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1

Simulation model and state analysis of ship transmission line

Hu Y., Xu M., Li Y.

Polish Maritime Research

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2018

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S 3

36--42

EN

In order to discuss the simulation model of the ship transmission line and the state of the transmission line, an early fault model is built according to the evolution principle of the short circuit fault of the transmission line and combining with the fault characteristics of the early fault. A small distributed ship transmission line system is built in MATLAB/ Simulink. Then, combined with the constructed fault module, the original short circuit module, and the load module, the various states (normal state, early fault state, severe early fault state, short circuit state) of the ship transmission line are stimulated, and the features of voltage signal in each state is analysed. It is concluded that, due to the normal operation of the ship transmission line system, the variation characteristics of the flow signal and voltage signal caused by the sudden load mutation, that is, the sudden load and the sudden increase load, are very similar to the changes caused by the early fault. Therefore, in order to find a more accurate early fault detection method, the state is divided into normal state, sudden load state, sudden increase and sudden decrease load state.

2

Synthesis and Characterization of PolyNIMMO-HTPB-polyNIMMO Triblock Copolymer as a Potential Energetic Binder

Wang X., Shu Y., Lu X., Mo H., Xu M.

Central European Journal of Energetic Materials

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2018

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Vol. 15, no. 3

456--467

EN

Triblock copolymer polyNIMMO-HTPB-polyNIMMO was synthesized by cationic ring opening polymerization of NIMMO (3-nitratomethyl-3-methyloxetane) in the presence of hydroxyl-terminated polybutadiene catalyzed by BF3·OEt2. The polymer was characterized by FT-IR, 1H NMR, 13C NMR spectroscopy, and GPC. DSC was used to investigate the thermal behaviour of the triblock copolymer and its exothermic decomposition peak was found to be at 215 °C. All of the results indicated that the triblock copolymer polyNIMMO-HTPB-polyNIMMO might serve as a potential energetic propellant binder.

3

Mixed Pseudo-orthogonal Frequency Coding for SAW RFID Tags

Xu M., Xiao X., Yuan Q., Zong Y.

Archives of Acoustics

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2018

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Vol. 43, No. 4

681--687

EN

A mixed pseudo-orthogonal frequency coding (Mixed-POFC) structure is proposed as a new spreadspectrum technique in this paper, which employs frequency and time diversity to enhance tag properties and balances the spectrum utilization and code diversity. The coding method of SAW RFID tags in this paper uses Mixed-POFC with multi-track chip arrangements. The cross-correlation and auto correlation of Mixed-POFC and POFC are calculated to demonstrate the reduced overlap between the adjacent center frequencies with the Mixed-POFC method. The center frequency of the IDT and Bragg reflectors is calculated by a coupling of modes (COM) module. The combination of the calculation results of the Bragg reflectors shows that compared with a 7-chip POFC, the coding number of a 7-chip Mixed-POFC is increased from 120 to 144 with the same fractional bandwidth of 12%. To demonstrate the validity of Mixed-POFC, finite element analysis (FEA) technology is used to analyze the frequency characteristics of Mixed-POFC chips. The maximum error between designed frequencies and simulation frequencies is only 1.7%, which verifies that the Mixed-POFC method is feasible.

4

Establishment of a rapid method to quantify eight flavonol glycosides for quality assessment of red toon using UPLC

Shen Y., Xu M., Deng P., Gu Q., Yin H., Xia G., Jia X., Yang H., Tam J.

Acta Chromatographica

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2018

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Vol. 30, no. 1

31--37

EN

Red Toon is a popular vegetable of favorable health benefits over Asia and Russia regions. In this study, isolation and identification of chemical constituents were performed to assess the quality of this functional food cultivated in various origins or harvested in different months. As a result, eight flavonol glycosides including rutin (I), myricitrin (II), quercetin-3-O-β-d-galactoranoside (III), quercetin-3-O-β-d-glucopyranose (IV), quercetin-3-O-α-l-arabinopyranoside (V), astragalin (VI), quercetin-3-O-α-l-rhamopyranoside (VII), and kaempferol-3-O-α-l-rhamopyranoside (VIII) were obtained. Among these, compounds III and V were isolated from Toona genus for the first time. Importantly, a rapid and convenient ultra-performance liquid chromatography (UPLC) method was developed to quantify the flavonol glycosides in Red Toon and validated for linearity, precision, stability, repeatability, and accuracy successively. In addition, it was found that total flavonoid glycosides (about 2.6%) in the food were kept at a higher level from April to June than other months of the year. Furthermore, their content in the Red Toon collected from ten different origins was also determined and compared, and the results suggested that the total flavonoid glycosides from Shandong Yantai were the highest, followed by Shandong Ximou, supporting a well-recognized viewpoint that Red Toon cultivated in Shandong Province, China, is considered genuine due to the best health benefits and flavor.

5

Application of ionic liquid-based ultrasonic-assisted extraction followed by rapid resolution LC-ESI/MS to chromone analysis from radix saposhnikoviae

Han Z., Xu M., Wang Y., Yang L., Han M.

Acta Chromatographica

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2017

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Vol. 29, no. 3

359--374

EN

Ionic liquid-based ultrasonic-assisted extraction (ILUAE) was successfully applied to the extraction of the four chromones (prim-O-glucosylcimifugin, cimifugin, 5-O-methylvisammioside, and sec-O-glucosylhamaudol) from Saposhnikovia divaricata (Radix Saposhnikoviae) for the first time. A series of l-alkyl-3-methylimidazolium ILs differing in anion and cation compositions was evaluated for extraction efficiency, and [C3MIM]Br was selected as the optimal solvent. In addition, ultrasound extraction parameters were optimized, and the chromones were directly quantified and analyzed by rapid resolution liquid chromatography-electrospray ionization/mass spectrometry (RRLC-ESI/MS). The optimal conditions were as follows: 0.4 M concentration of [C3MIM]Br, 20:1 solvent to solid ratio, and ultrasonic time, temperature, and frequency of 5 min, 40 °C, and 50 kHz, respectively. This approach obtained the highest extraction yield of 10.188 ± 0.473 mg g−1 for total chromones. Compared with regular UAE, the proposed approach exhibited a higher efficiency (61.56% increase) and shorter extraction time (nine times shorter). Also, ILUAE was an efficient, rapid, and simple sample preparation technique for extraction of chromones, and the established RRLC-DAD method could serve as a rapid and effective technique for extracting chromones from Radix Saposhnikoviae.

6

Internal quantum efficiency improvement of InGaN/GaN multiple quantum well green light-emitting diodes

Zhou Q., Xu M., Wang H.

Opto-Electronics Review

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2016

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Vol. 24, No. 1

1--9

EN

In recent years, GaN-based light-emitting diode (LED) has been widely used in various applications, such as RGB lighting system, full-colour display and visible-light communication. However, the internal quantum efficiency (IQE) of green LEDs is significantly lower than that of other visible spectrum LED. This phenomenon is called “green gap”. This paper briefly describes the physical mechanism of the low IQE for InGaN/GaN multiple quantum well (MQW) green LED at first. The IQE of green LED is limited by the defects and the internal electric field in MQW. Subsequently, we discuss the recent progress in improving the IQE of green LED in detail. These strategies can be divided into two categories. Some of these methods were proposed to enhance crystal quality of InGaN/GaN MQW with high In composition and low density of defects by modifying the growth conditions. Other methods focused on increasing electron-hole wave function overlap by eliminating the polarization effect.

7

Construction of Efficient MDS Matrices Based on Block Circulant Matrices for Lightweight Application

Han H., Tang C., Lou Y., Xu M.

Fundamenta Informaticae

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2016

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Vol. 145, nr 2

111--124

EN

Maximum distance separable (MDS) codes introduce MDS matrices which not only have applications in coding theory but also are of great importance in the design of block ciphers. It has received a great amount of attention. In this paper, we first introduce a special generalization of circulant matrices called block circulants with circulant blocks, which can be used to construct MDS matrices. Then we investigate some interesting and useful properties of this class of matrices and prove that their inversematrices can be implemented efficiently. Furthermore, we present some 4×4 and 8×8 efficient MDS matrices of this class which are suitable for MDS diffusion layer. Compared with previous results, our construction provides better efficiency for the implementation of both the matrix and the its inverse matrix.

8

The forwarding indices of graphs - a survey

Xu J.-M., Xu M.

Opuscula Mathematica

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2013

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Vol. 33, no. 2

345--372

EN

A routing R of a connected graph G of order n is a collection of n(n — 1) simple paths connecting every ordered pair of vertices of G. The vertex-forwarding index £(G,R) of G with respect to a routing R is defined as the maximum number of paths in R passing through any vertex of G. The vertex-forwarding index £(G) of G is defined as the minimum £(G,R) over all routings R of G. Similarly, the edge-forwarding index π (G,R) of G with respect to a routing R is the maximum number of paths in R passing through any edge of G. The edge-forwarding index π (G) of G is the minimum π(G, R) over all routings R of G. The vertex-forwarding index or the edge-forwarding index corresponds to the maximum load of the graph. Therefore, it is important to find routings minimizing these indices and thus has received much research attention for over twenty years. This paper surveys some known results on these forwarding indices, further research problems and several conjectures, also states some difficulty and relations to other topics in graph theory.

9

Significant effect of oxygen atmosphere on the structure, optical and electrical properties of Ti-doped In2O3 transparent conductive thin films

Dong C. J., Yu W. X., Xu M., Chen C., Song Z. Y., Li L., Wang Y. D.

Optica Applicata

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2011

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Vol. 41, nr 3

765--775

EN

Titanium-doped indium oxide (In2O3) transparent conductive thin films were deposited on glass and sapphire (0001) substrates with/without oxygen atmosphere by DC magnetron sputtering at 300 °C. The content of titanium is estimated to be about 1.8 at.% using energy dispersive spectroscopy. The smooth surfaces were covered with more uniform octahedral grains. X-ray diffraction measurements indicated that the preferential growth orientation along the (400) plane for the sample grown without oxygen atmosphere shifts to (222) for the sample grown in the oxygen atmosphere. The average optical transmittance of the sample grown with the introduction of oxygen varies from 70% to 90% in the visible region, which corresponds well to the variation of carrier and mobility. Hence, both intermediate dopant and oxygen atmosphere will provide the optimum balance between carrier concentration and mobility leading to the best transport properties of Ti-doped In2O3 films.

10

Fluoroimmunoassay of human thymidine kinase 1 using magnetic nanoparticles

Zhong S., Qi F., Xu M.

Chemia Analityczna

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2009

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Vol. 54, No. 5

827-839

EN

Human thymidine kinase 1 (hTKl) is a new tumor biomarker in serum. We developeda fluorescence enhancing immunoassay of hTKl, using magnetic nanoparticles (MNPs) j as the biomolecular immobilization mediator. The horseradish peroxidase labeled hTK 1 monoclonal antibody (HRP-Ab) competitively reacts with free hTKl in the detection solution and the hTKl bound to MNPs. After separation in a magnetic field, HRP-Ab bound to MNPs catalyzes oxidization of 3-(p-hydroxyphenyl)-propionic acid (HPPA) to form a iluorescent dimer product, 2,2'-dihydroxybiphenyl-5,5'-dipropionic acid, which leads to an enhanced fluorescent signal at 407 nm. The enhancement is inversely proportional to the hTKl concentration. The hTKl can be determined in the range 0.01-1 ng mL-1 and the detection limit reaches 0.008 ng mL-1. The hTKl concentrations in serum samples of several live cancer and healthy patients were correctly evaluated by the developed fluoroimmunoassay. This new immunoassay system is simple, fast, and sensitive for the detection of hTKl, offering a promising alternative method that can be extended to detect other biomarker molecules. It may have broad potential applications in clinical diagnosis.

PL

Ludzka tymidynowa kinaza 1 (hTK 1) jest nowym bioznacznikiem raka w surowicy. Opracowano metodę oznaczania (immunoassay) hTK l opartą na wzmocnieniu fluorescencji z wykorzystaniem magnetycznych nanocząsteczek (MNPs) jako mediatorów biomoleku-larnego unieruchomienia. Monoklonalne antyciało hTK l znakowane peroksydazą chrzanową (HRP-Ab) reaguje zarówno z wolnym hTK l jak i związanym z MNPs. Po wydzieleniu .. w polu magnetycznym, HRP-Ab związane z MNPs katalizuje utlenianie 3-(p-hydroksy-fenolo)-propionowego kwasu (HPPA) do fluoryzującego dimeru 2,2'-dihydroksybifenylu--5,5'-dipropionowego kwasu (HPPA) co prowadzi do zwiększenia fluorescencji w 407 nm. Wzmocnienie fluorescencji było odwrotnie proporcjonalne do stężenia hTK 1. Przedział oznaczania hTK l wynosił od 0,01 do l ngmL-1, a granica wykrywalności 0.008 ngml.-1. Opracowaną metodę zastosowano do oznaczania hTK l w próbkach surowicy zdrowych i chorych na raka pacjentów. Opracowana metoda jest prosta, szybka i czuła. Stanowi obiecującą alternatywę dla innych metod. Może być rozszerzona na inne bioznaczniki.

11

Examining and Promoting Chinese Seafarer Education and Training

Bao Y., Xu M.

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

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2008

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Vol. 2, no. 1

105--109

EN

China has potential to become a seafarer supply country for international labour market. The qualification and competency of Chinese seafarers is essential for the relief of the shortage of worldwide officer crew and to reduce human-related sea accidents, to ensure maritime safety and protect marine environment. Chinese seafarer education and training system takes an important role in training Chinese seafarers to be qualified and competent. It is necessary to highlight how the system functions. This paper is going to introduce Chinese MET systems, Seafarer MET Academies, Practice of seafarer MET, Quality Management of Chinese seafarer MET, Continuing Training for Chinese Seafarers in order to promote the national and international communication and cooperation in the shipping industry.

12

Generating new styles of Chinese strokes based on statistical model

Xu M., Dong J.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2007

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Vol. 11, No 1-2

129-136

EN

Chinese calligraphy is one of the most important Chinese arts: a form of entertainment as well as an embodiment of figurative thinking. In this paper, a statistical model-based approach to generating new styles of Chinese character strokes is proposed. Original calligraphy samples are aligned in a common co-ordinate frame and a training set consisting of landmarks is generated semi-automatically. The most significant features of the training set are extracted and a statistical model is built in order to generate strokes in new styles. The Bezier curve is used to fit the discrete contour data.

13

Preparation, Characterization of MCM-49 and Catalytic Performance of Pd/MCM-49 Catalysts in One-step Synthesis of MIBK from Acetone

Yang P., Wang Z., Yu J., Xu M., Liu Q., Jing S., Wu T.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 1

121-127

EN

Highly crystalline and pure MCM-49 was hydrothermally synthesized by a dynamic method, and it was used as supports to prepare Pd/MCM-49 catalysts by ion-exchange method. The physicochemical properties of the samples were characterized by XRD, TEM, TG-DTG and ICP. MCM-49 synthesized was markedly different from those in previous reports, showing much smaller crystals. One-step synthesis of methyl isobutyl ketone from acetone was investigated over Pd/MCM-49. These catalysts showed a high reactivity and selectivity to MIBK, reaching a conversion of 35.6% and a selectivity of 85% to MIBK. Stable MIBK yields were obtained during 60 h of time on stream.

14

Effect of spatial scale on relationship between plant species richness and microclimate in a forested ecosystem

Xu M., Qi Y.

Polish Journal of Ecology

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2000

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Vol. 48, nr 1

77-88

EN

This study examined how the correlation between plant species richness and microclimate varies when aggregation scales change from 10 to 3000 m. We measured soil moisture and air, soil and soil surface temperatures in the Southeastern Missouri Ozarks. Measurement were taken every 10 m along a 4250 m transect during the 1996 growing season. Plants up to 2 m above ground were sampled using 1 x 1 m^2 plots to record average height and coverage by species. We found that the correlation between understory plant species richness and temperature was, in general, highly dependent on spatial scale. The correlation coefficients were small, or even negative, at small scales, and the highest correlation occured around the 1500 m scale. Univariate linear regression analysis at 1500 m scale indicated that growing season mean temperatures of air, soil, and soil surface explained 83%, 76%, and 74% of the total variance in species richness, respectively. Microclimate variables, including seasonal mean, minimum and maximum temperatures of air, soil, and soil surface and seasonal soil moisture, explained 98% of the total variance in plant species richness (R^2=0,98, n=277, P<0,01) at 1500m scale. The results from this study suggest that the species-energy theory was adequately supported at certain spatial scales (around 1500m in this case), but less supported at other scales within the range under study. The findings indicate the necessity, feasibility, and difficulty to incorporate spatial scales explicitly into the species-energy theory.