检索结果-南通市图书馆

Pareto Minimizing Total Completion Time and Maximum Cost with Positional Due Indices

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2015年第3期3卷 381-387页

作者： Yuan gao jin-Jiang Yuan School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China

In this paper,we study the Pareto optimization scheduling problem on a single machine with positional due indices of jobs to minimize the total completion time and a maximum *** this problem,we give two O(n^(4))-time ... 详细信息

关键词： Scheduling Pareto optimization Maximum cost Positional due indices

The crystal chemistry and the compressibility of silicate-carbonate minerals:Spurrite,galuskinite and tilleyite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2015年第5期6卷 771-777页

作者： jing gao Xiang wu Shan Qin Key Laboratory of Orogenic Belts and Crustal Evolution.MOE School of Earth and Space SciencesPeking University

Spurrite Ca5（SiO4）2（CO3）,galuskinite Ca7（SiO4）3（CO3） and tilleyite Ca5（Si2O7）（CO3）2are three representative minerals formed in high-temperature skarns in the silicate-carbonate *** crystal chemistry and compressibility have been investigated using first-principles theoretical *** minerals are structurally described as the combination of interwoven layers constituted by Ca polyhedra and Si polyhedra,with the[CO3]triangles being 'separators' to depolymerize the Si-Ca *** the effect of pressure,the Si polyhedra and the[CO3]groups present rigid behaviors whereas the Ca-0 bonds undergo considerable *** pressure-induced abnormities in the lattice parameter variations have been identified,revealing the existence of subtle changes in the compression *** equations of state parameters are obtained:K0= 71.1（1） GPa,V0= 1003.31（4） A3and K0′ = 5.4（1）for spurrite;K0= 75.0（1） GPa.V0= 1360.30（7） A3,K0’ = 5.4（1） for galuskinite,and K0= 69.7（3） GPa,V0= 1168.90（2） A3and K0’ = 4.0（1） for *** compounds have similar K0values to calcite CaCO3but are much more compressible than larnite β-*** for these minerals,the bulk modulus exhibits a negative correlation with the[CO3]*** structural and compressional properties of silicate-carbonate minerals compared with silicates and carbonates are expected to be a guide for further investigations on Si polyhedra and[CO3]coexistent phases.

关键词： Silicate-carbonate minerals Crystal chemistry Comp

BaYOBO_(3):A deep-ultraviolet rare-earth oxy-borate with a large second harmonic generation response

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2021年第7期64卷 1184-1191页

作者： Mengen gao Hongping wu Hongwei Yu Zhanggui Hu Jiyang Wang Yicheng wu Tianjin Key Laboratory of Functional Crystal Materials Institute of Functional CrystalTianjin University of TechnologyTianjin 300384China

Deep-ultraviolet(UV)nonlinear optical(NLO)crystals with excellent performances are of great importance in laser science and ***,to design and synthesize an ideal deep-UV NLO material with a balance between second harmonic generation(SHG)response and UV cut-off edge is still a huge ***,a new oxy-borate BaYOBO_(3)(BaYBO)was designed and synthesized by substituting Be^(2+)with Y^(3+)from Sr_(2)Be_(2)B_(2(O_(7).The BaYBO features a stable three-dimensional framework and satisfies the property balance between a large SHG response(~2.6×KH_(2)PO_(4)KDP))and a short UV cut-off edge(<190 nm)as a promising deep-UV NLO *** study of structure-property relationship indicates that the large SHG response of BaYBO is mainly attributed to the coplanar arrangement and large number density of BO_(3 )*** results demonstrate that substituting Be^(2+)with Y^(3+)cations is also a feasible strategy for developing new deep-UV NLO crystals.

关键词： deep-ultraviolet nonlinear optical materials second harmonic generation structure-property relationship rare-earth cation

Oxide coating mechanism during fluidized bed reduction: solid-state reaction characteristics between iron ore particles and MgO

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1019-1028页

作者： Lei Guo jin-tao gao Yi-wei Zhong Han gao Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Experiments on the solid-state reaction between iron ore particles and MgO were performed to investigate the coating mechanism of MgO on the iron ore particles＇ surface during fluidized bed reduction. MgO powders and iron ore particles were mixed and compressed into briquettes and, subsequently, roasted at different temperatures and for different time periods. A Mg-containing layer was observed on the outer edge of the iron ore particles when the roasting temperature was greater than 1173 K. The concentration of Fe in the Mg-containing layer was evenly distributed and was approximately 10wt%, regardless of the temperature change. Boundary layers of Mg and Fe were observed outside of the iron ore particles. The change in concentration of Fe in the boundary layers was simulated using a gas–solid diffusion model, and the diffusion coefficients of Fe and Mg in these layers at different temperatures were calculated. The diffusion activation energies of Fe and Mg in the boundary layers in these experiments were evaluated to be approximately 176 and 172 k J/mol, respectively.

关键词： fluidized beds coating solid reaction ferric oxide magnesia diffusion coefficient

Surface-grafted block copolymer brushes with continuous composition gradients of poly(poly(ethylene glycol)-monomethacrylate) and poly(N-isopropylacrylamide)

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2011年第2期54卷 334-342页

作者： LI LinHui wu jinDan gao ChangYou MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Surface-grafted block copolymer brushes with continuous composition gradients containing poly(poly(ethylene glycol) monomethacrylate) (P(PEGMA)) and poly(N-isopropylacrylamide) (PNIPAAm) chains were fabricated by integration of the surface-initiated atom transfer radical polymerization (SI-ATRP) and continuous injection method. Three types of copolymer gradients were prepared: (1) a uniform P(PEGMA) layer was block copolymerized with a gradient PNIPAAm layer (PP1); (2) a gradient P(PEGMA) layer was block copolymerized with a uniform PNIPAAm layer (PP2); and (3) a gradient P(PEGMA) layer was inversely block copolymerized with a gradient PNIPAAm layer (PP3). The as-prepared gradients were characterized by ellipsometry, water contact angle and atomic force microscopy (AFM) to determine their alterations in thickness, surface wettability and morphology, confirming the gradient structures. In vitro culture of HepG2 cells was implemented on the gradient surfaces, revealing that the cells could adhere at 37 ℃ and be detached at 20 ℃. Introduction of the PEG chains as an underlying layer on the PNIPAAm grafting surfaces resulted in faster cell detachment compared with the PNIPAAm grafting surface.

关键词： gradients ATRP PNIPAAm cell attachment thermo-responsive

Synthesis, Characterization, and Catalytic Ethylene Oligomerization of Pyridine-imine Palladium Complexes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2018年第2期36卷 176-184页

作者： Xiao-Lin Chen Jie gao Heng Liao Hai-Yang gao Qing wu School of Materials Science and Engineering Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education Guangdong Laboratory of High-performance Polymer Composites Sun Yat-sen University

Two neutral five-membered pyridine-imine palladium complexes with the bulky dibenzhydryl（CH（Ph）2） substituted aniline were synthesized and fully characterized by nuclear magnetic resonance（NMR） and X-ray crystal diffraction. Well-defined cationic palladium complexes were further obtained by treatment of chloromethylpalladium complexes with sodium tetrakis（3,5-bis（trifluoromethyl）phenyl）borate（NaBArF） in CH3CN. Cationic palladium complexes were capable of catalyzing ethylene oligomerization without any cocatalysts. The influences of catalyst structure, reaction temperature, and ethylene pressure on ethylene oligomerization were studied in detail. The introduction of bulky benzhydryl（CH（Ph）2） on the ortho position of the aniline moiety enhanced catalytic activity, thermal stability of the catalyst, and molecular weight of the obtained products. Highly branched oligomers with molecular weights of 600-800 g/mol and narrow polydispersities（1.03-1.12） were produced.

关键词： Palladium Ethylene Oligomerization Branching

Rational manipulation of composition and construction toward Zn/Co bimetal hybrids for electromagnetic wave absorption

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第3期134卷 254-261页

作者： Xiuyun Ren Yihe Song Zhenguo gao Yalan wu Zirui Jia Guanglei wu Institute of Materials for Energy and Environment State Key Laboratory of Biofibers and Eco-TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710072China Department of Nephrology Xi’an People’s HospitalXi’an 710000China

Rational manipulation of multi-metal hybrids with controllable compositions and constructions is evolv-ing as an efficacious strategy for tunable electromagnetic(EM)characteristics and EM wave(EMW)***,a novel bi-orientation etching approach is proposed to regulate the chemical composi-tions and hybridization construction of Zn/Co hybrids,thence meeting the synergistic interaction among diverse compositions for ultra-high EMW *** to the stepwise heterometallic modi-fication by Zn in Co-ZIFs(Zn@Co-ZIF)and Co in Zn-ZIFs(Co@Zn-ZIF),corresponding pyrolysis products with variable Zn/Co atomic concentration and hybridization states(Zn@Co-C,Co@Zn-C)can be *** Co species was confirmed to have a positive impact on both the dielectric and magnetic response,while an appropriate amount of Zn hybridization in Co substance further enhanced the synergistic ef-fect between multiple loss mechanisms,promoting the minimum reflection loss and effective absorption bandwidth of Zn@Co-C reached-34.99 dB and 5.52 GHz(2.00 mm),***,this work re-veals the composition and construction dependency of bimetal hybrids on EMW absorption,which can be a strong reference for developing EMAs with diverse hybridization structures.

关键词： Hybridization Composition Construction Electromagnetic wave absorption

Topological-based bottleneck analysis and improvement strategies for traffic networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第10期52卷 2814-2822页

作者： JianJun wu ZiYou gao HuiJun Sun State Key Laboratory of Rail Traffic Control and Safety (Beijing Jiaotong University) Beijing 100044 China School of Traffic and Transportation Beijing Jiaotong University Beijing 100044 China MOE Key Laboratory for Urban Transportation Complex Systems Theory and Technology Beijing Jiaotong University Beijing 100044 China

A method is proposed to find key components of traffic networks with homogenous and heterogeneous topologies, in which heavier traffic flow is transported. One component, called the skeleton, is the minimum spanning tree (MST) based on the zero flow cost (ZCMST). The other component is the infinite incipient percolation cluster (IIC) which represents the spine of the traffic network. Then, a new method to analysis the property of the bottleneck in a large scale traffic network is given from a macroscopic and statistical viewpoint. Moreover, three effective strategies are proposed to alleviate traffic congestion. The significance of the findings is that one can significantly improve the global transport by enhancing the capacity in the ZCMST with a few links, while for improving the local traffic property, improving a tiny fraction of the traffic network in the IIC is effective. The result can be used to help traffic managers prevent and alleviate traffic congestion in time, guard against the formation of congestion bottleneck, and make appropriate policies for traffic demand management. Meanwhile, the method has very important theoretical significance and practical worthiness in optimizing traffic organization, traffic control, and disposal of emergency.

关键词： traffic congestion user equilibrium assignment heterogeneous and homogenous networks

Solid-gas interface thermal conductance for the thermal barrier coating with surface roughness:The confinement effect

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第12期31卷 418-423页

作者： Xue Zhao jin-wu Jiang Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Zhejiang Laboratory Hangzhou 311100China

The yttria-stabilized zirconia(YSZ)is a famous thermal barrier coating material to protect hot-end components of an *** a characteristic feature of the YSZ,the surface roughness shall play an important role in the interface thermal conductance between the YSZ and gas,considering that the gas is typically at an extremely high *** investigate the effect of the surface roughness on the thermal conductance of the YSZ-gas interface with surface roughness described by nanoscale pores on the surface of the *** reveal two competitive mechanisms related to the microstructure of the pore,i.e.,the actual contact area effect and the confinement *** increase of the pore depth will enlarge the actual contact area between the YSZ and gas,leading to enhancement of the solid-gas interface thermal *** contrast to the positive actual contact area effect,the geometry-induced confinement effect greatly reduces the interface thermal *** findings shall offer some fundamental understandings for the microscopic mechanisms of the YSZ-gas interface thermal conductance.

关键词： interface thermal conductance thermal barrier coating solid-gas interface confinement effect