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Design and fabrication of Nd-Fe-B magnet with excellent thermal stability

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Journal of Rare Earths 2024年第5期42卷 980-986,I0006页

作者： Rui Han Shengzhi dong dong li dongmin Zhang Hongsheng Chen Jiyuan Xu George CHadjipanayis Zhuolin li Ying Zhang Wei li Division of Functional Materials Research Central Iron and Steel Research InstituteBeijing100081China Department of Physics and Astronomy Sharp Lab University of DelawareNewarkDE19716USA Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing100190China

A novel Nd-Fe-B type permanent magnet with excellent thermal stability was designed by Co replacing Fe in the main phase and the grain boundary phase.The remanence and coercivity temperature coefficient reach 0.058%/℃and 0.465%/℃in the te mperature range from 25 to 100℃,which are much lower than those of commercial Nd-Fe-B magnet.An enhanced Curie temperature is obtained for the novel magnet due to the Co substitution,which significantly improves the operating temperature.The microstructure result reveals that an amorphous phase exists in the intergranular grains which is probably responsible for the deterioration of intrinsic coercivity.This work can provide a reference for the design and optimization of components of sintered Nd-Fe-B magnets with excellent thermal stability.

关键词： Thermal stability Remanence temperature coefficient Operating temperature Atomic substitution Rare earths

Effects of layer interactions on instantaneous stability of finite Stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： Chen ZHAO Zhenli CHEN C.T.MUTASA dong li School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

The stability analysis of a finite Stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite Stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. The oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. The effects of the Stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. The growth rates of two most unstable modes when δ lizing effect on the most unstable mode when δ lizing effect when δ > 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the Stokes-layer interactions are strong. We also find that the stability of the Stokes layer is closely related to the inflectional points of the base-flow velocity profile. The effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. The energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. The effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite Stokes layer instantaneous stability Stokes-layer interaction asynchronous oscillation

Deep learning-based optical aberration estimation enables offline digital adaptive optics and super-resolution imaging

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Photonics Research 2024年第3期12卷 474-484页

作者： CHANG QIAO HAOYU CHEN RUN WANG TAO JIANG YUWANG WANG dong li Department of Automation Tsinghua UniversityBeijing 100084China Institute for Brain and Cognitive Sciences Tsinghua UniversityBeijing 100084China National Laboratory of Biomacromolecules New Cornerstone Science LaboratoryCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China College of life Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Optical aberrations degrade the performance of fluorescence microscopy.Conventional adaptive optics(AO)leverages specific devices,such as the Shack–Hartmann wavefront sensor and deformable mirror,to measure and correct optical aberrations.However,conventional AO requires either additional hardware or a more complicated imaging procedure,resulting in higher cost or a lower acquisition speed.In this study,we proposed a novel space-frequency encoding network(SFE-Net)that can directly estimate the aberrated point spread functions(PSFs)from biological images,enabling fast optical aberration estimation with high accuracy without engaging extra optics and image acquisition.We showed that with the estimated PSFs,the optical aberration can be computationally removed by the deconvolution algorithm.Furthermore,to fully exploit the benefits of SFE-Net,we incorporated the estimated PSF with neural network architecture design to devise an aberration-aware deeplearning super-resolution model,dubbed SFT-DFCAN.We demonstrated that the combination of SFE-Net and SFT-DFCAN enables instant digital AO and optical aberration-aware super-resolution reconstruction for live-cell imaging.

关键词： optics resolution enable

Constructing inter-diffusive PtCuNi/WO_(3)interface to enhance the catalytic activity and stability in oxygen reduction

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Tungsten 2024年第2期6卷 293-303页

作者： Hao-Zhe Xu dong li Ying Chen Pin Fang Xiao-Xing Ke Olga Demidenko Yu-Jing li Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications Experimental Center of Advanced MaterialsSchool of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Scientifi c-Practical Materials Research Centre National Academy of Sciences of Belarus220072 MinskBelarus

Platinum-group-metal-based alloy nanocrystals have been considered as the most effi cient catalysts for oxygen reduction reaction(ORR).However,the poor stability issues limit their further deployment in industrialization.Tungsten oxide(WO_(3))has received attention due to its intrinsic electrochemical stability and proton absorption/desorption capability.In this work,we prepared PtCuNi/WO_(3)/C hybrid catalyst with inter-diff usive alloy/WO_(3)interface on carbon.The catalyst exhibits enhanced activity and stability associated with the WO_(3)content.The characterization results suggest that the increased activity originates from the complementary proton supply of non-stoichiometric H_(x)WO_(3).Moreover,WO_(3)prevents the particle from dissolution and detachment under vigorous electrochemical polarizations.The enhanced stability originates from the electronic interaction established between Pt and W.This work provides new strategies to design high-performance ORR catalysts by taking the merits of WO_(3)。

关键词： Tungsten oxide PtCuNi Interface Electronic interaction

Compound extreme inundation risk of coastal wetlands caused by climate change and anthropogenic activities in the Yellow River Delta,China

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Advances in Climate Change Research 2024年第1期15卷 134-147页

作者： Xiao-li WANG Ai-Qing FENG Xi-Yong HOU Qing-Chen CHAO Bai-Yuan SONG Yu-Bin liU Qi-Guang WANG He XU Yu-Xin ZHANG dong li li-Jie dong Yu GUO CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China Shandong Key Laboratory of Coastal Environmental Processes Yantai 264003China China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Tongji Urban Planning Design Research Institute Shanghai 200092China School of Geography and Tourism Qilu Normal UniversityJinan 250200China China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 10008China University of Chinese Academy of Sciences Beijing 100049China Marine Science and Technology College Zhejiang Ocean UniversityZhoushan 316022China

The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic contributions.However,these wetlands are also vulnerable to the dual threats of climate change and human disturbances.Despite substantial attention to the historical shifts in YRD's coastal wetlands,uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic activities.Based on a range of remote sensing data sources,this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and 2020.Subsequently,the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change(LUCC)simulation using System Dynamic-Future Land Use Simulation(SD-FLUS)model and the extreme water levels projection integrated future sea-level rise,storm surge,and astronomical high tide in 2030,2050,and 2100 under scenarios of SSP1-2.6,SSP2-4.5,and SSP5-8.5.Results revealed that YRD's coastal wetlands underwent a marked reduction,shrinking by 1688.72 km²from 2000 to 2020.This decline was mostly attributed to the substantial expansion in the areas of artificial wetlands(increasing by 823.78 km2),construction land(increasing by 767.71 km²),and shallow water(increasing by 274.58 km²).Looking ahead to 2030-2100,the fate of coastal wetlands appears to diverge based on different scenarios.Under the SSP1-2.6 scenario,the area of coastal wetland is projected to experience considerable growth.In contrast,the SSP5-8.5 scenario anticipates a notable decrease in coastal wetlands.Relative to the inundated area suffered from the current extreme water levels,the study projects a decrease of 6.8%-10.6%in submerged coastal wetlands by 2030 and 9.4%-18.2%by 2050 across all scenarios.In 2100,these percentages are projected to decrease by 0.4%(SSP2-4.5)and 27.1%(SSP5-8.5),but increase by 35.7%(SSP1-2.6).Results suggest that coastal wetlands in the YRD will face a serious compound risk from cli

关键词： Climate change Anthropogenic activities Compound extreme risk Coastal wetlands Yellow River Delta

The single-cell landscape reveals unique tumor subsets and microenvironments associated with poor clinical outcomes in primary testicular diffuse large B-cell lymphoma

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Genes & Diseases 2024年第1期11卷 80-83页

作者： Zhouliang Bian Benhong Gu Guohai Shi Jiahui Guo dong li Hanlin Zengg Bin Jiang Daliu Min Hengchuan Su Yanjie Zhang Department of Oncology Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 201900China Shanghai Institute of Precision Medicine Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200125China Department of Urology Tongren HospitalShanghai Jiao Tong University School of MedicineShanghai 200336China Department of Urology Fudan University Shanghai Cancer CenterShanghai200032China Department of Oncology Shanghai Medical CollegeFudan UniversityShanghai 200032China Department of Oncology Shanghai Jiao Tong University Affiliated Sixth People's HospitalShanghai 200233China

Diffuse large B cell lymphoma(DLBCL)is one of the most prevalent lymphoid malignancies.The current standard of care can cure about two-thirds of DLBCL patients.1 Primary testicular diffuse large B-cell lymphoma(PT-DLBCL)is a rare but highly aggressive form of mature B-cell lymphoma that accounts for approximately 1%-9%of testicular malignancies.Different from nodal DLBCL,PT-DLBCL has a markedly worse prognosis because of inferior response to the current treatment regimens and significant extranodal tropism.2 Three main questions remained unresolved in the field of PT-DLBCL research.

关键词： lymphoma markedly prognosis

Controlled growth of vertically stacked In_(2)Se_(3)/WSe_(2) heterostructures for ultrahigh responsivity photodetector

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Nano Research 2024年第3期17卷 1856-1863页

作者： Cheng Zhang Biyuan Zheng Guangcheng Wu Xueying liu Jiaxin Wu Chengdong Yao Yizhe Wang Zilan Tang Ying Chen lizhen Fang Luying Huang dong li Shengman li Anlian Pan Key Laboratory for Micro-Nano Physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Materials Science and EngineeringHunan UniversityChangsha 410082China

Transition metal dichalcogenides(TMDCs)are promising candidates for future optoelectronic devices accounting for their high carrier mobility and excellent quantum efficiency.However,the limited light absorption efficiency in atomically thin layers significantly hinders photocarrier generation,thereby impairing the optoelectronic performance and hindering practical applications.Herein,we successfully synthesized In_(2)Se_(3)/WSe_(2) heterostructures through a typical two-step chemical vapor deposition(CVD)method.The In_(2)Se_(3) nanosheet with strong light absorption capability,serving as the light absorption layer,was integrated with the monolayer WSe_(2),enhancing the photosensitivity of WSe_(2) significantly.Upon laser irradiation with a wavelength of 520 nm,the In_(2)Se_(3)/WSe_(2) heterostructure device shows an ultrahigh photoresponsivity with a value as high as 2333.5 A/W and a remarkable detectivity reaching up to 6.7×10^(12) Jones,which is the highest among almost the reported TMDCs-based heterostructures grown via CVD even some fabricated by mechanical exfoliation(ME).Combing the advantages of CVD method such as large scale,high yield,and clean interface,the In_(2)Se_(3)/WSe_(2) heterostructures would provide a novel path for future high-performance optoelectronic device.

关键词： transition metal dichalcogenides(TMDCs) In_(2)Se_(3) heterostructure photodetector ultrahigh responsivity

Highly selective growth of(6,5)single-walled carbon nanotubes from sigma phase alloy catalyst

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Nano Research 2024年第3期17卷 1999-2003页

作者： liantao Xin Chen Ma Qianru Wu Shaokang liu linhai li Xiuyun Zhang liu Qian Maoshuai He dong li Fangqian Han Shulan Hao lihu Feng Yahan li Huaping liu lili Zhang Chang liu Jin Zhang College of Chemistry and Molecular Engineering Qingdao University of Science and TechnologyQingdao 266042China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Physics Science and Technology Yangzhou UniversityYangzhou 225002China Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The chirality structure of a single-walled carbon nanotube(SWNT)strongly depends on the composition of catalyst used in the chemical vapor deposition process.In this study,we develop a porous magnesia supported manganese-rhenium(MnRe/MgO)catalyst for chirality-selective synthesis of SWNTs.Detailed characterizations reveal that(6,5)tubes with a selectivity higher than 70%are grown from the Re-rich MnRe/MgO catalyst.By comparing the SWNT growth results with those of monometallic Mn or Re,the formation of sigma phase,an intermetallic compound occurring in transition-metal alloy systems,is revealed to be crucial for the dominant synthesis of(6,5)SWNTs.This work not only extends the application of sigma phase alloy for catalytic synthesis of SWNTs,but also sheds lights on the growth of SWNTs with a high chirality selectivity.

关键词： single-walled carbon nanotubes sigma phase manganese-rhenium catalyst selective growth transition-metal alloy

Application of mesenchymal stem cell therapy for premature ovarian insufficiency: Recent advances from mechanisms to therapeutics

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World Journal of Stem Cells 2024年第1期16卷 1-6页

作者： Hang-Qi Hu Xi-Yan Xin Yu-Tian Zhu Rui-Wen Fan Hao-lin Zhang Yang Ye dong li Department of Traditional Chinese Medicine Peking University Third HospitalBeijing 100191China

The incidence of premature ovarian insufficiency(POI)is increasing worldwide,particularly among younger women,posing a significant challenge to fertility.In addition to menopausal symptoms,POI leads to several complications that profoundly affect female reproductive function and overall health.Unfortunately,current clinical treatment strategies for this condition are limited and often yield unsatisfactory outcomes.These approaches typically involve hormone repla-cement therapy combined with psychological support.Recently,mesenchymal stem cell(MSC)therapies for POI have garnered considerable attention in global research.MSCs can restore ovarian reproductive and endocrine functions through diverse mechanisms,including controlling differentiation,promoting angiogenesis,regulating ovarian fibrosis,inhibiting apoptosis,enhancing autocrine and paracrine effects,suppressing inflammation,modulating the immune system,and genetic regulation.This editorial offers a succinct summary of the application of MSC therapy in the context of POI,providing evidence for groundbreaking medical approaches that have potential to enhance reproductive health and overall well-being for women.

关键词： Mesenchymal stem cell therapy Mechanism Premature ovarian insufficiency Therapeutic Women