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Mechanical and damping performances of TPMS lattice metamaterials fabricated by laser powder bed fusion

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China Foundry 2024年第4期21卷 327-333页

作者： Yan-peng Wei Huai-qian Li Jing-jing han Ying-chun Ma Hao-ran Zhou Jing-chang cheng Jian Shi zhi-quan Miao Bo Yu Feng Lin National Key Laboratory of Advanced Casting Technologies Shenyang Research Institute of Foundry Co.Ltd.CAMShenyang 110022China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Key Laboratory of Space Physics Beijing 100076China

Lattice metamaterials based on three-period minimum surface(TPMS)are an effective means to achieve lightweight and high-strength materials which are widely used in various fields such as aerospace and ***,its vibration and noise reduction,and damping properties have not been fully ***,in this study,the TPMS structures with parameterization were designed by the method of surface migration,and the TPMS structures with high forming quality was manufactured by laser powder bed fusion(LPBF).The mechanical properties and energy absorption characteristics of the beam and TPMS structures were studied and compared by quasi-static *** modal shapes of the beam lattice structures and TPMS structures were obtained by the free modal analysis,and the damping properties of two structures were obtained by modal *** the two structures after heat treatment with the same porosity of 70%,the yield strength of the beam lattice structure reaches 40.76 MPa,elastic modulus is 20.38 GPa,the energy absorption value is 32.23 MJ·m^(-3),the damping ratio is 0.52%.The yield strength,elastic modulus,energy absorption value,and damping ratio of the TPMS structure are 50.74 MPa,25.37 GPa,47.34 MJ·m^(-3),and 0.99%,*** results show that TPMS structures exhibit more excellent mechanical properties and energy absorption,better damping performance,and obvious advantages in structural load and vibration and noise reduction compared with the beam lattice structures under the same porosity.

关键词： lattice metamaterials TPMS energy absorption damping laser powder bed fusion

Printable,flexible ceramic fiber paper based on electrospinning

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Rare Metals 2024年第6期43卷 2739-2746页

作者： Yong-Shuai Xie Yuan cheng Yang Lyu Rui Li Jie-Cai han National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150001China State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Based on the fact that it is challenging for the polymer flexible circuit substrates to meet the requirements of serving in high-temperature environments,this work proposed the idea of using printable ceramic fiber paper as a high-temperature flexible circuit substrate.A ceramic fiber paper with all ceramic components had been developed via electrospinning,solving the problems of low strength and severe strength drop at high temperatures of traditional ceramic fiber *** tensile strength of the prepared ceramic fiber paper is 2.63 MPa,and the reliable service temperature is 1200℃.Its bulk density is about 1.5 times that of traditional ceramic fiber *** can be printed with patterns by commercial inkjet printers like ordinary printing paper and has excellent *** feasibility of ceramic fiber paper as a flexible circuit substrate was verified by constructing a simple *** the fiber paper is significantly bent,the circuit still forms a complete path,which proves that it has a strong application potential for high-temperature flexible circuit substrate and is expected to promote the development of flexible electronic devices serving at extreme high-temperature environments.

关键词： Ceramic fiber paper High temperature Inkjet printing Flexible electronic

Discriminative explicit instance selection for implicit discourse relation classification

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Frontiers of Computer Science 2024年第4期18卷 129-138页

作者： Wei SONG Hongfei han Xu han Miaomiao cheng Jiefu GONG Shijin WANG Ting LIU Information Engineering College Capital Normal UniversityBeijing 100048China iFLYTEK AI Research Institute Hefei 230088China Research Center for Social Computing and Information Retrieval Harbin Institute of TechnologyHarbin 150006China

Discourse relation classification is a fundamental task for discourse analysis,which is essential for understanding the structure and connection of *** discourse relation classification aims to determine the relationship between adjacent sentences and is very challenging because it lacks explicit discourse connectives as linguistic cues and sufficient annotated training *** this paper,we propose a discriminative instance selection method to construct synthetic implicit discourse relation data from easy-to-collect explicit discourse *** expanded instance consists of an argument pair and its sense *** introduce the argument pair type classification task,which aims to distinguish between implicit and explicit argument pairs and select the explicit argument pairs that are most similar to natural implicit argument pairs for data *** also propose a simple label-smoothing technique to assign robust sense labels for the selected argument *** evaluate our method on PDTB 2.0 and PDTB *** results show that our method can consistently improve the performance of the baseline model,and achieve competitive results with the state-of-the-art models.

关键词： discourse analysis PDTB discourse relation implicit discourse relation classification data expansion

Recent process developments in beneficiation and metallurgy of rare earths:A review

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Journal of Rare Earths 2024年第4期42卷 629-642页

作者： Shaokai cheng Wenbo Li Yuexin han Yongsheng Sun Peng Gao Xiaolong Zhang School of Resources and Civil Engineering Northeastern UniversityShenyang110819China National-local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources Shenyang110819China

Rare earth elements(REEs)are irreplaceable materials supporting low-carbon technology and equip-ment,and their commercial demand and strategic position are becoming increasingly *** the continuous depletion of rare earth(RE)resources,developing high-efficiency beneficiation and eco-friendly metallurgical processes has attracted widespread *** paper reviews the major minerals exploited for RE production and their deposits,as well as the beneficiation and metallurgical processes of RE ***,monazite,mixed RE ores,and ion-adsorption clays are the main raw materials in the world to ***-bearing ores(except ion-adsorption minerals)are generally beneficiated by flotation,gravity and magnetic separation *** mainstream metallurgical processes for bastnaesite,monazite and mixed RE concentrates are oxidation roasting-HCl leaching,caustic soda decomposition and high-temperature concentrated sulfuric acid roasting,***-adsorption clays are directly processed by in situ leaching-precipitation/solvent *** achieve the sustainable development of RE resources,it is essential to further explore innovative techniques to achievecomprehensive utilization and cleaner production.

关键词： Rare earths Beneficiation processes Metallurgical processes Cleaner production

A Comparative Study on the Post-Buckling Behavior of Reinforced Thermoplastic Pipes(RTPs)Under External Pressure Considering Progressive Failure

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China Ocean Engineering 2024年第2期38卷 233-246页

作者： DING Xin-dong WANG Shu-qing LIU Wen-cheng YE Xiao-han College of Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China Department of Marine Technology Norwegian University of Science and Technology(NTNU)Trondheim NO-7491Norway

The collapse pressure is a key parameter when RTPs are applied in harsh deep-water *** investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are *** the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary *** for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with *** has been observed that the cross-section of the middle part collapses when it reaches the maximum *** collapse pressure obtained from the numerical simulations agrees well with that in the ***,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also *** has a relatively greater difference because of the ignorance of the progressive failure of *** the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.

关键词： reinforced thermoplastic pipes post-buckling behavior progressive failure of composites debonding initial ovality

Transcriptome-based analysis of key signaling pathways affecting the formation of primordial germ cell in chickens

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Journal of Integrative Agriculture 2024年第5期23卷 1644-1657页

作者： Ying Ding Qiong zhi Qisheng Zuo Kai Jin Wei han Bichun Li Key Laboratory of Animal Genetics Breeding and Molecular Design of Jiangsu ProvinceCollege of Animal Science and TechnologyYangzhou UniversityYangzhou 225009China Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China Yangzhou UniversityYangzhou225009China Poultry Research Institute Chinese Academy of Agricultural Sciences/Jiangsu Institute of Poultry ScienceYangzhou 225009China

Bone morphogenetic protein 4(BMP4)can induce the formation of chicken primordial germ cells(PGCs)in vitro;however,its regulatory mechanism in poultry remains *** study aimed to use RNA-seq to analyze PGCs in chicken embryos and iPGCs induced by BMP4 in vitro,clarify the internal regulatory factors of PGCs,analyze the mechanism of the formation of PGCs,and lay a theoretical foundation for the further optimization of PGCs induction *** stem cells(ESCs),PGCs and iPGCs induced by BMP4 in vitro were *** transcriptional maps of the three cell types were studied using *** results showed 6,142 genes differentially expressed between PGCs and iPGCs,of which 2,728 were upregulated in iPGCs and 3,414 were downregulated in *** to that in ESCs,BMP4 was significantly upregulated in PGCs and *** results showed that both the TGF-βand Wnt signaling pathways were activated during the formation of PGCs in vitro and in vivo,and the activation was more significant during iPGCs induced by *** expression of Nodal,an inhibitory factor of TGF-βsignaling,was significantly decreased in PGCs and iPGCs,but was not expressed in iPGCs,which further supports our ***,the Lysosome and PI3K-AKT signaling pathways were significantly enriched in PGCs and iPGCs,***,transmission electron microscopy(TEM)results showed that the number of autolysosomes was significantly higher after the addition of BMP4,which is consistent with the KEGG ***,the number of PGCs was significantly reduced after ATG14 was interfered in vivo and in *** conclusion,this study screened out the key signaling pathways during the formation of PGCs,aiming to provide help for enriching the mechanism network regulating PGCs formation in chicken and laying a theoretical foundation for further improving the efficiency of inducing PGCs in vitro.

关键词： RNA-seq BMP4 PGCs ATG14 chicken

Molecular mechanism for the unusual enhancement of the second-step chemiluminescence production from the carcinogenic tetrabromohydroquinone and H2O_(2)

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Journal of Environmental Sciences 2024年第7期141卷 330-342页

作者： Zi-han Wang Chun-Hua Huang zhi-Sheng Liu Li Mao Ben-Zhan Zhu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Environment and Resources University of Chinese Academy of SciencesBeijing 100049China

We have found recently that two-step intrinsic hydroxyl radical(·OH)-dependent chemiluminescence(CL)could be produced by carcinogenic tetrahaloquinone and H_(2)O_(2).However,the first-step CL was too fast to clearly detect the stepwise generation of·OH and CL,and to distinguish the exact dividing point between the first-step and second-step *** we found that,extremely clear two-step intrinsic CL could be produced by the relative slow reaction of tetrabromohydroquinone(TBHQ)with H_(2)O_(2),which was directly dependent on the two-step·OH ***,the second-step,but not the first-step CL production of TBHQ/H_(2)O_(2)(CRET donor)was markedly enhanced by fluorescein(a typical xanthene dye,CRET acceptor)through a unique chemiluminescence resonance energy transfer(CRET)*** novel CRET system of TBHQ/H_(2)O_(2)/fluorescein was successfully applied for the sensitive detection of TBHQ with the detection limit as low as 2.5μmol/*** findings will help to develop more sensitive and highly efficient CL or CRET systems and specific CL sensor to detect the carcinogenic haloquinones,which may have broad environmental applications.

关键词： Two-step chemiluminescence Bromohydroquinone Hydrogen peroxide Hydroxyl radical CRET

Accelerated aging and frailty in cardiovascular diseases

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Journal of Geriatric Cardiology 2024年第8期21卷 828-830页

作者： Xue-Hua cheng Tao WU Li han Department of Traditional Chinese Medicine Geriatrics Huadong Hospital Affiliated to Fudan UniversityShanghaiChina

Aging is the greatest risk factor for cardiovascular disease(CVD),which is the most common cause of death in European countries.[1]It is estimated that during the period from 2020 to 2022,there were 9.0%more excess deaths from CVD than expected.[2]By 2030,approximately 20%of the population will be aged 65 years and older,and CVD will account for 40%of deaths in this age group,[3]imposing a significant burden on the healthcare system and society as a *** is related to frailty,which represents the dynamic progression of physical and physiological decline in older *** limits an individual’s ability to recover from acute stressors and serves as a predictor of clinical adverse *** the uncertainties in screening,assessing,and managing frailty in clinical practice,emphasizing the connections between frailty,aging,and CVD will provide new insights for the prediction,prevention and management of CVD in the aging population.

关键词： aging prevention prediction

Compact magneto-optical traps using planar optics

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Chinese Physics B 2024年第9期33卷 93-108页

作者： zhi Tan Bo Lu chengyin han Chaohong Lee Institute of Quantum Precision Measurement State Key Laboratory of Radio Frequency Heterogeneous IntegrationCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China

Magneto-optical traps (MOTs) composed of magnetic fields and light fields have been widely utilized to cool andconfine microscopic particles. Practical technology applications require miniaturized MOTs. The advancement of planaroptics has promoted the development of compact MOTs. In this article, we review the development of compact MOTs basedon planar optics. First, we introduce the standardMOTs. We then introduce the gratingMOTs with micron structures, whichhave been used to build cold atomic clocks, cold atomic interferometers, and ultra-cold sources. Further, we introducethe integrated MOTs based on nano-scale metasurfaces. These new compact MOTs greatly reduce volume and powerconsumption, and provide new opportunities for fundamental research and practical applications.

关键词： magneto-optical trap (MOT) planar optics grating MOT metasurface MOT