Wyniki wyszukiwania - BazTech

1

Effect of intergrown particle liberation on difficult-to-separate coking coal flotation

Gui X., Liu J., Cao Y., Xing Y., Deng Y., Li S.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

279--294

EN

Flotation tests with intergrown particle liberation were conducted to explore a separation method of difficult-to-separate coking coal from the Tangshan Kailuan mine in China. The particle size distribution, density and coal petrography were investigated. The difficult-to-separate coking coal sample resulted in intergrown particles, such as non-liberated coal and rocks. Thus, intergrown coal particle liberation and re-separation tests were conducted. The results showed that grinding time had a great effect on the flotation performance. Grinding prompted coal to dissociate and improve the surface hydrophobic properties of minerals. However, heterogeneous fine silt covered the surface of coal particles when coal was ground too long. The inorganic mineral particles were over-ground and reduced the contact angle of coal. The results of coal rock dissociation and laboratory re-separation tests showed that clean coal combustible recovery increased through intergrown particle liberation and re-separation.

2

Foliar responses of Abie fargesii Franch. To altitude in the Taibai Mts, China

Xu P., Zhang X., Zhao C., Chen L., Gao X., Yao B., Deng J., Deng Y.

Polish Journal of Ecology

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2014

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Vol. 62, nr 3

479--492

EN

Physiological and ecological adaptations of altitudinal gradients reveal alpine plants’ ecological and evolutionary responses to environmental changes. Here we quantitatively investigated the variation in the foliar physiological and morphological traits of alpine tree species (Abies fargesii) along the altitudinal gradient in the Taibai Mountains, China. We collected the needle samples of Taibai fir (A. fargesii) from seven sites at altitudes of 2550, 2650, 2750, 2850, 2950, 3050 and 3150 m, respectively, and measured the 12 foliar physiological and morphological traits. Each set of needle sample (100 needles) was randomly selected from the upper- third of A. fargesii canopies. The results showed that leaf mass per unit area (LMA), stable carbon isotope composition (δ13C), stomatal rows (SR), leaf carbon concentration per unit area (Carea), leaf nitrogen concentration per unit leaf mass (Nmass) and area (Narea) linearly increase significantly while stomatal density (SD), number of stomata per unit nitrogen concentration (St/N) and per unit leaf mass (St/LM) decrease with the altitudes raise. Moreover, all measured traits presented both strong correlations and significantly linear relationships with the main climate factors such as the mean temperature, rainfall and relative humidity during the growing season as well as the altitudes, except for leaf free water concentration (LWC), leaf carbon concentration per unit leaf mass (Cmass) and C: N ratio. The patterns of foliar traits in response to altitudes imply that the alpine plants need higher cost (e.g. higher nutrient concentration) to adapt to the harsher environments along altitudinal gradient. Moreover, our results show that the variation patterns of the leaf traits for A. fargesii plants should be driven by the interactions of multi-climate factors because the abiotic factors that directly influence the growth of plants covary with the increasing altitudes.

3

DELA: A displacement estimated localization algorithm in the opportunistic communication based wireless sensor network

Deng Y., Yang Y., Xiong Y., Li L.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

112--115

EN

Localization is one of the key problems in our system to collect the data of movement rule of sediment transport by wind for the desertification research. We designed a full covered deployment scheme of base station for providing the basic service of data forwarding and localization first. Then we proposed a displacement estimated localization algorithm (DELA), which can help node to measure its displacement during each movement and then calculate the position. The experiment proved that the DELA is better than the trilateration in this scene.

PL

Przy badaniach pustynnienia i zbieraniu danych w warunkach ruchu osadów porywanych przez wiatr, jednym z kluczowych problemów jest lokalizacja. W opracowaniu, po pierwsze, dla zapewnienia podstawowej obsługi przekazywania danych o przemieszczaniu i lokalizacji, zaprojektowano układ stacji bazowych, całkowicie pokrywający rozmieszczenie węzłów pomiarowych. Następnie, zaproponowano algorytm szacunkowej lokalizacji przemieszczania (DELA), który pomaga węzłowi zmierzyć przemieszczenia podczas jego ruchu i następnie obliczyć pozycję. Badania eksperymentalne wykazują, że DELA daje lepsze wyniki niż trilateracja.

4

Diagnosis of incipient faults in nonlinear analog circuits

Deng Y., Shi Y., Zhang W.

Metrology and Measurement Systems

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2012

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Vol. 19, nr 2

203-218

EN

Considering the problem to diagnose incipient faults in nonlinear analog circuits, a novel approach based on fractional correlation is proposed and the application of the subband Volterra series is used in this paper. Firstly, the subband Volterra series is calculated from the input and output sequences of the circuit under test (CUT). Then the fractional correlation functions between the fault-free case and the incipient faulty cases of the CUT are derived. Using the feature vectors extracted from the fractional correlation functions, the hidden Markov model (HMM) is trained. Finally, the well-trained HMM is used to accomplish the incipient fault diagnosis. The simulations illustrate the proposed method and show its effectiveness in the incipient fault recognition capability.

5

Contribution of the vegetation layers in the nitrous oxide emission from alpine Kobresia humilis Serg. meadow ecosystem on the Tibetan Plateau

Du Y., Cao G., Deng Y., Sun G., Cui X.

Polish Journal of Ecology

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2010

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Vol. 58, nr 1

115-124

EN

Nitrous oxide (N[2]O) was one of the major atmospheric greenhouse gases. Its budget was poorly understood in alpine meadow, a dominant vegetation type on the Tibetan Plateau. To characterize a Kobresia humilis meadow on the plateau, N[2]O emission rates were monitored from June 2003 to June 2006 in the study area located at 3280 m a.s.l. Nine plots with 1 m x 1 m each were divided into three treatments, i.e. intact herbaceous community (HCK), removal of aboveground plant biomass (CBK), and removal of both above and belowground plant biomass (BSK), to estimate contribution of plants, r hizosphere and bulk soil to the total N[2]O emission. N[2]O emission from plant aboveground biomass was calculated by flux difference between HCK and CBK, denoted as F[(HCK-CBK)], from rhizosphere by F[(CBK-BSK)], and from bulk soil was the flux in BSK treatment. Static chambers (height 50 cm, area 0.5 x 0.5 m2 )were used for gas collection. N[2]O emission rate was significantly correlated with soil temperature at 5 cm depth in both HCK and BSK (P <0.001). Both treatments demonstrated a seasonal peak rate in growing season and minimum rate in dormancy period. The mean emission rates in the three years were 39.7[plus or minus]2.9 and 30.6[plus or minus]2.5 [mu]g m[^-2] h[^-1] in HCK and BSK, respectively, with the former significantly higher than the latter (P <0.05). In CBK, however, the emission rate did not show consistent correlation with soil temperature, especially in growing season. Its three-year mean emission rate was 36.2[plus or minus]3.3 [mu]g m[^-2] h[^-1]. In the K. humilis meadow, bulk soil contributed much more than plants and rhizosphere. The mean emission rate was 3.5[plus or minus]2.9, 5.7[plus or minus]3.8, and 30.6[plus or minus]2.5 [mu]g m[^-2] h[^-1] (P <0.001) from plants, rhizosphere and bulk soil, and these accounted for 9, 14 and 77%, separately. Our results implied that N[2]O emission rate decreased little with grazing as indicated by the difference between HCK and CBK in K. humilis meadow (P <0.05). N2O emission from alpine meadow could not be ignored in addressing regional greenhouse gases budget on the Tibetan Plateau, considering the vast area and much higher radiative forcing of N[2]O.

6

Reduced magnetic vector potential and electric scalar potential formulation for eddy current modeling

Zeng Z., Liu X., Deng Y., Udpa L., Udpa S.

Przegląd Elektrotechniczny

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2007

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R. 83, nr 6

35-37

EN

A finite element formulation using the reduced magnetic vector potential and the electric scalar potential is proposed for modeling eddy current nondestructive testing problems in which the probe coil scans across the sample. Excitation coil is not meshed and the remeshing is avoided during the motion of the coil. The mesh and system matrix remain unchanged with different coil positions. The incomplete factorization of the system matrix as preconditioner is performed only once during the entire scan, which results in a significant reduction of computation time.

PL

Zaproponowano sformułowanie metody elementów skończonych, wykorzystujące zredukowany wektorowy potencjał magnetyczny i skalarny potencjał elektryczny, do modelowania wiroprądowych badań nieniszczących, w których cewka jest przesuwana nad próbką. Cewka wzbudzająca nie jest dyskretyzowana na elementy skończone. Siatka i macierz układu pozostają niezmienione przy różnych położeniach cewki. Niepełna faktoryzacja macierzy jest wykonywana tylko raz podczas całego skanowania, co prowadzi do skrócenia czasu obliczeń.