Yiying Wu

Bio: Yiying Wu is an academic researcher from Ohio State University. The author has contributed to research in topics: Nanowire & Electrolyte. The author has an hindex of 66, co-authored 192 publications receiving 39403 citations. Previous affiliations of Yiying Wu include Lawrence Berkeley National Laboratory & University of California, Santa Barbara.

Room-temperature ultraviolet nanowire nanolasers

Abstract: Room-temperature ultraviolet lasing in semiconductor nanowire arrays has been demonstrated The self-organized, oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process These wide band-gap semiconductor nanowires form natural laser cavities with diameters varying from 20 to 150 nanometers and lengths up to 10 micrometers Under optical excitation, surface-emitting lasing action was observed at 385 nanometers, with an emission linewidth less than 03 nanometer The chemical flexibility and the one-dimensionality of the nanowires make them ideal miniaturized laser light sources These short-wavelength nanolasers could have myriad applications, including optical computing, information storage, and microanalysis

One‐Dimensional Nanostructures: Synthesis, Characterization, and Applications

Abstract: This article provides a comprehensive review of current research activities that concentrate on one-dimensional (1D) nanostructures—wires, rods, belts, and tubes—whose lateral dimensions fall anywhere in the range of 1 to 100 nm. We devote the most attention to 1D nanostructures that have been synthesized in relatively copious quantities using chemical methods. We begin this article with an overview of synthetic strategies that have been exploited to achieve 1D growth. We then elaborate on these approaches in the following four sections: i) anisotropic growth dictated by the crystallographic structure of a solid material; ii) anisotropic growth confined and directed by various templates; iii) anisotropic growth kinetically controlled by supersaturation or through the use of an appropriate capping reagent; and iv) new concepts not yet fully demonstrated, but with long-term potential in generating 1D nanostructures. Following is a discussion of techniques for generating various types of important heterostructured nanowires. By the end of this article, we highlight a range of unique properties (e.g., thermal, mechanical, electronic, optoelectronic, optical, nonlinear optical, and field emission) associated with different types of 1D nanostructures. We also briefly discuss a number of methods potentially useful for assembling 1D nanostructures into functional devices based on crossbar junctions, and complex architectures such as 2D and 3D periodic lattices. We conclude this review with personal perspectives on the directions towards which future research on this new class of nanostructured materials might be directed.

Catalytic Growth of Zinc Oxide Nanowires by Vapor Transport

Abstract: nanoparticles in dimethylsulfoxide onto the PLL film for about 20 min, after which it was rinsed in dimethylsulfoxide and then dichloromethane. From the molecular weight, the average length of the PLL is about 30 nm. Therefore, each polymer can accommodate about seven or eight nanoparticles. [20] L. Clarke, M. N. Wybourne, M. Yan, S. X. Cai, J. F. W. Keana, Appl. Phys. Lett. 1997, 71, 617. [21] A. A. Middleton, N. S. Wingreen, Phys. Rev. Lett. 1993, 71, 3198. [22] G. Y. Hu, R. F. O'Connell, Phys. Rev. B 1994, 49, 16 773. [23] A. J. Rimberg, T. R. Ho, J. Clarke, Phys. Rev. Lett. 1995, 74, 4714. [24] L. Clarke, M. N. Wybourne, M. Yan, S. X. Cai, L. O. Brown, J. Hutchison, J. F. W. Keana, J. Vac. Sci. Technol. B 1997, 15, 2925. [25] The capacitance matrix was calculated for different chain lengths using the software package FastCap MIT (1992). We used the nanoparticle dimensions given in the text and a ligand shell dielectric constant of 3. For nanoclusters away from the end of the chains we obtain Cdd » 0.04 aF and Cg » 0.17 aF. As expected, the value of Cg is slightly larger than the value calculated for an isolated metal sphere of radius a coated with a dielectric shell, Cg» (4pee0a)/(1 + (a/d)(e±1)) = 0.14 aF, where d is the total radius of the core plus ligand shell. [26] Simulations were carried out using both MOSES (Monte-Carlo SingleElectronics Simulator, R. H. Chen) and SIMON (Simulation of Nano Structures, C. Wasshuber). [27] S. Chen, R. S. Ingram, M. J. Hostetler, J. J. Pietron, R. W. Murray, T. G. Schaaff, J. T. Khoury, M. M. Alvarez, R. L. Whetton, Science 1998, 280, 2098. [28] L. Y. Gorelik, A. Isacsson, M. V. Voinova, B. Kasemo, R. I. Shekhter, M. Jonson, Phys. Rev. Lett. 1998, 80, 4526. [29] O. D. Häberlen, S. C. Chung, M. Stener, N. Rösch, J. Chem. Phys. 1997, 106, 5189. [30] Y. Awakuni, J. H. Calderwood, J. Phys. D: Appl. Phys. 1972, 5, 1038. [31] G. Markovich, C. P. Collier, J. R. Heath, Phys. Rev. Lett. 1998, 80, 3807. [32] C. P. Collier, R. J. Saykally, J. J. Shiang, S. E. Hendrichs, J. R. Heath, Science 1997, 277, 1978. [33] N. Mott, Metal Insulator Transitions, Taylor and Francis, London 1990.

Thermal conductivity of individual silicon nanowires

Abstract: The thermal conductivities of individual single crystalline intrinsic Si nanowires with diameters of 22, 37, 56, and 115 nm were measured using a microfabricated suspended device over a temperature range of 20–320 K. Although the nanowires had well-defined crystalline order, the thermal conductivity observed was more than two orders of magnitude lower than the bulk value. The strong diameter dependence of thermal conductivity in nanowires was ascribed to the increased phonon-boundary scattering and possible phonon spectrum modification.

Mesoporous Co3O4 nanowire arrays for lithium ion batteries with high capacity and rate capability.

Abstract: We report the high capacity and rate capability of mesoporous Co3O4 nanowire (NW) arrays as anodes in Li ion batteries. At a current of 1C, the NW arrays maintain a capacity of 700 mAh/g after 20 discharge/charge cycles. When the current is increased to 50C, 50% of the capacity can be retained. With their ease of large area synthesis and superior electrochemical properties, these Co3O4 NW arrays will be interesting for practical Li ion batteries.

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

A comprehensive review of zno materials and devices

Abstract: The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...

Dye-Sensitized Solar Cells

Abstract: Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. DSC research groups have been established around the worl ...