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Observation of atmospheric methane in the Arctic Ocean up to 87° north

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Science China Earth Sciences 2017年第1期60卷 173-179页

作者： zhang min QIAO FangLi SONG ZhenYa The First Institute of Oceanography State Oceanic Administration Qingdao 266061 China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology Qingdao 266237 China Key Lab of Marine Science and Numerical Modeling State Oceanic Administration Qingdao 266061 China

Although the Arctic methane reservoir is large,the emission of methane from the Arctic Ocean into the atmosphere remains poorly *** ship-borne measurements of atmospheric methane near the surface ocean were carried out during two cruises to investigate methane emission from the Arctic Ocean up to the latitude of 87°***-day air mass back trajectories along the cruise tracks indicated that the surface Arctic Ocean could be a potentially important source of methane to the *** bursts in methane concentration occurred mainly along the ocean frontal area,suggesting that frontal upwelling in the upper layer of the Arctic Ocean might contribute to methane emissions into the atmosphere.

关键词： Methane The Arctic Ocean Frontal upwelling

A closed-form solution for moving source localization using LBI changing rate of phase difference only

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Chinese Journal of Aeronautics 2014年第2期27卷 365-374页

作者： zhang min Guo Fucheng Zhou Yiyu College of Electronic Science and Engineering National University of Defense Technology

Due to the deficiencies in the conventional multiple-receiver localization syste,.ns based on direction of arrival （DOA） such as system complexity of interferometer or array and ampli- tude/phase unbalance between multiple receiving channels and constraint on antenna configuration, a new radiated source localization method using the changing rate of phase difference （CRPD） measured by a long baseline interferometer （LBI） only is studied. To solve the strictly nonlinear problem, a two-stage closed-form solution is proposed. In the first stage, the DOA and its changing rate are estimated from the CRPD of each observer by the pseudolinear least square （PLS） method, and then in the second stage, the source position and velocity are found by another PLS minimiza- tion. The bias of the algorithm caused by the correlation between the measurement matrix and the noise in the second stage is analyzed. To reduce this bias, an instrumental variable （IV） method is derived. A weighted IV estimator is given in order to reduce the estimation variance. The proposed method does not need any initial guess and the computation is small. The Cramer-Rao lower bound （CRLB） and mean square error （MSE） are also analyzed. Simulation results show that the proposed method can be close to the CRLB with moderate Gaussian measurement noise.

关键词： Changing rate of phase dif-ference Cramer-Rao lower bound Estimation bias Instrumental variable Least square Long baseline interferome-ter Radiated source localization

Corrosion Inhibition of SiCp/5A06 Aluminum Metal Matrix Composite by Cerium Conversion Treatment

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Chinese Journal of Aeronautics 2009年第6期22卷 670-676页

作者： Irfan Aziz zhang Qi Xiang min School of Materials Science and Engineering Beo'ing University of Aeronautics and Astronautics Beijing 100191 China

This article studies the effects of the CeCl3 concentrations in conversion solutions with and without addition of NaCl, pH-values of conversion solution, drying temperature, time and temperature of immersion on the Ce-conversion coatings for corrosion protection of the SiCp/5A06 Al-MMC and 5A06 Al-alloy in the 3.5% NaCl aqueous solution at room temperature. Potentiodynamic polarization tests reveal that the Ce-conversion treatment could markedly improve the pitting corrosion resistance of the composite and the matrix alloy in chloride containing environment. The best corrosion resistance effects are obtained for the samples treatment in 1% CeCl3.7H2O/3.5% NaCl solution at 45℃ for 60 min, followed by drying at 100 ℃ for 30 min. Examinations by means of scanning electron microscopy （SEM）, energy dispersion spectroscopy （EDS） and X-ray photoelectron spectroscopy （XPS） indicate that this behavior is due to the precipitation of Ce-oxides/hydroxides on the cathodic intermetallics and the Al-oxide film on the rest of the metal matrix.

关键词： cerium thermal coatings SiCp/5A06 Al matrix composites potentiodynamic polarization alkaline corrosion

Fixed-wing UAV guidance law for ground target over-flight tracking

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Journal of Systems Engineering and Electronics 2019年第2期30卷 384-392页

作者： zhang min ZHENG Chenming HUANG Kun College of Automation Engineering Nanjing University of Aeronautics and Astronautics

This paper studies the problem of tracking a ground target for a fixed-wing unmanned aerial vehicle(UAV) based on the proposed guidance law. The algorithm ensures that a UAV continuously overflies the target whether it is fixed or moving. The requirements of the UAV flight constraints such as bounded airspeed and acceleration are considered. A Lyapunov function is constructed to prove the stability of the proposed guidance law,and parameter design criteria have been developed. Considering the fixed and moving ground targets, numerical simulations are performed to verify the feasibility and benefits of the proposed guidance algorithm.

关键词： unmanned aerial vehicle (UAV) ground target guidance law over-flight stability

Experimental study of anti-cavitation mechanism of valve lintel natural aeration of high head lock

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Journal of Hydrodynamics 2020年第2期32卷 337-344页

作者： Xin Wang Ya-an Hu Jian-min zhang Hydraulic Engineering Department Nanjing Hydraulic Research InstituteNanjing210029China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing210029China

To study the serious valve top gap cavitation of Datengxia high head single-lift ship lock,the 1:1 scale slice experiment is carried out,to truly reveal the gap flow characteristics,as well as the valve top gap cavitation characteristics and the anti-cavitation mechanism of natural *** kinds of cavitation,namely,the throat cavitation,the mainstream inner cavitation,and the valve plate cavitation,are determined and they are found to occur step-by-step in the gap section in the development of the *** to the anti-cavitation mechanism of the natural aeration,the pressure of the gap flow through the ventilation is increased,to avoid the mainstream inner cavitation and the valve plate cavitation,and to weaken the throat *** negative pressure zone in the gap section gradually extends with the development of the cavitation until the gap section is filled with a stable−10 m water *** the natural aeration measure is employed,the pressure in the gap section approximately reaches the−2 m water head,and the cavitation *** systematic tests reveal the quadratic polynomial relationship between the pressure in the gap and the ventilation per meter *** pressure,which corresponds to the maximum value of the ventilation at the beginning of the gap,approximately reaches the−2 m water head,and the pressure and the ventilation reach the equilibrium state *** the pressure in the gap increases when the valve is opened,the ventilation gradually decreases until the natural aeration *** gap section length for the high head valves has a great effect on the natural aeration and should be long enough to maintain the stable negative pressure in the gap,whereas the throat width has a minimal *** can be used for the anti-cavitation design of the high head lock valve.

关键词： High head lock valve top gap cavitation natural aeration slice experiment

A Case Study on the Occurrence and Mobility of the Shale Oil from the Muli Coalfield,Qilian Mountain

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Acta Geologica Sinica(English Edition) 2016年第6期90卷 2267-2268页

作者： CHEN Xiaohui zhang min Key Laboratory of Exploration Technology for Oil & Gas Research Yangtze UniversityMinistry of Education College of Resources and Environment Yangtze University

Shale oil occurs in free state （including condensate state）, adsorption state （adsorbed on kerogen and mineral particles） and dissolved state （dissolved in natural gas, residual water, etc.） in shales and adjacent layers. The characterization of the occurrence of different hydrocarbons in shale oil, especially the quantitative separation of free hydrocarbons （mobile oil）, has been the current focus of shale oil research. Taken the shale oil from the Muli coalfield in Qilian Mountain as an example, this work extracted shale samples with organic solvents of different polarity to obtain different occurrence states of hydrocarbons in the oil-bearing shale and to reveal the compositional differences of the hydrocarbons. The result may provide new geochemical information for the occurrence and mobility of shale oil.

关键词： than EOM A Case Study on the Occurrence and Mobility of the Shale Oil from the Muli Coalfield,Qilian Mountain

Selective Deoxygenation of Nitrones Mediated by Sm/CoCl_26H_2O Reductive System

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Chinese Chemical Letters 2001年第11期12卷 945-946页

作者： Ji ming zhang Yong min zhang Department of Chemistry Zhejiang University(Xixi Campus)Hangzhou 310028 State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032

In the presence of metallic samariumcobalt (II) chloride hexahydrate, the nitrones can be reduced to the corresponding imines in moderate to high yields under mild and neutral conditions.

关键词： Nitrone samarium cobalt (II) chloride hexahydrate.

Geochemical characteristics of saturate hydrocar-bons in crude oils and source rocks of the Qaidam,Tarim,Tupran basins,NW China

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Chinese Journal Of Geochemistry 2012年第3期31卷 264-275页

作者： zhang min PAUL Philp Department of Geochemistry Yangtze UniversityJingzhou434023China The Key Laboratory of Oil&Gas Resources and Exploration Technology Ministry of EducationYangtze UniversityJingzhou434023China School of Geology and Geophysics University of OklahomaNormanOK 73019USA

Based on the systematic analyses of fifteen typical crude oils and ten typical potential source rocks col-lected from the Qaidam,Tarim and Turpan basins,Northwest China,the geochemical characteristics of the oils and source rocks were investigated and oil-source rock correlations *** oils and source rocks deposited in saline lacustrine environment from the western Qaidam Basin were characterized by n-alkanes with even car-bon-number preference in the C20-C28 range,low pristane/phytane(Pr/Ph) ratios(less than 0.5),and high abundances of C27 steranes,gammacerane and C35 *** oils and source rocks deposited in marine environment from the Tarim Basin were characterized by n-alkanes with even carbon-number preference in the C14-C18 range,relatively low Pr/Ph ratios(near to 1),high abundance of C28 steranes,and relatively high *** contrast,the oils and source rocks deposited in terrigenous bog environment from the Turpan Basin were characterized by relatively high Pr/Ph ratios(oil samples greater than 6) high abundance of C29 steranes,and relatively low gammacerane and C31-35 *** higher amounts of C37 and C38 n-alkanes of source rocks from the western Qaidam Basin and the Tarim Basin suggest an origin of these alkanes from functionalized C37 and C38 n-alkadienes and alkenones in prymnesiophytes living in lacustrine and marine ***-source rock correlations suggest oils in the west-ern Qaidam Basin were derived from the Oligocene Lower Ganchaigou Formation(E3),oils in the Tabei and Tazhong uplifts from the Tarim Basin have a genetic relationship with the Middle-Upper Ordovician source *** in the Turpan Basin generally fall into two genetic *** oils in the Taibei depression from the Turpan Basin were derived from the Lower-Middle Jurassic coal measures,but the fewer oils in this region are a mixed source derived from the Lower-Middle Jurassic coal measure and the Upper Permian source rocks.

关键词：地球化学特征塔里木盆地柴达木盆地中国西北地区烃源岩碳氢化合物原油吐鲁番盆地

Geochemical characteristics of aromatic hydrocarbons in saline lacustrine crude oils and their significance as exemplified by the south area of western Qaidam Basin

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Chinese Journal Of Geochemistry 2012年第4期31卷 476-484页

作者： MO Xiaoye zhang min Department of Geochemistry Yangtze UniversityJingzhou 434023China Key Laboratory of Exploration Technologies for Oil and Gas Resources Ministry of EducationYangtze UniversityJingzhou 434023China

Based on quantitative GC-MS analysis of 40 crude oil samples collected from the south area of western Qaidam Basin,one of the largest saline lacustrine basins in China,the geochemical characteristics of aromatic hydrocarbons in oils were studied systematically in this *** those constitutes,naphthalene(43% 59%),phenanthrene(12% 21%) and taromatic-sterane series(6% 28%) were the main ones of aromatic *** ratio of aromatic hydrocarbon maturity parameter *** hydrocarbon maturity parameter C 29 20S/(20S+20R) shows that some aromatic hydrocarbon maturity parameters are not suitable for low-mature oils,including MPI,MNR,DNR,***,maturity parameters for dibenzothiophene and taromatic-sterane series are more appropriate for low maturity saline lacustrine crude *** on the ratio of 4,6-DMDBT/1,4-DMDBT,the R c values are within the range of 0.59% 0.72%.However,the abundance of dibenzothiophene(DBT) is low,and the dibenzofuran(DBF) content is even lower,suggesting that the crude oils were formed in a saline lacustrine anaerobic *** high abundance of C 26 triaromatic steroid also indicates that the source material is brackish water-saline water with strong reducibility.

关键词：柴达木盆地西部地球化学特征湖相原油盐水湖芳香烃成熟度参数二苯并噻吩 GC-MS分析