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Safety analysis of temporary anchorage system for immersed tube in Shenzhen-Zhongshan Link

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 797-813页

作者： lei yan Jinning yan Guoping Xu Shuanhai he Zechen Zhang School of Highway Chang'an UniversityXi'an 710064China Key Laboratory of Transport Industry of Bridge Detection Reinforcement Technology Chang'an UniversityXi'an 710064China CCCC Highway Consultants Co.Ltd. Beijing 100088China

In the construction of the Shenzhen-Zhongshan Link,a temporary anchorage system,distributed uniformly along the pipe wall,has been *** assess the safety and reliability of this system,a combined method utilizing numerical analysis and model experiments was applied to study the safety of the temporary anchorage system and the reliability of the tension ***,an overall model of the caisson segment based on GINA rebound force was established to analyze the stress state of the entire ***,a comprehensive numerical analysis and model experiment verification were conducted for the single tensioning system,revealing its failure mode and safety *** results indicate that the tension rod systems are uniformly stressed at an average of 444 k N during underwater jointing,with a safety factor of *** this point,the maximum von Mises stresses appearing at the front plate corners and the lower edge of the U-groove,with stress values of 181.8 MPa and 172.4 MPa,and safety factors of 1.54 and 1.71,*** the tension rod force reaches 940 k N,the tensioning system reaches its bearing limit,with initial yielding occurring at the front plate *** experiments were conducted to verify the theoretical analysis results,under a test load of 444 k N,the stresses at the front plate corners and the lower edge of the U-groove were 159.6 and 195.9 MPa,*** the test load increased to 940 k N,these stresses reached 390 and 389 MPa,exhibiting good agreement with the numerical *** the uncertainty of loads and materials,a reliability analysis of the tension rods was conducted,yielding a reliability index of 4.34,meeting the secondary safety *** on the comprehensive analysis,it can be concluded that the temporary anchorage system in the caisson segments of the Shenzhen-Zhongshan Link exhibits excellent safety margins.

关键词： Tunnel engineering Immersed tube structure Anchorage system Full-scale model test Load bearing performance Safety assessment

CO_(2) corrosion of X80 steel welded joints under micro-turbulence induced by welding reinforcement height

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Journal of Iron and Steel Research International 2024年第4期31卷 1015-1032页

作者： Xiao-hui Dou Bin Li Zong-hao he Xin-wei Zhang Da-lei Zhang yan Li School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

Corrosion failure accidents owing to flow erosion and pipeline corrosion frequently occur during *** welding reinforcement height(WRH)can induce locally micro-turbulent flow field,which aggravates local corrosion of welded joints.A high wall shear stress(WsS)experimental setup was established to conduct the online electrochemical corrosion *** influence of WRH sizes on local corrosion of welded joints was studied at different flow *** electrochemical signals of the local corrosion of X80 welded joints at different flow rates were monitored in real time using electrochemical impedance spectroscopy and wire beam *** addition,the corrosion products composition and properties were *** results show that the micro-turbulent flow fields induced by the WRHs can enhance ion mass transfer near the welded *** corrosion products on the WRH surface also present different microscopic morphologies at different flow *** strong flow fields,the locally enhanced wsS can peel off the dense corrosion product partially,leading to the electrochemical distribution of large cathode and small anode,which accelerates the occurrence and development processes of the local corrosion of welded *** scientific guidelines for the corrosion protection of long-distance oil and gas pipelines can be potentially provided.

关键词： X80 steel welded joint Welding reinforcement height Micro-turbulence CO_(2)corrosion-Ion mass transfer

Fusion of a rice endogenous N-methylpurine DNA glycosylase to a plant adenine base transition editor ABE8e enables A-toK base editing in rice plants

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aBIOTECH 2024年第2期5卷 127-139页

作者： Yucai Li Shaoya Li Chenfei Li Chen Zhang lei yan Jingying Li Yubing he yan Guo Lanqin Xia Institute of Crop Sciences(ICS) Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural UniversityBeijing 100193China Hainan Yazhou Bay Seed Laboratory/National Nanfan Research Institute(Sanya) CAASSanya 572024China

Engineering of a new type of plant base editor for simultaneous adenine transition and transversion within the editing window will greatly expand the scope and potential of base editing in directed evolution and crop ***,we isolated a rice endogenous hypoxanthine excision protein,N-methylpurine DNA glycosylase(OsMPG),and engineered two plant A-to-K(K=G or T)base editors,rAKBE01 and rAKBE02,for simultaneous adenine transition and transversion base editing in rice by fusing OsMPG or its mutant mOsMPG to a plant adenine transition base editor,*** further coupled either OsMPG or mOsMPG with a transactivation factor VP64 to generate rAKBE03 and rAKBE04,*** these four rAKBEs,at five endogenous loci in rice protoplasts,indicated that rAKBE03 and rAKBE04 enabled higher levels of A-to-G base transitions when compared to ABE8e and ***,whereas rAKBE01 only enabled A-to-C/T editing at one endogenous locus,in comparison with rAKBE02 and rAKBE03,rAKBE04 could significantly improve the A-to-C/T base transversion efficiencies by up to 6.57-and 1.75-fold in the rice protoplasts,***,although no stable lines with A-to-C transversion were induced by rAKBE01 and rAKBE04,rAKBE04 could enable simultaneous A-to-G and A-to-T transition and transversion base editing,at all the five target loci,with the efficiencies of A-to-G transition and A-to-T transversion editing ranging from 70.97 to 92.31%and 1.67 to 4.84%in rice stable lines,***,these rAKBEs enable different portfolios of editing products and,thus,now expands the potential of base editing in diverse application scenario for crop improvement.

关键词： Rice(Oryza sativa L) Rice N-methylpurine DNA glycosylase(OsMPG) A-to-K base editor(AKBE) Transactivation module VP64

Corrosion behavior of Gd_(2)Zr_(2)O_(7)thermal barrier coatings under Fe-containing environmental sediment attack

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Journal of Advanced Ceramics 2024年第4期13卷 447-462页

作者： lei Guo yanyan Li Kai yan School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin 300072China Key Laboratory of Special Equipment Safety and Energy-saving for State Market Regulation China Special Equipment Inspection&Research InstituteBeijing 100029China

Environmental sediments mainly consisting of CaO–MgO–Al_(2)O_(3)–SiO_(2)(CMAS)corrosion are a serious threat to thermal barrier coatings(TBCs),in which Fe element is usually ***_(2)Zr_(2)O_(7)TBCs are famous for their excellent CMAS *** this study,the characteristics of Fe-containing environmental sediments(CMAS-Fe)and their corrosiveness to Gd_(2)Zr_(2)O_(7)coatings were *** types of CMAS-Fe glass with different Fe contents were *** melting points were measured to be 1322–1344℃,and the high-temperature viscosity showed a decreasing trend with increasing Fe *** corrosion behavior of four types of CMAS-Fe to Gd_(2)Zr_(2)O_(7)coatings at 1350℃was *** the initial corrosion stage(0.1 h),anorthite was precipitated in CMAS-Fe with a high Ca:Si ratio,while Fe-garnet was formed in the melt with the highest Fe *** the corrosion time resulted in the formation of a reaction layer,which exhibited an interpenetrating network composed of Gd-oxyapatite,ZrO_(2),and residual *** spinel was precipitated within the reaction *** 1 h or even longer time,the reaction layers tended to be stable and compact,which had comparable hardness and fracture toughness to those of Gd_(2)Zr_(2)O_(7)*** the cyclic CMAS-Fe attack,the residual CMAS-Fe in the interpenetrating network provided a pathway for the redeposited CMAS-Fe infiltration,resulting in the continuous growth of the reaction *** a result,the Gd_(2)Zr_(2)O_(7)coatings had a large consumption in the thickness,degrading the coating ***,the Gd_(2)Zr_(2)O_(7)coatings exhibit unsatisfactory corrosion resistance to CMAS-Fe attack.

关键词： thermal barrier coatings(TBCs) Gd_(2)Zr_(2)O_(7) Fe-containing CaO-MgO-Al2O3-SiO_(2)(CMAS) corrosion resistance reaction layer

Multi-field Coupled Inverse Hall–Petch Relations for Ferroelectric Nanocrystals

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Acta Mechanica Solida Sinica 2024年第1期37卷 139-147页

作者： Xiaodong Zhang Wei yan.xuhui Lou Yujun Chen Zhihong Zhou Qingyuan Wang Lianhua Ma Xiaobao Tian Non-Destructive Testing Laboratory School of Quality and Technical SupervisionHebei UniversityBaoding 071002China AVIC Huiyang Aviation Propeller Co. LtdBaoding 071051China Department of Mechanics and Engineering Sichuan UniversityChengdu 610065China Yibin Institute of Industrial Technology Sichuan University Yibin ParkYibin 644000China Research Institute of Interdisciplinary Sciences(RISE) Dongguan University of TechnologyDongguan 523808China School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China

Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction *** the grain size decreases to the nanoscale,the deformation mechanism in polycrystals shifts from being primarily mediated by dislocations to deformation occurring within the grains and grain ***,the mechanism responsible for fine-grain strengthening in ferroelectric materials remains unclear,primarily due to the complex multi-field coupling effect arising from spontaneous *** molecular dynamics simulations,we investigate the strengthening mechanism of barium titanate(BaTiO3),with extremely fine-grain *** material exhibits an inverse Hall–Petch relationship between grain size and strength,rooting in the inhomogeneous concentration of atomic strain and grain ***,we present a theoretical model to predict the transition from the inverse Hall–Petch stage to the Hall–Petch stage based on strength variations with size,which aligns well with the simulation *** has been found that the piezoelectric properties of the BaTiO3 are affected by polarization domain switching at various grain *** study enhances our understanding of the atomic-scale mechanisms that contribute to the performance evolution of fine-grain nano-ferroelectric *** also provides valuable insights into the design of extremely small-scale ferroelectric components.

关键词： Ferroelectrics Multi-field coupling Molecular dynamics Fine-grain reinforcement Inverse Hall-Petch effect

Mechanisms of tumor immunosuppressive microenvironment formation in esophageal cancer

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World Journal of Gastroenterology 2024年第16期30卷 2195-2208页

作者： Xiao-Jun Zhang yan Yu he-Ping Zhao lei Guo Kun Dai Jing Lv Department of Clinical Laboratory Honghui HospitalXi’an Jiaotong UniversityXi’an 710054Shaanxi ProvinceChina Department of Spinal Surgery Honghui HospitalXi’an Jiaotong UniversityXi’an 710054Shaanxi ProvinceChina Department of Clinical Laboratory Yanliang Railway Hospital of Xi’anXi’an 710089Shaanxi ProvinceChina

As a highly invasive malignancy,esophageal cancer(EC)is a global health issue,and was the eighth most prevalent cancer and the sixth leading cause of cancerrelated death worldwide in *** to its highly immunogenic nature,emerging immunotherapy approaches,such as immune checkpoint blockade,have demonstrated promising efficacy in treating EC;however,certain limitations and challenges still *** addition,tumors may exhibit primary or acquired resistance to immunotherapy in the tumor immune microenvironment(TIME);thus,understanding the TIME is urgent and crucial,especially given the importance of an immunosuppressive microenvironment in tumor *** aim of this review was to better elucidate the mechanisms of the suppressive TIME,including cell infiltration,immune cell subsets,cytokines and signaling pathways in the tumor microenvironment of EC patients,as well as the downregulated expression of major histocompatibility complex molecules in tumor cells,to obtain a better understanding of the differences in EC patient responses to immunotherapeutic strategies and accurately predict the efficacy of ***,personalized treatments could be developed to maximize the advantages of immunotherapy.

关键词： Esophageal cancer Esophageal squamous cell carcinoma Esophageal adenocarcinoma Tumor immune microenvironment Immunosuppression Immunotherapy

Self-powered stimuli responsive material for dual stimulation of heat and guest molecules

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Chinese Chemical Letters 2024年第2期35卷 590-593页

作者： Jintao Men Ke Xu Taiting Sha lei he yan Xu Jie Mu Tijian Yin Qiong Ye Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics and School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China

Stimuli-responsive smart materials exhibit reverse chemical/physical changes in response to external stimuli and research on stimuli-responsive smart materials with self-powered properties is still uncultivated ***,we report perovskite crystalline self-powered multiple stimuli-responsive materials triggered by chemical and thermal stimuli.[HMEP]PbI_(3)·(H_(2)O)(1;HMEP is a hydroxytris(1-methylethyl)phosphorus cation)crystallizes in a chiral space group P 21 at 293 K and has the piezoelectric reaction(d_(33)=10 pC/N and output voltage=1 V)of self-powered modes,this value is larger than the value of 3 pC/N for the classical piezoelectric material *** materials can generate energy due to mechanical deformation,and using thermal heating to lose water,[HMEP]PbI_(3)(2)can be obtained.2 crystallizes in the non-centrosymmetric space group,undergoes two reversible phase transitions at 243/255 K and 315/348 K,and shows second harmonic generation ***,2 can return to the hydrated form 1 after absorbing *** work will lay the foundation for self-powered stimuli-responsive compounds and contribute to the construction of novel organic-inorganic hybrid materials with second harmonic generation switching.

关键词： Self-powered Dual stimulation reactive Phase transition SHG switch Organic-inorganic hybrid perovskite

Effect of Low-temperature Imidization on Properties and Aggregation Structures of Polyimide Films with Different Rigidity

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Chinese Journal of Polymer Science 2024年第8期42卷 1134-1146页

作者： yan Jia lei Zhai Song Mo Yi Liu Li-Xin Liu Xin-Yu Du Min-Hui he Lin Fan Key Laboratory of Science and Technology on High-tech Polymer Materials Institute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

The traditional high-temperature preparation process of polyimide can cause many problems and limits the wider application in extreme *** important challenge to be solved urgently is the reduction of imidization *** this work,twelve kinds of polyimide films with different chain rigidity were prepared at low temperature of 200℃,in the absence or presence of imidazole used as the *** molecular rigidity and free volume were theoretically calculated,and relationship between structure and properties were systematically *** results show that imidization reaction under low temperatures is significantly affected by the rigidity of molecula r *** rigid structure of polyimide is not conducive to the low-temperature imidization,but this adverse effect can be eliminated by adding catalyst,resulting the notably increased imidization *** optical and thermal properties can be improved to a certain extent for the chemically catalyzed system,resulting in relatively higher heat resistance and thermal *** the mechanical performance could be determined by com plicating factors,greatly different from polyimide films prepa red by high temperature *** investigate aggregation structures of film s,the effect of chain rigidity and catalyst on the stacking or orientation of molecular chains was further *** wo rk can contribute to the understanding of chemically catalyzed imidization that is rarely reported in the existing research,and will provide guidance for the low-temperature preparation of high-performance polyimides.

关键词： Polyimide Imidization Catalyst Structure and properties Aggregation structures

Engineering the future cereal crops with big biological data:toward intelligence-driven breeding by design

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Journal of Genetics and Genomics 2024年第8期51卷 781-789页

作者： lei Liu Jimin Zhan Jianbing yan National Key Laboratory of Crop Genetic Improvement Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubei 430070China

How to feed 10 billion human populations is one of the challenges that need to be addressed in the following decades,especially under an unpredicted climate *** breeding,initiating from the phenotype-based selection by local farmers and developing into current biotechnology-based breeding,has played a critical role in securing the global food ***,regarding the changing environment and ever-increasing human population,can we breed outstanding crop varieties fast enough to achieve high productivity,good quality,and widespread adaptability?This review outlines the recent achievements in understanding cereal crop breeding,including the current knowledge about crop agronomic traits,newly developed techniques,crop big biological data research,and the possibility of integrating them for intelligence-driven breeding by design,which ushers in a new era of crop breeding practice and shapes the novel architecture of future *** review focuses on the major cereal crops,including rice,maize,and wheat,to explain how intelligence-driven breeding by design is becoming a reality.

关键词： Crop Big biological data Multi-omic Artificial intelligence Crop design breeding