Wyniki wyszukiwania - BazTech

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Simulation of a high-pressure water jet structure as an innovative tool for pulverizing copper ore in KGHM Polska Miedź S.A.

Borkowski P., Shimizu S., Peng G., Oguma Y.

Mining Science

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2015

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Vol. 22

147--159

EN

Effective comminution of copper ore for further processing during flotation is still a challenge, both as a technological problem as well as for the high energy costs of such processing. A high-pressure water jet is one alternative method of preparing copper ore for final flotation, causing distinct enlargement of the surface of micronized particles, which could be profitable for copper production. As a consequence of such innovative processing, particles of copper ore become micronized, ensuring grain fractions directly useful for flotation at the exit of the pulverizing apparatus (the hydro-jetting mill).The paper presents some results of simulation as well as describing an analysis of the phenomena occurring inside the high-pressure water and abrasive-water jets of specific structures, elaborated in the aspect of developing hybrid jets of maximum erosive efficiency, potentially useful for effective pulverization.

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Badania struktury i charakterystyki przepływu płaskiej strugi wodnej i wodnościernej

Borkowski P., Shimizu S., Peng G., Oguma Y.

Mechanik

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2015

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R. 88, nr 8-9CD1

50--54

PL

W referacie zaprezentowano istotne aspekty badań struktury i charakterystyki przepływu płaskiej strugi wodnej i wodno-ściernej wytwarzanej w dyszy szczelinowej. Badania takie przeprowadzane w Nihon University w Japonii, metodą prześwietlania takiej strugi suspensyjnej przy użyciu techniki laserowej (PIV), pozwalają na wyodrębnienie zachowań poszczególnych jej składników w strefie erozji oraz określenie rozkładów prędkości cząstek materiału ściernego.

EN

The paper presents the research of the structure and characteristics of flat jet, generated in fan-jet nozzle’s type, during water-and abrasive-water jet creation. Such kind research was conducted utilizing PIV system (a YAG type laser) for isolating different structures of the jet in the erosion zone as well as for determination of their velocity fields.

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Peng G., Wu C., Xu X., Yang D.

Polish Journal of Ecology

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2012

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Vol. 60, nr 2

311-321

EN

In woody perennials, leaf structure and biochemistry vary with tree age under changing environments. However, the related eco-physiological mechanisms have not been elucidated yet. In this study, we investigated agerelated responses of juvenile and mature subalpine fir trees (Abies faxoniana Rehder & E.H. Wilson.) growing at altitudes between 2,500 and 3,500 m in the Wanglang Natural Reserve in southwest China, to study the adaptive strategies of different age trees to suit changing environments. We found that there were distinct age- and altituderelated changes in the structural and biochemical characteristics of leaves. At all altitudes, mature trees exhibited higher area- and mass-based leaf nitrogen content (N[area], N[mass]), leaf mass per area (LMA) and stable isotope carbon composition ([delta^13]C), and a lower chlorophyll (Chl) content than those juvenile trees, except for N[mass] at 3,000 m as well as LMA at 2,750 m, where the values of N[mass] and LMA in mature trees were slightly lower than those in juvenile trees. Furthermore, leaf characteristics showed significant differences in the change rates with altitude between different age groups. Our results indicated that assimilative organs in mature trees do not suffering from nutrient deficiency and that juvenile and mature trees possess different adaptive growth strategies under changing environments, as indicated by higher leaf N content in mature trees and the opposite patterns of LMA and Chl content between two age groups. We also concluded that juvenile could be more sensitive to global warming due to a greater altitudinal influence on the leaf traits in juvenile trees than those in mature trees.

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HRTEM nanostructural evolution of onion-like spheres in polyacrylonitrile fibres during stabilization and carbonization

Wen Y., Li H., Peng G., Yang Y., Liu L.

Materials Science Poland

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2010

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Vol. 28, No. 2

479--490

EN

Ultrathin sections of polyacrylonitrile (PAN) fibre samples in the stabilization and carbonization stages were studied using high-resolution transmission electron microscopy. Supplementary analyses by the Fourier transform infrared, X-ray diffraction, thermogravimetry mass spectroscopy and elemental analysishave also been done. Results showed that the PAN fibres contained nanosized crystallites embedded in a continuous amorphous matrix. Amorphous onion-like spherical structures were also observed and their structural evolution was investigated. During the stabilization and carbonization process, the outer layers of the onion-like spheres gradually changed from an orderly layered structure into a disordered, dense structure due to cyclization and cross-linking reaction. During carbonization, the onion-like spheres became more dense and compact due to the merging of the ring structures. After carbonization, the onion-like spheres in the PAN fibres eventually turned into dense and amorphous domains of carbon fibres.