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Subaqueous volcanism in the Paleo-Pacific Ocean based on Jurassic basaltic tuff and pillow basalt in the Raohe Complex,NE China

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Science China Earth Sciences 2018年第8期61卷 1042-1056页

作者： SUN MingDao xu YiGang CHEN HanLin State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Earth Science College Zhejiang University Hangzhou 310027 China

On-land records of subaqueous explosive volcanic eruptions are rarely *** understand this phenomenon and discuss its global significance,we studied the geochronology and geochemistry of basaltic tuff and pillow basalt in the Raohe Complex,NE *** basaltic tuff consists of well-sorted vitreous,crystal(mostly clinopyroxene),and minor lithic *** is characterized by a high Mg O(15.7–15.9%)content and zero Eu anomalies(Eu/Eu~*=99–102).The tuff erupted at 172±1 Ma based on SHRIMP zircon U-Pb dating,coeval with the previously reported age of the pillow *** pillow basalt has intermediate Mg O content and weakly negative Eu anomalies(Eu/Eu~*=90–99).Based on immobile trace element discrimination,the basaltic tuff and pillow basalt belong to alkali basalt displaying an OIB-type trace element pattern,and consistent Nd isotope signatures ofε_(Nd)(t)=4.4–6.2,indicating an identical mantle *** pillow basalt has coupled Sr-Nd isotopic values,whereas the basaltic tuff has significantly higher initial^(87)Sr/^(86)Sr values that are similar to synchronous *** indicates that the elemental exchange between the mantle-derived material and seawater most likely occurred in a subaqueous explosive volcanic eruption,rather than in an effusive *** calculations suggest that the high efficiency of the Sr-isotope exchange between seawater and the mantle-derived material triggered by a subaqueous explosive volcanic eruption is likely one of the main reasons for the rapid decrease of the global seawater^(87)Sr/^(86)Sr value.

关键词： Raohe Complex Subaqueous volcanism Jurassic Paleo-Pacific Ocean Seawater Sr isotope

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国有企业经营者需求实证研究

经济体制改革 2017年第1期 109-115页

作者：年志远许家瞻吉林大学中国国有经济研究中心吉林大学经济学院

本文简评了国有企业经营者需求研究的现状,为国有企业经营者需求实证研究提供参考和启示;研究了国有企业经营者需求研究的原则,并依据该原则研究了国有企业经营者的6种主要需求:业绩需求、自我价值补偿需求、职业发展需求、权力需求、... 详细信息

本文简评了国有企业经营者需求研究的现状,为国有企业经营者需求实证研究提供参考和启示;研究了国有企业经营者需求研究的原则,并依据该原则研究了国有企业经营者的6种主要需求:业绩需求、自我价值补偿需求、职业发展需求、权力需求、职位和生活安全需求以及声誉需求;对国有企业经营者的6种主要需求进行了问卷调查,调查问卷设计采用李克特五级量表的样式。运用调查问卷得到的数据,对国有企业经营者6种主要需求进行了探索性因子检验和验证性因子检验。检验结果表明,国有企业经营者的6种主要需求符合实际情况,具有较强的可信度,可以作为对其激励的内容。

关键词：国有企业经营者需求实证探索性因子检验验证性因子检验

Convergent Richtmyer-Meshkov instability on two-dimensional tri-mode interfaces

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Science China(Physics,Mechanics & Astronomy) 2024年第12期67卷 106-118页

作者： Zhigang Zhai Jinru xu Xisheng Luo Advanced Propulsion Laboratory Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei230026China State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing100190China

Interfacial fluid mixing driven by a shock wave is a common phenomenon that occurs frequently in basic science research and in a variety of *** this work,shock-tube experiments on the developments of two-dimensional tri-mode interfaces accelerated by a convergent shock wave are *** sets of different combinations in the value of phase and that of amplitude in a tri-mode perturbed interface are studied to evaluate the effect of mode coupling on the amplitude growths of the basic *** qualitative results show that the phase combination obviously affects the interface morphologies and flow *** alternation of each mode amplitude does not affect the major flow features,such as the number and arrangement of the bubbles and spikes,but affects the local interface *** upon the phase combination,the mode amplitude growth is either promoted or suppressed by mode coupling relative to the single-mode *** considering the feedbacks from both the first-order and second-order mode couplings,the mode amplitude growth can be qualitatively *** to dual-mode interface,mode coupling occurs earlier in tri-mode *** the sets of parameters we studied,the effect of initial phase on the amplitude growth is greater and occurs earlier for the mode with low mode *** addition,the amplitude development of mode with high mode number is more affected by initial amplitudes of basic modes than that of mode with low mode *** introduction of the third mode affects the amplitude growths of original two modes,but has little effect on the final mixing width ***,a theoretical model is proposed to predict the amplitude growth of each basic mode.

关键词： convergent shock wave tri-mode interface mode-coupling

A CRACK CLOSURE MODEL FOR BRITTLE ROCK SUBJECTED TO COMPRESSIVE-SHEAR LOADING

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中国有色金属学会会刊：英文版 1999年第2期9卷 223-228页

作者： Chen, F Sun, ZQ xu, JC Cent S Univ Technol Opening Lab Mech Changsha 410083 Peoples R China

１ＩＮＴＲＯＤＵＣＴＩＯＮＣｏｍｐｒｅｓｓｉｏｎｓｈｅａｒｆｒａｃｔｕｒｅｏｆｒｏｃｋｗａｓｉｎｖｅｓｔｉｇａｔｅｄｂｙｍａｎｙｒｅｓｅａｒｃｈｅｒｓ，Ｒａｏｅｔａｌ［１］ｓｔｕｄｉｅｄｔｈｉｓｆａｉｌｕｒｅｍｏ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＣｏｍｐｒｅｓｓｉｏｎｓｈｅａｒｆｒａｃｔｕｒｅｏｆｒｏｃｋｗａｓｉｎｖｅｓｔｉｇａｔｅｄｂｙｍａｎｙｒｅｓｅａｒｃｈｅｒｓ，Ｒａｏｅｔａｌ［１］ｓｔｕｄｉｅｄｔｈｉｓｆａｉｌｕｒｅｍｏｄｅｕｓｉｎｇｆｏｕｒｐｏｉｎｔｂ...

关键词： crack closurecompressiveshear loadingstress intensity factor

Reduction of entropy uncertainty for qutrit system under non-Markov noisy environment

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Chinese Physics B 2020年第4期29卷 165-171页

作者： Xiong xu Mao-Fa Fang Synergetic Innovation Center for Quantum Effects and Applications Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of EducationSchool of Physics and ElectronicsHunan Normal UniversityChangsha 410081China

We explore the entropy uncertainty for qutrit system under non-Markov noisy environment and discuss the effects of the quantum memory system and the spontaneously generated interference(SGI)on the entropy uncertainty in *** results show that,the entropy uncertainty can be reduced by using the methods of quantum memory system and adjusting of ***,the entropy uncertainty can be decreased obviously when both the quantum memory system and the SGI are simultaneously applied.

关键词： entropy uncertainty relation non-Markov noisy qutrit and spontaneously generated interference

Dynamic Responses of Rotor Drops onto Double-decker Catcher Bearing

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Chinese Journal of Mechanical Engineering 2013年第1期26卷 104-113页

作者： ZHU Yili JIN Chaowu xu Longxiang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

In an active magnetic bearing （AMB） system, the catcher bearings （CBs） are indispensable to protect the rotor and stator in case the magnetic bearings fail. Most of the former researches associated with CBs are mainly focused on the dynamic responses of the rotor drops onto traditional single-decker catcher bearings （SDCBs）. But because of the lower limited speed of SDCB, it cannot withstand the ultra high speed rotation after rotor drop. In this paper, based on the analysis of the disadvantages of SDCBs, a new type of double-decker catcher bearings （DDCBs） is proposed to enhance the CB work performance in AMB system. In order to obtain thc accurate rotor movements before AMB failure, the dynamic characteristics of AMB are theoretically derived. Detailed simulation models containing rigid rotor model, contact model between rotor and inner race, DDCB force model as well as heating model after rotor drop are established. Then, using those established models the dynamic responses of rotor drops onto DDCBs and SDCBs are respectively simulated. The rotor orbits, contact forces, spin speeds of various parts and heat energies after AMB failure are mainly analyzed. The simulation results show that DDCBs can effectively improve the CBs limit rotational speed and reduce the following vibrations, impacts and heating. Finally, rotor drop experiments choosing different types of CBs are carried out on the established AMB test bench. Rotor orbits, inner race temperatures as well as the rotating speeds of both inner race and intermediate races after rotor drop are synchronously measured. The experiment results verify the advantages of DDCB and the correctness of theoretical analysis. The studies provide certain theoretical and experimental references for the application of DDCBs in AMB system.

关键词： active magnetic bearing dynamic stiffness rotor drop double-decker catcher bearing single-decker catcher bearing,heating

Degradation of polycyclic aromatic hydrocarbons by Pseudomonas ***2 isolated from active sewage sludge of chemical plant

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Journal of Environmental Sciences 2012年第12期24卷 2141-2148页

作者： Jing Ma Li xu Lingyun Jia School of Life Science and Biotechnology Dalian University of TechnologyLiaoning 116023China

It is important to screen strains that can decompose polycyclic aromatic hydrocarbons （PAHs） completely and rapidly with good adaptability for bioremedlation in a local area. A bacterial strain JM2, which uses pbenanthrene as its sole carbon source, was isolated from the active sewage sludge from a chemical plant in Jilin, China and identified as Pseudomonas based on 16S rDNA gene sequence analysis. Although the optimal growth conditions were determined to be pH 6.0 and 37~C, JM2 showed a broad pH and temperature profile. At pH 4.5 and 9.3, JM2 could degrade more than 40% of fluorene and phenanthrene （50 mg/L each） within 4 days. In addition, when the temperature was as low as 4~C, JM2 could degrade up to 24% fluorene and 12% phenanthrene. This showed the potential for JM2 to be applied in bioremediation over winter or in cold regions. Moreover, a nutrient augmentation study showed that adding formate into media could promote PAH degradation, while the supplement of salicylate had an inhibitive effect. Furthermore, in a metabolic pathway study, salicylate, phthalic acid, and 9-fluorenone were detected during the degradation of fluorene or phenanthrene. In conclusion, Pseudomonas sp. JM2 is a high performance strain in the degradation of fluorene and phenanthrene under extreme pH and temperature conditions. It might be useful in the bioremediation of PAHs.

关键词： polycyclic aromatic hydrocarbons Pseudomonas sp. biodegradation formate salicylate

Low-complexity fractional phase estimation for totally blind channel estimation

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Journal of Systems Engineering and Electronics 2015年第2期26卷 232-240页

作者： xu Wang Tao Yang Bo Hu Department of Electronic Engineering Fudan University Key Laboratory of EMW Information Fudan University

To remove the scalar ambiguity in conventional blind channel estimation algorithms, totally blind channel estimation （TBCE） is proposed by using multiple constellations. To estimate the unknown scalar, its phase is decomposed into a fractional phase and an integer phase. However, the maximum-likelihood （ML） algorithm for the fractional phase does not have closed-form solutions and suffers from high computational complexity. By ex- ploring the structures of widely used constellations, this paper proposes a low-complexity fractional phase estimation algorithm which requires no exhaustive search. Analytical expressions of the asymptotic mean squared error （MSE） are also derived. The theo- retical analysis and simulation results indicate that the proposed fractional phase estimation algorithm exhibits almost the same performance as the ML algorithm but with significantly reduced computational burden.

关键词： orthogonal frequency division multiplexing(OFDM) totally blind channel estimation(TBCE) scalar ambiguity fractional phase low-co

A CFD simulation of wave loads on a pile-type oscillating-water-column device

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Journal of Hydrodynamics 2019年第1期31卷 41-49页

作者： Zhenhua Huang Conghao xu Shijie Huang Department of Ocean and Resources Engineering School of Ocean and Earth Science TechnologyUniversity of Hawaii at ManoaHonoluluUSA

Oscillating-water-column (OWC) devices provide a practical and convenient way to convert wave energy to *** loads on bottom-sitting WECs are important design parameters for their foundation *** study considers an OWC integrated into a bottom-sitting pile structure (an OWC pile).Results from three-dimensional numerical simulations are used to examine the wave loads on an OWC *** appears that viscous loads and lateral loads are relatively *** the inline and vertical wave forces and the resulting overturning moment are not sensitive to the variability in wave period,but increase with wave *** suitable for the wave forces and overturning moment are proposed for estimating wave loads on the OWC pile.

关键词： Numerical simulation wave energy conversion OpenFOAM foundation safety