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1

Research on radiation characteristics of plasma Yagi antenna based on AIS base station in ships’ routeing waters

Sun Y., Chen Y., Kong F., Wei Y., Zhan F., Zhao J. S.

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

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2020

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Vol. 14, no. 1

179--184

EN

A Yagi plasma antenna model was established by HFSS according to the relationship between plasma dielectric constant and electron density. The patterns were simulated by changing plasma parameters and the number of director dipoles. Results show that when the passive vibrators were switched off, the antenna is omnidirectional antenna. The directionality increases with the increase of the number of passive dipole and the main lobe of which narrows down. Then the plasma Yagi antenna model is established by plasma tube, the gain changed by changing the number of passive dipoles, so the plasma Yagi antenna has a very good reconfigurability. Results prove that the feasibility of the plasma Yagi antenna can be used on AIS base station of Ships’ Routeing waters. It can promote the communication and capability of maritime supervision in Ships’ Routeing waters.

2

Flotation behavior and separation mechanism of quartz and iron minerals in α-bromolauric acid reverse flotation system

Han Y., Guo W., Zhu Y., Wei Y., Gu X.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

992--1003

EN

A new type collector α-Bromolauric acid (α-BLA) had been proved to be an efficient collector for quartz flotation. However, the effects of α-BLA on the flotation behavior of iron minerals and quartz-iron separation had not been investigated. In this study, collector α-BLA was synthesized in the laboratory. The flotation behavior of quartz, hematite and magnetite under α-BLA reverse flotation system were investigated and the separation mechanism of quartz-irons was studied by contact angle, zeta-potential and infrared spectroscopy. The results showed that the optimum flotation pH was 11.5 for quartz, 6.45 for hematite and 6.97 for magnetite. The best α-BLA concentrations was 75 mg/dm3 for quartz flotation, 125 mg/dm3 for hematite and magnetite flotation. The activator CaCl2 had little effect on the flotation of hematite and magnetite, but the minimum dosage 50 mg/dm3 of activator CaCl2 was necessary for quartz flotation. On the contrary, starch had no effect on the flotation of quartz, while the recoveries of magnetite and hematite tended to be 0% as starch concentration more than 80 mg/dm3. The separation mechanism of quartz from iron minerals under α-BLA reverse flotation system was that the starch could be selectively adsorbed on the surface of hematite and magnetite in the form of strong hydrogen bond adsorption. However, the same adsorption of starch did not occur on the surface of quartz, so the α-BLA can be successfully adsorbed on the surface of activated quartz to make the quartz strongly hydrophobic, and then to be floated out.

3

Some Novel Pythagorean Fuzzy Interaction Aggregation Operators in Multiple Attribute Decision Making

Gao H., Lu M., Wei G., Wei Y.

Fundamenta Informaticae

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2018

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Vol. 159, nr 4

385--428

EN

In this paper, we investigate the multiple attribute decision making problems with Pythagorean fuzzy information. Then, we utilize arithmetic and geometric operations to develop some Pythagorean fuzzy interaction aggregation operators: Pythagorean fuzzy interaction weighted average (PFIWA) operator, Pythagorean fuzzy interaction weighted geometric (PFIWG) operator, Pythagorean fuzzy interaction ordered weighted average (PFIOWA) operator, Pythagorean fuzzy interaction ordered weighted geometric (PFIOWG) operator, Pythagorean fuzzy interaction hybrid average (PFIHA) operator, Pythagorean fuzzy interaction hybrid geometric (PFIHG) operator, Pythagorean fuzzy interaction correlate aggregation operators, Pythagorean fuzzy interaction induced aggregation operators, Pythagorean fuzzy interaction induced correlate aggregation operators, Pythagorean fuzzy interactive power arithmetic and geometric aggregation operators. The prominent characteristic of these proposed operators are studied. Then, we have utilized these operators to develop some approaches to solve the Pythagorean fuzzy multiple attribute decision making problems. Finally, a practical example for selecting the service outsourcing provider of communications industry is given to verify the developed approach and to demonstrate its practicality and effectiveness.

4

Differential Fault Attacks on Lightweight Cipher LBlock

Wei Y., Rong Y., Fan C.

Fundamenta Informaticae

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2018

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Vol. 157, nr 1/2

125--139

EN

Lightweight block cipher is usually used in “Internet of Thing” to protect confidentiality as well as to authentication. LBlock is a lightweight block cipher designed for tiny computing devices, such as RFID tags and sensor network nodes. The cipher algorithm iterates a Feistel structure with SP type round function by 32 rounds. Its block size is 64 bits and key size is 80 bits. The designers show that LBlock is resistant against most classical attacks, such as differential and linear cryptanalysis. This paper proposed differential fault analysis on LBlock based on different depth of fault model, the theoretical analysis demonstrates that LBlock is vulnerable to deep differential fault attack due to its Feistel structure and diffusion layer. By injecting faults in the 27th round to the 29th round, a differential fault analysis on LBlock based on a nibble-oriented random fault model is presented. The experiment shows that 4.3 faults on average could recover a round key. For reveal the whole key information, 13.3 faults on average are needed. This indicates that cryptographic devices supporting LBlock should be carefully protected.

5

Correlation between δ13C and δ15N in flying fish (Exocoetus volitans) muscle and scales from the South China Sea

Wu L., Xu L., Sun J., Wang X., Wei Y., Li Y., Liu X.

Oceanological and Hydrobiological Studies

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2017

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Vol. 46, No. 3

307--313

EN

We collected flying fish (Exocoetus volitans) from the South China Sea to determine whether fish scale isotope values correlate with those from muscle, and discuss relevant eco-environmental implications. A significant positive correlation was determined between fish scales and muscle δ13C and δ15N, rendering a fish scale an alternative to muscle tissue for stable isotope analysis. However, muscle and scale isotopic offsets should be fully considered when using δ13C and δ15N to analyze the actual trophic level of fish and their food source. The average offsets of δ13C and δ15N between muscles and scales are -2.1 ± 0.5‰ and 2.3 ± 0.6‰, respectively, though these values vary slightly with fish mass. Weak correlations were found between δ13C and δ15N, both in the flying fish muscle and scales, suggesting that other factors are influencing δ13C and δ15N. Fish δ15N also correlates with the size of individuals, while δ13C reflects the marine habitat. Based on our data, it appears that more eco-environmental processes can be revealed from modern or ancient flying fish scales.

6

Using an Interdigital Micromixer for Separation of In3+ from Zinc Hydrometallurgical Process with D2EHPA as an Extractant

Li C., Jiang F., Ju S., Peng J., Wei Y., Zhang L.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

873--878

EN

Experiments were performed in an interdigital micromixer with 30 microchannels (40 μm width of each channel) to separate In3+, Fe3+ and Zn2+ from sulfate solutions using Di-(2-ethylhexyl)phosphoric acid (D2EHPA) as the extractant. The effects of pH, extractant concentration and flow rate on the extraction efficiency and flow rate on mass transfer coefficient of In3+, Fe3+ and Zn2+ were investigated. At a phase flow rate of 7.0 mL/min and initial solution pH of 0.423, the extraction efficiency of In3+, Fe3+ and Zn2+ was 99.29%, 3.43% and 2.54%, respectively and mass transfer coefficient of In3+, Fe3+ and Zn2+ was 144.307 s-1,1.018 s-1 and 0.750 s-1. Then, the loaded organic phase was stripped in an interdigital micromixer. At a phase flow rate of 9.0 mL/min and HCl concentration of 160 g/L, stripping efficiency of In3+ was 98.92% and mass transfer coefficient of In3+ was 169.808 s-1, while concentration of Fe3+ and Zn2+ was lower than 0.005 g/L with good separation of In3+ from Fe3+ and Zn2+.

7

Effect of gradient temperature rolling (GTR) and cooling on microstructure and properties of E40-grade heavy plate

Gaosheng L., Wei Y., Qingwu C., He Z.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 1

121--131

EN

Despite numerous investigations on gradient temperature rolling (GTR) and its influence on grain refining, no research exists on appropriate cooling after GTR, which is important in the microstructural control. This work focuses on the effect of final microstructure on heavy-plate properties and microstructural evolution during different rolling and cooling processes. GTR and uniform temperature rolling (UTR) were applied to E40-grade heavy plates. GTR plates were maintained at 1073 K at their surface and 1473 K at their core. After rolling, experimental plates were cooled at a series of rates. Their microstructure and mechanical properties were studied. The plate prepared using GTR and air cooling had the best integrated property because of its uniform and fine ferrite microstructure. The GTR plate strength increased gradually with a corresponding decrease in toughness as the cooling rate increased. The uniform temperature rolling plate cooled in water exhibited the worst mechanical properties.

8

Rare Earth Elements supply vs. clean energy technologies: new problems to be solve

Zhou B., Li Z., Zhao Y., Zhang C., Wei Y.

Gospodarka Surowcami Mineralnymi

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2016

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T. 32, z. 4

29--44

EN

Rare earth elements (REEs) provide important properties to clean energy technologies such as wind turbine and hybrid electric vehicles. The global REE demand will grow rapidly during the global transformation toward a greener economy in the next decades. This high demand will require a steady supply chain in the long run. China has a monopoly of global REE production and extraction. The global REE supply chain runs the risk of disruption along with Chinese REE policy evolution. To overcome this supply chain vulnerability, new strategies and measures should be adopted to satisfy future REE supply/demand. There is a pressing need to explore REE deposits, develop efficient REE recycling techniques from end-of-life products, improve substitution technologies for REEs, and reduce the number of critical REEs used in devices. Such measures are facing significant challenges due to environmental factors and an unbalanced market, and overcoming them requires efforts from government and REE companies.

PL

Pierwiastki ziem rzadkich (Rare Earths Elements) mają istotne znaczenie dla rozwoju czystych technologii energetycznych, takich jak turbiny wiatrowe czy pojazdy hybrydowe. Światowy popyt na REE będzie wzrastał w związku z globalną transformacją w kierunku bardziej czystej (ekologicznej) gospodarki w okresie najbliższych dziesięcioleci. Wysoki popyt wymagać będzie stabilnego łańcucha dostaw REE w dłuższej perspektywie. Chiny mają monopol w zakresie globalnej produkcji i wydobycia REE. Światowe dostawy REE obarczone są jednak ryzykiem zakłóceń wynikających z chińskiej polityki w tym zakresie. W związku z tym, powinny być przyjęte nowe środki i strategie w celu zaspokojenia przyszłego popytu/podaży na REE. Istnieje pilna konieczność: poszukiwania nowych złóż, opracowania skutecznych technik recyklingu z wycofanych z eksploatacji produktów, poprawy technologii z zastosowaniem substytutów REE oraz zmniejszenie liczby krytycznych pierwiastków ziem rzadkich w stosowanych urządzeniach. Działania te stanowią poważne wyzwanie ze względu na czynniki środowiskowe i niezrównoważony rynek (monopol podaży). Przezwyciężenie ich wymaga odpowiednich działań ze strony rządu i firm zajmujących się produkcją REE.

9

Structure and Properties of Modified Flax Yarn with Collagen

Sui Z., Pang W., Wei Y., Song J.

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 1 (109)

30--34

EN

The structure and property changes of collagen modified flax yarn were investigated in order to improve the usability of flax yarn. First flax yarn was treated with sodium hydroxide solution and next with chloroacetic acid to get carboxymethyl flax yarn. Then the carboxymethyl flax yarn was grafted with gelatin protein solution to obtain modified flax yarn. Reactive blue dye was used for the dyeing test of the modified flax yarn. Its structure was characterized and analysed by FT-IR, X-ray diffraction and SEM. Meanwhile breaking strength and elongation at break of the modified flax yarn and the exhaustion rate and fixation rate of reactive blue dye was tested, respectively. The results show that the carboxymethyl flax yarn and gelatin protein are combined with a chemical bond. The different mass concentration of the gelatin solution has some influence on the grafting rate of flax yarn grafted with collagen. After modification of the flax yarn, the breaking strength shows a little loss, the elongation at break increases to a certain degree, and the exhaustion and fixation rate of the reactive dye increase significantly.

PL

Badano strukturę i zmiany właściwości przędz lnianych modyfikowanych kolagenem w celu polepszenia właściwości użytkowych. W pierwszej fazie przędze traktowano roztworem wodorotlenku sodu, a następnie kwasem chlorooctowym w celu otrzymania karboksymetylocelulozy. Otrzymaną przędzę szczepiono roztworem protein. Przędzę barwiono reaktywnym barwnikiem niebieskim. Właściwości strukturalne przędzy zbadano stosując spektroskopię FTIR, dyfrakcję rentgenowską i SEM. Stwierdzono, że zmodyfikowane przędze posiadają nieznacznie mniejszą wytrzymałość na rozciąganie, natomiast większe wydłużenie przy zerwaniu. Stwierdzono również, że zdolności barwienia wzrosły znacznie po modyfikacji.

10

Ecological risk assessment of heavy metals in sediments of a riverine wetland, Huaihe River Watershed, China

Yuan H., Pan W., Zhu Z., Wei Y., Geng Q., An S.

Ecological Chemistry and Engineering. S

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2015

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Vol. 22, nr 2

231--242

EN

The concentrations of Zn, Cr, Cu, As, Cd, and Pb in sediment cores collected from a representative riverine wetland located in the Huaihe River watershed, China, dramaticlly increased from the bottom to upper layer of the cores. Application of principal component analysis (PCA) and enrichment factor (EF) suggested that heavy metals might primarily have been derived from the inflow of contaminated water from an industrial park and agricultural region. Component 1 of the PCA was dominated by Zn, Cr, Cu, Cd, and Pb, while Component 2 was dominated by As. Metals’ high concentrations and EF values showed that the anthropogenic pollutants have increased sharply in recent years and reflect the continuous development of industry and agriculture in the region of the wetland, with a corresponding dramatic deterioration of the environment due to constant effluent of pollutants. Cd exerted the highest potential ecological risk of individual metals of sediment cores. Additionally, integrated RI values for all metals indicated that sediments possessed low ecological risk from the bottom to about 6 cm depth of the cores, moderate ecological risk from about 5 cm depth upwards, then considerable ecological risk from 4 cm depth to the top layer of the sediment cores, which demonstrates a continuous deterioration of environmental quality in recent years in this region.

PL

Stężenia Zn, Cr, Cu, As, Cd i Pb w rdzeniach osadów pobranych z reprezentatywnych podmokłych terenów nadrzecznych, znajdujących się w zlewni rzeki Huaihe, Chiny, wykazały znaczne wzrosty od dołu do górnej warstwy rdzeni. Zastosowanie analizy głównych składowych (PCA) i czynnika wzbogacania (EF) wykazało, że źródłem metali ciężkich mogą być przede wszystkim zanieczyszczone wody z parku przemysłowego i z obszarów rolniczych regionu. Składowa 1 PCA było zdominowane przez Zn, Cr, Cu, Cd, i Pb, natomiast składowa 2 była zdominowana przez As. Duże stężenia metali i wartości EF wykazały, że antropogenne zanieczyszczenie gwałtownie wzrosło w ostatnich latach i odzwierciedla ciągły rozwój przemysłu i rolnictwa w regionie nadrzecznym, z odpowiednim drastycznym pogorszeniem stanu środowiska ze względu na stałe zanieczyszczenie ściekami. Cd stwarza największe potencjalne ryzyko ekologiczne spośród wszystkich metali rdzeni osadów. Dodatkowo, zintegrowane wartości RI dla wszystkich metali wskazują, że osady tworzyły niskie zagrożenie ekologiczne od dołu do około 6 cm głębokości rdzeni, umiarkowane ryzyko ekologiczne od około 5 cm głębokości do góry. Znaczne zagrożenie ekologiczne stwarzają osady od głębokości 4 cm do warstwy wierzchniej rdzenia, co świadczy o ciągłym pogarszaniu się jakości środowiska w ostatnich latach w tym regionie.

11

A Novel Multi-objective Optimization Dispatch Model for Hybrid Thermal-Wind-PV Power System

Wei Y., Niu D., Lu Y.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

18--20

EN

A novel multi-objective model for hybrid thermal-wind-PV power system is proposed in this paper to solve the problem of energy saving and emission reduction/economic dispatch which is optimized by proposed Karush-Kuhn-Tucker (KKT) and quantum genetic algorithm (QGA). Through detailed analyses, mathematical functions of power operation, energy consumption and emission and relevant constraint conditions are proposed, and then for the first time, the multi-objective optimization model of energy saving and emission reduction/economic dispatch including thermal power, wind power and PV power is established. KKT is used to transform multi-objective model into single-objective one, QGA is used to optimize the single-objective model, then a novel KKT and QGA is proposed. Several simulations including wind power, PV power and thermal power are proposed, which shows positive effects of wind power and PV power in energy saving and emission reduction. The experimental study shows that the proposed algorithm is more accurate and with less computational time than commonly used optimization methods. The actual implementation results prove that the model and algorithm are effective and practical to reduce power cost, energy consumption and emission.

PL

W artykule przedstawiono model hybrydowego systemu Odnawianych Źródeł Energii (termiczne, wiatrowe, fotowoltaika). W modelu wzięto pod uwagę optymalizację użytkowania (oszczędzanie energii oraz ekonomika wytwarzania). Wykorzystano metodę Karush-Kuhn-Tucker oraz QGA. Na podstawie analiz, opracowano funkcje matematyczne dotyczących przesyłu, emisji i zużycia energii oraz ograniczeń z nimi związanych. Wyniki badań symulacyjnych i eksperymentalnych potwierdzają skuteczność działania zaproponowanej optymalizacji.

12

Termodynamiczny model przemian fazowych podczas międzykrytycznego azotowania austenitycznego

Wei Y., Żurecki Z., Sisson R.D.

Inżynieria Powierzchni

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2013

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nr 2

56--62

PL

Artykuł opisuje wyniki pracy eksperymentalnej na stali AISI4140 (odpowiednik stali 42CrMo4) i badań wzajemnego oddziaływania azotowania i warunków chłodzenia oraz transformacje faz w obu typach azotowania: ferrytycznym (525°C) i międzykrytycznym austenitycznym (610°C). Termodynamiczny model użyty do wstępnego projektowania warunków procesu został również zastosowany do oceny mikrostruktury azotowanej warstwy. Badania struktur przeprowadzono za pomocą metod SEM, EPMA i EDS. W artykule przedstawiono także kinetykę wzrostu stref dyfuzyjnych oraz kontrolę wymiarową azotowanych części w wyniku zmian fazowych.

EN

This paper presents results of experimental work on AISI4140 steels, examining the interplay between the nitriding and cooling conditions and phase transformations in both ferritic (525oC) and subcritical, nitrogen-austenitic (610oC) processes. Thermodynamic model, used to design process conditions, is applied also in the microstructural interpretation of nitrided layers, examined via SEM, EPMA and EDS. Kinetics of interstitial diffusion and phase transformation-based dimensional control of nitrided parts are also presented.

13

Research on Energy-Saving Optimization Design of Bridge Crane

Yifei T., Zhaohui T., Wei Y., Zhen Y.

Eksploatacja i Niezawodność

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2013

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Vol. 15, no. 4

449--457

EN

Bridge crane is one of the most widely used cranes in our country, which is indispensable equipment for material conveying in the modern production. The security of bridge crane is always focused on when being used. The important indicators of crane performances include strength, stiffness, and crane weight, which mainly depend on the structure design of the bridge crane. So it is of importance to research on energy-saving optimization design by means of finite element analysis, ADMAS and Matlab. In this paper, the framework of energy-saving optimization is proposed. Secondly, taking 50 t – 31.5 m bridge crane as research object, its structure is described and the FE model of the bridge cranes is developed for the finite element analysis. Thirdly, shape optimal mathematical model of the crane is proposed for shape optimization as well as size optimal mathematical model for size optimization and topology optimal mathematical model for topology optimization. Besides, further comprehensive energy-saving optimizations are carried out as well as cross-section optimization. Finally, system-level energy-saving optimization design of bridge crane is further carried out with energy-saving transmission design results feedback to energy-saving optimization design of metal structure. The optimization results show that structural optimization design can reduce total mass of crane greatly by using the finite element analysis and optimization technology premised on the design requirements of cranes such as stiffness, strength and so on, thus energy-saving design can be achieved.

PL

Suwnica pomostowa jest jednym z najczęściej używanych typów suwnic w Chinach i stanowi niezbędne wyposażenie do transportu materiałów w nowoczesnej produkcji. Kluczową kwestią dotyczącą obsługi suwnicy pomostowej jest zawsze bezpieczeństwo. Ważnymi wskaźnikami wydajności suwnicy są m.in. wytrzymałość, sztywność oraz ciężar suwnicy, które zależą głównie od konstrukcji suwnicy. Konieczne są zatem badania nad optymalizacją energooszczędności konstrukcji za pomocą analizy elementów skończonych, ADMAS oraz Matlab. W niniejszej pracy zaproponowano koncepcję optymalizacji energooszczędności. Po drugie, opisano budowę suwnicy pomostowej (50 t – 31.5 m) oraz opracowano model MES suwnicy do analizy metodą elementów skończonych. Po trzecie, przyjmując minimalną pojemność jako funkcję celu, wysokość i szerokość suwnicy jako zmienne projektowe, a naprężenie, energię odkształcenia, modalnych jako ograniczenia, ustalono optymalny model matematyczny kształtu żurawia dla celów optymalizacyjnego projektowania kształtu. Po czwarte, przyjmując minimalny udział objętościowy jako funkcję celu, a grubości płyt jako zmienne projektowe, ustalono optymalny model matematyczny rozmiarów do celów optymalizacyjnego projektowania rozmiarów. Po piąte, przyjmując minimalny udział objętościowy jako funkcję celu, a gęstości materiału każdego z elementów jako zmienne projektowe, ustalono optymalny model matematyczny topologii do celów optymalizacyjnego projektowania topologii. Wreszcie, wykonano multidyscyplinarny energooszczędny projekt optymalizacyjny systemu suwnicy pomostowej, a wyniki energooszczędnego projektowania układu napędu zostały wykorzystane jako informacja zwrotna przy energooszczędnym projektowaniu optymalizacyjnym konstrukcji metalowej. Wyniki optymalizacji pokazują, że optymalizacyjne projektowanie konstrukcji z wykorzystaniem analizy MES oraz technologii optymalizacji opartej na wymogach projektowych dla suwnic, takich jak sztywność, wytrzymałość itd., może znacznie obniżyć całkowitą masę dźwigu, a co za tym idzie zwiększyć jego energooszczędność.

14

A web partition algorithm based on support vector machine

Zhang W., Zhang H., Zhang H., Chen G., Wei Y.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 1b

31-33

EN

In order to solve the problem of network traffic partition of crawler nodes and website nodes, a support vector machine web partition algorithm has been proposed. The algorithm reduces the load of the information collection system on the network through feature extraction, feature selection and support vector machine optimisation, thereby enhancing the response rate and crawling rate of the crawlers.

PL

Zaproponowano algorytm VSM do rozwiązywania problem podziału sieci ruchu na partycje przez węzły typu crawler i website. Algorytm redukuje przeciążenie napływem informacji przez ekstrakcję cech, selekcję cech i optymalizację VSM.

15

Improved linear complexities of the frequency hopping sequences in two optimal sets

Gao J., Li X., Wei Y.

Control and Cybernetics

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2012

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Vol. 41, no. 2

317-334

EN

For the anti-jamming purpose, high linear complexity is desired for each frequency hopping sequence in an optimal set. Using a proper power permutation, Wang has shown that an optimal set of frequency hopping sequences with small linear complexity can be transformed into a new optimal set of frequency hopping sequences with large linear complexity. This paper conains two results. First, we extend the result of Wang. A power permutation is only suitable for a special construction of optimal set of frequency hopping sequences, see Wang (2011). However, the power permutation chosen in this paper applies to the general construction of optimal set of frequency hopping sequences. Second, by using a binomial permutation polynomial P(x), which is different from those permutations used before, we obtain a novel optimal set of frequency hopping sequences with high linear complexity from an optimal set of frequency hopping sequences with small linear complexity. By counting the number of different roots in the sequence representation, we determine the linear complexities of the frequency hopping sequences in two optimal sets transformed by the power permutation or binomial permutation.

16

Infuence of Iron Ion on Thermal Behavior of Ammonium Nitrate and Emulsion Explosives

Xu Z., Liu D., Hu Y., Ye Z., Wei Y.

Central European Journal of Energetic Materials

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2010

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Vol. 7, nr 1

77-93

EN

The infuence of ferric nitrate on the thermal stability of ammonium nitrate and emulsion matrix were used to study with Accelerating Rate Calorimeter (ARC) and constant temperature thermal decomposition experiment in this paper. It is shown that ferric nitrate has signifcant catalytic property to the ammonium nitrate and emulsion matrix, which decrease the initial decomposition temperature of ammonium nitrate by 60.16 C and emulsion matrix by 30.33 C. The results of the infuence of ferric nitrate on catalysis of ammonium nitrate using ARC and constant temperature thermal decomposition experiment are the same. The most probable mechanism function, activation energy and the preexponential factor of ammonium nitrate with ferric nitrate were determined to be f(α) = 1-α, E = 195.41 kJ/mol, A = 2.08×1019 s-1. The kinetics of ammonium nitrate decomposition can be used to calculate the critical temperatures for ammonium nitrate decomposition with and without the presence of ferric nitrate, based on the Frank-Kamenetskii model of thermal explosion. Furthermore, as the iron-plate experiment shows, ferric nitrate can signifcantly reduce the critical temperature of emulsion matrix decomposition. Once the ferric nitrate interfuses in the ammonium nitrate and emulsion matrix, the thermal stability of ammonium nitrate and emulsion matrix is decreasing.

17

Voltammetric determination of caffeine at pt/carbon nanotubes composite modified glassy carbon electrode

Wei Y., Zhang L., Shao C., Li C.

Chemia Analityczna

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2009

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Vol. 54, No. 4

607-617

EN

Platinum nanoparticles (Pt) supported on carbon nanotubes (CNTs) were used to modify glassy carbon electrode (GCE) in order to determine caffeine. In 0.01 mol L-1 H2SO4 solution, the modified electrode (Pt-CNTs-GCE) showed obvious electrocatalytic activitytowards oxidation of caffeine. The oxidation peak current increased significantly and the oxidation potential shifted negatively. All experimental parameters were optimised.The magnitude of the oxidation peak current of caffeine was proportional to its concentration over the range 1.0 x 10-6-1.0 x l0-4mol L-1 and detection limit was 2 * 10-7 mol L-1. Relative standard deviation (RSD) of seven replicate determinations of l x 10-5 mol L-1caffeine was 2.03%. The proposed method was applied to the determination of caffeine in real samples with the recovery in the range from 96.5% to 102%.

PL

Nanocząsteczki platyny wsparte węglowymi nanorurkami użyto do modyfikacji elektrody z węgla szklistego w celu oznaczenia kofeiny. Zmodyfikowana elektroda wykazywała elektrokatalityczną aktywność w procesie utlenienia kofeiny. Prąd utleniania kofeiny wzrastał a potencjał piku woltamperometrycznego stawał się bardziej ujemny. Zoptymalizowano parametry eksperymentalne. Wysokość piku woltamperometrycznego rosła liniowo ze stężeniem kofeiny w zakresie 1.0x10-6-1.0x l O-4 mol L-1. Granica wykrywalności wyniosła 2 x 10-7mol L-1 a względne odchylenie standardowe dla stężenia l x 10-1mol L-1 wyniosło2.03%. Opracowaną metodę zastosowano do oznaczania kofeiny w rzeczywistych próbkach. Odzysk metody wyniósł od 96.5 do 102%.

18

Simultaneous HPLC-DAD analysis of five flavonoids in diabetic rat plasma and its application in the study of pharmacokinetics

Tang D, Yin Y, Zhang Z., Gao Y., Wei Y, Chen Y, Han Y.

Acta Chromatographica

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2009

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Vol. 21, no. 3

483--497

EN

A HPLC-DAD method for simultaneous analysis of five flavonoids (rutin, quercitrin, quercetin, kaempferol, and isorhamnetin) in diabetic rat plasma has been developed and validated. Separation of the five flavonoids was accomplished on a C 18 column (250 mm × 4.6 mm i.d., 5-µm particle) and detection was performed at 350 nm. The best resolution was achieved with a methanol-0.1% formic acid gradient at a flow rate of 1.0 mL min −1 . The correlation coefficients for all the calibration plots ( r > 0.999) showed linearity was good over the range tested. The relative standard deviation of the method was less than 7% and 10% for intra- and inter-day assays, and average recovery was between 77.2 and 99.2%. Sensitivity was high and detection limits were between 0.006 and 0.02 µg mL −1 . The method has been successfully used to determine drug concentrations in diabetic rat plasma samples and the pharmacokinetics of the drugs.

19

Determination of ethambutol at glassy carbon electrode modified with multiwall carbon nanotubes

Shao C., Wei Y., Li S., Li C.

Chemia Analityczna

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2008

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Vol. 53, No. 4

511-521

EN

A simple and convenient electrochemical method for direct determination of etharnbutol (EMB) using a glassy carbon electrode (GCE) modified with a film of multiwall carbon nanotubes (MWCNT) has been described. Electrochemical behavior of EMB has been investigated. Owing to the unique structure and extraordinary properties of MWCNT, the MWCNT film has shown an obvious electrocatalytic activity towards oxidation of EMB, since MWCNT greatly enhances the oxidation peak current of EMB and lowers its oxidation overpotential. All experimental parameters have been optimized. Under the optimum conditions the oxidation peak current was linearly proportional to the concentration of EMB in the range 8.0 x 10-6 to 2.5 x 10-4 mol L-1. The detection limit was 7.6 x 10-7 mol L-1 at 4 min accumulation, and the relative standard deviation (RSD) of eight determinations of 5 x 10-5 mol L-1 EMB was 4.1%. The proposed method has been successfully applied to the determination of EMB in drugs.

PL

Opisano prostą, wygodną metodę bezpośredniego oznaczania etambutolu (EMB) na elektrodach z węgla szklistego (GCE) modyfikowanych wielościennymi nanomrkami węglowymi (MWCNT). Zbadano elektrochemiczne zachowanie tego leku. Dzięki unikalnym właściwościom i strukturze MWCNT, modyfikowane GCE wykazywały aktywność elektrokatalityczną względem utleniania EMB (powiększenie prądu piku i obniżenie nadpotencjału). Zoptymalizowano parametry eksperymentalne pomiarów woltamperometrycznych. Prąd piku anodowego zależał liniowo od stężenia EMB w zakresie 8.0 x 10-6 to 2.5 x 10-4 mol L-1. Granica wykrywalności przy 4 min zatężaniu wynosiła 7.6 x 10-7 mol L-1, a względne odchylenie standardowe, obliczone z ośmiu pomiarów EMB o stężeniu 5 x 10-5 mol L-1 wynosiło 4,1%. Zaproponowanąmetodę z powodzeniem zastosowano do oznaczania EMB w lekach.

20

Femtosecond laser-induced damage in dielectrics

Peng Y., Wei Y., Lv Z.

Optica Applicata

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2004

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Vol. 34, nr 3

319-329

EN

We present a new method to investigate the ablation phenomenon by a 100 fs, 1053 nm Gaussian laser pulse in fused silica and describe the different mechanisms of ablation in long pulse and ultrashort pulse lasers. A modified rate equation is used to numerically calculate damage in dielectrics. In addition, we examine the respective role of ionization and avalanche ionization in femtosecond laser-induced damage. We find that present results are in quantitative agreement with those of earlier study.