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Influence of confined water on the limit support pressure of tunnel face in weakly water-rich strata

Journal of Central South University 2024年第8期31卷 2844-2859页

作者： Li, Yun-fa Wu, Guo-jun Chen, Wei-zhong yuan, jing-qiang Huo, Meng-zhe State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan China University of Chinese Academy of Sciences Beijing China

In the process of shield tunneling through soft soil layers, the presence of confined water ahead poses a significant threat to the stability of the tunnel face. Therefore, it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face. This study employed the finite element method (FEM) to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer. Subsequently, a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure, incorporating various influencing factors. The analysis yields the following conclusions: 1) The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable; 2) The limit support pressure increases approximately linearly with the pressure head, shield tunnel diameter, and tunnel burial depth. And inversely proportional to the thickness of the impermeable layer, soil cohesion and internal friction angle; 3) Through an engineering case study analysis, the results align well with those obtained from traditional theoretical methods, thereby validating the rationality of the equations proposed in this paper. Furthermore, the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness. It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling, thus better reflecting engineering reality.

关键词： weakly water-rich strata confined aquifer limit support pressure finite element method multiple linear regression

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注浆长度与套管类型对扩大头锚索性能的影响

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科学技术与工程 2024年第2期24卷 740-747页

作者：刘凯孙伟青李文辉耿林王响龙袁敬强青岛地质工程勘察院(青岛地质勘查开发局) 青岛266000 青岛地矿岩土工程有限公司青岛266000 中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室武汉430071

扩大头锚索因具有抗拔承载力大、支护效率高等优点在岩土工程中应用广泛,而注浆段落的长度和自由段保护套管的类型将对锚索受力变形特性产生影响。为此,依托实际工程开展了锚固段注浆+PE波纹管(设计方案)、全长注浆+聚乙烯(polyethylene... 详细信息

扩大头锚索因具有抗拔承载力大、支护效率高等优点在岩土工程中应用广泛,而注浆段落的长度和自由段保护套管的类型将对锚索受力变形特性产生影响。为此,依托实际工程开展了锚固段注浆+PE波纹管(设计方案)、全长注浆+聚乙烯(polyethylene, PE)波纹管(实际施工常用方案)、锚固段注浆+高密度聚乙烯(high density polyethylen, HDPE)套管、全长注浆+HDPE套管等四种不同工况扩大头锚索的现场拉拔试验,对比分析了不同工况下锚索的拉拔荷载-位移(Q-s)曲线、荷载-弹性位移(Q-se)曲线与荷载-塑性位移(Q-sp)曲线、自由段伸长量比例、刚度系数等受力变形特征。试验结果表明,相同注浆长度条件下,采用HDPE套管相比PE波纹管能够更好地发挥对自由段的隔离保护作用,保证自由段的变形性能;而采用相同套管类型时,注浆长度的增加会导致自由段伸长量值的减小,并会增大锚索刚度系数。在试验研究的基础上,提出现场锚索施工采用锚固段注浆+HDPE套管或全长注浆+HDPE套管的建议方案,从而保证锚索受力变形性能均达到设计预期。

关键词：扩大头锚索现场试验受力变形特性注浆长度套管类型

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Formation mechanisms of water inrush and mud burst in a migmatite tunnel：a case study in China

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Journal of Mountain Science 2017年第1期14卷 188-195页

作者： WU Guo-jun CHEN Wei-zhong yuan jing-qiang YANG Dian-sen BIAN Han-bian State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China Research Center of Geotechnical & Structural Engineering Shandong University Jinan 250061 China LEM3 Universitd de Lorraine Ile du Saulcy Metz 57045 France

This paper presents a case study of water inrush and mud burst occurring in a migmatite tunnel to study its formation mechanisms. The geological investigation and mineralogical analysis showed that water inrush and mud burst in the migmatite was closely related to the component of the host rock. High content of soluble minerals,e.g.,calcite and dolomite,would make the migmatite rock prone to be fragmentized,isintegrated and eventually form different sorts of connected or semi-connected veins. The field exploration revealed most cavities in the magmatite tunnel were eroded by groundwater and formed large interconnected networks. The two faults and the dike in the magmatite tunnel became the preferred paths and provided great convenience for plenty of precipitation and mud slurry. Due to high water pressure and blast disturbance,the cavities can soon connect each other as well as all sorts of veins,forming a complex ground channel for water inrush and mud burst. To estimate the potential occurrenceof water inrush and mud burst,the water bursting coefficient was employed. The results showed the water bursting coefficient of the magmatite tunnel was much bigger than the threshold values and it can be used to explain the accident of water inrush and mud burst occurring in the magmatite tunnel.

关键词： Water inrush Mud burst Migmatite Formation mechanism Tunnel

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Evaluation of mountain slope stability considering the impact of geological interfaces using discrete fractures model

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Journal of Mountain Science 2019年第9期16卷 2184-2202页

作者： WANG Lu-yu CHEN Wei-zhong TAN Xu-yan TAN Xian-jun yuan jing-qiang LIU Qi State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China University of Chinese Academy of Science Beijing 100049 China Research Center of Geotechnical and Structural Engineering Shandong University Jinan 250100 China

The stability of rock slope is often controlled by the existing discontinuous surfaces, such as discrete fractures, which are ubiquitously distributing in a geological medium. In contrast with the traditional approaches used in soil slope with a continuous assumption, the simulation methods of jointed rock slope are different from that of in soil slope. This paper presents a study on jointed rock slope stability using the proposed discontinuous approach, which considers the effects of discrete fractures. Comparing with traditional methods to model fractures in an implicit way, the presented approach provides a method to simulate fractures in an explicit way, where grids between rock matrix and fractures are independent. To complete geometric components generation and mesh partition for the model, the corresponding algorithms were devised. To evaluate the stability state of rock slope quantitatively, the strength reduction method was integrated into our analysis framework. A benchmark example was used to verify the validation of the approach. A jointed rock slope, which contains natural fractures, was selected as a case study and was simulated regarding the workflow of our framework. It was set up in the light of the geological condition of the site. Slope stability was evaluated under different loading conditions with various fracture patterns. Numerical results show that fractures have significant contributions to slope stability, and different fracture patterns would lead to different shapes of the slip surface. The devised method has the ability to calculate a non-circular slip surface, which is different from a circular slip surface obtained by classical methods.

关键词： Rock slope stability Discrete fractures Discontinuous approach Equivalent model Slip surface

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Remote sensing image encryption algorithm utilizing 2D Logistic memristive hyperchaotic map and SHA-512

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Science China(Technological Sciences) 2024年第5期67卷 1553-1566页

作者： LAI qiang LIU yuan YANG Liang School of Electrical and Automation Engineering East China Jiaotong UniversityNanchang330013China

The two-dimensional Logistic memristive hyperchaotic map(2D-LMHM)and the secure hash SHA-512 are the foundations of the unique remote sensing image encryption algorithm(RS-IEA)suggested in this *** proposed map is formed from the improved Logistic map and the memristor,which has wide phase space and hyperchaotic range and is exceptionally excellent to be utilized in specific *** proposed image algorithm uses the permutation-assignment-diffusion *** generates two position matrices in a progressive manner to achieve an efficient random exchange of pixel positions,assignment is carried through on the image pixels of the permutated image to entirely remove the original image information,strengthening the relationship between permutation and diffusion,and loop diffusion in two different directions can use subtle changes of pixels to affect the whole *** random key and plain-image SHA-512 hash values are used to produce an additional key,which is then utilized to figure out the permutation parameters and the initial value of a chaotic *** experimental results with the average NPCR=99.6094%(NPCR:number of pixels change rate),average UACI=33.4638%(UACI:unified average changing intensity),100%pass rate of the targets in the test set,the average correlation coefficient is 0.00075,and the local information entropy is 7.9025,which shows that the algorithm is able to defend against a variety of illegal attacks and provide more trustworthy protection than some of the existing state-of-the-art algorithms.

关键词： chaos memristive hyperchaotic map remote sensing SHA-512 image encryption RS-IEA

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Gelfand-Kirillov Dimension and Reducibility of Scalar Generalized Verma Modules for Classical Lie Algebras

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Acta Mathematica Sinica,English Series 2024年第3期40卷 658-706页

作者： Zhan qiang BAI jing JIANG School of Mathematical Sciences Soochow UniversitySuzhou 215006P.R.China E-mail:zqbai@*** jjsd6514@***

Let g be a classical complex simple Lie algebra and q be a parabolic *** M be a generalized Verma module induced from a one dimensional representation of *** M is called a scalar generalized Verma *** this paper,we will determine the reducibility of scalar generalized Verma modules associated to maximal parabolic subalgebras by computing explicitly the Gelfand-Kirillov dimension of the corresponding highest weight modules.

关键词： Generalized Verma module Gelfand-Kirillov dimension Young tableau

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Malvidin Mitigates Sepsis-induced Cardiac Injury by Modulating the TLR4-iNOS-COX-2 Inflammatory Pathway and the Bax/Bcl-2/Cyto-C Mitochondrial Apoptosis Pathway in a p38 MAPK-dependent Manner

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Biomedical and Environmental Sciences 2024年第2期37卷 221-227页

作者： ZHANG Wei yuan Si Long qiang jing Chao HUANG He LI Da SUN Ying ZHANG Hong Gang Department of Vascular Surgery The First People’s Hospital of LianyungangLianyungang 222005JiangsuChina Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening College of PharmacyJiangsu Ocean UniversityLianyungang 222005JiangsuChina Jinzhou Medical University postgraduate training base(Lianyungang First People’s Hospital) Lianyungang 222005JiangsuChina

In critical care medicine,sepsis is a dangerous systemic condition that is highly prevalent and is associated with high morbidity and mortality rates^([1]).The high mortality rate associated with sepsis is closely related to multi-organ dysfunction,with heart injury being particularly critical and considered the starting point of multi-organ injury^([2]).

关键词： mortality Apoptosis TLR4

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Finite-Time Stabilization for Constrained Discrete-time Systems by Using Model Predictive Control

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1656-1666页

作者： Bing Zhu Xiaozhuoer yuan Li Dai Zhiwen qiang IEEE the Seventh Research Division Beihang UniversityBeijing 100191China the School of Automation Beijing Institute of TechnologyBeijing 100081China

In this paper, a model predictive control(MPC)framework is proposed for finite-time stabilization of linear and nonlinear discrete-time systems subject to state and control constraints. The proposed MPC framework guarantees the finite-time convergence property by assigning the control horizon equal to the dimension of the overall system, and only penalizing the terminal cost in the optimization, where the stage costs are not penalized explicitly. A terminal inequality constraint is added to guarantee the feasibility and stability of the closed-loop *** feasibility can be improved via augmentation. The finite-time convergence of the proposed MPC is proved theoretically,and is supported by simulation examples.

关键词： Constraints deadbeat control finite-time stabilization model predictive control(MPC)

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Application of non-mydriatic fundus photography-assisted telemedicine in diabetic retinopathy screening

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World Journal of Diabetes 2024年第2期15卷 251-259页

作者： Wan Zhou Xiao-jing yuan Jie Li Wei Wang Hao-qiang Zhang yuan-yuan Hu Shan-Dong Ye Department of Endocrinology The First Affiliated Hospital of University of Science and Technology of ChinaDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001Anhui ProvinceChina Department of Endocrinology Anhui Provincial HospitalAffiliated to Anhui Medical UniversityHefei 230001Anhui ProvinceChina

BACKGROUND Early screening and accurate staging of diabetic retinopathy(DR)can reduce blindness risk in type 2 diabetes ***’s complex pathogenesis involves many factors,making ophthalmologist screening alone insufficient for prevention and ***,endocrinologists are the first to see diabetic patients and thus should screen for retinopathy for early *** To explore the efficacy of non-mydriatic fundus photography(NMFP)-enhanced telemedicine in assessing DR and its various *** This retrospective study incorporated findings from an analysis of 93 diabetic patients,examining both NMFP-assisted telemedicine and fundus fluorescein angiography(FFA).It focused on assessing the concordance in DR detection between these two ***,receiver operating characteristic(ROC)curves were generated to determine the optimal sensitivity and specificity of NMFP-assisted telemedicine,using FFA outcomes as the standard *** In the context of DR diagnosis and staging,the kappa coefficients for NMFPassisted telemedicine and FFA were recorded at 0.775 and 0.689 respectively,indicating substantial intermethod ***,the NMFP-assisted telemedicine’s predictive accuracy for positive FFA outcomes,as denoted by the area under the ROC curve,was remarkably high at 0.955,within a confidence interval of 0.914 to 0.995 and a statistically significant P-value of less than *** predictive model exhibited a specificity of 100%,a sensitivity of 90.9%,and a Youden index of *** NMFP-assisted telemedicine represents a pragmatic,objective,and precise modality for fundus examination,particularly applicable in the context of endocrinology inpatient care and primary healthcare settings for diabetic *** implementation in these scenarios is of paramount significance,enhancing the clinical accuracy in the diagnosis and therapeutic management of *** methodology not only streamlines patient evaluation

关键词： Diabetes Diabetic retinopathy Non-mydriatic fundus photography-assisted telemedicine Fundus fluorescein angiography

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Severe liver injury and clinical characteristics of occupational exposure to 2-amino-5-chloro-N,3-dimethylbenzamide: A case series

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Hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 186-194页

作者： Meng-Xiao Feng Hua Zou yuan-qiang Lu Department of Emergency Medicine The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Key Laboratory for Diagnosis and Treatment of Aging and Physic-chemical Injury Diseases of Zhejiang Province Hangzhou 310003China Occupational Health and Radiation Protection Institute Zhejiang Provincial Center for Disease Control and PreventionHangzhou 310051China

Background:The 2-amino-5-chloro-N,3-dimethylbenzamide is a key intermediate in the synthesis of pesticides and ***,no literature currently exists on 2-amino-5-chloro-N,3-dimethylbenzamide poisoning in *** study aimed to reveal the health hazard of this chemical for humans and summarize the clinical characteristics of patients with occupational 2-amino-5-chloro-N,3-dimethylbenzamide ***:This observational study included four patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning from June 2022 to July *** entire course of the incidents was described in *** 2-amino-5-chloro-N,3-dimethylbenzamide concentrations were detected by a mass ***-toxylin and eosin staining was performed to assess liver injury,and immunofluorescence was used to evaluate hepatic ***:The 2-amino-5-chloro-N,3-dimethylbenzamide powder(99%purity)entered the human body mainly via the skin and respiratory tract due to poor personal protective *** typical course of 2-amino-5-chloro-N,3-dimethylbenzamide poisoning was divided into latency,rash,fever,organic dam-age,and recovery phases in accordance with the clinical *** and fever may be the important premonitory symptoms for further organ *** chemical was detected in the blood of all patients and caused multiple organ injuries,predominantly liver injury,including kidney,myocardium,and *** patients recovered smoothly after comprehensive treatments,including artificial liver therapy,continuous renal replacement therapy,glucocorticoids,and other symptomatic and supportive *** patient survived by liver *** postoperative pathological findings of the removed liver showed acute liver failure,and immunofluorescence staining confirmed the abundance of mitophagy in residual ***:This study is the first to elaborate the clinical characteristics of patients with 2-amino-5-chloro-N,

关键词： 2-amino-5-chloro-N,3-dimethylbenzamide Poisoning Clinical characteristics Liver injury

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