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1st International Symposium on Combinatorics, Algorithms, Probabilistic and Experimental Methodologies, ESCAPE 2007

作者： Yiwei, Jiang An, Zhang Zhiyi, Tan Department of Mathematics State Key Lab. of CAD and CG Zhejiang University Hangzhou 310027 China College of Science Zhejiang Sci-tech University Hangzhou 310018 China Key Laboratory of Advanced Textile Materials and Manufacturing Technology Ministry of Education Zhejiang Sci-tech University

ISBN: (纸本)9783540744498

Nowadays, it is popular that the dealer makes profits by selling a kind of discount coupons, which can be used as money to purchase commodities with total cost less than or equal to the face value of the coupon. We can purchase a coupon at a price of 0 < s &le 1 times its face value and the number of potential purchasable coupons is a given integer l. The customer has the option to buy the goods by cash completely or by a discount coupon. However, each piece of goods can only use one coupon and the coupon used must have enough balance for the goods. The objective is to minimize the total cost for purchasing all the goods. In this paper, we reduce the problem to a special bin packing model. We consider the online problems for all 0 < s &le 1 and 1 &le l &le ∞. We present optimal online algorithms for all 0 < s &le 1 when l = ∞ and l = 1. For 2 &le l < ∞, we give both a lower bound and an algorithm, and show the algorithm is optimal for l = 2. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Online systems

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Nanoimprint lithography and surface modification as prospective technologies for heterogeneous integration

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physica status solidi c 2008年第12期5卷

作者： N. Kehagias W. Hu V. Reboud N. Lu B. Dong L. Chi H. Fuchs A. Genua J. A. Alduncín J. A. Pomposo D. Mecerreyes C. M. Sotomayor Torres Tyndall National Institute University College Cork Lee Maltings Cork Ireland State Key Laboratory of Supramolecular Structure and Materials Jilin University 130012 Changchun P.R. China Physikalisches Institut and Center for Nanotechnology (CeNTech) Westfälische Wilhelms-Universität 48149 Münster Germany New Materials Department Centre for Electrochemical Technologies (CIDETEC) San Sebastian Technology Park Paseo Miramón 196 Donostia-San Sebastián 20009 Spain Catalan Institute of Nanotechnology Campus de Bellaterra Edifici CM7 08193 Bellaterra Spain and Catalan Institute for Research and Advanced Studies ICREA 08010 Barcelona Spain

Nanoimprint lithography offers the possibility to pattern wafer-scale surfaces with nm-sized structures in polymers reaching the 10 nm lateral size. Printable polymers can be tailored to have a surface upon which molecules self-assemble. Furthermore, the resulting surfaces may be heterogeneously structured with or without etching away parts of imprinted polymers, in order to provide a flexible platform for structured surfaces with functional materials. We review progress in these combined approaches and discuss three examples: (a) a process to modify printed surfaces in order to grow polymer brushes, (b) a technique to realise patterned surfaces with different emission colours by using a one-step gas phase deposition of a single type of molecules on pre-patterned solid substrates and (c) a general method suitable to pattern different conducting polymer species at the nanoscale range by combining nanoimprint lithography process and a lift-off process. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

关键词： 33.20.−t 68.03.Cd 73.61.Ph 81.16.Nd 81.65.Cf

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Preparation and characterization of new microwave dielectric ceramics Ba_(3-n)La_(1+n)Ti_nNb_(3-n)O_(12)

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中国有色金属学会会刊：英文版 2006年第B02期16卷 521-523页

作者：方亮孟森森张辉吴伯麟 Key Laboratory of Nonferrous Materials and New Processing TechnologyMinistry of Education Guilin University of TechnologyGuilin 541004China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070China Key Laboratory of Nonferrous Materials and New Processing Technology Ministry of Education Guilin University of Technology Guilin 541004 China

A series of new microwave dielectric ceramics Ba3-nLa1+nTinNb3-nO12 (n=0,1,2) were prepared in the BaO-La2O3-TiO2-Nb2O5 system by high temperature solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction, scanning electron microscope, and microwave dielectric properties measurements. These samples were identified as single phase and adopted A4B3O12-type cation-deficient hexagonal perovskite structure, which can be described as consisting of identical perovskite-like blocks, three corner-sharing BO6 octahedra thick, separated by layers of vacant octahedral. These ceramics have high dielectric constants in the range of 48-42, high quality factors (Q×f) up to 38 000 GHz, and low temperature coefficient of resonant frequencies (τf) in the range of (-40-+6)×10-6℃-1. With increasing content of La and Ti, the dielectric constants slightly decrease butτf gradually increases.

关键词：微波陶瓷介电性质 Ba3-nLa1+nTinNb3-nO12 BaO-La2O3-TiO2-Nb2O5 制备

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Electrical and thermal properties of carbon nanotube bulk materials: Experimental studies for the 328–958K temperature range

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Physical Review B 2007年第20期75卷 205407-205407页

作者： Hai-Long Zhang Jing-Feng Li Bo-Ping Zhang Ke-Fu Yao Wei-Shu Liu Heng Wang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 People’s Republic of China State Key Laboratory of New Ceramics and Fine Processing Department of Materials Science and Engineering Tsinghua University Beijing 100084 People’s Republic of China Department of Mechanical Engineering Tsinghua University Beijing 100084 People’s Republic of China

We report on electrical and thermal properties in the temperature range from 328to958K of multiwall carbon nanotube (MWNT) bulk materials that were consolidated by spark plasma sintering. The rather dense MWNT bulk materials show exclusively nonmetallic temperature dependence of electrical conductivity from 328to958K, owing to the absence of metallic conduction mechanism in such a highly disordered system. The conductivity exhibited extremely weak temperature dependence with only 35% increase of room-temperature conductivity at 958K, which was explained by a heterogeneous model considering both fluctuation-assisted tunneling between nanotubes or shells of MWNT and variable-range hopping between graphite microphases that were observed to be dispersed in MWNT bulk materials. The results suggest that fluctuation-assisted tunneling governed this weak conductivity-temperature dependence. Metallic diffusion behavior was observed from 328to958K, and it indicates that phonon drag contributed little to the thermoelectric power of MWNT bulk materials. By contrast, we further show that the increase in sample dimensionality from individual MWNT to bulk materials tends to increase the metallic temperature dependence of electrical conductivity and remarkably decrease the magnitude of thermal conductivity. The geometric shift from graphene sheet to tubular nanotube for carbon-related bulk materials changes the conduction from the combination of n and p types to absolute p type.

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Characterization and properties of new dielectric ceramics Ba_5LnZnNb_9O_(30)(Ln=La, Nd and Sm)

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中国有色金属学会会刊：英文版 2006年第B02期16卷 534-537页

作者：朱文凤胡长征吴伯麟方亮 Key Laboratory of Nonferrous Materials and New Processing TechnologyMinistry of Education Guilin University of TechnologyGuilin 541004China Key Laboratory of Nonferrous Materials and New Processing TechnologyMinistry of Education Guilin University of Technology Guilin 541004China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Three novel dielectric ceramics Ba5LnZnNb9O30 (Ln= La, Nd and Sm) were synthesized and characterized in the BaO-Ln2O3-ZnO-Nb2O5 quaternary system, which formed the filled tungsten-bronze structures. The present ceramics exhibit high dielectric constant (εr) up to 310, low dielectric loss in the level of 10 3 at 1 MHz. Meanwhile, the temperature coefficients of the dielectric constant (τε) of Ba5LnZnNb9O3o varies from -1 390×10-6 to -1 220×10-6/℃as the radius of Ln3+ increases. The present ceramics are promising candidates for high dielectric constant and low loss dielectric ceramics.

关键词：介电陶瓷 Ba5LnZnNb9O30 Ba5NdZnNb9O30 Ba5SmZnNb9O30 合成介电性质表征

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Synthesis and X-ray Powder Diffraction Characterization of A new Niobate Crystal NaBa_2Li_(0.6)Nb_(4.8)Zn_(0.2)O_(15)

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Journal of Wuhan University of technology(materials Science) 2006年第1期21卷 1-3页

作者：欧阳世翕 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaChina Building Materials Academy Beijing 100024China

A new niobate compound was synthesized for the first time in Na2 O-BaO-Li2 O-ZnO-Nb2 O5 system by solid state reaction. The acw compound was studied by X-ray diffraction, electron probe, X-ray microanalysis, chemical analysis and SEM. The result of X-ray powder diffraction shows that NaBa2 Li0.6 Nb4.8 Zn0.2 O15 belongs to orthorhombic tungsten bronze structure, with space group Pba2（ 32 ） and lattice parameters a = 12.6115（2）A, b = 12.4981（2）A, C = 3.9479（3）A. The X-ray powder diffraction lines of the compoutid were well indexed.

关键词： nlobate ziac niobate structure XRD

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Effect of Nb in （La0.5Ce0.5）64-xAl16Ni5Cu15Nbx （x=0-5） bulk metallic glasses

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中国有色金属学会会刊：英文版 2006年第A02期16卷 131-135页

作者：张国庆刘金芳曾乔石汪丽娜刘今强蒋建中 Laboratory of New-Structured Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Key Laboratory of Advanced Textile Materials and Manufacturing Technology Ministry of Education Zhejiang Sci-Tech University Hangzhou 310018 China

The effect of Nb in (La0.5Ce0.5)(64-x)Al16Ni5Cu15Nbx (x=0-5, mole fraction) bulk metallic glasses was investigated by X-ray diffractometry, differential scanning calorimetry, and scanning electron microscopy. Fully amorphous rods up to 5 mm in diameter were obtained using copper mold. Their lower glass transition temperatures are of about 401-407 K and wide supercooled liquid regions are up to 75 K. The oxidation resistance of the LaCe-based glassy alloys can be largely enhanced by adding tiny Nb, which makes the developed LaCe-based bulk metallic glasses more attractive for potential industrial applications.

关键词：块状非晶态合金 (La0.5Ce0.5)64Al16Ni5Cu15Nbx 铸造抗氧化性能铌稀土元素

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Crystallization kinetics of (Ni_(0.75)Fe_(0.25)_(78-x)Nb_xSi_(10)B_(12)(x=0,5)amorphous alloys

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Rare Metals 2006年第4期25卷 342-348页

作者： CHEN Xueding WEI Hengdou WANG Xiaojun State Key Laboratory of Advanced New Non-ferrous Materials l.anzhou University of Technology l.anzhou 730050 China

Amorphous ribbons of （Ni0.75Fe0.25）78-xNbxSi10B12 （x = 0, 5） were prepared by a single roller melt-spinning technique in air atmosphere. The crystallization kinetics of the alloys were investigated by means of continuous heating, and the activation energies of the alloys were calculated using Kissinger plot method and Ozawa plot method on the basis of differential thermal analysis data. The crystallization products were analyzed by X-ray diffraction. After the （Ni0.75Fe0.25）78Si10B12 amorphous alloy was annealed at the temperatures 715 and 745 K, a single phase of γ-（Fe, Ni） solid solution with grain sizes of about 10.3 and 18.5 nm, respectively, precipitates in the amorphous matrix. The crystallized phases are γ-（Fe, Ni） solid solution, Fe2Si, Ni2Si, and Fe3B after annealing at 765 K. The （Ni0.75Fe0.25）73NbsSi10 B12 amorphous alloy was annealed at 720, 750, and 800 K; and the crystallization phases, γ（Fe, Ni） solid solution, （Fe, Ni）23B6. Ni31Si12 and Nb2NiB0.16 form simultaneously.

关键词： amorphous materials thermal analysis crystallization kinetics activation energy

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Structural and Dielectric Properties of Ba_5RNiNb_9O_(30)(R=La,Nd and Sm) ceramics

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Journal of Wuhan University of technology(materials Science) 2006年第3期21卷 109-112页

作者：徐慢 Key Laboratory of State Education Ministry of Silicate Materials Science and Engineering Wuhan University of Technology Wuhan 430070ChinaKey Laboratory of Nonferrous Materials and New Processing Technology Ministry of EducationGuilin University of Technology Guilin 541004China

Three novel Ba5RNiNb9O30（ R =La , Nd and Sm ） ceramics were prepared and characterized in the BaO-R2O3-NiO-Nb2O5 system. All three compounds are paraelectric phases adopting the filled tetragond tungsten bronze （TB） stracture at room temperature . At 1MHz , Ba5RNiNb9O30 ceramics have a high dielectric constants in the range 193-245.3, a low dielectric loss in range 0.0059-0.0087, and the temperature coefficientz of the dielectric constant （τε） in the range - 1 140- - 1 310×10^-6 ·℃^ -1 . Their temperature coefficients of the dielectric constant are significantly reduced compared to those of Ba5RTi3Ta7O30 （ R = La , Nd , Sm ） ceramics.

关键词： Tungsten bronze X-ray diffraction Dielectric properties

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A bulk metal/ceramic composite material with a cellular structure

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Chinese Science Bulletin 2006年第2期51卷 235-239页

作者： ZHAO Zhankui YAO Kefu LI Jingfeng Key Laboratory for Advanced Manufacturing by Materials Processing Technology Department of Mechanical Engineering Tsinghua Uni versity Beijing 100084 China Department of Materials Science and Engineering Changchun University of Technology Changchun 130012 China State Key Laboratory of New Ceramic and Fine Process Tsinghua University Beijing 100084 China

A bulk metal/ceramic composite material with a honeycomb-like micro-cell structure has been prepared by sintering the spherical Al90Mn9Ce1 alloy powders clad by Al2O3 nano-powder with the spark plasma sintering (SPS) technique. The as-prepared material consists of Al90Mn9Ce1 alloy cell and closed Al2O3 ceramic cell wall. The diameter of the cells is about 20―40 μm, while a thickness of the cell wall is about 1―2 μm. The ultimate compressive strength of the as-sintered materials is about 514 MPa, while its fracture strain is up to about 0.65 %. This composite material might possess good anti-corrosion, thermal endurance and other potential properties due to its unique microstructure. The result shows that the Al90Mn9Ce1/Al2O3 composite powders can be sintered by spark plasma sintering technique despite the large difference in their sintering temperature. This work offers a way of designing and preparing metal/ceramic composite material with functional property.

关键词：金属/陶瓷复合材料多孔结构制备方法火花等离子体烧结

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