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Erratum to:Vibration analysis of a gear-rotor-bearing system with outer-ring spalling and misalignment
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作者 徐宏阳 赵翔 +3 位作者 马辉 罗忠 韩清凯 闻邦椿 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第3期1032-1032,共1页
Because of an unfortunate mistake during the production of this article,Figure 13 was wrongly inserted.The corrected Figure 13 is shown as follows.
关键词 FIGURE outer ANALYSIS
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Pepper mild mottle virus coat protein interacts with pepper chloroplast outer envelope membrane protein OMP24 to inhibit antiviral immunity in plants 被引量:3
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作者 Kelei Han Hongying Zheng +11 位作者 Dankan Yan Huijie Zhou Zhaoxing Jia Yushan Zhai Jian Wu Yuwen Lu Guanwei Wu Shaofei Rao Jianping Chen Jiejun Peng Rende Qi Fei Yan 《Horticulture Research》 SCIE CSCD 2023年第5期16-28,共13页
Pepper mild mottle virus(PMMoV)is a devastating viral pathogen of pepper(Capsicum annuum)but it is unclear whether and how peppers protect against PMMoV infection.The expression of the chloroplast outer membrane prote... Pepper mild mottle virus(PMMoV)is a devastating viral pathogen of pepper(Capsicum annuum)but it is unclear whether and how peppers protect against PMMoV infection.The expression of the chloroplast outer membrane protein 24(OMP24)of C.annuum was upregulated under PMMoV infection and it interacted with PMMoV coat protein(CP).Silencing of OMP24 in either C.annuum or Nicotiana benthamiana facilitated PMMoV infection,whereas overexpression of N.benthamiana OMP24 in transgenic plants inhibited PMMoV infection.Both C.annuum OMP24(CaOMP24)and N.benthamiana OMP24(NbOMP24)localized to the chloroplast and have a moderately hydrophobic transmembrane domain that is necessary for their localization.Overexpression of CaOMP24 induced stromules,perinuclear chloroplast clustering,and accumulation of reactive oxygen species(ROS),the typical defense responses of chloroplasts transferring the retrograde signaling to the nucleus to regulate resistance genes.The expression of PR1 and PR2 was also upregulated significantly in plants overexpressing OMP24.Self-interaction of OMP24 was demonstrated and was required for OMP24-mediated plant defense.Interaction with PMMoV CP interfered with the self-interaction of OMP24 and impaired OMP24-induced stromules,perinuclear chloroplast clustering and ROS accumulation.The results demonstrate the defense function of OMP24 in pepper during viral infection and suggest a possible mechanism by which PMMoV CP modulates the plant defense to facilitate viral infection. 展开更多
关键词 outer IMMUNITY ENVELOPE
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A data assimilation-based forecast model of outer radiation belt electron fluxes 被引量:1
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作者 Yuan Lei Xing Cao +3 位作者 BinBin Ni Song Fu TaoRong Luo XiaoYu Wang 《Earth and Planetary Physics》 CAS CSCD 2023年第6期620-630,共11页
Because radiation belt electrons can pose a potential threat to the safety of satellites orbiting in space,it is of great importance to develop a reliable model that can predict the highly dynamic variations in outer ... Because radiation belt electrons can pose a potential threat to the safety of satellites orbiting in space,it is of great importance to develop a reliable model that can predict the highly dynamic variations in outer radiation belt electron fluxes.In the present study,we develop a forecast model of radiation belt electron fluxes based on the data assimilation method,in terms of Van Allen Probe measurements combined with three-dimensional radiation belt numerical simulations.Our forecast model can cover the entire outer radiation belt with a high temporal resolution(1 hour)and a spatial resolution of 0.25 L over a wide range of both electron energy(0.1-5.0 MeV)and pitch angle(5°-90°).On the basis of this model,we forecast hourly electron fluxes for the next 1,2,and 3 days during an intense geomagnetic storm and evaluate the corresponding prediction performance.Our model can reasonably predict the stormtime evolution of radiation belt electrons with high prediction efficiency(up to~0.8-1).The best prediction performance is found for~0.3-3 MeV electrons at L=~3.25-4.5,which extends to higher L and lower energies with increasing pitch angle.Our results demonstrate that the forecast model developed can be a powerful tool to predict the spatiotemporal changes in outer radiation belt electron fluxes,and the model has both scientific significance and practical implications. 展开更多
关键词 Earth’s outer radiation belt data assimilation electron flux forecast model performance evaluation
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A Lagrangian Trajectory Analysis of Azimuthally Asymmetric Equivalent Potential Temperature in the Outer Core of Sheared Tropical Cyclones
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作者 Yufan DAI Qingqing LI +1 位作者 Xinhang LIU Lijuan WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第9期1689-1706,共18页
In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examine... In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examined using a Lagrangian trajectory method.Evaporatively forced downdrafts in the outer rainbands can transport low-entropy air downward,resulting in the lowestθ_(e)in the downshear-left boundary layer.Quantitative estimations ofθ_(e)recovery indicate that air parcels,especially those originating from the downshear-left outer core,can gradually revive from a low entropy state through surface enthalpy fluxes as the parcels move cyclonically.As a result,the maximumθ_(e)is observed in the downshear-right quadrant of a highly sheared TC.The trajectory analyses also indicate that parcels that move upward in the outer rainbands and those that travel through the inner core due to shear make a dominant contribution to the midlevel enhancement ofθ_(e)in the downshear-left outer core.In particular,the former plays a leading role in suchθ_(e)enhancements,while the latter plays a secondary role.As a result,moist potential stability occurs in the middle-to-lower troposphere in the downshear-left outer core. 展开更多
关键词 tropical cyclone vertical wind shear outer core asymmetric equivalent potential temperature trajectory analysis
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Proteomic and Functional Analyses of Outer Membrane Vesicles Secreted by Vibrio splendidus
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作者 SONG Huimin RUAN Yilong +2 位作者 LI Ya YANG Huirong ZHANG Weiwei 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第5期1361-1369,共9页
Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are cru... Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are crucial to bacterial survival and virulence.In this study,the secretion of outer membrane vesicles(OMVs)by V.splendidus was determined,purified,and morphologically characterized.The protein composition of OMVs was analyzed by proteomic analysis.The results showed that approximately 120 proteins were contained in these OMVs,including outer membrane proteins,flagellins,ABC transporters,protease,and iron regulation proteins,etc.,which were involved in bacterial motility,formation of biofilms and the cell membrane components,and cellular localization based on their structural molecule activity,passive transmembrane transporter activity,channel activity,neurotransmitter receptor activity,extracellular ligand-gated ion channel activity,glutamate receptor activity,ligand-gated ion channel activity,and transmembrane signaling receptor activity.To explore the biological functions of OMVs in V.splendidus,the effects of OMVs on the bacterial adaption to iron limitation,antibiotic,and the coelomic fluid of the Apostichopus japonicus were confirmed.This study is the first time to show that V.splendidus secretes OMVs,and OMVs carry functional proteins that enhance bacterial survival under various stresses. 展开更多
关键词 Vibrio splendidus outer membrane vesicles(OMVs) proteomic analysis biological function
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On-Site Assessment of a Cryogenic Disinfectant for the Alpine Environment and Outer Packaging of Frozen Items
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作者 SHEN Jin YANG Bin +13 位作者 XIAO Jia Qing LI Lu Yao SUN Hui Hui DUAN Hong Yang ZHANG Wei LIANG Chen CHEN Lu LI Li CHEN Yan Yan LYU Yuan TANG Song WANG Jiao ZHANG Liu Bo WANG Lin 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第2期174-184,共11页
Objective To study the effectiveness and feasibility of cryogenic disinfectants in different cold scenarios and analyze the key points of on-site cryogenic disinfection.Methods Qingdao and Suifenhe were selected as ap... Objective To study the effectiveness and feasibility of cryogenic disinfectants in different cold scenarios and analyze the key points of on-site cryogenic disinfection.Methods Qingdao and Suifenhe were selected as application sites for the manual or mechanical spraying of cryogenic disinfectants.The same amount of disinfectant(3,000 mg/L)was applied on cold chain food packaging,cold chain containers,transport vehicles,alpine environments,and article surfaces.The killing log value of the cryogenic disinfectant against the indicator microorganisms(Staphylococcus aureus and Escherichia coli)was used to evaluate the on-site disinfection effect.Results When using 3,000 mg/L with an action time of 10 min on the ground in alpine regions,the surface of frozen items,cold-chain containers,and cold chain food packaging in supermarkets,all external surfaces were successfully disinfected,with a pass rate of 100%.The disinfection pass rates for cold chain food packaging and cold chain transport vehicles of centralized supervised warehouses and food processing enterprises were 12.5%(15/120),81.67%(49/60),and 93.33%(14/15),respectively;yet,the surfaces were not fully sprayed.Conclusion Cryogenic disinfectants are effective in disinfecting alpine environments and the outer packaging of frozen items.The application of cryogenic disinfectants should be regulated to ensure that they cover all surfaces of the disinfected object,thus ensuring effective cryogenic disinfection. 展开更多
关键词 Cryogenic disinfectant COVID-19 An alpine environment DISINFECTION outer packaging of frozen items
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Newly Detected Transmission of bla_(KPC-2) by Outer Membrane Vesicles in Klebsiella Pneumoniae
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作者 Liu-jun CHEN Xiao-peng JING +6 位作者 Dong-li MENG Ting-ting WU Huan ZHOU Rui-ling SUN Xiao-chun MIN Rong LIU Ji ZENG 《Current Medical Science》 SCIE CAS 2023年第1期80-85,共6页
Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins ... Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins and other factors involved in various biological processes,includingβ-lactamase and antibiotic-resistance genes.This study aimed to reveal the transmission mechanism of OMV-mediated drug resistance of Klebsiella(K.)pneumoniae.Methods We selected CR-KP producing K.pneumoniae carbapenemase-2(KPC-2)to study whether they can transfer resistance genes through OMVs.The OMVs of CR-KP were obtained by ultracentrifugation,and incubated with carbapenem-sensitive K.pneumoniae for 4 h.Finally,the carbapenem-sensitive K.pneumoniae was tested for the presence of bla_(KPC-2)resistance gene and its sensitivity to carbapenem antibiotics.Results The existence of OMVs was observed by the electron microscopy.The extracted OMVs had bla_(KPC-2)resistance gene.After incubation with OMVs,bla_(KPC-2)resistance gene was detected in sensitive K.pneumoniae,and it became resistant to imipenem and meropenem.Conclusion This study demonstrated that OMVs isolated from KPC-2-producing CR-KP could deliver bla_(KPC-2)to sensitive K.pneumoniae,allowing the bacteria to produce carbapenemase,which may provide a novel target for innovative therapies in combination with conventional antibiotics for treating carbapenem-resistant Enterobacteriaceae. 展开更多
关键词 bla_(KPC-2) carbapenem-resistant Klebsiella pneumoniae CARBAPENEMASE outer membrane vesicles simplified carbapenem inactivation method
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Effect of High-Speed Solar Winds Turbulence Upstream of the Earth’s Magnetosphere: Case of the Outer Minima of Solar Cycles 20, 21, 22, 23 and 24
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作者 Inza Gnanou Salfo Kabore +3 位作者 Aristide Marie Frédéric Gyebre Christian Zoundi Jean-Louis Zerbo Frédéric Ouattara 《Open Journal of Applied Sciences》 2023年第7期1145-1162,共18页
Highly turbulent environment, the solar wind is a stream of very energetic particles mainly made of protons and electrons. During its trip in the interplanetary space, this solar flow becomes more accelerated during t... Highly turbulent environment, the solar wind is a stream of very energetic particles mainly made of protons and electrons. During its trip in the interplanetary space, this solar flow becomes more accelerated during the outer minima (descending phases) of the solar cycles and can therefore influence all of humanity and its technology. These disturbances lead to socio-economic consequences requiring a precise knowledge of the climate variability. Using a statistical approach, we evaluate the response of the Earth’s magnetosphere to the High-Speed Solar Winds (HSSW) forcing during the peaks of the last five outer minima. To do so, 1UA data of solar wind and magnetic field parameters were extracted from OMNI browser. Analysis of the energetic solar plasma particles shows that strong geomagnetic field variations can occur even in the absence of large solar disturbances. While the normalized reconnection rate was estimated to be ~21% of the total variance of the magnetospheric variables, the upstream of the magnetic cavity was perturbed 80% of the time with large energies recorded. As a result, Earth’s magnetosphere becomes denser (i.e., more drag), which is a problem for spacecraft. Thus, the coupled solar wind-magnetosphere system follows scale-invariant dynamics and is in a state far from equilibrium. Our analysis provides insight into the main cause of geomagnetic storms with more than 97% of HSSW imposed in the range 300 - 850 km/s. These high-speeds lead to auroras that can disrupt electrical and communication systems. 展开更多
关键词 Solar Wind outer Minimum MAGNETOSPHERE Geomagnetic Field Solar Disturbances
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鲍曼不动杆菌OmpA蛋白的生物学特性分析
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作者 赵丹 李尼克 +3 位作者 李雯 彭春红 赵德刚 张湘燕 《贵州医药》 CAS 2024年第3期339-344,共6页
目的提取临床分离的鲍曼不动杆菌外膜蛋白A(OmpA)的基因,并进行生物学预测和分析。方法查询鲍曼不动杆菌OmpA基因序列,设计特异性PCR引物,以提取的鲍曼不动杆菌基因组DNA为模板,PCR扩增OmpA片段。回收目的片段,采用生物信息学软件分析O... 目的提取临床分离的鲍曼不动杆菌外膜蛋白A(OmpA)的基因,并进行生物学预测和分析。方法查询鲍曼不动杆菌OmpA基因序列,设计特异性PCR引物,以提取的鲍曼不动杆菌基因组DNA为模板,PCR扩增OmpA片段。回收目的片段,采用生物信息学软件分析OmpA蛋白的生物学特性。结果12株鲍曼不动杆菌多位点序列分型(MLST)序列分析有6个ST分型,分别是ST 208、ST 229、ST 191、ST 195、ST540、ST 1145,鲍曼不动杆菌OmpA基因序列全长为1070 bp的,单核苷酸多态性(SNP)位点较少,预测蛋白为跨膜蛋白,具有6种三级结构,均由β-桶状结构组成的保守结构域。结论临床分离的不同鲍曼不动杆菌株OmpA蛋白为结构相对保守的跨膜蛋白,具有维持细胞的形状和稳定性,参与细菌耐药机制及免疫原性作用。 展开更多
关键词 鲍曼不动杆菌 外膜蛋白A 空间结构 跨膜结构
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ODF1在胃肠道神经内分泌肿瘤中的表达及临床意义
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作者 李新军 刘敏 +2 位作者 李柏成 刘蒙蒙 刘宁宁 《诊断病理学杂志》 2024年第1期34-37,共4页
目的探讨ODF1在胃肠道神经内分泌肿瘤(NEN)中的表达及与临床病理特征和预后的关系。方法收集2008-01—2021-12;胃肠道NEN标本254例,包括168例神经内分泌瘤(NETs)和86例神经内分泌癌(NEC)。采用免疫组化法检测ODF1在上述组织中的表达,分... 目的探讨ODF1在胃肠道神经内分泌肿瘤(NEN)中的表达及与临床病理特征和预后的关系。方法收集2008-01—2021-12;胃肠道NEN标本254例,包括168例神经内分泌瘤(NETs)和86例神经内分泌癌(NEC)。采用免疫组化法检测ODF1在上述组织中的表达,分析其与临床病理特征和预后的关系。结果ODF1在168例NETs中全部弥漫阳性表达,在86例NEC中的阳性表达率为24.4%,而且均为局灶阳性染色。ODF1在胃肠道NETs和NEC中的表达差异有统计学意义(P<0.05)。ODF1的表达随着NEN分级增高、T分期增加、淋巴结转移和TNM分期增加而降低(P<0.05)。ODF1的表达与患者性别和年龄无关(P>0.05)。Kaplan-Meier生存分析和单因素COX分析显示ODF1阳性NEC患者的预后较好,多因素COX分析显示ODF1表达不是NEC独立的预后因子。结论ODF1在胃肠道NETs中表达显著高于NEC。ODF1水平随着NEN分级增高、T分期增加、淋巴结转移和TNM分期增加而降低,对预后预测有一定价值。 展开更多
关键词 神经内分泌肿瘤 胃肠道 精子尾部外周致密纤维1 免疫组化 预后
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高含水复杂断块油藏单层系边外注水开发模式
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作者 姚秀田 徐磊 +3 位作者 王冉冉 闫森 王明鹏 杨琴文 《油气地质与采收率》 CAS CSCD 北大核心 2024年第2期155-166,共12页
复杂断块油藏在开发后期面临综合含水率高、地层能量不足、剩余油分布复杂、井网适应性差等问题。以济阳坳陷沾化凹陷中部垦71断块油藏为例,基于水驱油藏的油包水和水包油2种油水分布状态,利用理论模型推导和数值模拟方法,开展了单层系... 复杂断块油藏在开发后期面临综合含水率高、地层能量不足、剩余油分布复杂、井网适应性差等问题。以济阳坳陷沾化凹陷中部垦71断块油藏为例,基于水驱油藏的油包水和水包油2种油水分布状态,利用理论模型推导和数值模拟方法,开展了单层系边外注水开发模式研究。结果表明:从采液端和注水端的受力分析可获得单层系开发的合理注水量、合理采液量和合理注采井距,单层系开发的合理注水压差、合理注水量、合理采液量是影响其剩余油饱和度、含水饱和度的关键因素,对油层合理地层压力水平及剩余油二次富集起主要控制作用。通过加大注采井距至油水边界外围,以2.9倍含油条带宽度为合理注采井距的临界值,采用短注长静置的非对称周期注采方式,建立单层系边外注水开发模式,有利于保持单层系的压力系统稳定和提高剩余油波及率,从而提高原油采收率。矿场实践表明,采用单层系边外注水开发模式后,垦71断块油藏日产油量提高至254 t/d,含水率控制在93.7%,采收率提高至31.53%,采油速率提高4.9%,显示出良好的增产效果。单层系边外注水开发模式解决了高含水复杂断块油藏开发中的剩余油分布分散、水驱波及率低和井网适应性差等难题,可为复杂断块油藏开发提供指导和借鉴。 展开更多
关键词 单层系边外注水 开发模式 周期注水 数值模拟 复杂断块油藏
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空间威慑到空间威胁:防止外空军备竞赛的规则解释与中国因应
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作者 高国柱 高岚 《北京航空航天大学学报(社会科学版)》 2024年第3期109-120,共12页
目前,外空军控规则的走向出现了明显分歧。一些国家提出所谓的“空间威胁”概念,意图推进“负责任外空行为准则”。威慑与威胁密切相关,没有威胁就没有威慑。当代国际法承认有限度威慑的合法性,也就意味着承认部分威胁的合法性。《联合... 目前,外空军控规则的走向出现了明显分歧。一些国家提出所谓的“空间威胁”概念,意图推进“负责任外空行为准则”。威慑与威胁密切相关,没有威胁就没有威慑。当代国际法承认有限度威慑的合法性,也就意味着承认部分威胁的合法性。《联合国宪章》中的威胁主要是指“武力威胁”,如果适用于外空领域,必须对空间威胁的所有可能要素加以分析,包括主观(意图)、实施主体(是否可归结为国家)、行为表现(可衡量、可归因、可证明)、损害后果、因果关系等,换言之,需达到一定的门槛——必须具备诉诸武力的极大可能性。一些国家列举的所谓“空间威胁”具有选择性和针对性,存在着覆盖不全和依赖主观判断的缺陷,依照现有国际法进行解释,这些所谓的“空间威胁”不能被确认为国际不法行为。当代国际外空军控规则是大国奉行威慑战略下彼此达成妥协的结果,如果无视这一历史趋势,强行推进有利于某些国家保持太空军事优势的规则,必然会破坏战略稳定与平衡,最终严重损害国际社会防止外空军备竞赛(PAROS)的集体努力。 展开更多
关键词 空间威慑 空间威胁 防止外空军备竞赛(PAROS) 威慑战略 外空军控规则
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内圣外王的期盼:中国古代君德论及其特征
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作者 王记录 刘饶 《河南师范大学学报(哲学社会科学版)》 北大核心 2024年第2期98-107,共10页
中国古代君德论起源于殷周,发展于两汉,兴盛于唐,繁荣于两宋,变革于明末清初,一脉相承而内容不断丰富。君德的内容包含了君主的德性、器识、才智、能力等诸多因素,主要体现在君主个人修养以及施政过程中如何处理君臣关系、君民关系等方... 中国古代君德论起源于殷周,发展于两汉,兴盛于唐,繁荣于两宋,变革于明末清初,一脉相承而内容不断丰富。君德的内容包含了君主的德性、器识、才智、能力等诸多因素,主要体现在君主个人修养以及施政过程中如何处理君臣关系、君民关系等方面。完善君德的方式主要有经筵讲读、皇储教育、家训教化、大臣谏诤、史书褒贬。古代君德论特征鲜明,君主地位的尊崇、历史的教训与现实的需要是君德论的起点,儒家“修齐治平”“内圣外王”理论是君德论的思想基础,读经观史,以经为则、以史为鉴是完善君德的重要手段,“致君尧舜”是君德修养的重点。古人已经形成了一套围绕君主而展开的关于君德修养的理论体系。同时也要看到,古人讨论君德,既存在“师道”与“君道”之间无法调和的矛盾,也没有进行制度层面的反思,反映的只是一种泛道德化的政治伦理观。 展开更多
关键词 君德论 君主修养 帝王学 内圣外王 历史教育
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增加革兰阴性菌外膜囊泡产量的研究进展
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作者 刘灿 闫晓阳 +2 位作者 曾焱 欧祥龙 廖永洪 《生物技术通报》 CAS CSCD 北大核心 2024年第3期100-108,共9页
外膜囊泡(OMVs)是由革兰阴性菌释放的一种囊泡状结构,在革兰阴性菌的生长、感染以及与周围环境交流等过程中发挥重要作用。由于OMVs无活性、不能复制且具有良好的免疫原性,被广泛应用于新型疫苗的研究。但天然OMVs产量低,无法达到规模... 外膜囊泡(OMVs)是由革兰阴性菌释放的一种囊泡状结构,在革兰阴性菌的生长、感染以及与周围环境交流等过程中发挥重要作用。由于OMVs无活性、不能复制且具有良好的免疫原性,被广泛应用于新型疫苗的研究。但天然OMVs产量低,无法达到规模化生产的要求,OMVs产量提升是OMVs疫苗产业化要解决的关键核心技术问题。本文主要从细菌基因改造、生长培养条件优化和OMVs生产纯化工艺优化3个方面对提升OMVs产量的研究进行综述,以期为OMVs疫苗产业化研究开发提供参考。 展开更多
关键词 外膜囊泡 疫苗开发 生物发生机制 产量增加机制
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唐五代建筑材等与平面主要尺度特征关联性研究
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作者 刘婷婷 段智钧 钱威 《古建园林技术》 2024年第2期20-23,共4页
本文搜集宋《营造法式》之前唐五代木构建筑遗存中的典型实例,研究材等与平面各主要尺度特征的关联性。探究建筑材等与建筑当心间、步架均值、外檐出跳均值等平面主要尺度的相关性,初步推论:唐五代木构建筑中,建筑的材等等级与当心间,... 本文搜集宋《营造法式》之前唐五代木构建筑遗存中的典型实例,研究材等与平面各主要尺度特征的关联性。探究建筑材等与建筑当心间、步架均值、外檐出跳均值等平面主要尺度的相关性,初步推论:唐五代木构建筑中,建筑的材等等级与当心间,有成正比的趋势。材等与步架比值在8.85~16.94的范围内,材等与外檐出跳比值在2.03~3.75的区域范围。为古建筑营造尺度规律的研究提供一定的参考。 展开更多
关键词 材等 当心间 步架 外檐出跳 关联性
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圆柱滚子轴承滚子对数修形优化研究
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作者 吕海霆 郭玉飞 +2 位作者 魏延刚 许凯 姚金池 《机电工程》 CAS 北大核心 2024年第4期604-612,共9页
为了提高轴承的疲劳寿命,采用Romax Designer工程分析软件,在充分考虑径向游隙和内外圈相对倾斜量(影响轴承寿命的主要因素)对修形效果影响的基础上,对某大兆瓦风电机组齿轮箱输出轴轴承进行了对数修形优化分析。首先,对国际标准ISO/TS ... 为了提高轴承的疲劳寿命,采用Romax Designer工程分析软件,在充分考虑径向游隙和内外圈相对倾斜量(影响轴承寿命的主要因素)对修形效果影响的基础上,对某大兆瓦风电机组齿轮箱输出轴轴承进行了对数修形优化分析。首先,对国际标准ISO/TS 16281寿命计算方法进行了简要分析;然后,对不同径向游隙情况下对数修形的效果进行了分析;最后,对不同内外圈相对倾斜量情况下对数修形的效果进行了分析。研究结果表明:以轴承最大接触应力最小为优化目标和以国际标准ISO/TS 16281寿命最长为优化目标的轴承对数修形,其最佳修形量不同,相应的ISO/TS 16281寿命有很大不同;在该轴承的具体条件下,以ISO/TS 16281寿命最长为优化目标的最佳修形凸度量对应的ISO/TS 16281寿命比以最大接触应力最小为优化目标的最佳修形凸度量对应的ISO/TS 16281寿命长2.39%~10.63%;以ISO/TS 16281寿命最长为优化目标的最佳修形凸度量对应的ISO/TS 16281寿命比未修形的ISO/TS 16281寿命长111.47%~1054.88%,建议以ISO/TS 16281寿命最长为优化目标对轴承进行修形优化设计。该研究结果可为滚子类轴承的优化设计提供参考。 展开更多
关键词 滚柱轴承 对数修形 接触应力 疲劳寿命 径向游隙 内外圈相对倾斜量 国际标准ISO/TS 16281
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月球站所的法律地位浅析
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作者 赵云 余佳颖 《北京航空航天大学学报(社会科学版)》 2024年第3期99-108,共10页
目前,月球活动正进入新的阶段——月球站所的筹备与建设。然而,现有相关国际法规范尚需完善,其中月球站所的法律地位是需首要考虑的问题。对月球站所法律地位问题的思考始于月球站所活动的特殊性:以人类社会的可持续发展为长远目标,开... 目前,月球活动正进入新的阶段——月球站所的筹备与建设。然而,现有相关国际法规范尚需完善,其中月球站所的法律地位是需首要考虑的问题。对月球站所法律地位问题的思考始于月球站所活动的特殊性:以人类社会的可持续发展为长远目标,开展于天体之上,将对天体表面固定区域进行使用且产生事实上的活动范围。合乎《外空条约》的月球站所建设是为全人类谋福利的自由探索和利用月球的活动,不存在既排他又永久地使用月球表面区域的情形,且在互惠基础上对他国开放。为此,建议在国际月球科研站活动中考虑“非排他”和“有时限”二者择一的规范路径以履行相应的国际法义务,并且明确国际月球科研站对他国开放的“互惠”前提与“参观”范畴。同时,需将月球站所的四个方面作为判断其法律地位的具体考量因素,即月球站所的使用目的与活动范围大小,月球站所的可移动性,月球站所的使用期限以及月球站所信息的通知、更新与公开。 展开更多
关键词 月球站所 不得据为己有 自由探索和利用 《外空条约》 国际月球科研站
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概率区间值犹豫模糊集多属性群决策模型及其应用
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作者 朱国成 张娟 徐健 《中国计量大学学报》 2024年第1期106-115,共10页
目的:研究概率区间值犹豫模糊集及应用。方法:将概率区间值犹豫模糊数,用区间值隶属度的中位数、区间值隶属度的清晰度以及概率构成的三维点坐标进行刻画,在此基础上提出了概率区间值犹豫模糊元的相关运算。根据概率区间值犹豫模糊元的... 目的:研究概率区间值犹豫模糊集及应用。方法:将概率区间值犹豫模糊数,用区间值隶属度的中位数、区间值隶属度的清晰度以及概率构成的三维点坐标进行刻画,在此基础上提出了概率区间值犹豫模糊元的相关运算。根据概率区间值犹豫模糊元的相关运算采用熵值法计算属性权重。最后基于TOPSIS思想给出了一个新的贴近度公式,并利用新的贴近度公式对方案排序。结果:建立的概率区间值犹豫模糊集多属性群决策模型可以有效排序方案。结论:将概率区间值犹豫模糊集采用区间值隶属度的中位数、区间值隶属度的清晰度以及概率来表示不仅可行,而且可以用来解决多属性群决策问题。 展开更多
关键词 概率区间值犹豫模糊集 三维点坐标 外值函数模型 内值函数模型 TOPSIS
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轴类零件的外圆自动光学检测方法设计与装置优化
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作者 蒋仲仁 《浙江国际海运职业技术学院学报》 2024年第1期1-4,共4页
本文针对轴类零件的外圆测量装置,利用光学测量原理,提出了轴类零件直径误差、外圆圆度误差、直线度误差等误差测量和计算的方法,并设计了装置的结构。对装置的测量误差做出分析,并提出了优化措施。
关键词 外圆检测 自动化 光学 误差分析
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无人机17kW电机振动噪声分析与巡航转速下尖端噪声优化
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作者 刘栋良 詹成根 +2 位作者 屈峰 陈黎君 史恒 《电工技术学报》 EI CSCD 北大核心 2024年第6期1749-1763,共15页
随着无人机的迅速发展,噪声问题影响消费者体验及AI交互、语音识别等技术,限制了无人机应用潜力。该文针对一台17 kW无人机用外转子永磁同步电机进行研究。为降低电机尖端振动噪声,且保留原电机电磁性能,重点提出优化磁极和定子开槽的... 随着无人机的迅速发展,噪声问题影响消费者体验及AI交互、语音识别等技术,限制了无人机应用潜力。该文针对一台17 kW无人机用外转子永磁同步电机进行研究。为降低电机尖端振动噪声,且保留原电机电磁性能,重点提出优化磁极和定子开槽的方法。具体以平均转矩、转矩脉动等作为约束条件,构建多目标优化数学模型,并利用混合粒子群优化算法求解。该文深入探讨磁极参数、定子开槽对低阶次径向气隙磁通密度空间谐波特征的影响。并对电机转子模态仿真,以研究径向电磁力与空间模态的作用机理。在多转速情况下,以巡航转速为重点,分析整体电机电磁振动噪声特征。最后,仿真和实验结果表明,电机在巡航转速下的尖端噪声显著减小。验证了优化结构对无人机电机尖端振动噪声有明显抑制作用,对解决无人机噪声问题具有重要意义。 展开更多
关键词 无人机外转子永磁同步电机 电磁振动噪声 巡航转速 混合粒子群优化算法
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