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Search Results: 1 - 10 of 246763 matches for " L Xian-Guo "
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Distribution characteristics of dissolved organic carbon in the sediment of multi-stage canal and ditch systems in wetlands of the Sanjiang Plain

XI Min,L Xian-Guo,

生态学报 , 2007,
Abstract: Land cultivation,drainage and irrigation not only arise movement and deposit of soil dissolved organic carbon(DOC) within the canals and ditches,but also lead to the difference of sediment DOC.Previous studies were mainly performed at plot-to-field scale,but little is known about the effect of intensive agricultural catchments on the distribution of sediment DOC beyond field edges.This study was conducted to examine the distribution characteristics of sediment DOC in multi-stage canal and ditch systems in the Sanjiang Plain.Sediment samples were collected from multi-stage canal and ditch systems,which have similar soils and land use patterns,and analyzed for DOC content.Those different units of canals and ditches varied from field-edge waterways to sizeable drainages.The proportion of sediment DOC increased gradually and the sediment DOC was transferred to the deeper sediment layers(40-60cm) with increased drainage area,such as from field canal,to lateral,to branch,to trunk, and to general main canal.Overall,the mean DOC content in sediment was the highest in general main canal(488.747mg/kg) and the lowest in the field canal(269.672mg/kg).The sediment DOC in 40-60cm layers was mainly accumulated in general main canal(1270.947mg/kg).The regions with the highest values for 20-40cm,10-20cm and 0-10cm sediment layers were mainly in the trunk canal(326.147mg/kg), field or lateral canal(360.547mg/kg and 360.547mg/kg),and branch or trunk canal(425.747mg/kg and 450.947mg/kg),respectively.Those canals and ditches collected and stored the DOC mass flows from wetland and farm,and then transferred them into rivers and lakes.Temporally repetitive drainage of canals and ditches transported DOC flows into canal and ditch systems by sporadic flows.The Land erosion controlled flows of DOC mass during storm events.Continuous flows of DOC interacted with multi-stage canal and ditch systems.The spatial distribution of sediment DOC appears,in certain extent,as horizontal distribution with hypsometric characteristics.Close relationships existed among DOC concentration,flux,period,frequency and duration and the distribution characteristics of DOC in sediment of multi-stage canal and ditch systems.In addition,the vegetative characteristics of the canals and ditches exerted an important influence on DOC distribution in the sediment of the multi-stage canal and ditch systems that had a response to processes of organic matter in the sediments such as decomposition,humification,and stabilization of organic matter.
patiotemporal Distribution Characteristics of Soil Iron in the Annular Wetland Under Different Water Regime

ZOU Yuan-chun,JIANG Ming,Lü Xian-guo,

环境科学 , 2009,
Abstract: The effect of water regime on the spatial distribution of total iron and the seasonal variation of dissolved iron in a typical annular wetland of Sanjiang Plain, Northeast China, was analyzed through in situ sampling of soils and soil solutions. The results showed that the average level of total iron of the wetland soil (0-60 cm) was (2.54 ± 0.73) × 10~4mg·kg~(-1) , which decreased gradually from the Calamagrostis angustifolia community in the edge of the annular wetland (2.91 ± 0.51)× 10~4mg· kg~(-1)], to the C. meyeriana community (2.60 ± 0.35) × 10~4mg·kg~(-)], the C. lasiocarpa community (2.48 ± 0.31)×10~4mg·kg~(-1)], and the of C. pseudocuraica community (2.17 ± 0.31) ×10~4mg·kg~(-1)] in the centre of the annular wetland. The iron solubility of perennial flooding soil was higher than seasonal flooding soil. The gross dissolved iron increased from soil thawing in the late spring (0.35 ± 0.086) mg·L~(-1)] to freezing in the late autumn (12.67 ± 2.92) mg·L~(-1)], because the soil iron was activated by continuous submergence. The reduced degree as shown by Fe~(3+)/Fe~(2+) increased with the increment of water depth or flooding duration. Significant and extremely significant correlations were observed between dissolved Fe~(3+) or Fe~(2+) and pH, TOC, TN and PO_4~(3+) , which suggested that the distribution of iron was influenced by the soil physical and chemical properties, and coupled with the transfer and transformation of C, N, and P elements.
Estimation on Benefit of Latent Soil Nutrient in Melmeg Reserve Wetlands

JIANG Ming,L Xian-guo,XU Lin-shu,YANG Qing,

自然资源学报 , 2005,
Abstract: 利用GIS手段,运用环境经济学评价方法对莫莫格自然保护区潜在土壤养分效益进行估算,同时对潜在土壤养分效益的空间分异进行探析.结果表明,莫莫格自然保护区湿地潜在土壤养分效益为153×108元,保护区单位面积潜在土壤养分效益为10.6×104元·hm-2;其中,中部湿地潜在土壤养分的效益为12.7×104元·hm-2,东部为12.2×104元·hm-2,西部为7.6×104元·hm-2,即中部>东部>西部.在湿地土壤养分中,有机质、全钾对潜在土壤效益的贡献率大,而全氮、全磷的贡献率最低.潜在土壤养分效益估算及其空间分异研究,弥补了湿地效益评估的空白;同时为湿地的恢复重建、湿地管理提供了必要的理论依据.
Distribution of Sediment Iron of the Ditch System in Sanjiang Plain,Northeast China

ZOU Yuan-chun,L Xian-guo,JIANG Ming,XI Min,

环境科学 , 2009,
Abstract: 以三江平原典型多级沟渠系统(毛渠-农渠-斗渠-支渠-干渠)为对象,研究了其0~60 cm沉积物全铁含量的空间分布特征.结果表明,多级沟渠系统中沉积物的平均铁含量为(3.02±0.10)×104 mg·kg-1,各类型、各等级的沉积物铁含量具有极显著差异(F=6.261,p<0.001),最高值出现在农田斗渠(3.71×104 mg·kg-1)中,而最低值出现在湿地斗渠(2.43×104 mg·kg-1)中.整个多级沟渠系统沉积物各层的铁含量没有显著性差异(F=0.093,p=0.693),但与沟渠相邻湿地同深度土层的铁含量相比,沟渠沉积物0~10 cm层、10~20 cm层分别增加了51.96%、62.22%.铁虽然具有一定的可迁移性,其最大累积处仅能延伸到第三等级的斗渠中,而非逐级递增.由于湿地保护和气候干热化,现阶段本区含铁径流量有逐渐减少的趋势.沉积物各层铁含量沿沟渠类型和等级的递变揭示了铁输移的历史变迁.
Research Progress of the Coupling Process of Fe and N in Wetland Soils

Yin Xiao-Min,Lü Xian-Guo,Jiang Ming,Zou Yuan-Chun,

环境科学 , 2010,
Abstract: The coupling process of the earth system is the key research content of earth surface system at present. Wetland is an important ecosystem on the earth surface. Wetland soil is under anaerobic conditions seasonally or perennially because of waterlogging, where the redox of Fe and N can be coupled by microbiology. The coupling process lies in three aspects: the microbial coupling of NO-3-reduction and Fe2+-oxidation, coupling of Fe3+-reduction and NH+4-oxidation and the interaction of NO-3 and Fe3+ during reduction. Getting the knowledge of the coupling process has important significance to understand the cycles of Fe and N in wetland soil. The article reviews the research status of the three aspects. In general, we have a comparatively deep understand of the coupling process of NO-3-reduction and Fe2+-oxidation than the latter two aspects. The research of microbial mechanism of the coupling process of Fe3+-reduction-NH+4-oxidation and the comprehensive evaluation of the environmental significance of coupling process of Fe and N in wetland soil should be strengthened in the future research, and then it can provide evidence for wetland protection and management.
Lycopene Enhances Antioxidant Enzyme Activities and Immunity Function in N-Methyl-N′-nitro-N-nitrosoguanidine–Induced Gastric Cancer Rats
Cong Luo,Xian-Guo Wu
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12053340
Abstract: To investigate anticancer effect of lycopene, we examined the effects of lycopene on the oxidative injury and immunity activities of N-methyl- N′-nitro- N-nitrosoguanidine (MNNG)-induced gastric cancer rats. The animals were divided into five groups. Group I served as the normal control and was given corn oil orally for 20 weeks. Group II were induced with MNNG 200 mg/kg body weight by oral gavage at days 0 and 14, and saturated NaCl (1 mL per rats) was given once every three days for four weeks until the end of the experimental period. Group III, IV and V were posttreated with lycopene (50, 100 and 150 mg/kg body weight, dissolved in corn oil) from the sixth week of MNNG (as in group II) induction up to the end of the experimental period. In the presence of MNNG, MDA and immunity levels were significantly increased, whereas enzymatic (SOD, CAT, and GPx) antioxidant activities were decreased in the treated rats compared with normal control rats. Administration of lycopene to gastric carcinoma-induced rats largely up-regulated the redox status and immunity activities to decrease the risk of cancer compared to group II. We conclude that up-regulation of antioxidants and immunity by lycopene treatment might be responsible for the anticancer effect in gastric?carcinoma.
Energy Loss Signals in the ALICE TRD
Xian-Guo Lu,for the ALICE Collaboration
Physics , 2012, DOI: 10.1016/j.nima.2012.05.015
Abstract: We present the energy loss measurements with the ALICE TRD in the $\beta\gamma$ range 1--10$^{4}$, where $\beta=v/c$ and $\gamma=1/\sqrt{1-\beta^2}$. The measurements are conducted in three different scenarios: 1) with pions and electrons from testbeams; 2) with protons, pions and electrons in proton-proton collisions at center-of-mass energy 7 TeV; 3) with muons detected in ALICE cosmic runs. In the testbeam and cosmic ray measurements, ionization energy loss (dE/dx) signal as well as ionization energy loss plus transition radiation (dE/dx+TR) signal are measured. With cosmic muons the onset of TR is observed. Signals from TeV cosmic muons are consistent with those from GeV electrons in the other measurements. Numerical descriptions of the signal spectra and the $\beta\gamma$-dependence of the most probable signals are also presented.
Characteristics of the soil seed banks and relationships with the vegetation in restored wetlands in Sanjiang Plain, northeast of China

WANG Guo-Dong,L Xian-Guo,JIANG Ming,WANG Ming,ZHAO Kui-Yi,LOU Yan-Jing,

植物生态学报 , 2012,
Abstract: Aims Seed banks are an important source of regenerative material in wetlands. Our objective was to study characteristics of the soil seed banks and relationships with the vegetation in different restoration successional stages. Methods We collected soil seed banks from different depths (0–5 cm, 5–10 cm and rhizomes) from farmed wetland, restored wetland in different successional stages and natural wetland and germinated them under two water regimes (flooded and non-flooded) in a greenhouse. We used quadrats to survey vegetation structure in natural wetland and restored wetlands of different successional stages. Important findings With increased the restoration time, seed bank composition and size increased, and the vegetation community showed succession from a xerophyte-dominated community to a wetland community dominated by Calamagrostis angustifolia. Number of species germinated from the seed banks was 24, 29 and 39, while 21, 25 and 14 species were recorded in the vegetation of in 7-year restored wetland, 14-year restored wetland and natural wetland, respectively. Wetland type, water regime, depth of burial significantly influenced both the species richness and seedling emergence (p < 0.01). Seed density varied with depth so that seed density was higher in 0–5 cm than in 5–10 cm. The seed density in 0–5 cm was four times as that in 5–10 cm in natural wetland while it was just 1.3 times in restored wetland. The similarity between layers was low. More species germinated under non-flooded condition than flooded and the life forms differed. Because the restoration time was short, the similarity between seed bank and vegetation in different restoration successional stages was always <30%. Many wetland species germinated from rhizome fragments, especially C. angustifolia and other wetland species. Our research suggests that the seed bank could retain and restore several wetland species in different restoration successional stages, which can be valuable for vegetation succession and wetland restoration.
Bis[μ-1-(2-pyridylmethyl)-1H-benzotriazole]disilver(I) bis(perchlorate)
Chun-Sen Liu,Xian-Guo Xiao,Min Hu
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809043669
Abstract: In the title centrosymmetric binuclear AgI complex, [Ag2(C12H10N4)2](ClO4)2, each AgI center is two-coordinated by one pyridine and one benzotriazole N-donor atom of two inversion-related 1-(2-pyridylmethyl)-1H-benzotriazole (L) ligands. This forms a unique box-like cyclic dimer with an intramolecular Ag...Ag separation of 4.479 (2) . Intermolecular C—H...O hydrogen-bonding interactions, involving uncoordinated ClO4 ions, link the binuclear units, forming a two-dimensional network parallel to (10overline{2}).
Landscape planning and ecology construction of wetland comprehensive protected area system in the Sanjiang Plain
LIU Hong-yu,LU Xian-guo,LIU Zhen-qian,
LIU Hong-yu
,LU Xian-guo,LIU Zhen-qian

环境科学学报(英文版) , 2000,
Abstract: Wetland is one of the richest biodiversity areas in the earth. The main purpose of establishing wetland protected area is to protect biodiversity, and the protection of ecosystem diversity and landscape diversity is the key to protect biodiversity. In order to protect regional ecosystem and landscape, it is a good way to establish wetland comprehensive protected area which connected wetland nature reserves by habitat corridors. The Sanjiang Plain as a study area, its landscape evaluation index system on wetland protected area was studied, and some problems on landscape planning and ecology construction were further approached in this paper.It showed that establishing wetland comprehensive protected area is very important to protect regional wetlands, to maintain ecological balance, and to improve the sustainable development of agriculture and industry in this region.
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