Wyniki wyszukiwania - Biblioteka Nauki

1

Phosphorus adsorption capacity evaluation for the substrates used in constructed wetland systems: a comparative study

100%

Dai H. , Hu F.

|

tom 26

|

nr 3

EN

To provide a selection criteria to choose substrates according to the quality of the water requiring treatment in constructed wetlands (CWs), phosphorus (P) adsorption properties of four quartz sands with different physicochemical characteristics and four substrates commonly used in CWs were tested and evaluated via both the Langmuir and Freundlich equations. The effects of organic maters (OM) on P adsorption capacities of the substrates were also studied to evaluate the practical values of the substrates. The Langmuir sorption isotherm was used to estimate the P adsorption capacities of the tested substrates in CWs. Overall, the maximum P adsorption for all of the tested substrates decreased as follows: furnace slag > ceramic > zeolite > activated carbon > quartz quartz sands. The P adsorption capacities were significantly influenced by grain size; specific surface area; Fe, Al, Mg, and Ca contents in the substrates; and the amount of added OM. The chemical precipitation of P by the substrates containing Fe was more effective than those containing Ca at the same level. Added OM impacts P sorption by influencing pH, and substrates containing higher Fe and Al concentrations and lower Ca concentrations were more resistant to decreases in the P adsorption capacities due to OM accumulation. Finally, a principle for selecting substrates for the treatment of wastewater with different characteristics was determined.

2

Data-driven Valued Tolerance Relation Based on the Extended Rough Set

80%

Wang G. , Guan L. , Wu W. , Hu F.

Fundamenta Informaticae

|

2014

|

tom Vol. 132, nr 3

349--363

EN

The classical rough set theory is based on the conventional indiscernibility relation. It is not very good for analyzing incomplete information. Some successful extended rough set models based on different non-equivalence relations have been proposed. The valued tolerance relation is such an extended model of classical rough set theory. However, the general calculation method of tolerance degree needs to know the prior probability distribution of an information system in advance, and it is also difficult to select a suitable threshold. In this paper, a data-driven valued tolerance relation (DVT) is proposed to solve this problem based on the idea of data-driven data mining. The new calculation method of tolerance degree and the auto-selection method of threshold do not require any prior domain knowledge except the data set. Some properties about the DVT are analyzed. Experiment results show that the DVT can get better and more stable classification results than other extended models of the classical rough set theory.

3

Dinosaur assemblages from the Middle Jurassic Shaximiao Formation and Chuanjie Formation in the Sichuan-Yunnan Basin, China

80%

Li K. , Yang C. , Hu F.

Volumina Jurassica

|

2011

|

tom Vol. 9, no. 1

21-42

EN

The Shaximiao Formation (Sichuan Basin, China), and the corresponding Chuanjie Formation of the neighboring Yunnan Basin (Sichuan-Yunnan Basin), representing continental Mesozoic strata, are distinguished from other Chinese Mesozoic units because of the large area over which they are distributed, their lithological characteristics and their abundant vertebrate fossils. This paper analyses and summarizes the dinosaur fossils from the Shaximiao Formation and compares them to other vertebrate groups of the same or similar ages, both in China and abroad. For the first time, this paper presents the viewpoint that the upper member of the Shaximiao Formation is of Middle Jurassic age (Bathonian–Callovian). Furthermore, we claim that the entire Shaximiao Formation is of Bajocian–Callovian age (middle-late part of Middle Jurassic). This conclusion is supported by the age inferred from invertebrate fossils and radiometric dating (165–178 Ma). The composition, evolution and geological age of the vertebrate fauna (particularly dinosaur fossils), as well as their comparison to the dinosaur fauna from the other parts of the Sichuan-Yunnan Basin (Chuanjie Fm.) is discussed. Middle Jurassic dinosaur assemblages from China show marked differences compared with other dinosaur assemblages in the world, and this is explained by geographical isolation.

4

Effects of Pinus massonian plantations on soil macroarthropods in degraded ultisol, Subtropical China

61%

Ding C. , Hu F. , Zhou J. , Cao Z. , Li H. , Dai Z.

Archives of Environmental Protection

|

2008

|

tom Vol. 34, no. 3

17-20

EN

In the degraded red soil of subtropical China, restoration activities during the last century have mainly relied on extensive plantations of Pinus massonian. We analyze the changes in the soil macroarthropods in P. massonian plantations and the possible relationships between these changes and soil chemical parameters. The study revealed significant differences in the abundance of soil macroarthropods between the P. massonian plantations and the natural regenerated mesophilous herbosa (Nl). The sharply differentiated pattern of soil macroarthropods seems closely linked to soil chemistry. Significant correlations of the abundance of soil macroarthropods with soil parameters suggest that their populations could have been affected by P massonian. The total abundance, the abundance of Hymenoptera and Termite were less in the P. massonian plantations when compared to the natural regenerated mesophilous herbosa (Nl). This survey showed that P.massonian could adversely affect the decomposer community which could lower the nutrient cycling rate, thus P.massonian may not be an ideal plantation for restoration of eroded Ultisol, Subtropical China.

5

Effect of varying NaCl doses on flavonoid production in suspension cells of Ginkgo biloba : relationship to chlorophyll fluorescence, ion homeostasis, antioxidant system and ultrastructure

51%

Chen Y. , Lin F. , Yang H. , Yue L. , Hu F. , Wang J. , Luo Y. , Cao F.

Acta Physiologiae Plantarum

|

2014

|

tom 36

|

nr 12

EN

Ginkgo suspension cells were used to investigate the mechanism that governs the shift between primary and secondary metabolism under NaCl elicitation. The production of three flavonol glycosides, chlorophyll fluorescence, ion content, the antioxidant system, and the cellular ultrastructure in the presence of NaCl doses from 5 to 175 mM were examined. At low salt doses (5–50 mM), cell growth and flavonol glycosides accumulation were stimulated without damaging cell structure or inducing oxidative stress by maintaining high K⁺ and chlorophyll content. At moderate salt doses (75–125 mM), the cells could withstand the salt stress without an impact on survival by changing internal cellular structure, maintaining high levels of K⁺ and Ca²⁺ and increasing anti-oxidative enzyme activities rather than flavonol glycosides to counteract the inhibition of the photosystem II, the accumulation of Na⁺ and hydrogen peroxide (H₂O₂) in the cells. This allowed cells to divert their metabolism from growth to defense-related pathways and tolerate NaCl stress. At higher salinity (150–175 mM), the cellular structure was damaged, and the high Na⁺ and low K⁺ content led to osmotic stress, and therefore, the stimulation of peroxidase (POD) and catalase (CAT) was not enough to cope with high H₂O₂ accumulation. The high production of flavonol glycosides may be a response of elicitation stimulation to serious damage at 175 mM NaCl. In conclusion, the use of 175 mM NaCl may be desirable for the induction of flavonol glycoside production in Ginkgo suspension cells.