Nuclear quantum effect on the hydrogen-bonded structure of guanine�Ccytosine pair

The structure of Watson?CCrick type guanine?Ccytosine (G?CC) base pair has been studied by classical hybrid Monte Carlo (HMC) and quantum path integral hybrid Monte Carlo (PIHMC) simulations on the semiempirical PM6 potential energy surface. For the three NH?X hydrogen-bonded moieties, the intramolecular NH bonds are found systematically longer while the H?X distance shorter in the PIHMC simulation than in the HMC simulation. We found that the hydrogen bonded length N?X correlates with the H?X distance, but not with the NH distance. A correlation is also between the neighboring hydrogen bonds in the G?CC base pair.     

Size-controlled deposition of Ag nanoparticles on alumina with the assistance of a photo-induced chromic reaction, and study of their catalytic properties

This paper describes a promising method to synthesize supported metal catalysts based on a photochromic reaction. Highly dispersed Ag nanoparticles (NPs) with a mean diameter of ca. 10 nm stabilized by 3-mercaptopropionic acid (3-MPA) were prepared as a colloidal precursor solution. The zeta electric potential was found to be negatively charged in the region of pH higher than 5 due to the presence of dissociated carboxylate ions (-COO(-)), which led to electric repulsion between Ag NPs and kept the solution in a highly dispersed colloidal state. In the presence of photochromic molecules, trans-2-hydroxychalcone, the photo-irradiation gradually decreased the electric charge on the nanoparticles owing to the formation of flavylium cations, which induced the assembly of Ag NPs. Such photo-induced assembly-dispersion control of Ag NPs enables size selective deposition on a catalyst support, which is controlled by varying the photo-irradiation time.     

Four-nucleon pickup reaction on 12 ⩽ A ⩽ 94 nuclei

The differential cross sections for the (d, ⁶Li) reaction on targets of ¹²C, ¹⁶O, ²⁴Mg, ⁴⁰Ca, ⁵⁸Ni and ⁹⁴Mo have been measured at E_d = 54.2 MeV. The measured angular distributions have been analyzed by finite-range DWBA calculations, and spectroscopic factors for an α-cluster transfer have been extracted. In the DWBA analysis using an optical model with a phenomenological Woods-Saxon potential, the spin-orbit part of the deuteron optical potential played a significant role in reproducing the measured angular distributions but the spin-orbit part of the ⁶Li optical potential had a minor effect. Relative spectroscopic factors extracted from the present data were compared with theoretical predictions together with the results from the (p, pα) reaction. The relative spectroscopic factors for 1p-shell nuclei were in quantitative agreement with theoretical predictions. However, there were certain discrepancies between the spectroscopic factors extracted from the (d, ⁶Li) reaction and those from the (p, pα) reaction, and the discrepancies increased with target mass number.     

Polymorphism of ZnTe at elevated pressure

Simultaneous measurements of the electrical resistance and X-ray diffraction under pressure have revealed that ZnTe exhibits two subsequent structural transitions at approximately 85 and 130 kbar, accompanied by a conspicuous rise and drop in the resistance, respectively.     

Rheological behavior in water of complexes formed from poly(sodium 2-(acrylamido)-2-methylpropanesulfonate) and positively charged rodlike micelles

The viscoelastic behavior of aqueous solutions of an ionic complex formed from poly(sodium 2-(acrylamido)-2-methylpropanesulfonate) and rodlike mixed micelles of dimethyloleylamine oxide (DMOAO) and hexadecyltrimethylammonium chloride (CTAC) was investigated under oscillatory conditions. The DMOAO/CTAC mixed micelles exhibited high zero-shear viscosities (eta0) depending on the mole fraction of CTAC in the mixed micelle (Y) in the range 0Y0.25. The addition of the polyanion had no effect on the rheological behavior of the mixed micelles when Y<0.02 at an ionic strength (mu) of 0.2. However, when Y was increased to a certain level (Yc), eta0 decreased drastically; Yc depended on mu but not on the polymer concentration. These observations indicate the formation of an ionic complex between the polymer and micelle when YYc. The reciprocal of steady-state compliance (Je(-1)) began to decrease gradually at Y approximately Yc and then leveled off at Y>0.06. The relaxation time (tau) was found to be more strongly dependent on Y. Thus, the large decrease in eta0 was attributed mainly to a decrease in tau while the number density of junctions decreased only slightly. Therefore, it is concluded that polymer-micelle complex maintains a rodlike structure with some entanglements remaining at Y<0.12.     

Crystal-face dependence and photoetching-induced increases of dye-sensitized photocurrents at single-crystal rutile TiO2 surfaces

Dye-sensitized photocurrents at (100)-, (001)-, and (110)-cut TiO(2) rutile surfaces were increased by photoetching of TiO(2), but the increasing ratio strongly depended on the cut crystal faces and the illumination intensity for the photoetching. For the (110)-cut surface, the photocurrent increase was moderately large and in proportion to the increase in the surface area of TiO(2) induced by the photoetching, irrespective of the illumination intensity for the photoetching. On the other hand, the photocurrent increases for the (001)- and (100)-cut surfaces, especially that for the (001)-cut surface, were prominent and largely exceeded the increases in the surface area. The results were explained by taking into account the following factors: (1) The (001)- and (100)-cut surfaces were thermodynamically unstable in contrast to the (110)-cut surface and had thicker inactive surface layers (or higher densities of surface defects), produced by surface reconstruction during heat treatment of TiO(2) at 550 degrees C in a hydrogen atmosphere for getting n-type semiconductivity. (2) Photoetching not only increased the surface area through formation of nanoholes and grooves at the surface but also effectively removed the thin inactive surface layers (or surface defects).     

Generic Initial Ideals,Graded Betti Numbers,and k-Lefschetz Properties

We introduce the k-strong Lefschetz property and the k-weak Lefschetz property for graded Artinian K-algebras, which are generalizations of the Lefschetz properties. The main results are:

1. Let I be an ideal of R = K[x ₁, x ₂,…, x _n ] whose quotient ring R/I has the n-SLP. Suppose that all kth differences of the Hilbert function of R/I are quasi-symmetric. Then the generic initial ideal of I is the unique almost revlex ideal with the same Hilbert function as R/I.

2. We give a sharp upper bound on the graded Betti numbers of Artinian K-algebras with the k-WLP and a fixed Hilbert function.