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Improvement of Microstructure and Mechanical Properties of Rapid Cooling Friction Stir-welded A1050 Pure Aluminum

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 134-141页

作者：许楠 LIU Lutao song Qining ZHAO Jianhua BAO Yefeng College of Materials Science and Engineering Hohai UniversityChangzhou 213200China

Two-mm thick A1050 pure aluminum plates were successfully joined by conventional and rapid cooling friction stir welding(FSW), respectively. The microstructure and mechanical properties of the welded joints were investigated by electron backscatter diffraction characterization, Vickers hardness measurements, and tensile testing. The results showed that liquid CO_(2) coolant significantly reduced the peak temperature and increased the cooling rate, so the rapidly cooled FSW joint exhibited fine grains with a large number of dislocations. The grain refinement mechanism of the FSW A1050 pure aluminum joint was primarily attributed to the combined effects of continuous dynamic recrystallization, grain subdivision, and geometric dynamic recrystallization. Compared with conventional FSW, the yield strength, ultimate tensile strength, and fracture elongation of rapidly cooled FSW joint were significantly enhanced, and the welding efficiency was increased from 80% to 93%. The enhanced mechanical properties and improved synergy of strength and ductility were obtained due to the increased dislocation density and remarkable grain refinement. The wear of the tool can produce several WC particles retained in the joint, and the contribution of second phase strengthening to the enhanced strength should not be ignored.

关键词： aluminum alloy friction stir welding recrystallization microstructure mechanical properties

CHIT1-positive microglia act as culprits for spinal motor neuron aging

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Science China(Life Sciences) 2024年第4期67卷 847-848页

作者： Zhao Wang Wantong Cai Weihong song Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine Vision and Brain Health)Institute of AgingKey Laboratory of Alzheimer’s Disease of Zhejiang ProvinceThe Second Affiliated HospitalWenzhou Medical UniversityWenzhou 325035China

Aging is one of the primary factors in spinal cord-associated disorders(Roberts,1990).However,the effects of aging on the spinal cord and the age-specific mechanisms underlying this relationship remain *** neurons(MNs... 详细信息

关键词： aging Roberts positive

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Ship recognition based on HRRP via multi-scale sparse preserving method

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Journal of Systems Engineering and Electronics 2024年第3期35卷 599-608页

作者： YANG Xueling ZHANG Gong song Hu College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Lab of Radar Imaging and Microwave Photonics Ministry of EducationNanjing 210016China Nanjing Marine Radar Institute Nanjing 210016China

In order to extract the richer feature information of ship targets from sea clutter, and address the high dimensional data problem, a method termed as multi-scale fusion kernel sparse preserving projection(MSFKSPP) based on the maximum margin criterion(MMC) is proposed for recognizing the class of ship targets utilizing the high-resolution range profile(HRRP). Multi-scale fusion is introduced to capture the local and detailed information in small-scale features, and the global and contour information in large-scale features, offering help to extract the edge information from sea clutter and further improving the target recognition accuracy. The proposed method can maximally preserve the multi-scale fusion sparse of data and maximize the class separability in the reduced dimensionality by reproducing kernel Hilbert space. Experimental results on the measured radar data show that the proposed method can effectively extract the features of ship target from sea clutter, further reduce the feature dimensionality, and improve target recognition performance.

关键词： ship target recognition high-resolution range profile(HRRP) multi-scale fusion kernel sparse preserving projection(MSFKSPP) feature extraction dimensionality reduction

Transfer of Highest Weight Modules and Small Unipotent Representations

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Acta Mathematica Sinica,English Series 2024年第3期40卷 772-791页

作者： Hai An HE Jing song HUANG Kayue Daniel WONG Department of Mathematics College of SciencesShanghai UniversityShanghai 200444P.R.China Newtouch Center for Mathematics of Shanghai University Shanghai 200444P.R.China Mathematics Research Center School of Science and EngineeringThe Chinese University of Hong KongShenzhen 518172P.R.China

We study the transfer between small special unipotent representations for all equal rank real forms of type E_(6) and E_(7). As a consequence, one can verify these modules are unitarity using the results of Wallach an... 详细信息

关键词： Unipotent representations Wallach representations Transfer of unitary modules

Telomere-to-telomere genome of the allotetraploid legume Sesbania cannabina reveals transposon-driven subgenome divergence and mechanisms of alkaline stress tolerance

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Science China(Life Sciences) 2024年第1期67卷 149-160页

作者： Haofei Luo Xiaofei Wang Changqing you Xuedan Wu Duofeng Pan Zhiyao Lv Tong Li Dongmei Zhang Zhongbao Shen Xiaodong Zhang Guodao Liu Kaixuan He Qingtong Ye Yajun Jia Qinghua Zhao Xian Deng Xiaofeng Cao Xianwei song Gai Huang State Key Laboratory of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Hainan Yazhou Bay Seed Lab Sanya 572025China University of Chinese Academy of Sciences Beijing 100049China Institute of Forage and Grassland Sciences Heilongjiang Academy of Agricultural SciencesHarbin 150086China Shandong Academy of Agricultural Sciences Jinan 250100China National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land Dongying 257345China Shandong Green Manure Ecological Technology Co. LtdDongying 257345China State Key Laboratory of Tropical Crop Breeding Chinese Academy of Tropical Agricultural SciencesHaikou 571101China

Alkaline soils pose an increasing problem for agriculture worldwide,but using stress-tolerant plants as green manure can improve marginal ***,we show that the legume Sesbania cannabina is very tolerant to alkaline conditions and,when used as a green manure,substantially improves alkaline *** understand genome evolution and the mechanisms of stress tolerance in this allotetraploid legume,we generated the first telomere-to-telomere genome assembly of *** spanning~2,087 *** assembly included all centromeric regions,which contain centromeric satellite repeats,and complete chromosome ends with telomeric *** genome analysis distinguished A and B subgenomes,which diverged approximately 7.9 million years *** genomic analysis revealed that the chromosome homoeologs underwent large-scale inversion events(>10 Mb)and a significant,transposon-driven size expansion of the chromosome 5A *** further identified four specific alkali-induced phosphate transporter genes in ***;these may function in alkali tolerance by relieving the deficiency in available phosphorus in alkaline *** work highlights the significance of *** as a green tool to improve marginal lands and sheds light on subgenome evolution and adaptation to alkaline soils.

关键词： Sesbania cannabina alkaline stress telomere-to-telomere genome legume green manure phosphate transporter allotetraploid

Integrative regulatory mechanisms of stomatal movements under changing climate

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Journal of Integrative Plant Biology 2024年第3期66卷 368-393页

作者： Jingbo Zhang Xuexue Chen Yajing song Zhizhong Gong State Key Laboratory of Nutrient Use and Management College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China State Key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBeijing 100094China Institute of Life Science and Green Development School of Life SciencesHebei UniversityBaoding 071001China

Global climate change-caused drought stress,high temperatures and other extreme weather profoundly impact plant growth and development,restricting sustainable crop *** cope with various environmental stimuli,plants can optimize the opening and closing of stomata to balance CO_(2)uptake for photosynthesis and water loss from *** cells perceive and integrate various signals to adjust stomatal pores through turgor pressure *** mechanisms and signaling networks underlying the stomatal movements in response to environmental stresses have been extensively studied and *** review focuses on the molecular mechanisms of stomatal movements mediated by abscisic acid,light,CO_(2),reactive oxygen species,pathogens,temperature,and other *** discussed the significance of elucidating the integrative mechanisms that regulate stomatal movements in helping design smart crops with enhanced water use efficiency and resilience in a climate-changing world.

关键词： environmental stress guard cell plant regulatory mechanisms stomatal movements

Effect of Air Distribution on the Transport Characteristics of Solid Particles in the Thermal Storage and Release System of Circulating Fluidized Bed

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Journal of Thermal Science 2024年第4期33卷 1554-1563页

作者： JI Zengcai song Guoliang TANG Zihua SUN Liwei State Key Laboratory of Coal Conversion Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Dalian National Laboratory for Clean Energy Dalian116023China

Solid particle heat storage technology offers a potential solution to the challenges posed by the significant growth of renewable energy sources,particularly in terms of grid security and ***,it has the capability to optimize the energy utilization efficiency of the power *** order to investigate the transport regulation characteristics of solid particles in the thermal storage and release system of a circulating fluidized bed(CFB),a test rig with a capacity of 0.1 MW(th)was *** rig was utilized to systematically study the transport regulation characteristics of solid particles under the double U-type valve feed structure and U-type valve discharge *** experimental findings indicate that the system's design enables efficient and rapid storage and release of solid particles in the *** air distribution mode,specifically the double U-type valve feed structure and the U-type valve discharge structure,significantly influence the feed and discharge characteristics of the ash storage *** was observed that the impact of loose air on these characteristics is more substantial than that of the return air,irrespective of the feed structure or the return *** adjusting the feed and discharge rate,it is recommended to adopt a scheme that involves coarse adjustment through loose air and fine adjustment through return air.

关键词： solid particle thermal storage air distribution mode transport regulation

Centennial Analysis of Human Activity Intensity and Associated Historical Events in Heilongjiang River Sino-Russo Watershed

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Chinese Geographical Science 2024年第2期34卷 280-293页

作者： song Chaoxue LI Xiaoling HE Hongshi Michael SUNDE School of Geographical Sciences Northeast Normal UniversityChangchun 130024China School of Natural Resources University of MissouriColumbia 65211USA

Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global *** the forces driving human activity change is important for the development of transborder *** this study,we used global historical land cover data,the hemeroby index model,and synthesized major historical events to analyze how human activity intensity changed in the Heilongjiang River(Amur River in Russia)watershed(HLRW).The results showed that there was a strong spatial heterogeneity in the variation of human activity intensity in the HLRW over the past century(1900-2016).On the Chinese side,the human activity intensity change shifted from the plain areas for agricultural reclamation to the mountainous areas for timber *** the Russian side,human activity intensity changes mostly concentrated along the Trans-Siberian Railway and the Baikal-Amur *** variation of human activity intensity tended to respond to regional events while regionalized variation tends to reflect national policy change or broad international *** similarities and differences between China and Russia in policies and positions in international events resulted in synchronous and asynchronous changes in human activity ***,policy shifts were often confined by the natural features of the *** results reveal the historical origins and fundamental connotations of watershed development and contribute to formulating regional management policies that coordinate population,eco-nomic,social,and environmental activities.

关键词： human activity intensity changes hemeroby index centennial scale Heilongjiang River(Amur River in Russia)watershed China Russia

Ultra-flexible all-in-one anti-freeze photothermally enhanced supercapacitors

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Nano Research 2024年第8期17卷 7221-7229页

作者： Yongxin Lu Keke Li Yan-Yan song Zhida Gao Condense matter of physics College of ScienceNortheazistern UniversityShenyang 110004China

Wearable electronics powered by flexible energy storage devices have captured global *** low-temperature conditions,unfortunately,solidification of flexible hydrogel electrolyte and decreased pseudo-capacity of these devices largely hamper their practical *** this study,photothermally-active Prussian blue(PB)was introduced onto poly(3,4-ethylenedioxythiophene)/polyacrylamide(PEDOT/PAM)networks to address the challenges of electrolyte solidification and degraded pseudo-capacitance for flexible all-in-one device at low *** as-constructed PB/PEDOT/PAM hydrogel device delivers stable electrochemical performance and remarkable mechanical property with 1652%***,this hydrogel device well retains its flexibility in cold environment with a freezing point below−30℃.The incorporation of PB extends the voltage range to 1.5 V as a single device,thus significantly enhancing the electrochemical performance as an all-inone integrated *** from the outstanding photo-to-thermal conversion ability of embedded PB nanocubes,the temperature of the assembled all-in-one PB/PEDOT/PAM device increased from^(−2)0 to 17.7℃ after solar-light irradiation for only 5 ***,the degraded pseudo-capacitance was subsequently boosted to 287.1%of its original capacitance at−20℃.This study establishes a connection between flexible all-solid-state hydrogel devices and photothermally enhanced pseudocapacitors in freezing environments,thereby expanding the potential applications of multi-functional pseudo-capacitors.

关键词： all-in-one energy storage devices all-solid-state photothermal flexible low temperatures