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Deformation behavior of Zr-based bulk metallic glass and composite in the supercooled liquid region

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Science china(Physics,Mechanics & Astronomy) 2008年第4期51卷 349-355页

作者： cHEN Qi LIU Lin cHAN k.c. State key Laboratory of Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China Department of Industrial and Systems Engineering Hong Kong Polytechnic UniversityHong KongChina

A Zr-based bulk metallic glass (BMG) with a composition of (Zr75cu25)78.5Ta4Ni10Al7.5 and a bulk metallic glass matrix composite (BMGc) with a composition of (Zr75cu25)74.5Ta8Ni10Al7.5 have been prepared by copper-mold casting. The compres-sive deformation behavior of the BMG and BMGc was investigated in the super-cooled region at different temperatures and various strain rates ranging from 8×10-4s-1 to 8×10-2s-1. It was found that both the strain rate and test temperature signifi-cantly affect the deformation behavior of the two alloys. The deformation follows Newtonian flow at low strain rates but non-Newtonian flow at high strain rates. The deformation mechanism for the two kinds of alloys was discussed in terms of the transition state theory.

关键词： bulk metallic glass composites supercooled liquid region compressive deformation free volume

THE 1-LAPLAcIAN cHEEGER cUT： THEORY AND ALGORITHMS

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Journal of computational Mathematics 2015年第5期33卷 443-467页

作者： k.c. chang Sihong Shao Dong Zhang LMAM and School of Mathematical Sciences Peking University Beijing 100871 China

This paper presents a detailed review of both theory and algorithms for the cheeger cut based on the graph 1-Laplacian. In virtue of the cell structure of the feasible set, we propose a cell descend （cD） framework for achieving the cheeger cut. While plugging the relaxation to guarantee the decrease of the objective value in the feasible set, from which both the inverse power （IP） method and the steepest descent （SD） method can also be recovered, we are able to get two specified cD methods. comparisons of all these methods are conducted on several typical graphs.

关键词： Spectral graph theory Spectral clustering 1-Laplace operator Graph Lapla-cian Eigenvalue problems cheeger constant Graph cut Optimization convergence

Restorating marine coastal ecosystem health as a new goad for integrated catchment management in Tolo Harbour,Hong kong,china

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chinese Journal of Population,Resources and Environment 2004年第2期2卷 11-19页

作者： Lam k.c. Department of Geography and Resoure management The Chinese University of Hong Kong.ShatinNew TerritoriesHong KongChinahe paper demonstrates why it is necessary to take the restoration of marine coastal ecosystem health as a new goal for integrated catchment management in coastal area of the Tolo Harbour. The present goal of integrated catchment management (ICM) in the Tolo Harbour is to meet with Water Quality Objectives. The performance of an ICM plan Tolo Harbour Action Plan (THAP) is evaluated by using marine coastal ecosystem health indicators including stress indicators and responses indicators. Since the implementation of THAP in 1988 some significant reduction in pollution loading has been observed - reduction of 83 % of BOD load and 82 % of TN between 1988 and 1999. There has been an improvement in the health state of Tolo Harbour marine coastal ecosystem as evidenced in the trends of the physical chemical and biological indicators although some reverse fluctuations in some periods exist. However this can only be considered as the first sign of the ecosystem health restoration since ecosystem health covers not only physical chemical and biological aspects of an ecosystem but also ecosystem-service-function aspect. It is recommended to take the restoration and protection of marine coastal ecosystem health as a new goal instead of water quality objective management for integrated catchment management in Tolo Harbour catchment. Steps to further improve the marine coastal ecosystem health of Tolo harbour are discussed in the paper.

The paper demonstrates why it is necessary to take the restoration of marine coastal ecosystem health as a new goal for integrated catchment management, in coastal area of the Tolo Harbour. The present goal of integrated catchment management (IcM) in the Tolo Harbour is to meet with Water Quality Objectives. The performance of an IcM plan, Tolo Harbour Action Plan (THAP), is evaluated by using marine coastal ecosystem health indicators including stress indicators and responses indicators. Since the implementation of THAP in 1988, some significant reduction in pollution loading has been observed - reduction of 83 % of BOD load and 82 % of TN between 1988 and 1999. There has been an improvement in the health state of Tolo Harbour marine coastal ecosystem as evidenced in the trends of the physical, chemical and biological indicators, although some reverse fluctuations in some periods exist. However, this can only be considered as the first sign of the ecosystem health restoration, since ecosystem health

关键词： Marine coastal ecosystem health integrated catchment management pollution loading indicator Tolo Harbour Action Plan.

Effect of promoters on dynamics of gas-solid fluidized bed——Statistical and ANN approaches

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china Particuology 2007年第6期5卷 401-407页

作者： Y.k. Mohanty k.c. Biswal G.k. Roy B.P. Mohanty Department of chemical Engineering GIET Gunupur 765 022 Rayagada Orissa India Department of chemical Engineering NIT Rourkela 769008 Orissa India

In this study, a bubbling fluidized bed column, 99 mm in inside diameter and 960 mm in height, was used to investigate the effect of rod and disc promoters on fluctuation and expansion ratios. Factorial design （statistical approach） and artificial neural network （ANN） models were developed to predict the fluctuation and expansion ratios in this gas-solid fluidized bed with varying gas flow rates, bed heights, particle sizes and densities. The fluctuation and expansion predicted using these statistical and ANN models, for beds with and without promoters, were found to agree well with corresponding experiments. The statistical model was found to be superior to the ANN model due to its ability to take into account both individual and interactive effects. The rod promoters were found to be more effective in reducing bed fluctuation, and in increasing bed expansion at high gas mass velocities.

关键词： Gas-solid fluidized bed Fluctuation ratio Expansion ratio Promoter Factorial design Artificial neural network

Zooplankton Research in Indian Seas:A Review

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Journal of Ocean University of china 2018年第5期17卷 1149-1158页

作者： SRIcHANDAN Suchismita BALIARSINGH S.k. PRAkASH Satya PANIGRAHY R.c. SAHU k.c. Indian National centre for Ocean Information Services Hyderabad 500090India Department of Marine Sciences Berhampur UniversityOdisha 760007India

To promote long-term studies on the distribution and diversity of marine zooplankton in Indian seas,a comprehensive review has been carried out based on the available *** studies in Indian waters started in the early 1900 s,and a plethora of literature has accumulated dealing with various aspects of zooplankton,especially from the Bay of Bengal,Arabian Sea and their associated estuaries and *** this review,a comprehensive description is offered on the species composition and distribution of zooplankton in the Indian *** is given to reflect the existing knowledge on the variations in zooplankton species composition in the Bay of Bengal and Arabian *** emerge as the most dominant component in all of these marine waters,as is the case *** are more diverse in the Bay of Bengal than in Arabian Sea.

关键词： zooplankton Arabian Sea Bay of Bengal coastal water oceanic water

Binding interaction of phosphorus heterocycles with bovine serum albumin:A biochemical study

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Journal of Pharmaceutical Analysis 2017年第1期7卷 19-26页

作者： Swarup Roy Raj kumar Nandi Sintu Ganai k.c. Majumdar Tapan k. Das Department of Biochemistry and Biophysics University of Kalyani Kalyani 741235 West Bengal India Department of chemistry University of Kalyani Kalyani 741235 West Bengal India

Interaction between bovine serum albumin(BSA) and phosphorus heterocycles(PHs) was studied using multispectroscopic techniques. The results indicated the high binding affinity of PHs to BSA as it quenches the intrinsic fluorescence of BSA. The experimental data suggested the fluorescence quenching mechanism between PHs and BSA as a dynamic quenching. From the UV–vis studies, the apparent association constant(k_(app)) was found to be 9.25×10~2, 1.27×10~4and 9.01×10~2L/mol for the interaction of BSA with PH-1, PH-2 and PH-3,respectively. According to the F?rster's non-radiation energy transfer(FRET) theory, the binding distances between BSA and PHs were calculated. The binding distances(r) of PH-1, PH-2 and PH-3 were found to be2.86, 3.03, and 5.12 nm, respectively, indicating energy transfer occurs between BSA and PHs. The binding constants of the PHs obtained from the fluorescence quenching data were found to be decreased with increase of temperature. The negative values of the thermodynamic parameters ΔH, ΔS and ΔG at different temperatures revealed that the binding process is spontaneous; hydrogen bonds and van der Waals interaction were the main force to stabilize the complex. The microenvironment of the protein-binding site was studied by synchronous fluorescence and circular dichroism(cD) techniques and data indicated that the conformation of BSA changed in the presence of PHs. Finally, we studied the BSA-PHs docking using Auto Dock and results suggest that PHs is located in the cleft between the domains of BSA.

关键词： BSA Spectroscopy Phosphorus heterocycles BSA-PHs docking

Numerical simulation and experimental validation of arc welding of DMR-249A steel

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Defence Technology（防务技术） 2016年第4期12卷 305-315页

作者： Rishi PAMNANI M. VASUDEVAN T. JAYAkUMAR R VASANTHARAJA k.c. GANESH Prototype Training centre Kalpakkam Tamil Nadu 603 127 India IGcAR Tamil Nadu 603 102 India Metallurgical and Materials Engg Dept NIT Warangal 506 004 India Dept of Mech Engg NITT Tiruchirappalli 620 015 India

The thermo-mechanical attributes of DMR-249 A steel weld joints manufactured by shielded metal arc welding(SMAW) and activated gas tungsten arc welding(A-GTAW) processes were studied using Finite Element Model(FEM) simulation. The thermal gradients and residual stresses were analyzed with SYSWELD software using double ellipsoidal heat source distribution model. The numerically estimated temperature distribution was validated with online temperature measurements using thermocouples. The predicted residual stresses profile across the weld joints was compared with the values experimentally measured using non-destructive techniques. The measured and predicted thermal cycles and residual stress profile was observed to be comparable. The residual stress developed in double sided A-GTAW joint were marginally higher in comparison to five pass SMAW joint due to phase transformation associated with high heat input per weld pass for A-GTAW process. The present investigations suggest the applicability of numerical modeling as an effective approach for predicting the thermo-mechanical properties influenced by welding techniques for DMR-249 A steel weld joints. The tensile, impact and micro-hardness tests were carried to compare the *** benefits of high productivity and savings of labor and cost associated with A-GTAW compared to SMAW process, the minor variation in residual stress build up of A-GTAW joint can be neglected to develop A-GTAW as qualified alternative welding technique for DMR-249 A steel.? 2016 china Ordnance Society. Production and hosting by Elsevier B.V. All rights reserved.

关键词： DMR-249A A-GTAW SMAW FEM SYSWELD Thermo-mechanical Simulation

cUTIN SYNTHASE 2 Maintains Progressively Developing cuticular Ridges in Arabidopsis Sepals

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Molecular Plant 2017年第4期10卷 560-574页

作者： Lilan Hong Joel Brown Nicholas A. Segerson Jocelyn k.c. Rose Adrienne H.k. Roeder Weiil institute for ceil and Molecular Biology Cornell University Ithaca NY 14853 USA Plant Biology Section School of Integrative Plant Science Cornell University Ithaca NY 14853 USA Field of Genetics Genomics and Development Cornell University Ithaca NY 14853 USA

The cuticle is a crucial barrier on the aerial surfaces of land plants, in many plants, including Arabidopsis, the sepals and petals form distinctive nanoridges in their cuticles. However, little is known about how the formation and maintenance of these nanostructures is coordinated with the growth and development of the underlying cells. Here we report the characterization of the Arabidopsis cutin synthase 2 （cus2） mutant, which causes a great reduction in cuticular ridges on the mature sepal epidermis, but only a moderate effect on petal cone cell ridges. Using scanning electron microscopy and confocal live imaging combined with quantification of cellular growth, we find that cuticular ridge formation progresses down the sepal from tip to base as the sepal grows, pcUS2：：GFP-GUS reporter expression coincides with cutic- ular ridge formation, descending the sepal from tip to base. Ridge formation also coincides with the reduction in growth rate and termination of cell division of the underlying epidermal cells. Surprisingly, cuticular ridges at first form normally in the cus2 mutant, but are lost progressively at later stages of sepal development, indicating that cUS2 is crucial for the maintenance of cuticular ridges after they are formed~ Our results reveal the dynamics of both ridge formation and maintenance as the sepal grows.

关键词： Arabidopsis thaliana cellular growth cUTIN SYNTHASE2 (cUS2) cuticular ridges nanoridges sepal

FATIGUE LIVES FOR INDUcTION HARDENED SHAFTS MATERIALS AccORDING TO THE ENVIRONMENTAL TEMPERATURES

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Acta Metallurgica Sinica(English Letters) 2005年第5期18卷 585-593页

作者： D.G. Lee k.c. Jang J.M. kuk I.S. kim korea Institute of Industrial Technology Gwangju 506-824 Korea Dept. of Mechanical Engineering Mokpo National University Mokpo 534-729 Korea

Rotary bending fatigue tests were carried out with two kinds of materials, S43c and S50c, using the front engine and front drive shaft （FF shaft） of vehicle. The specimens were induction hardened about 1.0mm depth from the specimen surface, and the hardness value on the surface was about HRc56-60. The tested environment temperatures were -30, 25 and 80℃ in order to look over effect of the induction hardening and the environmental temperatures on the fatigue characteristics. The fatigue limit of induction hardened specimens increased more about 45% than non-hardened specimens showing that the endurances of S43c and S50c were 98.1 and 107.9MPa in non-hardened samples, 147.1 and 156.9MPa in hardened samplesrespectably. The maximum tensile and compressive stress on the small circular defect was about ＋250 and -450MPa respectively when circular defect is situated on top and bottom. The fatigue life increased 80, 25 and -30℃ in order regardless of hardening. In comparison of the fatigue lives on the basis of tested result at 25℃, the fatigue lives of non-hardened specimens decreased about 35%, but that of hardened specimens decreased about only 5% at 80℃ more than at 25℃. And fatigue life of non-hardened and hardened specimens were about 110% and 120% higher at -30℃ than that of 25℃. Based on the result of stress distribution near the defect, the tensile and compressive stress repeatedly generated by load direction were the largest on the small circular defect due to the stress concentration.

关键词： induction hardening fatigue test front engine and front drive shaft,fatigue crack fatigue life fatigue life ratio