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The discovery of Late Triassic hypabyssal mafic dykes in the Huozhou complex and their geological significance:Evidence from petrology,geochemistry,and geochronology

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Acta Geochimica 2024年第6期43卷 1013-1036页

作者： Haiyan Liu chong Peng College of Geographical sciences Shanxi Normal UniversityTaiyuan 030031China Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China school of Geosciences University of EdinburghEdinburgh EH93JWUK

The Huozhou complex in the Trans-North China Orogen exhibits two events of mafic magmatism(separated by ca.700 Ma):Neoproterozoic(920±15 Ma)shimenyu diabase and Late Triassic(217±2.5 Ma)Xingtangsi *** have focused on systematic petrology,zircon U-Pb dating,Lu-Hf isotopes,and *** research findings indicate that the Late Triassic Xingtangsi diabase of the Huozhou complex can be classified as a transitional type between intermediate and mafic rocks based on their siO_(2)*** classification is supported by an average siO_(2)content of 53.94%,ranging from 53.33%to 54.28%.In the Zr/TiO_(2)*** diagram,all samples lie within the range of *** zircons from the Late Triassic Xingtangsi diabase have lowε_(Hf)(t)values ranging from-12.7 to-8.7,with an average ***,the single-stage model age T_(DM1)is estimated to be between 1207 and 1701 *** findings suggest that the magma responsible for the dyke originated from either partial melting or an enriched mantle source inside the Meso-Proterozoic lithospheric *** elevated concentrations of Th(thorium)and LREEs(light rare earth elements),as well as the Th/Yb and Th/Nb ratios,suggest the potential incorporation of subducted sediments within the magma source *** rock displays negative Nb,Ta,Zr,Hf,and Ti *** geochemical attributes align with the distinctive traits observed in volcanic rocks found within island *** formation of the Late Triassic Xingtangsi diabase is likely associated with the geological context of an arc setting,which arises from the collision between the Yangtze plate and the North China Craton.

关键词： Trans-North China Orogen Huozhou complex Geochemistry Hf isotope North China Craton

Local Magnetic Relaxation in High-Temperature superconductors

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Chinese Physics Letters 1997年第12期14卷 940-942页

作者： WEI chong-de Department of Physics Peking UniversityBeijing 100871

The local magnetic relaxation in superconducting slab is investigated numerically for Anderson-Kim model,U(j)=U_(c)(l-j/j_(c)),and periodic pinning *** relaxation of B(x,t)depends on the starting profile and the position *** is important to note that the relaxation of B(x,t)exhibits approximate scaling law for some initial condition,showing that the relaxation rate is roughly uniform over the *** long time,B(x,t)is towards an asymptotic behavior independent of x.

关键词： potential relaxation starting

2.7-Ga-old mafic dike in the Trans-North China Orogen of the North China Craton and its tectonic significance

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Acta Geochimica 2023年第6期42卷 1124-1129页

We studied an Archean mafic dike in the TransNorth China Orogen of the North China Craton, which has a magmatic age of 2701 ± 83 Ma and is currently the oldest mafic dike in the North China Craton. such an old dike is extremely rare in the world. The presence of mafic dikes indicates that the North China Craton was in a tensional tectonic environment at 2.7 Ga. Geochemical characteristics reveal that this mafic dike belongs to continental tholeiitic basalt. Results from Hf isotope analysis reveal that the mafic dike originates from a depleted mantle. The plate assembly in the North China landmass was realized during the Archean era(2.7 Ga), and a thick and stable continental crust was formed. Therefore, the first cratonization of the North China Craton was completed before 2.7 Ga. The intrusion of the 2.7-Ga-old mafic dike from the deep lithospheric mantle of the continent indicates that the North China Craton has undergone a period of extensional tectonic activity. This event marks a significant extensional event that occurred after the cratonization of the North China Craton.

关键词： Archean Mafic dike Trans-North China Orogen North China Craton Hf Cratonization

Effects of Flux Creep on the Magnetization Curves of High-Temperature superconductors

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Chinese Physics Letters 1998年第6期15卷 450-452页

作者： WEI chong-de Department of Physics Peking UniversityBeijing 100871

The effects of flux creep on the magnetization curves of high-temperature superconductors are investigated numerically for Anderson-Kim *** pinning energy at zero current density,U_(c),greatly influences the flux penetration process,a larger U_(c),value reults in a larger penetration *** characteristic of the magnetization curve is also a function of U_(c).The magnetization M and ΔM increase with the increasing U_(c) and depend on the magnetic induction B,so the critical current formula based on Bean model is pot accurate,especially for high-T_(c) superconductor,for which flux creep is a large effect.

关键词： creep magnetization superconductor

Measurements of Non-reacting and Reacting Flow Fields of a Liquid swirl Flame Burner

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Chinese journal of Mechanical Engineering 2015年第2期28卷 394-401页

作者： chong Cheng Tung HOCHGREB simone Faculty of Mechanical Engineering Universiti Teknologi Malaysia Department of Engineering University of Cambridge

The understanding of the liquid fuel spray and flow field characteristics inside a combustor is crucial for designing a fuel efficient and low emission *** of the flow field of a model gas turbine liquid swirl burner is performed by using a2-D particle imaging velocimetry（PIV）*** flow field pattern of an axial flow burner with a fixed swirl intensity is compared under confined and unconfined conditions,i.e.,with and without the combustor *** effect of temperature on the main swirling air flow is investigated under open and non-reacting *** result shows that axial and radial velocities increase as a result of decreased flow density and increased flow *** flow field of the main swirling flow with liquid fuel spray injection is compared to non-spray swirling *** of liquid fuel spray changes the swirl air flow field at the burner outlet,where the radial velocity components increase for both open and confined *** reacting condition,the enclosure generates a corner recirculation zone that intensifies the strength of radial *** reverse flow and corner recirculation zone assists in stabilizing the flame by preheating the *** flow field data can be used as validation target for swirl combustion modelling.

关键词： flow field swirl flame gas turbine burner particle imaging velocimetry(PIV)

Rectangle expansion A* pathfinding for grid maps

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Chinese journal of Aeronautics 2016年第5期29卷 1385-1396页

作者： Zhang An Li chong Bi Wenhao school of Aeronautics Northwestern Polytechnical University school of Electronics and Information Northwestern Polytechnical University

search speed, quality of resulting paths and the cost of pre-processing are the principle evaluation metrics of a pathfinding algorithm. In this paper, a new algorithm for grid-based maps, rectangle expansion A＊（REA＊）, is presented that improves the performance of A＊ significantly. REA＊ explores maps in units of unblocked rectangles. All unnecessary points inside the rectangles are pruned and boundaries of the rectangles （instead of individual points within those boundaries） are used as search nodes. This makes the algorithm plot fewer points and have a much shorter open list than A＊. REA＊ returns jump and grid-optimal path points, but since the line of sight between jump points is protected by the unblocked rectangles, the resulting path of REA＂ is usually better than grid-optimal. The algorithm is entirely online and requires no offline pre-processing. Experimental results for typical benchmark problem sets show that REA＊ can speed up a highly optimized A＊ by an order of magnitude and more while preserving completeness and optimality. This new algorithm is competitive with other highly successful variants of A＊.

关键词： Breaking path symmetries Grid Heuristic algorithms Path search Variant of A*

Kantorovich’s theorem for Newton’s method on Lie groups

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journal of Zhejiang University-science A(Applied Physics & Engineering) 2007年第6期8卷 978-986页

作者： WANG jin-hua LI chong Department of Mathematics Zhejiang University of Technology Hangzhou 310032 China Department of Mathematics Zhejiang University Hangzhou 310027 China

The convergence criterion of Newton’s method to find the zeros of a map f from a Lie group to its corresponding Lie algebra is established under the assumption that f satisfies the classical Lipschitz condition, and that the radius of convergence ball is also obtained. Furthermore, the radii of the uniqueness balls of the zeros of f are estimated. Owren and Welfert (2000) stated that if the initial point is close sufficiently to a zero of f, then Newton’s method on Lie group converges to the zero; while this paper provides a Kantorovich’s criterion for the convergence of Newton’s method, not requiring the existence of a zero as a priori.

关键词： Newton's method Lie group Kantorovich's theorem Lipschitz condition

Fuzzy finite difference method for heat conduction analysis with uncertain parameters

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Acta Mechanica sinica 2014年第3期30卷 383-390页

作者： chong Wang Zhi-Ping Qiu Institute of solid Mechanics Beihang University

A new numerical technique named as fuzzy finite difference method is proposed to solve the heat conduction problems with fuzzy uncertainties in both the phys- ical parameters and initial/boundary conditions. In virtue of the level-cut method, the difference discrete equations with fuzzy parameters are equivalently transformed into groups of interval equations. New stability analysis theory suited to fuzzy difference schemes is developed. Based on the parameter perturbation method, the interval ranges of the uncertain temperature field can be approximately predicted. subsequently, fuzzy solutions to the original difference equations are obtained by the fuzzy resolution theorem. Two numerical examples are given to demonstrate the feasibility and efficiency of the presented method for solving both steady-state and transient heat conduction problems.

关键词： Heat conduction Fuzzy uncertainties Finitedifference method Parameter perturbation stability analysis

Interval finite difference method for steady-state temperature field prediction with interval parameters

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Acta Mechanica sinica 2014年第2期30卷 161-166页

作者： chong Wang Zhi-Ping Qiu Institute of solid Mechanics Beihang University

A new numerical technique named interval finite difference method is proposed for the steady-state temperature field prediction with uncertainties in both physical parameters and boundary conditions. Interval variables are used to quantitatively describe the uncertain parameters with limited information. Based on different Taylor and Neumann series, two kinds of parameter perturbation methods are presented to approximately yield the ranges of the uncertain temperature field. By comparing the results with traditional Monte Carlo simulation, a numerical example is given to demonstrate the feasibility and effectiveness of the proposed method for solving steady-state heat conduction problem with uncertain-but-bounded parameters.

关键词： steady-state heat conduction Interval finite dif-ference Temperature field prediction Parameter perturba-tion method Interval uncertainties