Wyniki wyszukiwania - BazTech

1

UV-Vis spectroscopic detection coupled with chemometrics for the measurement of mixed organic acids in water samples enriched by radial electric focusing solid phase extraction

Guo Y., Liu X., Liu J., Bian X., Zhang Q., Pan J., Wan D.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 2

317--329

EN

Due to the difficulty of detecting traces of organic acid mixture in an aqueous sample and the complexity of resolving UV-Vis spectra effectively, a combinatory method based on a self-made radical electric focusing solid phase extraction (REFSPE) device, UV-Vis detection and partial least squares (PLS) calculation is proposed here. In this study, REFSPE was used to enhance the extraction process of analytes between the aqueous phase and the membrane phase to enrich the trace of mixed organic acid efficiently. Then, the analytes, which were eluted from the adsorption film by ethanol with the assistance of an ultrasonic cleaning machine, were detected with UV-Vis spectrophotometry. After that, the PLS method was introduced to solve the problem of overlapping peaks in UV-Vis spectra of mixed substances and to quantify each compound. The linearly dependent coefficients between the predicted value of the model and the actual concentration of the sample were all higher than 0.99. The limit values of detection for benzoic acid, phthalic acid and p-toluene sulfonic acid were found at 9.9 μg/L, 12.2 μg/L and 13.8 μg/L with the relative recovery values between 84.8% and 117.9%. The RSD (n = 20) values of each component are 1.17%, 1.11% and 0.86%, respectively. Therefore, the proposed combined method can determine traces of complex materials in an aqueous sample efficiently and has wonderful potential applications.

2

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.

3

Fault risk assessment of underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation

He D., Hu N., Hu L., Chen L., Guo Y., Chen S.

Polish Maritime Research

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2016

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nr 3

97--105

EN

Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME) systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR) and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF) risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system.

4

Core-shell SiO2/Ag composite spheres: synthesis, characterization and photocatalytic properties

Wu Z. G., Jia Y. R., Wang J., Guo Y., Gao J. F.

Materials Science Poland

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2016

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Vol. 34, No. 4

806--810

EN

Core-shell SiO2/Ag composite spheres with dense, complete and nanoscaled silver shell were prepared by using a novel facile chemical reduction method without surface modification of silica at room temperature. The core-shell composites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and energy dispersive X-ray spectroscopy (EDX). The photocatalytic properties towards the degradation of methyl orange (Mo) of the prepared SiO2//Ag composites were also tested. The studies showed that the surface of SiO2/ microspheres was homogeneously and completely covered by Ag nanoparticles and the composite exhibited excellent photocatalytic activities. The possible reaction mechanisms for the formation of the silica-silver core-shell spheres were also discussed in this paper.

5

Adaptative strategy of leaf traits to drought conditions: Quercus aliena var. acuteserrata forest (The Qinling Mts. China)

Wang M., Wan P., Chai Y., Guo Y., Zhang X., Yue M.

Polish Journal of Ecology

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2015

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Vol. 63, nr 1

77--87

EN

In a climax community where all species are sharing relatively similar and stable habitat, there are differences in leaf traits between deciduous trees and shrubs and dominant species and companion species, especially in leaf lifespan (LLs). What are the differences of relationships among leaf traits between deciduous trees and shrubs? What are the mechanisms of this phenomenon? Here, we presented a one-year observation and recorded the LLs followed a modified method in a Quercus aliena var. acuteserrata forest in the north slope of the Qinling Mountains, China. We found that (i) Different species in the same stand performed quite differently in their LLs (P <0.005). Average LLs of shrubs was slightly longer (P = 0.05) than that of deciduous trees. (ii) LLs showed a significant negative correlation with specific leaf area (SLA) and leaf nitrogen content (LNC) (P <0.05) in deciduous trees, however, a significant positive correlation with LNC and leaf carbon content (LCC) (P <0.05) was detected in shrubs. (iii) The comparison of the traits between dominant and companion species in arbor layer and shrub layer showed that there was no significant difference in LLs, LCC and LNC, except SLA in arbor layer. Our study indicated that the amount of light, at the community scale, might be a main factor determining the LLs of wood plants in deciduous forest. The difference between trees and shrubs in relationships among leaf traits suggests that deciduous trees and shrubs may take different strategies to adapt to the environment. SLA is likely to be a marker trait to distinguish dominant and companion species in arbor layer of deciduous broad leaved forest

6

Transparent fluorinate acrylic polyurethane with hydrophobicity obtained by crosslinking of hydroxyl-containing fluoroacrylate copolymer with HDI trimer

Guo Y., Tang D., Yang F.

Materials Science Poland

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2015

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Vol. 33, No. 3

451--459

EN

Hydroxyl-containing fluoroacrylate copolymers with different fluorine and hydroxyl concentrations were synthesized via free-radical solution polymerization. Transparent fluorinated polyurethane (FPU) films were prepared by curing the copolymers with HDI (hexamethylene diisocyanate) trimer. The Fourier transform infrared spectroscopy (FT-IR) results revealed introduction of fluorine both into the copolymer and polyurethane. X-ray photoelectron spectroscopy (XPS) analyses indicated that a gradient concentration of fluorine existed in the depth profile of the fluorinated polyurethane films. The highest contact angle (CA) was obtained for the FPU film with fluoroacrylate monomer concentration of 22 wt.% because of fluorine present on the film surface. The surface topographies detected by SEM and AFM indicated that surface roughness contributed little to the film hydrophobicity. By increasing the fluoroacrylate monomer concentration, the decreasing of crosslinking degree of hard segment resulted in lowering the first degradation temperature, while more C-F groups in soft segment led to higher second degradation temperature. UV-Vis spectrophotometer measurements indicated that the FPU film with the fluoroacrylate monomer concentration of 16 wt.% still had a high transmittance of more than 90 % in the whole visible wavelength range.

7

Study on Dissociation of Nano Bamboo Extractives

Zhang Z., Xue Q., Huang K., Ma Q., Guo Y.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

212--215

EN

Bamboo, which is considered one of the best renewable resources on the planet, has widely been used. However, the extractives has a serious influence on bamboo processing, pulping and papermaking. Therefore, bamboo extractives of Phyllostachys heterocycla was done in the different solution, and studied by GC-MS. The results showed that the optimal extracting time of ethanol extraction, benzene/ethanol extraction and acetic ether extraction reached the largest leaching rate of bamboo extractives was 8h, 7h and 6h, respectively. The bamboo benzene/alcohol extractives had a main retention time between 30-40 min and contained 55 components. The acetic ether extractives had a main retention time between 20-40 min and contain 46 components. The ethanol extractives had a main retention time below 40 min and contain 28 components,.

PL

W artykule przedstawiono wyniki analiz drewna bambusowego, pod względem wpływu jego ekstraktów na proces przetwórczy. W badaniu wykorzystano metodę GC-MS, na podstawie której wyznaczono szybkość wydobycia poszczególnych substancji. Dodatkowo określono skład każdego z wydobytych ekstraktów.

8

Research of the fault location method of distribution network

Li Y., Wang X., Guo Y.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

7--9

EN

The rough set theory is used to realize the automatic fault location method of the rural power distribution network. The decision table of the distribution network fault location is based on the fault complaints information. It is automatically formed by distribution network topology. Then the decision table is property reduced based on identifiable matrix. Finally improved value reduction method is used to form the fault diagnosis expert knowledge uniformly. Combined with the GIS platform, it designs the application program of the fault location and realizes the visual fault localization.

PL

W artykule zaproponowano wykorzystanie teorii zbiorów przybliżonych w tworzeniu metody lokalizacji awarii w sieci elektroenergetycznej na terenie wiejskim. Metoda bazuje na drzewie decyzyjnym, w którym zawiera informacja o zgłoszeniach awarii. Opracowany algorytm redukcji wielkości drzewa, w połączeniu z platformą Systemu Informacji Geograficznej (ang. Geographic Information System – GIS), pozwala na dokładne określenie miejsca awarii.

9

Thermal Analysis of the Heat Exchanger for Power Electronic Device with Higher Power Density

Liang Y., Zhang J., Li M., Guo Y., Yuan J.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 12a

328-332

EN

Liquid cooling system has been used in high power electronic device systems to cool down the temperature of power electronic device. Heat exchanger is an important part of liquid cooling system to transfer the heat generated by power electronic device into air. In this paper, a Streamline-upwind/Petrov-Galerkin (SUPG) stabilized finite element analysis method was proposed to solve the water and air governing formulas including the mass conservation equation, the momentum conservation and the energy conservation equation. Furthermore, the thermal characteristic of a heat exchanger is simulated and the result was compared with an experiment. The comparison shows that this method is effective.

PL

W artykule przedstawiono zagadnienie kontroli systemów chłodzenia w urządzeniach energoelektronicznych. Zaproponowano metodę SUPG (ang. Streamline-Upwind Petrov-Galerkin) do obliczania rozpływu cieczy i powietrza, z uwzględnieniem oszczędności ilości, energii oraz pędu środka chłodzącego. Otrzymane charakterystyki wymiany ciepła zostały przebadane symulacyjnie, a wyniki porównano z badaniami eksperymentalnymi.

10

An Anti-Clone Attack Key Management Scheme for DTMSN

Yang K, Guo Y.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 7b

361--364

EN

This paper proposes a novel anti-clone attack key management scheme for DTMSN based on Physical Unclonable Function (PUF). In this scheme, sensor nodes have PUF units in their microprocessors. According to DTMSN security requirements, we design two types of keys in our scheme and take advantages of the physical characteristics of PUF unit to prevent nodes from cloning. Analysis and simulation indicate that the scheme is not only efficient and resource-saving, but also can resist clone attack and many other network attacks.

PL

W artykule opisano sieć typu DTMSN – delay tolerant mobile service network. Celem było opracowanie systemu uniemożliwiającego klonowanie.

11

On the design of biodegradable hydrogels both thermosensitive and pH sensitive

Wang B., Guo Y., Hu G.

Materials Science Poland

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2010

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Vol. 28, No. 1

207--215

EN

A Pluronic oligo(?-caprolactone) block copolymer has been synthesized by ring opening polymerization of ?-caprolactone monomers in the presence of poly(ethylene oxide)-poly(propylene oxide) -poly(ethylene oxide) triblock copolymers, using stannous octoate as a catalyst, and then the block copolymer was terminated with an acryloyl group. A novel biodegradable pH- and temperature sensitive hydrogel has been fabricated by free radical copolymerization of diacylated macromer-methacrylic acid aqueous solution initiated by a redox initiator. The structures of products were characterized by the Fourier transform infrared spectroscopy. Variations of the equilibrium swelling ratio in various environmental solutions confirmed the pH- and temperature sensitivity of hydrogel, which were affected by the MAA content.

12

3D Measurement and Modelling of Magnetic Properties of Soft Magnetic Composite

Zhu J., Lin Z., Guo Y., Huang Y.

Przegląd Elektrotechniczny

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2009

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R. 85, nr 1

11-15

EN

The soft magnetic composite (SMC) is a new type of soft magnetic material made of insulated iron powders. Its special characteristics could enable the development of low cost high performance electrical machines. This paper presents the measurement and modelling of magnetic properties of SMC under 3D magnetizations. Detailed descriptions of the 3D magnetic property tester, principle of measurement, core loss models, and experimental results are included and discussed.

PL

Magnetycznie miękkie kompozyty (soft magnetic composites – SMC) są nowym rodzajem magnetycznie miękkich materiałów wykonanych z elektrycznie izolowanych cząsteczek proszku żelaza. Specjalne charakterystyki takich materiałów mogą umożliwić rozwój tanich i wydajnych maszyn elektrycznych. Artykuł prezentuje pomiary i modelowanie własności magnetycznych SMC w warunkach przemagnesowania 3D. Podano dokładny opis użytej techniki pomiarowej, modelu i wyników pomiarowych.

13

The growth morphology of ZnO hexangular tubes synthesized by the solvothermal method

Li Y., Liu X., Zou Y., Guo Y.

Materials Science Poland

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2009

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Vol. 27, No. 1

187--192

EN

A novel hexangular tube structure of ZnO has been successfully synthesized via the solvo-thermal method, using Zn(NO3)2o6H2O and NaOH as starting materials. The results showed that the supersaturation near the surface of ZnO crystal is higher than that inside the crystal, which leads to a preferential growth along c-axis of the side surface. The strain between the surface and the bulk of ZnO rods drives ZnO rods into tubular structure. The spectroscopic results show that ZnO tubes possess the wurtzite structure. Three emission peaks have been detected, a violet peak at about 399.9 nm, a blue emission at about 448.5 nm and a green emission at about 549.8 nm.

14

Blue shift of photoluminescence of Al2O3-morin nanocomposites

Liu X., Wang Q., Li Y., Guo Y.

Materials Science Poland

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2009

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Vol. 27, No. 4/1

1009--1014

EN

Using AlCl3 and ammonia as starting materials, Al2O3 nanoparticles were fabricated by the chemical precipitation method. Morin was chemically bound on the surface of Al2O3 nanoparticles by the ultrasonic method, and the Al2O3-morin fluorescent nanocomposite was obtained. Because of interaction between the morin molecules and the surface atoms of Al2O3 nanoparticles, a blue-shift of the photoluminescence was observed for the nanocomposites compared with that of morin.