High-Yield Growth and Tunable Morphology of Bi2Se3 Nanoribbons Synthesized on Thermally Dewetted Au

The yield and morphology (length, width, thickness) of stoichiometric Bi2Se3 nanoribbons grown by physical vapor deposition is studied as a function of the diameters and areal number density of the Au catalyst nanoparticles of mean diameters 8–150 nm formed by dewetting Au layers of thicknesses 1.5–16 nm. The highest yield of the Bi2Se3 nanoribbons is reached when synthesized on dewetted 3 nm thick Au layer (mean diameter of Au nanoparticles ~10 nm) and exceeds the nanoribbon yield obtained in catalyst-free synthesis by almost 50 times. The mean lengths and thicknesses of the Bi2Se3 nanoribbons are directly proportional to the mean diameters of Au catalyst nanoparticles. In contrast, the mean widths of the Bi2Se3 nanoribbons do not show a direct correlation with the Au nanoparticle size as they depend on the contribution ratio of two main growth mechanisms—catalyst-free and vapor–liquid–solid deposition. The Bi2Se3 nanoribbon growth mechanisms in relation to the Au catalyst nanoparticle size and areal number density are discussed. Determined charge transport characteristics confirm the high quality of the synthesized Bi2Se3 nanoribbons, which, together with the high yield and tunable morphology, makes these suitable for application in a variety of nanoscale devices.

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PEG1000 as a Low Melting and Ecofriendly Solvent for Air Oxidative and Catalyst Free 2,4-Disubstitute Quinazoline Synthesis

Letters in Organic Chemistry ◽

10.2174/1570178616666190417122005 ◽

2020 ◽

Vol 17 (9) ◽

pp. 709-716

Author(s):

Ebrahim Saeedian Moghadam ◽

Shahrzad Ghafary ◽

Mohsen Amini

Keyword(s):

Melting Point ◽

High Yield ◽

Purification Process ◽

Poly Ethylene Glycol ◽

Free Condition ◽

Catalyst Free ◽

Privileged Scaffold ◽

Quinazoline Derivatives ◽

Poly Ethylene ◽

Work Up

With regard to the importance of quinazoline as a privileged scaffold, herein we report the synthesis of twenty seven 2,4-disubstitute quinazoline derivatives in a new catalyst free condition. In the current work, poly ethylene glycol (PEG1000) as an inexpensive, very simple commercially available, ecofriendly and low melting point solvent was used. Air bubbling, a green oxidant, for oxidation purpose was also used. This is the first report about using PEG1000 as a solvent simultaneously with air bubbling as oxidant in quinazoline synthesis. All of the compounds 1-27 were synthesized in high yield with very simple work up and purification process without using column chromatography. All the structures were confirmed using 1H NMR, 13C NMR, IR, MS and elemental analysis.

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Non-isothermal crystallization behavior of spinel crystals in FeO-SiO2-TiO2-V2O3-Cr2O3 slag

Metallurgical Research & Technology ◽

10.1051/metal/2018033 ◽

2018 ◽

Vol 116 (1) ◽

pp. 110

Author(s):

Lixiong Shao ◽

Jiang Diao ◽

Wang Zhou ◽

Tao Zhang ◽

Bing Xie

Keyword(s):

Cooling Rate ◽

Crystallization Behavior ◽

Crystal Size ◽

Growth Mechanisms ◽

Vanadium Slag ◽

Growth Behaviour ◽

Temperature Range ◽

Chromium Spinel ◽

Mean Diameter ◽

The Mean

The growth behaviour of spinel crystals in vanadium slag with high Cr2O3 content was investigated and clarified by statistical analyses based on the Crystal Size Distribution (CSD) theory. The results indicate that low cooling rate and Cr2O3 content benefit the growth of spinel crystals. The chromium spinel crystals firstly precipitated and then acted as the heterogeneous nuclei of vanadium and titanium spinel crystals. The growth mechanisms of the spinel crystals at the cooling rate of 5 K/min consist two regimes: firstly, nucleation control in the temperature range of 1873 to 1773 K, in which the shapes of CSD curves are asymptotic; secondly, surface and supply control within the temperature range of 1773 to 1473 K, in which the shapes of CSD curves are lognormal. The mean diameter of spinel crystals increases from 3.97 to 52.21 µm with the decrease of temperature from 1873 to 1473 K.

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Combining Ability Analysis of Yield and Its Components in Cacao

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.3.509 ◽

1990 ◽

Vol 115 (3) ◽

pp. 509-512 ◽

Cited By ~ 9

Author(s):

Geok Yong Tan

Keyword(s):

Genetic Variability ◽

Combining Ability ◽

Theobroma Cacao ◽

Female Parent ◽

General Combining Ability ◽

High Yield ◽

Combining Ability Analysis ◽

The Mean ◽

Female Male Female ◽

Bean Weight

Six Trinitario females of cacao (Theobroma cacao L.) were crossed with nine Amazonian males in a factorial crossing design. The 54 hybrid progenies were used to estimate genetic variability due to general combining ability (GCA) and specific combining ability (SCA) for yield, pod production, pod weight, husk content, number of beans per pod, average bean weight, and pod value. The results demonstrated that GCA differed significantly for all characteristics from all three sources (Le., female + male, female, and male). SCA (female × male) was also significantly different for all characteristics. The ratio of GCA to SCA ranged from 7.1 for number of beans per pod to 25.7 for pod weight. This result suggested that a major portion of the genetic variability was additive in nature for these characteristics. Among the six Trinitarios, KA2-106 was the best female parent; it contributed high yield and all the desirable pod and bean characteristics into the hybrid progenies. Trinitario KA2-101 combined high pod production and yield, but tended to transmit below-average pod and bean characteristics to its progenies. Amazonians KEE6 and KEE12 were the two highest-yielding male parents, but had below-average bean number per pod and average bean weight. KEE42 and KEE43 combined high yield and transmitted good pod and bean characteristics to their progenies. Based on the GCA effects and the mean performance of the hybrid progenies, a multi-line cultivar consisting of 20 high-yielding crosses with good pod and bean characteristics is being produced in seed gardens for commercial planting.

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Evidence that Emission and Absorption Outflows in Quasars Are Related

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1142 ◽

2020 ◽

Author(s):

Xinfeng Xu ◽

Nadia L Zakamska ◽

Nahum Arav ◽

Timothy Miller ◽

Chris Benn

Keyword(s):

Electron Number Density ◽

Physical Parameters ◽

Evolutionary Stage ◽

Number Density ◽

Ionized Gas ◽

Measured Velocity ◽

Broad Absorption Line ◽

James Webb Space Telescope ◽

The Mean ◽

The One

Abstract We analyze VLT/X-shooter data for 7 quasars, where we study the relationships between their broad absorption line (BAL) and emission line outflows. We find: 1) the luminosity of the [O iii] λ5007 emission profile decreases with increasing electron number density ($n_\mathrm{\scriptstyle e}$) derived from the BAL outflow in the same quasar, 2) the measured velocity widths from the [O iii] emission features and C iv absorption troughs in the same object are similar, and 3) the mean-radial-velocity derived from the BAL outflow is moderately larger than the one from the [O iii] emission outflow. These findings are consistent with [O iii] and BAL outflows being different manifestations of the same wind, and the observed relationships are likely a reflection of the outflow density distribution. When we have outflows with smaller distances to the central source, their $n_\mathrm{\scriptstyle e}$ is higher. Therefore, the [O iii] emission is collisionally de-excited and the [O iii] luminosity is then suppressed. Comparisons to previous studies show that the objects in our sample exhibit broad [O iii] emission features similar to the ones in extremely-red-quasars (ERQs). This might imply that BAL quasars and ERQs have the same geometry of outflows or are at a similar evolutionary stage. We find that the physical parameters derived from the BAL outflows can explain the amount of observed [O iii] luminosity, which strengthens our claim that both BAL and [O iii] outflows are from the same wind. These estimates can be tested with upcoming James Webb Space Telescope, which will be able to spatially resolve some of the ionized gas outflows.

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Catalyst-Free Selective Oxidation of Diverse Olefins to Carbonyls in High Yield Enabled by Light under Mild Conditions

Organic Letters ◽

10.1021/acs.orglett.9b02569 ◽

2019 ◽

Vol 21 (19) ◽

pp. 7726-7730 ◽

Cited By ~ 6

Author(s):

Weiwei Yu ◽

Zhongkui Zhao

Keyword(s):

Selective Oxidation ◽

High Yield ◽

Mild Conditions ◽

Catalyst Free

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Evidence for Thermal Spike Effects in Ion-Irradiated Ni3Al

MRS Proceedings ◽

10.1557/proc-540-515 ◽

1998 ◽

Vol 540 ◽

Cited By ~ 3

Author(s):

M. L. Jenkins ◽

P. Mavani ◽

S. Müller ◽

C. Abromeit

Keyword(s):

Thermal Annealing ◽

Room Temperature ◽

Ion Irradiation ◽

Heavy Ion ◽

Irradiation Temperature ◽

Number Density ◽

Thermal Spike ◽

Sharp Fall ◽

Heavy Ion Irradiation ◽

The Mean

AbstractThe influence of the irradiation temperature Tirr on the development of disordered zones produced at displacement cascades in Ni3A1 by heavy-ion irradiation with 50 keV Ta+ and 300 keV Ni+ ions has been investigated. The normalised number density (yield) of disordered zones for 300 keV Ni+ irradiation showed a sharp fall between Tirr= 373 K and 573 K. For 50 keV Ni+ irradiation there was a similar fall between 573 K and 673 K. The mean diameters of the disordered zones produced by 300 keV Ni+ ions decreased by about 2 nm between room temperature and 573 K, and there was a tendency for larger zones to become more regular in shape. For 50 keV Ta+ ions, a similar trend was observed between 573 K and 873 K. An annealing experiment confirmed that disordered zones produced at lower temperatures were stable up to a temperature of about 673 K, showing that these trends cannot be due to thermal annealing of disordered zones. The experimental results are consistent with an increased tendency for reordering at the peripheries of disordered zones, due to the increased lifetimes of thermal spikes at higher irradiation temperatures.

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Large-Scale High-Yield Synthesis of PdCu@Au Tripods and the Quantification of their Luminescence Properties for Cancer Cell Imaging

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.49.85 ◽

2017 ◽

Vol 49 ◽

pp. 85-97

Author(s):

Bo Pang ◽

Xiang Xi Meng ◽

Yang Long Hou ◽

Hong Fang Sun ◽

Qiu Shi Ren

Keyword(s):

Quantum Yield ◽

Cross Section ◽

Large Scale ◽

Biomedical Application ◽

Au Nanoparticle ◽

Luminescence Properties ◽

Localized Surface Plasmon ◽

High Yield ◽

Two Photon

The synthesis of anisotropic branched gold nanoparticles remines to be challenging as their arm number and arm length could hardly be controlled, greatly limited their biomedical application. We report the large-scale high-yield synthesis of PdCu@Au tripods, and, for the first time, their two-photon luminescence properties with quantitative characterization of the two-photon action cross section as well as quantum yield. By introducing nitrogen protection to the synthesis of the PdCu bimetallic cores, this approach eliminates the oxidative etching caused by oxygen in the air, providing a 2.5 times higher synthetic yield of 70.4 %, which enables the large-scale preparation of PdCu@Au at ca. 380 mg per batch. By the conformal coating of PdCu bimetallic cores, the PdCu@Au tripods are prepared with a purity of >90 % with average arm length 45.3 ± 5.6 nm that is ideal for biomedical applications. The PdCu@Au tripods demonstrate a much brighter two-photon luminescence than that from Au nanorods, with a 3.6 ± 0.9 times larger two-photon action cross section and comparable quantum yield. Our result also shows the two-photon luminescence property of PdCu@Au tripods could be tuned by their distinct localized surface plasmon resonance property and, in turn, the different amount of Au coating. This tunability could be explained by the recently-proposed two-step excitation mechanism of two-photon luminescence in Au nanoparticle. The folate-targeted in vitro two-photon luminescence imaging of MDA-MB-435 breast cancer cells were also demonstrated to show the great potential using PdCu@Au tripods as novel multi-functional platforms for cancer theranostics.

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UV-enhanced room-temperature gas sensing of ZnGa2O4 nanowires functionalized with Au catalyst nanoparticles

Applied Physics A ◽

10.1007/s00339-013-7745-9 ◽

2013 ◽

Vol 114 (3) ◽

pp. 903-910 ◽

Cited By ~ 8

Author(s):

Sunghoon Park ◽

Soyeon An ◽

Youngho Mun ◽

Chongmu Lee

Keyword(s):

Room Temperature ◽

Gas Sensing ◽

Au Catalyst ◽

Catalyst Nanoparticles

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INTRACRANIAL ELECTROENCEPHALOGRAPHY WITH SUBDURAL GRID ELECTRODES

Neurosurgery ◽

10.1227/01.neu.0000324996.37228.f8 ◽

2008 ◽

Vol 63 (3) ◽

pp. 498-506 ◽

Cited By ~ 109

Author(s):

Jamie J. Van Gompel ◽

Gregory A. Worrell ◽

Michael L. Bell ◽

Todd A. Patrick ◽

Gregory D. Cascino ◽

...

Keyword(s):

Diagnostic Technique ◽

Partial Epilepsy ◽

High Yield ◽

Epileptogenic Zone ◽

Grid Monitoring ◽

Permanent Morbidity ◽

The Mean ◽

Intracranial Electroencephalography ◽

Intracranial Recordings

ABSTRACT OBJECTIVE Intracranial subdural grid monitoring is a useful diagnostic technique for surgical localization in patients with intractable partial epilepsy. The rationale for the present study was to assess the morbidity of intracranial recordings and the surgical outcomes. METHODS We retrospectively reviewed the clinical data for 189 unique patients undergoing 198 intracranial subdural grid monitoring sessions between 1996 and 2004 at a tertiary epilepsy center. RESULTS The mean age of patients undergoing monitoring was 28 ± 14 years. An average of 63 ± 23 electrodes were inserted. The mean duration of monitoring was 8 ± 4 days. Localization of an epileptogenic zone occurred in 156 sessions (79%) resulting in 136 resections (69%). There were 13 major complications (6.6%), including five infections and six hematomas. Three patients (1.5%) developed permanent deficits related to implantation. Sixty-two (47%) of 136 patients undergoing resection were seizure-free after resection. An additional 38 patients (28%) had a significant reduction in seizures. The mean follow-up was 51 ± 30 months. The duration of monitoring, bone flap replacement, number of electrodes, and perioperative corticosteroids were not associated with infection or complication. CONCLUSION Subdural grid monitoring for identification an epileptogenic focus is high yield, revealing a focus in 79% of monitoring sessions. Complications rarely result in permanent morbidity (1.5%). Surgical outcome indicated that 74% of patients experienced a favorable reduction in seizure tendency.

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