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Rate Dependence of Serrated Flow and Its Effect on Shear Stability of Bulk Metallic Glasses

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Journal of Iron and Steel Research International 2016年第1期23卷 24-30页

作者： bao-an sun Chain-tsuan LIU Yong YANG Centre for Advanced Structural Materials Department of Mechanical and Biomedical EngineeringCity University of Hong Kong

The rate dependence of serrated flow and its effects on the stability of shear banding were systematically investigated in a prototypic bulk metallic *** was found that with the increase of external strain rate,the serrated flow is gradually suppressed and could completely disappear at a critical strain *** serration size,characterized by the mean stress drop amplitude,decreases inversely with the strain rate,while the waiting time for serration decreases with the strain rate in a power-law *** rate dependence of the serrated flow has important effects on the dynamics and stability of shear banding process,and leads to an optimal plasticity achieved around the critical strain rate for the disappearance of serrated *** results are discussed and interpreted in terms of the microscopic deformation theory and the stick-slip dynamics of shear banding for bulk metallic glasses.

关键词： serrated flow bulk metallic glass shear band ductility stick-slip

Dissipativity Analysis of Neural Networks with Time-varying Delays

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International Journal of Automation and computing 2008年第3期5卷 290-295页

作者： Yan sun bao-Tong Cui School of Communication and Control Engineering 3iangnan University Wuxi 3iangsu 214122 PI~C

A new definition of dissipativity for neural networks is presented in this paper. By constructing proper Lyapunov functionals and using some analytic techniques, sufficient conditions are given to ensure the dissipativity of neural networks with or without time-varying parametric uncertainties and the integro-differential neural networks in terms of linear matrix inequalities. Numerical examples are given to illustrate the effectiveness of the obtained results.

关键词： Neural network dissipativity Lyapunov functional

Aerosol flotation of low-grade refractory molybdenum ores

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International Journal of Minerals,Metallurgy and Materials 2012年第12期19卷 1077-1082页

作者： Tao Xu Chun-bao sun Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China

The characteristics of aerosol flotation, which include the effect of the concentration and particle size of kerosene aerosol on the molybdenum （Mo） flotation index and the effect of kerosene aerosol dosing method on the kerosene dosage and flotation time, were studied in the flotation of low-grade refractory molybdenum ores using kerosene aerosol. The results revealed that the particle size and concentration of kerosene aerosol had little effect on the Mo grade but had significant effect on the Mo recovery. A smaller particle size and a lower con-centration of kerosene aerosol were beneficial to the Mo aerosol flotation. For the received Mo ore samples, the optimized particle size of kerosene aerosol was 0.3-2 μm and the optimized aerosol concentration was 14 mg/L. The compressed air atomizer had a more uniform dis-tribution of aerosol particles than the ultrasonic atomizer, and the aerosol concentration was controlled easily, so the compressed air atomizer was more suitable for the research of aerosol flotation. Compared with conventional flotation in which kerosene was directly added into the ore pulp, the flotation time was reduced by ~30%, and the dosage was decreased by ~20% in aerosol flotation, while the Mo flotation index was similar.

关键词： molybdenum ore treatment flotation kerosene aerosols particle size

Optimization and mechanism of gold-bearing sulfide flotation

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Rare Metals 2014年第3期33卷 363-368页

作者： Zhong-Mei sun Chun-bao sun Ji-Zhen Wang Wan-Zhong Yin School of Civil and Environmental Engineering University of Science and Technology Beijing Zijin Research Institute of Mining and Metallurgy School of Materials & Metallurgy Northeastern University College of Zi Jin Mining Fuzhou University

In order to overcome the difficulty of extracting gold from gold-bearing sulfide ore by cyanide process flotation was adopted based on mineralogical analysis Mineralogy shows that gold particles are of superfine structure and mainly enclosed by sulfide ores. Primary gold-bearing sulfide ore is fine-grained pyrite and arsenopyrite. The paper describes the effects of ratios and dosage of activators and collectors on the recovery and grade of gold concentrate. A proper flotation flowsheet was then proposed based on experimental condition and closedcircuit test. The gold concentrate with the gold grade of25.14 g ton-1and the recovery of 86.94 % is obtained after one rougher, three cleaners, and four scavengers from fine grinding flotation process. Furthermore, the mechanisms of combined activators and combined collectors were studied by thermodynamic calculation, and structure-activity relationship of flotation reagent was also explained

关键词： Gold Pyrite Arsenopyrite Activator Combined reagent Flotation

Invariants for a Class of Nongeneric Three-Qubit States

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Communications in Theoretical Physics 2006年第6期45卷 1007-1010页

作者： sun bao-Zhi FEI Shao-Ming Department of Mathematics Capital Normal University Beijing 100037 China Max-Planck-Institute for Mathematics in the Sciences 04103 Leipzig Germany Department of Mathematics Qufu Normal University Qufu 273165 China

We investigate the equivalence of quantum states under local unitary transformations. A complete set of invariants under local unitary transformations are presented for a class of non-generic three-qubit mixed states. It is shown that two such states in this class are locally equivalent if and only if all these invariants have equal values for them.

关键词： invariant quantum state local unitary transformation

A review of gold extraction using noncyanide lixiviants: Fundamentals, advancements, and challenges toward alkaline sulfur-containing leaching agents

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International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 417-431页

作者： Chun-bao sun Xiao-liang Zhang Jue Kou Yi Xing School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China

Alkaline sulfur-containing lixiviants,including thiosulfate,polysulfides,and alkaline sulfide solutions,stand out as a promising class of alternatives to cyanide because of their low toxicity,high efficiency,and strong *** this paper,we summarized the research progress and remaining challenges in gold extraction using these noncyanide *** a brief introduction to the preparation method,the transformation process of various sulfur-containing species in alkaline solutions was ***,some insights into the mechanism of gold leaching in alkaline sulfur-containing solutions were presented from different aspects,including thermodynamics analysis,electrochemical dissolution,and leaching ***,recent progress in in-situ generation of sulfur-containing anions from gold-bearing sulfide minerals was outlined as *** passivation caused by sulfur species was discussed in particular because it is considered the greatest challenge facing sulfur-containing leaching *** sulfur-containing lixiviants are expected to serve as alternatives in industrial applications of gold extraction,particularly for refractory gold ores containing copper and carbonaceous matter.

关键词： gold extraction sulfur-containing lixiviants degradation in-situ generation passivation

Extracting compressive stress-strain curve based on stick-slip shear banding process in bulk metallic glasses

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Journal of Iron and Steel Research International 2017年第4期24卷 372-377页

作者： Jing Hu Yun-xuan Weng Xiao-li Li bao-an sun School of Material and Mechanical Engineering Beijing Technology and Business University Herbert Gleiter Institute of Nanoscience Nanjing University of Science & Technology

Based on the stick-slip process,an effective method to extract the stress-strain curve directly from the crosshead displacement-load raw data in compression of bulk metallic glasses was *** method was tested in two bulk metallic glass samples with different plasticities and shear band *** extracted stress-strain curves were found to well resemble the stress-strain curve measured by a laser *** addition,the extracted curve could resolve fine structures of serrated flow much better than that measured by extensometer,thus facilitating the study of shear banding *** obtained by this method made the stick-slip dynamics of shear banding valid,and this method could be employed to obtain the real strain of small-sized metallic glass samples where extensometer cannot be applied.

关键词： Serrated flow Shear banding Stick-slip Stress-strain curve

A Method for Data Classification Based on Discernibility Matrix and Discernibility Function

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Wuhan University Journal of Natural Sciences 2006年第1期11卷 230-233页

作者： sun Shi-bao QIN Ke-yun School of Science Southwest Jiaotong UniversityChengdu 610031 Sichuan China Electronic Information Engineering College Henan University of Science and Technology Luoyang 471003Henan China

A method for data classification will influence the efficiency of classification. Attributes reduction based on discernibility matrix and discernibility function in rough sets can use in data classification, so we put forward a method for data classification. Namely, firstly, we use discernibility matrix and discernibility function to delete superfluous attributes in formation system and get a necessary attribute set. Secondly, we delete superfluous attribute values and get decision rules. Finally, we classify data by means of decision rules. The experiments show that data classification using this method is simpler in the structure, and can improve the efficiency of classification.

关键词： discernibility matrix discernibility function attributes reduction data classification

Advances on Seed Vigor Physiological and Genetic Mechanisms

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Agricultural Sciences in China 2007年第9期6卷 1060-1066页

作者： sun Qun WANG Jian-hua sun bao-qi Department of Seed Science College of Agriculture and Biotechnology China Agricultural University Beijing 100094 P.R.China

Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influenced by genetic background and environmental effects during seed development and storage conditions. The latest research on physiological mechanism in seed vigor showed that at the late stage of seed development, the development of seed vigor involves some stress-resistant substances including late embryogenesis abundant （LEA） protein, oligosaccharides and abscisic acid （ABA）. Whereas the loss of seed vigor, or seed aging and deterioration, could be attributed to lipid peroxidation, chromosome deformation and genes aberrance, and embryo protein degradation, etc. Seed vigor is a quantitative character controlled by multi-genes. Genetic and quantitative trait locus （QTL） analyses on seed-vigor trait in model plants, such as Arabidopsis and rice, are mostly concentrated on related morphology traits, whereas few physiological traits have been researched. It was concluded that, all of the QTL genetic characteristics of seed vigorincluding QTL quantities, its locus on chromosome, genetic effects, and interaction effects between genetic and environment, differed with plant species and used seed-vigor traits.

关键词： seed vigor physiological and genetic mechanism QTL analyses