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1

Leaching kinetic study of Y and Eu from waste phosphors using hydrochloric acid solution containing hydrogen peroxide

Yu M., Jiang Z., Mei G., Chen X.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

238--248

EN

The leaching kinetics of Y and Eu from waste phosphors using a hydrochloric acid (HCl) solution containing hydrogen peroxide (H2O2) were investigated. Characterization of the waste phosphors was performed using XRD to ascertain the phases as (Y0.95Eu0.05)2O3 (red phosphors), (Ce0.67Tb0.33)MgAl11O19 (green phosphors), (Ba0.9Eu0.1)Mg2Al16O27 (blue phosphors), and SiO2 (quartz). The influence of factors such as HCl concentration, addition amount of H2O2, temperature, and reaction time on the leaching performance of Y and Eu was investigated. The maximum leaching recoveries of Y (99.87%) and Eu (88.72%) were obtained at 4 M HCl, 0.2 cm3/g H2O2, 60 ℃ temperature, and 180 min of reaction time at a liquid-to-solid ratio of 7.5 cm3/g. Leaching kinetic results showed the best fit with the shrinking sphere model (1-(1-x)1/3)=kct), ensuring that the overall leaching process was governed by a chemical control mechanism. Activation energies of 42.35 and 33.28 kJ/mol were acquired for leaching of Y and Eu, respectively, at 40-70 ℃, which further supports the proposed chemical control leaching process.

2

Reciprocity relations for light wave scattered by a particulate collection

Jiang Z., Zhu Z., Wang T.

Optica Applicata

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2018

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Vol. 48, nr 4

661--670

EN

Two Fourier relations of light waves scattered by a random-distributed particulate medium have been investigated. We find that the scattered field and the particulate collection satisfy two Fourier relations, i.e. the spectral density is directly proportional to a Fourier transform of a convolution of correlation coefficient of each particle and correlation coefficient of distribution function of the whole collection, and the spectral degree of coherence is directly proportional to a Fourier transform of a convolution of strength of the scattering potential of each particle and strength of the distribution function of the whole collection. To illustrate these relations, behaviors of the far-field generated by Gaussian-correlated particles with Gaussian-correlated distributions have been discussed.

3

Summer distribution patterns of Trichodesmium spp. in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf

Jiang Z., Chen J., Zhou F., Zhai H., Zhang D., Yan X.

Oceanologia

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2017

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No. 59 (3)

248--261

EN

To examine the distribution of Trichodesmium relative to physicochemical factors during summer in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf, three cruises were conducted separately in June 2009, July 2011, and August 2009. Trichodesmium species found were T. thiebautii, T. erythraeum, and T. hildebrandtii. The population was dominated by T. thiebautii, which accounted for >85% of the samples found. Most of them were free trichomes. Colonial forms were rarely observed (approximately 10% of our samples), occurring only in offshore waters. The depth integrated abundances of Trichodesmium were 308 × 103, 1709 × 103, and 3448 × 103 trichomes m−2 in June, July, and August, respectively. Trichodesmium was distributed abundantly in the southern or southeastern part of our study area, where nutrients were low and light penetration, temperature, and salinity were high, which were influenced by the Taiwan Warm Current (TWC) and Kuroshio. Trichodesmium was found in low abundance in inshore, eutrophic, low-salinity waters, which were mainly controlled by the Changjiang Diluted Water (CDW) and coastal current. These results suggest that spatiotemporal changes in the summer Trichodesmium distribution correlate highly with the variations in physicochemical properties that are primarily controlled by the TWC, Kuroshio, and CDW. The summer N2 fixation rate of Trichodesmium was estimated at 12.3 μmol N m−2 d−1 in our study area, contributing >50% of biological N2 fixation.

4

Fast, accurate and robust retinal vessel segmentation system

Jiang Z., Yepez J., An S., Ko S.

Biocybernetics and Biomedical Engineering

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2017

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Vol. 37, no. 3

412--421

EN

The accurate segmentation of the retinal vessel tree has become the prerequisite step for automatic ophthalmological and cardiovascular diagnosis systems. Aside from accuracy, robustness and processing speed are also considered crucial for medical purposes. In order to meet those requirements, this work presents a novel approach to extract blood vessels from the retinal fundus, by using morphology-based global thresholding to draw the retinal venule structure and centerline detection method for capillaries. The proposed system is tested on DRIVE and STARE databases and has an average accuracy of 95.88% for single-database test and 95.27% for the cross-database test. Meanwhile, the system is designed to minimize the computing complexity and processes multiple independent procedures in parallel, thus having an execution time of 1.677 s per image on CPU platform.

5

An Amplitude-normalized Pseudo Well-log Construction Method and its Application on AVO Inversion in a Well-absent Marine Area

Fan Ch., Song Y., Zhang Y., Jiang Z.

Acta Geophysica

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2015

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Vol. 63, no. 3

761--775

EN

AVO inversion is hard to be efficiently applied in unexploited fields due to the insufficiency of well information. For the sake of AVO inversion in a well-absent area, the most conventional method is to construct pseudo well-logs by defining seismic processing velocity as the P-velocity and computing S-velocity and density using empirical formulas, yet the resolution of the corresponding earth models and final inverted results could be extremely low, and a rough formula could destroy the inversion thoroughly. To overcome this problem, an amplitudenormalized pseudo well-log construction method that reconstructs pseudo well-logs in accordance with computed P-wave reflection amplitudes and nearby drilling data is proposed in this paper. It enhances the inversion resolution efficiently with respect to the real elastic parameter relationships, so that the corresponding AVO inversion results are reasonably improved. In summary, the proposed method is successfully applied in the AVO inversion of a well-absent marine area, and could be valuable in the early phase, particularly of the offshore hydrocarbon exploration.

6

Evaluating the habitat quality of giant panda (Ailuropoda Melanoleuca) using Habitat Suitability Index (HSI)

Jian J., Jiang H., Jiang Z., Zhou G., Yu S., Peng S., Liu S., Liu S., Wang J.

Polish Journal of Ecology

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2012

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Vol. 60, nr 4

827--837

EN

Habitat quality for many wildlife populations has a spatial component related to the arrangement of habitat elements across large geographic areas. With remote sensing and GIS technology, this paper presents an approach to calculate Habitat Suitability Index (HSI) for Giant Pandas to evaluate the habitat quality. In this paper, a buffer of a given distance (30 km or more) to the Giant Panda distribution area estimated in three national surveys (1974, 1989 and 2002), which is located in Sichuan, Gansu and Shanxi provinces in western China, was used as the study area. In order to study different species group’s habitat quality, the study area is divided into five parts: the Qinling mountain systems, located in the southeast in Shanxi province, the Minshan mountain systems, located in the south in Gansu province and northwest in Sichuan province, the Qionglai mountain systems, the Xiangling mountain systems and the Liangshan mountain systems, located in the west of Sichuan province, conforming to the five big Giant Panda species groups. Three physical environmental factors (elevation, slope and aspect), one ecological factor (vegetation distribution) and several human-influence factors (distances to highways, general roads, inhabitants and rural areas) are selected as the influence factors to calculate HSI. Each factor was reclassified by grid-cell (30 × 30 m per cell) to the suitability index scale from 0 to 1 based on habitat affinities before final calculation. After analyzing the HSI values on the most Giant Panda distribution area, 0.0144 was considered as the threshold habitat quality. Then, HSI was calculated for five mountain systems for three periods conforming to three national surveys (1974, 1989 and 2002). Several benefits to the approach can be highlighted. Firstly, HSI can be used as the standard to evaluate the quality of Giant Panda habitat. Secondly, by using HSI maps from 1974, 1989 and 2002, we can see that the Giant Panda habitat was the largest in 1974, and was then reduced much before 1989. However, by 2002, it had recovered to some extent, which conforms to the habitat data from the three national surveys. Thirdly, the habitat changes in the five mountain systems examined in the study are different. Finally, nature reserves play an important role in the protection of Giant Panda habitat; there are more suitable habitats in nature reserves than non-protected areas.

7

Controllable synthesis of ZnO nanostructures by a simple solution route

Wang J., He S., Zhang S., Li Z., Yang P., Jing X., Zhang M., Jiang Z.

Materials Science Poland

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2009

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Vol. 27, No. 2

477--484

EN

Flower-shaped ZnO nanostructures, composed of ZnO nanorods, and sphere-shaped ZnO nanoclusters, composed of ZnO nanosheets, were synthesized by reacting zinc acetate dehydrate with sodium hydroxide and polyethylene glycol-20000 (PEG-20000) at 180 °C for 4 h in solution. The thickness of individual nanosheets is about 40-60 nm. The nanorods are of hexagonal shape with sharp tips, and have basic diameters of ca. 450-550 nm. The ZnO nanostructures were characterized by scanning electron microscropy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared, and Raman scattering measurements. The results demonstrated that the synthesized products are single crystalline with wurtzite hexagonal phase, the sphere-shaped ZnO grew in the [100] direction and the flower-shaped ZnO grew in the [001] direction.

8

Summer diet of two sympatric species of raptors Upland Buzzard (Buteo hemiliasius) and Eurasian Eagle Owl (Bubo bubo) in alpine meadow : problem of coexistence

Cui Q., Su J., Jiang Z.

Polish Journal of Ecology

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2008

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Vol. 56, nr 1

173-179

EN

Summer diets of two sympatric raptors Upland Buzzards (Buteo hemilasius Temminck et Schlegel) and Eurasian Eagle Owls (Bubo bubo L. subsp. Hemachalana Hume) were studied in an alpine meadow (3250 m a.s.l.) on Qinghai-Tibet Plateau, China. Root voles Microtus oeconomus Pallas, plateau pikas Ochotona curzoniae Hodgson, Gansu pikas O. cansus Lyon and plateau zokors Myospalax baileyi Thomas were the main diet components of Upland Buzzards as identified through the pellets analysis with the frequency of 57, 20, 19 and 4%, respectively The four rodent species also were the main diet components of Eurasian Eagle Owls basing on the pellets and prey leftovers analysis with the frequency of 53, 26, 13 and 5%, respectively. The food niche breadth indexes of Upland Buzzards and Eurasian Eagle Owls were 1.60 and 1.77 respectively (higher value of the index means the food niche of the raptor is broader), and the diet overlap index of the two raptors was larger (C[ue] = 0.90) (the index range from 0 - no overlap - to 1 - complete overlap). It means that the diets of Upland Buzzards and Eurasian Eagle Owls were similar (Two Related Samples Test, Z = -0.752, P = 0.452). The classical resource partitioning theory can not explain the coexistence of Upland Buzzards and Eurasian Eagle Owls in alpine meadows of Qinghai-Tibet Plateau. However, differences in body size, predation mode and activity rhythm between Upland Buzzards and Eurasian Eagle Owls may explain the coexistence of these two sympatric raptors.

9

Spectral Energy and Age Distributions for 51 Globular Cluster Candidates

Ma J., Zhou X., Chen J., Wu H., Kong X., Jiang Z., Zhu J., Xue S.

Acta Astronomica

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2002

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Vol. 52, No. 4

453--470

EN

This paper is the fourth in a series presenting spectrophotometry of 51 globular cluster candidates, that were detected by Mochejska et al. in the nearby galaxy M33 using the data collected by the DIRECT project. The frames of M33 in this study were taken as a part of the BATC Multicolor Sky Survey. We obtained the spectral energy distributions of these candidates in 13 intermediate-band filters. By comparing the integrated photometric measurements with theoretical stellar population synthesis models of Bruzual and Charlot, we estimated their ages. The BC96 models provide the evolution in time of the spectrophotometric properties of simple stellar populations for a wide range of stellar metallicity. Our results show that half of the candidates are younger than 108 years. We also find that globular clusters formed continuously in M33 from ≈4×106 to 1010 years. Our results are in agreement with Chandar et al. who estimated ages for 35 globular clusters candidates from our list by comparing the photometric measurements to integrated colors from theoretical models by Bertelli et al. The Kolmogorov-Smirnov test shows that the maximum value of the absolute difference of estimated ages between Chandar et al. and us is 0.48, and the significance level probability is 100.00%.

10

A soft palpation sensor and its application to measurement of the stiffness of prostate gland

Chonan S., Jiang Z., Tanaka M., Suga Y., Tanahashi Y.

Journal of Technical Physics

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1998

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Vol. 39, no 3-4

397-409

EN

This paper is a study on the development of a compact palpation sensor with the aim of developing an automatic sensing system for detecting both prostatic cancer and hypertrophy in vivo and noninvasively. The sensor is an assembly of layered media with two PVDF (polyvinylidene fluoride) patches embedded in a soft matrix material. First, the output voltage signals from the sensor are measured when the sensor is attached onto a linear translation stage and pressed against soft sample materials with a constant stroke and constant oscillation frequency. Then, the data processing for extracting the information on their stiffness is detailed. Finally, the clinical data measured on the stiffness of hardened and normal prostate glands are presented, which reveals the potential of the present probe for a compact palpation sensor.