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STuDY ON THE SiC_p./Al-AllOY COMPOSITE AuTOMOTIVE BRAKE ROTORS

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Acta Metallurgica Sinica(English letters) 2000年第4期13卷 974-980页

作者： Ding, z.l. Fan, Y.C. qi, H.B. Ren, D.l. Guo, J.B. Jiang, z.q. Shijiazhuang Railway Inst Shijiazhuang China

The SiCp/Al-alloy composite front brake rotors designed for Shanghai Santana cars were prepared by semi-solid stirring+liquid forging process. The composite brake rotors were subjected to dynamometer tests on a SCHENCK brake testing system, referring to Tl110 standard of VOlKSWAGEN Co. The friction coefficient and thermal response during fade testing and the wear performance of the composite rotors were studied as the functions of various parameters such as braking pressures, initial speeds, initial temperatures, torque and decelerations, and were compared with those of conventional cast iron rotors. The results show that the properties of the composite rotors can achieve the requirements of commercial cast iron rotors. The results also show that the friction coefficients of the composite rotors under different braking conditions are within the deviation band specified by the Tl110 standard, and the temperature rise of composite rotors is lower than that of cast iron rotors at the end of each fade stop. The wear resistance of composite rotors is higher than that of cast iron rotors. The friction mechanism and wear mechanism were analyzed.

关键词： Brakes Friction Metallic matrix composites Rotors Silicon carbide Wear resistance

A Gas Chromatographic Analysis of light Hydrocarbons on a Column Packed with Modified Silica Gel

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Chinese Chemical letters 2000年第11期11卷 1019-1022页

作者： lan X.z. zhu D.q. Wang q.H. zhou l.M. Guan Y.F. Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116012 China

A one-meter long column packed with silica gel is used to separate light hydrocarbons. The silica gel has been modified with several kinds of gas chromatography stationary phases. Among these, PEG 2000 shows fairly good effect when using 80-100 meshes silica gel for the separation of mixture of methane, ethane, ethylene, acetylene, propane, propylene and n-, i-butane. The different behavior of silica gel between batch to batch is also found. When silica gel is coated with a small amount of Al2O3 prepared with sol-gel method, better resolution has been observed on a 2-meter column compared with the non-modified silica gel.

关键词： li A Gas Chromatographic Analysis of light Hydrocarbons on a Column Packed with Modified Silica Gel

人工智能辅助压缩感知方案在膝关节MR成像中的可行性：一项前瞻性多阅片者研究

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国际医学放射学杂志 2024年第1期 129-129页

作者： q.z.Wang W.l.zhao X.Y.Xing Y.Wang P.J.Xin Y.Y.Chen 陈莉

摘要目的评价人工智能辅助压缩感知（ACS）加速二维快速自旋回波MRI与标准并行成像（PI）在3.0 T快速膝关节扫描中的影像质量和诊断效能。方法该前瞻性研究在

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EFFECTS OF zn CONCENTRATION ON WETTABIlITY OF Sn-zn AllOY ON Cu AND ON THE INTERFACIAl MICROSTRuCTuRE BETWEEN Sn-zn AllOY AND Cu

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Acta Metallurgica Sinica(English letters) 2006年第4期19卷 251-257页

作者： H.z. Huang X.q. Wei l. zhou X.D. liu G.l. Guo School of Materials Science and Engineering Nanchang University Nanchang 330047 China East China Institute of Technology Fuzhou 344000 China

The potential of using a hypoeutectic, instead of eutectic, Sn-zn alloy as a lead-free solder has been discussed. The nonequilibrium melting behaviors of a series of Sn-zn alloys were examined by differential thermal analysis. It was found that at a heating rate of 5℃/min, *** exhibited no melting range. Dipping and spreading tests were carried out to characterize the wettability of Sn-zn alloys on Cu. Both tests exhibited that Sn-6.5zn has significantly better wettability on Cu than Sn-9zn. The reaction layers formed during the spreading tests were examined. When the zn concentration fell between 2.5wt%-9wt%, two reaction layers were formed at the interface, a thick and flat Cu5zn8 adjacent to Cu and a thin and irregular Cu-zn-Sn layer adjacent to the alloy. Only a Cu0Sn5 layer was formed when the zn concentration decreased to 0.5wt%. The total thickness of the reaction layer（s） between the alloy and Cu was found to increase linearly with the zn concentration.

关键词： lead-free solder Sn-zn alloy wettability interface intermetallic compound

ElECTROCHEMICAl STuDY ON THE lOCAlIzED CORROSION OF TWO DIFFERENT TEMPER lY12 AllOYS

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Acta Metallurgica Sinica(English letters) 2005年第5期18卷 609-619页

作者： F.H. Cao l. Guo l.J. zhang z. zhang J. q. zhang Department of Chemistry Yuquan Campus Zhejiang University Hangzhou 310027 China State Key laboratory for Corrosion and Protection of Metals Institute of Metal Research The Chinese Academy of Sciences Shenyang 110016 China

The corrosion behavior of two different aged lY12 alloys in EXCO （234g/l NaCl, 50g/l KNO3 0.1M HNO3） and MIl-H-600 （35g/l NaCl, 5g/l （NH4）2SO4） solutions were studied using electrochemical impedance spectroscopy （EIS） in conjunction with SEM technique respectively, and the pH variation of the above accelerated corrosion solution during materials corroding was also measured to characterize the corrosion processes. At the beginning of corrosion, EIS plots exhibited two capacitive arcs in the high frequency range （Cd） and mediate frequency range （ Cf） originating from the original corroded surface and the newly formed interface respectively, and a low frequency inductive loop due to the relaxation phenomenon of reaction intermediates. In the EXCO,solution, the EIS results showed that once the exfoliation corrosion occurred, the inductive loop disappeared. The results also showed that the exfoliation corrosion susceptibility of state T6 is much higher than that of state T3, but the intergranular corrosion susceptibility has a reverse order. Based on the relationship of EIS results with SEM and metalloscopy morphologies of the corroding substrates and physic-chemical meaning of EIS parameters, an index （Cf/Cd） has been proposed to characterize the extent of the localized corrosion, which variation tallies with the real corrosion extent correctly. Meanwhile, good agreement was found between the experimental results and the electrochemical model proposed and, good coherence between the electrochemical features and the distribution type of constituent particles of corroding material was observed.

关键词： electrochemical impedance spectroscope lY12 alloy exfoliation corrosion intergranular corrosion

Investigation of protein-styrene oxide adducts as a molecular biomarker of human exposed to styrene

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Journal of Environmental Sciences 2001年第4期13卷 391-397页

作者： liu, S.-F. Fang, q.-M. Jin, z.-l. Rappaport, M.S. Res. Cntr. Eco-Environmental Sci. Chinese Academy of Sciences Beijing 100085 China

Hemoglobin-styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein-styrene oxide adducts in different biological samples with modified Raney-Ni procedure is described in this paper. The following biological samples have been investigated: fresh rat blood reacted with styrene oxide in vitro: rat blood reacted with styrene or styrene oxide in vivo: vein blood from workers exposed to styrene in two factories. The data showed that there was a good linear dose-response relationship between reacting dose of styrene oxide or styrene and amount of protein-styrene oxide adducts in both in vitro and in vivo experiments. For human samples, a dose-response relationship between protein adducts and styrene exposure can be found in glass fiber factory, but not in piano manufacture plant.

关键词： Blood Drug dosage Glass fibers Hemoglobin Manufacture Oxides Proteins Styrene

Random vibration of hysteretic systems under Poisson white noise excitations

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Applied Mathematics and Mechanics(English Edition) 2023年第2期44卷 207-220页

作者： lincong CHEN zi YuAN Jiamin qIAN J.q.SuN College of Civil Engineering Huaqiao UniversityXiamen 361021Fujian ProvinceChina Key laboratory for Intelligent Infrastructure and Monitoring of Fujian Province Xiamen 361021Fujian ProvinceChina Department of Mechanical Engineering School of EngineeringUniversity of CaliforniaMercedCA 95343U.S.A.

Hysteresis widely exists in civil structures,and dissipates the mechanical energy of *** on the random vibration of hysteretic systems,however,is still insufficient,particularly when the excitation is *** this paper,the radial basis function(RBF)neural network(RBF-NN)method is adopted as a numerical method to investigate the random vibration of the Bouc-Wen hysteretic system under the Poisson white noise *** solution to the reduced generalized Fokker-PlanckKolmogorov(GFPK)equation is expressed in terms of the RBF-NNs with the Gaussian activation functions,whose weights are determined by minimizing the loss function of the reduced GFPK equation residual and constraint associated with the normalization condition.A steel fiber reinforced ceramsite concrete(SFRCC)column loaded by the Poisson white noise is studied as an example to illustrate the solution *** effects of several important parameters of both the system and the excitation on the stochastic response are evaluated,and the obtained results are compared with those obtained by the Monte Carlo simulations(MCSs).The numerical results show that the RBF-NN method can accurately predict the stationary response with a considerable high computational efficiency.

关键词： random vibration Bouc-Wen hysteresis system non-Gaussian excitation Poisson white noise excitation radial basis function(RBF)neural network(RBF-NN)

Effects of Curing Condition on the Carbonation of Shrinkage-compensated Concrete

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武汉理工大学学报 2010年第17期32卷 103-107页

作者： MA J T Tu l q SHuI z H CHEN W School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Wuhan Harbour Engineering Design & Research Co. ltd Wuhan 430071China

Shrinkage-compensating concrete can enhance the permeability and strength. In addition,expansive admixture can densify concrete to advance the carbonation resistance ability. Due to special quality of ettringite,the relative humidity of curing environment has significant effect on the carbonation rate of concrete. This paper discusses the influence of environmental humidity on carbonation rate of shrinkage-compensating concrete. Four different curing conditions were set up,namely the natural environment (RH 60%),standard environment (RH 90%),early age water curing environment for 3 d and 7 d. After curing in these four environments for 28 d,an accelerated carbonation test was performed. Micro-hardness analysis was used to evaluate surface hardness,which depends on,to a great degree,the carbonation depth. TG-DSC analysis was used to study Ca(OH)2 content gradient in the surface layer of concrete in different environment. The results show that natural condition lead to a relatively worse carbonation degree,curing in water for 3 d is harmful to the carbonation resistance,while curing in water for 7 d lead to an equivalent carbonation degree with standard condition,which show the most improvement to carbonation resistance ability.

关键词： shrinkage-compensating concretes curing humility ettringite reaction carbonation rate

High mechanical strengths and ductility of stainless steel 304l fabricated using selective laser melting

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Journal of Materials Science & Technology 2019年第2期35卷 388-394页

作者： q.B.Nguyen z.zhu F.l.Ng B.W.Chua S.M.l.Nai J.Wei Singapore Institute of Manufacturing Technology Institute of Research and Development Duy Tan University

Achieving not only high mechanical strengths but also high ductility is recently established using an additive manufacturing technique called selective laser melting. In the present study, stainless steel 304 l fully dense samples were successfully printed using the 3 D systems – ProX 300 printing machine. The ductility and tensile yield strength were almost two and three times higher compared to those of ASTM cast's alloy. Honey comb like nano-cellular structure with different orientation was observed in the fine grains(~4μm) due to fast cooling rate. In addition, the formation of martensite phase in random grains is also a contributor to the strengths. Furthermore, negative residual stresses in the build and horizontal directions were detected and assisted further increase in the tensile strength. Fractography revealed the ductile feature of plastic deformation and the crack openings at unmelted particles or pores.

关键词： Additive manufacturing Stainless steel Powder Selective laser melting