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A new quantity in Finsler geometry

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Science China Mathematics 2024年第4期67卷 883-890页

作者： xiaohuan mo Xiaoyang Wang Key Laboratory of Pure and Applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081China

In this paper,we study a new Finslerian quantity■defined by the T-curvature and the angular metric *** show that the■-curvature not only gives a measure of the failure of a Finsler metric to be of scalar flag curvature but also has a vanishing *** find that the■-curvature is closely related to the Riemann curvature,the Matsumoto torsion and theΘ-*** solve ***’s open problem in terms of the■-***,we give a global rigidity result for Finsler metrics of negative Ricci curvature on a compact manifold via the■-curvature,generalizing a theorem previously only known in the case of negatively curved Finsler metrics of scalar flag curvature.

关键词： Finsler metric Finslerian quantity T-curvature -curvature Randers metric

烟草品种和垄作对土壤小型节肢动物多样性的影响

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西南农业学报 2024年第7期37卷 1450-1458页

作者：李治模于晓飞杨茂发杨相吴慧子温明霞黄纯杨杨大星贵州省烟草公司遵义市公司贵州遵义563000 贵州大学烟草学院/贵州省烟草品质研究重点实验室贵阳550025 贵阳学院生物与环境工程学院/贵州省山地珍稀动物与经济昆虫重点实验室/贵州省山地生物资源保护与高效利用工程中心贵阳550005

[目的]探明烟田小环境变化对小型土壤节肢动物群落组成和多样性的影响,为筛选喀斯特植烟区的适栽品种与种植模式提供科学依据。[方法]2022年7月使用干漏斗法对贵州省凤岗县云烟87和K326种植区的小型土壤节肢动物群落组成和多样性进行调... 详细信息

[目的]探明烟田小环境变化对小型土壤节肢动物群落组成和多样性的影响,为筛选喀斯特植烟区的适栽品种与种植模式提供科学依据。[方法]2022年7月使用干漏斗法对贵州省凤岗县云烟87和K326种植区的小型土壤节肢动物群落组成和多样性进行调查,分析小型土壤节肢动物与烟田小环境(品种、种植模式及其交互作用)之间的关联性。[结果]调查共获得小型土壤节肢动物6纲16目70科。云烟87与K326小型土壤节肢动物群落组成差异明显,其中,K326垄体与垄沟的小型土壤节肢动物群落组成存在极显著差异,但云烟87无显著差异;K326垄体与云烟87垄体小型土壤节肢动物群落组成差异极显著,而K326垄沟和云烟87垄沟小型土壤节肢动物群落组成无显著差异。K326小型土壤节肢动物类群数、密度和Shannon指数(H′)分别为4.18、5535.56和1.16,显著高于云烟87(2.12、1720.00和0.65),K326垄体小型土壤节肢动物类群数、密度和Shannon指数(H′)分别为5.47、10520.00和1.40,显著高于垄沟(2.90、551.11和0.92),云烟87垄体小型土壤节肢动物仅密度(3000.00)显著高于垄沟(400.00),类群数和Shannon指数(H′)无显著差异;云烟87垄体小型土壤节肢动物类群数、密度和Shannon指数(H′)分别为1.97、3000.00和0.61,显著低于K326垄体(5.47、10520.00和1.40),而云烟87和K326垄沟间小型土壤节肢动物类群数、密度和Shannon指数(H′)无显著差异。[结论]垄作引起的微地形变化对小型土壤节肢动物的影响受烟草品种调控,垄体小型土壤节肢动物对烟草品种变化较垄沟更为敏感。

关键词：垄沟垄体烟田小型土壤节肢动物多样性

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Finsler warped product metrics with special Riemannian curvature properties

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Science China Mathematics 2020年第7期63卷 1391-1408页

作者： Huaifu Liu xiaohuan mo Hongzhen Zhang College of Applied Sciences Beijing University of TechnologyBeijing 100124China Key Laboratory of Pure and Applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China

One of the fundamental problems in Finsler geometry is to study Finsler metrics of constant(or scalar)*** this paper,we refine and improve Chen-Shen-Zhao equations characterizing Finsler warped product metrics of scalar flag *** particular,we find equations that characterize Finsler warped product metrics of constant flag *** we improve the Chen-Shen-Zhao result on characterizing Einstein Finsler warped product *** its application we construct explicitly many new warped product Douglas metrics of constant Ricci curvature by using known locally projectively flat spherically symmetric metrics of constant flag curvature.

关键词： Finsler metric warped product flag curvature Einstein metric spherically symmetric metric

重型β地中海贫血儿童磁共振成像T2^(*)与生活质量的相关性研究

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中国医药导报 2024年第14期21卷 22-24页

作者：吴悦杜佳宜蓝翔刘丽丽田川莫笑欢叶中绿广东医科大学附属医院儿童医学中心广东湛江524000

目的研究重型β地中海贫血儿童心脏、肝脏磁共振成像(MRI)T2^(*)与生活质量的相关性。方法选取2015年1月至2022年1月于广东医科大学附属医院确诊β地中海贫血的52例患儿进行心脏、肝脏MRI T2^(*)检查,采用中文版儿童生存质量测定量表... 详细信息

目的研究重型β地中海贫血儿童心脏、肝脏磁共振成像(MRI)T2^(*)与生活质量的相关性。方法选取2015年1月至2022年1月于广东医科大学附属医院确诊β地中海贫血的52例患儿进行心脏、肝脏MRI T2^(*)检查,采用中文版儿童生存质量测定量表体系4.0版本(Peds QL4.0)评估生活质量。根据有无心脏受累将铁过载患儿分为两组:有肝脏铁过载但无心脏铁过载者为肝脏组(36例),心脏、肝脏均发生铁过载者为心肝组(16例)。比较两组生活质量与人口学特征,统计分析心脏与肝脏T2^(*)的相关性、MRI T2^(*)与量表总分及各维度分数的相关性。结果 52例患儿心脏铁过载发生率低于肝脏铁过载(P0.05)。两组人口学特征比较,差异无统计学意义(P>0.05)。Pearson相关性分析结果显示,心脏T2^(*)与Peds QL4.0总分及生理功能评分呈正相关(P0.05)。结论心脏铁过载发生率低于肝脏铁过载,且二者铁过载程度无相关性,不能通过肝脏铁负荷判断心脏铁过载程度。β地中海贫血患儿生活质量与心脏T2^(*)有相关性,与肝脏T2^(*)无关,提示心脏铁过载是影响生活质量的重要因素。

关键词：重型β地中海贫血磁共振成像铁过载生活质量

Over 50,000 Metagenomically Assembled Draft Genomes for the Human Oral Microbiome Reveal New Taxa

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Genomics, Proteomics & Bioinformatics 2022年第2期20卷 246-259页

作者： Jie Zhu Liu Tian Peishan Chen mo Han Liju Song Xin Tong xiaohuan Sun Fangming yang Zhipeng Lin Xing Liu Chuan Liu Xiaohan Wang Yuxiang Lin Kaiye Cai Yong Hou Xun Xu Huanming yang Jian Wang Karsten Kristiansen Liang Xiao Tao Zhang Huijue Jia Zhuye Jie BGI-Shenzhen Shenzhen 518083China Shenzhen Key Laboratory of Human Commensal Microorganisms and Health Research BGI-ShenzhenShenzhen 518083China Shenzhen Engineering Laboratory of Detection and Intervention of Human Intestinal Microbiome BGI-ShenzhenShenzhen 518083China Laboratory of Genomics and molecular Biomedicine Department of BiologyUniversity of CopenhagenCopenhagen DK-2100Denmark James D.Watson Institute of Genome Sciences Hangzhou 310058China BGI-Qingdao BGI-ShenzhenQingdao 266555China

The oral cavity of each person is home to hundreds of bacterial *** taxa for oral diseases have been studied using culture-based characterization as well as amplicon sequencing,metagenomic and genomic information remains scarce compared to the fecal ***,using metagenomic shotgun data for 3346 oral metagenomic samples together with 808 published samples,we obtain 56,213 metagenome-assembled genomes(MAGs),and more than 64%of the 3589 species-level genome bins(SGBs)contain no publicly available *** resulting genome collection is representative of samples around the world and contains many genomes from candidate phyla radiation(CPR)that lack ***,it enables the discovery of new taxa such as a genus Candidatus Bgiplasma within the family ***-scale metagenomic data from massive samples also allow the assembly of strains from important oral taxa such as Porphyromonas and *** oral microbes encode genes that could potentially metabolize *** from these findings,a strongly male-enriched Campylobacter species was *** samples would be more user-friendly collected than fecal samples and have the potential for disease ***,these data lay down a genomic framework for future inquiries of the human oral microbiome.

关键词： Metagenomics Human oral microbiome Metagenome-assembly genome Genome catalog Gender

WEYL CURVATURE OF A FINSLER SPACE

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Applied Mathematics(A Journal of Chinese Universities) 2005年第1期20卷 10-20页

作者： moxiaohuan LMAM SchoolofMathematicalSciencesPekingUniversityBeijing100871China.

The Weyl curvature of a Finsler metric is *** curvature constructed from Riemannain *** is an important projective invariant of Finsler *** author gives the necessary conditions on Weyl curvature for a Finsler metric to be Randers metric and presents examples of Randers metrics with non-scalar curvature.A global rigidity theorem for compact Finsler manifolds satisfying such conditions is *** is showed that for such a Finsler manifold,if Ricci scalar is negative,then Finsler metric is of Randers type.

关键词： Finsler manifold Weyl curvature flag curvature tensor.

On Riemann-Finsler geometry

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Chinese Science Bulletin 1998年第6期43卷 447-450页

作者： mo xiaohuan School of Mathematical Sciences, Peking University, Beijing 100871, China School of Mathematical Sciences Peking University Beijing China

The history of Finsler geometry is reviewed and briefly recent development in Finsler geometry and its application is completed systematically. Furthermore, an interesting open problem has been proposed in this field.

关键词： Finsler space Chern connection Hilbert form Minkowski potential projective sphere bundle.

On the Geometry of Horizontally Homotheitic Maps and Harmonic morphisms

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数学进展 1994年第3期 282-283页

作者：莫小欢

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ＯｎｔｈｅＧｅｏｍｅｔｒｙｏｆＨｏｆｉｚｏｎｔａｌｌｙＨｏｍｏｔｈｅｔｉｃＭａｐｓａｎｄＨａｒｍｏｎｉｃＭｏｒｐｈｉｓｍｓＭｏＸｉａｏｈｕａｎ（莫小欢）（ＰｅｋｉｎｇＵｎｉυｅｒｓｉｔｙ，Ｂｅｊｉｎｇ，１００８７１）ＣｏｍｍｕｎｉｃａｔｅｄｂｙＺｈａ...

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Some constructions of projectively flat Finsler metrics

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Science China Mathematics 2006年第5期49卷 703-714页

作者： mo xiaohuan, SHEN Zhongmin & yang Chunhong LMAM, School of Mathematical Sciences, Peking University, Beijing 100871, China Department of Mathematical Sciences, Indiana University-Purdue University, Indianapolis, IN 46202-3216, USA Department of Mathematics, Inner mongolia University, Hohhot 010021, China LMAM School of Mathematical Sciences Peking University Beijing China Department of Mathematical Sciences Indiana University-Purdue University Indianapolis USA Department of Mathematics Inner Mongolia University Hohhot China

In this paper, we find some solutions to a system of partial differential equations that characterize the projectively flat Finsler metrics. Further, we discover that some of these metrics actually have the zero flag ... 详细信息

关键词： Randers metric, (α,β)-metric, Finsler metric, projectively flat metric, Scurvature.