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1

Modeling the Bending and Recovery Behaviour of Woven Fabrics

Shi F., Zhao Y., Wu G., Zheng D.

Fibres & Textiles in Eastern Europe

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2017

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Vol. 25, no. 6 (126)

41--45

EN

On the basis of viscoelastic theory of textile material, the viscoelastic solid model consisting of a spring element and viscous element either in series or parallel is one of the most useful research models to study the mechanical behaviour of fabrics. This paper presents a method to study the bending behaviour of wool/polyester fabrics using a model consisting of the three-element model in parallel with a sliding element on the assumption that the internal frictional moment is a constant during the bending processes. From the needs of practical study, a testing method has been presented to study the bending behaviour of wool/polyester fabrics using a KES-FB3 compression tester. A comparison and analysis of the experimental results and theoretical predictions indicate that the agreement between them is satisfactory.

PL

Lepkosprężysty model bryłowy składający się z elementu sprężystego i elementu lepkiego, w układzie szeregowym lub równoległym, jest jednym z najbardziej użytecznych modeli służącym do badania mechanicznego zachowania się tkanin. W pracy przedstawiono metodę badania zachowania się zginanych tkanin wełniano-poliestrowych za pomocą modelu składającego się z trój-elementowego modelu równoległego z elementem przesuwnym przy założeniu, że wewnętrzny moment tarcia jest stały podczas procesów gięcia. Na podstawie praktycznych badań przedstawiono metodę badania zachowania się gięcia tkanin wełniano-poliestrowych przy użyciu testera kompresji KES-FB3. Stwierdzono zadowalającą zgodność między wynikami eksperymentów a przewidywaniami teoretycznymi.

2

Allometric Partitioning Theory Versus Optimal Partitioning Theory : The Adjustment of Biomass Allocation and Internal C-N Balance to Shading and Nitrogen Addition in Fritillaria unibracteata (Liliaceae)

Guo H., Xu B., Wu Y., Shi F., Wu C., Wu N.

Polish Journal of Ecology

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2016

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Vol. 64, nr 2

189--199

EN

Fritillaria unibracteata is a classic perennial alpine herb. In this study, we examined it's responses to shading (SH) and nitrogen addition (NA), as well as its correlation with internal C-N balance to detect how it adjusted to the changes of habitat conditions. Randomized block experiment was carried out in the field in Chuanbeimu Research Station in Songpan County, Sichuan Province, China (32°09′54″N, 103°38′36″E, altitude 3300 m a.s.l.). Two growing seasons after NA and SH, Fritillaria unibracteata's total plant biomass decreased significantly, with the proportion of biomass allocated to aboveground significantly increased. In addition, in this study, under both SH and NA treatments, Fritillaria unibracteata increased its biomass allocation to above-ground, which consisted with optimal partitioning theory. Moreover, Fritillaria unibracteata's biomass allocation was significantly correlated with its internal C-N status, regardless of nitrogen and light condition. We conclude that Fritillaria unibracteata optimizes its biomass allocation between root and shoot by adjusting its internal C-N balance, which would not be changed by the specialized resource storage organ-bulb.

3

Comparison of float-sink and progressive release flotation of ground products of coal middlings

Xie W., He Y., Luo C., Zhang X., Li H., Yu J., Wang H., Shi F.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

675--684

EN

An additional recovery of coking coal middlings can be utilized for increasing of the concentrate yield of coking coal. A combined flow sheet of comminution and flotation can realize this target. To investigate the effect of grinding process on further flotation of ground products, progressive release flotation tests were used to compare with the float-sink tests, which were regarded as a criterion. Coal middlings were ground by wet-milling with iron balls to <0.5 mm. Curves of ash vs. cumulative yields of sized products indicated that the concentrate yield of coal separated by progressive release flotation was lower than that of coal benefited by the float-sink test, with the same ash for four size fractions (0.5-0.25 mm, 0.25-0.125 mm, 0.125-0.074 mm and <0.074 mm). Distributions of elements conducted by energy disperse spectroscopy (EDX) showed that associated kaolinite was liberated and exposed on the surface. It led to the shift of local surface property from hydrophobicity to hydrophilicity. Meanwhile, analyses of chemical property performed by an X-Ray photoelectron spectrometer (XPS) depicted that the hydrophilic mineral FeOOH, which generated in the grinding process, was adsorbed on the coal surface. Flotation of the ground products were worsened due to the increase of hydrophilicity of the coal surface.

4

Effects of saline-alkaline stress on early growth strategy and colonization success of Flaveria bidentis ( L.) Kuntze (Asteraceae ) - a new exotic plant in Northern China

Chai M., Shi F., He K., Li R., Cao D., He Z.

Polish Journal of Ecology

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2012

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Vol. 60, nr 3

559-565

EN

Flaveria bidentis, an annual grass native to South America, has invaded into many countries all over the world, including South Africa and Egypt in Africa, Britain and France in Europe, Japan in Asia, and Australia. In China, this plant species has been widely distributed in Hebei province since 2001 of its first discovery in Tianjin. In salinized soil of northern China, F. bidentis has formed mono dominant communities owing to its opportunistic characteristics. In this study, we investigated germination rate, germination energy, germination index and vigor index in response to different saline-alkaline stresses. Lengths of seedling, hypocotyl, and radicle were also examined. During germination process, germination rate, germination energy, germination index, and vigor index decreased due to higher salinity and alkalinity (pH). Hypocotyl elongation was stimulated at low salinity and alkalinity, but decreased with increasing salinity and alkalinity. The lengths of radicle and seedling were inhibited sharply with increasing salinity and alkalinity. These results suggest that a reciprocal enhancement between salt stress and alkaline stress was a characteristic feature during seed germination of F. bidentis. Ungerminated seeds resumed to germinate after transferred to distilled water, indicating that seeds remained viable during their exposure to saline-alkaline stresses. Stepwise regression analysis indicated that the effects of salinity, alkalinity (pH), and buffer capacity on seed germination and seedling growth were significantly different in magnitude. Salinity and alkalinity (pH) were the dominant factors in seed germination and seedling growth of F. bidentis respectively. Further, the results of this study suggest that F. bidentis has developed excellent adaptative strategy in its early stage of life cycle which partially explains its current invasion success in northern China.

5

Effects of livestock exclusion on vegetation and soil properties under two topographic habitats in an alpine meadow on the eastern Qinghai-Tibetan Plateau

Shi F., Chen H., Wu Y., Wu N.

Polish Journal of Ecology

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2010

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Vol. 58, nr 1

125-133

EN

Long-term overgrazing has resulted in grassland deterioration and even desertification on the eastern Qinghai-Tibetan Plateau. In this paper, we examined the characteristics of vegetation and soil properties in the livestock-excluded pastures and the adjacent grazed pastures under two topographic habitats (the flat valley and the south-facing slope). Seven-year exclusion of livestock has enhanced aboveground live biomass, root biomass and litter accumulation. Livestock exclusion has also increased soil bulk density and soil water content, soil organic C concentration, total N concentration and its transformation rate, and soil microbial activity. The results showed that livestock exclusion has facilitated vegetation recovery and improved physical, chemical and biological properties of soil. However, livestock exclusion has significantly decreased graminoid biomass accumulation, especially on the flat valley, the biodiversity also significantly decreased there. The results suggested that long-term livestock exclusion was disadvantageous for palatable forage production and biodiversity protection on the flat valley. Compared to the flat valley, the grassland on the south-facing slope was under more severe degradation, and the reversion was in a slower process. Thus, the optimal grassland management in the livestock-excluded pasture on the flat valley should include a low or moderate grazing intensity or adopt an alternate grazing system, but more effective and even longer livestock exclusion practice should be taken on the south-facing slope.

6

The ecological profit in phenology and pollination of alien species Spartina alterniflora (Loisel) introduced to coastal wetlands in northern China

Shi F., Yuan Z., He K., Li J., Guo S.

Polish Journal of Ecology

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2009

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Vol. 57, nr 2

283-289

EN

For the plant species, effective phenology and pollination syndromes can increase viable seeds which enhance the species to colonize new areas. So the species with a suit of advantageous characteristics inherent in its reproductive ecology is critical to its dispersion. Spartina alterniflora - a perennial grass native to coastal marshes of America was introduced to China in 1979 and now it is distributed in the Tianjin coastal wetlands of northern China. Flowering phenology was examined and indicated that in northern localities, flowering initiated in mid-August and senescence occurred by the end of October. The pollen-ovule ratio was 9875 ([plus or minus]2150). Abundant pollen grains compensated for a lack of pollen viability. Pollen viability was 10% approximately when pollen released 4 hours, but stigma receptivity was above 10% when stigmas exserted 7 hours. Stigmas maintained viability longer than the period of pollen release, ensuring successful pollination. Scanning electron microscopy was used to observe stigma surface characters and pollen viability. Further investigation proved stigma adaptations to increase pollen capture and exterior pollen tube growth following pollination was beneficial to fertilization. The results suggested that flowering phenology and pollination traits are vital to pollination and production of viable seed, enabling the species to spread rapidly and succeed in new habitats of northern China.

7

Ecological adaptation strategies in alien species: effects of salinity, temperature and photoperiod on Spartina alterniflora Loisel. seed germination

Yuan Z., Shi F.

Polish Journal of Ecology

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2009

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Vol. 57, nr 4

677-684

EN

Spartina alterniflora (smooth cordgrass), a perennial grass native to the coastal marshes of eastern America, is widely distributed in northern China since 1979 of its introduction. In the tidal marshlands of north China, S. alterniflora has displaced native species and is presently dominant member of the community owing to its opportunistic characteristics. In this study we investigated S. alterniflora seed germination responses to different temperatures, between 5.25[degrees]C in one thermoperiod (16/26[degrees]C) and in two light treatments - 10/14h (night/day) photoperiod and dark conditions. Variations of seed germination at different storage temperatures and storage duration were also examined. In addition, the effect of different salt concentrations on seed germination was evaluated. The optimal temperature for germination was 25[degrees]C and 16/26[degrees]C (night/day) thermo-period - germination percentage was greater than 90%. Light intensity had no influence on the percent of seed germination and germination indices when seeds were exposed to identical temperatures. At 120 d of storage and -5, 0, and 5[degrees]C temperatures, germination percentage exceeded 75%. The optimal salinity level for seed germination was 150 mM NaCl. Germination percentages were highest (> 90%) when salinity did not exceed 450 mM NaCl. The ability of S. alterniflora seeds to germinate under a wide range of temperature and light conditions resulted in continued seedling development under high salinity.

8

Interactions of high current pulsed electron beam with phosphate laser glass

Wang C., Hao S., Shi F., Qi J., Tao Y., Wang B.

Materials Science Poland

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2007

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Vol. 25, No. 4

1101--1108

EN

Impact of electron beam bombardment on the surface of Nd3+ doped P2O5-B2O3-Al2O3-BaO laser glass was investigated. Physical properties of the bombarded glass were measured by 3D laser roughometer, microhardness tester, UV/VIS spectrometer, EDS and contact goniometer. Low beam energy had no significant impact on glass surface morphology and other properties. High beam energy increased glass surface roughness and decreased micro-hardness, UV/VIS transmittance and wetting angle. Thermal stress generated by high energy electron beam bombardment expanded the Griffith flaws and increased glass surface roughness.