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Austenitization Behaviors of X80 Pipeline Steel With High Nb and Trace Ti Treatment

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Journal of Iron and Steel Research International 2009年第6期16卷 58-62页

作者： liu qing-you SUN Xin-jun JIA Shu-jun ZHANG Lu-lin HUANG Guo-jian REN Yi Central Iron and Steel ReseaTch Institute Beijing 100081 China Anshan Iron and Steel Group Corporation Anshan 114021 Liaoning China

The austenitization behaviors of two high niohium-containing X80 pipeline steels with different titanium contents, including the dissolution of microalloying precipitates and the austenite grain growth, were investigated by using physical-chemical phase analysis method and microstructural observation. The results illustrated that most niobium could be dissolved into austenite during soaking at 1 180 ℃, whereas little amount of titanium could be dissolved. It was found that during soaking, the austenite grain growth rate was initially high, and then decreased after soaking for 1 h; moreover, the austenite grains grew up more rapidly at temperatures above 1 180 ℃ than below 1 180 ℃. The results show that the steel with titanium content of 0. 016% has a larger austenite grain size than that with titanium content of 0. 012% under the same soaking conditions, which is explained by considering the particle size distribution.

关键词： high Nb steel X80 pipeline steel austenite grain growth dissolution microalloying precipitate

Effect of Micro-Area pH Value on Formation of Different Rust Phases of Weathering Steel in Initial Corrosion Period

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Journal of Iron and Steel Research International 2010年第9期17卷 69-72,78页

作者： CHEN Xiao-ping WANG Xiang-dong liu qing-you MI Feng-yi CHEN Ying LI Yu-su Central Iron and Steel Research Institute Beijing 100081 China

The formation of protective rust layer of atmospheric corrosion resistance was discussed for weathering steel. The rust layers of experimental steels were made by using an accelerating industrial atmospheric corrosion test of dry-wet cyclic immersion. Furthermore XRD were used to measure and analyze the rust layers. The initial corrosion processes below thin water film were observed and the changes of micro-area pH value were measured. The results are as follows： The corrosion processes of P-RE weathering steel are obviously different from those of carbon steel. The surface of P-RE weathering steel rapidly forms a-FeOOH and the micro-area pH value is above 5.4 during the initial corrosion period. While the component of the rust layer for the carbon steel is mainly Fe3O4 and the microarea pH value is below 3.8.

关键词： weathering steel pH value micro area rust phase

Factors Affecting the Efficiency of Embryonic Cell Nuclear Transfer in Rabbits

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Agricultural Sciences in China 2005年第12期4卷 937-942页

作者： CUI Kui-qing liu qing-you XIE Ying WEI Jing-wei SHI De-shun Animal Reproduction Institute Guangxi University Nanning 530005 P.R.China

Factors affecting the efficiency of nuclear transfer （NT） in rabbits were examined in the present study. When 100 V mm of pulse strength and 15 us of pulse duration were employed, 3 and 4 electronic pulses resulted in significantly more cytoplasts fused with donor cells compared with 2 electronic pulses （P〈 0.05）, but no significant difference was found in the cleavage rate of reconstructed embryos among the three groups （P〉0.05）. When the duration and number of electronic pulse were fixed at 15 ps and 3 times, increase of pulse intensity from 100 V mm 1 to 150 V mm^-1 and 200 V mm^-1 resulted in a significantly decrease in the cleavage rate of reconstructed embryos （P〈 0.05）, although the fusion rate did not significantly differ among the three groups （P〉 0.05）. Significantly more reconstructed embryos cleaved and developed to blastocysts when they were derived from donor embryos at the 8-16-cell stage, in comparison with the reconstructed embryos derived from donor embryos at the compact morula stage （P 〈 0.05）, although the fusion rate was similar （P 〉 0.05）. Activation of cytoplasts prior to fusion increased the cleavage rate （P〈 0.05） and blastocyst development （P〈 0.05） of reconstructed embryos, but decreased the fusion rate （P 〈 0.05） compared with cytoplasts activated post fusion. More reconstructed embryos developed to blastocysts when they were cultured in TCM ＋ 3% OCS at the first 48 h and then cultured in TCM199＋ 10% FCS, in comparison with the reconstructed embryos cultured in either TCM199＋ 10% FCS or TCM199＋3% OCS （P 〈 0.05）. When 22 NT embryos were transferred into the oviducts of one recipient rabbit, one recipient rabbit delivered a female rabbit at 34 days of gestation. In conclusion, either electrofusion parameter or developmental stage of donor embryos have a significant effect on the efficiency of NT, NT embryos require different concentration of serum at their different development stages.

关键词： Rabbit Nuclear transfer Embryo

The effects of various factors on spontaneous imbibition in tight oil reservoirs

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Petroleum Science 2024年第1期21卷 315-326页

作者： Cheng liu Tian-Ru Wang qing you Yue-Chun Du Guang Zhao Cai-Li Dai School of Energy Resources China University of GeosciencesBeijing100083PR China School of Petroleum Engineering China University of PetroleumQingdao266580ShandongPR China

Slickwater fracturing fluids have gained widespread application in the development of tight oil reservoirs. After the fracturing process, the active components present in slickwater can directly induce spontaneous imbibition within the reservoir. Several variables influence the eventual recovery rate within this procedure, including slickwater composition, formation temperature, degree of reservoir fracture development, and the reservoir characteristics. Nonetheless, the underlying mechanisms governing these influences remain relatively understudied. In this investigation, using the Chang-7 block of the Changqing Oilfield as the study site, we employ EM-30 slickwater fracturing fluid to explore the effects of the drag-reducing agent concentration, imbibition temperature, core permeability, and core fracture development on spontaneous imbibition. An elevated drag-reducing agent concentration is observed to diminish the degree of medium and small pore utilization. Furthermore, higher temperatures and an augmented permeability enhance the fluid flow properties, thereby contributing to an increased utilization rate across all pore sizes. Reduced fracture development results in a lower fluid utilization across diverse pore types. This study deepens our understanding of the pivotal factors affecting spontaneous imbibition in tight reservoirs following fracturing. The findings act as theoretical, technical, and scientific foundations for optimizing fracturing strategies in tight oil reservoir transformations.

关键词： Tight oil reservoir Spontaneous imbibition Nuclear magnetic resonance Slickwater fracturing fluid Fluid utilization degree

Changes in microstructure and properties of weld heat-affected zone of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第8期31卷 2041-2052页

作者： Shu-jun Jia Qi-lin Ma Yu Hou Ba Li He-song Zhang qing-you liu Central Iron and Steel Research Institute Co. Ltd.Beijing 100081China Collaborative Innovation Center for Steel Commonality University of Science and Technology BeijingBeijing 100083China Construction Project Management Branch of China National Petroleum Pipeline Network Group Co. Ltd.Langfang 065000HebeiChina

The evolution of the microstructure and toughness of APL5L X80 pipeline steel after thermal welding simulation was investigated by X-ray diffraction,electron backscatter diffraction,and transmission electron *** results indicated that primary heat-affected zones can be divided into weld,coarse-grained,fine-grained,intercritical,and sub-critical *** microstructure of the weld zone is mainly composed of bainitic ferrite and a small amount of granular bainite;however,the original austenite grains are distributed in the columnar *** structure of the coarse-grained zone is similar to that of the weld zone,but the original austenite grains are *** contrast,the microstructure in the fine-grained zone is dominated by fine granular bainite,and the effective grain size is only 8.15μm,thus providing the highest toughness in the entire heat-affected *** intercritical and subcritical zones were brittle valley regions,and the microstructure was dominated by granular ***,the martensite-austenite(M/A)constituents are present in island chains along the grain boundaries,and the coarse size of the M/A constituents seriously reduces the *** results of the crack propagation analyzes revealed that high-angle grain boundaries can significantly slow down crack growth and change the crack direction,thereby increasing the material *** impact toughness of the low-temperature tempering zone was equivalent to that of the columnar grain zone,and the impact toughness was between those of the critical and fine-grained zones.

关键词： Welding thermal simulation Impact toughness Crack propagation Martensite-austenite constituent High-strength low-alloy steel weld Heat-affected zone

Sand control mechanism of radial well filled with phase change material in hydrate reservoir

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Petroleum Science 2024年第4期21卷 2571-2582页

作者： Xiao-Qiang liu Zhong-Xi Han Zhi-Lin Luo Hai-Long Lu Ying Sun qing you Tian-Kui Guo Zhan-qing Qu School of Energy Resources China University of Geosciences (Beijing) Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering China University of Geosciences (Beijing) China Research Institute of Petroleum Exploration and Development Engineering Technology Research Institute of Southwest Oil & Gas Field Company PetroChina Beijing International Center for Gas Hydrate School of Earth and Space Sciences Peking University School of Advanced Material Peking University Shenzhen Graduate School School of Petroleum Engineering China University of Petroleum (East China)

Radial well filled with phase change material has been proposed as a novel sand control method for hydrate exploitation. In order to reveal the sand control mechanism, CFD-DEM coupling method is applied to simulate the migration, settlement, and blockage processes of sand particles in the radial *** obtained results indicate that three scenarios have been recognized for sand particles passing through sand control medium, based on the diameter ratio of sand control medium to sand particle（Dd）:fully passing（Dd= 8.75-22.5）, partially passing and partially blocked（Dd= 3.18-5.63）, and completely blocked（Dd= 2.18-3.21）. After being captured by the sand control medium, sand particles can block pores, which increases fluid flow resistance and causes a certain pressure difference in the radial *** pressure in the radial well should be lower than the hydrate phase equilibrium pressure during sand control design, for the purpose of promoting hydrate decomposition, and sand capture. The length of the radial well should be optimized based on the reservoir pore pressure, production pressure difference,bottom hole pressure, and the pressure gradient in the radial well. It should be noticed that the sand control medium leads to a decrease in permeability after sand particles captured. Even the permeability is reduced to several hundred millidarcy, it is still sufficient to ensure the effective flow of gas and water after hydrate decomposition. Increasing fluid velocity reduces the blocking capacity of the sand control medium, mainly because of deterioration in bridging between sand particles.

关键词： Hydrate reservoir Sand control Radial well CFD-DEM

Graphene/Molybdenum Dichalcogenide-Based van der Waals Heterostructure Photodetectors: a Review

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新型炭材料(中英文) 2024年

作者： ZHANG Xin-hua liu Wei-Di GONG you-pin liu qing-feng CHEN Zhi-Gang Center of Quantum Materials and Devices at Institute of Advanced Interdisciplinary Studies Soft Matter and Interdisciplinary Research Center College of Physics Chongqing University School of Chemistry and Physic ARC Research Hub in Zero-emission Power Generation for Carbon Neutrality and Center for Materials Science Queensland University of Technology State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University

Graphene is widely used in photodetection due to its high carrier mobility and wide spectral absorption ***, the high dark current due to its low light absorption severely limits the performance of photodetection. Molybdenum dihalide(MoX2, X= S, Se and Te) has a high absorption coefficient, which can compensate high dark current in graphene-based photodetectors and result in outstanding photoelectronic properties in graphene/MoX2 van der Waals heterostructure(vdWH) *** this review, we firstly review working principles, performance indicators, and structures of photodetectors. After that, the significance of graphene/MoX2 vdWH photodetectors are highlighted from the material fundamental perspective. Preparation methodologies and performance enhancement strategies of graphene/MoX2 vdWH photodetectors are correspondingly summarized. In the end, we highlight the current challenges and future directions of the graphene/MoX2 vdWH photodetectors. This review will guide the design of high-performance vdWH photodetectors.

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薄板坯流程连铸连轧过程中的细晶化现象分析

钢铁 2005年第12期40卷 1-9页

作者：徐匡迪刘清友中国工程院北京100038 先进钢铁材料技术国家工程研究中心

研究了薄板坯连铸连轧工艺的铸坯凝固组织特征和钢带的组织演变规律.通过化学相分析、微观组织分析研究发现,微细AlN粒子在薄板坯连铸过程中可沉淀析出,铸坯经20～30 min均热后AlN仅部分溶解.对AlN析出的热力学和动力学分析也证实了AlN... 详细信息

研究了薄板坯连铸连轧工艺的铸坯凝固组织特征和钢带的组织演变规律.通过化学相分析、微观组织分析研究发现,微细AlN粒子在薄板坯连铸过程中可沉淀析出,铸坯经20～30 min均热后AlN仅部分溶解.对AlN析出的热力学和动力学分析也证实了AlN在铸坯上沉淀析出的合理性.这些在连轧开始前原始奥氏体中析出的AlN沉淀是抑制变形奥氏体再结晶晶粒长大,细化奥氏体组织,并最终使钢带组织细化的主要原因;同时,薄板坯连铸连轧流程冷却辊道短、冷却强度大等因素也是导致薄板坯连铸连轧过程中Al镇静钢组织细化的主要原因.

关键词：薄板坯连铸连轧 AlN 沉淀组织细化

Inhibiting shuttle effect of lithium polysulfides by double metal selenides for high-performance lithium-sulfur batteries

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Rare Metals 2024年第6期43卷 2546-2559页

作者： Lei Li Xue-Jing Yang Yi-Yang Li Bo Jin Hui liu Meng-Yang Cui Dong-Bo Guan Xing-you Lang qing Jiang Key Laboratory of Automobile Materials Ministry of Educationand College of Materials Science and EngineeringJilin UniversityChangchun 130022China

Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production ***,the low electronic conductivity of active material and shuttling effect of lithium polysulfides(LiPSs)limit the commercial development of *** solve these problems,we design a core-shell composite with nitrogen-doped carbon(NC)and two types of selenides(FeSe_(2)-NC@ZnSe-NC).The FeSe_(2)-NC@ZnSe-NC has a strong adsorption capacity,and can effectively adsorb *** the same time,it also effectively alleviates the shuttling effect of LiPSs,and improves the utilization of the active substance during the charge/discharge reaction *** mechanism involved in FeSe_(2)-NC@ZnSe-NC is demonstrated by both experiments and density-functional theory(DFT)*** electrochemical test results indicate that LSB with S/FeSe_(2)-NC@ZnSe-NC delivers an initial discharge capacity of 1260 mAh·g^(-1)at *** after 500 cycles at 1C,the capacity decay rate per cycle is 0.031%,and the capacity retention rate is 85%.The FeSe_(2)-NC@ZnSe-NC core-shell structure verifies a rational strategy to construct an electrode material for high-performance LSBs.

关键词： Lithium-sulfur batteries Shuttling effect Metal selenide Nitrogen-doped carbon Lithium polysulfides