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1

Adsorption efficiency of pentafluorobenzene on ionic liquids-based silicas

Wang X., Lin L., Xie J., Yan X., Xiao W., Tian P.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 3

47--52

EN

The adsorption of pentafl uorobenzene on nine ionic liquid-based silicas was investigated using solid phase extraction. The effects of several variables such as the type of ionic liquid groups, adsorption time, temperatures and water ratio in the solution system were experimentally evaluated. The imidazole-chloride ionic liquid group based silica exhibited the highest adsorption efficiency under the optimized conditions of 5 min adsorption at 30°C in water/methanol (30:70, vol%) solution. In addition, the effects of pH, as well as type and concentrations of chloride salts were investigated. At pH values other than neutral and high salt concentration, the adsorption efficiency was reduced. Finally, the relative standard deviation of less than 5.8% over a 5-day period showed a high precision for the nine tested sorbents.

2

Computational fluid dynamics (CFD) numerical simulation and particle image velocimetry (PIV) measurement of a packed flotation column

Yan X., Chen Z., Wang L.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

395--405

EN

Packing is a useful method to obtain a static separation environment for a high flotation recovery and selectivity. In this study, the single-phase flow field in a packed lab-scale cyclonic-static microbubble flotation column (FCSMC) was investigated by computational fluid dynamics (CFD) simulation. Turbulence model was verified by Particle Image Velocimetry (PIV) experiment; the simulation results obtained by the RSM (Reynolds Stress Model) are closer to the experimental data. Based on this validation, RSM turbulence model was used to obtain the effect of sieve-plate on the hydrodynamic characteristics in the column flotation zone. The results show that the sieve-plate packing arrangement greatly straightens the rotation flow and decreases the turbulence. To further improve the effect of packing, two layers of sieve plates were used, and one diameter (1D = 190 mm) was selected as the reasonable distance between the two layers of sieve plates. To quantitative evaluate the effect of sieve-plate packing, the logarithm of Pdk over the logarithm of Pdo was calculated based on the volume-averaged turbulence dissipation rate, increasing from 24.72 for one layer of sieve-plate packing to 216.96 for two layers of sieve-plate packing. The probability of detachment significantly decreased for two layers of sieve-plate packing, and the recovery efficiency was significantly improved.

3

Effects of Polymeric Binders on the RDX-based Explosive Response Character under Slow Cook-off Conditions

Yan X., Li X. D., Zhang Y. R., Liu L., Zhang X. M., Tan Y. X., Wang H., Wang X. Q.

Central European Journal of Energetic Materials

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2018

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Vol. 15, no. 2

339--350

EN

Due to safety requirements, insensitive behaviour under slow thermal heating (cook-off) conditions is a desirable behaviour for today’s munitions. In this paper a cook-off device is designed to test two groups of RDX-based PBX explosives. In the first group the binder type was varied and in the second group the binder content of the RDX-based explosive was changed. Eleven samples were examined in order to evaluate the influence of four different binders and seven different binder contents on the shell deformation and the degree of the involved reaction. The test results showed that the degree of the reaction can be improved by changing the binder content, but not by the binder type. This phenomenon was explained by the thermal-conduction theory.

4

Charging station location optimization of electric ship based on backup coverage model

Zhang W., Yan X., Zhang D.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 2

323--327

EN

In terms of electric ship energy requirement in navigation, the ship charging station location is especially important. In this paper, a multi-period ship charging station location optimization model is pro-posed to make location decision in overall, from initial possible station sites chosen to the capacity determination for the final location sites. In the first phase, from the perspective of external environment, find out all possible ship charging station candidate sites through the feasible analyze. In the second phase, taking the ship charging demands into consideration, the final ship charging station sites can be selected among the candidate sites based on backup coverage model. In the last phase, regarding the cost of construction and service capability for different grade as the main factor in capacity determination, the optimal capacity of each final ship charging station are determined by means of optimization method. Finally, an example of Yanqi lake in China is used to verify the validity of the proposed methodology. The reasonable location of charging station could ensure the electric energy supply and avoid congestion caused by ship charging gathering. The model can be easily generalized to other problems regarding facility allocation based on user demand.

5

A study of bubble-particle interactions in a column flotation process

Cheng G., Shi C., Yan X., Zhang Z., Xu H., Lu Y.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

17--33

EN

Bubble-particle interactions play an important role in flotation. This study examines the behaviour of bubble clusters in a turbulent flotation cell. Particularly, the bubble-particle interaction characteristics in flotation are investigated. The bubble size in a flotation column was measured using an Olympus i-SPEED 3 high-speed camera. Relationships between the circulating volume, bubble size and bubble terminal velocity were discussed. Probabilities of collision, attachment, detachment and acquisition between bubbles and particles in different circulating volumes were calculated based on the flotation kinetic theory. Using the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory, the relationship between the potential energy and distance in bubble-particle interaction was analysed. The results demonstrated that as the circulating volume increased, the bubble size and velocity decreased. When the circulating volume increased from 0.253 to 0.495 m3/h, the bubble diameter decreased from 511 to 462 μm, and the corresponding bubble velocity decreased from 43.1 to 37.5 mm/s. When the circulating volume remained constant as the particle size increased, probabilities of collision, attachment, detachment and acquisition increased. When the particle size remained constant as the circulating volume increased, these probabilities also increased. At a constant circulating volume as the particle size increased, the absolute value of the total potential energy between the particle and bubble increased. When the distance between the bubble and particle was 30 nm, the energy barrier appeared.

6

A cyclonic-static micro bubble flotation column for enhancing coalescence of oil droplets from emulsion

Li X., Yan X., Zhang H.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

307--320

EN

In this work a novel cyclonic-static micro bubble flotation column, using hydraulic separator with a conventional flotation column, was developed to separate oil droplets from emulsions. The system integrated the cyclonic and laminar flow coalescence with the pipe flow coalescence. The effect of process parameters such as circulation pressure, aeration rate, feed volumetric flow rate and viscosity of fluid on the efficiency of multi-flow pattern coalescence was investigated. The obtained results indicated that the coalescence efficiency increased with the circulation pressure, feed volumetric flow rate and aeration rate, whereas an increase in viscosity of fluid reduced the extent of coalescence. Besides, the size distribution of oil droplets in the cyclonic separator, pipe flow section and column flotation section were simulated in the flotation column using a special software. The simulation was compared with experimental data on the mean size of oil droplets.

7

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.

8

Electronic and optical properties of Mn–S co-doped anatase TiO2 from first-principles calculations

Wu G., Zheng S. K., Yan X.

Materials Science Poland

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2016

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Vol. 34, No. 1

38--44

EN

The electronic and optical properties of Mn–S co-doped anatase TiO2 were calculated using the plane-wave-based ultrasoft pseudopotential density functional method within its generalized gradient approximation (GGA). The calculated results show that the band gap of Mn–S co-doped TiO2 is larger than that of the pure TiO2, and two impurity bands appear in the forbidden band, one of which above the valence band plays a vital role for the improvement of the visible light catalytic activity. The Mn–S co-doped anatase TiO2 could be a potential candidate for a photo catalyst because of its enhanced absorption ability of visible light.

9

Incremental Localization Algorithm Based on Regularized Iteratively Reweighted Least Square

Yan X., Yang Z., Liu Y., Xu X., Li H.

Foundations of Computing and Decision Sciences

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2016

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Vol. 41, No. 3

183--196

EN

Incremental localization algorithm is a distributed localization method with excellent characteristics for wireless network. However, its estimated result is generally influenced by the heteroscedasticity arising from cumulative errors and the collineation among anchor nodes. We have proposed a novel incremental localization algorithm with consideration to cumulative errors and collinearity among anchors. Using iteratively reweighted and regularized method, the algorithm reduces the influences of errors accumulation and avoids collinearity problem between anchors. Simulation experiment results show that compared with the previous incremental localization algorithms, the proposed algorithm obtains a localization solution which not only has high accuracy but also high stability. Therefore, the proposed algorithm is suitable for different deployment environments and has high adaptability.

10

Apparel Design Safety and Production Criteria and Models

Chen L., Yan X., Gao C.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 6 (120)

32--38

EN

A safe apparel design and production (SADP) model was proposed as a system to guide the development of safe apparel. An objective analysis of user needs and examination of safe nutrients used in apparel design uncovered through related technical regulations/standards induction and recall case analysis led to the development of apparel safety needs criteria. The criteria were then translated into apparel safety attributes and used in the development of the SADP model. A theoretical evaluation model remained to be developed for apparel safety purposes using multi-part disassembly. It is hierarchically structured in accordance with apparel safety attributes, and demonstrates how the apparel design safety criteria was used by a design team or an industry worker. By the introduction of the apparel design safety evaluation model, a further shift to pro-action and to the prevention of losses will be made possible. The research also demonstrates the application of the SADP model to a textile product design problem.

PL

Zaproponowano kilka modeli bezpiecznego projektowania i produkcji odzieży jako systemu pozyskiwania odzieży bezpiecznej. Przeprowadzono obiektywną analizę potrzeb użytkownika, jak również stosowanych w projektowaniu i produkcji części składowych wyposażenia i odzieży. Doprowadziło to do opracowania kryteriów bezpieczeństwa projektowania i użytkowania.

11

High-efficiency carrier frequency estimation algorithm for real-time multi-domain communication signal analysis

Wang Q., Yang X., Yan X, Qin K.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 2

281--292

EN

Based on real-time multi-domain communication signal analysis architecture, a high-efficiency blind carrier frequency estimation algorithm using the power spectrum symmetry of the measured modulated signal is presented. The proposed algorithm, which utilizes the moving averaged power spectrum achieved by the realtime spectrum analysis, iteratively identifies the carrier frequency in according to the power difference between the upper sideband and lower sideband, which is defined and revised by the estimated carrier frequency in each iteration. When the power difference of the two sidebands converges to the preset threshold, the carrier frequency can be obtained. For the modulation analysis, the measured signal can be coarsely compensated by the estimated result, and the residual carrier frequency error is eliminated by a following carrier synchronization loop. Compared with previous works, owing to the moving averaged power spectrum normalization and the smart iterative step variation mechanism for the two sidebands definition, the carrier frequency estimation accuracy and speed can be significantly improved without increasing the computational effort. Experimental results are included to demonstrate the outstanding performance of the proposed algorithm.

12

Electronic Circuit Optimization Design Algorithm based on Particle Swarm Optimization

Yan X., Hu C., Yao H., Fan Y., Liang Q., Liu C.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

50--52

EN

A major bottleneck in the evolutionary design of electronic circuits is the problem of scale and the time required to evaluate the individuals, traditional genetic algorithm cannot solve these problems well. Particle Swarm Optimization (PSO) algorithm was developed under the inspiration of behavior laws of bird flocks, fish schools and human communities. In this paper, we use the PSO algorothm to solve the electronic circuit optimization design. The new algorithm keeps not only the fast convergence speed, but effectively improves the capability of global searching as well. The experiment results show that the PSO algorithm is efficient than traditional genetic algorithm.

PL

W artykule opisano zastosowanie algorytmu optymalizacji rojem cząstek w rozwiązywaniu zagadnienia optymalnego projektowania układów elektronicznych. Proponowane rozwiązanie pozwala na uzyskanie dużej szybkości konwergencji oraz efektywne polepszenie możliwości wyszukiwania globalnego. Wyniki eksperymentalne pokazują, że algorytm PSO jest efektywniejszy niż typowy algorytm genetyczny.

13

Orthogonal Evolutionary Algorithm and its Application in Circuit Design

Yan X., Wu Q., Liu H.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

7-10

EN

During the space electronic system in carries out the exploratory mission in the deep space, it maybe faced with kinds of violent natural environment, to electric circuit's performance, the volume, the weight and the stability proposed a higher request, the traditional circuit design method already more and more with difficulty satisfied this kind of request. In this paper, proposed a new orthogonal evolutionary algorithm which uses in the electronic system circuit optimization design and through the experiment proved, the algorithm obtains the circuit structure to surpass the tradition circuit design method. For the case studies, this means has proved to be efficient and the experiment results show that the new means have got the better results.

PL

W artykule zaproponowano nowy ortogonalny algorytm ewolucyjny pozwalający na optymalizację projektowania systemów elektronicznych. Eksperymenty dowiodły że alorytm jest znacznie skuteczniejszy od tradycyjnych metod projektowania.

14

An Improved Two-phase Commit Protocol Adapted to the Distributed Real-time Transactions

Yan X., Yang J., Fan Q.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

27-30

EN

Based on the existing two-phase commit protocol (2PC), this paper proposes a protocol adapted to the distributed real-time transaction commit, which can avoid the blocking problem when dealing with transactions by coordinator redundancy; additionally, by the "health loan" of the locked data, the concurrency of transaction implementation is expanded to save the waiting time. Experimental analysis shows that: when the average arrival interval time of transaction is small, the success rate of the improved commit protocol is significantly higher than that of 2PC.

PL

artykule zaproponowano protokół bazujący na dwufazowym protokole typu 2PC. Nowy protokół pozwala na oszczędność czasu oczekiwania – jeśli średni czas odstępu między transakcjami jest mały przepływność danych jest wyższa niż w klasycznym protokole 2PC.

15

A class of nonlocal integrodifferential equations via fractional derivative and its mild solutions

Wang J., Yan X., Zhang X. H., Wang T. M, Li X. Z.

Opuscula Mathematica

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2011

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Vol. 31, no. 1

119-135

EN

In this paper, we discuss a class of integrodifferential equations with nonlocal conditions via a fractional derivative of the type: [formula]. Some sufficient conditions for the existence of mild solutions for the above system are given. The main tools are the resolvent operators and fixed point theorems due to Banach's fixed point theorem, Krasnoselskii's fixed point theorem and Schaefer's fixed point theorem. At last, an example is given for demonstration.

16

Improvement of LiCoO2 cathodes by using Ag2V4O11 as an additive

Cao X., Liu J., Wan J., Xie L., Yan X., Wang H.

Materials Science Poland

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2009

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Vol. 27, No. 1

287--295

EN

LiCoO2/Ag2V4O11 composites were fabricated as cathode materials for lithium ion batteries by mechanical mixing of commercial LiCoO2 and Ag2V4O11 powders. The underlying principle of this idea was that the metallic silver particles were formed and acted as a conducting matrix when Ag2V4O11 cathode was electrochemically reduced which could significantly increase the electronic conductivity and decrease the polarization of cathode materials. The structure, morphology and electrochemical performance of bare LiCoO2 and LiCoO2/Ag2V4O11 composites were analyzed by XRD, SEM and charge-discharge test of CR2016 coin cells. The results show that a low amount of Ag2V4O11 additive can effectively enhance the discharge capacity and cycleability of LiCoO2. The composite containing 3 wt. % of Ag2V4O11 exhibits a higher discharge capacity and better cycle life than bare LiCoO2.

17

Surface Functionalization of Nonwovens by Aluminum Sputter Coating

Deng B., Wei Q., Gao W., Yan X.

Fibres & Textiles in Eastern Europe

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2007

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Vol. 15, no. 4 (63)

90--92

EN

Nonwoven materials have been widely used in many industries. The surface properties of nonwovens are of importance in the applications presented here. In this study, magnetron sputter coating was used to deposit functional metal aluminium (Al) nanostructures onto nonwoven material. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM) were employed to study the structure, topography and chemical composition of the material, respectively. The AFM results revealed the formation of functional nanostructures on the fiber surfaces. A full Energy Dispersive X-ray analysis (EDX) mounted on the ESEM was also used to detect the elemental composition of the functional fibers. EDX examination showed the change in the chemical compositions of the fiber surfaces. It was also found that the electrical resistance of aluminium (Al) sputtered nonwoven material was significantly decreased.

PL

Właściwości powierzchniowe włókna zmieniono poprzez magnetronowe napylanie powłok aluminiowych, tworząc nanostruktury na powierzchni włóknin. Dla zbadania struktury warstwy, jej topografii i składu chemicznego stosowano SEM, ESEM i AFM. Badania za pomocą AFM wykazały formowanie się funkcjonalnej nanostruktury na powierzchni włókniny. Rentgenograficzna analiza (EOX) sprzężona z ESEM również służyła dla detekcji pierwiastków zintegrowanych z funkcjonalną powierzchnią włóknin. Badania EDV uwidoczniły różnice w składzie chemicznym warstw powierzchniowych włóknin. Niezależnie od powyższych analiz, wykazano znaczne obniżenie oporności elektrycznej włóknin napylanych aluminium.

18

Investigation of (Beta-Cyclodextrin)-Lappaconitine Inclusion Complex

Yan X

Polish Journal of Chemistry

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2001

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Vol. 75, nr 9

1297-1302

EN

The structure of the inclusion complex of Lappaconitine (Lap) and _-cyclodextrin (_-CD) was studied by theUV, infrared, andNMRspectroscopy, as well as X-ray powder diffractometry. The stability constant of the complex in water is 275 M-1, determined from the straight line portion of the phase-solubility diagram.