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Biased transportations in a spatially asymmetric system at the nano-scale under thermal noise

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Science China(Physics,Mechanics & Astronomy) 2010年第8期53卷 1565-1567页

作者： WAN RongZheng FANG HaiPing Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China

Under the theory of ratchet effect for mesoand macro-scale systems, the additional perturbation with a long time correlation and the breaking of spatial inversion symmetry are two main ingredients to bring unidirected transportations. With the help of a simple model system, we show that a spatially asymmetric system of the nano-scale length may induce biased transportations under thermal noise.

关键词： ratchet effect nano-scale thermal noise

CATALYST TECHNOLOGY DEVELOPMENT FROM MACRO-,MICRO- DOWN TO nano-scale

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China Particuology 2005年第6期3卷 383-394页

作者： Wei Liu Coming Incorporated Science and Technology Division Sullivan Park Coming NY 14831 USA

Catalyst and catalytic process technology has been an ever-growing field that involves chemical engineering, chemistry, and material science. A number of excellent review articles and books have been published on the subject. In this work, the author reviews the evolution and development of catalyst products with multi-scale methodology. The catalyst technologies are classified into three levels, macro-scale （reactor size）, mini-and micro-scale （catalyst unit）, and nano-scale （catalyst intrinsic structures）. Innovation at different scales requires different sets of expertise, method, and knowledge. Specific examples of significant impact to practical application are used to illustrate technology development at each scale. The multi-scale analysis enables clear delineation of technology components and their relationship for a catalyst product and catalytic process. Manipulation of catalyst structures at nano-scale to increase intrinsic activity and/or selectivity is considered of large potential for future catalyst product development. Recent research results on Cu-CeO2 and Au-CeO2 composite catalysts for air pollution control and hydrogen production are used to show how novel catalytic properties can be discovered by unique combination of different but common materials at the nano-scale.

关键词： multi-scale nano-scale catalyst composite ceria copper gold

Synthesis of monodisperse erbium aluminum garnet (EAG) nanoparticles via a microwave method

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Journal of Rare Earths 2013年第5期31卷 490-496页

作者：胡松陆春华王卫丁明烨倪亚茹许仲梓 State Key Laboratory of Material-Orient Chemical Engineering College of Materials Science and EngineeringNanjing University of Technology

Abstract： Uniform Er3A15O12 spheres are of great value for fabricating optical ceramics. The highly monodisperse and size-controllable erbium aluminum garnet （EAG） precursors for transparent ceramics were successfully synthesized through a new microwave process. The precursors constituted of ultrafine particles joining together by a hydroxyls formed compact network structure in the absence of SO42 , however, the morphologies of the precursors exhibited spheres with trace amount of SO42-. With manipulated programming of microwave irradiation parameters, narrow distributed particles of 40-50 nm were finally obtained by a separation of nu- cleation and nanocrystal growth. The mechanism behind the influence of microwave irradiation parameters on the growth of EAG precursors was preliminarily analysed. Easily dispersible and pure phase EAG were obtained at 950℃. The as-prepared EAG powders were used to fabricate transparent ceramics and transparent polycrystalline EAG ceramics were obtained under hydrogen furnace at 1750℃ for 8 h.

关键词： erbium aluminum garnet microwave-assisted method nano-scale monodisperse transparent ceramic rare earths

An accurate analytical I-V model for sub-90-nm MOSFETs and its application to read static noise margin modeling

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第1期13卷 58-70页

作者： Behrouz AFZAL Behzad EBRAHIMI Ali AFZALI-KUSHA Massoud PEDRAM School of Electrical and Computer Engineering University of Tehran Department of Electrical Engineering University of Southern California

We propose an accurate model to describe the I-V characteristics of a sub-90-nm metal-oxide-semiconductor field-effect transistor(MOSFET) in the linear and saturation regions for fast analytical calculation of the *** model is based on the BSIM3v3 *** of using constant threshold voltage and early voltage,as is assumed in the BSIM3v3 model,we define these voltages as functions of the gate-source *** accuracy of the model is verified by comparison with HSPICE for the 90-,65-,45-,and 32-nm CMOS *** model shows better accuracy than the nth-power and BSIM3v3 ***,we use the proposed I-V model to calculate the read static noise margin(SNM) of nano-scale conventional 6T static random-access memory(SRAM) cells with high *** calculate the read SNM by approximating the inverter transfer voltage characteristic of the cell in the regions where vertices of the maximum square of the butterfly curves are *** results for the SNM are also in excellent agreement with those of the HSPICE simulation for 90-,65-,45-,and 32-nm *** in the presence of process variations and negative bias temperature instability(NBTI) shows that the model can accurately predict the minimum supply voltage required for a target yield.

关键词： Modeling nano-scale Process variation Read static noise margin(SNM) SRAM

Study of Fractal Characteristics of the Cementation Index in Shale Gas

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Acta Geologica Sinica(English Edition) 2020年第2期94卷 456-466页

作者： LIU Hongqi LIU Shiqiong LUO Xingping SUN Yangsha TIAN Jie LIANG Lixi LIU Xiangjun School of GeoScience and Technology Southwest Petroleum UniversityChengdu 610500China Institute of exploration and development Petrochina Xinjiang oilfield company.Junggar road 29#.KaramayXinjiangChina College of Petroleum Engineering.Southwest Petroleum University Chengdu 610500China

The description of pores and fracture structures is a consistently important issue and certainly a difficult problem, especially for shale or tight rocks. However, the exploitation of so-called unconventional energy, such as shale methane and tight-oil, has become more and more dependent on an understanding of the inner structure of these unconventional reservoirs. The inner structure of porous rocks is very difficult to describe quantitatively using normal mathematics, but fractal geometry, which is a powerful mathematical tool for describing irregularly-shaped objects, can be applied to these rocks. To some degree, the cementation index and tortuosity can be used to describe the complexity of these structures. The cementation index can be acquired through electro-lithology experiments, but, until now, tortuosity could not be quantitatively depicted. This research used the well-logging curves of a gas shale formation to reflect the characteristics of the rock formations, and the changes in the curves to indicate the changes of the rock matrix, the pores, the connections among the pores, the permeability, and the fluid type. The curves that are affected most by the rock lithology, such as gamma ray, acoustic logging, and deep resistivity curves, can provide significant information about the micro-or nanostructure of the rocks. If the rock structures have fractal characteristics, the logging curves will also have fractal properties. Based on the definition of a fractal dimension and the Hausdorff dimension, this paper presents a new methodology for calculating the fractal dimensions of logging curves. This paper also reveals the deep meaning of the rock cementation index, m, through the Hausdorff dimension, and provides a new equation to calculate this parameter through the resistivity and porosity of the formation. Although it represents a very important relationship between the saturation of hydrocarbons with pores and resistivity, the Archie formula was not availa

关键词： fractal geometry nano-scale well-logging curve cementation index tight rocks gas shale

Crystal Growth Kinetics and Size Controls——Ⅰ.for Some Anode Active Oxides

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Chinese Journal of Structural Chemistry 2010年第6期29卷 972-976页

作者：王欣唐中帜唐电 Institute for Materials Research of Fuzhou University

RuO2,IrO2 and PdO are the most frequently employed active oxides in titanium anode coatings,so studies on the kinetics of their crystal-growth are important for anode material *** this paper,the particle growths of RuO2,IrO2 and PdO with increased temperature were *** least-squares method was used to fit the kinetic *** a result,the two-stage phenomena are found in all three noble material *** linear regression equations are correct both for the first and second *** is suggested that based on the corresponding kinetics equation Ln D =-QL/kT ＋ a,the sizes of oxide particles can be controlled for the three noble oxides.

关键词： noble-metal oxides nano-scale kinetics

Abnormal Raman spectral phenomenon of silicon nanowires

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Chinese Science Bulletin 2000年第15期45卷 1351-1354页

作者： Wei Ding Leyu Li Bibo Li Shulin Zhang Peking Univ Dept Phys Beijing 100871 Peoples R China

The Raman spectra of two one-dimensional silicon nanowire samples with different excitation wavelengths were measured and an abnormal phenomenon was discovered that the Raman spectral features change with the wavelengths of excitation. Closer analysis of the crystalline structure of samples and the changes in Raman spectral features showed that the abnormal behavior is the result of resonance Raman scattering selection effect.

关键词： nano-scale materials Raman spectroscopy quantum confinement effect resonance Raman scattering.

Preparation and Structural Investigation of CuCl_2 Graphite Intercalation Compounds

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Acta Geologica Sinica(English Edition) 2008年第5期82卷 1056-1060页

作者： BIN Xiaopei CHEN Jiazang CAO Hong MA Enbao WANG Xuehua YUAN Jizhu School of Resource and Environmental Engineering Wuhan University of Technology Wuhan 430070 School of Materials Science and Engineering Wuhan Institute of Technology Wuhan 430074 State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001

Superfine graphite powder was prepared by ball-milling exfoliated graphite containing anhydrous CuCl2 in planetary ball milling systems. nano-scale CuCl2 graphite intercalation compounds were synthesized by heating a mixture of anhydrous CuCl2 and graphite nanosheets. Scanning electron microscopy, energy-dispersive X-ray spectroscopy and high-resolution transmission electron microscopy were performed to characterize the microstructures of stage-1 nano-scale CuCl2 graphite intercalation compounds. The structure and components of the domain wall and core in the nano-scale CuCl2 graphite intercalation compounds are described. The results show that the content of CuCl2 in the mixture plays a crucial role in the size of the nano-scale CuCl2 graphite intercalation compound.

关键词： nano-scale graphite intercalation compounds domain structure

Achievements and trends of solid oxide fuel cells in clean energy field: a perspective review

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Frontiers in Energy 2020年第2期14卷 359-382页

作者： Abdalla M.ABDALLA Shahzad HOSSAIN Pg MohdIskandr PETRA Mostafa GHASEMI Abul K.AZAD Faculty of Integrated Technologies Universiti Brunei DarussalamJalanTungku LinkGadong BE 1410Brunei Darussalam Mechanical Engineering Department Faculty of EngineeringSuez Canal UniversityIsmailia 41522Egypt Institute of Nuclear Science and Technology Bangladesh Atomic Energy CommissionGPO Box No 3787Dhaka 1000Bangladesh Petroleum Engineering Department Universiti Teknologi PETRONASSeri Iskandar31750 TronohPerakMalaysia

The main concerns in the world today,especially in the energy field,are subjected to clean,efficient,and durable sources of *** three aspects are the main goals that scientist are paying attention ***,the various types of energy resources include fossil and sustainable ones,but still some challenges are chasing these kinds from energy conversion,storage,and ***,the most reliable and considered energy resource nowadays is the utilized one which is as highly efficient,clean,and everlasting as ***,in this review,an attempt is made to highlight one of the promising types as a clean and efficient energy *** oxide fuel cell(SOFC)is the most efficient type of the fuel cell types involved with hydrogen and hydrocarbon-based fuels,especially when it works with combined heat and power(CHP).The importance of this type is due to its nature of work as conversion tool from chemical to electrical for generation of power without noise,pollution,and can be safely handled.

关键词： solid oxide fuel cells(SOFCs) clean energy design micro-scale nano-scale performance