Wyniki wyszukiwania - Biblioteka Nauki

1

Analyzing photosynthetic activity and growth of Soanum lycopersicum seedlings exposed to different light qualities

100%

Wu Q. , Su N. , Shen W. , Cui J.

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nr 06

EN

To investigate how light quality influences tomato (Solanum lycopersicum L) seedlings, we examined changes in plant growth, chloroplast ultrastructure, photosynthetic parameters and some photosynthesis-related genes expression levels. For this, tomato plants were grown under different light qualities with the same photosynthetic photon flux density: red (R), blue (B), yellow (Y), green (G) and white (W) lights. Our results revealed that, compared with plants grown under W light, the growth of plants grown under monochromatic lights was inhibited with the growth reduction being more significant in the plants grown under Y and G lights. However, the monochromatic lights had their own effects on the growth and photosynthetic function of tomato seedlings. The plant height was reduced under blue light, but expression of rbcS, rbcL, psbA, psbB genes was up-regulated, and the ΦPSII and electron transport rate (ETR) values were enhanced. More starch grains were accumulated in chloroplasts. The root elongation, net photosynthetic rate (Pn), NPQ and rbcS and psbA genes expression were promoted under red light. Yellow light- and green light-illuminated plants grew badly with their lower Rubisco content and Pn value observed, and less starch grains accumulated in chloroplast. However, less influence was noted of light quality on chloroplast structure. Compared with yellow light, the values of ΦPSII, ETR, qP and NPQ of plants exposed to green light were significantly increased, suggesting that green light was beneficial to both the development of photosynthetic apparatus to some extent.

2

Fuzzy-based positioning for mobile robots

100%

Shen W. , Gu J. , Meng M.

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tom Vol. 3, No. 3

3-12

EN

This paper proposes fuzzy-based positioning algorithms for an iRobot B21r mobile robot, which is equipped with a 180° scanning laser rangefinder and other sensors, in an indoor environment. A novel, dynamic error model for the laser rangefinder is built with consideration of the detection distance and the detection angle. A new concept, the virtual angular point, is introduced in this paper as one of the features for positioning a mobile robot. To position a mobile robot, three kinds of feature points, such as break points, real angular points, and virtual angular points, are employed in this paper. Based on fuzzy evaluation for the accuracy of each feature point, positions obtained by two arbitrary points are fused together by the weighted mean technique, in which weight is determined by the uncertainty represented by fuzzy numbers. Experimental study has been carried out to verify the effectiveness and the accuracy of the algorithms.

3

Homogenization of saturated double porous media with Eshelby-like velocity field

100%

Shen W. , Lanoye E. , Dormieux L. , Kondo D.

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tom Vol. 62, no. 5

1146--1162

EN

n this paper, we focus on strength properties of double porous materials having a Drucker–Prager solid phase at microscale. The porosity consists in two populations of micropores and mesopores saturated with different pressures. To this end, we consider a hollow sphere subjected to a uniform strain rate boundary conditions. For the microscale to mesoscale transition, we take advantage of available results by Maghouset al. (2009), while the meso to macro upscaling is performed by implementing a kinematical limit analysis approach using Eshelby like trial velocity fields. This two-step homogenization procedure delivers analytical expression of the macroscopic criterion for the considered class of saturated double porous media. This generalizes and improves previous results established by Shen et al. (2014). The results are discussed in terms of the existence or not of effective stresses. Some illustrations are provided.

4

Measuring the Blend Ratio of Wool/Cashmere Yarns Based on Image Processing Technology

88%

Qian K. , Li H. , Cao H. , Yu K. , Shen W.

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2010

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tom Vol. 18, no. 4 (81)

35--38

EN

In this study, an image processing technique was developed for testing the blend ratio of wool/cashmere yarns. Cashmere and wool were sliced and images clearly attributed to the obvious colour divergence after staining. In the image processing procedure, a support vector machine (SVM) was used to remove the background and separate wool and cashmere fibers. Some other parameters of the SVM were selected to identify wool and cashmere fibers beyond the colour character. When the wool and cashmere fibers were completely separated, the blend ratio was calculated by means of the picture-handling and data-handling functions of MATLAB software. This research work presents an accurate and fast method of analyzing the blend ratio, and the results obtained were a confirmation of this.

PL

Artykuł przedstawia szybką technikę przetwarzania obrazu opracowaną w celu wyznaczenia udziału przędz składowych w mieszankach wełna owcza/kaszmir. Przędze składowe spleciono, wybarwiono a w celu usunięcia tła z obrazu i rozdzielenia włókien wełny owczej i kaszmiru zastosowano urządzenie typu SVM, na którym ustawiono parametry odpowiadające przędzom składowym. Po całkowitym rozdzieleniu włókien wełny owczej i kaszmiru, wyznaczono ich udział w mieszance przy zastosowaniu programu MATLAB.

5

Hydrogen sulfide: a versatile regulator of environmental stress in plants

88%

Guo H. , Xiao T. , Zhou H. , Xie Y. , Shen W.

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nr 01

6

Genetic diversity of Poncirus and phylogenetic relationships with its relatives revealed by SSR and SNP/InDel markers

75%

Zhu S. , Wang F. , Shen W. , Jiang D. , Hong Q. , Zhao X.

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tom 37

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nr 07

EN

The polymorphic markers of nuclear SSR (simple sequence repeat), SNP (single nucleotide polymorphism)/ InDel (insertion–deletion length polymorphism), and cpSSR (chloroplast SSR) were used to evaluate the genetic diversity of 52 trifoliate oranges and their relatives. The two genomic DNA-based markers produced high values of PIC (polymorphic information content) at 0.45 for SNP/InDel and 0.32 for nuclear SSR, indicating that there is a large diversity of genetic variationvwithin the trifoliate oranges. Three UPGMA (unweighted pair-group method with arithmetic means) dendrograms were generated based on the results of three marker systems. At 0.76 of coefficient, all of Poncirus accessions were clustered into one group, except the 74-1 Early Poncirus, one of the three precocious trifoliate oranges, which was placed separately into another group by nuclear SSR. At a higher coefficient, the trifoliate oranges were discriminated into 4, 6 and 6 groups by nuclear SSR (0.86), SNP/InDel (0.95), and cpSSR (0.95), respectively. The results revealed that three precocious trifoliate oranges were originated from different sources. Hubei Early Poncirus and Beibei Early Poncirus were the asexual mutants of different trifoliate oranges, and 74-1 was probably a sexual hybrid. The present study also indicated that ‘Zhiwenzhou,’ a diploid chimera of trifoliate orange and Satsuma is more closely related to Satsuma rather than to trifoliate orange, which is in concordance with the results of morphological observation.

7

A burgeoning family of biological mediators: chemokines and chemokine receptors

75%

Le Y. , Gong W. , Shen W. , Li B. , Dunlop N. M. , Wang J. M.

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tom 48

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nr 3

8

Ultraviolet-C mediated physiological and ultrastructural alterations in Juncus effusus L. shoots

63%

Najeeb U. , Xu L. , Ahmed Z. I. , Rasheed M. , Jilani G. , Naeem M. S. , Shen W. , Zhou W.

Acta Physiologiae Plantarum

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2011

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tom 33

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nr 2

EN

Increased ultraviolet radiations intruding on the earth pose a serious threat to the unadapted plants. Due to the ecological and economic significance of mat rush (Juncus effusus L.), an in vitro experiment was conducted to unveil the toxic effects of ultraviolet radiation (UV-C) on its physiology and ultrastructure. The basal culm segments of plant were used for in vitro treatments of UV-C with different exposure times (15, 30 and 45 min). The treated segments were first transferred to 1/2 strength MS media and then shifted to soil-perlite mixture for further growth. With increasing exposure time to UV-C, there was significant reduction in plant growth and biomass, and increased activities of antioxidant enzymes. Physiological and ultrastructural alterations were observed in the shoots of UV-treated plants. These plants exhibited significant reduction in chlorophyll contents and noticeable modifications at the ultra-cellular levels. Cell and chloroplast size reduced greatly, and there was appearance of higher amounts of plastoglobuli in chloroplasts resulting in disruption of thylakoid integrity. The functional and ultrastructural alterations in the stressed plants suggest a potential hazard of UV-C radiation on this aquatic flora and thus the ecosystem. The study further explores that UV-C radiations trigger these modifications mainly by damaging the chloroplast.