Reaction of a diphosphene with various halogens

Bis(2,4,6-tri-$\text{tert}$-butylphenyl) diphosphene reacts with various halogens to give the corresponding phosphoric dihalides, haloarene, and arene depending upon the halogen and solvent used.     

A study on the utilization of the Youden plot to evaluate proficiency test results

Methods of utilizing the Youden plot obtained from interlaboratory comparison tests are proposed. The Youden plot is a powerful tool for visually evaluating between- or within-laboratory errors. However, there are no generally applicable methods to indicate the anomalies in the between- and the within-laboratory errors in qualitative terms. An evaluation frame was therefore developed in this study as an indication method. Moreover, the Youden plot is considered to be useful for visually assessing the comprehensive performance of laboratories using two types of results. Although the confidence ellipse has been proposed in ISO 13528:2005 for this purpose, robust determination of the parameters has not yet been implemented. In the present study, robust determination of one of the parameters, the correlation coefficient, was developed. Our proposals were analytically validated using two types of statistical models. In addition, the properties were evaluated through computational simulations. From the results obtained, it can be concluded that our proposals are practically applicable to actual interlaboratory comparison tests.     

Detecting a sodium chloride ion pair in ice using terahertz time-domain spectroscopy.

The hydrogen bond resonance of a sodium chloride (NaCl) ion pair trapped in aqueous ice has been observed by transmission terahertz time-domain spectroscopy. The absorption peak of a sodium chloride ion pair in ice is 1.65 THz at 83 K. By investigating the interaction of the cation and anion with other chemical compounds, we deduce that the absorption peak originates from the hydrogen bond resonance of sodium chloride and water molecules. The charge redistribution that occurs when other ion pairs are added to aqueous salt solution changes the absorption spectrum. Furthermore, the results also indicate that simple molecules such as sodium halides have fingerprints in the terahertz region when the ions are trapped in ice. NaCl ion pairs in seawater and in Ringer's solution were examined.     

Construction of a portfolio with shorter downside tail and longer upside tail

The purpose of this paper is to propose an algorithm for solving Rachev ratio optimization problem which is intended to construct a portfolio with shorter downside tail and longer upside tail. Moreover, we propose modified Rachev ratio to remove the theoretical flaw of Rachev ratio. Also, we will compare several portfolio models using the market data in Tokyo Stock Exchange. We believe that this paper is of interest to researchers and practitioners in the field of portfolio optimization.     

Maxwell speed distribution and analogue Hawking–Unruh temperature in an ontological model of a Harmonic oscillator ground state

Within an ontological (hidden variable) model of quantum fluctuation, one can discuss the actual   properties of a system regardless (independent) of measurement. Here we apply an ontological model proposed earlier to investigate a Harmonic oscillator in the quantum mechanical ground state. We first show that the actual speed of the oscillator fluctuates randomly following the Maxwell–Boltzmann distribution. On the other hand, the actual energy obeys a broad Gamma distribution with an average 3?ω/2$3?\omega /2$, where ω$\omega$ is the classical angular frequency, so that one may conclude that the outcome of a single energy measurement reveals the average of the actual energy. The distribution of actual speed (energy) thus formally resembles the distribution of speed (energy) of an ideal gas in thermal equilibrium of temperature T_g=?ω/2$T_g=?\omega /2$. We shall then argue that T_g$T_g$ can be written in a form analogous to the Hawking temperature for a Schwarzschild black hole in which the average distance of the oscillator from the origin plays the analogous role of the radius of the black hole event horizon. It can also be written in a form analogous to the Unruh temperature experienced by a body moving with a uniform acceleration. In the analogy, the oscillator suffers an effective acceleration which balances the attractive force of the trapping Harmonic potential, thus keeps its average position away from the origin.     

An efficient and versatile synthesis of all structural types of acylpolyamine spider toxins

An efficient and versatile synthesis of acylpolyamine spider toxins of all structural types classified by extensive MS analysis has been achieved. By using 2-nitrobenzenesulfonamide as an effective activating and/or protecting group (the Nosyl strategy), the naturally occurring toxins 1-8 corresponding to Types A-F were concisely synthesized in high overall yield.     

Polymerization initiated by the charge-transfer complex of styrene and maleic anhydride in the presence of cumene and of cumene and liquid sulfur dioxide

A polymerization was induced with a charge-transfer type of complex consisting of styrene and maleic anhydride in the presence a solvent such as ethyl benzene, cumene, or p-cymene. No polymer was obtained either when the solvent was missing from the polymerization system or when benzene, toluene, or xylene, which are relatively stable to hydrogen abstraction, was added to the polymerization system. An effective initiation, however, took place when cumene or p-cymene, each of which has a labile hydrogen on an α carbon, was added. On the basis of elementary analysis and infrared spectroscopy the formation of copolymer containing substantially equimolar amounts of styrene and maleic anhydride was ascertained. This polymerization was inhibited by the addition of DPPH, suggesting that the system styrene–maleic anhydride–cumene functions much as a conventional free-radical initiator. On the other hand, when a solution of cumene and liquid sulfur dioxide was added to the polymerization system, polystyrene was obtained. This polymerization was inhibited by the addition of a base such as dimethyl-formamide or dimethyl sulfoxide, indicating that the polymerization proceeds through carbonium ion intermediates. The addition of ethyl benzene or of p-cymene brought about the same result as cumene. It is conceivable that the polymerization is induced by the abstraction of hydrogen attached at the α position of cumene by means of the charge-transfer complex of styrene and maleic anhydride.