Wyniki wyszukiwania - Biblioteka Nauki

1

Influence of ephemeris error on GPS single point positioning accuracy

100%

Ma L. , Wang M.

Artificial Satellites : Journal of Planetary Geodesy

|

2013

|

tom Vol. 48, No. 3

125--139

EN

The Global Positioning System (GPS) user makes use of the navigation message transmitted from GPS satellites to achieve its location. Because the receiver uses the satellite's location in position calculations, an ephemeris error, a difference between the expected and actual orbital position of a GPS satellite, reduces user accuracy. The influence extent is decided by the precision of broadcast ephemeris from the control station upload. Simulation analysis with the Yuma almanac show that maximum positioning error exists in the case where the ephemeris error is along the line-of-sight (LOS) direction. Meanwhile, the error is dependent on the relationship between the observer and spatial constellation at some time period.

2

The effects of anisotropy of marine magnetic anomalies on the Curie point depth estimates from spectral analysis

100%

Wang M. , Liu Z.

Acta Geophysica

|

2018

|

tom Vol. 66, no. 5

1019--1030

EN

Azimuthally averaged power spectra are widely used in the Curie point depth (CPD) estimation with the implicit assumption that the magnetization distribution is random and uncorrelated. However, the marine magnetic anomalies are caused by bands of normal and reverse magnetization and show obvious trends. To investigate the effects of the anisotropy of marine magnetic anomalies on the CPD estimates, we develop 3D fractal striped magnetization models to produce lineated marine magnetic anomalies for the first time. We analyze the spectra anisotropy of the lineated magnetic anomalies of the synthetic fractal striped magnetization models and investigate its effects on the CPD estimates. The synthetic models and actual data show that the spectra of the lineated marine magnetic anomalies are directionally anisotropic. The amplitude response is strong and the slope of the logarithmic spectrum is large in a direction perpendicular to the stripes of magnetic anomalies, whereas the amplitude response is weak and the slope of the logarithmic spectrum is small in a direction parallel to the stripes of magnetic anomalies. The depth estimates in the perpendicular direction are close to the actual values, whereas the depths estimates in the parallel direction are significantly lower than the actual values. The actual marine magnetic anomalies of the South China Sea exhibit an anisotropic power spectrum that is consistent with the spectral anisotropy of magnetic anomalies of the synthetic fractal striped magnetization models.

3

On additive problems with prime numbers of special type

100%

Meng X. , Wang M.

Demonstratio Mathematica

|

2007

|

tom Vol. 40, nr 2

271-287

EN

Let Pk denote any integer with no more than k prime factors, counted according to multiplicity. It is proved that for almost all sufficiently large integers n, satisfying n is identical with 0 or 1 (mod 3), the equation n = p1+p2/2 +p2/3 has a solution in primes p1, p2, p3 such that p1+2 = P6, p2+2 = P5, p3+2 = P5. It is also proved that for every suffciently large integer M is identical with 0 or 2 (mod 3), the equation M = p1+p2/2+p2/3+p2/4+p2/5 has a solution in primes p1, ź ź ź , p5 such that p1+2 = P6, p2+2 = P5, p3+2 = P5, p4+2 = P2, p5+2 = P'/2.

4

A new species of Argyra Macquart, 1834 from China [Diptera: Dolichopodidae]

100%

Wang M. , Yang D.

Annales Zoologici

|

2004

|

tom 54

|

nr 2

EN

One species of the genus Argyra Macquart, 1834 from China is described as new to science. The species of the genus from China are keyed, and geographic distributions are updated and discussed.

5

Revision of the genus Nepalomyia Hollis, 1964 from Taiwan [Diptera: Dolichopodidae]

100%

Wang M. , Yang D.

Annales Zoologici

|

2004

|

tom 54

|

nr 2

EN

The genus Nepalomyia Hollis, 1964 is reported from Taiwan for the first time. The following 3 species are described as new to science: Nepalomyia taiwanensis, N. siveci, and N. horvati. A key is given to separate the species.

6

NanEffect of SiO2 Nanoparticles on the Wear Resistance of Starch Films

80%

Wu M. , Wang Y. , Wang M. , Ge M.

Fibres & Textiles in Eastern Europe

|

2008

|

tom Nr 4 (69)

96--99

EN

Nanoparticles have been increasingly used to improve the properties of polymer materials. In this study, SiO2 nanoparticles were added to starch for sizing applications in the textile industry. The effects of the content of SiO2 nanoparticles on the abrasion properties of the starch film were measured using a wear tester. The wearing surfaces were observed with Scanning Electronic Microscope, an Atom Force Microscope and a High Magnification Optical Microscope in order to better understand the wearing mechanism. The results showed that the best wear resistance was achieved when the content of SiO2 nanoparticles was about 3%. The wear resistance mechanism of starch film containing SiO2 nanoparticles was analysed.

PL

Nanocząstki są coraz częściej stosowane dla polepszenia właściwości materiałów polimerowych. W przedstawionych badaniach Nanocząstki SiO2 były dodawane do preparacji skrobiowych stosowanych w przemyśle włókienniczym. Mierzono wpływ zawartości nanocząstek SiO2 na wytrzymałość na ścieranie powłok skrobiowych za pomocą urządzenia do badania ścieralności. Powierzchnie ścierane były obserwowane za pomocą elektronowego mikroskopu skaningowego, mikroskopu sił atomowych i mikroskopu optycznego umożliwiającego duże powiększenie. Pozwoliło to lepiej zrozumieć mechanizm ścierania. Wyniki wskazują, że najlepszą odporność na ścieranie otrzymano kiedy zawartość nanocząstek SiO2 wynosiła około 3%. Analizowano mechanizm odporności na ścieranie folii skrobiowych z dodatkiem nanocząstek SiO2.

7

Point pattern analysis of different life stages of Haloxylon ammodendron in desert-oasis ecotone

80%

Wang M. , Zhang S. , Chu G.

Polish Journal of Environmental Studies

|

2014

|

tom 23

|

nr 6

EN

The Haloxylon ammodendron natural desert forest is an important vegetation formation and has a large distribution area in Junggar Basin, Xinjiang Province, China. In this paper, H. ammodendron populations were mapped, characterized and the spatial distribution patterns and spatial associations of H. ammodendron among different life stages (seedlings – S, juveniles – J, mature – M, overmature – O) were analyzed using O-ring univariate O11(r) and bivariate O12(r) statistics. We found that: (1) H. ammodendron was a regenerating population. (2) H. ammodendron (S), H. ammodendron (J), and H. ammodendron (M) showed significant aggregations at scale 0-8 m, 0-27 m, and 0-35 m, respectively, whereas H. ammodendron (O) tended to have random distributions at almost all scales. (3) The spatial associations between different life stages of H. ammodendron tended to turn from positive to negative if their size differences are enlarged increasingly. Strongly positive associations were found at small scales for only two pairs: H. ammodendron (S)-H. ammodendron (J), H. ammodendron (J)-H. ammodendron (M).

8

New species of Teuchophorus from China (Diptera: Dolichopodidae)

80%

Wang M. , Yang D. , Grootaert P.

Annales Zoologici

|

2006

|

tom 56

|

nr 2

9

Investigation of combined pollution between malathion and a variety of pollutants based on the fractional factorial design (resolution IV)

80%

Cheng B. , Li S. , Wang M. , Li Y.

Polish Journal of Environmental Studies

|

2015

|

tom 24

|

nr 5

10

In situ bioremediation of heavy metals in contaminated soil using microbial agents and planting experiments

80%

Zhan Q. , Qian C. , Wang M.

Polish Journal of Environmental Studies

|

2015

|

tom 24

|

nr 3

EN

In this paper, two kinds of microbial agents – carbonate-microbe agents (CMA) and phosphate-microbe agents (PMA) – were used to remedy heavy metals in contaminated soil. Contrastive analysis of the remedying effects by CMA and PMA was obtained. Meanwhile, green vegetable cultivation and a vegetable transplanting experiment were conducted in contaminated soil that had been remedied by two kinds of microbial agents. The planting experiment clearly contributed to analysis of the remedying effect. The experimental results indicated that two kinds of microbial agents had a remarkable remedying effect on the heavy metals; the remedying effect of Cr²⁺ and Pb²⁺ by CMA was better compared with PMA, while the remedying effect of Cd²⁺ and Zn²⁺ by PMA was better than CMA, and the remedying effect of Cu²⁺ was almost equally good by two kinds of microbial agents. Bud rate and growth momentum improved significantly in contaminated soil after remediation, the concentration of heavy metals in seedlings and vegetables was reduced greatly, and several heavy metals indices were lower than the national standards. For different heavy metals pollution, different microbial agents should be used: namely the CMA are suitable for remedying Cr²⁺ and Pb²⁺, whereas PMA are suitable for remedying Cd²⁺ and Zn²⁺.

11

Shrinkage Porosity Criterion and Its Application to A 5.5 Ton Steel Ingot

80%

Zhang C. , Zhang L. , Bao Y. , Wang M.

|

12

Visualization investigation on the marine data with multivariate statistical analysis methods

80%

Li Y. , Lu Z. , Wang M.

Polish Maritime Research

|

2017

|

tom S 2

89--94

EN

Marine information is an important way for us to know and study more about the ocean. Marine data makes the basic of marine information. Because of the huge quantity and diversity of marine data, and at the same time marine data is polyatomic variable, we start with statistical analysis methods to search for the regularity of the marine data. On one hand, we get the aggregate variation functions of the marine data by factor analyzing in aspect of the spatiality. Then we visually describe the marine status of the studied sea area with pre variogram function and post variogram function. On the other hand, we used cluster analysis method to get the verifying rule in time and make visible graphs of the marine data. In this way, we can also supply with the suggestions in classifying the sea seawater quality. The data processing result shows that the suggested methods in this article are both operable and effective. At the same time some reasonable suggestions are given in the article.

13

A New Fuzzy Iterative Learning Control Algorithm for Single Joint Manipulator

80%

Wang M. , Bian G. , Li H.

Archives of Control Sciences

|

2016

|

tom Vol. 26, no. 3

297--310

EN

This paper present a new fuzzy iterative learning control design to solve the trajectory tracking problem and performing repetitive tasks for rigid robot manipulators. Several times’ iterations are needed to make the system tracking error converge, especially in the first iteration without experience. In order to solve that problem, fuzzy control and iterative learning control are combined, where fuzzy control is used to tracking trajectory at the first learning period, and the output of fuzzy control is recorded as the initial control inputs of ILC. The new algorithm also adopts gain self-tuning by fuzzy control, in order to improve the convergence rate. Simulations illustrate the effectiveness and convergence of the new algorithm and advantages compared to traditional method.

14

Exploring root plasticity to resource patches based on swarm behavior

80%

Li S. , Liu X. , Wang M. , Yu W.

Acta Physiologiae Plantarum

|

2016

|

tom 38

|

nr 08

15

Analysis of root system architecture affected by swarming behavior

80%

Li S. , Yu W. , Liu X. , Wang M.

Journal of Horticultural Research

|

2020

|

tom 28

|

nr 1

16

Shrinkage Porosity Criterion and Its Application to A 5.5 Ton Steel Ingot

80%

Zhang C. , Bao Y. , Wang M. , Zhang L.

Archives of Foundry Engineering

|

2016

|

tom Vol. 16, iss. 2

27--32

EN

In order to predict the distribution of shrinkage porosity in steel ingot efficiently and accurately, a criterion R√L and a method to obtain its threshold value were proposed. The criterion R√L was derived based on the solidification characteristics of steel ingot and pressure gradient in the mushy zone, in which the physical properties, the thermal parameters, the structure of the mushy zone and the secondary dendrite arm spacing were all taken into consideration. The threshold value of the criterion R√L was obtained with combination of numerical simulation of ingot solidification and total solidification shrinkage rate. Prediction of the shrinkage porosity in a 5.5 ton ingot of 2Cr13 steel with criterion R√L>0.21 m･℃1/2･s-3/2 agreed well with the results of experimental sectioning. Based on this criterion, optimization of the ingot was carried out by decreasing the height-to-diameter ratio and increasing the taper, which successfully eliminated the centreline porosity and further proved the applicability of this criterion.

17

Isolation of quinolone alkaloids from Tetradium ruticarpum via preparative high-speed counter-current chromatography and evaluation of their binding affinities for bovine serum albumin

80%

Zou H. , Guo G. , Wang M. , Huang G.

Acta Chromatographica

|

2018

|

tom Vol. 30, no. 2

73--80

EN

By application of preparative high-speed counter-current chromatography (HSCCC) to the crude quinolone alkaloids (1.1 g) from the fruit of Tetradium ruticarpum, 1-methyl-2((6Z,9Z)-pentadecadienyl)-4(1H)-quinolone (1, 8.4 mg), dihydroevocarpine (2, 27.0 mg), and 1-methyl-2-pentadecyl-4(1H)-quinolone (3, 18.8 mg) were isolated in one step with sufficient purity using the solvent system composed of hexane–ethyl acetate–methanol–water (Hex–EtOAc–MeOH–H2O, 5:2:5:3). Further purification of the subfraction was performed by amending the solvent composition and achieved another three quinolone alkaloids, i.e., 1-methyl-2-undecylquinolin-4(1H)-one (4, 13.7 mg), (Z)-1-methyl-2-(tridec-5-en-1-yl) quinolin-4(1H)-one (5, 14.0 mg) from subfraction FR3-A3-85 using Hex–EtOAc–MeOH–H2O (5:3.5:8.75:8.25), and 1-methyl-2-nonylquinolin-4(1H)-one (6, 15.1 mg) from subfraction FR3-A3-36 using Hex–EtOAc–MeOH–H2O (5:3.8:5:4.8). The relationship between the structure of the six alkaloids and their affinities for bovine serum albumin (BSA) was investigated using fluorescence titration analysis. The length and the presence of double bond of the side chain affected their binding process with BSA. The binding behavior might influence their other biological activities.

18

A theoretical derivation of the dilatancy equation for brittle rocks based on Maxwell model

80%

Li J. , Huang H. , Wang M.

Acta Geophysica

|

2017

|

tom Vol. 65, no. 1

55--64

EN

In this paper, the micro-cracks in the brittle rocks are assumed to be penny shaped and evenly distributed; the damage and dilatancy of the brittle rocks is attributed to the growth and expansion of numerous micro-cracks under the local tensile stress. A single crack’s behaviour under the local tensile stress is generalized to all cracks based on the distributed damage mechanics. The relationship between the local tensile stress and the external loading is derived based on the Maxwell model. The damage factor corresponding to the external loading is represented using thep–alpha (p–α) model. A dilatancy equation that can build up a link between the external loading and the rock dilatancy is established. A test of dilatancy of a brittle rock under triaxial compression is conducted; the comparison between experimental results and our theoretical results shows good consistency.

19

All optical method to achieve gain-clamping in broadband distributed fiber Raman amplifiers

80%

Wei H. , Tong Z. , Wang M. , Jian S.

Optica Applicata

|

2004

|

tom Vol. 34, nr 3

365-372

EN

In this paper, we proposed that using a pair of fiber gratings in a section of the transmission fiber, a gain clamped broadband distributed fiber Raman amplifiers (DRA) can easily be made based on the utilization of the pumps’ interactions and uneven gain property along the fiber in the amplifier

20

Efficacy evaluation of two live virus vaccines against an emerging pseudorabies virus variant

80%

Wang M. , Wang L. , Zhao Q.

Polish Journal of Veterinary Sciences

|

2019

|

tom 22

|

nr 4