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Shield Excavation Analysis: Ground Settlement & Mechanical Responses in Complex Strata

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Structural Durability & Health Monitoring 2024年第3期18卷 341-360页

作者： Baojun qin Guangwei zhang Wei zhang CCCC Rail Transit Branch Beijing101300China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

This study delves into the effects of shield tunneling in complex coastal strata, focusing on how this constructionmethod impacts surface settlement, the mechanical properties of adjacent rock, and the deformation of tunnelsegments. It investigates the impact of shield construction on surface settlement, mechanical characteristics ofnearby rock, and segment deformation in complex coastal strata susceptible to construction disturbances. Utilizingthe Fuzhou Binhai express line as a case study, we developed a comprehensive numerical model using theABAQUS finite element software. The model incorporates factors such as face force, grouting pressure, jack force,and cutterhead torque. Its accuracy is validated against field monitoring data from engineering projects. Simulationswere conducted to analyze ground settlement and mechanical changes in adjacent rock and segments acrossfive soil layers. The results indicate that disturbances are most significant near the excavation zone of the shieldmachine, with a prominent settlement trough forming and stabilizing around 2.0–3.0 D from the excavation. Theexcavation face compresses the soil, inducing lateral expansion. As grouting pressure decreases, the segmentexperiences upward buoyancy. In mixed strata, softer layers witness increased cutting, intensifying disturbancesbut reducing segment floatation. These findings offer valuable insights for predicting settlements, ensuring segmentand rock safety, and optimizing tunneling parameters.

关键词： Shield construction complex strata finite element method mechanical properties of surrounding rock segment deformation settlement prediction

Intensified warming suppressed the snowmelt in the Tibetan Plateau

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Advances in Climate Change Research 2024年第3期15卷 452-463页

作者： Xiang LI Peng CUI Xue-qin zhang Fang zhang Key Lab of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China China‒Pakistan Joint Research Center on Earth Sciences Chinese Academy of Sciences and Higher Education CommissionIslamabad 45320Pakistan

Understanding how hydrological factors interrelate is crucial when examining the impact of climate warming on ***,these connections are often overlooked,leading to an unclear relationship between temperature and *** study investigates the complex interplay between temperature and snowmelt in the Tibetan Plateau from 1961 to 2020,focusing on how extreme high-temperature events affect the frequency of extreme *** a structural equation model,we detected three temperature-related factors that predominantly influenced snowmelt and extreme *** annual average temperature was found to have a significant indirect impact on snowmelt,mediated by changes in snowfall,snow depth and snow *** contrast,high-temperature days(daily maximum temperatures exceeding the 90th percentile)and heat waves(at least three consecutive high-temperature days)negatively affected extreme snowmelt directly or *** direct effect of increasing extreme temperature events was associated with an earlier onset of high-temperature periods,which accelerated snowmelt and shortened the duration of extreme snowmelt ***,the reduction in snow cover owing to warming emerged as a main factor suppressing snowmelt and extreme snowmelt *** also revealed spatiotemporal variations in the temperature‒snowmelt relationship that highly depended on changes in snowmelt *** study elucidated why warming suppresses snowmelt and extreme snowmelt events in the Tibetan Plateau,highlighting the mediating roles of snow-related and phenological *** findings will provide scientific support for climate simulation and water management policymaking in alpine regions worldwide.

关键词： Climate change Extreme temperature Snowmelt Structural equation model Tibetan Plateau

High-resolution spatiotemporal mapping:a comprehensive view of eukaryotic cell cycle proteome dynamics

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Signal Transduction and Targeted Therapy 2024年第6期9卷 2354-2356页

作者： Jing Zou Ziran qin Long zhang Life Sciences Institute Second Affiliated Hospital of the Zhejiang University School of MedicineThe MOE Key Laboratory of Biosystems Homeostasis&Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell BiologyZhejiang UniversityHangzhouZhejiangChina The MOE Basic Research and Innovation Center for the Targeted Therapeutics of Solid Tumors The First Affiliated HospitalJiangxi Medical CollegeNanchang UniversityNanchangChina Cancer Center Zhejiang UniversityHangzhouZhejiangChina

In a recent study published in Cell,Litsios et *** a highresolution spatiotemporal map of the eukaryotic cell cycle proteome.1 They identified proteome-level changes in both abundance and spatial distribution throughout the cell cycle and provided a valuable resource for future exploration into the global proteome dynamics that drive cell cycle progression(https://***/cellcycle).

关键词： al. cycle dynamics

Theoretical model of azimuthal combustion instability subject to non-trivial boundary conditions

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 113-130页

作者： qin, Lei Wang, Xiaoyu zhang, Guangyu Sun, Xiaofeng Beihang Univ Res Inst Aeroengine Beijing 100191 Peoples R China Beihang Univ Sch Energy & Power Engn Beijing 100191 Peoples R China

The problem of evaluating the sensitivity of non-trivial boundary conditions to the onset of azimuthal combustion instability is a longstanding challenge in the development process of modern gas turbines. The difficulty lies in how to describe three-dimensional in- and outlet boundary conditions in an artificial computational domain. To date, the existing analytical models have still failed to quantitatively explain why the features of the azimuthal combustion instability of a combustor in laboratory environment are quite different from that in a real gas turbine, making the stability control devices developed in laboratory generally lose the effectiveness in practical applications. To overcome this limitation, we provide a novel theoretical framework to directly include the effect of non-trivial boundary conditions on the azimuthal combustion instability. A key step is to take the non-trivial boundary conditions as equivalent distributed sources so as to uniformly describe the physical characteristics of the inner surface in an annular enclosure along with different in- and outlet configurations. Meanwhile, a dispersion relation equation is established by the application of three-dimensional Green's function approach and generalized impedance concept. Results show that the effects of the generalized modal reflection coefficients on azimuthal unstable modes are extremely prominent, and even prompt the transition from stable to unstable mode, thus reasonably explaining why the thermoacoustic instability phenomena in a real gas turbine are difficult to observe in an isolated combustion chamber. Overall, this work provides an effective tool for analysis of the azimuthal combustion instability including various complicated boundary conditions.

关键词： Combustion instability Aeroacoustics Modeling Optimization techniques Control SOUND-TRANSMISSION CALCULATIONS ACTUATOR DISK MODEL RADIATION IMPEDANCES ACOUSTIC RADIATION ACTIVE CONTROL BLADE ROW DUCT STABILITY PROPAGATION TURBOMACHINERY

Synergically regulated silver species and surface oxygen on manganese oxide for promoted activity of formaldehyde oxidation

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Journal of Environmental Sciences 2024年第4期138卷 709-718页

作者： Shuo Hu Jianghao zhang Xueyan Chen Xiaoxiao qin Jinshui Yao Changbin zhang School of Materials Science&Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Formaldehyde(HCHO)is a common indoor pollutant that is detrimental to human *** efficient removal has become an urgent demand to reduce the public health *** this work,Ag-MnO_(x)-based catalysts were prepared and activated under different atmosphere(i.e.,air,hydrogen(H_(2))and carbon monoxide(CO))for efficient oxidation of *** catalyst activated with CO(Ag/Mn-CO)displayed the highest activity among the tested samples with 90% conversion at 100℃ under a gas space velocity of 75,000 mL/(g_(cat)·hr).Complementary characterizations demonstrate that CO reduction treatment resulted in synergically regulated content of surface oxygen on support to adsorb/activate HCHO and size of Ag particle to dissociate oxygen to oxidize the adsorbed *** contrast,other catalysts lack for either abundant surface oxygen species or metallic silver with the appropriate particle size,so that the integrate activity is limited by one specific reaction *** study contributes to elucidating the mechanisms regulating the oxidation activity of Ag-based catalysts.

关键词： HCHO oxidation Ag-MnO_(x)-based catalyst Activation condition Synergic regulation Surface oxygen Oxidized Ag

Fracture mechanism of inclusions in thick plate center under tensile loading

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Journal of Iron and Steel Research International 2024年第5期31卷 1196-1209页

作者： Lei Hu Li-qin zhang Feng Hu Guo-hong zhang Kuan Zheng Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan430081HubeiChina Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081HubeiChina Analysis and Testing Center Wuhan University of Science and TechnologyWuhan430081HubeiChina

Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and *** formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization *** results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation *** local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the *** existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack *** difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.

关键词： Thick plate Inclusion Finite element simulation Critical fracture stress Fracture mechanism

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宪政视野下中国村民自治权问题探析

河北学刊 2013年第3期33卷 130-133页

作者：张秀芹南阳师范学院法学院河南南阳473061

当前,作为宪法性权力的村民自治权如何运行对当代中国基层宪政建设具有十分重要的基础性意义。本文通过对村民自治权运行状况的宪政审视,分析影响中国村民自治权良性运行的基层权力关系,在宪政的框架内研究村民自治的宪法依据具体到村... 详细信息

当前,作为宪法性权力的村民自治权如何运行对当代中国基层宪政建设具有十分重要的基础性意义。本文通过对村民自治权运行状况的宪政审视,分析影响中国村民自治权良性运行的基层权力关系,在宪政的框架内研究村民自治的宪法依据具体到村民自治权的宪法实践,从而保障村民自治权的良性运行以及村民自治的真正实现。

关键词：宪政村民自治权完善

Surface iodine and pyrenyl-graphdiyne co-modified Bi catalysts for highly efficient CO_(2) electroreduction in acidic electrolyte

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Nano Research 2024年第4期17卷 2381-2387页

作者： Min zhang Juan Wang Xin Rong xiu-Li Lu Tong-Bu Lu MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China

CO_(2) electroreduction to formic acid/formate would contribute to alleviating the energy and climate *** work reports a Bi-based catalyst derived from the in-situ electroreduction of Bi_(2)O_(2)CO_(3) modified with iodine and pyrenyl-graphdiyne(PGDY)on the surface for efficient electroreduction of CO_(2) in acidic electrolyte,with a high partial current density of 98.71 mA·cm^(-2) and high Faradaic efficiency(FE)>90%over the potential range from^(-1).2 to-1.5 V *** hydrogen electrode(RHE),as well as the long-term operational stability over 240 h without degradation in H-type *** results and density function theory calculations show that the synergistic effect of surface iodine and PGDY is responsible for this active and extremely stable process of CO_(2) electroreduction via lowering the energy barriers for formation of*OCHO intermediate,suppressing the competitive HER by enhancing the concentration of both K+and CO_(2) at reaction interface,as well as preventing the dissolution and re-deposition of active Bi atoms on surface during catalytic *** work provides new insight into designing highly active and stable electrocatalysts for CO_(2) reduction.

关键词： CO_(2) reduction electrocatalysis Bi-based catalysts acidic electrolyte

Monocyte to High-density Lipoprotein Cholesterol Ratio as a Predictor of Nonalcoholic Fatty Liver Disease in Childhood Obesity

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当代医学科学（英文） 2024年第4期44卷 692-697页

作者： Jun-feng zhang Feng-qing CAI xiu-cai zhang qing YE Department of Laboratory Medicine Children's HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthHangzhou 310052China

Objective:Inflammation is involved in the development and progression of nonalcoholic fatty liver disease(NAFLD).The monocyte to high-density lipoprotein cholesterol ratio(MHR)has emerged as a marker for various inflammation-related *** aim of the present study was to investigate the association between the MHR and NAFLD in a population with childhood ***:Based on hepatic ultrasound,a total of 504 children with obesity(357 with NAFLD and 147 without NAFLD)were included in the *** correlation between the MHR and NAFLD risk factors was assessed by Pearson's and Spearman's *** stepwise logistic regression analyses were conducted to explore the association between the MHR and the risk of ***:The MHR in patients with NAFLD was significantly greater than that in patients without NAFLD[0.52(0.44-0.67)versus 0.44(0.34-0.57),P＜0.001].Multivariate stepwise logistic regression analysis demonstrated that the MHR[odds ratio(OR):1.033,95％confidence interval(CI):1.015-1.051;P＜0.001]was an independent predictor of NAFLD in childhood obesity patients,as were age(OR:1.205,95％CI:1.059-1.371;P=0.005],waist circumference[OR:1.037,95％CI:1.008-1.067;P=0.012],and alanine transaminase[OR:1.067,95％CI:1.045-1.089;P＜0.001].Additionally,MHR quartiles showed a significant positive association with the incidence of NAFLD after adjusting for potential confounding ***:The present study showed that the MHR may serve as an available and useful indicator of NAFLD in individuals with childhood obesity.

关键词： marker monocyte-to-high-density lipoprotein ratio nonalcoholic fatty liver disease obesity