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Achieving a strong polypropylene/aluminum alloy friction spot joint via a surface laser processing pretreatment

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Journal of Materials Science & Technology 2020年第15期47卷 103-114页

作者： S.C.Han l.H.Wu C.y.Jiang N.li C.l.Jia P.Xue H.Zhang H.B.zhao D.R.Ni B.l.Xiao Z.y.Ma Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Department of Materials Science and Engineering Guilin University of TechnologyGuilin541006China

Strong metal/non-polar plastic dissimilar joints are highly demanded for the lightweight design in many fields,which,however,are rather challenging to achieve directly via *** this study,we designed a laser processing pretreatment on the Al alloy to create a deep porous Al surface structure,which was successfully joined to the polypropylene(PP) via friction spot welding.A maximum joint strength of29 MPa was achieved,the same as that of the base PP(*** joint efficiency reached 100%),much larger than ever *** joining mechanism of the Al alloy and the PP was mainly attributed to the large mechanical interlocking effect between the laser processed Al porous structure and the re-solidified PP and the formation of chemical bond at the *** deep porous Al surface structure modified by laser processing largely changed the Al-PP reaction *** evidence of the C-O-Al chemical bond was first time found at the non-polar plastic/Al joint interface,which was the reaction result between the oxide on the Al alloy surface and thermal oxidization products of the PP during *** study provides a new way for enhancing metal-plastic joints via surface laser treatment techniques.

关键词： Friction stir welding Hybrid joint Metal Polymer Surface treatment Interface

Correlation between depassivation and repassivation processes determined by single particle impingement:Its crucial role in the phenomenon of critical flow velocity for erosion-corrosion

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Journal of Materials Science & Technology 2021年第30期89卷 158-166页

作者： l.l.li Z.B.Wang S.y.He y.G.Zheng CAS Key laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Department of Physics Southern University of Science and TechnologyGuangdong 518055China

The correlation between depassivation and repassivation processes,which is significant in erosioncorrosion,was quantitatively investigated by single particle impingement tests at various flow velocities and impact *** results show that both repassivation and depassivation processes are associated with the kinetic energy of solid particle,and demonstrate that the repassivation is retarded by *** phenomenon probably results from the depassivation-induced microstructure *** this basis,the dependence of critical flow velocity(CFV)for erosion-corrosion on the solid particle concentration and diameter is further theoretically predicted and experimentally ***,the crucial role of depassivation-repassivation in CFV phenomenon is further highlighted.

关键词： Erosion-corrosion Stainless steel Depassivation-repassivation Single particle impact Passive film

Surface decoration of Halloysite nanotubes with POSS for fire-safe thermoplastic polyurethane nanocomposites

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Journal of Materials Science & Technology 2022年第6期101卷 107-117页

作者： Wei Wu Wanjing zhao Xianjing Gong Qijun Sun Xianwu Cao yujun Su Bin yu Robert K.y.li Roy A.l.Vellaisamy Department of Materials Science and Engineering City University of Hong KongTat Chee AvenueKowloonHong Kong SARChina National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing Engineering of Ministry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510640China National-certified Enterprise Technology Center Kingfa Science and Technology Co.Ltd.Guangzhou 510663China Centre for Future Materials University of Southern QueenslandToowoombaQueenslandAustralia James Watt School of Engineering University of GlasgowGlasgow G128QQUnited Kingdom

Halloysite nanotubes(HNTs)have been considered as a promising flame retardant fillers for *** this work,the polyhedral oligomericsilsesquioxane(POSS)containing amino group was covalently grafted on the surface of HNTs with 3-(2,3-epoxypropoxy)propytrimethoxysilane as a chemical *** POSS modified HNTs(HNTs-POSS)dispersed uniformly in the thermoplastic polyurethane(TPU)matrix and endowed TPU nanocomposites with enhanced tensile properties and fire *** calorimeter tests revealed that the introduction of 2 wt%HNTs-POSS to TPU matrix remarkably reduced the peak of heat release rate(PHRR)and total heat release(THR)by 60.0%and 18.3%,*** addition,the peak CO production rate and total smoke release(TSR)could be significantly suppressed by the addition of *** well dispersed HNTs in combination with the ceramified silicon network from the thermal decomposition of POSS contributed to the formation of a continuous and compact char layer,exhibiting a tortuous effect by inhibiting heat diffusion and evaporation of volatile *** addition,the released crystal water from HNTs could dilute the combustible volatiles and then decline the combustion *** tensile tests demonstrated that introduction of 2 wt%HNTs-POSS would enhance the maximum stress of TPU nanocomposite with a slight decrease of elongation at *** combination of HNTs and POSS through the construction of effective interfacial interactions provides a feasible way to effectively enhance the fire safety of TPU nanocomposites without scarifying ductility.

关键词： Thermoplastic polyurethane Halloysite nanotube POSS Flame retardancy Mechanical property

Magnetic/Magnetostrictive Properties Together with Resistivity and Corrosion Behaviors of CoFe_2 and Its Composite with CoFe_2N

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Journal of Materials Science & Technology 2017年第7期33卷 744-750页

作者： B.Q.Geng y.Q.Ma M.Wang Z.l.Ding W.H.Song B.C.zhao Key laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

The CoFe_2alloy（CF） was prepared by reducing CoFe_2O_4 in the H_2 ambient. Subsequently the CF sample was nitrided in the NH_3 atmosphere to produce the composite of CoFe_2N and CoFe_2. The magnetostriction, thermal expansion, resistivity and corrosion resistance of CF sample and the nitrided sample（CFN）at 1000？C were investigated. The saturation magnetostriction coefficiency λ_s and thermal expansion coefficient ？ at 300 K for the nitrided CFN were 50 ppm and 10 ppm/K, respectively, approximately equal to those for the CF sample. However, compared with CF, CFN presents a decrease in temperature coefficient R_λ（300 K） of magnetostriction by 11%. The smaller resistivity and improved corrosion resistance in the H_2SO_4 solution may expand the applications of the CoFe_2 in the fields needing lower resistivity or in the acidic environment.

关键词： CoFe alloy CoFe_2N alloy Magnetostriction Resistivity Corrosion resistance

Assessment of the crucial factors influencing the responses of ammonia and nitrous oxide emissions to controlled release nitrogen fertilizer: A meta-analysis

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Journal of Integrative Agriculture 2023年第11期22卷 3549-3559页

作者： lü Hui-dan WANG Xi-ya PAN zhao-long zhao Shi-cheng State Key laboratory of Efficient Utilization of Arid and Semi-arid Arable land in Northern China/Key laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China

Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduces reactive N loss and increases nitrogen use efficiency relative to conventional urea(CU). However, the crucial factors influencing the responses of NH3and N2O emissions to CRU relative to CU are still unclear. In this study, we evaluated the responses of NH3and N2O emissions to CRU based on collected field data with a meta-analysis. CRU reduced the NH3and N2O emissions by 32.7 and 25.0% compared with CU, respectively. According to subgroup analysis, CRU presented better mitigation of NH3and N2O emissions in soils with pH 6.5–7.5(–47.9 and –23.7%) relative to either pH7.5(–29.3 and –17.3%), and in the rice season(–34.8 and –29.1%) relative to the wheat season(–19.8 and –22.8%). The responses of NH3and N2O emissions to CRU increased from rainfed(–30.5 and –17.0%) to irrigated(–32.5 and –22.9%), and then to paddy(–34.8 and –29.1%) systems. In addition, the response of N2O emission mitigation increased with increases in soil total nitrogen(TN);however, soil TN did not significantly affect the response of NH3volatilization. The reduction in NH3emission was greater in sandy-textured soil(–57.7%) relative to loam-textured(–32.9%) and clay-textured(–32.3%) soils, whereas soil texture did not affect N2O emission. Overall, CRU was a good option for reducing the NH3and N2O emissions relative to CU in agricultural production. This analysis improves our understanding of the crucial environmental and management factors influencing the mitigation of NH3and N2O emissions under CRU application, and these site-specific factors should be considered when applying CRU to reduce reactive N loss and increase NUE.

关键词： controlled release urea NH volatilization N O emission environmental factor management practice

Compensating Errors in Cloud Radiative and Physical Properties over the Southern Ocean in the CMIP6 Climate Models

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Advances in Atmospheric Sciences 2022年第12期39卷 2156-2171页

作者： lijun zhao yuan WANG Chuanfeng zhao Xiquan DONG yuk l.yUNG Division of Geology and Planetary Science California Institute of TechnologyPasadenaCA 91125USA College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China Department of Hydrology and Atmospheric Sciences University of ArizonaTucsonAZ 85710USA Department of Earth Atmosphericand Planetary SciencesPurdue UniversityWest Lafayette 47907USA Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China

The Southern Ocean is covered by a large amount of clouds with high cloud ***,as reported by previous climate model intercomparison projects,underestimated cloudiness and overestimated absorption of solar radiation(ASR)over the Southern Ocean lead to substantial biases in climate *** present study revisits this long-standing issue and explores the uncertainty sources in the latest CMIP6 *** employ 10-year satellite observations to evaluate cloud radiative effect(CRE)and cloud physical properties in five CMIP6 models that provide comprehensive output of cloud,radiation,and *** simulated longwave,shortwave,and net CRE at the top of atmosphere in CMIP6 are comparable with the CERES satellite *** cloud fraction(CF)is also reasonably simulated in CMIP6,but the comparison of liquid cloud fraction(lCF)reveals marked biases in spatial pattern and seasonal *** discrepancies between the CMIP6 models and the MODIS satellite observations become even larger in other cloud macroand micro-physical properties,including liquid water path(lWP),cloud optical depth(COD),and cloud effective radius,as well as aerosol optical depth(AOD).However,the large underestimation of both lWP and cloud effective radius(regional means~20%and 11%,respectively)results in relatively smaller bias in COD,and the impacts of the biases in COD and lCF also cancel out with each other,leaving CRE and ASR reasonably predicted in *** error estimation framework is employed,and the different signs of the sensitivity errors and biases from CF and lWP corroborate the notions that there are compensating errors in the modeled shortwave *** correlation analyses of the geospatial patterns reveal that CF is the most relevant factor in determining CRE in observations,while the modeled CRE is too sensitive to lWP and *** relationships between cloud effective radius,lWP,and COD are also analyzed to explore the possible uncertainty sources in dif

关键词： cloud radiative effect cloud physics the Southern Ocean global climate models

Cadmium sulfide cage photocatalysis coupled electroactive biofilm for synergistic promotion of tetracycline degradation and electricity production

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Journal of Materials Science & Technology 2023年第35期166卷 86-97页

作者： Z.S.yuan J.X.Zou X.l.zhao J.y.Shi C.S.Guo M.yan School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

Tetracycline(TC)as a common broad-spectrum antibiotic,has been frequently detected in soil and sur-face *** becomes a great threat to the ecological ***,a device of photocatalysis as-sisted microbial fuel cell(photo-MFC)was constructed for TC degradation and energy *** this photo-MFC,cadmium sulfide(CdS)cage photocatalysis can degrade most of TC in a short *** the Co_(3)O_(4)@C-CC(carbonization and calcination of the ZIF-67 precursor in-situ grown on the carbon cloth(CC))bioanode degrades the rest of TC as well as the photocatalytic products,thus improving the *** co-existence of photocatalysis with bioanode changes the microbial community structure of the *** dominant phylum is Geobacter(60.2%)in normal MFC while that in photo-MFC are Pro-teobacteria(43.5%)and Geobacter(33.2%).Therefore,the synergistic effect of photocatalytic degradation and biodegradation achieves a chemical oxygen demand(COD)removal of 98.6%,which is higher than that of normal MFC(77.6%)or single CdS cage photocatalysis(23.8%).In addition,the photogenerated electrons can be transferred to the cathode,which reduces their combination with holes and increases the electricity generation of MFC,achieving a maximum power density of 3.37 W/m^(2).After degradation,the effluent with 200 mg l^(−1) TC exhibits no visible ***,electrochemical test,finite-difference time-domain(FDTD),density functional theory(DFT)calculation and the free radical trapping experiments verify the possible mechanisms of photocatalytic degradation in this *** strat-egy paves a new way for low energy consumption removal and energy recovery of organic pollutants.

关键词： Photo-MFC CdS cage Tetracycline degradation Mineralization Electricity production

Semiempirical prediction of the hyperpolarizabilities for cyanovinyl-substituted donor-acceptor molecules

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Chinese Journal of Chemistry 1996年第5期14卷 393-398页

作者： zhao, Cy Zhang, y Fang, WH you, XZ NANJING UNIV CTR ADV STUDIES SCI & TECHNOL MICROSTRUCTINST COORDINAT CHEMNANJING 210093JIANGSUPEOPLES R CHINA

We present here a systematically theoretical study on the nonlinearities and their structure-property relationship of cyanovinyl-substituted donor-acceptor molecules by virtue of semiempirical PM3/AM1-FF approach. Good consistency between measured and calculated hyperpolarizabilities is obtained. Results show that conformation has a significant effect on hyperpolarizabilities. The torsion angle change between two conjugated parts of the molecular systems can substantially alter the nonlinearities. The total amount of charge transfer difference from donor to acceptor has been introduced to understand the microscopic nature of the nonlinear optical properties for the title molecules. General guidelines may be sought out in the search of molecules with large values of beta. Some molecules with large molecular hyperpolarizabilities can be predicted by the optimization for the longer pi-electron systems with both acceptor and donor groups.

关键词： nonlinear optics hyperpolarizabilities PM3 method cyanovinyl-substituted molecules

An essential role for TAK1 in the contact hypersensitivity response

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Cellular & Molecular Immunology 2011年第4期8卷 315-324页

作者： yan G zhao yunqi Wang Weidong Hao yisong y Wan Department of Toxicology School of Public HealthPeking UniversityBeijingChina Department of Microbiology and Immunology Lineberger Comprehensive Cancer CenterUniversity of North Carolina at Chapel HillNCUSA

Contact hypersensitivity(CHS)is a delayed-type hypersensitivity that can be induced by haptens,such as 2,4-dinitrofluorobenzene(DNFB).Innate and adaptive immunities are both important for the development of *** treat CHS-related diseases,such as allergic contact dermatitis,a disease prevalent in industrialized countries,ways of interfering with improper immune function during CHS responses need to be *** growth factor-b-activated kinase-1(TAK1),a member of mitogen-activated protein kinase kinase kinase family,is important for both innate and adaptive *** thus hypothesized that the CHS response could be inhibited by interfering with TAK1 *** a mouse model in which TAK1 deletion can be locally induced,we observed that TAK deficiency led to an impaired CHS response and was associated with defective T-cell expansion,activation and interferon(IFN)-c *** addition,we investigated the effect of deleting TAK1 specifically in dendritic cells(DC)on the CHS *** found that when TAK1 is deficient in DC,the CHS response was abolished and hapten-elicited T-cell responses were ***,this study demonstrates an essential role of TAK1 in the induction of CHS and suggests that targeting TAK1 could be a viable approach to treat CHS.

关键词： CHS DC 2,4-dinitrofluorobenzene(DNFB) TAK1