다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Following pioneering work, solution-processable organic-inorganic hybrid perovskites-such as CH3NH3PbX3 (X = Cl, Br, I)-have attracted attention as light-harvesting materials for mesoscopic solar cells. So far, the perovskite pigment has been deposited in a single step onto mesoporous metal oxide films using a mixture of PbX2 and CH3NH3X in a common solvent. However, the uncontrolled precipitation of the perovskite produces large morphological variations, resulting in a wide spread of photovoltaic performance in the resulting devices, which hampers the prospects for practical applications. Here we describe a sequential deposition method for the formation of the perovskite pigment within the porous metal oxide film. PbI2 is first introduced from solution into a nanoporous titanium dioxide film and subsequently transformed into the perovskite by exposing it to a solution of CH3NH3I. We find that the conversion occurs within the nanoporous host as soon as the two components come into contact, permitting much better control over the perovskite morphology than is possible with the previously employed route. Using this technique for the fabrication of solid-state mesoscopic solar cells greatly increases the reproducibility of their performance and allows us to achieve a power conversion efficiency of approximately 15 per cent (measured under standard AM1.5G test conditions on solar zenith angle, solar light intensity and cell temperature). This two-step method should provide new opportunities for the fabrication of solution-processed photovoltaic cells with unprecedented power conversion efficiencies and high stability equal to or even greater than those of today's best thin-film photovoltaic devices.

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Sequential deposition as a route to high-performance perovskite-sensitized solar cells

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Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, burda@case.edu. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102

Chemistry and properties of nanocrystals of different shapes.

1. INTRODUCTION Among the classes of highly porous materials, metalÀorganic frameworks (MOFs) are unparalleled in their degree of tunability and structural diversity as well as their range of chemical and physical properties. MOFs are extended crystalline structures wherein metal cations or clusters of cations (\" nodes \") are connected by multitopic organic \" strut \" or \" linker \" ions or molecules. The variety of metal ions, organic linkers, and structural motifs affords an essentially infinite number of possible combinations. 1 Furthermore, the possibility for postsynthetic modification adds an additional dimension to the synthetic variability. 2 Coupled with the growing library of experimentally determined structures, the potential to computationally predict, with good accuracy, affinities of guests for host frameworks points to the prospect of routinely predesigning frameworks to deliver desired properties. 3,4 MOFs are often compared to zeolites for their large internal surface areas, extensive porosity, and high degree of crystallinity. Correspondingly, MOFs and zeolites have been utilized for many of the same applications

Metal–Organic Framework Materials as Chemical Sensors

Reactions of niobium cluster ions Nbx± (x = 2–16) with NO and NO2

Surface-enhanced Raman scattering of p-aminothiophenol and p-nitrothiophenol were obtained on the surface of Cu2O nanoparticles, showing novel spectral changes with morphology-dependent and time-dependent characteristics. The measured Raman signals were believed to partly originate from the newly produced surface species p,p′-dimercaptoazobenzene. The nature of surface chemisorption status during Raman measurement was investigated experimentally and theoretically via combined surface-enhanced Raman scattering and density functional theory study, indicating that surface catalytic reaction of p-aminothiophenol and p-nitrothiophenol could take place on the surface of oxide nanostructures as well as coinage metal material. Copyright © 2013 John Wiley & Sons, Ltd.

Direct observation of p,p′‐dimercaptoazobenzene produced from p‐aminothiophenol and p‐nitrothiophenol on Cu2O nanoparticles by surface‐enhanced Raman spectroscopy

Uniform ZnSe precursor (ZnSe : 0.38en, en = ethylenediamine) nanoribbon arrays are grown vertically on Zn foils in ethylenediamine (en) using a solvothermal method. After the annealing treatment in N2, the ZnSe nanoribbon arrays can be obtained without an obvious morphology change and the crystallinity of ribbons is greatly improved. The microstructures of both individual ZnSe precursor and ZnSe nanoribbons are investigated. Field emission characteristics show that the onset field required drawing a current density of ~0.1 µ A cm−2 from the ZnSe nanoribbons is 5.0 V µm−1 and the field enhancement factors are determined to be ~1382.

Vertically aligned zinc selenide nanoribbon arrays: microstructure and field emission

A technique has been developed to fabricate micro- or nanopumps based on porous alumina thin films. The main body of the nanopump consists of a porous alumina thin film (containing nano-sized channels of about 40-300 nm in diameter) with conductive surfaces (e.g. Au coating layers) on both sides of the film. Through the fabrication of nanochannels in (the alumina films) and the subsequent annealing and surface activation processes, high-efficiency micro- or nanopumps can be made. The nanofluidic flow through the nanochannels of the alumina thin films is driven by an electric field with no moving parts. The flow rate (up to 50 millilitres/(min·cm2)) of water through the alumina thin film can be continuously tuned through the intensity of the electric field, i.e., the DC electric potential applied across the nanochannels.

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Membrane nanopumps based on porous alumina thin films, membranes therefor and a method of fabricating such membranes

The one‐color resonant two‐photon ionization technique is employed to study jet‐cooled van der Waals (vdW) clusters of halobenzene and nitrogen through the S0→S1 transition around the 000 band. The spectra obtained exhibit rich information about the clusters’ intermolecular vdW vibrational modes and their solvent internal rotation. We have tentatively assigned all the observed spectral features to a single isomer of C6H5X⋅⋅⋅N2 (X=F, Cl, Br). The influence of X on the vdW vibrations and the internal rotation of N2 in the complex is investigated. The analysis of the influence of X on the 000 spectral shift suggests that the change in vdW interaction energy upon electronic excitation is mainly due to the dispersion term.

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Shihe Yang

Papers

Reactions of niobium cluster ions Nbx± (x = 2–16) with NO and NO2

Direct observation of p,p′‐dimercaptoazobenzene produced from p‐aminothiophenol and p‐nitrothiophenol on Cu2O nanoparticles by surface‐enhanced Raman spectroscopy

Vertically aligned zinc selenide nanoribbon arrays: microstructure and field emission

Membrane nanopumps based on porous alumina thin films, membranes therefor and a method of fabricating such membranes

Resonant two-photon ionization spectra of the van der waals complexes : c6h5x...n2 (x=f, cl, br)