检索结果-南通市图书馆

Interfacial friction effects on sealing performances of elastomer packer

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 2037-2047页

作者： Peng-Cheng Wang Ming-Hui Chen Jim Jenkinson yong-xin Song Li Sun Department of Mechanical Engineering University of HoustonHoustonTX77024USA Guren Nanomaterials Suzhou215127JiangsuChina Department of Marine Engineering Dalian Maritime UniversityDalian116026LiaoningChina

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic *** practice sealing performances of such plugs are normally evaluated through pressure tests,and in numerical simulation studies,maximum contact stress,average contact stress and contact length data are used to determine sealing quality between a packer and *** previous studies,the impact of friction forces on sealing performance is often *** work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing *** first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac *** we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution,deformation,and contact stress after *** the demonstration of validity of FEA method,we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress,average contact stress,contact stress distribution,and maximum mises stress for an actual packer used in plug *** addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial *** study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces.

关键词： Elastomer seal Friction Sealing performance Contact stress

High-temperature wetting behavior between slag and refractory

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1304-1319页

作者： yong-xin Wang Ya-ge Li Ya-bo Gao Zhong Huang Hai-jun Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Slag corrosion is one of the main factors of the damage of refractory,and its primary manifestations involve the melting of refractory in slag and the slag penetration into refractory,both of which are highly related to the wetting behavior between slag and *** high-temperature wettability could be characterized by parameters including the surface tension,adhesion work,and spreading coefficient of the slag on refractory surface,and it could be suppressed by altering the slag/refractory interface,thus resulting in an improved anti-corrosion *** this,the key knowledges of the slag corrosion,theory of wetting behavior and test of high-temperature contact angle were firstly ***,the major factors influencing the high-temperature slag wetting behavior were discussed based on the aspects of slag composition,refractory composition,and surface ***,the future research direction was proposed in this field.

关键词： High-temperature wetting Refractory Slag corrosion Surface tension

Assessing Dietary Consumption of Sodium and Potassium in China through Wastewater Analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第1期37卷 127-131页

作者： TAN Dong Qin LIANG Yi GUO Ting LI Yan Ying SONG yong xin WANG De Gao College of Environmental Science and Engineering Dalian Maritime UniversityDalian 116026LiaoningChina College of Marine Engineering Dalian Maritime UniversityDalian 116026LiaoningChina

A causal relationship has been reported between the average population salt(sodium chloride)intake and the increased risk of stroke and cardiovascular and cerebrovascular diseases in some epidemiological and clinical *** World Health Organization has recommended that a sodium intake of<2 g/day is preventive against cardiovascular disease,although the current intake is in excess in most countries.

关键词： Wastewater intake Potassium

Winter extreme precipitation over the Tibetan Plateau influenced by Arctic sea ice on interdecadal timescale

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第4期15卷 42-51页

作者： Qing-Quan LI Miao BI Song YANG Qing-Yuan WU Yi-Hui DING xin-yong SHEN Xiao-Ting SUN Meng-Chu ZHAO China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China CMA Key Open Laboratory of Transforming Climate Resources to Economy Chongqing Institute of Meteorological SciencesChongqing 401147China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Zhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

The Tibetan Plateau(TP)and the Arctic are the most sensitive regions to global climate ***,the interdecadal varibility of winter extreme precipitation over the TP and its linkage with Arctic sea ice are still *** this study,the characteristics and mechisnems of the TP extreme precipitation(TPEP)influenced by Arctic sea ice on interdecadal timescale are studied based on the daily precipitation,monthly sea ice concentration and ERA5 reanalysis data from 1980 to *** found that the dominant mode of the TPEP in winter mostly exhibits a uniform spatial variation on the interdecadal timescale,with an opposite weak variation in the southeastern TP,and the Arctic sea ice concentration(SIC)before 2002 are larger than that after *** interdecadal variation of TPEP is affected by two teleconnection wave trains regulated by the Barents and Kara Sea *** the light ice years,a remarkable positive geopotential height(HGT)anomaly appears over the Barents-Kara Sea and a remarkable negative HGT anomaly is located over the Lake *** wave trains originating over the Barents-Kara Sea can be *** southern branch forms a wave train through the North Atlantic along the subtropical westerly jet stream,showing a‘+-+-+'pattern of HGT anomalies from Arctic to the *** HGT anomaly controls the western TP,which creates dynamic and water vapor conditions for the *** northern branch forms a wave train through the Lake Baikal and the southeast of the TP,showing a‘+-+'HGT anomaly *** HGT anomaly controls the southeastern TP,which is not conducive to precipitation in the *** the SIC in the Barents-Kara Sea increases,the situation is *** above analysis also reveals the reason for the difference in the east-west distribution of the TPEP.

关键词： Arctic sea ice Tibetan Plateau Winter extreme precipitation Rossby wave activity Interdecadal variation

Dynamic simulation insights into friction weakening effect on rapid long-runout landslides:A case study of the Yigong landslide in the Tibetan Plateau,China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Geology 2024年第2期7卷 222-236页

作者： Zi-zheng Guo xin-yong Zhou Da Huang Shi-jie Zhai Bi-xia Tian Guang-ming Li School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China School of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Tianjin Municipal Engineering Design&Research Institute(TMEDI) Tianjin 300392China

This study proposed a novel friction law dependent on velocity,displacement and normal stress for kinematic analysis of runout process of rapid *** well-known Yigong landslide occurring in the Tibetan Plateau of China was employed as the case,and the derived dynamic friction formula was included into the numerical simulation based on Particle Flow *** showed that the friction decreased quickly from 0.64(the peak)to 0.1(the stead value)during the 5s-period after the sliding initiation,which explained the behavior of rapid movement of the *** monitored balls set at different sections of the mass showed similar variation characteritics regarding the velocity,namely evident increase at the initial phase of the movement,followed by a fluctuation phase and then a stopping *** peak velocity was more than 100 m/s and most particles had low velocities at 300s after the landslide *** spreading distance of the landslide was calculated at the two-dimension(profile)and three-dimension scale,*** with the simulation result without considering friction weakening effect,our results indicated a max distance of about 10 km from the initial unstable position,which fit better with the actual situation.

关键词： Rapid long-runout landslide PFC Friction weakening Three-dimension Numerical simulation Tibetan Plateau Hydrogeology Engineering Geological hazards survey engineering

Dynamic control of lipid provisioning in plant-fungal symbiosis

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2024年第3期17卷 367-367页

作者： Chun-Lin Shi yong-xin Liu ANGENOVO 0753 OsloNorway Shenzhen Branch Guangdong Laboratory of Lingnan Modern AgricultureGenome Analysis Laboratory of the Ministry of Agriculture and Rural AffairsAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen518120China

Arbuscular mycorrhizal(AM)fungi form a type of endomycorrhiza that helps plants capture nutrients from the *** provisioning plays a critical role in maintaining the AM fungi within the plant cortical cells during AM *** coordination of lipid provisioning with AM symbiosis is regulated by the lysin motif(LysM)and leucine-rich repeat receptor-like kinases(RLKs),including DOES NOT MAKE INFECTIONS 2(DMI2),through transcriptional programming(Shi et al.,2023).However,key components of the complete signaling pathway remain to be identified.

关键词： plant provision Lipid

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

论新质生产力与物质文明新形态的内在统一

毛泽东邓小平理论研究 2024年第2期 1-7,108页

作者：曹泳鑫上海社会科学院马克思主义学院

站在推动构建人类文明新形态的高度加以观照,“新质生产力”并非简单指向高新科学技术发展,而是成为一项顺应科技创新和工业革命大潮、适应现代社会化大生产的多要素创新发展和能力提升的综合战略。理解“新质生产力”,不仅要着眼于生产... 详细信息

站在推动构建人类文明新形态的高度加以观照,“新质生产力”并非简单指向高新科学技术发展,而是成为一项顺应科技创新和工业革命大潮、适应现代社会化大生产的多要素创新发展和能力提升的综合战略。理解“新质生产力”,不仅要着眼于生产力,还要着眼于生产关系和体制机制等层面;不仅要着眼于科学技术,还要着眼于全要素、全方位;不仅要着眼于物质文化,还要着眼于精神文化。新时代中国特色社会主义和中国式现代化将创造人类文明新形态,发展新质生产力内在要求创造社会主义物质文明新形态。中国“新质生产力”所包含的“物质文化”和“精神文化”两个层面,共同推进构建人类文明新形态,助推中国式现代化行稳致远。

关键词：新质生产力物质文明新形态人类文明新形态

高校思想政治教育数字化建设及其价值意蕴、风险表征与实践进路

在线全文

学校读者我要写书评

暂无评论

大学教育科学 2024年第1期 58-65页

作者：谷永鑫西安交通大学马克思主义学院西安710049

在数字时代,高校思想政治教育数字化建设成为大势所趋。数字技术与高校思想政治教育的全面融合,为深化思想政治教育改革创新、拓展思想政治教育独特优势、推进思想政治教育高质量发展提供了新的视角和动能。当前,高校思想政治教育数字... 详细信息

在数字时代,高校思想政治教育数字化建设成为大势所趋。数字技术与高校思想政治教育的全面融合,为深化思想政治教育改革创新、拓展思想政治教育独特优势、推进思想政治教育高质量发展提供了新的视角和动能。当前,高校思想政治教育数字化建设在探索过程中面临着思维认识工具化、关系互动失序化、范式变革割裂化、治理实践失范化等方面的潜在风险和现实挑战,必须进一步强化以价值塑造为核心的理念定位、优化以素养培育为基础的主客联动、形塑以融合创新为导向的育人范式、激发以效能提升为重点的治理优势,不断推动高校思想政治教育数字化建设朝着科学化、精准化、智能化方向发展。

关键词：教育数字化建设思想政治教育智能技术潜在风险优化策略

CaCl_(2)/H_(2)O_(2)引发木质素接枝天然橡胶的制备及其应用研究

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

高分子学报 2024年第1期55卷 120-128页

作者：胡洁冯振东段咏欣青岛科技大学橡塑材料与工程教育部重点实验室青岛266042

添加增容剂是改善极性木质素(LN)与非极性橡胶相容性差的有效措施之一,有助于提高LN补强效果.本文中采用CaCl_(2)/H_(2)O_(2)作为自由基引发体系制备了LN接枝的天然橡胶(LGN),并将其用于天然橡胶(NR)/LN复合材料的界面增容.研究表明,CaC... 详细信息

添加增容剂是改善极性木质素(LN)与非极性橡胶相容性差的有效措施之一,有助于提高LN补强效果.本文中采用CaCl_(2)/H_(2)O_(2)作为自由基引发体系制备了LN接枝的天然橡胶(LGN),并将其用于天然橡胶(NR)/LN复合材料的界面增容.研究表明,CaCl_(2)/H_(2)O_(2)不但可以引发LN产生大分子自由基,而且会氧化NR双键断裂生成不饱和酮,使NR分子量降低.对接枝过程中加料顺序进行调控,采用CaCl_(2)/H_(2)O_(2)先处理LN,不但可以有效地减轻NR的氧化降解,而且有助于LN产生更多的大分子自由基.采用傅里叶变换红外光谱(FTIR)对LN、NR和LGN化学结构的表征表明:LN接枝NR的机理为LN的酚羟基自由基与NR的甲基反应形成C―O―C键.得益于LGN优异的界面增容作用,增容后的NR/LN复合材料的拉伸强度和撕裂强度较增容前分别提高了14.3%和7.5%.

关键词：木质素天然橡胶 CaCl_(2)/H_(2)O_(2) 接枝增容剂复合材料