WERE U.S. CROP YIELDS RANDOM IN RECENT YEARS?

Crop Production/Industries,

Search for C=+C=+ charmonium and bottomonium states in e+e−→γ+Xe^+e^-\to \gamma+ X at B factories

We study the production of $C=+$ charmonium states $X$ in $e^+e^-\to \gamma + X$ at B factories with $X=\eta_c(nS)$ (n=1,2,3), $\chi_{cJ}(mP)$ (m=1,2), and $^1D_2(1D)$. In the S and P wave case, contributions of tree-QED with one-loop QCD corrections are calculated within the framework of nonrelativistic QCD(NRQCD) and in the D-wave case only the tree-QED contribution are considered. We find that in most cases the QCD corrections are negative and moderate, in contrast to the case of double charmonium production $e^+e^-\to J/\psi + X$, where QCD corrections are positive and large in most cases. We also find that the production cross sections of some of these states in $e^+e^-\to \gamma + X$ are larger than that in $e^+e^-\to J/\psi + X$ by an order of magnitude even after the negative QCD corrections are included. So we argue that search for the X(3872), X(3940), Y(3940), and X(4160) in $e^+e^-\to \gamma + X$ at B factories may be helpful to clarify the nature of these states. For completeness, the production of bottomonium states in $e^+e^-$ annihilation is also discussed.Comment: 13pages, 4 figure

Theoretical studies of 63Cu Knight shifts of the normal state of YBa2Cu3O7

The 63Cu Knight shifts and g factors for the normal state of YBa2Cu3O7 in tetragonal phase are theoretically studied in a uniform way from the high (fourth-) order perturbation formulas of these parameters for a 3d9 ion under tetragonally elongated octahedra. The calculations are quantitatively correlated with the local structure of the Cu2+(2) site in YBa2Cu3O7. The theoretical results show good agreement with the observed values, and the improvements are achieved by adopting fewer adjustable parameters as compared to the previous works. It is found that the significant anisotropy of the Knight shifts is mainly attributed to the anisotropy of the g factors due to the orbital interactions.Comment: 5 page

Laser-cooling-assisted mass spectrometry

Mass spectrometry is used in a wide range of scientific disciplines including proteomics, pharmaceutics, forensics, and fundamental physics and chemistry. Given this ubiquity, there is a worldwide effort to improve the efficiency and resolution of mass spectrometers. However, the performance of all techniques is ultimately limited by the initial phase-space distribution of the molecules being analyzed. Here, we dramatically reduce the width of this initial phase-space distribution by sympathetically cooling the input molecules with laser-cooled, co-trapped atomic ions, improving both the mass resolution and detection efficiency of a time-of-flight mass spectrometer by over an order of magnitude. Detailed molecular dynamics simulations verify the technique and aid with evaluating its effectiveness. Our technique appears to be applicable to other types of mass spectrometers.Comment: 6 pages, 4 figure

Application of Conjugable Oxidation Products Assay in Assessment of Gamma-Irradiated Palm Olein

Samples ojpalm olein were irradiated with y-rays up to 12kGy. The extent ojperoxidation in irradiated samples was determined by conjugable oxidation products (COP) assay and the result were compared with the UV absorbance at 232 nm. The two parameters were poorly correlated (r = 0.6321) within the range ofdoses used. The ifJect ofy-irradiation is mainly to oxidise linoleic acid (C18:2) as this component is the major diunsaturatedJatty acid in palm oil

Preservation of Oil Palm Fruits: Nonoxidative Effects of Ionizing Radiation on Palm Olein and Crude Palm Oil

The effect of gamma-irradiation on palm oil has been investigated. Irradiation doses (0.1 to 1 MGj') caused severe destruction of unsaturated but had little effect on saturated fatty acids. Similar effects were obsemed in irradiated samples stored for 1 and 2 months at room temperature. Radiation (uP to 30 kGy) also caused severe destruction of carotenes in crude palm oil, but had no significant effect on the free fatty acid content. These findings indicate that gamma-radiation may be used for preservation but not for sterilization of palm fruits