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Effect of icosahedral phase formation on the stress corrosion cracking(SCC)behaviors of the as-cast Mg-8%Li(in wt.%)based alloys 被引量:1
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作者 Shuo Wang Daokui Xu +2 位作者 Dongliang Wang Zhiqiang Zhang Baojie Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期225-236,共12页
Through exploring the stress corrosion cracking(SCC)behaviors of the as-cast Mg-8%Li and Mg-8%Li-6%Zn-1.2%Y alloys in a 0.1 M NaCl solution,it revealed that the SCC susceptibility index(I_(SCC))of the Mg-8%Li alloy wa... Through exploring the stress corrosion cracking(SCC)behaviors of the as-cast Mg-8%Li and Mg-8%Li-6%Zn-1.2%Y alloys in a 0.1 M NaCl solution,it revealed that the SCC susceptibility index(I_(SCC))of the Mg-8%Li alloy was 47%,whilst the I_(SCC)of the Mg-8%Li-6%Zn-1.2%Y alloy was 68%.Surface,cross-sectional and fractography observations indicated that for the Mg-8%Li alloy,theα-Mg/β-Li interfaces acted as the preferential crack initiation sites and propagation paths during the SCC process.With regard to the Mg-8%Li-6%Zn-1.2%Y alloy,the crack initiation sites included the I-phase and the interfaces of I-phase/β-Li andα-Mg/β-Li,and the preferential propagation paths were the I-phase/β-Li andα-Mg/β-Li interfaces.Moreover,the SCC of the two alloys was concerned with hydrogen embrittlement(HE)mechanism. 展开更多
关键词 Magnesium-lithium alloy Stress corrosion cracking I-phase Fracture analysis
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2010-2020年江苏省牛乳中SCC变化模式对奶牛场隐性乳房炎发病规律的影响
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作者 夏予馨 张昊冉 +5 位作者 周福振 周部 代旭 梁艳 杨章平 毛永江 《家畜生态学报》 北大核心 2024年第4期60-65,共6页
奶牛隐性乳房炎(subclinical mastitis,SCM)是一种无症状表现的乳房炎,通常表现为体细胞数(somatic cell count,SCC)升高、乳脂率下降等。为探究SCC变化模式影响下江苏地区奶牛场SCM发病规律的因素,本研究收集了江苏地区14个牧场2010-2... 奶牛隐性乳房炎(subclinical mastitis,SCM)是一种无症状表现的乳房炎,通常表现为体细胞数(somatic cell count,SCC)升高、乳脂率下降等。为探究SCC变化模式影响下江苏地区奶牛场SCM发病规律的因素,本研究收集了江苏地区14个牧场2010-2020年荷斯坦牛群体改良(dairy herd improvement,DHI)记录853936条,在划分4种SCC变化模式(持续健康、新感染、治愈和持续感染)基础上,利用卡方检验探究不同牧场规模、胎次、产犊季节、产犊间隔和305 d产奶量对荷斯坦牛4种SCC变化模式的影响。结果表明:所有DHI记录中4种SCC变化模式百分比分别为83.52%(持续健康)、6.02%(新感染)、5.89%(持续感染)和4.57%(治愈),牧场规模、胎次、产犊季节、产犊间隔和305 d产奶量对荷斯坦牛SCC变化模式分布均有极显著影响(P<0.01)。其中,中小型牧场、较高胎次、春季产犊、产犊间隔大于441 d和305 d产奶量为13001~15000 kg的奶牛下一泌乳月SCC升高的概率较大,增加了奶牛患SCM风险;规模在5000头以上的牧场、1胎牛、秋季产犊和305 d产奶量为9001~11000 kg的奶牛持续健康的比例均最高。综上所述,牧场规模、胎次、产犊季节、产犊间隔和305 d产奶量对SCC变化模式的分布均有极显著影响,该结果为江苏地区规模化牧场SCM防控提供了参考。 展开更多
关键词 scc变化模式 非遗传因素 荷斯坦牛 隐性乳房炎
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Recent research progress in the mechanism and suppression of fusion welding-induced liquation cracking of nickel based superalloys 被引量:1
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作者 Zongli Yi Jiguo Shan +2 位作者 Yue Zhao Zhenlin Zhang Aiping Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1072-1088,共17页
Nickel-based superalloys are extensively used in the crucial hot-section components of industrial gas turbines,aeronautics,and astronautics because of their excellent mechanical properties and corrosion resistance at ... Nickel-based superalloys are extensively used in the crucial hot-section components of industrial gas turbines,aeronautics,and astronautics because of their excellent mechanical properties and corrosion resistance at high temperatures.Fusion welding serves as an effective means for joining and repairing these alloys;however,fusion welding-induced liquation cracking has been a challenging issue.This paper comprehensively reviewed recent liquation cracking,discussing the formation mechanisms,cracking criteria,and remedies.In recent investigations,regulating material composition,changing the preweld heat treatment of the base metal,optimizing the welding process parameters,and applying auxiliary control methods are effective strategies for mitigating cracks.To promote the application of nickel-based superalloys,further research on the combination impact of multiple elements on cracking prevention and specific quantitative criteria for liquation cracking is necessary. 展开更多
关键词 nickel-based superalloy fusion welding liquation cracking cracking mechanism cracking suppression
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Exploring an eco-friendly approach to improve soil tensile behavior and cracking resistance 被引量:1
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作者 Lin Li Chao-Sheng Tang +5 位作者 Jin-Jian Xu Yao Wei Zhi-Hao Dong Bo Liu Xi-Ying Zhang Bin Shi 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4272-4284,共13页
Soil tensile strength is a critical parameter governing the initiation and propagation of tensile cracking.This study proposes an eco-friendly approach to improve the tensile behavior and crack resistance of clayey so... Soil tensile strength is a critical parameter governing the initiation and propagation of tensile cracking.This study proposes an eco-friendly approach to improve the tensile behavior and crack resistance of clayey soils.To validate the feasibility and efficacy of the proposed approach,direct tensile tests were employed to determine the tensile strength of the compacted soil with different W-OH treatment concentrations and water contents.Desiccation tests were also performed to evaluate the effectiveness of W-OH treatment in enhancing soil tensile cracking resistance.During this period,the effects of W-OH treatment concentration and water content on tensile properties,soil suction and microstructure were investigated.The tensile tests reveal that W-OH treatment has a significant impact on the tensile strength and failure mode of the soil,which not only effectively enhances the tensile strength and failure displacement,but also changes the brittle failure behavior into a more ductile quasi-brittle failure behavior.The suction measurements and mercury intrusion porosimetry(MIP)tests show that W-OH treatment can slightly reduce soil suction by affecting skeleton structure and increasing macropores.Combined with the microstructural analysis,it becomes evident that the significant improvement in soil tensile behavior through W-OH treatment is mainly attributed to the W-OH gel's ability to provide additional binding force for bridging and encapsulating the soil particles.Moreover,desiccation tests demonstrate that W-OH treatment can significantly reduce or even inhibit the formation of soil tensile cracking.With the increase of W-OH treatment concentration,the surface crack ratio and total crack length are significantly reduced.This study enhances a fundamental understanding of eco-polymer impacts on soil mechanical properties and provides valuable insight into their potential application for improving soil crack resistance. 展开更多
关键词 Clayey soil Tensile strength Eco-friendly approach Direct tensile test Desiccation cracking Crack resistance
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SCC,NSE在肺部感染性疾病中的表达
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作者 杨云飞 黎华 +2 位作者 卢秋杰 罗淋尹 何本进 《中文科技期刊数据库(文摘版)医药卫生》 2024年第3期0090-0093,共4页
探讨鳞状细胞相关抗原(SCC)、神经元特异性烯醇化酶(NSE)在肺部感染中的表达情况。方法 选取本院2022年1月至2023年2月间收治的肺部感染性疾病患者作为研究对象,共计80例,并择取同期的70例健康体检者为对照组,比较两组SCC、NSE的变化,... 探讨鳞状细胞相关抗原(SCC)、神经元特异性烯醇化酶(NSE)在肺部感染中的表达情况。方法 选取本院2022年1月至2023年2月间收治的肺部感染性疾病患者作为研究对象,共计80例,并择取同期的70例健康体检者为对照组,比较两组SCC、NSE的变化,并对肺部感染性疾病患者于治疗后检测SCC、NSE,分析较治疗前其SCC、NSE的变化。结果 观察组SCC、NSE水平较对照组高(P<0.05)。肺炎、肺结核、支气管肺炎SCC、NSE水平均呈上升趋势,组间对比(P>0.05)。观察组治疗后SCC、NSE水平较治疗前显著降低(P<0.05)。结论 NSE与 SCC在肺部感染中的表达呈正相关,可作为评价肺部感染严重程度,临床治疗有效性的指标,具有一定临床应用价值。 展开更多
关键词 肺部感染性疾病 scc NSE
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CA125、SCC、SOX2-Ab联合检测对早期肺癌诊断的临床价值研究
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作者 田佳 李震 +1 位作者 陈云浩 刘英超 《中国现代医生》 2024年第6期12-14,50,共4页
目的探讨血清糖类抗原125(carbohydrate antigen 125,CA125)、鳞状上皮细胞癌抗原(squamous cell carcinoma antigen,SCC)及干细胞核心转录因子性别决定区Y框蛋白2自身抗体(Sox2 autoantibodies,SOX2-Ab)联合检测对早期肺癌诊断的临床... 目的探讨血清糖类抗原125(carbohydrate antigen 125,CA125)、鳞状上皮细胞癌抗原(squamous cell carcinoma antigen,SCC)及干细胞核心转录因子性别决定区Y框蛋白2自身抗体(Sox2 autoantibodies,SOX2-Ab)联合检测对早期肺癌诊断的临床价值。方法选择2020年7月至2021年6月在聊城市第二人民医院进行健康查体者、肺部良性结节者、肺癌患者各50例,分别为查体组、良性结节组和肺癌组。应用化学发光分析仪及其相应配套试剂测定三组受试者血清CA125、SCC水平,选用适用的酶联免疫吸附试验测定三组受试者SOX2-Ab蛋白含量,并计算受试者操作特征曲线。结果肺癌组患者血清CA125、SCC、SOX2-Ab的水平分别为38.50(22.75,51.25)U/ml、3.08(1.40,3.60)ng/ml、13.45(10.80,15.43)ng/ml,均高于查体组、良性结节组;CA125、SCC、SOX2-Ab联合检测对早期肺癌的检测敏感度、特异性、准确性分别为91%、61%、86%,除特异性外均优于CA125、SCC、SOX2-Ab单独检测。结论CA125、SCC、SOX2-Ab联合检测对早期肺癌诊断敏感度较高,可作为早期肺癌筛查的检测方案。 展开更多
关键词 肺癌 糖类抗原125 鳞状上皮细胞癌抗原 性别决定区Y框蛋白2自身抗体 诊断价值
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Development and Catalytic Cracking Performance of Ultrastable Y Zeolite Rich in Secondary Pores
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作者 Li Jiaxing Wang Shengji +3 位作者 Sha Hao Wang Juan Zhou Lingping Wang Lixia 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第2期13-21,共9页
A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first t... A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first time in the world. The porestructure characteristics of the NSZ zeolite prepared for industrial use were analyzed and characterized using BET. The resultsindicate a significant increase in the secondary pore volume of NSZ zeolite compared to the existing ultra-stable zeolite HSZ-5, which is produced through a conventional gas-phase method. The average secondary pore volume to total pore volume ratioin NSZ zeolite was found to be 58.96% higher. The catalytic cracking performance of NSZ zeolite was evaluated. The resultsshowed that the NSC-LTA catalyst, with NSZ as the active component, outperformed the HSC-LTA catalyst with HSZ-5 zeolitein terms of obtaining more high-value products (gasoline and liquefied petroleum gas) during the hydrogenated light cycle oilprocessing. Additionally, the NSC-LTA catalyst showed a significant improvement in coke selectivity. 展开更多
关键词 GAS-PHASE ultra-stable ZEOLITE CATALYST catalytic cracking
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Cracking on a nickel-based superalloy fabricated by direct energy deposition
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作者 Xue Zhang Ya-hang Mu +4 位作者 Liang Ma Jing-jing Liang Yi-zhou Zhou Xiao-feng Sun Jin-guo Li 《China Foundry》 SCIE EI CAS CSCD 2024年第4期311-318,共8页
Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based superalloys.It is essential to investigate the location of cracks and their forming mechanism.This s... Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based superalloys.It is essential to investigate the location of cracks and their forming mechanism.This study extensively examines the impact of solidification process,microstructural evolution,and stress concentration on crack initiation during direct energy deposition(DED).The results emphasize that the crack formation is significantly related to large-angle grain boundaries,rapid cooling rates.Cracks caused by large-angle grain boundaries and a fast-cooling rate predominantly appear near the edge of the deposited samples.Liquation cracks are more likely to form near the top of the deposited sample,due to the presence ofγ/γ'eutectics.The secondary dendritic arm and the carbides in the interdendritic regions can obstruct liquid flow during the final stage of solidification,which results in the formation of solidification cracks and voids.This work paves the way to avoid cracks in nickel-based superalloys fabricated by DED,thereby enhancing the performance of superalloys. 展开更多
关键词 LOCATION cracks direct energy deposition nickel-based superalloys
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HZSM-5 zeolites undergoing the high-temperature process for boosting the bimolecular reaction in n-heptane catalytic cracking
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作者 Chenggong Song Zhenzhou Ma +6 位作者 Xu Hou Hao Zhou Huimin Qiao Changchang Tian Li Yin Baitang Jin Enxian Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期136-144,共9页
High-temperature treatment is key to the preparation of zeolite catalysts.Herein,the effects of hightemperature treatment on the property and performance of HZSM-5 zeolites were studied in this work.X-Ray diffraction,... High-temperature treatment is key to the preparation of zeolite catalysts.Herein,the effects of hightemperature treatment on the property and performance of HZSM-5 zeolites were studied in this work.X-Ray diffraction,N2physisorption,27Al magic angle spinning nuclear magnetic resonance(MAS NMR),and temperature-programmed desorption of ammonia results indicated that the hightemperature treatment at 650℃ hardly affected the inherent crystal and texture of HZSM-5zeolites but facilitated the conversion of framework Al to extra-framework Al,reducing the acid site and enhancing the acid strength.Moreover,the high-temperature treatment improved the performance of HZSM-5 zeolites in n-heptane catalytic cracking,promoting the conversion and light olefins yield while inhibiting coke formation.Based on the kinetic and mechanism analysis,the improvement of HZSM-5 performance caused by high-temperature treatment has been attributed to the formation of extra-framework Al,which enhanced the acid strength,facilitated the bimolecular reaction,and promoted the entropy change to overcome a higher energy barrier in n-heptane catalytic cracking. 展开更多
关键词 HZSM-5 N-HEPTANE Catalytic cracking High-temperature treatment Extra-framework Al
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Brønsted-acid sites induced photocatalytic cracking of low-polarity polyethylene plastics
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作者 Qianyou Wen Quan Zhang +6 位作者 Zhengzheng Liu Huining Wang Shuya Hao Fan Zhang Lijuan Zhang Qing Han Gengfeng Zheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期509-515,共7页
Polyolefins such as polyethylene(PE)are one of the largest-scale synthetic plastics and play a key role in modern society.However,polyethylene is extremely inert to chemical recycling owing to its lack of chemical fun... Polyolefins such as polyethylene(PE)are one of the largest-scale synthetic plastics and play a key role in modern society.However,polyethylene is extremely inert to chemical recycling owing to its lack of chemical functionality and low polarity,making it one of the most challenging environmental hazards globally.Herein,we developed a phosphorylated CeO_(2)catalyst by an organophosphate precursor and featured efficient photocatalysis of low-density polyethylene(LDPE)without the acid or alkaline pre-treatment.Compared to pristine CeO_(2),the surface phosphorylation allows to introduce Brønsted acid sites,which facilitate to form carbonium ions on LDPE via protonation.In addition,the suitable band structure of the phosphorylated CeO_(2)catalyst enables efficient photoabsorption and generates reactive oxygen species,leading to the C–C bond cleavage of LDPE.As a result,the phosphorylated CeO_(2)catalyst exhibited an outstanding carbon conversion rate of>94%after 48 h of photocatalysis under 50 mW/cm^(2)of simulated sunlight,with a high CO_(2)product selectivity of>99%.Furthermore,the PE microparticles with sizes larger than 10μm released from LDPE plastic wrap were directly and completely degraded by photocatalysis within 12 h,suggesting an attractive and environmentally benign strategy of utilizing solar energy-based photocatalysis for reducing potential hazards of LDPE plastic trashes. 展开更多
关键词 Photocatalytic cracking POLYETHYLENE Surface phosphorylation Bronsted-acid site Carbon conversion
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A molecular insight into coke formation process of vacuum residue in thermal cracking reaction
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作者 Ji-Guang Li Xin Guo Huan-Di Hou 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期2130-2138,共9页
Understanding the coking behaviors has been considered to be really essential for developing better vacuum residue processing technologies.A battery of thermal cracking tests of typical vacuum residue at 410℃ with va... Understanding the coking behaviors has been considered to be really essential for developing better vacuum residue processing technologies.A battery of thermal cracking tests of typical vacuum residue at 410℃ with various reaction time were performed to evaluate the coke formation process.The total yields of ideal components including naphtha,atmospheric gas oil(AGO)and vacuum gas oil(VGO)of thermal cracking reactions increased from 10.89%to 40.81%,and the conversion ratios increased from8.05%to 43.33%with increasing the reaction time from 10 to 70 min.The asphaltene content increased from 12.14%to a maximum of 22.39%and then decreased,and this maximum of asphaltene content occurred at the end of the coking induction period.The asphaltenes during the coking induction period,at the end and after coking induction period of those tested thermal cracking reactions were characterized to disclose the structure changing rules for coke formation process,and the coke formation pathways were discussed to reveal the coke formation process at molecular level. 展开更多
关键词 Vacuum residue Thermal cracking ASPHALTENE Coking induction period SULFUR NITROGEN
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Thermally-induced cracking behaviors of coal reservoirs subjected to cryogenic liquid nitrogen shock
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作者 Songcai Han Qi Gao +5 位作者 Xinchuang Yan Lile Li Lei Wang Xian Shi Chuanliang Yan Daobing Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2894-2908,共15页
The benefits of using cryogenic liquid nitrogen shock to enhance coal permeability have been confirmed from experimental perspectives.In this paper,we develop a fully coupled thermo-elastic model in combination with t... The benefits of using cryogenic liquid nitrogen shock to enhance coal permeability have been confirmed from experimental perspectives.In this paper,we develop a fully coupled thermo-elastic model in combination with the strain-based isotropic damage theory to uncover the cooling-dominated cracking behaviors through three typical cases,i.e.coal reservoirs containing a wellbore,a primary fracture,and a natural fracture network,respectively.The progressive cracking processes,from thermal fracture initiation,propagation or cessation,deflection,bifurcation to multi-fracture interactions,can be well captured by the numerical model.It is observed that two hierarchical levels of thermal fractures are formed,in which the number of shorter thermal fractures consistently exceeds that of the longer ones.The effects of coal properties related to thermal stress levels and thermal diffusivity on the fracture morphology are quantified by the fracture fractal dimension and the statistical fracture number.The induced fracture morphology is most sensitive to changes in the elastic modulus and thermal expansion coefficient,both of which dominate the complexity of the fracture networks.Coal reservoir candidates with preferred thermal-mechanical properties are also recommended for improving the stimulation effect.Further findings are that there exists a critical injection temperature and a critical in-situ stress difference,above which no thermal fractures would be formed.Preexisting natural fractures with higher density and preferred orientations are also essential for the formation of complex fracture networks.The obtained results can provide some theoretical support for cryogenic fracturing design in coal reservoirs. 展开更多
关键词 Coal reservoirs Cryogenic shock Thermal cracking behaviors Fracture morphology
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Preparation and Electrochemical Performance Study of Catalytic Cracking Oil Slurry-based Porous Carbon Materials
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作者 Liu Qi Zhao Gaiju +3 位作者 Liu Xingge Yu Hewei Sun Rongfeng Geng Wenguang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第2期34-45,共12页
Catalytic cracking oil slurry is a by-product of catalytic cracking projects,and the efficient conversion and sustainable utilization of this material are issues of continuous concern in the petroleum refining industr... Catalytic cracking oil slurry is a by-product of catalytic cracking projects,and the efficient conversion and sustainable utilization of this material are issues of continuous concern in the petroleum refining industry.In this study,oxygen-enriched activated carbon is prepared using a one-step KOH activation method with catalytic cracking oil slurry as the raw material.The as-prepared oil slurry-based activated carbon exhibits a high specific surface area of 2102 m^(2)/g,welldefined micropores with an average diameter of 2 nm,and a rich oxygen doping content of 32.97%.The electrochemical performance of the nitrogen-doped porous carbon is tested in a three-electrode system using a 6 mol/L KOH solution as the electrolyte.It achieves a specific capacitance of up to 230 F/g at a current density of 1 A/g.Moreover,the capacitance retention rate exceeds 89%after 10000 charge and discharge cycles,demonstrating excellent cycle stability.This method not only improves the utilization efficiency of industrial fuel waste but also reduces the production cost of supercapacitor electrode materials,thereby providing a simple and effective strategy for the resource utilization of catalytic cracking oil slurries. 展开更多
关键词 catalytic cracking slurry porous carbon SUPERCAPACITOR KOH activation
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Regulating metal-acid double site balance on mesoporous SiO_(2)-Al_(2)O_(3) composite oxide for supercritical n-decane cracking
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作者 Liu-Ling Chen Jun Zhang +5 位作者 Chun-Guang Li Li-Qun Fei Bo Wang Chen-Qi Zhang Yi Jiao Jian-Li Wang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2881-2891,共11页
The balance between metal and acid sites directly affects the preparation of high-performance cracking catalysts with high heat sink and low coking.Nevertheless,how to control acid-metal sites balance and its relation... The balance between metal and acid sites directly affects the preparation of high-performance cracking catalysts with high heat sink and low coking.Nevertheless,how to control acid-metal sites balance and its relationship with cracking performance are reported scarcely.In this work,a series of Pt/Al_(2)O_(3)-SiO_(2) dual sites catalysts with different metal to acid active sites ratio(C_(M)/C_(SA))were constructed by ethanolassisted impregnation method and the impact on n-decane cracking under supercritical conditions was systematically and deeply investigated.The results showed that the conversion and carbon deposition increased gradually with varied C_(M)/C_(SA)and reached the balance at C_(M)/C_(SA)of 0.13.The proper ratio C_(M)/C_(SA)(0.13)can balance the deep dehydrogenation coking over metal active sites and high heat sink of cracking over acid active sites,the chemical heat sink reaches amazing 1.75 MJ/kg and carbon deposition is only22.03 mg/cm^(2) at 750℃.Meanwhile,the few metal sites at low C_(M)/C_(SA)and the few strong acid sites at high C_(M)/C_(SA)are the main factors limiting the cracking activity.Low C_(M)/C_(SA)limit the activation of C-H bond and deep dehydrogenation of coking precursor,resulting in relative low cracking activity and carbon deposition,while high C_(M)/C_(SA)limit the activation of C-C bond and increase the deep dehydrogenation.In this contribution,design and construction of metal-acid dual sites can not only provide the technical solution for the preparation of high heat sink and low coking cracking catalyst,but also deepen the understanding of the cracking path of hydrocarbon fuel. 展开更多
关键词 Metal-acid dual sites balance Catalytic cracking Hydrocarbon fuels Chemical heat sink Carbon deposition
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Stress corrosion cracking behavior of buried oil and gas pipeline steel under the coexistence of magnetic field and sulfate-reducing bacteria
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作者 Jian-Yu He Fei Xie +3 位作者 Dan Wang Guang-Xin Liu Ming Wu Yue Qin 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1320-1332,共13页
Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil env... Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil environment. The SCC behavior of X80 pipeline steel under the magnetic field and sulfate-reducing bacteria(SRB) environment was investigated by immersion tests, electrochemical tests, and slow strain rate tensile(SSRT) tests. The results showed that the corrosion and SCC sensitivity of X80 steel decreased with increasing the magnetic field strength in the sterile environment. The SCC sensitivity was higher in the biotic environment inoculated with SRB, but it also decreased with increasing magnetic field strength, which was due to the magnetic field reduces microbial activity and promotes the formation of dense film layer. This work provided theoretical guidance on the prevention of SCC in pipeline steel under magnetic field and SRB coexistence. 展开更多
关键词 Magnetic field Sulfate-reducing bacteria Film layer Stress corrosion cracking Oil and gas pipelines
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Simulation of Corrosion-Induced Cracking of Reinforced Concrete Based on Fracture Phase Field Method
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作者 Xiaozhou Xia Changsheng Qin +2 位作者 Guangda Lu Xin Gu Qing Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2257-2276,共20页
Accurate simulation of the cracking process caused by rust expansion of reinforced concrete(RC)structures plays an intuitive role in revealing the corrosion-induced failure mechanism.Considering the quasi-brittle frac... Accurate simulation of the cracking process caused by rust expansion of reinforced concrete(RC)structures plays an intuitive role in revealing the corrosion-induced failure mechanism.Considering the quasi-brittle fracture of concrete,the fracture phase field driven by the compressive-shear term is constructed and added to the traditional brittle fracture phase field model.The rationality of the proposed model is verified by a mixed fracture example under a shear displacement load.Then,the extended fracture phase model is applied to simulate the corrosion-induced cracking process of RC.The cracking patterns caused by non-uniform corrosion expansion are discussed for RC specimens with homogeneous macroscopically or heterogeneous with different polygonal aggregate distributions at the mesoscopic scale.Then,the effects of the protective layer on the crack propagation trajectory and cracking resistance are investigated,illustrating that the cracking angle and cracking resistance increase with the increase of the protective layer thickness,consistent with the experimental observation.Finally,the corrosion-induced cracking process of concrete specimens with large and small spacing rebars is simulated,and the interaction of multiple corrosion cracking is easily influenced by the reinforcement spacing,which increases with the decrease of the steel bar interval.These conclusions play an important role in the design of engineering anti-corrosion measures.The fracture phase field model can provide strong support for the life assessment of RC structures. 展开更多
关键词 Fracture phase field corrosion-induced cracking non-uniform corrosion expansion protective layer thickness reinforcement concrete
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A multiscale adaptive framework based on convolutional neural network:Application to fluid catalytic cracking product yield prediction
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作者 Nan Liu Chun-Meng Zhu +1 位作者 Meng-Xuan Zhang Xing-Ying Lan 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2849-2869,共21页
Since chemical processes are highly non-linear and multiscale,it is vital to deeply mine the multiscale coupling relationships embedded in the massive process data for the prediction and anomaly tracing of crucial pro... Since chemical processes are highly non-linear and multiscale,it is vital to deeply mine the multiscale coupling relationships embedded in the massive process data for the prediction and anomaly tracing of crucial process parameters and production indicators.While the integrated method of adaptive signal decomposition combined with time series models could effectively predict process variables,it does have limitations in capturing the high-frequency detail of the operation state when applied to complex chemical processes.In light of this,a novel Multiscale Multi-radius Multi-step Convolutional Neural Network(Msrt Net)is proposed for mining spatiotemporal multiscale information.First,the industrial data from the Fluid Catalytic Cracking(FCC)process decomposition using Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)extract the multi-energy scale information of the feature subset.Then,convolution kernels with varying stride and padding structures are established to decouple the long-period operation process information encapsulated within the multi-energy scale data.Finally,a reconciliation network is trained to reconstruct the multiscale prediction results and obtain the final output.Msrt Net is initially assessed for its capability to untangle the spatiotemporal multiscale relationships among variables in the Tennessee Eastman Process(TEP).Subsequently,the performance of Msrt Net is evaluated in predicting product yield for a 2.80×10^(6) t/a FCC unit,taking diesel and gasoline yield as examples.In conclusion,Msrt Net can decouple and effectively extract spatiotemporal multiscale information from chemical process data and achieve a approximately reduction of 30%in prediction error compared to other time-series models.Furthermore,its robustness and transferability underscore its promising potential for broader applications. 展开更多
关键词 Fluid catalytic cracking Product yield Data-driven modeling Multiscale prediction Data decomposition Convolution neural network
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Parametric study on contact sensors for MASW measurement-based interfacial debonding detection for SCCS
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作者 Chen Hongbing Pang Xin +3 位作者 Gan Shiyu Li Yuanyuan Gokarna Chalise Nie Xin 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期331-344,共14页
Steel-concrete composite structures(SCCS)have been widely used as primary load-bearing components in large-scale civil infrastructures.As the basis of the co-working ability of steel plate and concrete,the bonding sta... Steel-concrete composite structures(SCCS)have been widely used as primary load-bearing components in large-scale civil infrastructures.As the basis of the co-working ability of steel plate and concrete,the bonding status plays an essential role in guaranteeing the structural performance of SCCS.Accordingly,efficient non-destructive testing(NDT)on interfacial debondings in SCCS has become a prominent research area.Multi-channel analysis of surface waves(MASW)has been validated as an effective NDT technique for interfacial debonding detection for SCCS.However,the feasibility of MASW must be validated using experimental measurements.This study establishes a high-frequency data synchronous acquisition system with 32 channels to perform comparative verification experiments in depth.First,the current sensing approaches for high-frequency vibration and stress waves are summarized.Secondly,three types of contact sensors,namely,piezoelectric lead-zirconate-titanate(PZT)patches,accelerometers,and ultrasonic transducers,are selected for MASW measurement.Then,the selection and optimization of the force hammer head are performed.Comparative experiments are carried out for the optimal selection of ultrasonic transducers,PZT patches,and accelerometers for MASW measurement.In addition,the influence of different pasting methods on the output signal of the sensor array is discussed.Experimental results indicate that optimized PZT patches,acceleration sensors,and ultrasonic transducers can provide efficient data acquisition for MASW-based non-destructive experiments.The research findings in this study lay a solid foundation for analyzing the recognition accuracy of contact MASW measurement using different sensor arrays. 展开更多
关键词 steel-concrete composite structures(sccS) interface debonding detection multi-channel analysis of surface waves(MASW) sensor selection comparative experimental study
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Effect of Shrinkage Reducing Agent and Steel Fiber on the Fluidity and Cracking Performance of Ultra-High Performance Concrete
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作者 Yong Wan Li Li +4 位作者 Jiaxin Zou Hucheng Xiao Mengdi Zhu Ying Su Jin Yang 《Fluid Dynamics & Materials Processing》 EI 2024年第9期1941-1956,共16页
Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects ... Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects of different types of cementitious materials,chemical shrinkage-reducing agents(SRA)and steel fiber(SF)were assessed.Compared with M2-UHPC and M3-UHPC,M1-UHPC was found to have better fluidity and shrinkage cracking performance.Moreover,different SRA incorporation methods,dosage and different SF types and aspect ratios were implemented.The incorporation of SRA and SF led to a decrease in the fluidity of UHPC.SRA internal content of 1%(NSRA-1%),SRA external content of 1%(WSRA-1%),STS-0.22 and STE-0.7 decreased the fluidity of UHPC by 3.3%,8.3%,9.2%and 25%,respectively.However,SRA and SF improved the UHPC shrinkage cracking performance.NSRA-1%and STE-0.7 reduced the shrinkage value of UHPC by 40%and 60%,respectively,and increased the crack resistance by 338%and 175%,respectively.In addition,the addition of SF was observed to make the microstructure of UHPC more compact,and the compressive strength and flexural strength of 28 d were increased by 26.9%and 19.9%,respectively. 展开更多
关键词 Ultra-high performance concrete chemical shrinkage reducing agent steel fiber shrinkage cracking repair and reinforcement
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宫颈癌患者血清SCC、CA125及PD-L1水平与细胞凋亡指数相关性的研究
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作者 吴倩 张微 方呈祥 《中国妇幼健康研究》 2024年第2期81-85,共5页
目的探讨宫颈癌患者不同临床病理特征的血清鳞状细胞癌抗原(SCC)、糖链抗原125(CA125)及可溶程序性死亡分子1(PD-L1)水平的变化,以及其与细胞凋亡指数的相关性。方法选取2020年10月至2022年2月在湖北民族大学附属民大医院就诊的76例宫... 目的探讨宫颈癌患者不同临床病理特征的血清鳞状细胞癌抗原(SCC)、糖链抗原125(CA125)及可溶程序性死亡分子1(PD-L1)水平的变化,以及其与细胞凋亡指数的相关性。方法选取2020年10月至2022年2月在湖北民族大学附属民大医院就诊的76例宫颈癌患者为实验组,另选同时期在院进行体检的76例健康妇女为对照组。采用电化学发光法测定两组的血清SCC、CA125及PD-L1水平;采用流式细胞术检测两组的细胞凋亡指数;比较两组的血清SCC、CA125及PD-L1水平及细胞凋亡指数,分析血清SCC、CA125及PD-L1水平与细胞凋亡指数的相关性。结果实验组的血清SCC、CA125及PD-L1水平均高于对照组,差异均有统计学意义(t值分别为28.539、18.713、14.414,P<0.05)。实验组的细胞凋亡指数(6.87±2.89)高于对照组的细胞凋亡指数(2.44±0.56),差异有统计学意义(t=13.132,P<0.001)。临床分期为Ⅲ~Ⅳ期宫颈癌患者的血清SCC、CA125及PD-L1水平均高于Ⅰ~Ⅱ期者(t值分别为14.444、6.047、8.401,P<0.05);肿瘤分化程度为高分化宫颈癌患者的血清SCC、CA125及PD-L1水平均高于中分化和低分化者(F值分别为177.105、32.848、31.386,P<0.05);淋巴结转移宫颈癌患者的血清SCC、CA125及PD-L1水平均高于淋巴结未转移者(t值分别为6.659、7.356、6.460,P<0.05);不同病理分类(鳞状细胞癌与腺癌)宫颈癌患者的血清SCC、CA125及PD-L1水平比较差异均无统计学意义(P>0.05)。宫颈癌患者的血清SCC、CA125及PD-L1水平均与细胞凋亡指数呈正相关(r值分别为0.689、0.662、0.495,P<0.05)。结论宫颈癌患者血清SCC、CA125及PD-L1水平显著升高,与临床分期、肿瘤分化程度及淋巴结转移密切相关,且均与细胞凋亡指数呈正相关,其可为临床宫颈癌的诊断治疗及监测提供参考。 展开更多
关键词 宫颈癌 鳞状细胞癌抗原 糖链抗原125 可溶程序性死亡分子1 细胞凋亡指数
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