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Influence of cutterhead opening ratio on soil arching effect and face stability during tunnelling through non-uniform soils

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Underground Space 2024年第4期17卷 45-59页

作者： xue-Jian Chen Pei-Pei fang Qiu-Nan Chen Jun Hu Kai Yao Yong Liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Hubei Technology Innovation Center for Smart Hydropower Wuhan 430000China College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China School of Civil Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Civil and Architectural Engineering Hainan UniversityHaikou 570228China School of Qilu Transportation Shandong UniversityJinan 250002China

Tunnelling has increasingly become an essential tool in the exploration of underground space.A typical construction problem is the face instability during tunnelling,posing a great threat to associated *** face instability often occurs with the soil arching *** study investigates the combined effect of cutterhead opening ratio and soil non-uniformity on soil arching effect and face stability,via conducting random finite-element analysis coupled with Monte–Carlo *** results underscore that the face stability is strongly associated with the evolution of stress *** obtained stability factors in the uniform soils can serve as a reference for the design of support pressure in practical tunnelling *** addition,non-uniform soils exhibit a lower stability factor than uniform soils,which implies that the latter likely yields an underestimated probability of face *** tunnel face is found to have a probability of failure more than 50%if the spatial non-uniformity of soil is *** the end,a practical framework is established to determine factor of safety(FOS)corresponding to different levels of probability of face failure considering various opening ratios in non-uniform *** required FOS is 1.70 to limit the probability of face instability no more than 0.1%.Our findings can facilitate the prediction of probability of instability in the conventionally deterministic design of face pressure.

关键词： Tunnel Face stability Soil arching effect Cutterhead opening ratio Non-uniform soil Random field

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Magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres derived from FeNi-LDH precursor anchoring on rGO nanosheets for enhanced electromagnetic wave absorption

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Journal of Materials Science & Technology 2024年第4期171卷 101-114页

作者： Kunyao Cao Yuan fang Shuai Wang Yue Zhang Jiayue Wen Jun Chen Rui Zhao Weidong xue School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China

Graphene has been extensively utilized in the domain of electromagnetic wave(EMW)absorption ma-terials because of its excellent electrical ***,the inferior impedance matching per-formance and the single loss mechanism vastly restrict the ***,it’s an effective strat-egy to solve these issues by introducing magnetic ***,layer double hydroxide(LDH)is an appropriate template to obtain magnetic component *** that ferromagnetic met-als such as Fe,Co,Ni,and their corresponding metal oxides are usually treated as magnetic compo-nents which are promising candidates for EMW absorption ***,in this work,a FeNi-layered double hydroxide-reduced graphene oxide(FeNi-LDH-rGO)aerogel was synthesized through a series of processes such as electrostatic self-assembly,hydrothermal,freeze-drying,and *** magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres were obtained from FeNi-LDH precursor,anchoring on rGO nanosheets after the annealing ***,the effects of different mass ratios of LDH to GO as well as different annealing temperatures of LDH-rGO aerogel on the EMW absorption prop-erty and impedance matching performance were *** a consequence,the fabricated ultralight 600LDH-rGO 2:1 aerogel shows a broad effective absorption bandwidth(EAB)of 7.04 GHz at a thickness of 2.3 mm with a low filling content of only 6 wt%and a low density of 4.4 mg/cm^(3).In conclusion,the synthetic LDH-rGO aerogels offer an effective strategy for preparing EMW absorption materials that own three-dimensional porous network structure and unique magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell struc-ture nanospheres.

关键词： Electrostatic self-assembly Electromagnetic wave absorption LDH-rGO aerogel Layered double hydroxide Reduced graphene oxide NiFe_(2)O_(4)@FeNi_(3)core-shell structure

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A confined growth strategy to construct 3DOM SiO_(2) nanoreactor insitu embedded Co_(3)O_(4) nanoparticles catalyst for the catalytic combustion of VOCs:Superior H_(2)O and SO_(2) resistance

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Nano Research 2024年第1期17卷 207-220页

作者： Weigao Han Shilin Wu fang dong Weiliang Han Yinghao Chu Linghui Su Zhicheng Tang State Key Laboratory for Oxo Synthesis and Selective Oxidation National Engineering Research Center for Fine Petrochemical IntermediatesLanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Dalian 116023China College of Architecture and Environment Sichuan UniversityChengdu 610000China

SO_(2)poisoning is a common problem in the catalytic combustion of volatile organic compounds(VOCs).In this work,we took three-dimensionally ordered macroporous and mesoporous(3DOM)SiO_(2)as the nanoreactor to protect active sites from SO_(2)erosion in the catalytic combustion of ***,the confined growth of metal active nanoparticles in the multi-stage pore is also full of *** we successfully confined Co_(3)O_(4)nanoparticles(NPs)in macroporous and mesoporous ***,the precursors’growth in the pore was controlled and nanoreactors with different pore sizes were prepared by adjusting the loading amount and preparation *** is discovered that the Co_(3)O_(4)NPs confined in 3DOM SiO_(2)nanoreactor showed superior sulfur and water *** functional theory(DFT)calculations verified that the Co-Si catalyst had high SO_(2)adsorption energy(-0.48 eV),which illustrated that SO_(2)was hard to attach to the surface of the Co-Si *** SiO_(2)nanoreactor had low SO_(2)adsorption energy(-5.15 eV),which indicated that SO_(2)was easily absorbed on SiO_(2)*** illustrated that the SiO_(2)nanoreactor could protect effectively active sites from SO_(2)erosion.

关键词： zeolitic imidazolate frameworks(ZIFs) Co_(3)O_(4) benzene catalytic combustion nanoreactor sulfur and water resistance

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Research on the identification of the production origin of Angelica dahurica using LIBS technology combined with machine learning algorithms

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Optoelectronics Letters 2024年第3期20卷 171-176页

作者： SUN Jiaxing LI Honglian YAO Yuhang YAN Qiongyan dong fang College of Quality and Technology Supervising Hebei UniversityBaoding 071000China National and Local Joint Engineering Center of Measuring Instruments and Metrology Systems Baoding 071000China Key Laboratory of Energy Measurement and Safety Detection Technology in Hebei Province Baoding 071000China

The origin of Angelica dahurica medicinal herbs varies, and their pharmacological effects also differ. In order to achieve rapid and accurate identification of the origin of Angelica dahurica medicinal herbs, this study utilizes laser induced breakdown spectroscopy(LIBS) technology combined with machine learning algorithms to identify the original source of Angelica dahurica. Sliced samples of Angelica dahurica were taken from four regions: Hebei, Henan, Zhejiang, and Sichuan. The spectral data from the sliced samples were used as features, and different algorithms including support vector machine(SVM), back propagation(BP) neural network, genetic algorithm-back propagation(GA-BP) neural network, particle swarm optimization-back propagation(PSO-BP) neural network, convolutional neural network(CNN), and CNN-SVM were employed to classify the origin of Angelica dahurica samples.

关键词： neural origin network

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A Methodology for Assessing Axial Compressor Stability with Inlet Temperature Ramp Distortion

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Journal of Thermal Science 2024年第3期33卷 856-871页

作者： SUN Dakun GU Benhao NING fangfei fang Yibo dong Xu XU Dengke SUN Xiaofeng School of Energy and Power Engineering Beihang UniversityBeijing102206China Research Institute of Aero-engine Beihang UniversityBeijing102206China

Based on a small perturbation stability model for periodic flow,the effects of inlet total temperature ramp distortion on the axial compressor are investigated and the compressor stability is quantitatively *** the beginning,a small perturbation stability model for the periodic flow in compressors is proposed,referring to the governing equations of the Harmonic Balance *** stability model is validated on a single-stage low-speed compressor TA36 with uniform inlet ***,the unsteady flow of TA36 with different inlet total temperature ramps and constant back pressure is simulated based on the Harmonic Balance *** on these simulations,the compressor stability is analyzed using the proposed small perturbation ***,the Dynamic Mode Decomposition method is employed to accurately extract pressure *** two parameters of the temperature ramp,ramp rate and Strouhal number,are discussed in this *** results indicate the occurrence and extension of hysteresis loops in the rows,and a decrease in compressor stability with increasing ramp *** performance is divided into two phases,stable and limit,based on the ramp ***,the model predictions suggest that a decrease in period length and an increase in Strouhal number lead to improved compressor *** DMD results imply that for compressors with inlet temperature ramp distortion,the increase of high-order modes and oscillations at the rotor tip is always the signal of decreasing stability.

关键词： axial compressor stability small perturbation model inlet temperature ramp distortion harmonic balance method dynamic mode decomposition method

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Simulating the evolution of focused waves by a two-layer Boussinesq-type model

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Acta Oceanologica Sinica 2024年第5期43卷 91-99页

作者： Ping Wang Zhongbo Liu Kezhao fang Wenfeng Zou Xiangke dong Jiawen Sun State Environmental Protection Key Laboratory of Marine Ecosystem Restoration National Marine Environmental Monitoring CenterDalian 116023China College of Transportation Engineering Dalian Maritime UniversityDalian 116026China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

Accurate simulation of the evolution of freak waves by the wave phase focusing method requires accurate linear and nonlinear properties,especially in deep-water *** this paper,we analyze the ability to simulate deep-water focused waves of a two-layer Boussinesq-type(BT)model,which has been shown to have excellent linear and nonlinear *** further improve the numerical accuracy and stability,the internal wavegenerated method is introduced into the two-layer Boussinesq-type ***,the sensitivity of the numerical results to the grid resolution is analyzed to verify the convergence of the model;secondly,the focused wave propagating in two opposite directions is simulated to prove the symmetry of the numerical results and the feasibility of the internal wave-generated method;thirdly,the limiting focused wave condition is simulated to compare and analyze the wave surface and the horizontal velocity of the profile at the focusing position,which is in good agreement with the measured *** the simulation of focused waves in very deep waters agrees well with the measured values,which further demonstrates the capability of the two-layer BT model in simulating focused waves in deep waters.

关键词： focused waves numerical simulation Boussinesq-type model velocity profile

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The reservoir characteristics and their controlling factors of the sublacustrine fan in the Paleogene dongying Formation, Bohai Sea,China

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Journal of Palaeogeography 2024年第1期13卷 127-148页

作者： Xiao-Jun Pang Guan-Min Wang Meng Zhao Qing-Bin Wang xue-fang Zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Tianjin Branch of China National Offshore Oil Corporation Limited Tianjin 300459China

Sublacustrine fan is an important element in continental lacustrine basins and is significant for reservoir exploration. Oil and gas resources have been found in the sublacustrine fan sandstone reservoirs of the Paleogene dongying Formation in the Bohai Sea. In this study, the characteristics of the sublacustrine fan reservoirs and the controlling factors are studied using information from logging, cores, physical properties,casting thin sections, X-ray diffraction of clay minerals, vitrinite reflectance, rock pyrolysis, manometry data,and 3D seismic data. The sublacustrine fans of the dongying Formation in the LD10, QHD34, and BZ21 structures show high-quality reservoirs with porosity >15 % and permeability >5 m D. The main controlling factors of the high-quality reservoirs are attributed to the favorable sedimentary facies type and negligible compaction,and cementation, substantial dissolution of K-feldspar, overpressure, and the development of faults and fractures. A high-quality sublacustrine fan reservoir model has been established to explain how these factors affected the physical properties. The favorable targets for oil and gas exploration in the dongying Formation of Bohai Sea include undercompacted sandy debris flow reservoirs showing the dissolution of K-feldspar, and the reservoirs which are connected to the source rocks by faults. This study provides insights to establish the relationship between sedimentology, diagenesis and reservoir quality. The results of this study are significant for the exploration and development of the sublacustrine fan sandstone reservoirs in the Bohai Sea and analogous sandstone reservoirs elsewhere.

关键词： Sublacustrine fan High-quality reservoir Dissolution Overpressure Fault Bohai Sea

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The Regulatory Role and Mechanism of Circadian Rhythm in Hemoglobin Co-cultured Neurovascular Unit

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Biomedical and Environmental Sciences 2024年第7期37卷 726-738页

作者： fang xue Wenchao Chen Xia Lian Guanghui He Jingyuan Tian Yinghong Liu Gaiqing Wang Department of Neurology The Second Clinical School of MedicineShanxi Medical UniversityTaiyuan 030002ShanxiChina The Second Clinical School of Medicine Shanxi Medical UniversityTaiyuan 030002ShanxiChina Department of Clinical lab The First People’s Hospital of ZhaotongZhaotong 657000YunnanChina Department of Neurology Sanya Central Hospital(Hainan Third People’s Hospital)Hainan Medical UniversitySanya 57200HainanChina

Objective Intracranial hemorrhage(ICH),the second most common subtype of stroke,exacerbates the disruption of the blood-brain barrier(BBB),leading to vasogenic edema,plasma protein extravasation,and infiltration of neurotoxic *** clearance capacity of the brain plays a crucial role in maintaining BBB homeostasis and facilitating patient recovery after *** study aimed to investigate the effect of circadian rhythms on BBB function,neuronal damage,and clearance *** The transwell model and hemoglobin were co-cultured to simulate the BBB environment after *** intervention with different light groups,neuronal apoptosis was determined,glial phagocytosis was analyzed,the expression of endogenous clearing-related proteins aquaporin 4(AQP4)and low-density lipoprotein receptor-related protein 1(LRP1)was detected by western blotting and immunofluorescence dual standard method,and the expression of the tight junction protein occludin and melatonin receptor 1A(MTNR1A)was quantitatively *** Circadian rhythms play a key role in maintaining the integrity of the BBB,reducing oxidative stress-induced neuronal damage,and improving microglial ***,the expression of occludin and MTNR1A in neurovascular unit(NVU)co-cultured with hemoglobin improved the expression of AQP4 and LRP1,the key proteins in the NVU's endogenous brain clearance *** Circadian rhythm(alternating black and white light)protects the NVU BBB function after ICH,promotes the expression of proteins related to the clearance of the hematoma,provides new evidence for the clinical treatment of patients recovering from ICH,and improves the circadian rhythm to promote brain metabolism and hematoma clearance.

关键词： Blood-brain barrier Circadian rhythm Neurovascular unit Melatonin receptor 1A Aquaporin-4

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Progressive meristem and single-cell transcriptomes reveal the regulatory mechanisms underlying maize inflorescence development and sex differentiation

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Molecular Plant 2024年第7期17卷 1019-1037页

作者： Yonghao Sun Liang dong Lu Kang Wanshun Zhong David Jackson fang Yang National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhan 430070China Hubei Hongshan Laboratory Wuhan 430070China Cold Spring Harbor Laboratory Cold Spring HarborNY 11724USA School of Agriculture Sun Yat-Sen UniversityShenzhen 518107China

Maize develops separate ear and tassel inflorescences with initially similar morphology but ultimately different architecture and *** detailed regulatory mechanisms underlying these changes still remain largely *** this study,through analyzing the time-course meristem transcriptomes and floret single-cell transcriptomes of ear and tassel,we revealed the regulatory dynamics and pathways underlying inflorescence development and sex *** identified 16 diverse gene clusters with differential spatiotemporal expression patterns and revealed biased regulation of redox,programmed cell death,and hormone signals during meristem differentiation between ear and ***,based on their dynamic expression patterns,we revealed the roles of two RNA-binding proteins in regulating inflorescence meristem activity and axillary meristem ***,using the transcriptional profiles of 53910 single cells,we uncovered the cellular heterogeneity between ear and tassel *** found that multiple signals associatedwith either enhancedcell death or reduced growth are responsiblefortassel pistil suppression,while part of the gibberellic acid signal may act non-cell-autonomously to regulate ear stamen arrest during sex *** further showed that the pistil-protection gene SILKLESS 1(SK1)functions antagonistically to the known pistil-suppression genes through regulating common molecular pathways,and constructed a regulatory network for pistil-fate ***,our study provides a deep understanding of the regulatory mechanisms underlying inflorescence development and sex differentiation in maize,laying the foundation for identifying new regulators and pathways for maize hybrid breeding and improvement.

关键词： maize inflorescence floral organ sex differentiation single-cell RNA sequencing RNA-binding protein

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Analysis of the influencing factors and clinical related characteristics of pulmonary tuberculosis in patients with type 2 diabetes mellitus

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World Journal of Diabetes 2024年第2期15卷 196-208页

作者： Han Shi Yuan Yuan xue Li Yan-fang Li Ling Fan xue-Mei Yang Department of Infectious Diseases The First Affiliated Hospital of Chengdu Medical CollegeChengdu 610500Sichuan ProvinceChina

BACKGROUND In China,the prevalence of type 2 diabetes mellitus(T2DM)among diabetic patients is estimated to be between 90%-95%.Additionally,China is among the 22 countries burdened by a high number of tuberculosis cases,with approximately 4.5 million individuals affected by active ***,T2DM poses a significant risk factor for the development of tuberculosis,as evidenced by the increased incidence of T2DM coexisting with pulmonary tuberculosis(T2DMPTB),which has risen from 19.3%to 24.1%.It is evident that these two diseases are intricately interconnected and mutually reinforcing in *** To elucidate the clinical features of individuals diagnosed with both T2DM and tuberculosis(T2DM-PTB),as well as to investigate the potential risk factors associated with active tuberculosis in patients with *** T2DM-PTB patients who visited our hospital between January 2020 and January 2023 were selected as the observation group,Simple DM patients presenting to our hospital in the same period were the control group,Controls and case groups were matched 1:2 according to the principle of the same sex,age difference(±3)years and disease duration difference(±5)years,patients were investigated for general demographic characteristics,diabetes-related characteristics,body immune status,lifestyle and behavioral habits,univariate and multivariate analysis of the data using conditional logistic regression,calculate the odds ratio(OR)values and 95%CI of OR *** A total of 315 study subjects were included in this study,including 105 subjects in the observation group and 210 subjects in the control *** of the results of both anthropometric and biochemical measures showed that the constitution index,systolic blood pressure,diastolic blood pressure and lymphocyte count were significantly lower in the case group,while fasting blood glucose and high-density lipoprotein cholesterol levels were significantly higher than those in the control ***

关键词： Type 2 diabetes Pulmonary tuberculosis Blood sugar Infection Risk factors

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