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Porosity model and pore evolution of transitional shales:an example from the Southern North China Basin

Petroleum Science 2020年第6期17卷 1512-1526页

作者： xiao-guang yang Shao-Bin Guo School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of EducationBeijing 100083China

The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal *** simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale,and X-ray diffraction(XRD),CO2 adsorption,N2 adsorption and high-pressure mercury injection(MIP)were then used to characterize shale diagenesis and ***,simulations of mechanical compaction adhering to mathematical models were performed,and a shale compaction model was proposed considering clay content and kaolinite *** advantage of this model is that the change in shale compressibility,which is caused by the transformation of clay minerals during thermal evolution,may be *** combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical *** interactions may then express the pore evolution of shale in actual conditions of ***,the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content,proving that other clay minerals such as illite-smectite mixed layers(I/S)and illite are conducive to the development of *** possessing a high clay mineral content have a higher porosity in shallow layers(3500 m).Both the amount and location of the increase in porosity differ at different geothermal *** geothermal gradients favor the preservation of high porosity in shale at an appropriate *** pore evolution of the marine-continental transitional shale is divided into five *** 2 possesses an Ro of 1.0%-1.6%and has high porosity along with a high specific surface *** 3 has an Ro of 1.6%-2.0%and contains a higher porosity with a low specific surface ***,Stage 4 has an Ro of 2.0%-2.9%with a low porosity and h

关键词： Thermal simulation Porosity model Pore evolution Transitional shale Southern North China Basin Shanxi formation

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Low-cycle fatigue lifetime estimation of Ti–6Al–4V welded joints by a continuum damage mechanics model

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Rare Metals 2016年第4期35卷 299-302页

作者： Hong-Yu Qi xiao-Lei Zheng xiao-guang yang School of Energy and Power Engineering Beihang University Beijing 100191 China

The low-cycle fatigue （LCF） behavior of directionally solidified nickel-based superalloy Ti-6A1-4V was studied under bare and electron beam welding condi- tions at room temperature. Results show that：（1） under the same test conditions, all the joints exhibit lower LCF lifetime than Ti-6A1-4V; （2） the failure of welded structures is mainly ascribed to the welding defect. A novel lifetime prediction methodology based on continuum damage mechanics is proposed to predict the lifetime of Ti-6A1-4V and its welded joints.

关键词： Electron beam welding Low-cycle fatigue Life estimation Continuum damage mechanics

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Purification and Immunity Analysis of Recombinant 6His-HPT Protein Expressed in ***

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Biomedical and Environmental Sciences 2003年第2期16卷 149-156页

作者： LI-CHEN yang ZHEN ZHU xiao-guang yang Plant Genetic Manipulation Laboratory Institute ofGeneticsChinese Academy of SciencesBeijing 100101China Key laboratory of Trace Element Nutrition ofthe Ministry of Health ChinaInstitute of Nutrition and Food SafetyChinese Centerfor Diseases Control and PreventionBeijing 100050Chin

To obtain HPT protein (Hygromycin B Phosphotransferase), a kind of plant selective maker gene product expressed from *** and to prepare the polyclonal antibody (pAbs) against it. Methods HPT cDNA fragment was obtained by PCR and was inserted into the prokaryotic expressing vector pBV222. Then the constructed recombinant plasmid pBV222-HPT was transfered into *** DH5?for HPT expression. The recombinant expressing system was confirmed by restriction endonuclease digestion, DNA sequencing and protein expression. *** cells were lysed by sonication and detergent dissolution. After cell membrane was extracted, the inclusion bodies were denatured by 8 mol/L Urea and purified with metal chelate affinity chromatography on Ni-NTA agarose under denaturing condition. The purified 6His-HPT was characterized by SDS-PAGE, and used to immunize rabbit. The titer and specificity of antisera were detected by ELISA and Western blot respecitively. Results Analysis of DNA sequence and restricted enzymes showed that the sequence of PBV222-HPT plasmid was correct. The amount of recombinant HPT expressed in *** accounted for 30% of total cellular proteins. From 1 liter of fermentative bacteria about 22 milligrams of pure recombinant HPT was isolated with purity above 95%. The recombinant HPT protein could produce high titer antiserum in rabbits and show good immunity activity. Western blot showed specific binding reaction between the antiserum to the purified 6His-HPT protein and their expressed products (plants protein and bacterial protein). Conclusion HPT protein can be expressed and purified from *** by a relatively simple method, which has high immunity activity.

关键词： Organisms Genetically Modified DNA Bacterial Electrophoresis Polyacrylamide Gel Escherichia coli Genetic Engineering Genetic Markers Phosphotransferases (Alcohol Group Acceptor) Plasmids Polymerase Chain Reaction Recombinant Proteins Research Support Non-U.S. Gov't

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A physically based methodology for predicting anisotropic creep properties of Ni-based superalloys

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Rare Metals 2016年第8期35卷 606-614页

作者： Jia Huang Duo-Qi Shi xiao-guang yang School of Energy and Power Engineering Beihang University

This paper is focused on developing suitable methodology for predicting creep characteristics （i.e., the minimum creep strain rate, stress rupture life and time to a specified creep strain） of typical Ni-based directionally solidified （DS） and single-crystal （SC） superalloys. A modem method with high accuracy on simulating wide ranging creep properties was fully validated by a sufficient amount of experimental data, which was then developed to model anisotropic creep characteristics by introducing a simple orientation factor defined by the ultimate tensile strength （UTS）. Physical confidence on this methodology is provided by the well-predicted transitions of creep defor- mation mechanisms. Meanwhile, this method was further adopted to innovatively evaluate the creep properties of different materials from a relative perspective.

关键词： Wilshire equations Anisotropic creepproperties Ni-based superalloy Prediction methodologyCreep mechanism

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High-temperature oxidation behavior of DZ125 Ni-based superalloy under tensile stress

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Rare Metals 2022年第12期41卷 4188-4193页

作者： Hong-Yu Qi xiao-Bo Liang Shao-Lin Li xiao-guang yang School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China

The key in antioxidant capacity of aero-engine hot components is the protective oxide *** factors can affect the performance of oxide *** effect of tensile stress on high-temperature oxidation behavior of directionally solidified DZ125 Ni-based superalloy was investigated by thermogravimetric analysis(TGA).Tensile samples were subjected to stress of 100 MPa,and the oxidation behavior was studied at 980℃in *** surface and cross-sectional morphologies of the oxidized coating were analyzed by scanning electron microscope(SEM).The influence of tensile stress on the oxidation behavior of directionally solidified DZ125 Ni-based superalloy at high temperature was *** show that an applied tensile stress generally leads to larger Cr/Ni mass ratio in the oxide scales,greater overall chromium depletion values directly under the oxide scales,lower specific weight gain values and thinner oxide *** factors are attributed to the formation of fast diffusion paths for Cr atoms to diffuse to the surface under tensile stress,thus causing a reduction in the duration of the less protective transient oxidation period and promoting a faster formation of the protective Cr_(2)O_(3)layer.

关键词： DZ125 Ni-based superalloy High-temperature oxidation Tensile stress Diffusion

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Tensile properties and failure analysis of Ti–6Al–4V joints by electron beam welding

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Rare Metals 2016年第6期35卷 450-455页

作者： xiao-guang yang Shao-Lin Li Hong-Yu Qi School of Energy and Power Engineering Beijing University of Aeronautics and Astronautics

The microstructural and mechanical characterization of electron beam welded joints of forged Ti-6Al- 4V were investigated. Microhardness tests indicate that the hardness of the fusion zone （FZ） is higher than that of the heat-affected zone （HAZ） and base metal. The tensile results show that the mechanical properties of the welded joints are comparable with those of the base metal in terms of static strength and are in accordance with the relationship between microstructure and mechanical properties of welded joints. The ultimate tensile strength of the weld is equal to that of the hourglass joint, which indicates that the mechanical properties of the longitudinal FZ and those of the transverse FZ are the same. Macromechanical behavior and macrofracture and microfracture of the base material, joint, and weld specimens are observed. A comparison among the three types of specimen fracture phenomena reveals the following distinctive differences：（1） the fracture mode, （2） the micrograph of the dimple pattern at the central region, and （3） the size of the dimple at the central region and the transition region.

关键词： Electron beam welding Microstructure Mechanical properties Failure model

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Evaluation of service-induced microstructural damage for directionally solidified turbine blade of aircraft engine

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Rare Metals 2019年第2期38卷 157-164页

作者： Wei-Qing Huang xiao-guang yang Shao-Lin Li School of Energy and Power Engineering Beihang University Beijing Key Laboratory of Aero-Engine Structure and Strength

Turbine blades of gas turbine engines usually suffer from severe operational conditions characterized by high temperature and stress. Severe operational conditions during service cause microstructural changes in turbine blades and degrade their mechanical properties. In this study, service-induced microstructural damages in serviced turbine blades manufactured from a directionally solidified superalloy were evaluated. The observed microstructural damage of the turbine blade mainly involves the coarsening and rafting of γ' precipitates. The leading edge of 60% height of the turbine blades undergone most severe microstructural damage with significant microstructural evolution at this area. Microstructural damage affects the mechanical properties such as Vickers hardness, that is,Vickers hardness decreases as the equivalent diameter decreases. Microstructural damage shows great positiondependent feature as service temperature and radial stress on blade changes. With the aid of energy-dispersive spectrometer(EDS) analysis on carbide, the transformation of carbide does not exist. In addition, no topological closed-packed phase exists in the turbine blade.

关键词： Service-induced Microstructural damage Directionally solidified Turbine blade: Aircraft engine

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Oxidation-induced damage of an uncoated and coated nickel-based superalloy under simulated gas environment

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Rare Metals 2018年第3期37卷 204-209页

作者： Shao-Lin Li Hong-Yu Qi xiao-guang yang School Of Energy and Power Engineering Beihang UniversityBeijing 100191 China Beijing Key Laboratory of Aero-Engine Structure and Strength Beijing 100191 China

Turbine blades and vans operated in an aggressive gas environment usually suffer from combined oxidation and cycle loading effects. The surface oxide layer will result in premature failure and lead to a significant reduction in the service lifetime. The effects of prior oxidation-induced damage under a simulated combustion-gas environment on the fatigue lifetime of the directionally solidified（DS） nickel-based superalloy DZ125 with and without an oxidation-resistant coating were presented. The fatigue lifetime of uncoated samples is adversely affected by prior oxidation exposure. The deterioration of fatigue lifetime in uncoated samples is associated with surface microstructural degradation, which occurs during prior exposure. However,the presence of MCrAlY coating is beneficial for the sample＇s lifetime under high stress. Further scanning electron microscopy（SEM） analysis demonstrates that the coating does not contribute to the initiation mode of fatigue cracks.

关键词： Gas environment Fatigue Lifetime Coating Superalloy

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Coalition Formation in Weighted Simple-majority Games under Proportional Payoff Allocation Rules

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International Journal of Automation and computing 2009年第3期6卷 217-222页

作者： Zhi-Gang Cao xiao-guang yang Key Laboratory of Management Decision and Information SystemsAcademy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 PRC

In this paper, we introduce a simple coalition formation game in the environment of bidding, which is a special case of the weighted majority game （WMG）, and is named the weighted simple-majority game （WSMG）. In WSMG, payoff is allocated to the winners proportional to the players powers, which can be measured in various ways. We define a new kind of stability： the counteraction-stability （C-stability）, where any potential deviating players will confront counteractions of the other players. We show that C-stable coalition structures in WSMG always contains a minimal winning coalition of minimum total power. For the variant where powers are measured directly by their weights, we show that it is NP-hard to find a C-stable coalition structure and design a pseudo-polynomial time algorithm. Sensitivity analysis for this variant, which shows many interesting properties, is also done. We also prove that it is NP-hard to compute the Holler-Packel indices in WSMGs, and hence in WMGs as well.

关键词： Weighted majority games (WMG) coalition formation bidding C-stability NP-hard.

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Low-cycle fatigue behavior of a directionally solidified Ni-based superalloy subjected to gas hot corrosion pre-exposure

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Rare Metals 2019年第3期38卷 227-232页

作者： Hong-Yu Qi Ji-Shen yang xiao-guang yang Shao-Lin Li School of Energy and Power Engineering Beihang University Collaborative Innovation Center of Advanced Aero-Engine

The influence of gas high-temperature hot corrosion(HTHC) pre-exposure on low-cycle fatigue(LCF)behavior was characterized for the directionally solidified(DS) Ni-based superalloy DZ125. Fatigue tests were carried out at 850 ℃ in the pre-exposed and unexposed specimens for 2, 15 and 25 h. Experimental results show that the porous corrosion scale and γ′-depleted layer formed in gas hot corrosion condition alter the crack initiation mechanisms of the superalloy. Fatigue cracks of the pre-exposed specimens originate from multiple surface locations where spalling of the corrosion products occur,while nucleation of unexposed specimen begins in the defects close to the surface. There is a significant reduction in LCF behavior for pre-exposed specimens in comparison with unexposed specimens.

关键词： Low-cycle fatigue Hot corrosion Preexposure Burner rig Ni-based superalloy

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