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Journal of Rare Earths 2024年第1期42卷 116-120,I0004页

作者： ruipeng qian Yuxuan Ma Fugang Chen Hui Sun Yong Zhao Yunlong Chen School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003China School of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiang212003China

Grain boundary diffusion process(GBDP)has been developed as an effective approach to increase the coercivity of sintered Nd-Fe-B magnets by regulating the compositions and phase distributions near grain *** work aims to explore how to select the optimum annealing temperature after *** this work GBDP was performed on a sintered Nd-Fe-B magnet using Dy_(70)Cu_(30) *** GBDP the low eutectic temperature of the grain boundary phases decreases from the initial 492 to 451℃.The magnetic property dependent on different annealing temperatures near the low eutectic temperature was *** magnetic properties,especially the squareness factor of demagnetization curve show a strong dependence on the annealing *** GBDP the optimal magnetic properties can be obtained after annealing just above the low eutectic temperature of the grain boundary *** mechanism is discussed based on the microstructure analysis.

关键词： Nd-Fe-B magnet Grain boundary diffusion Annealing Dy_(70)Cu_(30)alloy Rare earths

Study on the disaster caused by the linkage failure of the residual coal pillar and rock stratum during multiple coal seam mining:mechanism of progressive and dynamic failure

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International Journal of Coal Science & Technology 2023年第3期10卷 122-135页

作者： Yunliang Tan Qing Ma Xiaoli Liu Xuesheng Liu Derek Elsworth ruipengg qian Junlong Shang College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China Department of Energy and Mineral Engineering G3 Center and Energy InstituteThe Pennsylvania State UniversityUniversity ParkPA16803USA James Watt School of Engineering University of GlasgowGlasgowG128QQUK

Multi-seam mining often leads to the retention of a significant number of coal pillars for purposes such as protection,safety,or water ***,stress concentration beneath these residual coal pillars can significantly impact their strength and stability when mining below them,potentially leading to hydraulic support failure,surface subsidence,and rock *** address this issue,the linkage between the failure and instability of residual coal pillars and rock strata during multi-seam mining is examined in this *** controls include residual pillar spalling,safety factor(f.),local mine stiffness(LMS),and the post-peak stiffness(k)of the residual coal *** separating the two forms of failure,progressive versus dynamic,are *** failure results at lower stresses when the coal pillar transitions from indefinitely stable(f,>1.5)to failing(f,<1.5)when the coal pillar can no longer remain stable for an extended duration,whereas sud-den(unstable)failure results when the strength of the pillar is further degraded and *** transition in mode of failure is defined by the LMS/k *** transitions from quiescent to dynamic as LMS/k.<1,which can cause chain pillar instability propagating throughout the *** study provides theoretical guidance to define this limit to instability of residual coal pillars for multi-seam mining in similar mines.

关键词： Multi-seam mining Residual coal pillars Rock stratum Linkage instability mechanism Local mine stiffness

Monitoring and evaluation of disaster risk caused by linkage failure and instability of residual coal pillar and rock strata in multi-coal seam mining

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Geohazard Mechanics 2023年第4期1卷 297-307页

作者： Qing Ma Xiaoli Liu Yunliang Tan Yurui Wang Ruosong Wang Enzhi Wang Xuesheng Liu Zenghui Zhao Darui Ren Weiqiang Xie ruipeng qian Nan Hu State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing100084China College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdaoShandong266590China Shandong Energy Xinwen Group Xinjulong CO.LTD Shandong294718China

Comprehensive research methods such as literature research,theoretical analysis,numerical simulations and field monitoring have been used to analyze the disasters and characteristics caused by the linkage failure and instability of the residual coal pillars-rock strata in multi-seam *** effective monitoring area and monitoring design method of linkage instability of residual coal pillar-rock strata in multi-seam mining have been *** evaluation index and the risk assessment method of disaster risk have been established and the project cases have been applied and *** results show that:①The coal pillar will not only cause disaster in singleseam mining,but also more easily cause disaster in multi-seam *** instability of coal pillars can cause not only dynamical disasters such as rock falls and mine earthquakes,but also cause surface subsidence and other disasters.②When monitoring the linkage instability of residual coal pillar-rock strata,it is not only necessary to consider the monitoring of the apply load body(key block),the transition body(residual coal pillar)and the carrier body(interlayer rock and working face),but also to strengthen the monitoring of the fracture development height(linkage body).③According to the principles of objectivity,easy access and quantification,combined with investigation,analysis,and production and geological characteristics of this mining area,the main evaluation indexes of the degree of disaster caused by linkage instability of residual coal pillar-rock strata are determined as:microseismic energy,residual coal pillar damage degree,fracture development *** the evaluation index classification table was also given.④According to the measured value of the evaluation index,the fuzzy comprehensive evaluation method was used to calculate the disaster risk degree in the studied mine belongs to class III,that is,medium risk *** corresponding pressure relief technology was adopted on site,which ach

关键词： Multi-seam mining Residual coal pillar Linkage instability Rock burst Monitor and evaluation

A historical review of hybrid rice breeding

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Journal of Integrative Plant Biology 2024年第3期66卷 532-545页

作者： Xiaoming Zheng Fei Wei Cheng Cheng qian qian State Key Laboratory of Crop Gene Resources and Breeding Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China Yazhouwan National Laboratory Sanya City 572024China

The development of germplasm resources and advances in breeding methods have led to steady increases in yield and quality of rice (Oryza sativa L.). Three milestones in the recent history of rice breeding have contributed to these increases: dwarf rice breeding, hybrid rice breeding, and super rice breeding. On the 50th anniversary of the success of three-line hybrid rice,we highlight important scientific discoveries in rice breeding that were made by Chinese scientists and summarize the broader history of the field. We discuss the strategies that could be used in the future to optimize rice breeding further in the hope that China will continue to play a leading role in international rice breeding.

关键词： Chinese experience dwarf breeding hybrid rice breeding super rice breeding

Special issue:Catenary optics and catenary electromagnetics

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Opto-Electronic Advances 2024年第5期7卷 1-4页

作者： qian Sun Minghui Hong Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

As a natural mathematical form,a catenary is the curve that a hanging chain or cable adopts under its own weight when supported at its ends in a homogeneous gravitational *** unique shape arises from the balance of forces acting on each segment of the chain,resulting in a curve described by hyperbolic cosine *** functions play pivotal roles in describing the electromagnetic field,intensity distribution,and dispersion of structured light on the sub-wavelength scale^(1).

关键词： functions. field. optics

Molecular Mechanism of Rice Necrotic Lesion for Optimized Yield and Disease Resistance

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Rice science 2024年第3期31卷 285-299页

作者： HOU Xinyue WANG Yuping qian qian REN Deyong State Key Laboratory of Rice Biology and Breeding China National Rice Research InstituteHangzhou 310006China State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China Rice Research InstituteSichuan Agricultural UniversityChengdu 611130China

How to balance rice resistance and yield is an important issue in rice *** with mutated necrotic lesion genes often have persistent broad-spectrum resistance,but this broad-spectrum resistance usually comes at the expense of ***,many necrotic lesion mutants in rice have been identified,and these genes are involved in disease resistance *** review provides a detailed introduction to the characteristics,classification,and molecular mechanisms of necrotic lesion ***,we review the molecular regulatory pathways of genes involved in rice disease ***,we summarize the relationship between resistance and yield in rice using newly developed gene editing *** discuss a rational and precise breeding strategy to better utilize molecular design technology for breeding disease-resistant and high-yield rice varieties.

关键词： rice necrotic lesion regulation mechanism high yield high resistance

Localizing vitamin-C through nanoconfinement enables high-rate CO_(2) electrolysis to ethylene

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Science China Materials 2024年第3期67卷 1006-1008页

作者： Zhengyi qian Shaojun Guo School of Materials Science and Engineering Peking UniversityBeijing 100871China

The electrosynthesis of value-added fuels and chemicals from carbon dioxide reduction reaction(CO_(2)RR)is a promising approach for realizing the objectives of carbon neutrality[1].Nevertheless,the current production of desirable multicarbon(C_(2+))chemicals,such as ethylene(C_(2)H_(4)),still encounters challenges related to low selectivity,low current density,and the requirement for high-purity feeding gas[2].

关键词： enable purity dioxide

The tangential k-Cauchy-Fueter type operator and Penrose type integral formula on the generalized complex Heisenberg group

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 181-190页

作者： REN Guang-zhen SHI Yun KANG qian-qian Department of Mathematics Zhejiang International Studies UniversityHangzhou 310023China Department of Mathematics Zhejiang University of Science and TechnologyHangzhou 310023China

The tangential k-Cauchy-Fueter operator and k-CF functions are counterparts of the tangential Cauchy–Riemann operator and CR functions on the Heisenberg group in the theory of several complex variables,*** this paper,we introduce a Lie group that the Heisenberg group can be imbedded into and call it generalized complex *** investigate quaternionic analysis on the generalized complex *** also give the Penrose integral formula for k-CF functions and construct the tangential k-Cauchy-Fueter complex.

关键词： the generalized complex Heisenberg group the tangential k-Cauchy-Fueter type operator Penrose-type integral formula

Unveiling a half-century mystery of molecular bases for three-line hybrid rice breeding system

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Journal of Integrative Plant Biology 2024年第1期66卷 3-6页

作者： Xiaoming Zheng qian qian State Key Laboratory of Crop Gene Resources and Breeding Chinese Academy of Agricultural SciencesBeijing 100081China Yazhouwan National Laboratory No.8 Huanjin RoadYazhou DistrictSanya 572024China

Rice(Oryza sativa L.)isa staplecropforhalf theworld's Ipopulation and an important contributor to world food *** discovery and application of cytoplasmic male sterility(CMS)and fertility restoration(Rf)genetic materials have allowed the production of three-line hybrid rice(Kim and Zhang,2018),successfully harnessing heterosis in *** major CMS and/or Rf systems are commonly used to produce three-line hybrid rice:Wild Abortive(CMS-WA),Boroll(CMS-BT),and Honglian(CMS-HL).Among these,the CMS-WA system is the most widely employed(Sattari et al.,2007;Chen and Liu,2014;Huang et al.,2014).Several Rf genes from different CMS systems have been cloned in rice,including Rf4 for CMS-WA(Tang et al.,2014),Rf1a and Rf1b for CMS-BT(Wang et al.,2006),Rf5,and Rf6 for CMS-HL(Huet al.,2012;Huang et al.,2015),and Rf19for CMS-FA(Jiang et al.,2022).A molecular mechanism and evolutionary model for the CMS-WA gene WA352c have also been reported(Luo et al.,2013;Tang et al.,2017).

关键词： breeding fertility Wild

Spatial Distribution Pattern and Influencing Factors of Bed-and-breakfasts(B&Bs)from the Perspective of Urban-rural Differences:A Case Study of Jiaodong Peninsula,China

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Chinese Geographical Science 2024年第4期34卷 752-763页

作者： WANG Xinyue MA qian Management College Ocean University of ChinaQingdao 266100China

There are significant differences between urban and rural bed-and-breakfasts(B&Bs)in terms of customer positioning,economic strength and spatial *** identifying the differences in spatial characteristics and influencing factors of each type,is essential for creating urban and rural B&B agglomeration *** study used density-based spatial clustering of applications with noise(DBSCAN)and the multi-scale geographically weighted regression(MGWR)model to explore similarities and differences in the spatial distribution patterns and influencing factors for urban and rural B&Bs on the Jiaodong Peninsula of China from 2010 to *** results showed that:1)both urban and rural B&Bs in Jiaodong Peninsula went through three stages:a slow start from 2010 to 2015,rapid development from 2015 to 2019,and hindered development from 2019 to ***,urban B&Bs demonstrated a higher development speed and agglomeration intensity,leading to an increasingly evident trend of uneven development between the two sectors.2)The clustering scale of both urban and rural B&Bs continued to expand in terms of quantity and *** B&B clusters characterized by a limited number,but a higher likelihood of transitioning from low-level to high-level *** the number of rural B&B clusters steadily increased over time,their clustering scale was comparatively lower than that of urban B&Bs,and they lacked the presence of high-level clustering.3)In terms of development direction,urban B&B clusters exhibited a relatively stable pattern and evolved into high-level clustering centers within the main urban ***,rural B&Bs exhibited a more pronounced spatial diffusion effect,with clusters showing a trend of multi-center development along the coastline.4)Transport emerged as a common influencing factor for both urban and rural B&Bs,with the density of road network having the strongest explanatory power for their spatial *** terms of differences,populati

关键词： urban-rural bed-and-breakfasts(B&Bs) spatiotemporal evolution density-based spatial clustering of applications with noise(DBSCAN)model multi-scale geographically weighted regression(MGWR) Jiaodong Peninsula China