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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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A review of research on central crack in continuous casting strand

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Journal of Iron and Steel Research(International) 2023年第6期30卷 1073-1089页

作者： Yong-kun Yang Jia-yu Zhu Wei-an wang Yang wang jian-li wang Guan-jie wang Xiao-ming li School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055ShaanxiChina

Central crack is a common quality defect in continuous casting strand,which is difficult to fully weld in the rolling and forging processes,and has become a key technical problem that restricts the stable production of high-end alloy rod/forging/*** recent years,the central crack control has been one of the main focuses in high quality steel *** order to fully understand the central crack,the research status of central crack characteristics,formation mechanism,influencing factors,and control methods in the world was *** deficiencies in the research of the central crack and the key research directions in the future were pointed out,which will provide references for other scholars in this field of *** is found that alloying elements segregation during solidification and inclusions precipitated at grain boundaries are the main reasons for the central crack formation,while the unreasonable application of production processes can also induce the initiation of central *** optimization of alloying element composition and production process is helpful to reduce the initiation of central *** addition,the quantitative characterization mechanism based on steel grades,temperature,stress,and other factors induced central crack should be established in the further study,forming a systematic quantitative determination criterion and control strategy for coupling the composition,process and thermal/mechanical characteristic.

关键词： Central crack Continuous casting strand Formation mechanism Alloying element Control strategy

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Effect of CacO_(3) on volatilization of self-reduced zinc from blast furnace dust

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Journal of Iron and Steel Research(International) 2022年第9期29卷 1404-1411页

作者： Wei-an wang Xiao-ming li-Yun He Hao-dong Xi jian-li wang Guo-xing Qiu School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina

To solve the problem of low reduction extraction rate of zinc from blast furnace dust,the effects of CacO3 addition,reduction temperature,and reduction time on self-reduction zinc extraction were studied through high-temperature reduction experiment,and the mechanism of how CaCO_(3) addition promotes zinc ferrite reduction was *** zinc removal rate can reach 98.82%when the blast furnace dust is reduced at 1000℃ for 25 min by adding 10 mass%CaCO_(3).At low temperature,CaCO_(3) can enhance the reduction and decomposition of ZnFe_(2)O_(4)(which is difficult to reduce)into ZnO and low-valent iron *** CaCO_(3) is decomposed at high temperature,CO_(2) is produced to undergo gasification reaction with carbon in blast furnace dust,and co is generated to provide more reducing agents for the whole reduction *** generated by decomposition can also catalyze the gasification reaction of carbon,thus improving the removal rate of zinc in the reduction process of dust.

关键词： Blast furnace dust Self reducing zinc extraction Calcium carbonate Zinc ferrite

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奥氮平对乳腺癌相关巨噬细胞增殖与分化功能的影响

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中南药学 2024年第2期22卷 341-346页

作者：孟娟李东辉高元慧刘梅李建旺海口市人民医院肿瘤内科海口570208 海口市人民医院泌尿外科海口570208 海口市人民医院中心实验室海口570208

目的探讨奥氮平对乳腺癌细胞共培养体系中人急性髓系白血病细胞系THP-1细胞增殖和分化功能的影响。方法体外培养THP-1细胞、人乳腺癌MDA-MB-231细胞,建立THP-1与MDA-MB-231共培养组,用CCK-8法检测奥氮平处理后的THP-1单独组、共培养组中... 详细信息

目的探讨奥氮平对乳腺癌细胞共培养体系中人急性髓系白血病细胞系THP-1细胞增殖和分化功能的影响。方法体外培养THP-1细胞、人乳腺癌MDA-MB-231细胞,建立THP-1与MDA-MB-231共培养组,用CCK-8法检测奥氮平处理后的THP-1单独组、共培养组中THP-1的活性变化;用qRT-PCR法检测奥氮平对佛波酯诱导的THP-1单独组、共培养组中THP-1表面分子CD68、CD80、CD163的表达,以及炎症因子IL-1β、IL-6、IL-12、TGF-α、TGF-β和IL-10的表达,同时进一步检测巨噬细胞极化相关miRNA分子miRNA9、miRNA155和miRNA34a的表达。结果奥氮平能抑制THP-1单独组和共培养组中THP-1的增殖活性(P<0.05);在佛波酯诱导THP-1向巨噬细胞分化的研究中,奥氮平能够显著提高THP-1单独组CD68分子的表达(P<0.05),而在共培养组中CD68、CD80、CD163的表达则均显著升高(P<0.05)。在THP-1单独组中,奥氮平仅能够促进IL-12的表达;在共培养组中,奥氮平使CCL2、CXCL10、IL-1β、IL-10、IL-6、IL-12、TNF-α表达水平显著升高(P<0.05)。在巨噬细胞分化相关miRNA的研究中,在奥氮平作用下,THP-1单独组中miR155和Let7c的表达显著升高(P<0.05),miR146、miR9和miR34a的表达变化无差异;在与MDA-MB-231共培养条件下,miR34a和Let7c显著升高(P<0.05)。结论在肿瘤细胞存在的情况下,奥氮平可参与肿瘤相关巨噬细胞表面分子、炎症因子以及巨噬细胞极化相关miRNA分子表达的调节,这为进一步利用奥氮平治疗乳腺癌提供了新思路。

关键词：奥氮平乳腺癌急性髓系白血病THP-1细胞增殖分化

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MXene Key Composites:A New Arena for Gas Sensors

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Nano-Micro Letters 2024年第10期16卷 350-391页

作者： Yitong wang Yuhua wang Min jian Qinting jiang Xifei li Hubei Province Key Laboratory of Systems Science in Metallurgical Process Wuhan University of Science and TechnologyWuhan 430081People's Republic of China Key Materials and Components of Electrical Vehicles for Overseas Expertise Introduction Center for Discipline Innovation Institute of Advanced Electrochemical Energy and School of Materials Science and EngineeringXi'an University of TechnologyXi'an 710048People's Republic of China College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108FujianPeople's Republic of China

With the development of science and technology,the scale of industrial production continues to grow,and the types and quantities of gas raw materials used in industrial production and produced during the production process are also constantly *** gases include flammable and explosive gases,and even contain toxic ***,it is very important and necessary for gas sensors to detect and monitor these gases quickly and *** recent years,a new two-dimensional material called MXene has attracted widespread attention in various *** abundant surface functional groups and sites,excellent current conductivity,tunable surface chemistry,and outstanding stability make them promising for gas sensor *** the birth of MXene materials,researchers have utilized the efficient and convenient solution etching preparation,high flexibility,and easily functionalize MXene with other materials to pre-pare composites for gas *** has opened a new chapter in high-performance gas sensing materials and provided a new approach for advanced sensor ***,previous reviews on MXene-based composite materials in gas sensing only focused on the performance of gas sensing,without systematically explaining the gas sensing mechanisms generated by different gases,as well as summarizing and predicting the advantages and disadvantages of MXene-based composite *** article reviews the latest progress in the application of MXene-based composite materials in gas ***,a brief summary was given of the commonly used methods for preparing gas sens-ing device structures,followed by an introduction to the key attributes of MXene related to gas sensing *** article focuses on the performance of MXene-based composite materials used for gas sensing,such as MXene/graphene,MXene/Metal oxide,MXene/Transition metal sulfides(TMDs),MXene/Metal-organic framework(MOF),MXene/*** summarizes the advantages and disad

关键词： MXene Compound material Gas sensor Gas sensitive preparation Gas sensitivity performance

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Indexing dynamic encrypted database in cloud for efficient secure k-nearest neighbor query

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Frontiers of Computer Science 2024年第1期18卷 187-198页

作者： Xingxin li Youwen ZHU Rui XU jian wang Yushu ZHANG College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Mathematical Informatics University of TokyoTokyo 113-8654Japan Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China School of Computer Science China University of GeosciencesWuhan 430074China

Secure k-Nearest Neighbor(k-NN)query aims to find k nearest data of a given query from an encrypted database in a cloud server without revealing privacy to the untrusted cloud and has wide applications in many areas,such as privacy-preservingmachine elearning gand secure biometric *** solutions have been put forward to solve this challenging ***,the existing schemes still suffer from various limitations in terms of efficiency and *** this paper,we propose a new encrypt-then-index strategy for the secure k-NN query,which can simultaneously achieve sub-linear search complexity(efficiency)and support dynamical update over the encrypted database(flexibility).Specifically,we propose a novel algorithm to transform the encrypted database and encrypted query points in the *** indexing the transformed database using spatial data structures such as the R-tree index,our strategy enables sub-linear complexity for secure k-NN queries and allows users to dynamically update the encrypted *** the best of our knowledge,the proposed strategy is the first to simultaneously provide these two *** theoretical analysis and extensive experiments,we formally prove the security and demonstrate the efficiency of our scheme.

关键词： cloud computing secure k-NN query sub-linear complexity dynamicupdate

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Steady-state Voltage Security-constrained Optimal Frequency Control for Weak HVDC Sending-end AC Power Systems

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 658-669页

作者： Qiangqiang wang liangzhong Yao jian Xu Yuping Zheng Wei li Wei wang School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Hubei Engineering and Technology Research Center for AC/DC Intelligent Distribution Network(Wuhan University) Wuhan 430072China State Key Laboratory of Smart Grid Protection and Control NARI Group Corporation(State Grid Electric Power Research Institute)Nanjing 211106China

Due to the fact that a high share of renewable energy sources(RESs)are connected to high-voltage direct current(HVDC)sending-end AC power systems,the voltage and frequency regulation capabilities of HVDC sending-end AC power systems have *** has resulted in potential system operating problems such as overvoltage and overfrequency,which occur simultaneously when block faults exist in the HVDC *** this study,a steady-state voltage security-constrained optimal frequency control method for weak HVDC sending-end AC power systems is *** integrated virtual inertia control of RESs is employed for system frequency *** dynamic reactive power compensation devices are utilized to control the voltage of all nodes meet voltage security ***,an optimization model that simultaneously considers the frequency and steady-state voltage security constraints for weak HVDC sending-end AC power systems is *** optimal control scheme with the minimum total cost of generation tripping and additional dynamic reactive power compensation required is obtained through the optimization *** are conducted on a modified IEEE 9-bus test system and practical Qing-Yu line commutated converter based HVDC(LCC-HVDC)sending-end AC power system to verify the effectiveness of the proposed method.

关键词： Renewable energy source(RES) high-voltage direct current(HVDC) AC power system optimal frequency control steady-state voltage security dynamic reactive power compensation

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Multi-carrier Tb/s silicon photonic coherent receiver

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Science China(Information Sciences) 2024年第1期67卷 284-291页

作者： Zhen wang Xingfeng li Jingchi li jian SHEN Yong ZHANG Yikai SU State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic EngineeringShanghai Jiao Tong University

We propose a silicon polarization-diversity coherent receiver for wavelength-multiplexing transmission without using the large-footprint arrayed waveguide grating(AWG).We have integrated our proposed coherent receiver on the silicon-on-insulator(SOI) platform for high-capacity *** the proposed coherent receiver,high-frequency photocurrent signals from other wavelengths are suppressed by electrical low-pass ***,the signal-signal beat interference(SSBI) generated from each wavelength is eliminated by the balanced *** two features lend to the proposed coherent receiver being free of the mm-scale *** have demonstrated our proposed coherent receiver to detect a 1.12-Tb/s wavelength-division-multiplexed and polarization-division-multiplexed 16-ary quadrature amplitude modulation(PDM-16-QAM) *** compact footprint of the silicon chip promises small-form-factor receivers for future ultra-high-capacity coherent communication systems that require a high integration level and low fabrication cost.

关键词： silicon photonics optical receivers coherent communication wavelength-division-multiplexing(WDM) polarization-division-multiplexing(PDM)

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Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

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Advances in Climate Change Research 2024年第3期15卷 442-451页

作者： jian-Sheng HAO Yan wang Lan-Hai li Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences(CAS)Beijing 100101China Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone Urumqi 830011China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Tianshan Snowcover and Avalanche Observation and Research Station of Xinjiang Xinyuan 835800China CAS Research Center for Ecology and Environment of Central Asia Urumqi 830011China

Climate change alters snowpack evolution,which in turn influences the likelihood of snow avalanches and flood *** lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate-snowpack-snow *** restricts our understanding and poses challenges in the prediction of snow-related disaster *** such,this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to *** results reveal that the temperature increased significantly by 0.32°C per decade(plier ***,average and maximum snow depths increased along with an increase in peak snow water equivalent,thus indicating a higher frequency of extremely scarce or abundant snow *** low snowpack temperature gradient and earlier snowmelt dates in spring lead to earlier occurrences of snowmelt floods and wet *** the risks of these events increase,they pose greater threats to farmlands,road transportation,water-electricity infrastructure and several other human ***,these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

关键词： Climate change Snowpack variations Snow-related disaster Tianshan Mountains

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Magnesium-containing pellet regulating blast furnace ferrous burden interaction:softening-melting behavior and mechanism

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1623-1635页

作者： li-ming Ma jian-liang Zhang Yao-zu wang Xiao-yong Ma Gui-lin wang Zhuo li Hui-qing jiang Zheng-jian liu School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 100083China lingyuan Iron and Steel Group Co. Lingyuan 122500LiaoningChina

MgO participates in all stages of sintering,pelletizing,and blast furnace ironmaking,and synergistically optimizing the distribution of MgO in ferrous burden can effectively enhance the interaction within the ferrous burdens and optimize the softening-melting properties of the mixed ***-containing pellets mixed with low-MgO sinter or mixed with high-MgO sinter in the blast furnace ferrous burden structure have opposite softening-melting performance *** the structure of the ferrous burden is magnesium-containing pellets mixed with low-MgO sinter,the magnesium-containing pellets can enhance the interaction of the ferrous burden in the process of softening-melting,which can optimize the composition of the slag phase and improve the slag *** the structure of the ferrous burden is magnesium-containing pellets mixed with high-MgO sinter,the magnesium-containing pellets weaken the interaction of the ferrous burden in the process of softening-melting,increase the content of the high melting point solid-phase particles in the slag,lead to an increase in the viscosity of the slag and difficult separation of the slag and iron,and decrease the permeability of the charge ***,to ensure good permeability of the mixed burden,the following measures are suggested:optimizing the MgO distribution of the ferrous burden,reducing the MgO content of the sinter to 1.96 wt.%,increasing the MgO content of the pellets to 1.03-1.30 wt.%,controlling the MgO/Al_(2)O_(3) ratio of the mixed burden within 1.15-1.32,narrowing the position of the cohesive zone,and maintaining an S value(permeability index)of approximately 150 kPa℃.

关键词： Ironmaking Ferrous burden Softening-melting property Interaction Permeability Slag

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