101 research outputs found
Aqua(benzamidato-κN)bis[3,5-difluoro-2-(pyridin-2-yl)phenyl-κC 1]iridium(III) methanol monosolvate
In the title compound, [Ir(C11H6F2N)2(C7H6NO)(H2O)]·CH3OH, the IrIII ion adopts an octahedral geometry, and is coordinated by two 3,5-difluoro-2-(pyridin-2-yl)phenyl ligands, one molecule of water and one benzamidate anion. The two 2-(4,6-difluorophenyl)pyridyl ligands are arranged in a cis-C,C′ and trans-N,N′ fashion. Additionally, there is a bystanding methanol molecule outside the coordination sphere of the IrIII ion. In the crystal, molecules of the title compound are linked by O—H⋯O and O—H⋯N hydrogen bonds. One F atom of each ligand is equally disordered over two sites. The C atom of the solvent molecule is likewise disordered over two sites in a 0.589 (11):0.411 (11) ratio
Aqua[N-(1-naphthyl)acetamido-κN]bis[2-(2-pyridyl)phenyl-κ2 N,C 1]iridium(III) ethylene glycol hemisolvate
In the title compound, [Ir(C11H8N)2(C12H10NO)(H2O)]·0.5C2H6O2, the iridium center is coordinated by two N atoms and two C atoms from two 2-(2-pyridyl)phenyl (ppy) ligands, one N atom from the N-(1-naphthyl)acetamide ligand and one water O atom, forming a distorted octahedral environment. Molecules are linked by intermolecular O—H⋯O hydrogen bonds formed by the coordinated water molecule and the amide O atom of the N-(1-naphthyl)acetamide ligands
(E)-N,N′-Bis(2,6-dimethylphenyl)-N,N′-bis(trichlorosilyl)ethylene-1,2-diamine
The asymmetric unit of the title compound, C18H20Cl6N2Si2, contains one half of the centrosymmetric molecule. The two benzene rings are perpendicular to the plane of Si–N–C=C–N–Si fragment, making a dihedral angle of 89.9 (1)°. The crystal packing exhibits short intermolecular Cl⋯Cl contacts of 3.3119 (17) Å
Holistic Strategies Lead to Enhanced Efficiency and Stability of Hybrid Chemical Vapor Deposition Based Perovskite Solar Cells and Modules
Hybrid chemical vapor deposition (HCVD) is a promising method for the up-scalable fabrication of perovskite solar cells/modules (PSCs/PSMs). However, the efficiency of the HCVD-based perovskite solar cells still lags behind the solution-processed PSCs/PSMs. In this work, the oxygen loss of the electron transport layer of SnO2 in the HCVD process and its negative impact on solar cell device performance are revealed. As the counter-measure, potassium sulfamate (H2KNO3S) is introduced as the passivation layer to both mitigate the oxygen loss issue of SnO2 and passivate the uncoordinated Pb2+ in the perovskite film. In parallel, N-methylpyrrolidone (NMP) is used as the solvent to dissolve PbI2 by forming the intermediate phase of PbI2•NMP, which can greatly lower the energy barrier for perovskite nucleation in the HCVD process. The perovskite seed is employed to further modulate the kinetics of perovskite crystal growth and improve the grain size. The resultant solar cells yield a champion power conversion efficiency (PCE) of 21.98% (0.09 cm2) with a stable output performance of 21.15%, and the PCEs of the mini-modules are 16.16% (22.4 cm2, stable output performance of 14.72%) and 12.12% (91.8 cm2). Furthermore, the unencapsulated small area device shows an outstanding operational stability with a T80 lifetime exceeding 4000 h.journal articl
Topology hierarchy of transition metal dichalcogenides built from quantum spin Hall layers
The evolution of the physical properties of two-dimensional material from
monolayer limit to the bulk reveals unique consequences from dimension
confinement and provides a distinct tuning knob for applications. Monolayer
1T'-phase transition metal dichalcogenides (1T'-TMDs) with ubiquitous quantum
spin Hall (QSH) states are ideal two-dimensional building blocks of various
three-dimensional topological phases. However, the stacking geometry was
previously limited to the bulk 1T'-WTe2 type. Here, we introduce the novel
2M-TMDs consisting of translationally stacked 1T'-monolayers as promising
material platforms with tunable inverted bandgaps and interlayer coupling. By
performing advanced polarization-dependent angle-resolved photoemission
spectroscopy as well as first-principles calculations on the electronic
structure of 2M-TMDs, we revealed a topology hierarchy: 2M-WSe2, MoS2, and
MoSe2 are weak topological insulators (WTIs), whereas 2M-WS2 is a strong
topological insulator (STI). Further demonstration of topological phase
transitions by tunning interlayer distance indicates that band inversion
amplitude and interlayer coupling jointly determine different topological
states in 2M-TMDs. We propose that 2M-TMDs are parent compounds of various
exotic phases including topological superconductors and promise great
application potentials in quantum electronics due to their flexibility in
patterning with two-dimensional materials
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Role of emission controls in reducing the 2050 climate change penalty for PM2.5 in China
Previous studies demonstrated that global warming can lead to deteriorated air quality even when anthropogenic emissions were kept constant, which has been called a climate change penalty on air quality. It is expected that anthropogenic emissions will decrease significantly in the future considering the aggressive emission control actions in China. However, the dependence of climate change penalty on the choice of emission scenario is still uncertain. To fill this gap, we conducted multiple independent model simulations to investigate the response of PM2.5 to future (2050) climate warming (RCP8.5) in China but with different emission scenarios, including the constant 2015 emissions, the 2050 CLE emissions (based on Current Legislation), and the 2050 MTFR emissions (based on Maximum Technically Feasible Reduction). For each set of emissions, we estimate climate change penalty as the difference in PM2.5 between a pair of simulations with either 2015 or 2050 meteorology. Under 2015 emissions, we find a PM2.5 climate change penalty of 1.43 μg m−3 in Eastern China, leading to an additional 35,000 PM2.5-related premature deaths [95% confidence interval (CI), 21,000-40,000] by 2050. However, the PM2.5 climate change penalty weakens to 0.24 μg m−3 with strict anthropogenic emission controls under the 2050 MTFR emissions, which decreases the associated PM2.5-related deaths to 17,000. The smaller MTFR climate change penalty contributes 14% of the total PM2.5 decrease when both emissions and meteorology are changed from 2015 to 2050, and 24% of total health benefits associated with this PM2.5 decrease in Eastern China. This finding suggests that controlling anthropogenic emissions can effectively reduce the climate change penalty on PM2.5 and its associated premature deaths, even though a climate change penalty still occurs even under MTFR. Strengthened controls on anthropogenic emissions are key to attaining air quality targets and protecting human health in the context of future global climate change
Forced Notch Signaling Inhibits Commissural Axon Outgrowth in the Developing Chick Central Nerve System
BACKGROUND: A collection of in vitro evidence has demonstrated that Notch signaling plays a key role in the growth of neurites in differentiated neurons. However, the effects of Notch signaling on axon outgrowth in an in vivo condition remain largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the neural tubes of HH10-11 chick embryos were in ovo electroporated with various Notch transgenes of activating or inhibiting Notch signaling, and then their effects on commissural axon outgrowth across the floor plate midline in the chick developing central nerve system were investigated. Our results showed that forced expression of Notch intracellular domain, constitutively active form of RBPJ, or full-length Hes1 in the rostral hindbrain, diencephalon and spinal cord at stage HH10-11 significantly inhibited commissural axon outgrowth. On the other hand, inhibition of Notch signaling by ectopically expressing a dominant-negative form of RBPJ promoted commissural axonal growth along the circumferential axis. Further results revealed that these Notch signaling-mediated axon outgrowth defects may be not due to the alteration of axon guidance since commissural axon marker TAG1 was present in the axons in floor plate midline, and also not result from the changes in cell fate determination of commissural neurons since the expression of postmitotic neuron marker Tuj1 and specific commissural markers TAG1 and Pax7 was unchanged. CONCLUSIONS/SIGNIFICANCE: We first used an in vivo system to provide evidence that forced Notch signaling negatively regulates commissural axon outgrowth
Four new species of Phyllomyza Fallén from China (Diptera, Milichiidae)
Xi, Yuqiang, Yang, Ding (2013): Four new species of Phyllomyza Fallén from China (Diptera, Milichiidae). Zootaxa 3718 (6): 575-582, DOI: 10.11646/zootaxa.3718.6.
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