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1

On the Estimation of Fatigue Crack Initiation Life of H62 Brass

Zheng M., Zhang S., Peng Xiao Jian, Wang Yi

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

31--35

EN

In the present paper, the excavation of the energetic approach that estimates the fatigue crack initiation life of metal is conducted for H62 brass. The benefit of the energetic approach is the division of the actual applied strain range Δε into two parts, that is, a damage strain range Δεd that induces fatigue damage within the metal, and an undamaged strain range Δεc, which does not produce fatigue damage of the metal and corresponds to theoretical strain fatigue limit. The brightness of this approach is that the undamaged strain range Δεc can be estimated by the fundamental conventional parameters of metal in tensile test. The result indicated that the fatigue crack initiation life of H62 brass can be estimated by this approach successfully.

2

Optimization and evaluation of alkali-pretreated Paeonia ostii seed coats as adsorbent for the removal of MB from aqueous solution

Liu Q., Li T., Zhang S., Qu L., Ren B.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 3

29--36

EN

A novel efficient adsorbent, alkali-pretreated Paeonia ostii seed coats (AP-PSC), was investigated for the removal of methylene blue (MB) dye from solution. Orthogonal array design was applied to optimize the process parameters viz. alkali concentration, liquid-solid ratio (LSR) and pretreatment time. The results revealed that the optimal pretreatment conditions were at 0.8% (w/w) NaOH with LSR of 0.35 L g–1 treating for 50 min. Equilibrium and kinetic studies indicated that Langmuir isotherm and Pseudo-second-order models described the experimental data well. The maximum adsorption capability was of 368.2 mg g–1 for MB at 25°C. Thermodynamic parameters suggested that the AP-PSC adsorption process was physical, endothermic and spontaneous. Furthermore, the adsorption process was influenced by several interactive mechanisms, including ion-exchange, as well as Van der Waals forces and hydrogen bonds that occur concomitantly. It was concluded that AP-PSC may be potential as an efficient adsorbent to remove MB from solution.

3

Quaternion-based filtering for gyroless attitude estimation without an attitude dynamics model

Zhang S., Xing F., Sun T., You Z.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 3

631--643

EN

Conventionally, the filtering technique for attitude estimation is performed using gyros or attitude dynamics models. In order to extend the application range of an attitude filter, this paper proposes a quaternion-based filtering framework for gyroless attitude estimation without an attitude dynamics model. The attitude estimation system is established based on a quaternion kinematic equation and vector observation models. The angular velocity in the system is determined through observation vectors from attitude sensors and the statistical properties of the angular velocity error are analysed. A Kalman filter is applied to estimate the attitude error such that the effect from the angular velocity error is compensated with its statistical properties at each sampling moment. A numerical simulation example is presented to illustrate the performance of the proposed algorithm.

4

An integrated treatment technology for ground fissures of shallow coal seam mining in the mountainous area of southwestern China: a typical case study

Zhu H., He F., Zhang S., Yang Z.

Gospodarka Surowcami Mineralnymi

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2018

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T. 34, z. 1

119--138

EN

This article is the result of treatments on ground fissures for environmental protection and scientific shallow coal seam mining. In the southwestern mining area of China, the traditional longwall mining method has caused a large area of surface sinkhole, ground fissures, vegetation deterioration and disorderly coal gangue. To solve these problems, an integrated treatment technology that includes ground fissure treatment technology and underground backfilled technology was proposed as a solution. The technical principle and technical process were explained in detail; the ground fissure treatment technology involves a “three-step treatment method”, and the underground backfilled technology adopted a strip mining method with backfilling technology. The compression mechanical behavior of backfilled material, including coal gangue, fly ash and ordinary Portland cement, was studied; the mixed ratio of 1:0.3:0.18 was selected. In addition, the vertical stress, vertical displacement and plastic zone of the coal pillar were determined by FLAC3D numerical simulation, and a rational mining scheme of “11 m mining width, 2 m coal pillar width” was determined to be appropriate because of the lower vertical stress, smaller vertical displacement and better supporting capacity of the coal pillar. The monitoring results of ground sinkhole indicated that the maximal ground sinkhole deformation was 17.3 cm, and the deformation showed few changes after this technology was implemented. The treatment capacity of coal gangue and fly ash reached 821.150 t per year, and the vegetation survival rate of the ground fissure treatment area reached 85%. This integrated treatment technology could effectively control ground fissures and surface sinkhole as well as protect the environment.

PL

Artykuł jest opisem zapobiegania pęknięciom gruntu w celu ochrony środowiska, jak również naukowego podejścia do wydobywania płytko zalegających pokładów węgla. W południowo-zachodniej części górniczej Chin tradycyjna, ścianowa metoda wydobywania węgla, powodowała duży obszar powierzchniowego zapadliska, pęknięcia gruntu, pogorszenie stanu wegetacji roślin. W celu rozwiązania tych problemów zaproponowano zintegrowaną technologię zapobiegania, która obejmuje technologię zapobiegania pęknięciom gruntu i podziemną technologię podsadzki. Zasada i proces techniczny zostały szczegółowo opisane; technologia zapobiegania pęknięciom gruntu obejmuje „trójstopniową metodę zabiegu”, a technologia podsadzki zaadoptowała metodę wydobywania węgla pasami. Badano ściśliwość podsadzki, w tym odpadów węglowych, popiołu lotnego i zwykłego cementu portlandzkiego; wybrano mieszaninę o stosunku 1: 0,3: 0,18. Ponadto pionowe naprężenie, pionowe przemieszczenie i strefa plastyczności filaru węglowego zostały określone za pomocą symulacji numerycznej FLAC 3D. Racjonalny schemat wydobycia „szerokość wydobycia 11 m, szerokość filaru węglowego 2 m” był odpowiedni ze względu na niższą wartość naprężenia pionowego, mniejsze pionowe przemieszczenie i lepszą nośność filaru węglowego. Wyniki monitoringu pęknięć gruntu wskazują, że maksymalna deformacja gruntu wynosiła 17,3 cm i wykazała kilka zmian po wdrożeniu tej technologii. Ilość zagospodarowanych odpadów węglowych i popiołu lotnego wynosiła 821 150 Mg na rok, a wskaźnik przeżycia roślinności w obszarze zapobiegania pęknięciom gruntu osiągnął poziom 85%. Ta zintegrowana technologia zapobiegania może skutecznie kontrolować pęknięcia gruntu i deformację powierzchni, a także chronić środowisko.

5

A Color Image Watermarking Approach Based on Synchronization Correction

Wang X., Xu H., Zhang S., Liang L., Niu P., Yang H.

Fundamenta Informaticae

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2018

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Vol. 158, nr 4

385--407

EN

Digital watermarking has been proposed as an effective technology of copyright protection and content authentication, yet up to now, research on the robust watermarking against geometric attacks is still a challenging task. This paper presents a novel robust watermarking algorithm in nonsubsampled shearlet transform (NSST) domain using quaternion polar harmonic transform (PHT) and least squares support vector regression (LS-SVR), which is a recently developed geometric correction algorithm for digital color image. The major innovative works of the proposed approach lie in that (1) the NSST is applied to embed the watermark, which can provide the image function with nearly optimal approximation and employ fully the properties of human visual system (HVS), (2) the robust 2D transform, namely quaternion PHT is introduced to represent the characteristics of color image, and (3) the novel synchronous correction method is proposed using the excellent LS-SVR and quaternion PHTs, which can accurately estimate the geometric distortions parameters. In our experiments, we applied the proposed method to the standard color image test dataset, and the experimental results demonstrate that the proposed algorithm is not only invisible, but also robustness against common signal processing operations and geometric attacks.

6

Influence of Rib Structure and Elastic Yarn Type Variations on Textile Piezoresistive Strain Sensor Characteristics

Raji R. K., Miao X., Zhang S., Li Y., Wan A.

Fibres & Textiles in Eastern Europe

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2018

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Vol. 26, no. 5 (131)

24--31

EN

Production parameters have been established to play a fundamental role in dictating the physical characteristics and sensing properties of knitted sensors. This research studied the influence of elastic yarn type and rib fabric structure variation on the physical, tensile and conductive properties and sensitivity performance of knitted underwear strain sensors to be used for breathing mensuration. Four different structures in 1×1, 1×2, 1×3 and 2×2 mock ribs were knitted using covered elastic (CY) and bare strand elastic yarn (BS) combinations. These two parameters proffered unique physical, conductive and tensile characteristics to the samples. Wear and machine tests were conducted to ascertain the sensor’s piezoresistive responses. The machine test showed a higher piezoresistive response, with an average peak value (APV) from 1.70 Ω to 0.24 Ω, while those for the wear test recorded were around 0.0110 Ω to 1.867 Ω for all sample categories. However, sensors knitted with covered elastic yarns produced the best breathing test results (APV of 1.089 Ω – 1.86 Ω) compared to bare strand elastic yarns (APV 0.0027 Ω – 0.0790 Ω) when used in a wearable environment. Fabric structure variation had influences on both conductive and tensile characteristics; however, the effects on the piezoresistive response were negligible. The influences of the unique characteristics provided by these core parameters on sensor resistance values, piezoresistance, aging, ease of deformation and dimensional stability have also been discussed.

PL

W pracy badano wpływ struktury dzianiny i rodzaju przędzy na właściwości fizyczne, rozciągające i przewodzące oraz czułość dzianinowych czujników umieszczonych w wyrobach bieliźnianych. Czujniki mają znaleźć zastosowanie w pomiarach napięcia oddechowego. Badaniom poddano cztery różne dzianiny: 1 × 1, 1 × 2, 1 × 3 i 2 × 2, w procesie dziania wykorzystano kombinacje przędz elastycznych powlekanych (CY) i niepowlekanych (BS). Dało to unikalne właściwości fizyczne, przewodzące i rozciągające próbki. W celu ustalenia reakcji piezorezystywnych czujnika przeprowadzono dwa rodzaje testów. Test maszynowy wykazał wyższą reakcję piezorezystywną, ze średnią wartością szczytową (APV) od 1,70 Ω do 0,24 Ω, podczas gdy dla testu zużycia zarejestrowano około 0,0110 Ω do 1,867 Ω dla wszystkich kategorii próbek. Jednakże, czujniki dzianinowe z powleczonymi przędzami elastycznymi dały najlepsze wyniki testu oddychania (APV o wartości 1.089 Ω – 1.86 Ω) w porównaniu do niepowleczonych przędz elastycznych (APV 0,0027 Ω – 0,0790 Ω), podczas stosowania ich w środowisku noszenia. Zmiana struktury dzianiny miała wpływ na właściwości przewodzące i rozciągające, jednak wpływ na reakcję piezorezystywną był znikomy. Omówiono również wpływ unikalnych cech tych podstawowych parametrów na wartości rezystancji czujnika, odporność na piezorezystencję, starzenie, łatwość deformacji i stabilność wymiarową.

7

Analytical solutions for flexure of rectangular orthotropic plates with opposite rotationally restrained and free edges

Zhang S., Xu L.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 3

965--972

EN

The problem of flexural characteristics of rectangular orthotropic thin plates with opposite rotationally restrained and free edges subjected to arbitrary transverse loads is investigated in present study. By introducing a rotational fixity factor to simulate the elastic rotation restraint at plate edges, the finite integral transform method is employed to obtain exact analytical solution of the problem. Numerical solutions for rectangular plates with various aspect ratios and edge flexibility are investigated and compared to the results reported in previous research. The accuracy and convergence of the present formulation are assessed by comparing with previously reported results. The excellent agreement on the results between the proposed method and previous studies indicates that the proposed method is accurate and effective.

8

A facile and effective method for preparation of 2.5-furandicarboxylic acid via hydrogen peroxide direct oxidation of 5-hydroxymethylfurfural

Zhang S., Zhang L.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 1

11--16

EN

In this paper, 2,5-furandicarboxylic acid (FDCA) was efficiently prepared by the direct oxidation of 5-hydroxymethylfurfural (5-HMF) using hydrogen peroxide (H2O2) in alkaline conditions without any catalysts. The effects of reaction parameters on the process were systematically investigated and the optimal parameters were obtained as follows: molar ratio of 5-HMF:KOH: H2O2 was 1:4:8, reaction temperature and reaction time were determined as 70°C and 15 minutes, respectively. Under these conditions, the yield of FDCA was 55.6% and the purity of FDCA could reach 99%. Moreover, we have speculated the detailed oxidation mechanism of 5-HMF assisted by hydrogen peroxide in alkaline condition to synthesize FDCA.

9

Preparation and characterization of (Co0:3Zn0:7)(Ti1–xSnx)Nb2O8 microwave dielectric ceramics

Tang B., Zhang X., Fang Z., Liu Q., Zhang S.

Materials Science Poland

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2017

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Vol. 35, No. 2

405--411

EN

Zn0.7Co0.3 (Ti1-xSnx)Nb2O8 (x = 0.1, 0.15, 0.2, 0.25, 0.3, 0.35) microwave ceramics were prepared by traditional solidstate reaction method. The influences of Sn substituted for Ti on the phase constitution, crystal structure and microwave dielectric properties of Zn0.7Co0.3 (Ti1-xSnx)Nb2O8 ceramics were discussed. The XRD patterns revealed the main phase of ZnTiNb2O8 and little content of Zn0.17Ti0.5Nb0.33O2 secondary phase. With further substitution of Sn, the lattice constant, volume and apparent density of the ceramics increased, the ceramic structure reached a maximal compactness at x = 0.2 which was shown on SEM. Tremendous improvement of Q × f and a declining trend of Ɛr and τf were obtained with increasing x value. Appropriate substitution value (x = 0.10) would ensure excellent microwave dielectric properties (Ɛr = 34.1, Q × f = 40562 GHz, τf =-5 ppm/°C) of the ceramics sintered at 1080 °C.

10

Natural Fibres From the Bark of Mulberry Branches for Textile Application

Dong Z., Ding Z., Zhang S., Zhang Y., Fan H., Yang Y.

Fibres & Textiles in Eastern Europe

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2017

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Vol. 25, no. 3 (123)

20--25

EN

Fibers with low gum content were extracted from the bark of mulberry branches by a combination of bacteria and peroxide treatments. The bark of mulberry branches, with 30% cellulose, is a copious and inexpensive source of natural fibers. However, fibers extracted by microwave, enzyme or alkali had a high gum content (15.5% for hemicellulose and 8.6% for lignin), which rendered them difficult to be made into high- value textiles. In this research, strains with high polygalacturonase activities and subsequent hydrogen peroxide decreased the hemicellulose content to 2.5% and lignin content to 2.4%. Mulberry fibers in our study could be spun into yarns with a fineness of 18.2 tex. Compared to flax yarns, mulberry fiber yarns had a tenacity 20% higher, an elongation 18% higher and an unevenness 30% lower. Cotton/mulberry fiber fabrics had softer and smoother hand than cotton/flax fabrics. Overall, the fibers in our study show better potential for industrial textile applications than those in previous studies.

PL

Kora gałęzi morwy jest bogatym i niedrogim źródłem włókien naturalnych. W pracy przedstawiono proces otrzymywania włókien z kory morwy z wykorzystaniem szczepów bakteryjnych oraz nadtlenku wodoru, co zmniejszyło zawartość hemicelulozy do 2,5% i zawartości ligniny do 2,4%. W porównaniu do przędz lnianych, przędze z włókien morwy wykazywały o 20% wyższą wytrzymałość, o 18% wyższe wydłużenie i o 30% niższą nierównomierność. Tkaniny bawełniane z dodatkiem morwy miały bardziej miękki i gładszy chwyt, niż tkaniny bawełniane z dodatkiem lnu. Stwierdzono, że metoda pozyskiwania włókien z kory morwy przy zastosowaniu bakterii i nadtlenku wodoru może być stosowana do wyodrębniania włókien morwowych w celu produkcji wyrobów o wysokiej wartości i szerokim spektrum możliwości zastosowań przemysłowych.

11

A decision diagram based reliability evaluation method for multiple phased-mission systems

Zhang S., Sun S., Si S., Wang P.

Eksploatacja i Niezawodność

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2017

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Vol. 19, no. 3

485--492

EN

The multiple phased-mission system (MPMS) exists widely in practical engineering, such as aviation, spaceflight and navigation fields. Its distinct characteristic is that the system usually performs multiple missions and each mission consists of different phases. In this paper, we mainly focus on the reliability analysis for MPMS when the components have to accomplish different missions successively. A new modeling method is proposed for MPMS analysis based on the binary decision diagram (BDD) and multi-state multi-valued decision diagram (MMDD). Through this method, different phases of missions are combined with in the whole system by certain merging rules according to the operating time of a common component. Then, the system reliability can be calculated by the common calculation methods of decision diagrams by generating the through. Finally, two case studies are implemented to demonstrate the generation of BDD/MMDD models and the evaluation of system reliability. The experiment results verified the efficiency and accuracy of the proposed modeling methods.

PL

Systemy wielofazowe (Multiple Phased-Mission Systems, MPMS), t.j. systemy o wielu zadaniach okresowych są powszechnie stosowane w praktyce inżynieryjnej, np. w lotnictwie, lotach kosmicznych czy nawigacji. Cechą wyróżniającą tego typu systemy jest to, że zazwyczaj wykonują one wiele zadań, z których każde składa się z różnych faz. Głównym tematem poniższej pracy jest analiza niezawodności MPMS dla przypadków, kiedy elementy składowe muszą wykonywać różne misje jedna po drugiej. W artykule zaproponowano nową metodę modelowania dla celów analizy MPMS opartą na koncepcji binarnego diagramu decyzyjnego (binary decision diagram, BDD) oraz wielostanowego wielowartościowego diagramu decyzyjnego (multi-state multi-valued decision diagram, MMDD). Metoda ta polega na łączeniu różnych faz misji w obrębie systemu za pomocą pewnych reguł łączenia wedle czasu pracy wspólnego elementu składowego. Pozwala to na obliczanie niezawodności systemu za pomocą powszechnie stosowanych metod diagramów decyzyjnych poprzez generowanie drzew błędów. W pracy zaprezentowano dwa studia przypadku, które pokazują, w jaki sposób generuje się modele BDD/MMDD oraz ocenia niezawodność systemu. Wyniki eksperymentów wykazały wydajność oraz trafność proponowanych metod modelowania.

12

Logic Programming with Graded Introspection

Zhang Z., Wang B., Zhang S.

Fundamenta Informaticae

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2016

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Vol. 147, nr 1

133--158

EN

This paper develops a logic programming language, GI-log, that extends answer set programming language with a new graded modality Kω where ω is an interval satisfying ω ⊆ [0; 1]. The modality is used to precede a literal in rules bodies, and thus allows for the representation of graded introspections in the presence of multiple belief sets: KωF intuitively means: it is known that the proportion of the belief sets where F is true is in the interval ω. We define the semantics of GI-log, study the relation to the languages of strong introspections, give an algorithm for computing solutions of GI-log programs, and investigate the use of GI-log for formalizing contextual reasoning, conformant planning with threshold, and modeling a graph problem.

13

Mathematical Model of Embedded Temperature Sensing Fabric Heat Transmission

Zhang R., Deng N., Cheng B., Zhang S., Wu Y.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 5 (119)

73--79

EN

In order to explore effect factors in the measurement of temperature sensing fabric, a heat transmission mathematical model of temperature sensing fabric was established. The concept of surface contact thermal resistance associated with the material thermal conductivity, fabric layer number and yarn linear density between the fabric and sensor was proposed in the model, whose surface contact thermal resistance was produced in the process of fabric heat transmission. Some test samples were woven to prove the rationality of the model. The results demonstrated that the value measured would be influenced by the performances of surface contact thermal resistance, which was consistent with the derivation of the theoretical model. The raw material, fabric layer number and yarn linear density of temperature sensing fabric had a great effect on the measurement value. The correlation coefficient reached more than 0.988 among the experimental and theoretical values, respectively, which proved that the heat transmission mathematical model of temperature sensing fabric could be applied in the research of this fabric.

PL

Opracowano matematyczny model przepływu ciepła przez tkaninę zawierającą wbudowane czujniki temperatury w celu określenia wpływu poszczególnych czynników na przebieg pomiarów. Brano pod uwagę oporność termiczną styku czujników z tkaniną związaną z przewodnością termiczną materiału, ilość warstw i masę liniową przędz w obrębie tkaniny i czujników. Uzyskane współczynniki korelacji pomiędzy wartościami eksperymentalnymi i teoretycznymi przekraczały 0,988 co potwierdza, że opracowany przez nas matematyczny model przepływu ciepła w tkaninie pomiarowej można zastosować w tego typu badaniach.

14

Experimental investigation of a high temperature resistant and low friction fracturing fluid

Xiao B., Zhang S., Zhang J., Hou T., Guo T.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 1

37--47

EN

The performance of a hydraulic fracturing fluid (HFF) system directly determines the efficiency of stimulation. Since the targeted formations of most oil fields in China are characterized by large depth (~5000 m), high temperature (160 to 180 °C) and tight lithology, newer and suitable HFFs have to be developed. Based on a newly synthetized organo-boron/-zirconium cross-linking agent (Gh-g), a composite temperature stabilizer (WJ-6) and other optimized additives via indoor evaluation, this study introduced a novel HFF, which is thermally stable at high temperature (HT) up to 180 °C and exerted low friction pressures. The performance of HFF was evaluated in the laboratory. The experimental results showed that the HFF system performed well at HTs. It maintained a viscosity of 100 mPa•s or more after 90 min of shearing (170 s−1) at 180 °C. Furthermore, the system exhibited delayed cross-linking. It took 120 s for the cross-linking reaction to complete; therefore, the tube friction was reduced to a large extent. Another characteristic feature of the formulated HFF system was the low friction pressures, where the drag reduction percentage was in the range from 35% to 70%. Moreover, only minor damage was caused by the fluid to the formation core samples. The average core permeability damage was 19.6%. All these qualities ensure that this fluid system is in full compliance with the requirements of the fracturing treatment.

15

ABM with behavioral bias and applications in simulating china stock market

Wang G., Zhang S.

Journal of Artificial Intelligence and Soft Computing Research

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2015

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Vol. 5, No. 4

257--270

EN

One of the most important advantage of ABM (Agent-Based Modeling) used in social and economic calculation simulation is that the critical behavioral characteristics of the micro agents can be deeply depicted by the approach. Why, what and how real behavior(s) should be incorporated into ABM and is it appropriate and effective to use ABM with HSCA collaboration and micro-macro link features for complex economy/finance analysis? Through deepening behavioral analysis and using computational experimental methods incorporating HS (Human Subject) into CA (Computational Agent), which is extended ABM, based on the theory of behavioral finance and complexity science as well, we constructed a micro-macro integrated model with the key behavioral characteristics of investors as an experimental platform to cognize the conduction mechanism of complex capital market and typical phenomena in this paper, and illustrated briefly applied cases including the internal relations between impulsive behavior and the fluctuation of stock’s, the asymmetric cognitive bias and volatility cluster, deflective peak and fat-tail of China stock market.

16

Network resource reallocation strategy based on an improved capacity-load model

Zhou J., Huang N., Sun X., Xing L., Zhang S.

Eksploatacja i Niezawodność

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2015

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Vol. 17, no. 4

487--495

EN

Network resource reallocation is a common way to help restore performance of network systems subject to cascading failures. Majority of current network resource allocation strategies either give little regard to or make impractical assumptions about the relationship between capacity and load of network nodes, despite this relationship is closely related to the propagation of network failures. In this work we present and verify an improved nonlinear network capacity-load model based on the actual relation between network capacity and load. According to the verified model and realistic dynamic characteristics of network loads, we propose a new network resource reallocation strategy for networks under attacks from the perspective of maintenance. The strategy aims to effectively reallocate new capacity to network nodes after cascading failures occur. Both theoretical analysis and empirical studies are performed on three typical types of complex networks. Results show that the proposed network resource reallocation strategy is more efficient in mitigating devastating impact of cascading failures on network performance, in comparison to other three existing network resource reallocation strategies.

PL

Realokacja zasobów sieci jest powszechnym sposobem, stosowanym w celu przywrócenia działania systemów sieciowych objętych awariami kaskadowymi. Większość współczesnych strategii alokacji zasobów sieciowych kładzie mały nacisk lub czyni niepraktyczne założenia dotyczące zależności między przepustowością i obciążeniem węzłów sieci, choć zależność ta jest ściśle związana z rozchodzeniem się awarii sieci. W niniejszej pracy przedstawiono i zweryfikowano udoskonalony nieliniowy model przepustowości-obciążenia sieci na podstawie rzeczywistej relacji między przepustowością sieci i jej obciążeniem. Na podstawie zweryfikowanych modelu i realistycznych cech dynamicznych obciążeń sieciowych, proponujemy nową strategię realokacji zasobów dla sieci poddawanych atakom z perspektywy utrzymania ruchu. Celem strategii jest skuteczna realokacja nowej przepustowości węzłom sieci po wystąpieniu kaskadowych awarii. Przeprowadzono zarówno teoretyczne analizy, jak i badania empiryczne na trzech typowych rodzajach sieci złożonych. Wyniki pokazują, że proponowana strategia realokacji zasobów sieci jest bardziej skuteczna w zwalczaniu niszczącego wpływu kaskadowych awarii na przepustowość sieci w porównaniu do pozostałych trzech wykorzystywanych strategii realokacji zasobów sieciowych.

17

Electronic structures of Hg-doped anatase TiO2 with different O vacancy concentrations

Zheng S K, Wu G., Zhang S., Su J., Liu L.

Materials Science Poland

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2014

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Vol. 32, No. 1

93--97

EN

The electronic structures of Hg-doped anatase TiO2 with different O vacancy concentrations were calculated using the first-principles based on the density functional theory. The calculated results show that the forbidden band widths of Hgdoped anatase TiO2 widened along with the increase of O vacancy concentration, which is responsible for the blue shift in the absorption edges. It can be deduced from the present study that the Hg-doped TiO2 samples prepared in the experimental research contain a certain quantity of O vacancies.

18

A visualization system for oil spills IN Qinzhou Bay based on Google Earth

Dong Y., Hu B., Xie Z., Huang Y., Zhang S.

Journal of Power Technologies

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2014

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Vol. 94, nr 1

79--83

EN

This paper mainly aims to solve the visualization problem of oil spill. Combined with conditions on the ground of target research area Qinzhou Bay, important access to the sea for southwest China, the paper propose a model to construct the visualization system of oil spill, which relatively reveals as many as impact factors of oil spill and also is suitable for this region. The rich image resources of satellite remote sensing Google Earth is selected as the client during constructing the system. It combines Oracle which is suitable for storing large amounts of data as a backend database. This paper solves data exchange and data storage of KML between the Google Earth and Oracle by connecting them, which realizes the visualization of oil spill system in Qinzhou Bay.

19

Highly efficient organic ultraviolet photodetectors based on excellent Cu(I) complexes

Liu C. B., Su B., Liu M., Zhang X. X., Wang L., Zhang S., Che G. B., Xu Z. L.

Opto-Electronics Review

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2013

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Vol. 21, No. 3

288-292

EN

We demonstrate high response organic ultraviolet photodetectors using 4,4',4''-tris[3-methyl-pheny(phenyl)amino]tri-phenylamine (m-MTDATA) and two novel Cu(I) complexes, [Cu(DPEphos)(PyPhen)]BF (CuDP)(DPEphos = Bis [2-(diphenylphosphino)phenyl]ether, PyPhen = pyrazino[2,3-f][1,10]phenanthroline) and [Cu(DPEbenz)(PyPhen)] BF₄(CuBP) (DPEbenz = 1,2-bis(diphenylphosphino)benzene) to act as the electron donor and acceptor, respectively. Strong photoluminescence quenching of m-MTDATA by Cu(I) complexes is observed manifesting the efficient photoinduced charge transfer that occurs between m-MTDATA and Cu(I) complexes. The optimized photodetector based on CuBP exhibits a maxi-mum response of 276 mA/W at -12 V under an illumination of 365 nm UV light irradiation with an intensity of 1.75 mW/cm². The high response is attributed to feasible energy level match, efficient electron transfer from m-MTDATA to CuBP and skillful device design. More detailed working mechanism of harvesting high performance is also discussed.

20

Preparation, characterization and photocatalytic performances of materials based on CS2-modified titanate nanotubes

An H., Hu X., Zhu B., Song J., Zhao W., Zhang S., Huan W.

Materials Science Poland

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2013

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Vol. 31, No. 4

531--542

EN

CS2-modified titanate nanotubes (CS2/TiO2–NTs) are fabricated by reaction of CS2 and Ti–O2Na+ species on titanate nanotubes. Pb2+ ions are coated on the modified nanotubes by ion exchange (Pb/CS2/TiO2–NTs). The products are characterized by means of nitrogen adsorption-desorption isotherms at 77 K (BET method), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD), atomic absorption spectrometry (AAS), and diffuse reflectance spectroscopy (DRS). The photocatalytic performances of the products are evaluated by monitoring their catalytic activities for degradation of methyl orange under UV light irradiation. The effects of calcination temperature and atmosphere on the photocatalytic performance are investigated. The results reveal that the photocatalytic activities of CS2/TiO2–NTs and Pb/CS2/TiO2–NTs are far higher than that of primary nanotubes, and the optimum calcination temperature is 500 °C under N2 atmosphere. It is also discovered that physically adsorbed Pb2+ ions affect the photocatalytic activity of Pb/CS2/TiO2–NTs obviously. The photocatalytic activity of washed Pb/CS2/TiO2–NTs is higher than that of the unwashed one under the same thermal treatment and reaction conditions.