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Imbalanced rock burst assessment using variational autoencoder-enhanced gradient boosting algorithms and explainability

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Underground Space 2024年第4期17卷 226-245页

作者： Shan Lin Zenglong liang Miao dong Hongwei Guo Hong zheng Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University(PolyU)Hung HomKowloon 999077Hong KongChina

We conducted a study to evaluate the potential and robustness of gradient boosting algorithms in rock burst assessment,established a variational autoencoder(VAE)to address the imbalance rock burst dataset,and proposed a multilevel explainable artificial intelligence(XAI)tailored for tree-based ensemble *** collected 537 data from real-world rock burst records and selected four critical features contributing to rock burst ***,we employed data visualization to gain insight into the data’s structure and performed correlation analysis to explore the data distribution and feature ***,we set up a VAE model to generate samples for the minority class due to the imbalanced class *** conjunction with the VAE,we compared and evaluated six state-of-theart ensemble models,including gradient boosting algorithms and the classical logistic regression model,for rock burst *** results indicated that gradient boosting algorithms outperformed the classical single models,and the VAE-classifier outperformed the original classifier,with the VAE-NGBoost model yielding the most favorable *** to other resampling methods combined with NGBoost for imbalanced datasets,such as synthetic minority oversampling technique(SMOTE),SMOTE-edited nearest neighbours(SMOTE-ENN),and SMOTE-tomek links(SMOTE-Tomek),the VAE-NGBoost model yielded the best ***,we developed a multilevel XAI model using feature sensitivity analysis,Tree Shapley Additive exPlanations(Tree SHAP),and Anchor to provide an in-depth exploration of the decision-making mechanics of VAE-NGBoost,further enhancing the accountability of treebased ensemble models in predicting rock burst occurrences.

关键词： Gradient boosting VAE Ensemble learning Explainable artificial intelligence(XAI) Rock burst

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Fe-based multi-phase nanocrystalline ribbons with hierarchically flowerlike structured metal oxides after modified by Orange II for Cr^VI absorption

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Journal of Iron and Steel Research International 2018年第6期25卷 608-613页

作者： Shuang-qin Chen liang-zheng dong Ke-zhen Hui Zhen Peng Zhun Li Zhi-Chao Lu Yang Shao Ke-fu Yao School of Materials Science and Engineering TsinghuaUniversity Beijing 100084 China School of Materials Science and Engineering JiangsuUniversity Zhenjiang 212013 Jiangsu China China Iron & Steel Research Institute Group Beijing 100081China

Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange II solution）. It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures （Fe-MNRs ＋ FNs） exhibit good absorption property for a typical heavy metal ion （Cr^VI） in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs ＋ FNs could remove 99% CrvI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between Cr^VI and surface hydroxyl groups （O-H） of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs ＋ FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.

关键词： Fe-based multi-phase nanocrystalline ribbon Flowerlike nanostructure α-FeO(OH) Hexavalent chromium Wastewater treatment

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A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics

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Petroleum Science 2024年第1期21卷 327-342页

作者： Qian Zhang Wen-dong Wang Yu-liang Su Wei Chen zheng-dong Lei Lei Li Yong-Mao Hao Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Oil Development Branch Changqing Oilfield CompanyPetroChinaQingyang745708GansuChina PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China

A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation.

关键词： Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory

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Analysis and experimental study on resistance-increasing behavior of composite high efficiency autonomous inflow control device

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Petroleum Science 2024年第2期21卷 1290-1304页

作者： liang-liang dong Yu-Lin Zhang School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500SichuanChina State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina Oil and Gas Equipment Technology Sharing and Service Platform of Sichuan ProvinceChengdu610500SichuanChina

Bottom water coning is the main reason to reduce the recovery of horizontal bottom water reservoir. By water coning, we mean the oil-water interface changes from a horizontal state to a mound-shaped cone and breaks through to the wellbore. Autonomous inflow control device(AICD) is an important instrument maintain normal production after bottom water coning, however, the resistance increasing ability of the swirl type AICD is insufficient at present, which seriously affects the water control effect. Aiming this problem, this paper designs a multi-stage resistance-increasing and composite type AICD. The separation mechanism of oil-water two phases in this structure, the resistance form of oil-water single phase and the resistance-increasing principle of water phase are analyzed. Establishing the dual-phase multi-stage separation and resistance-increasing model, and verified by measuring the throttling pressure drop and oil-water volume fraction of the AICD, it is found that the composite type AICD has the effect of ICD and AICD at the same time, which can balance the production rate of each well section at the initial stage of production, delay the occurrence of bottom water coning. In the middle and later stages of production, water-blocking can be effectively increased to achieve water control and stable *** structural sensitivity analysis, the influence law of various structural parameters on the water control performance of composite AICD was obtained. The simulation calculation results show that,compared with the existing swirl type AICD, composite AICD has higher sensitivity to moisture content,the water phase throttling pressure drop is increased by 4.5 times on average. The composite AICD is suitable for the entire stage of horizontal well production.

关键词： Water control Flow separation Flow resistance-increasing AICD device Simulation and experiment

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The Emergence of Functional Ultrasound for Noninvasive Brain-Computer Interface

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Research 2024年第2期6卷 301-317页

作者： Hairong zheng Lili Niu Weibao Qiu dong liang Xiaojing Long Guanglin Li Zhiyuan Liu Long Meng Institute of Biomedical and Health Engineering Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen518055China Shenzhen Institute of Advanced Integration Technology Chinese Academy of Sciences and The Chinese University of Hong KongShenzhen518055China

A noninvasive brain-computer interface is a central task in the comprehensive analysis and understanding of the brain and is an important challenge in international brain-science *** implanted brain-computer interfaces are cranial and invasive,which considerably limits their *** development of new noninvasive reading and writing technologies will advance substantial innovations and breakthroughs in the field of brain-computer ***,we review the theory and development of the ultrasound brain functional imaging and its ***,we introduce latest advancements in ultrasound brain modulation and its applications in rodents,primates,and human;its mechanism and closed-loop ultrasound neuromodulation based on electroencephalograph are also ***,high-frequency acoustic noninvasive brain-computer interface is prospected based on ultrasound super-resolution imaging and acoustic tweezers.

关键词： breakthrough computer Computer

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Towards net zero carbon buildings:Accounting the building embodied carbon and life cycle-based policy design for Greater Bay Area,China

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Geoscience Frontiers 2024年第3期15卷 284-297页

作者： Hanwei liang Xin Bian liang dong Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Research Center of Urban Sustainable Development/School of Geographical Sciences Nanjing University of Information Science&Technology(NUIST)Nanjing 210044China Department of Architecture and Civil Engineering Chalmers University of TechnologySE-41296 GothenburgSweden Shenzhen Research Institute(SRI) City University of Hong KongShenzhenChina Department of Public and International Affairs(PIA) City University of Hong Kong999077Hong Kong Special Administrative Region School of Energy and Environment(SEE) City University of Hong Kong999077Hong Kong Special Administrative RegionChina Centre for Public Affairs and Law City University of Hong Kong999077Hong Kong Special Administrative RegionChina

Carbon mitigation of buildings is critical to promote a net-zero *** international society has vigorously promoted‘‘Net Zero Carbon Buildings”across the globe,and accounting for building carbon emissions is critical to support this *** carbon,which represents carbon emissions from the entire lifecycle of the buildings,is fundamental for realizing the idea of zero ***,only limited studies have been conducted so far that take into account the city *** paper aimed to act as a first try to account for the embodied carbon emissions in buildings in 2020 for the Guangdong-Hong Kong Macao Greater Bay Area in China(GBA).We integrated remote sensing techniques such as night-time light data(NLT)and building material flows analysis to calculate and spatialize the newly generated building material stocks(MS).Based on the MS data,we further applied life cycle assessment(LCA)to assess the embodied carbon in the *** results highlighted that over 163 million tons of embodied carbon in buildings of GBA are expected to be generated,from 497 million tons of newly generated building MS in *** embodied carbon in each life cycle stage is valuable for further lifecyclebased policy designs for:(i)supporting the updating of the green building certification system with consideration of the embodied carbon;(ii)promoting the green building material application and certification;and(iii)reducing the embodied carbon intensity from compact urban planning policy,such as the urban agglomeration policies in *** goal of this paper was to shed a light on reducing carbon emissions from the perspective of the entire lifecycle and promote the development of net zero carbon buildings in China and Asia-Pacific.

关键词： Net zero carbon building Embodied carbon Life cycle assessment Life cycle-based policies Greater Bay area

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Bottom-up construction of low-dimensional perovskite thick films for high-performance X-ray detection and imaging

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Light(Science & Applications) 2024年第9期13卷 1809-1819页

作者： Siyin dong zhenghui Fan Wei Wei Shujie Tie Ruihan Yuan Bin Zhou Ning Yang Xiaojia zheng liang Shen Sichuan Research Center of New Materials Institute of Chemical MaterialsChina Academy of Engineering PhysicsShuangliuChengduChina State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringInternational Center of Future ScienceJilin UniversityChangchunChina

Quasi-two-dimensional(Q-2D)perovskite exhibits exceptional photoelectric properties and demonstrates reduced ion migration compared to 3D perovskite,making it a promising material for the fabrication of highly sensitive and stable X-ray ***,achieving high-quality perovskite films with sufficient thickness for efficient X-ray absorption remains ***,we present a novel approach to regulate the growth of Q-2D perovskite crystals in a mixed atmosphere comprising methylamine(CH3NH2,MA)and ammonia(NH3),resulting in the successful fabrication of high-quality films with a thickness of hundreds of ***,we build a heterojunction X-ray detector by incorporating the perovskite layer with titanium dioxide(TiO2).The precise regulation of perovskite crystal growth and the meticulous design of the device structure synergistically enhance the resistivity and carrier transport properties of the X-ray detector,resulting in an ultrahigh sensitivity(29721.4μC Gyair−1 cm−2)for low-dimensional perovskite X-ray detectors and a low detection limit of 20.9 nGyair s−*** have further demonstrated a flat panel X-ray imager(FPXI)showing a high spatial resolution of 3.6 lpmm−1 and outstanding X-ray imaging capability under low X-ray *** work presents an effective methodology for achieving high-performance Q-2D perovskite FPXIs that holds great promise for various applications in imaging technology.

关键词： perovskite dimensional performance

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Different mechanisms underlie similar species-area relationships in two tropical archipelagoes

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Plant Diversity 2024年第2期46卷 238-246页

作者： Shengchun Li Tieyao Tu Shaopeng Li Xian Yang Yong zheng liang-dong Guo Dianxiang Zhang Lin Jiang Key Laboratory of Plant Resources Conservation and Sustainable Utilization South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China ECNU-Alberta Joint Lab for Biodiversity Study Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China School of Biological Sciences Georgia Institute of TechnologyAtlantaGA 30332USA Jiangxi Academy of Forestry Nanchang 330032China Institute of Eco-Chongming(IEC) Shanghai 202162China State Key Laboratory of Biocontrol School of EcologySun Yat-sen UniversityGuangzhou 510275China School of Geographical Sciences Fujian Normal UniversityFuzhou 350007China State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Despite much research in the field of island biogeography,mechanisms regulating insular diversity remain ***,we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelagoes in the South China *** found positive plant species-area relationships for both coral and continental ***,our results showed that different mechanisms contributed to similar plant species-area relationships between the two *** coral islands,soil nutrients and spatial distance among communities played major roles in shaping plant community structure and species *** contrast,the direct effect of island area,and to a lesser extent,soil nutrients determined plant species richness on continental ***,increasing soil nutrients availability(N,P,K)had opposite effects on plant diversity between the two *** summary,the habitat quality effect and dispersal limitation are important for regulating plant diversity on coral islands,whereas the passive sampling effect,and to a lesser extent,the habitat quality effect are important for regulating plant diversity on continental *** generally,our findings indicate that island plant species-area relationships are outcomes of the interplay of both niche and neutral processes,but the driving mechanisms behind these relationships depends on the type of islands.

关键词： Coral and continental islands Plant diversity Soil nutrients Species-area relationships The sampling effect

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A Degree Condition for Graphs Having All(a,b)-parity Factors

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 656-664页

作者： Hao-dong LIU Hong-liang LU School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'an 710049China

Let a and b be positive integers such that a≤b and a≡b(mod 2).We say that G has all(a,b)-parity factors if G has an h-factor for every function h:V(G)→{a,a+2,…,b-2,b} with b|V(G)| even and h(v)≡b(mod 2) for all v∈V(G).In this paper,we prove that every graph G with n≥2(b+1)(a+b) vertices has all(a,b)-parity factors if δ(G)≥(b^(2)-b)/a,and for any two nonadjacent vertices u,v ∈V(G),max{d_(G)(u),d_(G)(v)}≥bn/a+***,we show that this result is best possible in some sense.

关键词： degree condition all(a,b)-factors

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Three-dimensional finite element simulation and reconstruction of jointed rock models using CT scanning and photogrammetry

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1348-1361页

作者： Yingxian Lang zhengzhao liang Zhuo dong State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian116024China School of Energy Science and Engineering Henan Polytechnic UniversityJiaozuo454003China

The geometry of joints has a significant influence on the mechanical properties of *** simplify the curved joint shapes in rocks,the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical *** this study,the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample,*** describe the joint geometry,the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock *** comparison tests,the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing *** results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of *** presence of joints reduces the uniaxial compressive strength (UCS),elastic modulus,and released acoustic emission (AE) energy of rocks by 37%–67%,21%–24%,and 52%–90%,*** to the simplified joint sample,the proposed photogrammetry-based numerical model makes the most of the limited geometry information of *** UCS,accumulative released AE energy,and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based *** UCS value of the simplified joint sample (i.e.38.5 MPa) is much lower than that of the CT-based sample (i.e.72.3 MPa).Additionally,the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based *** scanning provides a reliable means to visualize the joints in rocks,which can be used to verify the reliability of photogrammetry *** application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.

关键词： X-ray computerized tomography(CT)scanning Photogrammetry Parallel computing Numerical simulation Uniaxial compression test Digital image processing

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