[Effects of Simulated Nitrogen Deposition on Soil Microbial Carbon Metabolism in Calamagrostis angustifolia Wetland in Sanjiang Plain].

Atmospheric nitrogen deposition has a crucial impact on the structure and function of soil microorganisms of wetland ecosystems. Therefore, carrying out a study on the effects of soil carbon metabolism capacity has a great significance for the protection and utilization of wetland ecosystems. In this study, the effects of simulated nitrogen deposition on the carbon metabolic capacity of soil microorganisms in Calamagrostis angustifolia wetland for five consecutive years was investigated using Biolog-Eco technology. The results showed:① soil water content (SMC), pH, nitrate nitrogen (NO3-), ammonium nitrogen (NH4+), dissolved organic carbon (DOC), and total nitrogen (TN) contents were significantly different (P<0.05) under different nitrogen deposition conditions. ② The average well color development (AWCD) values of soil microorganisms within different N depositions were in the order of CK (control)>HN (high nitrogen treatment)>LN (low nitrogen treatment). LN significantly reduced the Shannon diversity index of soil microorganisms, and HN significantly reduced the Pielou index of soil microorganisms (P<0.05). ③ LN significantly inhibited the intensity of the utilization of carbohydrates, alcohols, amines, and acids by soil microorganisms (P<0.05); HN significantly promoted the utilization of esters by microorganisms, but HN caused soil microorganisms to inhibit the carbon sources of carbohydrates, amines, and acids (P<0.05). ④ Redundancy analysis showed that NH4+, DOC, and pH were the main environmental factors affecting the functional diversity of soil microbial communities in Calamagrostis angustifolia wetland in the Sanjiang Plain. Long-term nitrogen deposition will lead to the reduction in soil microbial functional diversity; the microbial activity related to the utilization of carbon source substrates is also significantly reduced, and the ability of microorganisms to utilize a single carbon source substrate also changes.

Organoamine-Directed Assembly of 5p-4f Heterometallic Cluster Substituted Polyoxometalates: Luminescence and Proton Conduction Properties.

The assembly of heterometallic cluster substituted polyoxometalates (POMs) remains a great challenge for inorganic synthetic chemistry up to now. Herein, a series of 5p-4f heterometallic cluster substituted POMs were successfully isolated by a facile one-step hydrothermal reaction method, namely H17(H2en)3[SbIII9SbVLn3O14(H2O)3][(SbW9O33)3(PW9O34)]·28H2O(1-Ln, Ln = Ce, Sm, Eu, Gd, Tb, Dy) (en = ethylenediamine). Interestingly, by replacing en with imidazole, another series of 5p-4f heterometallic cluster substituted POMs H13(HIm)4K2Na4(H2O)9[SbIII9SbVLn3O14(H2O)3][(SbW9O33)3(PW9O34)]·26H2O (2-Ln, Ln = Sm, Eu, Gd, Tb, Dy, Im = imidazole) were obtained. Structural analyses indicate that both 1-Ln and 2-Ln are made up of an unprecedented 5p-4f heterometallic {Sb10Ln3O14(H2O)3} cluster stabilized simultaneously by mixed trilacunary heteropolyanions including {A-α-PW9O34} and {B-α-SbW9O33}. Impedance measurements indicate that both compounds exhibit different proton conduction properties, and the conductivity of 2 can reach up to 1.64 × 10-2 S cm-1 at 85 °C under 98% relative humidity. Moreover, the fluorescence emission behaviors of both compounds have been studied.

[Short-term response of carbon emission to snow cover change in Calamagrostis angustifolia wetlands of Sanjiang Plain, Northeast China]. / ä¸‰æ±Ÿå¹³åŽŸå°å¶ç« æ¹¿åœ°ç¢³æŽ’æ”¾å¯¹é›ªè¢«å˜åŒ–çš„çŸ­æœŸå“åº”.

To understand the response of Calamagrostis angustifolia wetland of the Sanjiang Plain to changes in snow cover, we examined the greenhouse gases emission flux of the removed snow treatment (0 cm, RS), the added snow treatment (50 cm, AS) and the control (20 cm, CK) of a C. angustifolia wetland, and their relations with environmental factors with the method of the static chamber-gas chromatography. The results showed that soil temperature, soil water content, and carbon emissions were lowest during the snow-covering period under all treatments, and gradually increased with time. With the increases of time and snow thickness, soil temperature was rised and the difference of three treatments gradually was decreased. Soil water content of RS was always lower than that of CK and AS. AS and CK could promote soil CO2 emission compared with RS during and after snowmelt. The soil cumulative CH4 emissions differed little among the treatments. There was significant correlation between soil temperature and cumulative CO2 and CH4 emissions. With the increases of soil temperature, soil cumulative CO2 emission continued to increase and soil cumulative CH4 emission decreased firstly and then increased rapidly. Soil water content was significantly correlated with cumulative CO2 and CH4 emissions. As the soil moisture increased, the cumulative soil CO2 emission gradually increased, reaching a certain threshold and then flattening, while soil cumulative CH4 emission continuously increased.

A Series of Cube-Shaped Polyoxoniobates Encapsulating Octahedral Cu12X m O n Clusters With Hydrolytic Decomposition for Chemical Warfare Agents.

This study reported a series of cube-shaped polyoxoniobates, {MCu12O8)(Cu12XmOn)(Nb7(OH)O21)8} [M = Nb(1, 2), Ln3+(3), X = I(1, m = 3, n = 3; 2, m = 5, n = 1), Br(3, m = 5, n = 1)]. As the first octahedral Cu12XmOn cluster incorporated polyoxoniobate, the cube-shaped three-shell structure of {MCu12O8)(Cu12XmOn)(Nb7(OH)O21)8} polyanion contains a {MCu12O8} body-centered cuboctahedron, a {Cu12XmOn} octahedron and a {Cu12(Nb7(OH)O21)8} cube. Compounds 1, 2, 3 show effective catalytic activities for the hydrolytic decomposition of chemical warefare agent simulants.

A Series of 3D Porous Lanthanide-Substituted Polyoxometalate Frameworks Based on Rare Hexadecahedral {Ln6W8O28} Heterometallic Cage-Shaped Clusters.

A series of 3D porous lanthanide-substituted polyoxometalate frameworks, Na2[Ln2(H2O)11]2[Ln3(H2O)3(α-SiW11O39)2]2·69H2O (1-Ln, Ln = Sm, Eu, Gd, Tb, and Dy), are built from novel hexadecahedral {Ln6W8O28} heterometallic cage-shaped clusters. Intriguingly, every tetrameric {[Ln3(H2O)3(α-SiW11O39)2]2}14- cage-cluster is linked with another eight tetrameric cage-clusters by Ln3+ cations, leading to a novel 3D inorganic porous framework, which exhibits good thermal and chemical stability, excellent water vapor adsorption capacity, and moderate proton conductive properties. Furthermore, the solid state luminescence spectra demonstrate that 1-Sm, 1-Eu, 1-Tb, and 1-Dy display the lanthanide characteristic emission bands. The temperature-dependent magnetic susceptibility indicates that there are antiferromagnetic interactions in 1-Tb and 1-Dy.

Responses of greenhouse gas emission to simulated nitrogen deposition in Calamagrostis angustifolia wetlands of Sanjiang Plain, China.

A long-term simulated nitrogen deposition experiment was carried out in Ecological Locating Research Station of the Institute of Nature and Ecology of Heilongjiang Academy of Sciences, with three different treatments including low nitrogen treatment (40 kg N·hm-2·a-1), high nitrogen treatment (80 kg N·hm-2·a-1) and the control (0 kg N·hm-2·a-1). The greenhouse gas emission fluxes were measured using a static box-gas chromatography method, with environmental factors being simultaneously investigated to understand the responses of greenhouse gas emission to the nitrogen deposition in the Calamagrostis angustifolia wetland. The results showed that low and high nitrogen treatments significantly increased the greenhouse gas emission fluxes. The CO2 emission flux increased by 47.5% and 47.9%, the CH4 emission fluxes increased by 76.8% and 110.1%, and the N2O emission fluxes increased by 42.4% and 10.6% in low nitrogen treatment and high nitrogen treatment, respectively. Low nitrogen input changed the seasonal dynamics of N2O emission fluxes but had no significant effect on that of CO2 and CH4 emissions. High nitrogen treatment did not affect the seasonal dynamics of greenhouse gas emissions. Soil temperature significantly positively correlated with CO2 and CH4 emission fluxes. There was no correlation between soil temperature and N2O emission flux because the factors affecting N2O emission were complex.

[Fungal Community Structure of Different Degeneration Deyeuxia angustifolia Wetlands in Sanjiang Plain].

To understand the wetland soil fungal community structure and diversity in different degeneration Deyeuxia angustifolia wetlands, the topsoil (0-20) of three different degeneration D. angustifolia wetlands were collected in the Sanjiang Plain field experiment station of the Institute of Nature and Ecology, Heilongjiang Academy of Sciences. The distribution and variation of soil fungal diversity were assessed by high-throughput sequencing method. The results showed that Shannon-Wiener index increased from marsh Deyeuxia angustifolia wetland marsh meadow Deyeuxia angustifolia wetland meadow Deyeuxia angustifolia wetland. Sequence blast showed that the fungal taxonomy belonged to Ascomycota, Basidiomycota, Chytridiomycota, Fungi_unclassified, Zygomycota, which dominant fungi were Fungi_unclassified (75.12%),Ascomycetes (56. 56%), Basidiomycetes (72.65%) in the three degeneration wetlands, respectively. The fungal structure compositions and diversities of marsh meadow Deyeuxia angustifolia wetland and meadow Deyeuxia angustifolia wetland were similar according to Heatmap analysis. The fungal community structure was influenced by soil nutrients (explained 88.62%) and plant composition (explained 9.85%) through the Variation partition analysis (VPA). In conclusion, the fungal community structure was significantly different, which was influenced by soil water content, in different degeneration Deyeuxia angustifolia wetlands in Sanjiang plain. The results may supply scientific basis for studying fungal diversity and spatial heterogeneity in degeneration wetlands.