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

Atomic layer deposition (ALD) is gaining attention as a thin film deposition method, uniquely suitable for depositing uniform and conformal films on complex three-dimensional topographies. The deposition of a film of a given material by ALD relies on the successive, separated, and self-terminating gas–solid reactions of typically two gaseous reactants. Hundreds of ALD chemistries have been found for depositing a variety of materials during the past decades, mostly for inorganic materials but lately also for organic and inorganic–organic hybrid compounds. One factor that often dictates the properties of ALD films in actual applications is the crystallinity of the grown film: Is the material amorphous or, if it is crystalline, which phase(s) is (are) present. In this thematic review, we first describe the basics of ALD, summarize the two-reactant ALD processes to grow inorganic materials developed to-date, updating the information of an earlier review on ALD [R. L. Puurunen, J. Appl. Phys. 97, 121301 (2005)], and give an overview of the status of processing ternary compounds by ALD. We then proceed to analyze the published experimental data for information on the crystallinity and phase of inorganic materials deposited by ALD from different reactants at different temperatures. The data are collected for films in their as-deposited state and tabulated for easy reference. Case studies are presented to illustrate the effect of different process parameters on crystallinity for representative materials: aluminium oxide, zirconium oxide, zinc oxide, titanium nitride, zinc zulfide, and ruthenium. Finally, we discuss the general trends in the development of film crystallinity as function of ALD process parameters. The authors hope that this review will help newcomers to ALD to familiarize themselves with the complex world of crystalline ALD films and, at the same time, serve for the expert as a handbook-type reference source on ALD processes and film crystallinity.

Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends

We review the current state of optical methods for sensing oxygen. These have become powerful alternatives to electrochemical detection and in the process of replacing the Clark electrode in many fields. The article (with 694 references) is divided into main sections on direct spectroscopic sensing of oxygen, on absorptiometric and luminescent probes, on polymeric matrices and supports, on additives and related materials, on spectroscopic schemes for read-out and imaging, and on sensing formats (such as waveguide sensing, sensor arrays, multiple sensors and nanosensors). We finally discuss future trends and applications and summarize the properties of the most often used indicator probes and polymers. The ESI† (with 385 references) gives a selection of specific applications of such sensors in medicine, biology, marine and geosciences, intracellular sensing, aerodynamics, industry and biotechnology, among others.

/pdf/optical-methods-for-sensing-and-imaging-oxygen-materials-2e0wvh0smm.pdf

Optical methods for sensing and imaging oxygen: materials, spectroscopies and applications

Detection of hazardous volatile organic compounds (VOCs) by metal oxide nanostructures-based gas sensors: A review

Xin Zhou,†,‡ Songyi Lee,† Zhaochao Xu,* and Juyoung Yoon*,† †Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 120-750, Republic of Korea ‡Research Center for Chemical Biology, Department of Chemistry, Yanbian University, Yanjii 133002, People’s Republic of China Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Shahekou, Dalian, Liaoning, People’s Republic of China

Recent Progress on the Development of Chemosensors for Gases.

Two-photon persistent hole burning is observed at T = 296 K in 5D1–7F0 and 5D0–7F0 transitions of Sm2+ ions in substitutionally disordered SrFCl1/2 single crystals, showing the ratio of inhomogeneous to homogeneous linewidth of 20 ÷ 25. The minimum hole widths of 3.5 cm-1 and 2.6 cm-1, respectively, were determined for these transitions. In fact, the applicability of persistent spectral hole burning, known as a low-temperature high-resolution spectroscopic method and a potential basis for the use of a new–spectral–dimension in optical data storage and processing, is demonstrated for the first time at room temperature in inorganic materials.

http://iopscience.iop.org/article/10.1209/0295-5075/16/6/010/pdf

Room Temperature Persistent Spectral Hole Burning in Sm-Doped SrFCl1/2Br1/2 Mixed Crystals

Semiconductor gas sensors

The Raman spectroscopy method was used for structural characterization of TiO2 thin films prepared by atomic layer deposition (ALD) and pulsed laser deposition (PLD) on fused silica and single-crystal silicon and sapphire substrates. Using ALD, anatase thin films were grown on silica and silicon substrates at temperatures 125–425 °C. At higher deposition temperatures, mixed anatase and rutile phases grew on these substrates. Post-growth annealing resulted in anatase-to-rutile phase transitions at 750 °C in the case of pure anatase films. The films that contained chlorine residues and were amorphous in their as-grown stage transformed into anatase phase at 400 °C and retained this phase even after annealing at 900 °C. On single crystal sapphire substrates, phase-pure rutile films were obtained by ALD at 425 °C and higher temperatures without additional annealing. Thin films that predominantly contained brookite phase were grown by PLD on silica substrates using rutile as a starting material.

https://www.degruyter.com/downloadpdf/j/phys.2006.4.issue-1/s11534-005-0009-3/s11534-005-0009-3.xml

Structural study of TiO2 thin films by micro-Raman spectroscopy

The search for p-type metal oxides with high gas response and stability is an important issue in gas sensor technology. In this work the p-type gas sensing properties of orthorhombic CaFe2O4 are demonstrated for the first time. CaFe2O4 nanopowders were successfully synthesized by the sol–gel auto-combustion method. The formation of orthorhombic CaFe2O4 compound was confirmed by X-ray diffraction, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analyses. The synthesized CaFe2O4 compound showed p-type gas sensing behaviour and high gas response towards ethanol (Rg/Ra = 41.5) at a concentration of 100 ppm. Moreover, the CaFe2O4 material tested during the experiments showed good stability.

Orthorhombic CaFe2O4: A promising p-type gas sensor

Abstract The search for p-type metal oxides with high gas response and stability is an important issue in gas sensor technology. In this work the p-type gas sensing properties of orthorhombic CaFe2O4 are demonstrated for the first time. CaFe2O4 nanopowders were successfully synthesized by the sol–gel auto-combustion method. The formation of orthorhombic CaFe2O4 compound was confirmed by X-ray diffraction, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analyses. The synthesized CaFe2O4 compound showed p-type gas sensing behaviour and high gas response towards ethanol (Rg/Ra = 41.5) at a concentration of 100 ppm. Moreover, the CaFe2O4 material tested during the experiments showed good stability.

Raivo Jaaniso

Papers

Room Temperature Persistent Spectral Hole Burning in Sm-Doped SrFCl1/2Br1/2 Mixed Crystals

Semiconductor gas sensors

Structural study of TiO2 thin films by micro-Raman spectroscopy

Orthorhombic CaFe2O4: A promising p-type gas sensor

Orthorhombic CaFe 2 O 4 : A Promising P-type Gas Sensor