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Self-assembly of Polyaniline： Mechanism Study

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Chinese Journal of Chemical Physics 2008年第2期21卷 187-192页

作者： Shi-yan Song Li-jia Pan Yun Li Yi Shi Lin Pu Rong Zhang You-dou Zheng National laboratory of solid state Microstructures Nanjing Department of Physics Nanjing University Nanjing 210093 China

Anisotropic polyaniline （PAni） plates decorated with self-aligned nanofiber arrays were synthesized under the hydrothermaI conditions. The formation mechanism of the self-assembled structures was investigated by studying the effect on PAni micro-structure with additive electrolyte in reaction system, and numerical simulation for dependence of systematic electrostatic energy on cross angles of self-assembled nanofiber arrays in grid textured PAni plates. It is proposed that the electrostatic interaction based on ionic doping charges plays an important role in the formation of the self-assembled PAni structures.

关键词： Polyaniline Self-assembly Ionic charge

Segregation of alloying atoms at a tilt symmetric grain boundary in tungsten and their strengthening and embrittling effects

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Chinese Physics B 2014年第10期23卷 388-393页

作者：李志武孔祥山刘伟刘长松方前峰 Key laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences

We investigate the segregation behavior of alloying atoms （Sr, Th, In, Cd, Ag, Sc, Au, Zn, Cu, Mn, Cr, and Ti） near Z3 （ 111 ） [1]-0] tilt symmetric grain boundary （GB） in tungsten and their effects on the intergranular embrittlement by performing first-principles calculations. The calculated segregation energies suggest that Ag, Au, Cd, In, Sc, Sr, Th, and Ti prefer to occupy the site in the mirror plane of the GB, while Cu, Cr, Mn, and Zn intend to locate at the first layer nearby the GB core. The calculated strengthening energies predict Sr, Th, In, Cd, Ag, Sc, Au, Ti, and Zn act as embrittlers while Cu, Cr, and Mn act as cohesion enhancers. The correlation of the alloying atom＇s metal radius with strengthening energy is strong enough to predict the strengthening and embrittling behavior of alloying atoms; that is, the alloying atom with larger metal radius than W acts as an embrittler and the one with smaller metal radius acts as a cohesion enhancer.

关键词： grain boundary segregation strengthening and embrittling effect alloying atom first-principlescalculations

Study of hybrid orientation structure wafer

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Journal of Semiconductors 2011年第6期32卷 21-23页

作者：谭开洲张静徐世六张正璠杨永晖陈俊梁涛 National laboratory of Analog Integrated Circuits Sichuan Institute of solid-state Circuits

Two types of 5μm thick hybrid orientation structure wafers,which were integrated by（110）or（100） orientation silicon wafers as the substrate,have been investigated for 15-40 V voltage ICs and MEMS sensor *** have been obtained mainly by SOI wafer bonding and a non-selective epitaxy technique,and have been presented in China for the first *** thickness of BOX SiO2 buried in wafer is 220 *** has been found that the quality of hybrid orientation structure with（100）wafer substrate is better than that with（110）wafer substrate by＂Sirtl defect etching of HOSW＂.

关键词： HOT SOI (110)crystal orientation 15-40 V ICs MEMS sensor

Interaction of hydrogen molecules on Ni-doped single-walled carbon nanotube

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Chinese Physics B 2009年第1期18卷 357-362页

作者：倪美燕王贤龙曾雉 Key laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of Sciences

Adsorption of hydrogen molecules on an Ni-doped （8,0） single-walled carbon nanotube （SWNT） is investigated by using first-principles density functional calculations. The result shows that a single Ni atom adsorbed on the bridge site of the tube could cannot dissociate the H2, however it can chemisorb three H2 at most, with the average binding energy per H2 suitable for the hydrogen storage at the room temperature. More H2 would physisorb around an Ni atom weakly. As for the SWNT with an Ni dimer adsorbed, we find that when the H2 approaches the Ni Ni bond, it dissociates without overcoming any barrier and makes bonds with Ni atom.

关键词： hydrogen storage doped carbon nanotube density functional theory

Design and application of a depletion-mode NJFET in a high-voltage BiCMOS process

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Journal of Semiconductors 2010年第8期31卷 70-73页

作者：刘勇唐昭焕王志宽杨永晖杨卫东胡永贵 Sichuan Institute of solid-state Circuits CETC National laboratory of Analog ICs

A novel depletion-mode NJFET compatible high-voltage BiCMOS process is proposed and experimentally demonstrated with a four-branch 12-bit DAC（digital-to-analog converter）.With this process,an NJFET with a pinch-off voltage ofabout-1.5 V and a breakdown voltage of about 16 V,an NLDDMOS（N-type lightly-dosed-drain in MOS） with a turn-on voltage of about 1.0 V and a breakdown voltage of about 35 V,and a Zener diode with a reverse voltage of about 5.6 V were *** results showed that the converter had a reference temperature coefficient of less than±25 ppm/℃,a differential coefficient error of less than±0.3 LSB,and a linear error of less than±0.5 *** depletion-mode NJFET and its compatible process can also be widely used for high-voltage ADCs or DACs.

关键词： depletion-mode NJFET high-voltage BiCMOS process ADC DAC temperature coefficient

A novel approach to fabricate Zn coating on Mg foam through a modified thermal evaporation technique

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Journal of Materials Science & Technology 2018年第9期34卷 1558-1563页

作者： Xingfu Wang Xinfu Wang Dan Wang Modi Zhao Fusheng Han Key laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences

Zn enriched coatings with distinct microstructures and properties were fabricated on Mg foams by a modified thermal evaporation technique using a tubular resistance furnace. As the temperature and kinetic energy of Zn vapor varied along the tubular system, a spatial variation of preparation conditions was created and the obtained coatings were found to follow two growth mechanisms： a thermal diffusion pattern in high-temperature zone and the a relatively low-temperature deposition model. AZn-based deposition coating with dense texture and nearly uniform structure was acquired while Mg foam was placed 20 cm far from the evaporation source, where the Zn vapor deposition model dominated the coating *** properties and bio-corrosion behaviors of the samples were investigated. Results showed that the Zn coatings brought dramatic improvements in compression strength, but exhibited differently in biodegradation performance. It was confirmed that the diffusion layer accelerated corrosion of Mg foam due to the galvanic effect, while the Zn-based deposition coating displayed excellent anti-corrosion performance, showing great potential as bone implant materials. This technique provides a novel and convenient approach to tailor the biodegradability of Mg foams for biomedical applications.

关键词： Biomaterials Mg foams Thermal evaporation technique Coatings Biodegradability

Experimental observations of ferroelectricity in double pyrochlore Dy2Ru2O7

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Frontiers of physics 2014年第1期9卷 82-89页

作者： Zai-Chun Xu Mei-Feng Liu Lin Lin Huimei Liu Zhi-Bo Yan Jun-Ming Liu laboratory of solid state Microstructures Nanjing University Nanjing 210093 China

Double pyrochlore Dy2Ru207 is synthesized and its magnetism and ferroelectricity below the Ru4＋ spin ordering temperature （NI00 K） are investigated. The ferroelectric transition appears at -18 K, much higher than the Dy3＋ spin ordering point at -1.8 K and lower than the Ru4＋ spin ordering point at -100 K. The measured electric polarization at ,-2 K is as big as 145℃/m2 in the polycrystalline samples. It is argued that the ferroelectricity is possibly ascribed to the electric dipole ordering arising from the collective monopole excitations in the Dy3＋ tetrahedrons in prior to the Dy3＋ spin ordering into spin-ice like state below -1.8 K.

关键词： pyrochlore oxides multiferroics magnetically induced ferroelectricity

Using coupling slabs to tailor surface-acoustic-wave band structures in phononic crystals consisting of pillars attached to elastic substrates

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Science China(Physics,Mechanics & Astronomy) 2017年第4期60卷 45-50页

作者： Heng Zhang SiYuan Yu FuKang Liu Zhen Wang MingHui Lu XiaoBo Hu YanFeng Chen XianGang Xu state Key laboratory of Crystal Materials Shandong University National laboratory of solid state Microstructures & Department of Materials Science and Engineering Nanjing University

The propagation of surface acoustic waves(SAWs) in two-dimensional phononic crystals(PnCs) with and without coupling-enhancement slabs was theoretically investigated using a three-dimensional finite element *** piezoelectric substrates,for example,lithium niobate(LiNbO_3),gallium nitride(GaN),and aluminium nitride(A1N),were taken into *** to the PnCs without coupling-enhancement slabs,the coupling between each pillar and its nearest neighbor was largely enhanced in the presence of *** bandwidth of the first directional band gap increased markedly compared with its initial value for the PnCs without a slab(within square symmetry).In addition,with increasing thicknesses of the slabs bonded between neighboring pillars,the first directional band-gap and second directional band gap of the PnCs tend to ***,the structure with coupling-enhancement slabs can be used as an excellent electrical band elimination filter for most electro-SAW devices,offering a new strategy to realize chip-scale applications in electroacoustic signal processing,optoacoustic modulation,and even SAW microfluidic devices.

关键词： surface acoustic waves(SAWs) phononic crystals(PnCs) tailored band structure

Effects of pre-deformation on the martensitic transformation and magnetocaloric property in Ni-Mn-Co-Sn ribbons

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Chinese Physics B 2010年第11期19卷 641-645页

作者：马胜灿轩海成张成亮王辽宇曹庆琪王敦辉都有为 National laboratory of solid state Microstructures and Key laboratory of Nanomaterials for Jiang Su Province Nanjing University

This paper investigates the martensitic transformation and magnetocaloric effect in pre-deformed Ni-Mn-Co Sn ribbons. The experimental results show that the reverse martensitic transformation temperature TM increases with the increasing pre-pressure, suggesting that pre-deformation is another effective way to adjust TM in ferromagnetic shape memory alloys. Large magnetic entropy changes and refrigerant capacities are obtained in these ribbons as well. It also discusses the origin of the enhanced martensitic transformation temperature and magnetocaloric property in pre-deformed Ni-Mn Co-Sn ribbons.

关键词： pre-deformation martensitic transformation magnetocaloric property