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Design and Cryogenic Performance of a Hexapod Platform for a Large Ground-based Wide Field Survey Telescope

Research in Astronomy and Astrophysics 2024年第1期24卷 178-187页

作者： Yang Yu Xue-Wen Wang Yu Zhang jia-lin sun Zhen-Bang Xu jian-Li Wang Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Chinese Academy of Sciences Key Laboratory of On-orbit Manufacturing and Integration for Space Optics System Changchun 130033China University of Chinese Academy of Sciences Beijing 100049China

The thermal gradient is an important factor that causes degradation to the image quality of telescopes. In order to ensure the accurate alignment of the primary focus unit and the primary mirror, the hexapod platform(as a corrector) is investigated in this paper. First, a ground-based telescope with 2.5 m aperture and 3.5 deg field of view is described. The telescope is under construction, and it is expected to be finished in 2023. Second, the hexapod platform with flexure hinges utilized to adjust the primary focus unit is proposed, which is applied as a ***, the inverse kinematics of the platform is established and an open-loop control system is built based on ***, the cryogenic performance test for the hexapod platform is performed. The experimental results show that the resolution and repeatability of the translation for the hexapod platform can be achieved at the micrometer *** resolution and repeatability of the rotation can be achieved at the arc-second level. Therefore, the cryogenic performance of the hexapod platform can meet the optical imaging requirements of the wide-field ground-based telescope. The kinematic analysis and cryogenic performance tests in the paper provide a technical reference for the precise alignment of the primary focus unit and the primary mirror, which can improve the imaging quality of the telescope.

关键词： methods:miscellaneous space vehicles:instruments telescopes miscellaneous

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Acatulides A-G,neuroprotective macrolides from Acaulium album H-JQSF

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Chinese Chemical Letters 2024年第3期35卷 379-383页

作者： Zhi-Wu Tong Ting-Ting Wang Pei Yang jia-lin sun Chen-Peng Zhang Salman Khan Xin-Cun Wang Rui-Hua jiao Hui-Ming Ge Wen-Ying Zhuang Gang Hu Ren Xiang Tan State Key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesNanjing UniversityNanjing 210023China State Key Laboratory Cultivation Base for TCM Quality and Efficacy Nanjing University of Chinese MedicineNanjing 210023China Insitute of Microbiology Chinese Academy of SciencesBeijing 100101China

Fungal symbionts co-evolve with hosts and microbial co-inhabitants to acquire an unpredictable potential for producing novel bioactive metabolites,but the knowledge about the topic remains patchy and *** we present the chemical characterization of acatulides A-G(1-7)as architecturally unprecedented macrolides from the solid-state culture of Acaulium album H-JQSF,an arthropod-associated *** acatulide structures were elucidated by spectroscopic analysis,modified Mosher's method and single-crystal X-ray *** plausible biosynthetic pathways for compounds 1-4 are ***,acatulides B-D(2-4)and G(7)were demonstrated to be neuroprotective against the 1-methyl-4-phenylpyridinium(MPP+)-induced damage to SH-SY5Y cells and nematode Caenorhabditis elegans(***).

关键词： Acaulium album Macrolides Acatulides A–G Mosher’s method Neuroprotective

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Novel Photodetectors Based on Double-Walled Carbon Nanotube Film/TiO2 Nanotube Array Heterodimensional Contacts

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Nano Research 2011年第9期4卷 901-907页

作者： Mingjie Yang jia-lin Zhu Wei Liu jia-lin sun Department of Physics and State Key Lab of Low-Dimensional Quantum Physics Tsinghua University Beijing 100084 China Laboratory of Advanced Materials Department of Material Science and Engineering Tsinghua University Beijing 100084 China

基于双 walled 碳 nanotube (DWCNT ) ，电影和 TiO2 nanotube 与 hetrodimensional 穿的光电探测器的一种新类型非欧姆的接触被制作了。由于维数差别效果， DWCNT film/TiO2 nanotube 数组光电探测器相对一台 Au film/TiO2 nanotube ... 详细信息

基于双 walled 碳 nanotube (DWCNT ) ，电影和 TiO2 nanotube 与 hetrodimensional 穿的光电探测器的一种新类型非欧姆的接触被制作了。由于维数差别效果， DWCNT film/TiO2 nanotube 数组光电探测器相对一台 Au film/TiO2 nanotube 数组设备展出高得多的 photocurrent-to-dark 电流比率和 photoresponse，甚至在小偏爱电压。photocurrent-to-dark 电流比率到达了四个数量级， 2467 A/W 的高 photoresponse 在 340 nm 在照耀之上被发现。而且，感光性的区域能被扩大到可见范围。photocurrent-to-dark 电流比率在 532 nm 在照耀之上到达了约三个数量级，在光子精力比 TiO2 的乐队差距低得多的地方。

关键词：双壁碳纳米管碳纳米管阵列阵列探测器非欧姆接触 TiO2 偏置电压二氧化钛光响应

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Fabrication of double-walled carbon nanotube film/TiO_2 nanotube array heterojunctions with length-dependent photoresponse for broad band photodetectors

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International Journal of Minerals,Metallurgy and Materials 2013年第3期20卷 307-312页

作者： Ming-jie Yang Wei Liu jia-lin sun Jin-quan Wei jia-lin Zhu Laboratory of Advanced Materials Department of Material Science and Engineering Tsinghua University State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Key Laboratory for Advanced Materials Processing Technology of Education Ministry Department of Mechanical Engineering Tsinghua University

A novel photodetector based on double-walled carbon nanotube （DWCNT） film/TiO2 nanotube array （TNA） heterojunctions was fabricated, which exhibited high photoresponse in a broad spectral range. The photoresponse of the detector was dramatically dependent on the length of the TNAs. High photocurrent-to-dark current ratio with a value of 3360 was observed in the visible range by optimizing the lengths of the TNAs. The photosensitive regions could be extended into the near-infrared range. These results reveal that DWCNT film/TNA heterojunctions show potential applications for broad band photodetectors.

关键词： photodetectors titanium dioxide carbon nanotubes heterojunctions

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Origin and evolution of false brinelling and fretting corrosion under rolling conditions

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Friction 2024年第4期12卷 618-631页

作者： Xin jia Lu HUANG Miao sun Wenbin LI National Institute of Metrology Beijing 100029China Yantai Tiancheng Machinery Co. Ltd.Yantai 264006China

Rolling bearings working in oscillating applications often suffer from false brinelling and fretting corrosion that limit their service *** present,the study of oscillation-induced failures is primarily dominated by a large number of sliding and bench ***,most of the previous work are not able to fully describe the two closely related but different failure *** this study,the origin and evolution of the two failures are thoroughly investigated under strictly controlled oscillating rolling *** results show that failure evolves from false brinelling to fretting corrosion under dry friction conditions regardless of the oscillation *** process is accompanied by a large area peeling and serious oxidation,and the oxygen content increases from 2.50 wt%to 21.22 wt%.Oxidation is a crucial factor in the evolution of false brinelling into fretting ***,the distribution of microwear and oxygen content depend on the oscillation *** lubrication conditions,the friction coefficient(COF)is smaller in the initial stage and led to local slip or transient instability of rolling ***,the size of the wear marks and COF increased and appeared to be larger than those under a dry friction ***,grease can separate the contact surfaces,only surface deformation owing to false brinelling and slight damage at the roughness level *** evolution of false brinelling and fretting corrosion is also closely related to residual *** brinelling often occurrs with residual stress accomulation,meanwhile,the residual stress increases from 120 to 300 *** peeling occurs,residual stress is *** failure pattern transformed from false brinelling to fretting corrosion and is accompanied by *** far,none of investigation is able to show satisfactory evolution of oscillating-induced failures,this study may contribute to more scientific understanding of rolling bearings against long-

关键词： oscillating false brinelling fretting corrosion wear residual stress

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Universal dynamic scaling and Contact dynamics in quenched quantum gases

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Frontiers of physics 2024年第2期19卷 213-220页

作者： jia-Nan Cui Zhengqiang Zhou Mingyuan sun School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Lab of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China

Recently universal dynamic scaling is observed in several systems,which exhibit a spatiotemporal self-similar scaling behavior,analogous to the spatial scaling near phase *** latter one arises from the emergent continuous scaling *** by this,we investigate the possible relation between the scaling dynamics and the continuous scaling symmetry in this *** derive a theorem that the scaling invariance of the quenched Hamiltonian and the initial density matrix can lead to the universal dynamic *** is further demonstrated both in a two-body system analytically and in a many-body system *** the latter one,we calculate the dynamics of quantum gases quenched from the zero interaction to a finite interaction via the non-equilibrium high-temperature virial expansion.A dynamic scaling of the momentum distribution appears in certain momentum-time windows at unitarity as well as in the weak interacting ***,this universal scaling dynamics persists approximately with smaller scaling exponents even if the scaling symmetry is fairly *** findings may offer a new perspective to interpret the related *** also study the Contact dynamics in the BEC−BCS ***,the half-way time displays a maximum near unitarity while some damping oscillations occur on the BEC side due to the dimer state,which can be used to detect possible two-body bound states in experiments.

关键词： dynamic scaling Contact dynamics quantum gases cold atom quench dynamics virial expansion continuous scaling symmetry

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Local Hybrid linear State Estimation for Electric Power Systems Using Stream Processing

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1259-1268页

作者： Kang sun Manyun Huang Zhinong Wei Yuzhang lin Guoqiang sun College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China Department of Department of Electrical and Computer Engineering University of Massachusetts LowellLowell MA 01854USA IEEE

The increasing penetration of renewable energy resources with highly fluctuating outputs has placed increasing concern on the accuracy and timeliness of electric power system state estimation(SE).Meanwhile,we note that only a fraction of system states fluctuate at the millisecond level and require to be *** such,refreshing only those states with significant variation would enhance the computational efficiency of SE and make fast-continuous update of states ***,this is difficult to achieve with conventional SE methods,which generally refresh states of the entire system every 4–5 *** this context,we propose a local hybrid linear SE framework using stream processing,in which synchronized measurements received from phasor measurement units(PMUs),and trigger/timingmode measurements received from remote terminal units(RTUs)are used to update the associated local ***,the measurement update process efficiency and timeliness are enhanced by proposing a trigger measurement-based fast dynamic partitioning algorithm for determining the areas of the system with states requiring *** particular,non-iterative hybrid linear formulations with both RTUs and PMUs are employed to solve the local SE *** timeliness,accuracy,and computational efficiency of the proposed method are demonstrated by extensive simulations based on IEEE 118-,300-,and 2383-bus systems.

关键词： Fast dynamic partitioning local hybrid linear state estimation phasor measurement units stream processing timeliness trigger/timing-mode measurements

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A noval iron-capturing nanocomposites against biofilms for disrupting bacterial nutritional balance

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Science China Chemistry 2024年第6期67卷 1760-1761页

作者： Jinying lin Qihang Ding Yao sun Department of Oral Implantology Jilin Provincial Key Laboratory of Tooth Development and Bone RemodelingSchool of StomatologyJilin UniversityChangchun130021China Department of Chemistry Korea UniversitySeoul02841Korea National Key Laboratory of Green Pesticide International Joint Research Center for Intelligent Biosensor Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhan430079China

Currently,the escalating crisis of bacterial infections and antibiotic resistance poses a significant global public health challenge[1-3].This situation has driven the search for novel antimicrobial ***,a crucial micr... 详细信息

关键词： metabolism resistance balance

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Novelty phase synthesis mechanism and morphology in resin-bonded Al–Al2O3–TiO2 composites at high temperatures under flowing N2

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1177-1185页

作者： Yang sun Yong Li Li-xin Zhang Shi-ming Li Ming-wei Yan jia-lin sun School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Sinosteel Refractory Co. Ltd. Henan 471039China Beijing Cisri-nmt Environmental Science and Technology Co. Ltd. Beijing 100083China

An Al–AlN core–shell structure is beneficial to the performance of Al–Al2O3 composites. In this paper, the phase evolution and microstructure of Al–Al2O3–TiO2 composites at high temperatures in flowing N2 were investigated after the Al–AlN core–shell structure was created at 853 K for 8 h. The results show that TiO2 can convert Al into Al3Ti(~1685 K), which reduces the content of metal Al and rearranges the structure of the composite. Under N2 conditions, Al3Ti is further transformed into a novelty non-oxide phase, TiCN. The transformation process can be expressed as follows: Al3Ti reacts with C and other carbides(Al4C3 and Al4O4C) to form TiCx(x < 1). As the firing temperature increases, Al3Ti transforms into a liquid phase and produces Ti(g) and TiO(g). Finally, Ti(g) and TiO(g) are nitrided and solid-dissolved into the TiCx crystals to form a TiCN solid solution.

关键词： aluminum titanium oxide alloys titanium carbonitride

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Biomimetic Gland Models with Engineered Stratagems

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Research 2024年第2期2023卷 583-612页

作者： Xiang lin lingyu sun Minhui Lu Yuanjin Zhao Department of Rheumatology and Immunology Nanjng Drum Tower HospitalSchool of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine Vision and Brain Health)Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiang 325001China Southeast University Shenzhen Research Institute Shenzhen 518071China

As extensively distributed tissues throughout the human body,glands play a critical role in various physiological ***,the construction of biomimetic gland models in vitro has aroused great interest in multiple *** the biological field,the researchers focus on optimizing the cell sources and culture techniques to reconstruct the specific structures and functions of glands,such as the emergence of organoid *** the perspective of biomedical engineering,the generation of biomimetic gland models depends on the combination of engineered scaffolds and microfluidics,to mimic the in vivo environment of glandular *** engineered stratagems endowed gland models with more biomimetic features,as well as a wide range of application *** this review,we first describe the biomimetic strategies for constructing different in vitro gland models,focusing on the role of microfluidics in promoting the structure and function development of biomimetic *** summarizing several common in vitro models of endocrine and exocrine glands,the applications of gland models in disease modelling,drug screening,regenerative medicine,and personalized medicine are ***,we conclude the current challenges and our perspective of these biomimetic gland models.

关键词： endowed constructing strata

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