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Coupling analysis method of grouting construction with deformation response of adjacent existing tunnel

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Underground Space 2024年第2期15卷 312-330页

作者： Ping-wei jiang Zhi-hong zhang hong Zheng jin-kun Huang Key Laboratory of Urban Security and Disaster Engineering of China Ministry of Education Beijing University of TechnologyBeijing 100124China China MCC17 Group Co.LTD MaanshanAnhui 243000China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In the new tunnel under close distance through the existing tunnel risk source,the grouting scheme developed to compensate for stratum losses is still based on empirical methods,relying on the overburden thickness of existing *** can potentially lead to an excessively high or low probability of uplift of existing *** a coupled deformation analysis method between the grouting construction and adjacent existing tunnels is of great theoretical significance for developing grouting *** order to reasonably limit the design parameters of grouting construction,based on the theory of fluid–solid coupling elastic pore-column expansion and the theory of random media,the calculation method of stratum displacement which simultaneously considers the coexistence of grout compaction expansion and permeability diffusion mode is derived,and the accuracy of the calculation method is verified by engineering *** accuracy of this calculation method was verified through engineering *** with the deformation coordination condition,the existing tunnel is regarded as an elastic Euler-Bernoulli continuous beam,and the finite element coupling balance equation of the interaction between the existing tunnel and the surrounding soil is *** on this,a coupling calculation model of the grouting construction and the deformation response of the adjacent existing tunnel is *** with three times of grouting construction examples in the shield tunneling project of Beijing Metro Line 12 under the existing airport line,the reliability of the coupling calculation model to determine the grouting construction parameters is *** calculation parameters in the coupling calculation model have clear physical meanings,which can provide a theoretical basis for the grouting design of similar risk source projects.

关键词： Grouting Close-range underpass Tunnel Random medium theory Euler-Bernoulli continuous beam

Efficient wide-bandgap perovskite solar cells with open-circuit voltage deficit below 0.4 V via hole-selective interface engineering

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Science China Chemistry 2024年第6期67卷 2102-2110页

作者： Xiaoyu ji Shuo zhang Furong Yu Huidong zhang Liqing Zhan Yue Hu wei-hong zhu Yongzhen Wu Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Shanghai Key Laboratory of Functional Materials ChemistryFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai200237China School of Chemistry University of EdinburghKing’s BuildingsEdinburghEH93FJUK

Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low ***,the open-circuit voltage(V_(OC))of WBG-PSCs is still unsatisfactory as the V_(OC)-deficit is generally larger than 0.45 ***,we report a buried interface engineering strategy that substantially improves the V_(OC)of WBG-PSCs by inserting amphiphilic molecular hole-selective materials featuring with a cyanovinyl phosphonic acid(CPA)anchoring group between the perovskite and *** assembly and redistribution of CPA-based amphiphilic molecules at the perovskite-substrate buried interface not only promotes the growth of a low-defect crystalline perovskite thin film,but also suppresses the photo-induced halide phase *** energy level alignment between wide-bandgap perovskite and the hole-selective layer is further improved by modulating the substituents on the triphenylamine donor moiety(methoxyls for MPA-CPA,methyls for Me PA-CPA,and bare TPA-CPA).Using a 1.68 e V bandgap perovskite,the Me PA-CPA-based devices achieved an unprecedentedly high V_(OC)of 1.29 V and PCE of 22.3%under standard AM 1.5 *** V_(OC)-deficit(<0.40 V)is the lowest value reported for *** work not only provides an effective approach to decreasing the V_(OC)-deficit of WBG-PSCs,but also confirms the importance of energy level alignment at the charge-selective layers in PSCs.

关键词： cyanovinyl phosphonic acid energy level alignment hole-selective material open-circuit voltage wide-bandgap perovskite

Design of dual-functional protic porous ionic liquids for boosting selective extractive desulfurization

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Petroleum Science 2024年第4期21卷 2817-2829页

作者： jin-Rui zhang jie Yin jing He hong-Shun Ran wei jiang hong-Ping Li Wen-Shuai zhu Hua-Ming Li Ming zhang School of the Environment and Safety Engineering & Institute for Energy Research Jiangsu University School of Chemistry and Chemical Engineering Jiangsu University

Porous ionic liquids have demonstrated excellent performance in the field of separation, attributed to their high specific surface area and efficient mass transfer. Herein, task-specific protic porous ionic liquids(PPILs) were prepared by employing a novel one-step coupling neutralization reaction strategy for extractive desulfurization. The single-extraction efficiency of PPILs reached 75.0% for ***, adding aromatic hydrocarbon interferents resulted in a slight decrease in the extraction efficiency of PPILs(from 45.2% to 37.3%, 37.9%, and 33.5%), indicating the excellent extraction selectivity of PPILs. The experimental measurements and density functional theory calculations reveal that the surface channels of porous structures can selectively capture dibenzothiophene by the stronger electrophilicity(Eint(HS surface channel/DBT)=-39.8 kcal mol-1), and the multiple extraction sites of ion pairs can effectively enrich and transport dibenzothiophene from the oil phase into PPILs through π...π, C-H...π and hydrogen bonds interactions. Furthermore, this straightforward synthetic strategy can be employed in preparing porous liquids, offering new possibilities for synthesizing PPILs with tailored functionalities.

关键词： Protic porous ionic liquids Extractive desulfurization Selectivity Density functional theory

Correlation between the neuroendocrine axis,microbial species,inflammatory response,and gastrointestinal symptoms in irritable bowel syndrome

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World Journal of Gastroenterology 2024年第35期30卷 3985-3995页

作者： Xin zhang wei-wei jin hong-Gang Wang Department of Gastroenterology Tongde Hospital of Zhejiang ProvinceTaizhou 524333Zhejiang ProvinceChina Department of Nutrition Tongde Hospital of Zhejiang ProvinceTaizhou 524333Zhejiang ProvinceChina Department of Gastroenterology Taizhou Municipal HospitalTaizhou 524333Zhejiang ProvinceChina

BACKGROUND This study examines the complex relationships among the neuroendocrine axis,gut microbiome,inflammatory responses,and gastrointestinal symptoms in patients with irritable bowel syndrome(IBS).The findings provide new insights into the pathophysiology of IBS and suggest potential therapeutic targets for improving patient *** To investigate the interactions between the neuroendocrine axis,gut microbiome,inflammation,and gastrointestinal symptoms in patients with *** Patients diagnosed with IBS between January 2022 and January 2023 were selected for the *** individuals undergoing routine check-ups during the same period served as the control *** were collected on neuroendocrine hormone levels,gut microbiome profiles,inflammatory biomarkers,and gastrointestinal symptomatology to analyze their interrelations and their potential roles in IBS *** IBS patients exhibited significant dysregulation of the neuroendocrine axis,with altered levels of cortisol,serotonin,and neuropeptides compared to healthy *** gut microbiome of IBS patients showed reduced diversity and specific alterations in bacterial genera,including Bifidobacterium,Lactobacillus,and Faecalibacterium,which were associated with neuroendocrine ***,elevated levels of inflammatory markers,such as C-reactive protein,interleukin-6,and tumor necrosis factor-α,were observed and correlated with the severity of gastrointestinal symptoms like abdominal pain,bloating,and altered bowel *** The findings suggest that targeting the neuroendocrine axis,gut microbiome,and inflammatory pathways may offer novel therapeutic strategies to alleviate symptoms and improve the quality of life in IBS patients.

关键词： Gastrointestinal symptoms Inflammatory response Intestinal microbiota Irritable bowel syndrome Neuroendocrine axis Relationship study

Implications for fault reactivation and seismicity induced by hydraulic fracturing

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Petroleum Science 2024年第2期21卷 1081-1098页

作者： Zi-Han Sun Ming-Guang Che Li-hong zhu Shu-Juan zhang ji-Yuan Lu Chang-Yu jin Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina Research Institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China The Exploration and Development Research Institute of Daqing Oilfield Limited Company Daqing163458HeilongjiangChina

Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as

关键词： Hydraulic fracturing Coulomb failure stress Rate-and-state fraction model Linear stability analysis Critical stiffness Seismically induced fault

Gas–solid reactor optimization based on EMMS-DPM simulation and machine learning

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Particuology 2024年第6期89卷 131-143页

作者： Haolei zhang Aiqi zhu ji Xu wei Ge State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Design,scaling-up,and optimization of industrial reactors mainly depend on step-by-step experiments and engineering experience,which is usually time-consuming,high cost,and high *** numerical simulation can reproduce high resolution details of hydrodynamics,thermal transfer,and reaction process in reactors,it is still challenging for industrial reactors due to huge computational *** this study,by combining the numerical simulation and artificial intelligence(AI)technology of machine learning(ML),a method is proposed to efficiently predict and optimize the performance of industrial reactors.A gas–solid fluidization reactor for the methanol to olefins process is taken as an example.1500 cases under different conditions are simulated by the coarse-grain discrete particle method based on the Energy-Minimization Multi-Scale model,and thus,the reactor performance data set is *** develop an efficient reactor performance prediction model influenced by multiple factors,the ML method is established including the ensemble learning strategy and automatic hyperparameter optimization technique,which has better performance than the methods based on the artificial neural ***,the operating conditions for highest yield of ethylene and propylene or lowest pressure drop are searched with the particle swarm optimization algorithm due to its strength to solve non-linear optimization *** show that decreasing the methanol inflow rate and increasing the catalyst inventory can maximize the yield,while decreasing methanol the inflow rate and reducing the catalyst inventory can minimize the pressure *** two objectives are thus conflicting,and the practical operations need to be compromised under different circumstance.

关键词： Discrete particle method Artificial intelligence Machine learning Particle swarm optimization Industrial reactor optimization

Taiji-TianQin-LISA network:Precisely measuring the Hubble constant using both bright and dark sirens

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 59-77页

作者： Shang-jie jin Ye-zhu zhang ji-Yu Song jing-Fei zhang Xin zhang Key Laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole binaries(MBHBs).In this work,we investigate the potential of GW standard sirens from the Taiji-TianQin-LISA network in constraining cosmological *** the optimistic scenario in which electromagnetic(EM)counterparts can be detected,we predict the number of detectable bright sirens based on three different MBHB population models,i.e.,popⅢ,Q3d,and *** results show that the TaijiTianQin-LISA network alone could achieve a constraint precision of 0.9%for the Hubble constant,meeting the standard of precision ***,the Taiji-TianQin-LISA network could effectively break the cosmological parameter degeneracies generated by the CMB data,particularly in the dynamical dark energy *** combined with the CMB data,the joint CMB+Taiji-TianQin-LISA data offerσ(w)=0.036 in the wCDM model,which is close to the latest constraint result obtained from the CMB+SN *** also consider a conservative scenario in which EM counterparts are not *** to the precise sky localizations of MBHBs by the Taiji-TianQin-LISA network,the constraint precision of the Hubble constant is expected to reach 1.2%.In conclusion,the GW standard sirens from the Taiji-TianQin-LISA network will play a critical role in helping solve the Hubble tension and shedding light on the nature of dark energy.

关键词： space-based gravitational wave detection standard sirens the Taiji-TianQin-LISA network the Hubble constant dark energy

Video caching and scheduling with edge cooperation

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Digital Communications and Networks 2024年第2期10卷 450-460页

作者： Zhidu Li Fuxiang Li Tong Tang hong zhang jin Yang School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Advanced Network and Intelligent Connection Technology Key Laboratory of Chongqing Education Commission of China Chongqing400065China Key Laboratory of Ubiquitous Sensing and Networking in Chongqing Chongqing400065China

In this paper,we explore a distributed collaborative caching and computing model to support the distribution of adaptive bit rate video *** aim is to reduce the average initial buffer delay and improve the quality of user *** the difference between global and local video popularities and the time-varying characteristics of video popularity,a two-stage caching scheme is proposed to push popular videos closer to users and minimize the average initial buffer *** on both long-term content popularity and short-term content popularity,the proposed caching solution is decouple into the proactive cache stage and the cache update *** the proactive cache stage,we develop a proactive cache placement algorithm that can be executed in an off-peak *** the cache update stage,we propose a reactive cache update algorithm to update the existing cache policy to minimize the buffer *** results verify that the proposed caching algorithms can reduce the initial buffer delay efficiently.

关键词： Video service Distributed and collaborative caching Long-term popularity Short-term popularity

Lift-Off Effect of Koch and Circular Differential Pickup Eddy Current Probes

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 283-293页

作者： Guolong Chen Zheng Cao Shuaishuai zhang ji wei wei Gao Wuyin jin School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050China

A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during the inspection of ***,the extent of the lift-off effect on differential probes,including different coil structures,*** this study,two planar eddy current probes with differential pickup structures and the same size,Koch and circular probes,were used to compare lift-off *** eddy current distributions of the probes perturbed by 0°and 90°cracks were obtained by finite element *** analysis results show that the 90°crack can impede the eddy current induced by the Koch probe even further at relatively low lift-off *** peak-to-peak values of the signal output from the two probes were compared at different lift-off distances using finite element analysis and experimental *** addition,the effects of different frequencies on the lift-off were studied *** results show that the signal peak-to-peak value of the Koch probe for the inspection of cracks in 90°orientation is larger than that of the circular probe when the lift-off distance is smaller than 1.2 *** addition,the influence of the lift-off distance on the peak-to-peak signal value of the two probes was studied via *** indicates that the influence becomes more evident with an increase in excitation *** research discloses the lift-off effect of differential planar eddy current probes with different coil shapes and proves the detection merit of the Koch probe for 90°cracks at low lift-off distances.

关键词： Eddy current testing Differential pickup probe Fractal Koch curve Flexible eddy current probe