SPAR: stochastic programming with adversarial recourse

We consider a general adversarial stochastic optimization model. Our model involves the design of a system that an adversary may subsequently attempt to destroy or degrade. We introduce SPAR, which utilizes mixed-integer programming for the design decision and a Markov decision process (MDP) for the modeling of our adversarial phase.     

Comments on transitions in bulk tetramethyltin Sn(CH3)4 and as adsorbate on a (0001) graphite plane

In the case of tetramethyltin, whether in bulk form or in the form of an adsorbate on (0001) graphite basal plane, it was found that anomalies in the Mössbauer or X-ray diffraction parameters occur at similar temperatures, viz: 83 K, 95 K, and 125 K. It is therefore suggested that these anomalies can be associated in some way with intramolecular rearrangements and be affected by intramolecular motions.Sponsored by the U.S.-Israel Binational Science Foundation     

Low temperature anharmonicity in Sn(CH3)4 due to methyl group reorientation: A Mössbauer study

The detailed temperature variation of the Mössbauer spectral intensity in Sn(CH₃)₄ displays a pronounced drop of the Debye temperature from _D 96K below the transition temperature (T _t 43K) to _D 76K above it. The transition atT _t is discussed in terms of recent INS and NMR results where increased motion of inequivalent CH₃ groups has been observed around the temperatureT _t .Supported by the U.S.-Israel Binational Science Foundation     

Thermometric standard for continuous scale verification in thermal analysis

Ionic temperature detectors are described and discussed as possible internal temperature standards for thermal analysis and calorimetry. The available scale from 200 °C to 900 °C is shown, together with the miniature dimensions.

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Zusammenfassung Ein neuer Typ von Temperaturstandards (Ionische Temperaturdetektoren) wird beschrieben und ihre Verwendung in der thermischen Analyse und Kalorimetrie diskutiert. Hervorzuheben sind ihre geringen Abmessungen. Ein Meßbereich von 200 bis 900 °C kann abgedeckt werden.

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. , 200–900°.

     

Ullmann diaryl ether synthesis: rate acceleration by 2,2,6,6-tetramethylheptane-3,5-dione

[reaction: see text]. In the copper salt catalyzed ether formation from aryl bromides or iodides and phenols, 2,2,6,6-tetramethylheptane-3,5-dione (TMHD) was found to greatly accelerate the ordinarily difficult reaction, making it occur under more moderate temperatures and reaction times. A series of aryl halides and phenols were shown to form ethers in NMP as the solvent, cesium carbonate as the base, and CuCl and TMHD as the catalysts. The reaction was shown to tolerate electron-rich aryl bromides and electron-neutral phenols.     

Rearrangement of cyclopropyl,substituted vinyl and alkyl groups to divalent carbon.

The relative carbenic migratory abilities of cyclopropyl, β,β-dimenthylvinyl, methyl, ethyl and isopropyl group have been determined.     

Single-molecule nanopore sensing of actin dynamics and drug binding

Actin is a key protein in the dynamic processes within the eukaryotic cell. To date, methods exploring the molecular state of actin are limited to insights gained from structural approaches, providing a snapshot of protein folding, or methods that require chemical modifications compromising actin monomer thermostability. Nanopore sensing permits label-free investigation of native proteins and is ideally suited to study proteins such as actin that require specialised buffers and cofactors. Using nanopores, we determined the state of actin at the macromolecular level (filamentous or globular) and in its monomeric form bound to inhibitors. We revealed urea-dependent and voltage-dependent transitional states and observed the unfolding process within which sub-populations of transient actin oligomers are visible. We detected, in real-time, filament-growth, and drug-binding at the single-molecule level demonstrating the promise of nanopore sensing for in-depth understanding of protein folding landscapes and for drug discovery.

Nanopipettes were used for real-time investigation into actin dynamics and drug binding at single-molecule resolution, showing promise for a better understanding of the mechanism of protein–protein interactions and drug discovery.     

Intramolecular behaviors of anthryldicarbenic systems: dibenzo[b,f]pentalene and 1H,5H-dicyclobuta[de,kl]anthracene

9,10-Bis[methoxy(trimethylsilyl)methyl]anthracenes (24), synthesized from 9,10-dilithioanthracene (26) and bromomethoxytrimethylsilylmethane (27, 2 equiv), decompose (550-650 degrees C/10(-3) mmHg) carbenically to dibenzo[b,f]pentalene (28, > 48%). 9,10-Anthryldicarbenes 39 or their equivalents convert to pentalene 28 rather than di-peri-cyclobutanthracenes 30 and 31, benzobiphenylene 32, or extended rearrangement products 33-38. Formation of 28 from 24 raises questions with respect to the behavior of 1,3,4,6-cycloheptatetraenyl-1-carbenes 49, 2,4,5,7-cyclooctatetraenylidene 51, 2,5,7-cyclooctatriene-1,4-diylidene 52, 1,2,4,5,7-cyclooctapentaene 53, and bicyclo[4.1.0]heptatrienyl-1-carbenes 54 and to carbon-skeleton and hydrogen rearrangements of anthryldicarbenes 39 and/or their equivalents at various temperatures. 1,5-Bis[methoxy(trimethylsilyl)methyl]anthracenes (25), prepared from 1,5-diiodoanthracene (63) and methoxytrimethylsilylmethylzinc bromide (57, 2 equiv) as catalyzed by PdCl(2)(PPh(3))(2), yield the di-peri-carbenic reaction product 1H,5H-dicyclobuta[de,kl]anthracene (30, > 40%) on pyrolysis at 550-650 degrees C/10(-3) mmHg. Proof of structure and various aspects of the mechanisms of formation of 30 are discussed.     

Thermolysis and photolysis of 4-diazo-1,2,3-triazoles in benzenoid solvents,systems which reveal decomposition of diazo compounds to carbenes to diazo compounds to carbenes.

4-Diazo-1,2,3-triazoles thermolyze and photolyze to 4$\text{H}$-1,2,3-triazolylidenes which (1) convert benzenes to 4-phenyl-1,2,3-triazoles or/and (2) isomerize to α-diazonitriles which react carbenically with benzenes by addition, ring-expansion or substitution processes.