Triviality of the ground-state metastate in long-range Ising spin glasses in one dimension

We consider the one-dimensional model of a spin glass with independent Gaussian-distributed random interactions, that have mean zero and variance $1/|i-j|^{2\sigma}$, between the spins at sites $i$ and $j$ for all $i\neq j$. It is known that, for $\sigma>1$, there is no phase transition at any non-zero temperature in this model. We prove rigorously that, for $\sigma>3/2$, any Newman-Stein metastate for the ground states (i.e.\ the frequencies with which distinct ground states are observed in finite size samples in the limit of infinite size, for given disorder) is trivial and unique. In other words, for given disorder and asymptotically at large sizes, the same ground state, or its global spin flip, is obtained (almost) always. The proof consists of two parts: one is a theorem (based on one by Newman and Stein for short-range two-dimensional models), valid for all $\sigma>1$, that establishes triviality under a convergence hypothesis on something similar to the energies of domain walls, and the other (based on older results for the one-dimensional model) establishes that the hypothesis is true for $\sigma>3/2$. In addition, we derive heuristic scaling arguments and rigorous exponent inequalities which tend to support the validity of the hypothesis under broader conditions. The constructions of various metastates are extended to all values $\sigma>1/2$. Triviality of the metastate in bond-diluted power-law models for $\sigma>1$ is proved directly.Comment: 18 pages. v2: subsection on bond-diluted models added, few extra references. 19 pages. v3: published version; a few changes; 20 page

A multifunctional azobenzene-based polymeric adsorbent for effective water remediation

The efficient removal of trace carcinogenic organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs) and ionic dyes, from water is an important technical challenge. We report a highly effective recyclable multifunctional azobenzene (AZ)-based silica-supported polymeric adsorbent which can simultaneously remove both PAHs and anionic dyes from water to below parts per billion (ppb) level based on multiple interactions such as the hydrophobic effect, [pi]–[pi] stacking and electrostatic interactions, thus providing a new strategy for designer water remediation materials

Supplementary document for Real-time Imaging of Electromagnetic Fields - 5853050.pdf

Real-time Imaging of Electromagnetic Fields: Supplemental Documen

Searching correlated patterns from graph streams

© 2013 IEEE. Mining the correlation has attracted widespread attention in the research community because of its advantages in understanding the dependencies between objects. In this paper, a correlated graph pattern searching scheme has been proposed, that is, provided with a query g as a structured pattern (i.e., a graph), our algorithm is capable of retrieving the top- k graphs that most likely correlated with g. Traditional methods treat graph streams as static records, which is computational infeasible or ineffective because of the complexity of searching correlated patterns in a dynamic graph stream. In this paper, by relying on sliding windows to separate graph streams in chunks, we propose a Hoe-PGPL algorithm to handle the top- k correlated patterns searching from a dynamic perspective. Our algorithm applies Hoeffding bound and two-level (Sliding window level and local batch level) candidate inspection to discover potential graph candidates and determine the similarity of these candidates without double-checking the previous stream. Theoretical analysis shows that our method can guarantee the quality of the returned answers, and our experiments also present that Hoe-PGPL has an excellent performance with aspects of precision, recall, runtime, and resource consumption.</p

Dendritic Molecular Template Mediates and Directs Self-Assembly of Uniform Gold Nanoclusters to One-Pot Afford 3D-Supported Active Catalysts

Uniform gold nanoclusters (AuNCs) are hardly available unless through abundant strong ligands (at the cost of low catalytic activity and narrow catalytic spectrum) or through well-defined (but expensive) templates, and it appears a tougher challenge for direct preparing supported and uniform AuNCs. Here, we show that with an amphiphilic and dendritic molecular template in hand, highly catalytically active, uniform, and supported AuNCs are one-pot achievable. Branched polyethylenimine (PEI) is modified with a few thioether groups and alkylated with hydrophobic acetyls and polystyrene chains to afford reverse micelle-like dendritic polymers. The structurally optimized dendritic polymer can act as a surfactant to mediate very stable water-in-oil high internal phase emulsion (HIPE) within a wide pH spectrum. Moreover, the dendritic polymer switches into the unimolecular state along the interface of the HIPE when pH is below 6, which is critical to the formation of uniform AuNCs. Experimentally, upon the transformation of HIPE into an open-cellular polyHIPE, the gold ions are simultaneously transformed into AuNCs. Direct preparation of the supported and uniform AuNCs (1.8 ± 0.2 nm) are feasible because the dendritic polymer can simultaneously act as a surfactant, a polymer ligand, and a unimolecular template. Meanwhile, the trace thioether groups in the PEI core reduce the size of AuNCs by enhancing nucleation of AuNCs since in the absence of thioether groups, larger particles are obtained. The supported AuNCs are catalytically active because they are stabilized by weak coligands. For the model reaction of the catalyzed reduction of 4-nitrophenol, the catalyst shows a turnover frequency of 112.5 h–1, which is very high. The catalyst is durable and well recyclable

Two-Photon Ratiometric Fluorescence Probe with Enhanced Absorption Cross Section for Imaging and Biosensing of Zinc Ions in Hippocampal Tissue and Zebrafish

Zinc ion (Zn²⁺) not only plays an important function in the structural, catalytic, transcription, and regulatory of proteins, but is also an essential ionic signal to regulate brain neurotransmitters pass process. In this work, we designed and synthesized an intramolecular charge transfer-based ratiometric two-photon fluorescence probe, P–Zn, for imaging and biosensing of Zn²⁺ in live cell, hippocampal tissue, and zebrafish. The developed probe demonstrated high two-photon absorption cross section (δ) of 516 ± 77 GM, which increased to 958 ± 144 GM after the probe was coordinated with Zn²⁺. Furthermore, this P–Zn probe quickly recognized Zn²⁺ with high selectivity, over other metal ions, amino acids, and reactive oxygen species. More interestingly, the initial emission peak of the present probe at 465 nm decreased with a new peak increased at 550 nm, leading to the ratiometric determination of Zn²⁺ with high accuracy. Finally, this two-photon fluorescence probe with high temporal resolution and remarkable analytical performance, as well as low-cytotoxicity, was successfully applied in imaging of live cells, hippocampal tissues, and zebrafishes. The present P–Zn probe combined with FLIM provided accurate mapping of Zn²⁺ distribution at single-cell level. More interestingly, the two-photon spectroscopic results demonstrated that the level of Zn²⁺ in hippocampal tissue of mouse with AD was higher than that in normal mouse brain

Dendritic Amphiphile Mediated One-Pot Preparation of 3D Pt Nanoparticles-Decorated PolyHIPE as a Durable and Well-Recyclable Catalyst

Straightforward organization of platinum nanoparticles (PtNPs) onto a macroscopic and robust material is described. PtNPs are in situ produced and stabilized by a dendritic amphiphile, where the latter consists of a hyperbranched polyethylenimine (PEI) as core and poly­(styrene-co-2-ethylhexyl acrylate (P­(St-EHA)) as shell. The resulting Pt@PEI@P­(St-EHA), upon mixing with biphasic water and oil (a mixture of EHA and a dimethacrylate cross-linker in toluene), can self-assemble along the water/oil (W/O) interface and result in a stable emulsion. At W/O = 80/20 (volume ratio), a high internal phase emulsion (HIPE) forms and can be radically transformed into an open-cellular and elastic monolith termed Pt-polyHIPE, with PtNPs decorated on the surface. The Pt-polyHIPE is mechanically robust, and the cross-linking homogeneity by the dimethacrylate is responsible for the strength. The Pt-polyHIPE shows an active catalytic property, as evaluated by reduction of 4-nitrophenol. The material is conveniently and well recyclable, showing no decrease in catalytic activity at least within 20 cycles. Energy-dispersive X-ray spectra and thermogravimetric analysis also support sufficient retaining of the Pt species, where the multivalent and multiligand PEI should be responsible for this property

Heteroatom/Heterocycle-Substituted Ketone Dyes as Efficient Photoinitiators in Visible Light-Emitting Diode/Near Infrared Light Photopolymerization with Enhanced Two-Photon Lithography Capability

Photopolymerization is a burgeoning technology with a wide range of applications from coatings and inks to nanotechnology. The development of photosensitized systems that can work at long wavelengths with safety and environmental friendliness, such as visible light-emitting diodes and near infrared light, is essential. In this study, a series of ketone dyes containing heteroatom/heterocyclic substituents were designed on the basis of the carbazole–coumarin backbone to compare with aryl ring-substituted ones. The photophysical and photochemical properties of the dyes were studied by UV–vis spectroscopy, time-dependent density functional theory calculations, fluorescence spectroscopy, and steady-state photolysis. The potential application of dyes in one/two-photon polymerization was investigated. Results showed that the introduction of heterocycles/heteroatoms has a considerable influence on the absorption and polymerization properties of dyes. CCK–Th, which contains a thiophene substitute, exhibits the most excellent light absorption properties as well as the fastest reaction efficiency with amine additives. Notably, when comparing the two-photon lithography capability, the photoresist containing 0.1 wt % CCK–Th, which can achieve a writing speed of 46 mm s–1, exhibits high two-photon sensitivity, about two times that of the benzene ring-substituted CCK–Ben. In addition, CCK–Th shows outstanding ability to construct complex three-dimensional patterns. These modified CCKs show great application potential in nanotechnology, additive manufacturing, and optoelectronics and provide design concepts for the development of photoinitiators