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Improving electrochemical performances of LiFePO_4 /C cathode material via a novel three-layer electrode 被引量:1
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作者 肖政伟 胡国荣 +1 位作者 杜柯 彭忠东 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3324-3329,共6页
As an improvement on the conventional two-layer electrode (active material layerlcurrent collector), a novel sandwich-like three-layer electrode (conductive layerlactive material layertcurrent collector) for catho... As an improvement on the conventional two-layer electrode (active material layerlcurrent collector), a novel sandwich-like three-layer electrode (conductive layerlactive material layertcurrent collector) for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3+/Fe2+ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte. 展开更多
关键词 lithium ion cells LIFEPO4 cathode electrode configuration three-layer electrode electrochemical performances
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Structure Design and Properties of Three-Layer Particleboard Based on High Voltage Electrostatic Field(HVEF) 被引量:1
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作者 Man Yuan Lu Hong +5 位作者 Zehui Ju Wenli Gu Biqing Shu Jianxin Cui Xiaoning Lu Zhiqiang Wang 《Journal of Renewable Materials》 SCIE EI 2021年第8期1433-1445,共13页
In this study,the effects of three different particle sizes of wood wastes(A=–8+12 mesh;B=–12+20 mesh;C=–20+30 mesh)and factory shavings(D)on the properties of particleboard were investigated.According to the test ... In this study,the effects of three different particle sizes of wood wastes(A=–8+12 mesh;B=–12+20 mesh;C=–20+30 mesh)and factory shavings(D)on the properties of particleboard were investigated.According to the test results,three-layer particleboard was designed.Particleboard face layers made with mixture of A,B,and C.The core layer made with D.The ratio of core layer to face layers is 50:50.Three-layer particleboard were fabricated with 12%urea-formaldehyde(UF)resins and three different high voltage electrostatic field intensities(0 kv,30 kv,60 kv).The internal bond(IB)strength,modulus of rupture(MOR),modulus of elasticity(MOE),thickness swelling(TS),and water absorption(WA)of particleboard were evaluated.The density distribution of the three-layer particleboard were examined by vertical density profiles(VDP),and the bonding mechanism and functional groups changes in the particles were analyzed by FTIR analysis.The results showed that HVEF treatment intensity play a remarkable role in properties of particleboard.The particleboard with higher electrostatic field intensities treatment has higher MOE,MOR,IB,and TS.Under HVEF treatment(60 kv),the MOR,modulus of MOE,and IB of three-layer particleboard were 23.61 N/mm^(2),2787.09 N/mm^(2),and 0.86 N/mm^(2),respectively.FTIR indicated that the surface activity of wood particles was increased electric field treatment. 展开更多
关键词 High voltage electric field three-layer particleboard physical property mechanical property
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Influence of negative information dissemination and vaccination behavioral decision-making on epidemic spreading in a three-layer network
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作者 Liang'an Huo Leyao Yin 《Chinese Physics B》 2025年第6期667-681,共15页
Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt pro... Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt protective measures.However, whether to disseminate specific information is also a behavioral decision. In light of this understanding, we develop a coupled information–vaccination–epidemic model to depict these co-evolutionary dynamics in a three-layer network. Negative information dissemination and vaccination are treated as separate decision-making processes. We then examine the combined effects of herd and risk motives on information dissemination and vaccination decisions through the lens of game theory. The microscopic Markov chain approach(MMCA) is used to describe the dynamic process and to derive the epidemic threshold. Simulation results indicate that increasing the cost of negative information dissemination and providing timely clarification can effectively control the epidemic. Furthermore, a phenomenon of diminishing marginal utility is observed as the cost of dissemination increases, suggesting that authorities do not need to overinvest in suppressing negative information. Conversely, reducing the cost of vaccination and increasing vaccine efficacy emerge as more effective strategies for outbreak control. In addition, we find that the scale of the epidemic is greater when the herd motive dominates behavioral decision-making. In conclusion, this study provides a new perspective for understanding the complexity of epidemic spreading by starting with the construction of different behavioral decisions. 展开更多
关键词 negative information VACCINATION epidemic spreading behavioral decision-making three-layer network
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A surrogate model for estimating rock stress by a hollow inclusion strain cell in a three-layer medium
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作者 Changkun Qin Wusheng Zhao +2 位作者 Weizhong Chen Peiyao Xie Shuai Zhou 《International Journal of Mining Science and Technology》 2025年第3期363-381,共19页
Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress te... Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress tensor by measuring strain using an HI strain cell.However,existing analytical solutions for stress calculation based on an HI strain cell in a double-layer medium are not applicable when an HI strain cell is used in a three-layer medium,leading to erroneous stress calculations.To address this issue,this paper presents a method for calculating stress tensors in a three-layer medium using numerical simulations,specifically by obtaining a constitutive matrix that relates strain measurements to stress tensors in a three-layer medium.Furthermore,using Latin hypercube sampling (LHS) and orthogonal experimental design strategies,764 groups of numerical models encompassing various stress measurement scenarios have been established and calculated using FLAC^(3D)software.Finally,a surrogate model based on artificial neural network (ANN) was developed to predict constitutive matrices,achieving a goodness of fit (R^(2)) of 0.999 and a mean squared error (MSE) of 1.254.A software program has been developed from this surrogate model for ease of use in practical engineering applications.The method’s accuracy was verified through numerical simulations,analytical solution and laboratory experiment,demonstrating its effectiveness in calculating stress in a three-layer medium.The surrogate model was applied to calculate mining-induced stress in the roadway roof rock of a coal mine,a typical case for stress measurement in a three-layer medium.Errors in stress calculations arising from the use of existing analytical solutions were corrected.The study also highlights the significant errors associated with using double-layer analytical solutions in a three-layer medium,which could lead to inappropriate engineering design. 展开更多
关键词 Stress measurement Over-coring stress relief method three-layer medium Surrogate model Numerical simulation
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Thermal and solutal Marangoni convection in three-layered viscous flows:Insights for liquid metal battery optimization
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作者 SHAHEEN Sidra HUANG Hu-lin +2 位作者 ARAIN Muhammad Bilal BHATTI Muhammad Mubashir KHALIQUE Chaudry Masood 《Journal of Central South University》 2025年第6期2087-2100,共14页
This study examines the intricate occurrences of thermal and solutal Marangoni convection in three-layered flows of viscous fluids,with a particular emphasis on their relevance to renewable energy systems.This researc... This study examines the intricate occurrences of thermal and solutal Marangoni convection in three-layered flows of viscous fluids,with a particular emphasis on their relevance to renewable energy systems.This research examines the flow of a three-layered viscous fluid,considering the combined influence of heat and solutal buoyancy driven Rayleigh-Bénard convection,as well as thermal and solutal Marangoni convection.The homotopy perturbation method is used to examine and simulate complex fluid flow and transport phenomena,providing important understanding of the fundamental physics and assisting in the optimization of various battery configurations.The inquiry examines the primary elements that influence Marangoni convection and its impact on battery performance,providing insights on possible enhancements in energy storage devices.The findings indicate that the velocity profiles shown graphically exhibit a prominent core zone characterized by the maximum speed,which progressively decreases as it approaches the walls of the channel.This study enhances our comprehension of fluid dynamics and the transmission of heat and mass in intricate systems,which has substantial ramifications for the advancement of sustainable energy solutions. 展开更多
关键词 viscous fluid three-layered closed geometries electrical conductivity thermal convection solutal convection mass diffusivity homotopy perturbation methods
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Trapped Modes in a Three-Layer Fluid
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作者 Sunanda Saha Swaroop Nandan Bora 《Journal of Marine Science and Application》 CSCD 2018年第1期45-56,共12页
In this work,trapped mode frequencies are computed for a submerged horizontal circular cylinder with the hydrodynamic set-up involving an infinite depth three-layer incompressible fluid with layer-wise different densi... In this work,trapped mode frequencies are computed for a submerged horizontal circular cylinder with the hydrodynamic set-up involving an infinite depth three-layer incompressible fluid with layer-wise different densities.The impermeable cylinder is fully immersed in either the bottom layer or the upper layer.The effect of surface tension at the surface of separation is neglected.In this set-up,there exist three wave numbers:the lowest one on the free surface and the other two on the internal interfaces.For each wave number,there exist two modes for which trapped waves exist.The existence of these trapped modes is shown by numerical evidence.We investigate the variation of these trapped modes subject to change in the depth of the middle layer as well as the submergence depth.We show numerically that two-layer and single-layer results cannot be recovered in the double and single limiting cases of the density ratios tending to unity.The existence of trapped modes shows that in general,a radiation condition for the waves at infinity is insufficient for the uniqueness of the solution of the scattering problem. 展开更多
关键词 Trappedmode three-layer FLUID CUT-OFF VALUE MULTIPOLES Pycnoclines
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Preparation of bilayer/three-layer PEO-carbon nanotube composite thin films and their toluene-sensing application
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作者 TAI HuiLing LIAO Jian +2 位作者 DAN WenChao DUAN ChengLi LI Xian 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第5期1124-1128,共5页
The bilayer poly(ethylene oxide)/multiple-walled carbon nanotubes(PEO/MWCNTs) and three-layer PEO/MWCNTs/PEO composite thin films were fabricated with the spraying process on the interdigitated transducers(IDTs) as ga... The bilayer poly(ethylene oxide)/multiple-walled carbon nanotubes(PEO/MWCNTs) and three-layer PEO/MWCNTs/PEO composite thin films were fabricated with the spraying process on the interdigitated transducers(IDTs) as gas sensors for toluene-sensing application.Compared with the bilayer thin film sensor,the sensor with three-layer thin films exhibited higher response values and better recovery property.The microstructures of sensing films were characterized by scanning electron microscopy(SEM) to indicate that the better sensing response of three-layer thin films might be ascribed to the sufficient adsorption of toluene molecules on the surfaces of upper and bottom PEO films.The selectivity of the three-layer film sensor was further investigated by comparing responses upon exposure to different interference vapors with the response to toluene exposure,and much higher response was observed in the case of toluene.Good repeatability of the three-layer film sensor was also observed. 展开更多
关键词 peO MWCNTS three-layer composite thin films gas sensors TOLUENE
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Study on Three-layered Grid Conceptual Prototype Using Ecological Network Computing Environment
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作者 皋磊 丁永生 任立红 《Journal of Donghua University(English Edition)》 EI CAS 2004年第5期8-11,共4页
Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems... Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems resemble the self-organizing and the healing properties of natural ecosystems. Some key ecological concepts and mechanisms are introduced into the design for the third generation grid computing architectures by inspiration of this resemblance. Also, an Ecological Network-based Computing Environment (ENCE) platform is designed in this paper. Based on the ENCE platform, a grid-computing model of three-layered grid conceptual prototype that embeds the ENCE layers is presented from the viewpoint of implementation. The implementation model should be useful to the design of the third generation grid systems. 展开更多
关键词 ecological network ECOSYSTEM grid system automation EMERGENCE three-layered grid conceptual prototype
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燃气PE管道第三方破坏失效分析
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作者 刘兵 王学礼 《科学技术创新》 2026年第3期57-60,共4页
为了评估燃气PE管道在第三方破坏作用下的失效风险及应急处理效果,开展燃气PE管道第三方破坏失效分析研究,通过介绍管道力学响应数值分析模型,分析PE管材的力学特性、土壤参数的影响及管道失效历程。基于故障树和模糊数学方法,建立第三... 为了评估燃气PE管道在第三方破坏作用下的失效风险及应急处理效果,开展燃气PE管道第三方破坏失效分析研究,通过介绍管道力学响应数值分析模型,分析PE管材的力学特性、土壤参数的影响及管道失效历程。基于故障树和模糊数学方法,建立第三方破坏失效概率模型,量化了关键风险因素的发生概率,并结合CFD模拟研究了燃气泄漏扩散规律。针对现场应急处理,提出阀门控制、临时封堵等技术方案。研究结果表明:第三方破坏下PE管道易形成大口径破裂,失效概率受施工管理和环境因素显著影响。泄漏扩散受风向和建筑布局制约,需动态调整警戒范围。快速应急措施可有效降低泄漏危害,为燃气管网安全管理提供理论依据和实践指导。 展开更多
关键词 燃气 pe管道 第三方 破坏 失效 燃气泄露
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基于Illumina PE300高通量测序的传统与工业化生产东北豆酱微生物群落分析
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作者 葛英亮 王艺臻 +1 位作者 仲瑞文 李明翠 《食品工业科技》 北大核心 2026年第2期217-226,共10页
为掌握传统与工业化生产东北豆酱中微生物差异,获取风险微生物信息,研究采用Illumina PE300技术对传统与工业化生产东北豆酱中细菌16S rDNA序列V3-V4区(338F/806R)和真菌ITS序列1区(ITS1F/ITS2R)扩增测序,进行生物信息学分析。结果表明... 为掌握传统与工业化生产东北豆酱中微生物差异,获取风险微生物信息,研究采用Illumina PE300技术对传统与工业化生产东北豆酱中细菌16S rDNA序列V3-V4区(338F/806R)和真菌ITS序列1区(ITS1F/ITS2R)扩增测序,进行生物信息学分析。结果表明,传统工艺生产豆酱中,乳杆菌属(Lactobacillus)、四链球菌属(Tetragenococcus)和芽孢杆菌属(Bacillus)等属的细菌及曲霉属(Aspergillus)、青霉属(Penicillium)、念珠菌属(Candida)和丝孢菌属(Trichosporon)等属的真菌丰度较高,其中存在肠杆菌(Enterobacteriaceae)和葡萄球菌(Staphylococcus)等潜在风险微生物,不同家庭生产豆酱中高丰度的明串珠菌属(Leuconostoc)等细菌和梗孢酵母属(Sterigmatomyces)、镰刀菌属(Fusarium)等真菌丰度存在明显差异。工业化生产豆酱中高丰度细菌为乳杆菌属(Lactobacillus)、真菌为曲霉属(Aspergillus),群落构成简单,在微生物群落组成和代谢功能等方面与传统工艺生产豆酱相比存在的差异明显。经PICRUSt2功能预测分析知:传统工艺生产豆酱在糖酵解、糖异生、甘油酸代谢、有机酸的转化、蛋白质的磷酸化、嘌呤代谢、乙醛酸循环等功能丰度占优,工业化生产豆酱中在蛋白质降解和氨基酸代谢功能方面具有较高的丰度,揭示了传统工艺生产豆酱风味更佳,而工业化生产豆酱风味更稳定且生产周期短的原因。采用自建风险菌16S rDNA全长基因数据库比对发现:工业化生产豆酱的生物安全性更好,传统工艺生产豆酱可能存在更多的风险菌如:创伤弧菌(Vibrio vulnificus)、金黄色葡萄球菌(Staphylococcus aureus)、产气荚膜梭菌(Clostridium perfringens)等,揭示传统豆酱发酵过程中可能存在厌氧环境控制不足、原料污染或加工环节卫生缺陷导致产毒菌株增殖风险,工业化生产工艺在控制潜在风险菌方面具有显著优势。本研究为优化豆酱生产工艺、提高产品质量和保障食品安全提供了科学依据。 展开更多
关键词 Illumina pe300测序 东北豆酱 微生物群落 评估 传统工艺 工业化生产 功能预测
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Direct-chill semi-continuous casting process of three-layer composite ingot of 4045/3004/4045 aluminum alloys 被引量:6
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作者 蒋会学 张海涛 +1 位作者 秦克 崔建忠 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第8期1692-1697,共6页
Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructur... Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructure and composition distribution of the composite interface were investigated.The results show that semi-solid layer with a certain thickness forms near the interface due to the effect of cooling plate,which ensures successful implementation of casting the composite ingot.Two different aluminum alloys are well bonded metallurgically.The mechanical properties of composite interface were measured,the tensile and shearing strengths of composite interface are 105 and 88 MPa,respectively,which proves that the composite interface is a kind of metallurgical bonding. 展开更多
关键词 aluminum alloys three-layer composite ingot direct-chill semi-continuous casting composite interface structures properties
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Cas9和PE介导湖羊骨骼肌卫星细胞MSTN基因敲除的研究 被引量:5
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作者 周磊 李东旭 +3 位作者 冒魏佳 刘孜斐 高雪 万永杰 《南京农业大学学报》 北大核心 2025年第2期419-426,共8页
[目的]本文利用CRISPR/Cas9系统和先导编辑(prime editor, PE)对湖羊骨骼肌卫星细胞中的肌肉生长抑制素(myostatin,MSTN)基因外显子进行敲除,旨在比较2种技术敲除MSTN基因的效率,以验证新型基因编辑工具PE用于湖羊骨骼肌卫星细胞上的可... [目的]本文利用CRISPR/Cas9系统和先导编辑(prime editor, PE)对湖羊骨骼肌卫星细胞中的肌肉生长抑制素(myostatin,MSTN)基因外显子进行敲除,旨在比较2种技术敲除MSTN基因的效率,以验证新型基因编辑工具PE用于湖羊骨骼肌卫星细胞上的可行性。[方法]针对湖羊MSTN基因的3个外显子分别设计向导RNA(single guide RNA,sgRNA)以及引导RNA(prime editing guide RNA,pegRNA),构建相应的质粒后将含有Cas9/sgRNA或PE/pegRNA的质粒共同转染湖羊骨骼肌卫星细胞。24 h后观察细胞荧光,48 h后再将细胞消化,使用流式细胞分选仪根据荧光强度筛选出转染成功的强阳性细胞,收集细胞,获得基因组DNA后进行桑格测序,检测2种基因编辑工具对MSTN基因的打靶效率。[结果]成功构建了分别针对湖羊骨骼肌卫星细胞MSTN基因3个外显子敲除的基因编辑工具,质粒测序结果显示序列插入正确;CRISPR/Cas9的编辑效率(65%、88%、91%)显著高于PE的编辑效率(57%、29%、33%),而PE的插入缺失率显著低于CRISPR/Cas9。[结论]在转染效率相近的情况下,CRISPR/Cas9相比于PE对于湖羊骨骼肌卫星细胞MSTN基因的敲除有更高的编辑效率。 展开更多
关键词 基因编辑 CRISPR/Cas9 先导编辑(pe) MSTN 湖羊 骨骼肌卫星细胞
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响应面法优化ZIF-67/PES吸附剂处理染料废水
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作者 林江丽 阿合也力开·叶尔肯 苏珍 《中国无机分析化学》 北大核心 2025年第9期1373-1384,共12页
通过采用响应面法(Response Surface Metho dology,RSM)中Box-Behnken设计(BBD)考察吸附时间、pH值、NaCl浓度等关键因素对吸附容量的影响,并通过方差分析(ANOVA)优化工艺参数,建立二次回归模型预测最佳吸附条件,优化ZIF-67/PES复合材... 通过采用响应面法(Response Surface Metho dology,RSM)中Box-Behnken设计(BBD)考察吸附时间、pH值、NaCl浓度等关键因素对吸附容量的影响,并通过方差分析(ANOVA)优化工艺参数,建立二次回归模型预测最佳吸附条件,优化ZIF-67/PES复合材料对三苯基甲烷染料(TPM)的吸附工艺,并验证方法可行性,以达到高效、经济且环保的废水处理效果。结果表明:对于孔雀石绿(MG),吸附时间(A)、pH值(B)、NaCl浓度(C)三个因素对吸附容量的影响程度是A>B>C,最佳吸附条件为吸附时间5.12 h、pH=7.19、NaCl浓度0.95 mol/L;对于品红酸(FA),三个因素对吸附容量的影响程度是A>C>B,最佳吸附条件为吸附时间1.32 h、pH=7.16、NaCl浓度0.95 mol/L;对于结晶紫(CV),影响程度是B>A>C,最佳吸附条件为吸附时间23.86 h、pH=11.18、NaCl浓度0.97 mol/L。在此条件下,验证ZIF-67/PES复合材料对MG、FA和CV的实际吸附容量与模型预测值相差分别为1.91%、1.34%、0.63%,均小于5%。这表明响应面优化其处理工艺是可行的,能为染料废水实际处理的最佳工艺条件提供参考。 展开更多
关键词 响应面法 ZIF-67/peS复合材料 三苯基甲烷染料 吸附
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埋地PE管道失效形式与影响因素研究进展
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作者 燕集中 沈利民 +3 位作者 浦江 汤文亮 嵇杉 袁颖 《化工机械》 2025年第3期365-372,共8页
PE管由于具有耐腐蚀、质量轻及抗震性好等优良性能而作为制造埋地管道的主要材料之一。然而服役过程中面临的复杂载荷及其相互之间的协同作用常使管道提前报废。从地面沉降、地表占压、管道缺陷以及地震引起的滑坡与断层错动几个方面对... PE管由于具有耐腐蚀、质量轻及抗震性好等优良性能而作为制造埋地管道的主要材料之一。然而服役过程中面临的复杂载荷及其相互之间的协同作用常使管道提前报废。从地面沉降、地表占压、管道缺陷以及地震引起的滑坡与断层错动几个方面对埋地PE管道失效形式与影响因素进行了综述,并对当前研究存在的问题及未来的研究方向进行了探讨。 展开更多
关键词 pe埋地管道 地面沉降 地表占压 管道缺陷 滑坡与断层错动
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基于改进SEWM-CRITIC博弈集成云的城市燃气PE管道风险评价方法
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作者 张鹏 刘为 +3 位作者 沈豪 肖博文 宋文琦 刘思铭 《安全与环境工程》 北大核心 2025年第2期116-123,132,共9页
为解决城市燃气PE管道的安全评估问题,提出一种基于博弈集成云模型的管道风险评价法。以西南某地区城市燃气PE管道为研究对象,通过全息直觉模糊集(HHM-IFS)选取并筛选了5项一级指标,22项二级指标;利用基于博弈论主客观权衡改进的结构熵... 为解决城市燃气PE管道的安全评估问题,提出一种基于博弈集成云模型的管道风险评价法。以西南某地区城市燃气PE管道为研究对象,通过全息直觉模糊集(HHM-IFS)选取并筛选了5项一级指标,22项二级指标;利用基于博弈论主客观权衡改进的结构熵权(SEWM)法与基于指标相关性的权重赋权系数(CRITIC)法,以云理论为基础构建了充分考虑模糊性与随机性的博弈集成云模型,并确定了管道风险等级。结果表明,该区燃气管道为中等风险等级,应该重点关注回填质量、自然灾害、钢塑接头腐蚀、运行误操作、地形以及生物侵蚀等风险薄弱项。分析结果与实际工程相吻合,证明了该方法是一种科学合理的评估方法,为更有效地评估城市燃气PE管道的安全状态提供了新途径。 展开更多
关键词 城市燃气pe管道 风险评价 博弈论 集成云模型 全息直觉模糊集(HHM-IFS)
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动态加载条件下青贮PE膜的机械特性研究
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作者 高东明 魏丹丹 万其号 《中国塑料》 北大核心 2025年第1期48-56,共9页
针对青贮聚乙烯(PE)膜在实际工况条件下处于动态拉伸,现有相关标准基于静态加载测得机械特性难以更好表征青贮PE膜实际工况条件下的相关特性。文章对PE膜的纵向(MD)、横向(TD)方向试样进行了不同拉伸速率下的单轴拉伸试验(应变范围控制... 针对青贮聚乙烯(PE)膜在实际工况条件下处于动态拉伸,现有相关标准基于静态加载测得机械特性难以更好表征青贮PE膜实际工况条件下的相关特性。文章对PE膜的纵向(MD)、横向(TD)方向试样进行了不同拉伸速率下的单轴拉伸试验(应变范围控制在200%以内),以及不同初始延伸率下的应力松弛试验。结果表明,PE膜的应力-应变(σ-ε)曲线呈现显著的速度依赖性和方向依赖性。拉伸过程中PE膜MD、TD方向均经历了二次屈服,随着拉伸速率增加,第二屈服伸长率减小。MD方向的第一、第二屈服强度与拉伸速率的对数(ln v)呈良好线性映射关系。拉伸速率增加可以提高PE膜的屈服强度,以实现对青贮草捆的紧密包裹,但是达到一定速率后,屈服强度变化将不再明显,而且还会降低PE膜的韧性。室温下,在较低(10%)到较高的固定初始延伸率(70%)范围内,MD、TD方向PE膜均出现了应力先快速后缓慢降低现象。广义七元件Maxwell模型能较好的描述PE膜应力松弛行为,可用于预测其长期应力松弛特性。随着延伸率增加,应力松弛量降低,应力衰减率降低,松弛模量降低,应力缓慢下降阶段模量更稳定。为实现对青贮的有效密封,要求PE膜兼具刚度和一定抗松弛能力,青贮裹包时PE膜延伸率控制在50%~70%之间较为合理。 展开更多
关键词 青贮pe 机械特性 拉伸速率 屈服伸长率 应力松弛
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探讨主动声源探测法在大埋深燃气PE管道探测中的应用
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作者 梁继东 邵言 《价值工程》 2025年第14期110-113,共4页
在城市化不断建设的过程中,地下管线网络日益复杂。其中,PE(聚乙烯)管道因其耐腐蚀、使用寿命长等特点,在燃气输送系统广泛使用。但由于地下管线的多样性,不同区域需要埋深处理,而这种情况使用传统的探测方法无法准确定位,基于此,本文... 在城市化不断建设的过程中,地下管线网络日益复杂。其中,PE(聚乙烯)管道因其耐腐蚀、使用寿命长等特点,在燃气输送系统广泛使用。但由于地下管线的多样性,不同区域需要埋深处理,而这种情况使用传统的探测方法无法准确定位,基于此,本文深入探讨主动声源探测法在大埋深燃气PE管道探测中的应用情况,详细介绍此项技术的原理,使用方式以及各类干扰问题,以此保证此项技术能够有效做出探测,为相关工作提供帮助。 展开更多
关键词 主动声源探测法 大埋深燃气管道 pe管道探测
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Deformation and heat treatment ability of three-layer 6009/7050/6009 Al alloy clad slab prepared by direct-chill casting 被引量:4
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作者 Guang-yuan YAN Feng MAO +2 位作者 Zhi-qiang CAO Ting-ju LI Tong-min WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第1期9-19,共11页
Three-layer6009/7050/6009aluminum alloy clad slab was fabricated by an innovative direct-chill casting process.To study the response of the clad slab to plastic deformation and heat treatments,homogenization annealing... Three-layer6009/7050/6009aluminum alloy clad slab was fabricated by an innovative direct-chill casting process.To study the response of the clad slab to plastic deformation and heat treatments,homogenization annealing,hot rolling,solution and aging were successively performed on the as-cast6009/7050/6009clad samples.The results revealed that excellent metallurgical bonding between7050alloy layer and6009alloy layer was achieved under optimal parameters.The clad ratio obviously decreased when the annealed sample was rolled to55%hot reduction level,and then changed slightly with further rolling.Furthermore,the content of rodlike Zn-rich phases increased significantly in7050alloy layer in the homogenized clad samples after rolling at55%,65%and75%hot reduction levels,and the higher level of hot reduction resulted in narrower diffusion layer.Subsequent solution and aging significantly improved the hardness in7050alloy layer,interfaces and6009alloy layers of the rolled samples except for the thin side for the75%hot reduction sample. 展开更多
关键词 aluminum alloy three-layer clad slab direct-chill casting plastic deformation heat treatment
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采用PE-ECC的钢混组合梁负弯矩区受力性能试验
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作者 许莉 花鹏 +2 位作者 张晓毅 杨明清 侯思远 《福州大学学报(自然科学版)》 北大核心 2025年第2期210-217,共8页
通过对实桥进行缩尺设计,对两根钢-混组合梁构件进行负弯矩作用下的抗弯受力性能试验,分析试验梁桥面板的承载力、裂缝、梁截面的应变和钢筋应变,以探究组合梁构件的受力和破坏规律.试验结果表明,在负弯矩作用下,采用工程水泥基复合材料... 通过对实桥进行缩尺设计,对两根钢-混组合梁构件进行负弯矩作用下的抗弯受力性能试验,分析试验梁桥面板的承载力、裂缝、梁截面的应变和钢筋应变,以探究组合梁构件的受力和破坏规律.试验结果表明,在负弯矩作用下,采用工程水泥基复合材料(ECC)的钢-混组合梁比普通钢-混组合梁的极限承载力略高.在纵向配筋相同的条件下,采用ECC的钢-混组合梁桥面板中含有的聚乙烯(PE)纤维能够发挥受拉作用,提高组合梁受拉区的极限应力水平,其抗弯承载力得到提高.采用PE-ECC作为桥面板材料,在负弯矩的作用下,不仅能有效控制裂缝的产生,还能延缓裂缝宽度的发展,提高桥面板整体的耐久性和安全性,强化其抗裂能力. 展开更多
关键词 pe-ECC 钢-混组合梁 负弯矩 模型试验
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PE-ECC构件冻融循环后承载性能试验研究
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作者 张志强 张康健 刘征 《铁道标准设计》 北大核心 2025年第8期1-11,共11页
为研究冻融循环作用对聚乙烯纤维工程水泥基复合材料(PE-ECC)构件承载力的影响,通过室内冻融循环试验和冻后四点弯曲试验,研究冻融循环作用下PE-ECC梁的破坏演化特征,并通过刚度、延性指数、能量吸收能力(EAC)等性能指标分析其承载性能... 为研究冻融循环作用对聚乙烯纤维工程水泥基复合材料(PE-ECC)构件承载力的影响,通过室内冻融循环试验和冻后四点弯曲试验,研究冻融循环作用下PE-ECC梁的破坏演化特征,并通过刚度、延性指数、能量吸收能力(EAC)等性能指标分析其承载性能劣化规律。结果表明:(1)试验梁在破坏时保持较好的完整性,冻融作用使PE纤维与基体的协同效应减弱,随着冻融循环次数增加,主裂缝数量减少,裂缝密度降低,分布更加分散;(2)试验梁的荷载-跨中挠度曲线呈现明显的弹性、屈服和破坏段,加载过程可分为弹性阶段、受拉区局部开裂阶段和屈服破坏阶段;(3)提高PE纤维含量可使基体结构更为紧密,降低冻融作用后的EAC损失并提升承载能力;(4)冻融循环后,PE-ECC试验梁跨中截面应变分布仍符合平截面假定,提出PE-ECC梁在弯曲荷载作用下各阶段承载力计算方法。研究成果可为PE-ECC梁的承载力设计和在寒区工程中的应用提供依据。 展开更多
关键词 pe-ECC 冻融循环 承载性能 破坏特征 受弯构件
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