2,160 research outputs found
3-Hydroxy-4-(3-hydroxyphenyl)-2-quinolone monohydrate
In the title compound, also known as viridicatol monohydrate, C15H11NO3·H2O, the dihedral angle between the benzene ring and quinoline ring system is 64.76 (5)°. An intramolecular O—H⋯O hydrogen bond occurs. The crystal structure is stabilized by classical intermolecular N—H⋯O and O—H⋯O hydrogen bonds and weak π–π interactions with a centroid–centroid distance of 3.8158 (10) Å
Broadband enhancement of light harvesting in luminescent solar concentrator
Luminescent solar concentrator (LSC) can absorb large-area incident sunlight,
then emit luminescence with high quantum efficiency, which finally be collected
by a small photovoltaic (PV) system. The light-harvesting area of the PV system
is much smaller than that of the LSC system, potentially improving the
efficiency and reducing the cost of solar cells. Here, based on Fermi-golden
rule, we present a theoretical description of the luminescent process in
nanoscale LSCs where the conventional ray-optics model is no longer applicable.
As an example calculated with this new model, we demonstrate that a slot
waveguide consisting of a nanometer-sized low-index slot region sandwiched by
two high-index regions provides a broadband enhancement of light harvesting by
the luminescent centers in the slot region. This is because the slot waveguide
can (1) greatly enhance the spontaneous emission due to the Purcell effect, (2)
dramatically increase the effective absorption cross-section of luminescent
centers, and (3) strongly improve the quantum efficiency of luminescent
centers. It is found that about 80% solar photons can be ultimately converted
to waveguide-coupled luminescent photons even for a low luminescent quantum
efficiency of 0.5. This LSC is potential to construct a tandem structure which
can absorb nearly full-spectrum solar photons, and also may be of special
interest for building integrated nano-PV applications
Thermodynamics and weak cosmic censorship conjecture of the torus-like black hole
After studying the energy-momentum relation of charged particles'
Hamilton-Jacobi equations, we discuss the laws of thermodynamics and the weak
cosmic censorship conjecture in torus-like black holes. We find that both the
first law of thermodynamic as well as the weak cosmic censorship conjecture are
valid in both the normal phase space and extended phase space. However, the
second law of thermodynamics is only valid in the normal phase space. Our
results show that the first law and weak cosmic censorship conjecture do not
depend on the phase spaces while the second law depends. What's more, we find
that the shift of the metric function that determines the event horizon take
the same form in different phase spaces, indicating that the weak cosmic
censorship conjecture is independent of the phase space.Comment: 15 page
Bis(2,6-dichlorobenzyl)selane
The title molecule, C14H10Cl4Se, features a selenide bridge between two dichlorobenzyl units. The dihedral angle between the two benzene rings is 107.9 (16)°. In the crystal, weak π–π face-to-face aromatic interactions are observed [centroid–centroid distance between two adjacent (but crystallographically different) phenyl rings = 3.885 (5) Å], providing some packing stability. Short Cl⋯Cl contacts of 3.41 (2) Å are observed
BIOMECHANICAL MEASUREMENT AND EVALUATION FOR WUSU COMPULSORY PROGRAM
INTRODUCTION: The Wusu compulsory program is a new form of competition. It differs from the Wusu optional program in that all the athletes must execute the same compulsory program. Following this, judges asses the level of expertise of athletes, by scores gained, based on their performance.
The comparability and objectivity in grading a compulsory program is better than in an optional program. So it is feasible to analyze technique of the Wusu compulsory program using a biomechanical measuring method. The compulsory exercise described as, “the turn about for flying kick on the right“, was measured and analyzed quantitatively in this paper.
With the calculations from this study, a new evaluation factor and advanced development of competitive Wusu wasdeveloped
Temperature-insensitive detection of low-concentration nanoparticles using a functionalized high-Q microcavity
The ability to detect nanoparticles in extremely dilute solutions in the presence of environmental noise is crucial for biosensing applications. In this paper we propose a scheme for detecting target nanoparticles through their scattering effects in a high-Q whispering gallery microcavity. The detection signal, defined as the total linewidth broadening of the two new split modes that appear upon nanoparticle adsorption, is highly sensitive and proportional to the nanoparticle concentration. Furthermore, this new method of detection eliminates the requirement for strict temperature control and is capable of distinguishing the signal from the biorecognitions (e.g., antibodies) initially attached to the resonator and that from the target nanoparticles (e.g., antigens)
Neuroprotective Effect of Paeonol Mediates Anti-Inflammation via Suppressing Toll-Like Receptor 2 and Toll-Like Receptor 4 Signaling Pathways in Cerebral Ischemia-Reperfusion Injured Rats
Paeonol is a phenolic compound derived from Paeonia suffruticosa Andrews (MC) and P. lactiflora Pall (PL). Paeonol can reduce cerebral infarction volume and improve neurological deficits through antioxidative and anti-inflammatory effects. However, the anti-inflammatory pathway of paeonol remains unclear. This study investigated the relationship between anti-inflammatory responses of paeonol and signaling pathways of TLR2 and TLR4 in cerebral infarct. We established the cerebral ischemia-reperfusion model in Sprague Dawley rats by occluding right middle cerebral artery for 60 min, followed by reperfusion for 24 h. The neurological deficit score was examined, and the brains of the rats were removed for cerebral infarction volume and immunohistochemistry (IHC) analysis. The infarction volume and neurological deficits were lower in the paeonol group (pretreatment with paeonol; 20 mg/kg i.p.) than in the control group (without paeonol treatment). The IHC analysis revealed that the number of TLR2-, TLR4-, Iba1-, NF-κB- (P50-), and IL-1β-immunoreactive cells and TUNEL-positive cells was significantly lower in the paeonol group; however, the number of TNF-α-immunoreactive cells did not differ between the paeonol and control groups. The paeonol reveals some neuroprotective effects in the model of ischemia, which could be due to the reduction of many proinflammatory receptors/mediators, although the mechanisms are not clear
Aquabis(5-butylpyridine-2-carboxylato)zinc monohydrate
In the title complex, [Zn(C10H12NO2)2(H2O)]·H2O, the ZnII ion is coordinated by two N and two O atoms from two 5-n-butylpyridine-2-carboxylato ligands and one O atom from a water molecule in a distorted square-pyramidal geometry. In the crystal, intermolecular O—H⋯O hydrogen bonds link molecules into a two-dimensional supramolecular structure parallel to (001)
3,6,8-Trihydroxy-3,4,5,7-tetramethyl-3,4-dihydroisocoumarin
In the title compound, C13H16O5, one of the three hydroxy groups is involved in intramolecular O—H⋯O hydrogen bonds. The other two hydroxy groups contribute to the three-dimensional hydrogen-bonding network, which consolidates the crystal packing
Requirements-driven self-repairing against environmental failures
Self-repairing approaches have been proposed to alleviate the runtime requirements satisfaction problem by switching to appropriate alternative solutions according to the feedback monitored. However, little has been done formally on analyzing the relations between specific environmental failures and corresponding repairing decisions, making it a challenge to derive a set of alternative solutions to withstand possible environmental failures at runtime. To address these challenges, we propose a requirements-driven self-repairing approach against environmental failures, which combines both development-time and runtime techniques. At the development phase, in a stepwise manner, we formally analyze the issue of self-repairing against environmental failures with the support of the model checking technique, and then design a sufficient and necessary set of alternative solutions to withstand possible environmental failures. The runtime part is a runtime self-repairing mechanism that monitors the operating environment for unsatisfiable situations, and makes self-repairing decisions among alternative solutions in response to the detected environmental failures
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