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Interlayer engineering for titanium clad steel by hot roll bonding

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Journal of Iron and Steel Research International 2018年第7期25卷 739-745页

作者： xi-yang chai Tao Pan Feng chai xiao-bing Luo Hang Su Zhi-gang yang Cai-fu yang Department of Structural Steels Central Iron and Steel Research Institute Beijing 100081 China School of Materials Science and Engineering Tsinghua University Beijing 100084 China

Hot roll bonding was carried out between commercially pure titanium TA2 and high-strength low-alloy steel Q390 using pure Nb or Mo interlayer at 950 ~C with a total reduction ratio of 86.7%. Interfacial microstructure and bonding properties of titanium clad steel plates were investigated by electron microscopy and mechanical tests. The results showed β-Ti, TiC and Fe2Ti reaction phases were generated at Ti/steel interface for the clad plates with no interlayer. Inserting Nb or Mo interlayer can effectively suppress the formation of brittle phases, while the weak bonding joint transferred to Nb/steel or Mo/steel interface. And some micro-voids were found at the interface of Nb/steel and Mo/steel. The improved shear strength of clad plates with Nb interlayer might be attributed to the elimination of brittle phases at bonding interface. The small size and little quantities of the micro-voids at Nb/steel interface had a relatively weak effect on shear strength. However, the large number and big size of micro-voids were responsible for the degradation of shear strength for the clad plates with Mo interlayer.

关键词： Titanium clad steel Interlayer - Interfacial microstructure Brittle phase Micro-void

Precipitation Behavior of V-N Microalloyed Steels during Normalizing

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Journal of Iron and Steel Research International 2015年第11期22卷 1037-1042页

作者： Tao PAN xi-yang chai Jin-guang WANG Hang SU Cai-fu yang Division of Structural Steels Central Iron and Steel Research Institute Division of Equipment Construction China Sinopec Engineering Incorporation

The precipitation behavior of V-N microalloyed steel during normalizing process was studied by physicochemical phase analysis and transmission electron microscopy（TEM）. The effect of precipitation behavior on mechanical properties was investigated by theoretical calculations. The results showed that 32.9% of V（C,N） precipitates remained undissolved in the austenite during the soaking step of the normalizing process. These precipitates prevented the growth of the austenite grains. During the subsequent cooling process, the dissolved V（C,N） re-precipitated and played a role in precipitation strengthening. The undissolved V（C,N） induced intragranular ferrite nucleation and refined the ferrite grains. Consequently, compared with hot-rolled steel, the normalized steel exhibited increased grain-refining strengthening but diminished precipitation strengthening, leading to an improvement of the impact energy at the expense of about 40 MPa yield strength.

关键词： normalizing V-N microalloyed steel precipitation strengthening grain-refining strengthening

Performance,microbial community and inhibition kinetics of long-term Cu2+ stress on an air-lift nitritation reactor with self-recirculation

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Journal of Environmental Sciences 2020年第5期32卷 117-127页

作者： Fan Feng Cheng-Shan Duan xi Tang xi Chen Xuan Lu xi-Lin chai Qaisar Mahmood Chong-Jian Tang Li-Yuan chai Department of Environmental Engineering School of Metallurgy and EnvironmentCentral South UniversityChangsha410083China National Engineering Research Centre for Control and Treatment of Heary Metal Pollution Changsha410083China The Jiangxi Provincial Collaborative Research Institute for Environmental Protection Industry Wannian335500China Jiangxi Gaia Environmental Science&Technology Co. Ltd.Shangrao334000China Department of Environmental Sciences COMSATS UniversityAbbottabadPakistan

Biological nitrogen removal process could be affected due to the presence of heavy metals owing to their toxicity and accumulation in the *** this study,the impact of Cu2+shock on a long-term nitritation operation was investigated in an air-lift reactor with *** the dynamics of microbial community and inhibition kinetics under Cu2+stress were *** results showed that Cu2+exerted severe inhibition on nitritation performance of an air-lift reactor(ALR)at 25 mg/*** corresponding NH4+-N removal efficiency decreased to below 50%,which was mainly due to the variation of microbial community structure,especially the inhibition of nitrifiers like Nitrosomonas(the relative abundance decreased from 30%to 1%after Cu2+inhibition).Kinetic parameters were obtained and compared after fitting the Haldane *** long-term Cu2+stress on the ALR aggravated the ammonium affinity and the resistance to substrate self-inhibition of the nitritation sludge,but reduced the resistance to Cu2+***,Cu2+acted as uncompetitive inhibitor on nitritation *** results provide new insights into the nitritation characteristics under long-term Cu2+stress.

关键词： Nitritation Cu2+inhibition Microbial structure Haldane model Kinetics

Conformational Behavior of Single Circular Semiflexible Polyelectrolyte in the Presence of Multivalent Counterions

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Chinese Journal of Polymer Science 2023年第3期41卷 448-458,I0010页

作者： Zhi-Yong yang Wen-Long Lin Ai-Hua chai Dan Lu Nian-Qian Kang Lin-xi Zhang Department of Physics Jiangxi Agricultural UniversityNanchang 330045China Lucheng College Wenzhou PolytechnicWenzhou 325006China College of data science Jiaxing UniversityJiaxing 314001China Department of Physics Zhejiang UniversityHangzhou 310027China

Langevin dynamics simulations are employed to explore the effects of chain stiffness and electrostatic interaction(EI) on the conformational behavior of a circular semiflexible polyelectrolyte(CSPE) in presence of trivalent *** investigate the effect of bending energy b and the dimensionless Bjerrum length A on the conformational behavior of the CSPE with a fixed chain *** competition among the EIs,chain stiffness and entropy of the system leads to rich conformations for the *** the b is less than or equal to 50,The shape of the CSPE changes from a oblate ring to a rod at small A,then to a toroid at intermediate A,and finally to a globule at very large ***,the globular conformation is not observed for large *** addition,we find that the number of torus ring increases with A increase,while decreases with b *** study should be helpful in gaining insight into the conformational behaviour of charged biopolymer.

关键词： Langevin dynamics simulation Circular semiflexible polyelectrolyte Trivalent counterions Electrostatic interaction

Compound of icariin,astragalus,and puerarin mitigates iron overload in the cerebral cortex of Alzheimer＇s disease mice

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Neural Regeneration Research 2018年第4期13卷 731-736页

作者： Yu Zhang Wei-Na Kong xi-Qing chai Department of Neurology the First Hospital of Hebei Medical University Shijiazhuang Hebei Province China Hebei Chemical and Pharmaceutical College Shijiazhuang Hebei Province China

Increasing evidence indicates that disruption of normal iron homeostasis may contribute to pathological development of Alzheimer＇s ***,astragalus,and puerarin have been shown to suppress iron overload in the cerebral cortex and improve spatial learning and memory disorders in Alzheimer＇s disease mice,although the underlying mechanism remains *** the present study,APPswe/PS1ΔE9 transgenic mice were administered icariin,astragalus,and puerarin（120,80,and 80 mg/kg,respectively,once a day,for 3 months）.Iron levels were detected by flame atomic absorption ***-1β,interleukin-6,and tumor necrosis factor-α levels were measured in the cerebral cortex by enzyme linked immunosorbent *** peroxidase and superoxide dismutase activity and malondialdehyde content were determined by *** results demonstrate that after treatment,iron levels and malondialdehyde content are decreased,while glutathione peroxidase and superoxide dismutase activities are ***,interleukin-1β,interleukin-6,and tumor necrosis factor-α levels were *** results confirm that compounds of icariin,astragalus,and puerarin may alleviate iron overload by reducing oxidative stress and the inflammatory response.

关键词： nerve regeneration Alzheimer's disease iron overload icariin astragalus puerarin oxidative stress inflammatory response neural regeneration

CRACKING BEHAVIOR AND MECHANICAL ANALYSIS ON DUPLEX STRUCTURE UNDER CYCLIC LOADING

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Acta Metallurgica Sinica(English Letters) 1992年第2期5卷 107-111页

作者： WANG Zhaoxia chai Donglang LIU Jinghua xi′an Jiaotong University,xi′an,China xi'an Jiaotong Univ Xi'an China

On the basis of stress-strain analysis under cyclic loading,the mechanism,origin and cyclic number of microcraek nucleation of duplex structure materials,saying ferrite plus martensite, have been experimentally studied and *** results are in fair mutual agreement. The morphology,distribution,size and relative quantities of the constitutional phase,especial ly strengthening phase,as well as the stress-strain distribution and variation in micro-region are directly influential in the origin of microcracks in duplex structure materials.

关键词： stress-strain analysis crack fatigue

Elastic twisting metamaterial for perfect longitudinal-torsional wave mode conversion

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Applied Mathematics and Mechanics(English Edition) 2023年第4期44卷 515-524页

作者： Shengjie YAO Yijun chai xiongwei yang Yueming LI State Key Laboratory for Strength and Vibration of Mechanical Structures Shaanxi Key Laboratory of Environment and Control for Flight VehicleSchool of AerospaceXi’an Jiaotong UniversityXi’an 710049China

In this work,we design a twisting metamaterial for longitudinal-torsional(L-T)mode conversion in pipes through exploring the theory of perfect transmodal FabryPerot interference(TFPI).Assuming that the axial and radial motions in pipes can be decoupled,we find that the metamaterial can be designed in a rectangular coordinate system,which is much more convenient than that in a cylindrical *** calculation with detailed microstructures shows that an efficient L-T mode conversion can be obtained in pipes with different *** addition,we fabricate mode-converting microstructures on an aluminum pipe and conduct ultrasonic experiments,and the results are in good agreement with the numerical *** expect that the proposed LT mode-converting metamaterial and its design methodology can be applied in various ultrasonic devices.

关键词： elastic wave mode conversion elastic metamaterial ultrasonic device

Optimal Pricing and Return-Freight Insurance:Strategic Analysis of E-Sellers in the Presence of Reputation Differentiation

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Journal of Systems Science & Complexity 2022年第6期35卷 2302-2318页

作者： yang Ying chai Rui SUN xinyu LI Yiming School of Economics and Management Xidian UniversityXi'an 710126China Research Center for Digital Economy(Greater Bay Area) School of Economics and Management Shenzhen Research InstituteTsinghua UniversityShenzhen 518057China Meituan BC BlockWangjing Hengdian BuildingBeijing 100102China School of Management Xi'an Jiaotong UniversityXi'an 710049China

Motivated by the practice that e-sellers cooperate with insurance companies to offer consumers the return-freight insurance(RI),this paper aims to investigate the competing e-sellers’RI *** the information asymmetry in the online context,reputation system is widely applied by *** an online market with two competing e-sellers that sell the same product but are differentiated in their reputation,this paper builds an analytical model to explore the e-sellers optimal pricing and RI *** with sellers’reputation and their RI strategies,the equilibrium outcomes under four cases are *** paper reveals the conditions that e-sellers are willing to offer ***,the findings demonstrate that low reputation e-seller is more likely to offer ***,when the sellers are more divergent,they are more likely to co-exist in the *** premium and RI compensation play critical roles in their *** introduction tends to increase the price,thus offsets the benefits of RI,but does not affect the total consumer surplus.

关键词： Game theory product returns reputation return-freight insurance

Straw strip mulching:A sustainable technology for saving water and improving efficiency in dryland winter wheat production

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Journal of Integrative Agriculture 2022年第12期21卷 3556-3568页

作者： LI Rui chai Shou-xi chai Yu-wei LI Ya-wei CHANG Lei CHENG Hong-bo Gansu Provincial Key Laboratory of Aridland Crop Science Lanzhou 730070P.R.China College of Agronomy Gansu Agricultural UniversityLanzhou 730070P.R.China College of Bioscience and Technology Gansu Agricultural UniversityLanzhou 730070P.R.China

An improved straw mulching model may be a sustainable agricultural production technology due to its improvements in soil water and the fertilizer environment by the recycling of waste straw resources.A four-year field experiment was conducted in a randomized block design on the Loess Plateau of northwestern China in 2015–2019,which aimed to study the effects of straw strip mulching(SSM)and conventional flat planting without mulching(CK)on soil water storage,water consumption characteristics,water use efficiency,precipitation use efficiency,winter wheat growth,economic benefits,and nutrient *** results obtained for the four years showed that the SSM treatment improved soil water storage in the 0–180 cm soil layer over the whole growth period,which was especially obvious in the 0–60 cm soil layer at the jointing and blooming *** with CK,SSM increased the contribution rate of precipitation to total evapotranspiration and increased it quite significantly by 20.4 percentage points in the earlier growth *** significantly reduced soil water storage consumption in the 0–180 cm soil layer and ultimately reduced evapotranspiration by 11.2 mm during the whole *** the 0–180 cm soil layer,SSM decreased evapotranspiration by 33.1 mm from the sowing to the jointing stages,but increased it by 19.5 mm from the jointing to the blooming *** addition,SSM improved the water use efficiency of grain yield by 21.6%and improved the precipitation use efficiency of grain yield by 18.6%,and it ultimately increased grain yield by 16.5%through improving spike number by 9.5%and kernel number per spike by 8.9%.SSM improved the water use efficiency of biomass yield by 13.5%and the precipitation use efficiency of biomass yield by 9.9%,and it ultimately increased biomass yield by 8.7%and plant height by 6.5%.Furthermore,SSM increased net income by 413 CNY ha–1 and the total amount of straw returned to the field after harvest by 8876–9619 kg ha–*** returning

关键词： soil water storage evapotranspiration water use efficiency soil nutrient