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Extraction kinetics of zinc by new extractant in ammoniacal system

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Journal of Central South University 2013年第7期20卷 1797-1804页

作者： HUANG Ling HE Jing CHEN Yong-ming YANG sheng-hai JIN sheng-ming tang Mo-tang School of Metallurgical Science and Engineering Central South University Changsha 410083 China Guangzhou Research Institute of Non-ferrous Metals Guangzhou 510000 China

The controlling step and the extraction reaction rate equation of zinc extraction from Zn（II）-NH3 solution by using a newly synthesized organic compound, 2-acetyl-3-oxo-dithiobutyric acid-myristyl ester as the zinc extractant, were clarified. The effects of agitation speed, specific interfacial area, temperature, extractant concentration and Zn ion concentration on the extraction rate are studied in constant interfacial area cell. The results show that the extraction rate depends on interfacial chemical reaction and diffusion by using this new extraetant to extract zinc, and the apparent activation energy of this extraction reaction is measured as 28.2 kJ/mol, which demonstrates that the extraction reaction is controlled by the mixed-controlled reaction rate. The apparent reaction orders a and b are measured as 1 and 0.38, and the constant k0 is 138.70. So, when extraction conditions are controlled as [HR]=20%-50%, T=0-30℃, N=120-177 r/min and S=72.6-127.5 m-1, the solvent extraction reaction rate can be depicted as v/（mol . m-2 . s-1 ） = 138.7. exp（ - 28 206/8.314T ）. [Zn 2＋ ]r ·[HR ]o0.38.

关键词： solvent extraction zinc 2-acetyl-3-oxo-dithiobutyric acid-myristyl ester kinetics

Chinese product of constacyclic and cyclic codes over finite rings

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The Journal of China Universities of Posts and Telecommunications 2013年第3期20卷 109-113页

作者： tang Yong-sheng ZHU Shi-xin School of Mathematics Hefei University of Technology Department of Mathematics Hefei Normal University

In this paper, we study the Gray images of the Chinese product of constacyclic and cyclic codes over a finite ring. We first introduce the Chinese product of constacyclic and cyclic codes over the finite ring. We then define a Gray map between codes over the finite ring and a finite field. We prove that the Gray image of the Chinese product of constacyclic codes over the finite ring is a distance-invariant quasi-cyclic code over the finite field. We also prove that each code over the finite field, which is the Gray image of the Chinese product of cyclic codes over the finite ring, is permutation equivalent to a quasi-cyclic code.

关键词： Chinese remainder theorem constacyclic codes cyclic codes quasi-cyclic codes

Circulating microRNAs: Novel biomarkers for esophageal cancer

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World Journal of Gastroenterology 2010年第19期16卷 2348-2354页

作者： Zhou, sheng-Li Wang, Li-dong Xinxiang Med Univ Canc Res Ctr Xinxiang 453003 Henan Peoples R China Zhengzhou Univ Basic Med Coll Henan Key Lab Esophageal Canc Res Zhengzhou 450052 Henan Peoples R China

Esophageal carcinogenesis is a multi-stage process, involving a variety of changes in gene expression and physiological structure change. MicroRNAs (miRNAs) are a class of small non-coding endogenous RNA molecules. Recent innovation in miRNAs profiling technology have shed new light on the pathology of esophageal carcinoma (EC), and also heralded great potential for exploring novel biomarkers for both EC diagnosis and treatment. Frequent dysregulation of miRNA in malignancy highlights the study of molecular factors upstream of gene expression following the extensive investigation on elucidating the important role of miRNA in carcinogenesis. We herein present a thorough review of the role of miRNAs in EC, addressing miRNA functions, their putative role as oncogenes or tumor suppressors and their potential target genes. The recent progresses in discovering the quantifiable circulating cancer-associated miRNAs indicate the potential clinical use of miRNAs as novel minimally invasive biomarkers for EC and other cancers. We also discuss the potential role of miRNAs in detection, screening and surveillance of EC as miRNAs can be a potential target in personalized treatment of EC.

关键词： Esophageal cancer Circulating microRNA

Molecular Dynamics Study of Star Polymer Melts under Start-up Shear

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Chinese Journal of Polymer Science 2022年第7期40卷 807-816页

作者： dong-dong Wang Kai-Feng Yu Xiao-Lei Xu Wen-sheng Xu Key Laboratory of Automobile Materials Ministry of Education and College of Materials Science and EngineeringJilin UniversityChangchun130025China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

It has been established that star polymers with a large number of arms display both the conventional chain relaxation and a slower interchain relaxation due to the formation of hard cores,which is called the local structural ***,we demonstrate that this unique relaxation property of multi-arm stars leads to unusual rheological *** study the response of star polymer melts with various arm numbers to start-up shear flow via nonequilibrium molecular dynamics *** simulation results indicate that the stress-strain response of multi-arm star polymer melts differs from that of star polymers with a small number of arms in both quantitative and qualitative *** the multi-arm star polymer melts exhibit an overshoot peak in the stress-strain curve both at relatively small and sufficiently large shear rates,two overshoot peaks appear when the flow strength is comparable to the relaxation time of the star *** double stress overshoot is absent in linear polymers and star polymers with a small number of arms and is evidently related to the presence of the local structural relaxation in star polymers with a large number of *** present a detailed analysis of the conformational and dynamical properties of star polymer melts under start-up shear to gain a molecular understanding of their stress response.

关键词： Simulation Star polymer Start-up shear

Metocean Design Parameter Estimation for Fixed Platform Based on Copula Functions

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Journal of Ocean University of China 2017年第4期16卷 635-648页

作者： ZHAI Jinjin YIN Qilin dong sheng College of Engineering Ocean University of China Qingdao 266100 P. R. China

Considering the dependent relationship among wave height,wind speed,and current velocity,we construct novel trivariate joint probability distributions via Archimedean copula *** 30-year data of wave height,wind speed,and current velocity in the Bohai Sea are hindcast and sampled for case *** kinds of distributions,namely,Gumbel distribution,lognormal distribution,Weibull distribution,and Pearson Type III distribution,are candidate models for marginal distributions of wave height,wind speed,and current *** Pearson Type III distribution is selected as the optimal *** and trivariate probability distributions of these environmental conditions are established based on four bivariate and trivariate Archimedean copulas,namely,Clayton,Frank,Gumbel-Hougaard,and Ali-Mikhail-Haq *** joint probability models can maximize marginal information and the dependence among the three *** design return values of these three variables can be obtained by three methods:univariate probability,conditional probability,and joint *** joint return periods of different load combinations are estimated by the proposed *** responses(including base shear,overturning moment,and deck displacement) are further *** the same return period,the design values of wave height,wind speed,and current velocity obtained by the conditional and joint probability models are much smaller than those by univariate *** the dependence among variables,the multivariate probability distributions provide close design parameters to actual sea state for ocean platform design.

关键词： Archimedean copulas univariate distribution bivariate distribution trivariate distribution platform response

Optical flare events on the RS Canum Venaticorum star UX Arietis

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Research in Astronomy and Astrophysics 2017年第6期17卷 55-66页

作者： dong-Tao Cao sheng-Hong Gu Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China University of Chinese Academy of Sciences Beijing 100049 China

Based on long-term high-resolution spectroscopic observations obtained during five observing runs from 2001 to 2004, we study optical flare events and chromospheric activity variability of the very active RS CVn star UX Ari. By means of the spectral subtraction technique, several optical chromospheric activity indicators （including the He IDa, Na I D1, D2 doublet, Ha and Ca II IRT lines） covered in our echelle spectra were analyzed. Four large optical flare events were detected on UX Ari during our observations, which show prominent He I D3 line emission together with great enhancement in emission of the Ha and Ca II IRT lines and strong filled-in or emission reversal features in the Na ! D1, D2 doublet lines. The newly detected flares are much more energetic than previous discoveries, especially for the flare identified during the 2002 December observing run. Optical flare events on UX Ari are more likely to be observed around two quadratures of the system, except for our optical flares detected during the 2004 November observing run. Moreover, we have found rotational modulation of chromospheric activity in the Ha and Ca II IRT lines, which suggests the presence of chromospherically active longitudes over the surface of UX Ari. The change in chromospherically active longitudes among our observing runs, as well as the variation in chromospheric activity level from 2001 to 2004, indicates a long-term evolution of active regions.

关键词： stars activity - stars chromospheres - stars binaries spectroscopic -stars flare -stars individual (UX Ari)

Dimensional Properties of Fractional Brownian Motion

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Acta Mathematica Sinica,English Series 2007年第4期23卷 613-622页

作者： dong sheng WU Yi Min XIAO Department of Statistics and Probability A-413 Wells Hall Michigan State University East Lansing MI 48824 USA

Let B^α = {B^α（t）,t E R^N} be an （N,d）-fractional Brownian motion with Hurst index α∈ （0, 1）. By applying the strong local nondeterminism of B^α, we prove certain forms of uniform Hausdorff dimension result... 详细信息

关键词： fractional Brownian motion Hausdorff dimension uniform dimension results strong local nondeterminism

Statistical Prediction for Annual Start Date and Duration of Sea-Ice Coverage at Qinhuangdao Observation Station

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Journal of Ocean University of China 2019年第6期18卷 1265-1272页

作者： JIAO Chunshuo ZHANG Wanlei dong sheng College of Engineering Ocean University of ChinaQingdao 266100China Qinhuangdao Marine Environmental Monitoring Central Station of SOA Qinhuangdao 066002China

Qinhuangdao City is located in the mid-latitude monsoon-affected region,and the timing of sea-ice coverage changes from year to year,making sea-ice forecasting *** this paper,we propose a statistical model using the 1980-2013 data collected at the Qinhuangdao observation *** start date and the duration of ice coverage are fitted with four marginal distributions,from which the best-fitted,i.e.,the Weibull distribution,is selected to form a joint probability density function(PDF),built by the Gaussian copula method,for the two *** a given start date forecast by the Gray-Markov model(GMM),the joint PDF becomes a conditional probability model,which predicts that the duration of ice coverage is most likely 33 days at the Qinhuangdao observation station in *** predicted duration value is only two days less than the actual *** results prove that the new prediction model is feasible and effective to predict the period of ice *** general sea-ice conditions that the sea ice would most likely form on December 8 and last for 80 days at the Qinhuangdao observation station could also be obtained from the joint *** statistical model provides a useful tool to forecast ice conditions for planning and management of maritime activities.

关键词： start date of sea ice duration of sea ice statistical prediction Weibull distribution Gaussian copula

GLCM Based Extraction of Flame Image Texture Features and KPCA-GLVQ Recognition Method for Rotary Kiln Combustion Working Conditions

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International Journal of Automation and computing 2014年第1期11卷 72-77页

作者： Jie-sheng Wang Xiu-dong Ren School of Electronic and Information Engineering University of Science and Technology Liaoning

According to the pulverized coal combustion flame image texture features of the rotary-kiln oxide pellets sintering process,a combustion working condition recognition method based on the generalized learning vector(GLVQ) neural network is ***,the numerical flame image is analyzed to extract texture features,such as energy,entropy and inertia,based on grey-level co-occurrence matrix(GLCM) to provide qualitative information on the changes in the visual appearance of the *** the kernel principal component analysis(KPCA) method is adopted to deduct the input vector with high dimensionality so as to reduce the GLVQ target dimension and network scale ***,the GLVQ neural network is trained by using the normalized texture feature *** test results show that the proposed KPCA-GLVQ classifer has an excellent performance on training speed and correct recognition rate,and it meets the requirement for real-time combustion working condition recognition for the rotary kiln process.

关键词： Rotary kiln pellets sintering texture features grey-level co-occurrence matrix kernel principal component analysis generalized learning vector quantization