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Hot deformation behavior and processing map of low-alloy offshore steel

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Journal of Iron and Steel Research International 2022年第3期29卷 474-483页

作者： Shi-ping Xi Xin-liang gao Wei Liu Yan-lu Lu Gui-qin fu Hui-cheng Tao Yong-chang Zang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao066004HebeiChina College of Metallurgy Northeastern UniversityShenyang110819LiaoningChina

The hot deformation behavior of a low-alloy offshore steel was systematically investigated within the temperature range of 850-1150℃ and strain rate range of 0.01-10 s^(-1),via hot compression *** hot working equation,grain size model and recrystallization kinetic models of the steel were developed by fitting the experimental *** results show that the decrease in Zener-Hollomon Z-parameter value(the increase in deformation temperature and the decrease in strain rate)is beneficial for the occurrence of dynamic recrystallization,and the grain size can be refined by increasing the Z-parameter value within the deformation range of dynamic ***,when the Z-parameter value is higher than 3.43×10^(16),dynamic recrystallization will be difficult to occur within the range of experimental deformation ***,processing maps at different strains were *** to the processing map and microstructural analysis,the optimal hot working conditions of the studied steel are within the temperature range of 1000-1100℃ and strain rate range of 0.1-1 s^(−1),and a complete recrystallization microstructure with fine homogeneous grains could be obtained.

关键词： Offshore steel Dynamic recrystallization Microstructure Hot deformation Processing map

Basic Soil Productivity of Spring Maize in Black Soil Under Long-Term Fertilization Based on DSSAT Model

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Journal of Integrative Agriculture 2014年第3期13卷 577-587页

作者： ZHA Yan WU Xue-ping HE Xin-hua ZHANG Hui-min GONG fu-fei CAI Dian-xiong ZHU ping gao Hong-jun Key Laboratory of Crop Nutrition and Fertilization Ministry of Agricultural/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences School of Plant Biology University of Western Australia Jilin Academy of Agricultural Sciences

Increasing basic farmland soil productivity has significance in reducing fertilizer application and maintaining high yield of crops. In this study, we defined that the basic soil productivity （BSP） is the production capacity of a farmland soil with its own physical and chemical properties for a specific crop season under local environment and field management. Based on 22-yr （1990-2011） long-term experimental data on black soil （Typic hapludoll） in Gongzhuling, Jilin Province, Northeast China, the decision support system for an agro-technology transfer （DSSAT）-CERES-Maize model was applied to simulate the yield by BSP of spring maize （Zea mays L.） to examine the effects of long-term fertilization on changes of BSP and explore the mechanisms of BSP increasing. Five treatments were examined：（1） no-fertilization control （control）; （2） chemical nitrogen, phosphorus, and potassium （NPK）; （3） NPK plus farmyard manure （NPKM）; （4） 1.5 time of NPKM （1.5NPKM） and （5） NPK plus straw （NPKS）. Results showed that after 22-yr fertilization, the yield by BSP of spring maize significantly increased 78.0, 101.2, and 69.4% under the NPKM, 1.5NPKM and NPKS, respectively, compared to the initial value （in 1992）, but not significant under NPK （26.9% increase） and the control （8.9% decrease）. The contribution percentage of BSP showed a significant rising trend （P〈0.05） under 1.5NPKM. The average contribution percentage of BSP among fertilizations ranged from 74.4 to 84.7%, and ranked as 1.5NPKM〉NPKM〉NPK〉NPKS, indicating that organic manure combined with chemical fertilizers （I.5NPKM and NPKM） could more effectively increase BSP compared with the inorganic fertilizer application alone （NPK） in the black soil. This study showed that soil organic matter （SOM） was the key factor among various fertility factors that could affect BSP in the black soil, and total N, total P and/or available P also played important role in BSP increasing. Compared with the chemical fertilization, a balanced chem

关键词： spring maize long-term fertilization basic soil productivity black soil DSSAT model

Hot Deformation Behavior of As-cast AISI M2 High-speed Steel Containing Mischmetal

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Journal of Iron and Steel Research International 2014年第1期21卷 60-68页

作者： Ming-gui QU Shu-hua SUN Xing-hong BAI Zhong-ping SHI Yang gao Wan-tang fu State Key Laboratory of Metastable Material Science and Technology College of Material Science and Engineering Yanshan University College of Science Yanshan University China First Heavy Industries

The hot deformation behavior of as-cast AISI M2 high-speed steel containing mischmetal （RE） has been investigated on a Gleeble-3500 simulator in the temperature range of 1000--1 150 ℃ and strain rate range of 0.01- 10 s 1 at true strain of 1.0. The mechanical behavior has been characterized using stress-strain curve analysis, kinetic analysis, processing maps, etc. Metallographic investigation was performed to evaluate the mechanism of flow insta- bility. The results show that the deformation activation energy decreases with increasing deformation temperature; the efficiency of power dissipation increases with decreasing strain rate and increasing temperature; flow instability is observed at low-to-medium temperature and higher strain rate region when the strain is smaller, but extends to lower strain rate and high temperature regions with the increment of strain, in which it is manifested as flow localization near the grain boundary. Hot deformation equations and processing maps are obtained. The optimal processing window is suggested and the deformation mechanism is dynamic recrystallization （DRX）.

关键词： as cast AISI M2 mischmetal flow stress activation energy hot deformation equation processing map

Prokaryotic Expression of Gly-Gln Dipeptide and Its Bioactive Analysis: A Novel Method for Short Peptide Production

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Agricultural Sciences in China 2010年第5期9卷 736-744页

作者： XU ping-wen FANG Xin-ling SHU Gang ZHU Xiao-tong LUO Zeng-fu JIANG Qing-yan gao ping ZHANG Yong-liang College of Animal Science South China Agricultural University Guangzhou 510642 P.R.China

Small bioactive peptides, with diverse biological functions, have received increasing attention as physiologically beneficial substances in animal production. The main obstacle to wide application of small bioactive peptides is a lack of costeffective methods for mass production. In this study, we mass-production method for small bioactive peptides. used glycyl-glutamine （Gly-Gln） as a test case to develop a novel The oligonucleotide encoding Gly-Gln pro-peptide （Gpp） was designed and synthesized. Gpp includes 3 Gly-Gln dipeptides and 2 enzymatic sites for pepsin and trypase, allowing direct digestion and absorption of Gly-Gln in the gastrointestinal tract. The Gpp oligonucleotides were linked to generate an oligomeric oligonucleotide segment containing 12 tandem copies of Gpp. This 12Gpp segment was cloned and expressed in Escherichia coli vector pET32a. By optimizing culture conditions [0.1 mmol L^-1 isopropyl-β-D- thiogalactopyranoside （IPTG）, 50 μg mL^-1 ampicillin （Amp）, 30℃ for 12 h], the thioredoxin fusion peptides reached 40% of total bacterial protein. After purification, the fusion protein was fed to Kunming mice to determine its effect on mouse immune function. The results showed that similar to Gly-Gln dipeptide, Gpp polymer protein could significantly suppress the proliferation of T and B lymphocytes in blood and spleen, and additionally could significantly improve interleukin-2 （IL-2） and interleukin-6 （IL-6） secretion of blood and spleen lymphocytes. These effects were not observed in mice fed a 2 amino acids mix （glycine and glutamine）. These evidences indicated that an efficient digestion of Gpp polymer protein could be achieved when ingested into the animal gut. The expression system in this study provides a potential production method for not only Gly-Gln dipeptide but also other short bioactive peptides.

关键词： glycyl-glutamine tandem expression gastrointestinal tract

Unlocking the stable interface in aqueous zinc-ion battery with multifunctional xylose-based electrolyte additives

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Journal of Energy Chemistry 2025年第1期100卷 770-778页

作者： Xiaoqin Li Jian Xiang Lu Qiu Xiaohan Chen Yinkun Zhao Yujue Wang Qu Yue Taotao gao Wenlong Liu Dan Xiao Zhaoyu Jin Panpan Li Institute for Advanced Study Chengdu University School of Mechanical Engineering Chengdu University College of Food and Biological Engineering Chengdu University Institute of fundamental and Frontier Sciences University of Electronic Science and Technology of China College of Materials Science and Engineering Sichuan University

The growth of dendrites and the side reactions occurring at the Zn anode pose significant challenges to the commercialization of aqueous Zn-ion batteries（AZIBs）. These challenges arise from the inherent conflict between mass transfer and electrochemical kinetics. In this study, we propose the use of a multifunctional electrolyte additive based on the xylose（Xylo） molecule to address these issues by modulating the solvation structure and electrode/electrolyte interface, thereby stabilizing the Zn anode. The introduction of the additive alters the solvation structure, creating steric hindrance that impedes charge transfer and then reduces electrochemical kinetics. furthermore, in-situ analyses demonstrate that the reconstructed electrode/electrolyte interface facilitates stable and rapid Zn2+ion migration and suppresses corrosion and hydrogen evolution reactions. As a result, symmetric cells incorporating the Xylo additive exhibit significantly enhanced reversibility during the Zn plating/stripping process, with an impressively long lifespan of up to 1986 h, compared to cells using pure ZnSO4electrolyte. When combined with a polyaniline cathode, the full cells demonstrate improved capacity and long-term cyclic stability. This work offers an effective direction for improving the stability of Zn anode via electrolyte design, as well as highperformance AZIBs.

关键词： Solvation

Linear recurring sequences and subfield subcodes of cyclic codes

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Science China Mathematics 2013年第7期56卷 1413-1420页

作者： gao ZhiHan fu FangWei Department of Combinatorics and Optimization University of Waterloo Chern Institute of Mathematics and LPMC Nankai University

Linear recurring sequences over finite fields play an important role in coding theory and cryptography. It is known that subfield subcodes of linear codes yield some good codes. In this paper, we study linear recurring sequences and subfield subcodes. Let Mqm(f(x)) denote the set of all linear recurring sequences over Fqm with characteristic polynomial f(x) over Fqm . Denote the restriction of Mqm(f(x)) to sequences over Fq and the set after applying trace function to each sequence in Mqm(f(x)) by Mqm(f(x)) | Fq and Tr( Mqm(f(x))), respectively. It is shown that these two sets are both complete sets of linear recurring sequences over Fq with some characteristic polynomials over Fq. In this paper, we firstly determine the characteristic polynomials for these two sets. Then, using these results, we determine the generator polynomials of subfield subcodes and trace codes of cyclic codes over Fqm .

关键词： linear recurring sequences characteristic polynomial cyclic codes subfield subcodes trace codes

Wiener Filtration Algorithm of an Ensemble Pulsar Timescale Based on a Power-law Model of Pulsar Power Spectrum

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Research in Astronomy and Astrophysics 2022年第10期22卷 129-140页

作者： Ting-gao Yang Ming-Lei Tong Yu-ping gao National Time Service Center Chinese Academy of SciencesXi'an 710600China Key Laboratory of Time and Frequency Primary Standards Chinese Academy of SciencesXi'an 71000China University of Chinese Academy of Sciences Beijing 100049China

An ensemble pulsar timescale derived from the traditional Wiener filtration still contains some high level *** improve this situation we developed a Wiener filtration algorithm of the ensemble pulsar timescale based on a power-law model of power spectrum for *** algorithm has three strengths:(1)mitigating spectral leakage between frequency bins for Fourier techniques;(2)using a power-law model for power spectrum;(3)signal realization in original residuals of data set by the power-law *** to improved algorithm we constructed an ensemble pulsar timescale EPT-TAI using timing data with respect to International Atomic Time(TAI)about 16 yr time span of ten pulsars from International Pulsar Timing Array second data release(version A).The results show that EPT-TAI detected correctly the differences TT(BIPM2015)-TAI between terrestrial time TT(BIPM2015)and *** frequency stabilityσzanalysis shows that EPT-TAI does not indicate red noise for 16 yr time interval,and fractional frequency stability for 8 yr and longer time intervals is slightly better than that of TT(BIPM2015)-*** for short time intervals of TT(BIPM2015)-TAI is better than that of EPT-TAI,but TT(BIPM2015)-TAI shows red noise for longer time *** the same algorithm we also derived an ensemble pulsar timescale EPT-TT(BIPM2015)with respect to TT(BIPM2015).The fractional frequency stability curve of EPT-TT(BIPM2015)shows similar characteristics as that of EPT-TAI but with slightly lower values.

关键词： (stars:)pulsars general-time-methods data analysis

Effects of film mulching regime on soil water status and grain yield of rain-fed winter wheat on the Loess Plateau of China

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Journal of Integrative Agriculture 2017年第11期16卷 2612-2622页

作者： XUE Nai-wen XUE Jian-fu YANG Zhen-ping SUN Min REN Ai-xia gao Zhi-qiang College of Agronomy Shanxi Agricultural University Taigu 030801 P.R. China

Shortages and fluctuations in precipitation are influential limiting factors for the sustainable cultivation of rain-fed winter wheat on the Loess Plateau of China. Plastic film mulching is one of the most effective water management practices to improve soil moisture, and may be useful in the Loess Plateau for increasing soil water storage. A field experiment was conducted from July 2010 to June 2012 on the Loess Plateau to investigate the effects of mulching time and rates on soil water storage, evapotranspiration （ET）, water use efficiency （WUE）, and grain yield. Six treatments were conducted：（1） early mulching （starting 30 days after harvest） with whole mulching （EW）; （2） early mulching with half mulching （EH）; （3） early mulching with no mulching （EN）; （4） late mulching （starting 60 days after harvest） with whole mulching （LW）; （5） late mulching with half mulching （LH）; and （6） late mulching with no mulching （LN）. EW increased precipitation storage efficiency during the fallow periods of each season by 18.4 and 17.8%, respectively. EW improved soil water storage from 60 days after harvest to the booting stage and also outperformed LN by 13.8 and 20.9% in each growing season. EW also improved spike number per ha by 13.8 and 20.9% and grain yield by 11.7 and 17.4% during both years compared to LN. However, EW decreased WUE compared with LN. The overall results of this study demonstrated that EW could be a productive and efficient practice to improve wheat yield on the Loess Plateau of China.

关键词： soil water status plastic film mulching precipitation storage efficiency winter wheat the Loess Plateau

Placement of unmanned aerial vehicles as communication relays in two-tiered multi-agent system:clustering based methods

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Journal of Systems Engineering and Electronics 2020年第2期31卷 231-242页

作者： WU gaofeng WAN Kaifang gao Xiaoguang fu Xiaowei School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710129China

The network performance and the unmanned aerial vehicle(UAV)number are important objectives when UAVs are placed as communication relays to enhance the multi-agent information *** problem is a non-deterministic polynomial hard(NP-hard)multi-objective optimization problem,instead of generating a Pareto solution,this work focuses on considering both objectives at the same level so as to achieve a balanced solution between *** on the property that agents connected to the same UAV are a cluster,two clustering-based algorithms,M-K-means(MKM)and modified fast search and find density of peaks(MFSFDP)methods,are first *** the former algorithm requires too much computational time and the latter one requires too many relays,an algorithm for the balanced network performance and relay number(BPN)is proposed by discretizing the area to avoid missing the optimal relay positions and defining a new local density function to reflect the network performance *** results demonstrate that the proposed algorithms are feasible and *** between these algorithms show that the BPN algorithm uses fewer relay UAVs than the MFSFDP and classic set-covering based algorithm,and its computational time is far less than the MKM algorithm.

关键词： unmanned aerial vehicle(UAV) relay communication clustering relay node placement wireless network