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Observation and computer simulation of multicomponent chemical short-range order (MCSRO) for the bulk metallic glasses

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Journal of University of Science and Technology Beijing 2005年第2期12卷 143-150页

作者： GuoliangChen XidongHui KefuYao HuaiyuHou XiongjunLiu MeilingWang GuangChen StateKeyLaboratoryforAdvancedMetalsandMaterials UniversityofScienceandTechnologyBeijingBeijing100083China／／DepartmentofMaterialScienceandEngineeringNanjingUniversityofScienceandTechnologyNanjing210094China StateKeyLaboratoryforAdvancedMetalsandMaterials UniversityofScienceandTechnologyBeijingBeijing100083China DepartmentofMechanicalEngineering TsinghuaUniversityBeijing100084China. DepartmentofMaterialScienceandEngineering NanjingUniversityofScienceandTechnologyNanjing210094China

The atomic configuration of chemical short-range order (CSRO) for the Zr-base metallic glasses was investigated by using nano-diffraction and high resolution transmission electronic microscopy (HRTEM) technology with a beam size of 0.5 nm. It is il- lustrated that the pattern of atomic configuration of CSRO might have various compound counterparts because of the chemical inter- action of bonding atoms. Some atomic configuration of MCSRO is similar to the icosahedral structure with 10-fold symmetry of very weak spots. In deed, the nano-beam technology could clearly detect the evolution of atomic configuration in nanometer scale during the transformation from the metallic melt to the primary crystallization. The local atomic configuration of CSRO is also investigated by molecular dynamics simulation (MD) for the Zr2Ni compound in a wider temperature range. The CSRO in the melt could be pic- torially demonstrated as distorted coordination polyhedron of the compound structure and/or the structure similar to cubo-octahedron analogs. The MD simulation illustrates that the atomic packing of long-range order disappears just above the melting point, but the chemical interaction of bonding atoms still exists that leads to form the various CSRO with the atomic configuration similar to stable or metastable unit cell of Zr2Ni compound. The icosahedral polyhedron became more abundance as the overheating temperature was raised.

关键词： bulk metallic glasses short-range order nano-diffraction and HRTEM technology molecular dynamic simulation

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Approach to Generalized Synchronization with Application to Chaos-Based Secure Communication

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Communications in Theoretical Physics 2004年第4期41卷 632-640页

作者： MINLe-Quan CHENGuan-Rong ZHANGXiao-Dan ZHANGXia-Hua YANGMiao DepartmentofMathematicsandMechanics UniversityofScienceandTechnologyBeijingBeijing100083China DepartmentofElectronicEngineering CityUniversityofHongKongHongKongChina

A constructive theorem is established for generalized synchronization (GS) related to C1 diffeomorphic transformations of unidirectionally coupled dynamical arrays. The theorem provides some interpretations about the underlying mechanism of various GS phenomena in nature. As a direct application of the theorem, a chaos-based secure Internet communication scheme is proposed. Moreover, a cellular neural network (CNN) of Chen's chaotic circuits with GS property is designed and studied. Numerical simulation shows that this Chen's CNN has high security and is fast and reliable for secure Internet communications.

关键词： synchronization neural network cellular chaos numerical using chaos numerical simulation

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Enhancement effect of orgnic solvents on the line intensity of lower power argon ICP-AES:PartⅡ A study on excitation characteristics of ICP

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Rare Metals 2002年第2期21卷 113-116页

作者： CAOYanqiu LUYiqiang SONGXuwen WANGLihua XINRenxuan ChemistryDepartment UniversityofScienceandTechnologyBeijingBeijing100083China NuclearInstituteofQinghuaUniversity Beiiing100081China

The effects of ethanol solutions on lower power Ar ICP dischargewere studied by measuring plasma temper- atures (gas temperature,excitation temperature, ionization temperature and electrontemperature) and electron number densities. The temperatures andelectron number densities were reduced with the increasing of ethanolconcentration. The ICP system is much apart from LTE ***, ethanol solutions will place a reducing effect on spectral lineIntensity.

关键词： Icp plasma temperatures ethanol

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SCC Susceptibility of Steel 16Mn in Nitrate Solution and Its Mechanism

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Journal of University of Science and Technology Beijing 2002年第1期9卷 31-35页

作者： YinshunWu ZHiFang 等 CorrosionandProtectionCenter UniversityofScienceandTechnologyBeijingBeijing100083China MedtronicsEnergyandComponentCenter MN55430USA

The SCC (stress corrosion cracking) susceptibility of steel l6Mn in nitratesolution was studied. The results showed that applied potential polarization would accelerate(anodic polarization) or retard (cathodic polarization) the SCC process. The study on phaseelectrochemistry revealed that there was significant difference in electrochemical performancebetween ferrite and pearlite of steel 16Mn. Pearlite preferentially corroded under the action ofgalvanic cell. The observation on time and in situ showed that corrosion started first at the phaseboundary between ferrite and pearlite, and the pearlite gradually corroded until disappeared, andthen corrosion crossed the phase boundary extending into the ferrite phase. According to this, ananodic dissolution mechanism of SCC was proposed, on which pre-existing sting active path and phaseelectrochemistry (PEAP-PEC) jointly came into action (SCC mechanism of PEAP-PEC).

关键词： SCC susceptibility SCC mechanism of PEAP-PEC steel 16Mn nitratesolution phase electrochemistry

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Non-equilibrium segregation of boron on grain boundary in Fe-30%Ni alloy

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Journal of University of Science and Technology Beijing 2002年第5期9卷 347-351页

作者： BingCao WueminWang 等 EditorialDepartmentofJ.Univ.Sci.Technol.Beijing Beijing100083China MaterialScienceandEngineeringSchool UniversityofScienceandTechnologyBeijingBeijing100083China

The moving boundary non-equilibrium segregation duringrecrystallization and the influence of pre-deformation in Fe-30/100Ni alloy at 1000 deg. C was investigated by the PTA(particle trackingautoradiography)technique, optical and electron microscopy. The re-Sults indicated that intensity of boron segregation on movingboundary after different deformation is concerned with thepre-deformation Degree and the moving speed of the boundary. TheTEM(transmission electron microscopy(result showed that thedislocation density Nearby the moving boundary increase *** phenomena are discussed by the widening grain boundary mechanism.

关键词： recrystallization segregation boron pre-deformation

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Rheologic behavior and PIM processing of WC-TiC-Co powder feedstock

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Journal of University of Science and Technology Beijing 2004年第4期11卷 334-337页

作者： XuanhuiQu JianxiangGao MingliQin ChangmingLei BeijingKeyLaboratoryforAdvancedPowderMetallurgyandParticulateMaterials UniversityofScienceandTechnologyBeijingBeijing100083China StateKeyLaboratoryforPowderMetallurgy CentralSouthUniversityChangsha410083China

An improved wax-based binder was developed for the powder injection molding(PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of thefeedstock were determined. It was found that the critical powder loading could achieve up to 62.5percent (volume fraction) and the feedstock exhibited a pseudo-plastic flow behavior. The injectionmolding, debinding and sintering processes were studied. The dimension deviation of the sinteredsamples could be controlled in the range of + -0.2 percent with the optimized processing parametersand the mechanical properties were better than or equivalent to those of the same alloy made byconventional press-sintering process.

关键词： powder injection molding (PIM) cemented carbides binder rheology mechanical properties

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Effects of [S] and T[O] on strength and toughness of high purification low alloy steel plates

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Journal of University of Science and Technology Beijing 2003年第5期10卷 27-30页

作者： ZengwuZhao XinhuaWang GuoweiChang MetallurgicalEngineeringSchool UniversityofScienceandTechnologyBeijingBeijing100083China BaotouUniversityofIronandSteelTechnology Baotou014010China

The effect of [S] on strength and toughness of low alloy steel plates inwhich sum of [P], [N], T[O] is less than 8x10^(-5) and the effect of T[O] on strength and toughnessof the steel plates in which sum of [S], [P], [N] is less than 7x10^(-5) were investigated. It isfound that the strength of the steel plates decreases with increasing [S] content when [S] is lessthan 4x10^(-5). When [S] varies within the range of 4x10^(-5)-1.2x10^(-4), [S] has no significanteffect on strength of the steel. The strength of the steel plates increases with increasing T[O]content when T[O] is less than 30x10^(-6), but decreases with increasing T[O] when T[O] is more than3x10^(-5). The difference between the LETT in plate length direction and LETT in width directiondecreases with decreasing [S] content. However, even when [S] is decreased to 9x10^(-6), thedifference of the LETT is still 16℃. When T[O] varies between 1.8x10^(-5) and 5.2x10^(-5), the lowtemperature impact toughness of the steel plates slowly decreases with T[O] increasing. When T[O]increases to more than 5.2x10^(-5), the low temperature toughness of the steel rapidly decreaseswith increasing T[O] content.

关键词： low alloy steel strength toughness sulfur oxygen tough-brittle transfertemperature (LETT)

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Computer simulation of order-disorder phase transition in the intercalation compounds M_(1/2)TiS_2 (M=Fe, Co, Ni)

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Rare Metals 2004年第2期23卷 161-164页

作者： LIZuoan SONGQinggong DepartmentofPhysicalChemistry UniversityofScienceandTechnologyBeijingBeijing100083China CollegeofScience CivilAviationUniversityofChinaTianjin300300China

Based on cluster variation method (CVM) and natural iteration method (MM),order-disorder phase transition in the intercalation compounds M_(1/2)TiS_2 is simulated bycomputer. The favorable conditions, under which 3^(1/2)a_0 x a_0 superstructure is formed, aregiven, and the results are in good agreement with the experiments and theoretical calculations. Therelationship between critical temperature and M-ion-vacancy interaction parameter is linear.

关键词： order-disorder phase transition cluster variation method natural iterationmethod intercalation compound

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Shrinkage and trajectory of the flat jet with inclination angle

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Journal of University of Science and Technology Beijing 2003年第3期10卷 21-25页

作者： ShufengYe YushengXie HongzhiGuo YeHuang ShantongJin InstituteofProcessEngineering ChineseAcademyofSciencesBeijing100080China DepartmentofThermalEngineering UniversityofScienceandTechnologyBeijingBeijing100083China

The performance of the flat jet with an inclination angle was investigated bya water model. A mathematical model for the shrinkage and the trajectory of the flat jet with aninclination angle was derived theoretically and verified by experimental data of the water *** experimental results indicate that the inclination angle (alpha) has no influence on theshrinkage of the flat jet, the shrinkage of the flat jet along the width direction decreases withthe increasing of the initial velocity at the exit (u_0) and the initial thickness of the flat jet(t_0). Enough bigger initial exit velocity (u_0) and initial thickness can suppress the shrinkage ofthe flat jet along the width direction and keep the flat jet stabilized. In addition, thetrajectory of the flat jet with an inclination angle is parabolic and must be taking intoconsideration when to determine the striking distance.

关键词： continuous reactor desulfurization flat jet modeling

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Cut slope reinforcement technique in open-pit mines

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Journal of University of Science and Technology Beijing 2004年第4期11卷 289-292页

作者： YongtaoGao JianboSun ShunchuanWu AibingJin CivilandEnvironmentalEngineeringSchool UniversityofScienceandTechnologyBeijingBeijing100083China HighwayDevelopmentLimitedCompanyofHenanProvince Zhengzhou450052China

The design and practice in supporting the cut slope of an open-pit mine wereintroduced, in which the high pressure grouting method was used in reinforcing the weak formation inthe slopes. Based on a detailed geological survey of the slope, a theoretical analysis was carriedout, and the design parameters were proposed, where the Tresca or Mohr-Coulomb yield criteria wasemployed. A patent technology, named 'Technology of high pressure and multiple grouting in differentlevels within a single hole', was employed in the construction. Anchor bars were also installed asgrouting proceeds. This method combines anchoring and grouting comprehensively and was foundsuccessful in practice.

关键词： mining engineering, open-pit slope weak formation supporting high pressuregrouting

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