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Geology and C-O isotope geochemistry of carbonate-hosted Pb-Zn deposits, NW Guizhou Province, SW China

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Chinese Journal Of Geochemistry 2013年第1期32卷 7-18页

作者： DOU Song zhou jiaxi Yunnan Nonferrous Metals Geological Bureau School of Geoscience and Info-Physics Central South University State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences

The Pb-Zn metallogenic district in NW Guizhou Province is an important part of the Yun-nan-Sichuan-Guizhou Pb-Zn metallogenic province, and also is one of the most important Pb-Zn producers in China. The hosting rocks of the Pb-Zn deposits are Devonian to Permian carbonate rocks, and the basement rocks are meta-sedimentary and igneous rocks of the Proterozoic Kunyang and Huili groups. The ore minerals are composed of sphalerite, galena and pyrite, and the gangue minerals are include calcite and dolomite. Geology and C-O isotope of these deposits were studied in this paper. The results show that δ13C and δ18O values of hydrothermal calcite, altered wall rocks-dolostone, sedimentary calcite and hosting carbonate rocks range from -5.3‰ to -0.6 ‰ (mean -3.4‰) and +11.3‰ to +20.9 ‰ (mean +17.2‰), -3.0‰ to +0.9 ‰ (mean -1.3‰) and +17.0‰ to +20.8‰ (mean +19.7‰), +0.6‰ to +2.5 ‰ (mean +1.4‰) and +23.4‰ to +26.5 ‰ (mean +24.6‰), and -1.8‰ to +3.9‰ (mean +0.7‰) and +21.0‰ to +26.8‰ (mean +22.9‰), respectively, implying that CO2 in the ore-forming fluids was mainly a result of dissolution of Devonian and Carboniferous carbonate rocks. However, it is difficult to evaluate the contribution of sediment de-hydroxylation. Based on the integrated analysis of geology, C and O isotopes, it is believed that the ore-forming fluids of these carbonate-hosted Pb-Zn deposits in this area were derived from multiple sources, including hosting carbonate rocks, Devonian to Permian sedimentary rocks and basement rocks (the Kun-yang and Huili groups). Therefore, the fluids mixing is the main precipitation mechanism of the Pb-Zn deposit in this province.

关键词：铅锌矿床碳酸盐岩碳氧同位素综合地质中国西南同位素地球化学贵州省托管

Strontium isotopic geochemistry of Tianqiao Pb-Zn deposit, Southwest China

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Chinese Journal Of Geochemistry 2014年第2期33卷 131-137页

作者： DOU Song LIU Jishun zhou jiaxi School of Geosciences and Info-physics Central South University Yunnan Nonferrous Metals Geological Bureau State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences

Tianqiao carbonate-hosted Pb-Zn deposit, controlled by NW-trending F37 thrust fault and NW-trending Tianqiao anticline, is located in the eastern part of Sichuan-Yunnan-Guizhou(SYG) Pb-Zn metallogenic province, southwestern Yangtze Block, southwest China. Ore bodies in this deposit are hosted in the Devonian-Carboniferous carbonate rocks, and ore minerals include sphalerite, galena and pyrite, while the gangue minerals are dominated by calcite and dolomite. Using high–precision solid thermal ionization mass spectrometry(TIMS), this paper reports the strontium isotopic compositions(0.7119 to 0.7167) of sulfide samples from the Tianqiao deposit in order to trace the origin of hydrothermal fluids. Compared with the country rocks, the calculated 87Sr/86Sr200 Ma values of sulfide range from 0.7118 to 0.7130, higher than those of the age-corrected Devonian to Permian sedimentary rocks(0.7073 to 0.7101) and the Middle Permian Emeishan flood basalts(0.7078 to 0.7039), but lower than those of the age-corrected Proterozoic basement rocks(such as the Kunyang and Huili Groups, 87Sr/86Sr200 Ma=0.7243 to 0.7288). This implies a mixed strontium source between the older basement rocks and the younger cover sequences. Together with geologic and previous isotopic evidences, we considered that the fluids' mixing is a possible mechanism for sulfide precipitation in the Tianqiao deposit.

关键词：同位素地球化学中国西南地区铅锌矿床天桥锶峨眉山玄武岩基底岩石碳酸盐岩

TRANSIENT THERMAL RESPONSE IN THICK ORTHOTROPIC HOLLOW CYLINDERS WITH FINITE LENGTH:HIGH ORDER SHELL THEORY

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Acta Mechanica Solida Sinica 2010年第2期23卷 156-166页

作者： jiaxi zhou Zichen Deng Xiuhui Hou Department of Engineering Mechanics Northwestern Polytechnical University Xi'an 710072 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China

The transient thermal response of a thick orthotropic hollow cylinder with finite length is studied by a high order shell theory. The radial and axial displacements are assumed to have quadratic and cubic variations through the thickness, respectively. It is important that the radial stress is approximated by a cubic expansion satisfying the boundary conditions at the inner and outer surfaces, and the corresponding strain should be least-squares compatible with the strain derived from the strain-displacement relation. The equations of motion are derived from the integration of the equilibrium equations of stresses, which are solved by precise integration method （PIM）. Numerical results ***, and compared with FE simulations and dynamic thermo-elasticity solutions, which indicates that the high order shell theory is capable of predicting the transient thermal response of an orthotropic （or isotropic） thick hollow cylinder efficiently, and for the detonation tube of actual pulse detonation engines （PDE） heated continuously, the thermal stresses will become too large to be neglected, which are not like those in the one time experiments with very short time.

关键词： dynamic thermo-elasticity thermal response high order shell theory thick hollowcylinder

Design and experimental study of a compact quasi-zero-stiffness isolator using wave springs

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Science China(Technological Sciences) 2021年第10期64卷 2255-2271页

作者： WANG Qiang zhou jiaxi WANG Kai XU DaoLin WEN GuiLin State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Changsha 410082China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China School of Mechanical and Electric Engineering Guangzhou UniversityGuangzhou 510006China

The quasi-zero-stiffness(QZS)vibration isolation has been proven to be an effective way to isolate low-frequency ***,most of the existing QZS isolators are space-consuming,which could not be employed in the space-limited *** this paper,a quite compact QZS isolator is engineered by connecting a pair of mutually repulsive magnet rings and a space-saving wave spring in parallel,called WQZS *** restoring force of the magnet ring is derived by the equivalent magnetic charge method,and an empirical formula for the restoring force of the wave spring is derived by the least squares method based on experimental *** dynamic model of the WQZS vibration isolation system is built,and the vibration isolation performance is evaluated through ***,an experimental prototype is fabricated,and the experimental tests on frequency sweep are carried *** results show that compared with the linear counterpart,the vibration isolation frequency of the WQZS isolator is reduced by 48.89%,and the peak transmissibility is decreased by 59.33%.Most importantly,the space occupancy of the WQZS isolator designed in this paper is much lower than that of the traditional QZS isolators,and thus it should be a potential solution for low-frequency vibration isolation in the space-limited environment.

关键词： quasi-zero-stiffness vibration isolator space saving magnet rings wave spring

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Multi-layer quasi-zero-stiffness meta-structure for high-efficiency vibration isolation at low frequency

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1189-1208页

作者： Jiahao zhou jiaxi zhou Hongbin PAN Kai WANG Changqi CAI Guilin WEN College of Mechanical and Vehicle Engineering Hunan UniversityChangsha410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body The Ministry of Science and TechnologyChangsha410082China School of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou310018China School of Mechanical Engineering Yanshan UniversityQinhuangdao066004Hebei ProvinceChina

An easily stackable multi-layer quasi-zero-stiffness(ML-QZS)meta-structure is proposed to achieve highly efficient vibration isolation performance at low ***,the distributed shape optimization method is used to design the unit cel,i.e.,the single-layer QZS(SL-QZS)***,the stiffness feature of the unit cell is investigated and verified through static ***,the unit cells are stacked one by one along the direction of vibration isolation,and thus the ML-QZS meta-structure is ***,the dynamic modeling of the ML-QZS vibration isolation metastructure is conducted,and the dynamic responses are obtained from the equations of motion,and verified by finite element(FE)***,a prototype of the ML-QZS vibration isolation meta-structure is fabricated by additive manufacturing,and the vibration isolation performance is evaluated *** results show that the vibration isolation performance substantially enhances when the number of unit cells *** importantly,the ML-QZS meta-structure can be easily extended in the direction of vibration isolation when the unit cells are properly ***,the ML-FQZS vibration isolation meta-structure should be a fascinating solution for highly efficient vibration isolation performance at low frequency.

关键词： quasi-zero stiffness(QZS) meta-structure high efficiency low frequency vibration isolation

Fractional nonlinear energy sinks

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Applied Mathematics and Mechanics(English Edition) 2023年第5期44卷 711-726页

作者： Shengtao ZHANG jiaxi zhou Hu DING Kai WANG Daolin XU College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

The cubic or third-power(TP)nonlinear energy sink(NES)has been proven to be an effective method for vibration suppression,owing to the occurrence of targeted energy transfer(TET).However,TET is unable to be triggered by the low initial energy input,and thus the TP NES would get failed under low-amplitude *** resolve this issue,a new type of NES with fractional nonlinearity,e.g.,one-third-power(OTP)nonlinearity,is *** dynamic behaviors of a linear oscillator(LO)with an OTP NES are investigated numerically,and then both the TET feature and the vibration attenuation performance are ***,an analogy circuit is established,and the circuit simulations are carried out to verify the design concept of the OTP *** is found that the threshold for TET of the OTP NES is two orders of magnitude smaller than that of the TP *** parametric analysis shows that a heavier mass or a lower stiffness coefficient of the NES is beneficial to the occurrence of TET in the OTP NES ***,significant energy transfer is usually accompanied with efficient energy ***,the OTP NES can realize TET under low initial input energy,which should be a promising approach for micro-vibration suppression.

关键词： fractional nonlinearity nonlinear energy sink(NES) targeted energy transfer(TET) micro-vibration control

Numerical and Experimental Investigations on Tunable Low-frequency Locally Resonant Metamaterials

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Acta Mechanica Solida Sinica 2021年第5期34卷 612-623页

作者： Qida Lin jiaxi zhou Hongbin Pan Daolin Xu Guilin Wen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Changsha410082China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha410082China School of Mechanical and Electric Engineering Guangzhou UniversityGuangzhou510006China

In this paper,a tunable locally resonant metamaterial is proposed for low-frequency band *** local resonator composed of two pairs of folded slender beams and a proof mass is designed based on the theory of compliant *** design optimization on geometric parameters is carried out to fulfil the quasi-zero-stiffness *** locally resonant metamaterial is formed by periodically arranged unit cells,and the transmittance of longitudinal wave is studied through three aspects:numerical predictions,finite element simulations and experimental *** variation trends revealed by these three methods match well with one another:the band gap moves to lower frequency and both its depth and width get smaller and smaller with the increase of pre-compression(Δ).The band gap overlays the frequency range of 73.10–92.38 Hz and 16.78–19.49 Hz atΔ=0mm andΔ=10mm,respectively,providing a wide range of ***,the ultralow-frequency band gap can be achieved asΔapproaches 10 *** study may provide an avenue for achieving the tunable ultralow-frequency locally resonant band gap.

关键词： Acoustic metamaterial Locally resonant band gap Tunability and ultralow frequency Quasi-zero stiffness

H-O-S-Cu-Pb Isotopic Constraints on the Origin of the Nage Cu-Pb Deposit, Southeast Guizhou Province, SW China

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Acta Geologica Sinica(English Edition) 2013年第5期87卷 1334-1343页

作者： zhou jiaxi WANG Jingsong YANG Dezhi LIU Jinhai State key Laboratory of Ore Deposits Geochemistry Institute of GeochemistryChinese Academy of Science The 102 Geological Team Guizhou Bureau of Exploration and Development of Geology and Mineral Resources The 112 Geological Team Guizhou Bureau of Exploration and Development of Geology and Mineral Resources

The Nage Cu-Pb deposit, a new found ore deposit in the southeast Guizhou province, southwest China, is located on the southwestern margin of the Jiangnan Orogenic Belt. Ore bodies are hosted in slate and phyllite of Neoproterozoic Jialu and Wuye Formations, and are structurally controlled by EW-trending fault. It contains Cu and Pb metals about 0.12 million tonnes with grades of 0.2 wt% to 3.4 wt% Cu and 1.1 wt% to 9.27 wt% Pb. Massive and disseminated Cu-Pb ores from the Nage deposit occur as either veinlets or disseminations in silicified rocks. The ore minerals include chalcopyrite, galena and pyrite, and gangue minerals are quartz, sericite and chlorite. The H-O isotopic compositions of quartz, S-Cu-Pb isotopic compositions of sulfide minerals, Pb isotopic compositions of whole rocks and ores have been analyzed to trace the sources of ore-forming fluids and metals for the Nage Cu-Pb deposit. The oSCUNBs values of chalcopyrite range from -0.09% to ＋0.33%0, similar to basic igneous rocks and chalcopyrite from magmatic deposits. J6SCUNBS values of chalcopyrite from the early, middle and final mineralization stages show an increasing trend due to 63Cu prior migrated in gas phase when fluids exsolution from magma, ja4ScDT values of sulfide minerals range from -2.7‰ to ＋2.8‰, similar to mantle-derived sulfur （0±3‰）. The positive correlation between J65CUNBs and ja4SCDT values of chalcopyrite indicates that a common source of copper metal and sulfur from magma. JDu2o- SMOW and JlSOH2O-SMOW values of water in fluid inclusions of quartz range from -60.7‰ to -44.4‰ and ＋7.9‰ to ＋9.0%0 （T=260℃）, respectively and fall in the field for magmatic and metamorphic waters, implicating that mixed sources for H20 in hydrothermal fluids. Ores and sulfide minerals have a small range of Pb isotopic compositions （208Pb/204pb=38.152 to 38.384, 207Pb/204Pb=15.656 to 17.708 and 206Pb/204Pb=17.991 to 18.049） that are close to orogenic belt and upper crust Pb evolution curve, and similar to

关键词： H-O-S-Cu-Pb isotopes sources of ore-forming fluids and metals ore genesis Nage Cu-Pbdeposit SW China

Design of quasi-zero-stiffness elastic diodes for low-frequency nonreciprocity through machine learning

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Acta Mechanica Sinica 2024年第7期40卷 137-151页

作者： Junsen He jiaxi zhou Kai Wang Qiang Wang College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan UniversityChangsha 410082China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHong KongChina

Elastic diodes with nonreciprocity have the potential to enable unidirectional modulation of elastic ***,it is a challenge to achieve nonreciprocity at low frequencies(<100 Hz)using existing elastic *** paper proposes a quasizero-stiffness(QZS)elastic diode to resolve such a tough issue and fulfill high-quality low-frequency *** proposed elastic diode is invented by combining a QZS locally resonant metamaterial with a linear one,where the beneficial nonlinearity of the QZS metamaterial facilitates opening an amplitude-dependent band gap at very low ***,the dispersion relation of the QZS metamaterial is derived theoretically based on the harmonic balance method(HBM).Then,the transmissibility of the QZS elastic diode in both the forward and backward directions is calculated through theoretical analyses and numerical ***,the influences of system parameters on the low-frequency nonreciprocal effect are *** results indicate that considerable nonreciprocity is observed at a quite low frequency(e.g.,9 Hz),which is achieved by amplitude-dependent local resonance combined with interface ***,a machine learning-based design optimization is introduced to evaluate and enhance the nonreciprocal effect of the QZS elastic *** the aid of machine learning(ML),the computational cost of predicting nonreciprocal effects during design optimization can be significantly *** design optimization,the nonreciprocal frequency bandwidth can be broadened while maintaining considerable isolation quality at low frequencies.

关键词： Nonreciprocity Low-frequency Elastic diode Quasi-zero-stiffness Nonlinear elastic metamaterials Machine learning