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An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
© 2015 American Chemical Society. All-solid-state Na-ion batteries that operate at or close to room temperature are a promising next-generation battery technology with enhanced safety and reduced manufacturing cost. An indispensable component of this technology is the solid-state electrolyte that allows rapid shuttling of the mobile cation (i.e., Na + ) between the cathode and anode. However, there are very few fast Na-ion conductors with ionic conductivity approaching that of the liquid counterparts (i.e., 1 mS cm -1 ). In this work, we present the synthesis and characterization of a fast Na-ion conductor, cubic Na 3 PSe 4 . This material possesses a room-temperature ionic conductivity exceeding 0.1 mS cm -1 and does not require high-temperature sintering to minimize grain boundary resistance, making it a promising solid-state electrolyte candidate for all-solid-state Na-ion battery applications. On the basis of density functional theory, nudged elastic band, and molecular dynamics investigations, we demonstrate that the framework of cubic Na 3 PSe 4 only permits rapid Na + diffusion with the presence of defects, and that the formation of the Na vacancy (charge-balanced by slight Se 2- oxidation) is more energetically favorable among the various defects considered. This finding provides important guidelines to further improve Na-ion conductivity in this class of materials.
Chemical nanosensors based on inorganic nanowires hold promise for the extremely sensitive, direct detection of pollutants, toxins and biomolecules on platforms small enough to be integrated on optoelectronic chips or even deployed in living organisms. This paper discusses two approaches to nanowire-based chemical and biological detection. First we review the development of electrically-driven nanowire gas sensors that function by an adsorbate-mediated conductivity mechanism. We then describe an alternative sensing strategy that exploits the excellent waveguiding ability of high-refractive-index nanowires to create subwavelength evanescent wave sensors that operate in solution with an optical, rather than electrical, readout.
A continuum theory for lipid membranes is developed that accounts for mechanical interactions between lipid tilt and membrane shape. For planar membranes, a linear version of the theory is used to predict tilt variations similar to those observed in experiments and molecular dynamics simulations.
The authors prove that the piecewise-linear Lorenz circuit is chaotic in the sense of Shilnikov. They first prove the existence of a heteroclinic orbit, and then prove an inequality among the eigenvalues. In addition to a detailed analysis of the piecewise linear dynamics, interval analysis is utilized to prove various inequalities. This novel approach can be applied to many other problems that require proving rigorously the existence of either a homoclinic or a heteroclinic orbit. With this proof, the piecewise-linear Lorenz circuit becomes one of the very few real physical systems where chaos has been observed by laboratory measurement, confirmed by simulation, and proved mathematically.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract The existing rules for combining peak response to individual components of ground motion are evaluated. The response values r e to two horizontal components of ground motion estimated by four multicomponent combination rules—SRSS‐, 30%‐, 40%‐ and simplified‐SRSS‐rules—are compared with the critical response, r cr , obtained by the CQC3‐rule, which takes into account the direction of the principal ground components with respect to the structural axes and provides the largest response over all possible seismic incident angles. The following results are obtained in the first part of the paper and are valid for any elastic structure and any earthquake design response spectrum: For realistic values of the ratio γ of the design spectra for the two principal components of ground motion the SRSS‐rule estimate lies between 0.79 r cr and 1.00 r cr , the Simplified‐SRSS‐rule estimate lies between 1.00 r cr and 1.26 r cr , the 40%‐rule estimate lies between 0.99 r cr and 1.25 r cr , and the 30%‐rule estimate lies between 0.92 r cr and 1.16 r cr . None of the multicomponent combination rules account for the increase in response of systems if the vibration periods of the two modes that contribute most to the response to the x ‐ and y ‐components of ground motion are close to each other. Evaluated in the second part of the paper is the accuracy of the multicomponent combination rules in estimating the response of a range of one‐storey systems with (a) symmetrical plan and (b) unsymmetrical plan, and of two multistorey buildings. The SRSS‐rule underestimates the response by up to 16% and the other three rules overestimate it by up to 18%. Although these errors appear to be smaller than the many approximations inherent in structural design, they can be eliminated with very little additional computation by using an explicit formula for the critical response based on the CQC3 rule. Copyright © 2001 John Wiley & Sons, Ltd.
<title>Abstract</title> Plastics have played a crucial role in shaping the modern era. However, they are produced almost exclusively from non-renewable feedstocks and face considerable challenges in recycling, especially crosslinked polymers used in consumer electronics, building materials, automotive parts, and aerospace composites1–3. Here, we integrate computational materials design, polymer chemistry, synthetic biology, and systems analysis into a workflow to accelerate the design of biorenewable polydiketoenamines (bioPDKs) with tailored properties and circularity through molecular engineering of their monomers, which are derived from β-keto-δ-lactones (BKDLs). Our approach leverages the modular assembly of hybrid polyketide synthases (PKSs) to enable the biosynthesis of BKDLs with diverse substituents at the γ- and δ-positions with defined stereochemistry. We exploit these features to tailor bioPDK hydrophobicity and depolymerization temperature in aqueous acid, which would be nearly impossible to do at scale using synthetic chemistry. In specific designs, we observe increases in bioPDK acidolysis above thresholds for comparable PDK materials derived from petrochemicals, which has implications for mixed-plastic and composite recycling, solvent and chemical resistance, and degradation.
Development in the WDM technologies has made multi-wavelength optical sources and components available. By combining WDM mux-demux and fast electro-optic switches, a fast configurable WDM add-drop filter can be obtained. This enables using WDM with TDM in a way that each TDM time slot is also wavelength multiplexed. Hence introducing a second dimension for switching in addition to the time dimension. This also alleviates the demanding requirement on TDM as the switching throughput increases. The number of channels that can be supported in a WDM/TDM hybrid switching system is the product of the number of time slots and the number of available wavelengths. We have done preliminary analysis on the system throughput. We will present implementation considerations of the above described systems, the give the comparison on the throughput and security sides.
The enantioselective intramolecular addition of silyl enol ethers and silyl ketene aminals onto alkyne is described. The reaction employs DTBMSegphos−Pd(II) or Binaphane−Pd(II) complexes as catalysts for the formation of methylene cyclopentane adducts from 1,6-enyne precursors. The utility of this reaction is illustrated by its application to the total synthesis of the cytotoxic cyclolaurane-type sesquiterpene, (−)-laurebiphenyl.
A simple LC circuit model recovers the surface plasmon dispersion relation. The model clearly reveals the role of kinetic inductance in shaping the dispersion and other key properties of surface plasmons.
Predation by fish (roach, Hesperoleucas symmetricus, and steelhead Oncorhynchus mykiss) produced strong cascading effects on biota associated with boulder—bedrock substrates in pools of a northern California river, but not on gravel—dwelling biota. Enclosure—exclosure experiments in the South Fork Eel River of northern California (39°44' N, 123°39'W) showed that fish, by suppressing densities of damselfly nymphs and other small predators, released algivorous chironomids (Pseudochironomus richardsoni) from predation. Chironomids in turn dramatically reduced algal standing crops. In contrast, fish had little effect on algae or invertebrates associated with gravel. Gravel—dwelling heptageniid mayflies were behaviorally inhibited from using tops of stones in fish enclosures, and stone surfaces had more chironomid tubes in fish enclosures than in fish exclosures. However, no effects on epilithic algae or densities of invertebrates comparable to those of biota on boulder—bedrock substrates were detected. These spatially varying predator effects in a river parallel results from marine benthic systems, where strong effects of large predators documented for rocky intertidal habitats and unvegetated soft bottoms are not conspicuous in seagrass beds.
Double duty for the tert-butyl residue: The bulky substituent in monomer 1 favors free-radical cyclopolymerization with maleic anhydride to give the regioregular nortricyclene copolymer 2. When the polymer is irradiated with a photoacid generator, the tert-butyl ester is cleaved and the polymer becomes soluble in aqueous base. This type of copolymer can be used in 193-nm microlithography; images with resolutions of less than 200 nm have been obtained.
