1,280 research outputs found

    Cross Breeding and Hybrid Identification of Sulphite-tolerant Hybrids of Saccharomyces uvarum

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    Yeast species belonging to Saccharomyces have great potential for the wine industry. However, the sulphite tolerance of most S. uvarum strains is quite poor compared with that of the other Saccharomyces strains. Inorder to get new S. uvarum strains with tolerance to sulphite, and also with good fermentation characteristics, 21 candidates were screened from three different crossing combinations of sensitive S. uvarum strains to one sulphitetolerant strain. Ten of these hybrids were sulphite tolerant and contained the FZF1 gene from both parents. Intersimple sequence repeat (ISSR) analysis confirmed their hybrid status, based on six primers that produced 55 clear and reproducible bands, including 32 that were polymorphic. Two hybrids had identical fingerprints, indicating that it was the same clone. Thus, nine different novel sulphite-resistant hybrids of S. uvarum were obtained. The selected hybrid strains fermented very well at 30ºC in Sauvignon Blanc grape juice containing 2 mM of sodium sulphite, with minor differences in fermentation performance. Two strains (namely C13 and C21) performed very similarly to the sulphite-tolerant parent A9 and a commercial S. cerevisiae strain EC1118, and the production offermentation aromas, namely propanol, isobutanol and isoamyl alcohol by C13 was found to be the highest. This is the first report of using hybridisation to breed the sulphite-tolerant S. uvarum strains

    Environmental Policy Analysis for Water Management in Lanzhou City

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    AbstractHuman activities significantly influence the integrality of ecosystems.Water plays a crucial role in ecosystems.In the last two decades,due to the over development of Lanzhou City,water environment becomes serious which is not compliance with the policy of sustainable development required by the local government.The existing policies and regulations related to water management in Lanzhou City is re-visited first in this paper.This includes the analysis of surface water and groundwater, investigation of current policies and regulations used for water management and their effects on water quality change, identification of the current problems resulting in water deterioration. Once the weaknesses of current environmental policies and regulations are figured out, they will be used to development of a comprehensive management system from the point of views engineering,legislative and social science.Finally nine corresponding implementation and management strategies based on this research are presented and will be reported to the local government

    Reworked Precambrian metamorphic basement of the Lhasa terrane, southern Tibet: Zircons/Titanite U-Pb geochronology, Hf isotope geochemistry

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    Due to the paucity of exposure, the formation and evolution of the Precambrian basement of the Lhasa terrane remain poorly known. Here we report zircon and titanite in situ U–Pb ages, bulk-rock geochemical and zircon Hf isotopic data on the orthogneisses from the Dongjiu area of the southern Lhasa subterrane (SLT), southern Tibet. Geochemical data suggest that the protoliths of the biotite-amphibole gneiss and biotite gneiss are granodiorite and granite, respectively. Inherited magmatic zircon cores from these orthogneisses give protolith crystalline ages of 1520–1506 Ma, whereas the overgrown zircon rims give metamorphic ages of 605–590 Ma. The Mesoproterozoic granitic rocks have bulk-rock εNd(t) values of −3.6 to +0.1 and zircon core εHf(t) values of −4.5 to +2.6, which give similar TDM2 ages of 2.35–2.05 Ga and 2.54–2.10 Ga respectively, suggesting their derivation from partial melting of Paleoproterozoic crustal material. The granitic rocks are also local provenance for the Mesoproterozoic detrital zircons in the Paleozoic strata in the Lhasa terrane. Titanite in situ U–Pb ages further indicate that the Dongjiu orthogneiss experienced more recent metamorphism at ~26 Ma. The mineral assemblage and thermobarometry calculations indicate that the Oligocene metamorphism occurred under medium-pressure (MP) amphibolite-facies conditions (5.4–7.2 kbar, 691–765 °C). We propose that the Dongjiu gneisses represent the Precambrian metamorphic basement of the Lhasa terrane, but have been intensively reworked by metamorphism in the SLT in response to the continued India-Asia convergence since the collision

    Deriving Effective Energy Loss Function for Silver from XPS Spectrum

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    AbstractXPS spectra of silver excited by synchrotron irradiation with energy same as Al Kα X-ray has been measured. After filtering spectrum noise, the inelastic background starting from the lower binding energy of photoelectrons is removed by an iteration procedure. The energy loss spectrum for a single sub-shell photoelectron is then extracted from the Ag 3p XPS spectrum. Based on this single sub-shell photoelectron energy loss spectrum the effective energy loss function (EELF) is obtained by the extended Landau approach. Monte Carlo simulation with the derived EELF can reproduce well the experimental XPS spectrum

    Degradation of Inorganic Nitrogen in Beiyun River of Beijing, China

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    AbstractNitrogen pollution characteristics of Beiyun River and the migration of inorganic nitrogen in sediment-water were studied using laboratory experiment. Extract NH4-N was the dominant pollutants in Beiyun River that caused the severe harm to aquatic system. NH4-N exchange in sediment-water system was observable at different sites. The calculating of NH4-N degradation coefficients showed there was little difference of NH4-N degradation rate at three sites of Beiyun River. Nitrification process was mainly occurred in 12 days and NH4-N can rapidly in the degradation without input

    A nondiagrammatic calculation of the Rho parameter from heavy fermions

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    A simple nondiagrammatic evaluation of the nondecoupling effect of heavy fermions on the Veltman's Rho parameter is presented in detail. This calculation is based on the path integral approach, the electroweak chiral Lagrangian formalism, and the Schwinger proper time method.Comment: 11 page

    Criss-crossing Laser Beams Zoom Electrons Along

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    Crossing two high-intensity laser beams in a plasma (a collection of charged particles) can have some interesting effects. In a recent experiment performed by researchers at the University of Michigan and the Institute of Physics in China, energy from a higher-power laser pulse was transferred to a lower-power laser pulse. The lower-power pulse had been accelerating electrons with its wakefield (like a wave accelerating a surfer). The extra energy to this lower-power pulse enhanced the electron acceleration and decreased the divergence of the electron beam. These features are desirable for proposed laser particle accelerators that would be powered by relatively inexpensive and convenient laser light, which is much more powerful than conventional radio-frequency waves

    How to guide a sustainable industrial economy: Emergy account for resources input of Chinese industry

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    AbstractEmergy analysis provides a feasible approach to evaluate the status and position of different energy carriers in the universal energy hierarchy. In this paper, an emergy-based method is conducted to measure the resources input of Chinese industry from 1997 to 2006. Resources inflows including fossil fuels, mineral resources, agricultural products, and other imported materials are accounted, based on which related indicators including resources intensity, industrial output, and environmental emissions are investigated. Results show a steady upward trend for the total resources input of Chinese industry during the past decade. The total resources input amounted to 1.53×1025 sej in 2006, of which non-renewable one accounted for 70.65% owing to the dominating input of fossil fuels and nonmetal minerals. Resources intensity measured by the ratio of resources input to industrial value added declined gradually during 1997–2002, but the rapid expansion of resource–intensive sub–sectors resulted in a reverse trend since 2003. The current resources use pattern of Chinese industry is characterized by increasing input of non-renewable resources, excessive expansion of resource–intensive production, and tremendous challenge from environmental pressure

    Noise-robust method for image segmentation

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    Segmentation of noisy images is one of the most challenging problems in image analysis and any improvement of segmentation methods can highly influence the performance of many image processing applications. In automated image segmentation, the fuzzy c-means (FCM) clustering has been widely used because of its ability to model uncertainty within the data, applicability to multi-modal data and fairly robust behaviour. However, the standard FCM algorithm does not consider any information about the spatial linage context and is highly sensitive to noise and other imaging artefacts. Considering above mentioned problems, we developed a new FCM-based approach for the noise-robust fuzzy clustering and we present it in this paper. In this new iterative algorithm we incorporated both spatial and feature space information into the similarity measure and the membership function. We considered that spatial information depends on the relative location and features of the neighbouring pixels. The performance of the proposed algorithm is tested on synthetic image with different noise levels and real images. Experimental quantitative and qualitative segmentation results show that our method efficiently preserves the homogeneity of the regions and is more robust to noise than other FCM-based methods
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