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Time-dependent deviation of bridge pile foundations caused by adjacent large-area surcharge loads in soft soils and its preventive measures

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 184-201页

作者： Shuanglong LI Limin WEI Jingtai NIU Zhiping DENG Bangbin WU wuwen qian Feifei HE School of Hydraulic Engineering Nanchang Institute of TechnologyNanchang 330099China School of Civil Engineering Central South UniversityChangsha 410075China

Time-dependent characteristics(TDCs)have been neglected in most previous studies investigating the deviation mechanisms of bridge pile foundations and evaluating the effectiveness of preventive measures.In this study,the stress-strain-time characteristics of soft soils were illustrated by consolidation-creep tests based on a typical engineering case.An extended Koppejan model was developed and then embedded in a finite element(FE)model via a user-material subroutine(UMAT).Based on the validated FE model,the time-dependent deformation mechanism of the pile foundation was revealed,and the preventive effect of applying micropiles and stress-release holes to control the deviation was investigated.The results show that the calculated maximum lateral displacement of the cap differs from the measured one by 6.5%,indicating that the derived extended Koppejan model reproduced the deviation process of the bridge cap-pile foundation with time.The additional load acting on the pile side caused by soil lateral deformation was mainly concentrated within the soft soil layer and increased with the increase in load duration.Compared with t=3 d(where t is surcharge time),the maximum lateral additional pressure acting on Pile 2#increased by approximately 47.0%at t=224 d.For bridge pile foundation deviation in deep soft soils,stress-release holes can provide better prevention compared to micropiles and are therefore recommended.

关键词： bridge pile foundation surcharge load soft soil time-dependent deformation interaction mechanism preventive measure

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An Investigation into the Compressive Strength,Permeability and Microstructure of Quartzite-Rock-Sand Mortar

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Fluid Dynamics & Materials Processing 2024年第4期20卷 859-872页

作者： Wei Chen wuwen Liu Yue Liang School of Civil Engineering Architecture and EnvironmentHubei University of TechnologyWuhan430068China

River sand is an essential component used as a fine aggregate in mortar and concrete.Due to unrestrained exploitation,river sand resources are gradually being exhausted.This requires alternative solutions.This study deals with the properties of cement mortar containing different levels of manufactured sand(MS)based on quartzite,used to replace river sand.The river sand was replaced at 20%,40%,60%and 80%with MS(by weight or volume).The mechanical properties,transfer properties,and microstructure were examined and compared to a control group to study the impact of the replacement level.The results indicate that the compressive strength can be improved by increasing such a level.The strength was improved by 35.1%and 45.5%over that of the control mortar at replacement levels of 60%and 80%,respectively.Although there was a weak link between porosity and gas permeability in the mortars with manufactured sand,the gas permeability decreased with growing the replacement level.The microstructure of the MS mortar was denser,and the cement paste had fewer microcracks with increasing the replacement level.

关键词： Manufactured sand quartzite compressive strength gas permeability microstructure

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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

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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 security.The 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 crops.Three 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

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Global patterns and ecological drivers of taxonomic and phylogenetic endemism in angiosperm genera

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Plant Diversity 2024年第2期46卷 149-157页

作者： Hong qian Brent D.Mishler Jian Zhang Shenhua qian Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL 62703USA University and Jepson Herbaria Department of Integrative BiologyUniversity of CaliforniaBerkeleyCA 94720-2465USA Center for Global Change and Complex Ecosystems Zhejiang Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Ministry of EducationChongqing UniversityChongqing 400045China

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current distributions.Here,we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the world.We identify centers of paleo-endemism and neo-endemism of angiosperm genera,and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions,particularly in Asia and Australia.Different categories of phylogenetic endemism centers can be differentiated using current climate conditions.Current climate,historical climate change,and geographic variables together explained~80%of global variation in taxonomic and phylogenetic endemism,while 42-46%,1%,and 15%were independently explained by these three types of variables,respectively.Thus our findings show that past climate change,current climate,and geography act together in shaping endemism,which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote endemism.Our study showed that many centers of phylogenetic endemism of angiosperms,including regions in Amazonia,Venezuela,and west-central tropical Africa that have not previously been identified as biodiversity hotspots,are missed by taxon-based measures of endemism,indicating the importance of including evolutionary history in biodiversity assessment.

关键词： Angiosperm Current climate Endemism Historical climate change Topographic heterogeneity

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Current situation and prospect for the diagnosis and treatment of pediatric critical rare diseases in China

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儿科学研究(英文) 2024年第1期8卷 66-71页

作者： Liu Yingchao qian Suyun Pediatric Intensive Care Unit Beijing Children’s Hospital Capital Medical University National Center for Children’s Health Beijing China

The onset of critical rare diseases (RDs) in children is rapid and dangerous, accompanied by a high mortality rate, which brings a heavy burden to both families and society. Multiple malformations, neuromuscular diseases, metabolic diseases, and heart diseases are the most common types of RDs in children of China, often manifesting with multiple organ dysfunction. At present, the diagnosis and treatment of critical RDs in children face challenges such as prolonged diagnosis time, a high misdiagnosis rate, limited treatment modalities, and a significant disease burden. However, with the progress in genetic testing technology, the establishment of multidisciplinary diagnosis and treatment platforms, and the implementation of relevant RD policies in China, children with critical RDs will received enhanced medical services, experience improved prognoses, and reintegrate into social life.

关键词： Children Critical Current situation Prospect Rare diseases

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Reveal more mechanisms of precondition mesenchymal stem cells inhibiting inflammation

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World Journal of Stem Cells 2024年第4期16卷 459-461页

作者： Yi Li qian-qian Chen En-qiang Linghu Department of Gastroenterology First Medical Center of Chinese PLA General HospitalBeijing 100853China Department of Gastroenterology and Hepatology First Medical Center of Chinese PLA General HospitalBeijing 100853China

Hypoxia can get more ability to inhibit inflammation.But how it impact on survival time of mesenchymal stem cells(MSCs)is confusing and how preconditioned MSCs inhibiting inflammation are partially known.Those issues ... 详细信息

关键词： Mesenchymal stem cell Hypoxia-inducible factor 1α Hypoxia Inflammation Macrophage

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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 breeding.Plants with mutated necrotic lesion genes often have persistent broad-spectrum resistance,but this broad-spectrum resistance usually comes at the expense of yield.Currently,many necrotic lesion mutants in rice have been identified,and these genes are involved in disease resistance pathways.This review provides a detailed introduction to the characteristics,classification,and molecular mechanisms of necrotic lesion formation.Additionally,we review the molecular regulatory pathways of genes involved in rice disease resistance.Concurrently,we summarize the relationship between resistance and yield in rice using newly developed gene editing methods.We 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

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Epidemiological research, burden, and clinical advances of inflammatory bowel disease in China

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中华医学杂志(英文版) 2024年第9期137卷 1009-1011页

作者： Yang Hong qian Jiaming Department of Gastroenterology Peking Union Medical College Hospital Chinese Academy of Medical Sciences &amp Peking Union Medical College Beijing China

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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

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