In this paper, we present a recently developed anisotropic 3-D inversion framework for interpreting controlled-source electromagnetic (CSEM) data in the frequency domain. The integrates high-order finite-element forward operator and Gauss–Newton algorithm. Conductivity constraints are applied using parameter transformation. We discretize continuous inverse problems on unstructured grids flexible treatment of arbitrarily complex geometries. Moreover, an mesh is more desirable comparison to...

The squeezing scenario in deep weak rock tunnels can hinder underground construction. However, due to the limitations of test technologies at hand, real excavation stress path cannot be mimicked laboratory. Thus, large deformation mechanism rocks still remains unclear. For this, a true triaxial apparatus (TTA) investigate mechanical responses under paths field and reveal is assembled developed Northeastern University, China. perform instantaneous unloading σ3 direction based on...

Abstract Many studies have highlighted the superior performance of iterative solvers employing auxiliary‐space Maxwell solver preconditioner in controlled‐source electromagnetic induction problems featuring isotropic conductivity. The importance considering presence electrical anisotropy data has been well recognized. However, anisotropic conductivity will impose difficulty robustly solving final system linear equations as may significantly increase its condition number and degrade...

The study of clastic rock failure evolution under true triaxial stress is an important research topic; however, it rarely studied systematically due to the limitation monitoring technology. In this study, compression tests were conducted on specimens investigate effect cementation and intermediate principal (σ2) mechanism. complete stress–strain curves obtained, while acoustic emission (AE) was monitored indirectly evaluate tensile shear cracks, crack imaged in real time by a high-speed...

ABSTRACT We present a numerical study for 3D time‐lapse electromagnetic monitoring of fictitious CO 2 sequestration using the geometry real geological site and suite suitable methods with different source/receiver configurations sensitivity patterns. All available information is processed directly implemented into computational domain, which discretized by unstructured tetrahedral grids. thus demonstrate performance capability our simulation techniques. The scenario considers injection in...

Based on the innovation-driven theory and ability-motivation-opportunity (AMO) perspective, we explore role of intellectual property protection (IPP) in enhancing radical technological innovation (RTI) national research project teams (NRPT). Survey data from 336 team members universities enterprises were used to analyze theoretical model this study, bringing chain-mediated effects milieu (IM) group potential (GP) for analysis, as well two-stage hybrid partial least squares structural...

Abstract We clarified three stages of dolomitization and secondary changes by studying the petrology geochemistry characteristics dolomite from Ma5 5 –Ma5 10 sub‐members Ordovician Majiagou Formation in Jingxi area Ordos Basin: (1) Syngenetic microbial is characterized formation with a mainly micrite structure horse tooth‐shape cements. (2) Seepage reflux during penecontemporaneous period superposed adjustment functions such as recrystallization stabilization middle‐deep burial stage,...

SUMMARY We present a goal-oriented adaptive finite-element algorithm for accurately modelling marine controlled-source electromagnetic responses in 3-D media with general electrical anisotropy. formulate the primal boundary value problem terms of total electric field applications. Following adaptivity concept, dual is derived from functional designed to measure data errors interest light quality. approximate solutions and formulations using edge method on tetrahedral grids flexible treatment...

During the progressive exploration of Jingbian Gas Field in Ordos Basin, multiple gas-bearing regions have been discovered dolomite reservoirs Middle Ordovician assemblages Lower Paleozoic Jingxi area, but these and intervals are significantly different terms gas enrichment degrees. So far, however, reasons for difference not figured out. In this paper, origin source natural area was investigated on basis geochemical data (e.g. composition carbon isotope), then main factors controlling...

In English learning, the teacher wrote text of test source according to their own experience. To reduce complex and repetitive tasks in teaching, teachers can focus on preparation, teaching response further improve ability. It has received questions through multiple channels created library quickly efficiently become fast-paced requirement writing. Machine learning is a mathematical training method that explores how computers mimic human writing behavior constantly accumulate experience...

The Multivariate Correlated Response Vector Generalized Linear Model is an important yet structurally complex class of generalized linear models. Commonly used variable selection methods, such as LASSO (Least Absolute Shrinkage and Selection Operator), are ineffective in efficiently identifying the crucial variables for this type model. In paper, we propose a novel method based on Markov chain Monte Carlo (MCMC) specifically Random Search method, to address issue. This approach proves be...

Seepage is a common hydrogeologic hazard in engineering. Determining the seepage paths vital for derisking instability of embankment structures. With improvement acquisition accuracy magnetic sensors, magnetometric resistivity method has become an emerging technology detecting through earth-filled dams. This technique nondestructive and gives prominent signals. However, resulting data have seen ambiguity fully determining targets. We develop induced gradient surveying approach to monitor...

Summary We present a new concept of designing multi-method electromagnetic field surveys taking into account all geological information available. There are three major ingredients necessary: 1. suite powerful 3D simulation algorithms able to deal with complex models, 2. workflow describe arbitrary geometry, and 3. laboratory measurements or other reliable assign realistic conductivities the scenario be simulated. With these we perform virtual experiment using our unstructured grid finite...