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Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

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science china Earth sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2, ZHAO Zhidan1,2, ZHANG Hongfei3, ZHANG Benren3 & CHEN Yuelong2 1. State Key Laboratory of Geological Processes and Mineral Resources, china university of Geosciences, Beijing 100083, china 2. School of Earth science and Mineral Resources, china university of Geosciences, Beijing 100083, china 3. faculty of Earth sciences, china university of Geosciences, Wuhan 430074, china 1. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China 2. School of Earth science and Mineral Resources China University of Geosciences Beijing 100083 China 3. faculty of Earth sciences China University of Geosciences Wuhan 430074 China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.27). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2Nb-Zr/4-Y and Ti/100-Zr-YX3 tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143)Nd/^(144)Nd (0.512955-0.512978). Pb isotopes are in the rangeof ^(206)Pb/^(204)Pb (18.054-20.562), ^(207)Pb/^(204)Pb (15.537-15.743) and ^(208)Pb/^(204)Pb(38.068-38.530). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

INFLUENCE OF ELECTROMAGNETIC STIRRING ON DENDRITIC STRUCTURE AND MECHANICAL PROPERTIES OF LOW SULPHUR STEEL

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Acta Metallurgica Sinica(English Letters) 1991年第1期4卷 75-78页

作者： HU Hanqi Zheng Riqi university of science and technology Beijing,Beijing,china Dept.of Foundry,faculty of Metallurgy,university of science and technology Beijing,Beijing 100083,china

The melt flow induced by the electromagnetic stirring in the molten low sulphur steel may re- fine the original austenite grains,but widen the secondary denritic arm *** a result, the ultimate tensile strength of the steel will be improved and the reduction of area will be re- markably *** microalloying by an addition of Ce may retard the unfavourable ef- fect of the electromagnetic stirring.

关键词： electromagnetic stirring dendritic structure plasticity

Modeling of Mechanical Behavior of Fractal Rock Joint

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 157-164页

作者： Jinan bang Marek A. Kwasniewski( Resources Engineering School. university of science and technology Beijing, Bejing 100083, china)( Rock Mechanics Laboratory, faculty of Mining and Geology, Technical university of Silesia, Gliwice , Poland) Resources Engineering School University of Science and Technology Beijing Beijing 100083 China Rock Mechanics Laboratory Faculty of Mining and Geology Technical University of Silesia Gliwice Poland

The present study shows that naturally developed fracture surfaces in rocks display the properties of self-affine fractals. Surface roughness can be quantitatively characterized by fractal dimension D and the intercept A on the log-log plot of variance: the former describes the irregularity and the later is statistically analogues to the slopes of asperities. In order to confirm the effects of these fractalparameters on the properties and mechanical behavior of rock joints, which have been observed in experiments under both normal andshear loadings, a theoretic model of rock joint is proposed on the basis of contact mechanics. The shape of asperity at contact is assumed to have a sinusoidal form in its representative scale r, with fractal dimension D and the intercept A. The model considers different local contact mechanisms, such as elastic deformation, frictional sliding and tensile fracture of the asperity. The empirical evolution law of surface damage developed in experiment is implemented into the model to up-date geometry of asperity in loading history. The effects of surface roughness characterized by D, A and re on normal and shear deformation of rock joint have been elaborated.

关键词： fractal roughness mechanical behavior rock joints fractal dimension the intercept contact mechanics normal stiffness shear stiffness, surface damage

Evaluation of genetic diversity and relationships within and between two breeds of duck based on microsatellite markers

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Progress in Natural science:Materials International 2009年第11期19卷 1581-1586页

作者： Fei Wu~a,Yinghua Huang~a,Ying Ma~b,Shengqiang Hu~c,Jinping Hao~c,Ning Li~a a State Key Laboratory for Agrobiotechnology,china agricultural university,Beijing 100193,china b College of animal science and Veterinary science,Inner Mongolia agricultural university,Hohhot 010018,china c Gold Star Duck Production Ltd.,Beijing 100076,china [a]State Key Laboratory for Agrobiotechnology China Agricultural University Beijing 100193 China [b]College of animal science and Veterinary science Inner Mongolia Agricultural University Hohhot 010018 China [c]Gold Star Duck Production Ltd. Beijing 100076 China

The genetic diversity of two natural populations(M,N) of Beijing duck(Anas platyrhynchos) and 11 artificially selected lines of Beijing duck(A,B,E-L,O) from china Gold Star Duck Production Ltd.,along with two Cherry Valley duck lines(C and D) from the British Cherry Valley Livestock Division,was evaluated using 18 microsatellite markers covering 16 linkage groups.A phylogenetic tree of the 15 populations of duck,formed of four main branches,was constructed from Nei’s DAgenetic *** mean genetic differentiation index(FST) in all loci,Nei’s standard genetic distance(Ds),and the genetic distance DAbetween the Beijing duck and the Cherry Valley duck were 0.075,0.143 and 0.142,*** results demonstrated a high degree of genetic similarity between the two breeds and supported the hypothesis that the Cherry Valley duck was derived from the Beijing *** FSTmatrix of seven clusters of Beijing duck suggested that the efficiency of selection was not significant to some extent and should be supplemented by marker -assisted selection.

关键词： Duck Microsatellite marker Genetic diversity Genetic distance

Layer structure,petroleum accumulation system and characteristic of subtle reservoir of continental basins in eastern china:Taking Jiyang depression for example

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science china Earth sciences 2008年第S2期51卷 146-155页

作者： XU HuaiMin1,XU ZhaoHui1,ZHANG ShanWen2,WANG ZhiGao2 & WANG YongShi2 1 faculty of Resource and Information technology,china university of Petroleum,Beijing 102249,china 2 Shengli Oil Field Ltd. Co.,SINOPEC,Dongying 257015,china 1. faculty of Resource and Information technology China University of Petroleum Beijing 102249 China 2. Shengli Oil Field Ltd. Co. SINOPEC Dongying 257015 China

The concept and division method for petroleum accumulation system,based on layer structure,are presented according to characteristics of layer structure and reservoirs. The petroleum accumulation system of Jiyang depression can be divided into four levels,namely petroleum accumulation system combination,petroleum accumulation system,oil-gas reservoir combination and reservoir. The petro-leum accumulation system combination includes three types of genetic pattern: other-source bur-ied-ridge accumulation system combination in pre-Paleogene,medium-deep layer self-source accu-mulation system combination in Paleogene,and shallow layer other-source accumulation system combination in Neogene. This paper also describes the reservoir types and their distribution charac-teristics of different petroleum accumulation system combinations and their interior units.

关键词： accumulation system Jiyang depression basin structure reservoir genetic pattern

Neural integrated control for a free-floating space robot with suddenly changing parameters

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science china(Information sciences) 2011年第10期54卷 2091-2099页

作者： ZHANG WenHui 1,2 ,QI NaiMing 2,MA Jing 1,3 & XIAO AYang 2 1 School of Electromechanical Engineering,Xuzhou Normal university,Xuzhou 221116,china 2 School of Aerospace,Harbin Institute of technology,Harbin 150001,china 3 Department of Engineering,Northeast agricultural university,Harbin 150001,china 1. School of Electromechanical Engineering Xuzhou Normal University Xuzhou 221116 China2. School of Aerospace Harbin Institute of Technology Harbin 150001 China3. Department of Engineering Northeast Agricultural University Harbin 150001 China

Because the state of a free-floating space robot model is uncertain and sudden changes in the model parameters might undermine the stability of the system,this paper proposes a control strategy based on a variable structure neural integrated *** scheme does not need a precise space robot model,making use of the radial basis function neural network ability approach to learn about an uncertain *** network weights are adjusted online in *** the early period of the control phase and parameter changes,the variable structure controller compensates for the uncertain model which the neural network could not learn *** also creates global asymptotic stability for the whole closed-loop *** results show that the controller can handle bad changeable conditions and has important application value for defense,aerospace and other major security fields.

关键词： neural network variable structure adaptive control global asymptotical stability

SHRIMP zircon U-Pb age and significance of Early Paleozoic volcanic rocks in East Kunlun orogenic belt, Qinghai Province, china

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science china Earth sciences 2006年第1期49卷 88-96页

作者： ZHU Yunhai1, LIN Qixiang1, JIA Chunxing2 & WANG Guocan1 1.faculty of Earth science, china university of Geosciences, Wuhan 430074, china 2.Regional Geological Survey Academy of Qinghai, Xining 800003, china 1. faculty of Earth science China University of Geosciences Wuhan 430074 China 2. Regional Geological Survey Academy of Qinghai Xining 800003 China

Early Paleozoic volcanic rocks in Nuomuhong area occurred as basalt slice and meta-volcanic slice. SHRIMP zircon U-Pb dating of the basalt slice and the meta-volcanic slice show that the age of the basalt slice is 419±5 Ma, and that of the meta-volcanic slice is 401± 6 Ma. These ages directly testify that there existed Early Paleozoic ocean-continent transform in East Kunlun, the basalt slice was formed in an extensional mid-ocean ridge setting and the meta-volcanic rock slice was formed in an extrusion subduction and collision setting. The inherited zircon age of 1734 Ma in volcanic rocks reflects that the base of East Kunlun may be Middle Proterozoic.

关键词： volcanic rocks, SHRIMP zircon U-Pb age, Early Paleozoic, East Kunlun orogenic belt.

Analysis of Stillbirth in Different Types of Sows

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agricultural sciences in china 2002年第6期1卷 702-706页

作者： CHU Ming-xing,WANG Ping-qing and WU Chang-xin( Institute of animal science , Chinese Academy of agricultural sciences , Beijing 100094 , P. R. china College ofBioengineering, Chongqing university, Chongqing 400044 , P. R . china College of animal science and technology,china agricultural university, Beijing 100094 , P.R. china) Institute of animal science Chinese Academy of Agricultural Sciences Beijing 100094 P. R. China College of Bioengineering Chongqing University Chongqing 400044 P. R . China College of animal science and technology China Agricultural University Beijing 100094 P. R . China

Statistical analysis was conducted on sow stillbirth traits of three mating types with 1686 litters including Erhualian, Large White and F1. The number of stillborn piglets per litter (NSB) in Erhualian, Large White and F1 averaged 0.87, 0.32, 0.72, and the percentage born alive (PBA) averaged 95.1%, 97.1% , 95.7% , respectively. The Erhualian pig with a higher litter size also had a higher stillbirth rate. The results of the variance analysis indicated that the mating type, parity, farrowing year X farrowing season interaction and the total number born had highly significant effects on both NSB and PBA in sows (P 0.05), and highly significant effects on PBA (P 23, the genetic correlation, phenotypic correlation and environmental correlation between them were -0.985, -0.947 and -0.942, respectively.

关键词： Sow Stillbirth Environmental effect Genetic analysis

Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

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Progress in Natural science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2, FENG Zhijing1 and CHENG Kai3(1. State Key Laboratory of Tribiology, Tsinghua university, Beijing 100084, china 2. Department of Material sciences, Changchun university of science and technology, Changchun 130021, china 3. faculty of Information and Engineering Systems, City Campus, Leeds LS1 3HE, UK) State Key Laboratory of Tribiology Tsinghua University Beijing 100084 China Department of Material sciences Changchun University of Science and Technology Changchun 130021 China faculty of Information and Engineering Systems City Campus Leeds LS1 3HE UK

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.22 nm root mean square (RMS) after 20 min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.