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Periodic orbits around areostationary points in the martian gravity field

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Research in Astronomy and Astrophysics 2012年第5期12卷 551-562页

作者： Xiao-Dong Liu Hexi Baoyin xing-rui ma School of Aerospace Tsinghua University 100084 Beijing China

This study investigates the problem of areostationary orbits around mars in three-dimensional space. Areostationary orbits are expected to be used to establish a future telecommunication network for the exploration of mars. However, no artificial satellites have been placed in these orbits thus far. The characteristics of the martian gravity field are presented, and areostationary points and their linear stability are cal- culated. By taking linearized solutions in the planar case as the initial guesses and utilizing the Levenberg-marquardt method, families of periodic orbits around areo- stationary points are shown to exist. Short-period orbits and long-period orbits are found around linearly stable areostationary points, but only short-period orbits are found around unstable areostationary points. Vertical periodic orbits around both lin- early stable and unstable areostationary points are also examined. Satellites in these periodic orbits could depart from areostationary points by a few degrees in longitude, which would facilitate observation of the martian topography. Based on the eigenval- ues of the monodromy matrix, the evolution of the stability index of periodic orbits is determined. Finally, heteroclinic orbits connecting the two unstable areostationary points are found, providing the possibility for orbital transfer with minimal energy consumption.

关键词： planets and satellites: mars -martian gravity field -- periodic orbit -- areostationary orbits

Optimal investment, retirement, and life insurance with consumption ratcheting and time-inhomogeneous utility

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Science China mathematics 2025年

作者： Jie xing Jingtang ma School of Big Data Application and Economics Guizhou University of Finance and Economics School of mathematics Southwestern University of Finance and Economics

In this paper, we study a portfolio selection problem of an investor with a retirement option, who has possibility to buy life insurance and does not tolerate any decline in consumption. The agent's optimization problem can be viewed as a mixed singular control and optimal stopping problem with time-inhomogeneous utility functions. The closed-form optimal solution is not available in general. We use the dual control method to convert the original problem into two classes of optimal stopping problems in finite and infinite *** show that the optimal consumption strategy and the best retirement time depend on the free-boundary functions which satisfy Fredholm and Volterra integral equations. We derive the closed-form formulas for these two free boundaries for some special cases and develop numerical methods to solve the integral equations of the free boundaries for general cases.

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Multi-receptive field interaction network for shape from polarization

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Science China(Information Sciences) 2025年第1期68卷 394-395页

作者： Yini PENG rui LIU Zhiyuan ZHANG Zhongyuan WANG Jiayi ma Xin TIAN Electronic Information School Wuhan University Computer Science School Wuhan University Wuhan Institute of Quantum Technology

Shape from polarization (SfP) method can use the polarization information in reflected light to estimate the surface normal of the target,which can further reconstruct the shape of the *** a simple image capture process,it can use low-cost equipment to meet a high precision imaging requirement,which can be used in remote scenes and other applications.

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Solution‑Processed Thin Film Transparent Photovoltaics:Present Challenges and Future Development

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Nano-Micro Letters 2025年第2期17卷 566-600页

作者： Tianle Liu Munerah M.S.Almutairi Jie ma Aisling Stewart Zhaohui xing Mengxia Liu Bo Hou Yuljae Cho UM-SJTU Joint Institute Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China School of Physics and Astronomy Cardiff UniversityCardiff CF243AAWalesUK Department of Electrical and Computer Engineering Yale UniversityNew HavenCT 06511USA Energy Sciences Institute Yale UniversityWest HavenCT 06516USA Future Photovoltaics Research Center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Electrical energy is essential for modern society to sustain economic *** soaring demand for the electrical energy,together with an awareness of the environmental impact of fossil fuels,has been driving a shift towards the utilization of solar ***,traditional solar energy solutions often require extensive spaces for a panel installation,limiting their practicality in a dense urban *** overcome the spatial constraint,researchers have developed transparent photovoltaics(TPV),enabling windows and facades in vehicles and buildings to generate electric *** TPV advancements are focused on improving both transparency and power output to rival commercially available silicon solar *** this review,we first briefly introduce wavelength-and non-wavelengthselective strategies to achieve *** of merit and theoretical limits of TPVs are discussed to comprehensively understand the status of current TPV *** we highlight recent progress in different types of TPVs,with a particular focus on solution-processed thin-film photovoltaics(PVs),including colloidal quantum dot PVs,metal halide perovskite PVs and organic *** applications of TPVs are also reviewed,with emphasis on agrivoltaics,smart windows and ***,current challenges and future opportunities in TPV research are pointed out.

关键词： Transparent semiconductors Solution-processable transparent solar cell Emerging solar cell materials Buildingintegrated photovoltaics

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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Science China Chemistry 2025年第1期68卷 174-180页

作者： Fan-Xiao Meng xing-Yu Wang Ka Lu Ju-Song Yang Fu-Min Zhang Ai-Jun ma Bao Du Yong-Qiang Tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

关键词： benzofuran atropisomers novel de novo synthetic strategy asymmetric formal [3 + 2] cycladdition Cu/SPDO complex DFT calculations

Li,Na,and Cs-based metal-organic frameworks for room temperature phosphorescence applications

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Science China Chemistry 2025年

作者： Jiaqi ma rui Feng Yanyuan Jia Mingshi Zhang Shuo Guo College of Chemistry and Chemical Engineering Inner Mongolia University School of materials Science and Engineering Smart Sensing Interdisciplinary Science Center Nankai University & TKL of Metal and Molecule Based Material Chemistry Key Laboratory of Advanced Energy materials Chemistry (Ministry of Education) Nankai University Department of Chemistry and Biochemistry University of California San Diego

The conventional design of metal-organic frameworks (MOFs) with room-temperature phosphorescence (RTP) mostly relies on using heavy metals,as the heavy atom effect can effectively increase the efficiency of intersystem crossing (ISC) to get a better phosphorescence *** the first time,we reported the highly efficient RTP of a lithium-based MOF IMU-101 with a lifetime (τ) of 299 ms and a quantum yield (QY) of 4.91%.In addition,MOFs IMU-102 and IMU-103,with sodium and cesium as metal nodes,were successfully *** phosphorescence properties of this series of alkali metal MOFs were systematically studied and *** crystallography and computational calculation show that the mechanism for achieving RTP for this material lies in the ultrashort coordination bond of Li,which enables the reduction of non-radiative ***-101,as a cheap and environmentally friendly room-temperature phosphorescent material,has been further developed into composite polymer inks and bulk *** makes them promising for applications in anti-counterfeiting and information encryption.

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Small extracellular vesicles derived from human induced pluripotent stem cell-differentiated neural progenitor cells mitigate retinal ganglion cell degeneration in a mouse model of optic nerve injury

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Neural Regeneration Research 2025年第2期20卷 587-597页

作者： Tong Li Hui-Min xing Hai-Dong Qian Qiao Gao Sheng-Lan Xu Hua ma Zai-Long Chi State Key Laboratory of Ophthalmology Optometry and Visual ScienceEye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina National Clinical Research Center for Ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina

Several studies have found that transplantation of neural progenitor cells(NPCs)promotes the survival of injured ***,a poor integration rate and high risk of tumorigenicity after cell transplantation limits their clinical *** extracellular vesicles(sEVs)contain bioactive molecules for neuronal protection and *** studies have shown that stem/progenitor cell-derived sEVs can promote neuronal survival and recovery of neurological function in neurodegenerative eye diseases and other eye *** this study,we intravitreally transplanted sEVs derived from human induced pluripotent stem cells(hiPSCs)and hiPSCs-differentiated NPCs(hiPSC-NPC)in a mouse model of optic nerve *** results show that these intravitreally injected sEVs were ingested by retinal cells,especially those localized in the ganglion cell *** with hiPSC-NPC-derived sEVs mitigated optic nerve crush-induced retinal ganglion cell degeneration,and regulated the retinal microenvironment by inhibiting excessive activation of *** analysis further revealed that hiPSC-NPC derived sEVs transported neuroprotective and anti-inflammatory miRNA cargos to target cells,which had protective effects on RGCs after optic nerve *** findings suggest that sEVs derived from hiPSC-NPC are a promising cell-free therapeutic strategy for optic neuropathy.

关键词： exosome miRNA neural progenitor cell neurodegeneration neuroinflammation neuroprotection optic nerve crush optic neuropathy retinal ganglion cell small extracellular vesicles

Postnatal development of rat retina:a continuous observation and comparison between the organotypic retinal explant model and in vivo development

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Neural Regeneration Research 2025年第3期20卷 900-912页

作者： Baoqi Hu rui Wang Hanyue Zhang Xiou Wang Sijia Zhou Bo ma Yan Luan Xin Wang Xinlin Chen Zhichao Zhang Qianyan Kang Department of Ophthalmology The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anShaanxi ProvinceChina Department of Ophthalmology The First Affiliated Hospital of Northwest UniversityXi’anShaanxi ProvinceChina Institute of Neurobiology Xi’an Jiaotong University Health Science CenterXi’anShaanxi ProvinceChina

The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell ***,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development ***,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo *** this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in ***,we used SOX2 and PAX6 immunostaining to identify retinal progenitor *** then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,***-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between ***,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,*** timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant *** study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina *** findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.

关键词： bipolar cells differentiation in vivo microglia Müller glia organotypic retinal explant culture postnatal retina development proliferation retinal progenitor cells

Hydration, Microstructure, and Properties of Sulphoaluminate Cement in Pure Water and Simulated Seawater

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Journal of Wuhan University of Technology(materials Science) 2025年第1期40卷 187-193页

作者： ma Jie China Railway Design Corporation Tianjin 300250China

Paste and mortar specimens were prepared with sulfoaluminate cement(SAC),P⋅O 42.5 ordinary Portland cement(OPC),and standard sand,and mixed and cured with pure water and artificial seawater,*** mechanical properties of mortar specimens were *** and microstructure of paste specimens were also investigated using X-ray diffraction(XRD),scanning electron microscope(SEM),and 27Al nuclear magnetic resonance(NMR),*** results indicate that SAC mortar samples mixed and cured by seawater have faster strength growth before 28 d and higher compressive strength than OPC mortar *** to curing in deionized water,the hydration products of SAC are somewhat coarser when cured in simulated *** evolution of aluminum phase hydration products during the hydration process of SAC mixed and cured in simulated seawater is quite different from that of *** 3 to 28 d,the content of each aluminum phase hydration product in SAC paste cured in simulated seawater changed little,while that in OPC paste changed significantly;for example,from 7 to 28 d,the content of ettringite(AFt)in OPC paste increased *** type of AFt formed loosely,harming the mortar's microstructure.

关键词： sulfoaluminate cement seawater mixing and curing 27Al NMR AFt