One-parameter flows with the pseudo orbit tracing property

A notion of the pseudo orbit tracing property (abbr. POTP) for oneparameter flows on compact metric spaces is discussed. The strong POTP, the strong finite POTP, the normal POTP, the weak POTP and the finite POTP for flows are defined, and the relation between these POTP's is clarified; these are equivalent to each other for flows with no fixed points, but that is not true for flows with fixed points. Moreover, the following is proved; (i) The restriction to the nonwandering set of a flow with the strong POTP has the strong POTP. (ii) If an expansive flow on the nonwandering set has the finite POTP, the flow splits into the finite union of subsystems with topological transitivity. (iii) Every isometric flow with the finite POTP is minimal. (iv) The direct product of flows with the strong POTP does not necessarily have the finite POTP.     

Constitution of two coloring matters in the flower petals of CarthamusTinctorius L.

Structures of the safflower red pigment carthamin and the yellow pigment safflor yellow A are shown to be expressed by 3 and 4 respectively, mainly on the basis of spectroscopic evidence.     

Blue-to-red chromatic sensor composed of gold nanoparticles conjugated with thermoresponsive copolymer for Thiol sensing

We describe the first determination of thiol compounds with gold nanocomposites composed of gold nanoparticles and thermoresponsive copolymers having polyamino groups. The gold nanocomposites, which are used as a chromatic sensor, reveal chromatic change from blue to red with thermal stimuli, heating followed by cooling the solution. The blue-to-red chromatic change results from disassembly of the gold nanocomposites, which arises from shrinkage of the thermoresponsive copolymers bound to the gold nanoparticle surfaces due to the phase transition induced by thermal stimuli. The disassembly is inhibited by addition of thiol compounds through displacement of the adhered thermoresponsive copolymers. The detached copolymers no longer influence morphological change of the gold nanocomposites. Corresponding with increase of concentration of the thiol compounds, a solution of the gold nanocomposites after the thermal stimuli shows chromatic change, which was quantified with the a* value in L*a*b* chromatic coordinates. A linear relationship between the a* value and concentration of cysteine, examined as a bio-important thiol, is obtained below 7x10(-6) mol dm(-3), estimating a detection limit defined as 3sigma of the blank to be 2.8x10(-7) mol dm(-3). The chromatic sensor of the gold nanocomposites is applied to the determination of cysteine in commercial supplements containing ascorbic acid, which seriously interferes with redox-based determination of cysteine. Analytical results obtained with the chromatic sensor are identical to those obtained with HPLC.     

Development of the new IC decapsulation technology

An IC is generally decapsulated with wet etching technology. The influences of environment and worker's health in usage and waste of the chemicals are seen as problems. Improvement of processing time is also needed. In order to overcome them, the laser processing technology is applied to IC decapsulation. In this paper, the relationship between processing condition and the processed surface quality is reported to select a suitable laser source. In addition, the new IC decapsulation technology, which is the combination of laser and wet etching, is proposed. To achieve the complex machining, firstly, the method of measuring the reflection light intensity of the laser is proposed to estimate the residual molding thickness. Secondly, the relationship between intensity of reflected laser and mold thickness to IC is shown to construct a mold thickness monitoring system. Finally, processing time and the volume of chemical solution used a process are compared with a conventional wet etching process.     

Synthesis and characterisation of hydrido molybdenum and tungsten complexes having a hemilabile tridentate Si,Si,O-ligand: observation of stepwise hydrosilylation of a nitrile to form an N-silylimine on the metal centre

Photoinduced decarbonylation of Cp*M(CO)(3)Me (M = Mo and W, Cp* = η(5)-C(5)Me(5)) in the presence of xantsilH(2) [xantsil = (9,9-dimethylxanthene-4,5-diyl)bis(dimethylsilyl)] in pentane gave bis(silyl)hydrido complexes Cp*M(κ(2)Si,Si-xantsil)(CO)(2)(H) (1a: M = Mo and 1b: M = W) through two-fold Si-H oxidative addition and methane elimination. Further irradiation of 1a,b in toluene afforded tridentate xantsil complexes Cp*M(κ(3)Si,Si,O-xantsil)(CO)(H) (2a: M = Mo and 2b: M = W) via CO dissociation. Reactions of complexes 2a,b with nitriles led to stoichiometric hydrosilylation at the C[triple bond, length as m-dash]N triple bond. Thus, reaction of 2a,b with t-BuCN at room temperature afforded N-silyliminoacyl complexes 3a,b, through insertion of a nitrile into the M-Si bond, and the products slowly isomerised to the corresponding N-silylimine complexes 4a,bvia intramolecular hydrogen migration. On the other hand, reaction of 2a,b with PhCN afforded N-silylimine complexes 5a,b directly. The molecular structures of 1a, 3a and 5b were determined by X-ray crystallography, revealing that complex 3a has a 3-centre-2-electron (3c-2e) Mo-Si-H bond.     

Synthesis and properties of long‐chain branched poly(ether sulfone)s by self‐polycondensation of AB2 type macromonomers

Long‐chain branched poly(ether sulfone)s (PESs) were synthesized via self‐polycondensation of AB₂ macromonomers. The linear PES oligomers synthesized by self‐polycondensation of 4‐chloro‐4′‐(4‐hydroxyphenyloxy)diphenyl sulfone were terminated with 4‐(3,5‐methoxyphenoxy)‐4′‐fluorodiphenyl sulfone to form AB₂ macromonomer precursors. After conversion from methoxy to hydroxy groups, the AB₂ macromonomers were self‐polycondensed to form long‐chain branched PESs. NMR measurements support the formation of the target macromonomers ( = 2930–67,800 (g mol^?1); M_n = number average molecular weight) and long‐chain branched PESs. Gel permeation chromatography with multiangle light scattering measurements indicated the formation of high‐molecular‐weight (M_w) polymers over 10⁴. The root‐mean‐square radius of gyration (R_g) suggests that the shape of the long‐chain branched PES synthesized from small AB₂ macromonomers in solution is similar to that of hyperbranched polymers. Increasing resulted in larger R_g, suggesting a transition from hyperbranched to a linear‐like architecture in the resulting long‐chain branched PESs. Rheological measurements suggested the presence of strongly entangled chains in the long‐chain branched PES. Higher tensile modulus and smaller elongation at the break were observed in the tensile tests of the long‐chain branched PESs. It is assumed that the enhanced molecular entanglement points may act as physical crosslinks at room temperature. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1825–1831     

Retention Behavior of Purine-Like Compounds on Titania and the Effect of Organic Modifiers Content in the Mobile Phase

The retention behavior of purine and purine-like compounds on titania was investigated in order to elucidate the strong retention of purine on titania. It was verified that, as expected, the strong retention stemmed from the formation of a chelate ring using the two nitrogen atoms N3 and N9 with titania. Purine has two possible tautometric forms because of proton tautomerism between N7 and N9. Hence, the lone pair of either of the two nitrogen atoms could be located immediately in an sp² orbital. Therefore, it was found that the lone pairs of N3 and N9 must be located in an sp² orbital, and the location is essential to forming the chelate with titania. Moreover, the effect of the presence of methanol and acetonitrile in the mobile phase on retention was also investigated. The retention strength increased with their content, but the tendency of this increase was different for the two organic solvents. It was concluded that the difference stems from the differing degrees of strength of the ligands, which includes the analytes and the solvents, as a result of competing with each other. Water and methanol acted as ligands strong enough to compete with the analytes, but acetonitrile did not, probably because it lacks hydroxy groups, which have a strong affinity for titania.     

Differences of fluorine in cements determined by photometric methods after distillation and pyrolysis.

Using a spectrophotometric method after distillation separation is a standard test method widely employed for the determination of fluorine (F) in cement. Using a flow injection (FI) method after pyrolysis separation for quantification of fluorine in cement has recently been developed. Differences between the fluorine content values obtained by each method have been noted. This paper documents the differences between fluorine content (distillation F) measured spectrophotometrically after distillation and that (pyrolysis F) determined using the FI method after pyrolysis for fourteen commercial Portland cements and identifies a factor contributing to the differences between distillation F and pyrolysis F values. A highly significant relationship existed between distillation F and pyrolysis F values for fourteen cements (r(2) = 0.998, p < 0.001).