Seungju Lee

We report a simple strategy for placing analyte molecules in hot spots between closely spaced nanowires leading to intense SERS enhancement. The results are highly reproducible from experiment to experiment likely because of the regularity of the SERS substrate, which consists of highly ordered and regular silver nanowires fabricated in porous aluminum oxide. Because the silver nanowires are sealed in the pores of PAO, this system is potentially immune to contamination until it is ready for use,

High Resolution Image Download MS PowerPoint Slide Using a series of highly regular nanostructures consisting of periodic Ag nanowires fabricated in porous aluminum oxide, we validate the overwhelmingly plasmonic origin of the most intense SERS signals such as those responsible for single-molecule SERS, demonstrating its sensitive dependence on the system's nanogeometry. By varying the interwire gap distance from 35 to 10 nm, the SERS intensity excited with 785 nm laser light, increased over 200

Single silver nanowires produced by DC electrodeposition in porous anodic alumina templates were surface-functionalized with the bifunctional molecule 4-aminobenzenthiol (ABT) then exposed to aqueous silver nanoparticles resulting in a silver nanoparticle-decorated silver nanowire. The polarization dependent surface-enhanced Raman (SERS) signal from this system showed significant intensity anisotropy when measured at a midsection of the nanowire, where the largest SERS intensities were observed

Metal ion carboxylato complexes possess ion-specific carboxylate Raman bands. Using this attribute we follow the chromatographic separation of a microliter aliquot of an initially equimolar solution of Pb(2+) and Hg(2+) using the surface-enhanced Raman spectroscopy spectra of their carboxylato complexes as unique identifiers. A glass capillary whose interior is lined with a dense layer of gold nanoparticles treated with 4-mercaptobenzoic acid simultaneously acts as a separation medium and an eff

The operator product expansion is used to obtain model-independent predictions for the first two moments of the renormalized $B$-meson light-cone distribution amplitude ${\ensuremath{\phi}}_{+}^{B}(\ensuremath{\omega},\ensuremath{\mu})$, defined with a cutoff $\ensuremath{\omega}\ensuremath{\le}{\ensuremath{\Lambda}}_{\mathrm{UV}}$. The leading hadronic power corrections are given in terms of the parameter $\overline{\ensuremath{\Lambda}}={m}_{B}\ensuremath{-}{m}_{b}$. From the cutoff dependence

A new class of enhanced nonperturbative corrections to the inclusive $\overline{B}\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$ decay rate is identified, which contribute first at order $\ensuremath{\Lambda}/{m}_{b}$ in the heavy-quark expansion and cannot be described using a local operator product expansion. Instead, these effects are described in terms of hadronic matrix elements of nonlocal operators with component fields separated by lightlike distances. They contribute to the high-en

Surface-immobilized, densely packed gold nanoparticles in contact with aqueous silver ions and exposed to red light rapidly photoreduce silver ions in solution producing radially symmetric metal deposits with diameters many times larger than the diameter of the illuminating laser beam. The average particle sizes in the deposit increase with radial distance from the center of the deposit. This reduction-at-a-distance effect arises from surface-plasmon-mediated photoemission, with the photoemitted

Perfluorocarboxylate-stabilized silver nanoparticles have been prepared uniformly via the thermal decomposition of layered silver perfluorocarboxylates (AgCO2(CF2)nCF3, n = 10, 12, 14 and 16).

A bstract We present a novel class of composite Higgs models in which the top and gauge partners responsible for cutting off the Higgs quadratic divergences form a continuum. The continuum states are characterized by their spectral densities, which should have a finite gap for realistic models. We present a concrete example based on a warped extra dimension with a linear dilaton, where this finite gap appears naturally. We derive the spectral densities in this model and calculate the full Higgs

This work demonstrates that optically tunable, SERS-active Ag films can be reproducibly fabricated on glass by the thermal decomposition of layered silver alkanecarboxylates.

We evaluate the capacity of direct sequence code-division multiple access (DS-CDMA) systems supporting multiclass on/off traffic in a multiple cell environment. For this purpose, given the requirements of bit energy-to-interference power spectral density ratios and outage probabilities, we obtain a set of all admissible points satisfying those requirements. Whether a point, denoting the number of calls for each class, is admissible or not is determined by numerically solving the nonlinear equati

Many techniques for calculating bit-error probabilities (BEPs) of direct-sequence spread-spectrum multiple-access systems (DS-SSMA) have been reported. Among them are the following three techniques: (1) the standard Gaussian approximation; (2) the improved Gaussian approximation; (3) and the simplified improved Gaussian approximation. We extend these techniques to derive the BEPs of multicode DS-SSMA systems. We assess the three techniques by comparing their results with the result of computer s

Off-shell Higgs bosons at the high mass tail may shed light on the underlying mechanism of the electroweak symmetry breaking. In the Standard Model, there is an exact cancellation of the logarithmic divergence between the box and Higgs-mediated triangle diagrams due to unitarity, such that the $gg\ensuremath{\rightarrow}ZZ(WW)$ process is left with a negligible ${V}_{L}{V}_{L}$ longitudinal mode contribution in the tail region of the off-shell Higgs boson. We propose to test the unitarity of the

본 연구는 최근 가족에 대한 여성의 가치관 변화 및 경제적인 이유로 인해 의도적으로 자녀를낳지 않는 부부가 늘어나는 상황에서 직장기혼여성 중 특히 무자녀인 여성들을 대상으로 향후이들의 출산계획에 미치는 요인을 규명하고, 이를 토대로 출산율의 회복을 위한 정책적 함의를 제시하는데 그 목적을 두고 있다. 이를 위해 여성가족패널의 1-5차 데이터를 이용하여 현재 직장에 종사하고 있는 가임 가능기(27-49세) 기혼 무자녀 여성(1,020명)을 대상으로 근로조건 및 출산장려제도가 첫 자녀 출산 의사에 미치는 영향을 교차분석 및 로지스틱 회귀분석을통해 분석하였다. 교차분석결과 근로 및 제도적 요인 변수 중 정규직 여부, 산전후휴가 제공여부, 육아휴직 제공여부, 출산장려금 제공여부와 이러한 제도에 대한 직장 여성들의 인식 정도가 첫 자녀 출산의사와 어느 정도 상관관계가 있음을 알 수 있었다. 반면 로지스틱 회귀분석의 결과 현재 진행되고 있는 다양한 정부주도형 출산장려정책들이 아직까지는 여성의