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Generalized Multivariate Gumbel Distributions——Dependence,Aging Properties and Applications

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Journal of Systems Science & Complexity 2016年第6期29卷 1752-1772页

作者： FANG Rui li xiaohu li linxiong Department of Mathematics Shantou University Department of Mathematical Sciences Stevens Institute of Technology Department of Mathematics University of New Orleans

This paper introduces a generalized multivariate Gumbel(GMG) distribution using a survival *** dependence properties of the GMG distribution and some analytical properties of the generators of the GMG distribution are ***,the authors also investigate the dependence behavior of the residual lifetime vector of the GMG *** an illustration,the GMG distribution is applied to fit a real data set.

关键词： Coefficient of orthant dependence residual lifetime vector survival copula upper orthantorder.

A NOTE ON THE RIGHT SPREAD ORDER ASSOCIATED WITH EXPONENTIAL DISTRIBUTIONS

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Journal of Systems Science & Complexity 2006年第1期19卷 108-113页

作者： xiaohu li School of Mathematics and Statistics Lanzhou UniversityLanzhou 730000 China

It is shown that the total life of a parallel system with independent and identical （i.i.d.） exponential components is smaller in the right spread order than an exponential life with the sane mean as the system. As applications, simple upper bounds for the mean and the variance of the life length of a parallel system with i.i.d. NBUE components are established, as well as the preservation property of the convolution of NBUE and exponential randorn variables.

关键词： Convolutions dispersive order majorization NBUE parallel system right spread order.

Investigation of Endwall Flow Behavior with Plasma Flow Control on a Highly Loaded Compressor Cascade

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Journal of Thermal Science 2012年第4期21卷 295-301页

作者： xiaohu ZHAO Yinghong li Yun WU Jun li Science and Technology on Plasma Dynamics Laboratory Air Force Engineering University Xi' an 710038 China

To discover the flow behavior in the endwall region and mechanism of plasma flow control on a highly loaded compressor cascade, distributions of static pressure coefficient, total pressure loss coefficient and streamline pat- tern were investigated. Results show that cross flow from the pressure surface to neighboring suction surface ex- ists under pitch-wise pressure gradient. The deflected endwall boundary layer flow interacts with the incoming flow, and then both of them leave off the endwall in tile form of a span-wise vortex. Effect of angle of attack on static pressure is greater than that of free stream velocity. The distinct variations of total pressure loss with end- wall actuations are mainly located within the outer verge of a triangular area with high total pressure loss. Effect of pitch-vAse actuation on separated flows is much better than that of stream-wise actuation, and both enhance with the increase of angle of attack and actuation strength. An efficient method for plasma flow control in the endwall region is the increase of actuation strength, such as adjusting discharge voltage or changing plasma power supply.

关键词： plasma flow control compressor cascade endwall region vortex

A new dynamic bacterial foraging optimization and its application on model reduction

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第2期6卷 107-131页

作者： Shenli Wu Sun’an Wang xiaohu li School of Mechanical Engineering Xi’an Jiaotong University Xi’an Shannxi710049P.R.China

Inspired by the foraging behavior of *** bacteria,bacterial foraging optimization(BFO)has emerged as a powerful technique for solving optimization ***,BFO shows poor performance on complex and high-dimensional optimization *** order to improve the performance of BFO,a new dynamic bacterial foraging optimization based on clonal selection(DBFO-CS)is *** of fixed step size in the chemotaxis operator,a new piecewise strategy adjusts the step size dynamically by regulatory factor in order to balance between exploration and exploitation during optimization process,which can improve convergence ***,reproduction operator based on clonal selection can add excellent genes to bacterial populations in order to improve bacterial natural selection and help good individuals to be protected,which can enhance convergence ***,a set of benchmark functions have been used to test the proposed *** results show that DBFO-CS offers significant improvements than BFO on convergence,accuracy and robustness.A complex optimization problem of model reduction on stable and unstable linear systems based on DBFO-CS is *** show that the proposed algorithm can efficiently approximate the systems.

关键词： Bacterial foraging optimization dynamic adjustment clonal selection model reduction

^(40)Ar/^(39)Ar ages of seamount trachytes from the South China Sea and implications for the evolution of the northwestern sub-basin

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Geoscience Frontiers 2015年第4期6卷 571-577页

作者： xiaohu li Jiabiao li Xing Yu Chunsheng Wang Fred Jourdan Key Laboratory of Submarine Geoscience State Oceanic Administration Second Institution of Oceanography State Oceanic Administration Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Western Australian Argon Isotope Facility Department of Applied Geology and Jd L Centre Curtin University

A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the ^40Ar/^39Ar age of trachytic samples collected from the Shuangfeng seamounts in the northwestern sub-basin of the South China Sea. The two samples yielded plateau ages of 23.80 ± 0.18 and 23.29 ± 0.22 Ma, respectively, which indicate magmatic activity in late Oligocene which helpful constraints the expansion time of the northwest sub-basin. Previous studies suggested that the northwestern sub-basin and southwestern sub-basin have experienced a relatively consistent expansion in the NW-SE direction followed by a late expansion of the eastern sub-basin. We concluded that the expansion of the northwestern sub-basin began prior to ca. 24 Ma, which also implicated magmatic events of a late or stop expansion of the northwestern sub-basin combined with our results of^40Ar/^39Ar age data and previous geophysical data.

关键词： ^40Ar/^39Ar datingSeamount trachyteNorthwest sub-basinExpansion historySouth China Sea

Chemical composition and petrogenesis of plagioclases in plagioclase-phyric basalts from the Southwest Indian Ridge(51°E)

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Acta Oceanologica Sinica 2020年第7期39卷 42-49页

作者： Jie li Jihao Zhu Fengyou Chu xiaohu li Zhimin Zhu Hao Wang Key Laboratory of Submarine Geosciences Ministry of Natural ResourcesHangzhou 310012China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China

Electron microprobe analysis was conducted on plagioclase from the plagioclase ultraphyric basalts(PUBs)erupted on the Southwest Indian Ridge(SWIR)(51°E)to investigate the geochemical changes in order to better understand the magmatic processes occurring under ultraslow spreading ridges and to provide insights into the thermal and dynamic regimes of the magmatic reservoirs and conduit *** phenocryst cores are generally calcic(An74–82)and are depleted in FeO and *** the phenocryst rims(An67–71)and the plagioclase in the groundmass(An58–63)are more sodic and have higher FeO and MgO contents than the phenocryst *** crystallization temperatures of the phenocryst cores and the calculation of the equilibrium between the phenocrysts and the matrix suggest that the plagioclase cores are unlikely to have crystallized from the host basaltic melt,but are likely to have crystallized from a more calcic *** enrichment in incompatible elements(FeO and MgO),as well as the higher FeO/MgO ratios of the outermost phenocryst rims and the groundmass,are the result of plagioclase-melt disequilibrium diffusion during the short residence time in which the plagioclase *** results indicate that an evolved melt replenishing under the SWIR(51°E)drives the eruption over a short period of time.

关键词： plagioclase–phyric basalt plagioclase phenocrysts magmatic evolution SWIR

Classification of Magmatic Sulphide Deposits in China and Mineralization of Small Intrusions

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Acta Geologica Sinica(English Edition) 2006年第3期80卷 412-419页

作者： TANG Zhongli YAN Haiqing JIAO Jiangang li xiaohu Chang＇an University Xi＇an Shaanxi 710054 Lanzhou University Lanzhou Gansu 730000

Many important metal resources, such as Ni （Cu, Co）, PGE, exist in magmatic sulfide deposits, are a hot spot in geological research. We divide the magmatic sulphide deposits in China into four types according to their tectonic setting, intruding mode, ore deposit mode, main metallogenic elements. The four types are as follows：（1） Small-intrusion deposits in paleo-continent; （2） Smallintrusion deposits in continental flood basalt; （3） Small-intrusion deposits in orogenic belt; and （4） The deposits associated with ophiolites. On the basis of the classification, we put forward that the main magmatic metallogenic type in China is small-intrusion metallogeny, and describe its characteristics from small intrusions related concept, three geologic settings, three volcanic-intrusive assemblages and metallogenic key factors. According to the experiences of prospecting at home and abroad, we point out that there is big potential in prospecting small-intrusion deposits, which need further study. At last, we indicate that small-intrusion metallogeny not only widely distributes in mafic-ultramafic intrusions, but also has an important economic value and scientific significance in intermediate-acid intrusions.

关键词： magmatic sulfide deposits classification small intrusions metallogenesis

Design and Analysis of Gecko-like Robot

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 224-236页

作者： MENG Cai WANG Tianmiao GUAN Shengguo ZHANG Long WANG Jing li xiaohu School of Astronautics Beihang University Beijing 100191 China School of Mechanical Engineering andAutomation Reihang University Beijing 100191 China School of Mechanical Engineering Beijing University of Science and Technology Beijing 100083 China

Gecko-like robot（Geckobot）,an important branch of bionic robotics,is a robot that simulates gecko＇s capacity to climb walls and *** work environment of the traditional wall-climbing robot is greatly limited as the moving structure and adsorption principle of the robot have nothing to do with the real ***,the adsorption principle and moving mode of the real gecko can provide a new way to break through the restrictions of the traditional wall-climbing *** by the moving mechanism of geckos, this paper develops the Geckobot with motile *** types of Geckobots are addressed：one with compliant flat bar as the body,and the other with prismatic joint as the *** compliant body not only resembles the moving mode of the real gecko body,but also simplifies the Geckobot＇s *** prismatic joint body is used to adapt the change of body length in ground-to-wall transition. The gait planning on the plane and the transition between perpendicular intersectional planes is discussed,with an emphasis on the analysis of the kinematics degree of freedom（DOF） and body *** pattern generator（CPG） neural network is realized in LabVIEW and utilized to control Geckobot＇s *** CPG scheme in Lab VIEW is given,and how CPG is used to control Geckobot to turn or move forward is *** are conducted in ADAMS to verify the feasibility of the structure design and gait planning and to acquire some parameters for practical Geckobot *** experiment with Geckobot-Ⅰand Geckobot-Ⅱon their crawling capacity on the plane and the ground-to-wall transition finds that the robot can complete the crawling movement and ground-to-wall transition,verifying the feasibility of the structure design,gait planning and the CPG motion *** Geckobot structure design approach,gait planning and the CPG motion control presented would be useful for the research on wall-climbing robots.

关键词： gecko-like robot structure design gait planning ground-to-wall transition central pattern generator

Major and trace element composition of surface sediments from the Southwest Indian Ridge:evidence for the incorporation of a hydrothermal component

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Acta Oceanologica Sinica 2016年第2期35卷 101-108页

作者： li Zhenggang CHU Fengyou JIN Lu li xiaohu DONG Yanhui CHEN ling ZHU Jihao Key Laboratory of Submarine Geoscience Second Institute of OceanographyState Oceanic Administration (SOA) Department of Earth Sciences Zhejiang University

Hydrothermal materials in deep-sea sediments provide a robust tracer to the localized hydrothermal activity at mid-ocean ridges. Major, trace and rare earth element（REE） data for surface sediments collected from the ultraslow spreading Southwest Indian Ridge are presented to examine the existence of hydrothermal *** carbonate oozes dominate all the sediment samples, with CaO content varying from 85.5% to 89.9% on a volatile-free basis. The leaching residue of bulk sediments by ~5% HCl is compositionally comparable to the Upper Continental Crust（UCC） in SiO_2, Al_2O_3, CaO, MgO, alkali elements（Rb, Cs） and high field strength elements（Nb, Ta, Zr, Hf, Ti）. These detritus-hosted elements are inferred to be prominently derived from the Australian continent by means of eolian dust, while the contribution of local volcaniclastics is insignificant. In addition, the residual fraction shows a clear enrichment in Fe, Mn, and Ba compared with the UCC. Combining the positive Eu anomaly of residual fraction which is opposed to the UCC but the characteristic of hydrothermal fluids and associated precipitates occurred at mid-ocean ridges, the incorporation of localized hydrothermal component can be constrained. REE mixing calculations indicate that more than half REE within the residual fraction（~55%–60%） are derived from a hydrothermal component, which is inferred to be resulted from a diffuse fluid mineralization. The low-temperature diffuse flow may be widely distributed along the slow-ultraslow spreading ridges where crustal faults and fissures abound, and probably have a great mineralization potential.

关键词： deep-sea sediments hydrothermal component diffuse fluid eolian dust Southwest Indian Ridge