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深水采油树Spring-Seal密封圈接触模型构建与实验测试
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作者 张红 龙圣均 +1 位作者 冯定 黄熠 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第8期112-119,共8页
为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分... 为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分析不同条件下S密封圈的密封性能,同时验证新建接触模型的合理性;利用实验测试S密封圈的实际密封效果。研究结果表明:S密封圈在高压、高温、低温等工况下能够长时间稳定工作且密封性能良好。研究结果可为S密封圈的接触研究及工程运用提供理论参考。 展开更多
关键词 S密封圈 接触模型 密封性能 实验
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Sealing capacity evaluation of underground gas storage under intricate geological conditions 被引量:1
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作者 Guangquan Zhang Sinan Zhu +4 位作者 Daqian Zeng Yuewei Jia Lidong Mi Xiaosong Yang Junfa Zhang 《Energy Geoscience》 EI 2024年第3期234-243,共10页
Evaluating underground gas storage(UGS)sealing capacity is essential for its safe construction and operational efficiency.This involves evaluating both the static sealing capacity of traps during hydrocarbon accumulat... Evaluating underground gas storage(UGS)sealing capacity is essential for its safe construction and operational efficiency.This involves evaluating both the static sealing capacity of traps during hydrocarbon accumulation and the dynamic sealing capacity of UGS under intensive gas injection and withdrawal,and alternating loads.This study detailed the methodology developed by Sinopec.The approach merges disciplines like geology,geomechanics,and hydrodynamics,employing both dynamic-static and qualitative-quantitative analyses.Sinopec's evaluation methods,grounded in the in situ stress analysis,include mechanistic studies,laboratory tests,geological surveys,stress analysis,and fluid-solid interactions.Through tests on the static and dynamic sealing capacity of UGS,alongside investigations into sealing mechanisms and the geological and geomechanical properties of cap rocks and faults,A geomechanics-rock damage-seepage mechanics dynamic coupling analysis method has been developed to predict in situ stress variations relative to pore pressure changes during UGS operations and evaluate fault sealing capacity and cap rock integrity,thereby setting the maximum operational pressures.Utilizing this evaluation technique,Sinopec has defined performance metrics and criteria for evaluating the sealing capacity of depleted gas reservoirs,enabling preliminary sealing capacity evaluations at UGS sites.These evaluations have significantly informed the design of UGS construction schemes and the evaluation of fault sealing capacity and cap rock integrity during UGS operations. 展开更多
关键词 Underground gas storage sealing capacity GEOMECHANICS Maximum operational pressure
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Interfacial friction effects on sealing performances of elastomer packer
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作者 Peng-Cheng Wang Ming-Hui Chen +2 位作者 Jim Jenkinson Yong-Xin Song Li Sun 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期2037-2047,共11页
Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic fracking.In practice sealing performances of such plugs ar... Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic fracking.In 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 casing.In previous studies,the impact of friction forces on sealing performance is often overlooked.This work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing performances.We first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac plug.Then 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 setting.With 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 products.In addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial stress.This 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. 展开更多
关键词 Elastomer seal FRICTION sealing performance Contact stress
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Evolution and Application of Sealing Ability of Gypsum Caprocks under Temperature-Pressure Coupling:An Example of the ZS5 Well in the Tazhong Area of the Tarim Basin
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作者 LIU Hua ZHAO Shan +3 位作者 YANG Xianzhang ZHU Yongfeng WANG Shen ZHANG Ke 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期168-184,共17页
Gypsum caprocks'sealing ability is affected by temperature-pressure coupling.Due to the limitations of experimental conditions,there is still a lack of triaxial stress-strain experiments that simultaneously consid... Gypsum caprocks'sealing ability is affected by temperature-pressure coupling.Due to the limitations of experimental conditions,there is still a lack of triaxial stress-strain experiments that simultaneously consider changes in temperature and pressure conditions,which limits the accuracy of the comprehensive evaluation of the brittle plastic evolution and sealing ability of gypsum rocks using temperature pressure coupling.Triaxial stress-strain tests were utilized to investigate the differences in the evolution of the confinement capacity of gypsum rocks under coupled temperaturepressure action and isothermal-variable pressure action on the basis of sample feasibility analysis.According to research,the gypsum rock's peak and residual strengths decrease under simultaneous increases in temperature and pressure over isothermal pressurization experimental conditions,and it becomes more ductile.This reduces the amount of time it takes for the rock to transition from brittle to plastic.When temperature is taken into account,both the brittle–plastic transformation's depth limit and the lithological transformation of gypsum rocks become shallower,and the evolution of gypsum rocks under variable temperature and pressure conditions is more complicated than that under isothermal pressurization.The sealing ability under the temperature-pressure coupling is more in line with the actual geological context when the application results of the Well#ZS5 are compared.This provides a theoretical basis for precisely determining the process of hydrocarbon accumulation and explains why the early hydrocarbon were not well preserved. 展开更多
关键词 temperature-pressure coupling gypsum caprocks brittle-plastic evolution sealing capacity Tarim Basin
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Fracture sealing performance of granular lost circulation materials at elevated temperature:A theoretical and coupled CFD-DEM simulation study
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作者 Chong Lin Qi-Cong Xu +4 位作者 Lie-Xiang Han Gao Li Hai He Hong-Ling Zhou Ji-Ping She 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期567-581,共15页
Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)formations.Lost circulation material(LCM)is a regular preventive and remedial measure for lost circulatio... Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)formations.Lost circulation material(LCM)is a regular preventive and remedial measure for lost circulation.However,conventional LCMs seem ineffective in high-temperature formations.This may be due to the changes in the mechanical properties of LCMs and their sealing performance under high-temperature conditions.To understand how high temperature affects the fracture sealing performance of LCMs,we developed a coupled computational fluid dynamics-discrete element method(CFD-DEM)model to simulate the behavior of granular LCMs in fractures.We summarized the literature on the effects of high temperature on the mechanical properties of LCMs and the rheological properties of drilling fluid.We conducted sensitivity analyses to investigate how changing LCM slurry properties affected the fracture sealing efficiency at increasing temperatures.The results show that high temperature reduces the size,strength,and friction coefficient of LCMs as well as the drilling fluid viscosity.Smaller,softer,and less frictional LCM particles have lower bridging probability and slower bridging initiation.Smaller particles tend to form dual-particle bridges rather than single-particle bridges.These result in a deeper,tighter,but unstable sealing zone.Reduced drilling fluid viscosity leads to faster and shallower sealing zones. 展开更多
关键词 Geothermal well drilling HTHP formationLost circulation material CFD-DEM Fracture sealing
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Dynamic evaluation on sealing capacity of caprocks of the Meso-Neoproterozoic reservoirs in Ordos Basin,China
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作者 Yusong Yuan Yunqin Hao Rongqiang Zhang 《Energy Geoscience》 EI 2024年第1期99-107,共9页
The Meso-Neoproterozoic is a new play in the Ordos Basin.A deeper understanding about the dynamic relationship between the caprocks and the source rocks is needed.Based on the comprehensive analysis of hydrocarbon sou... The Meso-Neoproterozoic is a new play in the Ordos Basin.A deeper understanding about the dynamic relationship between the caprocks and the source rocks is needed.Based on the comprehensive analysis of hydrocarbon source development characteristics of the Meso-Neoproterozoic and its overlying strata,as well as the formation contact relationships,lithology characteristics and exploratory drilling data,it is recognized that the Meso-Neoproterozoic contains two types of petroleum accumulation assemblage,that is,the“self-sourced indigenous”and“upper source rock-lower reservoir”assemblages.The former is mainly controlled by the development and distribution of source rocks of the Changcheng System,with the Lower Cambrian shale sequence as its caprock.The later is controlled by the superposition between the Meso-Neoproterozoic and its overlying source rocks and this assemblage is mainly distributed in Hangjinqi and Pingliang areas with the Carboniferous-Permian shale sequence as its caprock.The dynamic evaluation on the displacement pressure serves to reconstruct the displacement pressure history of the caprock.The results show that the shale sequence of the Cambrian Maozhuang Formation in well XY 1 in the southern Ordos Basin has possibly acquired the ability of sealing natural gas since the early of Late Triassic.Its displacement pressure increased rapidly up to 20 MPa during the Late Triassic-Jurassic and keeps at 9.2 MPa at present,indicating fair sealing ability.The Carboniferous-Permian caprocks in Hangjinqi area could have acquired the ability to seal natural gas in the Late Jurassic-Early Cretaceous,and the present-day displacement pressure is 9e12 MPa,indicating good sealing ability.The upper Paleozoic caprock in Pingliang area has been able to seal natural gas since the Early Jurassic,with a maximum displacement pressure of 23 MPa during the Cretaceous period and a current value of 17 e20 MPa,indicative of strong ability to seal natural gas.The sealing ability of caprocks of both the“selfsourced indigenous”and“upper source rock-lower reservoir”assemblages has come into being earlier than or at least no later than the peak gas generation of the source rocks and therefore the caprocks are dynamically effective in geohistory.The Meso-Neoproterozoic reservoirs in the Ordos Basin are well preserved and probabally of better potential for exploration in terms of the caprock-source rock combination. 展开更多
关键词 Ordos Basin MESO-NEOPROTEROZOIC Caprock sealing ability Displacement pressure
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Influence of pressure disturbance wave on dynamic response characteristics of liquid film seal for multiphase pump
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作者 Qing-Ping Li Jin-Ya Zhang +1 位作者 Jia-Xiang Zhang Yong-Xue Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期2048-2065,共18页
Slug flow or high GVF(Gas Volume Fraction)conditions can cause pressure disturbance waves and alternating loads at the boundary of mechanical seals for multiphase pumps,endangering the safety of multiphase pump units.... Slug flow or high GVF(Gas Volume Fraction)conditions can cause pressure disturbance waves and alternating loads at the boundary of mechanical seals for multiphase pumps,endangering the safety of multiphase pump units.The mechanical seal model is simplified by using periodic boundary conditions and numerical calculations are carried out based on the Zwart-Gerber-Belamri cavitation model.UDF(User Define Function)programs such as structural dynamics equations,alternating load equations,and pressure disturbance equations are embedded in numerical calculations,and the dynamic response characteristics of mechanical seal are studied using layered dynamic mesh technology.The results show that when the pressure disturbance occurs at the inlet,as the amplitude and period of the disturbance increase,the film thickness gradually decreases.And the fundamental reason for the hysteresis of the film thickness change is that the pressure in the high-pressure area cannot be restored in a timely manner.The maximum value of leakage and the minimum value of axial velocity are independent of the disturbance period and determined by the disturbance amplitude.The mutual interference between enhanced waves does not have a significant impact on the film thickness,while the front wave in the attenuated wave has a promoting effect on the subsequent film thickness changes,and the fluctuation of the liquid film cavitation rate and axial velocity under the attenuated wave condition deviates from the initial values.Compared with pressure disturbance conditions,alternating load conditions have a more significant impact on film thickness and leakage.During actual operation,it is necessary to avoid alternating load conditions in multiphase pump mechanical seals. 展开更多
关键词 Multiphase pump Liquid film seal Pressure disturbance wave Dynamic response characteristics
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Preparation and property of seal coating for gas turbine compressor
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作者 余沛坰 刘中华 +2 位作者 郑健生 徐伏根 陈千宝 《China Welding》 CAS 2024年第1期60-64,共5页
Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atm... Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atmospheric plasma spraying and top coating was prepared by flame spraying.The microstructure,mechanical properties and abradability of the coating were characterized by scanning elec-tron microscope(SEM),hardness tester,universal testing machine,thermal shock testing machine and abradability testing machine.The res-ults show that the overall spraying structure of the seal coating is uniform,the nickel metal phase is the skeleton supporting the entire coat-ing,and the coating is well bonded without separation.The seal coating has a bonding strength of not less than 7.7 MPa,excellent thermal stability,and thermal shock resistance cycle numbers at 500℃more than 50;the scratch length,deepest invasion depth and wear amount of the coating increase with rise of test temperature,with almost no coating adhesion,indicating that the seal coating has excellent abradability. 展开更多
关键词 gas turbine compressor seal coating MICROSTRUCTURE mechanical property abradability
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No-touch isolation technique in emergency pancreaticoduodenectomy for neoplastic hemorrhage: Two case reports and review of literature
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作者 Akihiro Cho Satoshi Katagiri +8 位作者 Masao Ota Shunsuke Onizawa Ryota Higuchi Toshiya Sugishita Yukiko Niwa Takeshi Ishita Toshihiko Mouri Akita Kato Moe Iwata 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第6期1910-1917,共8页
BACKGROUND Emergency pancreaticoduodenectomy(EPD)is a rare event for complex periam-pullary etiology.Increased intraoperative blood loss is correlated with poor post-operative outcomes.CASE SUMMARY Two patients underw... BACKGROUND Emergency pancreaticoduodenectomy(EPD)is a rare event for complex periam-pullary etiology.Increased intraoperative blood loss is correlated with poor post-operative outcomes.CASE SUMMARY Two patients underwent EPD using a no-touch isolation technique,in which all arteries supplying the pancreatic head region were ligated and divided before manipulation of the pancreatic head and duodenum.The operative times were 220 and 239 min,and the blood loss was 70 and 270 g,respectively.The patients were discharged on the 14^(th) and 10^(th) postoperative day,respectively.Thirty-two patients underwent EPD for the treatment of neoplastic bleeding.The mean operative time was 361.6 min,and the mean blood loss was 747.3 g.The comp-lication rate was 37.5%.The in-hospital mortality rate was 9.38%.CONCLUSION The no-touch isolation technique is feasible,safe,and effective for reducing intraoperative blood loss in EPD. 展开更多
关键词 no-touch isolation technique PANCREATICODUODENECTOMY Emergency pancre-aticoduodenectomy Neoplastic bleeding Superior mesenteric artery first approach Case report
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No-touch射频消融技术对小肝癌患者治疗获益及血清AFP、GPC3和无进展生存期的影响
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作者 王小东 王石 +3 位作者 郑宇 阿思根 武慧军 张建强 《现代消化及介入诊疗》 2024年第5期625-628,共4页
目的探究No-touch射频消融技术对小肝癌患者治疗获益及血清甲胎蛋白(AFP)、磷脂酰肌醇蛋白聚糖3(GPC3)和无进展生存的影响。方法选择2017年1月至2020年12月于内蒙古自治区人民医院就诊的小肝癌患者120例,将患者随机分为No-touch组(n=57... 目的探究No-touch射频消融技术对小肝癌患者治疗获益及血清甲胎蛋白(AFP)、磷脂酰肌醇蛋白聚糖3(GPC3)和无进展生存的影响。方法选择2017年1月至2020年12月于内蒙古自治区人民医院就诊的小肝癌患者120例,将患者随机分为No-touch组(n=57)和传统射频组(n=63)。所有患者均随访24个月,统计两组无进展生存情况、肿瘤复发情况及总生存情况。比较两组患者肿瘤灭活率、病灶灭活范围及其他手术相关指标,并观察患者手术前后血清肿瘤标志物、肝功能指标及T淋巴细胞亚群变化情况。结果No-touch组、传统组肿瘤完全灭活率分别为96.49%、88.89%,两组对比差异无统计学意义(P>0.05),No-touch组病灶灭活范围大于传统组,手术时间长于传统组(P<0.05);术后1个月,No-touch组AFP、GPC3水平低于传统组[(98.03±10.29)μg/L、(0.65±0.14)μg/L(103.28±10.81)μg/L、(0.73±0.17)μg/L,P<0.05];No-touch组术后1周的ALT、AST水平高于传统组,术后1个月的CD3^(+)、CD4^(+)值及CD4^(+)/CD8^(+)比值大于传统组(P<0.05);No-touch组无进展生存率高于传统组(68.42%vs 42.86%,P<0.05),对照组中位无进展生存期22.90个月;两组总生存率及复发率对比无明显差异(P>0.05);两组并发症发生率对比无明显差异(P>0.05)。结论相比于传统射频消融技术,No-touch射频消融技术治疗可有效扩大病灶灭活范围,降低血清肿瘤标志物水平,减轻对肝功能的影响,并能改善肿瘤免疫功能,提高无进展生存率。 展开更多
关键词 no-touch射频消融技术 传统射频消融技术 小肝癌 甲胎蛋白 磷脂酰肌醇蛋白聚糖3 无进展生存
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SEAL428采集设备原理分析
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作者 张迎春 《物探装备》 2024年第5期316-321,共6页
本文从Sercel公司用于陆地和海上勘探的428系列地震仪器产品性能特点出发,通过对比分析,总结海洋SEAL428系统的设计理念和数据采集原理。文章从两者的野外采集设备布设和连接方式切入,对比两套系统的设备架构、数据传输、设备布设灵活... 本文从Sercel公司用于陆地和海上勘探的428系列地震仪器产品性能特点出发,通过对比分析,总结海洋SEAL428系统的设计理念和数据采集原理。文章从两者的野外采集设备布设和连接方式切入,对比两套系统的设备架构、数据传输、设备布设灵活性、带道能力、采集设备种类、采集设备故障排查等方面的异同。重点对SEAL428地震采集仪器的数据采集原理进行分析,对SEAL428的“鬼对”传输技术、数字滤波器原理等进行深入探讨,以期为国内海洋物探装备技术提升提供参考。 展开更多
关键词 seal428 采集仪器 海上地震 FDU 鬼对
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Study on Sealing Characteristics of Sliding Seal Assembly of Aircraft Hydraulic Actuator
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作者 Weinan Li Saixin Shi +4 位作者 Hongxia Tang Liang Chen Jiawei Zhang Hao Tang Jianhua Zhao 《Instrumentation》 2024年第1期18-29,共12页
The hydraulic actuator,known as the"muscle"of military aircraft,is responsible for flight attitude adjustment,trajectory control,braking turn,landing gear retracting and other actions,which directly affect i... The hydraulic actuator,known as the"muscle"of military aircraft,is responsible for flight attitude adjustment,trajectory control,braking turn,landing gear retracting and other actions,which directly affect its flight efficiency and safety.However,the sealing assembly often has the situation of over-aberrant aperture fit clearance or critical over-aberrant clearance,which increases the failure probability and degree of movable seal failure,and directly affects the flight efficiency and safety of military aircraft.In this paper,the simulation model of hydraulic actuator seal combination is established by ANSYS software,and the sealing principle is described.The change curve of contact width and contact pressure of combination seal under the action of high-pressure fluid is drawn.The effects of different oil pressure,fit clearance and other parameters on the sealing performance are analyzed.Finally,the accelerated life test of sliding seal components is carried out on the hydraulic actuator accelerated life test rig,and the surface morphology is compared and analyzed.The research shows that the O-ring is the main sealing element and the role of the check ring is to protect and support the O-ring to prevent damage caused by squeezing into the fit clearance,so the check ring bears a large load and is prone to shear failure.Excessive fit clearance is the main factor affecting the damage of the check ring,and the damage parts are mainly concentrated at the edge of the sealing surface.This paper provides a theoretical basis for the design of hydraulic actuator and the improvement of sealing performance. 展开更多
关键词 hydraulic actuator contact stress sealing characteristics maximum shear stress
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Application of Choquet Integral-Importance-Performance Analysis and TOPSIS Methods in Approaching the Preference Factors of Calligraphy and Seal Engraving Imagery
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作者 Yu Hsuan Chang Jiann Sheng Jiang Min Min Lin 《Journal of Contemporary Educational Research》 2024年第5期276-288,共13页
Classical Chinese characters,presented through calligraphy,seal engraving,or painting,can exhibit different aesthetics and essences of Chinese characters,making them the most important asset of the Chinese people.Call... Classical Chinese characters,presented through calligraphy,seal engraving,or painting,can exhibit different aesthetics and essences of Chinese characters,making them the most important asset of the Chinese people.Calligraphy and seal engraving,as two closely related systems in traditional Chinese art,have developed through the ages.Due to changes in lifestyle and advancements in modern technology,their original functions of daily writing and verification have gradually diminished.Instead,they have increasingly played a significant role in commercial art.This study utilizes the Evaluation Grid Method(EGM)and the Analytic Hierarchy Process(AHP)to research the key preference factors in the application of calligraphy and seal engraving imagery.Different from the traditional 5-point equal interval semantic questionnaire,this study employs a non-equal interval semantic questionnaire with a golden ratio scale,distinguishing the importance ratio of adjacent semantic meanings and highlighting the weighted emphasis on visual aesthetics.Additionally,the study uses Importance-Performance Analysis(IPA)and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)to obtain the key preference sequence of calligraphy and seal engraving culture.Plus,the Choquet integral comprehensive evaluation is used as a reference for IPA comparison.It is hoped that this study can provide cultural imagery references and research methods,injecting further creativity into industrial design. 展开更多
关键词 Evaluation Grid Method Analytic Hierarchy Process CALLIGRAPHY seal engraving Importance-Performance Analysis Choquet integral TOPSIS
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Study on the effect of thermal deformation on the liquid seal of high-temperature molten salt pump in molten salt reactor 被引量:2
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作者 Xing‑Chao Shen Yuan Fu Jian‑Yu Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第2期128-138,共11页
The high-temperature molten salt pump is the core equipment in a molten salt reactor that drives the flow of the molten salt coolant.Rotor stability is key to the continuous and reliable operation of the molten salt p... The high-temperature molten salt pump is the core equipment in a molten salt reactor that drives the flow of the molten salt coolant.Rotor stability is key to the continuous and reliable operation of the molten salt pump,and the liquid seal at the wear ring can affect the dynamic characteristics of the rotor system.When the molten salt pump is operated in the hightemperature molten salt medium,thermal deformation of the submerged parts inevitably occurs,changing clearance between the stator and rotor,affecting the leakage and dynamic characteristics of the seal.In this study,the seal leakage,seal dynamic characteristics,and rotor system dynamic characteristics are simulated and analyzed using finite element simulation software based on two cases of considering the effect of seal thermal deformation effect or not.The results show a significant difference in the leakage characteristics and dynamic characteristics of the seal obtained by considering the effect of seal thermal deformation and neglecting the effect of thermal deformation.The leakage flow rate decreases,and the first-order critical speed of the seal-bearing-rotor system decrease after considering the seal’s thermal deformation. 展开更多
关键词 High-temperature molten salt pump seal thermal deformation Leakage characteristics seal dynamic characteristics Critical speed
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No-touch技术与传统拉钩治疗跟骨骨折疗效及术后切口并发症比较 被引量:2
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作者 廖正文 黄承夸 +1 位作者 陈仕 李炜 《中国骨伤》 CAS CSCD 2023年第4期302-308,共7页
目的:比较No-touch技术与传统拉钩治疗跟骨骨折的临床疗效。方法:回顾性分析2019年7月至2021年6月治疗的74例闭合性SandersⅡ-Ⅳ型跟骨骨折患者的临床资料。根据治疗方法不同分为No-touch组和常规组,每组37例。No-touch组男25例,女12例... 目的:比较No-touch技术与传统拉钩治疗跟骨骨折的临床疗效。方法:回顾性分析2019年7月至2021年6月治疗的74例闭合性SandersⅡ-Ⅳ型跟骨骨折患者的临床资料。根据治疗方法不同分为No-touch组和常规组,每组37例。No-touch组男25例,女12例;年龄19~70(42.64±14.16)岁;Sanders骨折分型,Ⅱ型17例,Ⅲ型14例,Ⅳ型6例;采用3枚2.0mm克氏针分别于距骨体、距骨颈、骰骨植入折弯,将皮瓣向上翻转暴露术区完成手术。常规组男30例,女7例;年龄19~67(41.56±11.38)岁;Sanders骨折分型,Ⅱ型17例,Ⅲ型12例,Ⅳ型8例;采用传统拉钩暴露术区完成手术。比较两组患者手术时间、术后切口并发症发生率、术后6个月美国足踝外科协会(American Orthopedic Foot and Ankle Society,AOFAS)踝-后足评分。结果:两组74例患者均获得随访,No-touch组随访时间6~17(9.57±2.72)个月,常规组随访时间6~16(9.14±2.71)个月,两组比较差异无统计学意义(P>0.05)。No-touch组手术时间(55.67±7.94)min明显少于常规组(70.16±9.41)min(P<0.05);No-touch组术后2周出现切口并发症4例,而常规组则出现8例,差异有统计学意义(P<0.05)。No-touch组AOFAS评分中日常活动及支撑情况、最大步行距离、地面步行情况、屈伸伸展及内外翻受限程度、足部对线及总分明显高于常规组(P<0.05)。而两组在疼痛、反常步态、踝-后足稳定性方面比较,差异无统计学意义(P>0.05)。根据AOFAS评分,No-touch组优19例,良16例,差2例;常规组优9例,良24例,差4例;两组比较差异无统计学意义(P>0.05)。结论:No-touch技术较传统拉钩治疗跟骨骨折,可明显缩短手术时间,降低术口并发症发生率,但两种方法均可提高术后踝关节功能恢复的优良率。 展开更多
关键词 跟骨骨折 no-touch 切口并发症
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Air tightness of compressed air storage energy caverns with polymer sealing layer subjected to various air pressures 被引量:5
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作者 Shikang Qin Caichu Xia Shuwei Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第8期2105-2116,共12页
During the operation of compressed air storage energy system,the rapid change of air pressure in a cavern will cause drastic changes in air density and permeability coefficient of sealing layer.To calculate and proper... During the operation of compressed air storage energy system,the rapid change of air pressure in a cavern will cause drastic changes in air density and permeability coefficient of sealing layer.To calculate and properly evaluate air tightness of polymer sealing caverns,the air-pressure-related air density and permeability must be considered.In this context,the high-pressure air penetration in the polymer sealing layer is studied in consideration of thermodynamic change of the cavern structure during the system operation.The air tightness model of compressed air storage energy caverns is then established.In the model,the permeability coefficient and air density of sealing layer vary with air pressure,and the effectiveness of the model is verified by field data in two test caverns.Finally,a compressed air storage energy cavern is taken as an example to understand the air tightness.The air leakage rate in the caverns is larger than that using air-pressure-independent permeability coefficient and air density,which is constant and small in the previous leakage rate calculation.Under the operating pressure of 4.5-10 MPa,the daily air leakage in the compressed air storage energy cavern of Yungang Mine with high polymer butyl rubber as the sealing material is 0.62%,which can meet the sealing requirements of compressed air storage energy caverns.The air tightness of the polymer sealing cavern is mainly affected by the cavern operating pressure,injected air temperature,cavern radius,and sealing layer thickness.The cavern air leakage rate will be decreased to reduce the cavern operating pressure the injection air temperature,or the cavern radius and sealing layer thickness will be increased. 展开更多
关键词 Compressed air storage energy Polymer sealing layer Air tightness Permeability coefficient Air density
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The “No-touch” technique improves the survival of patients with advanced hepatocellular carcinomas treated by liver transplantation: A single-center prospective randomized controlled trial 被引量:1
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作者 Xin Lin Min Xiao +5 位作者 Yang-Jun Gu Heng-Kai Zhu Meng-Xia Li Li Zhuang Shu-Sen Zheng Qi-Yong Li 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2023年第3期253-262,共10页
Background:Liver transplantation(LT)is the best treatment for patients with hepatocellular carcinoma(HCC).However,the surgical technique needs to be improved.The present study aimed to evaluate the“no-touch”techniqu... Background:Liver transplantation(LT)is the best treatment for patients with hepatocellular carcinoma(HCC).However,the surgical technique needs to be improved.The present study aimed to evaluate the“no-touch”technique in LT.Methods:From January 2018 to December 2019,we performed a prospective randomized controlled trial on HCC patients who underwent LT.The patients were randomized into two groups:a no-touch technique LT group(NT group,n=38)and a conventional LT technique group(CT group,n=46).Operative outcomes and survival in the two groups were analyzed.Results:The perioperative parameters were comparable between the two groups(P>0.05).There was no significant difference between the two groups in disease-free survival(DFS)(P=0.732)or overall survival(OS)(P=0.891).Of 36 patients who were beyond the Hangzhou criteria for LT,the DFS of the patients in the NT group was significantly longer than that in the CT group(median 402 vs.126 days,P=0.025).In 31 patients who had portal vein tumor thrombosis(PVTT),DFS and OS in the NT group were significantly better than those in the CT group(median DFS 420 vs.167 days,P=0.022;2-year OS rate 93.8%vs.66.7%,P=0.043).In 14 patients who had diffuse-type HCCs,DFS and OS were significantly better in the NT group than those in the CT group(median DFS 141 vs.56 days,P=0.008;2-year OS rate 75.0%vs.33.3%,P=0.034).Multivariate analysis showed that for patients with PVTT and diffusetype HCCs,the no-touch technique was an independent favorable factor for OS(PVTT:HR=0.018,95%CI:0.001-0.408,P=0.012;diffuse-type HCCs:HR=0.034,95%CI:0.002-0.634,P=0.024).Conclusions:The no-touch technique improved the survival of patients with advanced HCC compared with the conventional technique.The no-touch technique may provide a new and effective LT technique for advanced HCCs. 展开更多
关键词 no-touch technique Liver transplantation Hepatocellular carcinoma Surgical procedure SURVIVAL
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No-Touch桥静脉单支序贯与多支端侧吻合在冠状动脉旁路移植术中的应用价值对比
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作者 庄严 魏一鸣 +2 位作者 谢勇 李冬梅 李萍 《当代医药论丛》 2023年第9期50-52,共3页
目的:通过多项指标对比利用No-Touch(不接触)技术获取的桥静脉与冠状动脉靶血管进行单支序贯与多支端侧吻合在冠状动脉旁路移植术(CABG)中的应用价值。方法:选取2019年1月至2022年12月在佳木斯市中心医院进行CABG的患者82例为研究对象... 目的:通过多项指标对比利用No-Touch(不接触)技术获取的桥静脉与冠状动脉靶血管进行单支序贯与多支端侧吻合在冠状动脉旁路移植术(CABG)中的应用价值。方法:选取2019年1月至2022年12月在佳木斯市中心医院进行CABG的患者82例为研究对象。术中应用No-Touch技术获取桥静脉,并将多支桥静脉端侧吻合的患者纳入对照组,将单支桥静脉血管序贯式吻合的患者纳入观察组,对比两组的各项临床指标。结果:术后返回监护室1小时内(T_(1))及术后第1日(T2),观察组的心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)、氨基末端-B型脑钠肽前体(NT-proBNP)水平均低于对照组,差异有统计学意义(P<0.05)。术后3个月复查时,两组的cTnI、CKMB、NT-proBNP水平相近。观察组的手术时间、呼吸机应用时间、监护室停留时间、住院时间均短于对照组,术后12 h引流量少于对照组,住院费用低于对照组,差异有统计学意义(P<0.05)。结论:在CABG中,应用No-Touch技术获取的单支桥静脉血管行序贯式吻合是安全有效的,患者的近期疗效良好,其效果优于多支桥静脉端侧吻合。 展开更多
关键词 no-touch 桥静脉 单支序贯吻合 多支端侧吻合 冠状动脉旁路移植术
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Preparation and property of self-sealed plasma electrolytic oxide coating on magnesium alloy 被引量:1
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作者 Chen Ma Dong Wang +3 位作者 Jinyu Liu Ning Peng Wei Shang Yuqing Wen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第5期959-969,共11页
Plasma electrochemical oxidation (PEO) is a surface modification technology to form ceramic coatings on magnesium alloys However,its application is limited due to its defects.This work reports a novel preparation of i... Plasma electrochemical oxidation (PEO) is a surface modification technology to form ceramic coatings on magnesium alloys However,its application is limited due to its defects.This work reports a novel preparation of in-situ sealing of PEO coatings by four-layer voltage and sol addition.The morphology and structure were characterized by scanning electron microscopy (SEM),energy dispersive X-ray spectroscopy (EDS),and X-ray diffractometer (XRD).Image-Pro Plus 6.0 was used to determine the porosity of the coating,which was decreased from 8.53%to 0.51%.Simultaneously,the coating thickness was increased by a factor of four.The anti-corrosion performance of each sample was evaluated using electrochemical tests,and the findings revealed that the corrosion current density of coatings (i_(corr)) of the samples were lowered from 9.152×10^(-2) to 6.152×10^(-4) mA·cm^(-2),and the total resistance (R_(T)) of the samples were enhanced from 2.19×10^(4) to 2.33×10^(5)Ω·cm^(2).The salt spray test used to simulate the actual environment showed that corrosion points appeared on the surface of the coating only at the 336 h.In addition,the mechanism of PEO self-sealing behavior was described in this article. 展开更多
关键词 magnesium alloy in-situ sealing plasma electrolytic oxidation corrosion resistance
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MRI insight on multiphase flow in hydrate-bearing sediment and development mechanism of hydrate seal 被引量:1
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作者 Guo-Jun Zhao Ming-Jun Yang +2 位作者 Xin Lv Jia-Nan Zheng Yong-Chen Song 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3854-3864,共11页
Gas and water migration through the hydrate-bearing sediment are characteristic features in marine gas hydrate reservoirs worldwide.However,there are few experimental investigations on the effect of water-gas flow on ... Gas and water migration through the hydrate-bearing sediment are characteristic features in marine gas hydrate reservoirs worldwide.However,there are few experimental investigations on the effect of water-gas flow on the gas hydrate reservoir.In this study,gas-water migration in gas hydrate stability zone(GHSZ)was investigated visually employing a high-resolution magnetic resonance imaging(MRI)apparatus,and the formation of hydrate seal was experimentally investigated.Results revealed that normal flow of gas-water at the low flow rate of 1–0.25 mL/min will induce the hydrate reformation.Conversely,higher gas-water flow rates(at 2–0.5 and 4–1 mL/min)need higher reservoir pressure to induce the hydrate reformation.In addition,the hydrate reformation during the gas-water flow process produced the hydrate seal,which can withstand an over 9.0 MPa overpressure.This high overpressure provides the development condition for the underlying gas and/or water reservoir.A composite MRI image of the whole hydrate seal was obtained through the MRI.The pore difference between hydrate zone and coexistence zone produces a capillary sealing effect for hydrate seal.The hydrate saturation of hydrate seal was more than 51.6%,and the water saturation was more than 19.3%.However,the hydrate seal can be broken through when the overpressure exceeded the capillary pressure of the hydrate seal,which induced the sudden drop of reservoir pressure.This study provides a scientific explanation for the existence of high-pressure underlying gas below the hydrate layer and is significant for the safe exploitation of these common typical marine hydrate reservoirs. 展开更多
关键词 Gas hydrate Gas-water migration Underlying gas Hydrate seal Pore difference MRI
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