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Extraction of vanadium from high calcium vanadium slag using direct roasting and soda leaching

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International Journal of Minerals,Metallurgy and Materials 2012年第7期19卷 595-601页

作者： xin-sheng Li Bing Xie College of Materials Science and Engineering Chongqing University Chongqing 400044 China

The extraction of vanadium from high calcium vanadium slag was attempted by direct roasting and soda leaching. The oxidation process of the vanadium slag at different temperatures was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The effects of roasting temperature, roasting time, Na2CO3 concentration, leaching tem- perature, leaching time, and liquid to solid ratio on the extraction of vanadium were studied. The results showed that olivine phases and spinel phases in the vanadium slag were completely decomposed at 500 and 800℃, respectively. Vanadium-rich phases were formed at above 850℃. The leaching rate of vanadium reached above 90% under the optimum conditions： roasting temperature of 850℃, roasting time of 60 min, Na2CO3 concentration of 160 g/L, leaching temperature of 95℃, leaching time of 150 min, and liquid to solid ratio of 10：1 mL/g. The main impurities were Si and P in the leach liquor.

关键词： vanadium metallurgy extraction slag roasting leaching

Discussion on rotational tectonic stress field and the genesis of circum-Ordos landmass fault system

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Acta Seismologica Sinica(English Edition) 2004年第4期17卷 464-472页

作者： XIE xin-sheng(谢新生) Institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China

When the resultant of applied forces does not pass through the center of an active landmass, the landmass will rotate, giving rise to a rotational tectonic stress field. The motion of a fault along the principal stress plane is de-termined by the mechanic features of the plane. Tensile fractures occur on the faults in the direction of the principal extensional stress plane, and fault-depression basins will be formed under a long-term action. Thrusting and over-thrusting occur on faults in the direction of the principal compressional stress plane, or folds may be formed as a result. Information on geology shows that the North China landmass, which remained stable and intact for a long time, became disjointed in the Eogene period. In the course of disjunction, anticlockwise rotation took place in the Shanxi-Hebei-Shaanxi (Jin-Ji-Shan) landmass, giving rise to the fault-depression system in its periphery. In the Pliocene epoch the landmass lost stability and its eastern boundary moved westward. As a result, the Shanxi gra-ben system appeared and Ordos landmass was formed. Structural and mechanic features of the main faults around Jin-Ji-Shan landmass can be explained with principal stress plane of a rotational tectonic stress field.

关键词： landmass rotation rotational structure principal stress plane Jin-Ji-Shan landmass Ordos

Subcritical,Critical and Supercritical Size Distributions in Random Coagulation-Fragmentation Processes

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Acta Mathematica Sinica,English Series 2008年第1期24卷 121-138页

作者： xin sheng ZHANG Wei An ZHENG Department of Statistics Fudan University 200433 P R. China Department of Mathematics University of California Irvine CA USA

We consider the asymptotic probability distribution coagula-tion-fragmentation process in the thermodynamic limit of the size of a reversible random We prove that the distributions of small, medium and the largest clusters converge to Gaussian, Poisson and 0-1 distributions in the supercritical stage （post-gelation）, respectively. We show also that the mutually dependent distributions of clusters will become independent after the occurrence of a gelation transition. Furthermore, it is proved that all the number distributions of clusters are mutually independent at the critical stage （gelation）, but the distributions of medium and the largest clusters are mutually dependent with positive correlation coefficient in the supercritical stage. When the fragmentation strength goes to zero, there will exist only two types of clusters in the process, one type consists of the smallest clusters, the other is the largest one which has a size nearly equal to the volume （total number of units）.

关键词： asymptotic distribution coagulation-fragmentation process gelation transition

A fault diagnosis model based on weighted extension neural network for turbo-generator sets on small samples with noise

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Chinese Journal of Aeronautics 2020年第10期33卷 2757-2769页

作者： Tichun WANG Jiayun WANG Yong WU xin sheng College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Business Strategy and Innovation Griffith UniversityGold Coast CampusQLD 4222Australia School of Business Jiangsu Open UniversityNanjing 210036China

In data-driven fault diagnosis for turbo-generator sets,the fault samples are usually expensive to obtain,and inevitably with noise,which will both lead to an unsatisfying identification performance of diagnosis *** address these issues,this paper proposes a fault diagnosis model for turbo-generator sets based on Weighted Extension Neural Network(W-ENN).WENN is a novel neural network which has three types of connection weights and an improved correlation *** performance of the proposed model is validated against Extension Neural Network(ENN),Support Vector Machine(SVM),Relevance Vector Machine(RVM)and Extreme Learning Machine(ELM)based *** results indicate that,on noisy small sample sets,the proposed model is superior to the other models in terms of higher identification accuracy with fewer samples and strong noise-tolerant *** findings of this study may serve as a powerful fault diagnosis model for turbo-generator sets on noisy small sample sets.

关键词： Fault diagnosis Samples with noise Small samples learning Turbo-generator sets Weighted Extension Neural Network

A revised rotation curve of the Milky Way with maser astrometry

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Research in Astronomy and Astrophysics 2013年第7期13卷 849-861页

作者： Xiao-sheng xin xing-Wu Zheng School of Astronomy and Space Science Nanjing University

We reconstruct the rotation curve of the Milky Way using the new trigono-metric parallax and proper motion data for masers in 43 high-mass star-forming re-gions obtained by VLBI, as well as the existing data from the literature, based on a new set of galactic constants （R0, -0） = （8.4 kpc, 254 km s^-1） measured by Reid et al. The revised rotation curve of the Milky Way is almost fiat or slightly rising in the region from about 6 to 15 kpc. The rotation velocities within 5 kpc of the Galactic center, as determined by VLBI, differ from those obtained by measurement of the HI-and CO-line tangent velocities. We fitted the revised rotation curve arising from three mass components： the bulge, disk and dark matter halo. The total mass of the Milky Way is found to be 2.3× 10^11 M⊙ （20 kpc）. This is about 10% larger than that from Sofue et al, and is comparable with the mass of M31, 3.4× 10^11 M⊙ （35 kpc）, given by Carignan et al. The limited accurate observational data, especially the VLBI data, do not permit a fully satisfactory fit to the rotation curve. The extensive par-allax and proper motion data that will be produced by the Bar and Spiral Structure Legacy Survey project in the next few years should lead to considerable progress in understanding the rotation curve and dark matter halo of the Milky Way.

关键词： Galaxy: structure - Galaxy: bulge - Galaxy: disk - Galaxy: halo-dark matter - masers

Bayesian Lasso with Neighborhood Regression Method for Gaussian Graphical Model

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Acta Mathematicae Applicatae Sinica 2017年第2期33卷 485-496页

作者： Fan-qun LI xin-sheng ZHANG Department of Statistics School of Management Fudan University Institute of Statistics and Applied Mathematics Anhui University of Finance and Economics

In this paper, we consider the problem of estimating a high dimensional precision matrix of Gaussian graphical model. Taking advantage of the connection between multivariate linear regression and entries of the precision matrix, we propose Bayesian Lasso together with neighborhood regression estimate for Gaussian graphical model. This method can obtain parameter estimation and model selection simultaneously. Moreover, the proposed method can provide symmetric confidence intervals of all entries of the precision matrix.

关键词： gaussian graphical model regression precision matrix Bayesian Lasso Frobenius loss

Bayesian Estimation of Large Precision Matrix Based on Cholesky Decomposition

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Acta Mathematica Sinica,English Series 2019年第5期35卷 619-631页

作者： Fan Qun LI xin sheng ZHANG Institute of Statistics and Applied Mathematics Anhui University of Finance and Economics School of Management Fudan University

In this paper, we consider the estimation of a high dimensional precision matrix of Gaussian graphical model. Based on the re-parameterized likelihood, we obtain the full conditional distribution of all parameters in Cholesky factor. Furthermore, by imposing the prior information, we obtain the shrinkage Bayesian estimator of large precision matrix, and establish the asymptotic distribution of all parameters in the Cholesky factor. At last, we demonstrate our method through the simulation study and an application to telephone call center data.

关键词： Bayesian estimation Cholesky decomposition graphical model shrinkage

Molecular mechanism of SurA’s chaperoning function to outer membrane proteins revealed by purification-after-crosslinking single-molecule FRET

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Science China Chemistry 2020年第8期63卷 1142-1152页

作者： Chenhui He Sichen Pan Geng Li xin sheng Zhao School of Life Sciences Peking UniversityBeijing 100871China Biomedical Pioneering Innovation Center(BIOPIC) Peking UniversityBeijing 100871China Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Speciesand Department of Chemical BiologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

SurA is the major chaperone of outer membrane proteins(OMPs)in the *** molecular mechanism when SurA performs its chaperoning function is still ***,a purification-after-crosslinking(PAC)procedure was combined with single-molecule fluorescence resonance energy transfer(smFRET)to probe the conformations of SurA and OmpC in their *** found that SurA in the free state rearranges itself based on the crystal structure,except that the P2 domain moves towards the core domain with two major positions,forming a clamp-like conformation to accommodate *** obvious rearrangement of the P2 domain of SurA helps SurA to hold *** attaches to SurA randomly and has the propensity to be near the middle part of the *** noncollapsed and disordered conformations of OMPs provided by the OMPs?SurA complex are important to the subsequent delivery and folding process.

关键词： outer membrane proteins SurA smFRET crosslinking

The New Fault Tolerant Onboard Computer for Microsatellite Missions

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The Journal of China Universities of Posts and Telecommunications 2006年第1期13卷 6-9页

作者： WANG xin-sheng SUN Han-xu Automation School Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

This paper describes an onboard computer with dual processing modules. Each processing module is composed of 32 bit ARM reduced instruction set computer processor and other commercial-off-the-shelf devices. A set of fault handling mechanisms is implemented in the computer system, which enables the system to tolerate a single fault. The onboard software is organized around a set of processes that communicate among each other through a routing process. Meeting an extremely tight set of constraints that include mass, volume, power consumption and space environmental conditions, the fault-tolerant onboard computer has excellent data processing capability that can meet the erquirements of micro-satellite missions.

关键词： onboard computer fault tolerance commerciat-off-the-shelt