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Enhanced Raman Scattering by Quasi-phase-matched Processes in ax2 Photonic Crystal

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Enhanced Raman Scattering by Quasi-phase-matched Processes i...

第十二届全国量子光学学术会议

作者： P. Xu, Shining Zhu (national laboratory of solid State Microstnictures, nanjing university, nanjing, 2.0093, china)

＜正＞An intense comb-shaped Raman spectra were obtained from a two-dimensional nonlinearx photonic crystal -a hexagonally poled LiTaO3 crystal with lattice parameter 9 micros. The lowest Raman shift was down to 2 cm’ and the order of anti-stokes and stokes signals both achieved 11. The novel Raman spectra were mediated first by intense phonon-polariton fields, which were driven through the quasi-phase-matched coupling between the incident

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Dielectric superlattice and its physical properties

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Dielectric superlattice and its physical properties

第14届全国晶体生长与材料学术会议

作者： Y.Y.Zhu, S.N.Zhu,and N.B.Ming national laboratory of solid State microstructures, nanjing university nanjing 2.0093, china

INTERFACE CONSTRAINED GROWTH FOR SIZE CONTROL NANOFABRICATION:MECHENISM AND EXPERIMENTS

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INTERFACE CONSTRAINED GROWTH FOR SIZE CONTROL NANOFABRICATIO...

Asia Conference on Nanoscience and Nanotechnology Abstracts Book

作者： KUNJI CHEN KAI CHEN PEIGAO HAN LIN ZHANG XINFAN HUANG national laboratory of solid State microstructures and department of Physics nanjing university nanjing 2.0093 china

＜正＞ Low-dimensional semiconductor systems, such as nanocrystalline silicon （nc-Si）, are currently being studied for the purpose of new applications in both nanoelectronic and photoelectronic devices. The size control of uniform nc-Si grains is the key technology for the device application. We propose a model on constrained growth in a-SiNx/a-Si:H/a-SiNx sandwich structures to make uniform nc-Si grains. The model of the constrained growth of nc-Si has been studied in accordance with the classical thermodynamic theory. Firstly, we discuss quantitatively the effect of the interface and shape of the nc-Si on the crystal growth in relation to the Gibbs tree energy. During the growth processes, when the grain shape transforms from sphere-like（size ＜ a-Si thickness） to disc-like shape（size ≥a-Si thickness）, the interfacial energy between nc-Si and a-SiNx will influence the grain growth which induces the increase of the nc-Si growth free energy and finally causes the growth to hah. From our model, we have theoretically determined the critical a-Si sublayer thickness of 34nm for the constrained crystallization growth and interpreted the increase of the crystallization temperature in the ultra thin a-Si sublayer.

关键词： nanofabrication size control constrained growth

Two-dimensional thermoelasticity solution for functionally graded thick beams

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 451-460页

作者： Lü Chaofeng1, CHEN Weiqiu1 & ZHONG Zheng2 1. Department of Civil Engineering, Zhejiang university, Hangzhou 310027, china 2. Key laboratory of solid Mechanics of Ministry of Education, School of Aerospace Engineering and Ap- plied Mechanics, Tongji university, Shanghai 200092, china Department of Civil Engineering Zhejiang University Hangzhou 310027 China Key laboratory of solid Mechanics of Ministry of Education School of Aerospace Engineering Applied Mechanics Tongji University Shanghai 200092 China

Two-dimensional thermoelasticity analysis of functionally graded thick beams is presented using the state space method coupled with the technique of differential quadrature. Material properties vary continuously and smoothly through the beam thickness, leading to variable coefficients in the state equation derived from the elasticity equations. Approximate laminate model is employed to translate the state equation into the one with constant coefficients in each layer. To avoid numerical instability, joint coupling matrices are introduced according to the continuity conditions at interfaces in the approximate model. The differential quadrature procedure is applied to discretizing the beam in the axial direction to make easy the treatment of arbitrary end conditions. A simply-supported beam with exponentially varying material properties is considered to validate the present method. Numerical examples are performed to investigate the influences of relative parameters.

关键词： state equation differential quadrature approximate laminate model joint coupling matrices thermal stresses.

SURFACE AND SIZE EFFECTS OF MAGNETIC PROPERTIES FERROMAGNETIC NANOPARTICLES

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SURFACE AND SIZE EFFECTS OF MAGNETIC PROPERTIES FERROMAGNETI...

第8届国际材联电子材料国际研讨会

作者： Huang Zhigao Feng Qian Chen Zhigao Chen Shuiyuan Du Yuowei national laboratory of solid State microstructures nanjing university nanjing 2.0093 china Department of Physics Fujian Teachers university Fuzhou 350007 china

＜正＞ Recently, the magnetic properties of magnetic nanoparticles have become a hot topic in magnetic materials. Single magnetic cluster with a few hundred or thousand atoms and the clusters embedded in nonmagnetic matrixes have been studied. The cluster contains both core and surface spins. Surface anisotropy, exchange interaction being different from in the core and incomplete coordination shell give rise to a variety of spin configuration near the surface and complex slain distributions within a particle. Base on Monte Carlo

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High Density Multiplication of Graphoepitaxy Directed Block Copolymer Assembly on Rectangle Lattice Template

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High Density Multiplication of Graphoepitaxy Directed Block ...

中国化学会第27届学术年会

作者： Yu-qiang Ma national laboratory of solid State microstructures, nanjing university, nanjing 2.0093, china & Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow university, Suzhou 215006, china

＜正＞Generating high density-multiplied nanopatterns through the directed self-assembly of block copolymers （BCPs） will significantly influence the current microelectronics and storage industries

关键词： Block Copolymer High Density Multiplication of Graphoepitaxy Self Assembly

Friction-reducing and antiwear behavior of metal halide-stabilized linear phosphazene derivatives as lubricants for a steel-on-steel contact

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Science china(Technological Sciences) 2005年第3期48卷 282-291页

作者： ZHU Jiamei 1,2 , LIU Weimin 2 & LIANG Yongmin 2 1. School of Chemical Engineering and Technology, china university of Mining and Technology, Xuzhou 221008, china 2. State Key laboratory of solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, china 1. School of Chemical Engineering and Technology China University of Mining and Technology 221008 Xuzhou China 2. State Key laboratory of solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences 730000 Lanzhou China

A series of novel metal halide-stabilized linear phosphazene derivatives were synthesized. The friction-reducing and antiwear abilities of the resulting products as the lubricants for a steel-on-steel contact were comparatively investigated on an Optimol SRV oscillating friction and wear tester. The morphology of the worn steel surface was observed on a scanning electron microscope, while the chemical states of some typical elements on the worn steel surface were examined by means of X-ray photoelectron spectroscopy. It was found that both the side branch structures and central metals influenced the friction-reducing and antiwear behaviors of the synthetic derivatives as the lubricants, which was related to the different adsorption activities of the organic compounds composed of different organic ingredients and metallic ions on a nascent metal surface. All the synthetic lubricants except for the iron (III) derivative showed increased antiwear abilities with increasing metallic ionic radius. A protective layer originated from the tribochemical reaction together with the adsorbed boundary lubricating layer containing organic fluorine compounds, nitrogen oxide, and Fe 3 (PO 4 ) 2 plays an important role in improving the friction and wear behavior of the steel-on-steel system.

关键词： metal halide-stabilized linear phosphazene derivatives,lubricant,steel,tribological properties.

Experimental and numerical studies on new multi-dimensional earthquake isolation and mitigation device:Horizontal properties

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Science china(Technological Sciences) 2010年第10期53卷 2658-2667页

作者： XU ZhaoDong1, ZENG Xiao2, HUANG XingHuai1 & LU LiHeng1 1 RC&PC Key laboratory of MOE, Southeast university, nanjing 210096, china 2 Huaxin Past & Telecom Consulting and Designing Institute Co. Ltd, Hangzhou 310014, china 1. RC&PC Key laboratory of MOE Southeast University Nanjing 210096 China2. Huaxin Past & Telecom Consulting and Designing Institute Co. Ltd Hangzhou 310014 China

Earthquake is a complex multi-dimensional excitation. Counter-measures of such multi-dimensional excitation on many critical structures,such as long-span structures and high-rise buildings,must be taken into account to avert the structural failure. Many types of earthquake mitigation or isolation devices for mitigating earthquake-induced effects in the horizontal direction have been proposed and applied to real applications. However,study on multi-dimensional earthquake isolation and mitigation devices for structures has been received much less attention. In this paper,a new multi-dimensional earthquake isolation and mitigation device was developed and tested. Effects of excitation frequency and environmental temperature on horizontal properties of this device were considered. At the same time,fatigue properties of the device under different amplitude horizontal excitations were also studied experimentally. The equivalent standard solid model which can effectively describe the effect of frequency and temperature on the horizontal properties of the device was proposed and verified. From the experimental results,it may be concluded that the multi-dimensional earthquake isolation and mitigation device owns fine energy dissipation and fatigue resistance capabilities.

关键词： multi-dimensional earthquake isolation and mitigation device energy dissipation viscoelastic

Grouping of amino acids and recognition of protein structurally conserved regions by reduced alphabets of amino acids

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Science china(Life Sciences) 2007年第3期50卷 392-402页

作者： LI Jing1 & WANG Wei1,2 1 national laboratory of solid State Microstructure and Department of Physics, nanjing university, nanjing 2.0093, china 2 Interdisciplinary Center of Theoretical Studies, Chinese Academy of Sciences, Beijing 100080, china 1. national laboratory of solid State Microstructure and Department of Physics Nanjing University Nanjing 210093 China 2. Interdisciplinary Center of Theoretical Studies Chinese Academy of Sciences Beijing 100080 China

Sequence alignment is a common method for finding protein structurally conserved/similar regions. However, sequence alignment is often not accurate if sequence identities between to-be-aligned se- quences are less than 30%. This is because that for these sequences, different residues may play similar structural roles and they are incorrectly aligned during the sequence alignment using substitu- tion matrix consisting of 20 types of residues. Based on the similarity of physicochemical features, residues can be clustered into a few groups. Using such simplified alphabets, the complexity of protein sequences is reduced and at the same time the key information encoded in the sequences remains. As a result, the accuracy of sequence alignment might be improved if the residues are properly clustered. Here, by using a database of aligned protein structures (DAPS), a new clustering method based on the substitution scores is proposed for the grouping of residues, and substitution matrices of residues at different levels of simplification are constructed. The validity of the reduced alphabets is confirmed by relative entropy analysis. The reduced alphabets are applied to recognition of protein structurally conserved/similar regions by sequence alignment. The results indicate that the accuracy or efficiency of sequence alignment can be improved with the optimal reduced alphabet with N around 9.

关键词： Grouping of amino acids and recognition of protein structurally conserved regions by reduced alphabets of amino acids