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Global trends of tropopause folds in recent decades

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Atmospheric and Oceanic Science Letters 2024年第3期17卷 14-19页

作者： Yufeng Lin Wenshou Tian Haiyang xue Jiali Luo Jiankai Zhang Hongying Tian Wenjun Liang College of Atmospheric Sciences Lanzhou UniversityLanzhouChina School of Atmospheric Sciences Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-sen UniversityZhuhaiChina

对流层顶折卷是平流层-对流层物质交换的主要机制.本研究采用三维标记方法,利用1979-2020年间的ERA5再分析数据,分析了对流层顶折卷的时空变化特征及机理.研究结果表明,全球对流层顶折卷的多年变化趋势存在明显的季节性和区域性差异.总... 详细信息

对流层顶折卷是平流层-对流层物质交换的主要机制.本研究采用三维标记方法,利用1979-2020年间的ERA5再分析数据,分析了对流层顶折卷的时空变化特征及机理.研究结果表明,全球对流层顶折卷的多年变化趋势存在明显的季节性和区域性差异.总体上,对流层顶折卷呈增加趋势,其中北半球的春季,夏季和冬季,对流层顶折卷主要沿副热带急流区呈现明显增加的趋势.进一步分析表明,对流层顶折卷发生频率的增加与大气斜压性增大导致的锋生增强有关,而经向位温梯度的增大使得次级环流增强,也可能促进了对流层顶折卷活动的增多.

关键词：对流层顶折卷趋势锋生大气斜压性

A phylogenetic approach identifies patterns of beta diversity and floristic subregions of the Qinghai-Tibet Plateau

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Plant Diversity 2024年第1期46卷 59-69页

作者： Haibin Yu Man Yang Zixin Lu Weitao Wang Fangyuan Yu Yonghua Zhang xue Yin Hongjun Yu Junjie Hu David C.Deane Key Laboratory of Conservation and Application in Biodiversity of South China School of Life SciencesGuangzhou UniversityGuangzhou 510006China School of Ecology Sun Yat-Sen UniversityShenzhen 510275China School of Geography and Remote sensing Guangzhou UniversityGuangzhou 510006China College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China Centre for Future Landscapes and Department of Environment and Genetics La Trobe UniversityBundooraVIC 3083Australia

Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.

关键词： Biogeographical regionalization Phylogenetic beta diversity Seed plants Sørensen dissimilarity Qinghai-Tibet Plateau

锌基镀层热成形钢裂纹的产生、扩展机理及高温力学性能研究

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Journal of Central South University 2024年第2期31卷 399-415页

作者：李学涛朱国森马闻宇邵蓉张永强郑学斌 Research Institute of Technology of Shougang Group Co. Ltd.Beijing 100043China Beijing Key Laboratory of Green Recycling Process for Iron&Steel Production Technology Beijing 100043China Beijing Engineering Research Centre of Energy Steel Beijing 100043China

本文通过锌基镀层热成形钢的Gleeble试验和实际零件热冲压试验,在材料高温性能分析的基础上,建立了材料模型,用于高精度地拟合真应力和真应变之间的关系,进而研究成形温度、铁素体形成和弯曲变形对液态锌致基板脆裂(LMIE)的影响。结果表... 详细信息

本文通过锌基镀层热成形钢的Gleeble试验和实际零件热冲压试验,在材料高温性能分析的基础上,建立了材料模型,用于高精度地拟合真应力和真应变之间的关系,进而研究成形温度、铁素体形成和弯曲变形对液态锌致基板脆裂(LMIE)的影响。结果表明,真应力随着变形温度的下降而增加。当变形温度为820℃时,LMIE导致真应变较低,约为0.13。根据Gleeble热模拟测试和实际零件试验结果,建议成形温度为720℃,可以避免LMIE并保证材料的力学性能。在实际应用中,拉应力容易导致微裂纹的产生,而压应力可以抑制微裂纹的产生。随着成形温度的降低,镀层中微裂纹的数量和宽度降低,同时镀层厚度增加。镀层主要为固态α-Fe(Zn)相。通过减少在加热保温和成形过程中的液态相可以减少甚至避免LMIE裂纹的产生。

关键词：热成形钢锌基镀层断裂直接热冲压微观组织

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智慧物流嵌入农产品文化建设发展研究

物流工程与管理 2024年第1期46卷 104-107页

作者：薛成森山东外事职业大学山东威海264504

随着消费者对于农产品的品质和安全性要求不断提高,农产品文化建设愈发重要。智慧物流技术可以帮助农产品在市场上更好地传达其文化内涵,提升产品形象,增加产品附加值。文中通过灰色关联分析法研究农产品智慧物流发展的评价指标体系,确... 详细信息

随着消费者对于农产品的品质和安全性要求不断提高,农产品文化建设愈发重要。智慧物流技术可以帮助农产品在市场上更好地传达其文化内涵,提升产品形象,增加产品附加值。文中通过灰色关联分析法研究农产品智慧物流发展的评价指标体系,确定对其关联度较大的因素,从而提出建立农产品文化品牌标准化管理体系、建立农产品文化品牌溯源体系、塑造农产品品牌文化的智慧物流体系和农产品文化建设联合发展对策。

关键词：智慧物流农产品文化文化营销灰色关联分析

Microbiota in colorectal cancer related to liver metastasis

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Chinese Journal of Cancer Research 2024年第1期36卷 17-24页

作者： Peijun Wei Weiming Han Zitong Zhang xue Tian Chen Yang Qiaoxuan Wang Weihao Xie Ying Liu Yuanhong Gao Hui Chang Department of Radiation Oncology State Key Laboratory of Oncology in South ChinaGuangzhou 510060China Guangdong Provincial Clinical Research Center for Cancer Guangzhou 510060China Sun Yat-sen University Cancer Center Guangzhou 510060China Department of Pediatric Oncology State Key Laboratory of Oncology in South ChinaGuangzhou 510060China

The prevalence of colorectal cancer(CRC) is increasing annually and metastasis is the principal cause of death in patients with CRC, with the liver being the most frequently affected site. Many studies have shown a strong interplay between the gut flora, particularly Fusobacterium nucleatum(F. nucleatum), Escherichia coli, and Bacteroides fragilis, and the development of gut tumors. Some strains can induce gut inflammation and produce toxins that directly harm gut epithelial cells, ultimately accelerating the onset and progression of CRC. However,little clinical evidence exists on the specific interplay between the gut microflora and colorectal cancer liver metastasis(CRLM). Some research showed the existence of viable F. nucleatum in distant metastasis of CRC.Subsequently, gut microbiota products, such as lipopolysaccharides, sodium butyrate, and protein cathepsin K, were also found to affect the development of CRC. This article summarizes the mechanism and research status of the interplay between gut microflora and CRLM, discusses the importance of gut microflora in the treatment of CRLM, and proposes a new approach to understanding the mechanism of CRLM and potential treatments for the microbiome. It is anticipated that the gut microbiota will be a formidable therapeutic and prophylactic tool for treating and preventing CRLM.

关键词： Gut microbiota liver metastasis colorectal cancer

植被覆盖度增加对辽宁地区气温变化的影响研究

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大气科学 2024年第2期48卷 463-479页

作者：易雪李得勤杨森李涛公颖潘晓崔锦中国气象局沈阳大气环境研究所沈阳110166 东北冷涡研究重点开放实验室沈阳110166 西安财经大学统计学院西安710010

植被覆盖度(Fractional Vegetation Coverage,简称FVC)是陆面参数中重要的参数之一,植被覆盖度变化直接影响地表能量的再分配进而影响区域乃至全球气候变化,研究植被覆盖度增加对区域气候的影响对未来区域气候变化的预估具有重要意义,... 详细信息

植被覆盖度(Fractional Vegetation Coverage,简称FVC)是陆面参数中重要的参数之一,植被覆盖度变化直接影响地表能量的再分配进而影响区域乃至全球气候变化,研究植被覆盖度增加对区域气候的影响对未来区域气候变化的预估具有重要意义,这对适应和缓解全球气候变暖至关重要。本文利用2001~2018年中分辨率成像光谱仪(MODIS)产品的植被归一化指数(Normalized Difference Vegetation Index,简称NDVI)数据制作植被覆盖度,在辽宁地区分别进行了WRF模式默认植被覆盖度和实际植被覆盖度的长时间(2001~2018年)模式模拟试验,结论如下:(1)辽宁地区因植被覆盖度增加全省年平均气温降低了0.48℃,其中夏季降温幅度最大,降温0.71℃,春、秋两季平均降温0.35℃和0.66℃,冬季降温幅度最小0.2℃。植被覆盖度增加对日最高、最低气温也有明显的降温作用,其中日最低气温对植被覆盖度增加的响应大于最高气温,且植被覆盖度增加与气温降温的空间分布具有较好一致性。(2)2001~2018年年均和四季植被覆盖度的显著增加对年均和四季平均气温、日最高气温、日最低气温均有降温趋势,尤其是对日最低气温降温作用更明显。(3)植被覆盖度增加导致气温降低的主要原因是由于蒸散发的增加导致潜热通量增加,感热通量减少;而对于日最低气温降低,主要是由于植被覆盖度增加导致地表温度降低进而引起夜间向上长波辐射减少。总体而言,植被覆盖度增加越多降温效果越明显,进而减缓辽宁省气候变暖。

关键词：植被覆盖度气温 WRF 模式辽宁

LncRNA XR_378418对肝星状细胞生物学行为及转录组学影响

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安徽医科大学学报 2024年第1期59卷 127-132页

作者：张雪陈森汪小莉周秋梅安徽中医药大学药学院合肥230012 安徽中医药大学第一附属医院临床研究实验中心合肥230031

目的探究长链非编码RNA(LncRNA)XR_378418在肝星状细胞JS-1生物学行为中的作用,并基于转录组测序探索LncRNA XR_378418参与肝纤维化发生的潜在分子机制。方法构建重组质粒pcDNA-LncRNA XR_378418和pcDNA-NC,分别转染JS-1细胞;通过实时... 详细信息

目的探究长链非编码RNA(LncRNA)XR_378418在肝星状细胞JS-1生物学行为中的作用,并基于转录组测序探索LncRNA XR_378418参与肝纤维化发生的潜在分子机制。方法构建重组质粒pcDNA-LncRNA XR_378418和pcDNA-NC,分别转染JS-1细胞;通过实时荧光定量PCR(RT-qPCR)、细胞计数试剂盒8(CCK-8)以及划痕实验分别检测LncRNA XR_378418的表达水平、JS-1细胞增殖和迁移情况;通过高通量测序分析LncRNA XR_378418对JS-1细胞转录组学的影响。结果RT-qPCR结果显示,过表达组中的LncRNA XR_378418表达水平高于对照组(P<0.05);CCK-8和划痕结果显示,LncRNA XR_378418表达增加后,JS-1细胞增殖和迁移能力增强;高通量测序结果显示,共挑选出248个差异基因,其中上调的基因有127个、下调的基因有117个;基因本体论(GO)功能富集分析和京都基因与基因组百科全书(KEGG)功能富集分析结果显示,LncRNA XR_378418过表达改变了JS-1细胞部分基因的转录能力,参与调控细胞黏附、细胞自噬、Ca 2+信号传导等功能。结论LncRNA XR_378418可促进JS-1细胞增殖和迁移,影响JS-1细胞中细胞黏附、钙离子信号转导等相关基因的表达。

关键词：长链非编码RNA 肝纤维化肝星状细胞高通量测序

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多源数据驱动的台风动态风险评估

热带地理 2024年第6期44卷 1102-1112页

作者：刘蓓蓓赵飞王曦闫雪林森应急管理部国家减灾中心北京100124

灾害动态风险评估是灾前风险管理的重要依据。文章基于2009—2022影响中国东南5省的108个台风案例近4000个县级灾情,融合30类多源风险要素指标,建立台风动态风险评估样本库,并利用随机森林算法建立了6个台风灾害风险评估模型,用于灾害... 详细信息

灾害动态风险评估是灾前风险管理的重要依据。文章基于2009—2022影响中国东南5省的108个台风案例近4000个县级灾情,融合30类多源风险要素指标,建立台风动态风险评估样本库,并利用随机森林算法建立了6个台风灾害风险评估模型,用于灾害事件发生前对受灾人口、紧急转移安置人口、农作物受灾面积、倒塌和严重损坏房屋、直接经济损失等风险等级以及综合风险等级进行评估。通过实际灾情与模型结果进行验证,灾害风险评估结果准确率整体达到80%以上,表明该模型具有较好的泛化能力,可用于实际灾害评估工作。实验对比发现,训练样本量提高1~2个数量级能使模型评估准确率提升3%~14%,表明灾害风险大数据的积累对灾害风险评估研究具有重要意义。

关键词：台风灾害风险评估灾害大数据数据融合评估指标随机森林台风“暹芭”

On the Identification of N-rich Metal-poor Field Stars with Future Chinese Space Station Telescope

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Research in Astronomy and Astrophysics 2024年第1期24卷 151-164页

作者： Jiajun Zhang Baitian Tang Jiang Chang Xiangxiang xue JoséGFernández-Trincado Chengyuan Li Long Wang Hao Tian Yang Huang School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China CSST Science Center for the Guangdong-Hong Kong-Macao Greater Bay Area Sun Yat-sen UniversityZhuhai 519082China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210034China Key Lab of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Instituto de Astronomía Universidad Católica del NorteAv.Angamos 0610AntofagastaChile Key Lab of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

During the long term evolution of globular clusters(GCs), some member stars are lost to the field. The recently found nitrogen-rich(N-rich) metal-poor field stars are promising candidates of these GC escapees, since N enhancement is the fingerprint of chemically enhanced populations in GCs. In this work, we discuss the possibility of identifying N-rich metal-poor field stars with the upcoming Chinese Space Station Telescope(CSST). We focus on the main survey camera with NUV, u, g, r, i, z, y filters and slitless spectrograph with a resolution about 200.The combination of UV sensitive equipment and prominent N-related molecular lines in the UV band bodes well for the identification: the color–color diagram of(u-g) versus(g-r) is capable of separating N-rich field stars from normal halo stars, if metallicity can be estimated without using the information on u-band photometry.Besides, the synthetic spectra show that a signal-to-noise ratio of 10 is sufficient to identify N-rich field stars. In the near future, a large sample of N-rich field stars found by CSST, combined with state-of-the-art N-body simulations will be crucial to deciphering GC-Galaxy co-evolution.

关键词： stars:chemically peculiar stars:abundances techniques:photometric techniques:spectroscopic