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Influences of shale microstructure on mechanical properties and bedding fractures distribution

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Petroleum Science 2024年第3期21卷 1944-1954页

作者： Ming-Zhe Gu Mao Sheng Shi-Zhong Cheng Fan-Hao gong Gen-Sheng Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing2249China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Shenyang Center of China Geological Survey ShenyangLiaoning110034China

The difference in microstructure leads to the diversity of shale mechanical properties and bedding fractures distribution *** this paper,the microstructure and mechanical properties of Longmaxi marine shale and Qingshankou continental shale were studied by X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)with mineral analysis system,and ***,the typical bedding layers area was properly stratified using Focused Ion Beam(FIB),and the effects of microstructure and mechanical properties on the distribution patterns of bedding fractures were *** results show that the Longmaxi marine shale sample contains more clay mineral grains,while the Qingshankou continental shale sample contains more hard brittle mineral grains such as *** Longmaxi marine shale sample,hard brittle minerals with grain sizes larger than 20μm is1..24%and those with grain sizes smaller than 20μm is 1..22%.For Qingshankou continental shale sample,hard brittle minerals with grain sizes larger than 20μm is 40.7%and those with grain sizes smaller than 20μm is 1..82%.In comparison to the Qingshankou continental shale sample,the Longmaxi marine shale sample has a lower modulus,hardness,and *** shales are formed by alternating coarse-grained and fine-grained layers during *** average single-layer thickness of Longmaxi marine shale sample is greater than Qingshankou continental shale *** two types of shale have similar bedding fractures distribution patterns and fractures tend to occur in the transition zone from coarse-grained to fine-grained *** orientation of the fracture is usually parallel to the bedding plane and detour occurs in the presence of hard brittle *** fracture distribution density of the Longmaxi marine shale sample is lower than that of the Qingshankou continental shale sample due to the strong heterogeneity of the Qingshankou continental *** current resea

关键词： Shale Nanoindentation Microstructure Mechanical property Fracture

Enhanced wear prediction of tunnel boring machine disc cutters for accurate remaining useful life estimation using a hybrid model

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 642-662页

作者： Xinghai ZHOU Yakun ZHANG Guofang gong Huayong YANG Qiaosong CHEN Yuxi CHEN Zhixue SU The State Key Laboratory of Fluid Power&Mechatronic Systems Zhejiang UniversityHangzhou 310027China Guangzhou Rail Transit Construction Engineering Consulting Co. Ltd.Guangzhou 510000China China Railway Engineering Equipment Group Co. Ltd.Zhengzhou 450016China

In tunnel construction with tunnel boring machines(TBMs),accurate prediction of the remaining useful life(RUL)of disc cutters is critical for timely maintenance and replacement to avoid delays and cost *** paper introduces a novel hybrid model,integrating fundamental and data-driven approaches,to enhance wear prediction of TBM disc cutters and enable accurate RUL *** fundamental model is improved by incorporating composite wear mechanisms and load estimation techniques,showcasing superior prediction accuracy compared to single-mechanism ***,the hybrid model innovatively incorporates a data-driven supplementary residual term into the improved fundamental model,leading to a high-performance wear prediction *** actual field data from a highway tunnel project in Shenzhen,the performance of the hybrid model is rigorously tested and compared with pure fundamental and data-driven *** hybrid model outperforms the other models,achieving the highest accuracy in predicting TBM disc cutter wear(mean absolute error(MAE)=0.53,root mean square error(RMSE)=0.64).Furthermore,this study thoroughly analyzes the hybrid model’s generalization capability,revealing significant impacts of geological conditions on prediction *** model’s generalization capability is also improved by expanding and updating the data *** RUL estimation results provided by the hybrid model are straightforward and effective,making it a valuable tool by which construction staff can monitor TBM disc cutters.

关键词： tunnel boring machine disc cutter wear prediction remaining useful life field data hybrid model

Geometric and defects engineering collaboration for enhanced cascade enzymatic nanoreactors

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Nano Research 2024年第4期17卷 2451-2461页

作者： Zhichao Yu Ruijin Zeng Hexiang gong Yuan Gao Shuyun Chen Yunsen Wang Dianping Tang Key Laboratory for Analytical Science of Food Safety and Biology(MOE&Fujian Province) Department of ChemistryFuzhou UniversityFuzhou 350108China

Highly evolved multi-enzyme cascade catalytic reactions in organisms facilitate rapid transfer of substrates and efficient conversion of intermediates in the catalytic unit,thus rationalizing their efficient *** this study,pore-ordered mesoporous single-atom(Fe)nitrogen-doped carbon nanoreactors(Mp-Fe-CN)were designed,in which a reasonable pore size was designed as a natural enzyme trap coupled to a simulated enzyme center.A polarity-mediated strategy was developed to obtain atomically dispersed nanoporous substrates,with the finding that polarity-guided engineering of the nitrogen-ligand environment and vacancy cluster defects clearly affects nanoporous activity,accompanied by appreciable mesoporous pore size *** active center and distal N atom coordination of Fe-N_(4) affect the catalytic process of the nanozyme exposed by density functional theory(DFT),determining the contribution of hybridized orbitals to electron transfer and the decisive step.A cascade nanoreactor-based domain-limited sarcosine oxidase developed for non-invasive monitoring of sarcosine levels in urine for evaluation of potential prostate carcinogenesis as a proof of *** on the design of surface mesoporous channels of nanocatalytic units,a bridge was built for the interaction between nanozymes and natural enzymes to achieve cascade nanocatalysis of natural enzymatic products.

关键词： nanozyme single-atom catalyst bioreactor cascade catalysis non-Invasive sensing

Regulating Oxygen Vacancy Defects in Heterogeneous NiO-CeO_(2)−δ Hollow Multi-shelled Structure for Boosting Oxygen Evolution Reaction

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Chemical Research in Chinese Universities 2024年第3期40卷 475-483页

作者： WANG Huan gong Guannan SUN Guohua QI Jian YU Ranbo WANG Dan Hebei Key Laboratory of Flexible Functionals Materials School of Materials Science and EngineeringHebei University of Science and TechnologyShijiazhuang 050000P.R.China Department of Physical Chemistry School of Metallurgical and Ecological EngineeringUniversity of Science&Technology BejingBeijing 100083P.R.China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190P.R.China

CeO_(2) with excellent oxygen storage-exchange capacity and NiO with excellent surface activity were used to construct a heterogeneous NiO-CeO_(2)−δhollow multi-shelled structure(HoMS)by spray *** turned out that as the proportion of CeO_(2) increases,the overpotential and Tafel slope of NiO-CeO_(2)−δHoMSs first decreased and then *** is mainly because the construction of the NiO-CeO_(2)−δHoMSs not only increases the specific surface area,but also introduces oxygen vacancy defects,thus improving the interface charge transfer capability of the materials and further improving the oxygen evolution reaction(OER)***,the increase of the calcination temperature will induce the decay of the OER performance of NiO-CeO_(2)−δHoMSs,which is mainly due to the decrease of the specific surface area,the reduction of oxygen vacancy defects,and the weakening of interface charge transfer ***,a series of heterogeneous composite HoMSs,such as Ni/Co,Mo/Ni,Al/Ni and Fe/Ni oxides was successfully constructed by spray drying,which enriched the diversity of HoMSs.

关键词： Heterogeneous composite structure Hollow multishelled structure Oxygen vacancy defect Oxygen evolution reaction

Relative orbit determination algorithm of space targets with passive observation

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Journal of Systems Engineering and Electronics 2024年第3期35卷 793-804页

作者： DAI Chenchao QIANG Hongfu ZHANG Degang HU Shaolei gong Baichun Zhijian Laboratory Rocket Force University of EngineeringXi’an 710025China College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Flight Test Research Institute Xi’an 710089China Beijing Institute of Control and Electronic Technology Beijing 100038China

Angles-only relative orbit determination for space non-cooperative targets based on passive sensor is subject to weakly observable problem of the relative state between two spacecraft. Previously, the evidence for angles-only observability was found by using cylindrical dynamics, however, the solution of orbit determination is still not provided. This study develops a relative orbit determination algorithm with the cylindrical dynamics based on differential evolution. Firstly, the relative motion dynamics and line-of-sight measurement model for nearcircular orbit are established in cylindrical coordinate ***, the observability is qualitatively analyzed by using the dynamics and measurement model where the unobservable geometry is found. Then, the angles-only relative orbit determination problem is modeled into an optimal searching frame and an improved differential evolution algorithm is introduced to solve the problem. Finally, the proposed algorithm is verified and tested by a set of numerical simulations in the context of highEarth and low-Earth cases. The results show that initial relative orbit determination(IROD) solution with an appropriate accuracy in a relative short span is achieved, which can be used to initialize the navigation filter.

关键词： angles-only measurement relative orbit determination cylindrical coordinate differential evolution

Classification and rating of disintegrated dolomite strata for slope stability analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2552-2562页

作者： Wenlian Liu Xinyue gong Jiaxing Dong Hanhua Xu Peixuan Dai Shengwei Zhang Kunming Prospecting Design Institute of China Nonferrous Metals Industry Co. Ltd.Kunming650051China Key Laboratory of Geotechnical Engineering and Geological Disasters of Yunnan Province Kunming650051China Faculty of Electric Power Engineering Kunming University of Science and TechnologyKunming650500China

Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gaining increasing *** is primarily due to their unique properties,including low strength and loose *** methods for evaluating slope stability,such as basic quality(BQ)and slope stability probability classification(SSPC),do not adequately account for the poor integrity and structural fragmentation characteristic of disintegrated *** address this challenge,an analysis of the applicability of the limit equilibrium method(LEM),BQ,and SSPC methods was conducted on eight disintegrated dolomite slopes located in Baoshan,Southwest ***,conflicting results were ***,this paper introduces a novel method,SMRDDS,to provide rapid and accurate assessment of disintegrated dolomite slope *** method incorporates parameters such as disintegrated grade,joint state,groundwater conditions,and excavation *** findings reveal that six slopes exhibit stability,while two are considered partially ***,the proposed method demonstrates a closer match with the actual conditions and is more time-efficient compared with the BQ and SSPC ***,due to the limited research on disintegrated dolomite slopes,the results of the SMRDDS method tend to be conservative as a safety *** conclusion,the SMRDDS method can quickly evaluate the current situation of disintegrated dolomite slopes in the *** contributes significantly to disaster risk reduction for disintegrated dolomite slopes.

关键词： Disintegrated dolomite slope Basic quality(BQ) Slope stability probability classification (SSPC) Rock mass quality classification Limit equilibrium method(LEM)

Early peripheral perfusion index predicts 28-day outcome in patients with septic shock

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World Journal of Emergency Medicine 2024年第5期15卷 372-378页

作者： Cheng Chi Hao gong Kai Yang Peng Peng Xiaoxia Zhang Department of Emergency Peking University People's HospitalBeijing 100044China Department of Emergency Intensive Care Unit the First Affi liated Hospital of Xinjiang Medical UniversityUrumqi 830000China

BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic ***:This prospective cohort study,conducted at the emergency intensive care unit of Peking University People's Hospital,recruited 200 patients with septic shock between January 2023 and August *** patients were divided into survival(n=84)and death(n=1.6)groups based on 28-day *** evaluations included laboratory tests and clinical scores,with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 1. h after *** factors associated with mortality were analyzed using univariate and multivariate Cox regression *** operator characteristic(ROC)curve was used to assess predictive *** rates were compared,and Kaplan-Meier survival plots were ***:Compared to the survival group,patients in the death group were older and had more severe liver damage and coagulation dysfunction,necessitating higher norepinephrine doses and increased fl uid *** lactate levels and lower PPI levels at 0 h,6 h,and 1. h were observed in the death *** Cox regression identifi ed prolonged prothrombin time(PT),decreased 6-h PPI and 1.-h PPI as independent risk factors for *** area under the curves for 6-h PPI and 1.-h PPI were 0.802(95%CI 0.742-0.863,P1.and 0.945(95%CI 0.91.-0.974,P1.,respectively,which were superior to Glasgow Coma Scale(GCS),Sequential Organ Failure Assessment(SOFA)scores(0.864 and 0.928).Cumulative mortality in the low PPI groups at 6 h and 1. h was signifi cantly higher than in the high PPI groups(6-h PPI:77.52%vs.22.54%;1.-h PPI:92.04%vs.1..79%,P1..CONCLUSION:PPI may have value in predicting 28-day mortality in patients with septic shock.

关键词： Peripheral perfusion index Septic shock Prognosis Predictive value

Noise-Tolerant ZNN-Based Data-Driven Iterative Learning Control for Discrete Nonaffine Nonlinear MIMO Repetitive Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 344-361页

作者： Yunfeng Hu Chong Zhang Bo Wang Jing Zhao Xun gong Jinwu Gao Hong Chen State Key Laboratory of Automotive Simulation and Control Jilin UniversityJilin UniversityChangchun 130025China College of Communication Engineering Jilin UniversityJilin UniversityChangchun 130025China Department of Electromechanical Engineering University of MacaoMacao 999078China School of Artificial Intelligence Jilin UniversityChangchun 130012China IEEE College of Electronics and Information Engineering Tongji UniversityShanghai 200092China

Aiming at the tracking problem of a class of discrete nonaffine nonlinear multi-input multi-output(MIMO) repetitive systems subjected to separable and nonseparable disturbances, a novel data-driven iterative learning control(ILC) scheme based on the zeroing neural networks(ZNNs) is proposed. First, the equivalent dynamic linearization data model is obtained by means of dynamic linearization technology, which exists theoretically in the iteration domain. Then, the iterative extended state observer(IESO) is developed to estimate the disturbance and the coupling between systems, and the decoupled dynamic linearization model is obtained for the purpose of controller synthesis. To solve the zero-seeking tracking problem with inherent tolerance of noise,an ILC based on noise-tolerant modified ZNN is proposed. The strict assumptions imposed on the initialization conditions of each iteration in the existing ILC methods can be absolutely removed with our method. In addition, theoretical analysis indicates that the modified ZNN can converge to the exact solution of the zero-seeking tracking problem. Finally, a generalized example and an application-oriented example are presented to verify the effectiveness and superiority of the proposed process.

关键词： Adaptive control control system synthesis data-driven iterative learning control neurocontroller nonlinear discrete time systems

Interface Engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature

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Nano-Micro Letters 2024年第9期16卷 147-160页

作者： Cuiping Li Dan Li Shuai Zhang Long Ma Lei Zhang Jingwei Zhang Chunhong gong College of Chemistry and Molecular Sciences Henan UniversityKaifeng 475004People’s Republic of China National and Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004People’s Republic of China

Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction ***,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top ***,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening *** from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated ***,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.1. dB at 423 *** study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.

关键词： TiN nanotubes Interface engineering Polarization loss Impedance matching Electromagnetic wave absorption performance