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Effectiveness of hot deformation and subsequent annealing forβgrain refinement of Ti-5Al-5Mo-5V-1Cr-1Fe titanium alloy

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Rare Metals 2021年第12期40卷 3608-3615页

作者： yi-Min Cui Wei-Wei zheng Chao-Hua Li guan-Hua Cao Yan-Dong Wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

High strength titanium alloys suffer from a limited combination of strength and *** their micro structure,the coarseβgrain is a detrimental *** the present study,the effects of hot deformation and annealing treatment on theβgrain refinement of Ti-5 Al-5 Mo-5 V-1 Cr-1 Fe(TC18)titanium alloy have been investigated by using electronic backscattered diffraction(EBSD)and transmission electric microscopy(TEM).Hot compression tests of TC18 alloy were performed between 1073 and 1223 K at strain rates of 0.01 and 0.10 s^(-1)·Subsequent annealing treatments were conducted to investigate the effect of deformation microstructure on the recrystallization behavior ofβ*** results indicate that dynamic recovery(DRV)is the dominant restoration mechanism during hot *** dynamic recrystallization(dDRX)is significantly limited at a higher temperature in theβregion,whereas continuous dynamic recrystallization(cDRX)of theβphase is observed at a higher strain rate in the(α+β)*** final annealing microstructure is highly dependent on the deformation *** dDRX during hot deformation could not effectively refine theβ*** refined and uniformβgrains with an average grain size of 12μm are achieved by combining hot deformation and subsequent annealing in the(α+β)*** study provides a guide for theβgrain refinement of high strength titanium alloys.

关键词： Grain refinement Dynamic recrystallization Hot deformation High strength titanium alloy

Pairing effects on the fragment mass distribution of Th,U,Pu,and Cm isotopes

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Nuclear Science and Techniques 2023年第11期34卷 128-139页

作者： Xin guan Jin‑Huan zheng Mei‑Yan zheng Department of Physics Liaoning Normal UniversityDalian 116029China

In this article,a comprehensive study of the fission process of Th,U,Pu,and Cm isotopes using a Yukawa-folded meanfield plus standard pairing model is *** study focused on analyzing the effects of the pairing interaction on the fragment mass distribution and its dependence on nuclear *** significant role of pairing interactions in the fragment mass distributions of^(230)Th,^(234)U,^(240)Pu,and^(246)Cm was *** analysis revealed that increasing the pairing interaction strength decreased the asymmetric fragment mass distribution and increased the symmetric ***,the odd-even mass differences at symmetric and asymmetric fission points were examined,highlighting their sensitivity to changes in the pairing interaction *** analysis of the Th,U,Pu,and Cm isotope fragment mass distributions demonstrated the effectiveness of the model in reproducing the experimental *** addition,the effects of the zero-point energy and half-width parameter on the fragment mass distribution for^(240)Pu were ***,this study provides valuable insights into the fission process by emphasizing the importance of pairing interactions and their relationship with nuclear elongation.

关键词： Nuclear fission Pairing interaction Fragment mass distribution Actinide nuclei

Influence of Ru on Solidification Behavior, Microstructure and Hardness of Re-free Ni-based Equiaxed Superalloys with High Cr Content

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Journal of Materials Science & Technology 2016年第3期32卷 271-281页

作者： yingshuang guan Enze Liu Xiurong guan Zhi zheng School of Environmental and Chemical Engineering Shenyang Ligong University Shenyang 110159 China Superalloys Division Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The effect of Ru addition on solidification behavior, microstructure and hardness of Re-free Ni-based equiaxed superalloys with high Cr content has been investigated. With the increase of Ru, the solidus temperature of the alloys and the γ＂ solvus temperature decreased, respectively. However, the liquidus temperatures of the alloys bad no obvious change. The microstructure of the as-cast alloys was mainly composed of γ, γ＇, γ＇/γ＇ eutectic and MC carbides. The γ/γ＇ eutectic was completely dissolved after the heat treatment. The morphology of γ＇ was more cuboidal in heat-treated alloys with increasing Ru. Furthermore, the volume fraction of γ＇ in the as-cast and heat-treated alloys diminished upon the increase of Ru. It was noted that Ru addition changed the segregation behaviors of Cr and Mo in the alloys from positive segregation element to negative segregation element and promotes the segregation degree of W. As the Ru content increased, the magnitude of segregation of the positive segregation elements Ta and Ti increased accordingly. Meanwhile, the magnitude of Al segregation decreased and Ru tended to segregate in the dendrite core. In addition, the hardness of the alloys improved and their porosity reduced with increasing amount of Ru.

关键词： Ru Ni-based equiaxed superalloy Microstructure Segregation Hardness

Synthesis, Crystal Structure and Theoretically Study of 2-(Dimethylamino)-1,3-dithiocyanatopropane and Its Isomer

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Chemical Research in Chinese Universities 2011年第6期27卷 963-967页

作者： YU guan-ping MA yi LIU Zhuo WANG Gang LI zheng-ming State Key Laboratory of Elemento-organic Chemistry Research Institute of Elemento-organic Chemistry Nankai University Tianjin 300071 P. R. China

2-（Dimethylamino）-1,3-dithiocyanatopropane（1） has been prepared as a key intermediate synthesizing a natural insecticide Cartap by the reaction of 1-dimethylamino-2,3-dichloropropane with sodium thiocyanate. The crystal structures of compound 1 and its isomer 1-（dimethylamino）-2,3-dithiocyanotopropane（2） formed during the reaction were determined by X-ray single-crystal diffraction. Bond lengths in both the compounds are common and fall within normal ranges. There are some weak C―H×××N hydrogen bonds in the lattice of compound 1, which makes it form a three-dimensional network, which stabilize the crystal structure. No classic hydrogen bonds were founded in its isomer（2）, only van der Waals forces contribute to the stability of the structure. In addition, DFT and MP2 calculations with 6-311＋G（d, p） basis set have also been carried out to investigate the thermodynamic properties of compounds 1 and 2. The research will be applied to the further investigation of the tautomerization of compounds 1 and 2.

关键词： Cartap Crystal structure Theoretical calculation Thermodynamic property

A preliminary analysis and discussion of the condominium building collapse in surfside,Florida,US,June 24,2021

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Frontiers of Structural and Civil Engineering 2021年第5期15卷 1097-1110页

作者： Xinzheng LU Hong guan Hailin SUN yi LI Zhe zheng yifan FEI Zhi YANG Lingxiao ZUO Key Laboratory of Civil Engineering Safety and Durability of Ministry of Education Tsinghua UniversityBeijing 100084China School of Engineering and Built Environment Griffith University Gold Coast CampusQueensland 4222Australia China Architecture Design&Research Group Co. LtdBeijing 100044China Beijing Key Laboratory of Earthquake Engineering and Structural Retrofit Beijing University of TechnologyBeijing 100124China

On June 24,2021,a 40-year-old reinforced concrete flat plate structure building in Miami suffered a sudden partial *** study analyzed the overall performance and key components of the collapsed building based on the building design codes(ACI-318 and GB 50010).Punching shear and post-punching performances of typical slabcolumn joints are also studied through the refined finite element *** collapse process was simulated and visualized using a physics *** way of these analyses,weak design points of the collapsed building are *** differences between the reinforcement detailing of the collapsed building and the requirements of the current Chinese code are discussed,together with a comparison of the punching shear and post-punching *** simulated collapse procedure and debris distribution are compared with the actual collapse scenes.

关键词： progressive collapse flat plate simulation punching

Potential plausible role of Wharton’s jelly mesenchymal stem cells for diabetic bone regeneration

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World Journal of Stem Cells 2024年第8期16卷 824-826页

作者： Sheng zheng guan-Yu Hu Jun-Hua Li yi-Kai Li Department of Traditional Chinese Orthopedics and Traumatology Center for Orthopedic SurgeryThe Third Affiliated Hospital of Southern Medical UniversityGuangzhou 510630Guangdong ProvinceChina School of Traditional Chinese Medicine Southern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

This letter addresses the review titled“Wharton’s jelly mesenchymal stem cells:Future regenerative medicine for clinical applications in mitigation of radiation injury”.The review highlights the regenerative potential of Wharton’s jelly mesenchymal stem cells(WJ-MSCs)and describes why WJ-MSCs will become one of the most probable stem cells for future regenerative *** potential plausible role of WJ-MSCs for diabetic bone regeneration should be noticeable,which will provide a new strategy for improving bone regeneration under diabetic conditions.

关键词： Wharton’s jelly mesenchymal stem cells Vascular endothelial growth factor Osteogenesis Angiogenesis Diabetic bone regeneration

Icariin accelerates bone regeneration by inducing osteogenesisangiogenesis coupling in rats with type 1 diabetes mellitus

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World Journal of Diabetes 2024年第4期15卷 769-782页

作者： Sheng zheng guan-Yu Hu Jun-Hua Li Jia zheng yi-Kai Li Department of Traditional Chinese Orthopedics and Traumatology Center for Orthopedic SurgeryThe Third Affiliated Hospital of Southern Medical UniversityGuangzhou 510630Guangdong ProvinceChina School of Traditional Chinese Medicine Southern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Department of Endocrinology Peking University First HospitalBeijing 100034China

BACKGROUND Icariin(ICA),a natural flavonoid compound monomer,has multiple pharmacological ***,its effect on bone defect in the context of type 1 diabetes mellitus(T1DM)has not yet been *** To explore the role and potential mechanism of ICA on bone defect in the context of *** The effects of ICA on osteogenesis and angiogenesis were evaluated by alkaline phosphatase staining,alizarin red S staining,quantitative real-time polymerase chain reaction,Western blot,and ***-related assays were conducted to investigate the relationship between osteogenesis and angiogenesis.A bone defect model was established in T1DM *** model rats were then treated with ICA or placebo and micron-scale computed tomography,histomorphometry,histology,and sequential fluorescent labeling were used to evaluate the effect of ICA on bone formation in the defect *** ICA promoted bone marrow mesenchymal stem cell(BMSC)proliferation and osteogenic *** ICA treated-BMSCs showed higher expression levels of osteogenesis-related markers(alkaline phosphatase and osteocalcin)and angiogenesis-related markers(vascular endothelial growth factor A and platelet endothelial cell adhesion molecule 1)compared to the untreated *** was also found to induce osteogenesis-angiogenesis coupling of *** the bone defect model T1DM rats,ICA facilitated bone formation and CD31hiEMCNhi type H-positive capillary ***,ICA effectively accelerated the rate of bone formation in the defect *** ICA was able to accelerate bone regeneration in a T1DM rat model by inducing osteogenesis-angiogenesis coupling of BMSCs.

关键词： Icariin Osteogenesis-angiogenesis coupling Type 1 diabetes mellitus Bone defect Bone regeneration

Subsection and superposition method for reservoir formation damage evaluation of complex-structure wells

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Petroleum Science 2023年第3期20卷 1843-1856页

作者： guan-Cheng Jiang yi-zheng Li yin-Bo He Teng-Fei Dong Ke-Ming Sheng Zhe Sun Collge of Petroleum Engineering China University of Petroleum(Beijing)Bejing102249China State Key Laboratory of Petroleum Resources and Prospecting MOE Key Laboratory of Petroleum EngineeringChina Universityof Petroleum(Beijing)Beijing102249China College of Artificial Intelligence China University of Petroleum(Bejing)Beijing102249China Calgary Centre for Innovative Technology University of CalgaryCalgaryAB T2N 1N4Canada National Engineering Research Center of Oil&Gas Drilling and Completion Technology

Kinds of complex-structure wells can effectively improve production,which are widely ***,in the process of drilling and completion,complex-structure wells with long drilling cycle and large exposed area of reservoir can lead to the fact that reservoir near wellbore is more vulnerable to the working fluid invasion,resulting in more serious formation *** order to quantitatively describe the reservoir formation damage in the construction of complex-structure well,taking the inclined well section as the research object,the coordinate transformation method and conformal transformation method are given according to the flow characteristics of reservoir near wellbore in anisotropic *** the local skin factor in orthogonal plane of wellbore is *** the un-even distribution of local skin factor along the wellbore,the oscillation decreasing model and empirical equation model of damage zone radius distribution along the wellbore direction are established and then the total skin factor model of the whole well is superimposed to realize the reservoir damage evaluation of complex-structure *** the skin factor model with the production model,the production of complex-structure wells can be predicted more *** two field application cases show that the accuracy of the model can be more than 90%,which can also fully reflect the invasion characteristics of drilling and completion fluid in any well section of complex-structure wells in anisotropic reservoir,so as to further provide guidance for the scientific establish-ment of reservoir production system.

关键词： Complex-structure wells Reservoir formation damage Reservoir anisotropy Skin factor Production prediction model

Adaptive sampling strategy for characterizing spatial distribution of soil liquefaction potential using cone penetration test

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1221-1231页

作者： zheng guan Yu Wang Tengyuan Zhao Department of Architecture and Civil Engineering City University of Hong KongTat Chee AvenueKowloonHong KongChina School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an710049China

Characterizing spatial distribution of soil liquefaction potential is critical for assessing liquefactionrelated hazards(*** damages caused by liquefaction-induced differential settlement).However,in engineering practice,soil liquefaction potential is usually measured at limited locations in a specific site using in situ tests,*** penetration tests(CPTs),due to the restrictions of time,cost and access to subsurface *** these cases,liquefaction potential of soil at untested locations requires to be interpreted from limited measured data points using proper interpolation method,leading to remarkable statistical uncertainty in liquefaction *** underlines an important question of how to optimize the locations of CPT soundings and determine the minimum number of CPTs for achieving a target reliability level of liquefaction *** tackle this issue,this study proposes a smart sampling strategy for determining the minimum number of CPTs and their optimal locations in a selfadaptive and data-driven *** proposed sampling strategy leverages on information entropy and Bayesian compressive sampling(BCS).Both simulated and real CPT data are used to demonstrate the proposed *** examples indicate that the proposed method can adaptively and sequentially select the required number and optimal locations of CPTs.

关键词： Liquefaction potential Information entropy Cone penetration test(CPT) Site characterization Compressive sampling