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Inelastic Scattering of Dark Matter with Heavy Cosmic Rays

Research in Astronomy and Astrophysics 2024年第6期24卷 68-80页

作者： Keyu Lu Yue-Lin Sming Tsai Qiang yuan Le Zhang School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China CSST Science Center for the Guangdong-Hong Kong-Macao Greater Bay Area SYSUZhuhai 519082China Peng Cheng Laboratory Shenzhen 518000China

We investigate the impact of inelastic collisions between dark matter(DM)and heavy cosmic ray(CR)nuclei on CR *** approximate the fragmentation cross-sections for DM-CR collisions using collider-measured proton-nuclei scattering cross-sections,allowing us to assess how these collisions affect the spectra of CR boron and *** derive new CR spectra from DM-CR collisions by incorporating their cross-sections into the source terms and solving the diffusion equation for the complete network of reactions involved in generating secondary *** a specific example with a coupling strength of b_(χ)=0.1 and a DM mass of m_(χ)=0.1 GeV,considering a simplified scenario where DM interacts exclusively with oxygen,a notable modification in the boron-to-carbon spectrum due to the DM-CR interaction is ***,the peak within the spectrum,spanning from 0.1 to 10 GeV,experiences an enhancement of approximately 1.5 ***,in a more realistic scenario where DM particles interact with all CRs,this peak can be amplified to twice its original *** the latest data from AMS-02 and DAMPE on the boron-to-carbon ratio,we estimate a 95%upper limit for the effective inelastic cross-section of DM-proton as a function of DM *** findings reveal that at m_(χ)?2 MeV,the effective inelastic cross-section between DM and protons must be less than O(10^(-32))cm^(2).

关键词： elementary particles nuclear reactions nucleosynthesis abundances scattering astroparticle physics (cosmology:)dark matter

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Construction of multi-structures based on Cu NWs-supported MOF-derived Co oxides for asymmetric pseudocapacitors

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Journal of Materials Science & Technology 2021年第6期65卷 182-189页

作者： Ruimei yuan Hejun Li Xuemin Yin Peipei Wang Jinhua Lu Leilei Zhang State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research CenterNorthwestern Polytechnical UniversityXi'an 710072China

Cu@MOF core-shell nanowires are synthesized by introducing oxidizable and CTAB-modified metal nanowires as self-engaged templates and supporting MOFs for a one-dimension *** following thermal process is controlled to obtain several one-dimension structure s ofCuCo-mixed materials,such as nanorods,single-shell and double-shell *** hollow structure for electrode materials enlarges the surface area,provides buffer space for electrolyte to accelerate the ion/charge transfers and for the structure to reduce injuries of volume expansion during *** with some other merits,such as adequate oxidation of the MOFs,small crystal grains of the material,and well-mixed Cu/Co oxides,the double-shell Cu@MOF nanowires(CuCo-DS5)applied for pseudocapacitors deliver advanced electrochemical performance with a specific capacitance of 563.8 F g^(-1)at 1 A g^(-1)as well as an outstanding cycling stability with a 92%retention after 3000 cycles at 5 A g^(-1).Meanwhile,an asymmetric pseudocapacitor constructed with the CuCo-DS5 and active carbon(AC)shows a high specific capacitance and energy density.

关键词： Modified nanowires MOF-derived Hollow Core-shell Double-shell Energy storage

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Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

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Advances in Atmospheric Sciences 2024年第6期41卷 1251-1263页

作者： Hong HUANG Dan WU yuan WANG Zhen WANG Yu LIU College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China No.31631 Army of PLA Huizhou 516000China School of Atmospheric Sciences and Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing 210023China No.93721 Army of PLA Shuozhou 038300China

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track *** characteristics of the six hard-clustered ETCs with the highest membership coefficient are *** tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these *** landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one *** frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four *** surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying *** results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

关键词： Western North Pacific tropical cyclone extratropical transition fuzzy c-means clustering method

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In situ direct reprogramming of astrocytes to neurons via polypyrimidine tract-binding protein 1 knockdown in a mouse model of ischemic stroke

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Neural Regeneration Research 2024年第10期19卷 2240-2248页

作者： Meng yuan Yao Tang Tianwen Huang Lining Ke En Huang Key Laboratory of Brain Aging and Neurodegenerative Diseases of Fujian Province Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Human Anatomy School of Basic Medical SciencesFujian Medical UniversityFuzhouFujian ProvinceChina Scientific Research Center School of Basic Medical SciencesFujian Medical UniversityFuzhouFujian ProvinceChina Department of Neurology Fujian Medical University Union HospitalFuzhouFujian ProvinceChina Fujian Key Laboratory of Vascular Aging Fujian Medical UniversityFuzhouFujian ProvinceChina

In situ direct reprogramming technology can directly convert endogenous glial cells into functional neurons in vivo for central nervous system repair. Polypyrimidine tract-binding protein 1(PTB) knockdown has been shown to reprogram astrocytes to functional neurons in situ. In this study, we used AAV-PHP.e B-GFAP-sh PTB to knockdown PTB in a mouse model of ischemic stroke induced by endothelin-1, and investigated the effects of GFAP-sh PTB-mediated direct reprogramming to neurons. Our results showed that in the mouse model of ischemic stroke, PTB knockdown effectively reprogrammed GFAP-positive cells to neurons in ischemic foci, restored neural tissue structure, reduced inflammatory response, and improved behavioral function. These findings validate the effectiveness of in situ transdifferentiation of astrocytes, and suggest that the approach may be a promising strategy for stroke treatment.

关键词： astrocyte in situ direct reprogramming ischemic stroke miR-30 based shRNA neuron polypyrimidine tract-binding protein 1 transdifferentiation

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UAMP-Based Delay-Doppler Channel Estimation for OTFS Systems

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China Communications 2023年第10期20卷 70-84页

作者： Zhongjie Li Weijie yuan Qinghua Guo Nan Wu Ji Zhang Department of Electronic and Electrical Engineering Southern University of Science and TechonologyShenzhen 518055China School of Electrical Computer and Telecommunications EngineeringUniversity of WollongongWollongongNSW 2522Australia School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China School of Mathematics and Statistics Henan University of Science and TechnologyLuoyang 471000China

Orthogonal time frequency space(OTFS)technique,which modulates data symbols in the delay-Doppler(DD)domain,presents a potential solution for supporting reliable information transmission in highmobility vehicular *** this paper,we study the issues of DD channel estimation for OTFS in the presence of fractional *** first propose a channel estimation algorithm with both low complexity and high accuracy based on the unitary approximate message passing(UAMP),which exploits the structured sparsity of the effective DD domain channel using hidden Markov model(HMM).The empirical state evolution(SE)analysis is then leveraged to predict the performance of our proposed *** refine the hyperparameters in the proposed algorithm,we derive the update criterion for the hyperparameters through the expectation-maximization(EM)***,Our simulation results demonstrate that our proposed algorithm can achieve a significant gain over various baseline schemes.

关键词： orthogonal time frequency space(OTFS) channel estimation hidden Markov model(HMM) unitary approximate message passing(UAMP)

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Assessing the impacts of natural conditions and human activities on terrestrial water storage in Loess Plateau,China

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Journal of Mountain Science 2023年第7期20卷 1921-1939页

作者： WANG Cheng-xi YAN Jian-wu LIANG Wei SUN Shao-bo GOU Fen LI Xiao-fei LUO yuan-yuan WANG Feng-jiao School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China National Demonstration Center for Experimental Geography Education Shaanxi Normal UniversityXi'an 710119China Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China

The gravity recovery and climate experiment(GRACE)has emerged as a crucial source of land water storage information in hydrological analysis and *** factors contribute to regional terrestrial water storage(TWS),resulting in a complex *** the Loess Plateau region,the continuous alteration of natural conditions and profound impact of human activities have posed a serious threat to the natural ecosystem,leading to an escalating trend of TWS *** the specific analysis of how natural conditions and human activities affect TWS represents a pressing *** study employed the residual analysis method to discern the contribution rates of natural conditions and human activities,elucidated the spatial and temporal changes associated with each factor,and ascertained their individual *** findings indicated that TWS on the Loess Plateau exhibited a downward trend of-4.89 mm·a^(-1)from 2003 to *** combined effects of climate change and human activities accounted for alterations in water resource reserves across most areas of the Loess Plateau,with human activities predominantly driving these *** emerged as the primary natural factor influencing TWS variations,and NDVI demonstrated a positive feedback effect on TWS at approximately 30%.Substantial spatial disparities in TWS existed within the Loess Plateau,with human activities identified as the primary cause for the decreasing *** restoration plays a positive role in saving water resources in the Loess Plateau to some extent,and vegetation growth exceeding the regional load will lead to water shortage.

关键词： Terrestrial water storage Residual analysis Human activity the Loess Plateau

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Free-standing flexible graphene-based aerogel film with high energy density as an electrode for supercapacitors

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Nano Materials Science 2021年第1期3卷 68-74页

作者： Shijia yuan Wei Fan Yanan Jin Dong Wang Tianxi Liu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringInnovation Center for Textile Science and TechnologyDonghua University2999 North Renmin RoadShanghai201620PR China Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi214122PR China Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Centre for High-efficiency Display and Lighting TechnologySchool of Materials and EngineeringCollaborative Innovation Centre of Nano Functional Materials and ApplicationsHenan UniversityKaifeng475004PR China

Two-dimensional graphene film exhibits sluggish ion diffusivity while three-dimensional(3D)graphene aerogel has low packing density and poor mechanical ***,there is an urgent need for graphenebased film with both mechanical robustness and high specific ***,we present an easy and scalable strategy for fabricating a free-standing flexible graphene-based aerogel film electrode with a two-layered structure,in which the top layer is an interconnected macroporous reduced graphene oxide/carbon nanotube(RGO/CNT)aerogel,and the bottom layer is a flexible electrospun polyacrylonitrile(PAN)nanofiber *** porous 3D structure of the aerogel provides fast transport of electrolyte ions and electrons,while the nanofiber membrane provides both strong support for the aerogel and mechanical ***(PPy)can be uniformly loaded on RGO/CNT/PAN(RCP)composite aerogel film to provide pseudocapacitance,and nitrogen-doped RGO/CNT/carbon nanofiber(NRCC)aerogel film can be obtained by further *** resultant RCP@PPy-0.05//NRCC based asymmetric supercapacitor can have a maximum voltage of 1.7 V and a maximum energy density of 60.6 W h kg^(-1)at 850.2 W kg^(-1).This indicates that free-standing graphene-based aerogel film can be used in flexible supercapacitors.

关键词： Graphene Aerogel film Polypyrrole N-doping Supercapacitor

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Synergistic effect of Si and K in improving the growth,ion distribution and partitioning of Lolium perenne *** saline-alkali stress

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Journal of Integrative Agriculture 2021年第6期20卷 1660-1673页

作者： FAN yuan SHEN Wu-yan Pino VANESSA CHENG Fang-qin Institute of Resources and Environmental Engineering Shanxi University/State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste ResourcesTaiyuan 030006P.R.China Sydney Institute of Agriculture School of Life and Environmental SciencesThe University of SydneyNSW 2006Australia

The application of Si or K has proven to be beneficial for the growth of plants under saline-alkali stress. However, the synergistic effect of Si and K in improving the growth, ion distribution, and partitioning in Lolium perenne L. under saline-alkali stress remains unclear. In this study, the growth characteristics and ion-selective absorption of ryegrass(Lolium perenne L.) exposed to different levels of saline-alkali stress were evaluated. The growth parameters of ryegrass were significantly improved when Si was applied by itself or coupled with K under low saline-alkali stress. Under a high saline-alkali level, only simultaneous application of Si and K could significantly improve the growth of ryegrass. When Si and K were applied together, the K^(+)/Na^(+) and Ca^(2+)/Na^(+) ratios in root, stem, and leaf of ryegrass were maximally improved as compared to the individual treatments and control. The K^(+) and Ca^(2+) concentrations in the vacuole, cell wall, and organelle of leaf were increased dramatically. This improvement was due to the ability of applied ions to compete with Na^(+), allowing the plant to maintain osmotic potential and leaf water content. The concentration of Na^(+) was significantly reduced when Si and K were applied and mainly concentrated in the soluble fraction and cell wall. The Si concentration in ryegrass increased markedly by the combined application of Si and K, and most of it was accumulated in the cell wall and soluble fraction, which could help in chlorophyll synthesis, reduce membrane injury, and increase water absorption under saline-alkali stress. This study emphasized the advantage of Si and/or K on the growth of plants under different saline-alkaline levels and provided a guide for the production of Si-K fertilizer and its application in saline-alkali soil.

关键词： saline-alkali stress Si K ryegrass plants K+/Na+ compartmentation

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Robust magnetic laccase-mimicking nanozyme for oxidizing o-phenylenediamine and removing phenolic pollutants

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Journal of Environmental Sciences 2020年第2期32卷 103-111页

作者： Siqi Zhang Feifei Lin Qipeng yuan Juewen Liu Ye Li Hao Liang State key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Department of Chemistry and Waterloo Institute for Nanotechnology University of WaterlooWaterlooOntario N2L 3G1Canada Department of Biotechnology Beijing PolytechnicYi Zhuang Economic and Technological Development ZoneBeijing 100176China

In this study, we report a novel magnetic biomimetic nanozyme(Fe3O4@Cu/GMP(guanosine5′-monophosphate)) with high laccase-like activity, which could oxidize toxic ophenylenediamine(OPD) and remove phenolic *** magnetic laccase-like nanozyme was readily obtained via complexed Cu2+and GMP that grew on the surface of magnetic Fe3O4 *** prepared Fe3O4@Cu/GMP catalyst could be magnetically recycled for at least five cycles while still retaining above 70% *** a laccase mimic,Fe3O4@Cu/GMP had more activity and robust stability than natural laccase for the oxidization of ***3O4@Cu/GMP retained about 90% residual activity at 90℃ and showed little change at pH 3–9, and the nanozyme kept its excellent activity after long-term ***, Fe3O4@Cu/GMP had better activity for removing phenolic compounds, and the removal of naphthol was more than 95%.Consequently, the proposed Fe3O4@Cu/GMP nanozyme shows potential for use as a robust catalyst for applications in environmental remediation.

关键词： Nanozymes Laccase o-Phenylenediamine Phenolic compounds Magnetic nanoparticles

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Resolution enhancement of digital holographic microscopy via synthetic aperture:a review

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Light(Advanced Manufacturing) 2022年第1期3卷 82-97页

作者： Peng Gao Caojin yuan School of Physics and Optoelectronic Engineering Xidian UniversityXi’an 710071China Academy of Advanced Interdisciplinary research Xidian UniversityXi’an 710071China Key Laboratory for Opto-Electronic Technology of Jiangsu Province Nanjing Normal UniversityNanjing 210023China

Digital holographic microscopy(DHM),which combines digital holography with optical microscopy,is a wide field,minimally invasive quantitative phase microscopy(QPM)approach for measuring the 3D shape or the inner structure of transparent and translucent ***,limited by diffraction,the spatial resolution of conventional DHM is relatively low and incompatible with a wide field of view(FOV)owing to the spatial bandwidth product(SBP)limit of the imaging *** the past decades,many efforts have been made to enhance the spatial resolution of DHM while preserving a large FOV by trading with unused degrees of *** modulation techniques,such as oblique illumination,structured illumination,and speckle illumination,can enhance the resolution by adding more high-frequency information to the recording *** enhancement is also achieved by extrapolation of a hologram or by synthesizing a larger hologram by scanning the sample,the camera,or inserting a diffraction grating between the sample and the *** on-chip DHM,spatial resolution is achieved using pixel super-resolution *** this paper,we review various resolution enhancement approaches in DHM and discuss the advantages and disadvantages of these *** is our hope that this review will contribute to advancements in DHM and its practical applications in many fields.

关键词： Digital holographic microscopy Resolution enhancement Computational imaging Illumination modulation

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