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Texture Evolution, Formability and Ridging Resistance of a Sn-bearing Ferritic Stainless Steel Under Different Hot Band Annealing Temperatures

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Acta Metallurgica Sinica(English Letters) 2019年第11期32卷 1362-1372页

作者： Tong He-dan Guo yang Bai Tong He dan Guo Xiu-Ting liu Fang-Yuan Shao Yan-Dong liu Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education Northeastern UniversityShenyang 110819China Research Academy Northeastern UniversityShenyang 110819China

The microstructure, texture evolution and spatial orientation distribution during cold rolling and the subsequent annealing as well as formability and ridging of a Sn-bearing ferritic stainless steel under different hot band annealing temperatures were investigated. The four hot bands with annealing temperatures of 900, 950, 1000 and 1050 °C were all cold-rolled to 80% reductions and then were annealed at the same temperature of 900 °C. The results show that optimizing hot band annealing process is benefi cial to reduce the amount of {001} grains and weaken the texture intensity, and thus, to reduce ridging and improve formability. In the present study, the fi nal sheets with hot band annealing temperature of 900 °C possess small and inhomogeneous grains with a large amount of {001} orientations, which deteriorates the formability and increases the ridging. In comparison, the fi nal sheets with hot band annealing temperature of 950 °C are comprised of uniform and equiaxed //ND(ND: normal direction) recrystallized grains with a high texture intensity favorable for the improvement in r value and surface quality. However, when hot band annealing temperature further increases to 1000 and 1050 °C, it shows a sharp decrease in r value and a remarkable increase in ridging as a result of a reduction in γ-fi ber texture intensity and an increase in grain size in the fi nal sheets. Suitable controlling and optimizing hot band annealing process is essential to improve the formability and reduce the ridging.

关键词： Ferritic stainless steel Texture Formability Ridging

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Measurement and Assessment of Physical Activity by Information and Communication Technology

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Biomedical and Environmental Sciences 2017年第6期30卷 465-472页

作者： ZHANG Qun yang Xi liu dan ZHAO Wen Hua Chinese Center for Disease Control and Prevention Beijing 102206 China National Institute for Nutrition and Health Chinese Center for Disease Control and Prevention Beijing 100050 China

This study provides explorative insights into the information and communication technology （ICT） for promoting the physical activity level. ICT has provided innovative ideas and perspectives for PA measurement, assessment, evaluation and health intervention. ICT that aims to increase exercise for the entire population should be of a well-oriented and easy-to-use design with the options of tailored and personalized feedback, coaching, and ranking and supporting; it should be capable of setting goals and working with a schedule and be accompanied by a website to provide overviews of the users＇ exercise results and progress.

关键词： Physical activity Measurement Assessment Information and communicationtechnology

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Characterization of Fe_3Si-based coatings on low silicon steel by pulsed Nd:YAG laser cladding

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International Journal of Minerals,Metallurgy and Materials 2009年第2期16卷 208-214页

作者： dan-yang Dong Chang-sheng liu Sui-yuan Chen Bin Zhang Key Laboratory for Anisotropy and Texture of Materials of the Ministry of Education of China Northeastern University Shenyang 110004 China School of Science College Northeastern University Shenyang 110004 China

The Fe3Si based coating was produced on the Fe-1 Si steel surface by a pulsed Nd：YAG （yttrium aluminum garnet） laser. Its phase constitution and microstructure were characterized by using X-ray diffraction （XRD）, optical microscope （OM）, and field emission scanning electron microscope （FESEM） with associated energy dispersive spectroscopy （EDS） and transmission electron microscopy （TEM）. The hyperfine structure of the coating was studied by Mrssbauer spectra （MS） and the magnetic property was also measured at room temperature by a vibrating sample magnetometer （VSM）. The obtained coating is pore and crack-free with dense microstructure and high Si content. The metallurgical bonding between the coating and the substrate was realized. The microstructure of the coating is typical fine dendrites. The major phase was confirmed by XRD and TEM to be the ordering D03 structured Fe3Si phase. In addition, there were smaller amounts of the Fe5Si3 phase and the γ-Fe phase in the coating. Compared with the substrate, the laser cladding coating has a lower saturation magnetization and a higher coercive force. The poor magnetic property might be because of rapid solidification microstructure and phase constitution in the coating.

关键词： silicon steel laser cladding hyperfine structure magnetic property

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Corrosion Inhibition of X80 Steel in Simulated Marine Environment with Marinobacter aquaeolei

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Acta Metallurgica Sinica(English Letters) 2019年第11期32卷 1373-1384页

作者： M.Saleem Khan Dake Xu dan liu Yassir Lekbach Ke yang Chunguang yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Corrosion and Protection Division Shenyang National Laboratory for Material SciencesNortheastern UniversityShenyang 110819China Laboratory of Microbial Biotechnology Faculty of Science and TechnologySidi Mohamed Ben Abdellah UniversityB.P.2202FezMorocco

In the present study, a novel bacterium( Marinobacter aquaeolei) was examined for its corrosion inhibiting behaviour against X80 pipeline steel. Electrochemical results showed that X80 steel immersed in the solution inoculated with M. aquaeolei possessed very high corrosion resistance compared to that of abiotic control. Besides, scanning electron microscopy, confocal laser scanning microscopy and energy-dispersive X-ray spectroscopy were employed to analyse the corrosion product and the biofi lm formed on the metal surface. Fourier-transform infrared spectroscopy was also applied to determine the composition of extracellular polymeric substances(EPS). Above results indicated that the corrosion inhibition effciency observed in biotic medium was very high(91%), proving that M. aquaeolei was an effective inhibitive agent for the corrosion of carbon steel. The inhibition was credited to the formation of bacterial biofi lm and the compact protective layer of the secreted EPS. Thus, this study will introduce a natural, environmentally friendly and cost-effective system for the corrosion control of the carbon steel.

关键词： X80 pipeline steel Corrosion inhibition Marinobacter aquaeolei

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Temperature field test and prediction using a GA-BP neural network for CRTS Ⅱ slab tracks

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Railway Engineering Science 2023年第4期31卷 381-395页

作者： dan liu Chengguang Su Rongshan yang Juanjuan Ren Xueyi liu Highway School Chang’an UniversityXi’an 710064China China Railway First Survey and Design Institute Group Co.Ltd.Xi’an 710043China MOE Key Laboratory of High-Speed Railway Engineering Southwest Jiaotong UniversityChengdu 610031China College of Transportation Engineering Chang’an UniversityXi’an 710064China

The CRTS Ⅱ slab track, which is connected in a longitudinal direction, is one of the main ballastless tracks in China, with approximately 7365 km of operational track. Temperature loading is a very vital factor leading to slab track damages such as warping and cracking. While existing research on temperature distribution rests on either site tests in special environments or theoretical analysis, the long-term temperature field characteristics are not clear. Therefore, a long-term temperature field test for the CRTS Ⅱ slab track on bridge-subgrade transition section was conducted to analyze the temperature field. A GA-BP(genetic algorithm optimized back propagation) neural network was trained on the test data to predict the temperature field. The vertical and lateral temperature distributions in four typical days were carried out. We found that the temperature along the track was distributed in a nonlinear manner. This was particularly distinct in the vertical direction for depths of less than 300 mm. The highest and lowest daily temperatures and the daily range of the temperature were analyzed. With the increasing depth, the daily highest temperatures and range of the temperature were smaller, the daily lowest temperatures were higher, and the time corresponding to this peak value appeared later in the day. Both the highest and lowest daily temperature could be predicted using the GA-BP neural network, though the accuracy in predicting the highest temperature was higher than that in predicting the lowest temperature.

关键词： Ballastless track Long-term test Temperature distribution Correlation analysis Neural network

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An Efficient Trajectory Planning for Cellular-Connected UAV under the Connectivity Constraint

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China Communications 2021年第2期18卷 136-151页

作者： Dingcheng yang Qian dan Lin Xiao Chuankuan liu Laurie Cuthbert School of Information Engineering Nanchang UniversityNanchang 330031China School of Computer Science Jiangxi University of Traditional Chinese MedicineNanchang 330004China Information Systems Research Centre Macao Polytechnic InstituteMacaoChina

Unmanned Aerial Vehicles(UAVs)acting as aerial users to access the cellular network form a promising solution to guarantee its safe and efficient operations via the high-quality *** to the flexible mobility of UAVs and the coverage range limits of ground base station(GBS),the signalto-noise ratio(SNR)of the communication link between UAVs and GBS will *** is an important requirement to maintain the UAV’s cellular connection to meet a certain SNR requirement during the mission for UAV flying from take off to *** this paper,we study an efficient trajectory planning method that can minimize a cellular-connected UAV’s mission completion time under the connectivity *** conventional method to tackle this problem adopts graph theory or a dynamic programming method to optimize the trajectory,which generally incurs high computational ***,there is a nonnegligible performance gap compared to the optimal *** this end,we propose an iterative trajectory optimizing algorithm based on geometric ***,we apply graph theory to obtain all the possible UAV-GBS association sequences and select the candidate association sequences based on the topological relationship among UAV and ***,adopting the triangle inequality property,an iterative handover location design is proposed to determine the shortest flight trajectory with fast convergence and low computation ***,the best flight trajectory can be obtained by comparing all the candidate ***,we revealed the tradeoff between mission completion time and flight energy *** results validate that our proposed solution can obtain the effectiveness with set accuracy and outperform against the benchmark schemes with affordable computation time.

关键词： UAV communication trajectory planning cellular-connected UAV connectivity requirement

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Maize MS2 encodes an ATP-binding cassette transporter that is essential for anther development

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The Crop Journal 2021年第6期9卷 1301-1308页

作者： Qilong Xu Li yang dan Kang Zhenjing Ren Yunjun liu Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081China

The anther cuticle and pollen exine play a critical role in male gametophyte development. The sporopollenin precursors and cuticular lipid monomers are transported to the surface of the microspores and the epidermis by lipid transport proteins(LTPs) and ATP-binding cassette G(ABCG) transporters for the formation of the pollen wall and anther cuticle, respectively. However, the function of ABCG transporters in maize anther development is unclear. Here, we cloned the MS2 gene from the maize male sterile2 mutant using map-based cloning and determined that it encodes an ABCG transporter. MS2 protein was experimentally confirmed to be located on the cell membrane. The quantitative real-time PCR(qRT-PCR)results showed that MS2 was ubiquitously expressed in all vegetative and reproductive tissues, whereas a high transcriptional level of MS2 was observed in anthers, especially at the young microspore stage. Gas chromatography-mass spectrometry(GC–MS) analysis showed decreased accumulation of cutin and wax components in ms2 anthers, indicating that MS2 plays a role in the transport of lipid molecules to anther cuticle and pollen exine. To our knowledge, MS2 is the first reported ABCG transporter gene that participates in anther development in maize.

关键词： Zea mays ABCG transporter Male sterility Anther development

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Do cooperatives participation and technology adoption improve farmers’welfare in China?A joint analysis accounting for selection bias

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Journal of Integrative Agriculture 2021年第6期20卷 1716-1726页

作者： yang dan ZHANG Hui-wei liu Zi-min ZENG Qiao College of Economics and Management Southwest UniversityChongqing 400716P.R.China School of Business Chongqing College of HumanitiesScience and TechnologyChongqing 401524P.R.China

This study examines the impact of farmers’cooperatives participation and technology adoption on their economic welfare in China.A double selectivity model(DSM)is applied to correct for sample selection bias stemming from both observed and unobserved factors,and a propensity score matching(PSM)method is applied to calculate the agricultural income difference with counter factual analysis using survey data from 396 farmers in 15 provinces in *** findings indicate that farmers who join farmer cooperatives and adopt agricultural technology can increase agricultural income by 2.77 and 2.35%,respectively,compared with those non-participants and ***,the effect on agricultural income is found to be more significant for the low-income farmers than the high-income ones,with income increasing 5.45 and 4.51%when participating in farmer cooperatives and adopting agricultural technology,*** findings highlight the positive role of farmer cooperatives and agricultural technology in promoting farmers’economic *** on the findings,government policy implications are also discussed.

关键词： cooperatives double selectivity model propensity score matching sample selection bias technology adoption welfare improvement

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Deciphering impacts of climate extremes on Tibetan grasslands in the last fifteen years

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Science Bulletin 2019年第7期64卷 446-454页

作者： dan liu Tao Wang Tao yang Zhengjie Yan Yongwen liu Yutong Zhao Shilong Piao Key Laboratory of Alpine Ecology Institute of Tibetan Plateau Research Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences School of Life Sciences Lanzhou University College of Urban and Environmental Sciences and Sino-French Institute for Earth System Science Peking University

Climate extremes have emerged as a crucial driver of changes in terrestrial ecosystems. The Tibetan Plateau, facing a rapid climate change, tends to favor climate extremes. But we lack a clear understanding of the impacts of such extremes on alpine grasslands. Here we show that extreme events(drought,extreme wet, extreme cold and extreme hot) occurred at a frequency of 0.67–4 months decade^(-1) during2001–2015, with extreme precipitation predominantly occurring in June-to-August and extreme temperatures in May. Drought and extreme wet cause opposite and asymmetric effects on grassland growth,with drought-induced reductions greater than increases due to extreme wet. Grassland responses to extreme temperatures, which predominantly occur in May, show a dipole-like spatial pattern, with extreme hot(cold) events enhanced(reduced) growth in the eastern plateau but slightly reduced(enhanced) growth in the western plateau. These opposite responses to extreme temperatures over the eastern plateau are explained by the possibility that the occurrence of extreme cold slows the preseason temperature accumulation, delaying the triggering of spring phenology, while extreme hot hastens the accumulation. In the western plateau, in contrast, positive responses to extreme cold are induced by accompanying high precipitation. Furthermore, high extremeness of climate events generally led to a much lower extremeness in growth response, implying that the Tibetan grasslands have a relatively high resistance to climate extremes. The ecosystem models tested could not accurately simulate grassland responses to drought and extreme temperatures, and require re-parameterization before trust can be placed in their output for this region.

关键词： Drought Extreme cold Extreme hot Growth response Alpine grasslands Tibetan Plateau

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Note:Molecular simulation of the adsorption of linear alkane mixtures in pillared layered materials

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第2期8卷 331-334页

作者： LI Wen-zhuo CHE Yu-liang liu Zi-yang ZHANG dan Department of Chemistry Zhejiang University Hangzhou 310027 China

The adsorption isotherms of mixtures of linear alkanes, involving n-pentane, n-hexane, and n-heptane in pillared layered materials (PLMs) with three different porosities Ψ=0.98, 0.94 and 0.87, and three pore widths H=1.02, 1.70 and 2.38 nm at temperature T=300 K were simulated by using configurational-bias Monte Carlo (CBMC) techniques in grand canonical ensemble.A grid model was employed to calculate the interaction between a fluid molecule and two layered boards here. For alkane mixtures,the n-heptane, the longest chain component in alkane mixtures, is preferentially adsorbed at low pressures, with its adsorption increasing and then decreasing as the pressure increases continuously while the n-pentane, the shortest chain component in alkane mixtures, is still adsorbed at high pressures; the adsorption of the longest chain component of alkane mixtures increases as the pore width and the porosity of PLMs increase.

关键词： Molecular simulation Alkane mixtures Pillared layered materials (PLMs)

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