Wyniki wyszukiwania - Biblioteka Nauki

1

Effects of iron-modified biochar and AMF inoculation on the growth and heavy metal uptake of Senna occidentalis in heavy metal-contaminated soil

100%

Guo X. , Li H.

Polish Journal of Environmental Studies

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2019

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tom 28

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nr 4

EN

S. occidentalis can be used in pharmacology and vegetation restoration. A pot experiment was conducted to study the effects of biochar and mycorrhizal fungus inoculation on plant growth and heavy metal accumulation. The mycorrhizal infection rate was increased by apple branch biochar but decreased by coconut husk iron-modified biochar. Conversely, soil pH was not affected by mycorrhizal inoculation but was increased by biochar. Compared to the uninoculated control, the combination of apple branch biochar and mycorrhizal inoculation significantly increased the growth of stems, leaves and roots by 226.46%, 163.15% and 86.00%, respectively. The application of apple branch biochar increased the root Pb content, while root Cd, Cr, Cu and Fe were decreased by 36.30%, 13.63%, 3.09% and 7.66%, respectively. Furthermore, the content of all elements in the stems and leaves also decreased. The application of iron-modified biochar alone increased the content of all the elements in the roots by 4.23-109.33%. But their contents in stems and leaves were decreased by iron-modified biochar and mycorrhizal inoculation alone. The combination of biochar and mycorrhizal inoculation most effectively promoted plant growth, enhanced heavy metal uptake by the roots and produced a barrier effect that reduced the transfer of heavy metals from the roots to the shoots. This might constitute a feasible means of promoting the safe utilization of S. occidentalis in phytoremediation.

2

SDF-1/CXCR4 axis promotes osteogenic differentiation of BMSCs through the JAK2/STAT3 pathway

80%

Xiong W. , Guo X. , Cai X.

Folia Histochemica et Cytobiologica

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2021

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tom 59

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nr 3

3

Increased nitrous oxide emissions resulting from nitrogen addition and increased precipitation in an alpine meadow ecosystem

80%

Du Y. , Guo X. , Cao G. , Li Y.

Polish Journal of Environmental Studies

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2016

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tom 25

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nr 1

EN

The effects of nitrogen (N) addition and increased precipitation on nitrous oxide (N2O) emissions in alpine meadow ecosystems are still unclear. In this study, we measured N2O fluxes on the Tibetan plateau under interactions of moderate atmospheric N deposition and increased precipitation using a closed chamber method. Under all applied treatment conditions, the alpine meadow ecosystem acted as a source of N2O. The N2O emission rate reached a maximum of 74.83±14.40 μg m-2 h-1, with a significant increase in emission rate of 68.76% following N addition when compared with the control plot (p<0.05). Increased precipitation, and its interactive combination with N deposition, enhanced the N2O emission rate by 53.90% and 44.52%, respectively. However, there was no significant difference between these two treatments. Increased precipitation would help to mitigate N2O fluxes under global nitrogen deposition conditions.

4

Effects of combined amendments on growth and heavy metal uptake by Pakchoi (Brassica chinensis L.) planted in contaminated soil

80%

Li Z. , Zhu W. , Guo X.

Polish Journal of Environmental Studies

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2015

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tom 24

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nr 6

5

Preparation and Characterization of Desensitized ?-HNIW in Solvent-Antisolvent Recrystallizations

80%

Jiang X. , Guo X. , Ren H. , Jiao Q.

Central European Journal of Energetic Materials

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2012

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tom Vol. 9, nr 3

219-236

EN

The solubility of hexanitrohexaazaisowurtzitane (HNIW) in solvent and solvent-antisolvent mixtures, and the temperature at which the HNIW's polymorph transforms were studied. The solubility of HNIW in solvent-antisolvent mixtures was measured at 30 C and these data were fitted to a generalized solubility curve. Recrystallization experiments were conducted at 30 C in the case of saturation with the volume ratio of ethyl acetate to petroleum ether (chloroform) ranging from 0:1 to 4:1. Desensitized HNIW was obtained by ethyl acetate and petroleum ether crystallization and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), High Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM). The FTIR and XRD spectra confirmed the structural features of ε-HNIW. The blocklike ε-HNIW grains had an average particle size of 160 ?m and high purity (98.52%). The decomposition of ε-HNIW was observed in the temperature range of 225-246 C by Differential Scanning Calorimetry (DSC). Furthermore, the impact and friction sensitivity tests suggested that the desensitized ε-HNIW was less sensitive than raw HNIW. Small scale gap tests with desensitized ε-HNIW showed that these crystals are less sensitive to shock initiation.

6

Associations between polymorphism in the 2,4-dienoyl-CoA reductase 1 gene (DECR1) and growth traits of Shanxi White pig

80%

Li B. , Guo X. , Cao G. , Zhou Z.

Animal Science Papers and Reports

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2011

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tom 29

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nr 4

EN

A polymorphism within exon 2 of the 2, 4-dienoyl-CoA reductase gene (DECR1) was investigated by PCR-SSCP in 228 Shanxi White pigs. An association between the DECR1 polymorphism and growth traits in Shanxi White pigs was determined with an univariate animal model. The polymorphism was found within exon 2 of the DECR1, giving rise to genotypes AA, BB or AB. This polymorphism exhibited a significant effect of generation and sex (P<0.05, P<0.01) on growth traits and backfat thickness. At the age of six months BB pigs showed the body weight and chest girth higher than AA and AB animals. However, the polymorphism revealed no significant effects on other growth traits (P>0.05) though a trend of BB>AB>AA was showed.

7

Study on vegetation concrete technology for slope protection and greening engineering

80%

Cheng J. , Luo X. , Shen Z. , Guo X.

Polish Journal of Environmental Studies

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2020

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tom 29

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nr 6

8

Improving Waveform Inversion using Modified Interferometric Imaging Condition

71%

Guo X. , Liu H. , Shi Y. , Wang W. , Zhang Z.

Acta Geophysica

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2018

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tom Vol. 66, no. 1

71--80

EN

Similar to the reverse-time migration, full waveform inversion in the time domain is a memory-intensive processing method. The computational storage size for waveform inversion mainly depends on the model size and time recording length. In general, 3D and 4D data volumes need to be saved for 2D and 3D waveform inversion gradient calculations, respectively. Even the boundary region wavefield-saving strategy creates a huge storage demand. Using the last two slices of the wavefield to reconstruct wavefields at other moments through the random boundary, avoids the need to store a large number of wavefields; however, traditional random boundary method is less effective at low frequencies. In this study, we follow a new random boundary designed to regenerate random velocity anomalies in the boundary region for each shot of each iteration. The results obtained using the random boundary condition in less illuminated areas are more seriously affected by random scattering than other areas due to the lack of coverage. In this paper, we have replaced direct correlation for computing the waveform inversion gradient by modified interferometric imaging, which enhances the continuity of the imaging path and reduces noise interference. The new imaging condition is a weighted average of extended imaging gathers can be directly used in the gradient computation. In this process, we have not changed the objective function, and the role of the imaging condition is similar to regularization. The window size for the modified interferometric imaging condition-based waveform inversion plays an important role in this process. The numerical examples show that the proposed method significantly enhances waveform inversion performance.

9

Analytical investigation of grain size dependence of microhardness in high nickel-containing reheated weld metal

71%

Mao G. , Cao R. , Chen J. , Guo X. , Jiang Y.

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2017

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tom Vol. 17, no. 4

935--942

EN

Grain size dependence of microhardness has been addressed in the bainitic reheated weld metals by in situ observation of morphological evolution and characterization of microstructural development. A higher cooling rate promotes the boundary of smaller prior austenite grains to provide more effective sites for primary bainitic ferrite nucleation, yet a lower cooling rate is increasingly beneficial to sympathetic nucleation as well as impingement of secondary bainitic ferrite. The microstructures, obtained by cooling at a higher rate and composed of abundant lath bainite, are closer to the microstructures in the raw weld metal than those cooled at a lower rate, including lath bainite, acicular ferrite and intercritical ferrite. Microhardness is decisive by prior austenite grain size mainly, as well as microstructures. Smaller grains contribute notably to microhardness, and it is worth stressing that the sizes of smaller grains lie on prior austenite grain boundaries rather than the subboundaries generated by intragranular acicular ferrite and intercritical ferrite.

10

Dynamic-accumulative operation policy of continuous distillation for the purification of anisole

71%

Wang Z. , Li S. , Wang C. , Guo X. , Bai P.

Polish Journal of Chemical Technology

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2016

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tom Vol. 18, nr 1

33--39

EN

In the B10 isotope enrichment industry, the purification of anisole mixture makes great sense. A dynamic-accumulative operation policy of continuous distillation (DACD) with repeated filling and dumping of the still is proposed for the separation of trace heavy impurities in the recycled anisole. To simulate and optimize the purification process of anisole, a mathematical model of DACD is derived, and the computer codes are developed in the MATLAB environment. Moreover, the experiment is performed in a pilot-scale distillation column. The results show that the experimental date agrees well with simulation results. DACD could solve the difficulty of flow rate control when the bottom flow rate is very small in continuous distillation. The size of the still in this operation mode is also smaller than that in batch distillation. And the yield of anisole is raised to 99.91%. In a word, DACD is especially suitable for separating trace heavy impurities from the recycled anisole.

11

Effect of grazing intensity on soil and plant δ15N of an alpine meadow

71%

Du Y. , Guo X. , Zhou G. , Cao G. , Li Y.

Polish Journal of Environmental Studies

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2017

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tom 26

|

nr 3

EN

The mechanisms underlying the retention of inorganic N were still not well understood in an alpine meadow on the Tibetan Plateau as well as in other high-altitude meadow sites greatly grazed and disturbed. We conducted field soil and dominant species foliar nitrogen natural abundance of stable isotope ratios (δ¹⁵N) under four grazing intensities. It was demonstrated that soil δ¹⁵N decreased significantly from 5.83±0.20‰ to 2.17±0.48‰ at 0-10 cm with the elevation of grazing intensity. Grazing reduced the degree of ecosystem N openness. The δ¹⁵N value of surface soil was mainly affected by soil total nitrogen. Furthermore, the degree of nitrogen limitation increased with grazing elevation for sedge family and Gramineae family plants.

12

Exogenous ethylene enhanced the cadmium resistance and changed the alkaloid biosynthesis in Catharanthus roseus seedlings

61%

Chen Q. , Wu K. , Tang Z. , Guo Q. X. , Guo X. , Wang H.

Acta Physiologiae Plantarum

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2017

|

tom 39

|

nr 12

13

Morphological and biomass characteristic acclimation of trident maple (Acer buergerianum Miq.) in response to light and water stress

61%

Guo X. , Guo W. , Luo Y. , Tan X. , Du N. , Wang R.

Acta Physiologiae Plantarum

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2013

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tom 35

|

nr 04

EN

Acer buergerianum Miq. (Trident maple) is a native species of China with a large distribution, but exist in small population. Water and light are two important factors limiting plant growth and are crucial in the framework of forest regeneration. However, there is no consensus on how shade interacts with drought. Four hypotheses in the recent literature variously predict that shade will have a stronger, weaker or equal impact on seedlings under drought stress. This study investigated the interactive responses of A. buergerianum to light and water focusing on seedling growth, leaf morphology and biomass partitioning by performing a growth experiment in pots with different water supply regimes [15, 35, 55, 75, 95 % of field capacity (FC)] combined with two light regimes (10 and 66 % of full sunlight). After 123 days treatment, the results showed that shade greatly reduced growth and biomass, in contrast enhancing the amount of chlorophyll, the amount of water in the leaves, and the specific leaf area. Drought reduced growth, biomass, and the bulk of the leaves. Most leaf traits and biomass characteristics had strong interactions in their responses to light and water treatments. Allometric analysis revealed that water and light had no effects on root to shoot ratios, main root to lateral root ratios, and root mass ratios. Shade alleviated the negative impact of drought. A. buergerianum successfully adapted to the various light and water conditions. We recommend a water supply above 15 % FC to keep the seedlings vigorous, under both sunlight conditions.

14

Preparation and Properties of Natural Cellulose Fibres from

61%

Qu L. , Tian M. , Guo X. , Pan N. , Zhang X. , Zhu S.

Fibres & Textiles in Eastern Europe

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2014

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tom Vol. 22, no. 4 (106)

24--28

EN

Natural cellulose fibres from Broussonetia papyrifera (L.) Vent. (BP) bast were systematically investigated in this paper. To begin with, BP fibres were successively extracted from BP bast by four different degumming methods, among which the microwave-assisted method exhibited high efficiency. It was found that non-cellulose substances were sufficiently removed or reduced after the degumming process, but the cellulose I structure had not changed from bast to fibres based on the XRD and FTIR results. Meanwhile the BP fibres exhibited high crystallinity (75 ~ 77%), high breaking strength (2.19 ~ 2.39 cN/dtex) and a remarkable moisture region (6.3 ~ 8.7%), but low breaking elongation (1.0 ~ 2.1%). All those results indicated that the BP fibres had properties resembling those of traditional natural cellulose fibres (e.g. cotton and flax); therefore they could be viewed as a promising alternative source for natural cellulose bundle fibres.

PL

Artykuł poświecono systematycznym badaniom naturalnych włókien celulozowych z Broussonetia Papyrifera (BP). Włókna ekstrahowano z włókien łykowych BP poprzez 4 rożne metody odpreparowania pomiędzy z których metoda za pomocą zastosowania ultradźwięków pozwoliła na uzyskanie wysokiej wydajności. Stwierdzono, że nie celulozowe substancje były dostatecznie usunięte lub zredukowane po procesie odpreparowania. Dzięki badaniom XRD i FITR można było wykazać, że struktura celulozy (I) nie zmieniła się pomiędzy włóknami łykowymi i otrzymanymi z nich wyrobami. dalsze badania wykazały źe włókna BP maja wysoką krystaliczność (75 - 77%), wysoką wytrzymałość(2.19 - 2.39 cN/dtex) i znaczną pochłanialność wilgoci (6.3 - 8.7%) natomiast małe wydłużenie przy zerwaniu (1.0 - 2.1%). Wszystkie te wyniki wskazują,że włókna BP posiadają właściwości przypominające właściwości tradycyjnych, naturalnych włókien celulozowych (np. bawełny i lnu). Dlatego też badane włok-na można uważać jako alternatywne źródło naturalnych włókien celulozowych.

15

Ecological risk and economic loss estimation of heavy metals pollution in the Beijiang River

61%

He J. , Zhang H. , Zhang H. , Guo X. , Song M. , Zhang J. , Li X.

Ecological Chemistry and Engineering. S

|

2014

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tom Vol. 21, nr 2

189--199

EN

The distribution and extent of heavy metal accumulation in the fluvial sediment of the Beijiang River are described. The potential toxicity of this pollution was quantified using a consensus based sediment quality guidelines (SQGs) method and the Hakanson potential ecological risk index. The concentrations of Hg, As, Cu, Zn, Pb, Ni and Cr were high enough to damage the sediment biota on a frequent basis. The potential ecological risk was much higher in the downstream, urbanized reaches of the river than in the upstream reaches which are still rural, but all sections of the river posed at least a moderate level of ecological risk. Estimates of the economic loss associated with these pollutions were appreciable, and were mainly due to Hg and Cu. The Beijiang River basin is heavily polluted, posing environmental risks for the downstream reaches of the Pearl River, and economic loss to the whole watershed.

PL

W artykule opisano dystrybucję i stopień akumulacji metali ciężkich w rzecznych osadach rzeki Beijiang. Potencjalną toksyczność tych zanieczyszczeń obliczono za pomocą metody wytycznych jakości osadów (SQGs) opartej na konsensusie i za pomocą potencjalnego wskaźnika ryzyka ekologicznego Håkansona. Stężenia Hg, As, Cu, Zn, Pb, Ni i Cr były na tyle wysokie, aby uszkodzić biocenozy osadu. Potencjalne ryzyko ekologiczne było znacznie większe w dalszych, zurbanizowanych odcinkach rzeki niż na wcześniejszych odcinkach, które nadal są wiejskie, ale wszystkie odcinki rzeki reprezentowały co najmniej umiarkowany poziom ryzyka ekologicznego. Szacunki strat ekonomicznych związanych z tymi zanieczyszczeniami były znaczne, a to głównie ze względu na obecność Hg i Cu. Dorzecze rzeki Beijiang jest mocno zanieczyszczone, stwarzając zagrożenie dla środowiska w dalszym biegu rzeki Perłowej i możliwość strat ekonomicznych dla całej zlewni.

16

Preparation of Twinned Dendrites of Al-Zn Alloy with High Zn Content

61%

Gao K. , Song W. , Fan L. , Ding Y. , Guo X. , Zhang R.

|

tom 63

|

nr 4

17

Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

61%

Wen Y. , Zhang R. , Cang Y. , Zhang J. , Liu L. , Guo X. , Fan B.

Polish Journal of Chemical Technology

|

2015

|

tom Vol. 17, nr 1

62--65

EN

The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the first time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small amount of by-products. Our new method offers an attractive choice for the production of dimethyl carbonate in large-scale industry efficiently and environmental friendly.

18

Higher phenotypic plasticity does not confer higher salt resistance to Robinia pseudoacacia than Amorpha fruticosa

61%

Guo X. , Ren X.-H. , Eller F. , Li M.-Y. , Wang R.-Q. , Du N. , Guo W.-H.

Acta Physiologiae Plantarum

|

2018

|

tom 40

|

nr 04

19

Preparation of Twinned Dendrites of Al-Zn Alloy with High Zn Content

61%

Gao K. , Song W. , Fan L. , Ding Y. , Guo X. , Zhang R.

Archives of Metallurgy and Materials

|

2018

|

tom Vol. 63, iss. 4

1657--1662

EN

Twinned dendrites in Al-Zn alloy with high Zn content (40% wt.%) were successfully prepared by directional solidification. At different directional solidification rates (1000 and 1500 μm/s), microstructures and growth orientation variations of Al twinned dendrite and non-twinned dendrite were characterized. By using the inverted trapezoidal graphite sleeve at 1000 μm/s, Al twinned dendrite were formed to developed feather crystal structures in longitudinal section. Its primary and secondary twinned dendrite were grew along [110] direction. Moreover the deviation angle between [110] direction of Al twinned dendrite and the heat flow direction was about 27.15°. While not using the inverted trapezoidal graphite sleeve at 1000 and 1500 μm/s, Al dendrite was the non-twinned dendrite and the twinned dendrite was not appeared. The experimental results showed that the higher temperature gradient, a certain pulling rate and convection environment were the formation conditions of twinned dendrites.

20

Acer truncatum seedlings are more plastic than Quercus variabilis seedlings in response to different light regimes

61%

Guo X. , Wang R.-Q. , Wang C. D. , Xu F. , Zhao S. , Guo W.-H.

Dendrobiology

|

2016

|

tom 76

EN

In this study, we investigated responses of the mid-successional species Acer truncatum Bunge and the late-successional species Quercus variabilis Blume to three solar illumination conditions: (1) constant low light (CL), (2) constant high light (CH) and (3) low light first and high light afterwards (LH). The last treatment was to simulate a canopy opening. Both species exhibited increases in biomass, totally and in part, and decreases in leaf water content, specific leaf area and chlorophyll concentrations in LH treatment compared to CL treatment. For A. truncatum, exposure to high light condition (LH) increased crown area, and decreased root to shoot ratio, stem mass ratio and leaf perimeter. However, for Q. variabilis, LH treatment increased stem diameter at ground height, effective quantum yield, photochemical quenching and decreased maximum photosystem II quantum yield. The biomass allocation pattern did not change in Q. variabilis among three light conditions. With respect to newly developed leaves, no significant differences were found in leaf size of Q. variabilis between LH treatment and CH treatment while that of A. truncatum decreased in LH treatment. All chlorophyll fluorescence parameters in newly developed oak leaves in LH treatment increased compared to those of CH treatment while no difference was found for A. truncatum between LH and CH treatment. A. truncatum displayed a greater overall plasticity than Q. variabilis although the oak seedlings have a greater plasticity with respect to chlorophyll concentration and chlorophyll ﬂuorescence parameters. A. truncatum should be a better candidate for vegetation recovery, especially in places with heterogeneous light conditions.