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Gas Adsorption and Field Emission of Single-walled Carbon Nanotubes: the Role of Net Negative Charges

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Gas Adsorption and Field Emission of Single-walled Carbon Na...

Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed Sintering and Post Treatment

2003年纳米和表面科学与技术全国会议

作者： Ji Luo, z. X. z.ang, L.-M. peng, z. Q. Xue, and J. L. Wu* Department of Electronics, Peking University, Beijing 100871, China

In this paper, density-functional-theory calculations show that O2 and H2O behave differently when they are adsorbed on a single-walled carbon nanotube (SWNT) tip, especially if the tip carries a net negative charge as in the field-emission situation. H2O molecules can be adsorbed on both closed and open-ended SWNT’s, and the extra negative charge strengthens the adsorption. 02 molecules can be adsorbed on a closed SWNT, but they are desorbed when an extra negative charge is present. Quite differently, O2 molecules are

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 255-265页

作者： X.Y.Yue S.Y.peng X.z.ang C.N.He Y.z.Tian Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of Materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin300350China Research Centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution *** hot-pressed sintered and solution treated materials were rolled and *** precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron *** contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe *** Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 *** for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were *** findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability Strength Electrical conductivity

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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China Foundry 2024年第1期21卷 82-90页

作者： Kun Gao Yan peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray z.nes is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray z.neⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray z.nes

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Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

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Journal of Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： Kun Gao Yan peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation z.ne on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

Epidural Analgesia in the Latent Phase of Labor and the Risk of Cesarean Delivery A Five-year Randomiz.d Controlled Trial

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南京医科大学学报（自然科学版） 2009年第11期29卷 1628-1628页

作者： Wang, F. z. Shen, X. F. Guo, X. R. peng, Y. z. Gu, X.Q. Nanjing Med Univ Dept A nesthesiol Affiliated Nanjing Matern & Child Hlth Care Hosp Nanjing 210004 Jiangsu Peoples R China 不详

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PC/AT机中断设计

石油仪器 1996年第2期10卷 40-42页

作者：彭志德石油勘探仪器总厂地震仪分厂西安710054

PC／AT计算机无论在其功能上，还是使用的灵活性上正越来越来多地应用于工业控制系统，尤其是随着工控机的普及，模块式的搭配，各种数据处理模块和应用开发平台的出现，使工业控制领域中台式机或工控机的应用更加普及。文章通过介绍PC... 详细信息

PC／AT计算机无论在其功能上，还是使用的灵活性上正越来越来多地应用于工业控制系统，尤其是随着工控机的普及，模块式的搭配，各种数据处理模块和应用开发平台的出现，使工业控制领域中台式机或工控机的应用更加普及。文章通过介绍PC／AT机的中断系统，说明了该机的硬中断用法和针对硬中断的编程方法，并通过实例解释了硬中断编程应考虑的事项。例中，加上用户代码，即可构成一个用户硬中断控制过程，同时介绍了8259的硬中断的接口方式。

关键词：硬件软件中断设计微机

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Growth of Magnetite Nanoparticles under Magnetic Fields

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Science Foundation in China 2004年第Z1期 52-57页

作者： Wang J. peng z. M. Chen Q. W.(Structure Research Laboratory and Department of Materials Science & Engineering, University of Science & Technology of China, Hefei 230026)

1 IntroductionOver the past several years, the preparation and characteriz.tion of nanoscale magnetic materials, especially one-dimensional (ID) nanostructure, have attracted much attention as the nanomaterials would allow investigating the fundamental aspects of magnetic-ordering phenomena in magnetic materials with reduced dimensions and could lead to new potential applications such as data storage technology.

关键词： Growth of Magnetite Nanoparticles under Magnetic Fields

Semi-derived Ringel-Hall algebras and Hall algebras of odd-periodic relative derived categories

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Science China Mathematics 2024年第8期67卷 1735-1760页

作者： Ji Lin Liangang peng Department of Mathematics and Statistics Fuyang Normal UniversityFuyang 236037China School of Mathematics Sichuan UniversityChengdu 610064China

Let t be a positive integer and A be a hereditary abelian category satisfying some finiteness *** define the semi-derived Ringel-Hall algebra of A from the category C_(z.t)(A)of z.t-graded complexes and obtain a natural basis of the semi-derived Ringel-Hall ***,we describe the semiderived Ringel-Hall algebra by the generators and defining *** particular,if t is an odd integer,we show an embedding of the derived Hall algebra of the odd-periodic relative derived category in the extended semi-derived Ringel-Hall algebra.

关键词： hereditary abelian categories the categories of z.t-graded complexes semi-derived Ringel-Hall algebras derived Hall algebras

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Superior piez.electricity in lead-free barium titanate piez.ceramics

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Journal of Materiomics 2024年第3期10卷 694-706页

作者： Enpei Cai Shiqiang peng Qibin Liu School of Materials and Metallurgy Guizhou UniversityGuiyang550025China Key Laboratory of Advanced Manufacturing Technology of the Ministry of Education Guiyang550025China

Since the 21st century,increasing environmental protection and human health concern have been the driving force to develop lead-free piez.electric materials with enhanced performances,and phase en-gineering strategy has been validated to be a viable method in numerous ***,we gained a superb d_(33)~(637±30)pC/N in lead-free(1-x)(Ba_(0.93)Ca_(0.07))(Sn_(0.08)Ti_(0.92))O_(3-x)(Sb_(0.5)Li_(0.5))TiO_(3)[abbreviated as(1-x)BCST-xSLT,0≤x≤0.4%(in mole)]piez.electrics utiliz.ng chemical *** illustrate the relationship among composition-structure-performance,microstructure characteriz.tion,electrical properties measurement,first-principles calculation,and phase-field simulations were ***-resolved polariz.tion mapping of z.contrast imaging manifests the ferroelectric three phases(ReOeT)coexist at the nanoscale with nanoscale polariz.tion switching among *** calculations and simulations confirm that the high-density nano-domain boundary bridges the poly-phase coexisting nano-domains,which makes the polariz.tion reversal easy,thus significantly reducing the energy barrier and polariz.tion anisotropy among different phases.

关键词： Chemical doping Relaxor ferroelectrics Phase-field simulations Phase engineering strategy First-principles calculations