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Orientation and strain rate dependent tensile behavior of single crystal titanium nanowires by molecular dynamics simulations

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Journal of Materials Science & Technology 2018年第5期34卷 864-877页

作者： Le chang chang-Yu Zhou Hong-Xi Liu Jian Li xiao-Hua He School of Mechanical and Power Engineering Nanjing Tech University Nanjing 211816 China School of Mechanical Engineering Jiangsu University of Science and Technology Zhenjiang 212000 China

Molecular dynamics simulation was employed to study the tensile behavior of single crystal titanium nanowires（NWs）with[112^-0],[1^-100] and[0001]orientations at different strain rates from 10^8s^-1 to 10^11s^-*** strain rates are above 10^10s^-1,the state transformation from HCP structure to amorphous state leads to super plasticity of Ti NWs,which is similar to FCC *** strain rates are below 10^10s^-1,deformation mechanisms of Ti NWs show strong dependence on *** [112^-0] orientated NW.{101^-1} compression twins（CTs）and the frequently activated transformation between CTs and deformation faults lead to higher plasticity than the other two orientated ***,tensile deformation process along [112^-0] orientation is insensitive to strain *** [1^-100] orientated NW,prismaticslip is the main deformation mode at 10^8s^-*** the strain rate increases,more types of dislocations are activated during plastic deformation ***[0001]orientated NW,{101^-2} extension twinning is the main deformation mechanism,inducing the yield stress of [0001] orientated NW,which has the highest strain rate *** number of initial nucleated twins increases while the saturation twin volume fraction decreases nonlinearly with increasing strain rate.

关键词： Molecular dynamics Single crystal titanium nanowires Strain rate Orientation Plastic deformation mechanisms

Fault Feature Extraction of Diesel Engine Based on Bispectrum Image Fractal Dimension

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 216-226页

作者： Jian Zhang chang-Wen Liu Feng-Rong Bi xiao-Bo Bi xiao Yang State Key Laboratory of Engines Tianjin University

Fault feature extraction has a positive effect on accurate diagnosis of diesel engine. Currently, studies of fault feature extraction have focused on the time domain or the frequency domain of signals. However, early fault signals are mostly weak energy signals, and time domain or frequency domain features will be overwhelmed by strong back?ground noise. In order consistent features to be extracted that accurately represent the state of the engine, bispectrum estimation is used to analyze the nonlinearity, non?Gaussianity and quadratic phase coupling(QPC) information of the engine vibration signals under different conditions. Digital image processing and fractal theory is used to extract the fractal features of the bispectrum pictures. The outcomes demonstrate that the diesel engine vibration signal bispectrum under different working conditions shows an obvious differences and the most complicated bispectrum is in the normal state. The fractal dimension of various invalid signs is novel and diverse fractal parameters were utilized to separate and characterize them. The value of the fractal dimension is consistent with the non?Gaussian intensity of the signal, so it can be used as an eigenvalue of fault diagnosis, and also be used as a non?Gaussian signal strength indicator. Consequently, a symptomatic approach in view of the hypothetical outcome is inferred and checked by the examination of vibration signals from the diesel motor. The proposed research provides the basis for on?line monitoring and diagnosis of valve train faults.

关键词： Engine fault diagnosis Bispectrum image processing Fractal Signal processing

Absolute parameters and physical nature of two W-UMa type binaries:V1123 Tau and V1128 Tau

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Research in Astronomy and Astrophysics 2011年第5期11卷 583-593页

作者： xiao-BinZhang An-BinReni chang-QingLuc Yang-PingLuo NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012China InstituteofTheoreticalPhysics ChinaWestNormalUniversityNanchong637002China NationalAstronomicalObservatories／YunnanObservatory ChineseAcademyofSciencesKunming650011China

We present high-precision, multi-band CCD photometry of two less-studied close binaries V1123 Tau and V1128 Tau. Complete covered light curves and a number of new times of light minima of the two eclipsing systems were obtained, based on which, revised orbital elements and new ephemerides were given. By adopting the Wilson-Devinney method, the light curves were analyzed. The photometric solutions confirm the W UMa-type nature of the binary systems. With the less-massive secondary slightly cooler than the primary, V1123 Tau could be classified as an A- type contact system. While V1128 Tau is typically considered a W-type W UMa star, the surface temperature of its secondary component is determined to be absolutely higher than the primary by about 270 K. Combining with the results of radial-velocity solutions, we determined absolute parameters of the two systems. The mass, radius and luminosity for each component of V1123 Tau were derived as： 1.36 ±0.05M⊙, 1.37 ± 0.02R⊙, and 2.01± O.07L⊙ and 0.40±0.02M⊙, 0.80±0.01R⊙, and 0.67±0.04L⊙, respectively. For V1128 Tau, the absolute parameters were computed to be 1.09±0.03M⊙, 1.01±0.01R⊙, and 1.34±0.06Le and 0.58 ± 0.01M⊙, 0.76±0.01R⊙, and 0.91±0.05L⊙, respectively. Based on these results, the evolutionary status and the physical nature of the two binary systems are discussed, while also connecting with the theoretical models.

关键词： binaries: eclipsing-stars: late-type-stars: activity -stars: individ-ual (V1123 Tau Vl128 Tau)

Exploring optimal combination of a file system and an I/O scheduler for underlying solid state disks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第8期15卷 607-621页

作者： Hui SUN xiao QIN chang-sheng XIE National Laboratory for Optoelectronics and School of Science and Technology Huazhong University of Science and Technology Department of Computer Science and Software Engineering Auburn University

Performance and energy consumption of a solid state disk(SSD) highly depend on file systems and I/O schedulers in operating systems. To find an optimal combination of a file system and an I/O scheduler for SSDs, we use a metric called the aggregative indicator(AI), which is the ratio of SSD performance value(e.g., data transfer rate in MB/s or throughput in IOPS) to that of energy consumption for an SSD. This metric aims to evaluate SSD performance per energy consumption and to study the SSD which delivers high performance at low energy consumption in a combination of a file system and an I/O scheduler. We also propose a metric called Cemp to study the changes of energy consumption and mean performance for an Intel SSD(SSD-I) when it provides the largest AI, lowest power, and highest performance, respectively. Using Cemp, we attempt to find the combination of a file system and an I/O scheduler to make SSD-I deliver a smooth change in energy consumption. We employ Filebench as a workload generator to simulate a wide range of workloads(i.e., varmail, fileserver, and webserver), and explore optimal combinations of file systems and I/O schedulers(i.e., optimal values of AI) for tested SSDs under different workloads. Experimental results reveal that the proposed aggregative indicator is comprehensive for exploring the optimal combination of a file system and an I/O scheduler for SSDs, compared with an individual metric.

关键词： Solid state disk(SSD) Performance Energy consumption File system I/O scheduler

Overview on development of ASEAN traditional and herbal medicines

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Chinese Herbal Medicines 2021年第4期13卷 441-450页

作者： chang-xiao Liu Tianjin Institute of Pharmaceutical Research Tianjin 300462China State Key Laboratory of Drug Delivery Technology and Pharmacokinetis Tianjin 300462China China-ASEAN Joint Laboratory for International Cooperation in Traditional Medicine Research Nanning 530200China

Traditional medicine is an important and often underestimated part of health *** some countries,it has a long history of use in health maintenance and in disease prevention and treatment,particularly for *** has always emphasized the important role of traditional,complementary and alternative medicine in human *** this review article,the author provided some information from the following five aspects:(1)Development basis of China ASEAN traditional medicine and herbal medicine;(2)The development and afficacy of traditional medicine theory system;(3)Industry development and regulation management of traditional medicine and herbal medicine products;(4)China-ASEAN traditional medicine exchanges and cooperation to promote traditional medicine cooperation and medicine trade,and(5)Strengthening academic and industrial cooperation and promoting the healthy development of traditional medicine and herbal *** is believed that the information will have certain reference value for readers in studies on traditional and herbal medicines.

关键词： cooperation development herbal medicine information regulation research traditional medicine

Factor analysis on the purity of magnesium titanate directly prepared from seashore titanomagnetite concentrate through direct reduction

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International Journal of Minerals,Metallurgy and Materials 2020年第11期27卷 1462-1470页

作者： xiao-ping Wang Zhao-chun Li Ti-chang Sun Jue Kou xiao-hui Li School of Mining and Coal Inner Mongolia University of Science and TechnologyBaotou 014010China China Sinda Intellectual Property Limited Beijing 100033China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

Magnesium titanate was prepared directly through external coal reduction of seashore titanomagnetite concentrate and magnesium oxide(MgO).The effects of roasting temperature and the type and dosage of reductants on the purity of generated magnesium titanate particles were systematically *** electron microscopy and energy-dispersive spectroscopy analyses were performed to characterize the magnesium titanate particles and observe their purity under different *** showed that the roasting temperature remarkably influenced the purity of magnesium *** 1200,1300,and 1400℃,some magnesium ferrite and magnesium aluminate spinel were dissolved in magnesium ***,as the roasting temperature increased to 1500℃,relatively pure magnesium titanate particles were generated because no magnesium ferrite was dissolved in *** type and dosage of the reductants also remarkably affected the purity of magnesium *** amount of fine metallic iron disseminated in the magnesium titanate particles obviously decreased when lignite was used as a reductant at a dosage of 70wt%.Thus,high-purity magnesium titanate particles *** a roasting temperature of 1500℃and with 70wt%lignite,the magnesium titanate product with a yield of 30.63%and an iron content of 3.01wt%was obtained through magnetic separation.

关键词： seashore titanomagnetite magnesium oxide direct reduction magnesium titanate

SVR mathematical model and methods for sale prediction

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Journal of Systems Engineering and Electronics 2007年第4期18卷 769-773页

作者： Yi Yang Rong Fuli chang Huiyou xiao Zhijiao Computer Science Dept. Sun Yat-Sen Univ. Guangzhou 510275 P. R. China Software School Sun Yat-Sen Univ. Guangzhou 510275 P. R. China

Sale prediction plays a significant role in business management. By using support vector machine Regression （ε-SVR）, a method using to predict sale is illustrated. It takes historical data and current context data as inputs and presents results, i.e. sale tendency in the future and the forecasting sales, according to the user＇s specification of accuracy and time cycles. Some practical data experiments and the comparative tests with other algorithms show the advantages of the proposed approach in computation time and correctness.

关键词： regression support vector regression sale prediction

Effect of ultrasonic power introduced by a mold copper plate on the solidification process

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 139-146页

作者： xiao-fang Shi Li-zhong chang Jian-jun Wang school of metallurgy engineering anhui university of technologyMa'anshan 243002China

An electroslag furnace with ultrasonic vibration introduced by a mold copper plate was designed. The effects of ultrasonic power on the element distribution and compactness in electroslag remelting （ESR） ingots were studied, and the mechanism of ultrasonic assistance was analyzed in cold experiments. In the results, silicon, manganese and chromium are uniformly distributed at an ultrasonic power of 300-750 W. The absence of ultrasonic or higher ultrasonic power is not conducive to the uniformity of alloying elements. Carbon demon- strates a highly uneven distribution at 300 W, gradually reaches the uniform distribution as the ultrasonic power further increases, and shows the poor distribution at 1000 W. The compactness of ESR ingots gradually increases with increasing ultrasonic power and reaches the uni- form distribution at 500 W. A further increase in ultrasonic power does not improve the compactness. Introducing ultrasonic vibrations by a mold copper plate can improve the solidification quality; however, an appropriate ultrasonic power level should be determined.

关键词： electroslag remelting mold ultrasonic solidification

Stress relaxation of Si/Si_(1-x)Ge_x/Si structure prepared by ion implantation and subsequent annealing process

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Rare Metals 2011年第3期30卷 270-273页

作者： XU Wenting TU Hailing chang Qing xiao Qinghua General Research Institute for Nonferrous Metals Beijing 100088 China GRINM Semiconductor Materials Co. Ltd. Beijing 100088 China

The stress relaxation of 74Ge＋-implanted （100） silicon wafers was investigated. The implantation energy as a function of Si/Si1-xGex/Si struc-ture fluence and two kinds of thermal annealing were reported. The stress and stress relaxation after thermal annealing were calculated on the basis of Raman analysis, and were compared with those obtained from the calculation of virgin Si.

关键词： silicon wafers stress stress relaxation ion implantation annealing