Wyniki wyszukiwania - Biblioteka Nauki

1

Finite element analysis of a superelastic shape memory alloy considering the effect of plasticity

100%

Jiang X. , Li B.

Journal of Theoretical and Applied Mechanics

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2017

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tom Vol. 55 nr 4

1355--1368

EN

In the present study, a shape memory alloy (SMA) phenomenological constitutive model is proposed that is capable of describing SMA superelastic behavior and the plasticity effect. The phase transformation constitutive model, by using strain and temperature as control variables to judge the phase transformation points in order to avoid the complexity of transformation correction, incorporates plasticity described by the von Mises isotropic hardening model. Further, the proposed model is implemented into the finite element package ANSYS by the user subroutine USERMAT. The results produced by the proposed model of simulated superelastic and plasticity behavior are compared with experimental data taken from the literature.

2

Characteristics of diurnal water loss of five adjacent ecosystems at Changbai Mountains in Northeast China

100%

Chen X. , Li B.

Polish Journal of Ecology

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2004

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tom Vol. 52, nr 3

323-331

EN

Changes in ecosystem water consumption and hydrological processes following ecosystem alterations are important for environmental management and regional water supply. In this study on relatively dry days, the temporal dynamics of diurnal soil water contents at different soil depths were investigated within five adjacent ecosystems (primary forest and four ecosystems changed from the primary forest after human disturbance - clear-cut, grassland, shrub and secondary forest) at the altitude around 700 m a.s.l. at Changbai Mountain in Northeast China. On July 17, 2001 the diurnal water loss in the clear-cut was the highest among the five ecosystems and reached about 3.74x10^5 kg ha^-1, and it was lowest and about 1.07x10^5 kg ha^-1 in the primary forest of mixed broadleaved Korean pine forest. The temporal dynamics of soil water contents at different depths in the studied ecosystems were complicated but there were some common characteristics. First, soil water contents were higher at soil surface (about 0-10 cm) and then decreased with the soil depths. Second, soil moisture fluctuations were most rapid in the depths of 0-10 cm and 10-20 cm, and were comparatively slow and more moderate at the greater depths. The spatial and temporal changes of soil water content might be related with aboveground plants. Therefore, after the primary forest was converted to other ecosystems the hydrological characteristics of the ecosystem were changed, which would potentially affect regional hydrological processes.

3

Establishment of motion model for wave capture buoy and research on hydrodynamic performance of floating-type wave energy converter

100%

Gao H. , Li B.

Polish Maritime Research

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2015

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tom 22

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nr Special Issue S1

EN

Floating-type wave energy converter has the advantages of high wave energy conversion efficiency, strong shock resistance ability in rough sea and stable output power. So it is regarded as a promising energy utilization facility. The research on hydrodynamic performance of wave capture buoys is the precondition and key to the wave energy device design and optimization. A simplified motion model of the buoys in the waves is established. Based on linear wave theory, the equations of motion of buoys are derived according to Newton’s second law. The factors of wave and buoys structural parameters on wave energy absorption efficiency are discussed in the China’s Bohai Sea with short wave period and small wave height. The results show that the main factor which affects the dynamic responses of wave capture buoys is the proximity of the natural frequency of buoys to the wave period. And the incoming wave power takes a backseat role to it at constant wave height. The buoys structural parameters such as length, radius and immersed depth, influence the wave energy absorption efficiency, which play significant factors in device design. The effectiveness of this model is validated by the sea tests with small-sized wave energy devices. The establishment methods of motion model and analysis results are expected to be helpful for designing and manufacturing of floating-type wave energy converter

4

Establishment of motion model for wave capture buoy and research on hydrodynamic performance of floating-type wave energy converter

100%

Gao H. , Li B.

Polish Maritime Research

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2015

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tom S 1

106--111

EN

Floating-type wave energy converter has the advantages of high wave energy conversion efficiency, strong shock resistance ability in rough sea and stable output power. So it is regarded as a promising energy utilization facility. The research on hydrodynamic performance of wave capture buoys is the precondition and key to the wave energy device design and optimization. A simplified motion model of the buoys in the waves is established. Based on linear wave theory, the equations of motion of buoys are derived according to Newton’s second law. The factors of wave and buoys structural parameters on wave energy absorption efficiency are discussed in the China’s Bohai Sea with short wave period and small wave height. The results show that the main factor which affects the dynamic responses of wave capture buoys is the proximity of the natural frequency of buoys to the wave period. And the incoming wave power takes a backseat role to it at constant wave height. The buoys structural parameters such as length, radius and immersed depth, influence the wave energy absorption efficiency, which play significant factors in device design. The effectiveness of this model is validated by the sea tests with small-sized wave energy devices. The establishment methods of motion model and analysis results are expected to be helpful for designing and manufacturing of floating-type wave energy converter.

5

Simultaneous determination of antioxidants and ultraviolet stabilizers in polypropylene food packaging and food simulants by high-performance liquid chromatography

80%

Li B. , Wang Z. W. , Lin Q. B. , Hu C. Y.

Acta Chromatographica

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2017

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tom Vol. 29, no. 2

173--192

EN

The use of polypropylene materials in industry for food packaging is increasing. The presence of additives in the polymer matrix enables the modification or improvement of the properties and performance of the polymer, but these additives are potential risk for human health. In this context, an efficient analytical method for the quantitative determination of three antioxidants (2,6-di-tert-butyl-4-methylphenol (BHT), dibutylhydroxyphenylpropionic acid stearyl ester (Irganox 1076), and tns-(2.4-di-tert-butyl)-phosphite (Irgafos 168)) and five ultraviolet stabilizers (2-(2′-hydroxy-5′-methylphenyl) (UV-P), (2′-hydroxy-3′-tert-5′-methylphenyl)-5-chloroben zotriazole (UV-326), 2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327), 2-(2H-benzotriazol- 2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol(UV-329), and 2-hydroxy-4(octyloxy) benzophenone (UV-531)) in polypropylene food packaging and food simulants by high-performance liquid chromatography (HPLC) has been developed. Parameters affecting the efficiency in the process such as extraction and chromatographic condition were studied in order to determine operating conditions. The analytical method showed good linearity, presenting correlation coefficients (R ≥ 0.9977) for all additives. The limits of detection and quantification were between 0.03 and 0.30 μg mL−1 and between 0.10 and 1.00 μg mL−1 for eight analytes, respectively. Average spiked recoveries in blank polypropylene packaging and food simulants were in the range of 80.4–99.5% and 75.2–106.7%, with relative standard deviations in the range of 0.9–9.1% and 0.2–9.8%. Dissolving the polypropylene food packaging with toluene and precipitating by methanol was demonstrated more effective than ultrasonic extract with acetonitrile or dichloromethane for extracting the additives. The method was successfully applied to commercial polypropylene packaging determination, Irgafos 168 and UV-P were frequently found in six commercial polypropylene films, and the content ranged from 166.47 ± 5.11 to 845.27 ± 29.31 μg g−1 and 2.10 ± 0.29 to 19.23 ± 1.26 μg g−1, respectively.

6

On-the-fly diagnosability analysis of bounded and unbounded labeled Petri nets using verifier nets

80%

Li B. , Khlif-Bouassida M. , Toguéyni A.

International Journal of Applied Mathematics and Computer Science

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2018

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tom Vol. 28, no. 2

269--281

EN

This paper considers the problem of diagnosability analysis of discrete event systems modeled by labeled Petri nets (LPNs). We assume that the LPN can be bounded or unbounded with no deadlock after firing any fault transition. Our approach is novel and presents the on-the-fly diagnosability analysis using verifier nets. For a given LPN model, the verifier net and its reachability graph (for a bounded LPN) or coverability graph (for an unbounded LPN) are built on-the-fly and in parallel for diagnosability analysis. As soon as a diagnosability decision is established, the construction is stopped. This approach achieves a compromise between computation limitations due to efficiency and combinatorial explosion and it is useful to implement an engineering approach to the diagnosability analysis of complex systems.

7

Effects of Bothriochloa ischaemum characteristics induced by nitrogen addition on the process of slope runoff and sediment yield

80%

Li P. , Li B. , Wang J. , Liu G.

Polish Journal of Environmental Studies

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2021

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tom 30

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nr 1

8

Highly sensitive tunable diode laser absorption spectroscopy of CO2 around 1.53 m

80%

Liu Y. , Li B. , Zhai Y. , Wang A.

Optica Applicata

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2006

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tom Vol. 36, nr 1

15-22

EN

The absolute absorption spectrum intensities of carbon dioxide sample have been recorded with a tunable diode laser spectrometer in the spectral range 6506-6520 cm-1, which is suitable for the in situ sensing of carbon dioxide in the lower stratosphere, and were studied using a commercial telecommunication-type diode laser. The intensity of the weakest line we detected in this experiment is 9.116×10-27 cm-1/(moleculeźcm-2) at a pressure of 0.35 torr, and the corresponding absorption is 1.96×10-6 with SNR of 2.67.

9

Cadmium effects on mineral accumulation and selected physiological and biochemical characters of Salix babylonica L.

80%

Quyang J. , Li B. , Shang X. , Zou J.

Polish Journal of Environmental Studies

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2017

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tom 26

|

nr 6

EN

To understand the phytoremediation capability of Cd by Salix babylonica L. we studied Cd accumulation and translocation, antioxidant enzyme activities, lipid peroxidation, and soluble protein contents in S. babylonica exposed to 10, 50, and 100 μM Cd for 7, 14, 21, and 28 d. The results indicated that seedling growth was accelerated by 10 μM Cd, and significantly inhibited by 50 and 100 μM Cd. The contents of Fe and Mn decreased significantly. The superoxide dismutase (SOD) activity in roots exposed to Cd was significantly higher than that in leaves. The level of peroxidase (POD) was significantly higher than that of control except for the roots treated with 10 and 50 μM Cd on day 28. POD activity in leaves was lower than that in roots. The level of catalase (CAT) was significantly lower than that of control. At 100 μM Cd, malondialdehyde (MDA) content increased significantly during the whole experiment. 50 μM Cd could induce high content of MDA in leaves. In general, the contents of hydrogen peroxide (H₂O₂), superoxide anion (O₂·-), and soluble protein showed an increasing trend. S. babylonica could be an efficient phytoextraction plant as it had considerable ability to accumulate Cd.

10

The Revelation of Traffic Congestion Drift and Induction Mechanism under Information Modification

80%

Guo D. , Chen J. , Li B. , Li X.

Przegląd Elektrotechniczny

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2013

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tom R. 89, nr 3b

110--112

EN

It is shown in this paper that for the group of travelers, the individual's rational decision-making is not best, in some cases, still far away from the global peak. This conclusion has been proved by two common models --Greenshields and Underwood. Meanwhile, when the travelers know all the data of systems, congestion drift which can reduce the system throughput often occurs due to the conflict between individual rationality and global optimization. In this paper, we propose an induction mechanism which can greatly reduce the congestion drift by modifying some path information. The simulation experiments verify that the efficiency of the traffic system based on different network structure.

PL

W artykule opisano schemat postępowania przy wyborze optymalnego rozwiązania, w przypadku grupy podróżnych. Wstępną analizę przypadku wykonano na bazie modelu Greenshield i Undrwood, co wykazało, że rozwiązanie najlepsze indywidualnie, nie musi być optymalne dla grupy. Zaproponowane rozwiązanie redukuje pojawiający się zator uliczny. Badania symulacyjne potwierdzają skuteczność metody.

11

Ultrasound-assisted transdermal delivery of alendronate for the treatment of osteoporosis

80%

Li B. , Huang G. , Ma Z. , Qin S.

Acta Biochimica Polonica

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2020

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tom 67

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nr 2

12

Flow-injection chemiluminescence determination of hydrazine using on-line electrogenerated BrO- as the oxidant

80%

Li B. , Zhang Z. , Zheng X. , Xu C.

Chemia Analityczna

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2000

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tom Vol. 45, No. 5

709-717

EN

A novel chemiluminescence flow system for the determination of hydrazine is presented. It is based on the enhancement effect of hydrazine on the chemiluminescence reaction between luminol and BrO~ in alkaline media. The oxidant BrO(-) was on-line electroge-nerated by constant current electrolysis, resulting in the elimination of the inconvenience of its instability. The variables that affect the reaction were investigated and optimum condition was established. Hydrazine can be determined in the range of 0.01-10 ug ml(-1) with a detection limit of 0.003 ug ml-1 (3). A complete analysis could be done in 1 min with the relative standard deviation of 3.7%. The proposed method is suitable for the automatic and continuous on-line monitoring of low level of hydrazine. A few examples of the determination of hydrazine in drinking and river waters are given.

PL

Opisano nową przepływową metodę chemiluminoscencyjną oznaczania hydrozyny. Zasadą metody jest wpływ hydrazyny na zwiększenie intensywności chemilumines-cencji reakcji luninolu i BrCT w śrosowisku alkalicznym. Utleniacz BrCT był elektro-generowany bezpośrednio metodą elektrolizy stało prądowej w celu eliminacji niedogodności związanych z jego nietrwałością. Zbadano wpływ warunków reakcji na otrzymywane wyniki i ustalono warunki optymalne. Hydrazyna może być oznaczana w zakresie 0.01-10 ug ml(-1), a granica wykrywalności wynosi 0.003 ug(-1) (3o). Analiza może być wykonana w ciągu l min. Względne odchylenie standardowe wynosi 3.7%. Opracowana metoda nadaje się do automatycznego, ciągłego monitorowania małych stężeń hydrazyny. Podano przykłady oznaczania hydrazyny w wodzie rzecznej i pitnej.

13

Research on holocene loess erosion associated to climate evolution in China

80%

Chen Y. , Huo W. , Qian H. , Li B.

Polish Journal of Environmental Studies

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2020

|

tom 29

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nr 1

14

Fluorescence determination of hemoglobin based on its enzymatic activity

80%

Xu C. , Li B. , Zhang Z.

Chemia Analityczna

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2002

|

tom Vol. 47, No. 6

895-903

EN

A novel fluorescence system for determination of hemoglobin (Hb) is presented. It is based on the Hb-catalyzed oxidation of nonfluoroscent thiamine to fluorescent thiochrome by H(2)O(2) in basic medium. The enzymatic reaction at room temperature was studied by measuring the increase in fluorescence intensity of thiochrome at 440 nm in order to obtain the initial reaction rate. The initial reaction rate was linear with Hb concentration in the range of l.0 x 10(-7)-2.0 x 10(-10) mol L(-1) and the limit of detection was 4.6 x 10(-11) mol L(-1). The method is simple, sensitive and reliable for the determination of Hb and has been successfully applied to the determination of Hb in human urine.

PL

Przedstawiono nową, fluorescencyjną metodę oznaczania hemoglobiny (Hb). Podstawą metody jest reakcja utleniania tiaminy (nie wykazującej fluorescencji) do tiochromu (wykazującego fluorescencję). Reakcja ta, zachodząca pod wpływem H(2)O(2) w środowisku alkalicznym, jest enzymatycznie katalizowana przez Hb. W celu wyznaczenia początkowej szybkości reakcji badano ją w temperaturze pokojowej mierząc wzrost natężenia fluorescencji tiochromu przy długości fali 440 nm. Początkowa szybkość reakcji rosła ze wzrostem stężenia Hb w zakresie l x 10(-7)-2 x 10(-10) mol L(-1), a granica detekcji wynosiła 4.6 x 10(-11) mol L(-1). Opracowana metoda oznaczania Hb jest prosta, czuła i wiarygodna. Zastosowano jaz powodzeniem do oznaczania Hb w moczu ludzkim.

15

Review and assessment of the potential of post-IR IRSL dating methods to circumvent the problem of anomalous fading in feldspar luminescence

80%

Li B. , Jacobs Z. , Roberts R. G. , Li S.-H.

Geochronometria

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2014

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tom Vol. 41, no. 3

178--201

EN

Quartz has been the main mineral used for optically stimulated luminescence (OSL) dating of sediments over the last decade. The quartz OSL signal, however, has been shown to saturate at rel-atively low doses of ~200–400 Gy, making it difficult to be used for dating beyond about 200 thou-sand years (ka), unless the environmental dose rate is low. The infrared stimulated luminescence (IRSL) from feldspars has been shown to continue to grow to higher dose levels than quartz OSL. The application of IRSL dating of feldspars, however, has long been hampered by the anomalous fading effect. Recent progress in understanding anomalous fading of the infrared stimulated luminescence (IRSL) signals in potassium-feldspar has led to the development of post-IR IRSL (pIRIR) protocols and also a multiple elevated temperature (MET) stimulation (MET-pIRIR) protocol. These procedures have raised the prospect of isolating a non-fading IRSL component for dating Quaternary deposits containing feldspars. In this study, we review the recent progress made on (1) overcoming anomalous fading of feldspar, and (2) the development of pIRIR dating techniques for feldspar. The potential and problems associated with these methods are discussed.

16

Increased frequency of CD4plus CD25high FoxP3plus regulatory T cells in patients with hepatocellular carcinoma

80%

Feng X. , Li B. , Ye H. , Long D.

Archivum Immunologiae et Therapiae Experimentalis

|

2011

|

tom 59

|

nr 4

17

Fiber diameter influence on optical transport of dielectric particles along subwavelength optical fibers

80%

Zhang Y. , Lei H. , Li B.

Optica Applicata

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2013

|

tom Vol. 43, nr 4

707--718

EN

We investigate a fiber diameter influence on optical transport of dielectric particles along subwavelength optical fibers using a near infrared laser of 1.55 μm wavelength. Theoretical analysis indicates that at 1.55 μm, the evanescent field at the fiber surface increases at first and then decreases with an increase of the fiber diameter from 600 nm to 1.6 μm, exhibiting a maximum at the fiber diameter of 950 nm. Based on three-dimensional finite-difference time-domain simulations, optical scattering forces acted on the dielectric particles and transport velocities of the particles were calculated for two fibers in the diameters of 930 nm and 1.5 μm. To support the theoretical analysis, experiments were performed using the two fibers to transport SiO2 particles (sizes of 530 nm and 1.5 μm) and TiO2 particles (size of 1.5 μm). The results show that with the same laser power launched into the two fibers, larger transport velocities can be obtained along the 930 nm diameter fiber.

18

Residual doses and sensitivity change of post IR IRSL signals from potassium feldspar under different bleaching conditions

80%

Chen Y. , Li S.-H. , Li B.

Geochronometria

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2013

|

tom Vol. 40, no. 4

229--238

EN

The residual doses and sensitivity change for potassium-rich feldspar (K-feldspar) have been studied using the post-infrared infrared stimulated luminescence (pIRIR) and multi-elevated-temperature post-IR IRSL (MET-pIRIR) protocols. Laboratory simulated poorly-bleached and well-bleached samples were those K-feldspar grains bleached using a solar simulator for 10 minutes and 8 hours, respectively. The residual doses rise with stimulation temperature and time. The poorly-bleached sample has larger residual doses than the well-bleached sample, especially at high stimula-tion temperatures. The high-temperature pIRIR signals contain a large amount of hard-to-bleach sig-nals. A decrease of luminescence sensitivity was observed after conducting a high-temperature-treatment in the measurement cycles. The sensitivity decreases significantly between the first and the second cycle. The extent of decrease in sensitivity shows a clear temperature trend. The higher the stimulation temperature of pIRIR signals is, the larger the sensitivity decreases. This decrease is more severe for the poorly-bleached sample than for the well-bleached sample, and could possibly lead to problems in sensitivity correction.

19

Unionized acetate degradation at 45ºC anaerobic digestion: kinetics and inhibition

80%

Mohd N. S. , Li B. , Riffat R.

Polish Journal of Environmental Studies

|

2019

|

tom 28

|

nr 2

EN

This study demonstrated the degradation of unionized acetate in anaerobic digestion at 45ºC through the identification of kinetics and inhibition parameters. The kinetic parameters, Ks and rmax, were determined using Monod-based model for three different conditions, namely uninhibited, inhibited, and systems with high substrate condition. The Ks values for uninhibited condition were in the range of 0.124 to 0.191 mg/L as unionized HAc. Ks value of inhibited condition were at 0.027 mg/L as unionized HAc. Ks values for systems with high substrate condition were found to be in the range of 0.237 to 0.279 mg/L as unionized HAc. As for rmax, a 35ºC anaerobic digestion system showed the highest value at 0.166 mg/L/day – greater than the values of all 45ºC systems under all experimental conditions. Additionally, the inhibition parameter KI was also determined using the Michaelis-Menten model. The parameter was determined for inhibitory conditions resulting from high free NH₃ content. The inhibition type was uncompetitive with KI value of 0.072 mg/L as unionized HAc. The outcomes suggested that the methanogens responsible for the digestion process at 45ºC were thermo-tolerant acetate-utilizing methanogens of Methanosarcinaceae species, and the system will be totally inhibited with the presence of high free NH₃ content.

20

Associations between polymorphism in the 2,4-dienoyl-CoA reductase 1 gene (DECR1) and growth traits of Shanxi White pig

80%

Li B. , Guo X. , Cao G. , Zhou Z.

Animal Science Papers and Reports

|

2011

|

tom 29

|

nr 4

EN

A polymorphism within exon 2 of the 2, 4-dienoyl-CoA reductase gene (DECR1) was investigated by PCR-SSCP in 228 Shanxi White pigs. An association between the DECR1 polymorphism and growth traits in Shanxi White pigs was determined with an univariate animal model. The polymorphism was found within exon 2 of the DECR1, giving rise to genotypes AA, BB or AB. This polymorphism exhibited a significant effect of generation and sex (P<0.05, P<0.01) on growth traits and backfat thickness. At the age of six months BB pigs showed the body weight and chest girth higher than AA and AB animals. However, the polymorphism revealed no significant effects on other growth traits (P>0.05) though a trend of BB>AB>AA was showed.