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太空遗产保护 1

深空安全 1

空间立法 1

空间辐射威胁 1

自主制导方法；定点软着陆；动力下降；非线性规划 1

行星保护 1

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Principle and curve of planetary indexing cam mechanisms

LIU Ming-tao, ZHANG Ce, YANG Yu-hu

《机械工程前沿（英文）》 2006年 第1卷 第4期   页码 475-478 doi: 10.1007/s11465-006-0063-6

摘要： A new type of planetary indexing cam mechanism called type !c is presented. The transmission principle of type !c is discussed. Based on the principle of formation of conjugate tooth contour, the equations of the cam s pitch curve are derived. The continuity and symmetry of the cam s pitch curve are also analyzed. It can be concluded that: 1) This type has no output institution so the output precision can be improved; 2) The asymmetrical two-ring structure is used to overcome dead point and its phase angle is equal to (π - 2π/n); 3) The continuous condition of the cam s pitch curve is that the average transmission ratio is -n in an intermittent motion period.

关键词： continuity     planetary     average transmission     symmetry     intermittent    

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Analysis of planetary gear transmission in non-stationary operations

Fakher CHAARI, Mohamed Slim ABBES, Fernando Viadero RUEDA, Alfonso Fernandez del RINCON, Mohamed HADDAR

《机械工程前沿（英文）》 2013年 第8卷 第1期   页码 88-94 doi: 10.1007/s11465-013-0361-8

摘要：

Planetary gearboxes operate usually in non-stationary conditions generated mainly by variable loads applied to these transmissions. In order to understand the dynamic behavior of planetary gearboxes in such conditions, a mathematic model is developed including driving unit, transmission and load. The variability of load induces a variable speed of the transmission which is taken into account when characterizing the main dynamic parameter of the transmission which is the mesh stiffness function. This function is not periodic following the variability of the transmission speed. The computation of the dynamic response shows an intimate relation between the vibration amplitude level and the load value. As the load increase the vibration level increase. A combined amplitude and frequency modulation is observed which is well characterized using Short Time Fourier transform more suited than the spectral analysis.

关键词： planetary gearbox     non-stationary conditions     variable load     dynamic response     time frequency analysis    

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Planet position errors in planetary transmission: Effect on load sharing and transmission error

Miguel IGLESIAS, Alfonso FERNáNDEZ, Ana DE-JUAN, Ramón SANCIBRIáN, Pablo GARCíA

《机械工程前沿（英文）》 2013年 第8卷 第1期   页码 80-87 doi: 10.1007/s11465-013-0362-7

摘要：

In this paper an advanced model of spur gear transmissions developed by the authors is used to study the influence of carrier planet pin hole position errors on the behaviour of the transmission. The model, initially conceived for external gear modeling, has been extended with internal meshing features, and thus increasing its capabilities to include planetary transmission modeling. The new features are presented, along with the summary of the model general approach. The parameters and characteristics of the planetary transmission used in the paper are introduced. The influence of carrier planet pin hole position errors on the planet load sharing is studied, and several static cases are given as examples in order to show the ability of the model. Tangential and radial planet pin hole position errors are considered independently, and the effect of the load level is also taken into account. It is also given attention to the effect on the transmission error of the transmission. Two different configurations for the planetary transmission are used, attending to the fixed or floating condition of the sun, and the differences in terms of load sharing ratio are shown.

关键词： gear     planetary     epicyclic     transmission     load sharing     transmission error    

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美国DART航天器尽显小行星防御潜力

Chris Palmer

《工程（英文）》 2023年 第24卷 第5期   页码 7-9 doi: 10.1016/j.eng.2023.03.002

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Developing a new agenda for increased food and climate security

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023514

摘要：

● The urgent need to address increasing worldwide food and climate insecurity.

关键词： climate resilience     food security     human health     planetary health     regenerative agriculture    

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Advantageous mechanochemical synthesis of copper(I) selenide semiconductor, characterization, and properties

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 433-442 doi: 10.1007/s11705-021-2066-6

摘要： Copper(I) selenide-nanocrystalline semiconductor was synthesized via one-step mechanochemical synthesis after 5 min milling in a planetary ball mill. The kinetics of synthesis was followed by X-ray powder diffraction analysis and specific surface area measurements of milled 2Cu/Se mixtures. The X-ray diffraction confirmed the orthorhombic crystal structure of Cu2Se with the crystallite size ~25 nm. The surface chemical structure was studied by X-ray photoelectron spectroscopy, whereby the binding energy of the Cu 2p and Se 3d signals corresponded to Cu+ and Se2– oxidation states. Transmission electron microscopy revealed agglomerated nanocrystals and confirmed their orthorhombic structure, as well. The optical properties were studied utilizing ultraviolet-visible spectroscopy and photoluminescence spectroscopy. The direct bandgap energy 3.7 eV indicated a blue-shift phenomenon due to the quantum size effect. This type of Cu2Se synthesis can be easily adapted to production dimensions using an industrial vibratory mill. The advantages of mechanochemical synthesis represent the potential for inexpensive, environmentally-friendly, and waste-free manufacturing of Cu2Se.

关键词： Cu2Se     berzelianite     nanocrystalline semiconductor     mechanochemical synthesis     planetary ball mill    

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Coordinated shift control of nonsynchronizer transmission for electric vehicles based on dynamic tooth alignment

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 887-900 doi: 10.1007/s11465-021-0653-3

摘要： Multispeed transmissions can enhance the dynamics and economic performance of electric vehicles (EVs), but the coordinated control of the drive motor and gear shift mechanism during gear shifting is still a difficult challenge because gear shifting may cause discomfort to the occupants. To improve the swiftness of gear shifting, this paper proposes a coordinated shift control method based on the dynamic tooth alignment (DTA) algorithm for nonsynchronizer automated mechanical transmissions (NSAMTs) of EVs. After the speed difference between the sleeve (SL) and target dog gear is reduced to a certain value by speed synchronization, angle synchronization is adopted to synchronize the SL quickly to the target tooth slot’s angular position predicted by the DTA. A two-speed planetary NSAMT is taken as an example to carry out comparative simulations and bench experiments. Results show that gear shifting duration and maximum jerk are reduced under the shift control with the proposed method, which proves the effectiveness of the proposed coordinated shift control method with DTA.

关键词： electric vehicle     nonsynchronizer automated mechanical transmission (NSAMT)     planetary gear     coordinated shift control     dynamic tooth alignment    

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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： Analysis of planetary quarantine requirements [R].The evolution of planetary protection implementation on Mars landed missions [C].Europa planetary protection for Juno Jupiter orbiter [J].The European standard on planetary protection requirements [J].Planetary protection provisions for robotic extraterrestrial missions [EBOL]. 2011-03-20 [ 2022-05-

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    

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Planetary Homeostasis of Reactive Nitrogen Through Anaerobic Ammonium Oxidation

Guibing Zhu,Bangrui Lan,Shuci Liu,Cameron M. Callbeck,Shanyun Wang,Liping Jiang,Asheesh Kumar Yadav,Jan Vymazal,Mike S. M. Jetten,Ganlin Zhang,Yongguan Zhu,

《工程（英文）》 doi: 10.1016/j.eng.2023.09.013

摘要： The availability of nitrogen (N) is crucial for both the productivity of terrestrial and aquatic ecosystems globally. However, the overuse of artificial fertilizers and the energy required to fix nitrogen have pushed the global nitrogen cycle (N-cycle) past its safe operating limits, leading to severe nitrogen pollution and the production of significant amounts of greenhouse gas nitrous oxide (N2O). The anaerobic ammonium oxidation (anammox) mechanism can counteract the release of ammonium and N2O in many oxygen-limited situations, assisting in the restoration of the homeostasis of the Earth’s N biogeochemistry. In this work, we looked into the characteristics of the anammox hotspots’ distribution across various types of ecosystems worldwide. Anammox hotspots are present at diverse oxic–anoxic interfaces in terrestrial systems, and they are most prevalent at the oxic–anoxic transition zone in aquatic ecosystems. Based on the discovery of an anammox hotspot capable of oxidizing ammonium anoxically into N2 without N2O by-product, we then designed an innovative concept and technical routes of nature-based anammox hotspot geoengineering for climate change, biodiversity loss, and efficient utilization of water resources. After 15 years of actual use, anammox hotspot geoengineering has proven to be effective in ensuring clean drinking water, regulating the climate, fostering plant and animal diversity, and enhancing long-term environmental quality. The sustainable biogeoengineering of anammox could be a workable natural remedy to resolve the conflicts between environmental pollution and food security connected to N management.

关键词： biogeochemical N-cycle     oxic–anoxic interface     nature-based solution     biogeoengineering     nitrogen sustainable development    

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Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

Aijun Ding,Wei Nie,Xin Huang,Xuguang Chi,Jianning Sun,Veli-Matti Kerminen,Zheng Xu,Weidong Guo,Tuukka Petäjä,Xiuqun Yang,Markku Kulmala,Congbin Fu

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0877-3

摘要： The concept design and detailed information of the SORPES station are introduced. Main scientific findings based 5-year measurements at the station are summarized. The future outlook of the development plan and its implications are discussed. The results improved understanding of interaction of physical and chemical processes. More SORPES-type stations are need to in different regions in China and the world. This work presents an overall introduction to the Station for Observing Regional Processes of the Earth System – SORPES in Nanjing, East China, and gives an overview about main scientific findings in studies of air pollution-weather/climate interactions obtained since 2011. The main results summarized in this paper include overall characteristics of trace gases and aerosols, chemical transformation mechanisms for secondary pollutants like O , HONO and secondary inorganic aerosols, and the air pollution – weather/climate interactions and feedbacks in mixed air pollution plumes from sources like fossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.

关键词： Secondary pollution     Ground-based measurement     Planetary boundary layer meteorology     Earth system processes    

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行星表面动力着陆自主制导方法综述 Review

宋征宇1,5,王聪2,Stephan THEIL3,David SEELBINDER3,Marco SAGLIANO3,刘新福4,邵之江5

《信息与电子工程前沿（英文）》 2020年 第21卷 第5期   页码 649-808 doi: 10.1631/FITEE.1900458

摘要： 本文总结了天体表面精确软着陆的自主制导方法。首先回顾了动力下降制导方法的发展，重点介绍了其在约束处理和提升计算效率方面的贡献。随着对可重复使用运载器需求的不断增加，以及太空探索带来更多的科学回报，定点软着陆成为一项基本要求。不同于过去任务中公里级的着陆精度，未来行星着陆器在满足全部速度和姿态约束条件下，着陆位置精度要达到10米级，这项任务的困难引起学者对自主制导方法的兴趣。本文讨论了动力下降阶段一般性的3自由度和6自由度优化问题，并对比月球、火星和地球3种典型着陆场景的特点。在此基础上，通过比较解析制导方法、数值优化算法和基于学习的方法，详细阐述自主制导方法的特点和适应性，并讨论非凸问题的凸化处理和求解策略。随后提出自主制导方法工程应用的3个关键问题：物理可行性、模型精度和实时性。最后，简要介绍各国航天组织（包括美国、中国、法国、德国和日本）研发的垂直起降验证飞行器，以及目前在验证飞行器上开展的制导方法试验工作。

关键词： 自主制导方法；定点软着陆；动力下降；非线性规划    

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标题 作者 时间 类型 操作

Principle and curve of planetary indexing cam mechanisms

LIU Ming-tao, ZHANG Ce, YANG Yu-hu

期刊论文

Analysis of planetary gear transmission in non-stationary operations

Fakher CHAARI, Mohamed Slim ABBES, Fernando Viadero RUEDA, Alfonso Fernandez del RINCON, Mohamed HADDAR

期刊论文

Planet position errors in planetary transmission: Effect on load sharing and transmission error

Miguel IGLESIAS, Alfonso FERNáNDEZ, Ana DE-JUAN, Ramón SANCIBRIáN, Pablo GARCíA

期刊论文

美国DART航天器尽显小行星防御潜力

Chris Palmer

期刊论文

Developing a new agenda for increased food and climate security

期刊论文

Advantageous mechanochemical synthesis of copper(I) selenide semiconductor, characterization, and properties

期刊论文

Coordinated shift control of nonsynchronizer transmission for electric vehicles based on dynamic tooth alignment

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

Planetary Homeostasis of Reactive Nitrogen Through Anaerobic Ammonium Oxidation

Guibing Zhu,Bangrui Lan,Shuci Liu,Cameron M. Callbeck,Shanyun Wang,Liping Jiang,Asheesh Kumar Yadav,Jan Vymazal,Mike S. M. Jetten,Ganlin Zhang,Yongguan Zhu,

期刊论文

Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

Aijun Ding,Wei Nie,Xin Huang,Xuguang Chi,Jianning Sun,Veli-Matti Kerminen,Zheng Xu,Weidong Guo,Tuukka Petäjä,Xiuqun Yang,Markku Kulmala,Congbin Fu

期刊论文

行星表面动力着陆自主制导方法综述

宋征宇1,5,王聪2,Stephan THEIL3,David SEELBINDER3,Marco SAGLIANO3,刘新福4,邵之江5

期刊论文