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Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China
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作者 Rong Ma qi xu +3 位作者 Yongqian Gao Deli Peng Hang Sun Bo Song 《Plant Diversity》 SCIE CAS CSCD 2024年第2期158-168,共11页
Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and mai... Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change. 展开更多
关键词 Floral traits Fruit type Growth form Pollination system Reproductive phenology
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基于多性状模型内蒙古绒山羊早期生长性状基因组预测准确性研究
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作者 高林豫 许琦 +10 位作者 何钰霄 习海娇 刘一帆 张涛 李金泉 张燕军 王瑞军 吕琦 梅步俊 苏蕊 王志英 《遗传》 CAS CSCD 北大核心 2024年第5期421-430,共10页
内蒙古绒山羊是经过长期自然选择和人工选育后形成的优良家畜品种,是目前世界一流的绒肉兼用山羊。多性状动物模型被认为可以显著提高畜禽遗传评估的准确性,实现性状间的间接选择。本文基于内蒙古绒山羊个体的系谱、基因型、环境以及早... 内蒙古绒山羊是经过长期自然选择和人工选育后形成的优良家畜品种,是目前世界一流的绒肉兼用山羊。多性状动物模型被认为可以显著提高畜禽遗传评估的准确性,实现性状间的间接选择。本文基于内蒙古绒山羊个体的系谱、基因型、环境以及早期生长性状的表型记录,建立多性状动物模型,利用ABLUP、GBLUP、ssGBLUP三种方法进行早期生长性状(初生重、断乳重、断乳前平均日增重、周岁重)遗传参数及基因组育种值的估计,进一步利用五倍交叉验证方法评价基因组育种值估计准确性和可靠性。结果显示,3种方法估计的初生重遗传力为0.13~0.15,断乳重遗传力为0.13~0.20,日增重遗传力为0.11~0.14,周岁重遗传力为0.09~0.14,均属于中等偏低遗传力;断乳重和日增重、日增重和周岁重之间存在强的正遗传相关,相关系数分别为0.77~0.79和0.56~0.67,表型相关发现同样的规律;ABLUP、GBLUP和ssGBLUP法估计的初生重育种值准确性分别为0.5047、0.6694、0.7156,断乳重分别为0.6207、0.6456、0.7254;日增重分别为0.6110、0.6855、0.7357,周岁重分别为0.6209、0.7155、0.7756。综上所述,内蒙古绒山羊早期生长性状属于中等偏低遗传力,对其进行遗传选育改良速度相对较慢;通过对断乳重的选择可以实现其他生长性状的遗传改良;ssGBLUP方法估计内蒙古绒山羊早期生长性状基因组育种值的准确性和可靠性均最高,且显著高于ABLUP法,说明该方法是内蒙古绒山羊早期性状基因组选育的最佳方法。 展开更多
关键词 内蒙古绒山羊 早期生长性状 多性状动物模型 基因组育种值估计准确性
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Total flavonoids of Astragalus membranaceus protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity in mice by inhibiting ferroptosis through SLC7A11/GPX-4 signaling pathway 被引量:1
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作者 Zitian Gao Gaorui Wang +6 位作者 Yujie Chen Wuke Yuan Jun Cai Aiping Feng Jie Fang qi xu Xiaojun Wu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期414-420,共7页
Parkinson’s disease(PD)is a common neurodegenerative disorder with no cure.Astragalus membranaceus is used in Chinese culture as a food supplement to boost immunity.The present study aimed to explore the neuroprotect... Parkinson’s disease(PD)is a common neurodegenerative disorder with no cure.Astragalus membranaceus is used in Chinese culture as a food supplement to boost immunity.The present study aimed to explore the neuroprotective effects of total flavonoids extracted from A.membranaceus(TFA)and their protective mechanisms.TFA offered neuroprotection against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)in the mouse model of Parkinsonism,by improving behavior performance in the gait analysis and pole test,and inhibiting the decline of tyrosine hydroxylase(TH)positive neurons and TH protein expression in substantia nigra of mice.TFA also prevented 1-methyl-4-phenylpyridinium(MPP+)induced neurotoxicity in SHSY5Y cells,by increasing GSH and GSH/GSSG ratio,and reducing reactive oxygen species.In addition,the neuroprotective effects of TFA were associated with its ability to restore MPTP/MPP+induced downregulation of SLC7A11 and glutathione peroxidase 4(GPX-4).In conclusion,we demonstrated that TFA exerted significant neuroprotection against MPTP/MPP+induced neurodegeneration by inhibiting ferroptosis through the regulation of SLC7A11/GPX-4 axis,suggesting the use of TFA as a possible food supplement in the prevention of PD. 展开更多
关键词 Parkinson’s disease Total fl avonoids of Astragalus membranaceus Ferroptosis SLC7A11
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基于Cusp电子枪的太赫兹回旋管理论研究
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作者 齐旭 张一帆 +3 位作者 宋韬 王维 张开春 刘頔威 《真空电子技术》 2024年第3期22-27,共6页
为解决回旋管工作在太赫兹频段遇到的严重模式竞争问题,基于Cusp电子枪优异的谐波工作特性、渐变复合腔特殊的耦合机制,通过Cusp电子枪与渐变复合腔相结合实现了高次谐波工作的太赫兹回旋管。对Cusp电子枪的具体结构进行了优化,实现了电... 为解决回旋管工作在太赫兹频段遇到的严重模式竞争问题,基于Cusp电子枪优异的谐波工作特性、渐变复合腔特殊的耦合机制,通过Cusp电子枪与渐变复合腔相结合实现了高次谐波工作的太赫兹回旋管。对Cusp电子枪的具体结构进行了优化,实现了电压59 kV,电流0.92 A,横纵速度比1.36,引导中心半径为0.05 mm,速度离散低于5%的大回旋电子注。通过优化参数,实现了工作频率1 THz,输出功率0.5 kW的四次谐波回旋管。 展开更多
关键词 太赫兹 回旋管 Cusp电子枪 高次谐波 渐变复合腔
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区域财力均衡能否推进共同富裕——基于地级市财政决算数据的分析
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作者 许琪 黄志基 +1 位作者 周子欣 何杨 《工信财经科技》 2024年第4期43-58,共16页
共同富裕是中国特色社会主义伟大事业的重要组成部分,准确把握新时代推进共同富裕的可行路径对全面建成社会主义现代化强国具有深远意义。本文基于物质富裕、精神富裕、公平共享与可持续发展四个维度构建共同富裕指标体系,同时选取2013... 共同富裕是中国特色社会主义伟大事业的重要组成部分,准确把握新时代推进共同富裕的可行路径对全面建成社会主义现代化强国具有深远意义。本文基于物质富裕、精神富裕、公平共享与可持续发展四个维度构建共同富裕指标体系,同时选取2013—2019年市级财政收支数据,结合基尼系数计算出财力均衡度,实证检验区域财力均衡对共同富裕的影响及其机制。研究发现,财力均衡度对共同富裕具有显著的促进作用,且存在明显的财力异质性,财力水平高的地区该影响效应更强;同时公共服务均等化与市场一体化在该影响效应中发挥部分中介作用。本文丰富了财政视角下共同富裕关联研究及财力均衡对区域发展影响的理论探讨,为推进共同富裕的财政路径探索提供理论支撑。 展开更多
关键词 区域经济 共同富裕 财力均衡 公共服务均等化 市场一体化
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Gut microbiome and serum metabolome analyses identify Bacteroides fragilis as regulators of serotonin content and PRL secretion in broody geese
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作者 Yu Zhang Ning Zhou +7 位作者 Jia Wu Lina Song qiang Bao Kaiqi Weng Yang Zhang Wanwipa Vongsangnak Guohong Chen qi xu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期2033-2051,共19页
Broody behavior is regulated by hypothalamic prolactin secretion,which seriously affects egg production in poulty production.Numerous studies have provided evidence that animal behavior is governed by dynamic bidirect... Broody behavior is regulated by hypothalamic prolactin secretion,which seriously affects egg production in poulty production.Numerous studies have provided evidence that animal behavior is governed by dynamic bidirectional communication between specific gut bacteria and their host via the brain-gut-microbiome axis.However,little research focused on how the gut microbiota influence broody behavior in poultry.In this study,Zhedong white geese in laying and brooding phases were selected.Ten differentially abundant bacteria in cecum were detected between brooding and laying geese through metagenomic analyses and 16S rRNA sequencing(P<0.05),and Bacteroides fragilis was specifically identified as a key driver species in the brooding geese.Moverover,the serum metabolites were quantified,and the 313 differentially abundant metabolites were found between the two groups of different physiological geese.They were primarily enriched in the tryptophan metabolism pathways.Pearson correlation analyses revealed there was a significant positive correlation between B.fragilis abundance and the context of 11 tryptophan metabolism-related metabolites(such as serotonin,etc.)in broody geese,which hinted that those tryptophan metabolites might be produced or driven by B.fragilis.Finally,the serum hormone levels were also measured.We found there was a positive correlation between B.fragilis abundance and content of serotonin.Besides,prolactin secreted by the pituitary gland was greater in brooding geese than that in laying geese,which was also highly correlated with B.fragilis abundance.This result implied that B.fragilis could promote the secretion of prolactin by the pituitary gland.Together,the current study findings provided the information on gut microbiota influencing broody behavior,B.fragilis produced or driven more serum serotonin,and stimulated the pituitary gland to secret more prolactin,which potentially offered a new enlightenment for the intervention of broody behavior in poultry. 展开更多
关键词 GEESE broody behavior gut microbiota SEROTONIN PROLACTIN
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Simulation and fabrication of in vitro microfluidic microelectrode array chip for patterned culture and electrophysiological detection of neurons
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作者 Yan Yang Shihong xu +7 位作者 Yu Deng Yaoyao Liu Kui Zhang Shiya Lv Longze Sha qi xu Xinxia Cai Jinping Luo 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第2期1-10,共10页
To enable the detection and modulation of modularized neural networks in vitro,this study proposes a microfluidic microelectrode array chip for the cultivation,compartmentalization,and control of neural cells.The chip... To enable the detection and modulation of modularized neural networks in vitro,this study proposes a microfluidic microelectrode array chip for the cultivation,compartmentalization,and control of neural cells.The chip was designed based on the specific structure of neurons and the requirements for detection and modulation.Finite-element analysis of the chip’s flow field was conducted using the COMSOL Multiphysics software,and the simulation results show that the liquid within the chip can flow smoothly,ensuring stable flow fields that facilitate the uniform growth of neurons within the microfluidic channels.By employing MEMS technology in combination with nanomaterial modification techniques,the microfluidic microelectrode array chip was fabricated successfully.Primary hippocampal neurons were cultured on the chip,forming a well-defined neural network.Spontaneous electrical activity of the detected neurons was recorded,exhibiting a 23.7%increase in amplitude compared to neuronal discharges detected on an open-field microelectrode array.This study provides a platform for the precise detection and modulation of patterned neuronal growth in vitro,potentially serving as a novel tool in neuroscience research. 展开更多
关键词 Microfluidic Microelectrode array In vitro Neural chip
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Revealing the role of honokiol in human glioma cells by RNA-seq analysis
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作者 YUNBAO GUO xu LIU +5 位作者 qi xu XIAOTONG ZHOU JIAWEI LIU YANYAN xu YAN LU HAIYAN LIU 《BIOCELL》 SCIE 2024年第6期945-958,共14页
Background:Glioma is a kind of tumor that easily deteriorates and originates from glial cells in nerve tissue.Honokiol is a bisphenol compound that is an essential monomeric compound extracted from the roots and bark ... Background:Glioma is a kind of tumor that easily deteriorates and originates from glial cells in nerve tissue.Honokiol is a bisphenol compound that is an essential monomeric compound extracted from the roots and bark of Magnoliaceae plants.It also has anti-infection,antitumor,and immunomodulatory effects.In this study,we found that honokiol induces cell apoptosis in the human glioma cell lines U87-MG and U251-MG.However,the mechanism through which honokiol regulates glioma cell apoptosis is still unknown.Methods:We performed RNA-seq analysis of U251-MG cells treated with honokiol and control cells.Protein-protein interaction(PPI)network analysis was performed,and the 10 top hub unigenes were examined via real-time quantitative PCR.Furthermore,MAPK signaling and ferroptosis were detected via western blotting.Results:332 differentially expressed genes(DEGs)were found,comprising 163 increased and 169 decreased genes.Analysis of the DEGs revealed that various biological processes were enriched,including‘response to hypoxia’,‘cerebellum development cellular response to hypoxia,’‘iron ion binding,’‘oxygen transporter activity,’‘oxygen binding,’‘ferric iron binding,’and‘structural constituent of cytoskeleton.’Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis revealed that the DEGs were enriched in the following pathways:‘mitogen-activated protein kinases(MAPK)’,‘Hypoxia-inducible factor 1(HIF-1)’,‘ferroptosis,’‘Peroxisome proliferator-activated receptor(PPAR),’‘Phosphatidylinositol-4,5-bisphosphate 3-kinase(PI3K)-protein kinase B(Akt),’and‘phagosome.’Among these pathways,the MAPK signaling pathway and ferroptosis were verified.Conclusion:This study revealed the potential mechanism by which honokiol induces apoptosis and provided a comprehensive analysis of DEGs in honokiol-treated U251-MG cells and the associated signaling pathways.These data could lead to new ideas for future research and therapy for patients with glioma. 展开更多
关键词 Human glioma HONOKIOL RNA-SEQ APOPTOSIS Ferroptosis MAPK
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高熵合金的成分不均匀性及其特点
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作者 祁糈 陈雨洁 +1 位作者 方研 余倩 《电子显微学报》 CAS CSCD 北大核心 2024年第5期595-604,共10页
高熵合金由于其优异的力学性能而获得了极大的关注。然而理想固溶体模型往往无法完全准确描述和解析其性能的来源。由于高熵合金中合金元素种类多,数量大,导致其晶格的结构特征可能出现与传统合金不同。近年来,大量实验和理论研究结果... 高熵合金由于其优异的力学性能而获得了极大的关注。然而理想固溶体模型往往无法完全准确描述和解析其性能的来源。由于高熵合金中合金元素种类多,数量大,导致其晶格的结构特征可能出现与传统合金不同。近年来,大量实验和理论研究结果均证明了高熵合金中普遍存在元素分布非均匀性,可能是高熵合金的宏观力学性能有异于传统合金的重要原因。因此,本文从高熵合金中的成分涨落、短程有序和纳米析出相三个角度出发讨论,分析了元素分布不均匀性对其变形机制以及力学性能的影响,并对未来高强度、高塑性高熵合金的发展进行了展望。 展开更多
关键词 高熵合金 浓度波动 短程有序 力学性能与变形机制
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Scheduling on tractor and trailer transportation considering the influence of disrupted events based on the contract net and simulated annealing algorithm
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作者 qi xu Yongmei Zhong +2 位作者 Hailun Deng Xiang Wang Xingyue Chen 《Digital Transportation and Safety》 2024年第3期155-168,共14页
To provide a much more resilient transport scheme for tractor and trailer transportation systems,this paper explores the generation method of tractor and trailer transport schemes considering the influence of disrupte... To provide a much more resilient transport scheme for tractor and trailer transportation systems,this paper explores the generation method of tractor and trailer transport schemes considering the influence of disrupted events.Three states of tractors including towing loaded trailers,towing empty trailers,and idle driving are taken into account.Based on the disruption management theory,a scheduling model is constructed to minimize the total deviation cost including transportation time,transportation path,and number of used vehicles under the three states of tractors.A heuristics based on the contract net and simulated annealing algorithm is designed to solve the proposed model.Through comparative analysis of examples with different numbers of newly added transportation tasks and different types of road networks,the performance of the contract net algorithm in terms of deviations in idle driving paths,empty trailer paths,loaded trailer paths,time,number of used vehicles,and total deviation cost are analyzed.The results demonstrate the effectiveness of the model and algorithm,highlighting the superiority of the disruption management model and the contract net annealing algorithm.The study provides a reference for handling unexpected events in the tractor and trailer transportation industry. 展开更多
关键词 Tractor and trailer transportation Disrupted event Hub-and-spoke network Disruption management Contract net and simulated annealing algorithm
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基于工业物联网的企业级能源采集管理系统
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作者 王奕喆 戚旭 《一重技术》 2024年第3期61-63,58,共4页
针对工业物联网能源管控问题,以大型制造企业能源管理系统为背景,详细介绍数据采集方式、硬件配置、软件设置等,以及RTU功能、用途及通讯协议等。由RTU设备采集能源计量仪表数据,采用分布式系统架构传输数据,由实时数据库服务器管理数据... 针对工业物联网能源管控问题,以大型制造企业能源管理系统为背景,详细介绍数据采集方式、硬件配置、软件设置等,以及RTU功能、用途及通讯协议等。由RTU设备采集能源计量仪表数据,采用分布式系统架构传输数据,由实时数据库服务器管理数据,实现物联网能源的高效管理。 展开更多
关键词 能源计量 数据采集 RTU
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考虑转向延迟特性的自动驾驶车辆路径跟踪控制方法 被引量:1
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作者 吕颖 祁旭 +2 位作者 刘秋铮 王鑫煜 陈国迎 《汽车工程》 EI CSCD 北大核心 2023年第12期2234-2241,共8页
自动驾驶路径跟踪系统是实现L2级以上自动驾驶的重要支撑技术。线控转向系统存在的延迟响应特性会降低路径跟踪控制器的鲁棒性和控制精度,甚至在高车速下存在失稳现象。针对以上问题本文设计了前馈加有限时域全状态反馈的误差跟踪控制架... 自动驾驶路径跟踪系统是实现L2级以上自动驾驶的重要支撑技术。线控转向系统存在的延迟响应特性会降低路径跟踪控制器的鲁棒性和控制精度,甚至在高车速下存在失稳现象。针对以上问题本文设计了前馈加有限时域全状态反馈的误差跟踪控制架构,在此基础上将转向系统延时作为1阶惯性环节进行模型化表达,并作为状态变量增广融合到误差跟踪控制架构中。本文利用联合仿真试验对提出的跟踪控制器进行了对比验证,验证结果证明本文提出的控制器在直角弯道和高速换道场景下,最大横向误差小于0.3 m,转向盘的转角均方差分别降低1.93%和64.22%。最后的实车试验结果表明,本文提出的控制器在高速换道场景下能够有效提升横向控制精度,最大横向误差小于0.11 m。 展开更多
关键词 自动驾驶车辆 路径跟踪 转向延迟 全状态反馈 惯性环节
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Comparative histology,transcriptome,and metabolite profi ling unravel the browning mechanisms of calli derived from ginkgo(Ginkgo biloba L.)
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作者 Xiaoming Yang qi xu +5 位作者 Linlin Le Tingting Zhou Wanwen Yu Guibin Wang Fang-Fang Fu Fuliang Cao 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第3期677-691,共15页
Gingko biloba accumulates high levels of secondary metabolites of pharmaceutical value.Ginkgo calli develop a typical browning that reduces its regenerative capacity and thus its usefulness.To elucidate the browning m... Gingko biloba accumulates high levels of secondary metabolites of pharmaceutical value.Ginkgo calli develop a typical browning that reduces its regenerative capacity and thus its usefulness.To elucidate the browning mechanism,histological,transcriptomic,and metabolic alterations were compared between green and browning calli derived from immature ginkgo embryos.Histological observations revealed that browning calli had a more loosely arranged cell structure and accumulated more tannins than in green calli.Integrated metabolic and transcriptomic analyses showed that phenylpropanoid metabolism was specifi-cally activated in the browning calli,and 428 diff erentially expressed genes and 63 diff erentially abundant metabolites,including 12 fl avonoid compounds,were identifi ed in the browning calli compared to the green calli.Moreover,the expression of fl avonol synthase(FLS)and UDP-glucuronosyl-transferase(UGT)genes involved in the fl avonoid pathway was more than tenfold higher in browning calli than in green calli,thus promoting biosynthesis of fl avonol,which serves as a substrate to form glycosylated fl avonoids.Flavonoid glycosides constituted the major coloring component of the browning calli and may act in response to multiple stress conditions to delay cell death caused by browning.Our results revealed the cellular and biochemical changes in browning callus cells that accompanied changes in expression of browning-related genes,providing a scientifi c basis for improving ginkgo tissue culturability. 展开更多
关键词 GINKGO Callus browning Histology TRANSCRIPTOME METABOLITE Flavonoid biosynthesis
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盛鑫煤业地面灌注老巷充填技术研究与应用
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作者 冯海宁 祁旭 杨晋 《煤炭与化工》 CAS 2023年第10期31-33,72,共4页
为实现盛鑫煤业42201工作面的安全生产,开展了老巷充填技术研究。在对比不同老巷处理方式、不同注浆材料的基础上,确定采用高水材料地面灌注充填技术。在地面施工定向充填钻孔11个,采用化学材料对老巷进行密闭。对老巷进行充填后,工作... 为实现盛鑫煤业42201工作面的安全生产,开展了老巷充填技术研究。在对比不同老巷处理方式、不同注浆材料的基础上,确定采用高水材料地面灌注充填技术。在地面施工定向充填钻孔11个,采用化学材料对老巷进行密闭。对老巷进行充填后,工作面回采过程中工作阻力保持稳定,未发生明显的片帮、冒顶,取得了理想的充填效果。 展开更多
关键词 老巷 充填 高水材料 地面灌注 定向钻孔
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“动物遗传原理与育种方法”课程全程案例教学设计与实践 被引量:8
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作者 徐琪 张扬 +3 位作者 陈阳 吴信生 李碧春 陈国宏 《遗传》 CAS CSCD 北大核心 2019年第10期974-978,共5页
"动物遗传原理与育种方法"作为农业硕士专业学位(畜牧领域)一门主干课程,也是一门理论与实践相结合的课程。传统的举例教学方式不仅难以满足现代专业学位教学要求,而且也难以让学生系统掌握遗传育种理论与实践知识。本文在对... "动物遗传原理与育种方法"作为农业硕士专业学位(畜牧领域)一门主干课程,也是一门理论与实践相结合的课程。传统的举例教学方式不仅难以满足现代专业学位教学要求,而且也难以让学生系统掌握遗传育种理论与实践知识。本文在对开放式全程案例教学的内涵与特点进行分析的基础上,结合"动物遗传原理与育种方法"案例的教学实践,阐述了全程案例教学设计中典型案例选择、案例的课堂讲解和组织讨论、案例的课堂总结以及课程教学评价等设计技巧与注意事项,为农学专业学位研究生培养过程中案例教学法的应用和推广提供一定的参考。 展开更多
关键词 “动物遗传原理与育种方法”课程 专业学位研究生 案例教学法 教学模式
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从中心化辟谣到人机协同:中国网络辟谣平台的范式升级——基于1228条新冠疫情辟谣数据 被引量:13
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作者 徐琦 罗雪丹 《全球传媒学刊》 CSSCI 2021年第3期85-101,共17页
本文聚焦新冠疫情谣言治理问题,以中国互联网联合辟谣平台与腾讯较真事实查证平台为研究对象,基于对1228条辟谣数据的质化内容分析,阐述了官方商业网络辟谣平台在辟谣响应、辟谣议题、辟谣信源、鉴谣标注、辟谣传播和辟谣协作等方面的... 本文聚焦新冠疫情谣言治理问题,以中国互联网联合辟谣平台与腾讯较真事实查证平台为研究对象,基于对1228条辟谣数据的质化内容分析,阐述了官方商业网络辟谣平台在辟谣响应、辟谣议题、辟谣信源、鉴谣标注、辟谣传播和辟谣协作等方面的显著差异。通过深入对比不同网络辟谣平台运作流程与治理模式的根本差异,本文进一步论证了中国现阶段谣言治理正在从自上而下、中心化辟谣模式走向着眼互联网信息内容生态,以互联网平台企业为关键责任主体,去中心化、人机协同的谣言治理新范式。具体可从推行政府规制与平台治理双轮驱动,提升技术治谣、深化人机协同,建立重大突发公共事件应急联动谣言治理模式以及推行全民辟谣宣教、提升用户信息素养四个方面着手来推动谣言治理范式升级。 展开更多
关键词 新冠肺炎 辟谣平台 谣言治理 虚假信息 人机协同
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Evolution of Nonmetallic Inclusion during Steelmaking Process of Cold Heading Steel SWRCH35K
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作者 Mengxiong Li qi xu Jianli Li 《Journal of Minerals and Materials Characterization and Engineering》 CAS 2022年第5期438-445,共8页
In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS ... In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS and the image processing software Image-Pro-Plus6.0 were employed to analyze the chemical composition, morphology, quantity and size of non-metal inclusions in the steel samples. The results show that from BOF tapping to continuous casting tundish, the composition of inclusions in SWRCH35K steel changes from Al<sub>2</sub>O<sub>3</sub> &#8594;MgO·Al<sub>2</sub>O<sub>3</sub> &#8594;CaO-MgO-Al<sub>2</sub>O<sub>3</sub>-CaS, and the typical morphology of the inclusions in the steel gradually changes from irregular blocks and clusters to spherical. The number of inclusions in the BOF argon blowing station is the largest, 213&#35;/mm<sup>2</sup>, while the number of inclusions at the end of LF refining is the least, about 12&#35;/mm<sup>2</sup>, and there are basically no inclusions above 5 μm. In addition, LF calcium treatment will adversely affect the size and quantity control of inclusions in steel. In order to effectively reduce the large-size calcium-containing spherical oxide inclusions in cold heading steel, it is necessary to find a technical method that can replace LF calcium treatment to solve the problem of molten steel continuous casting. 展开更多
关键词 Cold Heading Steel INCLUSIONS LF Refining Calcium Treatment
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失效开启与失效关闭调压器的结构原理与应用 被引量:2
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作者 齐旭 《城市燃气》 2019年第3期14-18,共5页
本文介绍了失效开启与失效关闭调压器的定义、结构、工作原理,提出了信号管通气法则与“伪监控”的两个新概念,介绍了监控调压原理与失效开启调压器的应用,展望了失效开启调压器在我国的生产。
关键词 调压器 失效开启调压器 失效关闭调压器 监控调压 伪监控 信号管法则
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特发性肺纤维化与代谢失调的研究进展 被引量:3
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作者 连娜琦 毛靖 +5 位作者 姜淼 鲁芯羽 赵凤鸣 席蓓莉 齐栩 李育 《中国病理生理杂志》 CAS CSCD 北大核心 2022年第5期949-953,共5页
特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是一种病因不明的慢性间质性肺病(interstitial lung disease,ILD),该病在放射学和病理组织学上表现为间质性肺炎,并伴有实质纤维化和过度胶原沉积。IPF多发于65岁以上的吸烟者,常伴... 特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是一种病因不明的慢性间质性肺病(interstitial lung disease,ILD),该病在放射学和病理组织学上表现为间质性肺炎,并伴有实质纤维化和过度胶原沉积。IPF多发于65岁以上的吸烟者,常伴进行性呼吸困难和肺功能恶化,如不积极治疗,确诊后平均预期寿命仅有3~5年。随着全球人口老龄化,IPF对患者造成的生理、心理负担以及对社会造成的经济负担预计会稳步增加。抗纤维化药物(尼达尼布和吡非尼酮)能够延缓IPF的进展[1],但存在严重耐受性问题。肺移植是治愈IPF患者的唯一方法,不过出于年龄以及其他基础疾病等原因,该法仅适用于少数患者。亟需开发有效的IPF诊断监测方法以及新的IPF治疗药物。 展开更多
关键词 特发性肺纤维化 代谢失调 蛋白质组学 肺泡Ⅱ型上皮细胞
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天棚型转子动力吸振器的参数优化 被引量:1
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作者 刘子良 张钦 +3 位作者 太兴宇 许琦 姚红良 闻邦椿 《风机技术》 2019年第3期34-39,共6页
一阶共振响应过大是转子系统普遍存在的问题。提出天棚型转子动力吸振器的概念及结构规划,将其应用于转子一阶共振抑制。利用有限元理论对吸振器-转子耦合系统进行数学建模,并求解频响函数。基于频响函数规划参数的优化数学模型,并利用... 一阶共振响应过大是转子系统普遍存在的问题。提出天棚型转子动力吸振器的概念及结构规划,将其应用于转子一阶共振抑制。利用有限元理论对吸振器-转子耦合系统进行数学建模,并求解频响函数。基于频响函数规划参数的优化数学模型,并利用自适应粒子群优化算法求解。最后,分析了抑振性能对各参数的灵敏度。研究结果表明:天棚型转子动力吸振器能有效降低转子一阶共振振幅;其抑振性能比Voigt型吸振器具有更优异的抑振性能;抑振性能对频率比的灵敏度要远大于阻尼比。 展开更多
关键词 天棚型转子动力吸振器 一阶共振 参数优化 自适应粒子群优化算法 灵敏度
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