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Characterization of Phases in an As-cast Copper-Manganese-Aluminum Alloy

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journal of Materials Science & Technology 2006年第6期22卷 779-784页

作者： j.Iqbal f.Hasan f.Ahmad Department of Metallurgical and Materials Engineering University of Engineering and TechnologyLahorePakistan

Copper-manganese-aluminum （CMA） alloys, containing small additions of fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast （CMA） alloy of nominal composition Cu-14%Mn-8%Al-3%fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The room temperature microstructure exhibited four different types of precipitates inside the α-grains： the ＇large＇ dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in fe and Mn and had an fcc structure, while the ＇small＇ dendritic-shaped particles and the globular precipitates were based on feaAI and had DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientation-relationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on fe3Al and had the DO3 structure.

关键词： Orientation relationship DO3 structure Intermetallic phases

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Chinese Annals of Mathematics,Series B 2002年第2期23卷 253-266页

作者： j.f.RODRIGUES CMAf/Universidade

This paper presents new results for strong solutions and their coincidence sets of the obstacle problem for linear hyperbolic operators of first order. An inequality similar to the LewyStampacchia ones for elliptic and parabolic problems is shown. Under nondegeneracy conditions the stability of the coincidence set is shown with respect to the variation of the data and with respect to approximation by semilinear hyperbolic problems. These results are applied to the asymptotic stability of the evolution problem with respect to the stationary coercive problem with obstacle.

关键词： Hyperbolic obstacle problem Linear hyperbolic operator Strong solution

Genetic Crop Improvement： A Guarantee for Sustainable Agricultural Production

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Engineering 2018年第4期4卷 431-432页

作者： jianmin wan Chinese Academy of Agricultural Sciences Beijing 100081 China

Crop production provides food, feed, and other nutrients that support our everyday lives. Cereal crops, which include wheat （Triticum aestivurn）, rice （Oryza sativa）, maize （Zea mays）, barley （Hordeum vulgate）, millet （Setaria spp.）, sorghum （Sorghum bicolor）, rye （Secale cereale）, oats （Avena sativa）, and so forth, are the most important source of food for human consumption.

关键词：饲料食品工业发展现状生产技术

Synergistic interaction of metal–acid sites for phenol hydrodeoxygenation over bifunctional Ag/TiO_2 nanocatalyst

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Chinese journal of Chemical Engineering 2019年第2期27卷 349-361页

作者： Andrew Ng Kay Lup faisal Abnisa wan Mohd Ashri wan Daud Mohamed Kheireddine Aroua Department of Chemical Engineering Faculty of Engineering University of Malaya Centre for Carbon Dioxide Capture and Utilization School of Science and Technology Sunway University Department of Engineering Lancaster University

The use of silver metal for hydrodeoxygenation(HDO) applications is scarce and different studies have indicated of its varying HDO activity. Several computational studies have reported of silver having almost zero turnover frequency for HDO owing to its high C\\O bond breaking energy barrier and low carbon and oxygen binding *** this work, titania supported silver catalysts were synthesized and firstly used to examine its phenol HDO activity via experimental reaction runs. BET, XRD, fESEM, TEM, EDX, ICP–OES, Pyridine-fTIR, NH_3-TPD and H_2-TPD analyses were done to investigate its physicochemical properties. Phenomena of hydrogen spillover and metal–acid site synergy were examined in this study. With the aid of TiO_2 reducible support, hydrogen spillover and metal–acid site interactions were observed to a certain extent but were not as superior as other Pt, Pd, Ni-based catalysts used in other HDO studies. The experimental findings showed that Ag/TiO_2 catalyst has mediocre phenol conversion but high benzene selectivity which confirms the explanation from other computational studies.

关键词： Silver based catalyst Physicochemical properties Hydrogen spillover Metal-acid sites Hydrodeoxygenation

Regulation and integration of plant jasmonate signaling:a comparative view of monocot and dicot

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journal of Genetics and Genomics 2022年第8期49卷 704-714页

作者： Shiwei wan Xiu-fang Xin National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China University of Chinese Academy of Sciences Beijing 100049China CAS-jIC Center of Excellence for Plant and Microbial Sciences(CEPAMS) Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China

The phytohormone jasmonate plays a pivotal role in various aspects of plant life,including developmental programs and defense against pests and pathogens.A large body of knowledge on jasmonate biosynthesis,signal transduction as well as its functions in diverse plant processes has been gained in the past two *** addition,there exists extensive crosstalk between jasmonate pathway and other phytohormone pathways,such as salicylic acid(SA)and gibberellin(GA),in co-regulation of plant immune status,fine-tuning the balance of plant growth and defense,and so on,which were mostly learned from studies in the dicotyledonous model plants Arabidopsis thaliana and tomato but much less in ***,existing evidence suggests both conservation and functional divergence in terms of core components of jasmonate pathway,its biological functions and signal integration with other phytohormones,between monocot and *** this review,we summarize the current understanding on jA signal initiation,perception and regulation,and highlight the distinctive characteristics in different lineages of plants.

关键词： jasmonate Phytohormone Signaling Crosstalk Plant defense Development Stress response

Preparation of a cationic azobenzene dye-montmorillonite intercalation compound and its photochemical behavior

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journal of University of Science and Technology Beijing 2006年第3期13卷 281-286页

作者： Tao wan Yi Yuan Wenqiong He College of Materials and Chemistry ＆ Chemical Engineering Chengdu University of Technology Chengdu 610059 China

Montmorillonite/cationic azobenzene dye （GTL） intercalation compounds were prepared by the conventional ion exchange method. As compared with that of pure GTL, the thermal stability of the intercalated GTL was greatly enhanced, and the absorption band corresponding to azobenzene group in intercalated GTL shifted towards a longer wavelength by 55 nm, which could be ascribed to the strong conjugation of GTL supramolecular order structure （j cluster） confined in a nanoscale space of montmorillonite interlayer gallery. The microstructures of the resulting intercalation compounds could be successfully controlled by varying the amount of dye loaded as evidenced by the basal spacing of the intercalation compounds. The intercalated azo dye in the montmorillonite interlayer space exhibited reversible trans-to-cis photoisomerization and thermal cis-to-trans reaction. fTIR proved the successful intercalation of GTL into the silicate layer.

关键词： Na-montmorillonite azobenzene intercalation photoisomerization

Growth of Casting Microcrack and Micropore in Single-crystal Superalloys Analysed by Three-Dimensional Unit Cell

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journal of Materials Science & Technology 2006年第2期22卷 183-189页

作者： jiansong wan Zhenzhou LU Zhufeng YUE Department of Engineering Mechanics Northwestern Polytechnical University Xi＇an 710072 China

finite element （fE） analysis was employed to investigate the casting microcrack and micropore growth in nickel-base single-crystal superalloys DD3. Based on the finite deformation rate-dependent crystallographic constitutive equation, the simulations of casting microcrack and micropore growth in three-dimensional unit cell model were carried out in a range of parameters including stress triaxiality, Lode parameter and type of activated slip systems. The fE results show that the stress triaxiality has profound effects on growth behavior, and the Lode parameter is also important for the casting microcrack and micropore growth. The type of operative slip systems has remarkable effect on casting microcrack and micropore growth, so the life of single- crystal component is associated with the type of activated slip systems, which is related to Schmid factor and the number of activated slip systems. The growth comparison between microcrack and micropore reveals that when the material is subjected to large deformation, the growth rate of microcrack is faster than that of micropore, i.e. microcrack is more dangerous than micropore; the microcrack is easier to result in brittle fracture than micropore. The stress triaxiality and Lode parameter have strong influence on the growth of microcrack and micropore.

关键词： Casting micropore Casting crack Single-crystal superalloys Crystallographic constitutive equation

Amorphous particle deposition and product quality under different conditions in a spray dryer

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Particuology 2008年第4期6卷 265-270页

作者： Meng Wai Woo wan Ramli wan Daud Siti Masrinda Tasirin Meor Zainal Meor Talib Department of Chemical & Processing Engineering Universiti Kebangsaan Malaysia

Deposition of amorphous particles, as a prevalent problem particularly in the spray drying of fruit and vegetable juices, is due to low-molecular-weight sugars and is strongly dependent on the condition of the particles upon collision with the dryer wall. This paper investigates the condition of the amorphous particles impacting the wall at different drying conditions with the aim of elucidating the deposition mechanism and physical phenomena in the drying chamber. A model sucrose-maltodextrin solution was used to represent the low-molecular-weight sugar. Particle deposits were collected on sampling plates placed inside the dryer for analyses of moisture content, particle rigidity (using SEM) and size distribution. Moisture content was adopted as a general indicator of stickiness. Product particles collected at the bottom of the experimental dryer were found to have higher moisture than particle deposits on samplers inside the dryer. Moisture content profile in the dryer shows that apart from the atomizer region, where particles are relatively wet, particle deposits at other regions exhibit similar lower moisture content. At the highest temperature adopted in the experiments, particles became rubbery suggesting liquid-bridge formation as the dominant deposition mechanism. further analysis on particles size distribution reveals a particle segregation mechanism whereby smaller particles follow preferentially to the central air stream while larger particles tend to re-circulate in the chamber, as predicted in past CfD simulation. The findings from this work will form the basis and provide validating data for further modeling of wall deposition of amorphous particles in spray drying using CfD.

关键词： Powder handling Amorphous particles Deposition Particle condition Spray drying

Power cost minimization in data centers Via Lyapunov optimization

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High Technology Letters 2016年第4期22卷 355-361页

作者： Zhang Ran wan jianxiong School of Mathematics and Statistics of Central South University Changsha 410083 P. R. China School of Information Engineering Inner Mongolia University of Technology Hohhot 010051 P. R. China

With the advent of big data,the demand for computing has been increasing in a very large scale for the past decade,so geographically distributed data centers are erected in the direction of cloud computing development. A Lyapunov optimization approach is considered for the problem of minimizing energy cost for distributed Internet data centers( IDCs). By capturing the power cost of servers and cooling systems,the Lyapunov optimization technique is formulated to design a decisive strategy that offers provable power cost minimization and Qo S guarantees. The algorithm performance and effectiveness are validated via simulations driven by real world traces.

关键词： power cost quality-of-service(Qo S) workload