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International Journal of Mining Science and Technology 2024年第5期34卷 699-712页

作者： Binwei Xia Yanmin zhou Xingguo Zhang Lei zhou Zikun Ma State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China

Ground hydraulic fracturing plays a crucial role in controlling the far-field hard roof,making it imperative to identify the most suitable target stratum for effective *** experiments are conducted based on engineering properties to simulate the gradual collapse of the roof during longwall top coal caving(LTCC).A numerical model is established using the material point method(MPM)and the strain-softening damage constitutive model according to the structure of the physical *** simulations are conducted to analyze the LTCC process under different hard roofs for ground hydraulic *** results show that ground hydraulic fracturing releases the energy and stress of the target stratum,resulting in a substantial lag in the fracturing of the overburden before collapse occurs in the hydraulic fracturing *** hydraulic fracturing of a low hard roof reduces the lag effect of hydraulic fractures,dissipates the energy consumed by the fracture of the hard roof,and reduces the abutment ***,it is advisable to prioritize the selection of the lower hard roof as the target stratum.

关键词： Target stratum selection Ground hydraulic fracturing Hard roof control Fracture network Material point method

Shear strength degradation of gas hydrate-bearing sediment due to partial hydrate dissociation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2749-2763页

作者： Yuan zhou Jiazuo zhou Pan Chen Changfu Wei State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China China University of Geosciences Wuhan430074China

Extraction of methane hydrate from subseafloor reservoir may potentially trigger seabed slides and induce *** address the problems,it is crucial to properly characterize the phase equilibrium condition of pore hydrate and the shear strength of the *** one of the key constitutive components,the phase equilibrium condition enforces a constraint over pore gas pressure,temperature and unhydrated water *** a constraint,however,has been traditionally ignored in analyzing the mechanical behavior of hydrate-bearing *** this paper,a series of stepwise hydrate dissociation tests was performed,and the phase equilibrium condition of pore hydrate was determined,providing an effective way to evaluate the unhydrated water content during hydrate ***,a series of direct shear tests was also conducted to explore the shear strength characteristics of the *** is shown that the shear strength of the hydrate-bearing soil can be significantly influenced by pore gas pressure,unhydrated water content,hydrate saturation and several other *** particular,the measured shear strength depends upon the initial water content of the sample,pointing to a potential problem that the shear strength could be wrongly determined if not properly interpreted.A shear strength criterion,which enforces the equilibrium condition of pore hydrate,is developed for hydrate-bearing soil,establishing a link between the equilibrium condition and the shear *** proposed equation describes well the shear strength characteristics of hydrate-bearing soils,remarkably unifying the effects of pore pressure,temperature,water content and hydrate saturation.

关键词： Hydrate-bearing soil Phase equilibrium condition Shear strength Unhydrated water content Mechanical behavior

An automatic Q-factor matching method for eliminating 77%of the ZRO of a MEMS vibratory gyroscope in rate mode

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Microsystems & Nanoengineering 2024年第3期10卷 35-48页

作者： Jingbo Ren Tong zhou Yi zhou Yixuan Li Yan Su School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210000China

Mismatching quality factors(Q-factors)is one of the main factors causing zero-rate output(ZRO)in degenerate(DE)Micro-Electro-Mechanical Systems(MEMS)vibratory *** eliminate the ZRO of the DE MEMS gyroscope,this study introduces a method for real-time identification and automatic matching of Q-factors in rate *** leveraging the vibration characteristics of the DE MEMS vibratory gyroscope in rate mode,dedicated online test methods are designed to determine the Q-factors for both the drive and sense modes,enabling online identification of the Q-factor ***,an automatic Q-factor matching system is designed utilizing the mechanical-thermal dissipation mechanism of the resistive *** effectiveness of this proposed method is validated through simulations and experiments conducted on a MEMS disk resonator gyroscope(DRG).The results show a measurement error within 4%for Q-factor identification,and automatic Q-factor matching effectively reduces the ZRO by 77%.Employing this automatic Q-factor matching method successfully reduces the ZRO that is caused by the mismatching of Q-factors in the MEMS DRG from 0.11°/s to 0.025°/s and improves the bias instability(BI)from 0.40°/s to 0.19°/s.

关键词： matching mode method

Quantitative characterization of fusion state of virgin and aged asphalt using nano-ferrous ferric oxide tracer

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 467-480页

作者： Qiang Li Song Liu Huameng Wen zhou zhou College of Civil Engineering Nanjing Forestry UniversityNanjing 210037China School of Transportation Southeast UniversityNanjing 211189China

The exact evaluation of the fusion rate of virgin and aged asphalt is essential to optimize the performance of the recycled asphalt *** fusion rate index was developed by tracing the distribution of tracer asphalt,which contains nano-ferrous ferric oxide(nano-Fe_(3)O_(4))*** fusion simulation tests were performed on three types of asphalt to obtain different fusion states,and fatigue tests were performed to evaluate the influence of the fusion rate on the fatigue life of the recycled *** was found that the tracer asphalt containing 4%nano-Fe_(3)O_(4)shows the optimal trace effect,and the developed fusion rate index can quantitatively characterize the influence of different factors on the fusion state of the recycled *** fusion state is closely related to the fatigue performance of recycled asphalt,and the fusion rate index can fairly evaluate its fatigue *** relationship between the fusion rate and the fatigue life of recycled asphalt depends on the factors that cause the fusion rate *** the influence of the amount of rejuvenator,the fatigue life of recycled asphalt grows exponentially with increasing fusion rate due to enhancement of molecular motion as well as a supplement of lightweight *** the influence of heat preservation treatment,fatigue life increases linearly with increasing fusion *** proposed fusion rate index can be utilized to quantitatively characterize the fusion state of virgin and aged asphalt,thus providing a simple way to guide the practical application of recycled asphalt.

关键词： Recycled asphalt Rejuvenator Tracing technique Fusion rate Fatigue

Energy-information trade-off induces continuous and discontinuous phase transitions in lateral predictive coding

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 79-85页

作者： Zhen-Ye Huang Ruyi zhou Miao Huang Hai-Jun zhou Key Laboratory for Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China Minjiang Collaborative Center for Theoretical Physics Minjiang UniversityFuzhou 350108China

Lateral predictive coding is a recurrent neural network that creates energy-efficient internal representations by exploiting statistical regularity in sensory ***,we analytically investigate the trade-off between information robustness and energy in a linear model of lateral predictive coding and numerically minimize a free energy *** observed several phase transitions in the synaptic weight matrix,particularly a continuous transition that breaks reciprocity and permutation symmetry and builds cyclic dominance and a discontinuous transition with the associated sudden emergence of tight balance between excitatory and inhibitory *** optimal network follows an ideal gas law over an extended temperature range and saturates the efficiency upper bound of energy *** results provide theoretical insights into the emergence and evolution of complex internal models in predictive processing systems.

关键词： predictive coding recurrent neural network phase transition internal model free energy

General properties of the spectral form factor in open quantum systems

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Frontiers of physics 2024年第3期19卷 229-237页

作者： Yi-Neng zhou Tian-Gang zhou Pengfei Zhang Institute for Advanced Study Tsinghua UniversityBeijing 100084China Department of Physics Fudan UniversityShanghai 200438China

The spectral form factor(SFF)can probe the eigenvalue statistic at different energy scales as its time variable *** closed quantum chaotic systems,the SFF exhibits a universal dip-ramp-plateau behavior,which reflects the spectrum rigidity of the *** this work,we explore the general properties of SFF in open quantum *** find that in open systems the SFF first decays exponentially,followed by a linear increase at some intermediate time scale,and finally decreases to a saturated plateau *** derive general relations between(i)the early-time decay exponent and Lindblad operators;(ii)the long-time plateau value and the number of steady *** also explain the effective field theory perspective of general *** verify our theoretical predictions by numerically simulating the Sachdev−Ye−Kitaev(SYK)model,random matrix theory(RMT),and the Bose−Hubbard model.

关键词： spectral form factor open quantum system quantum chaos

Manipulating submolecular-scale phototautomerization

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Science China Materials 2024年第6期67卷 2048-2050页

作者： Ping zhou Hongliang Chen Stoddart Institute of Molecular Science Department of ChemistryZhejiang UniversityHangzhou 310058China Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials ZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou 311215China

A recent study on the submolecular-scale control of phototautomerization methods and the underlying reaction mechanisms was reported in Nature Nanotechnology by Guillaume and co-workers[1],elucidating how the field confinement effect generated by the scanning tunneling microscope(STM)tip precisely triggers the phototautomerization of a free-base phthalocyanine at the submolecular level and demonstrating that the reaction process can be finely controlled by adjusting either the laser excitation wavelength or the position of the tip.

关键词： tunneling excitation phthalocyanine

Origin and tectonic setting of low-Si alkaline magma

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Science China Earth Sciences 2024年第5期67卷 1417-1435页

作者： Qiushi zhou Rui WANG State Key Laboratory of Geological Processes and Mineral Resources and Institute of Earth SciencesChina University of GeosciencesBeijing 100083China Frontiers Science Center for Deep-time Digital Earth China University of Geosciences(Beijing)Beijing 100083China

Despite of the relatively rare occurrence of alkaline igneous rocks on Earth, they are the most diverse group of igneous rocks due to variations in their mineral assemblages and geochemical compositions. Alkaline igneous rocks are generally characterized by Si undersaturation, and K-Na(and in some cases C) enrichment. Although there is no unified alkaline igneous rock classification scheme, diagrams such as total alkalis-SiO_(2) or K_(2)O-SiO_(2) can be used to classify alkaline igneous rocks. The origins of silica-saturated alkaline rocks(SiO_(2)>52 wt.%) are relatively complex because multiple episodes of magmatism are often involved, therefore most studies have focused on the origins of silica-undersaturated alkaline *** experimental petrological studies have been conducted in the past few decades. Initially, it was considered that enrichment of trace elements was only achieved by low-degree partial melting of mantle peridotite, but the experimental melts could not reproduce the geochemical composition of natural alkaline igneous rocks. Subsequent studies have focused on carbonate-bearing eclogites that represent the average component of subducted oceanic crust. Although experimental studies indicate that silica-undersaturated and alkali-oversaturated melts can be generated from eclogites, some studies have considered that natural silica-undersaturated alkaline igneous rocks are the result of multi-stage source enrichment by incompatible elements. Low-degree partial melts of the mantle can be emplaced in the lithospheric mantle, forming veins consisting of phlogopite, amphibole, and pyroxene. Melting experiments including these components show that the produced melts better reproduce the naturally occurring silica-undersaturated alkaline magmas. Silica-deficient alkaline igneous rocks occur in various tectonic settings. Those in intraplate and divergent settings(i.e., mainly continental rifts) normally involve contributions from recycled components su

关键词： Alkaline igneous rock Tectonic setting Petrogenesis Big data

Novel rockburst prediction criterion with enhanced explainability employing CatBoost and nature-inspired metaheuristic technique

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Underground Space 2024年第6期19卷 101-118页

作者： Yingui Qiu Jian zhou School of Resources and Safety Engineering Central South UniversityChangsha 410083China

Rockburst is a major challenge to hard rock engineering at great *** and timely assessment of rockburst risk can avoid unnecessary casualties and property *** the existence of various methods for rockburst assessment,there remains an urgent need for a comprehensive and reliable criterion that is easy to both apply and *** a new rockburst criterion based on simple parameters can potentially fill this *** its advantages,this criterion can facilitate a more effective and efficient prediction of rockburst potential,thereby contributing significantly to enhancing safety *** this paper,combined with the internal and external factors of rockburst,four control variables(i.e.,integrity index,stress index,brittleness index,and elastic energy index)were selected to be incorporated into a comprehensive rockburstability index(RBSI).Based on 116 sets of rockburst cases,the rockburst potential was accurately quantified and predicted using the categorical boosting(CatBoost)model and the nature-inspired metaheuristic African vultures optimization algorithm(AVOA).In its performance validation,the criterion achieved the highest accuracy of 90.48%,verifying the reliability and effectiveness of the proposed RBSI ***,an interpretive method was applied to analyze the variable influence on the criterion,facilitating the explanation of predictions and the analysis of the formula’s robustness under different *** general,compared with existing criterion methods involving relevant indicators,the newly proposed RBSI criterion enhances the accuracy of rockburst potential prediction,and it can effectively and swiftly evaluate the preliminary risk of ***,a graphical user interface was developed to provide a clear visualization of the assessment of rockburst potential.

关键词： Rockburst criterion CatBoost Metaheuristic optimization Model interpretation Graphical user interface

Revealing the Void Formation Mechanism during Superplastic Deformation of a Fine-Grained Ni-Co-Base Superalloy

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 915-920页

作者： Rashad AAl-Hammadi Rui Zhang Chuanyong Cui Zijian zhou Yizhou zhou Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The mechanism behind void formation during superplasticity remains a subject of *** study presented a novel insight into the void formation in a fine-grained Ni-Co-based superalloy during *** was observed that the dissolution ofγ′-particles resulted in the creation of vacancies due to differences in atomic size between the matrix and the *** vacancies acted as inclusions,leading to the formation of ***,excessive void formation correlated with higher particle dissolution was experimentally observed,highlighting a direct relationship between void formation and particle dissolution.

关键词： Superplasticity Void formation Ni-Co-based superalloy Microstructure