农沟底泥和水稻秸秆热解制备生物碳球及其氨氮吸附研究

将农沟底泥和按其与水稻秸秆质量比20∶1、10∶1、20∶3、5∶1掺混的4种样品均制成?5 mm小球,600℃缺氧热解4 h成生物碳球,分别标记为SS-0、SS-50、SS-100、SS-150、SS-200。通过元素分析、BET-N2、SEM、FTIR及Boehm滴定法等表征了生物碳球的组成与结构,利用序批实验研究了其对氨氮的吸附动力学和等温吸附模型,考察了水温对吸附的影响。结果表明,添加水稻秸秆有利于增加生物碳球通透性和亲水性,提高其传质性能。表面酸性含氧官能团分别为2.74 mmol·L^(-1)、2.88 mmol·L^(-1)、3.71 mmol·L^(-1)、3.36 mmol·L^(-1)和3.03 mmol·L^(-1)。动力学研究表明,SS-0吸附氨氮符合准一级动力学方程,而准二级动力学方程能较好地描述SS-50、SS-100、SS-150和SS-200的吸附过程,除了内扩散外,还存在其他过程共同控制吸附速率。等温吸附曲线均符合Langmuir方程,高温有利于吸附。生物碳球对氨氮具有较好的吸附能力,在农田排水的氨氮治理方面有广阔的应用前景。

球碳衍生物在钕系催化剂催化丁二烯聚合中的应用──催化剂的相态

在Ｎｄ（ｎａｐｈ）３－Ａｌ（ｉ－Ｂ３）３－Ａｌ（ｉ－Ｂｕ）２Ｃｌ（简称Ｎｄ—Ａｌ－Ｃｌ）三元催化体系中加入球碳衍生物Ｃ６０Ｘｎ（Ｘ为某卤素基因），改善了催化剂的相态稳定性，同时对比考察了几种溶剂对Ｃ６０Ｘｎ的溶解性，发现溶解度都比加氢汽油好，以其催化丁二烯聚合，活性也有所提高。

球碳C_(60)/C_(70)及其衍生物与环烷酸钴反应的光谱研究

测定了球碳C60/C70及其衍生物C60Xn/C70Xn的加氢汽油溶液分别与环烷酸钴[Co(naph)2]反应的紫外可见吸收光谱及C60Xn与Co(naph)2反应沉淀物的红外吸收光谱。结果表明:C60/C70及其衍生物均可与Co2+发生配位反应,形成π配体络合物,讨论了可能的反应机理。

生物吸附及微生物降解对4-溴联苯醚污染水体的修复

多溴联苯醚(PBDEs)作为阻燃剂被广泛使用。因为它对人类的器官、神经系统和免疫系统的危害以及向周边环境的不断迁移,已经逐渐成为人们迫切需要处理的污染物之一。以同系物4-溴联苯醚(BDE-3)作为降解对象,将海藻酸钠和生物碳混合制成微球制剂,对该制剂吸附BDE-3的潜力、机制及添加降解菌Sphingomonas sp.DZ3后微球菌剂的吸附增益效应进行研究。结果表明:2%的海藻酸钠为微球制备的最佳质量浓度,该微球制剂在液相中的吸附过程符合Lagergren准一级动力学方程和Elovich方程,微球的最大吸附量为28.6 mg·g^(-1)。用添加微生物的微球菌剂对BDE-3污染水体进行修复时发现,微球菌剂在溶液中能加速BDE-3的降解,与游离的微生物相比,差异达极显著水平(P<0.01)。利用Monod降解动力学方程对该降解过程进行拟合,得到降解动力学方程为υ=υ_(max)·S/(K_S+S)=14.29·S/(31.71+S)。

Fabrication of cobalt aluminum-layered double hydroxide nanosheets/carbon spheres composite as novel electrode material for supercapacitors

A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a thickness of20nm.The galvanostatic charge-discharge test of the CoAl-LDH/CSs composite shows a great specific capacitance of1198F/g at1A/g(based on the mass of the CoAl-LDH/CSs composite)in6mol/L KOH solution,and the composite displays an impressive specificcapacitance of920F/g even at a high current density of10A/g.Moreover,the composite remains a specific capacitance of928F/gafter1000cycles at2A/g,and the specific capacitance retention is84%,indicating that the composite has high specific capacitance,excellent rate capability and good cycling stability in comparison to pristine CoAl-LDH.

一种太阳能光热蒸汽便携灭菌装置的设计

设计了一种基于生物质碳微球界面加热的太阳能光热蒸汽便捷设备,可用于野外医用器械灭菌以及蒸馏水制备等情形。装置创新性采用生物质材料碳化作为吸收体,同时引入菲涅尔透镜提高光聚焦,其原理是利用环境友好型碳微球漂浮于水界面进行光热转换,产生光热蒸汽。这样不仅比传统电力灭菌设备更节能,而且具有制作成本低、易回收、光能利用率高、杀菌周期更短、节约资源、性能稳定可长期使用等优点,可为推广使用更加节能、便捷的蒸汽灭菌设备提供借鉴,保证野外医疗废物被有效彻底处置。

Effects of slope position and land use on the stability of aggregateassociated organic carbon in calcareous soils

Topography and land use affect soil organic carbon(SOC) storage, stabilization, and turnover, through several biogeochemical processes. This study investigated the aggregate composition and SOC content of bulk soils and aggregates at different slope positions under different land uses in a typical karst catchment of southwestern China. Our results show that the proportion of macro-aggregates and the SOC content of bulk soils and aggregates at different slope positions decreased from the upper to the lower slope. The SOC content generally increased with an increase in the mean weight diameter and proportion of macro-aggregates under different land uses. Our results indicate that macro-aggregates in forest and grassland soils make a greater contribution to both aggregate composition and SOC content than that in arable land soils. Therefore,converting farmland to forest or grassland can facilitate the accumulation of macro-aggregates as well as the storage of SOC.

Soil Organic Carbon and Nutrients along an Alpine Grassland Transect across Northern Tibet

Soil carbon and nutrient contents and their importance in advancing our understanding of biogeochemical cycling in terrestrial ecosystem, has motivated ecologists to find their spatial patterns in various geographical area. Few studies have focused on changes in the physical and chemical properties of soils at high altitudes. Our aim was to identify the spatial distribution of soil physical and chemical properties in cold and arid climatic region. We also tried to explore relationship between soil organic carbon （SOC） and total nitrogen （TN）, total phosphorus （TP）, available nitrogen （AN）, available phosphorus （AP）, soil particle size distribution （PSD）. Samples were collected at 44 sites along a 300 km transect across the alpine grassland of northern Tibet. The study results showed that grassland type was the main factor influencing SOC, TN and TP distribution along the Gangdise Mountain-Shenzha-Shuanghu Transect. SOC, TN and TP contents were significantly higher in alpine meadow than alpine steppe ecosystems. SOC, TN, TP and AN contents in two soil layers （0-15 cm and 15-3o cm） showed no significant differences, while AP content in top soft （0-15 cm） was significantly higher than that in sub-top soil （15-30cm）. SOC content was correlated positively with TN and TP content （r = 0.901and 0.510, respectively）. No correlations were detected for clay content and fractal dimension of particle size distribution （D）. Our study results indicated the effects of vegetation on soil C, N and P seem to be more important than that of rocks itself along latitude gradient on the northern Tibetan Plateau. However, we did not found similar impacts of vegetation on soil properties in depth. Inaddition, this study also provided an interesting contribution to the global data pool on soil carbon stocks.

Variation in δ^(15)N of a lacustrine sedimentary sequence in the Nanling Mountains and its potential implication for climatic conditions over the past ~16000 years

Although extensive studies have been performed on nitrogen isotopes in lake sediments, understanding the complexity of the δ15N variation related to past environmental and climatic conditions still remains unclear. Supported by multi-proxy records including litho-units, organic carbon isotopes, ration of total organic carbon and total nitrogen, organic matter content, bulk dry density, the accumulation rate of organic matter, median grain size, magnetic susceptibility, and Rb/Sr and Ca/Mg ratios obtained from a sedimentary sequence in a small lake （i.e., Dahu Swamp） in the eastern Nanling Mountains in South China, we deduce that variation in the δ15N values results primarily from the sources of organic matter, which are significantly influenced by climatic conditions over the past -16 000 years. A low （or high） lake level resulting from dry （or wet） conditions would lead to more （or fewer） vascular plant remains in the sediments and stronger （or weaker） denitrification associated with hypolimnetic anoxia, resulting in lower （or higher） 615N values. In addition, dry （or wet） conditions would favor weakened （or strengthened） biogeochemical activity in the catchment, which could result in less （or more） external input of δ15N-enriched OM, thus leading to decreased （or increased） δ15N values. Our results indicate that the lake sediment δ15N record in the Nanling Mountains has the potential to provide valuable insight into past East Asian monsoon climate- driven environmental changes.

Microaerobic iron oxidation and carbon assimilation and associated microbial community in paddy soil

Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under microaerobic conditions.Here,we investigated kinetics of CO_2 assimilation and Fe(Ⅱ)oxidation in an incubation experiment with paddy soil under suboxic conditions,and profiled the associated microbial community using DNA-stable isotope probing and 16S r RNA gene-based sequencing.The results showed that CO_2 assimilation and Fe(II)oxidation in the gradient tubes were predominantly mediated by the microbes enriched in the paddy soil,primarily Azospirillum and Magnetospirillum,as their relative abundances were higher in the^( 13)C heavy fractions compared to^( 12)C heavy fractions.This study provided direct evidence of chemoautotrophic microaerophiles linking iron oxidation and carbon assimilation at the oxic–anoxic interface in the paddy soil ecosystem.

Soil Microbial Activities in Beech Forests Under Natural Incubation Conditions as Affected by Global Warming

Microbial activity in soil is known to be controlled by various factors. However, the operating mechanisms have not yet been clearly identified, particularly under climate change conditions, although they are crucial for understanding carbon dynamics in terrestrial ecosystems. In this study, a natural incubation experiment was carried out using intact soil cores transferred from high altitude(1 500 m) to low(900 m) altitude to mimic climate change scenarios in a typical cold-temperate mountainous area in Japan. Soil microbial activities, indicated by substrate-induced respiration(SIR) and metabolic quotient(q CO2), together with soil physicalchemical properties(abiotic factors) and soil functional enzyme and microbial properties(biotic factors), were investigated throughout the growing season in 2013. Results of principal component analysis(PCA) indicated that soil microbial biomass carbon(MBC) andβ-glucosidase activity were the most important factors characterizing the responses of soil microbes to global warming. Although there was a statistical difference of 2.82 ℃ between the two altitudes, such variations in soil physical-chemical properties did not show any remarkable effect on soil microbial activities, suggesting that they might indirectly impact carbon dynamics through biotic factors such as soil functional enzymes. It was also found that the biotic factors mainly controlled soil microbial activities at elevated temperature,which might trigger the inner soil dynamics to respond to the changing environment. Future studies should hence take more biotic variables into account for accurately projecting the responses of soil metabolic activities to climate change.

The POM-DOM piezophilic microorganism continuum(PDPMC)—The role of piezophilic microorganisms in the global ocean carbon cycle

The deep ocean piezosphere accounts for a significant part of the global ocean,hosts active and diverse microbial communities which probably play a more important role than hitherto recognized in the global ocean carbon cycle.The conventional biological pump concept and the recently proposed microbial carbon pump mechanism provide a foundation for our understanding of the role of microorganisms in cycling of carbon in the ocean.However,there are significant gaps in our knowledge and a lack of mechanistic understanding of the processes of microbially-mediated production,transformation,degradation,and export of marine dissolved and particulate organic matter(DOM and POM)in the deep ocean and the ecological consequence.Here we propose the POM-DOM piezophilic microorganism continuum(PDPMC)conceptual model,to address these important biogeochemical processes in the deep ocean.We propose that piezophilic microorganisms(bacteria and archaea)play a pivotal role in deep ocean carbon cycle where microbial production of exoenzymes,enzymatic breakdown of DOM and transformation of POM fuels the rapid cycling of marine organic matter,and serve as the primary driver for carbon cycle in the deep ocean.

Enhancing phytolith carbon sequestration in rice ecosystems through basalt powder amendment

Global warming as a result of rapid increase in atmospheric COa emission is significantly influencing world＇s economy and human activities. Carbon sequestra- tion in phytoliths is regarded as a highly stable carbon sink mechanism in terrestrial ecosystems to mitigate climate change. However, the response of plant phytolith-occluded carbon （PhytOC） to external silicon amendments remains unclear. In this study, we investigated the effects of basalt powder （BP） amendment on phytolith carbon sequestration in rice （Oryza sativa）, a high-PhytOC accumulator. The results showed that the contents of phytolith and PhytOC in rice increased with BP amendment. The PhytOC produc- tion flux in different rice plant parts varied considerably （0.005-0.041 Mg CO_2 ha^-1 a^-1）, with the highest flux in the sheath. BP amendment can significantly enhance flux of phytolith carbon sequestration in croplands by 150 %. If the global rice cultivation of 1.55 × 10^8 ha had a similar flux of PhytOC production in this study, 0.61× 10^7 to 1.54 × 10^7 Mg CO_2 would be occluded annually within global rice phytoliths. These findings highlight that exter- nal silicon amendment such as BP amendment represents an effective potential management tool to increase long- term biogeochemical carbon sequestration in crops such as rice and may also be an efficient way to mitigate the global warming indirectly.

Formation and influencing factors of carbonate source rock of the Lower Permian Chihsia Formation in Chaohu region, Anhui Province

Highly-mature carbonate source rock is essential to the exploration of oil and gas in southern China. In this study, the carbonate strata in the relatively well-developed Lower Permian Chihsia Formation (located in Chaohu, Lower Yangtze) were targeted, and the formation and influencing factors of source rock were discussed based on paleoenvironment reconstruction using comprehensive sedimentology, palynofacies, and organic geochemistry data. The results demonstrate that the Chihsia Formation is oxygen-deficient biogenic carbonate sediments, with marked variations in the organic and inorganic components, formed during a period of Permian transgression. The formation of source rock is the combined result of high bioproductivity and oxygen-deficient environment generated by transgression and oxygenation events which frequently occurred during transgression periods. Source rock was affected by self-dilution effects and diagenesis, causing its heterogeneous distribution in many intervals. Source rock is over 40 m thick, and can be identified based on its different organic, biological, and mineral composition characteristics. The carbonate rock appears to require no specific clay content in order to become a source rock. The combination of sedimentology, palynofacies, and organic geochemistry has provided an effective means for evaluating and predicting high-maturity carbonate source rock in the region.

Soil Microbiological Activity and Carbon Dynamics in the Current Climate Change Scenarios:A Review

Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues.Because of their prominent role in the global carbon balance and their possible role in carbon sequestration, soil microbes are very important organisms in relation to global climate changes. This review focuses mainly on the responses of soil microbes to climate changes and subsequent effects on soil carbon dynamics. An overview table regarding extracellular enzyme activities(EAA) with all relevant literature data summarizes the effects of different ecosystems under various experimental treatments on EAA. Increasing temperature, altered soil moisture regimes, and elevated carbon dioxide significantly affect directly or indirectly soil microbial activities.High temperature regimes can increase the microbial activities which can provide positive feedback to climate change, whereas lower moisture condition in pedosystem can negate the increase, although the interactive effects still remain unanswered. Shifts in soil microbial community in response to climate change have been determined by gene probing, phospholipid fatty acid analysis(PLFA),terminal restriction length polymorphism(TRFLP), and denaturing gradient gel electrophoresis(DGGE), but in a recent investigations,omic technological interventions have enabled determination of the shift in soil microbe community at a taxa level, which can provide very important inputs for modeling C sequestration process. The intricacy and diversity of the soil microbial population and how it responds to climate change are big challenges, but new molecular and stable isotope probing tools are being developed for linking fluctuations in microbial diversity to ecosystem function.

Controlled fabrication of fullerene derivative one-dimensional nanostructures via electrophoretic deposition of its clusters

Well-defined and controllable one-dimensional (1D) nanostructures of fullerene derivative have been pre- pared by an electrophoretic template synthesis method. The clusters of fullerene derivative formed in mixed solvents are introduced into the channels of porous alumina templates through a dc electric field. Four types of 1D nanostructures (solid nanowires, solid-wall nanotubes, porous nanowires and porous-wall nanotubes) have been obtained by changing the deposition parameters. This approach opens a new avenue to assemble fullerene derivatives, endohedral fullerenes, as well as other functional organic compounds, which can form clusters in 1D nanostructure arrays for applications in chemical sensors, light energy conversion devices and nano- scale electronic and optoelectronic devices.

Investigation on the aggregation properties of cationic [60]fullerene derivative

The UV-Vis spectra, HRTEM and AFM images of cationic fullerene derivative 1 with ammonium head group directly connected to C60 skeleton in tetrahydrofuran (THF)-water (H2O) binary mixtures and in pure H2O were investigated. It was found that the UV-Vis spectra of ammo-nium 1 in the THF-H2O mixtures with THF% ≥ 20% were nearly overlapped, while those with THF% < 20% showed broadened and red-shifted peaks, indicating the formation of aggregates. Corresponding to the UV-Vis spectral changes, the solvatochromism of ammonium 1 in THF-H2O mixtures was observed. Ammonium 1 in binary THF-H2O mixtures existing as the monomer state could aggregate upon pro-longed standing. Higher temperature and lower concentra-tion speeded up the aggregation process.