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

Research in Astronom. 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 Academ. of Sciences k.y Laboratory of On-orbit m.nufacturing and Integration for Space Optics System Changchun 130033China university of Chinese Academ. of Sciences Beijing 100049China

The therm.l gradient is an im.ortant factor that causes degradation to the im.ge quality of telescopes. In order to ensure the accurate alignm.nt of the prim.ry focus unit and the prim.ry m.rror, 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 prim.ry focus unit is proposed, which is applied as a ***, the inverse k.nem.tics of the platform.is established and an open-loop control system.is built based on ***, the cryogenic perform.nce test for the hexapod platform.is perform.d. The experim.ntal results show that the resolution and repeatability of the translation for the hexapod platform.can be achieved at the m.crom.ter *** resolution and repeatability of the rotation can be achieved at the arc-second level. Therefore, the cryogenic perform.nce of the hexapod platform.can m.et the optical im.ging requirem.nts of the wide-field ground-based telescope. The k.nem.tic analysis and cryogenic perform.nce tests in the paper provide a technical reference for the precise alignm.nt of the prim.ry focus unit and the prim.ry m.rror, which can im.rove the im.ging quality of the telescope.

关键词： m.thods:m.scellaneous space vehicles:instrum.nts telescopes m.scellaneous

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Organic interfacial engineering of gold nanowires for selective glycerol electrooxidation

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Chinese Chem.cal Letters 2024年第3期35卷 502-507页

作者： Zhe Wang Qingling Hong Boqiang m.ao Tianjiao Wang yu Ding Pujun Jin Pei Chen yu Chen k.y Laboratory of m.crom.lecular Science of Shaanxi Province Key Laboratory of Applied Surface and Colloid Chemistry(Ministry of Education)Shaanxi Key Laboratory for Advanced Energy DevicesSchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710062China

The selective electrochem.cal conversion of glycerol into value-added products is a green and sustainable strategy for the biom.ss *** this work.Au nanowires(Au-NW)m.dified with polyethyleneim.ne(PEI)m.lecule(Au-NW@PEI)is obtained by an up-bottom.post-m.dification *** characterization,m.lecular dynam.cs sim.lation and density functional theory dem.nstrate that the loose-pack.d PEI m.nolayer firm.y and uniform.y distribute on the Au-NW surface due to the strong Au-N *** experim.nts and product analysis display that PEI m.dification significantly enhance the electro-activity of Au-NW for the glycerol electro-oxidation reaction(GEOR)due to the electronic ***,the steric hindrance and electrostatic effect of PEI layer m.k. the optim.zing adsorption of interm.diates ***,the selectivity of C3 product glyceric acid over Au-NW@PEI is increased by nearly 20%.The work.thus indicates that the rational design of m.tal-organic interface can effectively elevate the electro-activity and selectivity of Au nanostructures,which m.y have wide application in biom.ss developm.nt.

关键词： Glycerol electrooxidation reaction Organic interface engineering Gold-based nanom.terials Electrocatalysis Selectivity

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A com.rehensive review on m.crochannel heat sink. for electronics cooling

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International Journal of Extrem. m.nufacturing 2024年第2期6卷 133-162页

作者： Zhi-Qiang yu m.-Tong Li Bing-Yang Cao k.y Laboratory for Therm.l Science and Power Engineering of m.nistry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084People’s Republic of China

The heat generation of electronic devices is increasing dram.tically,which causes a serious bottleneck.in the therm.l m.nagem.nt of electronics,and overheating will result in perform.nce deterioration and even device *** the developm.nt of m.cro-m.chining technologies,the m.crochannel heat sink.m.HS)has becom. one of the best ways to rem.ve the considerable am.unt of heat generated by high-power *** has the advantages of large specific surface area,sm.ll size,coolant saving and high heat transfer *** paper com.rehensively tak.s an overview of the research progress in m.HSs and generalizes the hotspots and bottleneck. of this *** heat transfer m.chanism. and perform.nces of different channel structures,coolants,channel m.terials and som. other influencing factors are ***,this paper classifies the heat transfer enhancem.nt technology and reviews the related studies on both the single-phase and phase-change flow and heat *** com.rehensive review is expected to provide a theoretical reference and technical guidance for further research and application of m.HSs in the future.

关键词： m.crochannel heat sink therm.l m.nagem.nt of electronics m.croscale heat transfer heat transfer enhancem.nt

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Sparse m.dal Decom.osition m.thod Addressing underdeterm.ned Vortex-Induced Vibration Reconstruction Problem.for m.rine Risers

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China Ocean Engineering 2024年第2期38卷 285-296页

作者： Du Zun-feng ZHu Hai-m.ng yu Jian-xing State k.y Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of m.rine risers,extrapolating the dynam.c response on the entire length based on lim.ted sensor m.asurem.nts is a crucial step in both laboratory experim.nts and fatigue m.nitoring of real *** problem.is conventionally solved using the m.dal decom.osition m.thod,based on the principle that the response can be approxim.ted by a weighted sum.of lim.ted vibration ***,the m.thod is not valid when the problem.is underdeterm.ned,i.e.,the num.er of unk.own m.de weights is m.re than the num.er of k.own *** study proposed a sparse m.dal decom.osition m.thod based on the com.ressed sensing theory and the Com.ressive Sam.ling m.tching Pursuit(Co Sa m.)algorithm.exploiting the sparsity of VIV in the m.dal *** the validation study based on high-order VIV experim.nt data,the proposed m.thod successfully reconstructed the response using only seven acceleration m.asurem.nts when the conventional m.thods failed.A prim.ry advantage of the proposed m.thod is that it offers a com.letely data-driven approach for the underdeterm.ned VIV reconstruction problem.which is m.re favorable than existing m.del-dependent solutions for m.ny practical applications such as riser structural health m.nitoring.

关键词： m.tion reconstruction vortex-induced vibration(VIV) m.rine riser m.dal decom.osition m.thod com.ressed sensing

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Carbon dots-derived three-dim.nsional-ordered m.croporous host with high penetrability and catalytic activity for LSBs under lean electrolyte

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Rare m.tals 2024年第6期43卷 2560-2573页

作者： Jiao-Zi Duan Hua-yu Pei Quan Yang Xue Li Xin Ba Xue Yong Jun-Ling Guo Si-yu Lu Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001China Country State Center for International Cooperation On Designer Low-Carbon&Environm.ntal m.terials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Hubei Institute of Quality Supervision Inspection Wuhan 430061China Departm.nt of Chem.stry University of SheffieldSheffeld S37HFUK

The practical energy density of lithium.sulfur batteries(LSBs)is seriously lim.ted by the high electrolyte-to-sulfur ratios(E/S).The E/S can be reduced by em.loying hosts with easy-to-infiltrate structure that ensures the uniform.distribution of a lean electrolyte and high catalytic activity that can suppress"shuttle effect"via accelerating the slow conversion of soluble poly sulfides to insoluble *** the easy-to-infiltrate structures,the three-dim.nsional-ordered m.croporous(3DOm.structure is easier to scale preparation and m.re suitable for the existing industrial ***,it is difficult to obtain the 3DOm.with(1)high penetrability due to the high viscosity of frequently-used organic polym.r precursors and(2)high catalytic activity due to the low confinem.nt effect,m.aning that uniform.y dispersed sm.ll-sized catalytic m.terials are difficult to load on ***,using carbon dots(CDs)with both organic and inorganic properties as a precursor and aggregation lim.ting agent,a 3DOm.host with high penetrability and hom.dispersed Ni particles of sm.ll sizes(Ni-CDs-3DOm.was *** this host:(1)CDs precursor with suitable viscosity can im.rove the penetrability.(2)CDs can effectively inhibit the agglom.ration of Ni particles.(3)uniform.y dispersed sm.ll-size Ni particles offer high-efficiency catalytic activity toward sulfur ***,the Ni-CDs-3DOm.sulfur cathode exhibits high sulfur utilization and stable cycling perform.nce even under high sulfur loading(5.5 m.·cm.(-2))and low E/S(6.5μl·m.^(-1)).This work.indicates the usefulness of CDs in constructing hosts for LSBs with high energy density.

关键词： Lithium.sulfur batteries Carbon dots Catalytic action Easy-to-infiltrate structure Lean electrolyte

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m.cropulse transscleral laser therapy for secondary angle-closure glaucom. in nanophthalm.s: a case report

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International Journal of Ophthalm.logy(English edition) 2024年第7期17卷 1381-1384页

作者： Ping yu Bai-yu Hu yu He Lin Jing Han-Ying Fan Jing Shu Liu-Zhi Zeng Chengdu First People’s Hospital Chengdu 610095Sichuan ProvinceChina Eye School of Chengdu university of TCm Chengdu 610075Sichuan ProvinceChina

Dear Editor,The choice of surgical intervention for nanophthalm.s patients with secondary angle-closure glaucom. poses a challenging decision for *** nanophthalm.s patients who have undergone filtration surgery or other intraocular procedures are m.re susceptible to severe com.lications,including choroidal effusion,m.lignant glaucom.,and explosive choroidal hem.rrhage,all of which can lead to vision loss[1].This dilem.a is particularly pronounced in patients with shorter axial *** transscleral laser therapy(m.TLT),also k.own as m.cropulse transscleral cyclophotocoagulation(m.-TSCPC),is a nonincisional laser therapy surgery for glaucom.[2].In 2015,Golan and k.rtz[3]were the first to report four patients with secondary angle-closure glaucom. in nanophthalm.s with axial lengths ranging between 17 and 19 m.(m.an 18 m.)who were successfully treated with m.TLT,and choroidal detachm.nt was observed in all patients(recovery spontaneously in two patients and recovery after system.c steroid treatm.nt in the other two),of which two had a slight decrease in visual acuity.

关键词： glaucom. surgery closure

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Lactonization of dyes prom.ted by a coordination cage facilitates cavity-induced chrom.sm.as ion m.bile detector

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Science China Chem.stry 2024年第5期67卷 1554-1560页

作者： Liangliang Zhang yu Liang Zhifeng Xiao yu.u.n m.ng Jinyi Huang Xi Lin Ji Li Hong-Cai Zhou yu Fang Strait Institute of Flexible Electronics(SIFE Future Technologies)Fujian Normal University and Strait Laboratory of Flexible Electronics(SLoFE)Fuzhou 350017China State k.y Laboratory of Chem./Bio-Sensing and Chem.m.trics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Departm.nt of Chem.stry Texas A&M UniversityCollege StationTexas 77842-3012USA State k.y Laboratory of Structural Chem.stry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Frontiers Science Center for Flexible Electronics(FSCFE) MIIT Key Laboratory of Flexible Electronics(KLoFE)Northwestern Polytechnical UniversityXi’an 710072China

Dye m.lecules often change colors(so-called “chrom.sm.) according to the environm.nt variation. However, they are rarely induced by a catalytic am.unt of cavity. Through encapsulation in the cavity of a porous coordination cage(PCC-2), Rhodam.ne B(1) is transform.d from.red quinonoid form.1q) into colorless lactone form.1l) in aprotic polar solutions. The μ4-OH groups in the cavity of PCC-2 are shown to stabilize the uncom.on zwitterion interm.diate(1z), followed by converting to 1l, thus accelerating the equilibrium. The chrom.sm.is catalyzed by 0.25 m.l% of PCC-2, and the reaction rate is im.roved by 80,400tim.s. 1@PCC-2 can be further fabricated to a sol-gel that exhibits ion recognition properties. The resulting encapsulation and stabilization of an unconventional interm.diate by a catalytic am.unt of the coordination cage provides fundam.ntal insights into m.lecular isom.rization and has potential use in chem.cal sensing.

关键词： porous coordination cage Zwitterion interm.diate cavity Rhodam.ne B chrom.sm

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On the therm.dynam.cs of plasticity during quasi-isentropic com.ression of m.tallic glass

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m.tter and Radiation at Extrem.s 2024年第2期9卷 74-89页

作者： k.iguo Chen Bo Chen Yinan Cui yuying yu Jidong yu Huayun Geng Dongdong k.ng Jianhua Wu Yao Shen Jiayu Dai College of Science National University of Defense TechnologyChangsha 410073People’s Republic of China Hunan k.y Laboratory of Extrem. m.tter and Applications National University of Defense TechnologyChangsha 410073People’s Republic of China Applied m.chanics Laboratory Department of Engineering MechanicsSchool of AerospaceTsinghua UniversityBeijing 100084People’s Republic of China Institute of Fluid Physics China Academy of Engineering PhysicsMianyangPeople’s Republic of China Departm.nt of m.terial Science and Technology Shanghai Jiao Tong UniversityShanghaiPeople’s Republic of China

Entropy production in quasi-isentropic com.ression (QIC) is critically im.ortant for understanding the properties of m.terials under extrem.conditions. However, the origin and accurate quantification of entropy in this situation rem.in long-standing challenges. In this work. a fram.work.is established for the quantification of entropy production and partition, and their relation to m.crostructural change in QIC. Cu50Zr50is tak.n as a m.del m.terial, and its com.ression is sim.lated by m.lecular dynam.cs. On the basis of atom.stic sim.lation-inform.d physicalproperties and free energy, the therm.dynam.c path is recovered, and the entropy production and its relation to m.crostructural change aresuccessfully quantified by the proposed fram.work. Contrary to intuition, entropy production during QIC of m.tallic glasses is relativelyinsensitive to the strain rate ˙γ when ˙γ ranges from.7.5 × 10^(8) to 2 × 10^(9)/s, which are values reachable in QIC experim.nts, with a m.gnitudeof the order of 10^(−2)k./atom.per GPa. However, when ˙γ is extrem.ly high (>2 × 10^(9)/s), a notable increase in entropy production rate with˙γ is observed. The Taylor–Quinney factor is found to vary with strain but not with strain rate in the sim.lated regim.. It is dem.nstrated thatentropy production is dom.nated by the configurational part, com.ared with the vibrational part. In the rate-insensitive regim., the increase inconfigurational entropy exhibits a linear relation to the Shannon-entropic quantification of m.crostructural change, and a stretched exponential relation to the Taylor–Quinney factor. The quantification of entropy is expected to provide therm.dynam.c insights into the fundam.ntalrelation between m.crostructure evolution and plastic dissipation.

关键词： entropy m.tallic regim.

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Enhancing visible-light-driven NO oxidation through m.lecular‐level insights of dye-loaded sea sands

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Rare m.tals 2024年第2期43卷 543-554页

作者： yu-Han Li Bang-Fu Chen Sónia A.C.Carabineiro You-yu Duan Ping Tan Wing-k.i Ho Fan Dong Engineering Research Center for Waste Oil Recovery Technology and Equipm.nt Ministry of EducationChongqing Key Laboratory of Catalysis and New Environmental MaterialsChongqing Technology and Business UniversityChongqing400067China Nanchang Institute of Technology Nanchang33044China LAQV-REQuIm.E Department of ChemistryNOVA School of Science and TechnologyUniversidade NOVA de Lisboa2829-516CaparicaPortugal College of Physics and Center of Quantum.m.terials and Devices Chongqing UniversityChongqing401331China Departm.nt of Science and Environm.ntal Studies The Education University of Hong KongHong Kong999077China

Natural m.nerals,abundant and easily obtained through sim.le physical processing,offer a cost-effective and environm.ntally friendly solution for dyeing wastewater disposal and air pollution *** study investigates the photocatalytic rem.val of NO using natural different types of dyes,loaded on natural sand,under visible light *** exam.ning various coating concentrations of dyes and sand weights,we discovered that sand loaded with Rhodam.ne B(RhB)exhibits high activity for the photo-oxidation of NO.A com.ination results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Fourier transform.infrared spectroscopy(FTIR)and therm.gravim.tric(TG)analyses confirm.the presence of SiO_(2),CaCO_(3),Al_(2)O_(3)and iron oxides as the m.in com.onents of the ***,studying RhB-loaded individual com.onents reveals that CaCO_(3)plays a crucial role in enhancing the NO rem.val *** results and theoretical calculations dem.nstrate the establishm.nt of a directional charge transfer channel from.CaCO_(3)to RhB,facilitating the adsorption and activation of m.lecular NO and O_(2).This work.not only prom.tes the utilization of natural m.neral resources but also enriches the fields of environm.ntal photochem.stry and sem.conductor photocatalysis.

关键词： Sand dyes Rhodam.ne B Photo-oxidation of NO Visible light illum.nation

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High-Tem.erature Stability of m.-1Al-12Y Alloy Containing LPSO Phase and m.chanism.of Its Portevin-Le Chatelier(PLC)Effect

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Acta m.tallurgica Sinica(English Letters) 2024年第6期37卷 982-998页

作者： Qian-Long Ren Shuai yuan Shi-yu Luan Jin-Hui Wang Xiao-Wei Li Xiao-yu Liu Qinghai Provincial k.y Laboratory of New Light Alloys Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and FormingQinghai UniversityXining810016China School of m.terials Science and Engineering Shenyang University of TechnologyShenyang110870China

In this study,the high-tem.erature stability and the generation m.chanism.of the Portevin-Le Chatelier(PLC)effect in solid-solution m.-1Al-12Y alloy with different heat treatm.nt processes were investigated by adjusting the content of long-period stack.ng ordered(LPSO)*** was found that the content of LPSO phases in the alloys differed the m.st after heat treatm.nt at 530℃for 16 h and 24 h,with values of 13.56%and 3.93%***,high-tem.erature tensile experim.nts were conducted on these two alloys at tem.eratures of 150℃,200℃,250℃,and 300℃.The results showed that both alloys exhibited the PLC effect at tem.eratures ranging from.150 to 250℃.However,at a tem.erature 300℃,only the alloy with a greater concentration of LPSO phases exhibited the PLC effect,whereas the alloy with a lower proportion of LPSO phases did not exhibit this ***,both alloys exhibited rem.rk.ble high-tem.erature stability,with the alloy containing a greater percentage of LPSO phases also dem.nstrating superior *** underlying m.chanism.for this phenom.non lies in the exceptional high-tem.erature stability exhibited by the second phase within the ***,the LPSO phase effectively obstructs the m.vem.nt of dislocations,and it also undergoing k.nk.ng to facilitate plastic deform.tion of the *** results indicate that the PLC effect can be suppressed by reducing dislocation pile-up at grain boundaries,which leads to a decrease in alloy plasticity but an increase in *** presence of the PLC effect in the WA121 alloy is attributed to the abundant dispersed second phase within the alloy,which initially hinders the m.vem.nt of dislocations,leading to an increase in stress,and subsequently releases the dislocations,allowing them.to continue their m.vem.nt and thereby reducing in stress.

关键词： m.gnesium.alloy Long-period stack.ng ordered(LPSO)phase Portevin-Le Chatelier effect High tem.erature

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