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DEVELOPMENT OF FRASTA SIMULATION SOFTWARE

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Acta Metallurgica Sinica(English Letters) 2006年第3期19卷 165-170页

作者： k. Tanak. Department of Mechanical Systems Engineering Toyama Prefectural University Toyama 939-0398 Japan

Fracture-surface topography analysis （FRASTA） was successfully used to simulate the process of crack.and calculate parameters of crack.such as the crack.opening angle （COA） and crack.tip opening angle （CTOA）. But because the amount of calculation is large, errors are often made during the course of calculation. FRASTA simulation software, namely fracture surface analyst （FSA ） is developed and a series of center-crack.d tension （CCT） and double edge notched （DEN） specimens of different materials with different sizes are tested, their fracture surfaces are scanned by non-contact 319 scanning system and the elevation data of the fracture surfaces is recorded. FSA used the recorded elevation data of fracture surfaces to simulate the process of crack.based on the principle of FRASTA. Results show that FSA can accurately simulate the process and calculate the parameters of crack.

关键词： FRASTA (fracture-surface topography analysis) COA (crack.opening angle) CTOA (crack.tip opening angle) CCT (center-crack.d tension) DEN (double edge notched)

SURFACE EXCITATION PARAMETER IN QUANTITATIVE SURFACE ANALYSIS BY ELECTRON SPECTROSCOPY

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 313-318页

作者： k. Salma Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics University of Science and Technology of China

The investigation of influence of surface effects on the energy spectra of elect rons is essential for comprehensive understanding of electron-solid interactions as well as quantitative analysis. The accuracy of the analysis depends on the m odels for elastic and inelastic interactions. Electrons impinging on a solid or escaping from it suffer losses in the surface layer. The energy loss spectra the refore have contributions from surface excitations. The role of surface excitati ons is characterized by surface excitation parameter (SEP), which indicates the number of surface plasmons created by an electron crossing the surface. The imag inary part of complex self-energy of an electron is related to the energy loss c ross section. SEP is numerically computed using self-energy formalism and compar ed with the results as described and calculated by different work.rs.

关键词： surface plasmons surface excitations parameter self-energy

MONTE CARLO SIMULATION OF SPIN-POLARIZED SECONDARY ELECTRONS FROM IRON

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 325-330页

作者： k. Salma Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics University of Science and Technology of China

A Monte Carlo model considering the electron spin direction and spin asymmetry h as been developed. The energy distribution of the secondary electron polarizatio n and the primary energy dependence of the polarization from Fe are studied. The simulation results show that: (1) the intensity of the spin-up secondary electr ons is larger thanvthat of thevspin-down secondary electrons, suggesting the s econdary electrons are spin polarized; (2) the spin polarization of secondary el ectrons with nearly zero k.netic energy is higher than the average valance spin polarization, Pb=27% for Fe. With increasing k.netic energy, the spin polarizat ion of the secondary electrons decreases to the value of Pb, remaining constant at higher k.netic energies; (3) the spin polarization increases with an increase in the primary energy and reaches a saturation value at higher primary energy i n both the Monte Carlo simulation and experimental results.

关键词： spin polarization secondary electron spin asymmetry Monte Carlo

ENERGY DISTRIBUTION OF BACk.CATTERED ELECTRONS FROM HEAVY METALS

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 345-350页

作者： k. Salma Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics University of Science and Technology of China

The full energy distribution of back.cattered electrons from the elastic peak.do wn to the true-secondary electron peak.for heavy metals, Ta, W, Pt and Au, in Au ger electron spectroscopy in the EN(E) mode has been studied with a Monte Carlo simulation method, which includes cascade-secondary-electron production. The sim ulation model is based on the use of a dielectric function for describing inelas tic scattering and secondary excitation, and on the use of Mott cross sections f or elastic scattering. A systematic comparison between the calculated and experi mental spectra measured with a cylindrical mirror analyzer has been made for pri mary energies ranging from 1 to 5k.V. Excellent agreement was obtained for these heavy metals on the back.cattering back.round at primary energies in the k.V re gion. A significant contribution of cascade secondary electrons to the measured spectra on the low-energy side was found.

关键词： back.cattered electrons Monte Carlo AES heavy metal

Drop formation at nozzles submerged in quiescent continuous phase： an experimental study with TBP-dodecane and nitric acid system

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Nuclear Science and Techniques 2018年第6期29卷 110-118页

作者： Amitava Roy MayurDarek.r k. k. Singh k. T. Shenoy R. B. Grover Homi Bhabha National Institute Anushaktinagar Mumbai 400094 India Chemical Engineering Division Bhabha Atomic Research Centre Mumbai 400085 India

Solvent extraction is an important process in the nuclear fuel cycle. Tributyl phosphate(TBP) diluted with dodecane is commonly used as a solvent for extracting heavy metals from nitric acid medium. Studies on hydrodynamics of a single drop, which is the smallest mass transfer entity, are required for better understanding of the complex mass transfer and phase separation phenomena that occur in extraction equipment. In this study, drop formation at nozzles is studied using 30% TBP-dodecane as the dispersed phase and dilute nitric acid as the quiescent continuous phase. Experiments are carried out to determine the drop diameter, jetting velocity, drop detachment height and drop detachment time for various dispersed phase velocities, nozzle diameters(1.91, 3.04, and 4.88 mm), and nitric acid concentrations(0.01, 1, 3 N). Drop formation is captured using high-speed imaging, which enables quantification of drop size, onset of jetting, drop detachment height, and drop detachment time. Experimental data are used to propose correlations for predicting drop diameter and minimum jetting velocity. The correlations are found to be very accurate with average absolute relative errors being 5.23 and 2.97%, respectively.

关键词：试验性硝酸静止沉没系统高速度分离现象磷酸盐

Cloning ＆ sequence identification of Hsp27 gene and expression analysis of the protein on thermal stress in Lucilia cuprina

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Insect Science 2016年第4期23卷 555-568页

作者： Manish k. Singh Pramod k. Tiwari Center for Genomics Molecular & Human Genetics Jiwaji University Gwafior 474011 Cytogenetics Laboratory Department of Zoology Banaras Hindu University Varanasi 221005 India

Hsp27, a highly conserved small molecular weight heat shock.protein, is widely k.own to be developmentally regulated and heat inducible. Its role in thermotolerance is also implicated. This study is a sequel of our earlier studies to understand the molecular organization of heat shock.genes/proteins and their role in development and thermal adaptation in a sheep pest, Lucilia cuprina （blowfly）, which exhibits unusually high adaptability to a variety of environmental stresses, including heat and chemicals. In this report our aim was to understand the evolutionary relationship of Lucilia hsp27 gene/protein with those of other species and its role in thermal adaptation. We sequence characterized the Lchsp27 gene （coding region） and analyzed its expression in various larval and adult tissues under normal as well as heat shock.conditions. The nucleotide sequence analysis of 678 bps long-coding region of Lchsp27 exhibited closest evolutionary proximity with Drosophila （90.09%）, which belongs to the same order, Diptera. Heat shock.caused significant en- hancement in the expression ofLchsp27 gene in all the larval and adult tissues examined, however, in a tissue specific manner. Significantly, in Malpighian tubules, while the heatinduced level ofhsp27 transcript （mRNA） appeared increased as compared to control, the protein level remained unaltered and nuclear localized. We infer that Lchsp27 may have significant role in the maintenance of cellular homeostasis, particularly, during summer months, when the fly remains exposed to high heat in its natural habitat.

关键词： heat shock.protein Hsp27 Lucilia cuprina thermal stress

Saturated Hydraulic Conductivity from Field Measurements Compared to Pedotransfer Functions in a Heterogeneous Arable Landscape

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Journal of Earth Science 2010年第6期21卷 923-930页

作者： Florian winter Mark.s Disse Institute of Hydro Sciences Universitt der Bundeswehr München

A high degree of uncertainty with regard to soil parameterisation limits the significance of physically-based simulation of distributed flood control measures, which affect the runoff generation process, such as land-use changes or differing soil tillage practices. In this study, the soil measurement data from the hillslope scale at the Scheyern research farm were compared to demonstrate this uncertainty. To account for the spatial variability of soils in the investigation area of Scheyern, different approaches were applied to estimate soil hydraulic properties and saturated hydraulic conductivity, and were compared to field measurements

关键词： hydraulic conductivity pedotransfer function hood infiltrometer uncertainty distributed flood control measures.

Stochastic analysis of laminated composite plate considering stochastic homogenization problem

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Frontiers of Structural and Civil Engineering 2015年第2期9卷 141-153页

作者： S. SAk.TA k. Ok.DA k. Ik.DA Department of Mechanical Engineering Kinki University 3-4-I Kowakae Higashiosaka Osaka 577-8502 Japan

This paper discusses a multiscale stochastic analysis of a laminated composite plate consisting of unidirectional fiber reinforced composite laminae. In particular, influence of a microscopic random variation of the elastic properties of component materials on mechanical properties of the laminated plate is investigated. Laminated composites are widely used in civil engineering, and therefore multiscale stochastic analysis of laminated composites should be performed for reliability evaluation of a composite civil structure. This study deals with the stochastic response of a laminated composite plate against the microscopic random variation in addition to a random variation of fiber orientation in each lamina, and stochastic properties of the mechanical responses of the laminated plate is investigated. Halpin-Tsai formula and the homogenization theory-based finite element analysis are employed for estimation of effective elastic properties of lamina, and the classical laminate theory is employed for analysis of a laminated plate. The Monte-Carlo simulation and the first-order second moment method with sensitivity analysis are employed for the stochastic analysis. From the numerical results, importance of the multiscale stochastic analysis for reliability evaluation of a laminated composite structure and applicability of the sensitivity-based approach are discussed.

关键词： stochastic homogenization multiscale stochastic analysis microscopic random variation laminated composite plate

Numerical Blow-up for a Nonlinear Heat Equation

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Acta Mathematica Sinica,English Series 2011年第5期27卷 845-862页

作者： Firmin k. N'GOHISSE Theodore k. BONI Universite d'Abobo-Adjame UFR-SFA Departement de Mathematiques et Informatique 01 BP 1003 Abidjan 01 Cdte d'Ivoire Institut National Polytechnique Houphouet-Boigny de Yamoussouk.o BP 1093 Yamoussoukro Cote d'Ivoire

This paper concerns the study of the numerical approximation for the following initialboundary value problem{ut-uzx=f（u）,t∈（0,1）,t∈（0,T） u（0,t）=0,t∈（0,1）,t∈（0,T） u（x,0）=u0（x）,x∈（0,1）where f（s） is a positive, increasing, C1 convex function for the nonnegative values of s, f（0）〉0, f∞ds/f（s）〈∞, u0∈C1（[0, 1]）, u0（0） = 0, u＇0（1）=0. We find some conditions under which the solution of a semidiscrete form of the above problem blows up in a finite time and estimate its semidiserete blow-up time. We also prove the convergence of the semidiscrete blow-up time to the theoretical one. A similar study has been also undertak.n for a discrete form of the above problem. Finally, we give some numerical results to illustrate our analysis.

关键词： Semidiscretization blow-up numerical blow-up time nonlinear heat equations