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https://www.readbyqxmd.com/read/28812880/an-exceptionally-narrow-band-gap-%C3%A2-4-ev-silicate-predicted-in-the-cubic-perovskite-structure-basio3
#1
Hidenori Hiramatsu, Hitoshi Yusa, Ryo Igarashi, Yasuo Ohishi, Toshio Kamiya, Hideo Hosono
The electronic structures of 35 A(2+)B(4+)O3 ternary cubic perovskite oxides, including their hypothetical chemical compositions, were calculated by a hybrid functional method with the expectation that peculiar electronic structures and unique carrier transport properties suitable for semiconductor applications would be hidden in high-symmetry cubic perovskite oxides. We found unique electronic structures of Si-based oxides (A = Mg, Ca, Sr, and Ba, and B = Si). In particular, the unreported cubic BaSiO3 has a very narrow band gap (4...
August 16, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28811577/dirac-point-induced-ultralow-threshold-laser-and-giant-optoelectronic-quantum-oscillations-in-graphene-based-heterojunctions
#2
Golam Haider, Rini Ravindranath, Tzu-Pei Chen, Prathik Roy, Pradip Kumar Roy, Shu-Yi Cai, Huan-Tsung Chang, Yang-Fang Chen
The occurrence of zero effective mass of electrons at the vicinity of the Dirac point is expected to create new paradigms for scientific research and technological applications, but the related discoveries are rather limited. Here, we demonstrate that a simple architecture composed of graphene quantum dots sandwiched by graphene layers can exhibit several intriguing features, including the Dirac point induced ultralow-threshold laser, giant peak-to-valley ratio (PVR) with ultra-narrow spectra of negative differential resistance and quantum oscillations of current as well as light emission intensity...
August 15, 2017: Nature Communications
https://www.readbyqxmd.com/read/28809680/high-performance-saw-resonator-on-new-multi-layered-substrate-using-litao3-crystal
#3
Tsutomu Takai, Hideki Iwamoto, Yuichi Takamine, Hisashi Yamazaki, Toshiyuki Fuyutsume, Haruki Kyoya, Takeshi Nakao, Hajime Kando, Masahiro Hiramoto, Takanori Toi, Masayoshi Koshino, Norio Nakajima
To develop the high performance filters and duplexers required for recent LTE frequency bands in mobile handsets, a surface acoustic wave (SAW) resonator is needed that have higher quality (Q) and a lower temperature coefficient of frequency (TCF). To achieve this, the authors focused on acoustic energy confinement in the depth direction for a rotated Y-X LiTaO3 (LT) substrate. Characteristics of multi-layered substrates with low impedance and high impedance layers under LT layer were studied numerically in terms of acoustic energy distribution, phase velocity, coupling coefficient and temperature characteristics employing a finite element method (FEM) simulation...
August 10, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28809160/w-n-tio2-with-positive-enough-level-of-valence-band-maximum-and-narrowing-bandgap-for-selective-aerobic-oxidation-in-visible-light-irradiation
#4
Mingming Zou, Lu Feng, Zhang Bingxue, Xinxin Zhou, Minghui Yang
A kind of surface complex (Triethylamine and mesoporous W-N-TiO2 microspheres with large surface area: 117.5 m2g-1) catalysis were achieved via visible-light photoredox catalysis. Triethylamine behaves as a true redox mediator due to donating ability seems to be highly favorable. With lower bandgap (2.43 eV) and more positive level of VBM (2.905 V), W-N-TiO2 sample has ability to play active catalytic role yielding excellent conversion of the selective oxidation of thioanisole (75.16 %) within 12 h visible light irradiation...
August 15, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28806820/didactic-training-vs-computer-based-self-learning-in-the-prediction-of-diminutive-colon-polyp-histology-by-trainees-a-randomized-controlled-study
#5
Taimur Khan, Birtukan Cinnor, Neil Gupta, Lindsay Hosford, Ajay Bansal, Mojtaba S Olyaee, Sachin Wani, Amit Rastogi
Background and study aim Experts can accurately predict diminutive polyp histology, but the ideal method to train nonexperts is not known. The aim of the study was to compare accuracy in diminutive polyp histology characterization using narrow-band imaging (NBI) between participants undergoing classroom didactic training vs. computer-based self-learning. Participants and methods Trainees at two institutions were randomized to classroom didactic training or computer-based self-learning. In didactic training, experienced endoscopists reviewed a presentation on NBI patterns for adenomatous and hyperplastic polyps and 40 NBI videos, along with interactive discussion...
August 14, 2017: Endoscopy
https://www.readbyqxmd.com/read/28801261/long-wavelength-red-light-produces-hyperopia-in-juvenile-and-adolescent-tree-shrews
#6
Timothy J Gawne, Alexander H Ward, Thomas T Norton
In infant tree shrews, exposure to narrow-band long-wavelength (red) light, that stimulates long-wavelength sensitive cones almost exclusively, slows axial elongation and produces hyperopia. We asked if red light produces hyperopia in juvenile and adolescent animals, ages when plus lenses are ineffective. Animals were raised in fluorescent colony lighting (100-300 lux) until they began 13 days of red-light treatment at 11 (n=5, "infant"), 35 (n=5, "juvenile") or 95 (n=5, "adolescent") days of visual experience (DVE)...
August 8, 2017: Vision Research
https://www.readbyqxmd.com/read/28799398/vibrational-spectroscopy-and-dynamics-of-w-co-6-in-solid-methane-as-a-probe-of-lattice-properties
#7
Raphael Thon, Wutharath Chin, Didier Chamma, Jean-Pierre Galaup, Aimeric Ouvrard, Bernard Bourguignon, Claudine Crépin
Methane solids present more than one accessible crystalline phase at low temperature at zero pressure. We trap W(CO)6 in CH4 and CD4 matrices between 8 and 35 K to probe the interaction between an impurity and its surrounding molecular solid under various physical conditions. Linear and nonlinear vibrational spectroscopies of W(CO)6 highlight different kinds of interaction and reveal new and remarkable signatures of the phase transition of methane. The structures in the absorption band of the antisymmetric CO stretching mode exhibit a clear modification at the transition between phase II and phase I in CH4 and motional narrowing is observed upon temperature increase...
December 7, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28798920/new-device-to-implement-the-adenoma-detection-rate
#8
REVIEW
Maddalena Zippi, Wandong Hong, Pietro Crispino, Giampiero Traversa
It is well-known that colonoscopy is considered the gold standard for colon cancer prevention. Although performed by experienced endoscopists, the matter remains of polyps missed during this examination. The reasons may include the size, shape and location of the lesions. Many colorectal cancer screening programs have been proposed to increase the adenoma detection rate. The substantial difference between these methods is whether the improvement in vision, particularly the detection of irregularities of the mucosa, is inside the endoscope electronic components (magnification, wide-angle vision, narrow band imaging, flexible spectral imaging colour enhancement, i-Scan) or outside the same, by the use of specific caps (EndoCuff, EndoVision, EndoRings)...
July 16, 2017: World Journal of Clinical Cases
https://www.readbyqxmd.com/read/28797796/low-134-cs-137-cs-ratio-anomaly-in-the-north-northwest-direction-from-the-fukushima-dai-ichi-nuclear-power-station
#9
Shingo Kobayashi, Takayuki Shinomiya, Takahiro Ishikawa, Hitoshi Imaseki, Kazuki Iwaoka, Hisashi Kitamura, Satoshi Kodaira, Keisuke Kobayashi, Masakazu Oikawa, Norihiro Miyaushiro, Yoshio Takashima, Yukio Uchihori
A low (134)Cs/(137)Cs ratio anomaly in the north-northwest (NNW) direction from the Fukushima Dai-ichi Nuclear Power Station (FDNPS) is identified by a new analysis of the (134)Cs/(137)Cs ratio dataset which we had obtained in 2011-2015 by a series of car-borne surveys that employed a germanium gamma-ray spectrometer. We found that the (134)Cs/(137)Cs ratio is slightly lower (0.95, decay-corrected to March 11, 2011) in an area with a length of about 15 km and a width of about 3 km in the NNW direction from the FDNPS than in other directions from the station...
August 7, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28796308/technical-note-the-effect-of-2d-excitation-profile-on-t1-measurement-accuracy-using-the-variable-flip-angle-method-with-an-average-flip-angle-assumption
#10
Bryant T Svedin, Dennis L Parker
PURPOSE: To study the accuracy and precision of T1 estimates using the Variable Flip Angle (VFA) method in 2D and 3D acquisitions. METHODS: Excitation profiles were simulated using numerical implementation of the Bloch equations for Hamming-windowed sinc excitation pulses with different time-bandwidth products (TBP) of 2, 6, and 10 and for T1 values of 295 ms and 1045 ms. Experimental data was collected in 5° increments from 5° to 90° for the same T1 and TBP values...
August 10, 2017: Medical Physics
https://www.readbyqxmd.com/read/28795772/the-potential-of-the-spectral-water-balance-index-wabi-for-crop-irrigation-scheduling
#11
Tal Rapaport, Uri Hochberg, Amnon Cochavi, Arnon Karnieli, Shimon Rachmilevitch
Hyperspectral sensing can detect slight changes in plant physiology, and may offer a faster and nondestructive alternative for water status monitoring. This premise was tested in the current study using a narrow-band 'water balance index' (WABI), which is based on independent changes in leaf water content (1500 nm) and the efficiency of the nonphotochemical quenching (NPQ) photo-protective mechanism (531 nm). The hydraulic, photo-protective and spectral behaviors of five important crops - grapevine, corn, tomato, pea and sunflower - were evaluated under water deficit conditions in order to associate the differences in stress physiology with WABI suitability...
August 10, 2017: New Phytologist
https://www.readbyqxmd.com/read/28795318/a-unified-methodology-based-on-sparse-field-level-sets-and-boosting-algorithms-for-false-positives-reduction-in-lung-nodules-detection
#12
Soudeh Saien, Hamid Abrishami Moghaddam, Mohsen Fathian
PURPOSE: This work aims to develop a unified methodology for the false positives reduction in lung nodules computer-aided detection schemes. METHODS: The 3D region of each detected nodule candidate is first reconstructed using the sparse field method for accurately segmenting the objects. This technique enhances the level set modeling by restricting the computations to a narrow band near the evolving curve. Then, a set of 2D and 3D relevant features are extracted for each segmented candidate...
August 9, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28794163/very-weak-oscillating-magnetic-field-disrupts-the-magnetic-compass-of-songbird-migrants
#13
Alexander Pakhomov, Julia Bojarinova, Roman Cherbunin, Raisa Chetverikova, Philipp S Grigoryev, Kirill Kavokin, Dmitry Kobylkov, Regina Lubkovskaja, Nikita Chernetsov
Previously, it has been shown that long-distance migrants, garden warblers (Sylvia borin), were disoriented in the presence of narrow-band oscillating magnetic field (1.403 MHz OMF, 190 nT) during autumn migration. This agrees with the data of previous experiments with European robins (Erithacus rubecula). In this study, we report the results of experiments with garden warblers tested under a 1.403 MHz OMF with various amplitudes (∼0.4, 1, ∼2.4, 7 and 20 nT). We found that the ability of garden warblers to orient in round arenas using the magnetic compass could be disrupted by a very weak oscillating field, such as an approximate 2...
August 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28793005/the-diagnostic-value-of-narrow-band-imaging-for-early-and-invasive-lung-cancer-a-meta-analysis
#14
Juanjuan Zhu, Wei Li, Jihong Zhou, Yuqing Chen, Chenling Zhao, Ting Zhang, Wenjia Peng, Xiaojing Wang
This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer...
July 2017: Clinics
https://www.readbyqxmd.com/read/28792208/fiber-coupled-substrate-integrated-hollow-waveguides-an-innovative-approach-to-mid-infrared-remote-gas-sensors
#15
Erhan Tütüncü, Vjekoslav Kokoric, Andreas WIlk, Felicia Seichter, Michael Schmid, William E Hunt, Anastacia M Manuel, Paul Mirkarimi, Jennifer B Alameda, J Chance Carter, Boris Mizaikoff
In this study, an innovative approach based on fiberoptically coupled substrate-integrated hollow waveguide (iHWG) gas cells for the analysis of low sample volumes suitable for remote broad- and narrow-band mid-infrared (MIR; 2.5-20 μm) sensing applications is reported. The feasibility of remotely addressing iHWG gas cells, configured in a double-pass geometry via a reflector, by direct coupling to a 7-around-1 mid-infrared fiber bundle is demonstrated, facilitating low-level hydrocarbon gas analysis. For comparison studies, two iHWGs with substrate dimensions of 50×50×12 mm (L × W × H) and geometric channel lengths of 138 mm and 58...
August 9, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28782001/effectiveness-of-computer-aided-diagnosis-of-colorectal-lesions-using-novel-software-for-magnifying-narrow-band-imaging-a-pilot-study
#16
Naoto Tamai, Yutaka Saito, Taku Sakamoto, Takeshi Nakajima, Takahisa Matsuda, Kazuki Sumiyama, Hisao Tajiri, Ryosuke Koyama, Shoji Kido
BACKGROUND AND STUDY AIMS:  Magnifying narrow-band imaging (M-NBI) enables detailed observation of microvascular architecture and can be used in endoscopic diagnosis of colorectal lesion. However, in clinical practice, differential diagnosis and estimation of invasion depth of colorectal lesions based on M-NBI findings require experience. Therefore, developing computer-aided diagnosis (CAD) for M-NBI would be beneficial for clinical practice. The aim of this study was to evaluate the effectiveness of software for CAD of colorectal lesions...
August 2017: Endoscopy International Open
https://www.readbyqxmd.com/read/28776994/metaheuristics-assisted-combinatorial-screening-of-eu-2-doped-ca-sr-ba-li-mg-al-si-ge-n-compositional-space-in-search-of-a-narrow-band-green-emitting-phosphor-and-density-functional-theory-calculations
#17
Jin-Woong Lee, Satendra Pal Singh, Minseuk Kim, Sung Un Hong, Woon Bae Park, Kee-Sun Sohn
A metaheuristics-based design would be of great help in relieving the enormous experimental burdens faced during the combinatorial screening of a huge, multidimensional search space, while providing the same effect as total enumeration. In order to tackle the high-throughput powder processing complications and to secure practical phosphors, metaheuristics, an elitism-reinforced nondominated sorting genetic algorithm (NSGA-II), was employed in this study. The NSGA-II iteration targeted two objective functions...
August 4, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28775371/scalable-and-transfer-free-fabrication-of-mos2-sio2-hybrid-nanophotonic-cavity-arrays-with-quality-factors-exceeding-4000
#18
Sebastian Hammer, H Moritz Mangold, Ariana E Nguyen, Dominic Martinez-Ta, Sahar Naghibi Alvillar, Ludwig Bartels, Hubert J Krenner
We report the fully-scalable fabrication of a large array of hybrid molybdenum disulfide (MoS2) - silicon dioxide (SiO2) one-dimensional, free-standing photonic-crystal cavities capable of enhancement of the MoS2 photoluminescence at the narrow cavity resonance. We demonstrate continuous tunability of the cavity resonance wavelength across the entire emission band of MoS2 simply by variation of the photonic crystal periodicity. Device fabrication started by substrate-scale growth of MoS2 using chemical vapor deposition (CVD) on non-birefringent thermal oxide on a silicon wafer; it was followed by lithographic fabrication of a photonic crystal nanocavity array on the same substrate at more than 50% yield of functional devices...
August 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28773923/room-temperature-electroluminescence-from-tensile-strained-si0-13ge0-87-ge-multiple-quantum-wells-on-a-ge-virtual-substrate
#19
Guangyang Lin, Ningli Chen, Lu Zhang, Zhiwei Huang, Wei Huang, Jianyuan Wang, Jianfang Xu, Songyan Chen, Cheng Li
Direct band electroluminescence (EL) from tensile-strained Si0.13Ge0.87/Ge multiple quantum wells (MQWs) on a Ge virtual substrate (VS) at room temperature is reported herein. Due to the competitive result of quantum confinement Stark effect and bandgap narrowing induced by tensile strain in Ge wells, electroluminescence from Γ1-HH1 transition in 12-nm Ge wells was observed at around 1550 nm. As injection current density increases, additional emission shoulders from Γ2-HH2 transition in Ge wells and Ge VS appeared at around 1300-1400 nm and 1600-1700 nm, respectively...
September 27, 2016: Materials
https://www.readbyqxmd.com/read/28773922/the-structural-photocatalytic-property-characterization-and-enhanced-photocatalytic-activities-of-novel-photocatalysts-bi%C3%A2-gasbo%C3%A2-and-bi%C3%A2-insbo%C3%A2-during-visible-light-irradiation
#20
Jingfei Luan, Yue Shen, Yanyan Li, Yaron Paz
In order to develop original and efficient visible light response photocatalysts for degrading organic pollutants in wastewater, new photocatalysts Bi₂GaSbO₇ and Bi₂InSbO₇ were firstly synthesized by a solid-state reaction method and their chemical, physical and structural properties were characterized. Bi₂GaSbO₇ and Bi₂InSbO₇ were crystallized with a pyrochlore-type structure and the lattice parameter of Bi₂GaSbO₇ or Bi₂InSbO₇ was 10.356497 Å or 10.666031 Å. The band gap of Bi₂GaSbO₇ or Bi₂InSbO₇ was estimated to be 2...
September 27, 2016: Materials
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