is *** view of the performance deviation of the divert control system,the mapping relationship between the guidance parameters and the impact deviation is analysed based on the variational *** addition,a fast iterative model of guidance parameters is designed for reference to the Newton iteration method,which solves the nonlinear strong coupling problem of the guidance parameter *** Carlo simulation results show that the prediction accuracy of the impact point is high,with a 3 σ prediction error of 4.5 m,and the guidance method is robust,with a 3 σ error of 7.5 *** the STM32F407 singlechip microcomputer,a single IPP takes about 2.374 ms,and a single guidance solution takes about9.936 ms,which has a good real-time performance and a certain engineering application value.

关键词： Ballistic missile High maneuver penetration Impact point prediction Supervised learning Online guidance Activation function

Dynamically Tunable and High-Contrast Graphene-Based Terahertz Electro-Optic Modulator

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Communications in Theoretical Physics 2019年第1期71卷 97-102页

作者： shao-peng li Jing Zhou Rui-ling Yin Qi-Bing Sun Department of Physics Shaanxi University of Science & Technology State Key Laboratory of Transient Optics and Photonics Technology Xi'an Institute of Optics and Precision MechanicsChinese Academy of Science (CAS)

We propose and discuss terahertz(THz) electro-optic modulator induced by periodically patterned graphene microcavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot(F-P) oscillations, plasmon-induced transparency(PIT) effect is achieved and the operation frequency can be dynamically tuned by graphene Fermi energies and structural parameters. The results reveal that modulation depth(MD) larger than 80% is obtained across a wide frequency range from 4.2 THz to 9.4 THz, and the largest MD and Q factor reaches 95% and 15.8, respectively. In addition, operation frequency range and MD can also be tuned by optimizing the structure parameters. This investigation promises the development of high-performance widely tunable THz modulator in chip integrated photonic circuits.

关键词： THz modulator graphene

Spatial scaling of soil microbial co-occurrence networks in a fragmented landscape

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mlife 2023年第2期2卷 209-215页

作者： Pandeng Wang shao-peng li Xian Yang Xingfeng Si Wen-Jun li Wensheng Shu lin Jiang State Key Laboratory of Biocontrol School of Ecology&School of Life SciencesSun Yat‐Sen UniversityGuangzhouChina School of Biological Sciences Georgia Institute of TechnologyAtlantaGeorgiaUSA Zhejiang Tiantong Forest Ecosystem National Observation and Research Station School of Ecological and Environmental SciencesEast China Normal UniversityShanghaiChina Institute of Eco‐Chongming(IEC) ShanghaiChina School of life Sciences South China Normal UniversityGuangzhouChina

Impact statement Habitat loss has been a primary threat to ***,species do not function in isolation but often associate with each other and form complex ***,revealing how the network complexity and stability scale with habitat area will give us more insights into the effects of habitat loss on *** this study,we explored the relationships between the island area and the network complexity and stability of soil *** found that the complexity and stability of soil microbial co‐occurrence networks scale positively with island area,indicating that habitat loss will potentially simplify and destabilize soil microbial networks.

关键词： soil habitat networks

Revisiting aerodynamic admittance functions of bridge decks

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第7期21卷 535-552页

作者： lin ZHAO Xi XIE Teng WU shao-peng li Zhi-peng li Yao-jun GE Ahsan KAREEM State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China Key Laboratory of Transport Industry of Wind Resistant Technology for Bridge Structures Tongji UniversityShanghai 200092China Department of Civil Structural and Environmental EngineeringUniversity at BuffaloBuffaloNY 14260USA School of Civil Engineering Central South UniversityChangsha 410000China Department of Civil&Environmental Engineering&Earth Sciences University of Notre DameNotre DameIN 46556USA

A framework was proposed to identify a comprehensive set of aerodynamic admittance functions for bridge decks. The contributions of the cross-spectra between longitudinal and vertical wind velocity components and between turbulence components and gust-induced forces were embedded in the identification procedure. To facilitate application of the identified functions in engineering practice, the concept of an equivalent aerodynamic admittance function was introduced and numerically validated. The equivalent aerodynamic admittance functions of a set of streamlined and bluff cross sections were identified experimentally in a wind tunnel. Buffeting analysis of a bridge deck was carried out and the response predicted using the identified aerodynamic admittance functions compared well with the measured response. In addition, a sensitivity analysis was performed to delineate the influence of aerodynamic and structural parameters on the buffeting response, thereby demonstrating the significance of the proposed identification framework.

关键词： Aerodynamic admittance function Bridge deck Buffeting analysis Wind tunnel test Sensitivity analysis

Design, assembly, and pre-commissioning of cryostat for 3W1 superconducting wiggler magnet

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Nuclear Science and Techniques 2020年第11期31卷 78-92页

作者： Miao-Fu Xu Xiang-Zhen Zhang Rui Ye Fu-San Chen Xiao-Chen Yang Tong-Xian Zhao shao-peng li Xian-Jing Sun liang-Rui Sun Chang-Cheng Ma Rui Ge Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Acceleration Physics and Technology Chinese Academy of SciencesBeijing 100049China Center for Superconducting RF and Cryogenics Institute of High Energy PhysicsBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

One of the most important devices for the High Energy Photon Source Test Facility project,the 2.6 T 32-pole 3W1 superconducting wiggler,was designed by the Institute of High Energy Physics(IHEP);its magnetic gap is 68 mm,and its storage energy is 286 *** will be installed at the storage ring of the Beijing Electron Positron Collider Upgrade Project at the IHEP to replace the old permanent *** primary purpose of the cryostat is to create a safe and reliable system and realize long-term operation with zero liquid helium *** maintain liquid helium temperature,four identical two-stage cryocoolers are placed symmetrically at the wiggler *** cryostat has only one 60 K thermal shield,which is used to reduce the heat load to the liquid helium *** cryostat has several novel features,including a suspension system with little heat leakage that is self-centered during cooling of the cryostat,a special copper liner and high-efficiency condensers,three pairs of binary current leads,and three-level safety *** cryogenic system has been cooled three times,and the residual cooling capacity is approximately 0.41 W at 4.2 K without current.

关键词： Cryostat Cryocooler Superconducting wiggler Superconducting insertion device

某特种车辆主体结构有限元接触问题的一种分析方法

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兵工学报 2007年第1期28卷 107-110页

作者：邵朋礼夏彬中国北方车辆研究所北京100072 中国兵器工业标准化研究所北京100089

对某特种车辆主体结构进行刚度和强度特性的有限元分析,车体上部的旋转塔可以绕其座圈转动,和车体的约束关系比较特殊,属于传统的大型非线性接触问题,这将耗费大量的计算机时。为解决这一问题,尝试使用耦合自由度法代替传统大型接触问... 详细信息

对某特种车辆主体结构进行刚度和强度特性的有限元分析,车体上部的旋转塔可以绕其座圈转动,和车体的约束关系比较特殊,属于传统的大型非线性接触问题,这将耗费大量的计算机时。为解决这一问题,尝试使用耦合自由度法代替传统大型接触问题的求解方法,以模拟车体和旋塔之间的滚珠特性及其约束关系,从而将车体和旋塔作为一个系统,较真实模拟此特种车辆的整车结构强度特性。此车辆受到的载荷工况包括旋塔分别受到火炮向前和向后不同角度的后坐冲击,以及路面障碍所产生的最大10g加速度的整车振动冲击。根据分析结果得出结论:结构静强度是满足要求的,为车体减轻质量设计提供了理论依据;该求解方法是有效的,同样可应用到其它类似大型结构的接触问题分析。

关键词：系统评估与可行性分析特种车辆有限元分析接触问题耦合自由度

Constraints on holographic QCD phase transitions from PTA observations

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 71-78页

作者： Song He li li Sai Wang shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin University School of Physical Science and Technology Ningbo University Max Planck Institute for Gravitational Physics (Albert Einstein Institute) CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences (UCAS) School of Physical Sciences University of Chinese Academy of Sciences (UCAS) Theoretical Physics Division Institute of High Energy Physics Chinese Academy of Sciences

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves(GWs) within the standard model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

物种定殖和丧失驱动近70年森林演替进程中的群落结构动态

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Journal of Plant Ecology 2023年第5期16卷 1-12页

作者： Shan Rao Xin-Yu Miao Shu-Ya Fan Yu-Hao Zhao Chi Xu shao-peng li Zhejiang Tiantong Forest Ecosystem National Observation and Research Station School of Ecological and Environmental SciencesEast China Normal UniversityShanghai 20024lChina School of life Sciences Nanjing UniversityNanjing 210023China Breeding Base for State Key Lab.of Land Degradation and Ecological Restoration in northwestern China Key Lab of Restoration and Reconstruction of Degraded Ecosystems in northwestern China of Ministry of EducationNingxia UniversityYinchuan 750021China

在过去的几十年中,揭示群落谱系和功能性状结构如何随着演替变化引起了广泛关注。但长期动态数据的缺乏限制了我们对于群落格局和构建机制的理解,这一问题在森林群落中尤为突出。本研究基于南京灵谷寺森林1951、1981、2002和2019年的定... 详细信息

在过去的几十年中,揭示群落谱系和功能性状结构如何随着演替变化引起了广泛关注。但长期动态数据的缺乏限制了我们对于群落格局和构建机制的理解,这一问题在森林群落中尤为突出。本研究基于南京灵谷寺森林1951、1981、2002和2019年的定点样带调查数据,分析了这一中国东南部亚热带森林68年的次生演替动态。研究发现,随着演替的深入,群落谱系和性状结构呈现相反的变化趋势。尽管近缘物种间的谱系距离在下降,物种间的平均谱系距离却在增加,群落谱系结构整体上趋于发散。相反,无论用平均还是最近距离作为度量,物种间的性状距离均随着演替逐渐下降,群落功能性状结构趋于聚集。我们进一步拆分了物种定殖和丧失对群落谱系和性状结构动态的相对贡献。结果表明:谱系结构趋于发散主要是由于定殖的物种本身亲缘关系较远,也和群落中原有的物种有着较远的亲缘距离;性状结构趋于聚集主要是因为那些与群落中原有的物种性状相似的物种具有更高的定殖机会但从群落中丧失的概率却更低。这一研究结果表明,拆分物种定殖和丧失过程是解开长期演替进程中群落动态和构建机制的关键。

关键词：群落构建竞争环境过滤森林演替谱系结构功能性状

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铝合金车体抗冲击能力的动态有限元仿真

兵工学报 2009年第1期30卷 1-4页

作者：杜志岐邵朋礼中国北方车辆研究所北京100072

在满足结构强度要求下,严格控制车体重量是空降特种车辆总体设计中需要把握的重要设计准则。通过试验研究简化了着地冲击过程仿真,建立了铝合金车体和焊缝的有限元模型;采用大位移、非线性、动态有限元方法,对于车体着陆过程进行了瞬态... 详细信息

在满足结构强度要求下,严格控制车体重量是空降特种车辆总体设计中需要把握的重要设计准则。通过试验研究简化了着地冲击过程仿真,建立了铝合金车体和焊缝的有限元模型;采用大位移、非线性、动态有限元方法,对于车体着陆过程进行了瞬态有限元结构强度分析和模态分析,得到了不同着陆状态下,车体位移、应力和应变的瞬态分布结果;验证了该有限元模型和分析方法的有效性,为车体结构的优化设计提供了可靠依据。

关键词：机械设计装甲车辆铝合金车体着地冲击有限元方法动态有限元分析