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1

Changes in the polarization states of random electromagnetic vortex beams propagating in biological tissues

Duan M., Wu Y., Su N.

Optica Applicata

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2018

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Vol. 48, nr 2

297--309

EN

The changes in the on-axis polarization state of random electromagnetic Gaussian Schell-model vortex beams propagating in biological tissues have been studied. In different media propagation, the bigger Cn2 is, the earlier the appearance of the inflexion points in the on-axis degree of the polarization P(0, 0, z) is. As the propagation distance increases, the values of the on-axis orientation angle θ(0, 0, z) undergo several processes: at the beginning they are positive, then gradually increase to the maximum, jump to a negative value, finally tend to a fixed value. The bigger Cn2 corresponds to previous jumping position. In the entire propagation, the values of the on-axis ellipticity ε(0, 0, z) are larger than the initial one. There exists a phenomenon that the values of P(0, 0, z), θ(0, 0, z) and ε(0, 0, z) keep their extremes in a length of propagation distances for the far infrared beams. The maximum of P(0, 0, z) is the smallest and the jumping range of θ(0, 0, z) is the largest for the ultraviolet beams. Compared with σyy > σxx, the changes in magnitudes in P(0, 0, z) are more obvious when σyy < σxx, the changes in θ(0, 0, z) are just the reverse for σyy < σxx.

2

Evaluation of an Intelligent Computer Method for the Automatic Mosaic of Sequential Slub Yarn Images

Li Z., Zhang N., Wu Y., Wang J., Pan R., Gao W.

Fibres & Textiles in Eastern Europe

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2018

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Vol. 26, no. 2 (128)

38--48

EN

This paper is the second part of a series reporting the recent development of a computerised method for automatic mosaic sequential yarn images. In our earlier work, an effective method for stitching sequence slub yarn images automatically was developed based on image processing and the normalised cross correlation (NCC) method. 100 image pairs of two kinds of slub yarn were measured in certain specific conditions, such as the frame rate, size of stitching template, etc., and the measurement results were evaluated with the manual method. In this paper, the effects of various influencing factors are numerically examined, including the stitching template size, threshold value, frame rate, and computing time of the mosaic algorithm. The feasibility and accuracy of the fully computerized method were evaluated further under the various influencing parameters. One hundred percent cotton ring spun single slub yarns of 27.8, 15.6, and 9.7tex were prepared and used for the evaluation. The measurement results obtained by the method proposed are analysed and compared with those measured manually by Adobe Photoshop. The experimental results show that the method proposed can accurately find the stitch position and has a high consistency with the manual method when the matching template is 100 × N pixels, the threshold value T1∈[20, 40] and T2∈[51, 80], and the frame rate is greater than 40fps.

PL

Artykuł jest drugą częścią serii opisującej opracowanie sekwencyjnej metody przetwarzania obrazu przędz ozdobnych. We wcześniejszej pracy opracowano skuteczną metodę oceny przędz w oparciu o przetwarzanie obrazu i znormalizowaną metodę korelacji krzyżowej (NCC). Zbadano w określonych warunkach (liczba klatek na sekundę, rozmiar szablonu szycia itp.) 100 par obrazów dwóch rodzajów przędz, a następnie oceniono wyniki pomiarów. Przeprowadzono eksperymenty mające na celu zbadanie wykonalności i dokładności proponowanej metody. W pracy przeanalizowano numerycznie wpływ różnych czynników tj. rozmiaru szablonu, wartości progowej, liczby klatek na sekundę i czasu obliczeń algorytmu mozaikowego. Wykonalność i dokładność w pełni skomputeryzowanej metody zostały poddane dalszej ocenie. Metodę manualnej segmentacji obrazu i metodę automatycznej identyfikacji powierzchni przędzy ozdobnej przy wykorzystaniu odpowiednio przygotowanego algorytmu opartego o techniki numeryczne. W metodzie ręcznej segmentacji wprowadzono zmienne oparte o prędkość odczytywania danych z obrazu, które następnie poddawano analizie. W metodzie automatycznej zaproponowano wprowadzenie innych bardzie przydatnych zmiennych do identyfikacji charakterystycznych cech strumienia włókien. Plan eksperymentu obejmował trzy rodzaje przędz bawełnianych wytworzonych na przędzarce obrączkowej (27,8, 15,6 i 9,7tex). Wyniki pomiarów zaproponowanej metody analizowano i porównywano z pomiarami wykonywanymi ręcznie. Wyniki eksperymentalne pokazały, że proponowana metoda może być z powodzeniem stosowana i ma wysoką zgodność z metodą ręczną, przy szablonie 100 x N pikseli, wartości progowej T1∈ [20, 40] i T2∈ [51, 80] oraz liczbie klatek na większej niż 40 klatek na sekundę.

3

A multi-stage risk-adjusted control chart for monitoring and early-warningof products sold with two-dimensional warranty

Dong F., Liu Z., Wu Y., Hao J.

Eksploatacja i Niezawodność

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2018

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Vol. 20, no. 2

300--307

EN

Warranty claims data contain valuable information about the quality and reliability of products. The monitoring and early-warning of warranty claims data are of great significance to the manufacturer by identifying and solving the emerging quality or reliability problem as soon as possible. However, though it has been used widely in the automobile industry, there are no studies that have been carried out on the monitoring and early-warning of claims data for products sold with two-dimensional warranty. In order to fill this gap, fitting the two-dimensional warranty claims data with accelerated failure model (AFT), a multi-stage riskadjusted control chart is proposed by this paper, for which a reasonable product sales tracking time and a monitoring time are suggested to reduce the influence of sales delay and fluctuating claim rates. Comparing with traditional Cumulative Sum Control Chart (CUSUM), the applicability and availability of the proposed model are demonstrated in the final.

PL

Roszczenia gwarancyjne stanowią cenne źródło informacji na temat jakości i niezawodności produktów. Monitorowanie danych dotyczących roszczeń gwarancyjnych i wczesne ostrzeganie w oparciu o te dane ma wielkie znaczenie dla producenta, ponieważ pozwala rozpoznawać i rozwiązywać pojawiające się problemy związane z niezawodnością w jak najkrótszym czasie. Chociaż ten rodzaj monitorowania i wczesnego ostrzegania jest szeroko stosowany w przemyśle motoryzacyjnym, nie przeprowadzono dotąd żadnych badań na temat tych procesów w odniesieniu do produktów sprzedawanych z gwarancją dwuwymiarową. W celu wypełnienia tej luki, dane o reklamacjach składanych na podstawie gwarancji dwuwymiarowych dopasowano modelem uszkodzeń przyspieszonych (accelerated failure model, AFT), a następnie przedstawiono koncepcję karty kontrolnej monitorowania wieloetapowego z korektą ryzyka, dla której zaproponowano odpowiedni czas śledzenia sprzedaży produktu i czas monitorowania, mając na uwadze zmniejszenie wpływu opóźnień w sprzedaży i wahań liczby roszczeń zgłaszanych z tytułu gwarancji. Możliwości zastosowania i dostępność proponowanego modelu porównano z tradycyjną kartą sum skumulowanych.

4

Modification Mechanism and Growth Process of Al3(Sc, Zr) Particles in As-cast Al-Si-Mg-Cu-Zr-Sc Alloy

Li Y., Du X., Fu J., Zhang Y., Zhang Z., Zhou S., Wu Y.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 2

51--56

EN

In this study, the modification mechanism and growth process of Al3(Sc, Zr) particles in as-cast Al-Si-Mg-Cu based alloy with addition of Sc and Zr were systematically investigated. It was found that 0.57 wt-%Sc addition caused a significant refinement in the average grain size of the investigated alloy, which brought about a remarkable transformation in as-cast microstructure, from thick dendritic shape to fine equiaxed structure. A large amount of primary Al3(Sc, Zr) particles with the dimension of around 5-6 μm were also observed within the equiaxed grain. Due to the identical orientation and similar crystal structure between primary Al3(Sc, Zr) particles and α-Al matrix, the primary particles always served as heterogeneous nucleus for the α-Al matrix. In addition, these cusped cubic primary Al3(Sc, Zr) particles showed triangle, star, rhomboid morphologies are generated from sectioning the particle in (111), (100) and (110) planes, respectively. Particularly, the typical eutectic structure which contained odd number-layer (Al3(Sc, Zr)+α-Al+ ... +Al3(Sc, Zr)) was observed within the investigated particles.

5

Construction of waveform library in cognitive radar

Guo Y., Wu Y., Liu H.

Polish Maritime Research

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2017

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S 2

22--29

EN

Based on the thoughts of cognitive radar, Fractional Fourier Transform (FrFT) is used to generate a rotatable waveform libraries of Frank coded/Barker coded waveform in this paper. Then, the ambiguity function is used to analyze the delay resolution, Doppler resolution, delay side-lobe level, and Doppler side-lobe level of the waveform libraries and orthogonality of them is also analyzed. Furthermore, we proved theoretically that there is a fixed coordinate transformation between the waveforms of library and its origin waveform. Therefore, the Cramér-Rao low bound (CRLB) of motion parameters can be computed easily using the waveforms of the libraries, which facilitate the subsequent waveform scheduled work. Simulation results show that the library waveforms can reduce delay resolution to satisfy the different situations and can bring significant benefits for delay resolution, orthogonality and reuse interval.

6

An analytical solution for dynamic response of water barrier subjected to strong shock waves caused by an underwater explosion to dams

Lu L., Zou D., Zhu Y., Dong Y., Zuo C., Wu Y.

Polish Maritime Research

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2017

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S 2

111--117

EN

Shock waves arriving at a dam site are close to plane waves when the center of an underwater explosion is far from the dam site. In general, the wave pressure is calculated with COLE empirical formula. The COLE formula is a negative exponential function with respect to time. In this paper, a new analytical solution algorithm is proposed, which does not require the use of step-by-step time integration. In Comparison with the step-by-step time integration, the proposed algorithm requires relatively less calculation and avoids high-frequency oscillation. Furthermore, the vertical upstream surface and the sloping upstream surface in two types of the dams are analyzed in this paper. The research results indicate that the analytical solution can be applied for a dam with a vertical upstream surface. However, because the upstream face of a dam is inclined, the analytical solution can be obtained only for dams that are at lower height. Whenever the height of a dam is higher, then no analytical solution can be obtained, and only the use of step-by-step time integration can obtain a solution.

7

Significance of Stump-Sprouting for the Population Size Structure and Spatial Distribution Patterns of Endangered Species, Magnolia cylindrical

Li J., Wu Y., Wu T., Cao L., Chen J., Qiu Z., Zhang Y., Xu G., Zhang J., Liu P.

Polish Journal of Ecology

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2017

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Vol. 65, nr 2

247--257

EN

Magnolia cylindrica Wils. is one of the third most-protected wild plants in China. To describe the size structure and dynamics of its population, field data were obtained from eight newly established sites, using a contiguous grid quadrate method in Jiulong Mountain of East China. The population size structure and spatial distribution pattern were discussed based on a theoretical distribution model and assembling intensity index. The population size structure showed a declining trend because of the lack of seedlings. The number of stump-sprouting, size class III (sapling trees) individuals was large enough to make up for the shortage of small seedlings and the complete regeneration of populations through sprouting. The distributions of M. cylindrica, both seedling populations (Group A) and overall populations (Group B), were mostly clumped. The spatial pattern intensities of the populations at different stages (mainly small trees, middle trees, and big trees) were higher for Group A than those for Group B. The two groups have the same tendency in that the pattern intensity declined from small trees to the larger ones. Group A and Group B differed in spatial pattern: small and middle trees were randomly distributed in seedling populations, but aggregated in overall populations. The populations of M. cylindrica (both group A and B) were characterized by the pattern scale between 16 to 32 m2, measured by Greig-Smith and Kershaw methods. These results suggest that sprouting should be seriously considered in population rehabilitation and forest tending management and the area of forest tending management should be close to the maximum intensity.

8

Measurement of the Heat of Reaction of Polytetrafluoroethylene/Aluminum Composites Based on Laser Initiation

Li S., Wu Y., Lin Q., Huang C., Yang S., Li J.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 3

534--546

EN

Polytetrafluoroethylene/aluminum (PTFE/Al) composites are reactive materials which can release energy due to exothermic chemical reactions initiated under shock loading conditions. In order to accurately measure the potential maximum heat of reaction of PTFE/Al composites in an inert atmosphere, we propose in this paper a heat of reaction measurement system based on laser initiation. Our results show that the measurement system successfully initiates the chemical reaction between PTFE and Al in an argon atmosphere. The comparison between theoretical calculations and experimental data demonstrates that our measurement method is highly accurate and exhibits excellent consistency. Thus, the heat of reaction measurement system based on laser initiation is applicable for measuring the heat of reaction of PTFE/Al composites and also other complicated reactive materials.

9

Biomass Allocation, Compensatory Growth and Internal C/N Balance of Lolium perenne in Response to Defoliation and Light Treatments

Wang L., Wang J., Liu W., Gan Y., Wu Y.

Polish Journal of Ecology

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2016

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Vol. 64, nr 4

485--499

EN

Light environments can have a considerable influence on how plants respond to defoliation through influencing the biomass allocation patterns and internal C/N ratio. Seedlings of Lolium perenne, a common perennial grass species, were grown for eight weeks under three different light environments (natural light, red light and shading) and two different defoliation treatments (no defoliation versus 50% aboveground biomass removal). This study was conducted to examine (1) the effects of light regimes and defoliation on biomass accumulation, biomass allocation and internal C/N ratio status in plants; (2) how the light regimes influence the pattern of compensatory growth after defoliation; and (3) the relationship between compensatory growth and the internal C/N ratio status. We found that red light altered the shoot-to-root allometry, enhanced the leaf C concentrations and induced N deficiency. By contrast, the leaf N concentrations of L. perenne were greater during shading treatment, which simultaneously enhanced shoot growth and stopped root growth. Under defoliation, red light increased shoot growth, not at the expense of root growth, which was not the same as in natural light and shading treatment. Moreover, regardless of the unclipped (no defoliation) and defoliation conditions, the L. perenne biomass partitioning between roots and shoots was significantly correlated with the leaf N concentrations and C/N ratio, indicating that allometric biomass allocation can be largely modulated by signals related to the C and N status of the plants. These results demonstrated that the leaf C and N status would be an appropriate indicator of compensatory growth after defoliation.

10

Assessing the Suitability of Habitat for Wintering Siberian Cranes (Leucogeranus leucogeranus) at Different Water Levels in Poyang Lake Area, China

Chen B., Cui P., Xu H., Lu X., Lei J., Wu Y., Shao M., Ding H., Wu J., Cao M., Liu G.

Polish Journal of Ecology

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2016

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Vol. 64, nr 1

84--97

EN

Poyang lake area (1000–3246 km2) is the most important wintering ground for the globally critically endangered Siberian crane (Leucogeranus leucogeranus). More than 98% of the Siberian crane population overwinters in Poyang lake area. Remote-sensing and the spatial analysis tools of geographic information system (GIS) technology were used to assess the suitability of the habitat for wintering Siberian cranes in Poyang lake area at different water levels. The results demonstrated that as the water level increased within the range of 7.93–12.16 m, the area of unsuitable habitat increased gradually, but the areas of good, fair and poor habitat decreased. When the water level reached 12.16 m, good habitat for Siberian cranes covered an area of only 3005 ha, which is only 0.93% of the area of the total lake area. When human disturbance factors including vehicles, fishing and construction activities were added to the analysis of the current distribution of Siberian crane habitat, the results again indicated that the area of good habitat decreased with an increase in water level within the range of 7.93–12.16 m. Additionally, the areas of good habitat occurred primarily in the region of two national nature reserves, which are the Poyang Lake National Nature Reserve and the Nanjishan National Nature Reserve. Our study provides important data and an important theoretical basis for water level management and nature reserve construction in Poyang lake area.

11

Allometric Partitioning Theory Versus Optimal Partitioning Theory : The Adjustment of Biomass Allocation and Internal C-N Balance to Shading and Nitrogen Addition in Fritillaria unibracteata (Liliaceae)

Guo H., Xu B., Wu Y., Shi F., Wu C., Wu N.

Polish Journal of Ecology

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2016

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Vol. 64, nr 2

189--199

EN

Fritillaria unibracteata is a classic perennial alpine herb. In this study, we examined it's responses to shading (SH) and nitrogen addition (NA), as well as its correlation with internal C-N balance to detect how it adjusted to the changes of habitat conditions. Randomized block experiment was carried out in the field in Chuanbeimu Research Station in Songpan County, Sichuan Province, China (32°09′54″N, 103°38′36″E, altitude 3300 m a.s.l.). Two growing seasons after NA and SH, Fritillaria unibracteata's total plant biomass decreased significantly, with the proportion of biomass allocated to aboveground significantly increased. In addition, in this study, under both SH and NA treatments, Fritillaria unibracteata increased its biomass allocation to above-ground, which consisted with optimal partitioning theory. Moreover, Fritillaria unibracteata's biomass allocation was significantly correlated with its internal C-N status, regardless of nitrogen and light condition. We conclude that Fritillaria unibracteata optimizes its biomass allocation between root and shoot by adjusting its internal C-N balance, which would not be changed by the specialized resource storage organ-bulb.

12

Experimental study on amplitude-frequency characteristic and basin stability of horizontally driven pendulum

Jia J., Wu Y., Liu W., Xiao J.

Journal of Theoretical and Applied Mechanics

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2016

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Vol. 54 nr 3

839--846

EN

In this article, an inverted pendulum system is set up to explore the dynamics of a horizontally driven pendulum which exhibits a great variety of dynamical behavior and appears in a wide range of applications in the field of engineering. The facility is efficient to experimentally explore two kinds of coexisting movement patterns in the horizontally driven pendulum, i.e. in-phase and anti-phase patterns between the angular velocity of the pendulum rod and the direction of the driving forces. Theoretical analysis is applied to reveal the regimes of the coexistence of the two movement patterns, which is promising to control the system to a desired pattern.

13

Method of Structure Design and Heat Treatment of an Integrated Consolidation Sensor and Embedded Temperature Sensing Fabric

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

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 5 (119)

68--72

EN

In order to solve the problem of temperature sensors easily slipping and improve the precision of temperature measurement in temperature sensing fabric, a specially designed fabric was developed. In this paper, the fabric comprised plain and multi-layered fabric. Sensors were embedded into the multi-layered fabric. The multi-layered fabric was treated by partial heat treatment to make the temperature sensors be fixed to the fabric. The temperature sensing fabrics were measured before and after the partial heat treatment. The results showed that during the heat treatment, the number of fabric layers and fabric organization had an effect on temperature measurement, and the values measured after partial heat treatment were closer to the true value than without treatment. In addition, with an increase in the number of fabric layesr, the values measured were closer to the real value. And the measurement results were closer to the true value when the multi-layered fabric’s organizational structure was plain.

PL

Dla uzyskania hybrydowego elementu pomiarowego opracowano taką strukturę tkaniny aby móc umieścić w niej czujniki temperatury. Wielowarstwową tkaninę poddano odpowiedniej obróbce termicznej umożliwiającej zamocowanie czujników w tkaninie. Stwierdzono, że ilość warstw tkaniny i ich rozmieszczenie ma wyraźny wpływ na uzyskiwaną dokładność pomiaru temperatury. Przy zwiększeniu ilości warstw wzrastała dokładność pomiaru.

14

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

|

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.

15

An electricity price-dependent control-limit policy for conditionbased maintenance optimization for power generating unit

Qian X., Wu Y.

Eksploatacja i Niezawodność

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2016

|

Vol. 18, no. 2

245--253

EN

For the control-limit policy of condition-based maintenance (CBM), it usually focuses on the internal condition of the equipment while neglecting the un-constant external conditions. However, the electricity price-dependent downtime cost have influence on the cost-effectiveness of control-limit policy for a generating unit in a power system. To make a linkage between CBM and the nonconstant cost model, an electricity price-dependent control-limit policy (EPCLP) is proposed to accommodate the time-dependent downtime costs. For the proposed EPCLP, preventive maintenance control-limits is much flexible to be adjusted to different electricity price levels, and the maintenance cost reduction can be achieved among the planning horizon as a result. The optimal control-limits and maintenance costs for different downtime-cost ratios, reliabilities, covariate processes and electricity price scenarios are analysed to compare the performances between the proposed policy and the constant control-limit policy. Through the sensitivity analysis, the application scope of the proposed policy is evaluated.

PL

Stosując strategie utrzymania ruchu uwzględniające bieżący stan techniczny obiektu (condition based maintenance, CBM) oparte na pojęciu progu konserwacji koniecznej (control limit), najczęściej przywiązuje się wagę do stanu samego sprzętu, ignorując przy tym niestałe warunki zewnętrzne. Należy jednak pamiętać, że w przypadku agregatów prądotwórczych wchodzących w skład układów elektroenergetycznych, koszty przestoju zależne od ceny energii elektrycznej mają wpływ na opłacalność stosowania strategii progu konserwacji koniecznej. Aby powiązać CBM z modelem kosztów niestałych, zaproponowano strategię progu konserwacji koniecznej, w której wysokość progu uzależniona jest od ceny prądu elektrycznego (electricity price-dependent control-limit policy, EPCLP). Przyjęcie takiej strategii pozwala uwzględnić koszty przestojów zależne od czasu. W EPCLP, progi czasowe konserwacji zapobiegawczej są bardzo elastyczne, co pozwala na ich regulację zgodnie z aktualną ceną energii elektrycznej. Strategia umożliwia redukcję kosztów w danym horyzoncie planowania. W celu porównania proponowanej strategii ze strategią stałego progu konserwacji koniecznej, w pracy przeanalizowano optymalne progi czasowe konserwacji koniecznej oraz koszty utrzymania ruchu dla różnych stosunków przestoju do kosztu, różnych wartości niezawodności, różnych procesów kowariantnych oraz różnych scenariuszy zmian cen energii elektrycznej. Zakres zastosowania proponowanej strategii oceniano za pomocą analizy czułości.

16

Color image analysis via Racah moments

Wu Y., Liao S.

Journal of Theoretical and Applied Computer Science

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2015

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Vol. 9, nr 4

8--18

EN

In this research, Racah moments color image descriptors are investigated. Channels separation for color images were involved in RGB color space, and Racah moments from each channel were computed individually. In experiments, we have performed the color image reconstructions from different color channels and various orders of Racah moments. Our experimental results have demonstrated that, by applying Racah moments, color images can be completely reconstructed without any information loss. We have also discovered that the individual set of Racah moments will uniquely describe the color image features, while the lower and higher orders of Racah moments will preserve more of features from the bottom right and top left regions of a color image, respectively.

17

Ultra-High Performance Liquid Chromatography—Tandem Mass Spectrometry for Rapid Analysis of Seven Phenolic Compounds of Sparganii Rhizoma

Wang X., Wu Y., Wu Q., Qian Y., Yue W., Liang Q.

Acta Chromatographica

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2015

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Vol. 27, no. 4

755--766

EN

The rhizome of Sparganium stoloniferum Buch.-Ham has been used as a traditional Chinese folk medicine for thousands of years. Phenolic compounds are the main bioactive ingredients of the plant. In order to determine the content of phenolic compounds from different major cultivations, a reliable method has been developed using ultra-high performance liquid chromatography coupled with a triple quadrupole electrospray tandem mass spectrometry. Seven compounds, including rutin, kaempferol, p-hydroxybenzaldehyde, formononetin, ferulic acid, vanillic acid, and p-coumaric acid, were simultaneously measured in 10 min. The established approach was fully validated in terms of linearity, sensitivity, precision, repeatability as well as recovery, and successfully applied to determine seven phenolic compounds of Rhizoma Sparganii. This study may be helpful in the quality control of Rhizoma Sparganii and can offer technical support for the pharmacological and clinical study of related drugs.

18

Thermal effect on damaged stay-cables

Wang L., Wu Y., Wang D.

Journal of Theoretical and Applied Mechanics

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2014

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Vol. 52 nr 4

1071--1082

EN

Cables may suffer severe damage in cable-stayed bridges, leading to cable relaxation and tension loss. Such a damage effect merges in the sag augmentation or tension tightened by the thermal effect. This paper is intended to investigate the static response of damaged cables coupled with the thermal effect. With the introduction of three damage parameters such as damage position, damage degree and damage range as well as temperature parameter, the dimensionless governing equations for cables are derived and the numerical method is employed to solve the nonlinear equations. The static behavior of damaged cables due to the thermal coupling effect is analyzed, and the way to remove the thermal effect is given. It shows that the aspect ratio is the major factor is the deflection of the mid-span and horizontal force in the cable, whereas the angle inclination is the next important parameter. Cables with the natural length close to the chord distance reveal the highest sensitivity to temperature, whereas pre-tensioned and non-pre-tensioned cables are less sensitive to the thermal effect. It further demonstrates that with more damage included, the sensitive scope of the variation coefficient of the axial force with aspect ratio and temperature changes dramatically.

19

Calibration experiments planing for identification of manipulator elastostatic parameters

Klimchik A., Pashkevich A., Wu Y., Caro S., Furet B.

Pomiary Automatyka Robotyka

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2013

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R. 17, nr 1

128-140

EN

The paper is devoted to the elastostatic calibration of industrial robots, which are used for precise machining of largedimensional parts made of composite materials. In this technological process, the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism. To estimate parameters of this model, an advanced calibration technique is applied that is based on the non-linear experiment design theory, which is adopted for this particular application. In contrast to previous works, it is proposed a concept of the user-defined test-pose, which is used to evaluate the calibration experiments quality. In the frame of this concept, the related optimization problem is defined and numerical routines are developed, which allow to generate optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments. Some specific kinematicconstraints are also taken into account, which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment. The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining.

PL

Artykuł jest poświęcony elastostatycznej kalibracji robotów przemysłowych, których używa się do precyzyjnej obróbki elementów o dużych gabarytach, wykonanych z materiałów kompozytowych. W tym procesie technologicznym komunikacja między robotem a obrabiaym przedmiotem skutkuje istotnymi elastycznymi odchyleniami elementów składowych manipulatora, które powinny być wyrównane przez sterownik robota (przy użyciu odpowiedniego modelu elastostatycznego owego mechanizmu). Aby oszacować parametry tego modelu, użyto zaawansowanej techniki kalibracji opartej na nieliniowej eksperymentalnej teorii konstrukcji, którą zaadaptowano do tej konkretnej aplikacji. W przeciwieństwie do poprzednich prac, ta proponuje pojęcie zdefiniowanego przez użytkownika testu, używanego do ewaluacji jakości eksperymentów dotyczących kalibrowania. W ramach tego pojęcia zdefiniowano problem powiązanej optymalizacji oraz wypracowano procedury numeryczne, co pozwala na wygenerowanie optymalnego zbioru ustawień konfiguracji manipulatora oraz odpowiednich sił/torów dla danej liczby eksperymentów związanych z kalibrowaniem. Pod uwagę zostały wzięte również niektóre swoiste kinematyczne ograniczenia, które zapewniają wykonalność eksperymentów dotyczących kalibracji dla uzyskanych konfiguracji, jak również pozwalają uniknąć kolizji pomiędzy manipulatorem robota a sprzętem pomiarowym. Wydajność/skuteczność wypracowanej techniki zilustrowano przez przykład zastosowania, którym obrazuje kalibrację elastostatyczną seryjnego manipulatora zastosowanego do obróbki zrobotyzowanej.

20

Effects of snowpack and litter decomposition on nitrogen dynamics in soil of the alpine zone of the Eastern Tibetan Plateau

Hu X., Wu Y., Wang Q., Liu L., Zuo W.-Q., Shi F.-S., Wu N.

Polish Journal of Ecology

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2013

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Vol. 61, nr 2

297--304

EN

Microbes remain active and play an important role in soil nitrogen (N) cycle during the winter in soil of the alpine zone. A shift from microbial N immobilization process dominant during summer to prevailing microbial mineralization process during the winter is observed. Warmer soil under deep snow cover may increase the microbial activity and rate of organic matter decomposition over the winter. Furthermore, severe shortages of dissolved carbon (C) in the winter may cause microbial mortality and lyses. Thus, C limitation on microbial growth and activity may have an important effect on winter N mineralization and even on soil N pools. However, the combined effects of additional organic C (litter inputs) and snow cover on soil N biogeochemical processes in the Tibetan Plateau remain unclear. In the current study, the in situ effects of snowpack and litter decomposition on N dynamics in the alpine zone of the Eastern Tibetan Plateau were investigated. Intact soil core incubations in three different snow regimes (0, 30 and 100 cm depth snow) in the winter were used to solve the problem by measure concentrations of mineral form of soil N. In addition, the litter bag method was used to analyze the litter decomposition over the winter. Our results indicate that the snow cover reduced the ammonium (NH4+-N) content, accelerate N mineralization in soil, and did not significantly change the dissolvable organic nitrogen (DON) and microbial biomass nitrogen (MBN). Meanwhile, snowpack increased the litter N content and accelerated litter decomposition in late winter. Litter addition reduced the MBN and NH4+-N contents in soil, but increased the nitrate (NO3--N) content and net N mineralization, suggesting that N availability to plants during the spring thaw period may be enhanced.