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1

Efficient sulfidization of lead oxide at high temperature using pyrite as vulcanizing reagent

Zheng Y.-X., Lv J.-F., Wang H., Wen S.-M., Huang L.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

270--277

EN

A sulfidization roasting-flotation process was usually viewed to be effective in treating the refractory oxide ore. In this paper, pyrite was proposed to be applied as a potential vulcanizing reagent to transform PbO or its surface to PbS based on feasibilities of technology and economy. The evolution process, phase and characteristics of crystal growth were investigated by TG, XRD and SEM-EDS, respectively, to interpret the interaction mechanism of lead oxide and pyrite at high temperature. It was found that the decomposition process of pyrite under argon atmosphere was a slow process of sulfur released from FeS2 to FexS, which made the process easier to be controlled. When PbO was introduced into the system, the initial solid-solid (PbO-FeS2) reaction and prevailing solid-gas (PbO-S2(g)) reaction occurred at about 500 °C and 700 °C, respectively. Combined with the SEM-EDS analyses results, the optimal temperature for the sulfidization of PbO should be in the range of 700-750 °C.

2

Copper adsorption reaction rate and ion exchange ratio during the copper activation of sphalerite

Liu J., Luo D., Huang L., Wang Y., Wen S.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

377--385

EN

A theoretical analysis method of the solution chemistry characteristic of Cu(II) at various pH values was developed. Using such method, the existence form of Cu species and their proportions in aqueous solution can be clearly determined. After that, the copper adsorption and ion exchange ratio (E) during the copper activation of sphalerite were investigated. The results indicated that the copper activation of sphalerite can be divided into two stages, i.e., the fast activation stage (t ≤4 min) and slow activation stage (t >4 min). The general form of the copper adsorption rate was determined as ΓCu=K1ln(t) +Γ1, which is confirmed by the data fitting of the fast activation stage. The lower activation pH results in higher ion exchange efficiency for Cu substituting Zn. For a strong acid pH of 4.1, the E maintains about 1:1 in the entire activation time range and is not dependent on the activation time. However, the value of E is greater than 1 under weak acidic (pH=6.2) and alkaline (pH=9.1) pH conditions and it significantly depends on the activation time. For such conditions, E decreases with increase in the activation time, which supports the ion exchange mechanism, but within short activation time, it is not a 1:1 ion exchange process.

3

Picea schrenkiana tree-ring chronologies development and vegetation index reconstruction for the Alatau Mountains, Central Asia

Zhang T., Zhang R., Lu B., Mambetov B. T., Kelgenbayev N., Dosmanbetov D., Maisupova B., Chen F., Yu S., Shang H., Huang L.

Geochronometria

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2018

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Vol. 45, no. 1

107--118

EN

In this study, a total of 176 tree cores from Schrenk spruce (Picea schrenkiana) were used to establish a tree-ring chronology and a 167-year July–October normalized differential vegetation index (NDVI) for the Alatau Mountains in Central Asia was reconstructed using this newly developed chronology. The tree-ring based NDVI reconstruction tracks the observed data well (r=0.577, p<0.01, n=25) and precisely captures the drought events recorded in historical documents that occurred over a large area in 1917 and 1938. After applying a 21-year moving average, three dense (1860–1870, 1891–1907, and 1950–1974) and three sparse (1871–1890, 1908–1949, and 1975–2006) vegetation coverage periods were found in this reconstruction. Spatial correlation proves that the reconstructed NDVI series contains climatic signals representative for a large area including southern Kazakhstan. Although a comparison between this reconstruction and four climatic reconstructions for southeastern Kazakhstan, Nilka (in the Ili region), the Issyk Lake, and the Aksu region reveals similar variations, the coherence between these reconstructions become weak with the increase in spatial distance from north to south. In addition to the local representation, it was also demonstrated that the newly developed NDVI index can indicate the large-scale circulations over Eurasia, with the higher NDVI associated with stronger westerly winds from the Atlantic to the Alatau Mountains, and the lower NDVI associated with the weaker winds.

4

Development of a Larix principis-rupprechtii tree-ring width chronology and its climatic signals for the southern Greater Higgnan Mountains

Zhang T., Yu S., Yuan Y., Huang L., Jiang S.

Geochronometria

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2018

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Vol. 45, no. 1

1--9

EN

Forty-one living larch (Larix principis-rupprechtii) trees collected from two sampling sites in 1310–1530 m a.s.l. in the southern Greater Higgnan Mountains in the northeastern China are used to develop a regional tree-ring width chronology. The credible chronology spans 185 years from 1830 to 2014. The results of correlation analyses indicate that moisture is the main climatic factor controlling radial growth of larch trees in this mountainous area. Spatial correlation proves that the regional tree-ring width chronology contains climatic signals representative for a large area including the eastern Mongolian Plateau and Nuluerhu Mountains. A comparison between the newly developed chronology and a May–July Palmer Drought Severity Index (PDSI) reconstruction for the Ortindag Sand Land reveals similar variations, particularly in the low-frequency domain. The tree-ring records also capture a severe and sustained drying trend recorded in the 1920s across a wide area of northern China.

5

Study of the impact of 220 kV SISFCL on the distance protection for transmission line

Luo Y., Shi T., Huang L.

Archives of Electrical Engineering

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2018

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Vol. 67, nr 1

151--163

EN

As the most typical application of superconducting technology, the Saturated Iron core Superconducting Fault Current Limiter (SISFCL) is a kind of ideal high voltage limiter, which can achieve noticeable limiting endless stream and has wide application prospect. However, the selectivity and sensitivity of the distance protection (DP) in the high voltage transmission network would be affected by the impedance characteristics of SISFCL. For these problems, firstly the structure and the working principle of the SISFCL are introduced briefly. Secondly, the impact mechanisms of 220 kV SISFCL on the original distance protection for the transmission line (TL) are analyzed. Then two methods of eliminating influences are deduced from the previous analysis and an improved setting method based on SISFCL for distance protection is proposed. Finally, we used EMTDC/PSCAD software to build the 220 kV SISFCL and distance protection model in the transmission network. The simulation results demonstrate that the proposed setting strategy can effectively improve the selectivity and sensitivity of distance protection and provide a reference for the practical applications of SISFCL applied to the transmission line.

6

Hexahydroquinoline derivatives : synthesis and anti-hepatoma cancer activity

Wang B., Jin W.-X., Zhang Y.-L., Huang L.

Przemysł Chemiczny

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2017

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T. 96, nr 4

897--900

EN

Arom. aldehydes were condensed in EtOH under boiling, pptd. by cooling to the room temp., sepd. by filtration, dried under vacuum and studied for anticancer activity against 3 human hepatoma tumor cell lines (SMMC-7721, BEL-740 and HCCLM3). Normal fibroblast cells WI 38 were also used. Fluorouracil was used as a ref. anticancer agent. One of the synthesized comps. showed a high inhibitory effect against 3 tumor cell lines (higher than the ref. agent). The compd. was non-cytotoxic to normal cells (IC50 values higher than 100 μg/mL).

PL

Przedstawiono syntezę i charakterystykę 4 pochodnych heksahydrochinoliny. Związki te zsyntetyzowano w reakcji kondensacji różnych aldehydów aromatycznych i oceniono pod kątem właściwości antyrakowych na podstawie badania 3 ludzkich linii komórkowych raka wątrobowokomórkowego (SMMC-7721, BEL-740 i HCCLM3). W badaniu wykorzystano także komórki WI 38 jako normalne fibroblasty. Najlepsze wyniki uzyskano dla związku 4, który wykazał najskuteczniejsze działanie hamujące rozwój 3 linii komórek rakowych. Działanie to okazało się skuteczniejsze niż w przypadku referencyjnego fluorouracylu. Ponadto związek ten nie działał cytotoksycznie na normalne komórki (IC₅₀ > 100 μg/mL).

7

Big data analysis and simulation of distributed marine green energy resources grid-connected system

Tian J., Huang L.

Polish Maritime Research

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2017

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S 3

182--191

EN

In order to improve the working stability of distributed marine green energy resources grid-connected system, we need the big data information mining and fusion processing of grid-connected system and the information integration and recognition of distributed marine green energy grid-connected system based on big data analysis method, and improve the output performance of energy grid-connected system. This paper proposed a big data analysis method of distributed marine green energy resources grid-connected system based on closed-loop information fusion and auto correlation characteristic information mining. This method realized the big data closed-loop operation and maintenance management of grid-connected system, and built the big data information collection model of marine green energy resources grid-connected system, and reconstructs the feature space of the collected big data, and constructed the characteristic equation of fuzzy data closed-loop operation and maintenance management in convex spaces, and used the adaptive feature fusion method to achieve the auto correlation characteristics mining of big data operation and maintenance information, and improved the ability of information scheduling and information mining of distributed marine green energy resources grid-connected system. Simulation results show that using this method for the big data analysis of distributed marine green energy resources grid-connected system and using the multidimensional analysis technology of big data can improve the ability of information scheduling and information mining of distributed marine green energy resources grid-connected system, realizing the information optimization scheduling of grid-connected system. The output performance of grid connected system has been improved.

8

A polarization selective beam splitter based on a subwavelength multisubpart profile grating structure

Xiao Y., Huang L., Wu H., Sun X., Xiao W., Duan J.

Optica Applicata

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2016

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Vol. 46, nr 4

665--672

EN

In this study, a polarization selective beam splitter constructed by only a single layer subwavelength multisubpart profile grating is presented. Rigorous coupled-wave analysis is adopted to investigate the properties of the structure. It is shown that for a transverse electric polarized wave, the device demonstrates very high reflectivity (>97%) from 1.46 to 1.58 μm; and for a transverse magnetic polarized wave, at the wavelength of 1.55 μm, it exhibits about 50/50 beam ratio under normal incidence. To evaluate the response of the polarizing beam splitters under variation in structure parameters, we also investigated the fabrication tolerances of the device.

9

Response of picophytoplankton to a warm eddy in the northern South China Sea

Wang J., Tan Y., Huang L., Ke Z., Tan J., Hu Z., Wang Q.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 2

145--158

EN

We investigated the distribution of several picophytoplankton groups (Prochlorococcus, Synechococcus, and picoeukaryotes) in relation to a warm eddy in the northern South China Sea in summer 2012. An anticyclonic eddy centered on 117°E longitude was identi ed during the sampling period using satellite data and hydrologic mapping. e layer of maximum Prochlorococcus and Synechococcus abundance within the eddy core dropped from 50 to 75 m, which was consistent with the subsurface chlorophyll a maximum. e water-column integrated abundance of Prochlorococcus, Synechococcus, and picoeukaryotes in the eddy core (9.67±0.23, 1.56±0.04, and 0.28±0.01 × 103 cells ml-1, respectively) was signi cantly lower (P<0.05) than that of the reference stations (25.10±2.32, 2.71±0.63, and 0.92±0.15 × 103 cells ml-1, respectively), and the abundance of Prochlorococcus in the core was also signi cantly lower than that at eddy edges (15.75±1.78 × 103 cells ml-1). However, there were no di erences in the water-column integrated Chl a between the eddy core and edge. Our ndings show that the warm eddy led to the reduced picophytoplankton abundance, especially of Prochlorococcus and picoeukaryotes, causing the layer of maximum picophytoplankton abundance to differ from that of the subsurface Chl a maximum.

10

Identity-based Signatures from Lattices : Simpler, Faster, Shorter

Tian M., Huang L.

Fundamenta Informaticae

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2016

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Vol. 145, nr 2

171--187

EN

Identity-based signature is an important technique for light-weight authentication. Recently, many efforts have been made to construct identity-based signatures over lattice assumptions since they would remain secure in future quantum age. In this paper we present a new identitybased signature scheme from lattice problems. This scheme is more efficient than other lattice-based identity-based signature schemes in terms of both computation and communication complexities. We prove its security in the random oracle model under short integer solution assumption that is as hard as approximating several worst-case lattice problems. We also extend the scheme to an identity-based message recovery signature scheme that has better performance.

11

Biomechanical simulation of needle insertion into cornea based on distortion energy failure criterion

Su P., Yang Y., Huang L.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 1

65--75

EN

Purpose: This paper is mainly about biomechanical behavior of needle insertion into cornea, and proposes a failure criterion to simulate the insertion process which has attracted considerable attention due to its importance for the minimally invasive treatment. Methods: In the process of needle insertion into cornea, tiny and complex insertion force is generated due to contact between needle and soft tissue. Based on the distortion energy theory, there is proposed a failure criterion of corneal material that can solve contact problem between rigid body and biological tissue in insertion simulation, where Cauchy stress of corneal material is the key to numerical calculation. A finite element model of in vivo cornea is built, and the cornea constrained by sclera is simplified to two layers containing epithelium and stroma. Considering the hyper-viscoelastic property of corneal material, insertion simulation is carried out. Results: By insertion experiment, the insertion force increases with insertion depth accompanying obvious fluctuations. Different insertion forces are generated at different speeds. The punctured locations are obvious in the force-displacement curves. The results of insertion simulation are generally consistent with experimental data. Maps of von Mises stress reflect the tissue injury of the cornea during insertion process, and punctured status corresponds to the point in the curves. Conclusions: The ability of this study to reproduce the behavior of needle insertion into cornea opens a promising perspective for the control of robotic surgery operation as well as the real-time simulation of corneal suture surgery.

12

Short-term variation in zooplankton community from Daya Bay with outbreaks of Penilia avirostris

Li K., Yin J., Tan Y., Huang L., Song X.

Oceanologia

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2014

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No. 56 (3)

583--602

EN

The zooplankton community structure in bays fluctuates as a result of anthropogenic activities in such waters. We focused on the short-term variability of a zooplankton community and compared its differences at the outflow of a nuclear power plant (ONPP), in a marine cage-culture area (MCCA) and in unpolluted waters (UW) in the south-west part of Daya Bay from 28 April to 1 June 2001. Environmental factors and zooplankton abundance differed significantly among stations at ONPP, MCCA and UW: high temperatures and a high zooplankton abundance occurred at ONPP, while a high chlorophyll a concentration and a low zooplankton abundance prevailed in MCCA. Statistical analysis revealed that the zooplankton diversity and abundance could be reduced by the activity of the marine cage-culture in a short time. Penilia avirostris made up an important component of the zooplankton in the study area, its abundance ranging widely from 16 to 7267 indiv. m-3 from April to June and peaking at the ONPP outflow. The outbreak of P. avirostris probably resulted from the combined effects of favourable water temperature, food concentration and its parthenogenetic behaviour.

13

An efficient algorithm for adaptive total variation based image decomposition and restoration

Liu X., Huang L.

International Journal of Applied Mathematics and Computer Science

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2014

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Vol. 24, no. 2

405--415

EN

With the aim to better preserve sharp edges and important structure features in the recovered image, this article researches an improved adaptive total variation regularization and H-1 norm fidelity based strategy for image decomposition and restoration. Computationally, for minimizing the proposed energy functional, we investigate an efficient numerical algorithm—the split Bregman method, and briefly prove its convergence. In addition, comparisons are also made with the classical OSV (Osher–Sole–Vese) model (Osher et al., 2003) and the TV-Gabor model (Aujol et al., 2006), in terms of the edge-preserving capability and the recovered results. Numerical experiments markedly demonstrate that our novel scheme yields significantly better outcomes in image decomposition and denoising than the existing models.

14

Cryptanalysis and Improvement of a Certificateless Multi-proxy Signature Scheme

Tian M., Yang W., Huang L.

Fundamenta Informaticae

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2014

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Vol. 129, nr 4

365--375

EN

Certificateless cryptography is a new type of public key cryptography,which removes the certificate management problem in traditional public key cryptography and the key escrow problem in identity-based public key cryptography. Multi-proxy signature is an extension of proxy signature, which allows an original signer authorizing a group of proxy signers and only the cooperation of all proxy signers in the group can create valid proxy signatures on behalf of the original signer. Recently, Jin andWen combined certificateless cryptographywith multi-proxy signature, and proposed a model as well as a concrete scheme of certificateless multi-proxy signature. They claimed that their scheme is provably secure in their security model. Unfortunately, in this paper by giving two attacks, we will show that their certificateless multi-proxy signature scheme can be broken. The first attack indicates their security model is flawed and the second attack indicates their certificateless multi-proxy signature scheme is insecure. Possible improvements are also suggested to prevent these attacks.

15

An Effective Method to Evaluate the Scientific Research Projects

Hou X., Huang L., Li X.

Foundations of Computing and Decision Sciences

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2014

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Vol. 39, No. 3

175--188

EN

The evaluation of the scientific research projects is an important procedure before the scientific research projects are approved. The BP neural network and linear neural network are adopted to evaluate the scientific research projects in this paper. The evaluation index system with 12 indexes is set up. The basic principle of the neural network is analyzed and then the BP neural network and linear neural network models are constructed and the output error function of the neural networks is introduced. The Matlab software is applied to set the parameters and calculate the neural networks. By computing a real-world example, the evaluation results of the scientific research projects are obtained and the results of the BP neural network, linear neural network and linear regression forecasting are compared. The analysis shows that the BP neural network has higher efficiency than the linear neural network and linear regression forecasting in the evaluation of the scientific research projects problem. The method proposed in this paper is an effective method to evaluate the scientific research projects.

16

A New Digital Image Hiding Encryption Algorithm Based on Dual Chaotic Systems

Zhang Y., Huang L., Karanfil Y. H., Wang Z.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

127--130

EN

To find new algorithms with good security, the authors proposed a new encryption algorithm based on dual chaotic systems. Firstly, the block of each pixel in the carrier image is determined with the Arnold mapping. And then with the chaotic sequence generated by Lorenz mapping, the specific location of each pixel in the corresponding block is determined. Finally, the pixels are hidden into the appropriate location by the chaotic sequence generated by Lorenz mapping. Theoretical analysis and practical tests show that this algorithm has enough key space and better key sensitivity.

PL

Poszukując nowych algorytmów z dobrym poziomem bezpieczeństwa, autorzy zaproponowali nowy algorytm szyfrowania oparty o podwójne systemy chaotyczne. Najpierw, blok każdego piksela w obrazie nośnika określany jest przez odwzorowanie Arnolda. Następnie, określane jest właściwe położenie każdego piksela w odpowiednim bloku przy pomocy sekwencji chaotycznej generowanej przez odwzorowanie Lorenza. W końcu piksele ukrywane są w odpowiednim położeniu przy pomocy sekwencji chaotycznej generowanej przez odwzorowanie Lorenza. Teoretyczne analizy i praktyczne testy wykazują, że zastosowany algorytm ma wystarczającą przestrzeń kluczy i lepszą czułość klucza.

17

Potential risk of Mesodinium rubrum bloom in aquaculture area of Dapeng'ao cove, China: diurnal changes in the ciliate community structure in the surface water

Liu H., Song X., Huang L., Tan Y., Zhong Y., Huang J. R.

Oceanologia

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2012

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No. 54 (1)

109-117

EN

Diurnal changes in the structure of the ciliate community in surface waters were studied in the aquaculture area of Dapeng'ao cove, China. Two periods of heavy rainfall occurred during the study period, intensifying water column stratification and influencing the water's properties. A total of 21 ciliate taxa from 15 genera were identified; the dominant species was Mesodinium rubrum. The maximum abundance of M. rubrum reached 3.92 × 104 indiv. dm-3, contributing 95.1% (mean value) to the total ciliate abundance. Diurnal changes in M. rubrum abundance were highly variable, the driving force probably being irradiance and food availability. The results suggest that M. rubrum may form blooms in aquaculture areas when there is a suitable physical regime with enriched nutrients, which is potentially harmful to the fish-farming industry.

18

A Precise and High Speed Charge-Pump PLL Model Based on SystemC/SystemC-AMS

Ma K., Van Leuken R., Vidojkovic M., Romme J., Rampu S., Pflug H., Huang L., Dolmans G.

International Journal of Electronics and Telecommunications

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2012

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Vol. 58, No. 3

225-232

EN

The Phase Locked Loop (PLL) has become an important part of electrical systems. When designing a PLL, an efficient and reliable simulation platform for system evaluation is needed. However, the closed loop simulation of a PLL is time consuming. To address this problem, in this paper, a new PLL model containing both digital and analog parts based on SystemC/SystemC-AMS (BETA version) is presented. Many imperfections such as Voltage Control Oscillator (VCO) noise or reference jitter are included in this model. By comparing with the Matlab model, the SystemC/SystemC-AMS model can dramatically reduce simulation time. Also, by comparing with Analog Devices ADI SimPLL simulation results, Cadence simulation results and real measurement results, the accuracy of the SystemC/SystemC-AMS model is demonstrated. The paper shows the feasibility of a unified design environment for mixed-signal modelling based on SystemC/SystemC-AMS in order to reduce the cost and design time of electrical systems.

19

Convergence and periodic properties of solutions for a class of delay difference equation

Zhu H., Huang L.

Fasciculi Mathematici

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2007

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Nr 37

121-128

EN

We propose a class of delay difference equation with piecewise constant nonlinearity. The convergence of solutions and the existence of globally asymptotically stable periodic solutions are investigated for such a class of difference equation.